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61.
First successful in vitro synthesis of functional photosynthetic phosphorylating membrane is reported. Etioplasts, highly enriched in cytoplasmic and plastid proteins, isolated from etiolated Cucumber cotyledons pretreated with kinetin and gibberellic acid, and illuminated in a cofactor fortified medium showed commencement of chlorophyll (Chl) synthesis immediately after illumination from exogenous δ-aminolevulinic acid, while photosystem I (PS I) activity commenced 15 min after the onset of illumination. When cotyledons pretreated with kinetin and gibberellic acid were illuminated directly, there was a lag phase of 30 min before the commencement of Chl synthesis and PS I activity developed after 1 h of illumination. In plastids developed both in vivo and in vitro, the electron flow from dichlorophenolindophenol to methyl-viologen was coupled to phosphorylation as observed by an increase in the electron transport rate on the addition of uncouplers. Analysis of polypeptide profiles of the greening plastids in vitro showed the disappearance of many higher molecular weight proteins during greening. Polypeptides of molecular weight 32, 20.5, 19.5 K absent in etioplasts appeared as distinct bands after 4 h of greening in vitro.  相似文献   
62.
The discovery of pedunculate specimens of pollen organ Dolerotheca in close association with Myeloxylon-type pinnae and Alethopteris-type pinnules provides evidence for the reconstruction of a petrified medullosan frond and the attachment of the microsporangiate fructification. Specimens of Dolerotheca villosa and D. formosa from Middle and Upper Pennsylvanian age strata of North America are borne on slender peduncles with anatomical features and vascularization identical to those of some level in a Myeloxylon-Alethopteris-type frond. Reconstruction of the frond reveals a large, repeatedly dichotomising organ that bears penultimate pinnae and ultimate pinnules in a pinnate arrangement. Examination of pinnules on the surface of coal ball material indicates that they conform to the compression genus Alethopteris. Identical numbers and arrangement of vascular bundles together with identical anatomical features and multicellular hairs indicate that the Dolerotheca campanulum is borne in the position of a penultimate pinna. A reconstruction of the frond with a proposed polled organ attachment is included.  相似文献   
63.
A modification of the recent rolling technique of Redgwell, R. J., Turner, N A., and Bieleski, R. L. [(1974) J. Chromatogr.88, 25–31] for stripping thin layers from chromatographic plates for radioactive measurements has been developed. Use of this rolling technique in the case of tritiated benzo[α]pyrene and metabolites yields erratic results. By the simple expedient of spraying (instead of rolling) of the Stripmix, highly reproducible data were obtained.  相似文献   
64.
Night shifts at work is the most frequent reasons for circadian rhythm disruption and subsequent psychological and physiological disturbances, especially increased risk of cardiovascular and respiratory ailments compared to daytime workers. Alternate nostril breathing for about 15 minutes was known to have effect over cardiac, respiratory parameters and muscle strength. Hence aim is of interest to assess the effects of alternate nostril breathing (ANB) on cardio-respiratory parameters and muscle strength among the rotating shift workers in the tertiary care hospital. This observational study was carried out in the department of Physiology after getting institutional ethical committee clearance. Around 140 rotating night shift workers of both sex of age 25-40 years with normal BMI and 140 non-shift workers age, sex and BMI matched were selected as study and control group respectively. Heart rate, blood Pressure, respiratory rate, peak expiratory flow rate, respiratory endurance, respiratory burst test, muscle strength and fatigue were recorded before and after 15 minutes of ANB. Shift workers were found to have significantly altered systolic (P=0.000) and diastolic (P=0.002) blood pressure and heart rate (P=0.010) compared to non-shift workers. Fatigue is altered significantly (P< 0.05) after ANB between both shift and non- shift workers. ANB can be used as a therapeutic module among the shift workers, to maintain their sound health and to improve their performance in the night duty.  相似文献   
65.
Background: Population-based studies describing the association between education and cancer incidence has not yet been reported from India. Methods: Information on the educational attainment of 4417 cancer cases aged 14 years and above, diagnosed during 2003–2006 in Dindigul district, Tamil Nadu, India, was obtained from the Dindigul Ambilikkai Cancer Registry, which registers invasive cancer cases by active methods from 102 data sources. Population distribution by 5-year age groups and for four educational levels namely no education, education ≤5 years, 6–12 years and >12 years, was obtained from census data. Standardized rate ratios based on age-standardized rates were calculated to study cancer risks for different educational levels. Results: Men and women with no education had higher overall cancer incidence rates compared to the educated population. The risk of cervix, mouth, esophagus, stomach and lung cancers were inversely associated with higher levels of education whereas a high incidence of breast cancer was observed with increasing educational levels. The standardized rate ratio of cervical cancer 0.32 (95% CI: 0.19–0.52) and of breast cancer was 6.08 (95% CI: 1.81–20.48) for women with more than 12 years of education compared to those with no education. There was paucity of cases in the highest education level for most cancers. Conclusion: With more and more women in rural India becoming educated, one could foresee breast cancer becoming more frequent even in rural areas of India in future.  相似文献   
66.
