全文获取类型
收费全文 | 932篇 |
免费 | 44篇 |
国内免费 | 1篇 |
出版年
2023年 | 8篇 |
2022年 | 22篇 |
2021年 | 29篇 |
2020年 | 12篇 |
2019年 | 25篇 |
2018年 | 31篇 |
2017年 | 30篇 |
2016年 | 36篇 |
2015年 | 45篇 |
2014年 | 67篇 |
2013年 | 71篇 |
2012年 | 82篇 |
2011年 | 88篇 |
2010年 | 59篇 |
2009年 | 41篇 |
2008年 | 34篇 |
2007年 | 50篇 |
2006年 | 30篇 |
2005年 | 27篇 |
2004年 | 29篇 |
2003年 | 25篇 |
2002年 | 23篇 |
2001年 | 8篇 |
2000年 | 10篇 |
1999年 | 3篇 |
1997年 | 4篇 |
1996年 | 5篇 |
1994年 | 5篇 |
1992年 | 8篇 |
1991年 | 8篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1988年 | 4篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1985年 | 8篇 |
1984年 | 10篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1976年 | 2篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1972年 | 4篇 |
1970年 | 1篇 |
1969年 | 3篇 |
1967年 | 2篇 |
1950年 | 1篇 |
排序方式: 共有977条查询结果,搜索用时 31 毫秒
301.
302.
Patrick Marcinek Aditya Nath Jha Vidyagouri Shinde Arun Sundaramoorthy Raja Rajkumar Naveen Chandra Suryadevara Sanjeev Kumar Neela Hoang van Tong Vellingiri Balachander Vijaya Lakshmi Valluri Kumarasamy Thangaraj Thirumalaisamy P Velavan 《PloS one》2013,8(8)
In recent years, genome wide association studies have discovered a large number of gene loci that play a functional role in innate and adaptive immune pathways associated with leprosy susceptibility. The immunological control of intracellular bacteria M. leprae is modulated by NOD2-mediated signaling of Th1 responses. In this study, we investigated 211 clinically classified leprosy patients and 230 ethnically matched controls in Indian population by genotyping four variants in NOD2 (rs9302752A/G), LRRK2 (rs1873613A/G), RIPK2 (rs40457A/G and rs42490G/A). The LRRK2 locus is associated with leprosy outcome. The LRRK2 rs1873613A minor allele and respective rs1873613AA genotypes were significantly associated with an increased risk whereas the LRRK2 rs1873613G major allele and rs1873613GG genotypes confer protection in paucibacillary and leprosy patients. The reconstructed GA haplotypes from RIPK2 rs40457A/G and rs42490G/A variants was observed to contribute towards increased risk whereas haplotypes AA was observed to confer protective role. Our results indicate that a possible shared mechanisms underlying the development of these two clinical forms of the disease as hypothesized. Our findings confirm and validates the role of gene variants involved in NOD2-mediated signalling pathways that play a role in immunological control of intracellular bacteria M. leprae. 相似文献
303.
304.
Population indices of bacteria and archaea were investigated from saline–alkaline soil and a possible microbe–environment pattern was established using gene targeted metagenomics. Clone libraries were constructed using 16S rRNA and functional gene(s) involved in carbon fixation (cbbL), nitrogen fixation (nifH), ammonia oxidation (amoA) and sulfur metabolism (apsA). Molecular phylogeny revealed the dominance of Actinobacteria, Firmicutes and Proteobacteria along with archaeal members of Halobacteraceae. The library consisted of novel bacterial (20%) and archaeal (38%) genera showing ≤95% similarity to previously retrieved sequences. Phylogenetic analysis indicated ability of inhabitant to survive in stress condition. The 16S rRNA gene libraries contained novel gene sequences and were distantly homologous with cultured bacteria. Functional gene libraries were found unique and most of the clones were distantly related to Proteobacteria, while clones of nifH gene library also showed homology with Cyanobacteria and Firmicutes. Quantitative real-time PCR exhibited that bacterial abundance was two orders of magnitude higher than archaeal. The gene(s) quantification indicated the size of the functional guilds harboring relevant key genes. The study provides insights on microbial ecology and different metabolic interactions occurring in saline–alkaline soil, possessing phylogenetically diverse groups of bacteria and archaea, which may be explored further for gene cataloging and metabolic profiling. 相似文献
305.
