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   476篇
  免费   20篇
  国内免费   29篇
耳鼻咽喉   7篇
儿科学   17篇
妇产科学   5篇
基础医学   34篇
口腔科学   20篇
临床医学   41篇
内科学   161篇
皮肤病学   11篇
神经病学   21篇
特种医学   49篇
外科学   63篇
综合类   13篇
预防医学   20篇
眼科学   4篇
药学   32篇
肿瘤学   27篇
  2023年   3篇
  2022年   6篇
  2021年   1篇
  2020年   3篇
  2019年   2篇
  2018年   7篇
  2017年   4篇
  2016年   2篇
  2015年   9篇
  2014年   6篇
  2013年   22篇
  2012年   10篇
  2011年   18篇
  2010年   22篇
  2009年   21篇
  2008年   23篇
  2007年   37篇
  2006年   22篇
  2005年   17篇
  2004年   24篇
  2003年   18篇
  2002年   12篇
  2001年   13篇
  2000年   8篇
  1999年   19篇
  1998年   17篇
  1997年   12篇
  1996年   16篇
  1995年   11篇
  1994年   17篇
  1993年   12篇
  1992年   4篇
  1991年   9篇
  1990年   6篇
  1989年   9篇
  1988年   13篇
  1987年   8篇
  1986年   11篇
  1985年   13篇
  1984年   8篇
  1983年   8篇
  1982年   6篇
  1981年   2篇
  1980年   4篇
  1978年   2篇
  1977年   2篇
  1976年   2篇
  1975年   3篇
  1974年   1篇
排序方式: 共有525条查询结果,搜索用时 15 毫秒
51.
52.

Background

Counseling in combination with pedometer use has proven to be effective in increasing physical activity and improving health outcomes. We investigated the cost-effectiveness of this intervention targeted at one million insufficiently active adults who visit their general practitioner in the Netherlands.

Methods

We used the RIVM chronic disease model to estimate the long-term effects of increased physical activity on the future health care costs and quality adjusted life years (QALY) gained, from a health care perspective.

Results

The intervention resulted in almost 6000 people shifting to more favorable physical-activity levels, and in 5100 life years and 6100 QALYs gained, at an additional total cost of EUR 67.6 million. The incremental cost-effectiveness ratio (ICER) was EUR 13,200 per life year gained and EUR 11,100 per QALY gained. The intervention has a probability of 0.66 to be cost-effective if a QALY gained is valued at the Dutch informal threshold for cost-effectiveness of preventive intervention of EUR 20,000. A sensitivity analysis showed substantial uncertainty of ICER values.

