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   14535篇
  免费   1105篇
  国内免费   49篇
耳鼻咽喉   105篇
儿科学   356篇
妇产科学   357篇
基础医学   1822篇
口腔科学   333篇
临床医学   1537篇
内科学   3222篇
皮肤病学   242篇
神经病学   1407篇
特种医学   692篇
外科学   2063篇
综合类   324篇
一般理论   11篇
预防医学   1060篇
眼科学   313篇
药学   936篇
中国医学   10篇
肿瘤学   899篇
  2023年   63篇
  2022年   90篇
  2021年   245篇
  2020年   138篇
  2019年   209篇
  2018年   287篇
  2017年   180篇
  2016年   191篇
  2015年   222篇
  2014年   363篇
  2013年   751篇
  2012年   838篇
  2011年   960篇
  2010年   516篇
  2009年   471篇
  2008年   867篇
  2007年   931篇
  2006年   942篇
  2005年   915篇
  2004年   799篇
  2003年   800篇
  2002年   784篇
  2001年   178篇
  2000年   159篇
  1999年   183篇
  1998年   203篇
  1997年   177篇
  1996年   160篇
  1995年   156篇
  1994年   142篇
  1993年   134篇
  1992年   154篇
  1991年   138篇
  1990年   101篇
  1989年   139篇
  1988年   140篇
  1987年   118篇
  1986年   128篇
  1985年   147篇
  1984年   165篇
  1983年   150篇
  1982年   139篇
  1981年   128篇
  1980年   132篇
  1979年   68篇
  1978年   69篇
  1977年   70篇
  1976年   77篇
  1974年   66篇
  1973年   48篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Multiple fistulae between all 3 major coronary arteries and the left ventricle were found at cardiac catheterization in a 69-year-old woman presenting with typical angina. Subsequent necropsy showed abnormal intramyocardial vessels communicating with the left ventricular lumen. This is the first report to document clinical, angiographic, and pathologic findings in this anomaly.  相似文献   
52.
本文在胃癌行全胃或胃大部切除术引起的中等程度应激病人,随机分组对比观察了全肠外营养或TPN加用1,6-二磷酸果糖的效果。结果显示,与单纯TPN相比,TPN加用FDP后血清皮质醇和胰高血糖素等应激激素水平有所下降,尿中3-甲基组氨酸排出减少,累积氮平衡增加。  相似文献   
53.
54.
Fear of falling and postural control in Parkinson's disease.   总被引:4,自引:0,他引:4  
This study investigated the relationship between fear of falling (FOF) and qualitative and quantitative postural control in Parkinson's disease (PD). Fifty-eight nondemented PD patients were studied along with age-matched healthy controls. The degree of FOF was estimated using the Activities-specific Balance Confidence scale. Qualitative postural control was evaluated using a component of the Unified Parkinson Disease Rating Scale. Postural control was quantified, using centre of pressure measures obtained from a force plate, for eight standing balance tests of different challenges. The results showed that FOF was more evident for PD patients when compared with healthy individuals of similar age. Furthermore, FOF was significantly associated with a qualitative estimate of postural control in PD; individuals with PD who had a greater degree of posture impairment reported greater FOF. The results also showed that an estimate of FOF may help to explain quantitative postural instability in PD. FOF, when coupled with a qualitative estimate of postural control, was able to explain a greater amount of variation in quantitative balance performance for five of the eight balance tests. When considered independently, the qualitative measure of postural control, in general, could not well predict quantitative balance performance. The greater degree of FOF and its possible association with altered postural control suggests that FOF should be considered as an important, independent risk factor in the assessment and treatment of postural instability in patients with PD.  相似文献   
55.
Probiotics as flourishing benefactors for the human body.   总被引:2,自引:0,他引:2  
This article provides a comprehensive review of the beneficial effects of various strains of probiotics in preventing and treating certain diseases. Currently, changed lifestyles as well as the increased use of antibiotics are significant factors challenging the preservation of a healthy intestinal microflora. The concept of probiotics is to restore and uphold a microflora advantageous for the human body. Probiotics are found in a number of fermented dairy products, infant formula, and dietary supplements. In the presence of prebiotics, which are nondigestible food ingredients favorable for probiotic growth, their survival in the intestine is ameliorated.  相似文献   
56.
57.
58.
Nonepileptic Posttraumatic Seizures   总被引:4,自引:2,他引:2  
Summary: Purpose: Epileptic posttraumatic seizures (PTSs) are a well-recognized consequence of head injury (HI), but HI and nonepileptic seizures (NESs) have not been related. We describe a significant subset of patients with NESs who had their seizures attributed to HI.
Methods: We reviewed the records of all patients diagnosed with NES at the University of Maryland Medical Center over a 6-year period (1989–1995) and selected patients with seizures attributed to a head injury occurring ≥3 years before the onset of their seizures.
Results: Of 157 patients with video-EEG confirmed NES, 37 (24%) had the onset of their seizures attributed to an HI. Their average age was 34 years (range, 15–56 years); 68% were women. Nonepileptic PTS usually developed within the first year after HI (89%). Convulsive symptoms were present in 54%. Whereas epileptic PTSs characteristically follow severe HI, the majority (78%) of our patients with nonepileptic PTSs sustained only mild HI. Before their HI, 76% of our patients were employed, working in the home, or students, but only 11% could continue those activities after developing nonepileptic PTSs.
Conclusions: Nonepileptic PTSs are frequently mistaken for epileptic PTSs and result in serious disability. The misdiagnosis of nonepileptic PTSs leads to ineffective and inappropriate treatment. Patients with intractable seizures after HIS, articularly mild HIS, should be carefully evaluated for NESs.  相似文献   
59.
Monosomy for the X chromosome is the most frequent cause of Turner's syndrome, a common clinical syndrome associated with particular physical and neurobehavioral features. The results from comprehensive assessment of prepubertal monozygotic female twins discordant for X monosomy are presented. Zygosity was established with DNA Fingerprinting and no evidence of chromosomal mosaicism was seen in either child. Physical features in the affected twin were relatively mild with respect to the full spectrum of physical malformations and disabilities associated with Turner's syndrome. The neurobehavioral phenotypes of the twins were compared. Although both sisters scored in the superior range of intelligence, the affected twin's Performance IQ was 18 points less than her sister, whereas Verbal IQ showed only a 3-point difference between the sisters. Other relative differences were noted within the executive, visuospatial, and visuomotor domains of function. Behavioral evaluation indicated greater problems with attention, hyperactivity, and anxiety in the affected twin. Quantitative analysis of brain anatomy revealed evidence of both general and regional effects of X monosomy on neurodevelopment. Cerebrospinal fluid volume was increased by 25% in the affected twin compared with her sister with a corresponding decrease in gray matter volume. The right frontal, right parietal–occipital, and left parietal-perisylvian regions showed the greatest discrepancy between the sisters with respect to increased cerebrospinal fluid and decreased gray matter volumes in the twin with X monosomy. Differences in the posterior fossa were also noted with a 50% relative increase in the volumes of the fourth ventricle and cisterna magna and a 10 to 15% relative reduction in size of the cerebellar vermis, pons, and medulla in the affected twin. The association between the neurobehavioral and neuroanatomical findings in the affected twin is discussed. The unique nature of the naturally occurring genetic phenomenon seen in this twin pair provides an opportunity to more fully elucidate the neurobehavioral phenotype associated with X monosomy and Turner's syndrome.  相似文献   
60.
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