全文获取类型
收费全文 | 70136篇 |
免费 | 5444篇 |
国内免费 | 3915篇 |
专业分类
耳鼻咽喉 | 295篇 |
儿科学 | 1295篇 |
妇产科学 | 439篇 |
基础医学 | 4833篇 |
口腔科学 | 612篇 |
临床医学 | 10468篇 |
内科学 | 6248篇 |
皮肤病学 | 266篇 |
神经病学 | 7461篇 |
特种医学 | 4458篇 |
外国民族医学 | 2篇 |
外科学 | 14281篇 |
综合类 | 13607篇 |
现状与发展 | 4篇 |
一般理论 | 1篇 |
预防医学 | 3706篇 |
眼科学 | 929篇 |
药学 | 6489篇 |
37篇 | |
中国医学 | 3463篇 |
肿瘤学 | 601篇 |
出版年
2024年 | 270篇 |
2023年 | 1221篇 |
2022年 | 2238篇 |
2021年 | 3153篇 |
2020年 | 2841篇 |
2019年 | 2272篇 |
2018年 | 2296篇 |
2017年 | 2601篇 |
2016年 | 2728篇 |
2015年 | 2606篇 |
2014年 | 4615篇 |
2013年 | 5499篇 |
2012年 | 4416篇 |
2011年 | 4852篇 |
2010年 | 4139篇 |
2009年 | 3841篇 |
2008年 | 3822篇 |
2007年 | 3757篇 |
2006年 | 3528篇 |
2005年 | 3096篇 |
2004年 | 2437篇 |
2003年 | 2162篇 |
2002年 | 1798篇 |
2001年 | 1565篇 |
2000年 | 1290篇 |
1999年 | 1047篇 |
1998年 | 902篇 |
1997年 | 803篇 |
1996年 | 666篇 |
1995年 | 552篇 |
1994年 | 424篇 |
1993年 | 333篇 |
1992年 | 277篇 |
1991年 | 202篇 |
1990年 | 186篇 |
1989年 | 167篇 |
1988年 | 120篇 |
1987年 | 115篇 |
1986年 | 102篇 |
1985年 | 131篇 |
1984年 | 83篇 |
1983年 | 50篇 |
1982年 | 58篇 |
1981年 | 63篇 |
1980年 | 55篇 |
1979年 | 32篇 |
1978年 | 19篇 |
1977年 | 19篇 |
1976年 | 20篇 |
1975年 | 9篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
经颅多普勒频谱参数与急性颅脑损伤患者颅内压的关系 总被引:2,自引:2,他引:0
目的探讨急性颅脑损伤患者的经颅多普勒频谱参数与颅内压的关系。方法应用TCD检测20例急性中、重型颅脑损伤患者双侧大脑中动脉,同时行颅内压监测。结果经颅多普勒频谱参数cf、PI、af、RI、ae均和ICP正相关,Vd、ac和ICP负相关,其中cf与ICP的相关系数最大。建立TCD相关参数与ICP的多元线性回归方程:ICP=0.312MAP-1.531Vd+21.437PI-15.059ac+38.722cf(P<0.001,R2=0.920估计值的标准差=4.0972mmHg)。结论经颅多谱勒频谱参数可以反应颅脑损伤患者的颅内压的改变。综合研究经颅多谱勒频谱参数、血压与颅内压的关系是应用经颅多普勒无创监测颅内压的方向。 相似文献
72.
Jennie Ponsford Rochelle Whelan-Goodinson Alex Bahar-Fuchs 《Brain injury : [BI]》2007,21(13):1385-1392
Primary objectives: To establish pre-morbid alcohol and drug use in persons with TBI, relative to controls, investigate how patterns of substance use change over time following TBI and identify factors associated with heavy post-injury substance use.
Methods and procedures: The Alcohol Use Disorders Identification test (AUDIT) and Drug Abuse Screening Test (DAST) was completed by 121 hospital inpatients with TBI, documenting pre-injury alcohol and drug use, and 133 demographically similar controls. Participants with TBI completed these measures and the Hospital Anxiety and Depression Scale (HADS) again 1 and 2 years post-injury and 76 also completed them at 3 years.
