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   3641篇
  免费   328篇
  国内免费   43篇
耳鼻咽喉   13篇
儿科学   54篇
妇产科学   80篇
基础医学   208篇
口腔科学   112篇
临床医学   510篇
内科学   438篇
皮肤病学   19篇
神经病学   108篇
特种医学   56篇
外科学   361篇
综合类   490篇
预防医学   727篇
眼科学   17篇
药学   388篇
  19篇
中国医学   155篇
肿瘤学   257篇
  2024年   7篇
  2023年   78篇
  2022年   138篇
  2021年   205篇
  2020年   227篇
  2019年   154篇
  2018年   151篇
  2017年   147篇
  2016年   152篇
  2015年   132篇
  2014年   251篇
  2013年   274篇
  2012年   221篇
  2011年   247篇
  2010年   186篇
  2009年   182篇
  2008年   131篇
  2007年   145篇
  2006年   117篇
  2005年   104篇
  2004年   100篇
  2003年   74篇
  2002年   60篇
  2001年   63篇
  2000年   58篇
  1999年   45篇
  1998年   38篇
  1997年   29篇
  1996年   36篇
  1995年   37篇
  1994年   27篇
  1993年   20篇
  1992年   10篇
  1991年   17篇
  1990年   15篇
  1989年   10篇
  1988年   4篇
  1987年   6篇
  1986年   8篇
  1985年   16篇
  1984年   10篇
  1983年   9篇
  1982年   16篇
  1981年   17篇
  1979年   7篇
  1977年   3篇
  1976年   6篇
  1975年   4篇
  1974年   4篇
  1973年   3篇
排序方式: 共有4012条查询结果,搜索用时 15 毫秒
1.
《Cancer radiothérapie》2022,26(4):611-615
In order to provide more convenient irradiation regimens for patient comfort, radiation facility organization and health expenses, new hypofractionated protocols have been evaluated. Moderately (dose/fraction: 2.3 to 3 Gy), then ultra (dose/fraction: 5.2 to 6.1 Gy) hypofractionated irradiations were first validated. The current question is: is it possible to go forward using extreme hypofractionated regimens (EHR) based on 1 to 3 fractions. Different irradiation techniques are under investigation. However, brachytherapy remains the smartest way to deliver a high dose in a small volume. We report prospective and retrospective study results which evaluated EHR for breast and prostate brachytherapy. While oncological outcome and toxicity profile appear extremely encouraging for low-risk breast cancer after a 1 to 4 fractions (6.25 to 20 Gy/fraction), the use of a single fraction of 19 to 23 Gy appears debatable for prostate cancer. Brachytherapy represents an emblematic example of EHR but longer follow-up and more mature results are awaited in order to specify the right indications and refine the EQD2 calculation method including new biological and technical factors.  相似文献   
2.
3.
PurposeAssess multiparametric-MRI (mp-MRI) diagnostic accuracy in the detection of local recurrence of prostate cancer (PCa) after radical prostatectomy (PR) and before radiation therapy (RT).Materials and methodsA total of 188 patients underwent 1.5-T mp-MRI after RP before RT. Patients were divided into 2 groups: with biochemical recurrence (group A) and without but with high risk of local recurrence (group B). Continuous variables were compared between 2 groups using Student-t test; categoric variables were analyzed using Pearson chi-square. ROC analysis was performed considering PSA before RT, ISUP, pT and pN as grouping variables.ResultsPCa recurrence (reduction of PSA levels after RT) was 89.8% in group A and 80.3% in group B. Comparing patients with and without PCa recurrence, there was a significant difference in PSA values before RT for group A and for PSA values before RT and after RT for group B. In group A, there was a significant correlation between PSA before RT and diameter of recurrence and between PSA before RT and time spent before recurrence. The mp-MRI diagnostic accuracy in detecting PCa local recurrence after RP is of 62.2% in group A and 38% in group B. Diffusion weighted imaging is the most specific MRI-sequence and dynamic contrast enhanced the most sensitive. For PSA = 0.5 ng/ml, the AUC decreases while sensitivity and accuracy increase for each MRI-sequence. For PSA = 0.9 ng/ml, dynamic contrast enhanced-AUC increases significantly.Conclusionmp-MRI should always be performed before RT when a recurrence is suspected. New scenarios can be opened considering the role of diffusion weighted imaging for PSA  0.5 ng/ml.  相似文献   
4.
Background: Intraductal carcinoma and cribriform (IDC/C) tumor features are well-established prognosticators of biochemical recurrence (BCR), metastasis, and prostate cancer (PCa)-specific mortality. However, approximately 70% of PCa patients undergoing a radical prostatectomy are IDC/C negative, yet up-to 20% of these patients progress and experience BCR. Thus, tumor histopathologic characteristics such as IDC/C alone are limited in their ability to predict disease progression. Conversely, several nomograms such as Cancer of the Prostate Risk Assessment-Surgery (CAPRA-S) have been developed to aid in the prognostication of BCR, but not yet widely applied in clinical settings. Materials and methods: In this study, we assessed the combined prognostic utility of IDC/C, and CAPRA-S for BCR in 3 PCa patient cohorts. Results: CAPRA-S+IDC/C improved the predictive accuracy of BCR in all 3 cohorts (P < .001). Specifically, among IDC/C negative cases, CAPRA-S improved the prognostication of BCR in low-risk (Cohort 1; P < .001, Cohort 2; P < .001, Cohort 3; P = .003), intermediate (Cohort 1; P < .001, Cohort 2; P = .006, Cohort 3; P = .03) and high-risk (Cohort 1-3; P < .001) patients. Conversely, IDC/C improved the prognostication of BCR among CAPRA-S low-risk (Cohorts 1; P < .001 and Cohort 3; P = .003) patients. Conclusion: Our results suggest the investigation of histopathological IDC/C features in CAPRA-S low-risk patients and conversely, nomogram CAPRA-S among IDC/C negative patients improves the identification of patients likely to experience BCR, which would otherwise be missed through current assessment regimens. These patients can be offered more intensive monitoring and adjuvant therapies upfront to circumvent the development of recurrent cancer or overtreatment at the time of surgery.  相似文献   
5.
