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排序方式: 共有673条查询结果,搜索用时 15 毫秒
31.
Kaur Parampreet Jindal Suruchi Yadav Bharat Yadav Inderjit Mahato Ajay Sharma Priti Kaur Satinder Gupta O. P. Vrána Jan Šimková Hana Doležel Jaroslav Gill Bikram Singh Meyer Klaus F. X. Khurana J. P. Singh N. K. Chhuneja Parveen Singh Kuldeep 《Molecular biology reports》2020,47(3):1991-2003
Molecular Biology Reports - Diploid A genome wheat species harbor immense genetic variability which has been targeted and proven useful in wheat improvement. Development and deployment of... 相似文献
32.
Carla Perrotta Silke Kleefeld Anthony Staines Prerna Tewari Anneclaire J. De Roos Dalsu Baris Brenda Birmann Brian Chiu Wendy Cozen Nikolaus Becker Lenka Foretova Marc Maynadié Alexandra Nieters Silvia de Sanjosé Lucia Miligi Adele Seniori Costantini Mark Purdue John Spinelli Pierluigi Cocco 《Cancer epidemiology》2013,37(3):300-305
Objective: We investigated occupational risk of multiple myeloma (MM) in a pooled analysis of five international case–control studies. Methods: We calculated the odds ratio and its 95% confidence interval for selected occupations with unconditional regression analysis in 1959 MM cases and 6192 controls, by pooling study-specific risks using random-effects meta-analysis. Exposure to organic solvents was assessed with a job-exposure matrix (JEM). Results: Gardeners and nursery workers combined, most likely exposed to pesticides, showed a 50% increase in risk (OR = 1.50, 95% CI 0.9–2.3), while other farming jobs did not. Metal processors (OR = 1.55, 95% CI 0.9–2.3), female cleaners (OR = 1.32, 95% CI 1.0–1.8), and high level exposure to organic solvents (OR = 1.38, 95% CI 0.96–1.8) also showed moderately increased risks. Conclusions: Additional case–control studies of MM aetiology are warranted to further investigate the nature of the repeatedly reported increase in MM risk in several occupational groups. 相似文献
33.
Chitobiase (CHB) is an important enzyme for the production of N-acetyl-d-glucosamine from the chitin biopolymer in the series of chitinolytic enzymes. Majority of over-expressed CHB (58 %) in E. coli expression system led to formation of inclusion bodies. The production and soluble yield of active CHB was enhanced by co-expression with GroEL/ES chaperonin, optimizing culture conditions and solubilization followed by refolding of remaining inactive chitobiase present in the form of inclusion bodies. The growth of recombinant E. coli produced 42 % CHB in soluble form and the rest (~58 %) as inclusion bodies. The percentage of active CHB was enhanced to 71 % by co-expression with GroEL/ES chaperonin system and optimizing culture conditions (37 °C, 200 rpm, IPTG—0.5 mM, l-arabinose—13.2 mM). Of the remaining inactive CHB present in inclusion bodies, 37 % could be recovered in active form using pulsatile dilution method involving denaturants (2 M urea, pH 12.5) and protein refolding studies (1.0 M l-arginine, 5 % glycerol). Using combinatorial approach, 80 % of the total CHB expressed, could be recovered from cells grown in one litre of LB medium is a step forward in replacing hazardous chemical technology by biotechnological process for the production of NAG from chitinous waste. 相似文献
34.
35.
Maheshwari P Songara B Kumar S Jain P Srivastava K Kumar A 《Biotechnology journal》2007,2(8):1026-1032
Fast-growing callus, cell suspension and root cultures of Vernonia cinerea, a medicinal plant, were analyzed for the presence of alkaloids. Callus and root cultures were established from young leaf explants in Murashige and Skoog (MS) basal media supplemented with combinations of auxins and cytokinins, whereas cell suspension cultures were established from callus cultures. Maximum biomass of callus, cell suspension and root cultures were obtained in the medium supplemented with 1 mg/L alpha-naphthaleneacetic acid (NAA) and 5 mg/L benzylaminopurine (BA), 1.0 mg/L NAA and 0.1 mg/L BA and 1.5 mg/L NAA, respectively. The 5-week-old callus cultures resulted in maximum biomass and alkaloid contents (750 microg/g). Cell suspension growth and alkaloid contents were maximal in 20-day-old cultures and alkaloid contents were 1.15 mg/g. A 0.2-g sample of root tissue regenerated in semi-solid medium upon transfer to liquid MS medium containing 1.5 mg/L NAA regenerated a maximum increase in biomass of 6.3-fold over a period of 5 weeks. The highest root growth and alkaloid contents of 2 mg/g dry weight were obtained in 5-week-old cultures. Maximum alkaloid contents were obtained in root cultures in vitro compared to all others including the alkaloid content of in vivo obtained with aerial parts and roots (800 microg/g and 1.2 mg/g dry weight, respectively) of V. cinerea. 相似文献
36.
