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   764篇
  免费   17篇
耳鼻咽喉   5篇
儿科学   49篇
妇产科学   18篇
基础医学   85篇
口腔科学   10篇
临床医学   94篇
内科学   171篇
皮肤病学   23篇
神经病学   42篇
特种医学   1篇
外科学   138篇
综合类   9篇
预防医学   18篇
眼科学   4篇
药学   52篇
中国医学   3篇
肿瘤学   59篇
  2023年   4篇
  2022年   21篇
  2021年   18篇
  2019年   5篇
  2017年   6篇
  2016年   4篇
  2015年   18篇
  2014年   14篇
  2013年   12篇
  2012年   16篇
  2011年   9篇
  2010年   15篇
  2009年   22篇
  2008年   13篇
  2007年   8篇
  2006年   39篇
  2005年   24篇
  2004年   20篇
  2003年   17篇
  2002年   12篇
  2001年   10篇
  2000年   5篇
  1999年   11篇
  1998年   36篇
  1997年   39篇
  1996年   29篇
  1995年   39篇
  1994年   29篇
  1993年   21篇
  1992年   16篇
  1991年   14篇
  1990年   3篇
  1989年   11篇
  1988年   7篇
  1987年   3篇
  1986年   9篇
  1985年   8篇
  1984年   9篇
  1981年   5篇
  1980年   3篇
  1979年   3篇
  1977年   4篇
  1976年   3篇
  1959年   7篇
  1958年   21篇
  1957年   30篇
  1956年   38篇
  1955年   30篇
  1954年   22篇
  1948年   4篇
排序方式: 共有781条查询结果,搜索用时 15 毫秒
31.
32.
Summary. Background: C4b‐binding protein (C4BP), a multimeric protein structurally composed of α chains (C4BPα) and a β chain (C4BPβ), regulates the anticoagulant activity of protein S (PS). Patients with sepsis have increased levels of plasma C4BP, which appears to be induced by interleukin (IL)‐6. However, it is not fully understood how lipopolysaccharide (LPS) and IL‐6 affect the plasma C4BP antigen level and C4BPα and C4BPβ expression in hepatocytes. Objectives: To assess the effect of LPS and IL‐6 on plasma C4BP, PS–C4BP complex levels, PS activity, and C4BP expression by rat liver in vivo and on C4BP expression by isolated rat hepatocytes in vitro. Results: Plasma C4BP antigen level transiently decreased from 2 to 12 h after LPS (2 mg kg?1) injection, and then it abruptly increased up to 24 h after LPS injection. Plasma C4BP antigen level increased until 8 h after IL‐6 (10 μg kg?1) injection, and then gradually decreased up to 24 h after IL‐6 injection. LPS significantly decreased the protein and mRNA expression of both C4BPα and C4BPβ in rat hepatocytes, and this effect was inhibited by NFκB and MEK/ERK inhibitors. IL‐6 mediated increase in C4BPβ expression in rat hepatocytes, which leads to increased plasma PS–C4BP complex level and to decreased plasma PS activity, was inhibited by inhibition of STAT‐3. Conclusion: LPS decreases both C4BPα and C4BPβ expression via the NFκB and MEK/ERK pathways, whereas IL‐6 specifically increases C4BPβ expression via the STAT‐3 pathway, causing an increase in plasma PS–C4BP complex, and thus decreasing the anticoagulant activity of PS.  相似文献   
33.
Objective: To investigate the diagnostic value of anti-neutrophil cytoplasmic antibodies (ANCA) in the diagnosis of ulcerative colitis (UC) in Japanese children.
Methodology Serum samples from 23 children with UC (17 Japanese, 6 non-Japanese), 27 children with Crohn's disease (CD) (10 Japanese, 17 non-Japanese), 10 children with other diarrhoeal diseases, and 33 normal, healthy adult volunteers were assayed for ANCA using an indirect immunofluorescence technique.
Results ANCA were detected in 6/17 (35%) UC patients and 0/10 (0%) CD patients in Japanese children, and in 3/6 (50%) UC patients and 3/17 (18%) CD patients in non-Japanese children. The difference in prevalence between Japanese and non-Japanese children with UC was not statistically significant ( P >0.05). ANCA were not found in other diarrhoeal patients and volunteers.
Conclusions Although ANCA have been reported to be useful in the diagnosis of UC in adults, they may be of limited use in Japanese children. This might reflect the heterogeneity of UC.  相似文献   
34.
