全文获取类型
收费全文 | 1359篇 |
免费 | 41篇 |
国内免费 | 27篇 |
专业分类
耳鼻咽喉 | 29篇 |
儿科学 | 32篇 |
妇产科学 | 19篇 |
基础医学 | 94篇 |
口腔科学 | 38篇 |
临床医学 | 186篇 |
内科学 | 102篇 |
皮肤病学 | 4篇 |
神经病学 | 35篇 |
特种医学 | 75篇 |
外科学 | 288篇 |
综合类 | 172篇 |
预防医学 | 103篇 |
眼科学 | 18篇 |
药学 | 57篇 |
中国医学 | 138篇 |
肿瘤学 | 37篇 |
出版年
2023年 | 14篇 |
2022年 | 45篇 |
2021年 | 56篇 |
2020年 | 47篇 |
2019年 | 31篇 |
2018年 | 43篇 |
2017年 | 41篇 |
2016年 | 45篇 |
2015年 | 49篇 |
2014年 | 71篇 |
2013年 | 66篇 |
2012年 | 48篇 |
2011年 | 102篇 |
2010年 | 103篇 |
2009年 | 63篇 |
2008年 | 80篇 |
2007年 | 56篇 |
2006年 | 42篇 |
2005年 | 65篇 |
2004年 | 44篇 |
2003年 | 50篇 |
2002年 | 28篇 |
2001年 | 34篇 |
2000年 | 16篇 |
1999年 | 12篇 |
1998年 | 17篇 |
1997年 | 12篇 |
1996年 | 5篇 |
1995年 | 10篇 |
1994年 | 11篇 |
1993年 | 6篇 |
1992年 | 10篇 |
1991年 | 4篇 |
1990年 | 4篇 |
1989年 | 7篇 |
1988年 | 3篇 |
1987年 | 8篇 |
1986年 | 5篇 |
1985年 | 8篇 |
1982年 | 3篇 |
1981年 | 3篇 |
1980年 | 7篇 |
1978年 | 3篇 |
1977年 | 5篇 |
1975年 | 4篇 |
1974年 | 7篇 |
1973年 | 8篇 |
1972年 | 5篇 |
1971年 | 5篇 |
1969年 | 4篇 |
排序方式: 共有1427条查询结果,搜索用时 15 毫秒
51.
52.
胸部双能减影与常规数字X线摄影对信号检出效能的比较 总被引:2,自引:0,他引:2
目的比较双能减影(DES)与常规数字X线摄影(CDR)对信号的检出效能。方法将200个直径为4mm塑料小球作为信号分别置于塑料板和健康志愿者右胸上部摄取CDR和DES片。由3位放射科医师用5等级判别法各自独立阅片,用ROCkit软件对观察结果进行ROC曲线分析。结果当信号置于塑料板上时,CDR和DES的Az值分别为0.9931和0.9879,P值为0.4851(双尾)>0.05,差异无统计学意义。当信号置于右胸上部时,CDR和DES的Az值分别为0.7276和0.8561,P值为0.0002(双尾)<0.01,差异有统计学意义。结论DES可以去除肋骨对胸部信号的遮挡,使DES对胸部信号的检出能力明显高于CDR,提示DES在胸部的应用具有良好的前景。 相似文献
53.
Our aim was to compare the quality of pelvicalyceal visualization on computed tomography (CT) urography using a small intravenous contrast material dose, hydration, and high-resolution multidetector CT (MDCT) with that of conventional helical CT. The test (MDCT) group (49 consecutive patients, 98 kidneys) was scanned 5 min following an intravenous bolus of 30 ml of iodinated contrast material. The control (helical CT) group (50 consecutive patients, 95 kidneys) was scanned 5 min following injection of 120–150 ml of intravenous contrast material. Enhancement and quality of calyceal detail were measured using a five-scale grading system (1 for no detail, 5 for cupped calyces). Calyceal attenuation was substantial in both groups (more than 220 Hounsfield units, HU) but less in the test group compared with the control group (mean 475 and 920 HU, respectively), p<0.0001. In the test group, the calyceal attenuation was less than 500 HU in the majority of cases (65/98 kidneys), while the opposite was true for the control group, where calyceal attenuation was more than 750 HU in 50/95 kidneys (p<0.001). The quality of calyceal detail was 3.4/5 in the test group compared with 1.8/5 in the control group (p<0.0001). The combination of hydration, low-contrast dose, and the high image resolution achieved with MDCT significantly improves calyceal visualization in CT urography. 相似文献
54.
