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   1246篇
  免费   49篇
  国内免费   7篇
耳鼻咽喉   18篇
儿科学   11篇
妇产科学   94篇
基础医学   131篇
口腔科学   22篇
临床医学   119篇
内科学   266篇
皮肤病学   17篇
神经病学   53篇
特种医学   79篇
外科学   253篇
综合类   8篇
一般理论   1篇
预防医学   55篇
眼科学   8篇
药学   43篇
肿瘤学   124篇
  2023年   8篇
  2022年   20篇
  2021年   25篇
  2020年   15篇
  2019年   41篇
  2018年   41篇
  2017年   18篇
  2016年   24篇
  2015年   29篇
  2014年   51篇
  2013年   65篇
  2012年   79篇
  2011年   85篇
  2010年   62篇
  2009年   70篇
  2008年   79篇
  2007年   72篇
  2006年   99篇
  2005年   65篇
  2004年   55篇
  2003年   43篇
  2002年   64篇
  2001年   29篇
  2000年   36篇
  1999年   18篇
  1998年   6篇
  1997年   6篇
  1996年   7篇
  1995年   6篇
  1994年   8篇
  1993年   2篇
  1992年   7篇
  1991年   11篇
  1990年   11篇
  1989年   4篇
  1986年   5篇
  1985年   2篇
  1984年   3篇
  1983年   2篇
  1982年   6篇
  1981年   3篇
  1980年   5篇
  1978年   2篇
  1977年   3篇
  1976年   3篇
  1975年   1篇
  1971年   1篇
  1962年   1篇
  1943年   1篇
  1941年   1篇
排序方式: 共有1302条查询结果,搜索用时 22 毫秒
71.
The human HER-2/neu gene encodes a 185 kDa transmembrane glycoprotein recognized by MHC class I-restricted CTLs. Here, we report that HER-2/neu peptide CTL epitopes can also be recognized by cytotoxic NK-T lymphocytes. Unfractionated peptides derived from HLA-A2(+), HER-2/neu(+) tumor cells acid cell extract (ACE), collected from patients with metastatic ovarian cancer, were used as antigen to generate in vitro cytotoxic effectors. ACE was able to elicit from cancer patients' PBMCs both alphabetaTCR(+)CD3(+)CD56(-) and alphaTCR(+)CD3(+)CD56(+) (NK-T) CTLs that lysed ACE-sensitized T2 cells in an HLA-A2-restricted manner. The same CTL lines also recognized T2 cells pulsed with HER-2/neu-derived CTL peptide epitopes, a HER-2/neu-transfected HLA-A2(+) cell line and autologous tumor cells. alphaTCR(+)CD3(+)CD56(+) CTL lines also exhibited NK-like cytotoxicity against autologous tumor cells. CTL clones were isolated from alphaTCR(+)CD3(+)CD56(+) bulk cultures displaying both MHC- and non-MHC-restricted cytotoxicity, thus confirming the dual cytolytic function of such cells. Our data demonstrate that ACE from metastatic ovarian tumors can be used as multiepitope vaccines for generating in vitro, besides classical CTLs, NK-T cells exerting efficient MHC- and non-MHC-restricted cytotoxicity against autologous tumor targets. Such NK-T cells expressing dual cytotoxic activity may prove advantageous in cancer immunotherapy.  相似文献   
72.
Targeting the optimal extent of lymph node dissection for gastric cancer   总被引:20,自引:0,他引:20  
Roukos DH  Kappas AM 《Journal of surgical oncology》2002,81(2):59-62; discussion 62
  相似文献   
73.
74.
Bacterial vaginosis (BV) is a polymicrobial infection of the vagina and should not be considered an exclusively sexually transmitted disease. We describe the case of a 17-year-old female virgin adolescent with recurrent malodorous vaginal discharge for 6 months. Before referral to us she had been treated unsuccessfully with conservative treatment options. Our investigation revealed Gardnerella vaginalis as the responsible factor for the vaginal infection. Because metronidazole treatment had failed as monotherapy, a new method was applied. Repeated vaginal washings with 3% H2O2, 15% NaCl and 10% providone iodine were initiated. At the end of each washing, vaginal walls were thoroughly cleaned up with a small gauze. After 10 days of treatment the odor and the vaginal discharge had ceased and 12 months later no relapse had occurred. It seems to be reasonnable to use this kind of treatment in recurrent BV. Received: January 3, 2001 · Revision accepted: April 23, 2002 E. G. Papanikolaou (corresponding author)  相似文献   
75.
Objective. To assess the frequency of increased signal intensity in the patellar tendon using three-dimensional T1-weighted MRI pulse sequences. Design and patients. Sixty patients were examined with a 1.0 T scanner (15mT/m gradient strength) using a quadrature coil. Three pulse sequences were applied in the sagittal plane: PD turbo spin echo (PD-TSE), 3D T1-weighted gradient echo with fat suppression (3D-T1-FFE-FS) and 3D T1-weighted echo planar imaging with fat suppression (3D-T1-EPI-FS). The high signal intensity areas were measured in their maximum length. The angle of the patellar tendon relative to the main field position was measured in the same slice. In eight patients with anterior knee pain, and in 11 with no anterior knee pain, a fourth T2-weighted TSE pulse sequence (T2-TSE) was obtained to rule out patellar tendinitis. Results. The correlation of the high signal intensity areas with the relative position of the tendon was found to be significant with the 3D sequences (P=0.03 for 3D-T1-FFE-FS and P=0.003 for 3D-T1-EPI-FS). The length of the high signal intensity area in the tendon was 5.4 mm with 3D-T1-FFE-FS, 4.9 mm with 3D-T1-EPI-FS and 3.1 mm with PD-TSE images. No patellar tendinitis was demonstrated on the T2-TSE images. Conclusion. The magic angle effect is commonly observed in the 3D based T1-weighted pulse sequences with fat suppression. The presence of the above sign must be recognized by radiologists, so that misdiagnosis of patellar tendinitis is avoided. Received: 31 March 2000 Revision requested: 11 July 2000 Revision received: 2 August 2000 Accepted: 26 October 2000  相似文献   
76.

