3,131 research outputs found
Toughening by nanostructure
Block copolymer modified epoxy resins have generated significant interest since it was demonstrated that the combination could lead to nanostructured thermosets through self-assembly. Over moderate to high polymer concentration the system behaves as expected for a block copolymer in a solvent selective for one block. Two types of copolymers have been studied: non-reactive and reactive modifiers. Morphologies such as copolymer vesicle and spherical/wormlike micelles can be formed under the appropriate conditions. The enhancement of the modified thermosets' mechanical properties depends on the morphology adopted by the polymers. Besides improving mechanical properties, the morphology was found to also have an effect on the glass transition in the studied systems. In this review we collect the available data on the block copolymers used to fabricate nanostructured epoxy resins and critically appraise the properties reported
Multidrug resistance proteins preferentially regulate natriuretic peptide-driven cGMP signalling in the heart & vasculature.
BACKGROUND & PURPOSE: Cyclic-3',5'-guanosine monophosphate (cGMP) underpins the bioactivity of nitric oxide (NO) and natriuretic peptides and is key to cardiovascular homeostasis. Cyclic GMP-driven responses are terminated primarily by phosphodiesterases but cellular efflux via multidrug resistance proteins (MRPs) might contribute. Herein, the effect of pharmacological blockade of MRPs on cGMP signalling in the heart and vasculature was investigated in vitro and in vivo. EXPERIMENTAL APPROACHES: Proliferation of human coronary artery smooth muscle cells (hCASMC), vasorelaxation of murine aorta and reductions in mean arterial blood pressure (MABP) in response to NO-donors or natriuretic peptides was determined in the absence and presence of the MRP inhibitor MK571. The ability of MRP inhibition to reverse morphological and contractile deficits in a murine model of pressure overload-induced HF was also explored. KEY RESULTS: MK571 attenuated hCASMC growth and enhanced the anti-proliferative effects of NO and ANP. MRP blockade caused concentration-dependent relaxations of murine aorta and augmented responses to ANP (and to a lesser extent NO). MK571 did not decrease MABP, but enhanced the hypotensive actions of ANP and improved structural and functional indices of disease severity in experimental HF. These beneficial actions of MRP inhibition were associated with a greater intra:extra -cellular cGMP ratio in vitro and in vivo. CONCLUSIONS & IMPLICATIONS: MRP blockade promotes the cardiovascular functions of natriuretic peptides in vitro and in vivo, with more modest effects on NO. MRP inhibition may have therapeutic utility in cardiovascular diseases triggered by dysfunctional cGMP signalling, particularly those associated with altered natriuretic peptide bioactivity
The Motor Dysfunction Seen in Isolated REM Sleep Behavior Disorder.
BACKGROUND: Isolated Rapid Eye Movement (REM) sleep Behavior Disorder (iRBD) requires quantitative tools to detect incipient Parkinson's disease (PD). METHODS: A motor battery was designed and compared with the Movement Disorder Society-Unified Parkinson's Disease Rating Scale part III (MDS-UPDRS-III) in people with iRBD and controls. This included two keyboard-based tests (BRadykinesia Akinesia INcoordination tap test and Distal Finger Tapping) and two dual tasking tests (walking and finger tapping). RESULTS: We included 33 iRBD patients and 29 controls. The iRBD group performed both keyboard-based tapping tests more slowly (P < 0.001, P = 0.020) and less rhythmically (P < 0.001, P = 0.006) than controls. Unlike controls, the iRBD group increased their walking duration (P < 0.001) and had a smaller amplitude (P = 0.001) and slower (P = 0.007) finger tapping with dual task. The combination of the most salient motor markers showed 90.3% sensitivity for 89.3% specificity (area under the ROC curve [AUC], 0.94), which was higher than the MDS-UPDRS-III (minus action tremor) (69.7% sensitivity, 72.4% specificity; AUC, 0.81) for detecting motor dysfunction. CONCLUSION: Speed, rhythm, and dual task motor deterioration might be accurate indicators of incipient PD in iRBD. © 2024 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society
Prevalence and Correlates of Fearing a Partner During the COVID-19 Pandemic in Britain: Findings from Natsal-COVID
