全文获取类型
收费全文 | 734篇 |
免费 | 47篇 |
国内免费 | 34篇 |
专业分类
儿科学 | 40篇 |
妇产科学 | 7篇 |
基础医学 | 80篇 |
口腔科学 | 24篇 |
临床医学 | 105篇 |
内科学 | 150篇 |
皮肤病学 | 15篇 |
神经病学 | 10篇 |
特种医学 | 115篇 |
外科学 | 99篇 |
综合类 | 16篇 |
预防医学 | 32篇 |
眼科学 | 2篇 |
药学 | 76篇 |
肿瘤学 | 44篇 |
出版年
2022年 | 2篇 |
2021年 | 7篇 |
2020年 | 5篇 |
2019年 | 4篇 |
2018年 | 14篇 |
2017年 | 5篇 |
2016年 | 9篇 |
2015年 | 15篇 |
2014年 | 30篇 |
2013年 | 30篇 |
2012年 | 30篇 |
2011年 | 20篇 |
2010年 | 29篇 |
2009年 | 40篇 |
2008年 | 16篇 |
2007年 | 35篇 |
2006年 | 22篇 |
2005年 | 17篇 |
2004年 | 15篇 |
2003年 | 10篇 |
2002年 | 16篇 |
2001年 | 10篇 |
2000年 | 19篇 |
1999年 | 23篇 |
1998年 | 39篇 |
1997年 | 40篇 |
1996年 | 39篇 |
1995年 | 26篇 |
1994年 | 36篇 |
1993年 | 22篇 |
1992年 | 8篇 |
1991年 | 6篇 |
1990年 | 8篇 |
1989年 | 20篇 |
1988年 | 25篇 |
1987年 | 13篇 |
1986年 | 15篇 |
1985年 | 11篇 |
1984年 | 8篇 |
1983年 | 8篇 |
1982年 | 13篇 |
1981年 | 15篇 |
1980年 | 12篇 |
1979年 | 3篇 |
1978年 | 4篇 |
1977年 | 2篇 |
1976年 | 8篇 |
1975年 | 7篇 |
1969年 | 1篇 |
1957年 | 1篇 |
排序方式: 共有815条查询结果,搜索用时 31 毫秒
71.
72.
保证输血时血清学方面的安全,首要的是对受血者与献血者ABO血型定型,血清学检查通常分两个步骤.正定型通常使用鼠源单克隆抗体检测红细胞表面是否存在A或B抗原.互补的实验即反定型,利用当红细胞上缺乏A或B抗原时,人群可天然产生相对应的抗体的原理,检测血清中是否存在抗-A或者抗-B抗体.确定了受血者红细胞表面的ABO抗原以及血浆中的抗体,便能确定血型,为其提供相合的血液. 相似文献
73.
保证输血时血清学方面的安全,首要的是对受血者与献血者ABO血型定型,血清学检查通常分两个步骤.正定型通常使用鼠源单克隆抗体检测红细胞表面是否存在A或B抗原.互补的实验即反定型,利用当红细胞上缺乏A或B抗原时,人群可天然产生相对应的抗体的原理,检测血清中是否存在抗-A或者抗-B抗体.确定了受血者红细胞表面的ABO抗原以及血浆中的抗体,便能确定血型,为其提供相合的血液. 相似文献
74.
