Synthesis, crystal structure, DNA binding and molecular docking studies of zinc(II) carboxylates

Publication date: 5 February 2018
Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 190
Author(s): Niaz Muhammad, Muhammad Ikram, Abdul Wadood, Sadia Rehman, Shaukat Shujah, Erum, Mehreen Ghufran, Shahnaz Rahim, Muzamil Shah, Carola Schulzke
New zinc(II) carboxylate complexes [Zn(3-F-C6H4CH2COO)2]n (1), [Zn3(3-F-C6H4CH2COO)6(Phen)2] (2) and [Zn3(3-F-C6H4CH2COO)6(bipy)2] (3) were synthesized and characterized by atomic absorption, single crystal structural analysis and IR studies. Complex 1 crystallizes as a coordination polymer constituting a web of μ−η¹,η¹ carboxylate bridged tetrahedral zinc centers. Complexes 2 and 3 comprise trinuclear zinc centers with two terminal fivefold coordinated slightly distorted square-pyramidal and central sixfold coordinated octahedral zinc centers. The complexes were also assessed for their DNA binding ability by UV/−Vis spectroscopy and their behavior rationalized theoretically by molecular docking studies. A DNA binding study has shown groove binding interactions with the complexes.

Graphical abstract

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Fluorescent ligand fishing combination with in-situ imaging and characterizing to screen Hsp 90 inhibitors from Curcuma longa L. based on InP/ZnS quantum dots embedded mesoporous nanoparticles

Publication date: 1 February 2018
Source:Talanta, Volume 178
Author(s): Yue Hu, Anchen Fu, Zhaoyi Miao, Xiaojing Zhang, Tianlin Wang, An Kang, Jinjun Shan, Dong Zhu, Wei Li
Although ligand fishing has been shown to be an efficient technique for the identification of bioactive components from complex mixtures such as natural products, it cannot be applied to biomedical image processing. Herein, a specific fluorescent ligand fishing combined with in situ imaging approach is presented for the identification of heat shock protein 90 (Hsp 90) inhibitors from complex matrixes, Curcuma longa L., using N-terminus immobilized Hsp 90α functionalized InP/ZnS quantum dots embedded mesoporous nanoparticles (i.e. Hsp 90α (NT)-FQDNs) as extraction sorbents and fluorescent tracer. The fished ligands were identified by liquid chromatography time-of-flight/mass spectrometry (LC-TOF/MS) and gas chromatography-mass spectrometry (GC-MS). Moreover, in situ imaging by confocal laser scanning microscopy (CLSM) was applied for evaluating the effect of fished-ligands on bioactivity-induced apoptosis morphologically in HeLa cells. MTT assay verified the bioactivity of the ligands and molecular docking results further provided convincing information to verify the feasible binding mode between ligands and protein. Twelve ligands as potential Hsp 90 inhibitors were ultimately fished and identified from Curcuma longa L. crude extracts. The proposed approach based on Hsp 90α functionalized nanocomposites is superior in the combination of highly specific screening efficiency and concurrent visual in situ imaging, which could have great promise for the development of other plant-derived Hsp 90 inhibitors, and providing a rapid and reliable platform for discovering biologically active molecules in natural products.

Graphical abstract

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Calculating fluoride concentrations data using ambient temperatures in drinking water distribution networks in select provinces of Iran

Publication date: December 2017
Source:Data in Brief, Volume 15
Author(s): Mohammad Ali Zazouli, Reza Sadeghnezhad, Laleh R. Kalankesh
Fluoride concentrations in drinking water were analyzed relative to air temperature data collected in different provinces of Iran. Determining suitable concentrations of fluoride in drinking water is crucial for communities because of the health effects of fluoride on humans. This study analyzed fluoride concentrations in drinking water from selected Iranian provinces. The data were derived mainly from a detailed literature review. The annual mean maximum temperatures (AMMTs) were collected from a popular website that maintains records of daily ambient temperature measurements for the last five years (2012–2016). Using regional ambient temperatures, the optimal value of fluoride in drinking water for each province was calculated by the Galgan and Vermillion formula. These optimal fluoride concentrations in drinking water for different Iranian regions were calculated to be 0.64–1.04mgF/L. Most of the selected provinces were found to have acceptable concentrations of fluoride, except for Alborz, Khuzestan, and Hormozgan, which reported concentrations of 0.66, 0.66, and 0.64mg/L, respectively.



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Transitioning from adequate to inadequate sleep duration associated with higher smoking rate and greater nicotine dependence in a population sample

Publication date: February 2018
Source:Addictive Behaviors, Volume 77
Author(s): Freda Patterson, Michael A. Grandner, Alicia Lozano, Aditi Satti, Grace Ma
IntroductionInadequate sleep (≤6 and ≥9h) is more prevalent in smokers than non-smokers but the extent to which sleep duration in smokers relates to smoking behaviors and cessation outcomes, is not yet clear. To begin to address this knowledge gap, we investigated the extent to which sleep duration predicted smoking behaviors and quitting intention in a population sample.MethodsData from current smokers who completed the baseline (N=635) and 5-year follow-up (N=477) assessment in the United Kingdom Biobank cohort study were analyzed. Multivariable regression models using smoking behavior outcomes (cigarettes per day, time to first cigarette, difficulty not smoking for a day, quitting intention) and sleep duration (adequate (7–8h) versus inadequate (≤6 and ≥9h) as the predictor were generated. All models adjusted for age, sex, race, and education.ResultsWorsening sleep duration (adequate to inadequate) predicted a more than three-fold higher odds in increased cigarettes per day (OR=3.18; 95% CI=1.25–8.06), a more than three-fold increased odds of not smoking for the day remaining difficult (OR=3.90; 95% CI=1.27–12.01), and a >8-fold increased odds of higher nicotine dependence (OR=8.98; 95% CI=2.81–28.66). Improving sleep duration (i.e., inadequate to adequate sleep) did not predict reduced cigarette consumption or nicotine dependence in this population sample.ConclusionTransitioning from adequate to inadequate sleep duration may be a risk factor for developing a more "hard-core" smoking profile. The extent to which achieving healthy sleep may promote, or optimize smoking cessation treatment response, warrants investigation.



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Biodistribution and safety of a live attenuated tetravalent dengue vaccine in the cynomolgus monkey

Publication date: 13 October 2017
Source:Vaccine, Volume 35, Issue 43
Author(s): Guillaume Ravel, Nathalie Mantel, Jeremy Silvano, Alexandra Rogue, Bruno Guy, Nicholas Jackson, Nicolas Burdin
BackgroundThe first licensed dengue vaccine is a recombinant, live, attenuated, tetravalent dengue virus vaccine (CYD-TDV; Sanofi Pasteur). This study assessed the biodistribution, shedding, and toxicity of CYD-TDV in a non-human primate model as part of the nonclinical safety assessment program for the vaccine.MethodsCynomolgus monkeys were given one subcutaneous injection of either one human dose (5log10 CCID50/serotype) of CYD-TDV or saline control. Study endpoints included clinical observations, body temperature, body weight, food consumption, clinical pathology, immunogenicity, and post-mortem examinations including histopathology. Viral load, distribution, persistence, and shedding in tissues and body fluids were evaluated by quantitative reverse transcriptase polymerase chain reaction.ResultsThe subcutaneous administration of CYD-TDV was well tolerated. There were no toxicological findings other than expected minor local reactions at the injection site. A transient low level of CYD-TDV viral RNA was detected in blood and the viral genome was identified primarily at the injection site and in the draining lymph nodes following immunization.ConclusionsThese results, together with other data from repeat-dose toxicity and neurovirulence studies, confirm the absence of toxicological concern with CYD-TDV and corroborate clinical study observations.



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Tetanus Toxoid carrier protein induced T-helper cell responses upon vaccination of middle-aged adults

Publication date: 9 October 2017
Source:Vaccine, Volume 35, Issue 42
Author(s): Marieke van der Heiden, Aafke Duizendstra, Guy A.M. Berbers, Annemieke M.H. Boots, Anne-Marie Buisman
IntroductionVaccines frequently induce suboptimal immune responses in the elderly, due to immunological ageing. Timely vaccination may be a strategy to overcome this problem, which classifies middle-aged adults asan interesting target group for future vaccine interventions. However, the immunological fitness of the middle-aged population is ill-defined. It is currently unknown whether effective T-cell help towards B-cells is initiated by conjugate-carrier vaccines at middle-age.AimWe characterized systemic Tetanus Toxoid (TT) specific T-helper cell responses in the circulation of middle-aged adults (50–65years of age, n=31) having received the MenACWY-TT vaccination.MethodsBlood samples were taken pre- as well as 7days, 28days, and 1year post-vaccination. TT-specific T-cell responses were determined by IFNγ Elispot and by the secretion of IFNγ, IL13, IL10, IL17, and IL21 in cell culture supernatants. Circulating CD4+CXCR5+ICOS+IL21+ cells were analyzed by flow cytometry, and meningococcal and TT-specific IgG responses by bead-based immunoassays. The correlation between the T-cell help and humoral responses was evaluated.ResultsVaccination with a TT-carrier protein induced a mixed TT-specific Th1 (IFNγ), Th2 (IL13, IL10), and Th17 (IL17) response in most participants. Additionally, circulating CD4+CXCR5+ICOS+IL21+ cells were significantly increased 7days post-vaccination. Pre-vaccination TT-specific cytokine production and post-vaccination Th2 responses correlated positively with the increase of CD4+CXCR5+ICOS+IL21+ cells. No correlation between T-cell help and antibody responses was found.ConclusionThe characteristics of the T-cell response upon a TT-carrier vaccination suggests effective T-cell help towards B-cells in response to meningococcal polysaccharides, although the absence of a correlation with the antibody responses warrants further clarification. However, the robust T-helper cell response in middle-aged adults, decades after previous TT vaccinations, strengthens the classification of this age group for future vaccine interventions in the context of population ageing.



