全文获取类型
收费全文 | 11681篇 |
免费 | 577篇 |
国内免费 | 226篇 |
专业分类
耳鼻咽喉 | 25篇 |
儿科学 | 196篇 |
妇产科学 | 154篇 |
基础医学 | 752篇 |
口腔科学 | 30篇 |
临床医学 | 1922篇 |
内科学 | 2763篇 |
皮肤病学 | 35篇 |
神经病学 | 763篇 |
特种医学 | 1258篇 |
外国民族医学 | 1篇 |
外科学 | 1615篇 |
综合类 | 1662篇 |
预防医学 | 297篇 |
眼科学 | 23篇 |
药学 | 639篇 |
6篇 | |
中国医学 | 107篇 |
肿瘤学 | 236篇 |
出版年
2024年 | 15篇 |
2023年 | 129篇 |
2022年 | 335篇 |
2021年 | 462篇 |
2020年 | 422篇 |
2019年 | 311篇 |
2018年 | 382篇 |
2017年 | 383篇 |
2016年 | 359篇 |
2015年 | 367篇 |
2014年 | 824篇 |
2013年 | 759篇 |
2012年 | 687篇 |
2011年 | 653篇 |
2010年 | 594篇 |
2009年 | 592篇 |
2008年 | 607篇 |
2007年 | 599篇 |
2006年 | 561篇 |
2005年 | 444篇 |
2004年 | 365篇 |
2003年 | 326篇 |
2002年 | 238篇 |
2001年 | 237篇 |
2000年 | 189篇 |
1999年 | 170篇 |
1998年 | 143篇 |
1997年 | 133篇 |
1996年 | 118篇 |
1995年 | 108篇 |
1994年 | 104篇 |
1993年 | 74篇 |
1992年 | 92篇 |
1991年 | 61篇 |
1990年 | 77篇 |
1989年 | 59篇 |
1988年 | 68篇 |
1987年 | 55篇 |
1986年 | 46篇 |
1985年 | 52篇 |
1984年 | 50篇 |
1983年 | 16篇 |
1982年 | 38篇 |
1981年 | 27篇 |
1980年 | 18篇 |
1979年 | 27篇 |
1978年 | 22篇 |
1977年 | 20篇 |
1976年 | 23篇 |
1975年 | 10篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Cholesterol atheromatous embolism: an increasingly recognized cause of acute renal failure 总被引:3,自引:1,他引:2
Scolari F.; Bracchi M.; Valzorio B.; Movilli E.; Costantino E.; Savoldi S.; Zorat S.; Bonardelli S.; Tardanico R.; Maiorca R. 《Nephrology, dialysis, transplantation》1996,11(8):1607-1612
BACKGROUND.: Cholesterol atheromatous embolism is a systemic disease resultingfrom cholesterol crystal embolization to many organs, includingthe kidney. Vascular surgery, vascular radiology investigationsand anticoagulation have been identified as inciting factors. METHODS.: Fifteen patients with extensive atherosclerosis, presentingwith simultaneous occurrence of acute renal failure and peripheralischaemic changes were diagnosed as having acute renal failuredue to cholesterol atheromatous embolism. RESULTS.: The patients, 12 men and three women, had an average age of65 years. In one patient, spontaneous occurrence of the diseasewas observed. An inciting factor was identified in 14 patients:aortography in 10, aortic surgery in two, and thrombolysis intwo. Clinical course of acute renal failure was quite variable.Four patients required dialysis; 11 were conservatively managed.All patients had concomitant skin lesions, including digitalmottling, cyanosis and gangrene of the toes, and livedo reticularisof the lower limb and abdomen. Eosinophilia was the most commonlaboratory abnormality. The diagnosis of cholesterol atheromatousembolism was confirmed by tissue examination in eight; in threeit was based on the finding of retinal cholesterol emboli; infourpatients it was made on clinical grounds. Seven patientsdied within 36 months. Death was most commonly from cardiaccauses. CONCLUSIONS.: Since the population at risk for cholesterol embolism is growingand the disease is iatrogenic in origin, we should expect todetect cholesterol embolism with greater frequency as causeof acute renal failure in the future. 相似文献
32.
