1,755 research outputs found

    Absence of microglia promotes diverse pathologies and early lethality in Alzheimer’s disease mice

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    Microglia are strongly implicated in the development and progression of Alzheimer's disease (AD), yet their impact on pathology and lifespan remains unclear. Here we utilize a CSF1R hypomorphic mouse to generate a model of AD that genetically lacks microglia. The resulting microglial-deficient mice exhibit a profound shift from parenchymal amyloid plaques to cerebral amyloid angiopathy (CAA), which is accompanied by numerous transcriptional changes, greatly increased brain calcification and hemorrhages, and premature lethality. Remarkably, a single injection of wild-type microglia into adult mice repopulates the microglial niche and prevents each of these pathological changes. Taken together, these results indicate the protective functions of microglia in reducing CAA, blood-brain barrier dysfunction, and brain calcification. To further understand the clinical implications of these findings, human AD tissue and iPSC-microglia were examined, providing evidence that microglia phagocytose calcium crystals, and this process is impaired by loss of the AD risk gene, TREM2

    Continuous hydrothermal flow synthesis of S-functionalised carbon quantum dots for enhanced oil recovery

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    Currently, there is a paucity in the exploration and application of carbon-based nanomaterials for enhanced oil recovery. Carbon quantum dots (CQDs), 0D materials consisting of a graphitic core covered by an amorphous carbon framework, were produced from glucose and p-sulfonic acid calix[4]arene (SCX4) via Continuous Hydrothermal Flow Synthesis (CHFS), an environmentally benign synthetic approach. The S-functionalised carbon quantum dots (S-CQDs) demonstrated excellent colloidal stability in aqueous and brine solutions, low retention on sand surface, and impressive enhanced oil recovery (EOR) of 17% at very low concentrations of 0.01 wt%. The mechanisms proposed for CQDs in increasing oil sweeping efficiency involves altering the carbonate rocks wettability towards water wet, and creating temporary log-jamming, where the ultra-small particle size (1.7 ± 0.7 nm) allows S-CQDs to recover oil trapped in tight reservoirs. The synthesised S-CQDs also demonstrate photoluminescence, pH stability in the range of 3–11 and have excitation independent behaviour (300–360 nm) with an emission peak at 433 nm

    Treatment of COVID-19 with remdesivir in the absence of humoral immunity: a case report

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    The response to the coronavirus disease 2019 (COVID-19) pandemic has been hampered by lack of an effective severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antiviral therapy. Here we report the use of remdesivir in a patient with COVID-19 and the prototypic genetic antibody deficiency X-linked agammaglobulinaemia (XLA). Despite evidence of complement activation and a robust T cell response, the patient developed persistent SARS-CoV-2 pneumonitis, without progressing to multi-organ involvement. This unusual clinical course is consistent with a contribution of antibodies to both viral clearance and progression to severe disease. In the absence of these confounders, we take an experimental medicine approach to examine the in vivo utility of remdesivir. Over two independent courses of treatment, we observe a temporally correlated clinical and virological response, leading to clinical resolution and viral clearance, with no evidence of acquired drug resistance. We therefore provide evidence for the antiviral efficacy of remdesivir in vivo, and its potential benefit in selected patients

    Human observers have optimal introspective access to perceptual processes even for visually masked stimuli

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    © 2015, eLife Sciences Publications Ltd. All rights reserved. Many believe that humans can âperceive unconsciouslyâ â that for weak stimuli, briefly presented and masked, above-chance discrimination is possible without awareness. Interestingly, an online survey reveals that most experts in the field recognize the lack of convincing evidence for this phenomenon, and yet they persist in this belief. Using a recently developed bias-free experimental procedure for measuring subjective introspection (confidence), we found no evidence for unconscious perception; participantsâ behavior matched that of a Bayesian ideal observer, even though the stimuli were visually masked. This surprising finding suggests that the thresholds for subjective awareness and objective discrimination are effectively the same: if objective task performance is above chance, there is likely conscious experience. These findings shed new light on decades-old methodological issues regarding what it takes to consider a neurobiological or behavioral effect to beâunconscious,â and provide a platform for rigorously investigating unconscious perception in future studies.Link_to_subscribed_fulltex

