Effect of Zr modification on solidification behavior and mechanical properties of Mg–Y–RE (WE54) alloy

AbstractMagnesium alloys containing rare earth elements (RE) have received considerable attention in recent years due to their high mechanical strength and good heat-resisting performance. Among them, Mg–5%Y–4%RE (WE54) magnesium alloy is a high strength sand casting magnesium alloy for use at temperatures up to 300 °C, which is of great interest to engineers in the aerospace industry. In the present work, the solidification behavior of Zr-containing WE54 alloy and Zr-free alloy was investigated by computer-aided cooling curve analysis (CA-CCA) technique. And the solidification microstructure and mechanical properties of them were also investigated comparatively. It is found from the cooling curves and as-cast microstructure of WE54 alloy that the nucleation temperature of α-Mg in WE54 alloy increases after Zr addition, and the as-cast microstructure of the alloy is significantly refined by Zr. While the phase constitution of WE54 alloy is not changed after Zr addition. These phenomena indicate that Zr acts as heterogeneous nuclei during the solidification of WE54 alloy. Due to refined microstructure, the mechanical properties of Zr-containing WE54 alloy is much higher than Zr-free WE54 alloy

A novel prognostic 7-methylguanosine signature reflects immune microenvironment and alternative splicing in glioma based on multi-omics analysis

Glioma is the most common type of central nervous system tumor with increasing incidence. 7-methylguanosine (m7G) is one of the diverse RNA modifications that is known to regulate RNA metabolism and its dysregulation was associated with various cancers. However, the expression pattern of m7G regulators and their roles in regulating tumor immune microenvironments (TIMEs) as well as alternative splicing events (ASEs) in glioma has not been reported. In this study, we showed that m7G regulators displayed a close correlation with each other and most of them were differentially expressed between normal and glioma tissues. Two m7G signatures were then constructed to predict the overall survival of both GBM and LGG patients with moderate predictive performance. The risk score calculated from the regression coefficient and expression level of signature genes was proved to be an independent prognostic factor for patients with LGG, thus, a nomogram was established on the risk score and other independent clinical parameters to predict the survival probability of LGG patients. We also investigated the correlation of m7G signatures with TIMEs in terms of immune scores, expression levels of HLA and immune checkpoint genes, immune cell composition, and immune-related functions. While exploring the correlation between signature genes and the ASEs in glioma, we found that EIF4E1B was a key regulator and might play dual roles depending on glioma grade. By incorporating spatial transcriptomic data, we found a cluster of cells featured by high expression of PTN exhibited the highest m7G score and may communicate with adjacent cancer cells via SPP1 and PTN signaling pathways. In conclusion, our work brought novel insights into the roles of m7G modification in TIMEs and ASEs in glioma, suggesting that evaluation of m7G in glioma could predict prognosis. Moreover, our data suggested that blocking SPP1 and PTN pathways might be a strategy for combating glioma

A comprehensive review of the human body burden of persistent organic pollutants (POPs) and associated health effects in an e-waste recycling area in China

Abstract Guiyu has been one of the world’s largest destinations for electronic waste (e-waste) recycling for decades. The recyling process in Guiyu relied on informal and family-based activities, which have led to severe environmental pollution and associated extensive health problems. This review examines the connections between exposure to persistent organic pollutants (POPs) and health outcomes, particularly in neonates, children and pregnant women. The residents in Guiyu exhibit high levels of contamination from POPs, especially PBDEs, PAHs and PCBs. Excessive exposure to these compounds have been associated with multi-system and long-term effects in children, changes in gestational age in pregnant mothers, and adverse birth outcomes in neonates. The findings raise concerns about the impact of POPs stemming from e-waste recycling on human health, and contribute to a better understanding of the need for monitoring sources, distribution, and effects of e-waste related-POPs in other regions of China and similar sites worldwide

