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The discontinuous precipitation behaviour and properties of Cu–Ti–Ni alloy during aging precipitation were studied by means of electron backscatter diffraction (EBSD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The results show that β’-Cu4Ti was formed in the matrix during the aging process of Cu–4Ti–1Ni alloy, and the cellular structure grows at the grain boundary in the form of discontinuous precipitation in the middle and late stages of aging, and expands to the interior of the grains with the aging time until the grains were completely covered, then a uniform Cu3Ti structure was formed. In addition, the coverage area of cellular tissue increases with aging time and temperature. Under different aging temperature conditions, the hardness of the alloy increases first and then decreases with the aging time, with a peak value of 319.8 HV and a strength of 782.2 MPa. The electrical conductivity increases rapidly and then increases slowly with aging time, reaching 15.5 IACS after aging at 500°C for 10 h. Based on the Avrami equation, the kinetic analysis of discontinuous precipitation at different temperatures was established. [ABSTRACT FROM AUTHOR]

Aim/Purpose: This study, drawing on and extending research on the adoption of information technologies (IT), develops a research model to investigate: (1) the key relative factors that affect the adoption of e-learning versus using IT in traditional classrooms; and (2) students' relative attitudes and relative intentions to use e-learning systems. Background: Since the advent of the COVID-19 pandemic, higher education institutions (HEIs) have rapidly adopted e-learning and students are now engaging with elearning systems. These systems present a new research opportunity for examining the relative efficacy of using e-learning systems versus using IT in traditional classrooms. Although prior research has examined various types of e-learning systems in different contexts and using various methodological approaches, evidence in the literature indicates that the relative efficacy of e-learning remains uncertain as little is known about the factors that affect the adoption and use of e-learning systems during COVID-19, as there is limited academic research. Methodology: The model is tested based on the perceptions of a group of 569 students of the adoption of e-learning versus using IT in traditional classrooms in the United Arab Emirates. The data were analyzed with IBM SPSS statistics 26 and partial least squares structural equation modeling (PLS-SEM) implemented in SmartPLS 3 software. Contribution: This research contributes to the literature by: (1) extending the UTAUT model to understand students' relative attitudes and relative behavioral intentions towards using e-learning systems; (2) an extension to e-learning studies to examine relative factors affecting the adoption of e-learning systems by comparing the perceptions of the same group of students on e-learning and using IT in a traditional classroom environment in the context of COVID-19; and (3) providing valuable practical implications for HEIs to improve pedagogical approaches and e-learning systems. Findings: The Findings suggest that relative computer self-efficacy, relative cognitive absorption, relative system interactivity, and relative system functionality each positively influence both relative performance expectancy and relative effort expectancy, which in turn affect relative attitude; and that relative intention to use is positively affected by relative attitude and relative facilitating conditions. Recommendations for Practitioners: Firstly, HEIs should feel more confident that e-learning systems indeed provide an appropriate learning approach, demonstrated by a high relative efficacy of elearning systems perceived by the sample students in this study. Thus, it seems fitting for HEIs to use e-learning systems to enhance the development and delivery of programs and the quality of student experience, especially in the context of COVID-19. Secondly, HEIs wishing to use e-learning systems successfully should at least pay attention to a few key factors to ensure that students will have a positive attitude toward using e-learning systems. Such factors include students' perceived usefulness of e-learning systems, developing encouraging facilitating conditions such as training, technical and IT support, thereby enabling students to use e-learning systems while enjoying their engagement with e-learning systems. Recommendations for Researchers: First, this study shows that relative to using IT in a classroom environment, elearning is favored by the students involved in this research. Second, this research indicates the value of examining relative antecedents and relative UTAUT related constructs, evaluating the relative perceptions of students, thereby understanding the relative efficacy of e-learning systems versus using IT in a traditional classroom environment in HEIs. Third, in addition to examining students' perceptions of different learning approaches, or comparing the relative efficacy of different learning approaches based on the perceptions of different groups of students, the relative approach based on comparing the perceptions of the same group of students used in this research could offer a new way to advance our understanding of IT adoption. Finally, this study demonstrates that relative attitude, relative performance expectancy, and relative facilitating conditions are the top three vital factors that affect the adoption and use of e-learning systems during the COVID-19 crisis. Impact on Society: The positive result of the students' relative perceptions of e-learning systems suggests that private and public organizations, as well as education policy-makers in providing the learning process, could certainly use e-learning systems as a valuable means of training and/or education, especially during the COVID-19 pandemic. Future Research: First, the result of this study is based on data collected from HEIs in the United Arab Emirates. This work could be extended to other HEIs in other countries. Second, this study uses a non-probability sampling approach to collect data, which may limit the validity of the findings. Thus, probability sampling could be an option for future research. Third, this study focuses on developing an understanding of the key relative antecedents that may affect students' relative attitudes and relative intentions to use e-learning systems. There might be other antecedents worth including in future research. Other potential Future Research may include using the relative approach employed in this study to examine IT adoption, or collecting data from a group of learners on different learning approaches for comparative research, which seems germane to comparing the relative efficacy of different learning modes. [ABSTRACT FROM AUTHOR]

