全文获取类型
收费全文 | 443篇 |
免费 | 24篇 |
国内免费 | 2篇 |
专业分类
儿科学 | 40篇 |
妇产科学 | 1篇 |
基础医学 | 67篇 |
口腔科学 | 10篇 |
临床医学 | 39篇 |
内科学 | 72篇 |
皮肤病学 | 7篇 |
神经病学 | 7篇 |
特种医学 | 46篇 |
外科学 | 77篇 |
综合类 | 34篇 |
预防医学 | 42篇 |
眼科学 | 1篇 |
药学 | 11篇 |
中国医学 | 2篇 |
肿瘤学 | 13篇 |
出版年
2022年 | 4篇 |
2021年 | 12篇 |
2020年 | 9篇 |
2019年 | 8篇 |
2018年 | 10篇 |
2017年 | 7篇 |
2016年 | 12篇 |
2015年 | 13篇 |
2014年 | 16篇 |
2013年 | 15篇 |
2012年 | 20篇 |
2011年 | 25篇 |
2010年 | 12篇 |
2009年 | 13篇 |
2008年 | 15篇 |
2007年 | 20篇 |
2006年 | 18篇 |
2005年 | 10篇 |
2004年 | 14篇 |
2003年 | 11篇 |
2002年 | 13篇 |
2001年 | 9篇 |
2000年 | 13篇 |
1999年 | 5篇 |
1998年 | 9篇 |
1997年 | 8篇 |
1996年 | 17篇 |
1995年 | 16篇 |
1994年 | 6篇 |
1993年 | 7篇 |
1991年 | 11篇 |
1990年 | 6篇 |
1989年 | 8篇 |
1988年 | 5篇 |
1987年 | 5篇 |
1986年 | 8篇 |
1985年 | 3篇 |
1984年 | 3篇 |
1980年 | 4篇 |
1978年 | 4篇 |
1977年 | 3篇 |
1975年 | 5篇 |
1973年 | 4篇 |
1972年 | 3篇 |
1971年 | 2篇 |
1969年 | 3篇 |
1967年 | 2篇 |
1963年 | 2篇 |
1943年 | 2篇 |
1935年 | 4篇 |
排序方式: 共有469条查询结果,搜索用时 15 毫秒
1.
2.
3.
Detailed pathological changes of human lumbar facet joints L1–L5 in elderly individuals 总被引:4,自引:1,他引:3
Facet joints play an important role in intervertebral load transmission and are crucial for rotational kinematics. Clinically, the role of facet joints as a possible source of low back pain is seen as controversial and at present is not sufficiently investigated. In this study, human lumbar facet (zygapopyhysial) joints from donors with advanced age were analyzed macroscopically, for degenerative changes. The aim was to determine the extent and morphology of degenerative changes in these joints. Lumbar facet joints (L1–L5) of 32 donors were studied (mean age 80.1±11.2 years). Joint capsules were carefully removed and joint surfaces (5 zones) examined using magnifying glasses and probes. In the result, the majority of facet joints showed cartilage defects of varying extent. Defects were located mostly at the margins of the articular surface, the central zone being relatively well preserved. Defect localization was different between superior (most cartilage defects in superior zone) and inferior (most defects inferiorly) facets. Further, defects were more severe caudal (level of L5) and in older persons. Osteophytes were present in up to 30%, located mostly at the latero-dorsal enthesis of the joint capsule on the superior facet. In conclusion, most margins of the articular facets are subject to degenerative changes in the lumbar spine of elderly persons, the topographical pattern being different in superior and inferior facets. This observation can be explained by the segmental motion patterns during extension/flexion movements of the facets. Sometimes, due to the marginal extension, it is obvious that not all changes can be assessed by CT or MRI. 相似文献
4.
5.