为了探讨动脉分支处及小动脉端侧吻合处的血液流动方式,采用微循环电视显微镜成像技术,活体观察大鼠肠系膜微动脉分支区域血液流动方式和红细胞流变行为,研究动脉血流方向的改变对血流方式的影响。实验中观察到,在形态各异的大鼠肠系膜微动脉分支区域血液流态为稳定层流;红细胞通过不规则变形能很好地适应血管腔不同的几何形态,以保持血液流态的稳定。结果表明,微小动脉血流方向的改变未能在分支区域导致湍流发生,小动脉端侧吻合只是人为增加了侧支循环,同样不会导致血流紊乱和增加血栓形成的危险 相似文献
33.
矽肺患者肺功能与血气分析 总被引:1,自引:0,他引:1
以67名Ⅱ、Ⅲ期矽肺患做了肺功能(VC,FVC,FEV,FEV1/FVC,MVV,DLCO和血气分析(PaO2,PaCogm2,pH)。结果表明Ⅲ期矽肺肺功能较Ⅱ期矽肺降低,其中VC,FVC、MVV降低有显著差异,PaO2和pH随矽肺期别增加呈降低有显著差异。PaO2降低尤为明显,PaCO2呈增高趋势。肺功能与PaO2改变显著相关,与PaCO2和PH无相关关系。PaO2〈10kPa发生率与尘肺劳动 相似文献
34.
Venous air embolism during surgery is a rare but important complication and can be rapidly fatal. We present two cases of fatal air embolism in the prone position occurring in small children undergoing surgery for progressive scoliosis.
Venous air embolism is a rare complication in the prone position. This is thought to be because in this position there is virtually no gravitational gradient between the site of surgery and the right atrium.
The possible sites of entry of air and ways that this may be minimized are discussed. 相似文献
Venous air embolism is a rare complication in the prone position. This is thought to be because in this position there is virtually no gravitational gradient between the site of surgery and the right atrium.
The possible sites of entry of air and ways that this may be minimized are discussed. 相似文献
35.
静脉血气分析及其临床应用进展 总被引:2,自引:0,他引:2
动脉血气分析是严重心肺疾病和许多代谢性疾病的重要检测手段,在血流动力学稳定状态下,动、静脉血气的CO2气体含量和酸碱参数非常接近,但在循环功能衰竭等情况下,动、静脉血气出现分离现象,此时可能需同时作静脉血气。静脉血气分析对危重患者特别是循环衰竭的患者可以提供组织氧合和酸碱状态更切实的评价,并可能对有效复苏提供更好的指导。 相似文献
36.
64层螺旋CT三联检查在急性胸痛诊断中的应用 总被引:13,自引:0,他引:13
目的探讨64层螺旋CT(MSCT)三联检查显示急性胸痛患者肺动脉、胸主动脉和冠状动脉病变的能力及其临床应用价值。方法70例患者进行64层MSCT回顾性心电门控肺动脉、胸主动脉和冠状动脉联合检查。采用多平面重组(MPR)、最大密度投影(MIP)、曲面重组(CPR)及容积再现(VR)多种重组技术显示肺动脉、胸主动脉和冠状动脉,评价成像质量能否满足临床诊断需要。结果平均扫描时间(8.5±1.0)s,总对比剂用量100ml。肺动脉和主动脉增强后CT值均≥200HU者占95.7%(67/70);冠状动脉显影图像质量优的节段占85.8%(720/839),图像质量良的节段占8.6%(72/839),图像质量差的节段占5.6%(47/839)。共检出冠状动脉狭窄≥50%者20例,肺动脉栓塞2例,主动脉夹层2例。结论64层MSCT三联检查能够在8s左右1次扫描完成肺动脉、胸主动脉和冠状动脉检查,图像质量可以满足临床诊断需要,在急性胸痛病因诊断中具有很高的临床应用价值。 相似文献
37.
