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71.
72.
Preeti Thagela Ravindra Kumar Yadav Vagish Mishra Keshawanand Tripathi Altaf Ahmad Anil Dahuja Pawan Kumar Singh Gerard Abraham 《Symbiosis (Philadelphia, Pa.)》2017,72(3):207-214
The nitrogen fixing aquatic pteridophyte Azolla is used as biofertilizer for rice paddy. It is also used as poultry and cattle feed due to high protein content. However, its mass cultivation and exploitation is constrained due to the abiotic stress conditions it is exposed to. The system is interesting due to the presence of symbiotic nitrogen fixing cyanobacteria and its interaction with the carbon fixing host. Therefore these interactions have to be studied at the molecular level using advanced techniques. Proteomics is a technique which can be employed to reveal the mechanism of cross talk between the host and its symbiont as well as its response to abiotc stress. The primary step that contributes to successful proteomic analysis is standardization of sound protocols for protein extraction and sufficient yield to initiate proteomic studies using 2-dimensional electrophoresis. However, reports are not available on the protein extraction procedures in Azolla. Therefore in the present study we attempted to optimize protein extraction protocol in the whole plant, roots and the chloroplast of Azolla microphylla using phenol extraction, TCA-acetone and phosphate buffer methods. Our studies showed the efficacy of phenol extraction method in terms of maximum yield and resolution of proteins in Azolla. 相似文献
73.
Terrence D. Hill Preeti Vaghela Christopher G. Ellison Sunshine Rote 《Biodemography and social biology》2017,63(2):167-188
Although numerous studies suggest that religious involvement is associated with better health and longer life expectancies, it is unclear whether these general patterns extend to cellular aging. The mechanisms linking indicators of religious involvement with indicators of cellular aging are also undefined. We employed longitudinal data from the 2004 and 2008 Health and Retirement Study, a national probability sample of Americans aged 50 and older, to test whether average telomere length varied according to level of religious attendance. We also tested several potential mechanisms. Our results showed that respondents who attended religious services more frequently in 2004 also exhibited fewer stressful events, lower rates of smoking, fewer symptoms of depression, and lower levels of C-reactive protein in 2008. Respondents who increased their level of attendance from 2004 to 2008 also exhibited lower rates of smoking in 2008. Although religious attendance was not directly associated with telomere length, our mediation analyses revealed significant indirect effects through depression and smoking, but not stressful events or C-reactive protein. We conclude that religious attendance may promote telomere length indirectly by reducing symptoms of depression and the risk of smoking. There was no evidence to support stressful events or C-reactive protein as mechanisms of religious attendance. 相似文献
74.
Dharmendra Sharma Chandra Mohini Chaturvedi 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》2009,179(7):811-819
The role of thyroid hormones in the regulation of adrenal function during stress has been documented in mammals, but only
limited reports are available in avian species. The present study was undertaken to analyze the effect of hyper- or hypothyroidism
on the adrenal activity under control (hydrated) and osmotically stressed (water deprived, WD) conditions, with special emphasis
on the expression of arginine vasotocin receptor VT2 (VT2R) in pituitary corticotrophs. Chickens were made hyper- or hypothyroidic
by injecting thyroxine (T4) and 2-thiouracil (TU), respectively for 14 days. After 10 days of injections, one sub-group of
both, T4- or TU-treated chickens were subjected to osmotic stress by water deprivation. Hyperthyroidism stimulated adrenal
steroidogenic activity compared to euthyroid control birds, but no change was observed in the expression of VT2R. On the other
hand, TU-induced hypothyroidism however showed no effect on adrenal gland, but a significant increase in the expression of
VT2R was observed. Neither hyper- nor hypothyroidism altered pro-opiomelanocortin (POMC) mRNA levels. Following osmotic stress,
no effect was observed either on the adrenal gland or on the VT2R expression in hyperthyroidic birds, but in hypothyroidic
birds, osmotic stress stimulated adrenal steroidogenic activity and decreased VT2R expression in comparison to its respective
controls (T4 or TU). Expression of POMC mRNA was again unaltered following osmotic stress. Although exact mechanism is not
clear, the data indicate that high plasma T4 level stimulates adrenal activity and may also modulate function of the pituitary–adrenal
axis during dehydration. 相似文献
75.
A controlled and up-scalable route for the biosynthesis of silver nanopartilces (NPs) mediated by fungal proteins of Coriolus versicolor has been undertaken for the first time. The fungus when challenged with silver nitrate solution accumulated silver NPs on its surface in 72h which could be reduced to 1h by tailoring the reaction conditions. Under alkaline conditions, the reaction was much faster and could easily proceed at room temperature even without stirring. The resulting Ag NPs displayed controllable structural and optical properties depending on the experimental parameters such as pH and reaction temperatures. The average size, morphology, and structure of particles were determined by AFM, TEM, XRD and UV/Visible absorption spectrophotometry. Fourier transform infrared study disclosed that the amino groups were bound to the particles, which was accountable for the stability of NPs. It further confirmed the presence of protein as the stabilizing and capping agent surrounding the silver NPs. Experiments were conducted both with, media in which fungus was initially harvested and that of pristine fungal mycelium alone. Under normal conditions, in the case of media extracellular synthesis took place whereby other than the fungal proteins, glucose was also responsible for the reduction. In the case of fungal mycelium, the intracellular formation of Ag NPs, could be tailored to give both intracellular and extracellular Ag NPs under alkaline conditions whereby the surface S-H groups of the fungus played a major role. 相似文献
76.
