Cu-In-Te ternary chalcogenides have unique crystal and band structures; hence they have received much attention in thermoelectrics. In this work we have observed an enhancement in Hall carrier ...concentration (
n
H
) and ultralow lattice thermal conductivity (
κ
L
) when Cu was added to ternary Cu
2.5+
δ
In
4.5
Te
8
(
δ
= 0-0.15) compounds. The enhancement in
n
H
is attributed to a degenerate impurity band at the G point in the valence band maximum (VBM), while the extremely low
κ
L
results from the increased lattice disorder. We thus obtained the minimum
κ
L
value of only 0.23 W K
−1
m
−1
in the sample at
δ
= 0.1 and 820 K, which is in good agreement with the calculation using the Callaway model. The highest thermoelectric figure of merit
ZT
is 0.84 for the material at
δ
= 0.1, which is about 0.38 higher than that of the pristine Cu
2.5
In
4.5
Te
8
.
Improvement of thermoelectric performance of copper-deficient compounds Cu
2.5+
δ
In
4.5
Te
8
(
δ
= 0-0.15) due to degenerate impurity band (IB) and ultralow lattice thermal conductivity.
MXenes, synthesized from MAX, have emerged as new energy-storage materials for a good combination of metallic conductivity and rich surface chemistry. The reported MXenes are synthesized mostly from ...Al-based MAX. It is still a big challenge to synthesize MXenes from abundant Si-based MAX because of its strong Ti–Si bonds. Here, we report for the first time a high-energy ultrasonic cell-crushing extraction method to successfully prepare Ti3C2T x MXenes from Si-based MAX using a single low-concentration etchant. This novel strategy for preparing MXenes has a high extraction efficiency and is a fast preparation process of less than 2 h for selective etching of Si. Furthermore, through the high-energy ball-milling technology, unique P–O–Ti bonded red phosphorus nanodot/Ti3C2T x (PTCT) composites were successfully prepared, which enable superior electrochemical performance in lithium- and sodium-ion batteries because of the double-morphology structure, where the amorphous nano red phosphorus particles were strongly absorbed to Ti3C2T x MXene sheets, facilitating the transport of alkali ions during cycling processes. This novel synthesis method of Ti3C2T x MXenes from Si-based MAX and unique P–O–Ti bonded PTCT composites opens a new door for preparing high-performance MXene-based materials and facilitating the development of low-cost MXenes and other two-dimensional materials for next-generation energy storage.
Press pack (PP) packaging technology has been applied to insulated-gate bipolar transistors (IGBTs) for high-voltage and high power density applications in recent years. The pressure distribution ...within PP IGBTs is very important because it affects both the electrical and thermal contact resistances, thermal cycling capability, and short-circuit current rating. Too much pressure will mechanically damage the chip and too little pressure will increase the thermal contact resistance, which eventually leads to chip thermal damage. In this paper, a finite-element multiphysics model cocoupled with an electrical field, thermal field, and mechanical field is proposed to analyze the collector current distribution, pressure distribution, and junction temperature distribution within PP IGBTs. The most important coupling variables, such as electrical and thermal contact resistances, for this cocoupled multiphysics model are calculated or measured by experiment through a single IGBT/fast-recovery diode chip submodule. Based on this multiphysics model, the influence of the high temperature generated by the chip's power dissipation on the pressure distribution within PP IGBTs (in the heating phase) is discussed, and then, compared with the pressure distribution in the clamping phase. The results show that the pressure distribution within PP IGBTs in the heating phase is extremely uneven and different from the value in the clamping phase. Furthermore, the mechanical model and its boundary conditions are verified through the pressure distribution experimental results in the clamping phase, which is measured based on the Fuji prescale film and the clamping test bench. Based on the simulation and experimental results, an optimization of the collector electrode and pedestal is proposed to improve the pressure distribution within PP IGBTs in the heating phase.
•RCHFDE is proposed to extract raw fault features of gear.•HHO is adopted to determine the optimal parameters of DDMA and KELM.•A novel fault diagnosis model based on RCHFDE, HHO-DDMA&KELM is ...proposed.•The gear diagnosis case demonstrates the validity and superiority of the model.
