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   855篇
  免费   77篇
  国内免费   15篇
耳鼻咽喉   2篇
儿科学   17篇
妇产科学   8篇
基础医学   86篇
口腔科学   26篇
临床医学   52篇
内科学   119篇
皮肤病学   31篇
神经病学   334篇
特种医学   88篇
外科学   84篇
综合类   13篇
一般理论   1篇
预防医学   15篇
眼科学   7篇
药学   27篇
中国医学   3篇
肿瘤学   34篇
  2021年   6篇
  2020年   12篇
  2019年   7篇
  2018年   7篇
  2017年   11篇
  2016年   9篇
  2015年   10篇
  2014年   15篇
  2013年   43篇
  2012年   21篇
  2011年   32篇
  2010年   31篇
  2009年   35篇
  2008年   27篇
  2007年   42篇
  2006年   40篇
  2005年   23篇
  2004年   26篇
  2003年   20篇
  2002年   30篇
  2001年   26篇
  2000年   36篇
  1999年   24篇
  1998年   34篇
  1997年   28篇
  1996年   21篇
  1995年   19篇
  1994年   16篇
  1993年   10篇
  1992年   11篇
  1991年   17篇
  1990年   15篇
  1989年   19篇
  1988年   18篇
  1987年   20篇
  1986年   22篇
  1985年   21篇
  1984年   10篇
  1983年   10篇
  1982年   9篇
  1981年   6篇
  1980年   7篇
  1979年   12篇
  1978年   11篇
  1977年   8篇
  1976年   10篇
  1975年   13篇
  1974年   11篇
  1973年   6篇
  1972年   8篇
排序方式: 共有947条查询结果,搜索用时 15 毫秒
1.
Coccidioidomycosis is an endemic fungal infection of the desert southwestern United States of particular concern for immunosuppressed renal transplant recipients. The clinical course of coccidioidomycosis can be severe in immunosuppressed patients, with high rates of dissemination and mortality, and antifungal prophylaxis is routinely administered to high-risk patients. We sought to determine the impact of coccidioidomycosis on patients who received their renal transplant at our hospital in Phoenix, Arizona. A retrospective records review of the first 205 patients who received a renal transplant between June 1999 and December 2003 identified 6 patients (3%) who had contracted coccidioidomycosis after transplantation. All six cases occurred more than 6 months after transplantation. Two of these six patients had disseminated coccidioidomycosis. Two patients, one with pulmonary infection and one with disseminated infection, died. None of the six patients with coccidioidomycosis after transplantation had identified risk factors before transplantation. No high-risk patient who received targeted antifungal prophylaxis had a reactivation of coccidioidomycosis after transplantation. Treatment for acute rejection and induction with antithymocyte globulin did not appear to increase the risk of subsequent coccidioidomycosis.  相似文献   
2.
Occurrence of the t(2;5)(p23;q35) in non-Hodgkin's lymphoma   总被引:9,自引:3,他引:6  
Primary CD30(Ki-1)-positive anaplastic large-cell lymphoma (ALCL) is considered by some to be a distinct clinicopathologic entity associated with the t(2;5) (p23;q35). However, the specificity of t(2;5) for ALCL has not been carefully studied. Therefore, we performed a detailed analysis of all cases of ALCL with abnormal cytogenetics results in the Nebraska Lymphoma Study Group registry, as well as all other cases of non-Hodgkin's lymphoma with t(2;5) in the registry. We found the t(2;5) in only five of 10 cases of ALCL, four of whom were young patients. However, we also found the t(2;5) in 11 other cases of nonanaplastic lymphoma, including eight children with typical peripheral T-cell lymphomas of various types. The t(2;5) was also found in three older adults with B-cell lymphomas of various types. Thus, the t(2;5) was not specific for CD30+ ALCL. However, t(2;5) may define a clinicopathologic entity in children and young adults characterized by variable morphologies with a T-cell or indeterminate phenotype, CD30-positivity, nodal disease with frequent extranodal involvement, advanced stage, and an excellent response to therapy, including bone marrow transplantation for relapsed disease. The clinical relevance of the t(2;5) in older patients requires further study.  相似文献   
3.
Auricular myoclonus.   总被引:1,自引:0,他引:1  
We describe a young man with a two and a half year history of idiopathic irregular contractions of an antitragicus muscle in the absence of a more generalized movement disorder. These contractions persisted in sleep and could not be replicated voluntarily. Because proximal nerve block temporarily eliminated the movements and complex hand movements reduced their amplitude and frequency, we suspect a central generator. However, these movements were not associated with any known pathologic condition.  相似文献   
4.
