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排序方式: 共有5256条查询结果,搜索用时 15 毫秒
61.
Oyundari Amartuvshin Chi‐Hung Lin Shao‐Chun Hsu Shih‐Han Kao Alvin Chen Wei‐Chun Tang Han‐Lin Chou Dong‐Lin Chang Yen‐Yang Hsu Bai‐Shiou Hsiao Elham Rastegari Kun‐Yang Lin Yu‐Ting Wang Chi‐Kuang Yao Guang‐Chao Chen Bi‐Chang Chen Hwei‐Jan Hsu 《Aging cell》2020,19(8)
Changes in mitochondrial dynamics (fusion and fission) are known to occur during stem cell differentiation; however, the role of this phenomenon in tissue aging remains unclear. Here, we report that mitochondrial dynamics are shifted toward fission during aging of Drosophila ovarian germline stem cells (GSCs), and this shift contributes to aging‐related GSC loss. We found that as GSCs age, mitochondrial fragmentation and expression of the mitochondrial fission regulator, Dynamin‐related protein (Drp1), are both increased, while mitochondrial membrane potential is reduced. Moreover, preventing mitochondrial fusion in GSCs results in highly fragmented depolarized mitochondria, decreased BMP stemness signaling, impaired fatty acid metabolism, and GSC loss. Conversely, forcing mitochondrial elongation promotes GSC attachment to the niche. Importantly, maintenance of aging GSCs can be enhanced by suppressing Drp1 expression to prevent mitochondrial fission or treating with rapamycin, which is known to promote autophagy via TOR inhibition. Overall, our results show that mitochondrial dynamics are altered during physiological aging, affecting stem cell homeostasis via coordinated changes in stemness signaling, niche contact, and cellular metabolism. Such effects may also be highly relevant to other stem cell types and aging‐induced tissue degeneration. 相似文献
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AbstractThe aim of this paper is to develop a simulation-aided PROMETHEE-TOPSIS approach for the selection of the most desirable groundwater remediation strategies. The combination methods enables a careful evaluation of the identified remediation alternatives in which their strong and weak points can be detected and a ranking is provided which facilitates the final selection for the decision-maker. The capabilities and effectiveness of the developed method are illustrated through a case study on the remedial alternative selection for a naphthalene contaminated site in Anhui, China. Four attributes (i.e., total pumping rate, total cost, mean residual contaminant concentration and maximum excess life time cancer risk) for fifty remedial alternatives in each duration are considered and analytic hierarchy process is used to determine the weight of attributes importance. The results demonstrates that the developed method could help decision makers obtain the useful ranking information strategies that covering a variety of decision-relevant remediation options, which is beneficial for public health and environmental protection. 相似文献
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Zhenhong Hu Han Y. H. Chen Chao Yue Xiao Ying Gong Junjiong Shao Guiyao Zhou Jiawei Wang Minhuang Wang Jianyang Xia Yongtao Li Xuhui Zhou Sean T. Michaletz 《Global Change Biology》2020,26(6):3429-3442
CO2 fluxes from wood decomposition represent an important source of carbon from forest ecosystems to the atmosphere, which are determined by both wood traits and climate influencing the metabolic rates of decomposers. Previous studies have quantified the effects of moisture and temperature on wood decomposition, but these effects were not separated from the potential influence of wood traits. Indeed, it is not well understood how traits and climate interact to influence wood CO2 fluxes. Here, we examined the responses of CO2 fluxes from dead wood with different traits (angiosperm and gymnosperm) to 0%, 35%, and 70% rainfall reduction across seasonal temperature gradients. Our results showed that drought significantly decreased wood CO2 fluxes, but its effects varied with both taxonomical group and drought intensity. Drought‐induced reduction in wood CO2 fluxes was larger in angiosperms than gymnosperms for the 35% rainfall reduction treatment, but there was no significant difference between these groups for the 70% reduction treatment. This is because wood nitrogen density and carbon quality were significantly higher in angiosperms than gymnosperms, yielding a higher moisture sensitivity of wood decomposition. These findings were demonstrated by a significant positive interaction effect between wood nitrogen and moisture on CO2 fluxes in a structural equation model. Additionally, we ascertained that a constant temperature sensitivity of CO2 fluxes was independent of wood traits and consistent with previous estimates for extracellular enzyme kinetics. Our results highlight the key role of wood traits in regulating drought responses of wood carbon fluxes. Given that both climate and forest management might extensively modify taxonomic compositions in the future, it is critical for carbon cycle models to account for such interactions between wood traits and climate in driving dynamics of wood decomposition. 相似文献
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Zhengyun Zou Qiuxiang Ou Yu Ren Qing Lv Lanqun Qin Lianjun Zhao Shu Su Xue Wu Hua Bao Ao Wang Dongqin Zhu Xiaonan Wang Yang W. Shao Baorui Liu 《Pigment cell & melanoma research》2020,33(4):601-611
