全文获取类型
收费全文 | 10277篇 |
免费 | 564篇 |
国内免费 | 40篇 |
专业分类
耳鼻咽喉 | 171篇 |
儿科学 | 353篇 |
妇产科学 | 247篇 |
基础医学 | 1367篇 |
口腔科学 | 222篇 |
临床医学 | 758篇 |
内科学 | 2550篇 |
皮肤病学 | 429篇 |
神经病学 | 770篇 |
特种医学 | 359篇 |
外科学 | 1454篇 |
综合类 | 41篇 |
一般理论 | 2篇 |
预防医学 | 806篇 |
眼科学 | 149篇 |
药学 | 526篇 |
中国医学 | 46篇 |
肿瘤学 | 631篇 |
出版年
2023年 | 60篇 |
2022年 | 143篇 |
2021年 | 336篇 |
2020年 | 124篇 |
2019年 | 289篇 |
2018年 | 375篇 |
2017年 | 194篇 |
2016年 | 183篇 |
2015年 | 232篇 |
2014年 | 383篇 |
2013年 | 454篇 |
2012年 | 487篇 |
2011年 | 557篇 |
2010年 | 330篇 |
2009年 | 356篇 |
2008年 | 456篇 |
2007年 | 484篇 |
2006年 | 469篇 |
2005年 | 490篇 |
2004年 | 504篇 |
2003年 | 506篇 |
2002年 | 474篇 |
2001年 | 348篇 |
2000年 | 393篇 |
1999年 | 308篇 |
1998年 | 84篇 |
1997年 | 66篇 |
1996年 | 80篇 |
1995年 | 58篇 |
1994年 | 53篇 |
1993年 | 49篇 |
1992年 | 175篇 |
1991年 | 142篇 |
1990年 | 146篇 |
1989年 | 129篇 |
1988年 | 126篇 |
1987年 | 109篇 |
1986年 | 93篇 |
1985年 | 85篇 |
1984年 | 66篇 |
1983年 | 41篇 |
1982年 | 23篇 |
1979年 | 48篇 |
1978年 | 24篇 |
1977年 | 24篇 |
1976年 | 28篇 |
1975年 | 36篇 |
1974年 | 41篇 |
1972年 | 27篇 |
1969年 | 23篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
A case of Rubinstein‐Taybi syndrome associated with growth hormone deficiency in childhood 下载免费PDF全文
2.
3.
José A. Lorente Pablo Cardinal-Fernández Diego Muñoz Fernando Frutos-Vivar Arnaud W. Thille Carlos Jaramillo Aida Ballén-Barragán José M. Rodríguez Oscar Peñuelas Guillermo Ortiz José Blanco Bruno Valle Pinheiro Nicolás Nin María del Carmen Marin Andrés Esteban Taylor B. Thompson 《Intensive care medicine》2015,41(11):1921-1930
4.
D Mezzano G E del Pino M Montesinos M E García E Aranda A Foradori 《Thrombosis and haemostasis》1991,66(2):254-258
Thrombocytopenia was induced in mongrel dogs by two mechanisms: immunologically, by intravenous injection of heterologous antiplatelet antibody, and non-immunologically, by circulating the blood through glass beads in anesthetized animals. The platelet content of 5-HT was monitored before and during the recovery of the blood platelet counts. This period is associated with the normalization of the mean platelet survival time and with a progressive increase in the mean age of the circulating platelet population. A continuous increment in platelet 5-HT closely followed the increase in platelet counts in both models of thrombocytopenia, and a strong correlation was found between the platelet age and 5-HT content. These findings support the concept that platelets accumulate 5-HT during their physiological aging process, contradicting the notion that a negative balance in 5-HT content results at the end of their physiological lifespan in circulation. These results are not in conflict with the concept that circulating platelets release and re-uptake 5-HT. 相似文献
5.
In the present paper, the results obtained are shown after a study by means of multivariant statistical analysis, of the quantity of Eimeria spp. oocyst elimination in sheep, bearing in mind the variations observed in the different areas, in the different age-groups, from month to month, and from year to year. Climatic factors, development of immunity, lambing seasons, and poor hygienic conditions seem to be the factors responsible for the statistically significant differences found when analysing the aforementioned main effects. 相似文献
6.
7.
