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   7787篇
  免费   376篇
  国内免费   119篇
耳鼻咽喉   20篇
儿科学   387篇
妇产科学   297篇
基础医学   970篇
口腔科学   115篇
临床医学   634篇
内科学   914篇
皮肤病学   208篇
神经病学   931篇
特种医学   112篇
外国民族医学   2篇
外科学   686篇
综合类   1008篇
预防医学   333篇
眼科学   126篇
药学   558篇
  1篇
中国医学   125篇
肿瘤学   855篇
  2024年   9篇
  2023年   53篇
  2022年   69篇
  2021年   161篇
  2020年   97篇
  2019年   526篇
  2018年   435篇
  2017年   279篇
  2016年   193篇
  2015年   158篇
  2014年   324篇
  2013年   291篇
  2012年   361篇
  2011年   410篇
  2010年   382篇
  2009年   341篇
  2008年   320篇
  2007年   327篇
  2006年   252篇
  2005年   202篇
  2004年   175篇
  2003年   168篇
  2002年   165篇
  2001年   122篇
  2000年   88篇
  1999年   84篇
  1998年   61篇
  1997年   69篇
  1996年   63篇
  1995年   49篇
  1994年   51篇
  1993年   29篇
  1992年   32篇
  1991年   34篇
  1990年   25篇
  1989年   21篇
  1988年   15篇
  1987年   13篇
  1986年   14篇
  1985年   209篇
  1984年   367篇
  1983年   196篇
  1982年   214篇
  1981年   252篇
  1980年   155篇
  1979年   173篇
  1978年   107篇
  1977年   76篇
  1976年   38篇
  1975年   14篇
排序方式: 共有8282条查询结果,搜索用时 15 毫秒
991.
The short- and long-term effects of various Nitro-Dur formulations on performance and hemodynamics were studied in 15 men with stable angina pectoris who also had a positive treadmill exercise test. A treadmill exercise score (TES) was used that quantified the “ischemic” ST segment response to exercise. The score incorporated information that reflected the rapidity of evolution of ST segment depression during exercise and the time required for it to resolve after cessation of exercise. In early tests (n = 10) Nitro-Dur improved both the TES (by 31%: p < 0.0001) and the time required for 1 mm ST segment depression (by 33%: p < 0.0001). At all dosage levels, Nitro-Dur also decreased resting systolic blood pressure and increased resting heart rate. No dose-response patterns emerged. Changes in TES and time to ST segment depression were greater with sublingual nitroglycerin than they were with Nitro-Dur. In tests conducted after prolonged dosage (n = 5), the effects of Nitro-Dur on blood pressure and heart rate became attenuated at weeks 2 and 4, although cardiac responsiveness was preserved, as reflected in the increased time required before the occurrence of 1 mm ST segment depression. The latter effect was also observed with sublingual nitroglycerin. The clinical relevance of these data to the design of individual patient therapy is discussed.  相似文献   
992.
993.
C Stasiek  M Zetin 《Psychosomatics》1985,26(5):394-6, 399, 402
Using specified criteria, Krauthammer and Kierman's review of the literature for causes for manic symptoms found cases of secondary mania owing to drugs, infection, neoplasm, epilepsy, and metabolic disturbances. We reviewed publications subsequent to their 1978 report for additional cases of secondary mania occurring in the absence of delirium and of prior affective illness. Our review reemphasizes the importance of the medical and neurologic history and examination, of a medication history, and of appropriate laboratory studies (electrolytes, thyroid function, syphilis serology) in evaluating manic patients for underlying medical conditions. Attention to the diagnosis of secondary mania is especially important in patients presenting with a first episode in later life and with a negative family history for mania.  相似文献   
994.
Two hundred and 25 unipolar depressives hospitalized during the 1930's were classified on the basis of documented communication of suicidal intent. A long term follow-up revealed 15 of the former patients had died by suicide. Communicated suicidal intent was documented in the index hospital record of all 15. The presence of communicated intent may distinguish a group of unipolar depressives at risk for suicide from those not at risk.  相似文献   
995.
Congenital Fiber Type Disproportion (CFTD) has recently been described as a consistent and stereotyped clinicopathological entity, including congenital non-progressive hypotonia and weakness, contractures, kyphoscoliosis, high arched palate, dislocated hips, short stature, and feet deformities. Our personal experience with this condition suggests a wider disparity in the physical appearance and associated abnormalities of affected individuals than the well-defined clinical syndrome previously described. We are presenting 5 cases, including 2 siblings, whose muscle biopsies satisfy the major histological and statistical criteria for the diagnosis. Although each child clearly had hypotonia and weakness consistent with a congenital myopathy, only 3 had a sufficient number of other similarities to establish the diagnosis clinically. The clinical spectrum of the other cases ranged from one infant whose only abnormality was mild hypotonia in the legs to another whose problems included severe motor impairment, marked mental retardation, growth failure, frontal bossing, abnormal hair, and scoliosis. Even in retrospect, the diagnosis of CFTD could not have been supported on clinical grounds alone. Therefore, CFTD is a congenital myopathy whose diagnosis can be made only by muscle biopsy, rather than a distinct syndrome whose diagnosis can be assumed on the basis of clinical characteristics alone.  相似文献   
996.
During the past 5 years, 20 phrenic nerve stimulators have been implanted in 11 patients who were ventilator dependent because of neurogenic respiratory failure. Ten patients had traumatic spinal cord lesions; the remaining patient suffered from a progressive demyelinating disease. There was no operative mortality. Complications included 1 stimulator malfunction and 1 pneumothorax. In spite of adjacent tracheostomies, there were no infections or wound complications. Of the 20 stimulators implanted, 13 initially produced good diaphragmatic function, 2 had fair function, and 5 had little or no function. Three patients became completely independent of their ventilators; 6 became partially independent, thus simplifying nursing care. There were no late complications. As of December, 1979, 7 patients had benefited or were continuing to benefit from phrenic nerve stimulation.  相似文献   
997.
A simple but effective technique is described for removing calcific and other debris following aortic and mitral valve replacement. This technique uses an Ellik evacuator, which is readily available in most operating rooms. An 11-year experience is presented, documenting the efficacy of this method in several hospitals.  相似文献   
998.
Night fears and sleeplessness in three children of varying ages arose from an initial anxious reaction to a realistic stimulus combined with its subsequent reinforcement because of its avoidance properties and of parental attention. Treatment using incompatible response training based on the principle of reciprocal inhibition and self-paced exposure along with operant reinforcement of appropriate sleep behavior was associated with the elimination of problem behavior within three or four sessions for all three children. Extended follow-up revealed maintenance of therapeutic gains accompanied by improvement in other areas of psychological functioning.  相似文献   
999.
1000.
An 11-item factor labeled Emotional Tension was recently located within a pool of 24 items which had been found to differentiate both adult male alcoholics and nonsubstance- abusing adult male psychiatric outpatients from putatively normal male adults and college students in a highly significant fashion. The item-unit-weighted scores on this factor of the following five male samples were compared: young alcohol offenders, adult outpatient alcoholics, young and adult nonsubstance-abusing psychiatric outpatients, and an unselected run of college students. While the scores of the young nonsubstance-abusing psychiatric outpatients were found to be indistinguishable from those of both adult patient groups, the scores of the young alcohol offenders were indistinguishable from those of college students. Scores on a similarly located, 11-item factor of Depression yielded identical results.  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