全文获取类型
收费全文 | 2171篇 |
免费 | 134篇 |
国内免费 | 76篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 174篇 |
妇产科学 | 29篇 |
基础医学 | 253篇 |
口腔科学 | 61篇 |
临床医学 | 273篇 |
内科学 | 528篇 |
皮肤病学 | 78篇 |
神经病学 | 78篇 |
特种医学 | 397篇 |
外科学 | 109篇 |
综合类 | 46篇 |
预防医学 | 102篇 |
眼科学 | 20篇 |
药学 | 107篇 |
2篇 | |
中国医学 | 1篇 |
肿瘤学 | 120篇 |
出版年
2023年 | 5篇 |
2022年 | 7篇 |
2021年 | 12篇 |
2020年 | 16篇 |
2019年 | 20篇 |
2018年 | 36篇 |
2017年 | 28篇 |
2016年 | 30篇 |
2015年 | 45篇 |
2014年 | 51篇 |
2013年 | 61篇 |
2012年 | 41篇 |
2011年 | 47篇 |
2010年 | 92篇 |
2009年 | 89篇 |
2008年 | 59篇 |
2007年 | 92篇 |
2006年 | 62篇 |
2005年 | 69篇 |
2004年 | 34篇 |
2003年 | 27篇 |
2002年 | 31篇 |
2001年 | 42篇 |
2000年 | 35篇 |
1999年 | 36篇 |
1998年 | 131篇 |
1997年 | 155篇 |
1996年 | 131篇 |
1995年 | 109篇 |
1994年 | 116篇 |
1993年 | 99篇 |
1992年 | 35篇 |
1991年 | 42篇 |
1990年 | 39篇 |
1989年 | 56篇 |
1988年 | 55篇 |
1987年 | 42篇 |
1986年 | 50篇 |
1985年 | 49篇 |
1984年 | 27篇 |
1983年 | 15篇 |
1982年 | 24篇 |
1981年 | 30篇 |
1980年 | 25篇 |
1979年 | 5篇 |
1978年 | 8篇 |
1977年 | 18篇 |
1976年 | 25篇 |
1975年 | 14篇 |
1973年 | 3篇 |
排序方式: 共有2381条查询结果,搜索用时 46 毫秒
71.
72.
73.
W. Andonotopo M. Stanojevic A. Kurjak G. Azumendi JM Carrera 《The Ultrasound Review of Obstetrics & Gynecology》2004,4(2):103-114
The aim of this paper was to review the clinical applications of four-dimensional ultrasonography in the assessment of fetal behavior. With the use of a computerized database, articles on three-dimensional ultrasonography were reviewed. Several applications of dynamic three-dimensional ultrasonography have been reported, including imaging of fetal movements, facial expression and fetal hand movements. The importance of the assessment of fetal behavior by four-dimensional sonography is stressed. Four-dimensional sonography seems to be a useful imaging tool for clinical problem solving in perinatology, especially in observing the development of the central nervous system in utero. 相似文献
74.
75.
SB Cho JH Kim S Cho JM Park YK Park SH Oh 《Journal of the European Academy of Dermatology and Venereology》2011,25(1):64-67
Background The clinical characteristics of vitiligo in children and adolescents with an emphasis on thyroid dysfunction have only been reported in a few studies. Objective The purpose of this study was to examine the characteristics of children and adolescents with vitiligo and compare the incidence of thyroid dysfunction between them and controls without vitiligo at the same age. Methods A retrospective analysis of 324 Korean children and adolescents with vitiligo was performed. The results of thyroid function screening tests in them (n = 254) were compared with controls (n = 122). Results Of the total 324 children and adolescents with vitiligo, vitiligo vulgaris was the most common type (42.3%) and the most commonly involved site was the face (54.6%). A total of 15 of 254 (5.9%) patients screened for thyroid function were diagnosed with thyroid disease (four had Hashimoto’s thyroiditis; two, Graves’ disease; seven, subclinical hypothyroidism; and two, subclinical hyperthyroidism). None of the 50 patients with segmental vitiligo showed any thyroid dysfunction (P = 0.047). There was no significant difference in the incidence of thyroid disease between children and adolescents with vitiligo and the control group, in which seven of 122 (5.7%) showed thyroid dysfunction. Conclusion In this study, we demonstrated the characteristics of children and adolescents with vitiligo and also observed no significant difference in the incidence of thyroid disease between children and adolescents with vitiligo and the control group. 相似文献
76.
77.
78.
S. Guerra A. Lopez-Picado H. Muñoz J.M. Marín I. Lete O. Echevarria 《Clínica e investigación en ginecología y obstetricia》2012
Breech presentation occurs in 3-4% of pregnancies and is a routine indication for cesarean section. The external version is a maneuver that has been performed since Hippocrates’ time. Nevertheless, despite decreasing the cesarean section rate, this technique is only offered to a small percentage of patients due to lack of awareness and the shortage of experienced obstetricians. The success rate ranges from 40-74%. Factors that can influence the success of the maneuver are gestational age, the amniotic fluid index, presentation, and the location of the placenta. The use of tocolytics and effective analgesia can facilitate the maneuver and improve the success rate. When a standardized protocol is followed and the technique is performed by an experienced gynecologist, the external cephalic version has an excellent safety profile and is an effective option that avoids surgery. 相似文献
79.
80.
S Echevarria F Casafont M Miera J L Lozano F de la Cruz G San Miguel F Pons Romero 《Hepato-gastroenterology》1991,38(4):307-310
Natural killer (NK) cell activity against K562 cell line, and interleukin-2 (IL-2) activity in supernatants from lectin-activated PBMC cultures from 17 patients with acute hepatitis B in the early phase of illness were studied. These patients showed enhanced NK cytotoxicity and higher levels of IL2 activity as compared with control subjects. There was a positive correlation between cytotoxicity values and levels of IL2 activity. Furthermore, in the recovery phase of illness there was a tendency towards normalization in both parameters. When patients were divided in accordance with markers of HBV replication, HBV-DNA positive patients showed increased NK cell activity and IL2 levels as compared with the control group, whereas in HBV-DNA-negative patients no differences were found. However, no differences were found between patients with HBeAg and patients with anti-HBe. These results suggest that natural cytotoxicity is increased early in the course of acute hepatitis B, while NK cell activity returns to normal later, during convalescence. Enhanced NK cell activity appears to be secondary, at least in part, to increased production of IL2. Natural cytotoxicity may be one mechanism that controls the HBV infection before other cytotoxic mechanisms become fully operative. 相似文献