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   3884篇
  免费   149篇
  国内免费   35篇
耳鼻咽喉   14篇
儿科学   61篇
妇产科学   38篇
基础医学   526篇
口腔科学   22篇
临床医学   747篇
内科学   869篇
皮肤病学   19篇
神经病学   308篇
特种医学   123篇
外科学   543篇
综合类   17篇
预防医学   183篇
眼科学   69篇
药学   270篇
中国医学   7篇
肿瘤学   252篇
  2023年   11篇
  2022年   22篇
  2021年   38篇
  2020年   20篇
  2019年   31篇
  2018年   48篇
  2017年   46篇
  2016年   36篇
  2015年   61篇
  2014年   102篇
  2013年   123篇
  2012年   258篇
  2011年   290篇
  2010年   146篇
  2009年   163篇
  2008年   277篇
  2007年   305篇
  2006年   301篇
  2005年   313篇
  2004年   293篇
  2003年   312篇
  2002年   257篇
  2001年   32篇
  2000年   40篇
  1999年   43篇
  1998年   46篇
  1997年   36篇
  1996年   33篇
  1995年   44篇
  1994年   37篇
  1993年   25篇
  1992年   21篇
  1991年   34篇
  1990年   14篇
  1989年   13篇
  1988年   20篇
  1987年   19篇
  1986年   15篇
  1985年   10篇
  1984年   18篇
  1983年   10篇
  1982年   16篇
  1981年   12篇
  1980年   11篇
  1979年   19篇
  1978年   6篇
  1977年   7篇
  1976年   4篇
  1974年   7篇
  1973年   4篇
排序方式: 共有4068条查询结果,搜索用时 0 毫秒
31.
Objective: To assess the long-term survival, the incidence of cardiac complications and the factors that predict outcome in asymptomatic patients with severe degenerative mitral regurgitation (MR) undergoing mitral valve repair. Methods: Up to 143 asymptomatic patients (mean age 63 ± 12 years) with severe degenerative MR who underwent mitral valve repair between 1990 and 2001 were subsequently followed up for a median of 8 years. The study population was subdivided into three subgroups: patients with left ventricular (LV) dysfunction and/or dilatation (n = 18), patients with atrial fibrillation and/or pulmonary hypertension (n = 44) and patients without MR-related complications (n = 81). Results: For the patients, 10-year overall and cardiovascular survival was 82 ± 4% and 90 ± 3%. At 10 years, patients without preoperative MR-related complications had significantly better overall survival than patients with preoperative LV dysfunction and/or dilatation (89 ± 4% vs 57 ± 13%, log rank p = 0.001). Patients without preoperative MR-related complications also tended to have a better 10-year overall and cardiovascular survival than patients with atrial fibrillation and/or pulmonary hypertension (overall survival of 79 ± 8%), although this did not reach statistical significance (log rank p = 0.17). Cox regression analysis identified the baseline left ventricular ejection fraction and age as the sole independent predictors of outcome. Conclusion: Our data indicate that in asymptomatic patients with severe degenerative MR, mitral valve repair is associated with an excellent long-term prognosis. Nonetheless, the presence of preoperative MR-related complications, in particular LV dysfunction and/or dilatation, greatly attenuates the benefits of surgery. This suggests that mitral valve repair should be performed early, before any MR-related complications ensue.  相似文献   
32.
BACKGROUND: Osteoradionecrosis (ORN) is a nonhealing wound of the bone that is difficult to manage. Is a treatment combining pentoxifylline (PTX) and tocopherol (vitamin E) boosted by clodronate effective in reversing this fibronecrotic process? METHODS: Eighteen consecutive patients previously irradiated for head and neck cancer had exteriorized mandible ORN. Length of exposed bone (L) was 13.4 +/- 8 mm, and the mean subjective objective medical management and analytic evaluation of injury (SOMA) score was 12.6 +/- 4.9. Between June 1995 and January 2002, all 18 were given a daily oral combination of 800 mg of PTX and 1000 IU of vitamin E for 6 to 24 months. In addition, the last eight patients who were the worst cases were given 1600 mg/day clodronate 5 days a week. RESULTS: The treatment was well tolerated. All patients improved at 6 months, with 84% mean L and 67% mean SOMA score reductions. Sixteen (89%) of 18 patients achieved complete recovery, 14 in 5 +/- 2.6 months. The remaining two patients exhibited a 75% response at 6 months. CONCLUSION: PTX-vitamin E boosted by clodronate is an effective treatment of mandibular ORN that induces mucosal and bone healing in a median period of 6 months.  相似文献   
33.
Although chemoembolization is known to be an effective palliative treatment in hepatocellular carcinoma, it has a limited effect in large tumors. We report the case of a patient with a large hepatocellular carcinoma of the left liver who had a significant and sustained clinical response after six sessions of chemoembolization with a pirarubicin/amiodarone/lipiodol emulsion. Pirarubicin is an anthracycline which penetrates faster than doxorubicin into cancer cells. Amiodarone is a multidrug resistance inhibitor. Polysorbate 80, an excipient of injectable amiodarone stabilizes the anthracycline/lipiodol emulsion. The clinical efficacy of this new formulation could be evaluated in a phase II clinical trial.  相似文献   
34.
