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   17584篇
  免费   1157篇
  国内免费   23篇
耳鼻咽喉   174篇
儿科学   704篇
妇产科学   696篇
基础医学   2175篇
口腔科学   246篇
临床医学   2823篇
内科学   3042篇
皮肤病学   361篇
神经病学   1538篇
特种医学   292篇
外科学   1578篇
综合类   310篇
一般理论   17篇
预防医学   2172篇
眼科学   372篇
药学   1041篇
中国医学   21篇
肿瘤学   1202篇
  2024年   17篇
  2023年   113篇
  2022年   186篇
  2021年   420篇
  2020年   311篇
  2019年   414篇
  2018年   438篇
  2017年   326篇
  2016年   372篇
  2015年   422篇
  2014年   579篇
  2013年   842篇
  2012年   1342篇
  2011年   1451篇
  2010年   769篇
  2009年   613篇
  2008年   1223篇
  2007年   1274篇
  2006年   1170篇
  2005年   1212篇
  2004年   1133篇
  2003年   1086篇
  2002年   900篇
  2001年   148篇
  2000年   130篇
  1999年   114篇
  1998年   182篇
  1997年   174篇
  1996年   121篇
  1995年   102篇
  1994年   101篇
  1993年   98篇
  1992年   78篇
  1991年   71篇
  1990年   70篇
  1989年   64篇
  1988年   55篇
  1987年   47篇
  1986年   55篇
  1985年   57篇
  1984年   67篇
  1983年   61篇
  1982年   55篇
  1981年   47篇
  1980年   54篇
  1979年   41篇
  1978年   33篇
  1977年   22篇
  1976年   16篇
  1972年   19篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
Chromosome 11q13 markers and D-type cyclins in breast cancer   总被引:7,自引:0,他引:7  
Summary One in six primary human breast cancers has DNA amplification centered on the cyclin D1 gene (CCND1) on chromosome 11q13. This genetic abnormality is preferentially associated with estrogen-receptor positive tumors and may define a sub-class of patients with an adverse prognosis. AlthoughCCND1 has the credentials of a cellular oncogene, being a target for chromosomal translocation and retroviral integration, the 11q13 amplicon encompasses several other markers andCCND1 is not the only candidate for the key gene on the amplified DNA. To assess their relative importance, we have constructed a physical map of the amplified DNA and compared the extent and frequency of amplification across the region. Since it is likely that the gene providing the selective force for amplification will be expressed at elevated levels, we have also examined expression of both RNA and protein. By these criteria, cyclin D1 remains the strongest candidate for the key oncogene on the amplicon and we are currently investigating the functional consequences of its over-expression.Presented by Gordon Peters at the 16th Annual San Antonio Breast Cancer Symposium, San Antonio TX, USA, November 4, 1993; Minisymposium on Molecular Genetics in Breast Cancer.  相似文献   
102.
103.
104.
105.
PURPOSE: To describe a randomized trial of a cognitive behavioral intervention on reducing symptom severity among patients diagnosed with solid tumors and undergoing a first course of chemotherapy and to determine whether the intervention had an additive or interactive effect on symptom severity in the presence of supportive care medications. PATIENTS AND METHODS: Patients (N = 237) were accrued from comprehensive and community cancer centers, interviewed, and randomly assigned to either the experimental intervention (n = 118) or conventional care (n = 119). A symptom severity index, based on summed severity scores across 15 symptoms, was the primary outcome. Each patient's site of cancer, stage at diagnosis, chemotherapy protocols, and use of supportive medications were learned from medical records. RESULTS: Groups were equivalent at baseline, and attrition by characteristics by group was not different. The proportion of patients not receiving chemotherapy at 10 and 20 weeks did not differ by group. At the 10- and 20-week observations, there was a significant interaction between the experimental group and baseline symptom severity. Patients in the experimental group who entered the trial with higher symptom severity reported significantly lower severity at 10 and 20 weeks. Controlling for chemotherapy treatment status at follow-up and supportive care medications did not alter the effect of the experimental intervention. CONCLUSION: Compared with conventional care alone, the experimental intervention was effective among patients who entered the trial with higher levels of symptom severity. Age, sex, site or stage of cancer, and supportive medications did not modify the effect of this cognitive behavioral intervention on symptom severity.  相似文献   
106.
Objective: Ataque de nervios is a common, self-labeled Hispanic folk diagnosis. It typically describes episodic, dramatic outbursts of negative emotion in response to a stressor, sometimes involving destructive behavior. Dissociation and affective dysregulation during such episodes suggested a link to childhood trauma. We therefore assessed psychiatric diagnoses, history of ataque, and childhood trauma in treatment-seeking Hispanic outpatients (N = 70). Significantly more subjects with an anxiety or affective disorder plus ataque reported a history of physical abuse, sexual abuse, and/or or a substance-abusing caretaker than those with psychiatric disorder but no ataque. In some Hispanic individuals, ataque may represent a culturally sanctioned expression of extreme affect dysregulation associated with childhood trauma. Patients with ataque de nervios should receive a thorough traumatic history assessment.  相似文献   
107.
Sarcomas--like leukemias, which are also mesodermal malignancies--carry biological significance disproportionate to their clinical frequency. Identification of mutations and translocations associated with these tumors has illuminated aberrant signaling pathways that cause these diseases, determine their behavior, and are therapeutic targets. Activated receptor-associated tyrosine kinase c-kit, mutated in most gastrointestinal stromal tumors, has proven a clinically effective target for enzyme inhibition. A translocation involving a single gene family, consisting of EWS and related genes, has been identified in five different sarcomas, and its chimeric protein products could prove similarly amenable to inhibitors. Resolution of the histopathological complexity is being aided by data from molecular and chromosomal characterization. Improvements in imaging, definition of prognostic factors, and surgical and radiotherapeutic treatment have resulted in improved local control. Continued progress will depend on further adapting the rapidly evolving technologies of genomics and proteomics. It will also depend upon accurate histopathological diagnosis based on validated reagents and consistent methodologies applied to adequate tissue samples derived from patients with complete clinical data. Finally, multicenter, coordinated trials, such as those that occurred with assessment of imatinib mesylate in metastatic gastrointestinal stromal tumors, will assure the most rapid reductions in morbidity and mortality.  相似文献   
108.
Systemic Lupus Erythematosus: Perinatal and Neonatal Implications   总被引:2,自引:0,他引:2  
Systemic lupus erythematosus (SLE) is a chronic autoimmune disorder that can affect almost all organ systems in the body. It is most common in women of childbearing age and may cause multiple peripartum complications. This article reviews the pathophysiology of SLE and the effects of SLE on fertility and pregnancy. The complexities of managing a pregnant patient with SLE are reviewed, and the importance of interdisciplinary collaboration discussed, as well as the effects of SLE on the fetus and a review of neonatal lupus erythematosus. Finally, a case report of a pregnant patient with SLE with challenging clinical management issues is presented.  相似文献   
109.
110.
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