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   184371篇
  免费   34102篇
  国内免费   2422篇
耳鼻咽喉   5538篇
儿科学   6292篇
妇产科学   3242篇
基础医学   7318篇
口腔科学   2277篇
临床医学   30126篇
内科学   53640篇
皮肤病学   7894篇
神经病学   17790篇
特种医学   7510篇
外国民族医学   4篇
外科学   45960篇
综合类   1055篇
现状与发展   72篇
一般理论   62篇
预防医学   10738篇
眼科学   3951篇
药学   3292篇
中国医学   50篇
肿瘤学   14084篇
  2024年   699篇
  2023年   4896篇
  2022年   1391篇
  2021年   3534篇
  2020年   6279篇
  2019年   2704篇
  2018年   8036篇
  2017年   7796篇
  2016年   8830篇
  2015年   8946篇
  2014年   16182篇
  2013年   16736篇
  2012年   7048篇
  2011年   7086篇
  2010年   11317篇
  2009年   15056篇
  2008年   7310篇
  2007年   5663篇
  2006年   8075篇
  2005年   5352篇
  2004年   4572篇
  2003年   3477篇
  2002年   3416篇
  2001年   4721篇
  2000年   3994篇
  1999年   4084篇
  1998年   4045篇
  1997年   3803篇
  1996年   3663篇
  1995年   3532篇
  1994年   2199篇
  1993年   1838篇
  1992年   2029篇
  1991年   2050篇
  1990年   1663篇
  1989年   1762篇
  1988年   1548篇
  1987年   1334篇
  1986年   1392篇
  1985年   1192篇
  1984年   957篇
  1983年   888篇
  1982年   799篇
  1981年   654篇
  1980年   616篇
  1979年   706篇
  1978年   637篇
  1977年   673篇
  1973年   563篇
  1972年   598篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.

Background

Partial nephrectomy (PN) is generally favored for cT1 tumors over radical nephrectomy (RN) when technically feasible. However, it can be unclear whether the additional risks of PN are worth the magnitude of renal function benefit.

Objective

To develop preoperative tools to predict long-term estimated glomerular filtration rate (eGFR) beyond 30 d following PN and RN, separately.

Design, setting, and participants

In this retrospective cohort study, patients who underwent RN or PN for a single nonmetastatic renal tumor between 1997 and 2014 at our institution were identified. Exclusion criteria were venous tumor thrombus and preoperative eGFR <15 ml/min/1.73 m2.

Intervention

RN and PN.

Outcome measurements and statistical analysis

Hierarchical generalized linear mixed-effect models with backward selection of candidate preoperative features were used to predict long-term eGFR following RN and PN, separately. Predictive ability was summarized using marginal RGLMM2, which ranges from 0 to 1, with higher values indicating increased predictive ability.

Results and limitations

The analysis included 1152 patients (13 206 eGFR observations) who underwent RN and 1920 patients (18 652 eGFR observations) who underwent PN, with mean preoperative eGFRs of 66 ml/min/1.73 m2 (standard deviation [SD] = 18) and 72 ml/min/1.73 m2 (SD = 20), respectively. The model to predict eGFR after RN included age, diabetes, preoperative eGFR, preoperative proteinuria, tumor size, time from surgery, and an interaction between time from surgery and age (marginal RGLMM2=0.41). The model to predict eGFR after PN included age, presence of a solitary kidney, diabetes, hypertension, preoperative eGFR, preoperative proteinuria, surgical approach, time from surgery, and interaction terms between time from surgery and age, diabetes, preoperative eGFR, and preoperative proteinuria (marginal RGLMM2). Limitations include the lack of data on renal tumor complexity and the single-center design; generalizability needs to be confirmed in external cohorts.

Conclusions

We developed preoperative tools to predict renal function outcomes following RN and PN. Pending validation, these tools should be helpful for patient counseling and clinical decision-making.

Patient summary

We developed models to predict kidney function outcomes after partial and radical nephrectomy based on preoperative features. This should help clinicians during patient counseling and decision-making in the management of kidney tumors.  相似文献   
32.
33.
34.
35.
36.
37.
38.
ABSTRACT

Adolescents and young adults smoke waterpipe tobacco (WT) and cigarillos, at least in part, based on erroneous beliefs that these products are safer than cigarettes. To address this challenge, we used a systematic, three-phase process to develop a health communication campaign to discourage WT and cigarillo smoking among at-risk (tobacco users and susceptible non-users) 16- to 25-year-olds. In Phase 1, we used a national phone survey (N = 896) to determine salient message beliefs. Participants reported constituents (i.e., harmful chemicals) emitted by the products were worrisome. In Phase 2, we developed and evaluated four message executions, with varying imagery, tone, and unappealing products with the same constituents, using focus groups (N = 38). Participants rated one execution highly, resulting in our development of a campaign where each message: (1) identified a tobacco product and constituent in the smoke; (2) included an image of an unappealing product containing the constituent (e.g., pesticides, gasoline) to grab attention; and (3) used a humorous sarcastic tone. In Phase 3, we tested the campaign messages (17 intervention and six control) with a nationally representative online survey (N = 1,636). Participants rated intervention and control messages highly with few differences between them. Exposure to messages resulted in significant increases in all risk beliefs from pre to post (< 0.05). For WT, intervention messages increased beliefs about addiction more than control messages (p < 0.05). This systematic, iterative approach resulted in messages that show promise for discouraging WT and cigarillo use.  相似文献   
39.
Marielle Kabbouche MD  FAHS 《Headache》2015,55(10):1426-1429
Status migrainosus is defined by the international classification of headache disorders (ICHD) criteria as a debilitating migraine lasting more then 72 hours. The epidemiology of status migrainosus is still unknown in adult and children, and frequently underdiagnosed. Children and adolescents often end up in the emergency room with an intractable headache that failed outpatient therapy. Six to seven percent of these children do not respond to acute infusion therapy and require hospitalization. It is imperative that more aggressive therapy is considered when patients are affected by a severe intractable headache to prevent further disability and returning the child to baseline activity. Multiple therapies are available for adults and children. Studies for acute therapy in the emergency room are available in adults and pediatric groups. Small studies are available for inpatient therapy in children and, along with available therapies for children and adolescents, are described in this review. A review of the literature shows growing evidence regarding the use of dihydroergotamine intravenously once patients are hospitalized. Effectiveness and safety have been proven in the last decades in adults and small studies in the pediatric populations.  相似文献   
40.
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