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31.
32.
S C Koh P C Wong R Yuen S E Chua B L Ng S S Ratnam 《Journal of reproduction and fertility》1992,96(2):407-413
The concentrations of tissue plasminogen activator (t-PA), urokinase plasminogen activator (u-PA) and plasminogen activator inhibitor (PAI-1) have been determined in endometrial curettings obtained from 46 subfertile women during proliferative, early or late secretory phases of the menstrual cycle. t-PA activity and antigen concentrations was significantly higher (P < 0.001) in late secretory endometrium than in proliferative or early secretory endometrium. Higher concentrations of PAI-1 antigen (P < 0.05) were also noted in late secretory phase than in proliferative and early secretory endometrium. However, u-PA concentration was not significantly different and no PAI activity could be demonstrated in the menstrual phases studied. Zymography studies confirmed the presence of both t-PA and u-PA in the endometrium. Ovarian hormonal patterns may therefore influence the activity of plasminogen activators especially of t-PA in the endometrium during various phases of the menstrual cycle. 相似文献
33.
Cymbidium mosaic virus (CyMV) is the most prevalent virus infecting orchids. Here, we report the isolation of partial cDNA clones encoding the genomic RNA of CyMV. Like most of the polyadenylated monopartite positive-strand RNA viruses, the open reading frame (ORF) coding for the viral coat protein (CP) is located at the 3 end. The ORF predicts a polypeptide chain of 220 amino acids with a molecular weight of 23 600. Sequence comparison of this ORF to the CP sequences of potato virus X(PVX) and white clover mosaic virus (WCIMV) revealed a strong amino acid homology in the mid-portion of the CP, but the overall homology was low. The CyMV CP gene was placed downstream of a cauliflower mosaic virus 35S promoter and the chimaeric gene was transferred into Nicotiana benthamiana. Transgenic plants expressing the CyMV CP were protected against CyMV infection. 相似文献
34.
Plant transcription factors: present knowledge and future challenges. 总被引:18,自引:0,他引:18
35.
A nuclear mutant of Chlamydomonas reinhardtii defective in photosynthetic photophosphorylation. Characterization of the algal coupling factor ATPase 总被引:10,自引:0,他引:10
Use of the Flagyl selection procedure [Schmidt et al. (1977) Proc. Natl Acad. Sci. USA, 74, 610-614] led to the isolation of a nuclear mutant of Chlamydomonas reinhardtii designated thm-24. This mutant displays normal electron transport rates in vitro, possesses high latent ATPase activity bound to the thylakoid membrane, but is incapable of photophosphorylation. Decay of the transmembrane potential, as indicated by the kinetics of the 520-nm absorption change after illumination, is unusually slow and markedly biphasic. Sodium dodecylsulfate/polyacrylamide gel electrophoresis of purified thylakoid membranes shows mutant thm-24 to be lacking a number of polypeptides including those previously designated 4.1, 4.2 and 8.1. Treatment of purified thylakoid membranes of wild-type and mutant algae, using the chloroform-release procedure of Beechey et al. [(1975) Biochem. J. 148, 533-537] resulted in the removal of ATPase activity from each strain. In wild-type cells, the ATPase activity was of heterogeneous enzymatic origin; fractionation of the chloroform-release extracts by non-denaturing polyacrylamide gel electrophoresis yielded three distinct bands displaying ATPase activity, designated ATPases I, II and III. In contrast, extracts from membranes of mutant thm-24 yielded only one ATPase-containing fraction, co-migrating with ATPase I from wild-type. Use of electrophoretic, immunological and enzymatic methods established a correspondence of the polypeptide subunits of ATPases II and III and those of spinach coupling factor, CF1. ATPase I from either algal strain was shown to be structurally distinct from high plant CF1 and to C. reinhardtii ATPases II and III. 相似文献
36.
37.