Background

Tissue genomic heterogeneity (t-HET) in patients with epithelial ovarian cancer (OVCA) is related to tissue plasticity, i.e., flexibility to adapt to adverse molecular environments. Here, we interrogated the presence and clinical relevance of OVCA t-HET.

Methods

We applied high-depth (>2000×) sequencing on 297 paraffin tissue samples (fallopian tubes, ovaries, intra-abdominal metastases) from 71 treatment-naïve patients who subsequently received first-line platinum-based chemotherapy. Based on tissue mutation patterns, we distinguished tissue genotypes into: no mutation (33/297 samples; 11.1%), stable (173; 58.2%) and unstable (91; 30.7%). We profiled genotypes per patient and assessed t-HET in 69 patients. Predicted pathogenic mutations refer to germline and/or tissues.

Results

Among all 71 patients, 46 (64.8%) had pathogenic BRCA1 mutations and 15 (21.7%) had BRCA1/2 disruption (i.e., pathogenic mutations with position-LOH). We classified 29 patients with t-HET (42%), all with pathogenic BRCA1; t-HET was observed in 64% with such mutations (p?<?0.001). As opposed to non-t-HET, matched tissues in t-HET shared pathogenic BRCA1 (p?<?0.001) but not BRCA2 and TP53. Germline BRCA1 mutations in tissues exhibited position-LOH; heterozygous status; or, partial loss of the inherited allele accompanied by additional clonal mutations. Patients with t-HET had worse outcome (log-rank p?=?0.048 [progression-free]; p?=?0.037 [overall survival]), including 12/15 patients with disrupted BRCA1/2 and 3 BRCA1 carriers with partial germline loss in tissues.

Conclusions

Pathogenic BRCA1 mutations appear necessary but may not be sufficient for the establishment of t-HET. t-HET may be associated with worse outcome, including in patients with disrupted BRCA1/2, which is usually considered as a favourable marker. OVCA t-HET may need to be addressed for treatment decisions.  相似文献   
77.
The proliferative activity in 70 cases of soft-tissue tumours was estimated immunohistochemically using the monoclonal antibody PC-10, which recognizes proliferating-cell nuclear antigen (PCNA) in paraffin sections. The PCNA index (i.e. the percentage of positive neoplastic nuclei) and to a lesser degree the PCNA count (i.e. the number of positive neoplastic nuclei per ten high-power fields) positively correlated with the malignancy grade (PCNA index:P<0.001; PCNA count:P<0.01). However, the range of values of PCNA index and PCNA count was similar between benign and grade I tumours. A statistically significant positive correlation was also established between PCNA index and PCNA count on the one hand and mitotic count on the other, but the correlation coefficient was low (r=0.351,P<0.01, andr=0.290,P<0.05 respectively). These results indicate that PCNA immunostaining may successfully be used as an adjunct to the conventional histopathological parameters in assessing the malignancy grade in soft-tissue tumours although it is of limited value in distinguishing between benign and grade I tumours.Abbreviations PCNA proliferating-cell nuclear antigen - HPF high-power field  相似文献   
78.
Sensitivity to vecuronium in myasthenia gravis: a dose-response study   总被引:3,自引:0,他引:3  
A cumulative dose plus infusion technique and integrated EMG monitoring of the first dorsal interosseous muscle were used to determine the potency of vecuronium in 20 normal patients and in ten patients with myasthenia gravis under thiamylal, N2O, O2, fentanyl anaesthesia. The mean (+/- SEM) values for ED50, ED90, and ED95 in the normal patients were 19 +/- 1, 31 +/- 1 and 36 +/- 2 micrograms.kg-1, respectively. Myasthenic patients showed increased sensitivity to vecuronium, the mean values for ED50, ED90, and ED95 were 10 +/- 2, 17 +/- 2 and 20 +/- 3 micrograms.kg-1, being 50, 55 and 56 per cent of normal, respectively. We did not demonstrate a difference in sensitivity to vecuronium between those myasthenic patients who received pyridostigmine preoperatively and those who did not, nor among those chronically treated with corticosteroids, compared with those who were not.  相似文献   
79.
It has been reported that the cyclin-dependent kinase inhibitor (CDKI) gene p15INK4B is frequently inactivated by genetic alterations and may be responsible for various malignant tumours. Another way of inactivation of this CDKI is by hypermethylation of 5'CpG islands in the promoter region of the p15INK4B gene and this inactivation seems to be a frequent event in various haematological malignancies. In the present study, we investigated the methylation status of the p151NK4B gene to clarify its role in the pathogenesis of childhood acute myeloid (AML) and acute lymphoblastic leukaemia (ALL). The study included 23 cases of B-cell origin ALL, 13 cases of T-cell origin ALL, 32 cases of AML, and 10 apparently healthy controls. Hypermethylation was studied by methylation-specific polymerase chain reaction. Hypermethylation of the p15INK4B gene was more frequent in cases with T-cell origin ALL (46.2%), but similar among children with B-cell origin ALL (13.0%) and AML (18.8%). Hypermethylation of p15INK4B may be involved in the pathogenesis of T-cell origin ALL, but not in that of AML or B-cell origin ALL.  相似文献   
80.
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