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An outbreak of acute respiratory illnesses in primary school children with low vaccine uptake, UK, 2016

Publication date: 9 October 2017
Source:Vaccine, Volume 35, Issue 42
Author(s): Daiga Jermacane, M. Gobin, N. Young, J. Yates, Gloria Osei Owusu




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Influenza epidemiology and immunization during pregnancy: Final report of a World Health Organization working group

Publication date: 13 October 2017
Source:Vaccine, Volume 35, Issue 43
Author(s): Deshayne B. Fell, Eduardo Azziz-Baumgartner, Michael G. Baker, Maneesh Batra, Julien Beauté, Philippe Beutels, Niranjan Bhat, Zulfiqar A. Bhutta, Cheryl Cohen, Bremen De Mucio, Bradford D. Gessner, Michael G. Gravett, Mark A. Katz, Marian Knight, Vernon J. Lee, Mark Loeb, Johannes M. Luteijn, Helen Marshall, Harish Nair, Kevin Pottie, Rehana A. Salam, David A. Savitz, Suzanne J. Serruya, Becky Skidmore, Justin R. Ortiz
From 2014 to 2017, the World Health Organization convened a working group to evaluate influenza disease burden and vaccine efficacy to inform estimates of maternal influenza immunization program impact. The group evaluated existing systematic reviews and relevant primary studies, and conducted four new systematic reviews. There was strong evidence that maternal influenza immunization prevented influenza illness in pregnant women and their infants, although data on severe illness prevention were lacking. The limited number of studies reporting influenza incidence in pregnant women and infants under six months had highly variable estimates and underrepresented low- and middle-income countries. The evidence that maternal influenza immunization reduces the risk of adverse birth outcomes was conflicting, and many observational studies were subject to substantial bias. The lack of scientific clarity regarding disease burden or magnitude of vaccine efficacy against severe illness poses challenges for robust estimation of the potential impact of maternal influenza immunization programs.



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Editorial Board/Aims and Scope

Publication date: 9 October 2017
Source:Vaccine, Volume 35, Issue 42





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Pain caused by measles, mumps, and rubella vaccines: A systematic literature review

Publication date: 9 October 2017
Source:Vaccine, Volume 35, Issue 42
Author(s): Corinne Willame, Ouzama Henry, Lan Lin, Volker Vetter, Laurence Baril, Nicolas Praet
PurposeThe risk of post-vaccination adverse events (AEs) is a primary public health concern. Among the AEs, pain is a significant source of anxiety for both children and their parents. This review describes and assesses the intensity of pain experienced by children post-vaccination with widely used Measles–Mumps–Rubella (MMR) vaccines.MethodsA systematic literature search was conducted in Pubmed, Embase and Cochrane to identify publications describing immediate pain at injection site (primary objective) or pain within days (secondary objective) after 2 specific MMR vaccines. Immediate pain ('acute pain' according to the Brighton Collaboration case definition) was defined as pain occurring at the time or within 5min of injection.ResultsFour studies, which compared the intensity of immediate injection site pain experienced by children after MMR vaccination, were identified. Various pain assessment tools and methods were used to quantify the intensity of pain, including the median difference in Visual Analog Scale scores between vaccine groups. All four studies showed significantly less immediate pain caused by Priorix (GSK Vaccines) compared with M-M-R II (Merck & Co., Inc.).ConclusionsTo our knowledge, this review summarizes for the first time the available scientific evidence on the intensity of pain following different MMR vaccines. It highlights that MMR vaccines can differ in terms of immediate pain. Further research may be needed to better understand the underlying reason for this observation. In this context, it is very important to understand which physicochemical properties are most relevant for the immediate pain profile of a vaccine to thereby support the development of vaccines with the best possible immediate pain profile.



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Human papillomavirus vaccines: WHO position paper, May 2017–Recommendations

Publication date: 13 October 2017
Source:Vaccine, Volume 35, Issue 43
Author(s): World Health Organization
This article presents the World Health Organization's (WHO) recommendations on the use of human papillomavirus (HPV) vaccines excerpted from the WHO position paper on Human papillomavirus vaccines: WHO position paper, May 2017, published in the Weekly Epidemiological Record [1]. This position paper replaces the 2014 WHO position paper on HPV vaccines [2].The position paper focuses primarily on the prevention of cervical cancer, but also considers the broader spectrum of cancers and other diseases preventable by HPV vaccination. It incorporates recent developments concerning HPV vaccines, including the licensure of a nonavalent (9-valent) vaccine and recent data on vaccine effectiveness, and provides guidance on the choice of vaccine. New recommendations are proposed regarding vaccination strategies targeting girls only or both girls and boys, and vaccination of multiple birth cohorts [3].Footnotes to this paper provide a number of core references including references to grading tables that assess the quality of the scientific evidence, and to the evidence-to-recommendation table. In accordance with its mandate to provide guidance to Member States on health policy matters, WHO issues a series of regularly updated position papers on vaccines and combinations of vaccines against diseases that have an international public health impact. These papers are concerned primarily with the use of vaccines in large-scale immunization programmes; they summarize essential background information on diseases and vaccines, and conclude with WHO's current position on the use of vaccines in the global context. Recommendations on the use of HPV vaccines were discussed by SAGE in October 2016; evidence presented at these meetings can be accessed at: http://ift.tt/2owj3Da.



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Editorial Board/Aims and Scope

Publication date: 13 October 2017
Source:Vaccine, Volume 35, Issue 43





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Cost of a measles outbreak in a remote island economy: 2014 Federated States of Micronesia measles outbreak

Publication date: 13 October 2017
Source:Vaccine, Volume 35, Issue 43
Author(s): Jamison Pike, Ashley Tippins, Mawuli Nyaku, Maribeth Eckert, Louisa Helgenberger, J. Michael Underwood
After 20years with no reported measles cases, on May 15, 2014 the Centers for Disease Control and Prevention (CDC) was notified of two cases testing positive for measles-specific immunoglobulin M (IgM) antibodies in the Federated States of Micronesia (FSM). Under the Compact of Free Association, FSM receives immunization funding and technical support from the United States (US) domestic vaccination program managed by the Centers for Disease Control and Prevention (CDC). In a collaborative effort, public health officials and volunteers from FSM and the US government worked to respond and contain the measles outbreak through an emergency mass vaccination campaign, contact tracing, and other outbreak investigation activities. Contributions were also made by United Nations Children's Emergency Fund (UNICEF) and World Health Organization (WHO). Total costs incurred as a result of the outbreak were nearly $4,000,000; approximately $10,000 per case. Direct medical costs (≈$141,000) were incurred in the treatment of those individuals infected, as well as lost productivity of the infected and informal caregivers (≈$250,000) and costs to contain the outbreak (≈$3.5 million). We assessed the economic burden of the 2014 measles outbreak to FSM, as well as the economic responsibilities of the US. Although the US paid the majority of total costs of the outbreak (≈67%), examining each country's costs relative to their respective economy illustrates a far greater burden to FSM. We demonstrate that while FSM was heavily assisted by the US in responding to the 2014 Measles Outbreak, the outbreak significantly impacted their economy. FSM's economic burden from the outbreak is approximately equivalent to their entire 2016 Fiscal Year budget dedicated to education.



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Telomerase based anticancer immunotherapy and vaccines approaches

Publication date: 13 October 2017
Source:Vaccine, Volume 35, Issue 43
Author(s): Chahal Kailashiya, Hanjabam Barun Sharma, Jyotsna Kailashiya
Telomerase is a Reverse Transcriptase that maintains the telomere length. It is absent in most somatic cells but is found in stem cells, germ cells and around 90% of cancers. It plays a crucial role in developing and maintaining cancer cells. Telomerase, a HLA class-I antigen, is able to stimulate cell mediated immune response by inducing cytotoxic T-cells. This property of telomerase is being exploited in targeting cancers by host's own immune responses; stimulated by various Human Telomerase Reverse Transcriptase (hTERT) derived vaccines. Many approaches and studies including clinical trials have shown effective anticancer responses of these vaccines, without toxicity to non cancer cells. In this article we have compiled different hTERT based anticancer immunotherapy approaches, vaccines and their performances.