Evaporation Process of Sessile Liquid Droplet and Layer in Steady State

The ethanol liquid droplet with constant contour and liquid layer with constant height in steady-state contained in the heated substrate under evaporation have been experimentally investigated utilizing infrared thermography and volume control technique. The heat and mass transfer and thermal flow patterns at the gas-liquid interface during droplet and layer evaporation are analyzed through their heat flux curves and interface temperature fields. Experimental results reveal that the steady-state evaporation of liquid droplet and layer at surface emerges after the evaporation rate is equal to replenishment rate by continuous liquid refilling and temperature filed becomes uniform. For evaporating droplets, there are two main stages during the evaporation evolution: unstable evaporation with decreasing heat flux and steady evaporation with constant heat flux. In the steady stage, the interface temperature gradually becomes uniform, and convection cells at the interface disappear. For evaporating layer, three main stages are present: first, the formation and splitting of Marangoni convection cells, then the hydrothermal wave propagating from "source" to "sink", and finally the stable flow stage without vortex cells. The results also show that the direction of the temperature gradient at evaporating droplet interface is opposite under different substrate materials (Aluminum and PTFE). The heat flux density of the evaporating droplet on Aluminum substrate is larger than that on PTFE, resulting in a higher evaporation rate. These new findings help to gain a better understanding of the coupling mechanism between phase change and thermal convection inside evaporating liquid droplets and layers

Data_Sheet_1_Application of visual placement of a nasojejunal indwelling feeding tube in intensive care unit patients receiving mechanical ventilation.ZIP

BackgroundCompared with nasogastric nutrition, nasojejunal nutrition may prevent some complications of critically ill patients by maintaining better nutritional status, and blind placement of nasojejunal dwelling feeding tubes is widely used. However, the visual placement seems to be safer and more effective than the blind placement, and is still seldom reported.ObjectiveWe tried to develop visual placement of a nasojejunal feeding tube in intensive care unit patients.MethodsA total of 122 patients receiving mechanical ventilation were admitted to the Department of Critical Care Medicine of the Fifth Affiliated Hospital of Wenzhou Medical University and received the placement of nasojejunal feeding tubes. These patients were randomly and evenly assigned into two groups, one group receiving visual placement of nasojejunal dwelling feeding tubes and another group receiving blind placement. Actual tube placement was confirmed by X-ray. The primary outcome included the success rates of first placement of feeding tubes. The secondary outcome included the time of tube placement, complications, the total cost, heart rates and respiratory rates.ResultsThe primary outcome showed that the success rates of first placement were 96.70% (59 cases/61 cases) in the visual placement group, and two cases failed due to pyloric stenosis and gastroparesis. The success rates were 83.6% (51 cases/61 cases) in the blind placement group and 10 cases failed due to either wrong placement or retrograde tube migration. The success rates in the visual placement group were higher than that in the blind placement group (P = 0.015). The secondary outcome showed that the time of tube placement in the visual placement group was shorter than that in the blind placement group (P 0.05).ConclusionCompared with the blind placement, the visual placement shortened the time of nasojejunal tube placement and increased success rates of first placement. The visual placement was more efficient, easy to operate, safe, and has potential clinical applications.</p

Ultra-high open-circuit voltage of tin perovskite solar cells via an electron transporting layer design.

Tin perovskite is rising as a promising candidate to address the toxicity and theoretical efficiency limitation of lead perovskite. However, the voltage and efficiency of tin perovskite solar cells are much lower than lead counterparts. Herein, indene-C60 bisadduct with higher energy level is utilized as an electron transporting material for tin perovskite solar cells. It suppresses carrier concentration increase caused by remote doping, which significantly reduces interface carriers recombination. Moreover, indene-C60 bisadduct increases the maximum attainable photovoltage of the device. As a result, the use of indene-C60 bisadduct brings unprecedentedly high voltage of 0.94 V, which is over 50% higher than that of 0.6 V for device based on [6,6]-phenyl-C61-butyric acid methyl ester. The device shows a record power conversion efficiency of 12.4% reproduced in an accredited independent photovoltaic testing lab

Ultra-high open-circuit voltage of tin perovskite solar cells via an electron transporting layer design.

Tin perovskite is rising as a promising candidate to address the toxicity and theoretical efficiency limitation of lead perovskite. However, the voltage and efficiency of tin perovskite solar cells are much lower than lead counterparts. Herein, indene-C60 bisadduct with higher energy level is utilized as an electron transporting material for tin perovskite solar cells. It suppresses carrier concentration increase caused by remote doping, which significantly reduces interface carriers recombination. Moreover, indene-C60 bisadduct increases the maximum attainable photovoltage of the device. As a result, the use of indene-C60 bisadduct brings unprecedentedly high voltage of 0.94 V, which is over 50% higher than that of 0.6 V for device based on [6,6]-phenyl-C61-butyric acid methyl ester. The device shows a record power conversion efficiency of 12.4% reproduced in an accredited independent photovoltaic testing lab