全文获取类型
收费全文 | 16185篇 |
免费 | 734篇 |
国内免费 | 702篇 |
专业分类
17621篇 |
出版年
2025年 | 1篇 |
2024年 | 203篇 |
2023年 | 214篇 |
2022年 | 464篇 |
2021年 | 831篇 |
2020年 | 528篇 |
2019年 | 627篇 |
2018年 | 629篇 |
2017年 | 527篇 |
2016年 | 622篇 |
2015年 | 899篇 |
2014年 | 1073篇 |
2013年 | 1207篇 |
2012年 | 1405篇 |
2011年 | 1259篇 |
2010年 | 780篇 |
2009年 | 684篇 |
2008年 | 752篇 |
2007年 | 627篇 |
2006年 | 608篇 |
2005年 | 489篇 |
2004年 | 431篇 |
2003年 | 332篇 |
2002年 | 347篇 |
2001年 | 315篇 |
2000年 | 254篇 |
1999年 | 249篇 |
1998年 | 165篇 |
1997年 | 130篇 |
1996年 | 133篇 |
1995年 | 125篇 |
1994年 | 137篇 |
1993年 | 92篇 |
1992年 | 96篇 |
1991年 | 70篇 |
1990年 | 67篇 |
1989年 | 58篇 |
1988年 | 56篇 |
1987年 | 31篇 |
1986年 | 33篇 |
1985年 | 19篇 |
1984年 | 23篇 |
1983年 | 12篇 |
1982年 | 8篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1979年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1933年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 10 毫秒
41.
Zigui Chen Rita Way Yin Ng Grace Lui Lowell Ling Agnes S. Y. Leung Chit Chow Siaw Shi Boon Wendy C. S. Ho Maggie Haitian Wang Renee Wan Yi Chan Albert Martin Li David Shu Cheong Hui Paul Kay Sheung Chan 《中国病毒学》2024,39(2):218-227
The SARS-CoV-2 Omicron variants are notorious for their transmissibility, but little is known about their subgenomic RNA (sgRNA) expression. This study applied RNA-seq to delineate the quantitative and qualitative profiles of canonical sgRNA of 118 respiratory samples collected from patients infected with Omicron BA.2 and compared with 338 patients infected with non-variant of concern (non-VOC)-D614G. A unique characteristic profile depicted by the relative abundance of 9 canonical sgRNAs was reproduced by both BA.2 and non-VOC-D614G regardless of host gender, age and presence of pneumonia. Remarkably, such profile was lost in samples with low viral load, suggesting a potential application of sgRNA pattern to indicate viral activity of individual patient at a specific time point. A characteristic qualitative profile of canonical sgRNAs was also reproduced by both BA.2 and non-VOC-D614G. The presence of a full set of canonical sgRNAs carried a coherent correlation with crude viral load (AUC = 0.91, 95% CI 0.88–0.94), and sgRNA ORF7b was identified to be the best surrogate marker allowing feasible routine application in characterizing the infection status of individual patient. Further potentials in using sgRNA as a target for vaccine and antiviral development are worth pursuing. 相似文献
42.
43.
Xiu-Qing Li Meng-Pan Cai Ming-Yang Wang Bo-Wen Shi Guo-Yu Yang Jiang Wang Bei-Bei Chu Sheng-Li Ming 《中国病毒学》2024,39(3):403-413
The pseudorabies virus (PRV) is identified as a double-helical DNA virus responsible for causing Aujeszky's disease, which results in considerable economic impacts globally. The enzyme tryptophanyl-tRNA synthetase 2 (WARS2), a mitochondrial protein involved in protein synthesis, is recognized for its broad expression and vital role in the translation process. The findings of our study showed an increase in both mRNA and protein levels of WARS2 following PRV infection in both cell cultures and animal models. Suppressing WARS2 expression via RNA interference in PK-15 cells led to a reduction in PRV infection rates, whereas enhancing WARS2 expression resulted in increased infection rates. Furthermore, the activation of WARS2 in response to PRV was found to be reliant on the cGAS/STING/TBK1/IRF3 signaling pathway and the interferon-alpha receptor-1, highlighting its regulation via the type I interferon signaling pathway. Further analysis revealed that reducing WARS2 levels hindered PRV's ability to promote protein and lipid synthesis. Our research provides novel evidence that WARS2 facilitates PRV infection through its management of protein and lipid levels, presenting new avenues for developing preventative and therapeutic measures against PRV infections. 相似文献
44.
