全文获取类型
收费全文 | 1700篇 |
免费 | 141篇 |
国内免费 | 1篇 |
专业分类
1842篇 |
出版年
2023年 | 6篇 |
2022年 | 23篇 |
2021年 | 33篇 |
2020年 | 35篇 |
2019年 | 33篇 |
2018年 | 47篇 |
2017年 | 30篇 |
2016年 | 45篇 |
2015年 | 73篇 |
2014年 | 76篇 |
2013年 | 107篇 |
2012年 | 153篇 |
2011年 | 124篇 |
2010年 | 81篇 |
2009年 | 74篇 |
2008年 | 91篇 |
2007年 | 92篇 |
2006年 | 70篇 |
2005年 | 65篇 |
2004年 | 72篇 |
2003年 | 60篇 |
2002年 | 52篇 |
2001年 | 31篇 |
2000年 | 18篇 |
1999年 | 14篇 |
1998年 | 14篇 |
1996年 | 6篇 |
1994年 | 10篇 |
1993年 | 10篇 |
1992年 | 21篇 |
1991年 | 14篇 |
1990年 | 19篇 |
1989年 | 16篇 |
1987年 | 12篇 |
1986年 | 15篇 |
1985年 | 5篇 |
1984年 | 15篇 |
1983年 | 11篇 |
1982年 | 13篇 |
1981年 | 10篇 |
1980年 | 9篇 |
1979年 | 14篇 |
1978年 | 14篇 |
1977年 | 20篇 |
1976年 | 11篇 |
1975年 | 7篇 |
1974年 | 7篇 |
1973年 | 11篇 |
1972年 | 13篇 |
1968年 | 5篇 |
排序方式: 共有1842条查询结果,搜索用时 15 毫秒
31.
32.
33.
Thirunavukkarasu Muralisankar Periyakali Saravana Bhavan Subramanian Radhakrishnan Chandirasekar Seenivasan Narasimman Manickam Veeran Srinivasan 《Biological trace element research》2014,160(1):56-66
The present study was conducted to assess the influence of dietary zinc nanoparticles (size 50 nm) on the growth, biochemical constituents, enzymatic antioxidant levels and the nonspecific immune response of the freshwater prawn, Macrobrachium rosenbergii post larvae (PL). The concentrations of dietary supplement zinc nanoparticles (ZnNPs) were 0, 10, 20, 40, 60 and 80 mg kg?1 with the basal diet, and the level of Zn in ZnNP-supplemented diets were 0.71, 10.61, 20.73, 40.73, 60.61 and 80.60 mg kg?1, respectively. ZnNP-incorporated diets were fed to M. rosenbergii PL (initial body weight, 0.18?±?0.02 g) in a triplicate experimental setup for a period of 90 days. ZnNP supplemented feed fed PL up to 60 mg kg?1 showed significantly (P?<?0.05) improved performance in survival, growth and activities of digestive enzymes (protease, amylase and lipase). The concentrations of biochemical constituents (total protein, total amino acid, total carbohydrate and total lipid), total haemocyte count and differential haemocyte count were elevated in 10–60 mg kg?1 ZnNP supplemented feed fed PL. However, the PL fed with 80 mg ZnNPs kg?1 showed negative results. Activities of enzymatic antioxidants [superoxide dismutase (SOD) and catalase (CAT)], metabolic enzymes [glutamate–oxaloacetate transaminase (GOT) and glutamate–pyruvate transaminase (GPT)] and the process of lipid peroxidation (LPO) in the hepatopancreas and muscle showed no significant alterations in 10–60 mg kg?1 ZnNP supplemented feed fed PL. Whereas, 80 mg ZnNPs kg?1 supplemented feed fed PL showed significant elevations in SOD, CAT, LPO, GOT and GPT. Therefore, 80 mg ZnNPs kg?1 was found to be toxic to M. rosenbergii PL. Thus, the study suggests that up to 60 mg ZnNPs kg?1 can be supplemented for regulating survival, growth and immunity of M. rosenbergii. 相似文献
34.
