This paper reports the growth mechanism of sol–gel-derived nanocrystalline ZnO powder. The influence of pH value of the sol on the crystallite size, morphology and structure of ZnO powder was ...investigated by using X-ray diffraction, transmission and scanning electron microscopy. Maximum size nanocrystallite (∼14
nm) of ZnO powder was obtained for pH value of 9. An increase in the band gap (blue shift) was observed with decrease in the size of the ZnO nanocrystallites. The variation in band gap was found to be in agreement with theoretical calculations using effective mass model. The growth mechanism of ZnO particles from zinc acetate dihydrate precursor by the sol–gel process has been discussed in terms of solvation, hydrolysis and polymerization. The synthesized ZnO powders were successfully used as the electrode material for dye-sensitized solar cells.
The mechanisms underlying the disproportionate effect of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection on patients with cardiovascular comorbidities, however, remain ...incompletely understood.1,2 SARS-CoV-2 infects the host using the angiotensin converting enzyme 2 (ACE2) receptor, which is expressed in several organs, including the lung, heart, kidney, and intestine. Intriguingly, SARS-CoV-2 can directly infect engineered human blood vessel organoids in vitro.4 Here we demonstrate endothelial cell involvement across vascular beds of different organs in a series of patients with COVID-19 (further case details are provided in the appendix). The vascular endothelium is an active paracrine, endocrine, and autocrine organ that is indispensable for the regulation of vascular tone and the maintenance of vascular homoeostasis.5 Endothelial dysfunction is a principal determinant of microvascular dysfunction by shifting the vascular equilibrium towards more vasoconstriction with subsequent organ ischaemia, inflammation with associated tissue oedema, and a pro-coagulant state.6 Our findings show the presence of viral elements within endothelial cells and an accumulation of inflammatory cells, with evidence of endothelial and inflammatory cell death.
Obesity has reached epidemic proportions in the United States and in much of the westernized world, contributing to considerable morbidity. Several of these obesity-related morbidities are associated ...with greater risk for death with coronavirus disease 2019 (COVID-19). Severe acute respiratory syndrome coronavirus 2 penetrates human cells through direct binding with angiotensin-converting enzyme 2 receptors on the cell surface. Angiotensin-converting enzyme 2 expression in adipose tissue is higher than that in lung tissue, which means that adipose tissue may be vulnerable to COVID-19 infection. Obese patients also have worse outcomes with COVID-19 infection, including respiratory failure, need for mechanical ventilation, and higher mortality. Clinicians need to be more aggressive when treating obese, especially severely obese, patients with COVID-19 infection.
In an early analysis of this trial, use of a magnetically levitated centrifugal continuous-flow circulatory pump was found to improve clinical outcomes, as compared with a mechanical-bearing axial ...continuous-flow pump, at 6 months in patients with advanced heart failure.
In a randomized noninferiority and superiority trial, we compared the centrifugal-flow pump with the axial-flow pump in patients with advanced heart failure, irrespective of the intended goal of support (bridge to transplantation or destination therapy). The composite primary end point was survival at 2 years free of disabling stroke (with disabling stroke indicated by a modified Rankin score of >3; scores range from 0 to 6, with higher scores indicating more severe disability) or survival free of reoperation to replace or remove a malfunctioning device. The noninferiority margin for the risk difference (centrifugal-flow pump group minus axial-flow pump group) was -10 percentage points.
Of 366 patients, 190 were assigned to the centrifugal-flow pump group and 176 to the axial-flow pump group. In the intention-to-treat population, the primary end point occurred in 151 patients (79.5%) in the centrifugal-flow pump group, as compared with 106 (60.2%) in the axial-flow pump group (absolute difference, 19.2 percentage points; 95% lower confidence boundary, 9.8 percentage points P<0.001 for noninferiority; hazard ratio, 0.46; 95% confidence interval CI, 0.31 to 0.69 P<0.001 for superiority). Reoperation for pump malfunction was less frequent in the centrifugal-flow pump group than in the axial-flow pump group (3 patients 1.6% vs. 30 patients 17.0%; hazard ratio, 0.08; 95% CI, 0.03 to 0.27; P<0.001). The rates of death and disabling stroke were similar in the two groups, but the overall rate of stroke was lower in the centrifugal-flow pump group than in the axial-flow pump group (10.1% vs. 19.2%; hazard ratio, 0.47; 95% CI, 0.27 to 0.84, P=0.02).
In patients with advanced heart failure, a fully magnetically levitated centrifugal-flow pump was superior to a mechanical-bearing axial-flow pump with regard to survival free of disabling stroke or reoperation to replace or remove a malfunctioning device. (Funded by Abbott; MOMENTUM 3 ClinicalTrials.gov number, NCT02224755 .).
