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   8462篇
  免费   531篇
  国内免费   13篇
耳鼻咽喉   80篇
儿科学   664篇
妇产科学   115篇
基础医学   998篇
口腔科学   136篇
临床医学   604篇
内科学   1516篇
皮肤病学   258篇
神经病学   507篇
特种医学   173篇
外科学   1119篇
综合类   199篇
一般理论   4篇
预防医学   524篇
眼科学   308篇
药学   985篇
中国医学   49篇
肿瘤学   767篇
  2023年   43篇
  2022年   63篇
  2021年   220篇
  2020年   146篇
  2019年   167篇
  2018年   242篇
  2017年   184篇
  2016年   222篇
  2015年   212篇
  2014年   317篇
  2013年   394篇
  2012年   573篇
  2011年   578篇
  2010年   379篇
  2009年   252篇
  2008年   472篇
  2007年   424篇
  2006年   376篇
  2005年   383篇
  2004年   387篇
  2003年   318篇
  2002年   253篇
  2001年   212篇
  2000年   167篇
  1999年   163篇
  1998年   85篇
  1997年   63篇
  1996年   59篇
  1995年   57篇
  1994年   40篇
  1992年   110篇
  1991年   92篇
  1990年   90篇
  1989年   100篇
  1988年   72篇
  1987年   74篇
  1986年   70篇
  1985年   84篇
  1984年   67篇
  1983年   62篇
  1980年   37篇
  1979年   72篇
  1978年   42篇
  1977年   42篇
  1976年   49篇
  1975年   66篇
  1974年   40篇
  1973年   61篇
  1971年   41篇
  1969年   39篇
排序方式: 共有9006条查询结果,搜索用时 31 毫秒
111.
PURPOSE: ANX7-GTPase located on chromosome 10q21 is significantly altered and associated with hormone-refractory metastatic prostate cancers. Therefore, we investigated whether levels of ANX7 correlate with breast cancer progression and survival EXPERIMENTAL DESIGN: A diagnostic tumor tissue microarray containing 525 human breast tissue specimens at different stages of the disease was assayed for ANX7 using immunocytochemical methods with ANX7 monoclonal antibody. A separate prognostic tumor tissue microarray containing 553 human breast tissue specimens annotated with clinicopathological parameters was assayed for ANX7, HER2, estrogen receptor, progesterone receptor, and p53 protein. RESULTS: We report here for the first time that the expression of ANX7-GTPase is significantly enhanced and associated with the presence of metastatic disease (P < 0.0001) in the 525 human breast tissue specimens analyzed. Furthermore, using a separate 553 case retrospective prognostic tumor tissue microarray, we found that increased ANX7 expression is also significantly associated with poor overall patient survival (P < 0.014). This is particularly true when restricted to patients in whom the BRE clinical grade is 2 (P < 0.001) or for whom there is a lack of HER2 expression (P < 0.002). Finally, Cox regression analysis shows that as the expression of ANX7 rises, the probability of survival decreases by more than 10-fold for those patients with HER2-negative tumors. These latter patients represented 66% of the population affected with breast cancer in this study. CONCLUSIONS: High levels of ANX7 in tumor correlate strongly with poor survival of HER2-negative patients and the most aggressive forms of breast cancer. This is the first study to demonstrate that ANX7 antibody has the potential for development into an in vivo diagnostic and therapeutic tool. This simple and reliable immunohistochemical assay may therefore become an important biomarker for metastatic breast cancer diagnosis and management of HER2-negative breast tumor patients.  相似文献   
112.
The concentration of chlorinated pesticides and heavy metals (lead and cadmium) was measured using gas liquid chromatography and the graphite tube atomizer of atomic absorption spectrophotometer, respectively, in semen samples collected from men in the normal human population. Significant concentrations of lead and cadmium were detected. Significant amounts of hexachlorocyclohexane (HCH) and its isomers alpha, beta, gamma and delta, the dichlorodiphenyl trichloroethane (DDT) metabolite 1,1,1-trichloro-2,2-bis (p chlorophenyl ethane) (pp'-DDE) and low values of 1,1,2-dichloro-2, 2-bis(p chlorophenyl ethane) (pp'-DDD) aldrin or endosulfan were detected. The presence of these xenobiotics in human semen might be related to the extensive use of pesticides, emission of exhaust from motor vehicles, consumption of tobacco and industrial operations.  相似文献   
113.
114.
115.
116.
117.