Purpose: The COVID-19 pandemic and lockdown restrictions introduced personal and relationship stressors that potentially increased the risk of intimate partner violence (IPV) for some. We estimated the population prevalence and correlates of fearing a partner in the first year of the pandemic in Britain. / Method: We used data from Natsal-COVID Wave 2—a web-panel survey undertaken one year after the initial British lockdown from 23 March 2020. Quotas and weighting were used to achieve a quasi-representative sample of the general population. Participants were asked about fearing a partner, which is a simple and valid screening tool to identify IPV experiences. / Results: In our sample (unweighted n = 6302, aged 18–59), 9.0% of women and 8.7% of men reported fearing a partner in the first year of the pandemic. Women (73.3%) were more likely than men (49.9%) to indicate that fearing a partner made them feel anxious or depressed; men were more likely to report increased substance use (30.8% vs. 18.4%) and affected work/studies (30.0% vs. 20.0%). For both women and men, fearing a partner during the first year of the pandemic was associated with established health and wellbeing outcomes like anxiety/depression, alcohol use, accessing sexual/reproductive health services, and relationship dissolution as well as feeling that the “pandemic made things worse” across various life domains. / Conclusions: Population-level estimates of IPV during the COVID-19 pandemic highlight harmful experiences that occurred alongside other wide-ranging hardships, and the associations presented identify key populations with potential ongoing need. We make recommendations for primary, secondary, and tertiary prevention of IPV
Organelles in Blastocystis that blur the distinction between mitochondria and hydrogenosomes.
addresses: Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, B3H 1X5, Canada. [email protected]: PMCID: PMC2428068types: Journal Article; Research Support, Non-U.S. Gov'tOpen Access Article. This is a copy of an article published in Current Biology © Elsevier. Current Biology is available online at: http://www.sciencedirect.com/science/journal/09609822Blastocystis is a unicellular stramenopile of controversial pathogenicity in humans. Although it is a strict anaerobe, Blastocystis has mitochondrion-like organelles with cristae, a transmembrane potential and DNA. An apparent lack of several typical mitochondrial pathways has led some to suggest that these organelles might be hydrogenosomes, anaerobic organelles related to mitochondria. We generated 12,767 expressed sequence tags (ESTs) from Blastocystis and identified 115 clusters that encode putative mitochondrial and hydrogenosomal proteins. Among these is the canonical hydrogenosomal protein iron-only [FeFe] hydrogenase that we show localizes to the organelles. The organelles also have mitochondrial characteristics, including pathways for amino acid metabolism, iron-sulfur cluster biogenesis, and an incomplete tricarboxylic acid cycle as well as a mitochondrial genome. Although complexes I and II of the electron transport chain (ETC) are present, we found no evidence for complexes III and IV or F1Fo ATPases. The Blastocystis organelles have metabolic properties of aerobic and anaerobic mitochondria and of hydrogenosomes. They are convergently similar to organelles recently described in the unrelated ciliate Nyctotherus ovalis. These findings blur the boundaries between mitochondria, hydrogenosomes, and mitosomes, as currently defined, underscoring the disparate selective forces that shape these organelles in eukaryotes
Flavour Physics in the Soft Wall Model
We extend the description of flavour that exists in the Randall-Sundrum (RS)
model to the soft wall (SW) model in which the IR brane is removed and the
Higgs is free to propagate in the bulk. It is demonstrated that, like the RS
model, one can generate the hierarchy of fermion masses by localising the
fermions at different locations throughout the space. However, there are two
significant differences. Firstly the possible fermion masses scale down, from
the electroweak scale, less steeply than in the RS model and secondly there now
exists a minimum fermion mass for fermions sitting towards the UV brane. With a
quadratic Higgs VEV, this minimum mass is about fifteen orders of magnitude
lower than the electroweak scale. We derive the gauge propagator and despite
the KK masses scaling as , it is demonstrated that the
coefficients of four fermion operators are not divergent at tree level. FCNC's
amongst kaons and leptons are considered and compared to calculations in the RS
model, with a brane localised Higgs and equivalent levels of tuning. It is
found that since the gauge fermion couplings are slightly more universal and
the SM fermions typically sit slightly further towards the UV brane, the
contributions to observables such as and , from the
exchange of KK gauge fields, are significantly reduced.Comment: 33 pages, 15 figures, 5 tables; v2: references added; v3:
modifications to figures 4,5 and 6. version to appear in JHE
What do rates of deposition of dental cementum tell us? Functional and evolutionary hypotheses in red deer.
