全文获取类型
收费全文 | 104646篇 |
免费 | 8724篇 |
国内免费 | 6121篇 |
专业分类
耳鼻咽喉 | 1113篇 |
儿科学 | 1544篇 |
妇产科学 | 2304篇 |
基础医学 | 12406篇 |
口腔科学 | 1949篇 |
临床医学 | 14014篇 |
内科学 | 16584篇 |
皮肤病学 | 895篇 |
神经病学 | 5673篇 |
特种医学 | 3529篇 |
外国民族医学 | 42篇 |
外科学 | 11237篇 |
综合类 | 14795篇 |
现状与发展 | 23篇 |
一般理论 | 20篇 |
预防医学 | 6119篇 |
眼科学 | 2864篇 |
药学 | 10701篇 |
56篇 | |
中国医学 | 4822篇 |
肿瘤学 | 8801篇 |
出版年
2024年 | 280篇 |
2023年 | 1503篇 |
2022年 | 3805篇 |
2021年 | 4972篇 |
2020年 | 3513篇 |
2019年 | 3232篇 |
2018年 | 3544篇 |
2017年 | 2923篇 |
2016年 | 2842篇 |
2015年 | 4407篇 |
2014年 | 5617篇 |
2013年 | 5009篇 |
2012年 | 7525篇 |
2011年 | 8265篇 |
2010年 | 4977篇 |
2009年 | 3815篇 |
2008年 | 5268篇 |
2007年 | 5524篇 |
2006年 | 5405篇 |
2005年 | 5699篇 |
2004年 | 3832篇 |
2003年 | 3399篇 |
2002年 | 3005篇 |
2001年 | 2441篇 |
2000年 | 2650篇 |
1999年 | 2703篇 |
1998年 | 1578篇 |
1997年 | 1481篇 |
1996年 | 1308篇 |
1995年 | 1161篇 |
1994年 | 982篇 |
1993年 | 635篇 |
1992年 | 998篇 |
1991年 | 805篇 |
1990年 | 684篇 |
1989年 | 600篇 |
1988年 | 593篇 |
1987年 | 529篇 |
1986年 | 420篇 |
1985年 | 330篇 |
1984年 | 208篇 |
1983年 | 159篇 |
1982年 | 85篇 |
1981年 | 98篇 |
1980年 | 83篇 |
1979年 | 115篇 |
1978年 | 54篇 |
1977年 | 56篇 |
1975年 | 44篇 |
1974年 | 45篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
151.
OBJECTIVE. In this article, we describe the implementation of a digital archive center for a radiology department in a 700-bed teaching hospital. MATERIALS AND METHODS. The archive center consists of two identical archive systems, each comprising five components: an archive server, a data-base server, an optical disk library, a stand-alone optical disk drive, and a communication network. An image management system controls the image traffic from acquisition devices to display stations. A fault-tolerant mechanism was built into the archive center to achieve a 100% uptime. RESULTS. The center has been in operation for over 6 months. We have not experienced a single total system failure during this period. It currently archives all digital images from three MR units and four CT scanners and selected images from three computed radiographic systems and two laser film digitizers. The center archives between 1.5 and 2.0 gigabytes of images per workday. CONCLUSION. With its built-in fault-tolerant mechanism, we believe that the implemented archive center is very reliable and is suitable for a radiology department to archive its digital images. 相似文献
152.
慢性肝病和肝癌中HCV核心区三种寡肽抗原的抗体检测 总被引:1,自引:0,他引:1
检测148例慢性肝病和肝癌患者血清中丙型肝炎病毒核心区3种寡肽抗原的抗体,结果显示其阳性率在慢性迁延型肝炎、慢性活动型肝炎、肝炎肝硬化和原发性肝癌患者分别为7.7%,23.1%,,23.5%和16.3%。在抗体阳性者中80%以上有乙型肝炎病毒感染证据,提示我国HBV和HVC重叠感染较为常见。 相似文献
153.
154.
The biomechanical effects of disc injury on flexion-extension were investigated in nine fresh porcine functional spinal units. Under 12 N-m in extension and 6 N-m in flexion, the range of motion among intact specimens were 23.11 degrees -33.29 degrees (mean = 26.07 degrees , SD = 3.25 degrees ), which shifted to 28.04 degrees -38.46 degrees (mean = 31.69 degrees , SD = 3.50 degrees ) when discs were injured. Similarly, the neutral zones among intact and disc injured specimens were 4.88 degrees -12.75 degrees (mean = 9.32 degrees , SD = 2.60 degrees ) and 9.50 degrees -24.43 degrees (mean = 16.80 degrees , SD = 4.69 degrees ) respectively. To obviate the differences between tested specimens, the changes of neutral zone and the range of motion after disc injury were normalized and expressed as ratios as compared to the same items before disc injury. The neutral zone ratio ranged from 1.29 to 3.18 (mean = 1.87, SD = 0.55, p < 0.01). For range of motion, it ranged from 1.13 to 1.42 (mean = 1.22, SD = 0.09, p < 0.01). The change of flexibility coefficient, however, was statistically insignificant in either flexion or extension. The model presented defines the range of motion, the neutral zone as well as the flexibility coefficient under a specific load. It suggests that major spinal instability can be elicited by a minimum flexion-extension moment, as reflected by a profound change of the neutral zone, after disc injury. 相似文献
155.
