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   960篇
  免费   46篇
  国内免费   33篇
耳鼻咽喉   6篇
儿科学   33篇
妇产科学   11篇
基础医学   110篇
口腔科学   13篇
临床医学   97篇
内科学   154篇
皮肤病学   52篇
神经病学   185篇
特种医学   50篇
外科学   147篇
综合类   12篇
预防医学   76篇
眼科学   5篇
药学   57篇
中国医学   1篇
肿瘤学   30篇
  2022年   7篇
  2021年   8篇
  2020年   10篇
  2019年   9篇
  2018年   17篇
  2017年   14篇
  2016年   11篇
  2015年   15篇
  2014年   24篇
  2013年   27篇
  2012年   53篇
  2011年   44篇
  2010年   31篇
  2009年   41篇
  2008年   28篇
  2007年   69篇
  2006年   59篇
  2005年   40篇
  2004年   36篇
  2003年   36篇
  2002年   28篇
  2001年   31篇
  2000年   26篇
  1999年   13篇
  1998年   18篇
  1997年   15篇
  1996年   9篇
  1995年   12篇
  1994年   11篇
  1993年   13篇
  1992年   26篇
  1991年   20篇
  1990年   17篇
  1989年   20篇
  1988年   17篇
  1987年   16篇
  1986年   11篇
  1985年   15篇
  1984年   9篇
  1982年   6篇
  1981年   10篇
  1979年   11篇
  1978年   9篇
  1977年   5篇
  1976年   8篇
  1975年   6篇
  1974年   5篇
  1904年   5篇
  1903年   8篇
  1902年   5篇
排序方式: 共有1039条查询结果,搜索用时 0 毫秒
1.
This third part of this series of articles on laboratory diagnostics of rheumatic diseases considers the rheumatic diseases caused by infection by microorganisms, or reactive arthritides. The basis for laboratory diagnostics of infection-reactive arthritides is the investigation of anti-infection antibodies. In some situations, DNA amplification methods may be helpful. Bacterially infected joints should be immediately examined by arthrocentesis and microscopic examination and laboratory culture of the synovial fluid.  相似文献   
2.
3.
Heterotopes Pankreasgewebe der Magenwand   总被引:2,自引:0,他引:2  
Heterotopic pancreas is an uncommon cause of gastrointestinal complaints such as epigastric pain, nausea, vomiting, and upper gastrointestinal bleeding. Despite the development of modern diagnostic procedures, it is still difficult to differentiate heterotopic pancreatic tissue from other benign or malignant gastric tumors. Local excision of the gastric wall is regarded as the diagnostic and therapeutic procedure of choice. We present two cases and an overview of the literature.  相似文献   
4.
In a multicenter study we selected 84 patients with fluctuating Parkinson's disease in order to evaluate the effects of controlled-release Sinemet 50/200 (=CR) versus standard Sinemet 25/100 (=STD) in an open-label 8-week titration period, followed by a double-blind, double-dummy 24-week treatment period. In contrast with previous double-blind studies, the efficacy of Sinemet CR proved to be significantly superior to that of Sinemet-STD according to NYUPDS and NUDS rating scales. This higher efficacy of Sinemet CR was not achieved at the expense of safety and/or tolerability. Actual total daily levodopa dosage in patients treated with Sinemet CR was increased by 33%; however, the plasma level of this dosage is calculated to be similar to that of the previous dosage of Sinemet-STD (bio-availability of Sinemet CR is 71%). Mean numbers of daily doses, off-hours, and off-periods were decreased significantly during Sinemet CR treatment. Although all other variables suggest that the number of on-hours had to be increased, statistical significance could not be reached in this respect.  相似文献   
5.
6.
7.
