80 research outputs found
High Step-Up Switched-Capacitor Active Switched-Inductor Converter with Self-Voltage Balancing and Low Stress
Zika Virus Dissemination from the Midgut of Aedes aegypti is Facilitated by Bloodmeal-Mediated Structural Modification of the Midgut Basal Lamina
The arboviral disease cycle requires that key tissues in the arthropod vector become persistently infected with the virus. The midgut is the first organ in the mosquito that needs to be productively infected with an orally acquired virus. Following midgut infection, the virus then disseminates to secondary tissues including the salivary glands. Once these are productively infected, the mosquito is able to transmit the virus to a vertebrate host. Recently, we described the midgut dissemination pattern for chikungunya virus in Aedes aegypti. Here we assess the dissemination pattern in the same mosquito species for Zika virus (ZIKV), a human pathogenic virus belonging to the Flaviviridae. ZIKV infection of secondary tissues, indicative of dissemination from the midgut, was not observed before 72 h post infectious bloodmeal (pibm). Virion accumulation at the midgut basal lamina (BL) was only sporadic, although at 96–120 h pibm, virions were frequently observed between strands of the BL indicative of their dissemination. Our data suggest that ZIKV dissemination from the mosquito midgut occurs after digestion of the bloodmeal. Using gold-nanoparticles of 5 nm and 50 nm size, we show that meal ingestion leads to severe midgut tissue distention, causing the mesh width of the BL to remain enlarged after complete digestion of the meal. This could explain how ZIKV can exit the midgut via the BL after bloodmeal digestion. Ingestion of a subsequent, non-infectious bloodmeal five days after acquisition of an initial, dengue 4 virus containing bloodmeal resulted in an increased number of virions present in the midgut epithelium adjacent to the BL. Thus, subsequent bloodmeal ingestion by an infected mosquito may primarily stimulate de novo synthesis of virions leading to increased viral titers in the vector
Expression and Functions of Fibroblast Growth Factor 10 in the Mouse Mammary Gland
Abstract: Fibroblast growth factor 10 (FGF10) is important as a mesenchymal mediator of epithelial growth and morphogenesis. In this study, the expression and localization of the FGF10 protein were detected by laser scanning confocal microscopy during mouse postnatal mammary gland development. Mammary explants were cultured to investigate the functions of FGF10. The results revealed that FGF10 localizes mainly in the mesenchyme near the ductal epithelial cells and the alveolar epithelial cells of the mammary gland. Peak FGF10 expression levels were observed at lactation day 10. FGF10 induced FGFR2-IIIb expression in the mammary epithelium, except in virgin or pregnant mice. FGF10 promoted the proliferation of mammary gland epithelial cells and reduced apoptosis. FGF10 is important during the mouse mammary gland growth, development, and reconstruction, and its effects are mediated by FGFR2-IIIb
miR-576-5p regulates the EMT process to inhibit migration and invasion of hepatocellular carcinoma cells
Objective To investigate the effect of miR-576-5P on the migration and invasion of hepatocellular carcinoma(HCC)cells by regulating epithelial-mesenchymal transition (EMT) process. Methods RT-qPCR was used to detect miR-576-5p expression level in HCC cells and normal liver cells, hepatocellular carcinoma tissues and paraneoplastic tissues from 27 patients who accepted hepatectomy from June 2020 to January 2021 in the Department of Hepatobiliary Surgery of the First Affiliated Hospital of Chongqing Medical University. MiR-576-5p mimics and mimics NC were transfected into hepG2 cells as the over-expression group(mimics group) and the control group(mimics NC group), and miR-576-5p inhibitor and inhibitor NC were transfected into SMMC-7721 cells as the de-expression group(inhibitor group) and the control group(inhibitor NC group). CCK-8 assay and EDU assay were used to detect the proliferative ability of cells. Transwell assay and wound healing assay were used to observe the changes of invasion and migration of cells in each group. The changes of expression level of E-cadherin, N-cadherin and snail in each group were detected