A prospective study of symptomatic bacteremia following platelet transfusion and of its management 总被引:6,自引:0,他引:6
EK Chiu ; KY Yuen ; AK Lie ; R Liang ; YL Lau ; AC Lee ; YL Kwong ; S Wong ; MH Ng ; TK Chan 《Transfusion》1994,34(11):950-954
BACKGROUND: The danger of bacteremia due to contaminated platelets is not well known. There are also no established guidelines for the management of febrile reactions after platelet transfusion. STUDY DESIGN AND METHODS: To determine the risk of symptomatic bacteremia after platelet transfusion, 3584 platelet transfusions given to 161 patients after bone marrow transplantation were prospectively studied. Platelet bags were routinely refrigerated for 24 hours after transfusion. Septic work-up was initiated for a temperature rise of more than 2 degrees C above the pretransfusion value within 24 hours of platelet transfusion or a temperature rise of more than 1 degree C that was associated with chills and rigor. Diagnosis of bacteremia after platelet transfusion was made only when the pairs of isolates from the blood and the platelet bags were identical with respect to their biochemical profile, antibiotic sensitivity, serotyping, or ribotyping. RESULTS: Thirty-seven febrile reactions, as defined above, occurred. Bacteremia subsequent to platelet transfusion was diagnosed in 10 cases. There was a 27-percent chance (95% CI, 15–43%) that these febrile reactions represented bacteremia that resulted from platelet transfusion. For a subgroup of 19 patients with a temperature rise of more than 2 degrees C, the risk of bacteremia was 42 percent (95% CI, 23–64%). Septic shock occurred in 4 of the 10 bacteremic patients. A rapid diagnosis was possible because the involved bacteria were demonstrated by direct Gram stain of the samples taken from the platelet bags of all 10 patients. CONCLUSION: Significant febrile reactions after platelet transfusion are highly likely to be indicative of bacteremia. Routine retention of platelet bags for subsequent microbiologic study was useful in the investigation of these febrile reactions. Empiric antibiotic therapy is indicated. 相似文献
75.
乙型肝炎病毒基因的整合机制及对宿主的影响 总被引:1,自引:0,他引:1
乙型肝炎病毒是导致慢性肝炎、肝纤维化、肝细胞癌的主要病因,目前认为乙型肝炎病毒基因整合在其致病机制中具有重要作用,本文试就该领域内目前研究成果做一综述. 相似文献
76.
77.
MH Sun G Mechtersheimer P Moellera CH Herfarth MV Knebel Doeberitz HK Scharkert T Lehnert J Gebert 《World journal of gastroenterology : WJG》2000,6(3)
AIM To study the clonality of the esophageal carcinosarcoma by using molecular approaches.METHODS Two esophageal carcinosarcomas were included in the study. Tumor area from dysplasticlesion, squamout cell carcinoma, basaloid cell carcinoma and spindle cell elements were microdissectedseparately. Each element was analyzed with 14 microsatellite markers and direct sequenced for p53 gene andras gene mutation.RESULTS Both tumors displayed a typical histologic feature of carcinosarcoma. Both cases showed thedivergent differentiation by immunohistochemistry study. In case 1 the identical LOH at p53 and hMLH1 lociwas detected. The heterogenous LOH was detected only in carcinosarcoma at RB1 and BRCA1 loci, whilethe LOH at ACTC locus was seen only in sarcoma. The same mutation of the splice site of exon 6-intron 6displayed in the two tumor elements. In case 2, a coordinate LOH at RB locus was demonstrated in threetypes of tumor elements: sqamous carcinoma, basaloid carcinoma and spindle cell element. A heterogenousLOH was seen only in spindle cells at TAP1 locus. No mutation in exon 5-8 of p53 gene has been found incase 2. No mutation of K-ras gene was found.CONCLUSION Although the different differentiation, the two elements of esophageal carcinosarcoma mayhave a single clonality. The p53 gene mutation occurred before the two differentiation directions switched.The distinct molecular genotype can be determined through molecular biological analysis. The microsatelliteprofiling can serve as an approach to find out which genetic alteration occurs before or after thedifferentiation is determines. 相似文献
78.
卒中是一种常见、严重的疾病,仅美国每年的新发病例就高达795000例,并已成为全世界人类死亡和残疾的主要病因。10年前,重组型组织纤溶酶原激活剂(recombinant tissue plasminogen activator,rt—PA)被批准用于治疗急性缺血性卒中。rt—PA应用指南建议,应在卒中发病后3h内静脉给予rt—PA,给药前应行头部CT检查,排除颅内出血。 相似文献
79.
急性缺血性卒中影像学检查的建议——美国心脏协会的科学声明(中) 总被引:1,自引:0,他引:1
2.3核磁共振血管成像(MRA)
2.3.1背景和方法:在头部MRI检查中常结合MRA,用于急性卒中患者病情评估以指导治疗决策的制定^[19]。日前,有几种不同的MRA技术用于脑血管成像,包括二维时间飞跃(timeof-flight,TOF)序列、三维TOF序列、 相似文献
80.