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91.
Assessment of wound-site redox environment and the significance of Rac2 in cutaneous healing 总被引:2,自引:0,他引:2
Ojha N Roy S He G Biswas S Velayutham M Khanna S Kuppusamy P Zweier JL Sen CK 《Free radical biology & medicine》2008,44(4):682-691
We have previously reported that H(2)O(2) is actively generated by cells at the wound site and that H(2)O(2)-driven redox signaling supports wound angiogenesis and healing. In this study, we have standardized a novel and effective electron paramagnetic resonance spectroscopy-based approach to assess the redox environment of the dermal wound site in vivo. Rac2 regulates inducible NADPH oxidase activation and other functional responses in neutrophils. Using Rac2-deficient mice we sought to investigate the significance of Rac2 in the wound-site redox environment and healing responses. Noninvasive measurements of metabolism of topically applied nitroxide (15)N-perdeuterated tempone in murine excisional dermal wounds demonstrated that the wound site is rich in oxidants, the levels of which peak 2 days postwounding in the inflammatory phase. Rac2-deficient mice had threefold lower production of superoxide compared to controls with similar wounds. In these mice, a lower wound-site superoxide level was associated with compromised wound closure. Immunostaining of wound edges harvested during the inflammatory phase showed that the numbers of phagocytic cells recruited to the wound site in Rac2-deficient and control mice were similar, but the amount of lipid peroxidation was significantly lower in Rac2-deficient mice, indicating compromised NADPH oxidase activity. Taken together, the findings of this study support that the wound site is rich in oxidants. Rac2 significantly contributes to oxidant production at the wound site and supports the healing process. 相似文献
92.
Cytosolic and nuclear progesterone receptors (PRc and PRn) under antiprogestin treatment were measured in rat deciduoma and compared with values for contralateral (nondeciduomatous) rat uterine tissue. Uterine PRc and PRn of the progesterone treated group were 101 +/- 8.7 and 4770 +/- 590 fmol/mg DNA respectively. After treatment with antiprogestins STS-557, 5 alpha-DNE, (5 alpha-dihydronorethisterone), 5 alpha-DNG (5 alpha-dihydronorgestrel), RU-22092 and RU-16556, PRc in the nondeciduomatous control horn ranged from 127 to 377 fmol/mg DNA and PRn from 2785 to 17925 fmol/mg DNA. In the decidual tissue, PRc decreased significantly (4.6 +/- 0.8 fmol/mg DNA) on 5 alpha-DNG treatment as compared with the progesterone alone treatment group (147 +/- 3.8). PRn in decidual tissue also decreased maximally on 5 alpha-DNG treatment. These results suggest that the interaction of antiprogestins may not be identical in control uterine tissue and in deciduoma. 相似文献
93.
Velayutham M Villamena FA Fishbein JC Zweier JL 《Archives of biochemistry and biophysics》2005,435(1):83-88
The cancer chemopreventive actions of oltipraz, a member of a class of 1,2-dithiolethiones, have been primarily associated with the induction of phase 2 enzymes mediated by a 41bp enhancer element known as the anti-oxidant response element in the promoter regions of many phase 2 genes. It has been suggested that oxygen radical formation by oltipraz may be a critical mechanism by which it exerts chemoprevention. Therefore, in the present work, studies were performed to directly determine if oltipraz generates oxygen free radicals. Electron paramagnetic resonance (EPR) spin trapping demonstrated that oltipraz slowly reacts in the presence of oxygen to generate the superoxide anion radical. This formation of superoxide by oltipraz was concentration- and time-dependent. EPR oximetry studies showed that oxygen was also slowly consumed paralleling the process of superoxide formation. Thus, oltipraz induced superoxide formation occurs and could be involved in the mechanism by which it exerts chemoprotection. 相似文献
94.
