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   1116篇
  免费   46篇
  国内免费   4篇
耳鼻咽喉   3篇
儿科学   19篇
妇产科学   38篇
基础医学   163篇
口腔科学   10篇
临床医学   79篇
内科学   175篇
皮肤病学   5篇
神经病学   138篇
特种医学   15篇
外科学   87篇
综合类   7篇
预防医学   170篇
眼科学   9篇
药学   174篇
中国医学   1篇
肿瘤学   73篇
  2022年   9篇
  2021年   9篇
  2020年   7篇
  2019年   8篇
  2017年   7篇
  2016年   14篇
  2015年   15篇
  2014年   14篇
  2013年   16篇
  2012年   31篇
  2011年   51篇
  2010年   31篇
  2009年   20篇
  2008年   32篇
  2007年   38篇
  2006年   45篇
  2005年   40篇
  2004年   46篇
  2003年   48篇
  2002年   34篇
  2001年   48篇
  2000年   42篇
  1999年   36篇
  1998年   13篇
  1993年   8篇
  1992年   16篇
  1991年   18篇
  1990年   27篇
  1989年   30篇
  1988年   20篇
  1987年   35篇
  1986年   26篇
  1985年   39篇
  1984年   23篇
  1983年   13篇
  1981年   7篇
  1980年   8篇
  1979年   25篇
  1978年   16篇
  1977年   14篇
  1976年   13篇
  1975年   14篇
  1974年   21篇
  1973年   17篇
  1971年   15篇
  1970年   11篇
  1969年   10篇
  1968年   7篇
  1967年   11篇
  1966年   9篇
排序方式: 共有1166条查询结果,搜索用时 15 毫秒
1.
Pharmaceutical preparations--containing aminophenazonum, noraminophenazonum sodium mesylicum, acidum acetylsalicylicum and aethylmorphinium chloratum--official in the VI. Edition of Formulae Normales have been investigated. Simple method for studying decomposition products--which can be carried out in pharmacies and can be followed the quality of products with during their usability--has been developed. The method proving and precluding the presence of decomposition products, respectively by means of preparing dilution sets has been capable of semiquantitative determination of decomposition products. DC Alufolien Kieselgel 60 F254 (Merck) layer was used. Temperature of laboratory was 22-26 degrees C and its relative humidity was 30-40%. Developing solvents were: acetone-ether-water (90:15:12) for aminophenazum; benzene-acetone-90% alcohol-wated (35: 33: 26: 11) for noraminophenazonum sodium mesylicum; methenol-glacial acetic acid-ether-benzene (1: 18: 60: 120) for acidum acetylsalicylicum; dichloromethane-methanol-concentrated ammonia (85: 15: 2) for aethylmorphinium chloratum. Detections were carried out under UV light and by using colour reagents (alcoholic ninhydrine solution for aminophenazonum, dimethylamino-benzaldehyde solution for noraminophenazonum sodium mesylicum). Rf-values of intact and decomposed compounds have been given in figures. Interfering effects of other components of preparations were studied too. These components had different Rf-values or did not react with the colour producing reagents in the applied systems.  相似文献   
2.
Colonies of toxin-producing Pasteurella multocida were detected with peroxidase-labeled monoclonal antibodies by a membrane assay. Examination of the specificity of the assay with 29 P. multocida cultures representing various geographic origins, hosts, and serotypes indicated that the test was specific for toxin-producing strains. No cross-reactions were observed with Bordetella species that can be associated with P. multocida in producing diseases in animals. A single membrane could be used to assay several isolated strains for toxin production or to enumerate toxin-producing colonies in mixed cultures. Toxin-producing P. multocida colonies were detected in primary cultures; hence, the assay appears to have good potential for widespread application with clinical samples.  相似文献   
3.
4.
Trisomy 18 is the second most common genetic defect after trisomy 21, almost 90% of which are due to additional chromosome from the mother. The parental origin of the additional chromosome can, if required, be determined by two methods: karyotyping, which takes several weeks; or, more recently, by polymerase chain reaction (PCR) which is often problematic. Fluorescent PCR of small tandem repeats (STRs) can determine the parental origin in the majority of cases within 5 h. Although the incidence of paternal origin is known for both trisomy 21 and trisomy 18, this technique can rapidly determine the parental origin in cases where there is insufficient samples to perform conventional tests. Determining parental origin by these methods may also have clinical significance in the diagnosis of chromosomal translocations or in the diagnosis of genetic disease using linkage analysis.  相似文献   
5.
Five-year follow-up study was carried out in pulmonary emphysematous patients with intermediate antitrypsin deficiency. The examinations showed no deterioration in the clinical state of the patients but in some parts of the controlled functional parameters a statistically significant worsening was found in this period of study.  相似文献   
6.
