全文获取类型
收费全文 | 1326篇 |
免费 | 67篇 |
国内免费 | 35篇 |
专业分类
耳鼻咽喉 | 21篇 |
儿科学 | 95篇 |
妇产科学 | 26篇 |
基础医学 | 131篇 |
口腔科学 | 37篇 |
临床医学 | 145篇 |
内科学 | 262篇 |
皮肤病学 | 35篇 |
神经病学 | 56篇 |
特种医学 | 198篇 |
外科学 | 142篇 |
综合类 | 27篇 |
预防医学 | 99篇 |
眼科学 | 16篇 |
药学 | 92篇 |
中国医学 | 3篇 |
肿瘤学 | 43篇 |
出版年
2023年 | 4篇 |
2022年 | 11篇 |
2021年 | 20篇 |
2020年 | 16篇 |
2019年 | 29篇 |
2018年 | 23篇 |
2017年 | 21篇 |
2016年 | 17篇 |
2015年 | 27篇 |
2014年 | 28篇 |
2013年 | 52篇 |
2012年 | 48篇 |
2011年 | 44篇 |
2010年 | 60篇 |
2009年 | 59篇 |
2008年 | 45篇 |
2007年 | 58篇 |
2006年 | 45篇 |
2005年 | 63篇 |
2004年 | 44篇 |
2003年 | 35篇 |
2002年 | 33篇 |
2001年 | 43篇 |
2000年 | 31篇 |
1999年 | 34篇 |
1998年 | 52篇 |
1997年 | 51篇 |
1996年 | 50篇 |
1995年 | 33篇 |
1994年 | 40篇 |
1993年 | 35篇 |
1992年 | 23篇 |
1991年 | 19篇 |
1990年 | 14篇 |
1989年 | 25篇 |
1988年 | 50篇 |
1987年 | 22篇 |
1986年 | 18篇 |
1985年 | 30篇 |
1984年 | 6篇 |
1983年 | 4篇 |
1982年 | 6篇 |
1981年 | 9篇 |
1980年 | 8篇 |
1979年 | 7篇 |
1978年 | 5篇 |
1977年 | 7篇 |
1976年 | 15篇 |
1975年 | 4篇 |
1969年 | 1篇 |
排序方式: 共有1428条查询结果,搜索用时 15 毫秒
1.
2.
M Ardigo I Malizewsky ML Dell'Anna E Berardesca M Picardo 《Journal of the European Academy of Dermatology and Venereology》2007,21(10):1344-1350
BACKGROUND: Vitiligo is the most common pigmentary disorder with a global incidence from 0.1% to 2% in different geographical areas. Histopathology and histochemistry have shown the reduction of melanocytes in achromic patches, but microscopic changes of lesional and non-lesional skin are still not completely understood. Reflectance confocal microscopy (RCM), based on the different light reflectance index of cutaneous structures, allowed in vivo, en face microscopic evaluation of superficial skin layers with a resolution similar to skin histology. AIM: The purpose of this study was to evaluate RCM features of lesional and non-lesional skin of vitiligo patients. Moreover, re-pigmented areas were taken into consideration in order to evaluate melanocyte response to ultraviolet B (UVB) radiation. SUBJECTS AND METHODS: Sixteen patients of different phototypes affected by active non-segmental vitiligo and 10 controls were enrolled in the study. In vivo skin imaging was done using a commercially available RCM (Lucid, Vivascope 1500. Re-pigmented areas from 6 to 16 patients (after UVB narrow-band therapy) were also examined. RESULTS: Vitiligo lesions showed the disappearance of the bright rings normally seen at the dermo-epidermal junction. Moreover, non-lesional skin of vitiligo patients showed unexpected changes as the presence of half-rings or scalloped border-like features of the bright papillary rings. In re-pigmented areas after UVB narrow band therapy, the presence of activated, dendritic melanocytes was seen. CONCLUSIONS: Considering our results, and following further studies, RCM clinical applications could be used in the therapeutic monitoring and evaluation of the evolution of vitiligo. 相似文献
3.
4.
高效液相色谱法测定右旋儿茶素血浆浓度及药代动力学参数 总被引:1,自引:0,他引:1
本文建立了体液中右旋儿茶素的RP-HPLC测定方法。采用C_(18)键合相硅胶为填料的固相提取柱进行样品预处理,右旋儿茶素的提取回收率为79.8%.应用二极管阵列检测器对色谱峰纯度进行鉴定。该法精密度好,方法回收率近100%,日内、日间的变异系数为2.4~5.6%,血浓69.6~1160 ng/ml范围内呈线性关系,r=0.9993。家兔静注右旋儿茶素18mg/kg,其药代动力学过程符合二室模型,分布相半衰期为0.129 h,消除相半衰期为1.19h。 相似文献
5.
