Membrane Biology

Interdigitation of Lipids Induced by Membrane–Active Proteins Abstract The membrane–active protein Nogo-66 is found to induce interdigitation in dimyristoylphosphocholine membranes. Extensive molecular dynamics simulations have been employed to probe the interactions of Nogo-66 with these model membranes. This phase change happens when the temperature is close to the main transition temperature of the membrane (Tm) and only in the presence of the protein. No similar interdigitation of the membrane lipids was observed temperatures well above Tm in the presence of the protein. In addition, in protein-free simulations, no interdigitation of the membrane lipids was found both at temperatures near or well above Tm indicating that the observed effect is caused by the interactions of Nogo-66 with the membrane. Analysis of the simulations suggest protein–membrane interactions, even if transient, alter the lifetimes of lipid head defects and can potentially alter the effective Tm and cause interdigitation. This study emphasize the importance of membrane–active proteins and their interactions with membranes leading to phase transitions which would affect other membrane-related processes such as domain formation.

Solid-State NMR Investigations of the MHC II Transmembrane Domains: Topological Equilibria and Lipid Interactions Abstract The major histocompatibility complex class II (MHC II) membrane proteins are key players in the adaptive immune response. An aberrant function of these molecules is associated with a large number of autoimmune diseases such as diabetes type I and chronic inflammatory diseases. The MHC class II is assembled from DQ alpha 1 and DQ beta 1 which come together as a heterodimer through GXXXG-mediated protein–protein interactions and a highly specific protein-sphingomyelin-C18 interaction motif located on DQA1. This association can have important consequences in regulating the function of these membrane proteins. Here, we investigated the structure and topology of the DQA1 and DQB1 transmembrane helical domains by CD-, oriented 2H and 15N solid-state NMR spectroscopies. The spectra at peptide-to-lipid ratios of 0.5 to 2 mol% are indicative of a topological equilibrium involving a helix crossing the membrane with a tilt angle of about 20° and another transmembrane topology with around 30° tilt. The latter is probably representing a dimer. Furthermore, at the lowest peptide-to-lipid ratio, a third polypeptide population becomes obvious. Interestingly, the DQB1 and to a lesser extent the DQA1 transmembrane helical domains exhibit a strong fatty acyl chain disordering effect on the inner segments of the 2H-labelled palmitoyl chain of POPC bilayers. This phosphatidylcholine disordering requires the presence of sphingomyelin-C18 suggesting that the ensemble of transmembrane polypeptide and sphingolipid exerts positive curvature strain.

Photolithographic Fabrication of Micro Apertures in Dry Film Polymer Sheets for Channel Recordings in Planar Lipid Bilayers Abstract Planar lipid bilayers constitute a versatile method for measuring the activity of protein channels and pores on a single molecule level. Ongoing efforts attempt to tailor this method for detecting biomedically relevant target analytes or for high-throughput screening of drugs. To improve the mechanical stability of bilayer recordings, we use a thin-film epoxy resist ADEX as septum in free-standing vertical bilayers. Defined apertures with diameters between 30 µm and 100 µm were micro-fabricated by photolithography. The performance of these septa was tested by functional reconstitution of the K+ channel KcvNTS in lipid bilayers spanned over apertures in ADEX or Teflon films; the latter is conventionally used in bilayer recordings and serves as reference. We observe that the functional properties of the K+ channel are identical in both materials while ADEX provides no advantage in terms of capacitance and signal-to-noise ratio. In contrast to Teflon, however, ADEX enables long-term experimental recordings while the stability of the lipid bilayer is not compromised by pipetting solutions in and out of the recording chamber. Combined with the fact that the ADEX films can be cleaned with acetone, our results suggest that ADEX carries great potential for multiplexing bilayer chambers in robust and reusable sensing devices. Graphical Abstract

Structural and Functional Determinants of AC8 Trafficking, Targeting and Responsiveness in Lipid Raft Microdomains Abstract The fidelity of cAMP in controlling numerous cellular functions rests crucially on the precise organization of cAMP microdomains that are sustained by the scaffolding properties of adenylyl cyclase. Earlier studies suggested that AC8 enriches in lipid rafts where it interacts with cytoskeletal elements. However, these are not stable structures and little is known about the dynamics of AC8 secretion and its interactions. The present study addresses the role of the cytoskeleton in maintaining the AC8 microenvironment, particularly in the context of the trafficking route of AC8 and its interaction with caveolin1. Here, biochemical and live-cell imaging approaches expose a complex, dynamic interaction between AC8 and caveolin1 that affects AC8 processing, targeting and responsiveness in plasma membrane lipid rafts. Site-directed mutagenesis and pharmacological approaches reveal that AC8 is processed with complex N-glycans and associates with lipid rafts en route to the plasma membrane. A dynamic picture emerges of the trafficking and interactions of AC8 while travelling to the plasma membrane, which are key to the organization of the AC8 microdomain.

Potassium Stimulation of IAA Transport Mediated by the Arabidopsis Importer AUX1 Investigated in a Heterologous Yeast System Abstract Auxin regulates diverse processes involved in plant growth and development. AUX1 is the first identified and most widely investigated auxin importer, and plays an important role in root gravitropism and the development of lateral root and root hair. However, the regulation of auxin transport by AUX1 is still not well understood. In this study, we examined the effect of metal ions on AUX1 transport function and found that the activity could be specifically stimulated four times by K+. Further experiments revealed the preference of KF on the enhancement of transport activity of AUX1 over KCl, KBr, and KI. In addition, the interaction between K+ and AUX1 confers AUX1 more resistant to thermal stress but more vulnerable to proteolysis. Conventional chemical modification indicated that the extracellular acidic amino acids of AUX1 play a key role in the K+ stimulation. Site-specific mutagenesis showed that the replacement of Asp166, Asp293, and Asp312 of AUX1 to alanine deteriorated the K+-stimulated auxin transport. By contrast, when these residues were mutated to glutamate, lysine, or asparagine, only the D312E variant restored the IAA transport activity to the wild-type level. It is thus convinced that D312 is presumably the most promising residue for the K+ stimulation on AUX1.

Modulatory Effect of Selected Dietary Phytochemicals on Delayed Rectifier K + Current in Human Prostate Cancer Cells Abstract Phytochemicals are ubiquitous in naturally occurring dietary elements that exhibits diverse pharmacological properties over various pathological disorders, including cancer. Voltage gated K+ (KV) channel in the plasma membrane contributes to wide range of cellular processes including cancer progression. Therefore, modulation of KV channel is being considered as a novel potential target for cancer therapy. The whole cell patch clamp technique was used to record the modulatory effect of chrysin, naringenin, caffeic acid, gallic acid, and zingerone on delayed rectifier potassium current (IK) in human prostate cancer cells LNCaP and PC-3. Among the tested compounds, zingerone blocked IK in a concentration-dependent manner in LNCaP cells and estimated the IC50 value of 141 μM and Emax was 81.3%. Further analysis of KV channel activation kinetics showed that zingerone induces a positive shift in the activation curve in LNCaP cells, whereas the inhibitory effect of gallic acid on IK was significantly less potent than the inhibition caused by zingerone. However, chrysin, naringenin, and caffeic acid did not modulate the KV channel conductance in LNCaP or PC-3 cells. Our findings confirmed that not all the tested phytochemicals to be effective modulators of IK and suggested that IK inhibitory effect of zingerone and gallic acid may be responsible for their anticancer effects in prostate cancer cells.

Essay on Biomembrane Structure Abstract Of all the macromolecular assemblies of life, the least understood is the biomembrane. This is especially true in regard to its atomic structure. Ideas on biomembranes, developed in the last 200 years, culminated in the fluid mosaic model of the membrane. In this essay, I provide a historical outline of how we arrived at our current understanding of biomembranes and the models we use to describe them. A selection of direct experimental findings on the nano-scale structure of biomembranes is taken up to discuss their physical nature, and special emphasis is put on the surprising insights that arise from atomic scale descriptions.

