首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   997篇
  免费   104篇
  国内免费   7篇
耳鼻咽喉   2篇
儿科学   19篇
妇产科学   22篇
基础医学   113篇
口腔科学   1篇
临床医学   92篇
内科学   188篇
皮肤病学   15篇
神经病学   59篇
特种医学   16篇
外科学   253篇
综合类   5篇
一般理论   1篇
预防医学   93篇
眼科学   21篇
药学   90篇
中国医学   8篇
肿瘤学   110篇
  2023年   14篇
  2022年   39篇
  2021年   60篇
  2020年   26篇
  2019年   37篇
  2018年   52篇
  2017年   34篇
  2016年   39篇
  2015年   51篇
  2014年   69篇
  2013年   79篇
  2012年   89篇
  2011年   62篇
  2010年   39篇
  2009年   29篇
  2008年   53篇
  2007年   58篇
  2006年   34篇
  2005年   35篇
  2004年   32篇
  2003年   32篇
  2002年   36篇
  2001年   11篇
  2000年   13篇
  1999年   11篇
  1998年   5篇
  1997年   2篇
  1996年   5篇
  1995年   2篇
  1994年   3篇
  1993年   6篇
  1992年   7篇
  1991年   6篇
  1990年   5篇
  1989年   3篇
  1988年   1篇
  1987年   1篇
  1986年   7篇
  1985年   6篇
  1984年   3篇
  1979年   1篇
  1976年   2篇
  1975年   1篇
  1974年   4篇
  1973年   2篇
  1971年   1篇
  1965年   1篇
排序方式: 共有1108条查询结果,搜索用时 18 毫秒
1.
Congenital rubella syndrome (CRS) results from maternal rubella virus infection in early pregnancy. Abnormal neuroimaging findings have been analyzed in a small number of CRS patients in the past; however, their clinical significance has been poorly addressed. Therefore, we have investigated the neuroimaging findings of 31 patients with CRS from previous studies. The most common finding was parenchymal calcification, which was observed in 18 of 31 patients (58.1%). A multivariable logistic regression model showed that it was associated with psychomotor or mental retardation (p = 0.018), suggesting that parenchymal calcification in CRS could be a prognostic factor.  相似文献   
2.
BACKGROUND: The aim of this study was to evaluate long-term results of laparoscopic anterior semifundoplication in patients with nonerosive (NERD) and erosive (ERD) gastroesophageal reflux disease.PATIENTS AND METHODS: The study includes the period from May 1997 to July 2005. Upper gastrointestinal endoscopy was performed in all 190 patients. The severity of reflux esophagitis was classified according to Savary and Miller (grades I-IV). A standardized questionnaire was used for follow-up, and the modified symptomatic DeMeester score was assessed.RESULTS: 58.5 years of age (range 27-80), patients with nonerosive reflux disease (n=83) were significantly older than those with erosive reflux disease (n=107) (48 years range 15-84) (p=0.0001). Patients with NERD had a lower modified symptomatic DeMeester score postoperatively of 0 (range 0-4) than patients with ERD, of 1 (range 0-5), though without statistical significance (p=0.151).CONCLUSION: Laparoscopic anterior semifundoplication leads to comparable symptomatic long-term results in both NERD and ERD. Anterior semifundoplication is a good therapeutic option for selected patients with persistent reflux-associated symptoms and endoscopically negative esophagitis.  相似文献   
3.
Follicular lymphomas (FLs) are a heterogeneous group of tumors, but prognostic factors are evaluated insufficiently in this common hematologic neoplasm. While bcl-6 and CD10 are expressed characteristically in FLs, their significance for biologic behavior of FL has not been studied previously. Samples from 73 patients with FL and clinical follow-up from 7 to 231 months were evaluated by immunohistochemical analysis. Patients with high levels of bcl-6 expression had favorable overall survival (OS) (P = .003), disease-specific survival (DSS) (P = .033), and time to treatment failure (P = .003) compared with patients with low levels of bcl-6 expression. Multivariate analysis showed that the results for OS, DSS, and time to treatment failure were independent of the international prognostic index. Patients with CD10+ FLs also had longer OS (P = .001), DSS (P = .007), and time to treatment failure (P = .004), and grade 1 FL was associated with better OS (P = .01) and a statistical trend for longer DSS (P = .05) and time to treatment failure (P = .05), but these results were not independent of bcl-6 expression or the international prognostic index in multivariate analysis.  相似文献   
4.
The variable regions of the heavy and light chains of the protective murine monoclonal antibody (MAb) 2H1 (m2H1) were expressed with the human constant region genes for immunoglobulin G2 (IgG2) and kappa, respectively, to construct a chimeric antibody (ch2H1). ch2H1 retains the specificity of the parent MAb, exhibits biological activity, and lacks the toxicity of the parent murine IgG1 in chronically infected mice.  相似文献   
5.