    Treatment of COVID-19 with remdesivir in the absence of humoral immunity: a case report

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    The response to the coronavirus disease 2019 (COVID-19) pandemic has been hampered by lack of an effective severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antiviral therapy. Here we report the use of remdesivir in a patient with COVID-19 and the prototypic genetic antibody deficiency X-linked agammaglobulinaemia (XLA). Despite evidence of complement activation and a robust T cell response, the patient developed persistent SARS-CoV-2 pneumonitis, without progressing to multi-organ involvement. This unusual clinical course is consistent with a contribution of antibodies to both viral clearance and progression to severe disease. In the absence of these confounders, we take an experimental medicine approach to examine the in vivo utility of remdesivir. Over two independent courses of treatment, we observe a temporally correlated clinical and virological response, leading to clinical resolution and viral clearance, with no evidence of acquired drug resistance. We therefore provide evidence for the antiviral efficacy of remdesivir in vivo, and its potential benefit in selected patients

    An evaluation of the effectiveness of annual health checks and quality of health care for adults with intellectual disability: an observational study using a primary care database

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    Background People with intellectual disability (ID) have poorer health than the general population; however, there is a lack of comprehensive national data describing their health-care needs and utilisation. Annual health checks for adults with ID have been incentivised through primary care since 2009, but only half of those eligible for such a health check receive one. It is unclear what impact health checks have had on important health outcomes, such as emergency hospitalisation. Objectives To evaluate whether or not annual health checks for adults with ID have reduced emergency hospitalisation, and to describe health, health care and mortality for adults with ID. Design A retrospective matched cohort study using primary care data linked to national hospital admissions and mortality data sets. Setting A total of 451 English general practices contributing data to Clinical Practice Research Datalink (CPRD). Participants A total of 21,859 adults with ID compared with 152,846 age-, gender- and practice-matched controls without ID registered during 2009–13. Interventions None. Main outcome measures Emergency hospital admissions. Other outcomes – preventable admissions for ambulatory care sensitive conditions, and mortality. Data sources CPRD, Hospital Episodes Statistics and Office for National Statistics. Results Compared with the general population, adults with ID had higher levels of recorded comorbidity and were more likely to consult in primary care. However, they were less likely to have long doctor consultations, and had lower continuity of care. They had higher mortality rates [hazard ratio (HR) 3.6, 95% confidence interval (CI) 3.3 to 3.9], with 37.0% of deaths classified as being amenable to health-care intervention (HR 5.9, 95% CI 5.1 to 6.8). They were more likely to have emergency hospital admissions [incidence rate ratio (IRR) 2.82, 95% CI 2.66 to 2.98], with 33.7% deemed preventable compared with 17.3% in controls (IRR 5.62, 95% CI 5.14 to 6.13). Health checks for adults with ID had no effect on overall emergency admissions compared with controls (IRR 0.96, 95% CI 0.87 to 1.07), although there was a relative reduction in emergency admissions for ambulatory care-sensitive conditions (IRR 0.82, 95% CI 0.69 to 0.99). Practices with high health check participation also showed a relative fall in preventable emergency admissions for their patients with ID, compared with practices with minimal participation (IRR 0.73, 95% CI 0.57 to 0.95). There were large variations in the health check-related content that was recorded on electronic records. Limitations Patients with milder ID not known to health services were not identified. We could not comment on the quality of health checks. Conclusions Compared with the general population, adults with ID have more chronic diseases and greater primary and secondary care utilisation. With more than one-third of deaths potentially amenable to health-care interventions, improvements in access to, and quality of, health care are required. In primary care, better continuity of care and longer appointment times are important examples that we identified. Although annual health checks can also improve access, not every eligible adult with ID receives one, and health check content varies by practice. Health checks had no impact on overall emergency admissions, but they appeared influential in reducing preventable emergency admissions. Future work No formal cost-effectiveness analysis of annual health checks was performed, but this could be attempted in relation to our estimates of a reduction in preventable emergency admissions. Funding The National Institute for Health Research Health Services and Delivery Research programme

    Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

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    Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis
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