全文获取类型
收费全文 | 18750篇 |
免费 | 930篇 |
国内免费 | 27篇 |
专业分类
19707篇 |
出版年
2024年 | 32篇 |
2023年 | 165篇 |
2022年 | 380篇 |
2021年 | 705篇 |
2020年 | 419篇 |
2019年 | 444篇 |
2018年 | 648篇 |
2017年 | 608篇 |
2016年 | 787篇 |
2015年 | 897篇 |
2014年 | 1141篇 |
2013年 | 1563篇 |
2012年 | 1645篇 |
2011年 | 1451篇 |
2010年 | 840篇 |
2009年 | 742篇 |
2008年 | 860篇 |
2007年 | 837篇 |
2006年 | 698篇 |
2005年 | 629篇 |
2004年 | 507篇 |
2003年 | 427篇 |
2002年 | 386篇 |
2001年 | 312篇 |
2000年 | 283篇 |
1999年 | 254篇 |
1998年 | 100篇 |
1997年 | 77篇 |
1996年 | 85篇 |
1995年 | 79篇 |
1994年 | 58篇 |
1993年 | 58篇 |
1992年 | 154篇 |
1991年 | 144篇 |
1990年 | 115篇 |
1989年 | 88篇 |
1988年 | 130篇 |
1987年 | 99篇 |
1986年 | 81篇 |
1985年 | 81篇 |
1984年 | 84篇 |
1983年 | 47篇 |
1982年 | 42篇 |
1981年 | 50篇 |
1980年 | 47篇 |
1979年 | 57篇 |
1978年 | 35篇 |
1977年 | 43篇 |
1976年 | 35篇 |
1975年 | 34篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Jha Anubhuti Kumar Anil Kumar Awanish 《International journal of peptide research and therapeutics》2020,26(3):1559-1566
International Journal of Peptide Research and Therapeutics - Candida albicans is the most common nosocomial systemic fungal infections causing high mortality/morbidity. Existing antifungal... 相似文献
992.
993.
Pande Babita Parveen Noorshama Parganiha Arti Pati Atanu Kumar 《Sleep and biological rhythms》2018,16(4):431-439
Sleep and Biological Rhythms - We studied patterns in the distribution of chronotype and sleep–wake behavior in a randomly chosen sample population of Indian teenagers consisting 965... 相似文献
994.
Biswajit Brahma Sushil Kumar Bidhan Chandra De Purusottam Mishra Mahesh Chandra Patra Deepak Gaur Meenu Chopra Devika Gautam Sourav Mahanty Hrudananda Malik Dhruba Malakar Tirtha Kumar Datta Sachinandan De 《PloS one》2015,10(3)
Nucleotide binding and oligomerization domain (NOD)-like receptors (NLRs) are innate immune receptors that recognize bacterial cell wall components and initiate host immune response. Structure and function of NLRs have been well studied in human and mice, but little information exists on genetic composition and role of these receptors in innate immune system of water buffalo—a species known for its exceptional disease resistance. Here, a comparative study on the functional domains of NOD1 and NOD2 was performed across different species. The NOD mediated in-vitro cellular responses were studied in buffalo peripheral blood mononuclear cells, resident macrophages, mammary epithelial, and fibroblast cells. Buffalo NOD1 (buNOD1) and buNOD2 showed conserved domain architectures as found in other mammals. The domains of buNOD1 and buNOD2 showed analogy in secondary and tertiary conformations. Constitutive expressions of NODs were ubiquitous in different tissues. Following treatment with NOD agonists, peripheral lymphocytes showed an IFN-γ response along-with production of pro-inflammatory cytokines. Alveolar macrophages and mammary epithelial cells showed NOD mediated in-vitro immune response through NF-κB dependent pathway. Fibroblasts showed pro-inflammatory cytokine response following agonist treatment. Our study demonstrates that both immune and non-immune cells could generate NOD-mediated responses to pathogens though the type and magnitude of response depend on the cell types. The structural basis of ligand recognition by buffalo NODs and knowledge of immune response by different cell types could be useful for development of non-infective innate immune modulators and next generation anti-inflammatory compounds. 相似文献
995.
Deidre A. Winnier Marcel Fourcaudot Luke Norton Muhammad A. Abdul-Ghani Shirley L. Hu Vidya S. Farook Dawn K. Coletta Satish Kumar Sobha Puppala Geetha Chittoor Thomas D. Dyer Rector Arya Melanie Carless Donna M. Lehman Joanne E. Curran Douglas T. Cromack Devjit Tripathy John Blangero Ravindranath Duggirala Harald H. H. G?ring Ralph A. DeFronzo Christopher P. Jenkinson 《PloS one》2015,10(4)
Type 2 diabetes (T2D) is a complex metabolic disease that is more prevalent in ethnic groups such as Mexican Americans, and is strongly associated with the risk factors obesity and insulin resistance. The goal of this study was to perform whole genome gene expression profiling in adipose tissue to detect common patterns of gene regulation associated with obesity and insulin resistance. We used phenotypic and genotypic data from 308 Mexican American participants from the Veterans Administration Genetic Epidemiology Study (VAGES). Basal fasting RNA was extracted from adipose tissue biopsies from a subset of 75 unrelated individuals, and gene expression data generated on the Illumina BeadArray platform. The number of gene probes with significant expression above baseline was approximately 31,000. We performed multiple regression analysis of all probes with 15 metabolic traits. Adipose tissue had 3,012 genes significantly associated with the traits of interest (false discovery rate, FDR ≤ 0.05). The significance of gene expression changes was used to select 52 genes with significant (FDR ≤ 10-4) gene expression changes across multiple traits. Gene sets/Pathways analysis identified one gene, alcohol dehydrogenase 1B (ADH1B) that was significantly enriched (P < 10-60) as a prime candidate for involvement in multiple relevant metabolic pathways. Illumina BeadChip derived ADH1B expression data was consistent with quantitative real time PCR data. We observed significant inverse correlations with waist circumference (2.8 x 10-9), BMI (5.4 x 10-6), and fasting plasma insulin (P < 0.001). These findings are consistent with a central role for ADH1B in obesity and insulin resistance and provide evidence for a novel genetic regulatory mechanism for human metabolic diseases related to these traits. 相似文献
996.