Role of Lipid Composition, Physicochemical Interactions, and Membrane Mechanics in the Molecular Actions of Microbial Cyclic Lipopeptides Abstract Several experimental and theoretical studies have extensively investigated the effects of a large diversity of antimicrobial peptides (AMPs) on model lipid bilayers and living cells. Many of these peptides disturb cells by forming pores in the plasma membrane that eventually lead to the cell death. The complexity of these peptide–lipid interactions is mainly related to electrostatic, hydrophobic and topological issues of these counterparts. Diverse studies have shed some light on how AMPs act on lipid bilayers composed by different phospholipids, and how mechanical properties of membranes could affect the antimicrobial effects of such compounds. On the other hand, cyclic lipopeptides (cLPs), an important class of microbial secondary metabolites, have received comparatively less attention. Due to their amphipathic structures, cLPs exhibit interesting biological activities including interactions with biofilms, anti-bacterial, anti-fungal, antiviral, and anti-tumoral properties, which deserve more investigation. Understanding how physicochemical properties of lipid bilayers contribute and determining the antagonistic activity of these secondary metabolites over a broad spectrum of microbial pathogens could establish a framework to design and select effective strategies of biological control. This implies unravelling—at the biophysical level—the complex interactions established between cLPs and lipid bilayers. This review presents, in a systematic manner, the diversity of lipidated antibiotics produced by different microorganisms, with a critical analysis of the perturbing actions that have been reported in the literature for this specific set of membrane-active lipopeptides during their interactions with model membranes and in vivo. With an overview on the mechanical properties of lipid bilayers that can be experimentally determined, we also discuss which parameters are relevant in the understanding of those perturbation effects. Finally, we expose in brief, how this knowledge can help to design novel strategies to use these biosurfactants in the agronomic and pharmaceutical industries.

The Structural and Functional Diversity of Intrinsically Disordered Regions in Transmembrane Proteins Abstract The intrinsically disordered proteins and protein regions (IDPs/IDPRs) do not have unique structures, but are known to be functionally important and their conformational flexibility and structural plasticity have engendered a paradigmatic shift in the classical sequence–structure–function maxim. Fundamental understanding in this field has significantly evolved since the discovery of this class of proteins about 25 years ago. Though the IDPRs of transmembrane proteins (TMP-IDPRs) comply with the broad definition of typical IDPs and IDPRs found in water-soluble globular proteins, much less is explored and known about them. In this review, we assimilate the key emerging biophysical principles from the limited studies on TMP-IDPRs and provide several context-specific biological examples to highlight the ubiquitous nature of TMP-IDPRs and their functional importance in cellular functions. Besides providing a spectrum of insights from sequence to structural disorder and functions, we also review the challenges and methodological advances in studying the structure–function relationship of TMP-IDPRs. We also lay stress upon the importance of an integrative framework, where ensemble-averaged (and mostly low-resolution) data from multiple experiments can be faithfully integrated with modelling techniques such as advanced sampling, coarse-graining, and free energy minimization methods for a high-fidelity characterization of TMP-IDPRs. We close the review by providing futuristic perspective with suggestions on how we could use the ideas and methods from the exciting field of protein engineering in conjunction with integrative modelling framework to advance the IDPR field and harness the sequence–disorder–function paradigm towards functional design of proteins.

Interaction of Antimicrobial Lipopeptides with Bacterial Lipid Bilayers Abstract The resistance of pathogens to traditional antibiotics is currently a global issue of enormous concern. As the discovery and development of new antibiotics become increasingly challenging, synthetic antimicrobial lipopeptides (AMLPs) are now receiving renewed attention as a new class of antimicrobial agents. In contrast to traditional antibiotics, AMLPs act by physically disrupting the cell membrane (rather than targeting specific proteins), thus reducing the risk of inducing bacterial resistance. In this study, we use microsecond-timescale atomistic molecular dynamics simulations to quantify the interaction of a short AMLP (C16-KKK) with model bacterial lipid bilayers. In particular, we investigate how fundamental transmembrane properties change in relation to a range of lipopeptide concentrations. A number of structural, mechanical, and dynamical features are found to be significantly altered in a non-linear fashion. At 10 mol% concentration, lipopeptides have a condensing effect on bacterial bilayers, characterized by a decrease in the area per lipid and an increase in the bilayer order. Higher AMLP concentrations of 25 and 40 mol% destabilize the membrane by disrupting the bilayer core structure, inducing membrane thinning and water leakage. Important transmembrane properties such as the lateral pressure and dipole potential profiles are also affected. Potential implications on membrane function and associated proteins are discussed.

Alexandros Sfakianakis
Anapafseos 5 . Agios Nikolaos
Crete.Greece.72100
2841026182

6948891480

alsfakia@gmail.com

Addiction Medicine

Multivisceral Failure in a Context of Serotonin Syndrome Induced by MDMA: The Investigation of a Unique and Nationwide Network The occasional ingestion of 3,4-methylenedioxy-N-methylamphetamine (MDMA) presents serious risks of side effects including death through multivisceral failure in a context of serotonin syndrome. The significant increasing evolution of illicit MDMA street dosages over the past 2 decades and the difficulty for physicians to know what quantity the patients may have consumed, make MDMA a drug with unpredictable effects. Through this case report of a 16-year-old Caucasian, we made use of a unique and nationwide French health monitoring system called TREND (Recent Trends and New Drugs)—SINTES (National Identification System for Drugs and Substances), which, combined with the hair follicle test, can assist medical practitioners in rapidly establishing a precise diagnosis and consequently provide the most appropriate treatment for each individual case in a timely manner. Send correspondence to Redwan Maatoug, MD, MSc, PhD Candidate, Psychiatrist, Addictologist, La Pitié Salêtrière Hospital, 47-83 Boulevard de l'hôpital, 75013 Paris, France. E-mail: redwanmaatoug@gmail.com Received 13 December, 2018 Accepted 19 April, 2019 Disclosure: All authors declare no competing interest. © 2019 American Society of Addiction Medicine

Adolescent SBIRT Practices Among Pediatricians in Massachusetts Objectives: Adolescent Screening, Brief Intervention, and Referral to Treatment (SBIRT) in primary care is a key strategy to prevent, identify, and respond to substance use problems and disorders, including opioid and other drug addictions. Despite substantial investment in recent years to increase its implementation, few studies have reported on recent levels of SBIRT implementation among pediatricians. We aimed to assess self-reported use of the SBIRT framework with adolescent patients among Massachusetts pediatricians, and describe trends since an earlier survey. Methods: We analyzed responses to a cross-sectional survey mailed in 2017 to a representative sample of pediatricians in Massachusetts. We computed response frequencies for all SBIRT practice questions. We used the chi-square test to compare current data to data collected in 2014, as we found no demographic differences between the 2 samples. Results: Nearly all pediatricians in the 2017 sample (n = 160) reported annual screening of their adolescent patients (99%). The majority reported giving positive reinforcement (87%), brief advice (92%), counseling (90%), and referral to treatment (66%) in response to screen results. Compared with 2014, a significantly higher proportion of pediatricians in 2017 referred patients who screened positively for problematic alcohol use, but perceived barriers to screening and follow-up remain, such as insufficient time to screen and patient refusal to return. Conclusions: Among respondents to a Massachusetts pediatrician survey, we found high rates of delivering SBIRT in accordance with published guidelines, though barriers remain. Whether the content of the counseling adheres to guidelines is unknown. Send correspondence to Sharon Levy, MD, MPH, Director, Adolescent Substance Use and Addiction Program, Boston Children's Hospital, 300 Longwood Avenue, Mailstop 3114, Boston, MA 02115. E-mail: Sharon.Levy@childrens.harvard.edu. Received 7 November, 2018 Accepted 5 May, 2019 Author contributions: Dr Straus, Ms Fluett, and Ms Strother designed the survey and collected data. Dr Harris carried out data analysis. Ms Wiseblatt carried out data analysis and drafted the initial manuscript. Dr Levy designed the survey, collected data, and drafted the initial manuscript. All authors reviewed and revised the manuscript. All authors approved the final manuscript as submitted and agree to be accountable for all aspects of the work. Funding: Centers for Medicaid and Medicare Service, State Innovation Model grant to the Commonwealth of Massachusetts (CMS-1G1-12-001) provided support for the administration of the 2014 and 2017 survey and the analysis of results. The authors have no conflicts of interest to disclose. © 2019 American Society of Addiction Medicine