Jin Zhao Yi‐Zhou Zhang Jianyu Chen Wenli Zhang Du Yuan Rodney Chua Husam N. Alshareef Yanwen Ma 《Liver Transplantation》2020,10(18)
The pursuit of more efficient carbon‐based anodes for sodium‐ion batteries (SIBs) prepared from facile and economical methods is a very important endeavor. Based on the crystallinity difference within carbon materials, herein, a low‐temperature selective burning method is developed for preparing oxygen and nitrogen codoped holey graphene aerogel as additive‐free anode for SIBs. By selective burning of a mixture of graphene and low‐crystallinity carbon at 450 °C in air, an elastic porous graphene monolith with abundant holes on graphene sheets and optimized crystallinity is obtained. These structural characteristics lead to an additive‐free electrode with fast charge (ions and electrons) transfer and more abundant Na+ storage active sites. Moreover, the heteroatom oxygen/nitrogen doping favors large interlayer distance for rapid Na+ insertion/extraction and provides more active sites for high capacitive contribution. The optimized sample exhibits superior sodium‐ion storage capability, i.e., high specific capacity (446 mAh g?1 at 0.1 A g?1), ultrahigh rate capability (189 mAh g?1 at 10 A g?1), and long cycle life (81.0% capacity retention after 2000 cycles at 5 A g?1). This facile and economic strategy might be extended to fabricating other superior carbon‐based energy storage materials. 相似文献
38.
Sharon A. Appleyard Safia Maher John J. Pogonoski Stephen J. Bent Xin-Yi Chua Annette McGrath 《Journal of fish biology》2021,98(5):1421-1432
Natural history collections are repositories of biodiversity and are potentially used by molecular ecologists for comparative taxonomic, phylogenetic, biogeographic and forensic purposes. Specimens in fish collections are preserved using a combination of methods with many fixed in formalin and then preserved in ethanol for long-term storage. Formalin fixation damages DNA, thereby limiting genetic analyses. In this study, the authors compared the DNA barcoding and identification success for frozen and formalin-fixed tissues obtained from specimens in the CSIRO Australian National Fish Collection. They studied 230 samples from fishes (consisting of >160 fish species). An optimized formalin-fixed, paraffin-embedded DNA extraction method resulted in usable DNA from degraded tissues. Four mini barcoding assays of the mitochondrial DNA (mtDNA) were characterized with Sanger and Illumina amplicon sequencing. In the good quality DNA (without exposure to formalin), up to 88% of the specimens were correctly matched at the species level using the cytochrome oxidase subunit 1 (COI) mini barcodes, whereas up to 58% of the specimens exposed to formalin for less than 8 weeks were correctly identified to species. In contrast, 16S primers provided higher amplification success with formalin-exposed tissues, although the COI gene was more successful for identification. Importantly, the authors found that DNA of a certain size and quality can be amplified and sequenced despite exposure to formalin, and Illumina sequencing provided them with greater power of resolution for taxa identification even when there was little DNA present. Overall, within parameter constraints, this study highlights the possibilities of recovering DNA barcodes for identification from formalin-fixed fish specimens, and the authors provide guidelines for when successful identification could be expected. 相似文献
39.
Chua Fu Yee Novakovic Zachary M. Grasso Patricia 《International journal of peptide research and therapeutics》2021,27(4):2223-2230
International Journal of Peptide Research and Therapeutics - Oral delivery of MA-[d-Leu-4]-OB3 has been shown to significantly improve energy balance, glycemic control, dyslipidemia, and episodic... 相似文献
40.
Sanghee Kim Jungeun Lee Jun-Yi Yang Choonkyun Jung Nam-Hai Chua 《Journal of Plant Biology》2013,56(1):39-48
Histone modifications are known to play important roles in plant development through epigenetic regulation of gene expression. How these modifications regulate downstream targets in response to various environmental cues and developmental stimuli is still largely unknown. Here, we provide evidence that Arabidopsis histone H3K4 methyltransferase SET DOMAIN GROUP2 (SDG2) is required for full activation of hormone responsive genes upon hormone treatment. The pleiotropic phenotypes of sdg2 were closely related to those of auxin deficient mutants and RNA analysis revealed that expression of early hormone responsive genes was significantly reduced in sdg2-5. By ChIP analyses we found that H3K4 tri-methylations on chromatin region of hormone responsive genes such as SAUR27, KIN1 and GASA6 were enriched in WT upon hormone treatments whereas these enrichments were largely abolished in sdg2-5. After hormone treatment, chromatin regions of responsive genes that accumulated H3K4me3 in WT overlapped with those displaying decreased H3K4me3 levels in sdg2-5. Histone H3K4 di-methylation levels on tested genes were increased rather than decreased in sdg2-5, suggesting that SDG2 mediates transition of H3K4me2 to H3K4me3. Taken together, we conclude that the SDG2 activity is required to regulate the expression of hormone responsive genes via histone H3K4 tri-methylation. 相似文献