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   4466篇
  免费   211篇
  国内免费   61篇
耳鼻咽喉   85篇
儿科学   162篇
妇产科学   177篇
基础医学   342篇
口腔科学   93篇
临床医学   364篇
内科学   1319篇
皮肤病学   34篇
神经病学   262篇
特种医学   139篇
外科学   860篇
综合类   106篇
一般理论   1篇
预防医学   183篇
眼科学   202篇
药学   229篇
中国医学   18篇
肿瘤学   162篇
  2024年   5篇
  2023年   33篇
  2022年   71篇
  2021年   129篇
  2020年   63篇
  2019年   92篇
  2018年   114篇
  2017年   90篇
  2016年   94篇
  2015年   153篇
  2014年   185篇
  2013年   242篇
  2012年   352篇
  2011年   366篇
  2010年   211篇
  2009年   185篇
  2008年   346篇
  2007年   378篇
  2006年   322篇
  2005年   317篇
  2004年   215篇
  2003年   198篇
  2002年   164篇
  2001年   58篇
  2000年   51篇
  1999年   44篇
  1998年   22篇
  1997年   36篇
  1996年   21篇
  1995年   18篇
  1994年   11篇
  1993年   9篇
  1992年   15篇
  1991年   22篇
  1990年   13篇
  1989年   13篇
  1988年   15篇
  1987年   11篇
  1986年   4篇
  1985年   10篇
  1984年   7篇
  1983年   8篇
  1981年   3篇
  1980年   4篇
  1979年   4篇
  1973年   2篇
  1956年   1篇
  1932年   1篇
  1931年   1篇
  1929年   1篇
排序方式: 共有4738条查询结果,搜索用时 15 毫秒
71.

Background

Oral anticoagulation is the mainstay of stroke prevention in atrial fibrillation (AF), but must be balanced against the associated bleeding risk. Several risk scores have been proposed for prediction of bleeding events in patients with AF.

Objectives

To compare the performance of contemporary clinical bleeding risk scores in 18 113 patients with AF randomized to dabigatran 110 mg, 150 mg or warfarin in the RE‐LY trial.

Methods

HAS‐BLED, ORBIT, ATRIA and HEMORR2HAGES bleeding risk scores were calculated based on clinical information at baseline. All major bleeding events were centrally adjudicated.

Results

There were 1182 (6.5%) major bleeding events during a median follow‐up of 2.0 years. For all the four schemes, high‐risk subgroups had higher risk of major bleeding (all P  < 0.001). The ORBIT score showed the best discrimination with c‐indices of 0.66, 0.66 and 0.62, respectively, for major, life‐threatening and intracranial bleeding, which were significantly better than for the HAS‐BLED score (difference in c‐indices: 0.050, 0.053 and 0.048, respectively, all P  < 0.05). The ORBIT score also showed the best calibration compared with previous data. Significant treatment interactions between the bleeding scores and the risk of major bleeding with dabigatran 150 mg BD versus warfarin were found for the ORBIT (P  = 0.0019), ATRIA (P  < 0.001) and HEMORR2HAGES (P  < 0.001) scores. HAS‐BLED score showed a nonsignificant trend for interaction (P  = 0.0607).

