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   1068篇
  免费   56篇
  国内免费   9篇
耳鼻咽喉   5篇
儿科学   26篇
妇产科学   8篇
基础医学   140篇
口腔科学   72篇
临床医学   59篇
内科学   226篇
皮肤病学   77篇
神经病学   41篇
特种医学   92篇
外科学   181篇
预防医学   34篇
眼科学   12篇
药学   82篇
中国医学   2篇
肿瘤学   76篇
  2023年   8篇
  2022年   18篇
  2021年   29篇
  2020年   26篇
  2019年   34篇
  2018年   33篇
  2017年   27篇
  2016年   23篇
  2015年   30篇
  2014年   41篇
  2013年   34篇
  2012年   49篇
  2011年   51篇
  2010年   24篇
  2009年   21篇
  2008年   51篇
  2007年   36篇
  2006年   37篇
  2005年   39篇
  2004年   40篇
  2003年   45篇
  2002年   46篇
  2001年   40篇
  2000年   36篇
  1999年   39篇
  1998年   14篇
  1997年   6篇
  1996年   6篇
  1995年   6篇
  1993年   4篇
  1992年   17篇
  1991年   7篇
  1990年   12篇
  1989年   23篇
  1988年   22篇
  1987年   26篇
  1986年   14篇
  1985年   25篇
  1984年   11篇
  1983年   10篇
  1979年   10篇
  1978年   5篇
  1977年   3篇
  1974年   5篇
  1973年   6篇
  1972年   8篇
  1969年   6篇
  1968年   3篇
  1967年   4篇
  1966年   6篇
排序方式: 共有1133条查询结果,搜索用时 15 毫秒
1.
PURPOSE: The purpose of this study was to examine changes of chewing movement and masticatory efficiency during the natural course of nonreducing disc displacement of the temporomandibular joint (TMJ). PATIENTS AND METHODS: The subjects were 15 patients who had been diagnosed with nonreducing disc displacement of the TMJ but had received no treatment. Chewing movement and masticatory efficiency were examined at the initial visit and at a mean follow-up of 21.7 months, using mandibular kinesiography and adenosine triphosphate ebteric-coated granules. As a control, 23 persons who had no current or previous TMJ symptoms were studied. RESULTS: The patients' clinical signs and symptoms tended to be alleviated during the follow-up period. In normal controls, chewing movement showed lateral excursion to the chewing side on both the right and left sides. In patients, chewing movement at the initial visit showed lateral excursion to the chewing side during chewing on the TMJ affected side, but no such deviation was noted during chewing on the TMJ unaffected side in the horizontal plane. However, chewing movement at follow-up became similar to that of controls. In patients, masticatory efficiency became better during the natural course, although that at follow-up did not always reach the control's level. CONCLUSION: In untreated patients with nonreducing disc displacement of the TMJ, chewing movement and masticatory efficiency tend to improve spontaneously.  相似文献   
2.
The purpose of this study is to evaluate the correlation between variation of the vertebral artery (VA) and the incidence of pontine infarction. A total of 206 patients were examined using magnetic resonance imaging (MRI) and 3-dimension time-of-flight MR angiography (MRA) of the brain. Of these, 54 patients had pontine infarctions (23 symptomatic and 31 asymptomatic), and the majority of them were located in the pontine base. The sites of dominant lesion in the pons were right in 18 cases, left in 8 cases, and bilateral in 28 cases. The number of patients with VA asymmetry (the ratio of internal diameters 1:2 or more) were 89 (43.2%). Of these, 67 patients had small diametric VA of right side, and 22 of left side. Among the 117 patients with normal VA pattern, 19 (16.2%) had infarction, while among the 89 patients with VA asymmetry, 35 (39.3%) had infarction. The patients with small diametric VA of right side significantly had infarctions in the same side of the pons. The results of this study suggest that VA asymmetry is considered to be one of the risk factors of pontine infarction and that MRA can be useful in the examination of the cerebral artery as a valuable and non-invasive screening method.  相似文献   
3.
4.
We report a malformed girl with a single chromosome band deletion of 4q26 in peripheral lymphocytes. This patient is the fourth case reported with an interstitial deletion involving 4q26 and has the smallest deletion of those reported. Deletion mapping indicates that psychomotor retardation, coloboma, prominent forehead, epicanthus, broad based nose, and broad, thin upper lip are associated with monosomy 4q26, and that gene(s) associated with Rieger syndrome can be excluded from the 4q26 segment.  相似文献   
5.
