全文获取类型
收费全文 | 2165篇 |
免费 | 86篇 |
专业分类
2251篇 |
出版年
2024年 | 6篇 |
2023年 | 7篇 |
2022年 | 35篇 |
2021年 | 60篇 |
2020年 | 35篇 |
2019年 | 37篇 |
2018年 | 45篇 |
2017年 | 51篇 |
2016年 | 69篇 |
2015年 | 79篇 |
2014年 | 124篇 |
2013年 | 161篇 |
2012年 | 197篇 |
2011年 | 185篇 |
2010年 | 104篇 |
2009年 | 92篇 |
2008年 | 120篇 |
2007年 | 118篇 |
2006年 | 134篇 |
2005年 | 85篇 |
2004年 | 86篇 |
2003年 | 91篇 |
2002年 | 83篇 |
2001年 | 14篇 |
2000年 | 9篇 |
1999年 | 10篇 |
1998年 | 27篇 |
1997年 | 12篇 |
1996年 | 7篇 |
1995年 | 16篇 |
1994年 | 6篇 |
1993年 | 12篇 |
1992年 | 12篇 |
1991年 | 15篇 |
1990年 | 5篇 |
1989年 | 10篇 |
1988年 | 8篇 |
1987年 | 11篇 |
1986年 | 4篇 |
1985年 | 7篇 |
1984年 | 13篇 |
1983年 | 4篇 |
1982年 | 9篇 |
1981年 | 7篇 |
1980年 | 10篇 |
1979年 | 6篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1973年 | 4篇 |
1972年 | 4篇 |
排序方式: 共有2251条查询结果,搜索用时 0 毫秒
991.
Two forms (A and B) of starch phosphorylase were found in the mature banana leaf by polyacrylamide gel electrophoresis and DEAE-cellulose chromatography. The young leaf contained only form A and the appearance of form B with leaf development was accompanied by a decrease in the content of form A. At a later stage of leaf maturity only form B could be found. The MWs of forms A and B were 450 000, and 220 000 respectively. 相似文献
992.
993.
994.
Sujith Rajan Abhishek Gupta Muheeb Beg Kripa Shankar Ankita Srivastava Salil Varshney Durgesh Kumar Anil Nilkanth Gaikwad 《Differentiation; research in biological diversity》2014
According to the World Health Organization obesity is defined as the excessive accumulation of fat, which increases risk of other metabolic disorders such as insulin resistance, dyslipidemia, hypertension, cardiovascular diseases, etc. There are two types of adipose tissue, white and brown adipose tissue (BAT) and the latter has recently gathered interest of the scientific community. Discovery of BAT has opened avenues for a new therapeutic strategy for the treatment of obesity and related metabolic syndrome. BAT utilizes accumulated fatty acids for energy expenditure; hence it is seen as one of the possible alternates to the current treatment. Moreover, browning of white adipocyte on exposure to cold, as well as with some of the pharmacological agents presents exciting outcomes and indicates the feasibility of transdifferentiation. A better understanding of molecular pathways and differentiation factors, those that play a key role in transdifferentiation are of extreme importance in designing novel strategies for the treatment of obesity and associated metabolic disorders. 相似文献
995.
Sukumaran Anil Mohamed Hashem Sajith Vellappally Shankargouda Patil H. M. H. N. Bandara L. P. Samaranayake 《Mycopathologia》2014,177(3-4):207-215
Paracoccidioides brasiliensis, a dimorphic pathogenic fungus, causes the principal form of systemic mycosis in Brazil. The literature furnishes only limited data on the ecology of this fungus in the state of Rio Grande do Sul, the southernmost state of Brazil. The purpose of this study was to evaluate the prevalence of fungal infection in wild animals, using serological tests and using the animals as sentinels of the presence of P. brasiliensis in three specified mesoregions of Rio Grande do Sul. A total of 128 wild animals from the three mesoregions were included in the study. The serum samples were evaluated by immunodiffusion and the enzyme-linked immunosorbent assay (ELISA) technique to detect anti-gp43 antibodies from P. brasiliensis. Two conjugates were tested and compared with the ELISA technique. Although no positive samples were detected by immunodiffusion, 26 animals (20 %), belonging to 13 distinct species, were found to be seropositive by the ELISA technique. The seropositive animals were from two mesoregions of the state. The results were similar according to the gender, age, and family of the animals, but differed significantly according to the conjugate used (p < 0.001), showing more sensitivity to protein A-peroxidase than to protein G-peroxidase. The finding that wild animals from the state of Rio Grande do Sul are exposed to P. brasiliensis suggests that the fungus can be found in this region despite the often-rigorous winters, which frequently include below-freezing temperatures. 相似文献
996.
997.
