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   714篇
  免费   20篇
  国内免费   1篇
儿科学   115篇
妇产科学   1篇
基础医学   33篇
口腔科学   4篇
临床医学   81篇
内科学   176篇
皮肤病学   6篇
神经病学   55篇
外科学   125篇
综合类   4篇
预防医学   3篇
眼科学   2篇
药学   75篇
中国医学   4篇
肿瘤学   51篇
  2018年   1篇
  2017年   4篇
  2016年   9篇
  2015年   14篇
  2014年   9篇
  2013年   14篇
  2012年   4篇
  2011年   3篇
  2010年   15篇
  2009年   18篇
  2008年   4篇
  2007年   27篇
  2006年   38篇
  2005年   19篇
  2004年   33篇
  2003年   24篇
  2002年   10篇
  2001年   9篇
  2000年   3篇
  1999年   32篇
  1998年   65篇
  1997年   42篇
  1996年   53篇
  1995年   42篇
  1994年   39篇
  1993年   37篇
  1992年   17篇
  1991年   15篇
  1990年   13篇
  1989年   6篇
  1988年   8篇
  1987年   10篇
  1986年   10篇
  1985年   8篇
  1984年   6篇
  1983年   4篇
  1982年   5篇
  1981年   13篇
  1980年   10篇
  1979年   14篇
  1978年   5篇
  1977年   2篇
  1976年   5篇
  1975年   2篇
  1973年   2篇
  1972年   4篇
  1971年   3篇
  1970年   2篇
  1968年   1篇
  1967年   2篇
排序方式: 共有735条查询结果,搜索用时 31 毫秒
71.
72.
A series of thyrotropin-releasing hormone (TRH) analogs in which the pyroglutamic acid residue was replaced by (S)-2-oxoimidazolidine-4-carboxylic acid (Oic-OH) and the related derivatives was prepared, and the central nervous system (CNS) actions were examined. Of these, 1-benzyl-Oic-His-Pro-NH2 (2c) showed the most potent activities, which were 1.5-8 times greater than those of TRH. Moreover, the thyrotropin (TSH)-releasing activity of 2c was about 1/16 times weaker than that of TRH.  相似文献   
73.
Tetrameric concanavalin A at neutral pH dissociated into the dimer when CuCl2 was added in a concentration range comparable to protomer concentration. This effect of CuCl2 was largely suppressed when NaCl concentration was increased. Neither the conformation of the protein nor its binding activity to 4-methylumbelliferyl α-D-man-nopyranoside was affected on addition of CuCl2.  相似文献   
74.
Trichosporon beigelii Pneumonia in a Patient with Malignant Histiocytosis   总被引:1,自引:0,他引:1  
A 30-year-old previously healthy housewife presented with bilateralpulmonary infiltrates. She was treated with various antibioticsbut died with disseminated intravascular coagulation. Culturesof tracheal aspirates obtained prior to her death yielded Trichosporonbeigelii. Postmortem examination revealed T. beigelii pneumoniawith fungal dissemination in other organs. In addition, manyorgans were found to be infiltrated with atypical mononuclearcells which exhibited cytochemical properties of histiocytes.It was considered, therefore, that T. beigelii pneumonia developedon the basis of underlying malignant histiocytosis. T. beigeliiin her lung sections was fluorescently stained with rabbit antiserumto the fungus isolated from the patient. This is the first reportof Trichosporon beigelii pneumonia associated with malignanthistiocytosis.  相似文献   
75.
76.
