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   14737篇
  免费   991篇
  国内免费   36篇
耳鼻咽喉   125篇
儿科学   608篇
妇产科学   461篇
基础医学   2136篇
口腔科学   256篇
临床医学   2053篇
内科学   2380篇
皮肤病学   284篇
神经病学   1653篇
特种医学   266篇
外科学   1009篇
综合类   155篇
现状与发展   1篇
一般理论   37篇
预防医学   2181篇
眼科学   207篇
药学   810篇
中国医学   11篇
肿瘤学   1131篇
  2023年   137篇
  2022年   156篇
  2021年   341篇
  2020年   253篇
  2019年   371篇
  2018年   372篇
  2017年   336篇
  2016年   293篇
  2015年   355篇
  2014年   508篇
  2013年   800篇
  2012年   1104篇
  2011年   1147篇
  2010年   582篇
  2009年   544篇
  2008年   992篇
  2007年   975篇
  2006年   1009篇
  2005年   997篇
  2004年   906篇
  2003年   834篇
  2002年   826篇
  2001年   106篇
  2000年   62篇
  1999年   107篇
  1998年   189篇
  1997年   149篇
  1996年   106篇
  1995年   110篇
  1994年   92篇
  1993年   77篇
  1992年   75篇
  1991年   48篇
  1990年   49篇
  1989年   39篇
  1988年   36篇
  1987年   24篇
  1986年   46篇
  1985年   43篇
  1984年   53篇
  1983年   65篇
  1982年   82篇
  1981年   53篇
  1980年   50篇
  1979年   31篇
  1978年   33篇
  1977年   21篇
  1976年   19篇
  1974年   22篇
  1972年   14篇
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
31.
32.
33.
This study compares the effects of the cancer experience on various aspects of marital and sexual functioning (e.g., communication, emotional support, body image, sexual satisfaction and frequency) for two groups of long-term cancer survivors (testicular cancer and Hodgkin's disease) and their spouses. Comparisons between the two patient groups showed significantly more survivors of Hodgkin's disease than testicular cancer reporting the emergence of special issues and changes in the marital relationship. No differences emerged between the spouse groups on sexual functioning variables; however, spouses of survivors of Hodgkin's disease were more likely than spouses of survivors of testicular cancer to report the development of special issues and communication difficulties. A substantial proportion of both survivor groups disclosed negative changes in body image and sexual frequency. Majorities of both survivors and spouses acknowledged that the illness had drawn them closer together. When representative marital/sexual functioning variables were used to predict Family Environment Scale (FES) scores for survivors and for spouses, changes in the spouse's importance, influence of the illness on the relationship, and changes in sexual frequency emerged as significant predictors. The clinical significance of long-term changes in marital and sexual functioning for the couple and the need for therapeutic interventions are discussed.  相似文献   
34.
We examined two recently developed measures of positive automatic thought, the Positive Automatic Thoughts Questionnaire (ATQ-P) and the Automatic Thoughts Questionnaire—Revised (ATQ-RP). Internal consistency, concurrent validity, and convergent and discriminant validity were addressed. Two hundred one undergraduates completed self-report measures of positive automatic thoughts, negative automatic thoughts, depressive symptoms, anxiety symptoms, and positive affectivity. The ATQ-P and ATQ-RP both showed high internal consistency, strong negative associations with depressive symptoms, specificity to depressive symptoms rather than anxiety symptoms, an average state-of-mind (SOM) ratio in the positive dialogue range, and a stronger relation with each other than with a measure of positive affectivity. The only notable difference between the measures was a significantly lower mean score (correcting for number of items) on the ATQ-RP. This paper is based on a thesis completed by the first author, under the supervision of the second author, in partial fulfillment of the requirements for the Master of Arts degree at American University. We are grateful to thesis committee members Lorah Dorn and Jim Gray for feedback on this material.  相似文献   
35.
Occupational therapy is based on core values of altruism, equality, and honoring the dignity of others. Embedded in these values is the ever-present negotiation of power. To honor the concern for the welfare of others, researchers are challenged to think about issues of power throughout the research process. This paper identifies dilemmas and raises questions researchers might ask themselves as they struggle to share power in the interpretive research process.  相似文献   
36.
This consensus paper on behalf of the Study Group on Sports Cardiology of the European Society of Cardiology follows a previous one on guidelines for sports participation in competitive and recreational athletes with supraventricular arrhythmias and pacemakers. The question of imminent life-threatening arrhythmias is especially relevant when some form of ventricular rhythm disorder is documented, or when the patient is diagnosed to have inherited a pro-arrhythmogenic disorder. Frequent ventricular premature beats or nonsustained ventricular tachycardia may be a hallmark of underlying pathology and increased risk. Their finding should prompt a thorough cardiac evaluation, including both imaging modalities and electrophysiological techniques. This should allow distinguishing idiopathic rhythm disorders from underlying disease that carries a more ominous prognosis. Recommendations on sports participation in inherited arrhythmogenic conditions and asymptomatic gene carriers are also discussed: congenital and acquired long QT syndrome, short QT syndrome, Brugada syndrome, catecholaminergic polymorphic ventricular tachycardia, arrhythmogenic right ventricular cardiomyopathy and other familial electrical disease of unknown origin. If an implantable cardioverter defibrillator is indicated, it is no substitute for the guidelines relating to the underlying pathology. Moreover, some particular recommendations for patients/athletes with an implantable cardioverter defibrillator are to be observed.  相似文献   
37.
