全文获取类型
收费全文 | 332篇 |
免费 | 24篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 8篇 |
儿科学 | 20篇 |
妇产科学 | 6篇 |
基础医学 | 16篇 |
口腔科学 | 105篇 |
临床医学 | 54篇 |
内科学 | 52篇 |
皮肤病学 | 3篇 |
神经病学 | 7篇 |
特种医学 | 32篇 |
外科学 | 22篇 |
综合类 | 3篇 |
预防医学 | 15篇 |
眼科学 | 1篇 |
药学 | 3篇 |
中国医学 | 1篇 |
肿瘤学 | 9篇 |
出版年
2023年 | 6篇 |
2022年 | 5篇 |
2021年 | 5篇 |
2020年 | 3篇 |
2019年 | 3篇 |
2018年 | 3篇 |
2017年 | 4篇 |
2016年 | 7篇 |
2015年 | 10篇 |
2014年 | 12篇 |
2013年 | 13篇 |
2012年 | 17篇 |
2011年 | 8篇 |
2010年 | 6篇 |
2009年 | 13篇 |
2008年 | 15篇 |
2007年 | 16篇 |
2006年 | 12篇 |
2005年 | 15篇 |
2004年 | 16篇 |
2003年 | 15篇 |
2002年 | 17篇 |
2001年 | 4篇 |
2000年 | 14篇 |
1999年 | 6篇 |
1998年 | 12篇 |
1997年 | 10篇 |
1996年 | 12篇 |
1995年 | 4篇 |
1994年 | 13篇 |
1993年 | 7篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 6篇 |
1989年 | 3篇 |
1988年 | 9篇 |
1987年 | 7篇 |
1985年 | 4篇 |
1984年 | 3篇 |
1982年 | 2篇 |
1980年 | 2篇 |
1979年 | 4篇 |
1978年 | 2篇 |
1977年 | 4篇 |
1975年 | 2篇 |
1966年 | 1篇 |
1962年 | 1篇 |
排序方式: 共有357条查询结果,搜索用时 0 毫秒
1.
2.
BACKGROUND: Chronic renal failure (CRF) is associated with an atherogenic
lipid profile and an increased risk of ischaemic cardiovascular disease.
The associated hyperlipidaemia is reportedly ameliorated by erythropoietin
(Epo) therapy. According to a recent report, rats studied 3 weeks after 5/6
nephrectomy and fed a high- protein diet exhibited increased activities of
hepatic HMG-CoA reductase (HMG-CoAR) and cholesterol 7 alpha-hydroxylase
(Ch-7 alpha- H), despite normal corresponding mRNA values. DESIGN AND
METHODS: This study was designed to examine the effects of naturally
progressing CRF of longer duration as well as those of Epo therapy on gene
expressions of the key factors involved in hepatic cholesterol metabolism,
i.e., LDL receptor (LDLR), HMG-CoAR, and Ch-7 alpha-H. Sprague-Dawley rats
were randomized to the CRF group (5/6 nephrectomy), Epo-treated CRF group
(given Epo 150 U/kg/twice weekly) and sham-operated, placebo- treated
normal controls. They were allowed free access to regular rat chow and
studied 6 weeks after surgery. Liver mRNAs and protein mass or activities
of the above factors were studied. RESULTS: Plasma cholesterol
concentration was significantly increased in the CRF group (P < 0.001)
and was modestly lowered (P < 0.05) by Epo therapy. However, microsomal
cholesterol concentration and LDLR, HMG-CoAR, and Ch-7 alpha-H mRNA as well
as HMG-CoAR activity, and Ch-7 alpha-H and LDLR protein mass measurements
were virtually identical in the three groups. Thus, hepatic LDLR, HMG-CoAR,
and Ch-7 alpha-H mRNA and protein measurements in rats with CRF were
similar to those of the normal control group representing an inappropriate
response to the associated hypercholesterolemia. Epo therapy led to partial
amelioration of CRF- associated hypercholesterolaemia with no discernible
effect on hepatic tissue expression of the above factors.
相似文献
3.
4.
Abstract: Haemoptysis in otherwise healthy children is an uncommon event. Two cases of massive haemoptysis, subsequently requiring lobectomy, are discussed. In each case, foreign vegetable matter was identified despite previously normal bronchoscopy and minimal changes on chest radiograph. 相似文献
5.
