全文获取类型
收费全文 | 921篇 |
免费 | 71篇 |
国内免费 | 46篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 56篇 |
妇产科学 | 20篇 |
基础医学 | 116篇 |
口腔科学 | 53篇 |
临床医学 | 136篇 |
内科学 | 231篇 |
皮肤病学 | 13篇 |
神经病学 | 46篇 |
特种医学 | 124篇 |
外科学 | 38篇 |
综合类 | 12篇 |
预防医学 | 54篇 |
眼科学 | 8篇 |
药学 | 72篇 |
1篇 | |
肿瘤学 | 55篇 |
出版年
2023年 | 10篇 |
2022年 | 12篇 |
2021年 | 18篇 |
2020年 | 17篇 |
2019年 | 16篇 |
2018年 | 20篇 |
2017年 | 16篇 |
2016年 | 18篇 |
2015年 | 31篇 |
2014年 | 30篇 |
2013年 | 41篇 |
2012年 | 25篇 |
2011年 | 29篇 |
2010年 | 28篇 |
2009年 | 28篇 |
2008年 | 24篇 |
2007年 | 52篇 |
2006年 | 24篇 |
2005年 | 32篇 |
2004年 | 26篇 |
2003年 | 23篇 |
2002年 | 28篇 |
2001年 | 16篇 |
2000年 | 18篇 |
1999年 | 18篇 |
1998年 | 45篇 |
1997年 | 52篇 |
1996年 | 56篇 |
1995年 | 44篇 |
1994年 | 32篇 |
1993年 | 32篇 |
1992年 | 4篇 |
1991年 | 11篇 |
1990年 | 7篇 |
1989年 | 15篇 |
1988年 | 24篇 |
1987年 | 19篇 |
1986年 | 14篇 |
1985年 | 15篇 |
1984年 | 6篇 |
1983年 | 8篇 |
1982年 | 9篇 |
1981年 | 9篇 |
1980年 | 11篇 |
1979年 | 2篇 |
1978年 | 4篇 |
1977年 | 8篇 |
1976年 | 2篇 |
1975年 | 5篇 |
1960年 | 1篇 |
排序方式: 共有1038条查询结果,搜索用时 15 毫秒
81.
BACKGROUND: Hospitals and blood centers throughout the United States use a variety of reagents and methods to perform pretransfusion testing. A survey was developed to determine the reagents and methods in use and their relative prevalence in different work settings. STUDY DESIGN AND METHODS: A national survey on pretransfusion testing was conducted. Surveys were distributed to state and regional blood bank associations, which then distributed them to hospitals and blood centers within their region. In most instances, the blood centers distributed the survey to the local hospitals. Completed surveys were returned to the authors for review, and all information was entered into a database for analysis. RESULTS: Analysis of the data shows that the majority of blood banks use monoclonal reagents for ABO testing and monoclonal-polyclonal blended reagents for Rh testing. The data show that anti-IgG and polyclonal antihuman globulin reagents are used almost equally for antibody screening (detection) tests and that most blood banks use a three-cell antibody-screening test. Slightly more than 50 percent of hospitals use an immediate-spin crossmatch in the absence of unexpected antibodies. CONCLUSION: A number of approved reagents and methods are used by blood bank laboratories for pretransfusion testing. Facility size (number of beds) and type tend to influence the choice of methods and reagents employed. This survey provides an opportunity for blood bank laboratories to compare their current practices with those of their peers. 相似文献
82.
DA Marcus L Scharff D Turk LM Gourley 《Cephalalgia : an international journal of headache》1997,17(8):855-862
A provocative double blind study of headache was performed using chocolate as the active agent and carob as the placebo. The chocolate and carob samples were formulated to duplicate products used in an earlier study (1) in which strong differential effects between the ability of chocolate and carob to trigger headache in migraine were shown. Sixty-three women with chronic headache (50% migraine, 37.5% tension-type, 12.5% combined migraine and tension-type) participated in the study. After 2 weeks of following a diet that restricted vasoactive amine-rich foods, each subject underwent double-blinded provocative trials with two samples of chocolate and two of carob presented in random order. Diaries were maintained by the subjects throughout the study, monitoring diet and headache. The results demonstrated that chocolate was not more likely to provoke headache than was carol in any of the headache diagnostic groups (2 (2) 0.36, p =0.83). Interestingly, these results were independent of subjects' beliefs regarding the role of chocolate in the instigation of headache (2 (1)=0.73, p =0.39). Headache diagnosis and the concomitant use of additional vasoactive amine-containing foods were also not associated with chocolate acting as a headache trigger. Thus, contrary to the commonly held belief of patients and physicians, chocolate does not appear to play a significant role in triggering headaches in typical migraine, tension-type, or combined headache sufferers. 相似文献
83.
