全文获取类型
收费全文 | 356篇 |
免费 | 18篇 |
国内免费 | 7篇 |
专业分类
儿科学 | 34篇 |
妇产科学 | 1篇 |
基础医学 | 39篇 |
口腔科学 | 5篇 |
临床医学 | 37篇 |
内科学 | 75篇 |
皮肤病学 | 17篇 |
神经病学 | 11篇 |
特种医学 | 55篇 |
外科学 | 26篇 |
综合类 | 6篇 |
预防医学 | 28篇 |
眼科学 | 16篇 |
药学 | 15篇 |
中国医学 | 2篇 |
肿瘤学 | 14篇 |
出版年
2022年 | 3篇 |
2021年 | 7篇 |
2020年 | 7篇 |
2019年 | 5篇 |
2018年 | 5篇 |
2017年 | 5篇 |
2016年 | 6篇 |
2015年 | 5篇 |
2014年 | 13篇 |
2013年 | 21篇 |
2012年 | 9篇 |
2011年 | 4篇 |
2010年 | 24篇 |
2009年 | 11篇 |
2008年 | 3篇 |
2007年 | 7篇 |
2006年 | 13篇 |
2005年 | 2篇 |
2004年 | 6篇 |
2003年 | 7篇 |
2002年 | 4篇 |
2001年 | 5篇 |
2000年 | 7篇 |
1999年 | 8篇 |
1998年 | 21篇 |
1997年 | 14篇 |
1996年 | 13篇 |
1995年 | 20篇 |
1994年 | 9篇 |
1993年 | 13篇 |
1992年 | 5篇 |
1991年 | 6篇 |
1990年 | 4篇 |
1989年 | 14篇 |
1988年 | 6篇 |
1987年 | 13篇 |
1986年 | 8篇 |
1985年 | 10篇 |
1984年 | 5篇 |
1983年 | 2篇 |
1982年 | 4篇 |
1981年 | 4篇 |
1980年 | 6篇 |
1979年 | 3篇 |
1977年 | 2篇 |
1971年 | 1篇 |
1966年 | 3篇 |
1961年 | 1篇 |
1960年 | 1篇 |
1959年 | 1篇 |
排序方式: 共有381条查询结果,搜索用时 15 毫秒
91.
Enhanced external counterpulsation
Extemal counterpulsation (ECP) was originally conceived to be a circulatory assist device to promote blood flow to areas of the heart muscle that were lacking adequate blood supply due to obstruction of the coronary artery. During ECP the lower extremities are compressed to squeeze both arterial and venous blood back to the heart during diastole, increasing coronary perfusion pressure and right ventricular filling. The compression is released during systole, 相似文献
Extemal counterpulsation (ECP) was originally conceived to be a circulatory assist device to promote blood flow to areas of the heart muscle that were lacking adequate blood supply due to obstruction of the coronary artery. During ECP the lower extremities are compressed to squeeze both arterial and venous blood back to the heart during diastole, increasing coronary perfusion pressure and right ventricular filling. The compression is released during systole, 相似文献
92.
93.
Three previously healthy infants presented with diarrhoea and pyrexia and deteriorated rapidly. Two patients had necrotizing bowel disease requiring aggressive surgical intervention. All survived. P. aeruginosa gastrointestinal infection in previously healthy children is an extremely rare condition with a high mortality. Ecthyma gangrenosum was present in over 60% of reported cases although often not recognized initially. A high index of clinical suspicion, including prompt recognition of ecthyma gangrenosum, is mandatory for an early diagnosis of P. aeruginosa gastrointestinal infection. Early diagnosis and treatment may improve the prognosis. 相似文献
94.
Different measures of the proportion of variation in a dependent variable explained by covariates are reported by different standard programs for logistic regression. We review twelve measures that have been suggested or might be useful to measure explained variation in logistic regression models. The definitions and properties of these measures are discussed and their performance is compared in an empirical study. Two of the measures (squared Pearson correlation between the binary outcome and the predictor, and the proportional reduction of squared Pearson residuals by the use of covariates) give almost identical results, agree very well with the multiple R2 of the general linear model, have an intuitively clear interpretation and perform satisfactorily in our study. For all measures the explained variation for the given sample and also the one expected in future samples can be obtained easily. For small samples an adjustment analogous to R2adj in the general linear model is suggested. We discuss some aspects of application and recommend the routine use of a suitable measure of explained variation for logistic models. 相似文献
95.