Accurate judgment of gear working state is essential to the normal operation of mechanical equipment. To effectively extract the dynamic features representing the gear state from the vibration signals, this paper proposes refined composite hierarchical fluctuation dispersion entropy (RCHFDE), where the composite hierarchical decomposition is employed to replace the traditional hierarchical decomposition to improve the performance of HFDE. Combining RCHFDE and manifold learning, a new gear fault diagnosis method is proposed. Firstly, RCHFDE is used to extract the original fault features. After that, optimized discriminant diffusion maps analysis is adopted to map high-dimensional features to low-dimensional subsets. Finally, the low-dimensional features are input into optimized kernel extreme learning machine to identify different fault states of gear. The experimental results show that, compared with other contrastive methods, the proposed method enjoys better performance, which can effectively complete the determination of different gear fault states.
Brown adipose tissue (BAT) is thermogenic, expressing high levels of uncoupling protein-1 to convert nutrient energy to heat energy, bypassing ATP synthesis. BAT is a promising therapeutic target for ...treatment of obesity and type 2 diabetes since it converts fatty acids into heat but mechanisms controlling brown adipogenesis remain unclear. Knockdown of acetyl-Coenzyme A acetyltransferase 1 (ACAT1) in C3H10T1/2 cells suppressed brown adipocyte maturation during the current study and ACAT1 overexpression promoted brown adipocyte maturation. The downstream target of AMP-activated protein kinase (AMPK), peroxisome proliferator-activated receptor gamma coactivator-1-α (PGC1α), was involved in the action of ACAT1 on brown adipocyte maturation. ACAT1 overexpression enhanced AMPK phosphorylation and promoted PGC1α expression. It is suggested that ACAT1 promotes brown adipocyte maturation by activating the AMPK-PGC1α signaling pathway.
•ACAT1 promoted differentiation of C3H10T1/2 cells into brown adipocytes.•ACAT1 activated the AMPK-PGC1α signaling pathway to enhance brown adipocyte maturation.•The mitochondrial location of ACAT1 was controlled by palmitoylation.
Endometriosis is a disease characterized by the ectopic growth of endometrial tissue (glands and stroma) outside the confines of the uterus and often involves vital organs such as the intestines and ...urinary system. Endometriosis is considered a refractory disease owing to its enigmatic etiology, propensity for recurrence following conservative or surgical interventions, and the absence of radical treatment and long-term management. In recent years, the incidence of endometriosis has gradually increased, rendering it a pressing concern among women of childbearing age. A more profound understanding of its pathogenesis can significantly improve prognosis. Recent research endeavors have spotlighted the molecular mechanisms by which microRNAs (miRNAs) regulate the occurrence and progression of endometriosis. Many miRNAs have been reported to be aberrantly expressed in the affected tissues of both patients and animal models. These miRNAs actively participate in the regulation of inflammatory reactions, cellular proliferation, angiogenesis, and tissue remodeling. Their capacity to modulate crucial signaling pathways, such as the Wnt/β-catenin signaling pathway, reinforces their potential utility as diagnostic markers or therapeutic agents for endometriosis. In this review, we provide the latest insights into the role of miRNAs that interact with the Wnt/β-catenin pathway to regulate the biological behaviors of endometriosis cells and disease-related symptoms, such as pain and infertility. We hope that this review will provide novel insights and promising targets for innovative therapies addressing endometriosis.
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•miRNAs play an important role in the pathogenesis of endometriosis.•Abnormal activation of the Wnt/β-catenin pathway, and crosstalk with miRNAs are closely related to disease progression.•The miRNA binding site SNPs associated with endometriosis.•By interacting with different signaling pathways, miRNAs might play different roles in endometriosis.•Therapies targeting the miRNA/Wnt/β-catenin pathway might provide a new insight in the options of clinical therapies.
Under rapid global climate change, the risk of ancient landslide reactivation induced by rainfall infiltration is increasing significantly. The contribution of cracks to the reactivation of ancient ...landslides, as an evolutionary product, is a topic that deserves attention; however, current research on this issue remains insufficient. In this study, taking the Woda landslide in the upper Jinsha River as a case study, we investigated the reactivation mechanisms of ancient landslides with and without cracks under rainfall based on model tests. The study showed that cracks influence the reactivation range and depth of ancient landslide. In cases where no cracks develop on ancient landslides, rainfall can only cause shallow sliding with failure concentrated at its front edge. Conversely, when cracks develop on ancient landslides, rainwater can quickly infiltrate into the sliding zone along the cracks and induce overall reactivation of the ancient landslide. Furthermore, the reactivation mechanism of ancient landslides without cracks is that the failure of ancient landslide foot results in progressive failure at the front of the ancient landslide. When cracks have developed at ancient landslides, the reactivation mechanism of which involves mid-rear ancient landslide creeping, tensile cracks develop on the mid-rear ancient landslide, with localized sliding at the front edge, tensile cracks extending, local sliding range extending, accelerated creeping, and progressive failure of the mid-rear ancient landslide. These findings shed light on how cracks influence rainfall-induced mechanisms of ancient landslide reactivation and hold great significance for advancing our understanding regarding these mechanisms.