Alternations in gut microbial composition (i.e. loss of microbial diversity or ‘gut dysbiosis’) have been associated with heart failure with reduced ejection fraction (HFrEF). It has also been ...suggested that increased chronic low‐level inflammation and immune system dysregulation seen in patients with HFrEF could be related to gut dysbiosis and increased intestinal permeability. Hence, the concept of modulating gut microbial composition with the goal of reducing systemic inflammation and controlling HFrEF progression has generated a substantial interest in the scientific community. However, several challenges to the gut dysbiosis theory remain as the exact gut microbial composition in HFrEF patients in these studies is not the same and a common microbiome linked to HFrEF is not yet established. With the advances in culture independent sequencing techniques it has also become evident that the gut microbiome may be much more diverse than previously believed. Further, various ‘omic’ technologies have enabled us to appreciate the potential role of gut microbial metabolites in various physiological processes in the host. Hence, identification of specific gut microbial metabolites may offer an alternative approach at solving this gut microbiome‐HFrEF puzzle. In the current review, we evaluate the concept of gut symbiosis, the potential role of gut dysbiosis in systemic inflammation and HFrEF, and finally highlight the challenges faced by the gut dysbiosis theory in HFrEF and provide a framework for the possible solutions.
Summary
Guidelines outlining recommended actions are difficult to implement in the stressful, time‐pressured situation of an airway emergency. Cognitive aids such as posters and algorithms improve ...performance during some anaesthetic emergencies; however, their effects on team behaviours have not been determined. In this study, 64 participants were randomly assigned into control (no cognitive aid) and intervention (cognitive aid provided) groups before a simulated ‘can't intubate, can't oxygenate’ scenario. Video analysis was undertaken of the non‐technical skills and technical performance during the scenarios. All categories had higher Anaesthetists’ Non‐Technical Skills (ANTS) scores when a cognitive aid was supplied (mean (SD) total ANTS score 10.4 (3.1) vs 13.2 (2.4), p < 0.001). The number of times the cognitive aid was used was associated with higher ANTS scores (ρ = 0.383, p = 0.002). A trend towards the establishment of an infraglottic airway within 3 min was also noted (control group 55.3% vs intervention 76.9%, p = 0.076). Non‐technical skills are improved when a cognitive aid is present during airway emergencies.
Continuous-flow left ventricular assist systems increase the rate of survival among patients with advanced heart failure but are associated with the development of pump thrombosis. We investigated ...the effects of a new magnetically levitated centrifugal continuous-flow pump that was engineered to avert thrombosis.
We randomly assigned patients with advanced heart failure to receive either the new centrifugal continuous-flow pump or a commercially available axial continuous-flow pump. Patients could be enrolled irrespective of the intended goal of pump support (bridge to transplantation or destination therapy). The primary end point was a composite of survival free of disabling stroke (with disabling stroke indicated by a modified Rankin score >3; scores range from 0 to 6, with higher scores indicating more severe disability) or survival free of reoperation to replace or remove the device at 6 months after implantation. The trial was powered for noninferiority testing of the primary end point (noninferiority margin, -10 percentage points).
Of 294 patients, 152 were assigned to the centrifugal-flow pump group and 142 to the axial-flow pump group. In the intention-to-treat population, the primary end point occurred in 131 patients (86.2%) in the centrifugal-flow pump group and in 109 (76.8%) in the axial-flow pump group (absolute difference, 9.4 percentage points; 95% lower confidence boundary, -2.1 P<0.001 for noninferiority; hazard ratio, 0.55; 95% confidence interval CI, 0.32 to 0.95 two-tailed P=0.04 for superiority). There were no significant between-group differences in the rates of death or disabling stroke, but reoperation for pump malfunction was less frequent in the centrifugal-flow pump group than in the axial-flow pump group (1 0.7% vs. 11 7.7%; hazard ratio, 0.08; 95% CI, 0.01 to 0.60; P=0.002). Suspected or confirmed pump thrombosis occurred in no patients in the centrifugal-flow pump group and in 14 patients (10.1%) in the axial-flow pump group.
Among patients with advanced heart failure, implantation of a fully magnetically levitated centrifugal-flow pump was associated with better outcomes at 6 months than was implantation of an axial-flow pump, primarily because of the lower rate of reoperation for pump malfunction. (Funded by St. Jude Medical; MOMENTUM 3 ClinicalTrials.gov number, NCT02224755 .).
The need for replacing conventional sources of energy with renewable ones has been on a swift rise since the last couple of decades. In this context, the progress in third-generation solar cells has ...taken a good leap in the last couple of years with increasing prospects of high efficiency, stability, and lifetime. Quite recently, a new form of carbon has been discovered accidentally in the form of carbon quantum dots (C QD), which is being pursued actively owing to its chemical stability and luminescent properties. In the current work, we report highly luminescent C QD prepared
via
a simple hydrothermal route. Transmission electron microscopy revealed an average particle size of 3.4 nm. The prepared C QD were used in a co-sensitized solar cell, where an improvement in the device characteristics was observed. The enhancement in the device characteristics is supported by impedance and electron life-time analysis. Further, the time-dependent analysis of the current and voltage revealed the functioning of the solar cell in real-time condition.
Carbon QD showing bright blue fluorescence aid in improving the photovoltaic parameters in a co-sensitized solar cell. Time-dependent
I
-
V
analysis revealed the real-time functioning of the device.
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