胶体磷酸铬^32P关节腔内注射改善佐剂型关节炎大鼠的相关指标 总被引:1,自引:0,他引:1
目的:观察胶体磷酸铬32P关节腔内注射治疗大鼠佐剂型关节炎的效果。方法:实验于2006-07/09在南京市第一医院动物实验室完成。选择6~8周龄清洁级SD雌性大鼠30只,按随机数字表法分为3组,正常对照组、模型组、胶体磷酸铬32P治疗组,每组10只。大鼠左足跖皮内注射完全弗氏佐剂0.1mL免疫法制备佐剂型关节炎模型。胶体磷酸铬32P治疗组于造模后10d左踝关节腔内注射37GBq/L胶体磷酸铬32P0.02mL,即0.74MBq,正常对照组和模型组分别给予等量生理盐水左踝关节腔内注射。①每2周观察1次大鼠左踝关节左右径宽度。②关节炎指数评定采用关节炎评分法(0~4分),分数越高,症状越重。③于用药后2,4,6周采用99Tcm-MDP显像感兴趣区分析法计算大鼠左踝关节区和右胫腓骨的放射性计数比。④于用药后4,6周测定血清肿瘤坏死因子和白细胞介素1β水平。⑤于用药后4,6周观察大鼠滑膜组织和软骨组织病理学改变。结果:纳入大鼠30只,均进入结果分析。①用药后2周模型组大鼠左踝关节左右径宽度大于正常对照组[分别为(7.82±0.36),(5.89±0.35)mm],差异有显著性意义(t=12.16,P<0.001),胶体磷酸铬32P治疗组大鼠左踝关节左右径宽度大于模型组,差异无显著性意义(P>0.05)。用药后6周胶体磷酸铬32P治疗组大鼠左踝关节左右径宽度小于模型组[分别为(6.87±0.27),(7.25±0.26)mm],差异有显著性意义(t=2.87,P<0.05)。②用药后2周和4周胶体磷酸铬32P治疗组大鼠关节炎指数高于模型组,用药后6周胶体磷酸铬32P治疗组大鼠关节炎指数低于模型组,两组间差异均无显著性意义(P>0.05)。③用药后2周模型组大鼠感兴趣区放射性计数比高于正常对照组(分别为2.05±0.20,1.46±0.15),差异有显著性意义(t=7.46,P<0.001)。用药后6周胶体磷酸铬32P治疗组大鼠感兴趣区放射性计数比低于模型组(分别为1.52±0.18,1.78±0.24),差异有显著性意义(t=2.45,P<0.05)。④用药后4,6周模型组大鼠血清肿瘤坏死因子和白细胞介素1β水平高于正常对照组,差异有显著性意义[用药后4周分别为(2.039±0.344),(1.115±0.192)μg/L;(0.305±0.034),(0.192±0.041)μg/L,t=7.42,6.71,P<0.001。用药后6周分别为(1.694±0.305),(1.126±0.256)μg/L;(0.259±0.027),(0.191±0.019)μg/L,t=4.03,5.83,P<0.01,0.001]。用药后4,6周胶体磷酸铬32P治疗组在血清肿瘤坏死因子和白细胞介素1β水平与模型组比较,差异无显著性意义(P>0.05)。⑤用药后4周胶体磷酸铬32P治疗组和模型组滑膜组织增生和炎症细胞浸润均较明显;用药后6周胶体磷酸铬32P治疗组与正常对照组比较仍有滑膜组织增生和炎症细胞浸润,与模型组比较滑膜组织增生程度明显减轻,而炎症细胞浸润程度稍轻。用药后6周胶体磷酸铬32P治疗组大鼠左踝关节的软骨组织未见有异常改变。结论:胶体磷酸铬32P关节腔注射可减轻完全弗氏佐剂免疫大鼠受注射关节的滑膜增生程度,改善关节肿胀症状,疗效肯定。 相似文献
84.
