全文获取类型
收费全文 | 13816篇 |
免费 | 748篇 |
国内免费 | 15篇 |
专业分类
耳鼻咽喉 | 319篇 |
儿科学 | 434篇 |
妇产科学 | 461篇 |
基础医学 | 1136篇 |
口腔科学 | 261篇 |
临床医学 | 1135篇 |
内科学 | 2771篇 |
皮肤病学 | 402篇 |
神经病学 | 721篇 |
特种医学 | 872篇 |
外科学 | 2949篇 |
综合类 | 166篇 |
一般理论 | 1篇 |
预防医学 | 1045篇 |
眼科学 | 349篇 |
药学 | 600篇 |
中国医学 | 5篇 |
肿瘤学 | 952篇 |
出版年
2023年 | 55篇 |
2021年 | 111篇 |
2020年 | 78篇 |
2019年 | 109篇 |
2018年 | 156篇 |
2017年 | 118篇 |
2016年 | 152篇 |
2015年 | 612篇 |
2014年 | 735篇 |
2013年 | 809篇 |
2012年 | 917篇 |
2011年 | 846篇 |
2010年 | 787篇 |
2009年 | 717篇 |
2008年 | 883篇 |
2007年 | 844篇 |
2006年 | 777篇 |
2005年 | 677篇 |
2004年 | 551篇 |
2003年 | 314篇 |
2002年 | 274篇 |
2001年 | 271篇 |
2000年 | 288篇 |
1999年 | 229篇 |
1998年 | 111篇 |
1997年 | 117篇 |
1996年 | 102篇 |
1995年 | 109篇 |
1994年 | 95篇 |
1993年 | 91篇 |
1992年 | 200篇 |
1991年 | 183篇 |
1990年 | 169篇 |
1989年 | 155篇 |
1988年 | 186篇 |
1987年 | 151篇 |
1986年 | 121篇 |
1985年 | 138篇 |
1984年 | 108篇 |
1983年 | 120篇 |
1982年 | 83篇 |
1981年 | 74篇 |
1980年 | 58篇 |
1979年 | 113篇 |
1978年 | 71篇 |
1977年 | 56篇 |
1976年 | 58篇 |
1974年 | 61篇 |
1973年 | 69篇 |
1970年 | 46篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
81.
82.
83.
E S Haug P Romundstad S Aune T B J Hayes H O Myhre 《European journal of vascular and endovascular surgery》2005,29(5):489-495
OBJECTIVES: To study early mortality and long-term survival of patients more than 80 years of age having elective open repair for abdominal aortic aneurysm (AAA). DESIGN: Retrospective multicenter cohort study. MATERIAL: One hundred and five patients, 23 women and 82 men, with a median age of 82 years, operated at three Norwegian hospitals during the period 1983-2002. METHOD: Survival analyses were based on data from medical records and the Norwegian Registrar's Office of Births and Deaths. Expected survival was based on mortality rates of the general population, matched by age, sex, and calendar period. Relative survival was calculated as the ratio between the observed and the expected survival. RESULTS: During the study period there has been a 10 fold increase in octogenarians treated with open operation for AAA. Early mortality (30-day) for the whole group of patients was 10.5% (95% confidence interval (95% CI) 5.3-18.0), and similar for both genders. The 5-year survival rate was 47% (95% CI 35.9-57.4), and not significantly different from that of a matched group in the general population. Patients aged 84 years or more had a median survival time of 35 months (95% CI 18.5-51.6). CONCLUSION: The number of AAA operations in octogenarians has increased considerably during 20 years. Octogenarians operated electively for AAA has higher 30-day mortality as compared to younger patients. Their long-term survival appears similar to a matched control group. The benefit of surgery must be carefully considered against the perioperative risk, especially for the oldest octogenarians. 相似文献
84.
At birth the human newborn is immature and has not yet acquired fully competent organ functions. During lactation especially the digestive tract and the immune system gain competence. Lactation is regulated by a complex interaction of numerous hormonal factors. Most important are probably prolactin and oxytocin—two hormones produced and secreted in the pituitary. The production and secretion of these two hormones is again regulated by several factors in the central nervous system and these mechanisms can be disturbed by a variety of exogenous factors such as drugs and any other substances interacting with dopamine metabolism in the brain. It is important to know these physiological interactions to be able to understand the regulation of lactation and to be able to assess which factors could interfere with this process. 相似文献
85.
