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   18025篇
  免费   1262篇
  国内免费   32篇
耳鼻咽喉   122篇
儿科学   803篇
妇产科学   515篇
基础医学   2328篇
口腔科学   278篇
临床医学   2814篇
内科学   3074篇
皮肤病学   192篇
神经病学   1510篇
特种医学   329篇
外国民族医学   2篇
外科学   1356篇
综合类   583篇
一般理论   40篇
预防医学   2681篇
眼科学   388篇
药学   1003篇
中国医学   8篇
肿瘤学   1293篇
  2023年   86篇
  2022年   147篇
  2021年   328篇
  2020年   210篇
  2019年   316篇
  2018年   337篇
  2017年   252篇
  2016年   327篇
  2015年   395篇
  2014年   509篇
  2013年   831篇
  2012年   1226篇
  2011年   1299篇
  2010年   608篇
  2009年   584篇
  2008年   1123篇
  2007年   1258篇
  2006年   1208篇
  2005年   1228篇
  2004年   1228篇
  2003年   1157篇
  2002年   1090篇
  2001年   200篇
  2000年   156篇
  1999年   190篇
  1998年   227篇
  1997年   209篇
  1996年   189篇
  1995年   181篇
  1994年   153篇
  1993年   132篇
  1992年   113篇
  1991年   113篇
  1990年   119篇
  1989年   109篇
  1988年   103篇
  1987年   86篇
  1986年   91篇
  1985年   84篇
  1984年   94篇
  1983年   87篇
  1982年   79篇
  1981年   98篇
  1980年   92篇
  1979年   81篇
  1978年   57篇
  1977年   65篇
  1976年   66篇
  1975年   40篇
  1974年   57篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
ABSTRACT

Measuring hope reliably and accurately remains an important research objective, not least in less prosperous settings where ‘holding on to hope’ may be critically important in the struggle against adverse life conditions. The State Hope Scale was designed for use in the US. Despite reported application in diverse cultures and using translations the scale has not been extensively validated outside US populations. This study contributes to a larger project exploring the measurement of hope and provides a critique of Snyder’s scale as used in a Tanzanian female population of 1021 urban microfinance participants. We evaluate the scale’s validity through assessment of the empirical distribution of scores, item response profiles, internal consistency and discriminatory ability. Participants mostly scored very high and many reached very near the maximum attainable score. Hardly any endorsed the negative half of the response scale. Several problems are discussed including poor discrimination and strong evidence of acquiescence response bias. We also found little association of the scale scores with hypothesised correlates of hope. Future improvements on the measurement of hope are recommended, especially in studies outside the narrow Western context in which the scale was devised.  相似文献   
2.
ABSTRACT

This work collates data from the analysis of complex mixtures analysed in STRmix during routine no-suspect volume crime work. It interrogates the upload rate for these types of mixtures and which component of the profile has been able to be interpreted for upload. The number of profiles giving multiple uploads and the amount of replicate PCR analysis has been collated.  相似文献   
3.

Background

The ZOE-50 (NCT01165177) and ZOE-70 (NCT01165229) phase 3 clinical trials showed that the adjuvanted recombinant zoster vaccine (RZV) was ≥90% efficacious in preventing herpes zoster in adults. Here we present a comprehensive overview of the safety data from these studies.

Methods

Adults aged ≥50 (ZOE-50) and ≥70 (ZOE-70) years were randomly vaccinated with RZV or placebo. Safety analyses were performed on the pooled total vaccinated cohort, consisting of participants receiving at least one dose of RZV or placebo. Solicited and unsolicited adverse events (AEs) were collected for 7 and 30?days after each vaccination, respectively. Serious AEs (SAEs) were collected from the first vaccination until 12?months post-last dose. Fatal AEs, vaccination-related SAEs, and potential immune-mediated diseases (pIMDs) were collected during the entire study period.

Results

Safety was evaluated in 14,645 RZV and 14,660 placebo recipients. More RZV than placebo recipients reported unsolicited AEs (50.5% versus 32.0%); the difference was driven by transient injection site and solicited systemic reactions that were generally seen in the first week post-vaccination. The occurrence of overall SAEs (RZV: 10.1%; Placebo: 10.4%), fatal AEs (RZV: 4.3%; Placebo: 4.6%), and pIMDs (RZV: 1.2%; Placebo: 1.4%) was balanced between groups. The occurrence of possible exacerbations of pIMDs was rare and similar between groups. Overall, except for the expected local and systemic symptoms, the safety results were comparable between the RZV and Placebo groups irrespective of participant age, gender, or race.

