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   1241篇
  免费   100篇
  国内免费   147篇
耳鼻咽喉   1篇
儿科学   59篇
妇产科学   7篇
基础医学   97篇
口腔科学   18篇
临床医学   224篇
内科学   350篇
皮肤病学   37篇
神经病学   81篇
特种医学   314篇
外科学   42篇
综合类   25篇
预防医学   43篇
眼科学   15篇
药学   124篇
  1篇
肿瘤学   50篇
  2023年   4篇
  2021年   5篇
  2020年   7篇
  2019年   8篇
  2018年   15篇
  2017年   6篇
  2016年   10篇
  2015年   15篇
  2014年   20篇
  2013年   37篇
  2012年   19篇
  2011年   25篇
  2010年   33篇
  2009年   52篇
  2008年   31篇
  2007年   113篇
  2006年   26篇
  2005年   45篇
  2004年   20篇
  2003年   13篇
  2002年   24篇
  2001年   34篇
  2000年   28篇
  1999年   26篇
  1998年   82篇
  1997年   82篇
  1996年   75篇
  1995年   71篇
  1994年   50篇
  1993年   56篇
  1992年   25篇
  1991年   24篇
  1990年   21篇
  1989年   63篇
  1988年   35篇
  1987年   38篇
  1986年   35篇
  1985年   29篇
  1984年   23篇
  1983年   19篇
  1982年   29篇
  1981年   15篇
  1980年   16篇
  1979年   8篇
  1978年   6篇
  1977年   17篇
  1976年   29篇
  1975年   13篇
  1973年   2篇
  1967年   2篇
排序方式: 共有1488条查询结果,搜索用时 15 毫秒
11.
The diagnosis of idiopathic Parkinson's disease (PD) can be achieved with high degrees of accuracy in cases with full expression of classical clinical features. However, diagnostic uncertainty remains in early disease with subtle or ambiguous signs. Functional imaging has been suggested to increase the diagnostic yield in parkinsonian syndromes with uncertain clinical classification. Loss of striatal dopamine nerve terminal function, a hallmark of neurodegenerative Parkinsonism, is strongly related to decreases of dopamine transporter (DAT) density, which can be measured by single photon emission computed tomography (SPECT). The use of DAT‐SPECT facilitates the differential diagnosis in patients with isolated tremor symptoms not fulfilling PD or essential tremor criteria, drug‐induced, psychogenic and vascular Parkinsonism as well as dementia when associated with Parkinsonism. This review addresses the value of DAT‐SPECT in early differential diagnosis, and its potential as a screening tool for subjects at risk of developing PD as well as issues around the assessment of disease progression. © 2007 Movement Disorder Society  相似文献   
12.
13.
14.
The bactericidal activities of various monotherapies and combined regimens were compared in mice at different stages after infection with Mycobacterium tuberculosis. These therapies mimicked the initial and continuation phases of chemotherapy for human tuberculosis. As monotherapy, the bactericidal activity of sparfloxacin (SPFX) was dose related; the activity of SPFX at 100 mg/kg of body weight was comparable to that of rifampin (RMP) and was significantly greater than those of isoniazid (INH), pyrazinamide (PZA), or ofloxacin (OFLO) during both the initial and continuation phases of chemotherapy. During the initial phase, the addition of SPFX did not enhance or diminish the activities of the combinations INH-RMP-PZA or RMP-PZA; the combinations SPFX-PZA-streptomycin (SM) and SPFX-PZA-kanamycin (KANA) displayed powerful bactericidal activity. Because the area under the plasma concentration-time curve of SPFX (100 mg/kg) in mice is similar to that of SPFX (400 mg) in humans, the promising bactericidal activity displayed by SPFX in mice might be achieved in humans by administration of the drug in a clinically tolerated dosage. In addition, the combinations SPFX-PZA-SM and SPFX-PZA-KANA may be useful for the treatment of multidrug-resistant tuberculosis.  相似文献   
15.
Patellofemoral joint: kinematic MR imaging to assess tracking abnormalities   总被引:4,自引:0,他引:4  
Shellock  FG; Mink  JH; Fox  JM 《Radiology》1988,168(2):551-553
The patellofemoral joint was imaged with magnetic resonance (MR) in the axial plane while the knee was positioned from 0 degrees to 32 degrees of flexion (nine positions). These multiple sequential images obtained within the early phases of flexion of the knee were viewed in a "cine-loop" format, producing a kinematic study that clearly demonstrated the relationship of the patella to the trochlear groove. Four healthy subjects and one patient with known bilateral subluxing patellae were studied. The preliminary results suggest that kinematic MR imaging of the patellofemoral joint is potentially useful for the evaluation of patellar tracking abnormalities.  相似文献   
16.
