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   1989篇
  免费   164篇
  国内免费   14篇
耳鼻咽喉   17篇
儿科学   105篇
妇产科学   36篇
基础医学   330篇
口腔科学   35篇
临床医学   255篇
内科学   342篇
皮肤病学   25篇
神经病学   189篇
特种医学   44篇
外科学   222篇
综合类   6篇
一般理论   2篇
预防医学   195篇
眼科学   38篇
药学   157篇
中国医学   4篇
肿瘤学   165篇
  2024年   6篇
  2023年   23篇
  2022年   32篇
  2021年   54篇
  2020年   59篇
  2019年   71篇
  2018年   76篇
  2017年   55篇
  2016年   73篇
  2015年   57篇
  2014年   97篇
  2013年   130篇
  2012年   145篇
  2011年   156篇
  2010年   78篇
  2009年   72篇
  2008年   134篇
  2007年   133篇
  2006年   125篇
  2005年   101篇
  2004年   102篇
  2003年   88篇
  2002年   90篇
  2001年   17篇
  2000年   13篇
  1999年   7篇
  1998年   12篇
  1997年   21篇
  1996年   6篇
  1995年   14篇
  1994年   13篇
  1993年   10篇
  1992年   9篇
  1991年   7篇
  1989年   7篇
  1988年   3篇
  1987年   4篇
  1986年   5篇
  1985年   3篇
  1984年   5篇
  1983年   5篇
  1982年   6篇
  1981年   4篇
  1980年   5篇
  1979年   4篇
  1978年   3篇
  1977年   3篇
  1975年   3篇
  1974年   3篇
  1936年   2篇
排序方式: 共有2167条查询结果,搜索用时 15 毫秒
21.
Mastectomy using ultrasonic dissection: effect on seroma formation   总被引:6,自引:0,他引:6  
Seroma formation is the most common complication after mastectomy. Among the several known etiological factors the surgical procedure used may be of importance for seroma formation. This prospective study was carried out to evaluate the ultrasonic energy dissection technique and its effect on seroma formation and other complications: 59 patients with operable breast cancer underwent modified radical mastectomy, performed in 30 of them with an Ultracision Harmonic scalpel and in 29 with scissors and electrocautery. In all cases a standard level II axillary dissection was performed with scissors. We found no differences in the outcome of surgery. Peroperative bleeding (median 300 ml, range 100-790 vs 300 ml, range 40-1400), drain volume (585 ml, range 130-1455) vs 645 ml, range 95-1570), seroma formation 50 (0-580) ml vs 105 (0-3775) ml and wound complications were about the same in both groups. In conclusion, neither clinical advantages or disadvantages of the ultrasound dissection technique were found.  相似文献   
22.
Background: The mechanisms underlying neuropathic pain are incompletely understood. Targeting specific molecular mechanisms in the pain signaling system may assist in understanding key features in neuropathic pains such as allodynia. This study examined the effect of systemically administered ketamine, an N-methyl-d-aspartate receptor antagonist and lidocaine, a sodium channel blocker, on spontaneous pain, brush-evoked pain, and pinprick-evoked pain in patients with nerve injury pain.

Methods: Twenty patients participated in two randomized, double-blinded, placebo-controlled, crossover experiments in which they, on four different days, received a 30-minute intravenous infusion of ketamine (0.24 mg/kg), lidocaine (5 mg/kg), or saline. Ongoing pain, pain evoked by brush and repetitive pinprick stimuli, and acetone was measured before, during, and after infusion.

Results: Ketamine significantly reduced ongoing pain and evoked pain to brush and pinprick, whereas lidocaine only reduced evoked pain to repetitive pinprick stimuli. In individual patients, there was no correlation between the pain-relieving effect of lidocaine and ketamine on ongoing or mechanically evoked pains.  相似文献   

23.

Objective

To evaluate the feasibility of multivariable risk stratification for early prostate cancer (PCa) detection in a primary healthcare diagnostic facility with regard to its effects on the referral rate and subsequent PCa diagnoses compared to a PSA threshold of 3.0 ng/mL as the current referral indicator.

Patients and Methods

In 2014, the Erasmus MC Cancer Institute and the primary healthcare diagnostic facility STAR-SHL (located in Rotterdam city centre) initiated this observational study, in which general practitioners (GPs) could refer men who wished to undergo PCa screening to STAR-SHL for consultation by specially trained personnel. Referral recommendations to secondary healthcare were based on the outcome of application of the Rotterdam Prostate Cancer Risk Calculator (RPCRC) and were compared to the current Dutch GPs' PSA referral threshold of 3.0 ng/mL. For data collection on PCa diagnoses, the study cohort was linked to the Dutch nationwide pathology databank (PALGA).

Results

Between January 2014 and February 2021, 507 men were referred for consultation and in 495 men prostate-specific antigen (PSA) was tested. The median (interquartile range) follow-up from consultation to PALGA linkage was 43 (25–65) months. In total, 279 men (56%) had a PSA level ≥3.0 ng/mL, of whom 68% (95% confidence interval [95% CI] 63–74) were considered at low risk according to the RPCRC. Within 1 year after consultation, one of these men (0.52%; 95% CI 0.092–2.9) was diagnosed with clinically significant (cs)PCa (i.e., International Society of Urological Pathology Grade Group ≥2). Thereafter, another four (2.1%; 95% CI 0.82–5.3) low-risk men were diagnosed with csPCa. Of the high-risk men who were biopsied within 1 year after consultation (n = 61), 77% (95% CI 65–86) were diagnosed with PCa and 49% (95% CI 37–61) with csPCa.

