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   2794篇
  免费   191篇
  国内免费   4篇
耳鼻咽喉   56篇
儿科学   122篇
妇产科学   104篇
基础医学   415篇
口腔科学   45篇
临床医学   248篇
内科学   525篇
皮肤病学   52篇
神经病学   384篇
特种医学   70篇
外国民族医学   1篇
外科学   369篇
综合类   15篇
预防医学   168篇
眼科学   58篇
药学   190篇
中国医学   4篇
肿瘤学   163篇
  2023年   11篇
  2022年   23篇
  2021年   50篇
  2020年   32篇
  2019年   65篇
  2018年   74篇
  2017年   41篇
  2016年   41篇
  2015年   56篇
  2014年   87篇
  2013年   138篇
  2012年   164篇
  2011年   162篇
  2010年   75篇
  2009年   83篇
  2008年   160篇
  2007年   148篇
  2006年   171篇
  2005年   182篇
  2004年   151篇
  2003年   130篇
  2002年   108篇
  2001年   100篇
  2000年   106篇
  1999年   74篇
  1998年   23篇
  1997年   13篇
  1996年   24篇
  1995年   23篇
  1994年   15篇
  1993年   13篇
  1992年   43篇
  1991年   40篇
  1990年   40篇
  1989年   37篇
  1988年   37篇
  1987年   31篇
  1986年   37篇
  1985年   24篇
  1984年   23篇
  1983年   11篇
  1982年   10篇
  1981年   11篇
  1980年   8篇
  1979年   14篇
  1978年   11篇
  1975年   8篇
  1974年   10篇
  1971年   8篇
  1967年   6篇
排序方式: 共有2989条查询结果,搜索用时 250 毫秒
1.
2.
Infection is one of the leading causes of mortality in dialysis patients, second only to cardiovascular disease. This retrospective study assessed the efficacy and clinical outcomes of influenza vaccination among hemodialysis (HD) patients. In the 2014–2015 season, 104 of 164 (63.6%) HD patients were vaccinated for influenza by the outpatient community health system facilities. Significantly more patients, 159 of 170 (93.8%), were vaccinated in 2015–2016 by the hospital dialysis unit staff during an inpatient HD session (P <0.001). A trend toward fewer complications from influenza infection was observed in vaccinated patients. Among HD patients with diabetes (who comprised 56% of the study population), the incidence of influenza was 17% among nonvaccinated patients vs. 6.3% among those who were vaccinated (P =0.026). The inpatient vaccination policy resulted in a greater rate of vaccination. HD patients with diabetes benefit from influenza vaccination, with a significantly lower incidence of influenza infection.  相似文献   
3.
4.
The aim of this study was to determine if handgrip strength (HGS) is a predictor of nutritional risk in community-dwelling older adults. A cross-sectional study was carried out to determine the relationship between HGS and nutritional risk using SCREEN 1. The setting was Congregate Nutrition program meal sites (n = 10) in North Central Florida and included community-dwelling older adults participating in the Congregate Nutrition program. Older adults (n = 136; 77.1 ± 8.9 y; 45 M, 91 F) participated in the study. Nutritional risk was identified in 68% of participants, with 10% exhibiting clinically relevant weakness (men, HGS < 26 kg; women, HGS < 16 kg), suggesting a vulnerable population. HGS was weakly associated with nutritional risk as assessed by SCREEN 1 (AUC = 0.59), but alternate cutpoints, 33 kg for men (mean of both hands) and 22 kg for women (highest of either hand), provided the best comparison to nutritional risk. In community-dwelling older adults, HGS was weakly associated with nutritional risk assessed using traditional screening. However, as existing research supports the inclusion of HGS in malnutrition screening in acute care, further research into the usefulness of HGS and possibly other measures of functional status in nutrition risk screening of community-dwelling older adults may be warranted.  相似文献   
5.
6.