Conclusions

Amongst the current clinical bleeding risk scores, the ORBIT score demonstrated the best discrimination and calibration. All the scores demonstrated, to a variable extent, an interaction with bleeding risk associated with dabigatran or warfarin.
  相似文献   
72.
BACKGROUND: Many patients with congestive heart failure do not receive the benefits of angiotensin-converting enzyme (ACE) inhibitors because of intolerance. We sought to determine the tolerability of an angiotensin II receptor blocker, candesartan cilexetil, among patients considered intolerant of ACE inhibitors. METHODS: Patients with CHF, left ventricular ejection fraction less than 35%, and history of discontinuing an ACE inhibitor because of intolerance underwent double-blind randomization in a 2:1 ratio to receive candesartan (n = 179) or a placebo (n = 91). The initial dosage of candesartan was 4 mg/d; the dosage was increased to 16 mg/d if the drug was tolerated. A history of intolerance of ACE inhibitor was attributed to cough (67% of patients), hypotension (15%), or renal dysfunction (11%). RESULTS: The study drug was continued for 12 weeks by 82.7% of patients who received candesartan versus 86.8% of patients who received the placebo. This 4.1% greater discontinuation rate with active therapy was not significant; the 95% confidence interval ranged from 4.8% more discontinuation with placebo to 13% more with candesartan. Titration to the 16-mg target dose was possible for 69% of patients who received candesartan versus 84% of those who received the placebo. Frequencies of death and morbidity were not significantly different between the candesartan and placebo groups (death 3.4% and 3.3%, worsening heart failure 8.4% and 13.2%, myocardial infarction 2.8% and 5.5%, all-cause hospitalization 12.8% and 18.7%, and death or hospitalization for heart failure 11.7% and 14.3%). CONCLUSIONS: Candesartan was well tolerated by this population. The effect of candesartan on major clinical end points, including death, remains to be determined.  相似文献   
73.
OBJECTIVE: Regular physical activity is associated with decreased morbidity and mortality. Traditionally, patients with rheumatoid arthritis (RA) have been advised to limit physical exercise. We studied the prevalence of physical activity and associations with demographic and disease-related variables in patients with RA from 21 countries. METHODS: The Questionnaires in Standard Monitoring of Patients with Rheumatoid Arthritis (QUEST-RA) is a cross-sectional study that includes a self-report questionnaire and clinical assessment of nonselected consecutive outpatients with RA who are receiving usual clinical care. Frequency of physical exercise (>or=30 minutes with at least some shortness of breath, sweating) is queried with 4 response options: >or=3 times weekly, 1-2 times weekly, 1-2 times monthly, and no exercise. RESULTS: Between January 2005 and April 2007, a total of 5,235 patients from 58 sites in 21 countries were enrolled in QUEST-RA: 79% were women, >90% were white, mean age was 57 years, and mean disease duration was 11.6 years. Only 13.8% of all patients reported physical exercise>or=3 times weekly. The majority of the patients were physically inactive with no regular weekly exercise: >80% in 7 countries, 60-80% in 12 countries, and 45% and 29% in 2 countries, respectively. Physical inactivity was associated with female sex, older age, lower education, obesity, comorbidity, low functional capacity, and higher levels of disease activity, pain, and fatigue. CONCLUSION: In many countries, a low proportion of patients with RA exercise. These data may alert rheumatologists to motivate their patients to increase physical activity levels.  相似文献   
74.
75.

Background and Objectives:

Our objective is to clarify the effect of previous transurethral resection of the prostate (TURP) or open prostatectomy (OP) on surgical, oncological, and functional outcomes after robot-assisted radical prostatectomy (RARP).

Methods:

Between August 1, 2009, and March 31, 2013, 380 patients underwent RARP. Of these, 25 patients had undergone surgery for primary bladder outlet obstruction (TURP, 20 patients; OP, 5 patents) (group 1). A match-paired analysis was performed to identify 36 patients without a history of prostate surgery with equivalent clinicopathologic characteristics to serve as a control group (group 2). Patients followed up for 12 months were assessed.

Results:

Both groups were similar with respect to preoperative characteristics, as mean age, body mass index, median prostate-specific antigen, prostate volume, clinical stage, the biopsy Gleason score, D''Amico risk, the American Society of Anesthesiologists (ASA) classification score, the International Prostate Symptom Score, continence, and potency status. RARP resulted in longer console and anastomotic time, as well as higher blood loss compared with surgery-naive patients. We noted a greater rate of urinary leakage (pelvic drainage, >4 d) in group 1 (12% vs 2,8%). The anastomotic stricture rate was significantly higher in group 1 (16% vs 2.8%). No difference was found in the pathologic stage, positive surgical margin, and nerve-sparing procedure between the groups. Biochemical recurrence was observed in 12% (group 1) and 11.1% (group 2) of patients, respectively. No significant difference was found in the continence and potency rates.

Conclusions:

RARP after TURP or OP is a challenging but oncologically promising procedure with a longer console and anastomosis time, as well as higher blood loss and higher anastomotic stricture rate.  相似文献   
76.

Background and Objectives:

Prostate cancer and inguinal hernia are common health issues in men aged more than 50 years. Recently, more data are accumulating that laparoscopic radical prostatectomy (LRP) and laparoscopic inguinal hernia repair (LIHR) can be performed in the same operation. The purpose of this study was to compare patients who underwent simultaneous extraperitoneal LRP (E-LRP) and LIHR with control patients who underwent only E-LRP in a matched-pairs design.

Methods:

Medical records of 215 patients were evaluated, and 20 patients who underwent E-LRP+LIHR were compared with 40 patients who underwent only E-LRP in a matched-pairs analysis. Preoperative clinical parameters (age, body mass index, prostate-specific antigen, clinical stage, Gleason score of the prostate biopsy, and prostate volume) and operative data (operation time, duration of catheterization, length of hospital stay, estimated blood loss, time to perform the anastomosis and its quality, and the percentage of patients with bilateral lymphadenectomy) were evaluated, as well as postoperative parameters (pathological stage, Gleason score, specimen weight, follow-up duration, biochemical recurrence, complication rates, and duration of postoperative analgesic treatment).

