221 research outputs found

    Estimation of the specific enthalpy–temperature functions for plastering mortars containing hybrid mixes of phase change materials

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    The use of phase change materials (PCMs) for the building sector is increasingly attracting attention from researchers and practitioners. Several research studies forwarded the possibility of incorporating microencapsulated PCM in plastering mortars for building facades, in pursuit of increased energy efficiency associated with the heat storage capacity of PCM. However, most of these studies are centred in the use of a single type of PCM, which is bound to be more adequate for a given season of the year (e.g. winter or summer) than for all the seasons. The study proposed in this work regards the evaluation of the possibility of using more than one kind of PCM, with distinct melting ranges, here termed as hybrid PCMs, in plastering mortars, to achieve adequately advantageous performance in all seasons of the year. To characterize the PCM, the specific enthalpy and phase change temperature should be adequately measured. The main purpose of this study was to show the conceptual feasibility of combining PCMs in mortars and to evaluate the behaviour of the resulting mortars with differential scanning calorimeter. The results showed that the behaviour of the mortar that contains more than one type of PCM can be predicted through the superposition of effects of the independent PCMs and no interaction occurs between them. The knowledge obtained from the experimental testing established bases for a framework of numerical simulation of real-scale applications, which can be used to ascertain the feasibility of the hybrid PCM concept for decreases in energy consumption of heating/cooling demands in the buildings.Fundação para a Ciência e a Tecnologia (FCT

    Oxidative stress, aging, and short peptides

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    This article reviews oxidative stress as one of the mechanisms impairing the functions of cells, organs, and tissues. Aging is associated with reductions in the activities of the enzymes of the antioxidant system. Reactive oxygen species formed in oxidant stress damage DNA, RNA, proteins, and lipids, leading to cell apoptosi

    Peptides: Prospects for use in the treatment of COVID-19

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    There is a vast practice of using antimalarial drugs, RAS inhibitors, serine protease inhibitors, inhibitors of the RNA-dependent RNA polymerase of the virus and immunosuppressants for the treatment of the severe form of COVID-19, which often occurs in patients with chronic diseases and older persons. Currently, the clinical efficacy of these drugs for COVID-19 has not been proven yet. Side effects of antimalarial drugs can worsen the condition of patients and increase the likelihood of death. Peptides, given their physiological mechanism of action, have virtually no side effect

    Cost-effectiveness of antivenoms for snakebite envenoming in 16 countries in West Africa

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    Background Snakebite poisoning is a significant medical problem in agricultural societies in Sub Saharan Africa. Antivenom (AV) is the standard treatment, and we assessed the cost-effectiveness of making it available in 16 countries in West Africa. Methods We determined the cost-effectiveness of AV based on a decision-tree model from a public payer perspective. Specific AVs included in the model were Antivipmyn, FAV Afrique, Echi-Tab-G and EchiTab-Plus. We derived inputs from the literature which included: type of snakes causing bites (carpet viper (Echis species)/non-carpet viper), AV effectiveness against death, mortality without AV, probability of Early Adverse Reactions (EAR), likelihood of death from EAR, average age at envenomation in years, anticipated remaining life span and likelihood of amputation. Costs incurred by the victims include: costs of confirming and evaluating envenomation, AV acquisition, routine care, AV transportation logistics, hospital admission and related transportation costs, management of AV EAR compared to the alternative of free snakebite care with ineffective or no AV. Incremental Cost Effectiveness Ratios (ICERs) were assessed as the cost per death averted and the cost per Disability-Adjusted-Life-Years (DALY) averted. Probabilistic Sensitivity Analyses (PSA) using Monte Carlo simulations were used to obtain 95% Confidence Intervals of ICERs. Results The cost/death averted for the 16 countries of interest ranged from 1,997inGuineaBissauto1,997 in Guinea Bissau to 6,205 for Liberia and Sierra Leone. The cost/DALY averted ranged from 83(9583 (95% Confidence Interval: 36-240)forBeninRepublicto240) for Benin Republic to 281 ($159-457) for Sierra-Leone. In all cases, the base-case cost/DALY averted estimate fell below the commonly accepted threshold of one time per capita GDP, suggesting that AV is highly cost-effective for the treatment of snakebite in all 16 WA countries. The findings were consistent even with variations of inputs in 1-way sensitivity analyses. In addition, the PSA showed that in the majority of iterations ranging from 97.3% in Liberia to 100% in Cameroun, Guinea Bissau, Mali, Nigeria and Senegal, our model results yielded an ICER that fell below the threshold of one time per capita GDP, thus, indicating a high degree of confidence in our results. Conclusions Therapy for SBE with AV in countries of WA is highly cost-effective at commonly accepted thresholds. Broadening access to effective AVs in rural communities in West Africa is a priority