Non-invasive detection of fecal protein kinase C betaII and zeta messenger RNA: putative biomarkers for colon cancer 总被引:2,自引:0,他引:2
Davidson LA; Aymond CM; Jiang YH; Turner ND; Lupton JR; Chapkin RS 《Carcinogenesis》1998,19(2):253-257
We have developed a non-invasive method utilizing feces, containing
sloughed colonocytes, as a sensitive technique for detecting diagnostic
colonic biomarkers. In this study, we used the rat colon carcinogenesis
model to determine if changes in fecal protein kinase C (PKC) expression
have predictive value in monitoring the neoplastic process. Weanling rats
were injected with saline or azoxymethane (AOM) and 36 weeks later fecal
samples and mucosa were collected, poly A+ RNA isolated, and quantitative
RT-PCR performed using primers to PKC betaII and zeta. Fecal PKC betaII and
zeta mRNA levels were altered by the presence of a tumor, with
tumor-bearing animals having a 3-fold higher (P < 0.05) PKC betaII
expression as compared with animals without tumors. In addition,
AOM-injection increased mucosal PKC betaII mRNA expression compared with
saline controls. No effect of tumor incidence on mucosal PKC betaII
expression was observed. In contrast, fecal PKC zeta expression was
2.5-fold lower (P < 0.05) in animals injected with azoxymethane versus
saline. Since tumor incidence exerts a reciprocal effect on fecal PKC
betaII and zeta mRNA expression, data were also expressed as the ratio
between PKC betaII and zeta. The isozyme ratio was strongly related to
tumor incidence, i.e. ratio for animals with tumors was 2.18 +/- 1.25,
animals without tumors was 0.50 +/- 0.16, P = 0.025. We demonstrate that
the expression of fecal PKC betaII and zeta may serve as a noninvasive
marker for development of colon tumors. A sensitive technique for the
detection of colon cancer is of importance since early diagnosis can
substantially reduce mortality.
相似文献
6.
7.
The impact of research education on student nurse attitude,skill and uptake of evidence‐based practice: a descriptive longitudinal survey 下载免费PDF全文
Matthew J Leach RN BN ND DipClinNutr PhD Anne Hofmeyer RN DipUnivTeach MPHC PhD Amanda Bobridge RN BN BHSc PhD 《Journal of clinical nursing》2016,25(1-2):194-203
8.
Prolactin regulates mammary epithelial cell proliferation via autocrine/paracrine mechanism 总被引:3,自引:0,他引:3
Prolactin (PRL) is essential for a number of developmental events in the mammary gland. Work with PRL and PRL receptor knockout
mice has shown that PRL indirectly regulates ductal side branching during puberty and directly controls lobuloalveolar development
and lactogenesis during pregnancy. Anterior pituitary or placental PRL is thought to be responsible for these functions via
an endocrine mechanism; however, PRL is also produced in a number of extrapituitary sites including the mammary gland. The
physiologic relevance of mammary PRL remains unknown. In this study we utilized mammary recombination in Rag1−/− hosts, to determine whether mammary PRL plays a role in the regulation of mammary gland development. Mammary glands formed
with the PRL gene deleted from either the epithelium, stroma, or both displayed normal development, on the basis of whole
mount and hematoxylin and eosin histology, during puberty and lactation. At the end of pregnancy, a 2.8-fold decrease in bromodeoxyuridine
incorporation was observed in the epithelial cells of mammary glands formed using PRL knockout epithelium compared with those
formed using wildtype epithelium. No balancing alteration in the rates of apoptosis was detected. Thus, mammary-derived PRL
influences mammary epithelial cell proliferation via an autocrine/paracrine mechanism, establishing a physiologic function
for mammary PRL during mammopoiesis. 相似文献
9.
Prolactin (PRL) is necessary for the genesis of mammary alveolar buds and for lactation. A cDNA library enriched for PRL-dependent
genes was made by suppression subtractive hybridization. Aldolase C/zebrin (AldC/zebrin), a “brain-specific” aldolase, was
found to be PRL-dependent in the mouse mammary glands. AldC/zebrin was preferentially expressed in the alveolar buds. Expression
of the gene in the ovary was also evident. During pregnancy, mammary AldC/zebrin mRNA levels were elevated beginning at midpregnancy
(d 10 of pregnancy) in accordance with the genesis of the lobuloalveolar system, and the expression level was gradually increased
through the end of pregnancy. Lactating mammary gland contained a very high level of AldC/zebrin mRNA, and the gene expression
decreased during involution. By contrast, levels of aldolase A and B mRNA expression in the mammary glands were less affected
by pregnancy and lactation. The selective regulation of AldC/zebrin may contribute to a shift in nutrient metabolism during
pregnancy and lactation to facilitate epithelial growth and biosynthesis of milk constituents. 相似文献
10.