by Western blotting. Results The expression of miR-576-5p in HCC tissues was significantly lower than that in matched adjacent tissues(P < 0.001), and the expression of miR-576-5p was lower in HCC cells than that of normal liver cells(P < 0.001). SMMC-7721 inhibitor group had enhanced proliferative capacity (P < 0.001, P < 0.001), significantly increased wound healing rate (P < 0.001) and significantly increased migration and invasive perforated cells (P < 0.001, P < 0.01), compared to the inhibited NC group. HepG2 mimics group had lower proliferative capacity(P < 0.01, P < 0.01), significantly lower wound healing rate(P < 0.01), and significantly fewer migration and invasive perforated cells than the mimics NC group(P < 0.001, P < 0.01). The hepG2 mimics group showed a obviously increase in the expression of E-cadherin and a decrease in the expression of N-cadherin and snail compared to the mimics NC group (P < 0.001, P < 0.05, P < 0.05), while the completely opposite changes occurred in the SMMC-7721 inhibitor groups (P < 0.05, P < 0.001, P < 0.01). Conclusion MiR-576-5p inhibits the proliferation of hepatocellular carcinoma cells and prevents the EMT process to inhibit invasion and migration of cells
SUZ12 Depletion Suppresses the Proliferation of Gastric Cancer Cells
Background/Aims: SUZ12 and EZH2 are two main components of polycomb repressive complex 2 (PRC2) that is known to be of great importance in tumorigenesis. EZH2 has been reported to play a vital role in pathogenesis of human cancer. However, whether SUZ12 has equivalent roles in tumorigenesis has not been demonstrated. Here, we investigated a possible role of SUZ12 for the proliferation of gastric cancer cells. Methods: Western-blot analysis was used to detected the levels of SUZ12, H3K27me3, EZH2 and p27 in ten gastric cell lines. SUZ12 was depleted by RNA interference. Cell cycle was detected by flow cytometry. Luciferase assays was to analyze whether miR-200b directly regulate SUZ12. Results: We found that SUZ12 depletion mediated by RNA interference (RNAi) led to a reduction of gastric cell numbers and arrested the cell cycle at G1/S point. As an important G1/S phase inhibitory gene, p27 is re-induced to some extent by SUZ12 knockdown. Furthermore, we demonstrated that SUZ12 was directly downregulated by miR-200b. Conclusion: We provide evidence suggesting that SUZ12 may be a potential therapeutic target for gastric cancer
Robust Electrocatalytic Li2S Redox of Li-S Batteries Facilitated by Rationally Fabricated Dual-Defects
The commercialization of lithium-sulfur batteries with ultra-high theoretical energy density is restricted mainly by the notorious polysulfides "shuttle effect" and slow Li2S redox reaction kinetics. A sulfur host material with high catalytic activity and high conductivity is greatly desired to improve its electrochemical performance. Herein, a sulfur host material, etched cotton@petroleum asphalt carbon (eCPAC), with high specific surface area and excellent catalytic activity, is demonstrated based on a synergistic strategy of introducing intrinsic lattice defects and composite carbon structure. Benefiting from in situ coupling of amorphous and crystalline materials, eCPAC exhibits high conductivity and high sulfur adsorbability. Furthermore, eCPAC containing dual intrinsic defect sites can catalyze the bidirectional sulfur chemistry of Li2S and capture polysulfides, which is also demonstrated by systematic density functional theory calculations and the potential intermittent titration technique. S@eCPAC/Li cells exhibit excellent cycling stability and rate performance, with an average capacity decay rate of only 0.05% over 1000 cycles at 0.5 C and even 0.03% over 600 cycles at 5 C. Meanwhile, the practicality of eCPAC is proven in high-load batteries and pouch batteries. eCPAC provides a reliable strategy for achieving a win-win situation of capturing polysulfides and accelerating Li2S redox kinetics
Robust Electrocatalytic Li2S Redox of Li-S Batteries Facilitated by Rationally Fabricated Dual-Defects
