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981.
982.
983.
Peijun Zhang Yong Yang Jiabo Han Zhichuang Lu Limei Wang Jiashen Tian Qinguo Wang 《Theriogenology》2014
Spotted seals (Phoca largha) are ice-breeding phocid found in eight different breeding colonies all over the world. They exhibit a seasonal breeding pattern, with annual and synchronous cycles; however, little is known about their reproductive endocrinology. In this study, we measured serum testosterone, progesterone, and 17β-estradiol concentrations in captive spotted seals (simple number: female n = 68; male n = 89) throughout a full reproductive cycle. Males that were older than 4 years had significant testosterone fluctuations and were, therefore, classified as sexually mature. These animals show significant seasonal changes in testosterone levels, with average peak concentrations of 10.81 ± 9.57 nmol/L (±SD) from November to February, compared with mean concentrations of 1.42 ± 3.09 nmol/L throughout the remainder of the year. Females that reported a significant variation in progesterone concentrations and were older than 4 years were considered to be sexually mature. In these females, progesterone levels increased in February, remained elevated for 7 months with a mean value of 37.39 ± 17.03 nmol/L, and then dropped to 0.74 ± 0.54 nmol/L. Serum 17β-estradiol levels were also found to be significantly increased in January, remained so for 8 months (15.80 ± 14.15 ng/L), and then declined after August (7.77 ± 6.78 ng/L). In seals, mating typically occurs in February and March, 1 month after the observed peaks in testosterone and estradiol concentrations and corresponding to the increase in progesterone. A moderate positive correlation between testosterone and progesterone concentrations in sexually mature males was also observed (Spearman rho, r = 0.63, P < 0.01). In sexually immature females, progesterone and estradiol concentrations were found to be significantly lower than those in mature females. Finally, the observed patterns of estradiol and progesterone in sexually mature females suggest that embryonic diapause or successful implantation occurs in August. 相似文献
984.
Genome-wide screen identifies signaling pathways that regulate autophagy during
Caenorhabditis elegans development 下载免费PDF全文
Bin Guo Xinxin Huang Peipei Zhang Linxiang Qi Qianqian Liang Xuebo Zhang Jie Huang Bin Fang Wenru Hou Jinghua Han Hong Zhang 《EMBO reports》2014,15(6):705-713
The mechanisms that coordinate the regulation of autophagy with developmental signaling during
multicellular organism development remain largely unknown. Here, we show that impaired function of
ribosomal protein RPL-43 causes an accumulation of SQST-1 aggregates in the larval intestine, which
are removed upon autophagy induction. Using this model to screen for autophagy regulators, we
identify 139 genes that promote autophagy activity upon inactivation. Various signaling pathways,
including Sma/Mab TGF-β signaling, lin-35/Rb signaling, the XBP-1-mediated
ER stress response, and the ATFS-1-mediated mitochondrial stress response, regulate the expression
of autophagy genes independently of the TFEB homolog HLH-30. Our study thus provides a framework for
understanding the role of signaling pathways in regulating autophagy under physiological
conditions.Subject Categories: Autophagy & Cell Death; Signal Transduction; Membrane & Intracellular Transport 相似文献
985.
A Hierarchically Organized Photoelectrode Architecture for Highly Efficient CdS/CdSe‐Sensitized Solar Cells 下载免费PDF全文
Jong Hoon Park Dong Hoe Kim Seong Sik Shin Hyun Soo Han Myeong Hwan Lee Hyun Suk Jung Jun Hong Noh Kug Sun Hong 《Liver Transplantation》2014,4(3)
A form of photoelectrode architecture suitable for inorganic semiconductor solar cells is reported. The developed architecture consists of hierarchically organized TiO2 nanostructures with several tens of nanometer‐sized particles that have a large surface area and open channels with several hundred‐nanometer‐gaps perpendicular to the substrate. These are tailored by controlling the kinetic energy of the ablated species during pulsed laser deposition (PLD). To fabricate the solar cells, CdS and CdSe inorganic sensitizers are assembled onto the architecture by successive ionic layer adsorption and reaction and polysulfide solution is used as an electrolyte with lead sulfide counter‐electrodes. The inorganic semiconductor solar cells using the developed architecture (PLD‐TiO2) show high energy conversion efficiencies of 5.57% compared to a conventional mesoporous TiO2 film(NP‐TiO2) (3.84%) with an optical mask at 1 sun of illumination. The improved cell performance of PLD‐TiO2 is attributed to greater light‐harvesting ability, which results in the enhancement of the Jsc value. PLD‐TiO2 absorbs more CdS/CdSe because of its larger surface area and excellent adhesion properties with fluorine‐doped tin oxide (FTO) substrates. Additionally, due to its unique channel‐shaped architecture, PLD‐TiO2 has a longer electron lifetime compared to NP‐TiO2. 相似文献
986.