Cognitive evoked potentials and disorders of recent memory   总被引:1,自引:0,他引:1  
P3 potentials evoked by spoken words were recorded from seven patients with disorders of recent memory and seven age-matched controls. Inclusion criteria included a clearly identifiable P3 to pure tone stimuli. Absence or marked decrement of P3 to word stimuli was seen in the patients even though they could perform the word task. The results are consistent with an encoding disorder and failure in elaboration of information processing.  相似文献   
5.
6.
Winkler  ML; Olsen  WL; Mills  TC; Kaufman  L 《Radiology》1987,165(1):203-207
Two fast magnetic resonance (MR) imaging techniques, advanced Fourier and partial-flip imaging, were used at 0.35 T to examine 21 patients with suspected intracranial lesions; the results were quantitatively compared with a conventional spin-echo study. Both of the fast MR techniques yielded a fourfold reduction in imaging time per section. The advanced Fourier sequence showed contrast that was identical to the conventional spin-echo study with signal-to-noise ratios of 58% and 57% for the first and second echoes, respectively. The partial-flip sequence showed a contrast of 109% and 57% for lesions versus substantia alba, and 107% and 78% for substantia grisea versus substantia alba relative to the first and second echoes of the conventional spin-echo study. The partial-flip sequence was particularly sensitive to magnetic susceptibility; this produced artifacts that may undermine the usefulness of partial flip for routine screening in certain parts of the brain. However, this susceptibility significantly improved the detection of intracranial hemorrhage when compared with the spin-echo sequence, particularly when combined with phase mapping of the partial-flip study.  相似文献   
7.
8.
Deficits in visual-spatial ability can be associated with Parkinson's disease (PD), and there are several possible reasons for these deficits. Dysfunction in frontal-striatal and/or frontal-parietal systems, associated with dopamine deficiency, might disrupt cognitive processes either supporting (e.g., working memory) or subserving visual-spatial computations. The goal of this study was to assess visual-spatial orientation ability in individuals with PD using the Mental Rotations Test (MRT), along with other measures of cognitive function. Non-demented men with PD were significantly less accurate on this test than matched control men. In contrast, women with PD performed similarly to matched control women, but both groups of women did not perform much better than chance. Further, mental rotation accuracy in men correlated with their executive skills involving mental processing and psychomotor speed. In women with PD, however, mental rotation accuracy correlated negatively with verbal memory, indicating that higher mental rotation performance was associated with lower ability in verbal memory. These results indicate that PD is associated with visual-spatial orientation deficits in men. Women with PD and control women both performed poorly on the MRT, possibly reflecting a floor effect. Although men and women with PD appear to engage different cognitive processes in this task, the reason for the sex difference remains to be elucidated.  相似文献   
9.
Dopamine agonist therapy for neglect in humans   总被引:4,自引:0,他引:4  
Lesions of ascending dopaminergic pathways induce neglect in animals. Apomorphine, a dopamine receptor agonist, decreases the magnitude of neglect in rats with cortical lesions. We treated two patients with 15 mg of bromocriptine daily for 3 to 4 weeks, one with chronic (longer than 6 months) and one with relatively more acute disabling neglect. Tests for neglect that significantly improved on therapy and worsened after its withdrawal included line, letter, and geometric figure cancellation tasks. Neither patient noted any untoward effects. Based on this open trial of dopamine agonist therapy in humans with neglect, larger controlled studies may be warranted.  相似文献   
10.
Hydrocortisone was added to cultures of human peripheral blood leucocytes 30 min before the addition of phytohaemagglutinin (PHA) or pokeweed mitogen (PWM). A concentration of 10 μg/ml of hydrocortisone inhibited a major part of the blastogenic response to PHA at 3 days of incubation and prevented a decline in the number of macrophages. A portion of corticosteroid-resistant PHA-stimulated blasts was observed in all experiments. Hydrocortisone (10 μg/ml) caused a slight decrease in the mitogenic response to PWM at 2 and 3 days of incubation, but at 5 days the proportion of blasts equalled or exceeded that seen in cultures with PWM alone. Hydrocortisone did not prevent the virtual disappearance of macrophages from cultures incubated with PWM or with a combination of PHA and PWM. The effect of hormone on both lymphocytes and macrophages indicated that the principal action of PWM was on a subpopulation of lymphocytes not responsive to PHA. In addition a small number of corticosteroid-sensitive cells was transformed by PWM early in incubation. Results indicated that the prior addition of corticosteroids to leucocyte cultures was useful in determining the response of segments of the circulating lymphocyte population to different mitogenic stimulants.  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