Michael S. Runyon MD Peter B. Richman MD Jeffrey A. Kline MD 《Academic emergency medicine》2007,14(1):53-57
Background Several clinical decision rules (CDRs) have been validated for pretest probability assessment of pulmonary embolism (PE), but the authors are unaware of any data quantifying and characterizing their use in emergency departments. Objectives To characterize clinicians' knowledge of and attitudes toward two commonly used CDRs for PE. Methods By using a modified Delphi approach, the authors developed a two‐page paper survey including 15 multiple‐choice questions. The questions were designed to determine the respondents' familiarity, frequency of use, and comprehension of the Canadian and Charlotte rules. The survey also queried the frequency of use of unstructured (gestalt) pretest probability assessment and reasons why physicians choose not to use decision rules. The surveys were sent to physicians, physician assistants, and medical students at 32 academic and community hospitals in the United States and the United Kingdom. Results Respondents included 555 clinicians; 443 (80%) work in academic practice, and 112 (20%) are community based. Significantly more academic practitioners (73%) than community practitioners (49%) indicated familiarity with at least one of the two decision rules. Among all respondents familiar with a rule, 50% reported using it in more than half of applicable cases. A significant number of these respondents could not correctly identify a key component of the rule (23% for the Charlotte rule and 43% for the Canadian rule). Fifty‐seven percent of all respondents indicated use of gestalt rather than a decision rule in more than half of cases. Conclusions Academic clinicians were more likely to report familiarity with either of these two specific decision rules. Only one half of all clinicians reporting familiarity with the rules use them in more than 50% of applicable cases. Spontaneous recall of the specific elements of the rules was low to moderate. Future work should consider clinical gestalt in the evaluation of patients with possible PE. 相似文献
38.
Ø. Lidegaard 《Acta neurologica Scandinavica》1987,75(6):427-433
The mortality of cerebrovascular diseases in Denmark was analysed for men and women 15-44 years of age, in a 14-year period before and after the appearance of oral contraceptives (OC) in 1966. 1,670 deaths were registered over 28 years, during which the female incidence of cerebrovascular deaths increased by 19% (P less than 0.025), while the male mortality was unchanged. Women showed a percentage increase in deaths from cerebral thromboembolic attacks (CTA) of 33%, men a fall of 14%. The increase of female CTA deaths was most pronounced in the young fertile group, the age group with a high OC use. A relative risk of CTA of 3.3-4.5 for OC users compared with non-users could explain the CTA trend difference between women and men. No other single risk factor responsible for the observed trends could be identified. Both women and men had a significant increase in the mortality of subarachnoidal hemorrhages, and a significant fall in the mortality of intracerebral hemorrhages. 相似文献
39.
多糖硫酸脂(PSS)治疗缺血性脑血管病临床观察和实验室研究 总被引:1,自引:0,他引:1
应用PSS治疗270例缺血性脑血管病并进行了临床、实验室以及动物试验的观察.总有效率为92.27%;显效率65.24%,与对照组相比较有显著性差异(P<0.005).实验室观察发现PSS有显著的抗凝血、降低血粘度,降低血脂及血管扩张作用.动物实验也说明了这一点. 相似文献
40.
Karl Lehner M.D. Maximilian Reiser Ulrich Gebhardt Andreas Heuck Jürgen Schaff 《Cardiovascular and interventional radiology》1987,10(2):71-74
In contrast to conventional film angiography, the perfusion pattern of hepatic arterial chemotherapy was consistently visualized
by DSA in 40 patients with implanted Infusaid pump or Port-A devices. Incomplete perfusion of a liver region by the cytotoxic
agent was recognized by DSA as accurately as by nuclide scintigraphy. Furthermore, DSA appeared to be more sensitive in determining
aberrantly perfused extrahepatic regions; this was especially true when there was a nonligated right hepatic artery. Specific
details of vascular lesions and associated complicating events also could be satisfactorily analyzed by DSA only. 相似文献