Ionic liquids (ILs) are generally considered as the green replacement for conventional volatile organic solvents. Nonetheless, their high solubility in water with proven toxic effects on aquatic biota has questioned their green credentials. In the present study, the detoxification potential of Acadian marine plant extract powder (AMPEP) prepared from the brown alga Ascophyllum nodosum was investigated against the 1-alkyl-3-methylimidazolium bromide [C12mim]Br ionic liquid-induced toxicity and oxidative stress in marine macroalga Ulva lactuca. The IL ([C12mim]Br) at LC50 (70 μM) exposure triggered the generation of reactive oxygen species (ROS) such as O 2 ·? , H2O2 and OH· causing membrane and DNA damage together with inhibition of antioxidant systems in the alga. The supplementation of AMPEP (150 μg mL?1) to the culture medium significantly reduced the accumulation of ROS and lipid peroxidation together with the inhibition of lipoxygenase (LOX) activity specially LOX-2 and LOX-3 isoforms. This is for the first time wherein comet assay was performed to ascertain the protective role of AMPEP against DNA damage in algal tissue grown in medium supplemented with IL and AMPEP. The AMPEP showed protective role against DNA damage (5–45 % tail DNA) when compared to those of grown in IL alone (45–70 % tail DNA). Further, specific isomorphs of different antioxidant enzymes such as superoxide dismutase (Mn-SOD-1, ~150 kDa), ascorbate peroxidase (APX-4, ~55 kDa), glutathione peroxidase (GSH-Px-2, ~55 kDa) and glutathione reductase (GR-1, ~180 kDa) responded specifically to AMPEP supplementation. It is evident from these findings that AMPEP could possibly be used for circumventing the negative effects arising from ILs-induced toxicity in marine ecosystem. 相似文献
306.
307.
Neeraj Kumar Damini Sood Aditya Gupta Niraj
Kumar Jha Pallavi Jain Ramesh Chandra 《Bioscience reports》2020,40(12)
Immunotherapy is a breakthrough approach for cancer treatment and prevention. By exploiting the fact that cancer cells have overexpression of tumor antigens responsible for its growth and progression, which can be identified and removed by boosting the immune system. In silico techniques have provided efficient ways for developing preventive measures to ward off cancer. Herein, we have designed a potent cytotoxic T-lymphocyte epitope to elicit a desirable immune response against carcinogenic melanoma-associated antigen-A11. Potent epitope was predicted using reliable algorithms and characterized by advanced computational avenue CABS molecular dynamics simulation, for full flexible binding with HLA-A*0201 and androgen receptor to large-scale rearrangements of the complex system. Results showed the potent immunogenic construct (KIIDLVHLL), from top epitopes using five algorithms. Molecular docking analyses showed the strong binding of epitope with HLA-A*0201 and androgen receptor with docking score of −780.6 and −641.06 kcal/mol, respectively. Molecular dynamics simulation analysis revealed strong binding of lead epitope with androgen receptor by involvement of 127 elements through atomic-model study. Full flexibility study showed stable binding of epitope with an average root mean square deviation (RMSD) 2.21 Å and maximum RMSD value of 6.48 Å in optimal cluster density area. The epitope also showed remarkable results with radius of gyration 23.0777 Å, world population coverage of 39.08% by immune epitope database, and transporter associated with antigen processing (TAP) affinity IC50 value of 2039.65 nm. Moreover, in silico cloning approach confirmed the expression and translation capacity of the construct within a suitable expression vector. The present study paves way for a potential immunogenic construct for prevention of cancer. 相似文献
308.
An alkaliphilic, moderately thermophilic and halophilic bacterial isolate capable of producing a high titer of extracellular
thermo-alkali-stable, cellulase-free endoxylanase was isolated from the paper mill effluents. It was identified as Bacillus halodurans. The purified xylanase was active from pH 7 to 12 and 30 to 100°C with optimal activity at pH 9.0 and 80°C. It had T1/2 values of 40 and 15 min at 70 and 80°C, respectively. Activity was stimulated by dithiothreitol but strongly inhibited by
N-bromosuccinimide. Its action on birchwood xylan and agro-residues liberated xylooligosaccharides of 2–7 degree of polymerization,
and thus, the mode of action is similar to endoxylanases of the family 10 glucoside hydrolases. 相似文献
309.
310.
The present study firstly reports the cytological and molecular marker assisted differentiation of isomorphic population of
Gracilaria
corticata (J. Agardh) with inter and intra-phasic genetic diversity analysis using ISSR markers. The genetic diversity of inbreeding
population of G. corticata as determined in terms of percentage of polymorphic loci (PPL), average heterozygosity (He) and Shannon’s Weaver index (I)
were 59.80, 0.59 and 1.21, respectively. The inter-phasic pair-wise average polymorphism were found to be 31.6% between male
and female, 24.0% in male and tetrasporophyte and 25.3% in female and tetrasporophyte. The intra-phasic average polymorphisms
were calculated as a maximum of 5.5% between females, 4.2% between males and the lowest 2.4% between tetrasporophytes. The
primer 10 generated a marker of 800 bp specific to male and 650 bp to female gametophyte, while the primer 17 generated a
marker of 2,500 bp specific to tetrasporophyte. Both the UPGMA based dendrogram and PCA analysis clustered all the three life
phases differentially as distinct identity. Cytological analysis by chromosome count revealed 24 chromosomes in both haploid
male and female gametophytes (N) and 48 for diploid (2 N) tetrasporophyte further confirming their genetic distinctness. The
life phase specific markers reported in this study could be of help in breeding programmes where differentiation of life phases
at the early developmental stages is crucial. 相似文献