Carcinoma of the hepaticopancreatic ampullar region: role of US 总被引:3,自引:0,他引:3
Hepaticopancreatic ampullar tumors are so called because they are located at the confluence of the bile duct, pancreatic duct, and duodenum. Jaundice is an early sign of the disease and often leads to early diagnosis and favorable prognosis compared with other tumors that occur in this area. Of eight patients who underwent ultrasound (US) in the past 5 years, six (75%) were found to have tumor. The sizes of the tumors ranged from 1.6 to 2 cm. An intraluminal, polypoid mass in the distal part of the common bile duct was seen in four patients. In the other two patients, a sharply delineated mass gave rise to abrupt termination of the distal duct. Improved US resolution, more experience with this modality, and accurate diagnosis of these tumors with US will contribute to improved detection and prompt treatment. 相似文献
6.
A Muoz A I Ballesteros J A Brandariz Castelo 《AJNR. American journal of neuroradiology》1998,19(3):496
We report the sudden development of an inflammatory process thought to be of the floor of the mouth with subsequent involvement of the respiratory airway. MR imaging showed an enhancing posterior lingual lesion, consistent with an abscess. Immediate surgical drainage relieved the symptoms. MR imaging allowed accurate diagnosis, which was essential for surgical planning in a condition that was otherwise difficult to diagnose. 相似文献
7.
Hueber DM Franceschini MA Ma HY Zhang Q Ballesteros JR Fantini S Wallace D Ntziachristos V Chance B 《Physics in medicine and biology》2001,46(1):41-62
The frequency-domain multiple-distance (FDMD) method is capable of measuring the absolute absorption and reduced scattering coefficients of optically turbid media. Absolute measurement of absorption at two near-infrared (NIR) wavelengths makes possible the quantitation of tissue haemoglobin concentration and tissue haemoglobin oxygen-saturation (StO2). However, errors are introduced by the uncertainties of background absorption and the dissimilarities between real tissues and the simplified mathematical model on which these measurements are based. An FDMD-based tissue instrument has been used for the monitoring of tissue haemoglobin concentration and oxygenation in the brain of newborn piglets during periods of hypoxia and hyperoxia. These tissue haemoglobin saturation values were compared with arterial saturation (SaO2) and venous saturation (SvO2) measured by blood gas analyses. A linear correlation was observed between StO2 and the average of SaO2 and SvO2. However, StO2 is not equal to any fixed weighted average of SaO2 and SvO2 unless we introduce an effective background tissue absorption. The magnitude of the background absorption was about 0.08 cm(-1) at 758 nm and 0.06 cm(-1) at 830 nm, and it was nearly consistent between piglets. The origin of this 'effective' background absorption may be real, an artefact caused by the application of a simplified model to a complex sample, or a combination of factors. 相似文献
8.
González-Pinto A Ballesteros J Aldama A Pérez de Heredia JL Gutierrez M Mosquera F González-Pinto A 《Journal of affective disorders》2003,76(1-3):95-102
OBJECTIVE: An alternative to the categorical classification of psychiatric diseases is the dimensional study of the signs and symptoms of psychiatric syndromes. To date, there have been few reports about the dimensions of mania, and the existence of a depressive dimension in mania remains controversial. The aim of this study was to investigate the dimensions of manic disorder by using classical scales to study the signs and symptoms of affective disorders. METHODS: One-hundred and three consecutively admitted inpatients who met DSM IV criteria for bipolar disorder, manic or mixed were rated with the Young Mania Rating Scale (YMRS) and the Hamilton Depression Rating Scale (HDRS-21). A principal components factor analysis of the HDRS-21 and the YMRS was carried out. RESULTS: Factor analysis showed five independent and clinically interpretable factors corresponding to depression, dysphoria, hedonism, psychosis and activation. The distribution of factor scores on the depressive factor was bimodal, whereas it was unimodal on the dysphoric, hedonism and activation factors. Finally, the psychosis factor was not normally distributed. LIMITATIONS: Patients of the sample were all medicated inpatients. CONCLUSIONS: Mania seems to be composed of three core dimensions, i.e. hedonism, dysphoria and activation, and is frequently accompanied by a psychotic and a depressive factor. The existence of a depressive factor suggests that it is essential to evaluate depression during mania, and the distribution of the depressive factor supports the existence of two different states in mania. 相似文献
9.
Human mini-chromosomes in mouse embryonal stem cells 总被引:3,自引:2,他引:3
We have introduced human mini-chromosomes of 4 Mb and approximately 15 Mb
in size into mouse embryonal stem cells. Although these human mini-
chromosomes are stable in hamster and chicken cells, they re-arrange or
segregate aberrantly in the embryonal stem cells and are rapidly lost in
the absence of selection. However, one of the mini-chromosomes re-
arranged, acquired mouse centromeric sequences and was then stably
maintained for at least 60 population doublings in culture. This mini-
chromosome, which is 4 Mb in size, is a candidate for a mouse germ line
chromosome vector.
相似文献
10.