The commercialization of lithium-sulfur batteries with ultra-high theoretical energy density is restricted mainly by the notorious polysulfides "shuttle effect" and slow Li2S redox reaction kinetics. A sulfur host material with high catalytic activity and high conductivity is greatly desired to improve its electrochemical performance. Herein, a sulfur host material, etched cotton@petroleum asphalt carbon (eCPAC), with high specific surface area and excellent catalytic activity, is demonstrated based on a synergistic strategy of introducing intrinsic lattice defects and composite carbon structure. Benefiting from in situ coupling of amorphous and crystalline materials, eCPAC exhibits high conductivity and high sulfur adsorbability. Furthermore, eCPAC containing dual intrinsic defect sites can catalyze the bidirectional sulfur chemistry of Li2S and capture polysulfides, which is also demonstrated by systematic density functional theory calculations and the potential intermittent titration technique. S@eCPAC/Li cells exhibit excellent cycling stability and rate performance, with an average capacity decay rate of only 0.05% over 1000 cycles at 0.5 C and even 0.03% over 600 cycles at 5 C. Meanwhile, the practicality of eCPAC is proven in high-load batteries and pouch batteries. eCPAC provides a reliable strategy for achieving a win-win situation of capturing polysulfides and accelerating Li2S redox kinetics
Multifunctional Applications of Ionic Liquids in Polymer Materials: A Brief Review
As a new generation of green media and functional materials, ionic liquids (ILs) have been extensively investigated in scientific and industrial communities, which have found numerous ap-plications in polymeric materials. On the one hand, much of the research has determined that ILs can be applied to modify polymers which use nanofillers such as carbon black, silica, graphene oxide, multi-walled carbon nanotubes, etc., toward the fabrication of high-performance polymer composites. On the other hand, ILs were extensively reported to be utilized to fabricate polymeric materials with improved thermal stability, thermal and electrical conductivity, etc. Despite substantial progress in these areas, summary and discussion of state-of-the-art functionalities and underlying mechanisms of ILs are still inadequate. In this review, a comprehensive introduction of various fillers modified by ILs precedes a systematic summary of the multifunctional applications of ILs in polymeric materials, emphasizing the effect on vulcanization, thermal stability, electrical and thermal conductivity, selective permeability, electromagnetic shielding, piezoresistive sensitivity and electrochemical activity. Overall, this review in this area is intended to provide a fundamental understanding of ILs within a polymer context based on advantages and disadvantages, to help researchers expand ideas on the promising applications of ILs in polymer fabrication with enormous potential
Preparation of Pd/Ce(F)-MCM-48 catalysts and their catalytic performance of n-heptane isomerization
Ce and F were added to MCM-48 molecular sieve by hydrothermal synthesis, and Pd/Ce(F)-MCM-48 metal acid bifunctional catalysts were prepared by impregnation method. The physical and chemical properties of Ce(F)-MCM-48 and Pd/Ce(F)-MCM-48 were characterized by X-ray diffraction, scanning electron microscope, NH3 temperature programmed desorption instrument, Fourier infrared spectrometer, and X-ray photoelectronic spectrometer characterization methods. The results showed that when the molar ratio of the raw materials was n(Ce):n(TEOS) = 0.02 and n(NaF):n(TEOS) = 0.10, Ce(F)-MCM-48-0.10 molecular sieve had a high degree of order and large specific surface area and pore volume, the total acid content increased, and the acid strength also increased. And it had an acidic center and generated certain oxygen vacancies. The catalyst prepared after Pd impregnation had good dispersibility. 0.4% Pd/Ce(F)-MCM-48-0.10 catalyst still maintained the crystalline phase of MCM-48 molecular sieve. A micro-reaction device was used to examine the catalytic performance of n-heptane isomerization of Pd/Ce(F)-MCM-48-0.10 catalysts. When the hydrogen flow rate was 30 mL·min−1, reduction temperature was 300°C, reduction time was 4 h, weight hourly space velocity was 7.6 h−1, and reaction temperature was 280°C, 0.4% Pd/Ce(F)-MCM-48-0.10 catalyst was used in the heptane isomerization reaction, where the conversion of n-heptane was 67.3% and the selectivity of isoheptane was 96.5%
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