Several C1-imino conjugates of d-galactose, d-lactose and d-ribose, where the nitrogen center was substituted by the salicylidene or naphthylidene, were synthesized and characterized. Similar C2-imino conjugates of d-glucose have also been synthesized. All the glyco-imino-conjugates, which are transition state analogues, exhibited 100% inhibition of the activity towards glycosidases extracted from soybean and jack bean meal. Among these, a galactosyl-napthyl-imine-conjugate (1c) showed 50% inhibition of the activity of pure α-mannosidase from jack bean at 22 ± 2.5 μM, and a ribosyl-naphthyl-imine-conjugate (3c) showed at 31 ± 5.5 μM and hence these conjugates are potent inhibitors of glycosidases. The kinetic studies suggested non-competitive inhibition by these conjugates. The studies are also suggestive of the involvement of aromatic, imine and carbohydrate moieties of the glyco-imino-conjugates in the effective inhibition. The binding of glyco-imino-conjugate has been established by extensive studies carried out using fluorescence emission and isothermal titration calorimetry. The conformational changes resulted in the enzyme upon interaction of these derivatives has been established by studying the fluorescence quench of the enzyme by KI as well as from the secondary structural changes noticed in CD spectra. All these studies revealed the difference in the binding strengths of the naphthylidene vs. salicylidene as well as galactosyl vs. lactosyl moieties present in these conjugates. The differential inhibition of these glyco-conjugates has been addressed by quantifying the specific interactions present between the glyco-conjugates and the enzyme by using rigid docking studies. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   
67.
The microbial transformation of coumarin (1) and 6-methyl coumarin (2) using Colletotrichum capsici gave 2-(3'-hydroxypropyl) phenol (3) and 2-(3'-hydroxypropyl)-4-methyl phenol (4). The phytopathogenic fungi effectively reduced the 2H-pyran-2-one moiety of both parent coumarins to respective alcohols.  相似文献   
68.
The use of conventional and unconventional reaction methodology for the hydrolysis of the acetate group in zaluzanin D resulted in hydration of the 11,13 exocyclic bond along with deacetylation. But the microorganism E. coli selectively cleaved the acetate group to yield zaluzanin C.  相似文献   
69.
Membrane microdomains rich in cholesterol and sphingolipids, including gangliosides (GGs), are known to be important regions for cell signaling and binding sites for various pathogens. Cholesterol depletion inhibits the cellular entry of pathogens and also reduces inflammatory signals by disrupting microdomain structure. Our previous study showed that dietary gangliosides increased total ganglioside incorporation while decreasing cholesterol in the intestinal mucosa. We hypothesized that diet-induced reduction in cholesterol content in the intestinal mucosa disrupts microdomain structure resulting in reduced pro-inflammatory signals. Male weanling Sprague-Dawley rats were fed semipurified diets for 2 weeks. Experimental diets were formulated to include either ganglioside-enriched lipid (GG diet, 0.02% gangliosides [w/w of diet] ) or polyunsaturated fatty acid (PUFA diet, 1% arachidonic acid and 0.5% docosahexaenoic acid, w/w of total fat), in a control diet containing 20% fat. Levels of cholesterol, GG, caveolin, platelet activating factor (PAF), and diglyceride (DG) were measured in the microdomain isolated from the intestinal brush border. The GG diet increased total gangliosides by 50% with a relative increase in GD3 and a relative decrease in GM3. Cholesterol content was also reduced by 23% in the intestinal microdomain. These changes resulted in a significant decrease in the ratio of cholesterol to ganglioside. The GG diet and the PUFA diet were both associated with reduction in caveolin, PAF, and DG content in microdomains, whereas no change occurred in the ganglioside profile of animals fed the PUFA diet. Dietary gangliosides decrease the cholesterol/ganglioside ratio, caveolin, PAF and DG content in microdomains thus exerting a potential anti-inflammatory effect during gut development.  相似文献   
70.
Vanadium has recently been reported to induce interphase and M-phase (mitotic) programmed cell death via the generation of hydroxyl free radicals (OH*). In this paper, the effects of antioxidants on: (a) vanadyl[IV]-generated OH* free radical levels; and (b) cellular glutathione in vanadyl [IV]-treated Chang liver cells were evaluated. The surface morphology of vanadyl-treated mitotic cells was studied by confocal and scanning microscopy. The free radical scavengers zinc chloride, glucose and thiourea reduced the levels of vanadyl-induced OH* free radicals and partially prevented the depletion of cellular glutathione. Concurrent with OH* free radical production, vanadyl-treated telophase cells exhibited excessive cell blebbing and cell shrinkage. The morphological features demonstrated in vanadyl-induced mitotic programmed cell death as a consequence of oxidative stress is novel.  相似文献   
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