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   734篇
  免费   53篇
  国内免费   60篇
耳鼻咽喉   17篇
儿科学   46篇
妇产科学   11篇
基础医学   100篇
口腔科学   16篇
临床医学   97篇
内科学   185篇
皮肤病学   34篇
神经病学   17篇
特种医学   92篇
外科学   47篇
综合类   20篇
一般理论   1篇
预防医学   50篇
眼科学   4篇
药学   58篇
中国医学   2篇
肿瘤学   50篇
  2023年   4篇
  2022年   5篇
  2021年   8篇
  2020年   8篇
  2019年   13篇
  2018年   17篇
  2017年   9篇
  2016年   14篇
  2015年   17篇
  2014年   29篇
  2013年   35篇
  2012年   20篇
  2011年   25篇
  2010年   38篇
  2009年   31篇
  2008年   32篇
  2007年   60篇
  2006年   19篇
  2005年   22篇
  2004年   18篇
  2003年   9篇
  2002年   9篇
  2001年   12篇
  2000年   6篇
  1999年   16篇
  1998年   36篇
  1997年   39篇
  1996年   25篇
  1995年   22篇
  1994年   29篇
  1993年   20篇
  1992年   7篇
  1991年   13篇
  1989年   18篇
  1988年   20篇
  1987年   11篇
  1986年   5篇
  1985年   11篇
  1984年   9篇
  1983年   5篇
  1982年   14篇
  1981年   13篇
  1980年   9篇
  1979年   6篇
  1978年   8篇
  1977年   8篇
  1976年   10篇
  1975年   5篇
  1970年   5篇
  1968年   5篇
排序方式: 共有847条查询结果,搜索用时 10 毫秒
61.
This was a 12-month extension of a randomized, investigator-blinded, multicenter, 8-week trial with triple combination (TC) cream in facial melasma. A total of 585 patients were enrolled in the study and 569 patients received study medication. Three hundred eighty-nine patients completed 6 months of treatment and 327 patients completed 12 months of treatment. TC cream demonstrated a favorable safety profile: only 14 patients (2.5%) discontinued the study due to treatment-related adverse events (AEs). The 2 cases of skin atrophy were mild and did not lead to withdrawal. From the 23 cases of mild telangiectasia, only 2 resulted in discontinuation. All others were transient. Results confirmed those of a previous smaller study, with both physicians and patients reporting clinically significant improvements in melasma. By month 12, 80% of patients had lesions completely cleared or nearly cleared. Once daily application of TC cream applied intermittently over a long period is a safe, tolerable, and effective treatment for moderate to severe melasma of the face.  相似文献   
62.

Background  

The purpose of this study was to evaluate the long-term results of partial liver resection for benign liver lesions.  相似文献   
63.
Summary. Available data suggests that lettuce big-vein disease is caused by the ophiovirus Mirafiori lettuce big-vein virus (MLBVV) but not by the varicosavirus Lettuce big-vein-associated virus (LBVaV), although the latter is frequently associated with the disease. Since the disease occurs worldwide, the putative coat protein (CP) open reading frames of geographically distinct isolates of MLBVV and LBVaV were sequenced. Comparison of both nucleotide and amino acid sequences showed a high level of sequence similarity among LBVaV isolates. Phylogenetic analysis of LBVaV CP nucleotide sequences showed that most of the Spanish isolates clustered in a phylogenetic group whereas English isolates were more similar to the USA isolate. An Australian isolate was closely related to the Dutch isolate. Genetic diversity among MLBVV CP nucleotide sequences was higher ranging from 0.2% to 12%. Phylogenetic analysis of MLBVV CP nucleotide sequences revealed two distinct subgroups. However, this grouping was not correlated with symptom development on lettuce or the geographic origin of the MLBVV isolates. Finally, a quick method based on RFLP analysis of RT-PCR amplicons was developed for assigning MLBVV isolates to the two subgroups.  相似文献   
64.
65.
I. L  ng  L. Feuer  K. N    m  K. Torok  L. Kalm  r  P. Gergely 《Immunological investigations》1981,10(6):499-509
The effects of in vitro and in vivo treatment with glutaurine, a newly discovered parathyroid hormone possessing immunostimulative activity, on human antibody-dependent cell-mediated cytotoxicity (ADCC) were studied in 15 tumor patients and healthy subjects in a xenogeneic test system using chicken erythrocytes as target cells. A marked increase in “K” cell activity was observed in 8 tumor patients with originally low cytotoxic capacity, while originally normal ADCC activity of other tumor patients and healthy subjects was not significantly influenced by glutaurine treatment. The changes in cytotoxicity were not accompanied by changes in lymphocyte populations.

