88 research outputs found
Transmission of new CRF07_BC Strains with 7 amino acid deletion in Gag p6
A 7 amino acid deletion in Gag p6 (P6delta7) emerged in Chinese prevalent HIV-1 strain CRF07_BC from different epidemic regions. It is important to determine whether this mutation could be transmitted and spread. In this study, HIV-1 Gag sequences from 5 different epidemic regions in China were collected to trace the transmission linkage and to analyze genetic evolution of P6delta7 strains. The sequence analysis demonstrated that P6delta7 is a CRF07_BC specific deletion, different P6delta7 strains could be originated from different parental CRF07_BC recombinants in different epidemic regions, and the transmission of P6delta7 strain has occurred in IDU populations. This is for the first time to identify the transmission linkage for P6delta7 strains and serves as a wake-up call for further monitoring in the future; In addition, P6delta7 deletion may represent an evolutionary feature which might exert influence on the fitness of CRF07_BC strain
Inhibition of microRNA-383 promotes apoptosis of human colon cancer cells by upregulation of caspase-2 gene expression
Purpose: To investigate microRNA-383 (miR-383) as a therapeutic target for the management of colon cancer.Methods: Total RNA was isolated using RNeasy RNA isolation kit according to the manufacturer’s instructions. cDNA was synthesized using RevertAid cDNA synthesis kit. Expression analysis was carried out by quantitative real-time polymerase chain reaction (RT-PCR). Cell proliferation was examined using CellTiter 96 AQueous One Solution Cell Proliferation Assay system, while apoptosis was detected by 4',6-diamidino-2-phenylindole (DAPI) and annexin V/PI double staining followed by flow cytometry. The miR-383 target was delimited using TargetScan software. Protein expression analysis was carried out by western blotting.Results: The results indicate that miR-383 was highly expressed in colon cancer cells. Down-regulation of miR-383 inhibited cancer cell proliferation, and promoted apoptosis and cell cycle arrest. Furthermore, in silico analysis revealed caspase-2 gene to be the downstream target of miR-383, a finding that was further confirmed by western blotting.Conclusion: The results reveal that miR-383 may be an important target to tackle the increasing incidence of colon cancer. Thus, drugs that target miR-383 and inhibit its expression can potentially be developed for the treatment of colon cancer.Keywords: MicroRNA, Colon cancer, Cell proliferation, Apoptosis, Protein expressio
Multiple independent introductions of HIV-1 CRF01_AE identified in China: what are the implications for prevention?
BackgroundHIV-1 CRF01_AE accounts for an important fraction of HIV infections in Asia including China, but little is known about the phylogenetic and evolutionary history of this CRF (circulating recombinant form). In the current study, we collected a large number of 1,957 CRF01_AE gag p17 sequences with known sampling year (1990-2010) from 5 global regions representing 15 countries to better understand the phylogenetic relationships and epidemic history of CRF01_AE strains in China.Methodology/principal findingsCRF01_AE gag p17 sequences were retrieved from public databases to explore phylogenetic relationships and phylogeographic dynamics of CRF01_AE in Asia by using maximum-likelihood phylogenetics and Bayesian coalescent-based analyses. We found close phylogenetic relationships between sequences from Thailand, Vietnam and China. Moreover, at least 5 independent introductions and 5 independent autochthonous clades of CRF01_AE, which descended from Thailand or Vietnam were identified in China from 1991 through 2003.Conclusion/significanceThe current study not only defines the migration of CRF01_AE clades to/in Asia, but also demonstrates the criticalness of identifying the circulating strains in the population for the development of vaccine and microbicides
Descriptions of Pedesta wangi sp. nov. and the female of P. xiaoqingae (Huang & Zhan, 2004) from China (Lepidoptera: Hesperiidae)
Xue, Guoxi, Li, Meng, Zhu, Jianqing, Lu, Weicheng, Li, Jialing, Zheng, Bowen (2019): Descriptions of Pedesta wangi sp. nov. and the female of P. xiaoqingae (Huang & Zhan, 2004) from China (Lepidoptera: Hesperiidae). Zootaxa 4700 (3): 356-364, DOI: https://doi.org/10.11646/zootaxa.4700.3.