The incidence of melanoma is rising globally including China. Comparing to Caucasians, the incidence of non‐cutaneous melanomas is significantly higher in Chinese. Herein, we performed genomic profiling of 89 Chinese surgically resected primary melanomas, including acral (n = 54), cutaneous (n = 22), and mucosal (n = 13), by hybrid capture‐based next‐generation sequencing. We show that mucosal melanomas tended to harbor more pathogenic mutations than other types of melanoma, though the biological significance of this finding remains uncertain. Chromosomal arm‐level alterations including 6q, 9p, and 10p/q loss were highly recurrent in all subtypes, but mucosal melanoma was significantly associated with increased genomic instability. Importantly, 7p gain significantly correlated with unfavorable clinical outcomes in non‐cutaneous melanomas, representing an intriguing prognostic biomarker of those subtypes. Furthermore, focal amplification of 4q12 (KIT, KDR, and PDGFRα) and RAD51 deletion were more abundant in mucosal melanoma, while NOTCH2 amplification was enriched in acral melanoma. Additionally, cutaneous melanomas had higher mutation load than acral melanomas, while mucosal melanomas did not differ from other subtypes in mutation burden. Together, our data revealed important features of acral and mucosal melanomas in Chinese including distinctive driver mutation pattern and increased genomic instability. These findings highlight the possibilities of combination therapies in the clinical management of melanoma. 相似文献
65.
Jia Zhou Tiffanie Maree Nelson Carlos Rodriguez Lopez Roshmi Rekha Sarma Shao Jia Zhou Lee Ann Rollins 《Molecular ecology resources》2020,20(4):844-855
Noninvasive sampling methods for studying intestinal microbiomes are widely applied in studies of endangered species and in those conducting temporal monitoring during manipulative experiments. Although existing studies show that noninvasive sampling methods among different taxa vary in their accuracy, no studies have yet been published comparing nonlethal sampling methods in adult amphibians. In this study, we compare microbiomes from two noninvasive sample types (faeces and cloacal swabs) to that of the large intestine in adult cane toads, Rhinella marina. We use 16S rRNA gene sequencing to investigate how microbial communities change along the digestive tract and which nonlethal sampling method better represents large intestinal microbiota. We found that cane toads' intestinal microbiota was dominated by Bacteroidetes, Proteobacteria and Firmicutes and, interestingly, we also saw a high proportion of Fusobacteria, which has previously been associated with marine species and changes in frog immunity. The large and small intestine of cane toads had a similar microbial composition, but the large intestine showed higher diversity. Our results indicate that cloacal swabs were more similar to large intestine samples than were faecal samples, and small intestine samples were significantly different from both nonlethal sample types. Our study provides valuable information for future investigations of the cane toad gut microbiome and validates the use of cloacal swabs as a nonlethal method to study changes in the large intestine microbiome. These data provide insights for future studies requiring nonlethal sampling of amphibian gut microbiota. 相似文献
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David S. Goodsell Christine Zardecki Luigi Di Costanzo Jose M. Duarte Brian P. Hudson Irina Persikova Joan Segura Chenghua Shao Maria Voigt John D. Westbrook Jasmine Y. Young Stephen K. Burley 《Protein science : a publication of the Protein Society》2020,29(1):52-65
Analyses of publicly available structural data reveal interesting insights into the impact of the three‐dimensional (3D) structures of protein targets important for discovery of new drugs (e.g., G‐protein‐coupled receptors, voltage‐gated ion channels, ligand‐gated ion channels, transporters, and E3 ubiquitin ligases). The Protein Data Bank (PDB) archive currently holds > 155,000 atomic‐level 3D structures of biomolecules experimentally determined using crystallography, nuclear magnetic resonance spectroscopy, and electron microscopy. The PDB was established in 1971 as the first open‐access, digital‐data resource in biology, and is now managed by the Worldwide PDB partnership (wwPDB; wwPDB.org ). US PDB operations are the responsibility of the Research Collaboratory for Structural Bioinformatics PDB (RCSB PDB). The RCSB PDB serves millions of RCSB.org users worldwide by delivering PDB data integrated with ~40 external biodata resources, providing rich structural views of fundamental biology, biomedicine, and energy sciences. Recently published work showed that the PDB archival holdings facilitated discovery of ~90% of the 210 new drugs approved by the US Food and Drug Administration 2010–2016. We review user‐driven development of RCSB PDB services, examine growth of the PDB archive in terms of size and complexity, and present examples and opportunities for structure‐guided drug discovery for challenging targets (e.g., integral membrane proteins). 相似文献
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