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Live-attenuated tetravalent dengue vaccines: The needs and challenges of post-licensure evaluation of vaccine safety and effectiveness

Publication date: 9 October 2017
Source:Vaccine, Volume 35, Issue 42
Author(s): Ole Wichmann, Kirsten Vannice, Edwin J. Asturias, Expedito José de Albuquerque Luna, Ira Longini, Anna Lena Lopez, Peter G. Smith, Hasitha Tissera, In-Kyu Yoon, Joachim Hombach
Since December 2015, the first dengue vaccine has been licensed in several Asian and Latin American countries for protection against disease from all four dengue virus serotypes. While the vaccine demonstrated an overall good safety and efficacy profile in clinical trials, some key research questions remain which make risk-benefit-assessment for some populations difficult. As for any new vaccine, several questions, such as very rare adverse events following immunization, duration of vaccine-induced protection and effectiveness when used in public health programs, will be addressed by post-licensure studies and by data from national surveillance systems after the vaccine has been introduced. However, the complexity of dengue epidemiology, pathogenesis and population immunity, as well as some characteristics of the currently licensed vaccine, and potentially also future, live-attenuated dengue vaccines, poses a challenge for evaluation through existing monitoring systems, especially in low and middle-income countries. Most notable are the different efficacies of the currently licensed vaccine by dengue serostatus at time of first vaccination and by dengue virus serotype, as well as the increased risk of dengue hospitalization among young vaccinated children observed three years after the start of vaccination in one of the trials. Currently, it is unknown if the last phenomenon is restricted to younger ages or could affect also seronegative individuals aged 9years and older, who are included in the group for whom the vaccine has been licensed. In this paper, we summarize scientific and methodological considerations for public health surveillance and targeted post-licensure studies to address some key research questions related to live-attenuated dengue vaccines. Countries intending to introduce a dengue vaccine should assess their capacities to monitor and evaluate the vaccine's effectiveness and safety and, where appropriate and possible, enhance their surveillance systems accordingly. Targeted studies are needed, especially to better understand the effects of vaccinating seronegative individuals.



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Assessing care-givers’ satisfaction with child immunisation services in Zambia: Evidence from a national survey

Publication date: 9 October 2017
Source:Vaccine, Volume 35, Issue 42
Author(s): Chitalu Miriam Chama-Chiliba, Felix Masiye, Chrispin Mphuka
AimThe main aim of this study was to assess care-giver satisfaction with vaccination services in public health facilities in Zambia, and examine its determinants.MethodsThis study used data from a recent population-based household survey, conducted from May to August 2015. Respondent satisfaction with vaccination services received during the last visit was measured on a five point Likert scale ranging from 1 to 5. We used an ordered logistic regression model to analyse the significance of perceived quality of vaccination services, immunisation delivery mode and a range of individual characteristics in predicting care-giver satisfaction.ResultsFindings show that one in five care givers were unsatisfied with the vaccination services that they had received, with rural populations showing a significantly higher level of satisfaction. Poor quality of care, defined by long waiting times, poor quality of communication between health staff and care givers, long distance to vaccination sites, mode of delivery, and personal characteristics were among major factors driving care-giver satisfaction ratings. We also find that receiving a vaccination at outreach mode of delivery was associated with higher odds of greater satisfaction compared to on-facility vaccination services. The odds of satisfaction were lower for respondents living further away from a health facility, which emphasizes the importance of access in seeking vaccination services.ConclusionThese findings suggest that major improvements in quality of vaccination and service organisation will be needed to increase client satisfaction and service utilisation.



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Attitudes towards Zika screening and vaccination acceptability among pregnant women in Malaysia

Publication date: 13 October 2017
Source:Vaccine, Volume 35, Issue 43
Author(s): Li Ping Wong, Haridah Alias, Jamiyah Hassan, Sazaly AbuBakar
The aim of this study was to examine the willingness of pregnant women to have prenatal screening for the Zika virus (ZIKV). Secondly, the study also assessed the acceptability of a hypothetical Zika vaccination and its association with the health belief model (HBM) constructs. A cross-sectional study was conducted from 4th October to 11th November 2016, among pregnant women who attended antenatal care at the University Malaya Medical Centre (UMMC), Kuala Lumpur, Malaysia. The majority (81.8%) was willing to be tested for ZIKV and 78% felt that their spouse would be willing to be tested for ZIKV. A total of 94% expressed a willingness to receive a Zika vaccination if available. The participants expressed high perceived benefits of a ZIKV vaccination. Although many have a high perception of the severity of ZIKV, the proportion with a strong perception of their susceptibility to ZIKV was low. In the multivariate analysis of all the HBM constructs, cue-to-action, namely physician recommendation (odds ratio [OR]=2.288; 95% confidence interval [CI] 1.093–4.793) and recommendation from friends or relatives (OR=4.030; 95% CI 1.694–9.587), were significantly associated with a willingness to be vaccinated against ZIKV. The favourable response to a Zika vaccination implies that more research attention has to be given to develop a vaccine against ZIKV. Should the vaccine be available in the future, publicity and healthcare providers would play a vital role in ensuring vaccine uptake among pregnant women.



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Determinants of under-immunization and cumulative time spent under-immunized in a Quebec cohort

Publication date: 13 October 2017
Source:Vaccine, Volume 35, Issue 43
Author(s): Shauna O'Donnell, Eve Dubé, Bruce Tapiero, Arnaud Gagneur, Margaret K. Doll, Caroline Quach
BackgroundUnder-immunization refers to a state of sub-optimal protection against vaccine preventable diseases. Vaccine coverage for age may not capture intentional or non-intentional spacing of vaccines in the recommended provincial immunization guidelines. We aimed to identify factors associated with coverage and under-immunization and to determine the number of days during which children were under-immunized during their first 24months of life.MethodsSecondary analysis of children ≤3years recruited through active surveillance for gastroenteritis from three Quebec pediatric emergency departments from 2012 to 2014. Vaccination status for children at least 24months of age was determined using provincial immunization guidelines. Cumulative days under-immunized were calculated for DTaP-VPI-Hib, PCV, MMR, and Men-C-C. Factors associated with up-to-date (UTD) status at 24months of life and for under-immunization ≥6months were analyzed using logistic regression.ResultsOf 246 eligible children, 180 (73%) were UTD by 24months of life. The mean cumulative days under-immunized for MMR was 107days, for PCV 209days, for Men-C-C 145days, and for DTaP-VPI-Hib 227days. Overall, 149 children (60%) experienced delay for at least 1 vaccine. Factors associated with both an UTD status at 24months and concurrently associated with being under-immunization ≥6months, included timely initiation of immunization (OR=5.85; 95% CI: 2.80–12.22) and (OR=0.13; 95% CI: 0.07–0.24), failure to co-administer 18-month vaccines (OR=0.15; 95% CI: 0.10–0.21) and (OR=3.29; 95% CI: 2.47–4.39), and having a household with ≥3 children under 18years ((OR=0.50; 0.28–0.86) and (OR=2.99; 1.45–6.22), respectively.ConclusionPaired with an unexpected low level of coverage at 24months of life, the majority of our cohort also experienced a state of under-immunization for a least one vaccine. Estimates of coverage do not capture intentional or non-intentional gaps in protection from vaccine preventable illnesses. Timely preventive care should be prioritized.



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Reaching every child with rotavirus vaccine: Report from the 10th African rotavirus symposium held in Bamako, Mali

Publication date: 9 October 2017
Source:Vaccine, Volume 35, Issue 42
Author(s): Samba O. Sow, A. Duncan Steele, Jason M. Mwenda, George E. Armah, Kathleen M. Neuzil
The Center for Vaccine Development – Mali (CVD – Mali), the World Health Organization's regional office in Africa (WHO/AFRO), and the CVD at the University of Maryland School of Medicine hosted the 10th African Rotavirus Symposium in Bamako, Mali on 1–2 June 2016. The symposium is coordinated by WHO/AFRO, the Regional Rotavirus Reference Laboratories, and the African Rotavirus Network (ARN), with support from the Bill & Melinda Gates Foundation. The event brings together leading rotavirus researchers, scientists, and policy-makers from across Africa and the world. Over 150 participants, from 31 countries, including 27 in Africa, joined forces to address the theme "Reaching Every Child in Africa with Rotavirus Vaccines." This symposium, the first in francophone Africa, occurred at an unprecedented time when 33 African countries had introduced rotavirus vaccines into their national immunization programs. The symposium concluded with a Call to Action to introduce rotavirus vaccines in the 21 remaining African countries, to increase access in countries with existing vaccination programs, and to continue surveillance and research on rotavirus and other diarrheal diseases.



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Debate on vaccines and autoimmunity: Do not attack the author, yet discuss it methodologically

Publication date: 9 October 2017
Source:Vaccine, Volume 35, Issue 42
Author(s): Nicola Luigi Bragazzi, Abdulla Watad, Howard Amital, Yehuda Shoenfeld
Since Jenner, vaccines and vaccinations have stirred a hot, highly polarized debate, leading to contrasting positions and feelings, ranging from acritical enthusiasm to blind denial. On the one hand, we find anti-vaccination movements which divulge and disseminate misleading information, myths, prejudices, and even frauds, with the main aim of denying that vaccination practices represent a major public health measure, being effective in controlling infectious diseases and safeguarding the wellbeing of entire communities. Recently, the authors of many vaccine safety investigations are being personally criticized rather than the actual science being methodologically assessed and critiqued. Unfortunately, this could result in making vaccine safety science a "hazardous occupation". Critiques should focus on the science and not on the authors and on the scientists that publish reasonably high-quality science suggesting a problem with a given vaccine. These scientists require adequate professional protection so there are not disincentives to publish and to carry out researches in the field. The issues for vaccine safety are not dissimilar to other areas such as medical errors and drug safety.



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Using campaigns to improve perceptions of the value of adult vaccination in the United States: Health communication considerations and insights

Publication date: 9 October 2017
Source:Vaccine, Volume 35, Issue 42
Author(s): Glen J. Nowak, Angela K. Shen, Jason L. Schwartz
Vaccines have much relevance and promise for improving adult health in the United States, but to date, overall use and uptake remain far below desired levels. Many adults have not received recommended vaccinations and many healthcare providers do not strongly and actively encourage their use with patients. This has led some public health and medical experts to conclude that adult vaccines are severely undervalued by the U.S. public and healthcare providers and to call for campaigns and communication-based efforts to foster increased appreciation, and in turn, higher adult immunization rates. A narrative integrative review that draws upon the vaccine valuation and health communication literatures is used to develop a framework to guide campaign and communication-based efforts to improve public, provider, and policymakers' assessment of the value of adult vaccination. The review does this by: (1) distinguishing social psychological value from economic value; (2) identifying the implications of social psychological value considerations for adult vaccination-related communication campaigns; and (3) using five core health communication considerations to illustrate how social psychological notions of value can be integrated into campaigns or communication that are intended to improve adult vaccination value perceptions and assessments, and in turn, motivate greater support for and uptake of recommended adult vaccines.