Investigation of hyperpolarized substrate metabolism has been showing utility in real‐time determination of in‐cell and in vivo enzymatic activities. Intracellular reaction rates may vary during the course of a measurement, even on the very short time scales of visibility on hyperpolarized MR, due to many factors such as the availability of the substrate and co‐factors in the intracellular space. Despite this potential variation, the kinetic analysis of hyperpolarized signals typically assumes that the same rate constant (and in many cases, the same rate) applies throughout the course of the reaction as observed via the build‐up and decay of the hyperpolarized signals. We demonstrate here an acquisition approach that can null the need for such an assumption and enable the detection of instantaneous changes in the rate of the reaction during an ex vivo hyperpolarized investigation, (i.e. in the course of the decay of one hyperpolarized substrate dose administered to a viable tissue sample ex vivo). This approach utilizes hyperpolarized product selective saturating‐excitation pulses. Similar pulses have been previously utilized in vivo for spectroscopic imaging. However, we show here favorable consequences to kinetic rate determinations in the preparations used. We implement this acquisition strategy for studies on perfused tissue slices and develop a theory that explains why this particular approach enables the determination of changes in enzymatic rates that are monitored via the chemical conversions of hyperpolarized substrates. Real‐time changes in intracellular reaction rates are demonstrated in perfused brain, liver, and xenograft breast cancer tissue slices and provide another potential differentiation parameter for tissue characterization.  相似文献   
7.
There is an increasing request by patients or their representatives not to have some data registered in their clinical history or if such data exists to be deleted. Without doubt, this is so because such clinical data is accessed by various professionals who in most cases are not directly involved in caring for such patients. On the other hand, such data is copied and iteratively and unnecessary reproduced in various discharge reports and others forms. The problem arises when such controversial data refer to particularly sensitive clinical aspects such as assisted reproduction techniques, which invades personal and family privacy. Therefore, the question is who determines what data should be recorded in the medical records and according to what criteria should be taken that decision?  相似文献   
8.
9.
10.
Glandular odontogenic cyst: treatment and recurrence.   总被引:3,自引:0,他引:3  
PURPOSE: To investigate the correlation between clinical characteristics, radiologic features, treatment modalities, and treatment outcome of glandular odontogenic cyst, and to suggest a treatment protocol based on these results. PATIENTS AND METHODS: The study included a total of 56 cases, 49 from the literature and 7 new cases. Demographic data, locularity and radiographic extension, cortical plate integrity, treatment modalities, follow-up, and recurrence were analyzed. RESULTS: There were 34 male and 22 female patients aged 14 to 74 years (mean, 48 years). The mandible was involved in 41 cases (73.2%) and the maxilla in 15 (26.8%), predominantly in the anterior region; 53.6% of the lesions were unilocular and 46.4% multilocular. Large lesions were found in 78.5% of cases. Cortical integrity was compromised in 53.6% (cortical perforation in 39.3% and thinning or erosion of the cortical plate in 14.3%). Recurrence occurred at a rate of 29.2%, within 0.5 to 7 years (mean, 2.9 years). Mean follow-up was also 2.9 years. Two patients had 3 recurrences each. Recurrence was associated with minor surgery such as enucleation or curettage; none of the patients treated by peripheral ostectomy, marginal resection, or partial jaw resection had a recurrence. Compared with the patients without recurrence, the recurrence group had a higher frequency of multilocularity than the nonrecurrent group (64.3% vs 41.2%) and of compromised cortical integrity (71.4% vs 47.1%). CONCLUSION: Glandular odontogenic cyst is an aggressive lesion. Treatment by enucleation or curettage alone is associated with a high recurrence rate. Small unilocular lesions can be treated by enucleation. In large uni- or multilocular lesions, an initial biopsy is recommended. Surgical treatment of large lesions should include enucleation with peripheral ostectomy for unilocular cases and marginal resection or partial jaw resection in multilocular cases. Marsupialization followed by second phase surgery is an option for lesions approaching vital structures. Follow-up should continue for at least 3 years (up to 7 years in cases with features associated with increased risk).  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