全文获取类型
收费全文 | 667篇 |
免费 | 73篇 |
国内免费 | 3篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 11篇 |
妇产科学 | 4篇 |
基础医学 | 67篇 |
口腔科学 | 15篇 |
临床医学 | 54篇 |
内科学 | 150篇 |
皮肤病学 | 24篇 |
神经病学 | 81篇 |
特种医学 | 14篇 |
外科学 | 63篇 |
综合类 | 18篇 |
预防医学 | 127篇 |
眼科学 | 6篇 |
药学 | 77篇 |
中国医学 | 1篇 |
肿瘤学 | 30篇 |
出版年
2022年 | 8篇 |
2021年 | 29篇 |
2020年 | 13篇 |
2019年 | 20篇 |
2018年 | 12篇 |
2017年 | 9篇 |
2016年 | 12篇 |
2015年 | 10篇 |
2014年 | 14篇 |
2013年 | 21篇 |
2012年 | 41篇 |
2011年 | 42篇 |
2010年 | 16篇 |
2009年 | 29篇 |
2008年 | 41篇 |
2007年 | 36篇 |
2006年 | 26篇 |
2005年 | 29篇 |
2004年 | 44篇 |
2003年 | 26篇 |
2002年 | 29篇 |
2001年 | 14篇 |
2000年 | 25篇 |
1999年 | 9篇 |
1998年 | 8篇 |
1996年 | 5篇 |
1995年 | 6篇 |
1994年 | 11篇 |
1992年 | 8篇 |
1991年 | 5篇 |
1990年 | 9篇 |
1989年 | 8篇 |
1988年 | 6篇 |
1987年 | 5篇 |
1986年 | 6篇 |
1985年 | 9篇 |
1984年 | 5篇 |
1983年 | 8篇 |
1982年 | 7篇 |
1981年 | 5篇 |
1980年 | 5篇 |
1978年 | 8篇 |
1977年 | 5篇 |
1975年 | 4篇 |
1973年 | 7篇 |
1971年 | 5篇 |
1969年 | 5篇 |
1968年 | 4篇 |
1967年 | 5篇 |
1965年 | 5篇 |
排序方式: 共有743条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Barry W McColl Ailsa L McGregor Andrew Wong Julian D Harris Andrea Amalfitano Sandra Magnoni Andrew H Baker George Dickson Karen Horsburgh 《Journal of cerebral blood flow and metabolism》2007,27(3):477-487
Apolipoprotein E (apoE, protein; APOE, gene) is the major lipid-transport protein in the brain and plays an important role in modulating the outcome and regenerative processes after acute brain injury. The aim of the present study was to determine if gene transfer of the epsilon3 form of APOE improves outcome in a murine model of transient focal cerebral ischaemia. Mice received an intrastriatal injection of vehicle, a second-generation adenoviral vector containing the green fluorescent protein gene (Ad-GFP) or a vector containing the APOE epsilon3 gene (Ad-APOE) 3 days before 60 mins focal ischaemia. Green fluorescent protein expression was observed in cells throughout the striatum and subcortical white matter indicating successful gene transfer and expression. ApoE levels in the brain were significantly increased after Ad-APOE compared with Ad-GFP or vehicle treatment. Ad-APOE treatment reduced the volume of ischaemic damage by 50% compared with Ad-GFP or vehicle treatment (13+/-3 versus 29+/-4 versus 27+/-5 mm(3)). The extent of postischaemic apoE immunoreactivity was enhanced in Ad-APOE compared with Ad-GFP or vehicle treated mice. These results show the ability of APOE gene transfer to markedly improve outcome after cerebral ischaemia and suggest that modulating apoE levels may be a potential strategy in human stroke therapy. 相似文献
5.
Intra-amniotic inflammation in human gastroschisis: possible aetiology of postnatal bowel dysfunction 总被引:1,自引:0,他引:1
John J. Morrison Lecturer/Senior Registrar Nigel Klein Consultant † Lyn S. Chitty Consultant Gabriella Kocjan Consultant Denise Walshe Laboratory Assistant † Mark Goulding Laboratory Assistant † Michael P. Geary Research Fellow Agostino Pierro Consultant § Charles H. Rodeck Professor 《BJOG : an international journal of obstetrics and gynaecology》1998,105(11):1200-1204
6.
7.
Summary In the rat, prolonged administration of the luteinizing, hormone-releasing hormone agonist buserelin (25 μg/kg body wt/day
s.c.) lowers blood estradiol, raises bone resorption, and induces osteopenia. The present study was undertaken to determine
whether withdrawal of buserelin normalizes blood estradiol, slows bone resorption, and corrects buserelin-mediated osteopenia.
Four groups of female rats with45Ca-labeled bones were studied: group 1A received 0.2 ml saline s.c. daily for 4 weeks; group 2A received 0.2 ml buserelin
s.c. daily for 4 weeks; group 1B received 0.2 ml saline s.c. daily for 8 weeks; group 2B received 0.2 ml buserelin s.c. daily
for 4 weeks followed by 0.2 ml saline s.c. daily for 4 weeks. Bone resorption was monitored by measuring urinary45Ca and hydroxyproline. The rats in groups 1A and 2A were killed after 4 weeks and those in groups 1B and 2B after 8 weeks.
