全文获取类型
收费全文 | 2658篇 |
免费 | 246篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 37篇 |
儿科学 | 138篇 |
妇产科学 | 88篇 |
基础医学 | 360篇 |
口腔科学 | 55篇 |
临床医学 | 317篇 |
内科学 | 511篇 |
皮肤病学 | 63篇 |
神经病学 | 302篇 |
特种医学 | 48篇 |
外科学 | 308篇 |
综合类 | 26篇 |
一般理论 | 4篇 |
预防医学 | 311篇 |
眼科学 | 59篇 |
药学 | 153篇 |
中国医学 | 5篇 |
肿瘤学 | 124篇 |
出版年
2024年 | 7篇 |
2023年 | 34篇 |
2022年 | 66篇 |
2021年 | 103篇 |
2020年 | 48篇 |
2019年 | 64篇 |
2018年 | 84篇 |
2017年 | 49篇 |
2016年 | 56篇 |
2015年 | 67篇 |
2014年 | 92篇 |
2013年 | 120篇 |
2012年 | 188篇 |
2011年 | 187篇 |
2010年 | 98篇 |
2009年 | 107篇 |
2008年 | 181篇 |
2007年 | 170篇 |
2006年 | 145篇 |
2005年 | 146篇 |
2004年 | 139篇 |
2003年 | 125篇 |
2002年 | 112篇 |
2001年 | 51篇 |
2000年 | 41篇 |
1999年 | 45篇 |
1998年 | 35篇 |
1997年 | 27篇 |
1996年 | 13篇 |
1995年 | 17篇 |
1994年 | 18篇 |
1993年 | 14篇 |
1992年 | 23篇 |
1991年 | 12篇 |
1990年 | 12篇 |
1989年 | 13篇 |
1988年 | 15篇 |
1987年 | 12篇 |
1986年 | 15篇 |
1985年 | 18篇 |
1984年 | 7篇 |
1983年 | 11篇 |
1982年 | 8篇 |
1981年 | 13篇 |
1979年 | 11篇 |
1978年 | 8篇 |
1975年 | 8篇 |
1974年 | 9篇 |
1972年 | 6篇 |
1971年 | 9篇 |
排序方式: 共有2909条查询结果,搜索用时 15 毫秒
91.
Christina Corre Miriam Friedel Dulcie A. Vousden Ariane Metcalf Shoshana Spring Lily R. Qiu Jason P. Lerch Mark R. Palmert 《Brain structure & function》2016,221(2):997-1016
Males and females exhibit several differences in brain structure and function. To examine the basis for these sex differences, we investigated the influences of sex hormones and sex chromosomes on brain structure and function in mice. We used the Four Core Genotype (4CG) mice, which can generate both male and female mice with XX or XY sex chromosome complement, allowing the decoupling of sex chromosomes from hormonal milieu. To examine whole brain structure, high-resolution ex vivo MRI was performed, and to assess differences in cognitive function, mice were trained on a radial arm maze. Voxel-wise and volumetric analyses of MRI data uncovered a striking independence of hormonal versus chromosomal influences in 30 sexually dimorphic brain regions. For example, the bed nucleus of the stria terminalis and the parieto-temporal lobe of the cerebral cortex displayed steroid-dependence while the cerebellar cortex, corpus callosum, and olfactory bulbs were influenced by sex chromosomes. Spatial learning and memory demonstrated strict hormone-dependency with no apparent influence of sex chromosomes. Understanding the influences of chromosomes and hormones on brain structure and function is important for understanding sex differences in brain structure and function, an endeavor that has eventual implications for understanding sex biases observed in the prevalence of psychiatric disorders. 相似文献
92.
93.
McMorran BJ Patat SA Carlin JB Grimwood K Jones A Armstrong DS Galati JC Cooper PJ Byrnes CA Francis PW Robertson CF Hume DA Borchers CH Wainwright CE Wainwright BJ 《Clinical chemistry》2007,53(10):1782-1791
BACKGROUND: Airway inflammation in cystic fibrosis (CF) is exaggerated and characterized by neutrophil-mediated tissue destruction, but its genesis and mechanisms remain poorly understood. To further define the pulmonary inflammatory response, we conducted a proteome-based screen of bronchoalveolar lavage fluid (BALF) collected from young children with and without CF experiencing endobronchial infection. METHODS: We collected BALF samples from 45 children younger than 5 years and grouped them according to the presence of respiratory pathogens: > or = 1 x 10(5) colony-forming units (CFU)/mL BALF (18 and 12 samples with and without CF, respectively) and <1 x 10(5) CFU/mL (23 and 15 samples). BALF proteins were analyzed with SELDI-TOF mass spectrometry (MS) and H4 ProteinChips. Proteins were identified and characterized using trypsin digestion, tandem MS, Fourier transform ion cyclotron resonance MS, immunoblotting, and ELISA. RESULTS: The SELDI-TOF MS BALF profiles contained 53 unique, reliably detected proteins. Peak intensities of 24 proteins differed significantly between the CF and non-CF samples. They included the neutrophil proteins, alpha-defensin 1 and 2, S100A8, S100A9, and S100A12, as well as novel forms of S100A8 and S100A12 with equivalent C-terminal deletions. Peak intensities of these neutrophil proteins and immunoreactive concentrations of selected examples were significantly higher in CF than non-CF samples. CONCLUSIONS: Small neutrophil-derived BALF proteins, including novel C-terminal truncated forms of S100A proteins, are easily detected with SELDI-TOF MS. Concentrations of these molecules are abnormally high in early CF lung disease. The data provide new insights into CF lung disease and identify novel proteins strongly associated with CF airway inflammation. 相似文献
94.
