全文获取类型
收费全文 | 130823篇 |
免费 | 45982篇 |
国内免费 | 1728篇 |
专业分类
耳鼻咽喉 | 2097篇 |
儿科学 | 5147篇 |
妇产科学 | 1556篇 |
基础医学 | 21902篇 |
口腔科学 | 6488篇 |
临床医学 | 18109篇 |
内科学 | 32176篇 |
皮肤病学 | 8127篇 |
神经病学 | 16979篇 |
特种医学 | 3930篇 |
外国民族医学 | 6篇 |
外科学 | 19883篇 |
综合类 | 5657篇 |
现状与发展 | 10篇 |
一般理论 | 76篇 |
预防医学 | 8660篇 |
眼科学 | 3056篇 |
药学 | 10595篇 |
38篇 | |
中国医学 | 3293篇 |
肿瘤学 | 10748篇 |
出版年
2024年 | 187篇 |
2023年 | 829篇 |
2022年 | 1870篇 |
2021年 | 3790篇 |
2020年 | 6860篇 |
2019年 | 12300篇 |
2018年 | 11749篇 |
2017年 | 12937篇 |
2016年 | 13411篇 |
2015年 | 13846篇 |
2014年 | 14245篇 |
2013年 | 15021篇 |
2012年 | 8140篇 |
2011年 | 8214篇 |
2010年 | 11642篇 |
2009年 | 7562篇 |
2008年 | 5253篇 |
2007年 | 3979篇 |
2006年 | 3675篇 |
2005年 | 3303篇 |
2004年 | 2873篇 |
2003年 | 2644篇 |
2002年 | 2656篇 |
2001年 | 1586篇 |
2000年 | 1384篇 |
1999年 | 901篇 |
1998年 | 459篇 |
1997年 | 450篇 |
1996年 | 371篇 |
1995年 | 299篇 |
1994年 | 251篇 |
1993年 | 250篇 |
1992年 | 362篇 |
1991年 | 318篇 |
1990年 | 312篇 |
1989年 | 245篇 |
1988年 | 223篇 |
1987年 | 209篇 |
1986年 | 211篇 |
1985年 | 202篇 |
1984年 | 213篇 |
1983年 | 194篇 |
1982年 | 175篇 |
1981年 | 196篇 |
1980年 | 172篇 |
1979年 | 155篇 |
1977年 | 131篇 |
1975年 | 131篇 |
1974年 | 126篇 |
1973年 | 131篇 |
排序方式: 共有10000条查询结果,搜索用时 8 毫秒
51.
G. Y. Meyer‐Rochow A. J. Gill L. W. Delbridge S. B. Sidhu M. S. Sywak 《ANZ journal of surgery》2007,77(Z1):A22-A22
Purpose Parathyroid carcinoma (PC) is rare and accounts for less than 1% of all cases of primary hyperparathyroidism (PHPT). The definitive histopathologic diagnosis of PC requires unequivocal invasion or metastasis which may be absent at first presentation. As a result, many cases of PC can only be diagnosed retrospectively. Parafibromin is the protein encoded by HRPT2 which is mutated and not expressed in many parathyroid carcinomas. Given that PCs generally weigh more than parathyroid adenomas (PA)s, we hypothesized that amongst large PAs there may be a high incidence of occult PC which could be identified by negative staining for parafibromin. Methodology 57 parathyroid glands weighing greater than 2 grams excised from 1998–2006 were identified from the University of Sydney Endocrine Surgical Database. Two specimens with a histopathologic diagnosis of PC were excluded. Immunohistochemical staining for parafibromin was performed on the remaining 55 PAs. Results Of the 55 specimens stained for parafibromin only one definite negative stain was detected. This case was originally classified as an “atypical adenoma” because it showed nuclear and architectural atypia without unequivocal evidence of invasive growth. In view of the negative staining for parafibromin it therefore probably represents occult carcinoma. There has been no evidence of recurrence or metastasis after 6.5 years. Conclusions Complete loss of staining for parafibromin is very rare in giant parathyroid adenomas suggesting that occult carcinoma is equally rare. As a result routine immunohistochemical staining for parafibromin does not appear to be an effective screening test for carcinoma in large PA without histopathologic features of PC. 相似文献
52.
