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   19536篇
  免费   1024篇
  国内免费   97篇
耳鼻咽喉   226篇
儿科学   449篇
妇产科学   288篇
基础医学   2416篇
口腔科学   551篇
临床医学   1389篇
内科学   5372篇
皮肤病学   403篇
神经病学   1642篇
特种医学   363篇
外科学   2982篇
综合类   127篇
一般理论   6篇
预防医学   1541篇
眼科学   496篇
药学   1074篇
  1篇
中国医学   53篇
肿瘤学   1278篇
  2024年   14篇
  2023年   145篇
  2022年   382篇
  2021年   723篇
  2020年   334篇
  2019年   625篇
  2018年   735篇
  2017年   413篇
  2016年   447篇
  2015年   559篇
  2014年   717篇
  2013年   934篇
  2012年   1557篇
  2011年   1645篇
  2010年   883篇
  2009年   848篇
  2008年   1330篇
  2007年   1321篇
  2006年   1255篇
  2005年   1189篇
  2004年   1039篇
  2003年   914篇
  2002年   803篇
  2001年   198篇
  2000年   178篇
  1999年   191篇
  1998年   152篇
  1997年   135篇
  1996年   104篇
  1995年   84篇
  1994年   84篇
  1993年   63篇
  1992年   89篇
  1991年   82篇
  1990年   64篇
  1989年   35篇
  1988年   31篇
  1987年   35篇
  1986年   35篇
  1985年   29篇
  1984年   31篇
  1983年   20篇
  1982年   34篇
  1981年   27篇
  1980年   17篇
  1978年   10篇
  1977年   11篇
  1975年   9篇
  1974年   24篇
  1973年   9篇
排序方式: 共有10000条查询结果,搜索用时 156 毫秒
71.
Treatment of chronic osteomyelitis of distal tibia is complex. It often requires the association of antibiotic therapy and a surgical procedure. This consists of exhaustive debridement of infected bone and soft tissue which must have adequate cutaneous coverage and vascular supply which enables creating a barrier to microorganisms and greater resistance to infection. Free or pedicled muscular flaps have been the techniques most often used for this type of lesions. Free flaps require a precise microsurgical technique and prolonged surgery. Pedicled muscular flaps do not provide sufficient coverage and vascularisation of the distal tibia for large size defects. The fasciocutaneous flap has been used for the treatment of coverage defects in the perimalleolar area and the heel. We report the utility of this flap as management of chronic osteomyelitis of the distal third of the tibia with complete healing of the infection and correct cutaneous coverage without complications.  相似文献   
72.
Our objective was to evaluate the frequency of neoplastic and preneoplastic skin lesions in Parkinson's disease (PD) patients when compared with an aged-matched population. We performed a cross-sectional survey in PD patients and in an age-matched control group. Patients and controls were examined by a movement disorder specialist and a dermatologist. 150 PD patients and 146 controls were included. Thirty-five PD patients (23.3%) presented skin lesions that could be classified as neoplastic or preneoplastic vs. 20 subjects in the control group (13.7%) (OR 95%, CI 1.92 [1.05, 3.51]). However, this difference lost statistical significance when adjusted for gender (recruitment of controls was matched just for age with an over representation of males in the PD group). Twenty-nine PD patients (19%) presented actinic keratosis and basal cell carcinoma was diagnosed in 4 patients (3%). Although nonconclusive, our results are in agreement with previous studies suggesting an increased risk of skin cancer in PD patients. The frequency of actinic keratosis in PD patients and the associated risk to develop melanoma recommends its screening in future epidemiological studies.  相似文献   
73.
Resumen La técnica del cultivo celular es la que ha permitido conocer el comportamientoin vitro de las células cancerosas. En esta revisión pretendemos introducir las peculiaridades básicas del cultivo celular, referido especialmente a líneas cancerosas mamarias, relacionar el origen de las líneas celulares más utilizadas en la investigación de este cáncer, mencionar las técnicas de laboratorio que pueden aplicarse sobre estos cultivos y ejemplificar la utilidad de las mismas, tomando como modelo diversos trabajos que estudian los efectos del factor de crecimiento epidérmico sobre líneas celulares hormonoindependientes de cáncer de mama.   相似文献   
74.
75.
76.
77.
Although tricyclic antidepressant are especially useful in the treatment of chronic pain conditions, most of the work about its mechanism of action has been made on acute pain tests. The present study was aimed at studying the role played by noradrenergic and opioidergic influences on the antinociceptive activity of subchronically administered clomipramine in the formalin test (a tonic pain model) in rats. Clomipramine produced antinociception after 7 days, administration (2.5 mg/kg/day), an effect equivalent to that obtained by acute morphine (5 mg/kg). The antinociceptive effect of clomipramine was inhibited by the following: nonspecific blocking of alpha1-and alpha2-adrenoceptors by phentolamine, specific blocking of alpha1-adrenoceptors by prazosin; stimulation of alpha2 receptors by clonidine; and blocking of the opioid receptors by naloxone. Blocking the alpha2-receptors with yohimbine did not antagonize the effect of clomipramine. These results suggest that clomipramine produces antinociception in this test, partly via the participation of the endogenous opioid system and partly by further activating or potentiating previously activated noradrenergic pathways which are involved in the control of pain information.  相似文献   
78.
Recently, we demonstrated that neural responses within the whisker region of the primary somatosensory cortex (SIw) of rats are profoundly influenced by the spatiotemporal attributes of ipsilateral, as well as contralateral, whisker stimuli. As inactivation of one SIw eliminates in the intact SIw both ipsilaterally evoked responses and the influence of ipsilateral stimulation on contralaterally evoked activity, we proposed that interhemispheric interactions between the SIws may be important for integrating bilateral whisker information. To test whether rats can recognize the bilateral nature of a whisker stimulus, we developed a tactile discrimination task that required rats to conjointly determine distances to a left and a right discriminandum as equidistant or non-equidistant using only their facial whiskers. All rats trained in this task achieved performance levels indicative of an ability to integrate bilateral whisker information. Testing during unilateral, as well as bilateral, inactivation of the SIws indicated that rats rely on both SIws for detecting the bilateral nature of a whisker stimulus. Rats were unable to perform the task without both sets of whiskers, a fact that indicates that the whiskers (and not other modalities) were used to perform this task. The findings presented here indicate that rats can solve a task that requires the conjoint detection of left and right whisker-mediated distance information and implicate the SIws as central to this ability.  相似文献   
79.
80.
Ossifying fibromyxoid tumor of soft parts   总被引:1,自引:0,他引:1  
Ossifying fibromyxoid tumors (OFT) of soft parts are very rare neoplasms recently described by Enzinger et al. (1). They usually present as well-circumscribed, slow-growing, asymptomatic subcutaneous masses. A characteristic finding is a fibrous capsule and an incomplete peripheral shell of mature bone. Although most cases behave as benign tumors, a high rate of local recurrences have been described. We describe a 43-year-old male with a perianal subcutaneous tumor of 10 years evolution. The histopathology was compatible with OFT. Due to the subcutaneous location of OFF, both the dermatologist and dermatopathologist need to know about this rare tumor.  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