OBJECTIVES: The role of EEG and evoked potentials has not been evaluated in predicting the prognosis of tuberculous (TB) meningitis. The present study was aimed at evaluating the prognostic significance of clinical, radiological, and neurophysiological variables using multi-variable analysis. METHODS: Patients with TB meningitis diagnosed on the basis of clinical, radiological, and CSF criteria have been prospectively evaluated. All the patients were subjected to a detailed neurological evaluation. The outcome was defined 6 months after starting treatment on the basis of the Barthel index (BI) score into poor (BI <12) and good recovery (BI> or =12). Death was included in the poor recovery group for statistical analysis. Thirteen clinical (age, sex, seizure, focal weakness, stage of meningitis, Glasgow coma scale score, methyl prednisolone therapy), CT (infarction, hydrocephalus, tuberculoma) and neurophysiological (EEG, motor and somatosensory evoked potentials) variables were evaluated employing single variable logistic regression followed by multivariable logistic regression analysis. The best set of predictors were obtained by stepdown logistic regression analysis. RESULTS: Fifty four patients were included in the present study. Their age ranged between 5 and 62 years, 11 were children younger than 12 years and 14 were female. Nine patients were in stage I meningitis, 12 in stage II, and 33 in stage III. On single variable logistic regression analysis the significant predictors of 6 months outcome of TB meningitis included focal weakness, Glasgow coma scale (GCS), motor evoked potential (MEP) and somatosensory evoked potential (SEP). On multivariable analysis the best set of predictors comprised focal weakness, GCS, and SEP. CONCLUSIONS: In patients with TB meningitis focal weakness, GCS, and SEP are the best predictors of 6 month outcome.  相似文献   
118.
PURPOSE: To present a new technique of ocular fixation to restore and maintain the ocular alignment in primary position for patients with total third nerve paralysis. METHOD: We fixated the globe (medial rectus muscle insertion) to the medial palpebral ligament insertion at the anterior lacrimal crest by using nonabsorbable 5-0 polyester sutures in a prospective study of 5 patients (5 eyes) with congenital total third nerve paralysis. A large recession of the lateral rectus muscle (12 to 16 mm) was also performed in four patients. RESULTS: Four patients achieved satisfactory ocular alignment and one patient had residual exotropia. After an initial exotropic shift, no significant change in ocular alignment was observed during the follow-up period of 6 to 9 months. Mild fullness and congestion over the medial rectus muscle area was observed in the immediate postoperative period in all the patients, which resolved in about two months time. CONCLUSION: This technique of ocular fixation is easy, safe, and effective for the management of exotropia secondary to total third nerve paralysis.  相似文献   
119.
A case of Takayasu's arteritis resulting in extensive fusiform aneurysmal dilatation of the entire aorta extending from the aortic root to the abdominal bifurcation associated with aortic regurgitation is described. She underwent successful radical replacement of the aortic root, ascending, transverse arch and proximal part of the descending aorta employing simultaneous modified Bentall and Elephant trunk techniques. During aortic arch replacement the brain was protected by selective antegrade innominate perfusion under moderate hypothermia. A pattern to the best of our knowledge, has not been reported earlier.  相似文献   
120.
PURPOSE: In a living related transplantation program it is not always possible to find an ideal donor. Sometimes the only available donor in the family has some benign disease or suboptimal renal anatomy or physiology, or is too old to be accepted and defined as a marginal donor. However, with proper screening the donor pool can be increased by accepting these marginal donors and treating the benign diseases which is beneficial to the donor. We evaluate the outcome of grafts from marginal donors. MATERIALS AND METHODS: From July 1988 to August 1997, 581 live related transplantations were performed. Of the donors 52 were older than 60 years and 34 had associated benign renal or nonrenal anomaly or disease. These donors were accepted after thorough questioning and consultation with family members. The recipients of graft from elderly donors were evaluated for the number of rejections, serum creatinine at last followup and graft survival. RESULTS: Of the recipients 52 received grafts from elderly donors with a mean age of 62.6+/-3.7 years. Mean followup was 34.14+/-0.7 months. The 2 and 5-year actuarial graft survival was 96% and 74%, respectively. Creatinine was normal (less than 1.5) in 37% of recipients and 1.5 to 2.5 mg.% in 46%. The rejection rate in postoperative month 1 was 29%. All donors underwent simultaneous surgery to treat the benign disease, and all did well after surgery. CONCLUSIONS: By accepting these marginal donors a 14.6% increase in the living related donor pool was achieved without compromising recipient or donor safety. Otherwise these recipients would have been forced to undergo unrelated transplantation or be maintained on dialysis, which is particularly difficult in a developing country. Donors with associated disease benefited from cure.  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