目的:探讨可调脉宽倍频Nd:YAG532nm激光联合皮肤再生技术治疗红色增生性瘢痕的疗效.方法:总结我科采用可调脉宽倍频Nd:YAG532nm波长激光联合皮肤再生技术治疗红色增生性瘢痕的病例,激光治疗参数:脉宽为20ms~40ms,能量密度为24~40J/cm2,光斑直径为3mm,分别对手术切口条形瘢痕和挫伤及烧烫伤后片状瘢痕的治疗效果进行评价.结果:红色瘢痕每次经激光加皮肤再生技术治疗后症状和体征都减轻,4次治疗后手术切口条形瘢痕的总有效率为100%,显效率为96%,挫伤及烧烫伤后片状瘢痕的总有效率为90%,显效率为70%.结论:可调脉宽倍频Nd:YAG532nm激光联合皮肤再生技术治疗红色增生性瘢痕的疗效良好. 相似文献
55.
56.
Reinforced silicone elastomer sheeting,an improved method of temporary abdominal closure in damage control laparotomy 总被引:5,自引:0,他引:5
BACKGROUND: The ability to massively transfuse and resuscitate critically ill surgical patients has resulted in unprecedented survival and a new set of complications including abdominal compartment syndrome (ACS) and the "unclosable" abdomen. Traditional methods of temporary abdominal closure have met with several limitations, not the least of which is a marked delay in achieving definitive fascial closure. Since 1991, we have consistently used reinforced silicone elastomer (Silastic) sheeting as a form of temporary abdominal closure in these settings. We report our results using this technique in a large cohort of critically ill surgical patients. METHODS: All patients undergoing silicone elastomer temporary abdominal closure since 1991 were identified and their charts abstracted for principal diagnosis and indication for temporary abdominal closure, fluid requirements, number of operations, and time to fascial closure. Time to definitive closure in the respective groups was analyzed using Kaplan-Meir survival curves and the Wilcoxon rank-sum test. Odds ratios for death were analyzed using logistic regression. RESULTS: One hundred thirty-four patients underwent temporary abdominal closure with silicone elastomer over this period and only 62% (83) survived their hospital admission. Trauma and ruptured abdominal aortic aneurysm were the most frequent diagnoses. The most frequent indication was edema precluding abdominal closure. The mean crystalloid and blood requirements in the 24 hours preceding temporary abdominal closure were 21 +/- 16 L and 15 +/- 11 U, respectively. Of survivors, 75% (63 of 83) achieved fascial closure during their index admission. The median time to fascial closure in patients ultimately closed was 5 days. The median time to closure and the proportion of patients ultimately closed varied with the indication for closure with an earlier and greater chance of success in patients who could not tolerate closure (ACS) or could not be closed primarily (edema). Age-adjusted mortality was 5 times (95% confidence interval: 2 to 13) higher in patients developing ACS. CONCLUSIONS: Nylon reinforced silicone elastomer is a safe, reliable material for temporary abdominal closure in severely ill patients. Primary fascial closure can be obtained in a timely fashion in the majority of patients. The success of obtaining definitive fascial closure depends on the indication for temporary abdominal closure, with visceral edema and ACS having the highest likeliest of early success. 相似文献
57.
Andrea Ruggeri Angelo Pichierri Nicola Marotta Roberto Tarantino Roberto Delfini 《European spine journal》2012,21(2):364-372
The objective of this study was to describe step by step our surgical technique of laminotomy and analyze our series with
regard to spinal deformities (risk and predisposing factors), postoperative pain and rate of postoperative contusions. Data
regarding patients who underwent our technique of laminotomy (N = 40, mean follow-up: 52 ms) (N = 40) between 2002 and 2006 were retrospectively evaluated. The technique used is illustrated in depth. Chronic pain was
present in 30% with a mean score of 3/10 cm (Graphic Rating Scale). Postoperative kyphoses occurred in three patients, all
below 35 years of age and with laminotomies which involved C2 and/or C7. None of these deformities required further surgical
treatment because they were self-limiting or asymptomatic at a mean follow-up of 52 months. Based on the results, our technique
proved to be safe and effective in terms of late deformities, blood loss, early and chronic postoperative pain and protection
from postoperative accidents over the surgical site. 相似文献
58.