Neighborhood Modularization-based Artificial Bee Colony Algorithm for Disassembly Planning with Operation Attributes
Abstract The recycling and remanufacturing of end-of-life products are significant for environmental protection and resource conservation. Disassembly is an essential process of remanufacturing end-of-life products. Effective disassembly plans help improve disassembly efficiency and reduce disassembly costs. This paper studies a disassembly planning problem with operation attributes, in which an integrated decision of the disassembly sequence, disassembly directions, and disassembly tools are made. Besides, a mathematical model is formulated with the objective of minimizing the penalty cost caused by the changing of operation attributes. Then, a neighborhood modularization-based artificial bee colony algorithm is developed, which contains a modular optimized design. Finally, two case studies with different scales and complexities are used to verify the performance of the proposed approach, and experimental results show that the proposed algorithm outperforms the two existing methods within an acceptable computational time
Leptin Promotes HTR-8/SVneo Cell Invasion via the Crosstalk between MTA1/WNT and PI3K/AKT Pathways
The process of placental invasion is essential for a successful pregnancy. Leptin is involved in trophoblast invasiveness, and its dysregulation is connected with a series of diseases, including preeclampsia. However, the knowledge of the precise mechanisms in leptin-induced trophoblast invasiveness is still limited. According to the present research, transwell assay suggested that leptin is a dose- and time-dependent regulator in inducing HTR-8/SVneo cell invasion. Western blot analysis and immunofluorescence staining revealed that leptin-induced MMP9 expression is essential in the invasion process of HTR-8/SVneo cells. Mechanistically, we demonstrated that leptin activated β-catenin via the crosstalk between the MTA1/WNT and PI3K/AKT pathways. Besides, we showed that downregulating the key molecules in the signaling pathways by siRNA can inhibit leptin-induced MMP9 expression and further suppress invasion of HTR-8/SVneo cells. In conclusion, our study revealed a new regulatory mechanism of leptin-induced HTR-8/SVneo cell invasiveness and will provide novel insights into the causes and potential therapeutic targets for diseases related to dysregulation of trophoblast invasion in the future
Synthesis of ethyl 4-(2-fluoro-4-nitrophenoxy) picolinate
Cancer has seriously affected people's production and life. The appearance of anti-cancer drugs has brought good news to people. Ethyl 4-(2-fluoro-4-nitrophenoxy) picolinate is an important basic skeleton of a small molecule inhibitor of c-Met and a major intermediate in cancer therapy. A rapid and efficient method for the synthesis of compound 8 was established. Compound 8 was synthesized from picolinic acid by acylation and substitution. These steps were weight gain reaction. The synthesis method was optimized and the structure was confirmed by hydrogen NMR spectroscopy
Optimization of high-energy ball-milling time for Fe1.1Se0.5Te0.5 polycrystalline superconductors
The Fe1.1Se0.5Te0.5 polycrystalline superconductors were prepared by a high-energy hall-milling (HEBM) technique. Ball-milling times of 0, 2, 4, 6, and 8 h were adopted to optimize this technique. The influences of ball-milling time on the phase distributions of milled powders and sintered hulks, the morphology of hall-milled powders, and superconducting properties of final sintered bulks were systematically studied. It was found that with increasing ball-milling time, the ball-milled powders changed from a crystal to a noncrystalline and then to an alloy. At the same time, the main phases in ball-milled powders changed from original mixed powders of Fe, Se, and Te to (Se, Te) solid solution, and then to the two phases of beta-Fe(Se, Te) and delta-Fe(Se, Te), accordingly. Due to the reduction in diffusion length, it was more likely for HEBM powders to form FeSeTe ternary alloys. Thus, the obtained Fe(Se, Te) bulk with HEBM time of 4 h exhibited the highest T-c of 14.3 K and the largest content of superconducting phase. However, in the samples achieved by longer HEBM time, phase segregation and oxidation were observed. Therefore, the HEBM time of 4 h is the most suitable for the fabrication of high-quality precursor powders according to these experiments
Synthesis of ethyl 4-(2-fluoro-4-nitrophenoxy) picolinate
Cancer has seriously affected people's production and life. The appearance of anti-cancer drugs has brought good news to people. Ethyl 4-(2-fluoro-4-nitrophenoxy) picolinate is an important basic skeleton of a small molecule inhibitor of c-Met and a major intermediate in cancer therapy. A rapid and efficient method for the synthesis of compound 8 was established. Compound 8 was synthesized from picolinic acid by acylation and substitution. These steps were weight gain reaction. The synthesis method was optimized and the structure was confirmed by hydrogen NMR spectroscopy
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