Results: Participants with TBI showed similar levels of drug and alcohol use to controls pre-injury, with 31.4% of the TBI group and 29.3% of controls drinking at hazardous levels. Alcohol and drug use declined in the first year post-injury, but increased by 2 years post-injury, with only 21.4% of participants with TBI reporting abstinence from alcohol and 25.4% drinking at hazardous levels. Only 9% showed a drug problem, but 24% had returned to some drug use. Those showing heavy alcohol use post-injury were young, male and heavy drinkers pre-injury. Drug and alcohol use was similar at 3 years post-injury.
Conclusions: More active intervention is needed to reduce alcohol and drug use following TBI. 相似文献
Methods and procedures: The Alcohol Use Disorders Identification test (AUDIT) and Drug Abuse Screening Test (DAST) was completed by 121 hospital inpatients with TBI, documenting pre-injury alcohol and drug use, and 133 demographically similar controls. Participants with TBI completed these measures and the Hospital Anxiety and Depression Scale (HADS) again 1 and 2 years post-injury and 76 also completed them at 3 years.
Results: Participants with TBI showed similar levels of drug and alcohol use to controls pre-injury, with 31.4% of the TBI group and 29.3% of controls drinking at hazardous levels. Alcohol and drug use declined in the first year post-injury, but increased by 2 years post-injury, with only 21.4% of participants with TBI reporting abstinence from alcohol and 25.4% drinking at hazardous levels. Only 9% showed a drug problem, but 24% had returned to some drug use. Those showing heavy alcohol use post-injury were young, male and heavy drinkers pre-injury. Drug and alcohol use was similar at 3 years post-injury.
Conclusions: More active intervention is needed to reduce alcohol and drug use following TBI. 相似文献
73.
Primary objective: This study seeks to extend previous findings by documenting memory performance in a sample of 70 children at 5 years post-injury. It was anticipated that increasing injury severity would be associated with decreased performance on working and complex memory tasks. It was also expected that injury severity would significantly predict memory, but that the time from insult to subsequent testing would be associated with an increased relationship to non-injury factors.
Research design: Participants were assessed at 5 years post-injury, aged between 6-14 years, using measures of immediate, working and complex memory.
Methods and procedures: The sample comprised 18 children who had sustained a severe TBI, 24 with a moderate TBI, 11 with a mild TBI and 17 healthy controls, matched for age, gender and socio-economic-status.
Results: Results indicated that severe TBI was associated with decreased complex auditory-verbal memory performance, although children with TBI did not display impairment on immediate, working or complex visual-spatial memory. While injury severity significantly predicted complex memory outcome, non-injury factors failed to significantly predict either working or complex memory performance.
Conclusions: Future research should be engineered towards further clarifying what influences recovery from childhood TBI in the elongated post-injury period. 相似文献
Research design: Participants were assessed at 5 years post-injury, aged between 6-14 years, using measures of immediate, working and complex memory.
Methods and procedures: The sample comprised 18 children who had sustained a severe TBI, 24 with a moderate TBI, 11 with a mild TBI and 17 healthy controls, matched for age, gender and socio-economic-status.
Results: Results indicated that severe TBI was associated with decreased complex auditory-verbal memory performance, although children with TBI did not display impairment on immediate, working or complex visual-spatial memory. While injury severity significantly predicted complex memory outcome, non-injury factors failed to significantly predict either working or complex memory performance.
Conclusions: Future research should be engineered towards further clarifying what influences recovery from childhood TBI in the elongated post-injury period. 相似文献
74.