《Gait & posture》2020
IntroductionInjury prevention programs for athletes are still limited by a lack of understanding of specific risk factors that can influence injuries within different sports. The majority of studies on volleyball have not considered the movement patterns when moving in different directions or in planned and unplanned block jump-landings.MethodsThis study investigated all planes mechanics between the lead and trail limb when moving in dominant and non-dominant directions, for both planned and unplanned jump-landings in thirteen semi-professional female volleyball players. Ankle, knee and hip joint kinematics, kinetics and joint stiffness were recorded.ResultsOur results showed statistically significant differences between the lead limb and the trail limb in the hip flexion angles, moments and velocity; in the knee flexion angles, moments, stiffness, power and energy absorption and in the ankle dorsiflexion, power and energy absorption, showing a tendency where the lead limb has a higher injury risk than the trail limb. When considering planned versus unplanned situations, there were statistically significant differences in knee flexion angles, moments, power and energy absorption; and hip contact angle, flexion angular velocity and energy absorption, with musculoskeletal adaptations in the planned situations.DiscussionIt appears that the role of the limb, either lead or trail, is more important than the limb dominance when performing directional jump-landings, with the lead limb having a higher implication on possible overuse injuries than the trail limb. Furthermore, planned movements showed a difference in strategy indicating greater implications to possible overuse injuries than in the unplanned situations which may be associated with more conscious thought about the movements.ConclusionCoaches should consider unilateral coordination training in both landing directions for the lead and trail limb, and should adapt training to replicate the competition environment, using unplanned situations to minimize asymmetries to might reduce injury risks. 相似文献
59.
Anna-Liisa Svedström-Oristo Terttu Pietilä Ilpo Pietilä Hans Helenius Pentti Alanen Juha Varrela 《Acta odontologica Scandinavica》2013,71(3):160-166
There is no general agreement on criteria that could be applied to distinguish between orthodontically acceptable and non-acceptable occlusions after the completion of dental development. The aim of the present study was to analyse morphological and functional features that could be used as an index to define an acceptable occlusion in young adults. Three expert panels representing specialists in orthodontics and stomatognathic physiology participated in a modified Delphi method. Each panel responded to a questionnaire concerning the usefulness of various occlusal features, and a set of characteristics was selected on the basis of the responses; thereafter, applicability of the chosen characteristics and their cutoffs for an acceptable-non-acceptable dichotomy was tested clinically. To obtain a consensus level of 100%, the last panel session was completed with a group discussion. Assessments made using the morphological criteria were compared with those made with the dental health component of the Index of Orthodontic Treatment Need. The selected morphological characteristics consisted of overjet, overbite, canine relationship, crossbite, scissors bite and midline deviation. The functional evaluation comprised assessments of discrepancy between the centric relation and the intercuspal position, working- and non-working-side contacts and protrusion contacts. The dental health component and our morphological criteria showed different sensitivity to contact point displacements, interdigitation in buccal segments and increased overbite. This study provides a set of morphological and functional indicators reflecting the current consensus opinion of Finnish professionals. Further studies are needed to analyse the reproducibility of assessment of the characteristics included. 相似文献
60.
磁外科是一门新型的外科技术体系,按照临床应用及原理的不同可以将磁外科技术分为以下5类:磁压榨技术、磁导航技术、磁锚定技术、磁悬浮技术以及磁示踪技术。不同的磁外科技术以其独特的优势创新了多种新型外科诊断和治疗方法,同时也优化了众多传统的外科诊疗手段。目前,磁外科技术已经在管腔重建、组织牵引暴露以及病变追踪等领域应用并展现出了良好的应用前景。在疝和腹壁外科手术中,磁外科技术具备优化某些手术操作的潜质,如在腔镜疝修补手术中利用磁力导航可以使得疝补片术中移动和固定更灵活,磁力锚定可以使得腔镜手术更微创,磁力牵引可以使腹壁组织游离更便捷,而磁力吻合可以使得腹腔感染控制和减容更安全。 相似文献