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DNA vaccines against leptospirosis: A literature review

Publication date: 9 October 2017
Source:Vaccine, Volume 35, Issue 42
Author(s): Marcelle Moura Silveira, Thaís Larré Oliveira, Rodrigo Andrade Schuch, Alan John Alexander McBride, Odir Antônio Dellagostin, Daiane Drawanz Hartwig
Leptospirosis is an infectious disease caused by pathogenic Leptospira species. The vaccines that are currently available for leptospirosis are composed of whole-cell preparations and suffer from limitations such as low efficacy, multiple side-effects, poor immunological memory and lack of cross-protection against different serovars of Leptospira spp. In light of the global prevalence of this disease, the development of a more effective vaccine against leptospirosis is of paramount importance. Genetic immunization is a promising alternative to conventional vaccine development. In the last 25years, several novel strategies have been developed for increasing the efficacy of DNA vaccines. Examples of such strategies include the introduction of novel plasmid vectors, adjuvants, alternate delivery routes, and prime-boost regimens. Herein we discuss the latest and most promising advances that have been made in developing DNA vaccines against leptospirosis. We also deliberate over the future directions that must be undertaken in order to improve results in this field.



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Prevaccination epidemiology of herpes zoster in Denmark: Quantification of occurrence and risk factors

Publication date: 9 October 2017
Source:Vaccine, Volume 35, Issue 42
Author(s): Sigrun A.J. Schmidt, Mogens Vestergaard, Lisbeth M. Baggesen, Lars Pedersen, Henrik C. Schønheyder, Henrik T. Sørensen
BackgroundHerpes zoster (HZ) is a vaccine-preventable disease caused by reactivation of the varicella-zoster virus. Unfortunately, formulation of recommendations on routine immunization is hampered by a lack of data on disease burden, since most countries do not record cases of HZ in the general population. We developed and validated an algorithm to identify HZ based on routinely collected registry data and used it to quantify HZ occurrence and risk factors in Denmark prior to marketing of the HZ vaccine.MethodsWe included patients aged ≥40years with a first-time systemic Acyclovir, Valacyclovir, or Famciclovir prescription or a hospital-based HZ diagnosis in the Danish nationwide health registries during 1997–2013. In a validation substudy (n=176), we computed the proportion of persons with HZ among patients who redeemed antiviral prescriptions. In a cohort study, we computed age-specific rates of HZ (45,297,258 person-years). In a case-control study, we then computed odds ratios (ORs) for common chronic diseases and immunosuppressive factors among HZ cases (n=189,025) vs. matched population controls (n=945,111).ResultsMedical record review confirmed HZ in 87% (95% confidence interval: 79–93%) of persons ≥40years who dispensed antivirals at doses recommended for HZ. HZ rates increased from 2.15/1000 person-years in 40-year-olds to 9.45/1000 person-years in 95-year-olds. Rates were highest in women. HZ was diagnosed during hospitalization among 3.5%. As expected, persons with severe immunosuppressive conditions had the highest ORs of HZ (between 1.82 and 4.12), but various autoimmune diseases, asthma, chronic kidney disease, and inhaled glucocorticoids were also associated with increased ORs (between 1.06 and 1.64).ConclusionThis algorithm is a valid tool for identifying HZ in routine healthcare data. It shows that HZ is common in Denmark, especially in patients with certain chronic conditions. Prioritized vaccination of such high-risk patients might be an option in countries considering alternatives to universal vaccination.



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The Efficacy of Aerobic Exercise and Resistance Training as Transdiagnostic Interventions for Anxiety-Related Disorders and Constructs: A Randomized Controlled Trial

Publication date: Available online 23 September 2017
Source:Journal of Anxiety Disorders
Author(s): Daniel M. LeBouthillier, Gordon J.G. Asmundson
Evidence supports exercise as an intervention for many mental health concerns; however, randomized controlled investigations of the efficacy of different exercise modalities and predictors of change are lacking. The purposes of the current trial were to: (1) quantify the effects of aerobic exercise and resistance training on anxiety-related disorder (including anxiety disorders, obsessive-compulsive disorder, and posttraumatic stress disorder) status, symptoms, and constructs, (2) evaluate whether both modalities of exercise were equivalent, and (3) to determine whether exercise enjoyment and physical fitness are associated with symptom reduction. A total of 48 individuals with anxiety-related disorders were randomized to aerobic exercise, resistance training, or a waitlist. Symptoms of anxiety-related disorders, related constructs, and exercise enjoyment were assessed at pre-intervention and weekly during the 4-week intervention. Participants were further assessed 1-week and 1-month post-intervention. Both exercise modalities were efficacious in improving disorder status. As well, aerobic exercise improved general psychological distress and anxiety, while resistance training improved disorder-specific symptoms, anxiety sensitivity, distress tolerance, and intolerance of uncertainty. Physical fitness predicted reductions in general psychological distress for both types of exercise and reductions in stress for aerobic exercise. Results highlight the efficacy of different exercise modalities in uniquely addressing anxiety-related disorder symptoms and constructs.



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Randomized controlled trial of internet-delivered cognitive behaviour therapy comparing standard weekly versus optional weekly therapist support

Publication date: Available online 23 September 2017
Source:Journal of Anxiety Disorders
Author(s): H.D. Hadjistavropoulos, L.H. Schneider, M. Edmonds, E. Karin, M.N. Nugent, D. Dirkse, B.F. Dear, N. Titov
Internet-delivered cognitive behaviour therapy (ICBT) is effective for treating anxiety and depression. The relative benefits of offering standard weekly compared to optional weekly therapist support in conjunction with ICBT within routine care has not been examined. Patients seeking ICBT for depression and or anxiety in routine care were randomized to standard (n=92) or optional (n=88) weekly support. The optional approach resulted in therapists receiving half as many messages from (1.70 vs. 3.96) and sending half as many messages to patients (3.62 vs. 7.29). Optional Support was associated with lower completion rates (56.6% versus 82.4%), but, similar to Standard Support, resulted in large reductions on the GAD-7 (within Cohen's d≥1.08; avg. reduction ≥47%) and PHQ-9 (within Cohen's d≥0.82; avg. reduction ≥43%) at post-treatment and 3-month follow-up. Optional weekly support appears clinically effective and acceptable for many patients and may reduce costs, but safety requires monitoring given lower completion rates.



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Klebsiella sp. confers enhanced tolerance to salinity and plant growth promotion in oat seedlings (Avena sativa)

Publication date: Available online 23 September 2017
Source:Microbiological Research
Author(s): Swapnil Sapre, Iti Gontia-Mishra, Sharad Tiwari
Plant growth and yield is adversely affected by soil salinity. Salt tolerant plant growth-promoting rhizobacteria (PGPR) strain IG 3 was isolated from rhizosphere of wheat plants. The isolate IG 3 was able to grow in presence of NaCl ranging from 0-20% in Luria Bertani medium. The present study was planned to evaluate the role of inoculation of PGPR strain IG 3 and its efficacy in augmenting salt tolerance in oat (Avena sativa) under NaCl stress (100mM). The physiological parameter such as shoot length, root length, shoot dry weight, root dry weight and relative water content (RWC) were remarkably higher in IG 3 inoculated plants in comparison to un-inoculated plants under NaCl stress. Similarly, the biochemical parameters such as proline content, electrolyte leakage and malondialdehyde (MDA) content and activities of antioxidant enzymes were analyzed and found to be notably lesser in IG 3 inoculated oat plants in contrast to un-inoculated plants under salt stress. Inoculation of IG 3 strain to oat seedlings under salt stress positively modulated the expression profile of rbcL and WRKY1 genes. Root colonization of root surface and interior was demonstrated using scanning electron microscopy and tetrazolium staining, respectively. Due these outcomes, it could be implicated that inoculation of PGPR strain IG 3 enhanced plant growth under salt stress condition. This study demonstrates that PGPR play an imperative function in stimulating salt tolerance in plants and can be used as biofertilizer to enhance growth of crops in saline areas.



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Soft obturator prosthesis for postoperative soft palate carcinoma: A clinical report

Publication date: Available online 23 September 2017
Source:The Journal of Prosthetic Dentistry
Author(s): Tomohisa Ohno, Kyoko Hojo, Ichiro Fujishima
An intraoral prosthesis with a soft flexible obturator was provided for a patient with a soft palate perforation after surgical and chemoradiotherapy treatments of a soft palate tumor. An obturator composed of movable and flexible silicone was attached to a structure similar to a palatal lift; it was therefore able to move according to the movement of the soft palate, which was confirmed by endoscopic examination. The application of this prosthesis resulted in complete disappearance of hypernasality and food reflux, and the patient was able to eat without particular limitation during daytime wearing. This type of prosthesis represents a potential prosthetic approach to a soft palate nasal-oral fistula.