Poverty and Excess Length of Hospital Stay in Neonatal Opioid Withdrawal Syndrome Objectives: To study the impact of sociodemographic factors on length of stay (LOS) for infants with neonatal opioid withdrawal syndrome (NOWS) secondary to fetal opioid exposure. Methods: In this retrospective cohort study, we included term infants with NOWS, excluding those with other significant medical issues. Comprehensive clinical and sociodemographic data were collected. Multivariate regression modeling was used to identify factors which contributed to excess LOS, which was defined as the number of days beyond the standard monitoring and/or treatment protocol. Results: In all, 129 infants were identified; mean gestational age of 37.9 ± 1.3 weeks and mean body weight of 2880 ± 496 g. Among them, 68% of infants were exposed to opioids; 27% were exposed to methadone; and 67% required pharmacologic treatment. The degree of poverty was assessed using the Area Deprivation Index (ADI) based on the mother's address at the time of birth. Median LOS for treated infants was 23 days versus 8 days for those who did not need pharmacologic treatment. The median excess LOS was 4 days (range 0–24). Excess hospital days were strongly correlated with degree of deprivation in the mother's community (r = 0.55, P < 0.01). ADI remained a strong predictor of excess LOS, even when controlling for pharmacologic treatment, placement in state's custody, race, and gestational age at birth. Conclusions: These results suggest poverty is associated with excess LOS and that early allocation of resources for at-risk families may help to reduce overall length of hospital stay. Send correspondence to: Zachary A. Vesoulis, MD, Department of Pediatrics, Washington University School of Medicine, 1 Children's Place, St. Louis, MO 63110. E-mail: vesoulis_z@kids.wustl.edu. Received 10 January, 2019 Accepted 11 March, 2019 Funding: This work was supported by the following grants: Washington University Institute of Clinical and Translational Sciences KL2 Training Program (NIH/NCATS KL2 TR000450); the Barnes-Jewish Hospital Foundation and the Washington University Institute of Clinical and Translational Sciences Clinical and Translational Funding Program (NIH/NCATS UL1 TR000448). The authors report no conflicts of interest. © 2019 American Society of Addiction Medicine

How Might Maternal Poverty Impact the Course of Neonatal Opioid Withdrawal Syndrome? Neonatal Opioid Withdrawal Syndrome (NOWS) is an increasing problem in the midst of the current opioid epidemic, frequently associated with pharmacologic treatment and prolonged hospitalizations. NOWS is a highly variable condition with many clinical and genetic variables contributing to the clinical course. Social variables such as maternal poverty remain understudied. In this commentary, we review one of the first studies of the association between maternal poverty and infant hospital length of stay in infants with NOWS. This has important implications for designing population level interventions to improve NOWS outcomes. Send correspondence to Elisha M. Wachman, MD, Boston Medical Center, 771 Albany Street, Dowling 4103, Boston, MA 02118. E-mail: Elisha.Wachman@bmc.org Received 26 March, 2019 Accepted 31 March, 2019 Financial disclosures: No funding was provided for this manuscript. Dr Wachman has no conflicts of interest to disclose. © 2019 American Society of Addiction Medicine

The Role of Hospitalists in Treating Opioid Use Disorder No abstract available

The Role of Hospitalists in Treating Opioid Use Disorder No abstract available

Exploring the Effects of Vitamin D Supplementation on Cognitive Functions and Mental Health Status in Subjects Under Methadone Maintenance Treatment Objectives: Vitamin D deficiency may be linked to several mental complications including cognitive deficits, depression, and anxiety in patients under methadone maintenance treatment (MMT). This study was designed to explore the effect of vitamin D supplementation on cognitive functions and mental health parameters in subjects under MMT. Methods: This randomized, double-blinded, placebo-controlled clinical trial was carried out among 64 patients under MMT. Participants were randomly allocated to receive either 50,000 IU vitamin D supplements (n = 32) or placebo (n = 32) every 2 weeks for 24 weeks. Cognitive functions and mental health parameters were taken at baseline and posttreatment to evaluate relevant variables. Results: After the 24-week intervention, compared with the placebo, serum 25(OH) vitamin D levels significantly increased in participants who received vitamin D supplements (β 14.50; 95% confidence interval [CI], 13.17–15.83; P < 0.001). In addition, compared with the placebo, subjects who received vitamin D had a significant reduction in Iowa Gambling Task (β −6.25; 95% CI, −8.60 to −3.90; P < 0.001), and significant increases in Verbal Fluency Test (β 2.82; 95% CI, 0.78–4.86; P = 0.007), Immediate Logic Memory (β 1. 32; 95% CI, 0.27–2.37; P = 0.01), Reverse Digit Span (β 2.06; 95% CI, 1.18–2.94; P < 0.001) and visual working memory (β 0.75; 95% CI, 0.33–1.16; P = 0.001). Also, vitamin D supplementation significantly improved BDI (β −2.76; 95% CI, −3.97 to −1.55; P < 0.001) compared with the placebo. When we applied Bonferroni correction, LM-Immediate (P = 0.07) became nonsignificant, and other mental health parameters did not alter. Conclusions: Overall, taking 50,000 IU vitamin D supplements every 2 weeks for 24 weeks by patients under MMT had beneficial effects on cognitive functions and some mental health parameters. Further studies are needed to confirm our findings. Send correspondence to Zatollah Asemi, PhD, Research Center for Biochemistry and Nutrition in Metabolic Diseases, Kashan University of Medical Sciences, Kashan, Iran. E-mail: asemi_r@yahoo.com Received 8 May, 2018 Accepted 9 May, 2019 The authors report no conflicts of interest. Clinical trial registration number: www.irct.ir: IRCT2017101133079N4. © 2019 American Society of Addiction Medicine

Editor's note: Congratulations to the 2019 Author and Reviewer Award Winners No abstract available

Prenatal Practice Staff Perceptions of Three Substance Use Screening Tools for Pregnant Women Objective: There is a need to identify an acceptable and comprehensive substance use screening tool for pregnant women in the United States. This qualitative study sought to better understand prenatal practice staff perceptions of three existing substance use screening tools for use among pregnant women in an outpatient practice setting. Methods: Eight focus groups with 40 total participants were conducted with clinical and administrative staff of 2 diverse Maryland prenatal practices to determine the acceptability and usability of 3 substance use screening tools (4P's Plus, NIDA-Modified Alcohol, Smoking and Substance Involvement Screening Test, and the Substance Use Risk Profile-Pregnancy scale). The focus groups were digitally recorded, transcribed, coded, and analyzed using thematic analysis. Results: Participant perceptions of screening tools were dependent upon screening tool length, tone, comprehensiveness, subjectivity, time frame of questions, and scoring and clinician instructions. Most participants preferred the 4P's Plus screening tool because it is brief, comprehensive, easy for the patient to understand, and excludes judgmental language and subjective questions. Conclusions: These results provide valuable insight into the specific needs and preferences of prenatal practice staff as it relates to prenatal substance use screening and provides evidence that the 4P's Plus may be a preferred screening tool for standardized use in prenatal care. Send correspondence to Victoria H. Coleman-Cowger, PhD, The Emmes Company, LLC, 401N. Washington Street, Suite 700, Rockville, MD 20850. E-mail: vcolemancowger@emmes.com Received 7 December, 2018 Accepted 18 March, 2019 Funding: Research reported in this publication was supported by the National Institute on Drug Abuse of the National Institutes of Health under Award Number R01DA041328. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health or the Health Resources and Services Administration. The authors report no conflicts of interest. © 2019 American Society of Addiction Medicine

