435 research outputs found

    Metallo-Graphene Nanocomposite Electrocatalytic Platform for the Determination of Toxic Metal Ions

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    A Nafion-Graphene (Nafion-G) nanocomposite solution in combination with an in situ plated mercury film electrode was used as a highly sensitive electrochemical platform for the determination of Zn2+, Cd2+, Pb2+ and Cu2+ in 0.1 M acetate buffer (pH 4.6) by square-wave anodic stripping voltammetry (SWASV). Various operational parameters such as deposition potential, deposition time and electrode rotation speed were optimized. The Nafion-G nanocomposite sensing platform exhibited improved sensitivity for metal ion detection, in addition to well defined, reproducible and sharp stripping signals. The linear calibration curves ranged from 1 μg L−1 to 7 μg L−1 for individual analysis. The detection limits (3σ blank/slope) obtained were 0.07 μg L−1 for Pb2+, Zn2+ and Cu2+ and 0.08 μg L−1 for Cd2+ at a deposition time of 120 s. For practical applications recovery studies was done by spiking test samples with known concentrations and comparing the results with inductively coupled plasma mass spectrometry (ICP-MS) analyses. This was followed by real sample analysis

    The diverse nature of island isolation and its effect on land bridge insular faunas

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    Aim: Isolation is a key factor in island biology. It is usually defined as the distance to the geographically nearest mainland, but many other definitions exist. We explored how testing different isolation indices affects the inference of impacts of isolation on faunal characteristics. We focused on land bridge islands and compared the relationships of many spatial and temporal (i.e., through time) isolation indices with community‐, population‐ and individual‐level characteristics (species richness, population density and body size, respectively). Location: Aegean Sea islands, Greece. Time period: Current. Taxon: Many animal taxa. Methods: We estimated 21 isolation indices for 205 islands and recorded species richness data for 15 taxa (invertebrates and vertebrates). We obtained body size data for seven lizard species and population density data for three. We explored how well indices predict each characteristic, in each taxon, by conducting a series of ordinary least squares regressions (controlling for island area when needed) and a meta‐analysis. Results: Isolation was significantly (and negatively) associated with species richness in 10 of 15 taxa. It was significantly (and positively) associated with body size in only one of seven species and was not associated with population density. The effect of isolation on species richness was much weaker than that of island area, regardless of the index tested. Spatial indices generally out‐performed temporal indices, and indices directly related to the mainland out‐performed those related mainly to neighbouring islands. No index was universally superior to others, including the distance to the geographically nearest mainland. Main conclusions: The choice of index can alter our perception of the impacts of isolation on biological patterns. The nearly automatic, ubiquitous use of distance to the geographically nearest mainland misrepresents the complexity of the effects of isolation. We recommend the simultaneous testing of several indices that represent different aspects of isolation, in order to produce more constructive and thorough investigations and avoid imprecise inference

    Strategies for achieving viral hepatitis C micro-elimination in the Netherlands.

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    The Netherlands is striving to achieve national elimination of the hepatitis C virus (HCV) as one of the first countries worldwide. The favorable HCV epidemiology with both low prevalence and incidence, together with access to care and treatment, present excellent conditions to further build on towards this objective. The Dutch national plan on viral hepatitis, introduced in 2016, defines targets in the HCV healthcare cascade and provides a structural framework for the development of elimination activities. Since many different stakeholders are involved in HCV care in the Netherlands, focus has been placed on micro-elimination initiatives as a pragmatic and efficient approach. These numerous micro-eliminations projects have brought the Netherlands closer to HCV elimination. In the near future, efforts specifically have to be made in order to optimize case-finding strategies and to successfully accomplish the nationwide implementation of the registration and monitoring system of viral hepatitis mono-infections, before this final goal can be reached. The upcoming years will then elucidate if the Dutch' hands on approach has resulted in sufficient progress against HCV and if the Netherlands will lead the way towards nationwide HCV elimination

    Working in group living homes for older people with dementia: the effects on job satisfaction and burnout and the role of job characteristics

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    ABSTRACT Background: Group living homes are a fast-growing form of nursing home care for older people with dementia. This study seeks to determine the differences in job characteristics of nursing staff in group living homes and their influence on well-being. Methods: We examined the Job Demand Control Support (JDCS) model in relation to 183 professional caregivers in group living homes and 197 professional caregivers in traditional nursing homes. Multilevel linear regression analysis was used to study the mediator effect of the three job characteristics of the JDCS-model (demands, control and social support) on job satisfaction and three components of burnout (emotional exhaustion, depersonalization and decreased personal accomplishment). Results: Demands were lower in group living homes, while control and social support from co-workers were higher in this setting. Likewise, job satisfaction was higher and burnout was lower in group living homes. Analysis of the mediator effects showed that job satisfaction was fully mediated by all three psychosocial job characteristics, as was emotional exhaustion. Depersonalization was also fully mediated, but only by control and social support. Decreased personal accomplishment was partially mediated, again only by job characteristics, control and support. Conclusion: This study indicates that working in a group living home instead of a traditional nursing home has a beneficial effect on the well-being of nursing staff, largely because of a positive difference in psychosocial job characteristic

    Serum contactin-1 as a biomarker of long-term disease progression in natalizumab-treated multiple sclerosis.

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    BACKGROUND: Natalizumab treatment provides a model for non-inflammation-induced disease progression in multiple sclerosis (MS). OBJECTIVE: To study serum contactin-1 (sCNTN1) as a novel biomarker for disease progression in natalizumab-treated relapsing-remitting MS (RRMS) patients. METHODS: Eighty-nine natalizumab-treated RRMS patients with minimum follow-up of 3 years were included. sCNTN1 was analyzed at baseline (before natalizumab initiation), 3, 12, 24 months (M) and last follow-up (median 5.2 years) and compared to 222 healthy controls (HC) and 15 primary progressive MS patients (PPMS). Results were compared between patients with progressive, stable, or improved disability according to EDSS-plus criteria. RESULTS: Median sCNTN1 levels (ng/mL,) in RRMS (baseline: 10.7, 3M: 9.7, 12M: 10.4, 24M: 10.8; last follow-up: 9.7) were significantly lower compared to HC (12.5; p ⩽ 0.001). It was observed that 48% of patients showed progression during follow-up, 11% improved, and 40% remained stable. sCNTN1 levels were significantly lower in progressors both at baseline and at 12M compared to non-progressors. A 1 ng/mL decrease in baseline sCNTN1 was consistent with an odds ratio of 1.23 (95% confidence interval 1.04-1.45) (p = 0.017) for progression during follow-up. CONCLUSION: Lower baseline sCNTN1 concentrations were associated with long-term disability progression during natalizumab treatment, making it a possible blood-based prognostic biomarker for RRMS

    Struggles over access to the Muslim public sphere: Multiple publics and discourses on agency, belonging and citizenship (Introduction to the Themed Section)

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    Abstract This introductory essay provides the context for the articles in this Themed Section. Despite the diversity in locations, historical backgrounds and contemporary processes of change, all contributors to this Themed Section focus on the struggle of Muslim groups over access to an emergent Muslim public sphere. They highlight the contestations of and shifts in the notions of agency, belonging, and citizenship in nation-states with Muslim communities within its borders. The introduction consists of two parts. The first part reviews the notion of the public sphere as conceptualized by Habermas and critiqued by scholars of a diversity of backgrounds. In relation to the concept of the Muslim public sphere, three aspects of critique are given closer c
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