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   1646篇
  免费   99篇
  国内免费   4篇
耳鼻咽喉   9篇
儿科学   59篇
妇产科学   25篇
基础医学   191篇
口腔科学   74篇
临床医学   202篇
内科学   307篇
皮肤病学   38篇
神经病学   109篇
特种医学   151篇
外科学   179篇
综合类   21篇
预防医学   164篇
眼科学   18篇
药学   113篇
中国医学   11篇
肿瘤学   78篇
  2023年   12篇
  2022年   32篇
  2021年   38篇
  2020年   29篇
  2019年   39篇
  2018年   49篇
  2017年   25篇
  2016年   44篇
  2015年   48篇
  2014年   57篇
  2013年   83篇
  2012年   74篇
  2011年   86篇
  2010年   83篇
  2009年   63篇
  2008年   74篇
  2007年   75篇
  2006年   71篇
  2005年   59篇
  2004年   48篇
  2003年   55篇
  2002年   43篇
  2001年   44篇
  2000年   28篇
  1999年   31篇
  1998年   39篇
  1997年   37篇
  1996年   41篇
  1995年   30篇
  1994年   30篇
  1993年   27篇
  1992年   11篇
  1991年   17篇
  1990年   9篇
  1989年   26篇
  1988年   19篇
  1987年   16篇
  1986年   13篇
  1985年   22篇
  1984年   11篇
  1983年   7篇
  1982年   8篇
  1981年   10篇
  1979年   6篇
  1978年   8篇
  1977年   16篇
  1976年   8篇
  1975年   10篇
  1972年   8篇
  1970年   6篇
排序方式: 共有1749条查询结果,搜索用时 15 毫秒
1.
This paper presents a case for careful consideration of theory in planning to implement evidence-based practices into clinical care. As described, theory should be tightly linked to strategic planning through careful choice or creation of an implementation framework. Strategies should be linked to specific interventions and/or intervention components to be implemented, and the choice of tools should match the interventions and overall strategy, linking back to the original theory and framework. The thesis advanced is that in most studies where there is an attempt to implement planned change in clinical processes, theory is used loosely. An example of linking theory to intervention design is presented from a Mental Health Quality Enhancement Research Initiative effort to increase appropriate use of antipsychotic medication among patients with schizophrenia in the Veterans Health Administration.  相似文献   
2.
Liver hemangioma: US-guided 18-gauge core-needle biopsy   总被引:6,自引:0,他引:6  
Heilo  A; Stenwig  AE 《Radiology》1997,204(3):719
  相似文献   
3.
4.
BACKGROUND: There are obvious advantages to increasing donor retention. However, for reasons of blood safety, certain donors may, in fact, be more desirable to retain than others. “Safe” donors are defined as those who provided a blood donation that was negative on all laboratory screening tests and who subsequently reported no behavioral risks in response to an anonymous survey. This study identifies the most important factors affecting the intention of “safe” donors to provide another donation. STUDY DESIGN AND METHODS: An anonymous survey asking about donation history, sexual history, injecting drug use, and recent donation experience was mailed to 50,162 randomly selected allogeneic donors (including directed donors) who gave blood from April through July or from October through December 1993 at one of the five United States blood centers participating in the Retrovirus Epidemiology Donor Study. Before mailing, questionnaires were coded to designate donors with nonreactive laboratory screening tests at their most recent donation. RESULTS: A total of 34,726 donors (69%) responded, with substantially higher response among repeat donors. According to reported intentions only, the vast majority of “safe” donors indicated a high likelihood of donating again within the next 12 months. Only 3.4 percent reported a low likelihood of donating again. A comparison of those likely to return and those unlikely to return reveals significant differences in demographics and in ratings of the donation experience. A higher proportion of those unlikely to return were first-time donors, minority-group donors, and donors with less education. The highest projected loss among “safe” donors was seen for those who gave a fair to poor assessment of their treatment by blood center staff or of their physical well-being during or after donating. CONCLUSION: These data suggest that efforts to improve donors' perceptions of their donation experience, as well as attention to the physical effects of blood donation, may aid in the retention of both repeat and first-time donors.  相似文献   
5.
Three areas with special relevance to liability and child therapy are considered: informed consent, confidentiality, and child-abuse reporting laws. In each area, issues that may be confronted in therapy or in research on therapy are discussed, and a sampling of relevant laws is explored. Suggestions for avoiding potential liability and protecting the interests of minor clients are considered.  相似文献   
6.