John F. Fraser MBChB ; Leila Cuttle BSc ; Margit Kempf BmedLSci ; Gael E. Phillips MBBS ; Peter K. O'Rourke PhD ; Kelvin Choo MBBS ; Mark T. Hayes PhD ; Roy M. Kimble MBChB 《Wound repair and regeneration》2005,13(2):189-197
Early to mid-term fetuses heal cutaneous incisional wounds without scars; however, fetal response to burn injury has not been ascertained. We present a fetal model of thermal injury and subsequent analysis of fetal and lamb response to burn injury. A reproducible deep dermal burn injury was created in the fetus by application of water at 66 degrees C for 7 seconds, and at 82 degrees C for 10 seconds to the lamb. Macroscopically, the area of fetal scald was undetectable from day 7 post injury, while all lamb scalds were readily identified and eventually healed with scarring. Using a five-point histopathology scoring system for alteration in tissue morphology, differences were detected between control and scalded skin at all stages in lamb postburn, but no difference was detected in the fetal model after day 7. There were also large differences in content of alpha-smooth muscle actin and transforming growth factor-beta1 between control and scalded lamb and these differences were statistically significant at day 14 (P < 0.01). This novel model of fetal and lamb response to deep dermal injury indicates that the fetus heals a deep burn injury in a scarless fashion. Further elucidation of this specific fetal process of burn injury repair may lead to improved outcome for patients with burn injury. 相似文献
86.
N. Hayes R. Rollins A. Weinberg O. Brawley C. Baquet J. S. Kaur N. A. Palafox 《Cancer causes & control : CCC》2005,16(1):41-50
During the last two decades extraordinary progress in developing and using effective cancer prevention strategies, early detection interventions, and cancer treatments has been made. This progress has resulted in an overall decline in mortality rates for all cancers combined. Nonetheless, cancer is the second most common cause of death in the United States. Although cancer is a diagnosis that many survive, cancer experiences across populations may vary considerably. These differences in cancer experiences have created an unequal disease burden that presents distinct professional and moral challenges to our nation. Many cancer control plans suggest specific strategies that prioritize eliminating cancer-related disparities. This article describes certain cancer-related disparities in the United Sates and gives several examples of how communities and disenfranchised populations are using comprehensive cancer control (CCC) approaches to eliminate these disparities. One or two interventions are highlighted in each example. 相似文献
87.
PD Dr. M.W. Strik S. Anders M. Barth E. Bärlehner C. Benecke T. Benhidjeb 《Der Chirurg》2007,78(12):1139-1144
BACKGROUND: The axillobilateral breast approach (ABBA) is a procedure allowing thyroid resection without scarring at the neck. We operated on a series of 26 patients with this technique. METHOD: Via incisions at the edge of the mamilla and axilla, trocars are placed subcutaneously under the platyma. Dissection is performed bluntly and with an ultrasonographic scalpel under videoscopic control. The procedure itself corresponds to conventional surgery. The specimen is removed through the axillary trocar. RESULTS: Twenty-six female patients underwent thyroid resection using the ABBA technique. Subtotal resection was performed in 24. Mean operation times were 111 min (unilateral) and 187 min (bilateral). In none of these cases was conversion necessary. One transient recurrent laryngeal nerve palsy and one paresis of the arm plexus were found postoperatively. CONCLUSION: In selected patients the ABBA technique is feasible and safe with the mandatory radicalness. The primary aim of this method is the cosmetic result. 相似文献
88.
PD Dr. B. Clasbrummel B. Jettkant N. DeLuca G. Muhr G. Möllenhoff 《Trauma und Berufskrankheit》2007,9(2):84-87
The life time of hip endoprostheses is in part limited by aseptic loosening. The aim of this study was to produce a digital system for recording shaft loosening in such endoprostheses using acceleration sensors. Four identical prosthetic shafts were each set with 3.2-axial acceleration sensors and placed in artificial femurs. In order to simulate a firm fit, one prosthesis was fixed with bone cement; a loose fit was fixed with a surrounding silicon shell 0.5 mm thick. Simulation of the transition from firm to loose in the other two prostheses was attained by the distal 2/3 or 1/3 being cemented, with the rest surrounded by a silicone shell. A weak oscillation was initiated via a damped falling weight. Using a fast Fourier transformation it was possible to make a global evaluation of the measurement curves. A wavelet transformation could be used to differentiate firm or loose prostheses. A third order Daubechies filter recognized the deviation in the main oscillation, made visible by an increase in amplitude. The results encourage the development of an implantable, telemetrically functioning total system which would allow digital quality assurance when integrated into the endoprosthesis. 相似文献
89.