Purpose To demonstrate that laparoscopic adjustable gastric banding may promote oesophageal dilatation or interfere with oesophageal motility. Methodology We report a case of a 67 year old female with a complex medical history who developed secondary achalasia from a slipped laparoscopic adjustable gastric band for weight loss. This led to recurring episodes of aspiration pneumonia requiring multiple admissions at North Shore Hospital, Auckland, New Zealand. Results A decision was made to remove the gastric band, five years after its initial insertion. At one month follow up, she was swallowing normally and oesophageal manometry had returned to normal. Conclusion Oesophageal dysmotility is sometimes seen in patients who have bands that are adjusted too tightly or in whom the band has slipped. This can lead to serious complications if unrecognized and incorrectly treated. Oesophageal symptoms in patients with adjustable bands must be considered secondary to the band until proven otherwise ie removal of the band or complete deflation. 相似文献
53.
54.
55.
56.
Paul Wan Sia Heng Tin Wui Wong Wai See Cheong 《European journal of pharmaceutical sciences》2003,19(5):381-393
The melt agglomeration process of lactose powder with hydrogenated cottonseed oil (HCO) as the hydrophobic meltable binder was investigated by studying the physicochemical properties of molten HCO modified by sucrose stearates S170, S770 and S1570. The size, size distribution, micromeritic and adhesion properties of agglomerates as well as surface tension, contact angle, viscosity and specific volume of molten HCO, with and without sucrose stearates, were examined. The viscosity, specific volume and surface tension of molten HCO were found to be modified to varying extents by sucrose stearates which are available in different HLB values and melt properties. The growth of melt agglomerates was promoted predominantly by an increase in viscosity, an increase in specific volume or a decrease in surface tension of the molten binding liquid. The agglomerate growth propensity was higher with an increase in inter-particulate binding strength, agglomerate surface wetness and extent of agglomerate consolidation which enhanced the liquid migration from agglomerate core to periphery leading to an increased surface plasticity for coalescence. The inclusion of high concentrations of completely meltable sucrose stearate S170 greatly induced the growth of agglomerates through increased specific volume and viscosity of the molten binding liquid. On the other hand, the inclusion of incompletely meltable sucrose stearates S770 and S1570 promoted the agglomeration mainly via the reduction in surface tension of the molten binding liquid with declining agglomerate growth propensity at high sucrose stearate concentrations. In addition to being an agglomeration modifier, sucrose stearate demonstrated anti-adherent property in melt agglomeration process. The properties of molten HCO and melt agglomerates were dependent on the type and concentration of sucrose stearate added. 相似文献
57.
Abstract – Traumatic dental injuries often occur to the teeth and their supporting tissues and they are the main reasons for emergency visit to a dental clinic. Management of a fracture depends on its position and the extent of root involvement. Horizontal root fractures are not seen frequently and the treatment consists of reduction and long‐term rigid fixation of the coronal segment. The present case demonstrates the successful management of two horizontally fractured maxillary central incisors with a follow‐up period of 9 months. 相似文献
58.
目的 系统评价碘盐预防碘缺乏病的效果.方法 计算机检索Cochrane Central Register of Controlled Trial(Cochrane图书馆2009年第4期)、MEDLINE(1966~2009.12)、Ovid Medline(1966~2009.12)、Embase数据库(1986~2009.12)、CBM光盘版(1978~2009.12)、CNKI(1980~2009.12)以及VIP(1989~2009.12),并且追查纳入文献的参考文献.按纳入和排除标准由2名评价者独立选择试验、提取资料,交叉核对并进行方法学质量评估,对同质研究采用RevMan 5.0软件进行Meta分析.结果 共纳入5篇随机对照研究,842例研究对象,儿童组碘盐和空白食盐的甲肿率结果比较无统计学意义[OR=1.19,95%CI(0.74,1.92)],成人组碘盐和其他形式的补碘措施比较,碘盐组甲肿率、甲状腺体积均低于其他形式的补碘组.结论 碘盐能显著改善成人的碘营养状况,副作用还需大量高质量的随机对照试验来验证. 相似文献
59.
60.
Selecting an appropriate working correlation structure is pertinent to clustered data analysis using generalized estimating equations (GEE) because an inappropriate choice will lead to inefficient parameter estimation. We investigate the well‐known criterion of QIC for selecting a working correlation structure, and have found that performance of the QIC is deteriorated by a term that is theoretically independent of the correlation structures but has to be estimated with an error. This leads us to propose a correlation information criterion (CIC) that substantially improves the QIC performance. Extensive simulation studies indicate that the CIC has remarkable improvement in selecting the correct correlation structures. We also illustrate our findings using a data set from the Madras Longitudinal Schizophrenia Study. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献