BACKGROUND: Based on single case reports, parvovirus B19 (B19) has repeatedly been proposed as an etiologic agent in patients with Henoch-Sch?nlein purpura (HSP), perhaps causing vasculitis by direct invasion of vascular endothelial cells because of the tissue distribution of the cellular B19 receptor. A cohort of children with HSP and other vasculitic diseases was investigated and compared with healthy control children to assess the role of B19 as well as parvovirus V9 (a putative emerging B19-like virus). PATIENTS AND METHODS: Serum samples from 36 children with HSP (n = 29) or other vasculitic diseases (n = 7) were examined, and 38 healthy bone marrow donors were used as controls. The presence of specific B19 and V9 IgM and IgG antibodies was determined with a recently developed enzyme-linked immunosorbent assay, and viral DNA was detected by a novel nested PCR. RESULTS: Specific IgM was not present in any of the patient or control serum samples. B19 DNA was detected in one patient, a previously healthy 8-year-old boy diagnosed with HSP, whereas none of the controls was B19-positive. V9 was not detected in any of the clinical or control samples. It seems likely that B19 infection might have triggered the development of HSP in the B19-positive patient, because B19 viremia is otherwise uncommon. CONCLUSIONS: Although causality is difficult to construe in single cases, the data indicate that B19 is not a common contributing factor in the pathogenesis of vasculitis and that this pathogen is only rarely associated temporally with HSP or vasculitic diseases in children.  相似文献   
38.
A model for university/early childhood partnerships located in the community was designed based on previous and present characteristics of university/school teaching centers and professional development schools. The long-range goals of this collaborative model were to raise the quality of future preschool and child care teachers, to enhance university early childhood teacher education programs, and to strengthen child care and preschool programs. The present case study focused on the first step of developing a viable model for sustained rather than temporary partnerships. Formal collaborative roles supported by higher level administrative commitment were found to be necessary to overcome differences in goals and values. Overcoming such institutional differences may be easier to accomplish in smaller early childhood programs. Future early childhood partnerships need to be developed and evaluated to determine the long-term impact of this partnership model on enhancing early childhood programs and on producing better teachers.This study could not have been done without the active support of the Head Start staff members, the 13 Roosevelt University early childhood students, and Elizabeth Jones, the Head Start director.  相似文献   
39.
40.
ABSTRACT: Background: Hands‐and‐knees positioning during labor has been recommended on the theory that gravity and buoyancy may promote fetal head rotation to the anterior position and reduce persistent back pain. A Cochrane review found insufficient evidence to support the effectiveness of this intervention during labor. The purpose of this study was to evaluate the effect of maternal hands‐and‐knees positioning on fetal head rotation from occipitoposterior to occipitoanterior position, persistent back pain, and other perinatal outcomes. Methods: Thirteen labor units in university‐affiliated hospitals participated in this multicenter randomized, controlled trial. Study participants were 147 women laboring with a fetus at ≥37 weeks’ gestation and confirmed by ultrasound to be in occipitoposterior position. Seventy women were randomized to the intervention group (hands‐and‐knees positioning for at least 30 minutes over a 1‐hour period during labor) and 77 to the control group (no hands‐and‐knees positioning). The primary outcome was occipitoanterior position determined by ultrasound following the 1‐hour study period and the secondary outcome was persistent back pain. Other outcomes included operative delivery, fetal head position at delivery, perineal trauma, Apgar scores, length of labor, and women's views with respect to positioning. Results: Women randomized to the intervention group had significant reductions in persistent back pain. Eleven women (16%) allocated to use hands‐and‐knees positioning had fetal heads in occipitoanterior position following the 1‐hour study period compared with 5 (7%) in the control group (relative risk 2.4; 95% CI 0.88–6.62; number needed to treat 11). Trends toward benefit for the intervention group were seen for several other outcomes, including operative delivery, fetal head position at delivery, 1‐minute Apgar scores, and time to delivery. Conclusions: Maternal hands‐and‐knees positioning during labor with a fetus in occipitoposterior position reduces persistent back pain and is acceptable to laboring women. Given this evidence, hands‐and‐knees positioning should be offered to women laboring with a fetus in occipitoposterior position in the first stage of labor to reduce persistent back pain. Although this study demonstrates trends toward improved birth outcomes, further trials are needed to determine if hands‐and‐knees positioning promotes fetal head rotation to occipitoanterior and reduces operative delivery. (BIRTH 32:4 December 2005)  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