变应性亚败血症33例报告 总被引:1,自引:0,他引:1
本文报告33例变应性亚败血症,均以发热起病,伴有一过性皮疹和/或关节、肌肉酸痛,实验室检查以白细胞总数明显增高、血沉显著增快和粘蛋白增多为主要特点。本组病例初诊误诊率为82.8%,起病至确诊时间平均48d,提示本病早期确诊较难,应提高对本病的充分认识。 相似文献
156.
There is little information concerning the effects of passive exercise training in healthy humans. This prompted an investigation to evaluate muscle activity and the associated changes in strength and lean body mass resulting from a passive exercise program. Twenty-eight healthy volunteers, aged 26 to 44 years, participated in this six-week study. Lean body mass changes were evaluated by tetrapolar bioelectric impedance measurements, strength changes by isokinetic strength evaluation, and muscle activity by surface EMG techniques. Reproducible muscle activity was recorded in all three muscles studied during two of three preselected exercises. This involuntary muscle activity was attributed to fusimotor and postural reflexes. No significant change (p greater than .05), however, occurred in muscle strength or lean body mass at the end of the six weeks. Lack of these physiologic changes in light of the documented muscle activity is attributed to insufficient training effect. 相似文献
157.
目的 研究巢湖水有机提取物致突变性。方法 单细胞凝胶电泳技术测定鱼红细胞DNA损伤效应。结果 巢湖源水引起慧星细胞的百分率最高 (5 7.2 5 % ) ,滤前水最低 (2 7.6 3% ) ,出厂水经过二次加氯后慧星细胞的百分率有所上升 (4 4 .0 0 % )。结论 巢湖源水具有潜在致突变性 ,经混凝、活性炭吸附及沉淀处理后其DNA损伤作用有所下降 ,但氯化消毒可增加水中有机提取物的DNA损伤作用。 相似文献
158.
TuberculosisandSchistosomiasisarethemajorcontagiousdiseaseswhicharethemostdangeroustothepeople’shealth Inordertogetridofthem ,wemustlookforamoreusefulvaccine Bythetech niquesofmolecularbiology ,2 6 0 0 0DaGlutathionStransferase (GST) genewasclonedintotheE coli MycobacteriumtransferringandexpressionvectorpBCG 2 0 0 0totransformittoMycobacteriumsmeg matismc2 15 5 (MS)andBCGseparatelyinordertoconstructrMS Sj2 6GSTvaccineandrBCG Sj2 6GSTvaccine Inthisstudy ,theBALB/cmicewereimmu niz… 相似文献
159.
目的:研究失血性休克状态下骨骼肌缺血再灌注对休克发展的影响。方法:雌性家兔12只,随机等分为休克对照组(Ⅰ组)和休克伴双后肢缺血再灌注组(Ⅱ组)。戊巴比妥钠麻醉,气管切开,自主呼吸,并全身肝素化。经左颈外静脉,按1ml·kg-1·min-1的速度放血5分钟,停5分钟,以左颈总动脉MAP达4.0±0.2kPa为休克开始,此时Ⅱ组阻断腹主动脉末端,90分钟后松开。结果:休克后120分钟,血中TXB2、TXB2/6-keto-PGF1α、乳酸、酸性磷酸酶及Mg2+,Ⅱ组均显著高于Ⅰ组,而休克90分钟时,各值两组间无显著性差异。结论:失血性休克状态下肢体骨骼肌缺血再灌注可能对休克的发展产生不利影响。 相似文献
160.
X M Huang 《Health services management research》1994,7(1):2-8
Patient waiting time in outpatient clinics is often the major reason for patients' complaints about their experiences of visiting outpatient clinics. Therefore, patient satisfaction with waiting time plays a crucial role in the process of health quality assurance or quality management. This paper reports the results of a survey on patient attitude towards waiting in an outpatient surgery clinic. Generally patients appear reasonably satisfied if they wait no more than 37 minutes when arriving on time, and no more than 63 minutes when late for appointments. Patients coming up to 15 minutes early are prepared to take full responsibility for the extra waiting caused, but the patients coming even earlier intend to be seen earlier and are only prepared to wait 15 minutes longer than otherwise. The potential applications of patient attitude towards waiting in the quality assurance process, ie setting up waiting time limits and designing patient dispatching rules, are also discussed. 相似文献