The prevalent manual assembly process for satellites is marked by inefficiencies and a heightened risk of collision, thus limiting its scalability and potential for integration. To address these ...limitations, the adoption of industrial robots for an intelligent assembly mode has emerged as a promising alternative. Nonetheless, the implementation of an industrial robot satellite assembly system brings its own challenges, including low accuracy of the robot, large manufacturing errors of the satellite products and accumulated errors in the picking and placing process. As the main positioning feature, the detection of holes plays an important role in solving these problems. This paper introduces a novel binocular vision hole recognition system, coupled with an associated hole recognition algorithm, aiming at enhancing the detection accuracy of characteristic holes of satellite products. The proposed methodology includes the development of a confidence-based indicator to assess the quality of two-dimensional hole detection, and an iterative optimization of the fitting ellipse. Furthermore, a confidence-based neighborhood denoising two-stage fitting method is designed for accurate hole positioning. Experimental results validate the proposed methodology, showcasing a recognition accuracy of 0.060 mm and an assembly accuracy within 0.2 mm, thereby fulfilling the requirements of the industrial robot satellite assembly system.
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•Address the measurement difficulties in the robotic satellite assembly systems.•Present an ellipse fitting method to improve the accuracy of ellipse fitting.•Propose a neighborhood denoising method to realize precise identification.•Establish a satellite assembly system with the recognition accuracy of 0.060 mm.
Fatty acids have a high turnover rate in cancer cells to supply energy for tumor growth and proliferation. Lipolysis is particularly important for the regulation of fatty acid homeostasis and in the ...maintenance of cancer cells. In the current study, we explored how 2,4-Dienoyl-CoA reductase (DECR1), a short-chain dehydrogenase/reductase associated with mitochondrial and cytoplasmic compartments, promotes cancer cell growth. We report that DECR1 overexpression significantly reduced the triglyceride (TAG) content in HeLa cells; conversely, DECR1 silencing increased intracellular TAG content. Subsequently, our experiments demonstrate that DECR1 promotes lipolysis via effects on hormone sensitive lipase (HSL). The direct interaction of DECR1 with HSL increases HSL phosphorylation and activity, facilitating the translocation of HSL to lipid droplets. The ensuing enhancement of lipolysis thus increases the release of free fatty acids. Downstream effects include the promotion of cervical cancer cell migration and growth, associated with the enhanced levels of p62 protein. In summary, high levels of DECR1 serves to enhance lipolysis and the release of fatty acid energy stores to support cervical cancer cell growth.
•DECR1 overexpression reduced TAG contents while its silencing increased TAG contents in HeLa cells.•Direct interaction of DECR1 with HSL increases HSL phosphorylation and translocation to LDs for inducement of lipolysis.•Lipolysis thus increases the release of free fatty acids that promotes the cervical cancerious cells migration and growth.
The New Delhi Metallo-β-lactamase (NDM) is among the most threatening forms of carbapenemases produced by K. pneumoniae, well-known to cause severe worldwide infections. The molecular epidemiology of ...blaNDM-1-harboring K. pneumoniae is not well elucidated in Pakistan. Herein, we aim to determine the antibiotics-resistance profile, genes type, molecular type, and plasmid analysis of 125 clinically isolated K. pneumoniae strains from urine samples during July 2018 to January 2019 in Pakistan. A total of 34 (27.2%) K. pneumoniae isolates were carbapenemases producers, and 23 (18.4%) harbored the blaNDM-1 gene. The other carbapenemases encoding genes, i.e., blaIMP-1 (7.2%), blaVIM-1 (3.2%), and blaOXA-48 (2.4%) were also detected. The Multi Locus Sequence Typing (MLST) results revealed that all blaNDM-1-harboring isolates were ST11. The other sequence types detected were ST1, ST37, and ST105. The cluster analysis of Xbal Pulsed Field Gel Electrophoresis (PFGE) revealed variation amongst the clusters of the identical sequence type isolates. The blaNDM-1 gene in all of the isolates was located on a 45-kb IncX3 plasmid, successfully transconjugated. For the first time, blaNDM-1-bearing IncX3 plasmids were identified from Pakistan, and this might be a new primary vehicle for disseminating blaNDM-1 in Enterobacteriaceae as it has a high rate of transferability.
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