Summary Results of DNA study on two patients of gonadal dysgenesis with a 45,X/46,X,Ynf (non-fluorescent Y chromosome) karyotype are described. In one patient who developed gonadoblastoma, all 12 loci on the non-fluorescent part of Yq were detected. Another patient did not have gonadoblastoma at 20 years, and only the proximal 6 loci out of 12 were detected.  相似文献   
6.
To clarify the role of IP-10 in autoimmune liver diseases, we studied the serum levels of IP-10 in 14 patients with autoimmune hepatitis (AIH), 23 patients with primary biliary cirrhosis (PBC), and 65 patients with chronic viral hepatitis (20 type B and 45 type C). The hepatic expression of IP-10 mRNA and the correlation between the serum levels of IP-10 and clinical parameters were also evaluated. In addition to 20 healthy controls, 16 rheumatoid arthritis (RA) patients were included as an extrahepatic inflammatory disease. The serum level of IP-10 was significantly (P < 0.02) higher in patients with AIH, PBC, and chronic hepatitis B and C than in healthy controls, and it was significantly correlated (P < 0.05) with the serum levels of aspartate aminotransferase and alanine aminotransferase in patients with AIH, PBC, and chronic hepatitis B and C. The serum level of IP-10 was not elevated in RA patients. After successful treatment of AIH and chronic hepatitis C, the serum level of IP-10 decreased to the same level as in healthy volunteers. As we previously showed in cases with chronic hepatitis B or C, in situ hybridization in both AIH and PBC cases demonstrated the expression of IP-10 mRNA in hepatocytes around focal or lobular necrosis surrounded by infiltrating mononuclear cells, whereas IP-10 mRNA was not expressed in areas around the damaged bile ducts in PBC cases. The present results suggest that IP-10 is specifically produced by hepatocytes in inflammatory areas irrespective of the aetiology of hepatitis, and that IP-10 may help to recruit T cells to the hepatic lesions in autoimmune liver diseases as well as in chronic viral hepatitis.  相似文献   
7.
8.
Poly(N-vinylcarbazole), (PNVC), was prepared, fractionated by gel permeation chromatography, and then characterized by viscometry and vapour pressure osmometry. The fractionated PNVC species with relatively narrow molecular weight distributions were successfully used to measure both their electrical dark-conductivity and photoconductivity using a surface type cell in high vacuum (ca. 10?7 mm Hg) at room temperature. A molecular weight dependent photoconductivity was found for the fractionated PNVCs with weight average molecular weights in the range of 1,2·103 to 2,4·105. This observation is in contradiction to Epping's results who has found a molecular weight independent photoconductivity in the molecular weight range of 3·105 to 7·106. Our molecular weight dependence may be well understood in terms of the interrupted overlap of the π-electrons of adjacent carbazolyl groups at the terminal parts of the polymer chains, this effect being all the more stronger the smaller the molecular weight is.  相似文献   
9.
10.
PURPOSE: The aim of this study was to determine whether chemokines such as serum IP-10 levels in patients with biliary atresia (BA) correlate with liver function and histology and assess its value as a medium to long-term prediction of prognosis in postoperative BA patients. METHODS: Thirty postoperative BA patients (mean age, 10.8+/-3.5 years) and eight normal controls (mean age, 10.3+/-3.3 years) were studied. The BA patients were divided into three groups according to liver function. Group I (n = 8) was jaundice free, had normal liver function and no evidence of severe cholangitis or portal hypertension. Group II (n = 12) had moderate liver dysfunction. Group III (n = 10), had severe liver dysfunction. Hepatic histology was assessed using conventional needle biopsy. Serum IP-10 levels were determined using a specific enzyme-linked immunosorbent assay (ELISA). RESULTS: Serum levels of IP-10 in group III (458.0+/-240.0 pg/mL) were significantly higher than those in group II (233.6+/-126.9 pg/mL; P < .0001). Levels in group II were also significantly higher than those in group I (144.8+/-23.4 pg/mL; P < .05), but there was no significant difference between group I and controls (107.9+/-34.0 pg/mL). Liver biopsy findings showed a progression of fibrosis and mononuclear cell infiltration from group I to group III. There was intimal hyperplasia and swelling of endothelial cells of branches of the hepatic artery in the portal area in group III. CONCLUSION: Because IP-10 levels correlate closely with histological findings in postoperative BA patients, it would appear to play a specific role in hepatocyte death and hepatic artery changes, thus providing important information about progressive fibrosis in BA patients that facilitates treatment decision making and prediction of prognosis.  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