全文获取类型
收费全文 | 787篇 |
免费 | 31篇 |
国内免费 | 10篇 |
专业分类
耳鼻咽喉 | 12篇 |
儿科学 | 9篇 |
妇产科学 | 6篇 |
基础医学 | 42篇 |
口腔科学 | 8篇 |
临床医学 | 67篇 |
内科学 | 134篇 |
皮肤病学 | 11篇 |
神经病学 | 29篇 |
特种医学 | 119篇 |
外国民族医学 | 1篇 |
外科学 | 253篇 |
综合类 | 14篇 |
预防医学 | 51篇 |
眼科学 | 12篇 |
药学 | 23篇 |
肿瘤学 | 37篇 |
出版年
2023年 | 3篇 |
2022年 | 7篇 |
2021年 | 7篇 |
2020年 | 5篇 |
2019年 | 14篇 |
2018年 | 16篇 |
2017年 | 9篇 |
2016年 | 21篇 |
2015年 | 20篇 |
2014年 | 22篇 |
2013年 | 26篇 |
2012年 | 37篇 |
2011年 | 43篇 |
2010年 | 40篇 |
2009年 | 34篇 |
2008年 | 38篇 |
2007年 | 40篇 |
2006年 | 29篇 |
2005年 | 40篇 |
2004年 | 29篇 |
2003年 | 37篇 |
2002年 | 37篇 |
2001年 | 24篇 |
2000年 | 22篇 |
1999年 | 17篇 |
1998年 | 15篇 |
1997年 | 18篇 |
1996年 | 12篇 |
1995年 | 12篇 |
1994年 | 7篇 |
1993年 | 5篇 |
1992年 | 8篇 |
1991年 | 8篇 |
1990年 | 9篇 |
1989年 | 5篇 |
1988年 | 3篇 |
1987年 | 6篇 |
1986年 | 7篇 |
1985年 | 5篇 |
1982年 | 4篇 |
1979年 | 7篇 |
1977年 | 13篇 |
1976年 | 13篇 |
1975年 | 4篇 |
1974年 | 8篇 |
1973年 | 3篇 |
1972年 | 5篇 |
1971年 | 5篇 |
1968年 | 5篇 |
1943年 | 2篇 |
排序方式: 共有828条查询结果,搜索用时 0 毫秒
1.
A neuroendocrine carcinoma of the thymus with an ectopic adrenocorticotropic hormone (ACTH) syndrome and melanocytic differentiation is described. ACTH, neuron-specific enolase (NSE) and S-100 protein were identified in the tumor by immunocytochemistry. Neurosecretory granules and melanosomes could be demonstrated in different cell populations by electronmicroscopy. The clinicopathologic findings are presented. The literature is briefly discussed. 相似文献
2.
3.
Rechtsanwalt und Notar Dr. iur.
Franz-Josef Dahm Fachanwalt für Verwaltungsrecht Essen 《MedR Medizinrecht》2004,22(3):175-176
Ohne Zusammenfassung 相似文献
4.
5.
6.
In a catamnestic study an analysis of the clinical results as well as of the spermatograms are reported on 545 andrological patients with "atrophy" (that means reduced testis volume) or absence of one testis and a contralaterally normal developed testis. It can be demonstrated that there do not exist any differences concerning the size and consistency of the present testis and with regard to absence or lost of one testis (hemicastration). In case of testicular atrophy exists a more disadvantageous reproductive function. In case of tumor as a reason for hemicastration the teratoma shows better conditions for the quality of the spermatograms and for reproduction. Accordingly the histological findings of the testis after hemicastration/absence are not so large in the present remained testis. In cases of one-sided orchitis the spermatogram quality is better than in one-sided varicocele with atrophy at the same side. 相似文献
7.
8.
Analysis of human dentine by infrared spectrophotometry suggests that ball-grinding may result in damage of the apatite crystallites.
The present study includes further assessments of this effect by X-ray diffraction, infrared spectroscopy, and electron microscopy.
Each of three coarse-ground dentine samples (Group I) was divided into three portions of 30 mg. One of these portions was
ball-ground for approximately 1 min (Group II), the second portion for 6 min (Group III), and the third portion for 23 min
(Group IV). The 002 reflection showed line broadening, most marked from Group II to III. Electron microscopy showed a gradual
change in crystallite appearance with increased grinding, most pronounced from Group II to III. These observations indicate
that by prolonged grinding a limit is approached where no further changes in the crystallites occur. Electron microscopy also
indicated that fracture of the crystallites might have occurred. This was probably accompanied by strains in the lattice.
The infrared spectra indicated that no breakdown of the apatite structure had occurred during the entire grinding. 相似文献
9.
Abstract: We report the first case of fatal anthrax meningoencephalitis in Hong Kong over the past 60 years. A 13 year-old boy presented with right lower quadrant pain, diarrhoea and progressive headache. Lumbar puncture yielded gram positive bacilli initially thought to be Bacillus cereus, a contaminant. He was treated with ampicillin and cefotaxime, but died 3 days after hospitalization. The organism isolated from blood and cerebrospinal fluid was later identified as Bacillus anthracis. 相似文献
10.
A prospective study of methylenetetrahydrofolate reductase and methionine synthase gene polymorphisms, and risk of colorectal adenoma 总被引:8,自引:2,他引:8
Chen J; Giovannucci E; Hankinson SE; Ma J; Willett WC; Spiegelman D; Kelsey KT; Hunter DJ 《Carcinogenesis》1998,19(12):2129-2132
We examined the relationship between a functional polymorphism (667C--
>T, ala-->val) of the methylenetetrahydrofolate reductase gene
(MTHFR) and the risk of colorectal adenomas in the prospective Nurses'
Health Study. Among 257 incident polyp cases and 713 controls, the MTHFR
val/val polymorphism [relative risk (RR) = 1.35, 95% confidence interval
(CI) 0.84-2.17] was not significantly associated with risk of adenomas.
This lack of association was observed for both small (RR = 1.36, 95% CI
0.76-2.45) and large (RR = 1.32, 95% CI 0.66-2.66) adenomas. Furthermore,
there was no significant interaction between this polymorphism and
consumption of either folate, methionine or alcohol. We also examined the
relationship of a newly identified polymorphism (asp919gly) of the
methionine synthase gene (MS) with the risk of colorectal adenomas in the
same population. The MS gly/gly polymorphism was also not significantly
associated with risk of colorectal adenomas (RR = 0.66, 95% CI 0.26-1.70).
These results, which need to be confirmed in other studies, suggest that
the MTHFR val/val polymorphism, which has been previously inversely
associated with risk of colorectal cancer, plays a role only in a late
stage (adenoma-- >carcinoma) of colorectal tumorigenesis, and/or may
protect against malignant transformation in the subset of benign adenomas,
which may progress to malignancy.
相似文献