    Profiling of cardio-metabolic risk factors and medication utilisation among Type II diabetes patients in Ghana: a prospective cohort study

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    Background: Type II diabetes mellitus (T2DM) is complicated by multiple cardio-metabolic risk factors. Controlling these factors requires lifestyle modifications alongside utilisation of anti-diabetic medications. Different glucose lowering [(biguanides (BIGs), sulfonylureas (SUAs), thiazolidinediones (TNZ)], lipid lowering (statins), and anti-hypertensive medicines [angiotensin converting enzyme inhibitors (ACEIs), calcium channel blockers (CCBs), angiotensin II receptor blockers (ARBs) and central acting drugs (CADs)] have been approved for controlling hyperglycaemia, dyslipidaemia and hypertension respectively. Here, we examined factors that characterise T2DM and explored the response to medication therapy among T2DM patients. Methods: This prospective cohort study recruited 241 T2DM patients reporting at a clinic in Ghana, from January through to August, 2016. Each patient’s demographic, medications and anthropometric data was obtained while information on medication adherence was captured using Morisky adherence scale-8 (MMAS-8). Fasting blood samples were collected for biochemical analysis. Results: The mean age of participants was 57.82 years for baseline and six-month follow-up. Physical activity differed at baseline and follow up (p \u3c 0.05) but not body mass index (BMI). BIG alone, or in combination with SUA and TNZ did not improve glycaemic status at follow up (p \u3e 0.05). Many participants using either ACEI or ARB were able to control their blood pressures. Among dyslipidaemia patients under statin treatment, there was an improved lipid profile at follow-up. Conclusions: Statin medications are effective for reducing dyslipidaemia in T2DM patients. However, control of modifiable risk factors, particularly blood glucose and to a lesser degree blood pressure is suboptimal. Addressing these will require concomitant interventions including education on medication adherence and correct dietary plans, lifestyle modifications and physical activity

    Rifampicin for Continuation Phase Tuberculosis Treatment in Uganda: A Cost-Effectiveness Analysis

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    In Uganda, isoniazid plus ethambutol is used for 6 months (6HE) during the continuation treatment phase of new tuberculosis (TB) cases. However, the World Health Organization (WHO) recommends using isoniazid plus rifampicin for 4 months (4HR) instead of 6HE. We compared the impact of a continuation phase using 6HE or 4HR on total cost and expected mortality from the perspective of the Ugandan national health system.Treatment costs and outcomes were determined by decision analysis. Median daily drug price was US0.115forHRandUS0.115 for HR and US0.069 for HE. TB treatment failure or relapse and mortality rates associated with 6HE vs. 4HR were obtained from randomized trials and systematic reviews for HIV-negative (46% of TB cases; failure/relapse -6HE: 10.4% vs. 4HR: 5.2%; mortality -6HE: 5.6% vs. 4HR: 3.5%) and HIV-positive patients (54% of TB cases; failure or relapse -6HE: 13.7% vs. 4HR: 12.4%; mortality -6HE: 16.6% vs. 4HR: 10.5%). When the initial treatment is not successful, retreatment involves an additional 8-month drug-regimen at a cost of 110.70.Themodelpredictedamortalityrateof13.3110.70. The model predicted a mortality rate of 13.3% for patients treated with 6HE and 8.8% for 4HR; average treatment cost per patient was predicted at 26.07 for 6HE and $23.64 for 4HR. These results were robust to the inclusion of MDR-TB as an additional outcome after treatment failure or relapse.Combination therapy with 4HR in the continuation phase dominates 6HE as it is associated with both lower expected costs and lower expected mortality. These data support the WHO recommendation to transition to a continuation phase comprising 4HR

    A chemical probe for BAG1 targets androgen receptor-positive prostate cancer through oxidative stress signaling pathway

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    BAG1 is a family of polypeptides with a conserved C-terminal BAG domain that functions as a nucleotide exchange factor for the molecular chaperone HSP70. BAG1 proteins also control several signaling processes including proteostasis, apoptosis and transcription. The largest isoform, BAG1L, controls the activity of the androgen receptor (AR) and is upregulated in prostate cancer. Here, we show that BAG1L regulates AR dynamics in the nucleus and its ablation attenuates AR target gene expression especially those involved in oxidative stress and metabolism. We show that a small molecule, A4B17 that targets the BAG domain downregulates AR target genes similar to a complete BAG1L knockout and upregulates the expression of oxidative stress-induced genes involved in cell death. Furthermore, A4B17 outperformed the clinically approved antagonist enzalutamide in inhibiting cell proliferation and prostate tumor development in a mouse xenograft model. BAG1 inhibitors therefore offer unique opportunities for antagonizing AR action and prostate cancer growth
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