The authors have studied tolerance of multibacillary patients to 4 MDT regimens. These 4 regimens consist of: One supervised part in which RMP-ETH combination in once-monthly administered; furthermore, in 2 of these regimens, is included one "starter phase" with daily doses of that combination for 2 months. One self-administered part during which CLO is associated either to DDS for new cases, or to ETH for relapses. Clinical Supervision: Out to 310 multibacillary patients, 7 cases of hepatitis with or without icterus, but no death due to the treatment. Interruptions of MDT have been temporary and have been observed in 0.9 to 5.6% of the patients according to the therapeutic regimen. Checking SGOT: The SGOT were abnormally high in 16.3% of the patients before treatment. These pre-existing liver damages do not favour the appearance of intolerance disorders. During MDT, abnormal increases in SGOT are observed in 27% of the patients but there is no exact correlation between the absorbed doses of ETH and the frequency in SGOT increases. The clinical or biological evidence of liver damages occur rather early (1st, 2nd month) in regimens with "starter phase", and later (4th-8th month) in those without "starter phase". But introduction of "Starter phase" does not increase the global frequency of such intolerance accidents. ETH combined with RMP, must be used under steady clinical and biological supervision. Recalling the results of a previous survey, the authors consider that a long duration of MDT is not necessary. For the multibacillary leprosy treatment, they propose a diphasic regimen, more easily applicable in the field than the WHO protocols. In this diphasic regimen, the only part which must be supervised is the initial "starter phase" of 2 month. It consists of daily administration of 3 antibacillary drug among which RMP and ETH. The second phase is a relay treatment using 2 drugs, CLO combined with DDS or ETH, self-administered until smear negativity.  相似文献   
17.
Marrow regeneration after mechanical depletion   总被引:1,自引:0,他引:1  
Brecher  G; Tjio  JH; Smith  WW; Haley  JE 《Blood》1976,48(5):679-686
The origin of marrow regeneration after mechanical depletion was reinvestigated in mouse chimeras. The results were compatible with the local origin of stem cells from remnants of incompletely removed marrow, but not with their origin from a common precursor of both bone and hemopoietic cell lines. In transplanted femurs depleted by a modified technique of in vivo evacuation of marrow, hemopoietic regeneration failed to occur. The presence of hemopoietic stem cells in the Haversian canals was thus excluded. The demonstration of ample hemopoiesis with minimal bone formation in nondepleted controls in which bone marrow initially became necrotic provided new evidence that osteogenesis was not a prerequisite of hemopoietic regeneration.  相似文献   
18.
A 15 year old boy with autoimmune polyendocrinopathy-candidosis-ectodermal dystrophy syndrome suffered recurrent episodes of severe intractable diarrhoea, steatorrhoea, and hypocalcaemia. The only treatment modality, which controlled the malabsorption syndrome, was immunosuppression with intravenous high dose methylprednisolone and oral methotrexate maintenance therapy.  相似文献   
19.
A 54-year-old man was treated with weekly 24-h infusion of high-dose 5-fluorouracil (2600 mg/m2) and leucovorin (100 mg/m2) for metastatic colon cancer. At first, he tolerated the treatment well and no significant toxicity was identified. After a total of eight courses of treatment, a stable disease was observed, but mild shortness of breath was found on occasion. The patient had no previous history of cardiac disease and the heart performance assessed by left ventricular ejection fraction before treatment was normal. Unfortunately, acute pulmonary edema with lethal cardiogenic shock occurred during the ninth course of treatment, in spite of intensive medical treatment. The chest X-ray showed extreme cardiomegaly. Repeated assessment of his heart function by echocardiogram and ventricular ejection fraction revealed a very poor cardiac performance. Toxic cardiogenic shock during weekly 24-h infusion of high-dose 5-fluorouracil and leucovorin is extremely rare. To the best of our knowledge, no case has been reported in the English literature. We report a case and the relevant literature about the incidence, clinical picture and possible pathophysiology on 5-fluorouracil-related cardioxicity is reviewed.   相似文献   
20.
Background. Routine lateral turning of patients has become an accepted standard of care to prevent complications of immobility. The haemodynamic and oxygenation effects for patients in both lateral positions (45°) are still a matter of debate. We aimed to study the effect of these positions on blood pressure, heart rate and oxygenation in a general intensive care population. Design. Observational study. Method. Twenty stable intensive care unit patients had intra‐arterial blood pressure recordings in the supine and lateral positions with the correction of hydrostatic height compared with a fixed reference point (phlebostatic level). A multilevel model was used to analyse the data. Results. Mean arterial pressure readings in the lateral positions were, on average, 5 mmHg higher than in the supine position (p < 0·001). There were no significant differences between mean arterial pressure recordings in the left and right lateral position (p = 1·0). No important differences in oxygenation and heart rate were observed. After correction for covariates, the effects persisted. Conclusion. Our study demonstrated an increase, albeit small, in blood pressure in the lateral positions. No major differences between the left and right lateral position were found. No important differences in oxygenation and heart rate were observed. Relevance to clinical practice. Turning haemodynamically stable patients in the intensive care unit has no important effects on blood pressure measurements when continuous hydrostatic height correction is applied.  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