Congenital abnormal communications between separated pulmonary tissue and the oesophagus are rarities. Only about 50 cases have been reported in the literature. For all different forms the term of bronchopulmonary foregut malformation (BPFM) was first applied by Gerle and his coworkers in 1968. Major symptoms of this condition involved respiratory distress, cough, dyspnea, vomiting and repeated pneumonia. This paper presents reports of two own patients. In both cases was confirmed a bronchopulmonary foregut malformation in the lower right thorax with ectopic main bronchus communicating into the distal oesophagus. According to the literature we describe our own experience and discuss embryologic pathogenesis and surgical consequences for children. 相似文献
6.
A. Heider S. Santibanez A. Tischer E. Gerike N. Tikhonova G. Ignatyev M. Mrazova G. Enders E. Schreier 《Archives of virology》1997,142(12):2521-2528
Summary. The sequence of the 300 nucleotides region of the measles virus genome was determined that includes a part of the 3′-untranslated
region of the matrix (M) gene, the intergenic region and a part of the 5′-untranslated region of the fusion (F) gene [M-F
region] for vaccine strain Leningrad-16 and 14 wild-type isolates. The data obtained demonstrate the variability of this long
non-coding M-F region. No mutations in this region of the genome were found which seem to be specific for vaccine strains
of measles virus (MV).
Accepted August 1, 1997 Received June 2, 1997 相似文献
7.
Fernando de Ory José Manuel Echevarría George Kafatos Cleo Anastassopoulou Nick Andrews Josephine Backhouse Guy Berbers Blazena Bruckova Daniel I Cohen Hester de Melker Irja Davidkin Giovanni Gabutti Louise M Hesketh Kari Johansen Sari Jokinen Lindsay Jones Anika Linde Elisabeth Miller Jo?l Mossong Anthony Nardone Maria Cristina Rota Andreas Sauerbrei Fran?ois Schneider Zahava Smetana Annedore Tischer Athanassios Tsakris Robert Vranckx 《Journal of clinical virology》2006,36(2):111-118
BACKGROUND: The aim of the European Sero-Epidemiology Network (ESEN2) is to harmonise the serological surveillance of vaccine-preventable diseases in Europe. OBJECTIVE: To allow comparison of antibody prevalence in different countries by standardising results into common units. STUDY DESIGN: For varicella zoster virus (VZV), a reference laboratory established a panel of 148 samples, characterised by indirect enzyme-immunoassay (ELISA), indirect immunofluorescence, and complement fixation test. Fifty-seven samples were also studied by the fluorescence antibody to membrane antigen test. The geometric mean of the antibody activity (GMAA) obtained from four ELISA determinations was used to characterise each sample of the panel as positive (GMAA: >100 mIU/ml), equivocal (GMAA: 50-100 mIU/ml) or negative (GMAA: <50 mIU/ml) for antibody to VZV (anti-VZV). Thirteen laboratories, using five different ELISA tests, tested the panel. RESULTS: Agreement with the reference laboratory was above 85% in all cases, and the R(2) values obtained from regression analysis of the quantitative results were always higher than 0.87. Finally, the regression equations could be used to convert national values into a common unitage. CONCLUSION: This study confirmed that results for anti-VZV obtained by different ELISA methods can be converted into common units, enabling the comparison of the seroprevalence profiles obtained in the participant countries. 相似文献
8.
Canfield MC; Tamarappoo BK; Moses AM; Verkman AS; Holtzman EJ 《Human molecular genetics》1997,6(11):1865-1871
Congenital nephrogenic diabetes insipidus (NDI) is a rare disease caused
most often by mutations in the vasopressin V2 receptor (AVPR2). We studied
a family which included a female patient with NDI with symptoms dating from
infancy. The patient responded to large doses of desmopressin (dDAVP) which
decreased urine volume from 10 to 4 I/day. Neither the parents nor the
three sisters were polyuric. The patient was found to be a compound
heterozygote for two novel recessive point mutations in the aquaporin-2
(AQP2) gene: L22V in exon 1 and C181W in exon 3. Residue Cys181 in AQP2 is
the site for inhibition of water permeation by mercurial compounds and is
located near to the NPA motif conserved in all aquaporins. Osmotic water
permeability (Pf) in Xenopus oocytes injected with cRNA encoding C181W-AQP2
was not increased over water control, while expression of L22V cRNA
increased the Pf to approximately 60% of that for wild-type AQP2.