Thrombosis in inflammatory bowel disease: clinical setting, procoagulant profile and factor V Leiden 总被引:7,自引:0,他引:7
Jackson LM; O'Gorman PJ; O'Connell J; Cronin CC; Cotter KP; Shanahan F 《QJM : monthly journal of the Association of Physicians》1997,90(3):183-188
Patients with inflammatory bowel disease have an increased frequency of
thromboembolism, and microvascular thrombosis has been proposed as a
contributory pathogenic factor. The mechanism of enhanced procoagulant
activity is not understood. We examined the clinical setting of
thromboembolic events in 52 patients with Crohn's disease or ulcerative
colitis, and assessed the procoagulant laboratory profile, including Factor
V Leiden, in a subset of 20 patients to identify procoagulant risk factors.
Patients who developed thrombosis tended to be young; 60% of thrombotic
events occurred in patients under 50 years. Multiple thromboembolic
episodes occurred in 13% and unusual sites of thrombosis (e.g.
intracardiac, cerebral, inominate veins) in 11%. No risk factor was
identifiable in 52% of cases and two-thirds of thromboses occurred in an
out-patient setting. The mortality rate was 8%. Evidence for inflammatory
disease activity was found in only 45% of patients with ulcerative colitis
at the time of the thromboembolic event, in contrast to 89% of those with
Crohn's disease. Assays for specific coagulation defects were negative in
all cases tested (protein S, C were normal in 17/17; anti-thrombin III,
anti-phospholipid antibodies and activated protein C resistance were
negative in 20/20, and only 1/20 patients was found to be heterozygous for
Factor V leiden. Thrombosis in inflammatory bowel disease is important
because it occurs in a young population, often in unusual sites, and has a
high mortality. The development of thrombosis is related to active
inflammatory disease in most patients with Crohn's disease but apparently
not in those with ulcerative colitis. Since approximately half of the
patients had no other identifiable risk factor, there remains a substantial
group of patients with IBD who develop thrombosis for unknown reasons.
相似文献
85.
Pritt BS Sloan LM Johnson DK Munderloh UG Paskewitz SM McElroy KM McFadden JD Binnicker MJ Neitzel DF Liu G Nicholson WL Nelson CM Franson JJ Martin SA Cunningham SA Steward CR Bogumill K Bjorgaard ME Davis JP McQuiston JH Warshauer DM Wilhelm MP Patel R Trivedi VA Eremeeva ME 《The New England journal of medicine》2011,365(5):422-429
86.
The potential of rapid, quantitative, and sensitive diagnosis has led to many innovative ‘lab on chip’ technologies for point
of care diagnostic applications. Because these chips must be designed within strict cost constraints to be widely deployable,
recent research in this area has produced extremely novel non-conventional micro- and nano-fabrication innovations. These
advances can be leveraged for other biological assays as well, including for custom assay development and academic prototyping.
The technologies reviewed here leverage extremely low-cost substrates and easily adoptable ways to pattern both structural
and biological materials at high resolution in unprecedented ways. These new approaches offer the promise of more rapid prototyping
with less investment in capital equipment as well as greater flexibility in design. Though still in their infancy, these technologies
hold potential to improve upon the resolution, sensitivity, flexibility, and cost-savings over more traditional approaches. 相似文献
87.
Patrick W Dielissen Ben JAM Bottema Petra Verdonk Toine LM Lagro-Janssen 《BMC medical education》2009,9(1):58
Background
We recently set standards for gender-specific medicine training as an integrated part of the GP training curriculum. This paper describes the programme and evaluation of this training. 相似文献88.
89.
Aníbal E Carbajo Carolina Vera Paula LM González 《International journal of health geographics》2009,8(1):44-10
Background
Oligoryzomys longicaudatus (colilargo) is the rodent responsible for hantavirus pulmonary syndrome (HPS) in Argentine Patagonia. In past decades (1967–1998), trends of precipitation reduction and surface air temperature increase have been observed in western Patagonia. We explore how the potential distribution of the hantavirus reservoir would change under different climate change scenarios based on the observed trends. 相似文献90.
Israeli RS Rosenberg SJ Saltzstein DR Gottesman JE Goldstein HR Hull GW Tran DN Warsi GM Lacerna LV 《Clinical genitourinary cancer》2007,5(4):271-277