全文获取类型
收费全文 | 177025篇 |
免费 | 1163篇 |
国内免费 | 28篇 |
专业分类
耳鼻咽喉 | 1133篇 |
儿科学 | 6669篇 |
妇产科学 | 3027篇 |
基础医学 | 16753篇 |
口腔科学 | 1583篇 |
临床医学 | 12703篇 |
内科学 | 31090篇 |
皮肤病学 | 673篇 |
神经病学 | 16523篇 |
特种医学 | 9085篇 |
外科学 | 28979篇 |
综合类 | 2395篇 |
一般理论 | 1篇 |
预防医学 | 18215篇 |
眼科学 | 2754篇 |
药学 | 9621篇 |
中国医学 | 623篇 |
肿瘤学 | 16389篇 |
出版年
2022年 | 34篇 |
2021年 | 70篇 |
2020年 | 31篇 |
2019年 | 54篇 |
2018年 | 21968篇 |
2017年 | 17400篇 |
2016年 | 19546篇 |
2015年 | 927篇 |
2014年 | 834篇 |
2013年 | 816篇 |
2012年 | 6998篇 |
2011年 | 21048篇 |
2010年 | 18832篇 |
2009年 | 11573篇 |
2008年 | 19541篇 |
2007年 | 21752篇 |
2006年 | 574篇 |
2005年 | 2233篇 |
2004年 | 3418篇 |
2003年 | 4411篇 |
2002年 | 2553篇 |
2001年 | 316篇 |
2000年 | 463篇 |
1999年 | 198篇 |
1998年 | 257篇 |
1997年 | 260篇 |
1996年 | 143篇 |
1995年 | 140篇 |
1994年 | 143篇 |
1993年 | 100篇 |
1992年 | 66篇 |
1991年 | 121篇 |
1990年 | 153篇 |
1989年 | 126篇 |
1988年 | 97篇 |
1987年 | 74篇 |
1986年 | 44篇 |
1985年 | 58篇 |
1984年 | 43篇 |
1983年 | 40篇 |
1982年 | 55篇 |
1980年 | 65篇 |
1978年 | 34篇 |
1970年 | 25篇 |
1969年 | 25篇 |
1938年 | 60篇 |
1937年 | 25篇 |
1934年 | 34篇 |
1932年 | 56篇 |
1930年 | 48篇 |
排序方式: 共有10000条查询结果,搜索用时 93 毫秒
21.
Background
The telomeric region of mouse chromosome 12 has previously shown frequent allelic loss in murine lymphoma. The Bcl11b gene has been identified and suggested as a candidate tumor suppressor gene within this region. In this study, we aimed to elucidate whether Bcl11b is mutated in lymphomas with allelic loss, and whether the mutations we detected conferred any effect on cell proliferation and apoptosis. 相似文献22.
23.
24.
Abstract Surgical treatment of proximal humeral fractures still remains a challenge. This is primarily due to the fact that sufficient
implant fixation in humeral head fractures is often not achieved due to substantial bone tissue loss with increasing age.
In the last few years the locking plates and locking nails have been introduced into clinical practice with varying results.
The biomechanical studies have focused on locking plate osteosynthesis as well. The following paper focuses on bone quality,
biomechanical studies and biology of proper osteosynthesis and reviews the most recent literature. 相似文献
25.
26.
27.
28.
Tarek A. Amer Tarek F. Elwakil Mahmoud S. Elbasiouny 《European journal of plastic surgery》2007,30(2):67-73
Haemangiomas are the most common tumours of infancy. They typically proliferate then involute with considerable variation
as regards to their rates of proliferation and involution. Haemangioma of the nasal tip is a lesion of special characteristics.
During proliferation, it expands, contracts and deviates the nasal cartilages. Particularly, it regresses slowly and frequently
involutes incompletely. That is why excision of the lesion is frequently suggested. The present study was conducted to evaluate
open rhinoplasty after initial non-excision treatment modalities namely, intra-lesional corticosteroid injections and laser
treatment, as a protocol of treatment for nasal tip haemangiomas. Twelve patients with nasal tip haemangiomas were included
in the present study. Patients of both sexes, of different ages, with deep and mixed haemangiomas were studied. Disfigurement
was the constant presenting symptom. Initial non-excision treatment reported different responses as denoted by the regression
of the lesions’ size. Haemangiomas constantly extended between the medial crura of the alar cartilages as noted by the constant
widening of the columella pre-operatively and the obvious separation of the nasal cartilages intra-operatively. This separation
was constantly found to require approximation by sutures. The results of the present study concluded that whenever an early
presentation with nasal tip haemangioma could be established, initial non-excision treatment followed by open rhinoplasty
could be a useful protocol of treatment. Within the limitations of the present study, this protocol could achieve an early,
safe and effective treatment for nasal tip haemangiomas with provisionally acceptable cosmetic outcomes so far. 相似文献
29.
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
30.