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   870篇
  免费   34篇
  国内免费   1篇
耳鼻咽喉   27篇
儿科学   33篇
妇产科学   41篇
基础医学   84篇
口腔科学   20篇
临床医学   45篇
内科学   237篇
皮肤病学   2篇
神经病学   45篇
特种医学   35篇
外科学   129篇
综合类   5篇
一般理论   1篇
预防医学   10篇
眼科学   3篇
药学   42篇
肿瘤学   146篇
  2022年   7篇
  2021年   7篇
  2020年   6篇
  2019年   8篇
  2018年   10篇
  2017年   5篇
  2016年   10篇
  2015年   10篇
  2014年   13篇
  2013年   16篇
  2012年   42篇
  2011年   35篇
  2010年   29篇
  2009年   11篇
  2008年   32篇
  2007年   32篇
  2006年   32篇
  2005年   53篇
  2004年   42篇
  2003年   48篇
  2002年   41篇
  2001年   41篇
  2000年   45篇
  1999年   24篇
  1998年   8篇
  1997年   10篇
  1996年   6篇
  1995年   4篇
  1994年   9篇
  1993年   7篇
  1992年   28篇
  1991年   16篇
  1990年   19篇
  1989年   29篇
  1988年   24篇
  1987年   17篇
  1986年   14篇
  1985年   14篇
  1984年   16篇
  1983年   6篇
  1981年   4篇
  1979年   6篇
  1977年   6篇
  1976年   5篇
  1975年   4篇
  1973年   6篇
  1972年   5篇
  1971年   10篇
  1969年   4篇
  1967年   3篇
排序方式: 共有905条查询结果,搜索用时 15 毫秒
901.
The present study used a self-reporting questionnaire to compare suicide risk in outpatients being treated for substance use disorder at specialized hospitals to suicide risk in outpatients being treated for depressive disorder at general psychiatric clinics. Although patients in both groups exhibited an equal severity of depression, the patients with drug use disorder had a higher suicide risk than those with depressive disorder. These findings indicate that drug-abusing patients at specialized hospitals may have a severe risk of committing suicide, suggesting that carefully assessing the comorbidity of depression with drug abuse may be required for preventing suicide in drug-abusing patients.  相似文献   
902.
N-acetylglucosaminyltransferase V (GnT-V) is an enzyme that catalyses beta1-6 branching of N-acetylglucosamine on asparagine-linked oligosaccharides of cell proteins. The present study aimed to investigate GnT-V expression and its prognostic significance in endometrial cancer. N-acetylglucosaminyltransferase V expression was studied by immunohistochemistry in 74 surgically resected endometrial cancers, and the staining intensity was evaluated. High GnT-V expression in tumour cells was found in 43 (58.1%) of the 74 cases, and was positively correlated with advanced patient age, histological grade, and lymph vascular space involvement. Patients with high GnT-V expression had significantly impaired overall survival and progression-free survival (PFS) (P=0.0041 and P=0.0023, respectively) compared to patients with low expression of GnT-V. On multivariate analysis, GnT-V expression was an independent prognostic factor for PFS (P=0.0364). beta1-6 branching of asparagine-linked oligosaccharides was also detected in GnT-V-positive endometrial cancer cells by leukoagglutinating phytohaemagglutinin (L(4)-PHA) staining, and the molecular size of the major glycoproteins recognised by L(4)-PHA was approximately 60-200 kDa by lectin blot analysis. These results suggested that high GnT-V expression was correlated with an unfavourable clinical outcome, and that GnT-V is involved in the malignant potential of endometrial cancer by increasing the synthesis of beta1-6 branching of asparagine-linked oligosaccharides.  相似文献   
903.
Aims:  Frequent onset of several mental disorders starts around undergraduate age for university students. Mental health check-ups of the new students might help provide them with useful supports for improving their mental health. However, few studies have examined the validity of the check-up methods.
Methods:  Whether the scores of a five-factor personality inventory (NEO-FFI) at matriculation predict the needs of mental care and treatment during the first year of the undergraduate course were examined in 8287 new students of a university in Tokyo.
Results:  Logistic regression showed that high neuroticism, low extraversion and high openness of NEO-FFI, majoring in literature/philosophy/ psychology and living out of home were associated with need for mental care/treatment, in addition to the previous use of mental care services.
Conclusions:  Personality inventory such as five-factor ones may be a useful supplemental tool for mental health check-up at matriculation to predict future needs of mental support in undergraduate university students. Students who smoke, live alone out of home and major in subjects such as philosophy might need to be more carefully supported than other students.  相似文献   
904.
BACKGROUND & AIMS: Chromosomal allelic losses have a varying frequency in colorectal cancer. The aim of this study was to define the target region of allelic loss on chromosome 22q in human colorectal carcinogenesis. METHODS: Fifty-seven pairs of matched normal colonic mucosa and tumor specimens from patients with colorectal cancer, as well as 15 colon cancer-derived cell lines, were genotyped using 15 microsatellite markers spanning chromosome 22q. A potential candidate gene was analyzed by a single-strand conformation polymorphism (SSCP)/direct DNA sequencing approach. RESULTS: After excluding 7 tumors with evidence of microsatellite instability, allelic loss was observed in 11 of the informative tumors (22%), 5 of which exhibited losses in all informative loci. The remaining 6 tumors showed variable patterns of partial allelic loss on chromosome 22q, thereby localizing a minimal region of allelic deletion between markers D22S1171 and D22S928. Physical mapping showed that this interval was 0.57 cM consisting of approximately 425 kilobases. Database searches identified the NBK/BIK gene, a proapoptotic BCL-2 family member, as a candidate gene in that region. However, SSCP/sequencing analysis excluded mutations of this gene. CONCLUSIONS: This study provides evidence for the involvement of putative tumor-suppressor gene(s) on chromosome 22q in human colorectal carcinogenesis. The identification of a 0.5-cM interval serves as the basis for the isolation of such a gene by positional cloning.  相似文献   
905.
Maxillectomy for oral tumours often results in debilitating oral hypofunction, which markedly decreases quality of life. Dysphagia, in particular, is one of the most serious problems following maxillectomy. This study used swallowing sounds as a simple evaluation method to evaluate swallowing ability in maxillectomy patients with and without their obturator prosthesis placed. Twenty‐seven maxillectomy patients (15 men, 12 women; mean age 66.0 ± 12.1 years) and 30 healthy controls (14 men, 16 women; mean age 44.9 ± 21.3 years) were recruited for this study. Participants were asked to swallow 4 mL of water, and swallowing sounds were recorded using a throat microphone. Duration of the acoustic signal and duration of peak intensity (DPI) were measured. Duration of peak intensity was significantly longer in maxillectomy patients without their obturator than with it (< .05) and was significantly longer in maxillectomy patients without their obturator than in healthy controls (< .025 after Bonferroni correction). With the obturator placed, DPI was significantly longer in maxillectomy patients who had undergone soft palate resection than in those who had not (< .05). These results suggest swallowing ability in maxillectomy patients could be improved by wearing an obturator prosthesis, particularly during the oral stage. However, it is difficult to improve the oral stage of swallowing in patients who have undergone soft palate resection even with obturator placement.  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