犬冠状动脉定量狭窄造成急性心肌缺血,观察巴曲酶(batroxobin)对冠脉循环及血流动力学的影响。结果显示,batroxobin可剂量依赖性地增加缺血心脏冠脉血流量,2BU·kg-1(0.1BU·kg-1·min-1)iv后40min,缺血犬冠脉流量比盐水对照组增加12%,此时小冠脉阻力由4.1±0.5降至3.2±0.5mmHg·min·ml-1,而大冠脉阻力无明显变化;给药后120min,上述作用仍然持续,且冠脉总阻力降低13%,左室压上升及下降最大速率与盐水对照组相比分别增大14%和16%。结果表明,batroXobin在冠脉低灌流状态下仍可降低小冠脉阻力,增加冠脉流量,这可能是其改善缺血犬冠状循环及心脏功能的机理之一。 相似文献
96.
目的:比较转换曲线分光光度法与6波长计算分光光度法的实用性。方法:分别用转换曲线分光光度法及
其改良法计算文献实例。结果:转换曲线分光光度法及其改良法对实例处理结果基本一致。结论:6波长计算分光
光度法在一定条件下比转换曲线分光光度法操作更简单,实用。 相似文献
97.
CK Hari MS FRCS J Hanif FRCS A Frosh FRCS 《International journal of clinical practice》2001,55(8):571-572
A 23-year-old female with progressive sensorineural hearing loss developed widespread blistering eruptions while under evaluation for the hearing loss. The lesions showed findings characteristic of linear IgA disease (LAD) on histochemical studies. Linear IgA disease is a dapsone responsive autoimmune subepidermal blistering disease characterised by linear IgA deposits in the basement membrane zone. The complete spectrum of this systemic disease is still not clear and this is the first report of association between LAD and sensorineural deafness. 相似文献
98.
黄花远志根化学成分的分离和结构鉴定 总被引:16,自引:0,他引:16
从黄花远志(Polygala arilata Buch-Ham.)根中分离得到7个化合物,根据光谱(UV,IR,MS,1HNMR,DIFNOE和13CNMR)解析和理化性质,分别鉴定为1-甲氧基-2,3-亚甲二氧基口山酮(I)、1,7-二羟基-2,3-亚甲二氧基口山酮(II)、1,6,7-三羟基-2,3-二甲氧基口山酮(II)、对羟基苯甲酸(IV)、远志醇(V)、豆甾醇(VI)、豆甾醇β-D-吡喃葡萄糖甙(VII)。其中,I和II为新化合物,VI和VI为首次从该植物中分得。化合物I~II有抑制醛糖酶的作用。 相似文献
99.
Anterior temporal lobes and hippocampal formations: normative volumetric measurements from MR images in young adults 总被引:25,自引:0,他引:25
Jack CR Jr; Twomey CK; Zinsmeister AR; Sharbrough FW; Petersen RC; Cascino GD 《Radiology》1989,172(2):549-554
Volumes of the right and left anterior temporal lobes and hippocampal formations were measured from magnetic resonance images in 52 healthy volunteers, aged 20-40 years. Subjects were selected by age, sex, and handedness to evaluate possible effect of these variables. Data were normalized for variation in total intracranial volume between individuals. Right-left asymmetry in the volumes of the anterior temporal lobes and hippocampal formations was a normal finding. The anterior temporal lobe of the non-dominant (right) hemisphere was larger than the left by a small (mean right-left difference, 2.3 cm3) but statistically significant amount (P less than .005) in right-handed subjects. No significant effect of age or sex was seen in normalized right or left anterior temporal lobe volume. The right hippocampal formation was larger than the left for all subjects by a small (mean right-left difference, 0.3 cm3) but statistically significant amount (P less than .001). No effect of age, sex, or handedness was seen in normalized hippocampal formation volumes. 相似文献
100.