INTRODUCTION: Electrolyte abnormalities are considered a correctable cause of a life-threatening ventricular arrhythmia according to American Heart Association/American College of Cardiology Practice Guidelines, and ventricular tachycardia or ventricular fibrillation in the setting of an electrolyte abnormality is considered a class III indication for defibrillator implantation. However, there are little data to support this recommendation. The purpose of this study was to determine the risk of a recurrent sustained ventricular arrhythmia in patients with a low serum potassium concentration at the time of an initial episode of a sustained ventricular arrhythmia. METHODS AND RESULTS: One hundred sixty-nine consecutive patients who presented with a sustained ventricular arrhythmia and a serum potassium concentration determined on the day of the arrhythmia underwent defibrillator implantation. All patients had structural heart disease and left ventricular ejection fraction of 0.32+/-0.15. On the day of the index arrhythmia, 30% of the patients had a serum potassium concentration <3.5 or >5.0 mEq/L, including 7% who had a serum potassium concentration <3.0 or >6.0 mEq/L. For the entire cohort of patients, freedom from a recurrent sustained ventricular arrhythmia was 18% at 5 years and was not significantly different among patients with a serum potassium concentration <3.5 mEq/L (23%), between 3.5 and 5.0 mEq/L (16%), and >5.0 mEq/L (5%; P = 0.1). CONCLUSION: The results of the present study suggest that patients with structural heart disease and an abnormal serum potassium concentration at the time of an initial episode of sustained ventricular tachycardia or ventricular fibrillation are at high risk for a recurrent ventricular arrhythmia; therefore, implantable defibrillator therapy may be reasonable.  相似文献   
77.
Skeletal muscle is a very rare location for the metastasis of renal cell carcinoma (RCC) and only one case of solitary metastasis to the psoas muscle has been reported. We present a 63-year-old male patient with late recurrence (14 years) after left side radical nephrectomy for RCC. He first visited Chikushi Hospital, Fukuoka University, Japan in January 2000 for a postoperative follow-up because he had shifted residence to the area. Follow-up was by abdominal computed tomography (CT) and chest X-ray. In December 2001, a CT scan showed a 1.5 cm enhanced mass in the right psoas muscle without any other metastasis. The mass was resected that month and histological study showed RCC metastasis.  相似文献   
78.
Bovine plasma albumin Fr. V(BPA) contains small amounts of proteolytic enzyme which catalyzes a very limited cleavage of BPA in the F-form near pH 3.8, resulting in the formation of partially hydrolyzed BPA(BPA*). BPA* had a tendency to form a transparent gel at pD 4.0 (pD range of the F-form) above 7%. Highly purified proteolytic enzyme-free bovine mercaptalbumin (BMA) was in a transparent solution at pD 4.0 even at 12.4%. after 5 days incubation at 35°. Cross-relaxation times (TIS) between irradiated protein protons and observed protons, such as side chain and water protons, were studied on BMA solution and BPA*-gel. TIS values of BMA solution, obtained by the saturation transfer (SATUR) and inversion recovery (INVER) methods, were a single kind of TIS for each side chain. Those of BPA*-gel by the SATUR method indicated the presence of two kinds of TIS, that is, short and long TIS values for each side chain. However, those by the INVER method showed a single kind of TIS for each side chain, corresponding to the long TIS value by the SATUR method. The short TIS values of BPA*-gel, observed by the SATUR method, may be due to immobile joint parts of fibrous BPA* aggregates. TIS values from protein to water protons (TIS(HDO)) in BPA*-gel, obtained by the INVER method, were far shorter than those in BMA solution, indicating a large amount of hydration of BPA* and rapid exchange between bound and bulk water in the gel state.  相似文献   
79.
Both CD4 and CD8 T cells are subdivided into two phenotypically distinct sublineages via another two T cell markers, Leu-8 and CD11b antigens. The proportions of these four T cell subsets, CD4+Leu8+, CD4+Leu8-, CD8+11b+ and CD8+11b-, were studied in patients with auto-immune chronic active hepatitis (CAH) and compared with disease controls (hepatitis B surface antigen positive chronic active hepatitis) and healthy controls. We found that the proportion of CD4+Leu8+ cells was significantly reduced compared with controls (P less than 0.01), whereas those of the other cells were almost identical in all 3 groups. The absolute number of these CD4+Leu8+ cells was also lower than that of controls (P less than 0.01). Thus, the present study suggests that a reduced number of CD4+Leu8+ cells is associated with the aberrant immune response in auto-immune CAH.  相似文献   
80.
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