Job Satisfaction Among Methadone Maintenance Treatment Clinic Service Providers in Jiangsu, China: A Cross-sectional Survey Objective: Service providers' job satisfaction is critical to the stability of the work force and thereby the effectiveness of methadone maintenance treatment (MMT) programs. This study aimed to explore MMT clinic service providers' job satisfaction and associated factors in Jiangsu, China. Methods: This secondary study used baseline data of a randomized interventional trial implemented in Jiangsu, China. A survey was conducted among 76 MMT service providers using the computer-assisted self-interview (CASI) method. Job satisfaction responses were assessed via a 30-item scale, with a higher score indicating a higher level of job satisfaction. Perceived institutional support and perceived stigma due to working with drug users were measured using a 9-item scale. Correlation and multiple linear regression analyses were performed to identify factors associated with job satisfaction. Results: Correlation analyses found a significant association between job satisfaction and having professional experience in the prevention and control of HIV, other sexually transmitted infections, or other infectious diseases (P = 0.046). Multiple regression analyses revealed that working at MMT clinics affiliated with Center for Disease Control and Prevention sites was associated with a lower level of job satisfaction (P = 0.014), and perception of greater institutional support (P = 0.001) was associated with a higher level of job satisfaction. Conclusion: Job satisfaction among MMT clinic service providers was moderate in our study. Our findings suggest that institutional support for providers should be improved, and that acquisition of additional expertise should be encouraged. This is an open access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal. http://creativecommons.org/licenses/by-nc-nd/4.0 Send correspondence to Zunyou Wu, PhD National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention, 155 Changbai Road, Beijing 102206, China. E-mail: wuzy@263.net, wuzunyou@chinaaids.cn Received 25 April, 2018 Revised 11 November, 2018 Accepted 5 December, 2018 The authors declare no conflicts of interest. © 2019 American Society of Addiction Medicine

Alexandros Sfakianakis
Anapafseos 5 . Agios Nikolaos
Crete.Greece.72100
2841026182

6948891480

alsfakia@gmail.com

Cell Biology and Toxicology

Keeping our eyes on CRISPR: the "Atlas" of gene editing

Off-target challenge for base editor-mediated genome editing

The insect, Galleria mellonella , is a compatible model for evaluating the toxicology of okadaic acid Abstract The polyether toxin, okadaic acid, causes diarrhetic shellfish poisoning in humans. Despite extensive research into its cellular targets using rodent models, we know little about its putative effect(s) on innate immunity. We inoculated larvae of the greater wax moth, Galleria mellonella, with physiologically relevant doses of okadaic acid by direct injection into the haemocoel (body cavity) and/or gavage (force-feeding). We monitored larval survival and employed a range of cellular and biochemical assays to assess the potential harmful effects of okadaic acid. Okadaic acid at concentrations ≥ 75 ng/larva (≥ 242 μg/kg) led to significant reductions in larval survival (> 65%) and circulating haemocyte (blood cell) numbers (> 50%) within 24 h post-inoculation. In the haemolymph, okadaic acid reduced haemocyte viability and increased phenoloxidase activities. In the midgut, okadaic acid induced oxidative damage as determined by increases in superoxide dismutase activity and levels of malondialdehyde (i.e. lipid peroxidation). Our observations of insect larvae correspond broadly to data published using rodent models of shellfish-poisoning toxidrome, including complementary LD50 values: 206–242 μg/kg in mice, ~ 239 μg/kg in G. mellonella. These data support the use of this insect as a surrogate model for the investigation of marine toxins, which offers distinct ethical and financial incentives.

Targeting neddylation inhibits intravascular survival and extravasation of cancer cells to prevent lung-cancer metastasis Abstract Metastasis is the leading cause of tumor-related death from lung cancer. However, limited success has been achieved in the treatment of lung cancer metastasis due to the lack of understanding of the mechanisms that underlie the metastatic process. In this study, Lewis lung carcinoma (LLC) cells which expressed green fluorescent protein in the nucleus and red fluorescent protein in the cytoplasm were used to record metastatic process in real-time via a whole-mouse imaging system. Using this system, we show the neddylation inhibitor MLN4924 inhibits multiple steps of the metastatic process, including intravascular survival, extravasation, and formation of metastatic colonies, thus finally suppressing tumor metastasis. Mechanistically, MLN4924 efficiently inhibits the expression of MMP2, MMP9, and vimentin and disrupts the actin cytoskeleton at an early stage to impair invasive potential and subsequently causes a DNA damage response, cell cycle arrest, and apoptosis upon long exposure to MLN4924. Furthermore, MMP2 and MMP9 are overexpressed in patient lung adenocarcinoma, which conferred a worse overall survival. Together, targeting the neddylation pathway via MLN4924 suppresses multiple steps of the metastatic process, highlighting the potential therapeutic value of MLN4924 for the treatment of metastatic lung cancer.

Studies on combination of oxaliplatin and dendrosomal nanocurcumin on proliferation, apoptosis induction, and long non-coding RNA expression in ovarian cancer cells Abstract Drug resistance remains a major challenge in the treatment of patients with ovarian cancer. Therefore, the development of new anticancer drugs is a clinical priority to develop more effective therapies. New approaches to improve clinical outcomes and limit the toxicity of anticancer drugs focus on chemoprevention. The aim of this study was to determine the effects of dendrosomal nanocurcumin (DNC) and oxaliplatin (Oxa) and their combination on cell death and apoptosis induction in human ovarian carcinoma cell lines analyzed by MTT assay and flow cytometry, respectively. The synergism effect of Oxa and DNC was analyzed using the equation derived from Chou and Talalay. In addition, real-time PCR was used to measure the effect of this combination on the expression levels of long non-coding RNAs with different expression in ovarian cancer and normal ovaries. Our data showed that the effect of DNC on cell death is more than curcumin alone in the same concentration. The greatest cell death effect was observed in combination of Oxa with DNC, while Oxa was added first, followed by DNC at 4 h interval (0/4 h). The findings indicated that DNC induced apoptosis significantly in both cell lines as compared to control groups; however, combination of both agents had no significant effect in apoptosis induction. In addition, combination of both agents significantly affects the relative expression of long non-coding RNAs investigated in the study as compared with mono therapy.

The effects of five types of tea solutions on epiboly process, neural and cardiovascular development, and locomotor capacity of zebrafish Abstract The effects of teas on embryonic development are still known little. The objective of this study was to compare and analyze developmental effects of green tea, delicate flavor oolong tea, strong flavor oolong tea, black tea, and pu'er tea using zebrafish embryos. Embryos were exposed in tea solutions from one-cell stage; the morphology, locomotor capacity, and gene expression of embryos or larvae were analyzed. The results showed that either tea could decrease the length of body and the size of head and eyes. The effect of green tea had the most significant effects on morphology. Only green tea disturbed cell movement, epiboly, and nervous system development. All five tea solutions caused heart structure alternations and lowered heart rates, and effects caused by green tea were severe. Green tea inhibited the formation of dorsal aorta and segmental arteries and decreased the velocity and total movement distance of larvae. In conclusion, the toxicity of green tea to epiboly, neural and cardiovascular development, and locomotor capacity is more severe than that of other teas. Our study played a warning role for safety consumption of teas and provided references for further study of tea's physiological and pharmacological effects and biological activity.

Off-target genome editing: A new discipline of gene science and a new class of medicine Abstract With an increasing growth of genome editing, off-target effects such as non-specific genetic modifications resulting from the designed process of genome editing become a new discipline of gene science and new class medicine. The degree of short-term and long-term side effects and toxicity or dynamics of the primary and secondary off-target genome editing varies with the application of different methodologies of gene editing and measuring, readouts of genetic modifications, or comparison reference. Measurements of dynamic off-target effects caused directly or indirectly by genome editing are critical in clinical application of gene editing. The quality of genome editing methods is one of the decisive factors in the occurrence of off-target effects. Mechanisms by which off-target effects of genome editing occurs are more complex and comprehensive than we expected. The heterogeneity of off-target effects of gene-edited cells at single-cell levels should be defined during the development and formation of cell clusters. In addition to off-target effects on gene-edited cells per se, alterations of gene sequence, structure, dimension, and function of related regulators caused by off-target effects may also influence intercellular communications and interactions between gene-edited cells, between gene-edited cells and non-edited cells, or between non-edited cells. Thus, controlling, measuring, defining, categorizing, and predicting off-target genome editing need to be standardized and prioritized before clinical application of gene editing.