6.
ContextPalliative care is gaining ground globally and is endorsed in high-level policy commitments, but service provision, supporting policies, education, and funding are incommensurate with rapidly growing needs.ObjectivesThe objective of this study was to describe current levels of global palliative care development and report on changes since 2006.MethodsAn online survey of experts in 198 countries generated 2017 data on 10 indicators of palliative care provision, fitted to six categories of development. Factor analysis and discriminant analysis showed the validity of the categorization. Spearman correlation analyses assessed the relationship with World Bank Income Level (WBIL), Human Development Index (HDI), and Universal Health Coverage (UHC).ResultsNumbers (percentages) of countries in each development category were as follows: 1) no known palliative care activity, 47 (24%); 2) capacity-building, 13 (7%); 3a) isolated provision, 65 (33%); 3b) generalized provision, 22 (11%); 4a) preliminary integration into mainstream provision, 21 (11%); 4b) advanced integration, 30 (15%). Development levels were significantly associated with WBIL (rS = 0.4785), UHC (rS = 0.5558), and HDI (rS = 0.5426) with P < 0.001. Net improvement between 2006 and 2017 saw 32 fewer countries in Categories 1/2, 16 more countries in 3a/3b, and 17 more countries in 4a/4b.ConclusionPalliative care at the highest level of provision is available for only 14% of the global population and is concentrated in European countries. An 87% global increase in serious health-related suffering amenable to palliative care interventions is predicted by 2060. With an increasing need, palliative care is not reaching the levels required by at least half of the global population.  相似文献   
7.
8.
ObjectiveTo describe the characteristics of paediatric patients with suspected poisoning treated by advanced life support (ALS) units, and to evaluate quality indicators (QI) for the prehospital emergency care of these patients.MethodA one-year observational study of patients under 18 years of age exposed to poisoning and treated by an ALS unit of the Medical Emergency System in Catalonia. Severe clinical criteria were defined, with 8 QI being evaluated for prehospital emergency care of poisoned paediatric patients.ResultsThe study included a total of 254 patients, with a median age of 14 years-old (p25-75 = 7-16), with intentional poisoning in 50.8% of cases. The most frequently involved toxic agent was carbon monoxide (CO) (33.8%). Poisoning was found in 48.8% of those patients, being serious in 16.5%. Intentionally (OR 5.1; 95% CI: 1.9-13.8) and knowledge of the time of exposure (OD 3.1; 95% CI: 1.3-7.3) were independent risk factors associated with the appearance of severe clinical symptoms. Five QI did not reach the quality standard and included, availability of specific clinical guidelines, activated charcoal administration in selected patients, oxygen therapy administration at maximum possible concentration in carbon monoxide poisoning, electrocardiographic assessment in patients exposed to cardiotoxic substances, and recording of the minimum data set.ConclusionsPaediatric patients attended by ALS units showed specific characteristics, highlighting the involvement of CO and adolescents with voluntary poisoning. The QI assessment was useful to detect weak points in the quality of care of these patients and to develop strategies for improvement.  相似文献   
9.
Selective protection of the normal host tissues from the toxic effects of anticancer agents would allow the use of higher, probably more effective, doses of the drugs. It has been demonstrated that delayed high-dose uridine administration after 5-fluorouracil decreases the extent of myelosuppression and causes faster regeneration of the bone marrow. We studied the biochemical consequences of the gastrointestinal toxicity caused by 5-fluorouracil and the potential of high-dose uridine treatment to influence these adverse effects. 5-Fluorouracil caused dose-related decreases in the biochemical parameters (thymidine kinase, sucrase, maltase, alkaline phosphatase) selected as early markers of the impaired metabolic activity of the intestinal mucosa. The nadir of the biochemical changes was reached between 24 h and 72 h after 5-fluorouracil treatment, and complete regeneration of the mucosa took 6–7 days. Delayed high-dose uridine administration failed to mitigate the severity of the gastrointestinal damage that ensued after 5-fluorouracil treatment, but caused significantly earlier regeneration of the mucosa.  相似文献   
10.
The region is characterized by diversity in cultural, political, economic and health conditions. Blindness in the region varies from 6.4% to 0.2% with cataract ranking highly as an underlying cause. There is a need to develop national policies to deliver affordable, technically suitable, and cost effective management plans to reduce cataract. Economic, demographic, health, and manpower statistics are essential information to be considered in formulating such policies.  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