Conclusion

In a primary healthcare diagnostic facility, the RPCRC could reduce up to 68% of referrals to secondary healthcare, as compared to a PSA referral threshold of 3.0 ng/mL. Deploying the RPCRC in this setting resulted in a high csPCa detection rate in those men biopsied. This strategy can be considered safe since the observational data showed low proportions of csPCa among men at low risk.  相似文献   
24.
Baelum V, Hintze H, Wenzel A, Danielsen B, Nyvad B. Implications of caries diagnostic strategies for clinical management decisions. Community Dent Oral Epidemiol 2011. © 2011 John Wiley & Sons A/S Abstract – Objectives: In clinical practice, a visual–tactile caries examination is frequently supplemented by bitewing radiography. This study evaluated strategies for combining visual–tactile and radiographic caries detection methods and determined their implications for clinical management decisions in a low‐caries population. Methods: Each of four examiners independently examined preselected contacting interproximal surfaces in 53 dental students aged 20–37 years using a visual–tactile examination and bitewing radiography. The visual–tactile examination distinguished between noncavitated and cavitated lesions while the radiographic examination determined lesion depth. Direct inspection of the surfaces following tooth separation for the presence of cavitated or noncavitated lesions was the validation method. The true‐positive rate (i.e. the sensitivity) and the false‐positive rate (i.e. 1‐specificity) were calculated for each diagnostic strategy. Results: Visual–tactile examination provided a true‐positive rate of 34.2% and a false‐positive rate of 1.5% for the detection of a cavity. The combination of a visual–tactile and a radiographic examination using the lesion in dentin threshold for assuming cavitation had a true‐positive rate of 76.3% and a false‐positive rate of 8.2%. When diagnostic observations were translated into clinical management decisions using the rule that a noncavitated lesion should be treated nonoperatively and a cavitated lesion operatively, our results showed that the visual–tactile method alone was the superior strategy, resulting in most correct clinical management decisions and most correct decisions regarding the choice of treatment.  相似文献   
25.
BACKGROUND: Differences between studies in rates of severe hypoglycaemia in type 1 diabetic cohorts are common and poorly understood. The purpose of this study was to assess the frequency of severe hypoglycaemia in unselected patients treated in different secondary care centres and to evaluate the influence of risk markers, clinical setting and selection. METHODS: Cross-sectional Danish-British multicentre survey of 1076 consecutive adult patients with clinical type 1 diabetes who completed a detailed questionnaire on hypoglycaemia and related issues. Key variable was the self-reported rate of severe hypoglycaemia during the preceding year. RESULTS: The overall rate of severe hypoglycaemia in the preceding year was 1.3 episodes/patient-year and episodes were reported by 36.7% of subjects. The distribution was highly skewed with 5% of subjects accounting for 54% of all episodes. There were no significant differences between countries or centres. Reduced hypoglycaemia awareness, peripheral neuropathy and smoking were the only significant risk markers of severe hypoglycaemia in a stepwise multivariate analysis. In a subgroup selected to be similar to the Diabetes Control and Complications Trial (DCCT) cohort, the rate of severe hypoglycaemia was 0.35 episodes/patient-year and only retinopathy was a significant risk marker together with state of awareness. CONCLUSION: Severe hypoglycaemia remains a significant clinical problem in type 1 diabetes. The rate of severe hypoglycaemia and the influence of risk markers are very sensitive to selection and differences in rates between centres or studies seem to disappear after correction for differences in clinical characteristics. Smoking is a novel overall risk marker of severe hypoglycaemia.  相似文献   
26.
27.
BACKGROUND: To assess health-related quality of life (HRQOL) in patients after cardiac surgery with emphasis on sex differences. DESIGN AND METHODS: Between September 2004 and September 2005, 534 patients (413 males and 121 females) were consecutively included. HRQOL was measured by the short-form 36 (SF-36) before surgery with follow-up 6 and 12 months after surgery. RESULTS: Five hundred and twenty-one patients were alive after 12 months, 462 (89%) and 465 (89.4%) responded after 6 and 12 months, respectively. Female patients had less favorable scores than male patients on most subscales of the SF-36 both before and after surgery. Both male and female patients improved substantially after surgery, but female patients reported significantly less improvement on two of eight subscales of the SF-36; role emotional and bodily pain. CONCLUSION: The study demonstrates that there are sex differences concerning HRQOL both before and after cardiac surgery. A clear overall improvement in HRQOL over the first year after cardiac surgery, more specifically during the first 6 months for both sexes was found.  相似文献   
28.
29.

A recent qualitative study published in Neuroethics by Schembs and colleagues explores how functional neurodiagnostics of consciousness inform surrogate decision making in cases of disorders of consciousness. In this commentary, we argue that the chosen methodology significantly limits the scope of the potential conclusions and suggest an embedded ethnographic approach of co-presence as an alternative.

  相似文献   
30.
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