This study attempted to identify factors associated with mortality among human immunodeficiency virus (HIV)-infected adults starting a protease inhibitor (PI)-containing therapy. Among 1155 patients consecutively enrolled in the APROCO study between May 1997 and June 1998, clinical characteristics were as follows: median age, 36 years; median baseline CD4 cell count, 288 cells/mm(3); and median baseline plasma HIV RNA load, 4.4 log(10) copies/mL. After a median follow-up of 27 months, 48 deaths had occurred, of which 44% were related to acquired immune deficiency syndrome. The mortality rate was 2.9% at 12 months. When both data at baseline and data at 4 months after the start of PI therapy were considered, factors independently associated with mortality were (Cox model) low baseline plasma creatinine level, low school education level, low CD4 cell count at 4 months, low hemoglobin level, and elevated hepatic transaminase levels. Thus, social context plus clinical and biologic data, including the 4-month response to treatment, must be considered in treatment of HIV-infected patients.  相似文献   
35.
Allergic rhinitis (AR) is impacted by allergens and air pollution but interactions between air pollution, sleep and allergic diseases are insufficiently understood. POLLAR (Impact of air POLLution on sleep, Asthma and Rhinitis) is a project of the European Institute of Innovation and Technology (EIT Health). It will use a freely-existing application for AR monitoring that has been tested in 23 countries (the Allergy Diary, iOS and Android, 17,000 users, TLR8). The Allergy Diary will be combined with a new tool allowing queries on allergen, pollen (TLR2), sleep quality and disorders (TRL2) as well as existing longitudinal and geolocalized pollution data. Machine learning will be used to assess the relationship between air pollution, sleep and AR comparing polluted and non-polluted areas in 6 EU countries. Data generated in 2018 will be confirmed in 2019 and extended by the individual prospective assessment of pollution (portable sensor, TLR7) in AR. Sleep apnea patients will be used as a demonstrator of sleep disorder that can be modulated in terms of symptoms and severity by air pollution and AR. The geographic information system GIS will map the results. Consequences on quality of life (EQ-5D), asthma, school, work and sleep will be monitored and disseminated towards the population. The impacts of POLLAR will be (1) to propose novel care pathways integrating pollution, sleep and patients’ literacy, (2) to study sleep consequences of pollution and its impact on frequent chronic diseases, (3) to improve work productivity, (4) to propose the basis for a sentinel network at the EU level for pollution and allergy, (5) to assess the societal implications of the interaction. MASK paper N°32.  相似文献   
36.
Ce3+-doped Y3Al5O12 (YAG:Ce) nanocrystals were synthesized by a unique solvothermal method, under sub-critical conditions. A home-made autoclave was used, operating in a larger pressure and temperature range than that with conventional commercial equipment and allowing direct in situ photoluminescence (PL) and X-ray absorption characterizations. The study of various synthesis conditions (pressure, temperature, precursor concentration, reaction time) allowed the best reaction conditions to be pinpointed to control YAG:Ce nanocrystal size, as well as crystal quality, and to get efficient optical properties. Without any post thermal treatment, we succeeded in obtaining well-crystallized YAG:Ce nanocrystals (30–200 nm), displaying typical PL properties of YAG:Ce with a maximal emission at 550 nm. The pristine 100 nm-sized YAG:Ce nanoparticles present an internal quantum yield of about 40 ± 5%. In situ X-ray absorption near edge spectroscopy demonstrates the presence of Ce4+ in nanocrystals elaborated at high temperature, resulting from the oxidation of Ce3+ during the crystallization process.

This modified solvothermal method, combined with in situ photoluminescence measurements, allows the synthesis of well-crystallized size-controlled YAG:Ce nanocrystals.  相似文献   
37.
Among protease inhibitors, atazanavir has not been associated with urolithiasis in clinical studies. We describe 11 cases of atazanavir-associated urolithiasis in patients with human immunodeficiency virus (HIV) infection. Patients with low water intake, high urinary pH, and a prior history of urinary stones may have a higher risk of atazanavir-associated urine crystallization.  相似文献   
38.
39.
Endodontic treatment success is achieved not only when the cement provides a hermetic seal but also when the injured periapical tissue is regenerated. Howe  相似文献   
40.
BackgroundMuscle weakness is common in patients who survive a stay in the intensive care unit (ICU). Quadriceps strength (QS) measurement allows evaluation of lower limb performances that are associated with mobility outcomes.ObjectivesThe objective of the study was to characterise the range of QS in ICU survivors (ICUS) during their short-term evolution, by comparing them with surgical patients without critical illness and with healthy participants. The secondary aim was to explore whether physical activity before ICU admission influenced QS during that trajectory.MethodsPatients with length of ICU stay ≥2 days, adults scheduled for elective colorectal surgery, and young healthy volunteers were included. Maximal isometric QS was assessed using a handheld dynamometer and a previously validated standardised protocol. The dominant leg was tested in the supine position. ICUSs were tested in the ICU and 1 month after ICU discharge, while surgical patients were tested before and on the day after surgery, as well as 1 month after discharge. Healthy patients were tested once only. Patients were classified as physically inactive or active before admission from the self-report.ResultsThirty-eight, 32, and 34 participants were included in the ICU, surgical, and healthy groups, respectively. Demographic data were similar in the ICUS and surgical groups. In the ICU, QS was lower in the ICU group than in the surgical and healthy groups (3.01 [1.88–3.48], 3.38 [2.84–4.37], and 5.5 [4.75–6.05] N/kg, respectively). QS did not significantly improve 1 month after ICU discharge, excepted in survivors who were previously physically active (22/38, 56%): the difference between the two time points was ?6.6 [?27.1 to ?1.7]% vs 20.4 [?3.4 to 43.3]%, respectively, in physically inactive and active patients (p = 0.002).ConclusionsPatients who survived an ICU stay were weaker than surgical patients. However, a huge QS heterogeneity was observed among them. Their QS did not improve during the month after ICU discharge. Physically inactive patients should be early identified as at risk of poorer recovery.  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