7.
An Australian school of nursing's attempt to introduce an evaluation process required by management for clinical educators involved in undergraduate preregistration education is discussed Reliance on student feedback and clinical agencies' perceptions of the quality of teaching were seen as inadequate mechanisms for evaluation The evaluation process adopted incorporated observation of the educators together with self-reflection on their performance We conclude that post-briefings were poorly used and generally not reflective Educators relied heavily on their clinical skills and used a limited range of teaching strategies Whilst evaluation of clinical educators was time consuming and therefore costly, it is argued that it is essential to the integrity of the course The evaluation process has provided direction for support and development of clinical educators within the context of the curriculum  相似文献   
8.
Crosslineage T-cell receptor delta (TCR delta) rearrangements are widely used as tumor markers for the follow up of minimal residual disease in childhood B-precursor acute lymphoblastic leukemia (ALL) by polymerase chain reaction (PCR). The major drawback of this approach is the risk of false-negative results due to clonal evolution. We investigated the stability of V delta 2D delta 3 rearrangements in a group of 56 childhood B-precursor ALL patients by PCR and Southern blot analysis. At the PCR level, V delta 2D delta 3-to-J alpha rearranged subclones (one pathway for secondary TCR delta recombination) were demonstrated in 85.2% of V delta 2D delta 3-positive patients tested, which showed that small subclones are present in the large majority of patients despite apparently monoclonal TCR delta Southern blot patterns. Sequence analysis of V delta 2D delta 3J alpha rearrangements showed a biased J alpha gene usage, with HAPO5 and J alpha F in 26 of 32 and 6 of 32 clones, respectively. Comparison of V delta 2D delta 3 rearrangement status between diagnosis and first relapse showed differences in seven of eight patients studied. In contrast, from first relapse onward, no clonal changes were observed in six patients studied. To investigate the occurrence of crosslineage TCR delta rearrangements in normal B and T cells, fluorescence-activated cell sorter-sorted peripheral blood CD19+/CD3- and CD19-/CD3+ cell populations from three healthy donors were analyzed. V delta 2D delta 3 rearrangements were detected at low frequencies in both B and T cells, which suggests that V delta 2-to-D delta 3 joining also occurs during normal B-cell differentiation. A model for crosslineage TCR delta rearrangements in B-precursor ALL is deduced that explains the observed clonal changes between diagnosis and relapse and is compatible with multistep leukemogenesis of B-precursor ALL.  相似文献   
9.
The lived experience of clinical educators   总被引:1,自引:0,他引:1  
This phenomenological study was undertaken to discover the everyday meanings which clinical educators of pre-registration Bachelor of Nursing students attached to their experiences as clinical educators The researcher employed a qualitative design using audiotaped in-depth interviews with four registered nurses employed as clinical educators in four different schools of nursing in Victoria, Australia Using hermeneutics, thematic analysis revealed five themes of meaning central to the lived experiences of clinical educators They are (a) being human, (b) having standards, (c) developing own teaching style, (d) learn as you go, and (e) not belonging The first three themes are described in the literature on clinical education, however, the latter two are unique to this research The results of this study indicate there is need for extensive preparation and on-going support of clinical educators The researcher, who is respectful of the enormity of the task which educators face in preparing students for practice, speculates whether clinical educators are the vanguards of student learning in the clinical field It is evident that the participants of this study did not possess many of the role requirements of clinical educators identified in the literature Further studies are needed which explore the link between student learning and clinical educator support  相似文献   
10.
Intracerebral vascular reactivity induced by the nitric oxide (NO) donor isosorbide dinitrate (IDN, 5 mg sublingually) is more major and longer-lasting in migraine patients who develop delayed headache in response to the drug. The headache is purportedly due to neuronally-mediated vascular mechanisms. Indomethacin inhibits prostaglandin synthesis, which is involved in NO generation. Indomethacin also decreases cerebral blood flow by constricting precapillary resistance vessels. In the present study, the hemodynamic effects of indomethacin were evaluated in migraine patients and healthy controls by means of transcranial Doppler monitoring. Indomethacin caused a significant decrease in mean flow velocity in the middle cerebral artery. This was an additional effect to the mean velocity decrease induced by IDN. The interactions between the two drugs suggest that their effects on cerebral hemodynamics (and pain) may be of relevance both in understanding the role of NO in migraine pathogenesis and in evaluating symptomatic treatments for migraine attacks.  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