Co-injection of the mutant cRNAs with the wild-type cRNA did not affect the
function of the wild-type AQP2. Immunolocalization of AQP2-transfected CHO
cells showed that the C181W mutant had an endoplasmic reticulum-like
intracellular distribution, whereas L22V and wild-type AQP2 showed endosome
and plasma membrane staining. Water permeability assays showed a high Pf in
cells expressing wild-type and L22V AQP2. This study indicates that AQP2
mutations can confer partially responsive NDI.
相似文献
9.
Presence of antibodies reacting with porcine circovirus in sera of humans,mice, and cattle 总被引:20,自引:0,他引:20
I. Tischer L. Bode J. Apodaca H. Timm D. Peters R. Rasch S. Pociuli E. Gerike 《Archives of virology》1995,140(8):1427-1439
Summary Antibodies reacting with porcine circovirus (PCV) were found in sera of humans, mice, and cattle by means of an indirect immunofluorescence assay (IFA) and an ELISA. In man, the highest seroprevalence (23.9% in IFA and 30.2% in ELISA) was found among hospitalized patients with fever of partially unclear etiology. Non-hospitalized healthy persons of the former German Democratic Republic showed a significantly higher number of positive sera (IFA=20%) than blood donors from Berlin-West (IFA=8.6%). Murine sera reacted positive with PCV in IFA between 12 to 69% in different breeding groups and about 35% of cattle sera were found reactive with PCV in IFA. Double-staining IFAs, immuno-electron microscopy and immunoblotting showed that non-porcine antibodies reacted with PCV structural antigen. Mathematical analysis releaved that in ELISA, non-porcine antibodies reacted specifically with PCV. Loss of binding specificity of non-porcine antibodies in ELISA after storage of sera and lower maximal optical densities obtained at equal titers in ELISA with non-porcine than with porcine sera suggest that antibodies in man, mice and cattle are caused by related species specific viruses sharing antigenic epitopes with PCV. 相似文献
10.
Philipp Bohm Jürgen Scharhag Florian Egger Karl-Heinz Tischer David Niederseer Christian Schmied Tim Meyer 《The Canadian journal of cardiology》2021,37(1):105-112
BackgroundKnowledge about causes of sports-related sudden cardiac arrest (SrSCA) may influence national strategies to prevent such events. Therefore, we established a prospective registry on SrSCA to estimate the incidence and in particular describe the etiologies of SrSCA in the general population in Germany.MethodsThe registration of SrSCA based upon 4 pillars: a web-based platform to record SrSCA cases in competitive and recreational athletes, media-monitoring, cooperation with the German Resuscitation Registry, and 15 institutes of forensic medicine.ResultsAfter an observation period of 6 years, a total of 349 cases was recorded (mean age 48.0 ± 12.7 years); 109 subjects survived. Most of the cases occurred during nonelite competitive or recreational sports. Bystander cardiopulmonary resuscitation (CPR) was initiated in 262 cases (75%); however, rhythm analysis and defibrillation (if indicated) was mainly performed by medical services. In patients ≤ 35 years of age, premature coronary artery disease (CAD) and sudden arrhythmic death syndrome (SADS) prevailed, followed by myocarditis. In athletes ≥ 35 years of age, CAD predominated.ConclusionsCountry-specific registries are necessary to define the national screening and prevention strategy optimally. In Germany, premature CAD, SADS, and myocarditis are the leading causes of SrSCA in young athletes, reinforcing the great disparity of the prevalence of cardiac diseases among different countries. Extension of on-site SCD-prevention campaigns, with training of CPR and explanation of the efficient use of automated external defibrillators (AEDs), may decrease the burden of SrSCD. 相似文献