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Kinetics of interfacial polycondensation reactions – Development of a new method and its validation

Publication date: 3 October 2017
Source:Polymer, Volume 127
Author(s): Subhalaxmi Behera, Akkihebbal K. Suresh
The structure and function of the thin polymeric functional layer in reverse osmosis membranes depend on the kinetics of the interfacial polycondensation (IP) reaction by which the film is formed. It has been a challenge to achieve a quantitative understanding of these kinetics because of the high velocity of the reactions and the complex geometry of the support membrane in which the reaction takes place. In this work, we describe a novel and convenient technique for studying such kinetics, and demonstrate the method on the IP reaction between meta-phenylene diamine and trimesoyl chloride. The method involves studying the reaction in a simple geometry of a drop-continuous phase interface in an emulsion, under such conditions that all transport resistances are eliminated. The reaction course is followed through an on-line pH measurement using a fast probe. Interfacial areas available for reaction are measured by an encapsulation technique, under the conditions of reaction. The methods developed have been used to study the kinetics of the m-PDA-TMC reaction as a function of m-PDA concentration and surfactant (tween-85) concentration, and a surface-area based rate function has been shown to fit the data adequately.

Graphical abstract

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Crystallization of polypropylene in the presence of biomass-based fillers of different compositions

Publication date: 3 October 2017
Source:Polymer, Volume 127
Author(s): Jordi Girones, Loan T.T. Vo, Jean-Marc Haudin, Lionel Freire, Patrick Navard
Natural fillers composed of cellulose, lignin and fillers with a varying lignin/cellulose ratio (flax, jute, curauà fibers and miscanthus stem fragments) were used to prepare composites with polypropylene using the same procedure, with or without a maleic anhydride–grafted polypropylene (MA-g-PP) coupling agent. A clear acceleration of the crystallization kinetics was observed in the presence of miscanthus stem fragments. For non-coupled composites, the size and aspect ratio of fragments had no significant influence onto the crystallization kinetics of polypropylene. The presence of the MA-g-PP coupling agent increased even more the kinetics. A clear effect of the nature of the polymers present in the filler was observed. There is a direct relationship between the values of the Avrami kinetic constant k for the six fillers and their lignin content, the more effective to enhance crystallization kinetics being pure cellulose. Lignin has no effect onto the crystallization kinetics of polypropylene.

Graphical abstract

http://ift.tt/2ylAXwN

Polycarbonates derived from propylene oxide, CO2, and 4-vinyl cyclohexene oxides terpolymerization catalyzed by bifunctional salcyCoIIINO3 complex and its post-polymerization modification

Publication date: 27 October 2017
Source:Polymer, Volume 129
Author(s): Hongye Zhang, Binyuan Liu, Huining Ding, Junwu Chen, Zhongyu Duan
Terpolymerizations of CO2, propylene oxide (PO), and 4-vinyl cyclohexene oxide (VCHO) were successfully catalyzed by a single cobalt(III) complex of a salen-type ligand bearing one quaternary ammonium salt on the five-position of each aromatic ring. The influences of various reaction conditions such as molar ratio of the monomers, reaction time and reaction temperature on the terpolymerization progress were investigated. The resulting terpolymers showed only one thermolysis peak and one adjustable glass-transition temperature (Tg) dependable on vinyl cyclohexene carbonate (VCHC) unit content with the relationship of "Tg (°C) = 64 × FVinyl + 39". Furthermore, the epoxy group was incorporated by oxidation of vinyl group of PVCHC units and the cyclic carbonate (CC) functional group was achieved by reaction of CO2 with epoxy-functionalized terpolymer. The linear dependencies of the Tg on the mole fractions ratio of pendent epoxy and CC groups on the poly(cyclohexene carbonate) main chain were also observed. Notably, the Tg of fully CC-functionalized PCHC was up to 196 °C, which was the highest Tg of CO2-based polycarbonate reported at the absence of cross-linked structure.

Graphical abstract

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Glass transition of poly (methyl methacrylate) filled with nanosilica and core-shell structured silica

Publication date: 3 October 2017
Source:Polymer, Volume 127
Author(s): Yihu Song, Jing Bu, Min Zuo, Yang Gao, Wenjing Zhang, Qiang Zheng
Core-shell (CS) nanocomposite particles with 53.4 wt% cross-linked poly (methyl methacrylate) (PMMA) shell of 11.6 nm in thickness were fabricated via miniemulsion polymerization of methyl methacrylate in the presence of modified nanosilica. The influence of nanosilica and CS nanoparticles on glass transition and segmental dynamics of PMMA in the nanocomposites prepared via solution casting was compared. The remarkable depression (≥10 °C) of glass transition temperature (Tg) induced by the incorporation of SiO2 and CS was both observed at low loadings. Here, different mechanisms were responsible for the effect of SiO2 and CS on the segmental acceleration of PMMA matrix. The formation of rigid amorphous fraction (RAF) layer around SiO2 with the thickness of 16.4 nm led to the adjacent molecular packing frustration, while the "lubrication" effect of nonwetting interface between the grafted crosslinked chains and matrix chains resulted in the segmental acceleration and the reduction of dynamic fragility.

Graphical abstract

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Reactive supramolecular filler for elastomer reinforcement

Publication date: 27 October 2017
Source:Polymer, Volume 129
Author(s): Xin Tan, Yihong Zhao, Mengsha Qian, Gary R. Hamed, Li Jia
A reactive amphiphile, SA1, which comprises a mercaptodecyl oleophilic tail and a β-alanine oleophobic moiety, has been introduced to serve as the building block for supramolecular filler. At least a fraction of SA1 reacts in situ during mechanically mixing and vulcanization with SBR via thiol-ene reaction. Some oxidative dimerization also concomitantly occurs to give DSA1. The chemical coupling between SA1 and SBR results in drastically improved filler domain dispersion. Short fibrous crystalline domains, which are likely composed of SA1, SA1 grafted to SBR, and DSA1, less than 10 nm in width and a few tens to one hundred nanometers in length are observed by TEM. The filler domains are evenly distributed in the SBR. In contrast, the simple filler PA1 forms large irregular aggregates on the length scale of hundreds of nanometers. The improved filler dispersion and filler-rubber interaction allow effective energy dissipation and result in significantly improved mechanical properties.A solution-mixing method proves feasible for mixing SA1 and SBR and actually has resulted in better mechanical properties than the mechanical mixing method. Since the conventional mechanical mixing method for rubber compounding is highly energy-intensive, avoidance of the mechanical mixing method is another practical advantage for the novel strategy of supramolecular reinforcement.

Graphical abstract

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Oxygen permselectivities through supramolecular polymer membranes prepared by highly selective photocyclic aromatization of poly(substituted acetylene)

Publication date: 3 October 2017
Source:Polymer, Volume 127
Author(s): Guanwu Yin, Eri Ohtaka, Toshiki Aoki, Jianjun Wang, Masahiro Teraguchi, Takashi Kaneko
In order to estimate oxygen permselectivities through a supramolecular polymer membrane for the first time, we prepared three kinds of composite membranes consisting of a supramolecular polymer membrane and a conventional organic polymer membrane. Supramolecular polymer membranes were prepared by using highly selective photocyclic aromatization of poly(substituted acetylene)s. It was found that the supramolecular polymer membrane had oxygen permselectivity (α = PO2/PN2) around three in spite of its low molecular weight.

Graphical abstract

http://ift.tt/2hrEZwX

Polystyrene-block-polyethylene-block-polystyrene triblock copolymers: Synthesis and crystallization-driven self-assembly behavior

Publication date: 16 October 2017
Source:Polymer, Volume 128
Author(s): Sen Xu, Chongyin Zhang, Lei Li, Sixun Zheng
In this work, we reported the synthesis of a series of novel semicrystalline ABA triblock copolymers with polyethylene midblock and polystyrene endblocks via the combination of ring-opening metathesis polymerization (ROMP), hydrogenation and reversible addition-fragmentation chain transfer (RAFT) polymerization. First, an α,ω-dihydroxyl-terminated polycyclooctadiene (PCOD) was synthesized via the ROMP of cyclooctadiene by the use of the Grubbs second generation catalyst and with cis-2-butene-1,4-diol as the chain transfer agent. The α,ω-dihydroxyl-terminated PCOD was then hydrogenated into an α,ω-dihydroxyl-terminated polyethylene (PE); the latter was allowed to react with 2-methyl-2-[(dodecylsulfanylthiocarbonyl) sulfanyl]propanoic acid to afford a macromolecular chain transfer agent (i.e., Macro-CTA) for the RAFT polymerization of styrene. By controlling the lengths of PS endblocks, a series of polystyrene-block-polyethylene-block-polystyrene (PS-b-PE-b-PS) triblock copolymers were obtained. The successful synthesis of the ABA triblock copolymers were demonstrated by means of nuclear magnetic resonance (NMR) spectroscopy and gel permeation chromatography (GPC). The results of differential scanning calorimetry (DSC) and atomic force microscopy (AFM) indicate that the PS-b-PE-b-PS triblock copolymers were microphase-separated in bulks and their morphologies were quite dependent on the mass ratios of PE to PS blocks. Transmission electron microscopy (TEM), atomic force microscopy (AFM) and dynamic light scattering (DLS) showed that the triblock copolymers displayed crystallization-driven self-assembly (CDSA) behavior in selective solvent (viz. 1,4-dioxane). Depending on the lengths of PS blocks, the CDSA behavior of all the triblock copolymers generated spherical and cylindrical micelles. It was found that the quantity of the cylindrical micelles increased with decreasing the lengths of PS blocks.