Rajesh Kumar Tewari Soo Yeon Lee Eun Joo Hahn Kee Yoeup Paek 《Plant biotechnology reports》2007,1(4):227-235
Nitric oxide (NO) is a diffusible, gaseous signaling molecule. In plants, NO influences growth and development, and it can
also affect plant responses to various stresses. Because NO induces root differentiation and interacts with reactive oxygen
species, we examined the temporal effect of NO elicitation on root growth, saponin accumulation and antioxidant defense responses
in the adventitious roots of mountain ginseng (Panax ginseng). The observations revealed that NO is involved in root growth and saponin production. Elicitation with sodium nitroprusside
(SNP) activated O2
−-generating NADPH oxidase (NOX) activity, which most probably subsequently enhanced growth of adventitious roots of mountain
ginseng. A severe inhibition of NOX activity and decline in dry weight of SNP elicited adventitious roots in the presence
of NOX inhibitor (diphenyl iodonium, DPI), which further supports involvement of NOX in root growth. Enhanced activities of
antioxidant enzymes by SNP appear to be responsible for low H2O2, less lipid peroxidation, and modulation of ascorbate and non-protein thiol statuses in the adventitious roots of mountain
ginseng. Dry mass, saponin content and NOX activity was related with NO content present in adventitious roots of mountain
ginseng. 相似文献
37.
Modeling breast cancer in vivo and ex vivo reveals an essential role of Pin1 in tumorigenesis 总被引:6,自引:0,他引:6 下载免费PDF全文
Phosphorylation on certain Ser/Thr-Pro motifs is a major oncogenic mechanism. The conformation and function of phosphorylated Ser/Thr-Pro motifs are further regulated by the prolyl isomerase Pin1. Pin1 is prevalently overexpressed in human cancers and implicated in oncogenesis. However, the role of Pin1 in oncogenesis in vivo is not known. We have shown that Pin1 ablation is highly effective in preventing oncogenic Neu or Ras from inducing cyclin D1 and breast cancer in mice, although it neither affects transgene expression nor mammary gland development. Moreover, we have developed an ex vivo assay to uncover that a significant fraction of primary mammary epithelial cells from Neu or Ras mice display various malignant properties long before they develop tumors in vivo. Importantly, these early transformed properties are effectively suppressed by Pin1 deletion, which can be fully rescued by overexpression of cyclin D1. Thus, Pin1 is essential for tumorigenesis and is an attractive anticancer target. Our ex vivo assay can be used to study early events of breast cancer development in genetically predisposed mice. 相似文献
38.
Bhat BA Ponnala S Sahu DP Tiwari P Tripathi BK Srivastava AK 《Bioorganic & medicinal chemistry》2004,12(22):5857-5864
A number of thiazolidine-2,4-diones derivatives having carboxylic ester appendage at N-3 were synthesized and their antihyperglycemic activity was evaluated. Many of these derivatives as well as their corresponding carboxylic acid showed significant improvement on post-prandial hyperglycemia in normal rats, in contrast to their poor agonist activity at PPARgamma. 相似文献
39.
Bacteriophage lambda integrase (lambda-Int) is the prototypical member of a large family of enzymes that catalyze site-specific DNA recombination via the formation of a Holliday junction intermediate. DNA strand cleavage by lambda-Int is mediated by nucleophilic attack on the scissile phosphate by a conserved tyrosine residue, forming an intermediate with the enzyme covalently attached to the 3'-end of the cleaved strand via a phosphotyrosine linkage. The crystal structure of the catalytic domain of lambda-Int (C170) obtained in the absence of DNA revealed the tyrosine nucleophile at the protein's C terminus to be located on a beta-hairpin far from the other conserved catalytic residues and adjacent to a disordered loop. This observation suggested that a conformational change in the C terminus of the protein was required to generate the active site in cis, or alternatively, that the active site could be completed in trans by donation of the tyrosine nucleophile from a neighboring molecule in the recombining synapse. We used NMR spectroscopy together with limited proteolysis to examine the dynamics of the lambda-Int catalytic domain in the presence and absence of DNA half-site substrates with the goal of characterizing the expected conformational change. Although the C terminus is indeed flexible in the absence of DNA, we find that conformational changes in the tyrosine-containing beta-hairpin are not coupled to DNA binding. To gain structural insights into C170/DNA complexes, we took advantage of mechanistic conservation with Cre and Flp recombinases to model C170 in half-site and tetrameric Holliday junction complexes. Although the models do not reveal the nature of the conformational change required for cis cleavage, they are consistent with much of the available experimental data and provide new insights into the how trans complementation could be accommodated. 相似文献
40.
Degumming of buel (Grewia optiva) bast fibres by pectinolytic enzyme from Bacillus sp. DT7 总被引:1,自引:0,他引:1
Des R. Kashayp Pawan K. Vohra Sanjeev K. Soni Rupinder Tewari 《Biotechnology letters》2001,23(16):1297-1301
An alkalophilic and thermotolerant, pectinase-producing Bacillus sp. DT7 effectively removed pectic substances from buel (Grewia optiva) bast fibres. A novel combined (chemical and enzymatic) treatment was used to degum buel bast fibres, which was followed by the release of galacturonic acid (575 mol g–1 dry fibres) and a decrease in dry weight (43%) of these fibres. 相似文献