Cementum is a bone connective tissue that provides a flexible attachment for the tooth to the alveolar bone in many mammalian species. It does not undergo continuous remodelling, unlike non-dental bone, which combined with its growth pattern of seasonal layering makes this tissue uniquely suitable as a proxy for tracking changes in body repair investment throughout an animal´s life. We tested functional and sexual selection hypotheses on the rate of cementum deposition related to the highly polygynous mating strategy of red deer. We used a sample of 156 first lower molars from wild Scottish red deer of known age between 1 and 17 years old, approximately balanced by sex and age class. Cementum deposition on the inter-radicular pad increased with age at a constant average rate of 0.26 mm per year, with no significant differences between sexes. Cementum deposition was independent of (i) tooth wear, other than that associated with age, and (ii) enamel and dentine micro-hardness. The results partially supported the hypothesis that the main function of cementum is the repositioning of the tooth to maintain opposing teeth in occlusion. However, teeth that had more wear or males´ teeth that had faster rates of tooth wear than those of females did not present the expected higher rates of cementum deposition
PlantFuncSSR: Integrating first and next generation transcriptomics for mining of SSR-functional domains markers
© 2016 Sablok, Pérez-Pulido, Do, Seong, Casimiro-Soriguer, La Porta, Ralph, Squartini, Muñoz-Merida and Harikrishna. Analysis of repetitive DNA sequence content and divergence among the repetitive functional classes is a well-accepted approach for estimation of inter- and intrageneric differences in plant genomes. Among these elements, microsatellites, or Simple Sequence Repeats (SSRs), have been widely demonstrated as powerful genetic markers for species and varieties discrimination. We present PlantFuncSSRs platform having more than 364 plant species with more than 2 million functional SSRs. They are provided with detailed annotations for easy functional browsing of SSRs and with information on primer pairs and associated functional domains. PlantFuncSSRs can be leveraged to identify functional-based genic variability among the species of interest, which might be of particular interest in developing functional markers in plants. This comprehensive on-line portal unifies mining of SSRs from first and next generation sequencing datasets, corresponding primer pairs and associated in-depth functional annotation such as gene ontology annotation, gene interactions and its identification from reference protein databases. PlantFuncSSRs is freely accessible at: http://www. bioinfocabd.upo.es/plantssr
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2D-cadmium MOF and gismondine-like zinc coordination network based on the N-(2-tetrazolethyl)-4′-glycine linker
We have designed and synthesized two new metal-organic-frameworks (MOFs) using the novel N-(2-tetrazolethyl)-4′-glycine spacer (TeGly)2−. These materials exhibit intense photoluminescence.This work was supported by the MEC of Spain (Project CTQ2011-24478) and the Junta de Andalucía (FQM-1484). D. F.-J. thanks the Royal Society for a University Research Fellowship.This is the author accepted manuscript. The final version is available from the Royal Society of Chemistry via http://dx.doi.org/10.1039/C5NJ00011
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