Incubation of effector ceils with glutaurine in vitro caused no change in ADCC activity in lymphocyte populations. Some similarities between the effects of glutaurine treatment on ADCC and that of dialysable leukocyte extracts are discussed.  相似文献   
66.
Single-detector helical CT in PET-CT: assessment of image quality   总被引:1,自引:0,他引:1  
OBJECTIVE: CT in positron emission tomography (PET)-CT imaging is often performed as a single scan from the base of the skull to the groin, potentially resulting in degradation of the quality of CT scans depending on the position of the patient's arms and mode of breathing and the use and timing of IV contrast injection. The aim of our study was to assess the impact of artifacts on the diagnostic quality of CT scans using a single-detector helical CT scanner in PET-CT imaging. MATERIALS AND METHODS: Two radiologists retrospectively evaluated the diagnostic image quality of CT scans obtained with PET-CT in 81 patients with lymphoma. The severity of the artifacts related to the position of the patient's arms beside the body, the influence of breathing motion, and the presence of contrast material in the upper thoracic veins were ranked using a 4-point scale. RESULTS: Performing CT with the patient's arms positioned beside the body resulted in streak artifacts, predominantly in the upper abdomen, that were graded as mild in 22%, moderate in 40%, and severe in 38% of the scans. A patient's weight significantly correlated with the degree of severity of the artifacts (p < 0.05). Shallow breathing by the patient during scanning caused blurring and double-imaging, again predominantly in the upper abdomen, that were graded as mild in 23%, moderate in 49%, or severe in 28% of the scans. In 84% of the CT scans obtained with IV contrast material, the image quality of the upper thoracic region was moderately (27%) or severely (57%) degraded by streak artifacts from highly concentrated contrast material in the upper thoracic veins. CONCLUSION: The use of a single-detector CT scanner in whole-body PET-CT decreases the image quality of CT scans because of streak artifacts that occur predominantly in scans of the upper abdomen. Scanning with the patient's arms raised eliminates the streak artifacts in scans of the abdominal region. With the new generation of PET-CT devices equipped with MDCT scanners, breathing motion artifacts can be expected to be eliminated if protocols for breath-hold CT are applied. Reversing the direction of CT scanning allows one to avoid imaging the thoracic region at a time when undiluted IV contrast material is still present in the upper thoracic veins.  相似文献   
67.

Background  

This article discusses the design of a study on the prevalence of health problems (both physical and mental) and the utilisation of health care services among asylum seekers and refugees in the Netherlands, including factors that may be related to their health and their utilisation of these services.  相似文献   
68.
69.
Nicholas Torok 《The Laryngoscope》1977,87(11):1870-1877
The clinical experience is increasing, but still there is no uniform understanding in the substrate of Ménière's disease. The criteria of the diagnosis is loose and great controversy exists in the therapeutic efforts. A bewildering number of concepts and methods have been suggested and praised as the best answers in solving the problem until the next claim of success shatters the popularity of earlier allegations. The array of articles in the world literature for the past 25 years treats the entity of Ménière's disease in general and from the viewpoint of etiology, pathology, histology, clinical diagnosis and treatment. This review is concerned primarily with the treatment aspect of the literature. All the published ideas, regimens and techniques have one significant feature in common. They all claim success but not in 100% of the cases. Recovery varies from about 60% to 80%. Those cases considered “improved” are 20% to 30% and the rate of failure is between 10% and 25%. The diagnostic tools and capabilities have improved considerably. For treatment, except for reasonable medical or surgical palliation, nothing more can be offered than was offered a half century ago.  相似文献   
70.
杜晓川  贾红梅  莫显斌 《医学争鸣》1999,20(9):S046-S046
1 病例报告 男,7岁.因双下肢不等长,右膝及右踝关节骨性肿大就诊.无明显外伤史,亦无红、肿、热、痛病史.查体:发育正常,营养良好.双下肢不等长,左60cm,右64cm,有跛行.右膝及右踝内侧肿大,肤色正常,关节活动无异常.X线:右侧半身诸关节(肩、肘、腕、髋、膝、踝)骨骺及干骺发育均较左侧增大,肢体较长,骨骺出现亦较对侧提早.如右尺骨茎突骨骺较左侧提早出现(图1).右肘关节肱骨小头骨骺较左侧增大(图2).右髋臼发育浅平,边缘毛糙,右股骨头骨骺较左侧明显增大,其距泪滴之距离较左侧大1.0cm,呈…  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