During pregnancy, the appropriate allocation of nutrients between the mother and the fetus is dominated by maternal-fetal interactions, which is primarily governed by the placenta. The syncytiotrophoblast (STB) lining at the outer surface of the placental villi is directly bathed in maternal blood and controls feto-maternal exchange. The STB is the largest multinucleated cell type in the human body, and is formed through syncytialization of the mononucleated cytotrophoblast. However, the physiological advantage of forming such an extensively multinucleated cellular structure remains poorly understood. Here, we discover that the STB uniquely adapts to nutrient stress by inducing the macropinocytosis machinery through repression of mammalian target of rapamycin (mTOR) signaling. In primary human trophoblasts and in trophoblast cell lines, differentiation toward a syncytium triggers macropinocytosis, which is greatly enhanced during amino acid shortage, induced by inhibiting mTOR signaling. Moreover, inhibiting mTOR in pregnant mice markedly stimulates macropinocytosis in the syncytium. Blocking macropinocytosis worsens the phenotypes of fetal growth restriction caused by mTOR-inhibition. Consistently, placentas derived from fetal growth restriction patients display: 1) Repressed mTOR signaling, 2) increased syncytialization, and 3) enhanced macropinocytosis. Together, our findings suggest that the unique ability of STB to undergo macropinocytosis serves as an essential adaptation to the cellular nutrient status, and support fetal survival and growth under nutrient deprivation. [ABSTRACT FROM AUTHOR]

Background. Metformin has been reported to decrease insulin resistance and is associated with a lower risk of pregnancy-induced hypertension and preeclampsia. It is widely accepted that the placenta plays a crucial role in the development of preeclampsia. Our aim is to explore the effect of metformin on preeclampsia. Study Design. We examined control diet-fed (isocaloric diet) pregnant mice (CTRL group), pregnant mice fed a high-fat diet (HF group), and high-fat-diet-fed pregnant mice treated with metformin (HF-M group). The HF mice were fed a high-fat diet six weeks before pregnancy to establish a preeclampsia-like model; then, the group was randomly divided into a HF group and a HF-M group after pregnancy. Blood pressure, urine protein, pregnancy outcomes, protein expression, and histopathological changes in the placentas of all groups were examined and statistically analysed. Results. We observed that metformin significantly improved high blood pressure, proteinuria, and foetal and placental weights in the HF-M group compared with the HF group. Metformin significantly improved placental labyrinth and foetal vascular development in preeclampsia. In addition, metformin effectively increased matrix metalloproteinase-2 (MMP-2) and vascular endothelial growth factor (VEGF) levels in the placenta. Conclusions. Our results suggest that metformin can improve preeclamptic symptoms and pregnancy outcomes. [ABSTRACT FROM AUTHOR]

Experimental data are presented on the bias dependence of the photocurrent of short-wave infrared n+-on-p Hg1-xCdxTe (MCT) photodiodes responding to an attenuated Nd: yttrium lithium fluoride laser, and the results are interpreted using the sweep-out theory. At high photon injection level, it is observed that the photocurrent is linearly dependent at reverse bias before saturating, and a high reverse bias is required to recover the linear response of the photocurrent to the irradiance. The conventional photocurrent model fails to explain our observations. The bias dependence is attributed to recombination of the photogenerated carriers instead of their being swept out of the depletion region, as a result of the partial cancellation of the built-in field by the spatial distribution of the high density of photogenerated electrons and holes in this region. An interpretation based upon the photoconductivity of MCT photoconductors is proposed and found to be in good agreement with the experimental results. [ABSTRACT FROM AUTHOR]

Abstract  This paper seeks to identify a new and useful role for systems thinking in improving qualitative research quality. Firstly, it reflects upon the main characteristics and difficulties of qualitative research. Secondly, it critically reviews some of the techniques suggested to improve research credibility, transferability, dependability and confirmability. Thirdly, it explains the concept of pattern-matching and its role in designing case studies. Based on these, the paper examines the pattern-matching role of systems thinking in enhancing the trustworthiness of qualitative research. Finally, a case study is described to illustrate how pattern-matching is embedded in systems perspective to improve research trustworthiness. The paper highlights that when systems thinking is combined with pattern-matching properly in qualitative research, it can help the investigators to develop a fuller and richer understanding of a phenomenon, and can enable others interested in the research to recover how conclusions have been made and to make informed judgement about the research findings. [ABSTRACT FROM AUTHOR]