Urinary dysfunction is very common in idiopathic Parkinson's disease (PD) and manifests primarily with symptoms of overactive bladder (OAB). Affection of central serotonergic systems has been suggested to play a role in OAB. The objective of this study was to evaluate whether in PD patients with OAB symptoms a specific alteration of the brainstem raphe (BR), which contains serotonergic neurons, can be detected with transcranial sonography (TCS). Of 116 PD patients enrolled, 19 had PD-related OAB symptoms (OAB+) unlike remaining 97 patients (OAB−). Patients were examined by a sonographer blinded to the clinical data. Reduced echogenicity of BR was found in 12 (63%) OAB+ patients but only in 18 (19%) of 93 assessable OAB− patients (Mann–Whitney U -test, P  < 0.001). In OAB+ patients, lower raphe echogenicity score was associated with longer duration of OAB symptoms ( anova , P  = 0.033). Other TCS findings such as echogenicity of substantia nigra, thalami, lenticular and caudate nuclei, and widths of third and lateral ventricles did not differ between OAB+ and OAB− patients. TCS findings suggest a pathogenetic role of BR in OAB related to PD. Alterations may reflect disturbance of its central serotonergic system.  相似文献   
8.
Seven different density gradient-forming materials were compared as to their efficacy for rat islet purification. Continuous density gradients were used in order to determine the bouant densities of the different pancreatic tissue components. Hand-picked islets served as a control. A significant separation of large numbers of slets from the exocrine tissue band was only seen in the albumin, dextran-40, and metrizamide gradients. Pure islet preparations could not be obtained with any of the gradients studied as none of the gradients completely separated lymph nodes, vessels, and ducts from the islets. Gradients containing sucrose resulted in low islet yields. The islet yields obtained with the other gradients were in the same range as those obtained by hand-picking. Metrizamide gave significantly higher yields than the widely used Ficoll. Judged both in terms of numbers of islets and their in vitro function, the best results were obtained with metrizamide and dextran-40.  相似文献   
9.
Patients with syphilitic infections are at risk of development of symptomatic neurosyphilis. Adequate treatment with 2.4-7.2 x 10(6) units benzyl penicillin-G intramuscularly within 1 year after infection will rule out this risk. However, more than 1 year after infection this treatment is not fully reliable. In asymptomatic CNS involvement (asymptomatic neurosyphilis) only intravenous penicillin treatment is considered to be adequate in the prevention of neurosyphilis. In this study we redefined criteria for this condition by comparing serum and cerebrospinal fluid (CSF) samples of symptomatic neurosyphilitic patients with those of latent syphilitic patients without CNS involvement. Diagnostic criteria of the World Health Organization and of Centers of Disease Control for asymptomatic neurosyphilis (positive CSF Venereal Disease Research Laboratory (VDRL) test, combined with raised CSF cell count and/or protein content) were studied and compared with some newer parameters such as signs of intrathecal treponemal antibody production (Treponema pallidum haemagglutination assay and intrathecal Treponema pallidum assay index), immunoglobulin G (IgG) and M (IgM) index. The results of this study in 203 syphilitic patients revealed that either a positive CSF-VDRL or combination of a raised IgG and/or IgM index with an elevated CSF cell count both are useful criteria for "ruling-in" asymptomatic neurosyphilis.  相似文献   
10.
A polymerase chain reaction with nested primer pairs based on the DNA sequence of the 39-kDa bmp gene of Treponema pallidum subsp. pallidum is described. The method allowed the detection of purified T. pallidum DNA equivalent to the amount of DNA in a single bacterium and was specific for T. pallidum subspecies. After concentration of DNA, using diatomaceous earth, it was possible to detect about 100 treponemes in 1 ml of cerebrospinal fluid. Cerebrospinal fluid samples from a total of 29 symptomatic and asymptomatic patients with neurosyphilis were tested for the presence of treponemal DNA before and at various intervals after intravenous treatment with penicillin. Prior to the penicillin treatment, we detected T. pallidum DNA in 5 of 7 patients with acute symptomatic neurosyphilis, in none of the 4 patients with chronic symptomatic neurosyphilis tested before treatment, and in 2 of 16 patients with asymptomatic neurosyphilis. Unexpectedly, T. pallidum DNA was also often detected in cerebrospinal fluid long after intervenous treatment with penicillin, sometimes up to 3 years after therapy.  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