Prithiksha Ramkaran Sajidah Khan Alisa Phulukdaree Devapregasan Moodley Anil A. Chuturgoon 《Cell biochemistry and biophysics》2014,68(2):259-266
Modulation of nuclear factor KappaB (NF-κB) activation may play a role in regulating inflammatory conditions associated with coronary artery disease (CAD). MicroRNA-146a (miR-146a) primarily targets interleukin-1 receptor-associated kinase 1 (IRAK-1) and tumour necrosis factor receptor associated factor 6 (TRAF-6), which results in inhibition of NF-κB via the TLR pathway. This study investigated the influence of the miR-146a GC rs2910164 on miR-146a expression in young South African Indians with CAD. CAD patients and controls were genotyped by PCR–RFLP and miRNA-146a levels were measured by qPCR. IRAK-1, TRAF-6 and NF-κB expression was determined by Western blot. No differences in genotypic frequency was found (GG: 45 vs. 47 %, GC: 46 vs. 41 %, CC: 9 vs. 12 %) in controls and patients respectively (odds ratio = 1.025; 95 % confidence interval 0.6782–1.550; p = 0.9164). Significantly higher levels of miR-146a was associated with CAD patients with the CC genotype (6.25-fold increase relative to controls and patients with the wildtype variant, p < 0.0001). Significantly lower levels of IRAK-1 (0.38 ± 0.02; p = 0.0072) and TRAF-6 (0.44 ± 0.02; p = 0.0146) was found in CAD patients with the CC genotype. The lowest levels of NF-κB and C-reactive protein were found in patients with the homozygous C allele compared to the heterozygous GC and wildtype variants. We propose a role for miR-146a in TLR signalling through a negative feedback mechanism involving the attenuation of NF-κB by down-regulation of IRAK-1 and TRAF-6. Our observations implicate miR-146a as a target for lowering inflammation in CAD patients. 相似文献
998.
Sanjog Garyali Anil Kumar M. Sudhakara Reddy 《Biotechnology and Bioprocess Engineering》2014,19(5):908-915
The optimization of taxol production by Fusarium redolens by one factor at a time (OFAT) approach led to production of 70 μg/L of taxol. With sucrose and NH4NO3 as the carbon and nitrogen sources and medium volume (V m ) to flask volume (V f ) ratio of 0.2, a greater taxol production was attained. NH4NO3, MgSO4?7H2O and NaOAc at 6.25, 0.63, and 1.25 g/L, were the significant factors for attaining the highest taxol production. The optimization of culture variables led to the production of taxol from 66 to 198 μg/L, which is three fold higher than that in the unoptimized medium. Current study results suggested the success of Response Surface Methodology in enhancing the production of fungal taxol. 相似文献
999.
Vasundhera Gupta Gunjan Sharma T. N. R. Srinivas P. Anil Kumar 《Antonie van Leeuwenhoek》2014,106(6):1097-1103
A Gram-negative, rod shaped, motile, aerobic bacterium, designated as strain AK49T was isolated from a water sample from a mangrove forest in Coringa village, Andhra Pradesh, India. Strain AK49T was observed to form yellow coloured, smooth, circular, convex colonies on marine agar, with entire margins. Cells of strain AK49T are 0.5–1.0 µm wide and 1.5–3.5 µm long. Growth was observed at 25–37 °C (optimum 30 °C), 2–6 % NaCl (optimum 2 %) and pH 6–8 (optimum 7). Phylogenetic analysis based on 16S rRNA gene sequences showed that the strain AK49T is closely related to two species recently reclassified as members of the genus Aliiglaciecola: Aliiglaciecola lipolytica JCM 15139T (sequence similarity 95.43 %) and Aliiglaciecola litoralis JCM 15896T (sequence similarity 96.91 %). The major cellular fatty acids of strain AK49T were found to include C16:0, C18:1ω7c and summed feature 3 (C16:1ω7c/C15:0 iso-2-OH). The polar lipid content of cell membrane was found to include phosphatidylethanolamine, phosphatidylglycerol, an unidentified aminolipid, an unidentified lipid and an unidentified glycolipid. The genomic DNA G+C content of strain AK49T was determined to be 41.9 mol%. Based on the taxonomic methods, including chemotaxonomic, phenotypic and phylogenetic approaches, strain AK49T is described here as a novel species belonging to the genus Aliiglaciecola, for which the name Aliiglaciecola coringensis sp. nov. is proposed. The type strain of Aliiglaciecola coringensis sp. nov. is AK49T (=MTCC 12003T = JCM19197T). 相似文献
1000.
Enzymatic and Regulatory Attributes of Trehalose‐6‐Phosphate Phosphatase from Candida utilis and its Role During Thermal Stress 下载免费PDF全文