Tripathi RP Verma SS Pandey J Agarwal KC Chaturvedi V Manju YK Srivastva AK Gaikwad A Sinha S 《Bioorganic & medicinal chemistry letters》2006,16(19):5144-5147
A series of 9-substituted tetrahydroacridines were synthesized by nucleophilic substitution of chloro group with different nucleophiles in 9-chlorotetrahydroacridine (2). The latter could be obtained by POCl(3) mediated cyclization of the intermediate enamine, which in turn, was prepared by acid catalyzed condensation of anthranilic acid and cyclohexanone. Most of the compounds on antitubercular evaluation against M. tuberculosis H37 Rv and H37 Ra strains exhibited potent activities with MIC 6.125-0.78 microg/mL comparable to the standard drugs. 相似文献
77.
The use of quantitative structure-activity relationships, since its advent, has become increasingly helpful in understanding many aspects of biochemical interactions in drug research. This approach was utilized to explain the relationship of structure with biological activity of selective COX-2 inhibitors. The enormity of the COX-2 discovery is reflected in the unprecedented speed at which research laboratories have sought to validate its clinical implications. Presented herein is a series of 21 derivatives of meclofenamic acid with selective COX-2 inhibitory activity. Several statistically significant regression expressions were obtained for both COX-1 and COX-2 inhibition using sequential multiple linear regression analysis method. Two of these models were selected and validated further, which revealed the importance of Kier molecular flexibility index for COX-2 inhibitory activity and the number of hydrogen bond donor atoms for COX-1 inhibitory activity. Additionally, linear correlation of molecular flexibility with COX-1 and COX-2 inhibitory activities revealed that flexibility of molecules at COX-2 active site can improve the selectivity of COX-2 inhibitors. 相似文献
78.
Punita Verma R. Sagar Hariom Verma Preeti Verma Dharmendra K. Singh 《Journal of Plant Ecology》2015,8(3):321
Aim European and North American studies have suggested that nitrogen (N) depositions reduce plant diversity and increase primary productivity due to changes in plant traits. To predict the vegetation response to future global change, experimental validations from other regions are widely needed. We assessed the effects of N treatment by urea fertilization on the diversity and biomass of the herbaceous plant traits (HPTs) in a dry tropical environment of India.Methods Diversity and biomass of different HPTs were determined on the basis of data collected in year 2010, from 135, 1 m × 1 m plots distributed over 15 locations. The plots were treated with urea fertilizer in different doses (Control, 60kgNha-1 yr-1 and 120kg N ha-1 yr-1) since 1st January 2007. The plots were ordinated and data were subjected to appropriate statistical analyses.Important findings Correspondence analysis (CA) suggested uniqueness of species composition due to N amendment. Species number and biomass of the trait categories varied due to N fertilization and traits. All studied trait categories (except N-fixers) yielded maximum mean species number at moderate level of N fertilization. Different levels of N fertilization exhibited different species diversity–primary productivity (D-P) relationships. Further, study showed reduction in plant diversity due to increase in biomass at high rates of N addition.Conclusions Tall, erect, non N-fixers, annuals, grasses HPTs were favoured by N enrichment. N dose above 60kg enhanced the biomass of fast growing, erect, annuals, non N-fixers, nitrophilic HPTs. The changes in traits with N addition, especially the increase in annuals and grasses and decrease in typically N-rich N-fixers, have implications for sustainable cattle production. 相似文献
79.
80.
Secondary metabolites have been found to have interesting applications over and above their well-known medical uses, e.g., as antimicrobials, etc. These alternative applications include antitumor, cholesterol-lowering, immunosuppressant, antiprotozoal, antihelminth, antiviral and anti-ageing activities. Polyene antibiotics, such as amphotericin B, are of use as antiprion agents, antitumor drugs and against leishmaniasis. Other microbial natural products that show antibiotic activity are used against cancer e.g., doxorubicin, neomycin, β-lactams, bleomycin and rapamycin. Macrolide antibiotics, such as erythromycin, clarithromycin and azithromycin, improve pulmonary function in patients suffering from panbion cholitis. Pigments like prodigiosin and shikonin have antitumor activity, while violacein has anti-ulcer and antitumor activity and also acts as an antiprotozoal agent. Statins, in addition to lowering cholesterol and LDL levels, also decrease elevated C-reactive protein (CRP) levels independent of their cholesterol effects. Immunosppressants have many alternative effects: (i) Cyclosporin is proving useful in treatment of inflammatory disease such as asthma and muscular dystrophy. (ii) Rapamycin is extremely useful in preventing restenosis of stents grafted in balloon angioplasty. (iii) Tacrolimus and ascomycin help in treating inflammatory skin disease such as allergic contact dermatitis and psoriasis. Artemisinin, an antimalarial agent, is also showing antitumor activity. Other natural products, including those from plants (betulinic acid and shikonin), animals (bryostatins) and microbes (squalestatin and sophorolipids) have a multiplicity of potentially useful actions. Unexpected functions of known secondary metabolites are continuously being unraveled, and are fulfilling some of the needs of present day medicine and show great promise for the future. 相似文献