Endoplasmic reticulum stress leads to mitochondria-mediated apoptosis in cells treated with anti-HIV protease inhibitor ritonavir Abstract Background and Aims Endoplasmic reticulum (ER) stress is a growing concern for drug-induced toxicity which causes several side effects. Ritonavir, a potent HIV protease inhibitor, induces both ER and mitochondrial stress; however, the missing link between ER stress and mitochondrial damage has been unknown. In the present study, we have studied the sequential events that occur during ritonavir-induced cell cytotoxicity and elucidate the link between ER stress and mitochondrial damage. Methods Cytotoxicity of ritonavir was calculated on different cells; Huh-7.5, 293T, HeLa, and Hepa RG cells using the MTT assay and also by measuring total protein content. Cellular stress response was evaluated by RT-PCR for stress marker genes. Entry of drug into the mitochondrial compartment was evaluated by HPLC. Mitochondria-mediated apoptosis was analyzed by western blotting. Results Ritonavir treatment initially triggered ER stress during the early hours of treatment. Consequently, the BAX was activated which permeabilized the mitochondrial outer membrane. Simultaneously, upon entry of the drug into the mitochondrial compartment, change in mitochondrial membrane potential was observed which led to the release of cytochrome c in the cytoplasm. Release of cytochrome c activated mitochondria-mediated apoptosis by the activation of caspase-9/7 and parp-1. Conclusion The cytotoxic effects of ritonavir involved the interplay of ER stress and mitochondria-mediated apoptosis. This unusual mechanism of drug-induced toxicity expands our knowledge in understanding side effects caused by ritonavir.

Drp1-associated mitochondrial dysfunction and mitochondrial autophagy: a novel mechanism in triptolide-induced hepatotoxicity Abstract Triptolide being an active ingredient of Chinese herbal plant Tripterygium wilfordii Hook f. has severe hepatotoxicity. Previous studies from our lab reported triptolide-induced mitochondrial toxicity in hepatocytes. However, biomolecular mechanisms involved in triptolide-induced mitochondrial dysfunction are not yet entirely clear. We explored the connection between mitochondrial fragmentation and mitophagy in triptolide-induced hepatotoxicity. Triptolide caused an increase in ROS production, a decrease in mitochondrial depolarization, a diminution of ATP generation, a decline in mitochondrial DNA copy number, mitochondrial fragmentation, and disturbance in mitochondrial dynamics in a concentration-dependent manner in L02 cells. Disturbance in mitochondrial dynamics was due to an increased expression of Drp1 fission protein in vitro and in vivo. L02 cells exhibited an increase in the colocalization of lysosomes with mitochondria and autophagosomes with mitochondria in triptolide treated group as compared to control group which was inhibited by Mdivi-1. Transmission electron micrographs of rat liver tissues treated with triptolide (400 μg/kg) revealed activation of mitophagy which was prevented by Mdivi-1 co-treatment. Taken together, our results showed that mitochondrial fission-associated mitophagy is a novel mechanism involved in triptolide-induced hepatotoxicity. For the alleviation of triptolide-induced hepatotoxicity, mitochondrial fission and mitochondrial autophagy signaling pathway can be targeted as a new therapeutic strategy. Graphical abstract ᅟ

Peroxiredoxin 4 ameliorates amyloid beta oligomer-mediated apoptosis by inhibiting ER-stress in HT-22 hippocampal neuron cells Abstract Alzheimer's disease (AD) is a neurodegenerative disorder caused by amyloid beta oligomers (AβO), which induce cell death by triggering oxidative stress and endoplasmic reticulum (ER) stress. Oxidative stress is regulated by antioxidant enzymes, including peroxiredoxins. Peroxiredoxins (Prx) are classified into six subtypes, based on their localization and cysteine residues, and protect cells by scavenging hydrogen peroxide (H2O2). Peroxiredoxin 4 (Prx4) is unique in being localized to the ER; however, whether Prx4 protects neuronal cells from AβO-induced toxicity remains unclear, although Prx4 expression is upregulated in AβO-induced oxidative stress and ER stress. In this study, we established HT-22 cells in which Prx4 was either overexpressed or silenced to investigate its role in AβO-induced toxicity. AβO-stimulation of HT-22 cells with overexpressed Prx4 caused decreases in both AβO-induced ROS and ER stress (followed by ER expansion). In contrast, AβO stimulation caused increases in both ROS and ER stress that were notably higher in HT-22 cells with silenced Prx4 expression than in HT-22 cells. Consequently, Prx4 overexpression decreased apoptotic cell death and ameliorated the AβO-induced increase in intracellular Ca2+. Therefore, we conclude that Prx4 has a protective effect against AβO-mediated oxidative stress, ER stress, and neuronal cell death. Furthermore, these results suggest that Prx4 may be a target for preventing AβO toxicity in AD. Graphical abstract .

Alexandros Sfakianakis
Anapafseos 5 . Agios Nikolaos
Crete.Greece.72100
2841026182

6948891480

alsfakia@gmail.com

Primary Prevention

Program Capacity to Deliver Prevention Services to Children of Adult Clients Receiving Substance Use Disorder Treatment Abstract Children whose parents have a history of substance use are at elevated risk of developing substance use disorders (SUDs) and related debilitating behaviors. Although specialty treatment programs are uniquely positioned to deliver prevention care to children of adult clients, these programs may have limited capacity to implement prevention and early intervention care services, particularly in racial and ethnic minority communities. We merged data from program surveys and client records collected in 2015 to examine the extent to which program capacity factors are associated with the odds of delivering prevention and early intervention services for children of adult clients attending outpatient SUD treatment in low-income minority communities in Los Angeles County, California. Our analytic sample consisted of 16,712 clients embedded in 82 programs. Our results show that 85% of these programs reported delivering prevention care services, while 71% of programs delivered early intervention services. Programs with organizational climates supporting change and those that served a high number of clients annually were more likely to implement both prevention and early intervention practices. Programs accepting Medicaid payments and serving clients whose primary drug was marijuana were more than three times as likely to implement prevention services. Overall, our findings suggest both program- and client-level characteristics are associated with delivering preventive care offered to children of adult clients receiving SUD treatment in communities of color. As Medicaid has become a major payor of SUD treatment services and marijuana use has been legalized in California, findings identify capacity factors to deliver public health prevention interventions in one of the nation's largest public SUD treatment systems.

Meta-Review on the Effectiveness of Classroom-Based Psychological Interventions Aimed at Improving Student Mental Health and Well-Being, and Preventing Mental Illness Abstract This meta-review summarizes existing evidence from systematic reviews and meta-analyses on the effectiveness of school-based psychological interventions aimed at improving student mental health and well-being, and preventing mental illness. Systematic reviews and meta-analyses were identified via the electronic databases PsycINFO, Web of Knowledge, Medline, Embase, and HMIC (Health Management Information Consortium). Ten systematic reviews and meta-analysis were eligible for inclusion in the final analyses. These systematic reviews and meta-analyses evaluated the effects of five types of school-based psychological interventions: Mindfulness, Social Emotional Learning, Cognitive Behavioral Therapy, Yoga, and Body-Image. Overall effectiveness reported in the included studies was significant for the most part, and ranging from small to large with respect to the effect size. The authors of all of the studies emphasized the need for additional high-quality trials to further examine the effectiveness of school-based psychological interventions aimed at improving student mental health and well-being, and preventing mental illness.

Tailgating Protective Behavioral Strategies Mediate the Effects of Positive Alcohol Outcome Expectancies on Game Day Drinking Abstract Although a growing body of evidence suggests protective behavioral strategies are associated with lower alcohol use among college students, we know little about what contributes to students' decisions to use these strategies. Alcohol outcome expectancies have been associated with alcohol use among college students, and may contribute to their decisions to use protective behavioral strategies while drinking in contexts associated with an elevated risk for heavy alcohol use. University football game tailgating is one high-risk context that has received limited empirical attention with respect to identifying risk and protective factors for use. We sought to determine whether expectancy effects on tailgating drinking may be attributable to the approach or avoidance of protective strategies in this context. We expected college students who perceive greater positive expectancies to report engaging in more protective strategies on game day, whereas we hypothesized greater negative expectancies would be associated with less use of protective strategies. College students (N = 231) reported outcome expectancies online within 7 days of tailgating and quantity of alcoholic drinks consumed while tailgating, as well as whether they used limiting consumption (i.e., counting drinks, alternating drinking water and alcohol) and harm reduction (HR; i.e., sober transportation) strategies 48 h after tailgating. Results indicated higher positive expectancies were associated with greater use of HR strategies. Positive expectancies were indirectly positively related to greater game day tailgating drinking and negatively to odds of abstaining through the use of protective strategies, and unique indirect effects were observed for HR strategies. These findings highlight important individual differences that contribute to the use of protective behaviors, and suggest that expectancy-challenge interventions may be tailored to address unsafe drinking practices and promote college student health.

