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   1649815篇
  免费   134276篇
  国内免费   2802篇
耳鼻咽喉   22368篇
儿科学   54136篇
妇产科学   46984篇
基础医学   233624篇
口腔科学   48291篇
临床医学   145962篇
内科学   324531篇
皮肤病学   34710篇
神经病学   134931篇
特种医学   66261篇
外国民族医学   474篇
外科学   251801篇
综合类   40201篇
现状与发展   3篇
一般理论   599篇
预防医学   126548篇
眼科学   37505篇
药学   124083篇
  6篇
中国医学   3018篇
肿瘤学   90857篇
  2018年   15885篇
  2016年   13866篇
  2015年   16084篇
  2014年   22191篇
  2013年   33572篇
  2012年   45935篇
  2011年   48523篇
  2010年   28380篇
  2009年   27215篇
  2008年   46281篇
  2007年   48687篇
  2006年   49414篇
  2005年   48077篇
  2004年   47276篇
  2003年   45284篇
  2002年   44162篇
  2001年   76024篇
  2000年   78631篇
  1999年   66791篇
  1998年   18279篇
  1997年   16802篇
  1996年   16757篇
  1995年   16425篇
  1994年   15404篇
  1993年   14507篇
  1992年   55661篇
  1991年   53946篇
  1990年   52726篇
  1989年   50961篇
  1988年   47389篇
  1987年   46696篇
  1986年   44433篇
  1985年   42990篇
  1984年   32208篇
  1983年   27760篇
  1982年   16422篇
  1981年   14676篇
  1980年   13744篇
  1979年   30540篇
  1978年   21180篇
  1977年   17859篇
  1976年   16756篇
  1975年   17620篇
  1974年   21536篇
  1973年   20715篇
  1972年   18870篇
  1971年   17783篇
  1970年   16299篇
  1969年   15284篇
  1968年   13953篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
22.
The Latin American population has a double way of immigration, one toward the United States by proximity and another toward Spain by sociocultural affinity. This population increase is affecting organ donation and transplantation in receiving countries.

Objective

To analyze the brain death (BD) concept knowledge in the Dominican Republic immigrant population in Florida (United States) and Spain.

Method

Population under study: Population born in the Dominican Republic, resident in Florida (United States) and in Spain. Inclusion criteria: Population older than 15 years stratified by age and sex. Assessment instrument: Donation attitude questionnaire PCID-DTO-Ríos. Fieldwork: Random selection based on stratification. Immigration support association collaboration in Florida and Spain was needed to locate potential respondents. Completion was anonymous and self-administered, with verbal consent.

Results

A total of 123 respondents, 57 residents in Spain and 66 in Florida, have been included in the study. The 27% (n = 33) of the respondents knowledgeable of the BD concept consider it the death of an individual. Of the remainder, 52% (n = 64) do not know about it, and the remaining 21% (n = 26) believe it does not mean the death of a patient. No differences were observed regarding migration countries (P > .05). There was no association of the BD concept with other psychosocial factors analyzed or with the attitude toward organ donation.

Conclusions

Knowledge of the BD concept among the Dominican immigrant population is similar in Spain and Florida, and, unlike most studies, there is no objective association with the attitude toward organ donation.  相似文献   
23.
Abstract

Purpose: We examined underlying psychosocial processes of a behavioral treatment for urinary incontinence (UI) of prostate cancer survivors.

Design: Secondary analysis of data collected from a clinical trial.

Sample: Two hundred forty-four prostate cancer survivors who participated in a clinical trial of behavioral intervention to UI as intervention or control subjects.

Methods: The participants had a 3-month behavioral intervention or usual care and were followed up for an additional 3?months. They were assessed at baseline, 3, and 6?months. Latent growth curve models were performed to examine trajectories of each study variable and relationships among the variables.

Findings: Increasing self-efficacy and social support were significantly and independently associated with more reduction of urinary leakage frequency over time.