Results:

No statistically significant differences were found in the preoperative and operative parameters between the 2 study groups. Pathological parameters and the follow-up period and complication rates were similar between the 2 groups.

Conclusion:

Performing LIHR and E-LRP during the same operation is safe and feasible in the treatment of patients with prostate cancer and inguinal hernia.  相似文献   
77.
This study aims to evaluate the microclimate and development of pressure ulcers and superficial skin changes. A prospective cohort study was conducted in an acute care ward in Indonesia. Risk factors for pressure ulcers and superficial skin changes were identified based on the Bergstrom Braden conceptual model. Microclimate data were collected every 3 days for 15 days while the development of pressure ulcers and superficial skin changes was observed every day. Pressure ulcers and superficial skin changes were developed in 20 of the 71 participants. Total mean difference in skin temperature was higher for patients with pressure ulcers and superficial skin changes (0·9 ± 0·6°C) compared with controls (0·6 ± 0·8°C) (P = 0·071). Binary logistic regression predictor values for pressure ulcers and superficial skin changes were 0·111 for type of sheet and 0·347 for Braden Scale results. In conclusion, difference in skin temperature seems to be a predictor for pressure ulcer development and superficial skin changes, while synthetic fibre sheets are able to maintain a beneficial microclimate.  相似文献   
78.
79.
Erem C  Kocak M  Onder Ersoz H  Ersoz S  Yucel Y 《Endocrine》2005,28(2):225-230
Cystic adrenal masses are a relatively rare condition, and are usually nonfunctioning and asymptomatic. Differential diagnosis includes pheochromocytoma (PHEO) and adrenal carcinoma; 8-10% of patients with PHEO may be completely asymptomatic. Moreover, fewer than 10% of PHEOs secrete pure epinephrine. We report a case of a E-secreting pure cystic PHEO presenting with an incidental adrenal mass. A 49-year-old Turkish woman was hospitalized at Farabi Hospital for further examinations of a right adrenal cystic mass with a thick wall that was incidentally discovered by abdominal ultrasonography during examination for nausea, vomiting, headache, and angina-like chest pain in another hospital. On admission, her blood pressure was 100/60 mmHg. Tension Holter monitoring revealed paroximal hypertension (178/136 mmHg) and hypotension (78/54 mmHg) attacks. Of urinary catecholamines and its metabolites, only urine metanephrine was markedly increased, despite a urine epinephrine level near the upper limit of normal ranges. Abdominal computed tomography and magnetic resonance imaging studies revealed a cystic round tumor approx 5 cm in diameter, located in the right adrenal gland. Right adrenalectomy was performed; the surgical specimen revealed pure cystic PHEO. Postoperatively, the urine metanephrine level returned to normal range and urine epineprine level was decreased approx 60%. In conclusion, a diagnosis of E-secreting PHEO should be considered in patients with nonspecific symptoms, presenting with an incidental cystic adrenal mass, even in the absence of hypertension.  相似文献   
80.
[Purpose] To assess the effects of different numbers of platelet-rich plasma (PRP) applications on pain and physical function in grade 3 knee osteoarthritis (OA). [Subjects and Methods] A total of 102 patients with grade 3 knee OA were randomly divided into three groups: Group 1 received a single injection of PRP, Group 2 received two injections of PRP two weeks apart, Group 3 received three injections of PRP at 2-weeks intervals. All patients were evaluated with a visual analog scale (VAS), the Western Ontario and McMaster Universities Arthritis Index (WOMAC), and the Timed-Up and Go test (TUG) before the treatment and at 1, 3 and 6 months after the treatment. [Results] Ninety-eight patients (15 males, 83 females) completed the study. The mean ages of the patients were 53.5±6.6, 54.9±5.3, and 55.1±5.6 years in Group 1, Group 2, and Group 3, respectively. Statistically significant improvements were noted in all of the evaluated measures in all of the groups. The mean differences of Group 1-Group 2 and Group 1-Group 3 WOMAC total, WOMAC pain, WOMAC stiffness, and WOMAC function scores were statistically significant. [Conclusion] PRP is an effective treatment for functional status and pain in moderate knee osteoarthritis and a minimum of two injections is appropriate.Key words: Platelet-rich plasma effectiveness, Moderate, Knee osteoarthritis  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