Determinants of Parental Intentions to Vaccinate Kindergarten Children Against Seasonal Influenza in Xiamen, China Abstract Seasonal influenza epidemics occur almost every year, and children under 6 years of age constitute one of the most susceptible groups. While free vaccinations are offered to preschool children in some large cities in China, Xiamen lacks a free vaccination policy and other effective policies aimed at increasing parents' acceptance of the vaccine. Using the health belief model (HBM), we sought to: (1) investigate the determinants of parents' intentions to vaccinate their kindergarten children against seasonal influenza if the free policy were implemented, and (2) explore the possible interaction effects between "cues to action" and "perceived susceptibility" and/or "perceived severity." A total of 1350 parents with kindergarten children were selected by stratified random sampling from half the population in Xiamen, of whom 1211 responded effectively to our survey. Scobit models with testing for interactions among the key concepts of the HBM were used to investigate factors associated with parents' intentions to vaccinate their children. In total, 85.1% of 1211 parents reported that they were willing to vaccinate their children if free influenza vaccinations were offered, although only 37 children (3.1%) had received influenza vaccination in the previous year, and 261 (21.6%) had been vaccinated since birth. Parents' perceived susceptibility (AOR = 1.77), perceived benefits (AOR = 3.12), perceived barriers (AOR = 0.38) and cues to action (AOR = 3.54) in terms of childhood vaccination against influenza were significantly associated with their vaccination intentions. The only observed interaction effect was between perceived susceptibility and cues to action (AOR = 1.57), which had additive effects on strengthening parental intentions to vaccinate their children. Our findings can be used as a basis for formulating government strategies aimed at improving influenza vaccination coverage among children in kindergarten and guiding culturally informed primary prevention efforts among their parents.

Is Weight Discrimination Associated With Physical Activity Among Middle Aged and Older Adults? Abstract Older adults (> 65) are less physically active than all other adult age groups. Although experiences of weight discrimination have been inversely associated with physical activity in several studies of middle-aged and older adults, the role of weight discrimination in this relationship has not been sufficiently explicated. Using data from the Health and Retirement Study (a longitudinal panel study of U.S. adults aged 50 and older), we hypothesized that, among middle aged and older adults, weight discrimination would (a) be inversely related to respondents' reported level of physical activity; and (b) partially mediate the relationship between BMI and physical activity. Using multiple logistic regression analysis, we found an inverse relationship between weight discrimination and vigorous physical activity (OR = 0.79; 95% CI [0.66, 0.94]), as well as between weight discrimination and moderate physical activity (OR = 0.76; 95% CI [0.62, 0.92]). Weight discrimination mediated 13% of the relationship between BMI and vigorous physical activity, as well as 9% of the relationship between BMI and moderate physical activity. Weight discrimination may thus pose a barrier to regular physical activity among middle aged and older adults. Future research and interventions should identify effective ways of mitigating barriers experienced because of weight discrimination in the promotion of physical activity among these age groups, as well as how we may effectively reduce the perpetration of weight discrimination in various settings.

Replication of It's Your Game…Keep It Real! in Southeast Texas Abstract Despite the recent efforts of the Office of Adolescent Health to replicate programs with demonstrated efficacy, there are still few evidence-based HIV, sexually transmitted infection (STI), and teen pregnancy prevention programs that have been replicated in "real-world" settings. To test the effectiveness of It's Your Game…Keep It Real! (IYG), an evidence-based STI and pregnancy prevention program for middle schools, the curriculum was implemented by teachers in urban and suburban middle schools in Southeast Texas from 2012 to 2015. IYG was evaluated using a group-randomized wait-list controlled effectiveness trial design in which 20 middle schools in nine urban and suburban school districts in Southeast Texas were randomized equally, using a multi-attribute randomization protocol, to either the intervention condition (received IYG) (n = 10 schools comprising 1936 eligible seventh graders) or the comparison condition (received usual care) (n = 10 schools comprising 1825 eligible seventh graders). All students were blinded to condition prior to administering the baseline survey. The analytic sample comprised 1543 students (n = 804, intervention; n = 739, comparison) who were followed from baseline (seventh grade) to the 24-month follow-up (ninth grade). Multilevel regression analyses were conducted to assess behavioral and psychosocial outcomes at follow-up. There were no significant differences in initiation of vaginal or oral sex between study conditions at follow-up. However, at 12-month follow-up, compared with students in the comparison condition, students in the intervention condition reported increased knowledge, self-efficacy, and perceived favorable norms related to HIV/STIs, condoms, and/or abstinence; decreased intentions to have sex; and increased intentions to use birth control. Knowledge outcomes were statistically significant at 24-month follow-up. This IYG effectiveness trial did not replicate the behavioral effects of the original IYG efficacy trials. However, it adds to the growing literature on the replication of evidence-based programs, and underscores the need to better understand how variations in implementation, setting, and measurement affect the behavioral impact of such programs. Clinical trial registration clinicaltrials.gov (NCT03533192).

Preventing Adolescent Substance Use: A Content Analysis of Peer Processes Targeted Within Universal School-Based Programs Abstract Universal school-based substance use prevention programs are widely disseminated and often include a focus on peer relationships. Network theory and social network analysis (SNA) have emerged as useful theoretical and methodological frameworks for examining the role of peer relationships in prevention and intervention research. We used content analysis to systematically code the peer processes targeted by three universal school based prevention programs. We found that programs focused on peer socialization more than peer selection, and programs focused about evenly on descriptive and injunctive norms. Programs varied in their focus on positive and negative peer processes and behaviors, but most references to peer processes focused on positive processes and negative behaviors. The focus on peer processes at the dyadic, subgroup, and network levels varied across the three programs, with the heaviest focus on network level processes. When peer processes were targeted, it was rare that lessons focused on peer processes for an extended (> 50%) amount of the lesson content. However, when peer processes were a focus, discussion and reflection were commonly encouraged. These patterns are considered in the context of non-intervention research on adolescent peer relations, which highlights the importance of peer selection and dyad-level processes, and the existence of positive peer processes that promote adolescent development. In doing so, we provide a framework that can be used to (1) examine the extent to which a particular program focuses on the different peer processes, and (2) inform systematic experimental studies of the extent to which particular peer processes are malleable in response to intervention efforts.

Linking Sleep to Externalizing Behavioral Difficulties: A Longitudinal Psychometric Survey in a Cohort of Italian School-Age Children Abstract We examined the longitudinal relationship between sleep problems and behavioral problems at primary school in Italian children. We recruited a school-based sample of 227 children (age range 6–10 years) in schools located in Pisa (Italy). Parents completed the Sleep Disturbance Scale for Children (SDSC), and teachers completed the Strengths and Difficulties Questionnaire (SDQ) to evaluate children's behavioral difficulties. We used a two-step robust regression approach to identify which aspects of sleep problems might affect children's behavior at school. After removing socio-demographic effects, results indicated an association between an increase in sleep problems and the worsening of inattentive and hyperactive behavioral problems at school 1 year later. This association was particularly robust in children whose sleep problems had gotten worse over the year. We found no associations between child sleep problems and conduct problems in school settings. Schools may be a suitable arena in which to identify and prevent the development of severe externalizing behaviors through screening procedures and intervention for children's sleep problems.

