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   2097篇
  免费   96篇
  国内免费   12篇
耳鼻咽喉   30篇
儿科学   117篇
妇产科学   61篇
基础医学   178篇
口腔科学   70篇
临床医学   193篇
内科学   398篇
皮肤病学   26篇
神经病学   119篇
特种医学   119篇
外科学   412篇
综合类   30篇
预防医学   97篇
眼科学   88篇
药学   152篇
中国医学   11篇
肿瘤学   104篇
  2024年   1篇
  2023年   13篇
  2022年   28篇
  2021年   41篇
  2020年   33篇
  2019年   39篇
  2018年   55篇
  2017年   52篇
  2016年   65篇
  2015年   92篇
  2014年   76篇
  2013年   105篇
  2012年   154篇
  2011年   139篇
  2010年   68篇
  2009年   75篇
  2008年   170篇
  2007年   192篇
  2006年   126篇
  2005年   149篇
  2004年   146篇
  2003年   134篇
  2002年   103篇
  2001年   29篇
  2000年   13篇
  1999年   22篇
  1998年   10篇
  1997年   6篇
  1996年   8篇
  1995年   9篇
  1994年   5篇
  1993年   6篇
  1992年   8篇
  1991年   3篇
  1990年   1篇
  1988年   4篇
  1987年   1篇
  1986年   1篇
  1985年   3篇
  1984年   4篇
  1983年   2篇
  1982年   1篇
  1981年   2篇
  1980年   1篇
  1978年   1篇
  1977年   2篇
  1976年   2篇
  1975年   3篇
  1974年   1篇
  1973年   1篇
排序方式: 共有2205条查询结果,搜索用时 15 毫秒
11.
Jervell and Lange-Nielsen syndrome: neurologic and cardiologic evaluation   总被引:3,自引:0,他引:3  
Recurrent syncope, malignant ventricular arrhythmias, and sudden death are complications of the long QT syndrome (LQTS). Two well-known syndromes with long QT intervals are known. The Jervell and Lange-Nielsen syndrome (JLNS) is characterized by prolongation of the QT interval, deafness, and autosomal-recessive inheritance, and the Romano-Ward syndrome is characterized by a prolonged QT interval, autosomal-dominant inheritance, and no deafness. In the present study assessment was performed of the diagnostic importance of the ventricular derepolarization parameters, clinical features, and prevalence of JLNS among 132 children with congenital hearing loss (CHL). In the CHL group the mean QT, QTc, JT, and JTc intervals and the dispersion values (QT-d, JT-d, QTc-d, and JTc-d) were significantly longer than those of control subjects (n = 96) (P < 0.05). Patients with CHL and JLNS (n = 5) had significantly longer mean values of QT, QTc, JT, and JTc intervals and dispersion values than those of CHL without JLNS (n = 127) and control subjects (P < 0.05). The results suggest that assessment of ventricular derepolarization parameters in children with CHL will be helpful in the early detection of JLNS because infants with CHL cannot accurately describe the symptoms of syncope.  相似文献   
12.
13.
In the blood samples obtained from a total of 68 patients with cancers of the urinary bladder, prostate, and cervix, who applied to the Departments of Urology, Obstetrics, and Gynecology of Hacettepe Medical Faculty, neutralizing antibodies were sought for against herpes simplex type 2 by neutralization test. The same test was applied to 35 control patients with no known malignancies. In contrast to the presence of the antibody in 62.86% of the control subjects, this ratio was 90.70% in patients with cancer of the urinary bladder, 87.50% in those with prostatic carcinoma, and 88.89% in those with cancer of the cervix.  相似文献   
14.
In hypersensitive reactions to native L‐asparaginase, either premedication and desensitization or substitution with polyethylene glycol conjugated asparaginase (PEG‐ASP) is preferred. Anaphylaxis with PEG‐ASP is rare. An 8‐year‐old girl and a 2.5‐year‐old boy, both diagnosed as having acute lymphoblastic leukemia, presented with native L‐asparaginase hypersensitivity and substitution with PEG‐ASP was preferred. They received a premedication (methylprednisolone, hydroxyzine and ranitidine) followed by desensitization with PEG‐ASP infusion. Both patients developed anaphylaxis with peg‐asparaginase. These are the first reported cases of anaphylactic reaction to PEG‐ASP, despite the application of both premedication and desensitization. Anaphylaxis with PEG‐ASP is very rare and premedication and desensitization protocols may not prevent these hypersensitive reactions.  相似文献   
15.