Endom Ismail Omimah Khaled Jaber Nofal Rajalingham Sakthiswary Syahrul Sazliyana Shaharir Radhika Sridharan 《PloS one》2016,11(4)
ObjectiveInterleukin-1 receptor antagonist (IL-1Ra) acts as an inhibitor of IL-1; which is one of the culprit cytokines in rheumatoid arthritis (RA). Although +2018 polymorphism of IL-1Ra has been implicated in the pathogenesis of RA, its importance remains poorly understood. Hence, the purpose of this study was to determine the clinical significance of interleukin-1 receptor antagonist (IL-1Ra) +2018 polymorphism in RA.MethodsPolymerase chain reaction (PCR) and sequencing were used to determine the genotypes of the IL-1Ra +2018 for 77 RA patients and 18 healthy controls. All RA patients were assessed for the disease activity score that includes 28 joints (DAS28) and radiographic disease damage based on Modified Sharp Score (MSS).ResultsThe frequency of the T/T and C/T genotypes did not differ significantly (p = 0.893) between the RA patients and the controls. The C/T genotype had significantly higher mean disease activity (DAS 28) and disease damage (MSS) scores with p values of 0.017 and 0.004, respectively. Additionally, the ESR (erythrocyte sedimentation rate), CRP (C-reactive protein), the number of swollen and tender joints were higher for the C/T individuals. On multivariate analysis the CRP, swollen joint count and MSS remained significant with the following p values i.e. 0.045, 0.046 and less than 0.05.ConclusionsC/T genotype of IL-1Ra +2018 prognosticates more aggressive disease in RA. 相似文献
35.
JH Shazia Fathima Jayaraman Selvaraj Venkatacalam Sivabalan Umapathy Vidhya Rekha Rajagopal Ponnulakshmi Veeraraghavan Vishnupriya Malathi Kullappan Radhika Nalinakumari Sreekandan Surapaneni Krishna Mohan Periyasamy Vijayalakshmi 《Bioinformation》2021,17(1):212
The mTOR (mammalian or mechanistic Target of Rapamycin) is linked with oral cancer. Therefore, it is of interest to study the molecular docking-based binding of paclitaxel (a FDA approved drug for oral cancer) and its analogues with mTOR. Hence, we report the binding features of 10-Deacetyltaxol, 7-Epi-10-deacetyltaxol, 7-Epi-Taxol and 6alpha-Hydroxypaclitaxel with mTOR for further consideration. 相似文献
36.
37.
38.
39.
Huan J Subramanian S Jones R Rich C Link J Mooney J Bourdette DN Vandenbark AA Burrows GG Offner H 《Journal of immunology (Baltimore, Md. : 1950)》2004,172(7):4556-4566
Our previous studies demonstrated that oligomeric recombinant TCR ligands (RTL) can treat clinical signs of experimental autoimmune encephalomyelitis (EAE) and induce long-term T cell tolerance against encephalitogenic peptides. In the current study, we produced a monomeric I-A(s)/PLP 139-151 peptide construct (RTL401) suitable for use in SJL/J mice that develop relapsing disease after injection of PLP 139-151 peptide in CFA. RTL401 given i.v. or s.c. but not empty RTL400 or free PLP 139-151 peptide prevented relapses and significantly reduced clinical severity of EAE induced by PLP 139-151 peptide in SJL/J or (C57BL/6 x SJL)F(1) mice, but did not inhibit EAE induced by PLP 178-191 or MBP 84-104 peptides in SJL/J mice, or MOG 35-55 peptide in (C57BL/6 x SJL/J)F(1) mice. RTL treatment of EAE caused stable or enhanced T cell proliferation and secretion of IL-10 in the periphery, but reduced secretion of inflammatory cytokines and chemokines. In CNS, there was a modest reduction of inflammatory cells, reduced expression of very late activation Ag-4, lymphocyte function-associated Ag-1, and inflammatory cytokines, chemokines, and chemokine receptors, but enhanced expression of Th2-related factors, IL-10, TGF-beta3, and CCR3. These results suggest that monomeric RTL therapy induces a cytokine switch that curbs the encephalitogenic potential of PLP 139-151-specific T cells without fully preventing their entry into CNS, wherein they reduce the severity of inflammation. This mechanism differs from that observed using oligomeric RTL therapy in other EAE models. These results strongly support the clinical application of this novel class of peptide/MHC class II constructs in patients with multiple sclerosis who have focused T cell responses to known encephalitogenic myelin peptides. 相似文献
40.