T. Rajesh S. Maruthasalam K. Kalpana K. Poovannan K. K. Kumar E. Kokiladevi D. Sudhakar R. Samiyappan P. Balasubramanian 《Biologia Plantarum》2016,60(4):749-756
Development of transgenic plants by introducing defense genes is one of the strategies to engineer disease resistance. Transgenic ASD16 rice plants harbouring rice chitinase chi11 gene, belonging to a PR-3 group of defense gene conferring sheath blight (Rhizoctonia solani Kuhn) resistance, were used in this study. Three T2 homozygous lines (ASD16-4-1-1, 5-1-1, and 6-1-1) were identified from seven putative (T0) transgenic lines expressing chi11 using Western blotting analysis. The inheritance of sheath blight resistance in those lines was studied over generations. The stability of chi11 expression up to T4 generation in all the three homozygous lines was proved by Western blot and the stability of sheath blight resistance in the homozygous lines was proved up to T4 generation using detached leaf and intact leaf sheath assays. Among the three homozygous lines tested, ASD16-4-1-1 showed consistent results in all the generations and gave a better protection against the sheath blight pathogen than the other two lines. 相似文献
997.
Andrea Seim Gulzar Omurova Erlan Azisov Kanaat Musuraliev Kumar Aliev Timur Tulyaganov Lyutsian Nikolyai Evgeniy Botman Gerd Helle Isabel Dorado Li?an Sandra Jivcov Hans W. Linderholm 《PloS one》2016,11(4)
Assessments of climate change impacts on forests and their vitality are essential for semi-arid environments such as Central Asia, where the mountain regions belong to the globally important biodiversity hotspots. Alterations in species distribution or drought-induced tree mortality might not only result in a loss of biodiversity but also in a loss of other ecosystem services. Here, we evaluate spatial trends and patterns of the growth-climate relationship in a tree-ring network comprising 33 juniper sites from the northern Pamir-Alay and Tien Shan mountain ranges in eastern Uzbekistan and across Kyrgyzstan for the common period 1935–2011. Junipers growing at lower elevations are sensitive to summer drought, which has increased in intensity during the studied period. At higher elevations, juniper growth, previously favored by warm summer temperatures, has in the recent few decades become negatively affected by increasing summer aridity. Moreover, response shifts are observed during all seasons. Rising temperatures and alterations in precipitation patterns during the past eight decades can account for the observed increase in drought stress of junipers at all altitudes. The implications of our findings are vital for the application of adequate long-term measures of ecosystem conservation, but also for paleo-climatic approaches and coupled climate-vegetation model simulations for Central Asia. 相似文献
998.
Synthesis of functional human immunodeficiency virus tat protein in baculovirus as determined by a cell-cell fusion assay. 总被引:3,自引:3,他引:3 下载免费PDF全文
The human immunodeficiency virus tat protein is a strong trans-activator of the expression of mRNAs originating from the viral long terminal repeat. We have expressed the first 72 amino acids (coding exon 1) of this protein in eucaryotic Spodoptera frugiperda SF9 cells by using a baculovirus vector, Autographa californica nuclear polyhedrosis virus. We show that the baculovirus vector stably produced the 72-amino-acid form of the tat protein but was unable to stably synthesize a larger 101-amino-acid full-length version of the same polypeptide. The 72-amino-acid tat protein, when introduced into mammalian fibroblasts by using a cell-cell fusion technique, functionally trans-activated the expression of the human immunodeficiency virus long terminal repeat. 相似文献
999.
Venkatasamy Vignesh Durairaj Rajesh Karuppaiah Parthiban Sridhar Arun Kamaraj Sathish Kumar Ramasamy Thirumurugan 《International journal of peptide research and therapeutics》2021,27(3):1709-1718
International Journal of Peptide Research and Therapeutics - Subtilosin A, a cyclic peptide from Bacillus subtilis is known for its antimicrobial activity against a diverse range of bacteria.... 相似文献
1000.
Samaiya Puneet K. Krishnamurthy Sairam Kumar Ashok 《Molecular and cellular biochemistry》2021,476(12):4421-4434
Molecular and Cellular Biochemistry - Perinatal asphyxia (PA)-induced brain injury may present as hypoxic-ischemic encephalopathy in the neonatal period, and long-term sequelae such as spastic... 相似文献