Implications for psychosocial oncology: Providing problem-solving skills and social support, including peer support, are essential for empowering patients to reduce UI.  相似文献   
24.
25.
Landgraf  R. 《Der Diabetologe》2006,2(1):S5-S8
NAFDM, the National Action Forum for Diabetes Mellitus, is an umbrella organisation for the leading diabetes organisations in Germany. Since its foundation at the end of 2004, NAFDM has brought together the activities of these organisations, which up to now were frequently working independently of each other, under a single ‘roof’. Supported by a central coordination unit, three project groups work successfully on the topics scientific research and healthcare research, patient care and prevention. Activities and results are shared and thus integrated into the network. The working groups are supported by NAFDM’s medical and health-policy steering groups. Apart from a number of successful events, two key publications have meanwhile come out: one on the status of prevention and one analysing the healthcare situation for diabetics in Germany. All people interested in diabetology are invited to join in and work with the NAFDM.  相似文献   
26.
Multi-day signals, generally with duration of 2-10 days, are a prominent temporal variation type of radon (Rn) in geogas in the unsaturated zone. Rare multi-day Rn signals have been found which are characterized by: (a) a declining limb lasting up to 10 days which conforms to the radioactive decay of Rn, (b) recurs at the same location and (c) is recorded in diverse situations-volcanic and seismogenic. It suggested that a Rn blob is injected at a lower level on a steady upward flow of geogas whereby the rise and final fall of the signal are attributed to the edges of the blob while the central Rn-decay segment records the passing of the decaying blob itself. Rn-decay signals are a small subset of multi-day Rn signals which are considered as highly irregular and unusable for the understanding of geophysical processes. In difference, it is concluded that multi-day Rn signals are probably proxies of subtle geodynamic processes at upper crustal levels and are therefore significant for studying such processes.  相似文献   
27.
On September 11, 2001 two hijacked airplanes struck the Twin Towers at the World Trade Center in New York City. All of the remains (19,915) were examined by the Office of Chief Medical Examiner (OCME) of New York City. The major goals of the OCME were to accurately identify the decedents and to promptly issue death certificates. As of September 2005, there were 1594 identifications of a total of 2749 people reported missing. Of these, 976 were identified by a single means, which included DNA analysis in 852 of the victims. Use of legal statues can assist in the timely issuance of death certificates in mass fatalities, which benefit surviving family members. DNA analysis markedly improves the ability to identify remains and has become the standard method for identification in these types of disasters. Certain postmortem tissue samples are better suited for DNA analysis and yield better results than others.  相似文献   
28.
We used the dual capability of hyperpolarized 129Xe for spectroscopy and imaging to develop new measures of xenon diffusing capacity in the rat lung that (analogously to the diffusing capacity of carbon monoxide or DLCO) are calculated as a product of total lung volume and gas transfer rate constants divided by the pressure gradient. Under conditions of known constant pressure breath-hold, the volume is measured by hyperpolarized 129Xe MRI, and the transfer rate is measured by dynamic spectroscopy. The new quantities (xenon diffusing capacity in lung parenchyma (DLXeLP)), xenon diffusing capacity in RBCs (DLXeRBC), and total lung xenon diffusing capacity (DLXe)) were measured in six normal rats and six rats with lung inflammation induced by instillation of fungal spores of Stachybotrys chartarum. DLXeLP, DLXeRBC, and DLXe were 56 +/- 10 ml/min/mmHg, 64 +/- 35 ml/min/mmHg, and 29 +/- 9 ml/min/mmHg, respectively, for normal rats, and 27 +/- 9 ml/min/mmHg, 42 +/- 27 ml/min/mmHg, and 16 +/- 7 ml/min/mmHg, respectively, for diseased rats. Lung volumes and gas transfer times for LP (TtrLP) were 16 +/- 2 ml and 22 +/- 3 ms, respectively, for normal rats and 12 +/- 2 ml and 35 +/- 8 ms, respectively, for diseased rats. Xenon diffusing capacities may be useful for measuring changes in gas exchange associated with inflammation and other lung diseases.  相似文献   
29.
30.
BACKGROUND: The laparoscopic resection of rectal cancer shows morbidity and oncological safety comparable to the open approach, but morbidity increases after conversion to open resection. No oncological long-term results are available for the latter patients. METHODS: From 01/01/2000-31/12/2002, patients with curatively resected rectal cancer enrolled in a observational study were evaluated for morbidity, mortality, tumor- and local recurrence rate, paying attention to patients with conversion from laparoscopic to open resection. RESULTS: 237 (3.3%) of 7,189 patients underwent laparoscopic resection (ITT). These patients showed significantly more T1/2 tumors (P<0.001) in earlier UICC stages (P<0.001) than open resected patients. 35 (14.8%) of 237 laparoscopic procedures were converted. Compared with patients receiving complete laparoscopic or open resection, these patients showed significantly higher frequencies of intraoperative (P<0.001) and general postoperative complications (P=0.003) as well as the highest overall morbidity (P=0.031). After a median follow-up of 30.1 months, the highest 5-year local recurrence rate was found in the converted group (16.0%). The laparoscopically resected patients showed a local recurrence rate of 3.3%, patients with open resection of 12.4% (P=0.082). The disease-free survival rate did not differ between the groups (P=0.585). CONCLUSION: Laparoscopic resection of rectal cancer provides oncological results similar to open resection. After conversion, the short and oncological long-term outcomes were worse. Considering a conversion rate of 15%, only a strict indication for the laparoscopic approach can be allowed, and laparoscopic resection should be performed at centers.  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