全文获取类型
收费全文 | 5524篇 |
免费 | 426篇 |
国内免费 | 18篇 |
专业分类
耳鼻咽喉 | 86篇 |
儿科学 | 89篇 |
妇产科学 | 75篇 |
基础医学 | 965篇 |
口腔科学 | 53篇 |
临床医学 | 566篇 |
内科学 | 1187篇 |
皮肤病学 | 147篇 |
神经病学 | 511篇 |
特种医学 | 310篇 |
外科学 | 611篇 |
综合类 | 31篇 |
一般理论 | 2篇 |
预防医学 | 330篇 |
眼科学 | 130篇 |
药学 | 409篇 |
中国医学 | 9篇 |
肿瘤学 | 457篇 |
出版年
2023年 | 26篇 |
2022年 | 82篇 |
2021年 | 145篇 |
2020年 | 64篇 |
2019年 | 113篇 |
2018年 | 132篇 |
2017年 | 116篇 |
2016年 | 147篇 |
2015年 | 191篇 |
2014年 | 202篇 |
2013年 | 259篇 |
2012年 | 365篇 |
2011年 | 434篇 |
2010年 | 238篇 |
2009年 | 284篇 |
2008年 | 416篇 |
2007年 | 377篇 |
2006年 | 413篇 |
2005年 | 380篇 |
2004年 | 405篇 |
2003年 | 349篇 |
2002年 | 290篇 |
2001年 | 56篇 |
2000年 | 40篇 |
1999年 | 38篇 |
1998年 | 66篇 |
1997年 | 59篇 |
1996年 | 33篇 |
1995年 | 30篇 |
1994年 | 25篇 |
1993年 | 18篇 |
1992年 | 14篇 |
1991年 | 12篇 |
1990年 | 8篇 |
1989年 | 7篇 |
1988年 | 7篇 |
1986年 | 11篇 |
1985年 | 5篇 |
1982年 | 13篇 |
1981年 | 7篇 |
1980年 | 5篇 |
1979年 | 5篇 |
1978年 | 10篇 |
1977年 | 4篇 |
1975年 | 4篇 |
1974年 | 7篇 |
1973年 | 7篇 |
1972年 | 3篇 |
1971年 | 4篇 |
1970年 | 3篇 |
排序方式: 共有5968条查询结果,搜索用时 15 毫秒
71.
Coamplification of DDX1 correlates with an improved survival probability in children with MYCN-amplified human neuroblastoma. 总被引:3,自引:0,他引:3
Axel Weber Patricia Imisch Eckhard Bergmann Holger Christiansen 《Journal of clinical oncology》2004,22(13):2681-2690
PURPOSE: Amplification of the MYCN oncogene at chromosome 2p24-25 identifies an aggressive subtype of human neuroblastoma with a poor clinical outcome. Differences in amplicon structure and coamplification of genes telomeric and centromeric to the MYCN oncogene have previously been described. A relevant role of gene coamplification for neuroblastoma pathogenesis remains elusive. PATIENTS AND METHODS: We analyzed 98 primary neuroblastoma tumors with MYCN amplification for coamplification of seven additional genes at chromosome 2p24-25 (DDX1, NAG, NSE1, LPIN1, EST-AA581763, SMC6, and SDC1). Two semiquantitative multiplex polymerase chain reactions were used to obtain the amplification status of the target genes in relation to a reference gene on chromosome 2q (Inhibin-beta-b). Furthermore, mRNA expression pattern of coamplified genes in a subset of tumors was analyzed. RESULTS: Our results show that the frequency of gene coamplification on 2p24-25 in neuroblastoma is correlated directly to the physical distance to MYCN. Coamplification is correlated to an upregulated gene expression for DDX1 and NAG. Coamplification of the DDX1 gene within 400kb telomeric to MYCN identifies a subgroup of advanced stage neuroblastoma tumors with a more favorable outcome (P =.027, log-rank test). A high expression level of DDX1 is associated with a trend towards a better survival probability (P =.058, log-rank test). CONCLUSION: Our results indicate that DDX1 coamplification correlates with a better prognosis and improved patient survival in MYCN-amplified neurobastoma. 相似文献
72.