Aminotetralin derivatives M-8 and JOD-176, were studied in relation to isoproterenol for beta-adrenergic activity. M-8 and JOD-176 were found to be very weak in activating cardiac beta-receptors. These compounds were also found to be considerably more active in uterine and bronchial smooth muscle. Because these compounds were also shown to be very inactive in vascular smooth muscle, the possibility that beta-receptors in different smooth muscle types may also differ was suggested.  相似文献   
16.
While various molecular profiling methods have been described for the early diagnosis and prognostic process of endometrial cancer, the most common gynaecological cancer, the data obtained remain insufficient. The present study aimed to investigate the protein and gene expression of periostin and its role as a new biomarker in the diagnosis, treatment and prognosis of endometrial cancer. A total of 15 patients diagnosed with endometrial cancer at the Department of Pathology, Zeynep Kamil Training and Research Hospital (Istanbul, Turkey) and 15 patients who were operated on for non-tumour-related reasons, between December 2019 and May 2020, were included in the study. The cases diagnosed with endometrial cancer were divided into three groups: International Federation of Gynaecology and Obstetrics grades I, II and III. Pathology tumour blocks were selected for enzyme-linked immunosorbent assay and PCR studies in which periostin gene expression and protein levels were measured, respectively. A significant increase in periostin gene expression was observed in the endometrial cancer samples compared with that in the controls (3.40±0.66 vs. 2.23±0.47). The protein level of periostin in the tissues was found to be higher in the endometrial cancer samples than that in the control group (1.59±0.31 vs. 0.94±0.22). The levels of periostin protein and gene expression detected in the endometrial cancer samples increased as the grade increased. To the best of our knowledge, the current study is the first to determine the levels of periostin protein and gene expression in endometrial cancer. The results suggested that periostin may be used as a biomarker in the determination of higher histological grade in endometrial cancer.  相似文献   
17.
18.
Background and Aim:  Hepatic alveolar echinococcosis (HAE) involves both the vascular and biliary structures of the liver. Endoscopic retrograde cholangiopancreatography (ERCP) is said to be an alternative for the diagnosis and treatment of biliary complications of HAE. We present here our experience with ERCP in HAE.
Methods:  We followed 13 patients who underwent ERCP for the treatment of biliary complications of HAE in the endoscopy unit of our clinic at Ataturk University School of Medicine, Erzurum between January 2002 and June 2008.
Results:  Eight men and five women were followed up. Mean age was 43.2 (24–64 years). All patients had non-resectable HAE. Indications for ERCP were biliary fistula in seven patients, obstructive jaundice in five patients and cholangitis in one patient. Endoscopic sphincterotomy (ES) was carried out in 12 patients, and in one patient with biliary leakage, a stent was inserted into the right hepatic branch. ERCP findings were dilated common bile duct, irregular narrowing and distortion of the common bile duct and common hepatic duct, communication with the cystic cavity or biliocutaneous fistula and complete disappearance of the biliary tree above the level of the common hepatic duct or hepatic bifurcation. In patients with biliary leakage, biliary drainage decreased only in two patients after ERCP and in patients with obstructive jaundice, the high bilirubin levels decreased in only one patient.
Conclusion:  ERCP showed structural changes of the external biliary tract and ES has a limited effect on these changes and stents can be used in selected cases.  相似文献   
19.
BACKGROUND: A large number of studies have demonstrated that various kinds of DNA damage accumulate during aging and that oxidative stress possibly contributes to this process. Glutathione S-transferase M1 (GSTM1) can prevent their possible effects on DNA via detoxification of reactive substances that induced oxidative stress. OBJECTIVE: To investigate the relationship between GSTM1 polymorphism and DNA sensitivity to oxidative stress with age, we used micronucleus (MN) frequency as a marker of DNA damage in lymphocytes from young and elderly subjects. Methods: This study was performed in 30 young (age range 20-36 years) and 30 elderly (age range 66-87 years) healthy individuals who were chosen on the basis of their GSTM1 genotype (15 GSTM1 null and 15 GSTM1 positive for each group). Lymphocytes were cultured after Ficoll isolation and treated for 48 h with a 30-muM dose of cumene hydroperoxide (CumOOH), a dose that does not decrease cell viability. RESULTS: There was no significant difference in the MN frequency observed in control cultures from young and elderly individuals. However, the MN frequency in CumOOH-treated cultures was significantly higher in the elderly group than the young group (p < 0.001). No association was found between the GSTM1 phenotype and CumOOH-induced MN frequency. CONCLUSIONS: The results suggest that lymphocytes of elderly individuals are more susceptible to in vitro MN induction by CumOOH. However, this difference in susceptibility is not explained by the lack of GSTM1.  相似文献   
20.
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