CARING: The Impact of a Parent–Child, Play-Based Intervention to Promote Latino Head Start Children's Social–Emotional Development Abstract CARING is a preventive, play-based, parent–child intervention designed to promote preschoolers' social–emotional development by strengthening their bonds with their parents. We describe the qualitative impact of the CARING Preschool program on Latino preschool children and their parents. One hundred and eleven Latino families participated in a larger study of the efficacy of the CARING preschool program. Of these families, 40 participated in this qualitative study. We invited families to participate in a focus group after completing the intervention. We used an inductive approach based on grounded theory to identify thematic categories. Parents reported substantial changes in themselves, their children and the quality of their relationships with their children as a result of their participation in CARING. Parents also reported an increased understanding of their children's needs, their ability to use at home the skills learned during the intervention, and improved parent–child communication. In addition, parents reported the social skills and self-regulation abilities of their children improved. These findings highlight the promise of preventive, low-cost interventions for families facing socioeconomic and psychosocial adversity, and their potential role in strengthening parent–child relationships. Results highlight cultural parenting practices and implications for intervention with Latino families.

Framework for Supporting Adolescent Peer Leaders: A Pilot Using Text Messaging in a School-Based Substance Use Prevention Program Abstract Training peer leaders (PLs) as implementation agents is a state-of-the-art approach in prevention, but the field lacks frameworks for providing support. Text messaging, a powerful tool for direct intervention, may be useful in this regard. We introduce a conceptual framework for engaging, retaining, and educating adolescent PLs and conduct a pilot test of this framework using text messages for delivery to middle school PLs in a new, peer-led substance use prevention program. Fifty eighth-graders were recruited as PLs. We used a newly-developed framework to create text messages to strengthen peer leaders': (a) mission, agency, and team identity; (b) connection to adult mentors; (c) content knowledge and application to their own lives; and (d) preparation for prevention activities. Thirty-four texts were sent to PLs over 4 months. PL replies and participation were recorded to track engagement. Forty-one PLs (71%) received texts and completed baseline and post-program surveys. Parents and school staff completed post-program questionnaires. Eighty-five percent of PLs responded to at least one text message. Response rates for specific messages varied from 22 to 56%. Students were most likely to reply to texts about preparation for their own prevention activities in the school. Ninety-five percent of PLs said they read messages even when they did not reply. Eighty-three percent of PLs said the messages helped them accomplish their mission. PLs reported that they wanted to receive messages in the future. PL attendance had very little variability in two of the three schools, but replies to texts were associated with better attendance in one school. Our study provides a framework for supporting adolescent peer leaders in a network intervention. Automated text messaging supporting middle school PLs was feasible, engaging, and well-received. Texting activity was associated with participation in school-based activities. Future priorities include systematically varying text support to determine its true effect on implementation and on involvement by less engaged PLs.

Alexandros Sfakianakis
Anapafseos 5 . Agios Nikolaos
Crete.Greece.72100
2841026182

6948891480

alsfakia@gmail.com

Hazardous Materials

Removal of Cr3+ from tanning effluents by adsorption onto phosphate mine waste: Key parameters and mechanisms Publication date: 15 October 2019 Source: Journal of Hazardous Materials, Volume 378 Author(s): Amal Oumani, Laila Mandi, Fatima Berrekhis, Naaila Ouazzani Abstract The present study aims to investigate key parameters and mechanisms affecting Cr3+ removal from tanning wastewater using phosphate mine waste (PW) as adsorbent in batch mode. The initial Cr3+ concentration was 3920 mg.L−1. The maximum removal capacity of Cr3+ was found to be 97.23 mg.g−1 using 40 g.L−1 of PW at 50 °C and at 200 rpm of stirring speed. Thermodynamic studies indicated that Cr3+ sorption is endothermic reaction of a physico-chemical adsorption process. Kinetic data were satisfactorily described by a pseudo-second order model. Cr3+ removal is probably involving several mechanisms: PW surface dissolution, precipitation, co-precipitation, ion exchange and adsorption. The chromium sorption seems modifying the crystalline structure of the adsorbent. Adsorption isotherm was described by Freundlich, Langmuir and Redlich-Peterson models. But statistically, Freundlich fit better the experimental data. Five error functions were used to check this result. Treatment of chromium effluent using PW as adsorbent can also eliminate more than 60% of organic matter and then can be considered as an effective biomaterial for tanning wastewater treatment.

Experimental study on explosion characteristics of ethanol gasoline–air mixture and its mitigation using heptafluoropropane Publication date: 15 October 2019 Source: Journal of Hazardous Materials, Volume 378 Author(s): Guochun Li, Xishi Wang, Hongli Xu, Yangpeng Liu, Heping Zhang Abstract Ethanol gasoline is being widely used as a new environmentally friendly and energy-saving alternative energy, and the control/reduction of its fire/explosion risk has become an important aspect, not only for its production and storage, but also for its transport and application. This study aims to investigate the explosion characteristics of ethanol gasoline and its mitigation using heptafluoropropane in a restricted vessel. The flame propagation was visualized using a Phantom high-speed camera at 3000 fps, the explosion overpressure was measured using PCB pressure sensors, and the gas released from the vent was collected and analyzed using a gas chromatography-mass spectrometer. The results indicate that heptafluoropropane has a good suppression effect on the flame propagation speed and the explosion overpressure. The maximum overpressure of an ethanol gasoline explosion is approximately 456 kPa, and the overpressure reduction exceeds 60% when the concentration of heptafluoropropane addition is 10%, whereas an explosion is completely mitigated when the concentration of heptafluoropropane continuously increases. In addition, different flame colors during the mitigation process, such as blue, yellow, and purple, were observed and analyzed. The results of this study will be valuable for further understanding ethanol gasoline explosion mitigation and designing optimum heptafluoropropane explosion mitigation systems. Graphical abstract

Interaction with low molecular weight organic acids affects the electron shuttling of biochar for Cr(VI) reduction Publication date: 15 October 2019 Source: Journal of Hazardous Materials, Volume 378 Author(s): Zibo Xu, Xiaoyun Xu, Xinyi Tao, Chengbo Yao, Daniel C.W. Tsang, Xinde Cao Abstract Biochar can act as "electron shuttle" in soil redox reactions. It is possible that biochar accepts the electrons from low molecular weight organic acids (LMWOAs) in soil and then transfer them to the acceptors, e.g., Cr(VI). This study evaluated the interaction between seven soil LMWOAs and peanut shell biochar (BC) as well as its effect on the electron shuttling of biochar for Cr(VI) reduction. Both redox reactions and sorption process occurred during the interaction of biochar and LMWOAs, which altered the contents of Cr(VI) reduction-relevant groups (i.e., CO and CO) on the surface of biochar. The redox reactions were more important to the electron transfer between biochar produced at 400℃ (BC400) and LMWOAs due to the repeated cycle of reduction-oxidation of surface functional groups. The reduction rate of Cr(VI) by LMWOAs mediated by BC400 was 1.10–7.09 × 10−3 h-1, among which tartaric acid had the best reduction efficiency due to its highest reducing capability. For biochar produced at 700℃ (BC700), the sorption process of LMWOAs was the key factor to the direct electron shuttling process through the conjugated structure of biochar. The reduction rate of Cr(VI) by LMWOAs mediated by BC700 was significantly higher and ranged 7.40–864 × 10−3 h-1, with the oxalic acid having the best reduction efficiency due to its highest sorption capacity by BC700. The results obtained from this study can help to establish the linkage between biochar and LMWOAs in soil electron network, which better explains the multifunctional roles of biochar during the redox processes such as Cr(VI) reduction in soil. Graphical abstract

Preparation and characterization of styrene-butadiene-styrene membrane incorporated with graphene nanosheets for pervaporative removal of 1,2,4-trimethylbenzene from water Publication date: 15 October 2019 Source: Journal of Hazardous Materials, Volume 378 Author(s): S.A. Mousavinezhad, S.M. Mousavi, E. Saljoughi Abstract In the present study, novel styrene-butadiene-styrene (SBS) membranes were prepared by the addition of graphene (Gr) nanosheets to the casting solution and were utilized in the pervaporative separation of a dilute solution of 1,2,4-trimethylbenzene (1,2,4-TMB) as a volatile organic compound (VOC) in water. Several characterizations such as field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), mechanical tensile test, and determination of water contact angle and swelling degree were conducted to investigate the properties of the prepared membranes. The results showed that with the addition of Gr the membrane thermal stability and hydrophobicity were increased while there was an optimum Gr loading to achieve the highest elastic modulus and tensile strength. Moreover, it was found that by increasing the Gr concentration up to 0.5 wt. %, the separation factor and pervaporation separation index (PSI) were increased by 250% and 43% compared to pure SBS membrane and reached 930 and 545 kg/m2h, respectively.

