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   5640篇
  免费   369篇
  国内免费   3篇
耳鼻咽喉   84篇
儿科学   178篇
妇产科学   175篇
基础医学   809篇
口腔科学   176篇
临床医学   479篇
内科学   1222篇
皮肤病学   75篇
神经病学   737篇
特种医学   301篇
外国民族医学   1篇
外科学   769篇
综合类   99篇
一般理论   3篇
预防医学   294篇
眼科学   72篇
药学   193篇
中国医学   1篇
肿瘤学   344篇
  2021年   75篇
  2019年   69篇
  2018年   97篇
  2017年   75篇
  2016年   96篇
  2015年   89篇
  2014年   126篇
  2013年   177篇
  2012年   222篇
  2011年   221篇
  2010年   163篇
  2009年   124篇
  2008年   220篇
  2007年   210篇
  2006年   190篇
  2005年   217篇
  2004年   170篇
  2003年   195篇
  2002年   183篇
  2001年   150篇
  2000年   173篇
  1999年   147篇
  1998年   74篇
  1997年   69篇
  1996年   68篇
  1995年   50篇
  1993年   50篇
  1992年   134篇
  1991年   140篇
  1990年   116篇
  1989年   124篇
  1988年   90篇
  1987年   111篇
  1986年   97篇
  1985年   109篇
  1984年   75篇
  1983年   64篇
  1982年   67篇
  1981年   54篇
  1980年   42篇
  1979年   63篇
  1978年   50篇
  1977年   58篇
  1975年   67篇
  1974年   44篇
  1973年   49篇
  1972年   49篇
  1971年   40篇
  1969年   42篇
  1967年   43篇
排序方式: 共有6012条查询结果,搜索用时 15 毫秒
101.
102.
103.
104.

Objectives

Anti–programmed cell death 1 (PD-1)/programmed death ligand 1 (PD-L1) immunotherapy has demonstrated success in the treatment of advanced NSCLC. Recently, PD-1/PD-L1 blockade also has demonstrated interesting results in small trials of neoadjuvant treatment in stage IB to IIIA NSCLC. In addition, several clinical trials using anti–PD-1/PD-L1 immunotherapy as an adjuvant or neoadjuvant treatment in patients with resectable stage NSCLC are ongoing. However, few analyses of anti–PD-1/PD-L1 immunotherapy–related biomarkers in early-stage squamous cell lung carcinoma (SqCLC) have been reported. In this study, we evaluated PD-L1 protein expression, tumor mutation burden, and expression of an immune gene signature in early-stage SqCLC, providing data for identifying the potential role for patients with anti–PD-1/PD-L1 treatment in early-stage SqCLC.

Methods

A total of 255 specimens from patients with early-stage SqCLC were identified within participating centers of the Strategic Partnering to Evaluate Cancer Signatures program. PD-L1 protein expression by immunohistochemistry was evaluated by using the Dako PD-L1 22C3 pharmDx kit on the Dako Link 48 auto-stainer (Dako, Carpinteria, CA). Tumor mutation burden (TMB) was calculated on the basis of data from targeted genome sequencing. The T-effector and interferon gamma (IFN-γ) gene signature was determined from Affymetrix gene chip data (Affymetrix, Santa Clara, CA) from frozen specimens.

Results

The prevalence of PD-L1 expression was 9.8% at a tumor proportion score cutoff of at least 50%. PD-L1 mRNA and programmed cell death 1 ligand 2 mRNA positively correlated with PD-L1 protein expression on tumor cells (TCs) and tumor-infiltrating immune cells. PD-L1 protein expression on tumor-infiltrating immune cells was correlated with the T-effector and IFN-γ gene signature (p < 0.001), but not with TMB. For TCs, all of these biomarkers were independent of each other and neither PD-L1 protein expression, TMB, or T-effector and IFN-γ gene signatures were independently prognostic for patient outcomes.

Conclusions

Evaluation of PD-L1 expression, TMB, and T-effector and IFN-γ gene signatures in the cohort with early-stage SqCLC found them to be independent of each other, and none was associated with overall survival. Our results also support the hypothesis that PD-L1 expression is regulated by an intrinsic mechanism on TCs and an adaptive mechanism on immune cells.  相似文献   
105.
106.
107.
The natural history of functional morbidity in hospitalized older patients   总被引:7,自引:1,他引:7  
This study provides data on changes in the functional status of older patients that are associated with acute hospitalization. Seventy-one patients over the age of 74 admitted to the medical service of Stanford University Hospital between February and May 1987 received functional assessments covering seven domains: mobility, transfer, toileting, incontinence, feeding, grooming, and mental status. Assessments were obtained by report from the patient's caregiver (or the patient when he or she lived alone) for 2 weeks before admission; from the patient's nurse on day 2 of hospitalization and on the day before discharge; and again from the caregiver (or patient) 1 week after discharge. The sample had a mean age of 84, covered 37 Diagnostic Related Groups, and had a median length of stay of 8 days. Between baseline and day 2, statistically significant deteriorations occurred for the overall functional score and for the individual scores for mobility, transfer, toileting, feeding, and grooming. None of these scores improved significantly by discharge. In the case of mobility, 65% of the patients experienced a decline in score between baseline and day 2. Between day 2 and discharge, 67% showed no improvement, and another 10% deteriorated further. These data suggest that older patients may experience a burden of new and worsened functional impairment during hospitalization that improves at a much slower rate than the acute illness. An awareness of delayed functional recovery should influence discharge planning for older patients. Greater efforts to prevent functional decline in the hospitalized older patient may be warranted.  相似文献   
108.
Tumor tissue specimens of 25 patients with various entities of Non-Hodgkin's lymphomas were examined for the presence of Epstein-Barr virus (EBV) nucleic acids and EBV nuclear antigens (EBNA) by in situ hybridization and anticomplement immunofluorescence. In tumor cells of five patients EBV nucleic acid and EBNA were demonstrated. The histopathologic examinations revealed in these cases one Burkitt's lymphoma, two centroblastic lymphomas and each one lymphoplasmocytic and lymphocytic lymphoma.  相似文献   
109.
110.
Patients undergoing peripheral vascular surgery are at increased risk of postoperative cardiac complications. To evaluate the role of dipyridamole echocardiography in predicting major cardiac events, 109 unselected patients undergoing elective peripheral vascular surgery were prospectively studied. Preoperative dipyridamole echocardiograms were interpreted by an echocardiographer unaware of all clinical data. Patients were followed up until hospital discharge by research physicians without knowledge of dipyridamole echocardiography results. Outcomes were classified using strict predefined criteria by reviewers unaware of other clinical and echocardiographic data. Of the 109 patients, 9 (8%) had positive studies defined as development of new regional wall motion abnormalities or worsening of preexistent wall motion abnormalities. Of these 9 patients, 7 had postoperative events, including 3 cardiac deaths, 1 nonfatal myocardial infarction, 2 with unstable angina, and 1 with pulmonary edema. Only 1 event occurred among the 100 patients with negative studies. The sensitivity and specificity of dipyridamole echocardiography for predicting cardiac events after vascular surgery were 88 and 98%, respectively; the positive and negative predictive values were 78 and 99%. The relative risk of having a cardiac event if dipyridamole echocardiography was abnormal was 78 (95% confidence interval, 11 to 564; p less than 0.0001). If these results are extended and confirmed by other investigators, preoperative dipyridamole echocardiography may be an important screening test for patients undergoing elective peripheral vascular surgery.  相似文献   
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