R. J. Wechsler Mark E. Schweitzer David Karasick Diane M. Deely William Morrison 《Skeletal radiology》1998,27(1):1-6
Since the degree of comminution, fracture alignment, and articular congruity of intra-articular calcaneal fractures are important
determinants in surgical treatment and patient prognosis, we review helical computed tomographic (CT) technique and features
for detecting and assessing the extent of acute calcaneal fractures. Helical CT can be used to classify these fractures and
facilitate the surgeon’s understanding of the anatomy and position of the fracture components in all orthogonal planes independently
of the patient’s condition, foot placement in the CT gantry, or other injuries. 相似文献
75.
M. Antonelli M. L. Moro R. R. D'Errico G. Conti M. Bufi A. Gasparetto 《Intensive care medicine》1996,22(8):735-741
Objective The aim of this study was to identify risk factors and to describe epidemiological patterns for early—(EOB) and late—onset bacteremias (LOB) after trauma.Design A prospective study conducted on 141 consecutive trauma patients.Setting A general intensive care unit (ICU) of a university hospital.Patients All multiple trauma patients admitted to our general intensive care unit (ICU) from December 1990 to May 1992 were prospectively enrolled in the study. The following information was collected for each patient and recorded in a computer database: demography, severity of trauma according to the Abbreviated Injury Scale (AIS), severtity of trauma according to the Glasgow Coma Scale (GCS), presence of pneumothorax, pulmonary contusion, rib fractures, hemothorax, and abdominal trauma, use of mechanical ventilation, and placement of central venous catheters. Bacteremias were defined as EOB when onset occurred within 96 h after trauma, and as LOB when appearing after 96 h from trauma.Results Thirty-seven patients developed bacteremia during their ICU stay (26%): 11 (29.7%) EOB and 26 (70.3%) LOB. Gram-positive cocci were isolated more frequently in EOB than in LOB (x
2=4.1,P=0.04). The risk of EOB was significantly increased by the presence of pulmonary contusion [relative risk (RR) 15.0; confidence interval (CI) 1.99-113.25], pneumonia before the onset of bacteremia (RR 3.56; CI 1.17-10.69), AIS score greater than 32 and an abdominal injury score greater than 9 (RR 3.11; CI 1.02-9.49), while intravascular catheters and mechanical ventilation did not represent risk factors for EOB. LOB had a very different pattern and their risk was significantly increased by exposure to intravascular catheters (RR 4.96; CI 1.23-19.94) and to mechanical ventilation lasting more than 7 days (RR 3.6; CI 1.6-8.1).Conclusions Scoring with the AIS of the abdominal and thoracic trauma at admission to the ICU appears a useful tool for identifying trauma patients at increased risk of EOB. A rigorous policy of catheter placement and maintenance as a means of reducing late bacteremias in trauma patients is essential. 相似文献
76.
77.
MASASHI YOSHIDA GO WAKABAYASHI HIDEKI ISHIKAWA YOSHIHIDE OTANI MOTOHIDE SHIMAZU TETSURO KUBOTA KOICHIRO KUMAI IWAO KUROSE SOICHIRO MIURA HIROMASA ISHII MASAKI KITAJIMA 《Journal of gastroenterology and hepatology》1998,13(1):104-108
The effects of camostat mesilate, a synthetic serine protease inhibitor on gastric microcirculation and active oxygen species generated by leucocytes from the gastric and jugular veins in the early period after thermal injury were assessed. Male Wistar rats were anaesthetized and a 30% full skin-thickness dorsal burn was inflicted. Camostat mesilate (100 mg/kg) was dissolved in distilled water and administered orally to rats 40 min before thermal injury (the camostat group). The control animals (the vehicle group) were administered distilled water orally. Rolling leucocytes as well as Monastral blue B deposits in venules were observed using in vivo microscopy. Active oxygen species were measured by chemiluminescence. Camostat mesilate decreased the total length of gastric erosion, venular deposits of Monastral blue B, and rolling of leucocytes in venules, and relatively increased luminol-dependent chemiluminescence activity generated by zymosan-stimulated leucocytes 15 min after thermal injury. These results suggest that serine proteases are involved in the formation of gastric erosions and gastric microcirculatory disturbance in the early period after thermal injury. 相似文献
78.