Carlin Lee Obiajulu Agha Mengyao Liu Michael Davies Lauren Bertoy Hubert T. Kim Xuhui Liu Brian T. Feeley 《Journal of orthopaedic research》2020,38(5):1113-1121
Fatty infiltration (FI) of rotator cuff (RC) muscles is common in patients with RC tears. Studies have demonstrated that fibro-adipogenic progenitors (FAPs), a population of resident muscle stem cells, are the main contributors of FI, which adversely affects muscle quality and RC repair success. Although FI is common in RC injuries, it is not frequently reported after other musculotendinous injuries. Additionally, studies have shown the development of different pathology patterns across muscle groups suggestive of intrinsic differences in cellular composition and behavior. This study evaluates FAP distribution and differentiation properties across anatomic locations in mice. Muscles from seven different anatomic locations were harvested from PDGFRα-eGFP FAP reporter mice. FAPs were quantified using histology and FACS sorting with BD Aria II with CD31−/CD45−/Integrinα7−/Sca-1+ and PDGFRα reporter signal (n = 3 per muscle). The cells were analyzed for adipogenesis using immunocytochemistry and for proliferation properties with Brdu-Ki67 staining. In a separate group of mice, RC and tibialis anterior muscles received glycerol injection and were harvested after 2 weeks for FI quantification (n = 4). One-way analysis of variance was used for statistical comparisons among groups, with significance at p < 0.05. FAPs from the RC, masseter, and paraspinal muscles were more numerous and demonstrated greater proliferative capacity and adipogenic potency than those from the tibialis anterior and gastrocnemius. The RC demonstrated significantly greater levels of FI than the tibialis anterior after glycerol-injection injury. Clinical Significance: This study suggests differences in FAP distribution and differentiation characteristics may account for the propensity to develop FI in RC tears as compared with other musculotendinous injuries. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:1113-1121, 2020 相似文献
95.
96.
97.
98.
99.
Therapeutic efficacy and safety of platelets treated with a photochemical process for pathogen inactivation: the SPRINT Trial 总被引:9,自引:1,他引:9
下载免费PDF全文
![点击此处可从《Blood》网站下载免费的PDF全文](/ch/ext_images/free.gif)
McCullough J Vesole DH Benjamin RJ Slichter SJ Pineda A Snyder E Stadtmauer EA Lopez-Plaza I Coutre S Strauss RG Goodnough LT Fridey JL Raife T Cable R Murphy S Howard F Davis K Lin JS Metzel P Corash L Koutsoukos A Lin L Buchholz DH Conlan MG 《Blood》2004,104(5):1534-1541
We report a transfusion trial of platelets photochemically treated for pathogen inactivation using the synthetic psoralen amotosalen HCl. Patients with thrombocytopenia were randomly assigned to receive either photochemically treated (PCT) or conventional (control) platelets for up to 28 days. The primary end point was the proportion of patients with World Health Organization (WHO) grade 2 bleeding during the period of platelet support. A total of 645 patients (318 PCT and 327 control) were evaluated. The primary end point, the incidence of grade 2 bleeding (58.5% PCT versus 57.5% control), and the secondary end point, the incidence of grade 3 or 4 bleeding (4.1% PCT versus 6.1% control), were equivalent between the 2 groups (P =.001 by noninferiority). The mean 1-hour posttransfusion platelet corrected count increment (CCI) (11.1 x 10(3) PCT versus 16.0 x 10(3) control), average number of days to next platelet transfusion (1.9 PCT versus 2.4 control), and number of platelet transfusions (8.4 PCT versus 6.2 control) were different (P <.001). Transfusion reactions were fewer following PCT platelets (3.0% PCT versus 4.4% control; P =.02). The incidence of grade 2 bleeding was equivalent for PCT and conventional platelets, although posttransfusion platelet count increments and days to next transfusion were decreased for PCT compared with conventional platelets. 相似文献
100.
Genghis Khan (Gek) as a putative effector for Drosophila Cdc42 and regulator of actin polymerization
下载免费PDF全文
![点击此处可从《Proceedings of the National Academy of Sciences of the United States of America》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Liqun Luo Tzumin Lee Linus Tsai Gale Tang Lily Y. Jan Yuh Nung Jan 《Proceedings of the National Academy of Sciences of the United States of America》1997,94(24):12963-12968
The small GTPases Cdc42 and Rac regulate a variety of biological processes, including actin polymerization, cell proliferation, and JNK/mitogen-activated protein kinase activation, conceivably via distinct effectors. Whereas the effector for mitogen-activated protein kinase activation appears to be p65PAK, the identity of effector(s) for actin polymerization remains unclear. We have found a putative effector for Drosophila Cdc42, Genghis Khan (Gek), which binds to Dcdc42 in a GTP-dependent and effector domain-dependent manner. Gek contains a predicted serine/threonine kinase catalytic domain that is 63% identical to human myotonic dystrophy protein kinase and has protein kinase activities. It also possesses a large coiled-coil domain, a putative phorbol ester binding domain, a pleckstrin homology domain, and a Cdc42 binding consensus sequence that is required for its binding to Dcdc42. To study the in vivo function of gek, we generated mutations in the Drosophila gek locus. Egg chambers homozygous for gek mutations exhibit abnormal accumulation of F-actin and are defective in producing fertilized eggs. These phenotypes can be rescued by a wild-type gek transgene. Our results suggest that this multidomain protein kinase is an effector for the regulation of actin polymerization by Cdc42. 相似文献