PD Dr. A. Gries N. Russ G. Conrad Ch. Müller-Ramcke J. Braun 《Notfall & Rettungsmedizin》2007,10(2):137-143
The 2006, annual meeting of the senior physicians and emergency medical technicians of the German Air Rescue Service (Deutschen Rettungsflugwacht, DRF) was titled “From Concept to Practice”. The themes of security in the air rescue services and the current practice of cardiopulmonary respiration were discussed. In addition, different concepts and networks for treating patients with acute coronary syndrome or severe trauma were presented. The training of emergency technicians and quality assessment using the database of the whole TeamDRF was explained. New helicopter stations as well as long-range transport using normal aviation by the TeamDRF were presented. 相似文献
90.
Rajiv Jalan Rebecca Gooday Ronan E. O'Carroll Doris N. Redhead Robert A. Elton Peter C. Hayes 《Journal of hepatology》1995,23(6)
Background/Aims: This study was designed to assess changes in: (a) neuropsychological tests, measures of memory, quality of life and scores for anxiety and depression; (b) liver function tests; and (c) the relationship between these following transjugular intrahepatic portosystemic stent-shunt.Methods: Twenty-nine patients undergoing transjugular intrahepatic portosystemic stent-shunt for recurrent variceal haemorrhage, 12 matched patients with cirrhosis and variceal haemorrhage manage with variceal band ligation and 16 normal controls were studied. Patients in any of the groups who were clinically encephalopathic were excluded from the study. Serial changes in the conventional liver function tests and Indocyanine green clearance, and psychometric function (Hospital Anxiety Depression Scale, Rivermead Behavioral Memory Test, Quality of Life and the memory and reaction sub-tests of the Cambridge Automated Neuropsychological Test Assessment Battery) were measured prior to and 1, 3, 9 and 15 months following transjugular intrahepatic portosystemic stent-shunt.Results: Over a mean follow up of 9.1 months in the transjugular intrahepatic portosystemic stent-shunt group (range 3–28), one patient (3%) developed clinically detectable encephalopathy. Sixty-seven percent of patients with cirrhosis showed evidence of subclinical encephalopathy as compared with the control population. Significant deterioration occurred in the reaction sub-tests of the Cambridge Automated neuropsychological Test Assessment Battery in patients, both in the transjugular intrahepatic portosystemic stent-shunt group and the controls with cirrhosis, during follow up. Transjugular intrahepatic portosystemic stent-shunt was followed by significant deterioration in levels of anxiety and psychological component of the quality of life. The Rivermead Behavioural Memory Test and the memory sub-test of the Cambridge Automated Neurpsychological Test Assessment Battery did, however, improve significantly at 1 and 15 months after transjugular intrahepatic portosystemic stent-shunt, respectively. Serum alanine aminotransferase, bilirubin and indocyanine green clearance deteriorated significantly following transjugular intrahepatic portosystemic stent-shunt (p<0.001, p<0.001 and p<0.0001, respectively). Significant correlation was observed between changes in the indocyanine green clearance and changes in the complex and simple reaction time subtests of the Cambridge Automated Neuropsychological Test Assessment Battery (r=0.6 and r=0.66, respectively).Conclusions: The results of this study showed that about 67% of patients with cirrhosis were subclinically encephalopathic and that temporary deterioration occurred in the Cambridge Automated Neuropsychological Test Assessment Battery during follow up, both in patients having transjugular intrahepatic portosystemic stent-shunt and in the controls with cirrhosis. These parallel the changes in the liver function tests and indocyanine green clearance. Temporary deterioration was also observed in the Quality of Life and Hospital Anxiety Depression Scale in the transjugular intrahepatic portosystemic stent-shunt group, although the measures of memory improved. Further studies should address the biochemical mechanisms of these changes and the role of prophylactic measures. 相似文献