L István  E Marton 《Orvosi hetilap》1989,130(52):2791-2796
Between 1983-1987 16 patients with advanced stage Hodgkin disease, most of whom in an immunsuppressed, immundeficient state, were treated with a new "post-COPP", or "post-ABVD" reserve-protocol. In all cases megavoltage Co radiotherapy and COPP (CVPP) or ABVD polychemotherapy had previously been. Compared with the previously administered polychemotherapy the new 3-component cytostatic agent was well tolerated by the patients. The LEAMP-protocol therapy is therefore recommended in cases of ineffective combined radiochemotherapy (chemoresistance) or intolerance to chemotherapy. In four cases prolonged, complete, in nine cases partial remission was achieved and in more than a half of the patients favourable clinical effects and changes were experienced. In two cases temporary, partial remission was seen. One cases, because of the short period of treatment could not be evaluated. On the basis of the longitudinal observations the results achieved seemed subjectively and objectively favourable. The LEAMP-protocol was found to be well tolerated and satisfactorily effective.  相似文献   
7.
BACKGROUND: The rate and severity of hypertension increase dramatically after menopause. Complications seem to be more frequent and marked in hypertensive patients with greater blood pressure (BP) variability, and antihypertensive treatment does not easily reduce this variability. The effect of hormone replacement therapy (HRT) on BP and its variability is not well understood in moderate to severe hypertension, but estrogen may have calcium channel-blocking properties. Cardiovascular events occur more frequently in the morning, likely in part because of a rise in BP. DESIGN: We prospectively studied 34 postmenopausal women with treated hypertension (mean age = 53 years) and receiving a cyclic combination of estradiol and norgestrel for 19 weeks with 24-h ambulatory BP monitoring. RESULTS: Mean daily BP and its variability decreased significantly with HRT (149.3 +/- 6.1 mm Hg vs. 140.3 +/- 8.5 mm Hg [p < 0.001]; diastolic: 95.4 +/- 4.7 mm Hg vs. 92.4 +/- 7.2 mm Hg [p < 0.05]). There was also a significant decrease in the early morning BP values after HRT (154.0 +/- 6.9 mm Hg vs. 145.6 +/- 11.0 mm Hg [p < 0.001]; diastolic: 98.0 +/- 4.8 mm Hg vs. 95.1 +/- 10.0 mm Hg [p < 0.05]). Subjects who were taking calcium channel blockers (n = 11) had only half the reduction in 24-h systolic BP compared with those who were not taking calcium channel blockers (5.3 mm Hg vs. 10.5 mm Hg), and the reduction in those who were taking calcium channel blockers failed to reach statistical significance. CONCLUSIONS: Our results demonstrate that HRT may have a role in decreasing the severity of hypertension, and the mechanism of its action might be through calcium channels.  相似文献   
8.
9.
The rate of recovery and the mean time to detection of mycobacteria in clinical specimens were evaluated with two nonradiometric broth-based systems, the Mycobacteria Growth Indicator Tube (MGIT) and MB Redox systems. The data obtained for each system were compared with each other and with those obtained with the L?wenstein-Jensen (LJ) and Middlebrook 7H11 reference media. A total of 117 mycobacterial isolates (Mycobacterium tuberculosis, n = 112; nontuberculous mycobacteria, n = 5) were detected in 486 clinical specimens. The recovery rates for M. tuberculosis were 91 of 112 (81.3%) isolates with MGIT and 81 of 112 (72.3%) isolates with MB Redox. The combination of MGIT plus MB Redox recovered 104 of the 112 (92.9%) M. tuberculosis isolates. MGIT plus LJ plus Middlebrook 7H11 recovered 106 of the 112 (94.6%) isolates, MB Redox plus LJ plus Middlebrook 7H11 recovered 99 of the 112 (88.4%) isolates, and LJ plus Middlebrook 7H11 recovered 84 of the 112 (75. 0%) isolates. The mean time to detection of M. tuberculosis in smear-positive specimens was 7.2 days with MGIT, 6.9 days with MB Redox, 20.4 days with LJ, and 17.6 days with Middlebrook 7H11. The mean time to detection of M. tuberculosis in smear-negative specimens was 19.1 days with MGIT, 15.5 days with MB Redox, 25.8 days with LJ, and 21.6 days with Middlebrook 7H11. The contamination rates were 4.4, 3.8, 2.1, and 2.7% for MGIT, MB Redox, LJ, and Middlebrook 7H11, respectively. In conclusion, MGIT and MB Redox can be viable tools in the routine mycobacteriology laboratory.  相似文献   
10.
Summary Ultrastructural features of muscle spindles were studied in biopsy material from 100 patients suffering from classical rheumatoid arthritis. Thickening of the outer capsule, increased amount of extracellular ground substance within the inner capsule, and marked thickening of the basement membrane of capillary blood vessels supplying the muscle spindles were observed. Chronic inflammatory cells and macrophages were present within the spindles. Changes affecting the intrafusal muscle fibres were also seen. They were manifest as atrophy and degeneration of the intrafusal muscle fibres, absence of the specialised junctional complexes, and of the intercellular bridges, microladders and satellite cells. It is suggested that the changes affecting the intrafusal muscle fibres are probably secondary. Damage to the myelinated nerves was present, while the sensory and motor nerve endings were well preserved.Temporary Research Fellow the Rotterdam Centre for Rheumatic Disease Present address: Division of Pathology, Department of Obstetrics and Gynaecology, University of Chicago, Chicago, Illinois 60637, USA  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