Chromosomal instability rather than p53 mutation is associated with response to neoadjuvant cisplatin-based chemotherapy in gastric carcinoma. 总被引:6,自引:0,他引:6
Katja Ott Holger Vogelsang James Mueller Karen Becker Martina Müller Ulrich Fink J?rg Rüdiger Siewert Heinz H?fler Gisela Keller 《Clinical cancer research》2003,9(6):2307-2315
PURPOSE: The objective of the study was to evaluate microsatellite alterations [microsatellite instability (MSI) and loss of heterozygosity (LOH)] and mutation in the p53 gene in relation to response and patient survival to a cisplatin-based neoadjuvant chemotherapy in gastric cancer. EXPERIMENTAL DESIGN: Fifty-three pretherapeutic gastric carcinoma biopsies were analyzed with 11 microsatellite markers. The entire coding region of the p53 gene (exons 2-11) was analyzed for mutations by denaturing high-pressure liquid chromatography and sequencing. p53 protein expression was evaluated by immunohistochemistry. Patients were treated with a cisplatin-based, neoadjuvant chemotherapy regimen. Therapy response was evaluated by computed tomography scan, endoscopy, and endoluminal ultrasound. The median follow-up of the patients was 45.6 months. RESULTS: p53 mutations were identified in 19 of the 53 (36%) analyzed tumors. No significant association with response or survival was found for p53 mutation or for p53 protein expression. MSI (either high-grade MSI or low-grade MSI) did not show a correlation with response. With respect to LOH, LOH at chromosome 17p13 showed a significant association with therapy response (P = 0.022) but did not reach statistical significance in terms of patient survival. The global LOH rate, expressed as fractional allelic loss (FAL), was assessed, and tumors were classified into tumors with a high (>0.5), medium (>0.25-0.5), and low (0-0.25) FAL value. A statistically significant association of FAL with therapy response was found (P = 0.003), with a high FAL being related to therapy response. The sensitivity, specificity, positive predictive value, and negative predictive value for FAL > 0.5 were 45%, 93%, 82%, and 72%, respectively. CONCLUSIONS: A high level of chromosomal instability (high FAL value) defines a subset of patients who are more likely to benefit from cisplatin-based neoadjuvant chemotherapy. p53 mutation status is not significantly associated with therapy response and is not a useful marker for response prediction. 相似文献
73.
74.
Thomas Elter Peter Borchmann Holger Schulz Marcel Reiser Sven Trelle Roland Schnell Markus Jensen Peter Staib Timo Schink?the Hartmut Stützer Jürgen Rech Martin Gramatzki Walter Aulitzky Ibrahim Hasan Andreas Josting Michael Hallek Andreas Engert 《Journal of clinical oncology》2005,23(28):7024-7031
PURPOSE: To determine the efficacy and safety of a newly developed concomitant administration of fludarabine and alemtuzumab (FluCam) in patients with relapsed or refractory B-cell chronic lymphocytic leukemia (B-CLL). PATIENTS AND METHODS: A total of 36 patients were treated in this phase II study (median age, 61.47 years; mean number of prior chemotherapies, 2.6; Binet stage C, n = 28). After an initial dose escalation of alemtuzumab over 3 days, alemtuzumab 30 mg and fludarabine 30 mg/m2 were administered on 3 consecutive days. Treatment was repeated after 28 days for up to six cycles. Restaging (following National Cancer Institute criteria) was carried out after cycles 2 and 4 and 1 month after the end of treatment. RESULTS: The overall response rate was 83% (11 complete responses, 19 partial responses, one stable disease, and five progressive diseases). Two patients with progressive disease developed fungal pneumonias, and one patient died as a result of Escherichia coli sepsis. Two subclinical cytomegalovirus reactivations occurred. CONCLUSION: The new FluCam regimen is effective and feasible in patients with relapsed and refractory B-CLL. 相似文献
75.
Sandra Barman Cecilia Fager Magnus Röding Niklas Lorén Christian von Corswant Eva Olsson David Bolin Holger Rootzén 《Journal of pharmaceutical sciences》2021,110(7):2753-2764
Pore geometry characterization-methods are important tools for understanding how pore structure influences properties such as transport through a porous material. Bottlenecks can have a large influence on transport and related properties. However, existing methods only catch certain types of bottleneck effects caused by variations in pore size. We here introduce a new measure, geodesic channel strength, which captures a different type of bottleneck effect caused by many paths coinciding in the same pore. We further develop new variants of pore size measures and propose a new way of visualizing 3-D characterization results using layered images. The new measures together with existing measures were used to characterize and visualize properties of 3-D FIB-SEM images of three leached ethyl-cellulose/hydroxypropyl-cellulose films. All films were shown to be anisotropic, and the strongest anisotropy was found in the film with lowest porosity. This film had very tortuous paths and strong geodesic channel-bottlenecks, while the paths through the other two films were relatively straight with well-connected pore networks. The geodesic channel strength was shown to give important new visual and quantitative insights about connectivity, and the new pore size measures provided useful information about anisotropies and inhomogeneities in the pore structures. The methods have been implemented in the freely available software MIST. 相似文献
76.
77.
78.
79.