The mineral contents of the femoral bones and the whole skeletons were measured. Buserelin lowered blood estradiol, elevated
urinary45Ca and urinary hydroxyproline, and lowered femur and total body calcium and45Ca in group 2A vs. 1A (P<0.05). By contrast all these measurements became similar in groups 2B and 1B. Thus, osteopenia generated by a 4-week period
of buserelin-mediated hypo-estrogenism is reversible by withdrawing buserelin for 4 weeks. Consequently, buserelin administration
and withdrawal may be used to study effects of inducing and reversing estrogen-deficiency bone loss in the rat. 相似文献
8.
Distribution of mutations in the PEX gene in families with X-linked hypophosphataemic rickets (HYP) 总被引:8,自引:0,他引:8
Rowe PS; Oudet CL; Francis F; Sinding C; Pannetier S; Econs MJ; Strom TM; Meitinger T; Garabedian M; David A; Macher MA; Questiaux E; Popowska E; Pronicka E; Read AP; Mokrzycki A; Glorieux FH; Drezner MK; Hanauer A; Lehrach H; Goulding JN; O'Riordan JL 《Human molecular genetics》1997,6(4):539-549
Mutations in the PEX gene at Xp22.1 (phosphate-regulating gene with
homologies to endopeptidases, on the X-chromosome), are responsible for
X-linked hypophosphataemic rickets (HYP). Homology of PEX to the M13 family
of Zn2+ metallopeptidases which include neprilysin (NEP) as prototype, has
raised important questions regarding PEX function at the molecular level.
The aim of this study was to analyse 99 HYP families for PEX gene
mutations, and to correlate predicted changes in the protein structure with
Zn2+ metallopeptidase gene function. Primers flanking 22 characterised
exons were used to amplify DNA by PCR, and SSCP was then used to screen for
mutations. Deletions, insertions, nonsense mutations, stop codons and
splice mutations occurred in 83% of families screened for in all 22 exons,
and 51% of a separate set of families screened in 17 PEX gene exons.
Missense mutations in four regions of the gene were informative regarding
function, with one mutation in the Zn2+-binding site predicted to alter
substrate enzyme interaction and catalysis. Computer analysis of the
remaining mutations predicted changes in secondary structure,
N-glycosylation, protein phosphorylation and catalytic site molecular
structure. The wide range of mutations that align with regions required for
protease activity in NEP suggests that PEX also functions as a protease,
and may act by processing factor(s) involved in bone mineral metabolism.
相似文献
9.
Ruth Naughton-Doe MSc PhD Ailsa Cameron MSc John Carpenter B.Sc. Cert. App. Soc. Studies C.Q.S.W. C.Psychol. AFBPsS DSc 《Health & social care in the community》2021,29(5):1285-1295
This paper explores the potential contribution of timebanking, an innovative volunteering scheme, to the co-production of preventive social care with adults in England. Interest in volunteering in social care has increased as one proposed solution to the international crisis of a rising demand for services in juxtaposition with decreased resources. Volunteering has been particularly promoted in preventive services that prevent or delay care needs arising. Despite sustained interest in volunteering and co-production in social care, little is known about how theory translates into practice. Reporting implementation data from a Realistic Evaluation of six case studies in England, this paper explores one volunteering scheme, timebanking. The research explores how timebanks were working, what contribution they can make to adult social care, and whether they are an example of co-production. Data collected included interviews, focus groups or open question responses on surveys from 84 timebank members, and semi-structured interviews with 13 timebank staff. Each timebank was visited at least twice, and all timebank activity was analysed for a period of 12 months. Data were triangulated to improve reliability. The research found that in practice, timebanks were not working as described in theory, there were small numbers of person-to-person exchanges and some timebanks had abandoned this exchange model. Timebanks faced significant implementation challenges including managing risk and safeguarding and the associated bureaucracy, a paternalistic professional culture and the complexity of the timebank mechanism which required adequate resources. Lessons for timebanks are identified, as well as transferable lessons about co-production and volunteering in social care if such schemes are to be successful in the future. 相似文献
10.
Inter-relation between "classic" motor neuron disease and frontotemporal dementia: neuropsychological and single photon emission computed tomography study. 总被引:1,自引:1,他引:0 下载免费PDF全文
P R Talbot P J Goulding J J Lloyd J S Snowden D Neary H J Testa 《Journal of neurology, neurosurgery, and psychiatry》1995,58(5):541-547
The purpose of this study was to examine the possible association between "classic" motor neuron disease (cMND) and frontotemporal dementia (FTD), using neuropsychological evaluation and single photon emission computed tomography (SPECT). Psychological tests assessing language, perceptuospatial, memory, and "frontal lobe" functions were given to patients with cMND and test scores were compared with those of normal control subjects. 99mTc-HMPAO SPECT was performed on patients with cMND, FTD and motor neuron disease (FTD/MND), FTD alone, and normal control subjects. Regional cerebral blood flow indices (rCBFi) were determined in 36 cortical regions, and differences between grouped rCBFi data were investigated by canonical discriminant analysis. There were significant group differences in the scores of picture sequencing and token tests in patients with cMND compared with normal controls. Regional CBFi data showed frontal and anterior temporal reductions in patients with cMND compared with normal controls. A similar pattern of SPECT abnormality was seen in patients with FTD/MND and FTD alone, but to a more pronounced degree than in patients with cMND. Neuropsychological and SPECT findings in cMND, FTD/MND, and FTD showed a common pattern of cerebral involvement, most pronounced in the second two conditions. It is suggested that cMND, FTD/MND, and FTD represent a clinical range of a pathological continuum. 相似文献