Introduction and objectiveResearch on the utility of meditative and mind-body (MB) practices has increased dramatically in the last two decades and both have been suggested as useful adjuncts in coping with stressors associated with cancer survivorship. There exists little data on use among genitourinary (GU) cancer survivors. This study seeks to describe meditative and MB utilization among GU cancer survivors.MethodsAnalysis of data from the 2012 and 2017 National Health Interview Survey was conducted. Patients aged 40 and older reporting a history of any cancer diagnosis (including 3 GU cancers) were included in the analysis. We explored questions about meditative and MB practices in the past 12 months. Complex Samples Logistic regression was performed to compare the relationship between cancer status and use of these practices.ResultsSelf-reported meditative practices were more prevalent in 2017 (17%) than in 2012 (5%). Patients who self-reported a cancer diagnosis of any kind were significantly more likely to utilize meditative practices. Patients with kidney cancer were significantly more likely to meditate and trended towards higher MB utilization. In contrast, bladder cancer patients were less likely to meditate and use MB practices. Increases in meditation were greater than those seen for MB in all groups.ConclusionsMeditative and MB practices increased in prevalence between 2012 and 2017 with notable heterogeneity between cancer types. Given the potential benefit, more broad incorporation into survivorship programs may be warranted. Future work should explore the significance of this heterogeneity and the utility of these practices to patients with urologic malignancy.  相似文献   
6.
Objective To detect new mutations among 29 glucose-6-phosphate dehydrogenase (G6PD) deficient individuals from Yunnan province. Methods The nitroblue tetrazolium (NBT) method was used to screen G6PD deficient individuals. Mutation was identified by single strand conformation polymorphism (SSCP), amplification created restriction site (ACRS), amplification refractory mutation system (ARMS) and DNA sequencing. Results Among 29 cases, 18 cases of G1388A, 1 case of C1004A, and 1 case of G1381A were identified. Nine cases remained to be defined. The G1381A mutation is a novel mis-sense mutation, with a substitution of threonine for alanine (A461T). The resultant G6PD had reduced enzymatic activity. In addition, G1381A caused a restriction site of Stu I to disappear, providing a rapid method for the detection of this mutation. Conclusion A novel mis-sense mutation G1381A was found. This mutation results in a substitution of threonine for alanine, producing enzyme with reduced activity. The loss of the Stu I restriction site offers a rapid method for the detection of this mutation.  相似文献   
7.
A novel series of 2,6-diphenoxypyridines has been designed to inhibit factor Xa, a serine protease strategically located in the coagulation cascade. The evolution from the photochemically unstable bisamidine (Z,Z)-BABCH to potent bisamidine compounds with a pyridine heterocycle as the core scaffold has been achieved. The most potent compound in the series, 6h, has a Ki for human factor Xa of 12 nM. The selectivity of 6h against bovine trypsin and human thrombin was greater than 90- and 1000-fold, respectively. Two proposed modes of binding of 6h to factor Xa are made based on the crystal structures of 6h by itself and of 6h bound to bovine trypsin.  相似文献   
8.
PurposeTo topographically map all of the thickness differences in individual retinal layers between early/intermediate age-related macular degeneration (AMDearly/AMDint) and normal eyes and to determine interlayer relationships.MethodsNinety-six AMDtotal (48 AMDearly and 48 AMDint) and 96 normal eyes from 192 participants were propensity-score matched by age, sex, and refraction. Retrospective optical coherence tomography (OCT) macular cube scans were acquired, and high-density (60 × 60 0.01-mm2) grid thicknesses were custom extracted for comparison between AMDtotal and normal eyes corrected for confounding. Resultant “normal differences” underwent cluster, interlayer correlation, and dose–response analyses for the retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer (INL), outer plexiform layer (OPL), outer nuclear layer + Henle''s fiber layer (ONL+HFL), inner and outer segment (IS/OS) thickness, and retinal pigment epithelium (RPE) to Bruch''s membrane (BM) thickness.ResultsAMDtotal inner retinal clusters demonstrated extensively thinned RNFL, GCL, IPL, and paracentral INL and thickened INL elsewhere, with normal difference means ranging from −8.13 µm (95% confidence interval [CI], −11.12 to −5.13) to 1.58 µm (95% CI, 1.07–2.09) (P < 0.0001 to P < 0.05). Outer retinal clusters displayed thinned paracentral OPL/ONL+HFL, central IS/OS, and peripheral RPE–BM and thickened central RPE–BM, with means ranging from −1.31 µm (95% CI, −2.06 to −0.55) to 2.99 µm (95% CI, 0.97–5.01] (P < 0.0001 to P <0.05). Effect sizes (−2.56 to 9.93 SD), cluster sizes, and eccentricity effects varied. All interlayer correlations were negligible to moderate regardless of AMD severity. Only the RPE–BM was partly thicker with greater AMD severity (up to 5.44 µm; 95% CI, 4.88–6.00; P < 0.01).ConclusionsFrom the early stage, AMD eyes demonstrate thickness differences compared to normal with unique topographies across all retinal layers. Poor interlayer correlations highlight that the outer retina inadequately reflects complete retinal health. The clinical importance of OCT assessment across all individual retinal layers in early/intermediate AMD requires further investigation.  相似文献   
9.
10.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号