Graphical abstract

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Living polymerization of higher 2-alkene with α-diimine nickel catalysts: Synthesis and characterization of high molecular weight poly(2-alkene)s

Publication date: 3 October 2017
Source:Polymer, Volume 127
Author(s): Fuzhou Wang, Ryo Tanaka, Zhengguo Cai, Yuushou Nakayama, Takeshi Shiono
A series of higher 2-alkenes, i.e., 2-pentene, 2-hexene and 2-octene were polymerized with phenyl substituted α-diimine nickel complexes in combination with modified methylaluminoxane (MMAO) to produce branched poly(2-alkene)s with high molecular weight and narrow molecular weight distribution (Mw/Mn < 1.8). At 0 °C, these 2-alkenes polymerized in a living manner to produce amorphous polymers with glass transition temperature of –70 ∼ –65 °C. The microstructures of the produced polymers indicated the 2,3- and 3,2-insertion followed by chain-walking and the incorporation of a small amount of 1-alkene formed by isomerization. The branch structures were significantly depended on the polymerization temperature, and the ratio of methyl branch predominantly derived from 3,2-insertion was increased with increasing the polymerization temperature.

Graphical abstract

http://ift.tt/2hrErXV

Mesostructured ZnO/Au nanoparticle composites with enhanced photocatalytic activity

Publication date: 16 October 2017
Source:Polymer, Volume 128
Author(s): Carina Bojer, Judith Schöbel, Thomas Martin, Thomas Lunkenbein, Daniel R. Wagner, Andreas Greiner, Josef Breu, Holger Schmalz
Ease of catalyst separation from reaction mixtures represents a significant advantage in heterogeneous photocatalytic wastewater treatment. However, the activity of the catalyst strongly depends on its surface-to-volume ratio. Here, we present an approach based on cylindrical polybutadiene-block-poly(2-vinylpyridine) polymer brushes as template, which can be simultaneously loaded with zinc oxide (ZnO) and gold (Au) nanoparticles. Pyrolytic template removal of the polymer yields in mesostructured ZnO/Au composites, showing higher efficiencies in the photocatalytic degradation of ciprofloxacin and levofloxacin (generic antibiotics present in clinical wastewater) as compared to neat mesostructured ZnO. Upscaling of the presented catalyst is straightforward promising high technical relevance.

Graphical abstract

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Sulfonated polystyrene nanoparticles coated with conducting polyaniline and their electro-responsive suspension characteristics under electric fields

Publication date: 3 October 2017
Source:Polymer, Volume 127
Author(s): Shang Hao Piao, Chun Yan Gao, Hyoung Jin Choi
Core-shell structured conducting polyaniline (PANI)-coated polystyrene (PS) composite nanospherical particles were synthesized and assessed as a candidate for electrorheological (ER) materials. Monodisperse PS nanospheres were initially synthesized by a dispersion polymerization process and their surface was modified using concentrated sulfuric acid. This allowed the aniline monomer to be adsorbed easily on the sulfonated PS nanosphere and polymerized further by forming a PS/PANI nanosphere. The ER performance of their suspension dispersed in silicone oil was examined using a rotational rheometer under a variety of electric field strengths. The Bingham fluid model was used to analyze their flow curves to understand the interrelation between shear stress and shear rate. The relationship between the yield stress and electric field strength showed a slope of 2.0 following a polarization model. The dielectric spectra showed a good correlation with the ER performance of the ER fluid.

Graphical abstract

http://ift.tt/2hrEJhu

[PCL-b-P(THF-co-CL)]m multiblock copolymer synthesized by Janus polymerization

Publication date: 16 October 2017
Source:Polymer, Volume 128
Author(s): Huan Qiu, Zhening Yang, Muhammad Ijaz Shah, Zhengwei Mao, Jun Ling
Multiblock copolymers (MBCPs) composing of poly(ε-caprolactone) (PCL) and poly(tetrahydrofuran-co-ε-caprolactone) (P(THF-co-CL)) segments are synthesized in a one-step process by "Janus polymerization", a newly raised synthetic protocol. Janus polymerization includes an anionic and a cationic ring-opening polymerization on both ends of a single living polymer chain, and finally couples into MBCPs. The well-defined MBCPs have relatively high molecular weights up to 131 kg/mol and exhibit thermoplastic elastic property with excellent elongation of 2610% in tensile tests. The repeating blocks form phase separation structures observed by AFM responsible for the elasticity. The biodegradable elastomers have negligible cytotoxicity. According to the physiochemical properties observed in this work, such multiblock elastic poly(ether-ester)s are promising materials in many fields.

Graphical abstract

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Organic dispersion of polyaniline and single-walled carbon nanotubes and polyblends with poly(methyl methacrylate)

Publication date: 27 October 2017
Source:Polymer, Volume 129
Author(s): Thomas Farrell, Kan Wang, Cheng-Wei Lin, Richard B. Kaner
Traditionally, in situ polymerization has been used to make polymer-carbon nanotube composites. Here, we report a simple method of mixing polyaniline with single-walled carbon nanotubes in a variety of organic solvents via ultrasonication. The maximum loading fraction of SWCNTs in the composites is determined by the conformation of the polyaniline chains. The type of solvent used has the greatest influence on the conformation of the polyaniline chains. Furthermore, the composites can be easily blended with poly(methyl methacrylate) (PMMA), to form polyblends. The electrical conductivities and transparencies of the polyblend films are reported.

Graphical abstract

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Porous lignin based poly (acrylic acid)/organo-montmorillonite nanocomposites: Swelling behaviors and rapid removal of Pb (II) ions

Publication date: 16 October 2017
Source:Polymer, Volume 128
Author(s): Yanli Ma, Ling Lv, Yuanru Guo, Yujie Fu, Qian Shao, Tingting Wu, Sijie Guo, Kai Sun, Xingkui Guo, Evan K. Wujcik, Zhanhu Guo
Lignin grafted N, N′-methylene-bisacrylamide (LM) was copolymerized with acrylic acid (AA) to fabricate lignin based poly (acrylic acid) (LBPAA) nanocomposites, and organo-montmorillonite (OrgMMT) was uniformly dispersed in LBPAA by ultrasonic method. The water absorbency in KCl solution was 302.9 g/g for LBPAA/OrgMMT (3 wt% OrgMMT, 43.65 wt% LM, and 53.35 wt% poly(acrylic acid) (PAA)), higher than PAA/OrgMMT (104.5736 g/g), and PAA (131.8 g/g). The Pb²⁺ adsorption for LBPAA/OrgMMT was demonstrated to be pH-dependent and followed Freundlich multilayer adsorption, with the removal following a pseudo-second-order kinetic model. The Pb²⁺ absorption capacity of LBPAA (PAA 48.50/48.50 LM)/OrgMMT (3 wt%) was 1.0803 mmol·g⁻¹, the highest among the composites. When the mole ratio of Na⁺ and Pb²⁺ was less than 0.21, the Pb²⁺ adsorption capacity of LBPAA/OrgMMT decreased slightly. The negative ΔG0 indicated that the Pb²⁺ adsorption process for composite hydrogel and PAA was spontaneous. XPS analysis data indicated that Pb²⁺ ions formed Pb-O bonds by hydroxyl groups and carboxyl groups for efficient lead ion adsorption. This study demonstrates that LBPAA/OrgMMT can be used as a water retention agent with salt tolerance and as an adsorbent for removing Pb²⁺ ions from industrial waste water.

Graphical abstract

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Necklace-shaped dimethylsiloxane polymers bearing polyhedral oligomeric silsesquioxane cages with alternating length chains

Publication date: 3 October 2017
Source:Polymer, Volume 127
Author(s): Naohiro Katsuta, Marie Yoshimatsu, Kunihiro Komori, Tsubasa Natsuaki, Kazuya Suwa, Kiyoshi Sakai, Takashi Matsuo, Tomoyuki Ohba, Shinobu Uemura, Satoshi Watanabe, Masashi Kunitake
Necklace-shaped dimethylsiloxane (DMS) polymers bearing polyhedral oligomeric silsesquioxane (POSS) cages with "alternating modulated chain" arrangements were synthesized, by the polycondensation of a dimeric POSS precursor and dimethyl oligo-siloxane dichloride. Films of POSS-DMS polymers with "alternating modulated chain" arrangements were highly transparent. This observation is consistent with amorphous structures. Along with "constant chain" and "random chain" type polymers, three different chain arrangements of necklace-shaped polymers can now be produced. The physical properties of the three polymer types with constant POSS cage contents were compared. "Alternating modulated chain" type polymers had lower glass transition temperatures than the other two polymer types. This was attributed to the cooperative relaxation of long chain moieties that comprised half of the connecting chains. "Alternating modulated chain" type POSS-DMS polymers with average chain lengths of three to four exhibited heat resistances of over 470 °C in air.

Graphical abstract

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Hierarchically porous silica composites via a colloidal reaction sequence

Publication date: 16 October 2017
Source:Polymer, Volume 128
Author(s): Ran Yu, Guoliang Li, Wei Huang, Klaus Tauer
A new class of polymeric colloids, multiple suspension particles (MSP), with a size of several micrometers consisting of many small polystyrene particles with a diameter below 100 nm grown in a poly (N-isopropyl acrylamide) precursor scaffold is obtained, as reported in our previous paper. Herein, the unique MSP are applied as template for silica nanocasting and hierarchically organized porous silica with raspberry-like aggregation structure is obtained. The aggregates with a diameter of about 1 μm are composed of thousands of hollow silica particles, which are with a size of about 70 nm originating from polystyrene particles and with mesopores of about 5.8 nm on the shell from PNIPAM chains. The aggregates have high specific surface area and pore volume. With the advantage of high mass transport contributed by macropores and of high specific surface area due to mesopores, the hierarchically organized structure has great potential application in catalysis field.