Chi Zhang Tao Zhou Wei Tang Changbao Han Limin Zhang Zhong Lin Wang 《Liver Transplantation》2014,4(9)
An innovative design is reported of a direct‐current triboelectric nanogenerator (DC‐TENG) based on a rotating disk design for harvesting rotational mechanical energy. The DC‐TENG consists of two disks and two pairs of flexible electric brushes that are made of carbon fiber and contact two electrodes, respectively. During the rotation, two disks have distinct triboelectric polarities for a cyclic in‐plane charge separation between them and an alternating current is generated between the two electrodes. Because of the sliding contact and automatically switch between the electric brushes and the two electrodes, the current is reversed in the second half of the cycle and a direct current is generated. The role that the rotating speed and the segmentation number have is thoroughly investigated and shows that there is direct current enhancement not only at higher speed but also with more segments. The DC‐TENG has been demonstrated as a constant current source for directly and continuously driving electronic devices and/or charging an energy storage unit without a rectifier bridge. This work presents a novel DC‐TENG technology and opens up more potential applications for harvesting rotational mechanical energy and powering electronics. 相似文献
987.
Xiao‐Jing Wang Dao‐Lai Zhang Zhi‐Gang Xu Ming‐Liang Ma Wen‐Bo Wang Lin‐Lin Li Xiao‐Lin Han Yuqing Huo Xiao Yu Jin‐Peng Sun 《Journal of neurochemistry》2014,131(6):699-711
The cadherin epidermal growth factor (EGF) laminin G (LAG) seven‐pass G‐type receptors (CELSRs) are a special subgroup of adhesion G protein‐coupled receptors, which are pivotal regulators of many biologic processes such as neuronal/endocrine cell differentiation, vessel valve formation, and the control of planar cell polarity during embryonic development. All three members of the CELSR family (CELSR1‐3) have large ecto‐domains that form homophilic interactions and encompass more than 2000 amino acids. Mutations in the ecto‐domain or other gene locations of CELSRs are associated with neural tube defects and other diseases in humans. Celsr knockout (KO) animals have many developmental defects. Therefore, specific agonists or antagonists of CELSR members may have therapeutic potential. Although significant progress has been made regarding the functions and biochemical properties of CELSRs, our knowledge of these receptors is still lacking, especially considering that they are broadly distributed but have few characterized functions in a limited number of tissues. The dynamic activation and inactivation of CELSRs and the presence of endogenous ligands beyond homophilic interactions remain elusive, as do the regulatory mechanisms and downstream signaling of these receptors. Given this motivation, future studies with more advanced cell biology or biochemical tools, such as conditional KO mice, may provide further insights into the mechanisms underlying CELSR function, laying the foundation for the design of new CELSR‐targeted therapeutic reagents.
988.
Cochlioquinone Derivatives with Apoptosis‐Inducing Effects on HCT116 Colon Cancer Cells from the Phytopathogenic Fungus Bipolaris luttrellii L439 下载免费PDF全文
A new cochlioquinone derivative, cochlioquinone F ( 1 ), as well as three known compounds, anhydrocochlioquinone A ( 2 ), isocochlioquinone A ( 3 ), and isocochlioquinone C ( 4 ), were isolated from the PDB (potato dextrose broth) culture of the phytopathogenic fungus Bipolaris luttrellii. The structure of 1 was elucidated on the basis of NMR techniques. The apoptosis‐inducing effects of compounds 1 – 4 were evaluated against HCT116 cancer cells. Compound 2 exhibited the strongest activity in inducing apoptosis on HCT116 cells within the range of 10–30 μM . In addition, the caspase activation, the release of cytochrome c from mitochondria, and the downregulation of Bcl‐2 protein in HCT116 cells treated with compound 2 were detected. 相似文献
989.
Fuyuan Li Ning Ma Ruiqi Zhao Guodong Wu Yanfen Zhang Yu Qiao Dong Han Ya Xu Ying Xiang Bingzhu Yan Jianfeng Jin Guixiang Lv Lei Wang Changqing Xu Xu Gao Shanshun Luo 《Journal of cellular and molecular medicine》2014,18(6):966-974
The transition from liver fibrosis to hepatocellular carcinoma (HCC) has been suggested to be a continuous and developmental pathological process. MicroRNAs (miRNAs) are recently discovered molecules that regulate the expression of genes involved in liver disease. Many reports demonstrate that miR‐483‐5p and miR‐483‐3p, which originate from miR‐483, are up‐regulated in HCC, and their oncogenic targets have been identified. However, recent studies have suggested that miR‐483‐5p/3p is partially down‐regulated in HCC samples and is down‐regulated in rat liver fibrosis. Therefore, the aberrant expression and function of miR‐483 in liver fibrosis remains elusive. In this study, we demonstrate that overexpression of miR‐483 in vivo inhibits mouse liver fibrosis induced by CCl4. We demonstrate that miR‐483‐5p/3p acts together to target two pro‐fibrosis factors, platelet‐derived growth factor‐β and tissue inhibitor of metalloproteinase 2, which suppress the activation of hepatic stellate cells (HSC) LX‐2. Our work identifies the pathway that regulates liver fibrosis by inhibiting the activation of HSCs. 相似文献
990.
Hao?Chen Ran?Gilad-Bachrach Kyoohyung?Han Zhicong?Huang Amir?Jalali Kim?LaineEmail author Kristin?Lauter 《BMC medical genomics》2018,11(4):81