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排序方式: 共有421条查询结果,搜索用时 31 毫秒
411.
Tzu-Lung Lin Chia-Chen Lu Wei-Fan Lai Ting-Shu Wu Jang-Jih Lu Young-Mao Chen Chi-Meng Tzeng Hong-Tao Liu Hong Wei Hsin-Chih Lai 《蛋白质与细胞》2021,12(5):394-410
Traditional Chinese Medicine(TCM)has been exten-sively used to ameliorate diseases in Asia for over thousands of years.However,owing to a lack of formal scientific validation,the absence of information regard-ing the mechanisms underlying TCMs restricts their application.After oral administration,TCM herbal ingredients frequently are not directly absorbed by the host,but rather enter the intestine to be transformed by gut microbiota.The gut microbiota is a microbial com-munity living in animal intestines,and functions to maintain host homeostasis and health.Increasing evi-dences indicate that TCM herbs closely affect gut microbiota composition,which is associated with the conversion of herbal components into active metabo-lites.These may significantly affect the therapeutic activity of TCMs.Microbiota analyses,in conjunction with modern multiomics platforms,can together identify novel functional metabolites and form the basis of future TCM research. 相似文献
412.
Wen-Cheng Chen Yi-Shiuan Tzeng Hung Li Wei-Sheng Tien Ying-Chieh Tsai 《Cell and tissue research》2010,342(1):75-85
Stromal-derived factor (SDF)-1/CXCL12 is a cytokine that is involved in organogenesis, hematopoiesis, chemoattraction, and
wound healing. An SDF-1 knockout mouse (SDF-1-/-) has provided important insights into the role of SDF-1 in fetal development. Because the SDF-1 knockout is lethal in the
perinatal period, we have created a conditional SDF-1 knockout mouse. In the present study, we induced conditionally knocked
out SDF-1 in neonatal mice and found that lung development was compromised; neonatal lungs showed increased alveolar airspace
and abnormal ultrastructure. Conditional knockout of SDF-1 in adult mice resulted in an emphysemic morphology, with increased
alveolar airspace and thickened alveolar septa. Fluorescence angiography showed pulmonary vessel hyperdilation. To determine
whether the hyperdilation involved nitric oxide, we inhibited endothelial nitric oxide synthase (eNOS) with N (G)-nitro-L-
arginine methyl ester. This resulted in the inhibition of pulmonary vessel hyperdilation. Western blot results showed increased
phosphorylation of eNOS in our induced SDF-1 knockout mice, indicating that eNOS is normally repressed in the presence of
SDF-1, and that activation of eNOS contributes to pulmonary pathology. Thus, a conditional knockout mouse has been successsfully
created for SDF-1; initial characterization indicates that SDF-1 is intimately involved in lung development and physiology. 相似文献
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414.
David R. Wilson Mark P. Suprenant John H. Michel Ellen B. Wang Stephany Y. Tzeng Jordan J. Green 《Biotechnology and bioengineering》2019,116(5):1220-1230
Intracellular delivery of nucleic acids to mammalian cells using polyplex nanoparticles (NPs) remains a challenge both in vitro and in vivo, with transfections often suffering from variable efficacy. To improve reproducibility and efficacy of transfections in vitro using a next-generation polyplex transfection material poly(beta-amino ester)s (PBAEs), the influence of multiple variables in the preparation of these NPs on their transfection efficacy was explored. The results indicate that even though PBAE/pDNA polyplex NPs are formed by the self-assembly of polyelectrolytes, their transfection is not affected by the manner in which the components are mixed, facilitating self-assembly in a single step, but timing for self-assembly of 5–20 min is optimal. In addition, even though the biomaterials are biodegradable in water, their efficacy is not affected by up to eight freeze-thaw cycles of the polymer. It was found that there is a greater stability of nucleic acid-complexed polymer as a polyplex nanoparticle compared with free polymer. Finally, by exploring multiple buffer systems, it was identified that utilization of divalent cation magnesium or calcium acetate buffers at pH 5.0 is optimal for transfection using these polymeric materials, boosting transfection several folds compared with monovalent cations. Together, these results can improve the reproducibility and efficacy of PBAE and similar polyplex nanoparticle transfections and improve the robustness of using these biomaterials for bioengineering and biotechnology applications. 相似文献
415.