ABSTRACT. CRP, α1-acid glycoprotein and haptoglobin were studied in 13 septic shock neonates. Endotoxin was recovered from eight infants. Serum Cortisol concentration from infants with en-dotoxemia (917 ± 596 ng/ml) was significantly higher than that from infants without en-dotoxemia (398 ± 239 ng/ml). Serum Cortisol correlated well with immature neutrophil counts denned as the unit "band/neutrophil". Increased Cortisol level and immature neutrophil counts preceded the elevation of CRP, α1-acid glycoprotein and haptoglobin in four extremely premature neonates. We conclude that positive interactions between endotoxin, Cortisol and acute phase protein synthesis are present in the initial period of infection, and delayed acute phase protein synthesis is suspected in extremely premature neonates.  相似文献   
35.
目的:研究以电热针治疗风寒湿痹及虚痹的疗效。方法:将电热针与毫针分别应用到30例痹证患者2个疗程中,详细观察其局部症状、VAS、血沉、CRP、抗“O”的改善情况。结果:以电热针治疗痹证及虚痹的有效率96.7%,毫针有效率80.0%。结论:电热针及毫针治疗痹证的方法可广泛应用到临床治疗当中。  相似文献   
36.
Morphologic Change During Para-Hisian Pacing. Para-Hisian pacing, a useful method to differentiate conduction over an accessory pathway from conduction over the AV node, is assessed essentially by comparing the timing of local atrial electrograms between Hisbundle captured heats and His-bundle noncaptured heats. We describe the case of a patient with a permanent form of junctional reciprocating tachycardia, in whom an atrial double potential was recorded only during the tachycardia at the right posterior septum. During para-Hisian pacing, a morphologic change in the atrial electrogram at the posterior septum was also identified, as well as a change in the retrograde atrial sequence. Since the morphologic change of atrial electrograms during para-Hisian pacing cannot be demonstrated in a patient without an accessory pathway, this new finding could he considered a new additional diagnostic criterion suggesting the presence of an accessory pathway.  相似文献   
37.
N-Acetylglucosaminyltransferase III (GnT III) catalyses the addition of N-acetylglucosamine through a β 1–4 linkage to the mannose of the trimannosyl core, resulting in conversion of the concanavalin A (Con A)-reactive glycan into a non-reactive state. In this study, we measured GnT III activity to evaluate its diagnostic efficacy and its therapeutic effect on hepatocellular carcinoma (HCC). Concanavalin A-non-reactive fraction of serum transferrin (Tf) was also determined since the sugar chains of Tf are one of the possible candidates for the product of GnT III. Serum samples (159) were used from patients with HCC (89), liver cirrhosis (30), chronic hepatitis (19), alpha-fetoprotein (AFP) producing gastric carcinoma metastatic to the liver (five) and healthy controls (16). N-Acetyl-glucosaminyltransferase III activity was determined by high performance liquid chromatography. The reactivity of serum Tf to Con A was also analysed in 21 paired HCC samples before and after treatment by crossed immuno-affinoelectrophoresis. N-Acetylglucosaminyltransferase III activity from the HCC group (153 ± 72 pmol/mL/h) was significantly higher than that from liver cirrhosis (99 ± 67 pmol/mL per h), chronic hepatitis (84 ± 39pmol/mL per h) and the normal controls (62 ± 16pmol/mL per h). N-Acetylgiucosaminyltransferase III activity of 21 patients with HCC was significantly reduced after treatment such as transcatheter arterial chemoembolization and/or percutaneous ethanol infection therapy, (123 ± 77 to 100 ± 60pmol/mL per h). Commensurate decreases of AFP and des-γ-carboxy prothrombin with GnT III activity were also observed after treatment. The Con A-non-reactive fraction (n= 21; 6.4 ± 2.3%) in patients with HCC after treatment was significantly lower than before (8.2 ± 2.4%). The present study suggests that GnT III activity is a possible and in the diagnosis and evaluation of HCC, especially when other tumour markers are negative.  相似文献   
38.
The ultrastructural effects of a Leydig cell tumour of the testis on nontumorous testicular tissue have not yet been reported. Described here are the electron microscopic findings in the nonneoplastic testicular tissue of a patient with a feminizing testicular Leydig cell neoplasm. Serial studies were carried out over a period of 3 1/2 years prior to removal of the tumour. The overall general picture was characterized by progressive degeneration of Leydig cells, cells of the germinal series and Sertoli cells. Concomitantly, there was increasing thickening and fibrosis of the tubular walls. Cytoplasmic focal accumulations of glycogen, increasing with the duration of the disease, were conspicuous in many spermatogonia. All of these alterations are nonspecific and are attributable to adverse endocrine effects introduced by the oestrogen-secreting tumour. They were present bilaterally and were more prominent on the tumour-bearing side. Attention is drawn to the role of artifacts, fixation technique and degenerative processes in the production and appearance of certain ultrastructural findings, such as ‘light’ and ‘dark’ cells, myelin figures, membranous whorls and focal glycogen accumulations.  相似文献   
39.
40.
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