Yongxin Nie;Hui Wang;Guan Zhang;Haiping Ding;Beibei Han;Lei Liu;Jian Shi;Jiyuan Du;Xiaohu Li;Xinzheng Li;Yajie Zhao;Xiaocong Zhang;Changlin Liu;Jianfeng Weng;Xinhai Li;Xiansheng Zhang;Xiangyu Zhao;Guangtang Pan;David Jackson;Qin-Bao Li;Philip S. Stinard;Jennifer Arp;Martin M. Sachs;Steven Moose;Charles T. Hunter;Qingyu Wu;Zhiming Zhang; 《The Plant journal : for cell and molecular biology》2024,118(2):457-468
Carotenoids perform a broad range of important functions in humans; therefore, carotenoid biofortification of maize (Zea mays L.), one of the most highly produced cereal crops worldwide, would have a global impact on human health. PLASTID TERMINAL OXIDASE (PTOX) genes play an important role in carotenoid metabolism; however, the possible function of PTOX in carotenoid biosynthesis in maize has not yet been explored. In this study, we characterized the maize PTOX locus by forward- and reverse-genetic analyses. While most higher plant species possess a single copy of the PTOX gene, maize carries two tandemly duplicated copies. Characterization of mutants revealed that disruption of either copy resulted in a carotenoid-deficient phenotype. We identified mutations in the PTOX genes as being causal of the classic maize mutant, albescent1. Remarkably, overexpression of ZmPTOX1 significantly improved the content of carotenoids, especially β-carotene (provitamin A), which was increased by ~threefold, in maize kernels. Overall, our study shows that maize PTOX locus plays an important role in carotenoid biosynthesis in maize kernels and suggests that fine-tuning the expression of this gene could improve the nutritional value of cereal grains. 相似文献
45.
46.
Yufang Lu;Fangjia Wang;Ju Min;Herbert J. Kronzucker;Yao Hua;Haoming Yu;Feng Zhou;Weiming Shi; 《Global Change Biology》2024,30(5):e17333
Plant metabolites significantly affect soil nitrogen (N) cycling, but their influence on nitrous oxide (N2O) emissions has not been quantitatively analyzed on a global scale. We conduct a comprehensive meta-analysis of 173 observations from 42 articles to evaluate global patterns of and principal factors controlling N2O emissions in the presence of root exudates and extracts. Overall, plant metabolites promoted soil N2O emissions by about 10%. However, the effects of plant metabolites on N2O emissions from soils varied with experimental conditions and properties of both metabolites and soils. Primary metabolites, such as sugars, amino acids, and organic acids, strongly stimulated soil N2O emissions, by an average of 79%, while secondary metabolites, such as phenolics, terpenoids, and flavonoids, often characterized as both biological nitrification inhibitors (BNIs) and biological denitrification inhibitors (BDIs), reduced soil N2O emissions by an average of 41%. The emission mitigation effects of BNIs/BDIs were closely associated with soil texture and pH, increasing with increasing soil clay content and soil pH on acidic and neutral soils, and with decreasing soil pH on alkaline soils. We furthermore present soil incubation experiments that show that three secondary metabolite types act as BNIs to reduce N2O emissions by 32%–45%, while three primary metabolite classes possess a stimulatory effect of 56%–63%, confirming the results of the meta-analysis. Our results highlight the potential role and application range of specific secondary metabolites in biomitigation of global N2O emissions and provide new biological parameters for N2O emission models that should help improve the accuracy of model predictions. 相似文献
47.