Graphical abstract

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Improved permeability by incorporating polysiloxane in SBS block copolymers for CH4/N2 gas separation

Publication date: 3 October 2017
Source:Polymer, Volume 127
Author(s): Jujie Luo, Tengyang Zhu, Yanhui Song, Ziqin Si
Poly(styrene-b-butadiene-b-styrene) (SBS) block copolymer has been recently demonstrated to be a polymer membrane material with high selectivity for CH4/N2 gas separation. In this study, two effective approaches of grafting and crosslinking have been explored to improve the gas permeability of SBS polymer by introducing polysiloxane (silicone) polymers to SBS backbone via hydrosilylation reaction. First, a series of novel poly(styrene-b-butadiene-b-styrene)-g-poly(dimethylsiloxane) (SBS-g-PDMS) graft copolymers were synthesized via the hydrosilylation reaction of SBS carbon double bonds and silanes (Si-H) from monohydride terminated PDMS. We found that CH4 permeability was increased 40% by grafting only 1.24% PDMS in SBS. Second, to supplement additional silicone to SBS, the hydrosilylation reaction of SBS carbon double bonds and silanes from poly(methylhydrosiloxane) was used to prepare novel SBS-silicone cross-linked polymer membranes. It was demonstrated that CH4 permeability could be improved by 214%, achieving 118 Barrer when 45 wt% silicone was incorporated in SBS. This successful example of improving gas permeation by molecular design could open up new avenues for researchers to develop future polymer membranes with both high selectivity and permeability for industrial applications including methane enrichment from coalbed gases.

Graphical abstract

http://ift.tt/2hrUDZh

Cryogelation within cryogels: Silk fibroin scaffolds with single-, double- and triple-network structures

Publication date: 16 October 2017
Source:Polymer, Volume 128
Author(s): Berkant Yetiskin, Caner Akinci, Oguz Okay
Mechanically strong silk fibroin cryogels with two generations of pores were produced by carrying out the cryogelation reactions within the pores of the initial single-network (SN) fibroin cryogels. In this way, cryogels with interpenetrated and interconnected double- (DN), and triple-network (TN) structures were produced from fibroin solutions frozen at −18 °C in the presence of butanediol diglycidyl ether cross-linker and N,N,N′,N′-tetramethylethylenediamine as a pH regulator. Cryogel scaffolds formed at fibroin concentrations above 25 wt% exhibit a Young's modulus between 66 and 126 MPa, and sustain around 90% compressions under 87–240 MPa stresses. These values are the largest reported so far for fibroin scaffolds and hence the materials have promising applications in bone tissue engineering. We also show that the improvement in the mechanical performance of cryogels after multiple-networking is due to their increased content of fibroin network. Both DN and TN cryogels have two generations of interconnected macropores with diameters 20–30 μm and 3–9 μm. The size of both large and small pores could be adjusted by the relative amounts of fibroin in the network components.

Graphical abstract

http://ift.tt/2hrSjl9

Magnetodielectric effect in magnetoactive elastomers: Transient response and hysteresis

Publication date: 3 October 2017
Source:Polymer, Volume 127
Author(s): Inna A. Belyaeva, Elena Yu. Kramarenko, Mikhail Shamonin
Magnetodielectric properties of magnetoactive elastomers comprising micrometer-sized iron particles dispersed in compliant elastomer matrices are experimentally studied in stepwise time-varying dc magnetic fields. It is found that imposition of magnetic field significantly increases both the effective lossless permittivity of these composite materials as well as their effective conductivity. These magnetodielectric effects are more pronounced for larger concentrations of soft-magnetic filler particles and softer elastomer matrices. The largest observed relative change of the effective dielectric constant in the maximum magnetic field of 0.57 T is of the order of 1000%. The largest observed absolute change of the loss tangent is approximately 0.8. The transient response of the magnetodielectric effect to a step magnetic-field excitation can be rather complex. It changes from a simple monotonic growth with time for small magnetic-field steps (<0.1 T) to a non-monotonic behavior with a significant rapidly appearing overshoot for large magnetic-field steps (>0.3 T). The settling time to the magnetic-field step excitation can reach roughly 1000 s and it depends on the applied magnetic field and sample composition. There is also significant hysteresis of the magnetodielectric effect on the externally applied magnetic field. These findings are attributed to the rearrangement of ferromagnetic filler particles in external magnetic fields. The results will be useful for understanding and predicting the transient behavior of magnetoactive elastomers in applications where the control magnetic field is time dependent.

Graphical abstract

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Initiation of cavitation upon drawing of pre-oriented polypropylene film: In situ SAXS and WAXD studies

Publication date: 16 October 2017
Source:Polymer, Volume 128
Author(s): Bijin Xiong, Jian Kang, Ran Chen, Yongfeng Men
Initiation of cavitation upon drawing of pre-oriented polypropylene films has been investigated via in-situ small angle X-ray scattering (SAXS) and wide angle X-ray diffraction (WAXD) techniques. The macroscopic strains for the initiation of the cavitation εcav and for the initiation of crystal shear εcs have been estimated from in-situ SAXS and WAXD tests respectively. Local crystal shear appears before cavitation upon drawing in machine direction (MD) has been revealed via comparison of εcs and εcav. The initial size of the cavities in MD is larger than the long period of crystalline lamellae while the size in transverse direction is inversely proportional to the relative fraction of daughter lamellae. Macroscopic critical stresses for the initiation of cavitation σcav and for the initiation of crystal shear σcs have been estimated as well. The critical stress σcav is independent on the crystallinity, whereas σcs increases with increasing crystallinity. The mechanism for the initiation of cavitation has been proposed, i.e. the cavitation is initiated by the breakage of crystalline lamellae at the anchor point of the daughter lamellae.

Graphical abstract

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Concentration dependent response to pH modification and salt addition of polymeric dispersions of C60 fullerenes

Publication date: 3 October 2017
Source:Polymer, Volume 127
Author(s): Neta Cohen, Yael Levi-Kalisman, Rachel Yerushalmi – Rozen
Diblockopolymers containing the pH-responsive monomer 2-(diethylaminoethyl) methacrylate (DEAEMA) were synthesized via RAFT polymerization. cryo-TEM imaging revealed the formation of micelles that were used for dispersion of C60 fullerenes in native pH, and their responsiveness to pH modification and salt addition was monitored at different concentrations. Concentration-dependent responsiveness was observed: Just above the CMC in native pH, pH reduction results in precipitation (release) of pre-dispersed C60. At high polymer concentrations the C60 dispersions are non-responsive. Dispersions of Carbon Black, a colloidal particle of much larger diameter, characterized as a reference system, showed a different nanomorphology and were not responsive to pH modifications, due to a different dispersion mechanism. We concluded that good size matching between the dispersed particles is necessary for the formation of micelle-entrapped dispersions, and that the responsivity of the C60 dispersion to pH reduction is limited to a concentration range between the CMC in native conditions and the CMC in acidic conditions.

Graphical abstract

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Using the virtual-abstract instructional sequence to teach addition of fractions

Publication date: November 2017
Source:Research in Developmental Disabilities, Volume 70
Author(s): Emily C. Bouck, Jiyoon Park, Jessica Sprick, Jordan Shurr, Laura Bassette, Abbie Whorley
Background/aims/methodsLimited literature examines mathematics education for students with mild intellectual disability. This study investigated the effects of using the Virtual-Abstract instructional sequenceto teach middle school students, predominantly with mild intellectual disability, to add fractions of unlike denominators. Researchers used a multiple probe across participants design to determine if a functional relation existed between the Virtual-Abstract instructional sequence strategy and students' ability to add fractions with unlike denominators.Procedures/outcomesThe study of consisted of three-to-nine baseline sessions, 6–11 intervention sessions, and two maintenance sessions for each student. Data were collected on accuracy across five addition of fractions with unlike denominators problems.Results/conclusionsThe VA instructional strategy was effective in thestudents to add fractions with unlike denominators; a functional relation existed between the VA instructional sequence and adding fractions with unlike denominators for three of the four students.ImplicationsThe Virtual-Abstract instructional sequencemay be appropriate to support students with mild intellectual disability in learning mathematics, especially when drawing or representing the mathematical concepts may prove challenging.



http://ift.tt/2fIxDVJ

Autoantibodies of IgM and IgG classes show differences in recognition of multiple autoantigens in chronic obstructive pulmonary disease

Publication date: Available online 23 September 2017
Source:Clinical Immunology
Author(s): Reham Shindi, Amna Almehairi, Ola H. Negm, Noor Kalsheker, Nichola S. Gale, Dennis J. Shale, Timothy W. Harrison, Charlotte E. Bolton, Michelle John, Ian Todd, Patrick J. Tighe, Lucy C. Fairclough
Autoimmunity occurs in chronic obstructive pulmonary disease (COPD). We describe an antigen microarray for detecting serum autoantibodies (AAbs) to determine how IgM, as well as IgG, AAbs distinguish patients with COPD from controls with a history of smoking without COPD. All COPD patients' sera contained elevated levels of AAbs to some of 30 autoantigens. There were significant differences in the autoantigenic specificities of IgM AAbs compared to IgG AAbs in the COPD sera: for example, AAbs to histone and scl-70 were mainly IgG, whereas AAbs to CENP-B and La/ssB were mainly IgM; by contrast, IgM and IgG AAbs to collagen-V were equally prevalent. Thus, a combination of IgM and IgG AAbs specific for multiple autoantigens are detected in all cases of COPD at a level at which all non-COPD controls are negative for AAbs. This highlights the importance of different classes of AAbs to a range of autoantigens in COPD.