Amanda J Cocks Anthony O'Connell Hugh Martin 《Burns : journal of the International Society for Burn Injuries》1998,24(8):717-724
This is a retrospective review of all burns patients admitted to a paediatric intensive care unit (PICU) over a 7 year period. Resuscitation fluid therapy and clinical course are presented. Ninety-eight new burns victims were admitted with a mortality rate of 10.2%, all in burns of greater than 25% body surface area (BSA). The incidence of ARDS was 20%, with an 18% mortality rate. Of 85 patients with burns greater than 5% BSA, 33 received the hospital-recommended colloid-based resuscitation formula, 46 received a combination of crystalloids and colloids and in 6 patients the resuscitation regimen was not able to be determined. The aetiology, age distribution, sex ratio, severity of burns and length of stay in hospital did not alter significantly over the study period. The number of burns admissions to PICU increased, as did their duration of intubation and ICU stay. The hospital-recommended resuscitation formula consistently underestimated the fluid volume required for adequate resuscitation. No statistically significant difference in adverse effects was found between the resuscitation groups. This study is unable to recommend a definitive approach to the fluid resuscitation of burns shock in paediatrics and the best approach is one of meticulous fluid resuscitation titrated on clinical effect. 相似文献
79.
Vivian Khamis 《Journal of traumatic stress》1993,6(4):555-559
The current study aimed to assess the prevalence of PTSD among Palestinians who sustained serious bodily injuries during theintifada, as well as to delineate factors having an effect on the development and attenuation of PTSD symptomatology. Results indicated evidence of high prevalence of PTSD among the injured. No significant differences in PTSD prevalence for demographic, situational, and trauma-related variables were found except for the age factor. Prevalence of PTSD among adolescents was significantly higher than among adults. It seemed that the injury itself was so intensely overwhelming that the other variables were overshadowed. Implications for further research and stress management techniques were discussed. 相似文献
80.
Superior mesenteric artery is more important than inferior mesenteric artery in maintaining colonic mucosal perfusion and integrity in rats 总被引:1,自引:0,他引:1
Dr. Felix W. Leung MD Kenny C. Su MD Jose M. Pique MD Gerard Thiefin MD Edward Passaro Jr MD Paul H. Guth MD 《Digestive diseases and sciences》1992,37(9):1329-1335
Mucosal hemodynamics (by reflectance spectrophotometry) and mucosal damage (by histologic examination) following acute colonic ischemia were evaluated in different anatomic locations in the colon of anesthetized rats. The reflectance spectrophotometer provides an index of mucosal hemoglobin concentration (IHB) and an index of oxygen saturation of hemoglobin (ISO2). The patterns of ischemia without congestion (IHB, ISO2) during superior mesenteric artery occlusion, and ischemia with congestion (IHB, ISO2) during portal vein occlusion, previously demonstrated in the stomach and duodenum, are also applicable to the colon. The significant linear correlations between changes (as percent of baseline) in IHB, ISO2, and hydrogen gas clearance suggest that changes in these indices are adequate indicators of changes in colonic mucosal perfusion. Superior mesenteric artery ligation produced significant reductions in both indices, and an increase in damage in the mucosa of the cecum, transverse colon, splenic flexure, and left colon, but not the rectum. Inferior mesenteric artery ligation produced only slight reduction in these indices and minimal damage only in the mucosa of the splenic flexure. These results support the hypothesis that the superior mesenteric artery is more important than the inferior mesenteric artery in maintaining colonic perfusion and colonic mucosal integrity in the rat.Supported by the American Society for Gastrointestinal Endoscopy Career Development Award (H850208, H870212), Veterans Administration Medical Research Funds; and in part by research grants (0162-01, 0162-02; 0291-01) from the Smokeless Tobacco Research Council, Inc.; and by funds provided by the Cigarette and Tobacco Surtax Fund of the State of California through the Tobacco Related Disease Research Program of the University of California. 相似文献