Sophia Barber;Veronica Gomez-Godinez;Joy Young;Abigail Wei;Sarah Chen;Anna Snissarenko;Sze Sze Chan;Chengbiao Wu;Linda Shi; 《Journal of biophotonics》2024,17(3):e202300370
Axonal degeneration is a key component of neurodegenerative diseases such as Huntington's disease (HD), Alzheimer's disease, and amyotrophic lateral sclerosis. Nicotinamide, an NAD+ precursor, has long since been implicated in axonal protection and reduction of degeneration. However, studies on nicotinamide (NAm) supplementation in humans indicate that NAm has no protective effect. Sterile alpha and toll/interleukin receptor motif-containing protein 1 (SARM1) regulates several cell responses to axonal damage and has been implicated in promoting neuronal degeneration. SARM1 inhibition seems to result in protection from neuronal degeneration while hydrogen peroxide has been implicated in oxidative stress and axonal degeneration. The effects of laser-induced axonal damage in wild-type and HD dorsal root ganglion cells treated with NAm, hydrogen peroxide (H2O2), and SARM1 inhibitor DSRM-3716 were investigated and the cell body width, axon width, axonal strength, and axon shrinkage post laser-induced injury were measured. 相似文献
48.
Sai J. Ganesan Michael J. Feyder Ilan E. Chemmama Fei Fang Michael P. Rout Brian T. Chait Yi Shi Mary Munson Andrej Sali 《Protein science : a publication of the Protein Society》2020,29(6):1486-1501
Exocyst is an evolutionarily conserved hetero‐octameric tethering complex that plays a variety of roles in membrane trafficking, including exocytosis, endocytosis, autophagy, cell polarization, cytokinesis, pathogen invasion, and metastasis. Exocyst serves as a platform for interactions between the Rab, Rho, and Ral small GTPases, SNARE proteins, and Sec1/Munc18 regulators that coordinate spatial and temporal fidelity of membrane fusion. However, its mechanism is poorly described at the molecular level. Here, we determine the molecular architecture of the yeast exocyst complex by an integrative approach, based on a 3D density map from negative‐stain electron microscopy (EM) at ~16 Å resolution, 434 disuccinimidyl suberate and 1‐ethyl‐3‐(3‐dimethylaminopropyl)carbodiimide hydrochloride cross‐links from chemical‐crosslinking mass spectrometry, and partial atomic models of the eight subunits. The integrative structure is validated by a previously determined cryo‐EM structure, cross‐links, and distances from in vivo fluorescence microscopy. Our subunit configuration is consistent with the cryo‐EM structure, except for Sec5. While not observed in the cryo‐EM map, the integrative model localizes the N‐terminal half of Sec3 near the Sec6 subunit. Limited proteolysis experiments suggest that the conformation of Exo70 is dynamic, which may have functional implications for SNARE and membrane interactions. This study illustrates how integrative modeling based on varied low‐resolution structural data can inform biologically relevant hypotheses, even in the absence of high‐resolution data. 相似文献
49.
Xiaojing Shi Yong Zhang 《Protein science : a publication of the Protein Society》2020,29(9):1924-1930
Cathepsin L (CTSL) is a cysteine protease involved in a variety of physiological and pathological processes. Potent inhibitors against CTSL have long been sought for drug development. Due to insufficient specificity and suboptimal pharmacological properties for current CTSL inhibitors, novel agents are still required for selectively blocking CTSL activity. Here we generated a humanized antibody inhibitor of CTSL by genetically fusing the inhibitory propeptide of procathepsin L to the N‐terminus of the light chain of a humanized antibody. The resulting antibody fusion could be stably expressed and displays highly potent inhibition activity and specificity toward CTSL. This work demonstrates a new approach for the rapid generation of antibody inhibitors of CTSL. It can possibly be extended to create inhibitory antibodies targeting other cathepsin proteases, providing novel research and therapeutic tools. 相似文献
50.
Yuan Shi Yuandong Zhu Xiao Zheng Zhuojun Zheng 《Journal of cellular physiology》2020,235(10):6536-6547