http://ift.tt/2fpCFJO

Circulating B cells in type 1 diabetics exhibit fewer maturation-associated phenotypes

Publication date: Available online 23 September 2017
Source:Clinical Immunology
Author(s): Patrick Hanley, Jennifer A. Sutter, Noah G. Goodman, Yangzhu Du, Debora R. Sekiguchi, Wenzhao Meng, Michael R. Rickels, Ali Naji, Eline T. Luning Prak
Although autoantibodies have been used for decades as diagnostic and prognostic markers in type 1 diabetes (T1D), further analysis of developmental abnormalities in B cells could reveal tolerance checkpoint defects that could improve individualized therapy. To evaluate B cell developmental progression in T1D, immunophenotyping was used to classify circulating B cells into transitional, mature naïve, mature activated, and resting memory subsets. Then each subset was analyzed for the expression of additional maturation-associated markers. While the frequencies of B cell subsets did not differ significantly between patients and controls, some T1D subjects exhibited reduced proportions of B cells that expressed transmembrane activator and CAML interactor (TACI) and Fas receptor (FasR). Furthermore, some T1D subjects had B cell subsets with lower frequencies of class switching. These results suggest circulating B cells exhibit variable maturation phenotypes in T1D. These phenotypic variations may correlate with differences in B cell selection in individual T1D patients.



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Reduction-melting extraction of trace elements from hazardous waste glass from an old glasswork’s dump in the southeastern part of Sweden

Abstract

At the southeastern part of Sweden, old art and crystal waste glass has been identified as a hazardous waste due to high weight concentrations of Pb (32.398%), Cd (0.085%), and As (1.976%). The reduction-melting technique was used to investigate the extraction of these trace elements from powder waste glass of particle size < 1 mm. Following a factorial design technique, the experimental results of the reduction-melting method showed that 99.9% of Pb, 100% of Cd, and 99% of As could be extracted. For a batch of 10 g powder waste glass, the found experimental and theoretical optimum operating conditions were 1100 °C of melting temperature, 5 g of Na₂CO₃, 2 g of carbon, and 120 min of melting time. The reduction-melting method displayed promising results which might help in recycling the extracted trace elements and glass compared to the current used solution of landfilling as hazardous wastes.

http://ift.tt/2y1cbGa

Characterizing groundwater quality ranks for drinking purposes in Sylhet district, Bangladesh, using entropy method, spatial autocorrelation index, and geostatistics

Abstract

Drinking water is susceptible to the poor quality of contaminated water affecting the health of humans. Thus, it is an essential study to investigate factors affecting groundwater quality and its suitability for drinking uses. In this paper, the entropy theory, multivariate statistics, spatial autocorrelation index, and geostatistics are applied to characterize groundwater quality and its spatial variability in the Sylhet district of Bangladesh. A total of 91samples have been collected from wells (e.g., shallow, intermediate, and deep tube wells at 15–300-m depth) from the study area. The results show that NO₃⁻, then SO₄²⁻, and As are the most contributed parameters influencing the groundwater quality according to the entropy theory. The principal component analysis (PCA) and correlation coefficient also confirm the results of the entropy theory. However, Na⁺ has the highest spatial autocorrelation and the most entropy, thus affecting the groundwater quality. Based on the entropy-weighted water quality index (EWQI) and groundwater quality index (GWQI) classifications, it is observed that 60.45 and 53.86% of water samples are classified as having an excellent to good qualities, while the remaining samples vary from medium to extremely poor quality domains for drinking purposes. Furthermore, the EWQI classification provides the more reasonable results than GWQIs due to its simplicity, accuracy, and ignoring of artificial weight. A Gaussian semivariogram model has been chosen to the best fit model, and groundwater quality indices have a weak spatial dependence, suggesting that both geogenic and anthropogenic factors play a pivotal role in spatial heterogeneity of groundwater quality oscillations.

http://ift.tt/2xthY4s

Informal E-waste recycling in developing countries: review of metal(loid)s pollution, environmental impacts and transport pathways

Abstract

Crude or primitive recycling practices are often adopted in material resource recovery from E-waste in developing nations. Significant human health and environmental impacts may occur because of such practices. Literature on metal(loid)s pollution during E-waste processing is fragmented. Here, I review the health and environmental impacts of E-waste recycling operations and transport pathways of metal(loid)s, dispersed during operations. This paper is organised into five sections. Section 1 relates to the background of global E-waste generation and legal/illegal trade, citing specific cases from Ghana and other developing nations. Section 2 provides a brief information on sources of metal(loid)s in E-waste. Section 3 describes characteristics of informal E-waste recycling operations in developing nations. Section 4 examines the health and environmental impacts in E-waste recycling while section 5 evaluates major transport pathways of metal(loid)s contaminants.

http://ift.tt/2y0DWyP

Spatial distribution correlation of soil-gas radon (222Rn) and mercury with leveling deformation in northern margin fault zone of West Qinling, China

Publication date: November 2017
Source:Journal of Environmental Radioactivity, Volumes 178–179
Author(s): Chenhua Li, Hui Zhang, Hejun Su, Huiling Zhou, Yanhong Wang
This study concerns measurement of ²²²Rn and mercury concentrations in soil-gas in the northern margin fault zone of West Qinling, Tibet (China). Based on profiles crossing perpendicularly the different segments of the fault at six different locations, the relations between the gas measurements, fault deformation, and seismic activity in each segment of the studied fault were analyzed, determining seismic risks in the fault zone. Soil-gas data are heterogeneous, but appear relatively organized along the three segments of the fault. The detailed multidisciplinary analysis reveals complex interactions between the structural setting, uprising fluids, leveling and seismic activity in different fault segments. The results for both fault soil gas and deformation indicated relatively stronger fault activity in the Wushan segment in the middle-eastern segment of the northern margin fault zone of West Qinling and lower activity in the Zhangxian segment, whereas the fault in the Tianshui segment was relatively locked. Additionally, in the Wushan strike-slip pull-apart area, the active influence of fluid activities facilitated the occurrence of small to medium-sized seismic events, which prevented the occurrence of larger events; in contrast, in the Tianshui segment, the west Zhangxian segment, the weak fluid activities and the corresponding strain rate will probably lead to strong earthquake buildup.



http://ift.tt/2fpCqhM

Structural impacts on the timing and amplitude of the negative BOLD response

Publication date: January 2018
Source:Magnetic Resonance Imaging, Volume 45
Author(s): David Provencher, Alexandre Bizeau, Guillaume Gilbert, Yves Bérubé-Lauzière, Kevin Whittingstall
The positive (PBR) and negative BOLD responses (NBR) arising in task-fMRI display varying magnitudes and dynamics across voxels. While the effects of structure, particularly of veins, on the PBR have been studied, little is known of NBR-structure relationships. Like the PBR, the NBR is often used as a surrogate marker of neuronal activation in both basic and clinical research and assessing its relationship with cortical structure may help interpret group differences. We therefore investigated how local structure affects BOLD amplitude and timing in PBR and NBR areas using multi-band fMRI during visual stimulation to obtain high temporal resolution (TR=0.45s) data combined with T1 imaging and susceptibility-weighted imaging (SWI) to quantify the local densities of gray/white matter and veins, respectively. In both PBRs and NBRs, larger venous density was consistently associated with larger BOLD amplitude and delay, up to 1–2s larger relative to areas devoid of large veins. Both binary and sinusoidal visual stimulus modulation yielded similar activation maps and results, suggesting that underlying vasculature affects PBR and NBR temporal dynamics in the same manner. Accounting for structural impacts on PBR and NBR magnitude and timing could help enhance activation map accuracy, better assess functional connectivity, and better characterize neurovascular coupling.



http://ift.tt/2fiXbbt

Effective tumor immunity to melanoma mediated by B16F10 cancer stem cell vaccine

Publication date: November 2017
Source:International Immunopharmacology, Volume 52
Author(s): Fengshu Zhao, Rong Zhang, Jing Wang, Di Wu, Meng Pan, Miao Li, Mei Guo, Jun Dou
Although tumor vaccines have been considered a promising immunotherapy approach, therapeutic tumor vaccines are mostly disappointing in the clinic due to vaccine weak immunogenicity. Cancer stem cells (CSCs) may broaden the antigenic breadth and effectively induce the immune responses against autologous cancer cells. Here we report on the development of the B16F10 CD133⁺CD44⁺CSCs (B16F10 CSCs) vaccine to induce tumor immunity to melanoma in mice. Efficacy of against melanoma was evaluated by analysis of tumor growth and mouse survival. Immunogenicity was assessed by ELISA and flow cytometric assays, including serum cytokines, cytotoxic activity of NK cells and splenocytes in the immunized mice. The results showed that the B16F10 CSC vaccine resulted in tumor shrinkage and mouse lifespan extension. The cytotoxic activity and IFN-γ level were significantly increased in mice immunized with B16F10 CSC vaccine compared with the mice immunized with control vaccines. Additionally, New York esophageal squamous cell carcinoma-1, an efficient tumor associated antigen over-expressed by B16F10 CSCs, was markedly reduced in expression in melanoma tissue, suggesting decrease of CSC subpopulation due to B16F10 CSC vaccination. Collectively, the findings may represent a new powerful approach for treatment of melanoma by B16F10 CSC vaccination.



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