Activation of fulvic acid-like in paper mill effluents using H2O2/TiO2 catalytic oxidation: Characterization and salt stress bioassays Publication date: 15 October 2019 Source: Journal of Hazardous Materials, Volume 378 Author(s): Yuanyuan Yao, Chun Wang, Xiaoqi Wang, Yuechao Yang, Yongshan Wan, Jianqiu Chen, Fangjun Ding, Yafu Tang, Zhonghua Wang, Lu Liu, JiaZhuo Xie, Bin Gao, Yuncong C. Li, Gilbert C. Sigua Abstract Increasing environmental concerns about organic waste in paper mill effluents demand alternative wastewater management technology. We reported novel activation of fulvic acid-like in paper mill effluents using hydrogen peroxide (H2O2) as oxidizer and titanium oxide (TiO2) as catalyst. Spectroscopic characteristics of fulvic acid-like in paper mill effluents before and after activation (PFA and PFA-Os, respectively) were compared with a benchmark fulvic acid extracted from leonardite (LFA). Results indicated that PFA-Os exhibited less lignin structures, more functional groups and lower molecular weight than PFA, sharing much similarity with LFA. Among PFA-Os with varying degrees of oxidation, PFA-O-3 activated with 1:2 vol ratio of paper mill effluent and 30% H2O2 for 20 min digestion at 90 °C stands out to be the optimal for further examination of its biological activity. Bioassays with rice seed/seedling indicated that applications of LFA at 2–5 mg-C/L and PFA-O-3 at 60–100 mg-C/L significantly increased rice seed germination rate and seedling growth under salt stress imposed with 100 mM NaCl. The mechanism was mainly through reduced oxidative damage via activation of antioxidative enzymes and lipid peroxidation. This study provides the needed technical basis of safer and cleaner technologies for innovative management of paper mill effluents. Graphical abstract

Tuning ignition and energy release properties of Zirconium powder by atomic layer deposited metal oxide coatings Publication date: 15 October 2019 Source: Journal of Hazardous Materials, Volume 378 Author(s): Lijun Qin, Ting Gong, Jianguo Li, Ning Yan, Longfei Hui, Hao Feng Abstract Ultra-fine powders of reactive metals are promising fuels/additives for propellants. However, the metal surfaces make these materials very unstable in ambient atmosphere. This study explored the method of applying thin films of inorganic materials onto the surface of Zr powder and investigated the effects of different surface coatings on the energy release and ignition process of Zr. Thin films of Al2O3 and ZnO were deposited on a commercial micron-scale Zr powder by atomic layer deposition (ALD). Growth kinetics of ALD films on the Zr particles were studied using various tools. Chemical and structural characterizations revealed that the Zr particles were completely encapsulated by uniform Al2O3 or ZnO films. The thicknesses of the encapsulation layers could be precisely controlled. ALD Al2O3 coatings exhibited a unique surface-sealing effect, which inhibited the low temperature oxidation of Zr in ambient air. Laser and electrostatic discharge (ESD) ignition tests revealed that ALD Al2O3 coatings extended the ignition delay and reduced the ESD sensitivity of the Zr powder. In comparison, ALD ZnO coatings could not form effective gas diffusion barriers, therefore they could not change the oxidation process of Zr and only showed modest effects on ignition and ESD sensitivity of the Zr powder. Graphical abstract

Petroleum-contaminated sites: Decision framework for selecting remediation technologies Publication date: 15 October 2019 Source: Journal of Hazardous Materials, Volume 378 Author(s): Brício Marcelino da Silva, Leila Teresinha Maranho

The application of machine learning methods for prediction of metal sorption onto biochars Publication date: 15 October 2019 Source: Journal of Hazardous Materials, Volume 378 Author(s): Xinzhe Zhu, Xiaonan Wang, Yong Sik Ok Abstract The adsorption of six heavy metals (lead, cadmium, nickel, arsenic, copper, and zinc) on 44 biochars were modeled using artificial neural network (ANN) and random forest (RF) based on 353 dataset of adsorption experiments from literatures. The regression models were trained and optimized to predict the adsorption capacity according to biochar characteristics, metal sources, environmental conditions (e.g. temperature and pH), and the initial concentration ratio of metals to biochars. The RF model showed better accuracy and predictive performance for adsorption efficiency (R2 = 0.973) than ANN model (R2 = 0.948). The biochar characteristics were most significant for adsorption efficiency, in which the contribution of cation exchange capacity (CEC) and pHH2O of biochars accounted for 66% in the biochar characteristics. However, surface area of the biochars provided only 2% of adsorption efficiency. Meanwhile, the models developed by RF had better generalization ability than ANN model. The accurate predicted ability of developed models could significantly reduce experiment workload such as predicting the removal efficiency of biochars for target metal according to biochar characteristics, so as to select more efficient biochar without increasing experimental times. The relative importance of variables could provide a right direction for better treatments of heavy metals in the real water and wastewater. Graphical abstract

Sequential biowashing-biopile processes for remediation of crude oil contaminated soil in Kuwait Publication date: 15 October 2019 Source: Journal of Hazardous Materials, Volume 378 Author(s): Taein Kim, Jin-Kyung Hong, Eun Hea Jho, Guyoung Kang, Dong Jin Yang, Sung-Jong Lee Abstract The application of biological processes for remediation of the aged crude oil-contaminated soil of Kuwait can be an inefficient way, thus, this study developed 20 d-sequential biowashing and biopile processes where the biowashing step uses an enrichment culture of the indigenous soil bacterial community and the biopile step includes hemoglobin-catalyzed oxidation (HCO). The residual total petroleum hydrocarbons (TPH) concentrations and CO2 generation were measured to determine the removal efficiency, and the bacterial community changes were studied to investigate the effect of the sequential processes on the soil indigenous bacterial community. The enrichment culture grown on hemoglobin showed an increased surface activity, and this promoted desorption and emulsification of crude oil from the soil sample in the biowashing step resulting in 75% TPH removal. Potential surfactant-producing bacterial species were observed in the soil sample after biowashing. The HCO in the beginning of the biopile step removed 21% of the residual TPH, and further TPH removal was observed with a longer biopile period. Overall, the sequential biowashing and biopile processes removed 86% TPH. The results show that the developed sequential biowashing and biopile processes can be used to efficiently remediate the aged crude oil-contaminated soil of Kuwait.

Development of a magnetic core-shell Fe3O4@TA@UiO-66 microsphere for removal of arsenic(III) and antimony(III) from aqueous solution Publication date: 15 October 2019 Source: Journal of Hazardous Materials, Volume 378 Author(s): Pengfei Qi, Rong Luo, Thomas Pichler, Jianqiang Zeng, Yan Wang, Yuhua Fan, Kunyan Sui Abstract Removal of trivalent species of As and Sb from wastewater is crucial due to their more toxic and mobile properties. In this study, a novel magnetic core-shell microsphere Fe3O4@TA@UiO-66 was developed via in-situ crystal growth of UiO-66 around the magnetic Fe3O4 modified by Tannic Acid (TA). Characterization of the microsphere by transmission electron microscopy (TEM) and X-ray diffraction spectroscopy (XRD) confirmed that UiO-66 was adhered on the surface of Fe3O4 functionalized by TA. Adsorption experiments showed that the magnetic Fe3O4@TA@UiO-66 had high adsorption capacity for As(III) and Sb(III) and could be rapidly separated from aqueous media within two minutes after treatment. The adsorption kinetics and adsorption isotherms were described well by the pesudo-second order model and Langmuir model, respectively. In addition, the composite exhibited excellent removal performance for As(III) and Sb(III) in a broad solution chemistry environment, including pH and co-existing anions. Based on X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) measurement, we proposed that the removal mechanism was mainly controlled through a synergistic interaction of surface complexation and hydrogen bonding. This study indicates the potential of the magnetic microsphere to be used as an effective material for the removal of As(III) and Sb(III) from water. Graphical abstract

Alexandros Sfakianakis
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