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   440519篇
  免费   32420篇
  国内免费   1781篇
耳鼻咽喉   4875篇
儿科学   11545篇
妇产科学   8587篇
基础医学   57555篇
口腔科学   8833篇
临床医学   43436篇
内科学   93145篇
皮肤病学   5911篇
神经病学   42589篇
特种医学   14619篇
外国民族医学   24篇
外科学   67910篇
综合类   6681篇
现状与发展   2篇
一般理论   592篇
预防医学   39023篇
眼科学   10529篇
药学   30011篇
  6篇
中国医学   718篇
肿瘤学   28129篇
  2023年   1867篇
  2022年   3075篇
  2021年   8495篇
  2020年   5086篇
  2019年   8244篇
  2018年   9454篇
  2017年   7300篇
  2016年   7951篇
  2015年   9423篇
  2014年   14009篇
  2013年   19812篇
  2012年   29613篇
  2011年   31525篇
  2010年   17829篇
  2009年   16045篇
  2008年   28797篇
  2007年   30374篇
  2006年   29714篇
  2005年   30139篇
  2004年   28512篇
  2003年   26686篇
  2002年   25208篇
  2001年   3896篇
  2000年   3010篇
  1999年   4246篇
  1998年   5614篇
  1997年   4760篇
  1996年   4199篇
  1995年   3868篇
  1994年   3355篇
  1993年   3095篇
  1992年   2407篇
  1991年   2244篇
  1990年   2027篇
  1989年   1897篇
  1988年   1952篇
  1987年   1936篇
  1986年   1917篇
  1985年   2026篇
  1984年   2611篇
  1983年   2511篇
  1982年   3063篇
  1981年   2844篇
  1980年   2622篇
  1979年   1500篇
  1978年   1668篇
  1977年   1535篇
  1976年   1392篇
  1975年   1140篇
  1974年   1108篇
排序方式: 共有10000条查询结果,搜索用时 765 毫秒
111.
112.
113.
114.
Conclusion: Recurrent respiratory papillomatosis (RRP) patients with high surgical treatment frequency (≥ 1/year, HF) were significantly younger and had a more widespread laryngeal disease compared to a low frequency treated group (< 1 treatment/year, LF). This study confirms the existence of a clinical RRP group, not primarily related to HPV sub-type, but more care-intensive and in need of more vigilant follow-up. Objectives: RRP is associated with high morbidity due to its influence on breathing and voice. The purpose of this study was to characterize RRP patients in northern Sweden and investigate possible predictor factors affecting therapeutic needs. Method: Patients from the regional referral area (northern Sweden) were categorized for age, disease duration, juvenile or adult onset, profile of disease development, number of surgical sessions in relation to disease duration, laryngeal deposition of papilloma, gender, and HPV sub-types, in order to identify patients with increased need for frequent surgical treatment. Results: The median age of the RRP patients (n = 48) was 44.5 years; 34 (71%) were males and 14 (29%) females, most were infected with HPV 6. Patients with high surgical treatment frequency/year were significantly younger and showed more widespread papillomatous vegetation in the larynx, compared to the low frequency treated group.  相似文献   
115.
Contraceptive use is an important strategy for the prevention of unwanted pregnancy and avoidance of induced abortion. Of all the contraception methods, emergency contraceptive (EC) offers the last chance to achieve this. However, few studies have documented the use of EC among young people in Ghana. This study explored knowledge and usage of EC as well as the factors associated with it among University of Cape Coast students. Data were obtained on the knowledge and usage of ECs among University of Cape Coast students in 2013. Logistic regression analysis was used to investigate the association between students’ socio-demographic characteristics and EC knowledge and use. More male students (72 %) than females (59 %) were sexually active. Fifty-seven percent of the respondents had ever heard of EC and 36 % had ever used EC. Although males were more likely to be sexually active, females were more likely to have knowledge of EC use compared to males. The study underscores the need to increase awareness regarding EC among University students in order to offer them the opportunity that EC provides if other forms of contraceptives are missed.  相似文献   
116.
BackgroundNeoadjuvant yttrium-90 transarterial radioembolization (TARE) is increasingly being used as a strategy to facilitate resection of otherwise unresectable tumors due to its ability to generate both tumor response and remnant liver hypertrophy. Perioperative outcomes after the use of neoadjuvant lobar TARE remain underinvestigated.MethodsA single center retrospective review of patients who underwent lobar TARE prior to major hepatectomy for primary or metastatic liver cancer between 2007 and 2018 was conducted. Baseline demographics, radioembolization parameters, pre- and post-radioembolization volumetrics, intra-operative surgical data, adverse events, and post-operative outcomes were analyzed.ResultsTwenty-six patients underwent major hepatectomy after neoadjuvant lobar TARE. The mean age was 58.3 years (17–88 years). 62% of patients (n=16) had primary liver malignancies while the remainder had metastatic disease. Liver resection included right hepatectomy or trisegmentectomy, left or extended left hepatectomy, and sectorectomy/segmentectomy in 77% (n=20), 8% (n=2), and 15% (n=4) of patients, respectively. The mean length of stay was 8.3 days (range, 3–33 days) and there were no grade IV morbidities or 90-day mortalities. The incidence of post hepatectomy liver failure (PHLF) was 3.8% (n=1). The median time to progression after resection was 4.5 months (range, 3.3–10 months). Twenty-three percent (n=6) of patients had no recurrence. The median survival was 28.9 months (range, 16.9–46.8 months) from major hepatectomy and 37.6 months (range, 25.2–53.1 months) from TARE.ConclusionsMajor hepatectomy after neoadjuvant lobar radioembolization is safe with a low incidence of PHLF.  相似文献   
117.
118.
119.
120.

Background

Nursing Home Compare (NHC) ratings, created and maintained by Medicare, are used by both hospitals and consumers to aid in the skilled nursing facility (SNF) selection process. To date, no studies have linked NHC ratings to actual episode-based outcomes. The purpose of this study was to evaluate whether NHC ratings are valid predictors of 90-day complications, readmission, and bundle costs for patients discharged to an SNF after primary total joint arthroplasty (TJA).

Methods

All SNF-discharged primary TJA cases in 2017 at a multihospital academic health system were queried. Demographic, psychosocial, and clinical variables were manually extracted from the health record. Medicare NHC ratings were then collected for each SNF. For patients in the Medicare bundle, postacute and total bundle cost was extracted from claims.

Results

Four hundred eighty-eight patients were discharged to a total of 105 unique SNFs. In multivariate analysis, overall NHC rating was not predictive of 90-day readmission/major complications, >75th percentile postacute cost, or 90-day bundle cost exceeding the target price. SNF health inspection and quality measure ratings were also not predictive of 90-day readmission/major complications or bundle performance. A higher SNF staffing rating was independently associated with a decreased odds for >75th percentile 90-day postacute spend (odds ratio, 0.58; P = .01) and a 90-day bundle cost exceeding the target price (odds ratio = 0.69; P = .02) but was similarly not predictive of 90-day readmission/complications.

Conclusion

Results of our study suggest that Medicare's NHC tool is not a useful predictor of 90-day costs, complications, or readmissions for SNFs within our health system.  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