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   3399篇
  免费   315篇
  国内免费   15篇
耳鼻咽喉   40篇
儿科学   87篇
妇产科学   49篇
基础医学   453篇
口腔科学   82篇
临床医学   439篇
内科学   717篇
皮肤病学   21篇
神经病学   170篇
特种医学   124篇
外科学   385篇
综合类   64篇
一般理论   5篇
预防医学   411篇
眼科学   68篇
药学   272篇
  2篇
中国医学   10篇
肿瘤学   330篇
  2023年   25篇
  2022年   47篇
  2021年   112篇
  2020年   77篇
  2019年   79篇
  2018年   119篇
  2017年   79篇
  2016年   74篇
  2015年   112篇
  2014年   142篇
  2013年   161篇
  2012年   229篇
  2011年   220篇
  2010年   140篇
  2009年   133篇
  2008年   193篇
  2007年   213篇
  2006年   163篇
  2005年   176篇
  2004年   193篇
  2003年   171篇
  2002年   133篇
  2001年   72篇
  2000年   87篇
  1999年   56篇
  1998年   30篇
  1997年   24篇
  1996年   14篇
  1995年   16篇
  1994年   13篇
  1993年   26篇
  1992年   46篇
  1991年   39篇
  1990年   26篇
  1989年   37篇
  1988年   24篇
  1987年   28篇
  1986年   24篇
  1985年   11篇
  1984年   21篇
  1983年   13篇
  1982年   11篇
  1981年   13篇
  1980年   7篇
  1979年   12篇
  1977年   14篇
  1976年   7篇
  1972年   7篇
  1971年   6篇
  1970年   6篇
排序方式: 共有3729条查询结果,搜索用时 11 毫秒
51.
52.
BACKGROUND/AIMS: Length of stay is an important marker of medical resource consumption. In the modern managed care era physicians are driven to deliver the highest quality of care while using fewest resources. Hepatectomy represents a technically challenging and resource-intensive procedure, particularly in the setting of hepatic malignancy and liver cirrhosis. For improving quality of surgical management in such cases, we aimed to identify the factors affecting length of stay after hepatectomy for patients with hepatocellular carcinoma. METHODOLOGY: A total of 375 consecutive surgical hepatocellular carcinoma patients at a tertiary referral center during a 7-year period were reviewed. Length of stay after hepatectomy longer than 14 days was defined as prolonged length of stay. Patients were divided into two groups according to their length of stay. Patients with length of stay less than or equal to 14 days were in Group A and those with length of stay longer than 14 days were in Group B. Data for comparative analysis between both groups were categorized according to preoperative patients' clinical demographic factors, operation-related factors, and pathological factors. The significant univariate factors were used for subsequent multivariate analysis. RESULTS: The significant independent factors were patients' preoperative prothrombin activity, intraoperative blood transfusion, surgical complication, and the time to abdominal drain removal. Among these independent factors, surgical complication (p < 0.001, relative risk 7.01, and 95% confidence interval 3.46 to 14.18) was the most powerful factor for prolonged length of stay after elective hepatectomy for hepatocellular carcinoma. CONCLUSIONS: Most of the independent factors for prolonged length of stay after elective hepatectomy for hepatocellular carcinoma patients are operation-related and surgeon-dependent. The surgeon plays a key role in determining length of stay. By minimizing blood transfusion, surgical complication, and the time to abdominal drain removal, length of stay can be significantly decreased in hepatocellular carcinoma patients undergoing hepatectomy.  相似文献   
53.
Linker  CA; Ries  CA; Damon  LE; Rugo  HS; Wolf  JL 《Blood》1993,81(2):311-318
We have studied the use of a new preparative regimen for the treatment of patients in remission of acute myeloid leukemia (AML) with autologous bone marrow transplantation. Chemotherapy consisted of busulfan 1 mg/kg every 6 hours for 4 days (total dose, 16 mg/kg) on days -7 through -4 followed by an intravenous infusion over 6 to 10 hours of etoposide 60 mg/kg on day -3. Autologous bone marrow, treated in vitro with 100 micrograms/mL of 4-hydroperoxycyclophosphamide, was infused on day 0. We have treated 58 patients up to the age of 60 years, 32 in first remission, 21 in second or third remission, and 5 with primary refractory AML unresponsive to high-dose Ara-C, but achieving remission with aggressive salvage regimens. Of the first remission patients, there has been 1 treatment related death and 5 relapses. With median follow-up of 22 months, the actuarial relapse rate is 22% +/- 9% and disease-free survival is 76% +/- 9% at 3 years. Patients with favorable French-American-British (FAB) subtypes (M3 or M4 EO) did especially well, with no relapses seen in 15 patients observed for a median of 30 months. Actuarial relapse rate at 3 years was 48% for first remission patients with less favorable FAB subtypes. Of patients in second or third remission, there were 5 treatment related deaths and 4 relapses. With median follow-up of 22 months, the actuarial relapse rate is 25% +/- 11% and disease-free survival is 56% +/- 11% at 3 years. Four of five primary refractory patients died during treatment and 1 remains in remission with short follow-up. These preliminary data are very encouraging and, if confirmed, support the use of autologous purged bone marrow transplantation using aggressive preparative regimens as one approach to improve the outcome of adults with AML.  相似文献   
54.
Type 2 diabetes mellitus (T2DM) is a worldwide heath problem that is characterized by insulin resistance and the eventual loss of β cell function. As recent studies have shown that loss of ribosomal protein (RP) S6 kinase 1 (S6K1) increases systemic insulin sensitivity, S6K1 inhibitors are being pursued as potential agents for improving insulin resistance. Here we found that S6K1 deficiency in mice also leads to decreased β cell growth, intrauterine growth restriction (IUGR), and impaired placental development. IUGR is a common complication of human pregnancy that limits the supply of oxygen and nutrients to the developing fetus, leading to diminished embryonic β cell growth and the onset of T2DM later in life. However, restoration of placental development and the rescue of IUGR by tetraploid embryo complementation did not restore β cell size or insulin levels in S6K1–/– embryos, suggesting that loss of S6K1 leads to an intrinsic β cell lesion. Consistent with this hypothesis, reexpression of S6K1 in β cells of S6K1–/– mice restored embryonic β cell size, insulin levels, glucose tolerance, and RPS6 phosphorylation, without rescuing IUGR. Together, these data suggest that a nutrient-mediated reduction in intrinsic β cell S6K1 signaling, rather than IUGR, during fetal development may underlie reduced β cell growth and eventual development of T2DM later in life.  相似文献   
55.