Pallavi Vedantam Tzuen-Rong Jeremy Tzeng Aaron Kenneth Brown Ramakrishna Podila Alekhya Rao Kiesha Staley 《Plasmonics (Norwell, Mass.)》2012,7(2):301-308
The molecular basis of the diversity of fimbrial lectins dictates the extent of adhesion in different types of Escherichia coli strains to mammalian cells. The mechanism of receptor binding by E. coli in eukaryotic cells differs based on the adhesin domains, patterns in the macromolecular structure and the ligand-binding groove. Current sensor technologies utilize biosensors that are based on the carbohydrate moieties that are involved in pathogen adhesion to host cells. Nanoparticles have been extensively used as carriers for pathogen detection. Gold nanoparticles (Au NPs) of 200?nm size were functionalized with two distinct glycoconjugates mannose (Mn?CAu NPs) and Neu??c(??2-3)-Gal-(??1-4)Glc?CPaa (Sg?CAu NPs) in order to investigate primary and fine sugar specificity of uropathogenic E. coli ORN178 and enterotoxigenic E. coli 13762, respectively. The UV-Vis measurement of pristine, 16-mercaptohexadecanoic acid (MHDA)/2-(2-aminoethoxy)ethanol (AEE)/sugar functionalized Au NPs showed a surface plasmon resonance band for Au. Dynamic light scattering analysis showed that the mean averages of the MHDA/AEE/Mn?CAu NP samples increased due to aggregation. The negative zeta potentials of the samples were indicative of aggregation. Fine sugar specificity was observed when Neu??c(??2-3)-Gal-(??1-4)Glc?CPaa functionalized Au NPs (Sg?CAu NPs) specifically showed binding with E. coli 13762 but not with E. coli ORN178. This specificity of E. coli strains to identify and bind to characteristic sugar moieties can be used in the development of biodiagnostic tools with Au NPs as carriers for diagnosis/treatment of human and veterinary diseases. In regards to the growing antibiotic resistance of microorganisms, gold nanoparticles can also be functionalized specifically to reverse adhesion of E. coli to host tissue and can be detected by their optical properties. 相似文献
416.
Transgenic animals of the line 8 contain the WAP-SV-T transgene. Females of this line synthesise the SV40 T-antigen in mammary gland epithelial cells during pregnancy and the lactation period. All females are ‘milk-less’ and the offspring have to be nursed by foster mothers. The reason for this phenomenon is a premature apoptosis during late pregnancy. Nonetheless a significant number of mammary epithelial cells escape apoptosis and all transgenic females develop breast cancer after the first lactation period. 相似文献
417.
A net-draft-tube, modified airlift reactor and a stirred-tank reactor were used for thuringiensin production by Bacillus thuringiensis subsp. darmstadiensis growing with various concentrations of molasses. The optimum concentration of molasses for thuringiensin production in both reactors was 15 g/l. There was a 6 h delay in sporulation in the modified airlift reactor compared with that in the stirred-tank reactor. Thuringiensin yield in the modified airlift reactor (2.2 g/l) was consequently higher than that in the stirred-tank reactor (1.1 g/l). 相似文献
418.
Abundance and distribution of nanoplankton in the epipelagic subtropical/tropical open Atlantic Ocean 总被引:1,自引:0,他引:1
Paffenhofer G.-A.; Tzeng M.; Hristov R.; Smith C. L.; Mazzocchi M. G. 《Journal of plankton research》2003,25(12):1535-1549
The objective of this research was to quantify the abundanceand distribution of nanoplanktonic particles available to frequentlyoccurring juvenile and adult planktonic copepods in the epipelagialof the open subtropical and tropical ocean. We chose locationsoff Puerto Rico and off the Bahamas to achieve our purpose.The hydrography for all stations revealed a thin upper mixedlayer, a thermocline with varying temperature decreases, salinitiesapproaching and surpassing 37 相似文献
419.
420.
Kang-Ning Shen Wade Brian Jamandre Chih-Chieh Hsu Wann-Nian Tzeng Jean-Dominique Durand 《BMC evolutionary biology》2011,11(1):83