Conclusions

No safety concerns arose, supporting the favorable benefit-risk profile of RZV.  相似文献   
4.
166Ho-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetramethylene-phosphonate (DOTMP) is a tetraphosphonate molecule radiolabeled with 166Ho that localizes to bone surfaces. This study evaluated pharmacokinetics and radiation-absorbed dose to all organs from this beta-emitting radiopharmaceutical. METHODS: After two 1.1-GBq administrations of 166Ho-DOTMP, data from whole-body counting using a gamma-camera or uptake probe were assessed for reproducibility of whole-body retention in 12 patients with multiple myeloma. The radiation-absorbed dose to normal organs was estimated using MIRD methodology, applying residence times and S values for 166Ho. Marrow dose was estimated from measured activity retained after 18 h. The activity to deliver a therapeutic dose of 25 Gy to the marrow was determined. Methods based on region-of-interest (ROI) and whole-body clearance were evaluated to estimate kidney activity, because the radiotracer is rapidly excreted in the urine. The dose to the surface of the bladder wall was estimated using a dynamic bladder model. RESULTS: In clinical practice, gamma-camera methods were more reliable than uptake probe-based methods for whole-body counting. The intrapatient variability of dose calculations was less than 10% between the 2 tracer studies. Skeletal uptake of 166Ho-DOTMP varied from 19% to 39% (mean, 28%). The activity of 166Ho prescribed for therapy ranged from 38 to 67 GBq (1,030-1,810 mCi). After high-dose therapy, the estimates of absorbed dose to the kidney varied from 1.6 to 4 Gy using the whole-body clearance-based method and from 8.3 to 17.3 Gy using the ROI-based method. Bladder dose ranged from 10 to 20 Gy, bone surface dose ranged from 39 to 57 Gy, and doses to other organs were less than 2 Gy for all patients. Repetitive administration had no impact on tracer biodistribution, pharmacokinetics, or organ dose. CONCLUSION: Pharmacokinetics analysis validated gamma-camera whole-body counting of 166Ho as an appropriate approach to assess clearance and to estimate radiation-absorbed dose to normal organs except the kidneys. Quantitative gamma-camera imaging is difficult and requires scatter subtraction because of the multiple energy emissions of 166Ho. Kidney dose estimates were approximately 5-fold higher when the ROI-based method was used rather than the clearance-based model, and neither appeared reliable. In future clinical trials with 166Ho-DOTMP, we recommend that dose estimation based on the methods described here be used for all organs except the kidneys. Assumptions for the kidney dose require further evaluation.  相似文献   
5.
6.
This paper reports an inter-rater reliability study on the Functional Independence Measure (FIM). The FIM measures inpatient burden of care, as reflected in 18 self care items, rated on a seven point scale from dependent to independent. The subjects were 40 occupational therapists, divided according to experience with the FIM and randomly assigned to a FIM training or non-training group. Subjects rated video tapes of four stroke patients on transfers, bathing, dressing, grooming, toileting and eating items from the FIM. Rater consensus was calculated using the intraclass correlation coefficient (ICC), percentage agreement and a measure of disagreement. Rating accuracy was measured by comparisons with an expert rater. Ratings were most reliable when done by clinicians with no prior FIM experience, from the FIM training group. It is strongly recommended that all clinicians undergo FIM training before using this tool to ensure acceptable reliability.  相似文献   
7.
8.
9.
PURPOSE: To provide a model for assessing occupational therapy workforce needs by using a demand-based approach to determine current workforce status in the Northwest region. Regional information may have implications for addressing national occupational therapy service needs. METHOD: A questionnaire was sent to a proportional random sample of 234 facilities that hire occupational therapy practitioners. Data were collected in July-August 2003 using structured mailing and follow-up procedures. RESULTS: Response rate was 79%. Twenty-four percent reported occupational therapy vacancies and 11% occupational therapy assistant vacancies; 48% predicted an increase in occupational therapy positions in the next 2 years and 41% an increase in occupational therapy assistant positions. Sixty-three percent of respondents reported difficulty in hiring. DISCUSSION: This study identifies an occupational therapy workforce shortage in the Northwest. Management of a shortage is critical, for even short-term adjustments could lead to permanent changes in service provision. This study demonstrates the importance of current information on the status of the national workforce and serves as a model for future studies.  相似文献   
10.
我们现在要尽量使这些治疗方法进入临床试验证明他们的可行性现在脊髓损伤的临床试验基金很有限,所以只有很少的这些治疗方法真正用于病人主要的制药厂开始对脊髓损伤治疗产生兴趣,我们现在还有很多工作要做,但是前景方向十分清楚,我们需要努力快速的工作。  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