Background

Patients are increasingly confronted with systems for rating hospitals. However, the correlations between publicized ratings and actual outcomes after pancreatectomy are unknown.

Methods

The Massachusetts Division of Health Care Finance and Policy Hospital Inpatient Discharge Database was queried to identify pancreatic cancer resections carried out during 2005–2009. Hospitals performing fewer than 10 pancreatic resections in the 5-year period were excluded. Primary outcomes included mortality, complications, median length of stay (LoS) and a composite outcomes score (COS) combining primary outcomes. Ranks were determined and compared for: (i) volume, and (ii) ratings identified from consumer-directed hospital ratings including the US News & World Report (USN), Consumer Reports, Healthgrades and Hospital Compare. An inter-rater reliability analysis was performed and correlation coefficients (r) between outcomes and ratings, and between rating systems were calculated.

Results

Eleven hospitals in which a total of 804 pancreatectomies were conducted were identified. Surgical volume correlated with overall outcome, but was not the strongest indicator. The highest correlation referred to that between USN rank and overall outcome. Mortality was most strongly correlated with Healthgrades ratings (r = 0.50); however, Healthgrades ratings demonstrated poorer correlations with all other outcomes. Consumer Reports ratings showed inverse correlations.

Conclusions

The plethora of publicly available hospital ratings systems demonstrates heterogeneity. Volume remains a good but imperfect indicator of surgical outcomes. Further systematic investigation into which measures predict quality outcomes in pancreatic cancer surgery will benefit both patients and providers.  相似文献   
56.
57.
We described influences on past research participation among low-income persons living with HIV (PLWH) and examined whether such influences differed by study type. We analyzed a convenience sample of individuals from a large, urban clinic specializing in treating low-income PLWH. Using a computer-assisted survey, we elicited perceptions of research and participating in research, barriers, benefits, "trigger" influences, and self-efficacy in participating in research. Of 193 participants, we excluded 14 who did not identify any type of study participation, and 17 who identified "other" as study type, resulting in 162 cases for analysis. We compared results among four groups (i.e., 6 comparisons): past medical participants (n=36, 22%), past behavioral participants (n=49, 30%), individuals with no past research participation (n=52, 32%), and persons who had participated in both medical and behavioral studies (n=25, 15%). Data were analyzed using chi-square tests for categorical variables and ANOVA for continuous variables. We employed a multinomial probit (MNP) model to examine the association of multiple factors with the outcome. Confidence in ability to keep appointments, and worry about being a 'guinea pig' showed statistical differences in bivariate analyses. The MNP regression analysis showed differences between and across all 6 comparison groups. Fewer differences were seen across groupings of medical participants, behavioral participants, and those with no past research experience, than in comparisons with the medical-behavioral group. In the MNP regression model 'age' and level of certainty regarding 'keeping yourself from being a guinea pig' showed significant differences between past medical participants and past behavioral participants.  相似文献   
58.
59.
Chu CH  Chau AM  Lo EC  Lam A 《General dentistry》2012,60(3):210-5; quiz 216-7
Tooth decay or cavities (dental caries) can have a significant impact on children's quality of life, causing pain, infection, and other problems in the oral environment. Good oral health is a fundamental element of good general health for children, yet dental caries is still prevalent among children in many countries. Dental caries is well-understood, and effective prevention is an attainable goal. Dental professionals should actively engage with communities--in particular, the underprivileged--to identify dental caries problems and implement appropriate and effective community oral health programs (COHPs) to improve oral health and reduce oral health inequalities. This paper discusses COHPs as well as the steps involved in caries prevention for children. These steps cannot ensure the success of every COHP, but they are helpful for developing, integrating, expanding, and enhancing them. The effectiveness of COHPs for the prevention of caries in children varies from country to country, according to cultural, social, economic, and health care settings. Careful consideration of the local situation is required when selecting the elements of COHPs.  相似文献   
60.
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