8.
9.
This study investigates whether tissue recoil or patient intrinsic factors influence the final position of the nipple areola
complex (NAC) after reduction mammoplasty.
The age, pre-operative ptosis, BMI and weight of the tissue resected were recorded as patient intrinsic factors in 37 patients
undergoing reduction mammoplasty. The “spring-back” value was defined as the distance from the sternal notch to a nipple landmark
on the breast meridian with the patient sitting up, minus the same measurement repeated with the patient recumbent to eliminate
the pull of gravity on the breast. Spring back was measured pre-operatively for the nipple and nipple mark then post-operative
for the nipple. The difference in centimeters between the final post-operative distance from the sternal notch to the nipple
and the level intended by the pre-operative nipple mark was termed the “judgment error.” The final position of the post-operative
nipple and the judgment error was compared to the spring-back values and patient intrinsic factors.
Pre-operative ptosis was statistically related to increasing patient BMI and mass of tissue resected per breast. Pre-operative
spring-back values for the nipple increased with increasing ptosis, BMI and decreasing age. Spring-back values were greater
in the lower pole of the breast than in the upper pole. The final position of the nipple was higher than the pre-operative
mark in 65% of cases, lower in 8% and as marked in 27% of cases. The post-operative NAC was, on average, 0.6 cm higher than
planned pre-operatively. The post-operative distance from the sternal notch to the nipple increased with increasing pre-operative
ptosis, mass of breast tissue resected per breast and all three spring-back values. The difference between the level of the
pre-operative mark and the final nipple position showed a weak correlation with post-operative spring-back values.
The parameters of ptosis, BMI, weight of tissue resected per breast and pre-operative nipple spring back reflect body habitus
and breast size. Spring-back values vary between the upper and lower pole of the breast. The final NAC position was higher
than that intended at pre-operative marking in the majority of cases. The surgeon instinctively marks the nipple lower in
patients with greater pre-operative ptosis and in whom a larger resection is anticipated. Judgment error did not relate to
intrinsic factors nor to pre-operative spring-back values; hence, these parameters cannot be applied as predictive tools for
more accurate pre-operative marking of the nipple position. This study suggests that the pre-operative nipple mark should
be placed, with the patient sitting up, at least 23 cm from the sternal notch and 0.6 cm lower than the final position estimated
using the inframammary crease as a landmark.
An invited commentary on this paper is available at . 相似文献
10.
Manuel Sosa P. Saavedra J. del Pino-Montes J. Alegre R. Pérez-Cano G. Martínez Díaz Guerra M. Díaz-Curiel C. Valero M. Muñoz-Torres A. Torrijos J. Mosquera C. Gómez-Alonso GIUMO Study Group 《Journal of clinical densitometry》2005,8(4):430-435
Measurement of ultrasonographic parameters provides information concerning not only bone density but also bone architecture. We investigated the usefulness of ultrasonographic parameters and bone mineral density (BMD) to evaluate the probability of Colles' fracture. Two-hundred eighty-nine postmenopausal women (62.3 +/- 8.7 yr) with (n = 76) and without (n = 213) Colles' fracture were studied. BMD of lumbar spine and proximal femur was evaluated in all women by dual-energy X-ray absorptiometry (DXA) and speed of sound (SOS), broadband ultrasound attenuation (BUA), and stiffness in the calcaneus were measured by a Sahara ultrasonometer (Hologic). Patients suffering from Colles' fracture had lower values of BMD adjusted by height at the lumbar spine, L2-L4 (0.797 g/cm2 vs 0.860 g/cm2), femoral neck (0.685 g/cm2 vs 0.712 g/cm2 ), SOS (1518 m/sg vs 1525 m/sg), and stiffness (74.6 vs 77.7) (p < 0.05). Nevertheless, BUA values were similar in both groups. After stepwise logistic regression analysis, the area found under receiver operating characteristic (ROC) curves was 0.60 for L2L4 and 0.63 for a formula combining L2L4 and height. Our data suggest that patients suffering from Colles' fracture have lower values of BMD by DXA, SOS, and stiffness. However, the ability of these techniques to discriminate is low because the values for the area under ROC curve are 0.60 for L2-L4 and 0.63 for a formula derived of the combination of L2-L4 and height. 相似文献