Conclusion

Counseling in combination with pedometer use aiming to increase physical activity may be a cost-effective intervention. However, the intervention only yields relatively small health benefits in the Netherlands.  相似文献   
53.
54.
A murine hybridoma clone is described that grows continuously in culture and produces a monoclonal antibody we have called Royal Free Monoclonal Antibody to factor IX No. 1 (RFF-IX/1). This has high affinity for a coagulation site on factor IX. RFF-IX/1 immobilised on sepharose can be used to deplete factor IX from normal human plasma. This immunoaffinity depleted plasma is indistinguishable from severe Christmas disease plasma and can be used as the substrate in a one stage coagulation assay for factor IX. The affinity column has high capacity and can be regenerated so that large scale production from normal plasma of factor IX deficient plasma as a diagnostic reagent is now feasible.  相似文献   
55.
Vroman  L; Adams  AL; Fischer  GC; Munoz  PC 《Blood》1980,55(1):156-159
Using ellipsometry, anodized tantalum interference color, and Coomassie blue staining in conjunction with immunologic identification of proteins adsorbed at interfaces, we have previously found that fibrinogen is the main constituent deposited by plasma onto many man- made surfaces. However, the fibrinogen deposited from normal plasma onto glass and similar wettable materials is rapidly modified during contact activation until it can no longer be identified antigenically. In earlier publications, we have called this modification of the fibrinogen layer "conversion," to indicate a process of unknown nature. Conversion of adsorbed fibrinogen by the plasma was not accompanied by marked change in film thickness, so that we presumed that this fibrinogen was not covered but replaced by other protein. Conversion is now showen to be markedly delayed in plasma lacking high molecular weight kininogen, slightly delayed in plasma lacking factor XII, and normal in plasma that lack factor XI or prekallikrein. We conclude that intact plasma will quickly replace the fibrinogen it has deposited on glass-like surfaces by high molecular weight kininogen and, to a smaller extent, by factor XII. Platelets adhere preferentially to fibrinogen-coated surfaces; human platelets adhere to hydrophobic nonactivating surfaces, since on these, adsorbed firbinogen is not exchanged by the plasma. The adsorbed fibrinogen will be replaced on glass-like surfaces during surface activation of clotting, and platelets failing to find fibrinogen will not adhere.  相似文献   
56.
BACKGROUND: Relations between general practitioners and the hospital consultants are often considered difficult, and occasionally generate conflicts, potentially affecting the patient management and healthcare system organisation. These views, however, have partly been contradicted by structured surveys and qualitative studies. AIMS: We conducted a survey on the general practitioners' opinions regarding their relations with the gastroenterological-endoscopy services in order to explore current attitudes, any negative aspects and assess scope for improvement. SUBJECTS AND METHODS: Structured questionnaires were sent to 221 general practitioners in the Veneto region of Italy; the questionnaire was based on 26 questions concerning their subjective relations with the gastroenterologists, expertise in the gastroenterological problems and perceived efficiency of gastroenterological services. RESULTS: As many as 106 doctors answered the postal questionnaire (mean: 15 per province; range 5-20). Responses to the structured questions totalled to 2,339 items, out of which 1,234 (53%) presented positive responses, particularly with regard to admissions' management and the adequacy of referral reports. Many general practitioners reported of their participation in the meetings on gastroenterological problems. Homecare referrals were limited in number, even for the patients with tube feeding. CONCLUSIONS: Relations between the general practitioners in Veneto and local gastroenterological services were generally good, possibly reflecting the well-developed outreach network. This liaison could be further improved via closer interrelations based not only on the patient referrals but also on the professional and information exchange to promote successful practice.  相似文献   
57.
Knupp  CL; White  GC d 《Blood》1985,65(3):578-583
To determine the relationship between equilibrium binding of thrombin to sites on the platelet surface and the cleavage of membrane glycoprotein V (GPV) by thrombin, we examined the effect of active site- modified thrombin (1-chloro-3-tosylamido-7-amino-L-2-heptanone thrombin toslysCH2-thrombin) on the binding of native thrombin to platelets and on the hydrolysis of GPV by native thrombin. ToslysCH2-thrombin inhibited binding of native thrombin to high affinity sites on the platelet surface. In contrast, hydrolysis of GPV by native thrombin, even at threshold thrombin concentrations, was not inhibited by pretreatment with toslysCH2-thrombin at concentrations up to 210 nmol/L. ToslysCH2-thrombin also had no appreciable effect on platelet aggregation or release of 14C-serotonin induced by native thrombin. Because toslysCH2-thrombin does not inhibit platelet release, aggregation, or GPV hydrolysis by native thrombin but does inhibit high affinity surface binding by native thrombin, these results indicate that thrombin binding and hydrolysis of GPV are separate and unrelated events.  相似文献   
58.
A 35-year-old Asian Indian female previously diagnosed with bilateral anterior uveitis and on oral methotrexate developed bilateral anterior uveitis following first/second dose of coronavirus disease 2019 (COVID-19) vaccination. She had skipped her weekly dose of oral methotrexate following first dose of vaccination. Following the second dose, she reduced her oral methotrexate from 25 to 15 mg on her own, but did not stop like the previous occasion. She had extensive workup for her uveitis in the past with only positive severe acute respiratory syndrome coronavirus (SARS-CoV-2) antibodies. She developed unilateral anterior uveitis after she had COVID-19 in July 2022, which resolved with topical steroids and continuation of immunosuppression. This report illustrates that COVID-19 or its vaccination may presumably play a role in triggering the immune system and can cause recurrent ocular inflammation even in the absence of an extraocular inflammation.  相似文献   
59.
Since Kangaroo Mother Care (KMC) was developed in Colombia in the 1970s, two trends in clinical application emerged. In low income settings, the original KMC model is implemented. This consists of continuous (24 h/day, 7 days/week) and prolonged mother/parent–infant skin‐to‐skin contact; early discharge with the infant in the kangaroo position; (ideally) exclusive breastfeeding; and, adequate follow‐up. In affluent settings, intermittent KMC with sessions of one or a few hours skin‐to‐skin contact for a limited period is common. As a result of the increasing evidence of the benefits of KMC for both infants and families in all intensive care settings, KMC in a high‐tech environment was chosen as the topic for the first European Conference on KMC, and the clinical implementation of the KMC model in all types of settings was discussed at the 7th International Workshop on KMC. Kangaroo Mother Care protocols in high‐tech Neonatal Intensive Care Units (NICU) should specify criteria for initiation, kangaroo position, transfer to/from KMC, transport in kangaroo position, kangaroo nutrition, parents’ role, modification of the NICU environment, performance of care in KMC, and KMC in case of infant instability. Conclusion: Implementation of the original KMC method, with continuous skin‐to‐skin contact whenever possible, is recommended for application in high‐tech environments, although scientific evaluation should continue.  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