Huarong Li Andrew J. Bowling Premchand Gandra Murugesan Rangasamy Heather E. Pence Robert E. McEwan Chitvan Khajuria Blair D. Siegfried Kenneth E. Narva 《Insect Science》2018,25(1):45-56
Western corn rootworm (WCR, Diabrotica virgifera virgifera LeConte) is highly sensitive to orally delivered double‐stranded RNA (dsRNA). RNAi in WCR is systemic and spreads throughout the insect body. This raises the question whether transitive RNAi is a mechanism that functions in WCR to amplify the RNAi response via production of secondary siRNA. Secondary siRNA production is achieved through RNA‐dependent RNA polymerase (RdRP) activity in other eukaryotic organisms, but RdRP has not been identified in WCR and any other insects. This study visualized the spread of the RNAi‐mediated knockdown of Dv v‐ATPase C mRNA throughout the WCR gut and other tissues using high‐sensitivity branched DNA in situ hybridization. Furthermore, we did not detect either secondary siRNA production or transitive RNAi in WCR through siRNA sequence profile analysis. Nucleotide mismatched sequences introduced into either the sense or antisense strand of v‐ATPase C dsRNAs were maintained in siRNAs derived from WCR fed with the mismatched dsRNAs in a strand specific manner. The distribution of all siRNAs was restricted to within the original target sequence regions, which may indicate the lack of new dsRNA synthesis leading to production of secondary siRNA. Thus, the systemic spread of RNAi in WCR may be derived from the original dsRNA molecules taken up from the gut lumen. These results indicate that the initial dsRNA dose is important for a lethal systemic RNAi response in WCR and have implications in developing effective dsRNA traits to control WCR and in resistance management to prolong the durability of RNAi trait technology. 相似文献
95.
The methanol extract of the rhizome of Bergenia ciliata Sternb. (Saxifragaceae) has been evaluated for its potential in a cough model induced by sulphur dioxide gas in mice. The extract exhibited significant anti-tussive activity in a dose-dependent manner, as compared with control. The antitussive activity of the extract was comparable to that of codeine phosphate (10 mg/kg body wt.), a standard anti-tussive agent. The extract at doses of 100, 200 and 300 mg/kg body wt. (p.o.) showed significant inhibition of cough reflex by 28.7, 33.9 and 44.2%, respectively, within 90 min of the experiment. 相似文献
96.
Vinnakota Rajesh Ramakrishnan Anantha Maharasi Samdani A. Venugopal M. Anjali Ram B. Sri Krishnan S. Navaneetha Murugesan Dhandapani Sankaranarayanan Kavitha 《Protoplasma》2016,253(6):1593-1597
Protoplasma - Climate change drastically affects the cultivation of rice, and its production is affected significantly by water stress. Adaptation of a plant to water deficit conditions is... 相似文献
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Granulosa, theca and corpus luteum cells of the goat ovary were isolated and incubated separately for 6 hours, with or without various modulators. Arachidonic acid (AA, 10 ng to 100 μg/ml), the precursor for prostaglandin synthesis, produced a dose-dependent increase in progesterone (P4) and estradiol-17β (E2) productin by all the cell types. Prostaglandin synthetase inhibitors, aspirin (10−6−10−3M) and indomethacin (100 ng−1 mg/ml), produced a dose-dependent decrease in arachidonic acid-stimulated (100 μ/ml) steroid production. Prostacyclin synthetase stimulators, trapidil (1.6 μg− 1 mg/ml) and dipyridamole (10−6−10−3M), when added alone or along with AA, did not effect steroid production. Up to 100 μg/ml of U-51605 (9,11-azoprosta-5, 13-dienoic acid), a prostacyclin synthetase inhibitor, did not inhibit basal or AA-stimulated steroid production. Prostacyclin (PGl2) and its stable analog 6βPGl1(0.01–10μg/ml) produced a dose-dependent increase in P4 and E2 production in all three cell types. Increase at 1 and 10μg/ml was significant in all cases. 6-keto-PGE1 (an active metabolite of PGl2 in certain systems) produced an increase in steroid production which was significant in theca at 1μg/ml concentrations but had no significant effect on granulosa and corpus luteum cells at any dose level. 6-keto-PGf1 alpha (stable metabolite of PGl2) was without effect inthe present system. The lack of effect of PGl2 at lower concentrations was not altered by either differentiation of the cells with FSH and testosterone or addition of steroid precursors, testosterone and pregnenolene. The present results indicate that AA- stimualted steroid production in the goat ovarian cell type is mediated by prostaglandins other than PGl2 though PGl2 itself can positively modulate the steroid production. 相似文献
100.
Beena Elizabeth Thomas Banurekha Velayutham Kannan Thiruvengadam Dina Nair Sukendu Bikas Barman Lavanya Jayabal Senthanro Ovung Soumya Swaminathan 《PloS one》2016,11(1)