全文获取类型
收费全文 | 699篇 |
免费 | 31篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 59篇 |
妇产科学 | 3篇 |
基础医学 | 82篇 |
口腔科学 | 16篇 |
临床医学 | 95篇 |
内科学 | 158篇 |
皮肤病学 | 23篇 |
神经病学 | 14篇 |
特种医学 | 146篇 |
外国民族医学 | 1篇 |
外科学 | 50篇 |
综合类 | 12篇 |
预防医学 | 24篇 |
眼科学 | 4篇 |
药学 | 18篇 |
肿瘤学 | 24篇 |
出版年
2022年 | 2篇 |
2021年 | 10篇 |
2020年 | 3篇 |
2019年 | 3篇 |
2018年 | 7篇 |
2017年 | 5篇 |
2016年 | 8篇 |
2015年 | 15篇 |
2014年 | 15篇 |
2013年 | 23篇 |
2012年 | 16篇 |
2011年 | 33篇 |
2010年 | 35篇 |
2009年 | 22篇 |
2008年 | 15篇 |
2007年 | 18篇 |
2006年 | 15篇 |
2005年 | 13篇 |
2004年 | 8篇 |
2003年 | 13篇 |
2002年 | 10篇 |
2001年 | 6篇 |
2000年 | 3篇 |
1999年 | 4篇 |
1998年 | 36篇 |
1997年 | 48篇 |
1996年 | 45篇 |
1995年 | 36篇 |
1994年 | 24篇 |
1993年 | 24篇 |
1992年 | 7篇 |
1991年 | 15篇 |
1990年 | 11篇 |
1989年 | 18篇 |
1988年 | 27篇 |
1987年 | 21篇 |
1986年 | 26篇 |
1985年 | 15篇 |
1984年 | 5篇 |
1983年 | 5篇 |
1982年 | 5篇 |
1981年 | 14篇 |
1980年 | 6篇 |
1979年 | 6篇 |
1978年 | 8篇 |
1977年 | 9篇 |
1976年 | 5篇 |
1975年 | 9篇 |
1965年 | 1篇 |
1835年 | 1篇 |
排序方式: 共有732条查询结果,搜索用时 15 毫秒
11.
J-L Stievenart EA Cabanis P Menard J Knoplioch A Lopez J Tamraz M-T Iba-Zizen B Philippe G Prevost J-C Bertrand 《Surgical and radiologic anatomy : SRA》1993,15(1):47-54
Summary In view of the variety of 3D representation techniques, a clinical study was carried out in order to evaluate their respective usefulness. It appears that a single technique cannot be claimed to be valid for all clinical situations and that a combination of representations brings more relevant information. Among the different techniques a clear delineation must be established between those which allow the accurate definition of landmarks (multiplanar reformation, surface representation), and those which do not (integral shading, reconstructed radiology). The main point is the possibility to recognize anatomical landmarks on these latter modes and to choose oblique cut planes in relation to them. Visualization quality is strongly dependent upon the acquisition protocol which must provide a spatial resolution as isotropic as possible.
Une revue de différents modes de visualisation en haute résolution d'un objet volumique avec des applications
Résumé Face à la variété des techniques de représentation 3D une étude clinique a été conduite pour évaluer leurs utilités respectives. Il apparait qu'une technique unique ne peut pas convenir à toutes les situations cliniques et qu'une combinaison de différents modes de présentation apporte une information plus pertinente. Parmi les différentes techniques une distinction claire doit être établie entre celles qui autorisent la prise de repères précis (reformatage multiplanaire, représentation de surface), et celles qui ne le permettent pas (ombrage intégral, radiologie reconstruite). Le point principal est la possibilité de reconnaître des repères anatomiques sur ces derniers modes et de choisir des plans de coupe en relation avec eux. La qualité de la visualisation dépend étroitement du protocole d'acquisition qui doit fournir une résolution aussi isotrope que possible.相似文献
12.
Igarashi S; Takiyama Y; Cancel G; Rogaeva EA; Sasaki H; Wakisaka A; Zhou YX; Takano H; Endo K; Sanpei K; Oyake M; Tanaka H; Stevanin G; Abbas N; Durr A; Rogaev EI; Sherrington R; Tsuda T; Ikeda M; Cassa E; Nishizawa M; Benomar A; Julien J; Weissenbach J; Tsuji S 《Human molecular genetics》1996,5(7):923-932
Machado-Joseph disease (MJD) is an autosomal dominant neurodegenerative
disorder caused by unstable expansion of a CAG repeat in the MJD1 gene at
14q32.1. To identify elements affecting the intergenerational instability
of the CAG repeat, we investigated whether the CGG/GGG polymorphism at the
3' end of the CAG repeat affects intergenerational instability of the CAG
repeat. The [expanded (CAG)n-CGG]/[normal (CAG)n- GGG] haplotypes were
found to result in significantly greater instability of the CAG repeat
compared to the [expanded (CAG)n- CGG]/[normal (CAG)n-CGG] or [expanded
(CAG)nGGG]/[normal (CAG)n-GGG] haplotypes. Multiple stepwise logistic
regression analysis revealed that the relative risk for a large
intergenerational change in the number of CAG repeat units (< -2 or >
2) is 7.7-fold (95% CI: 2.5-23.9) higher in the case of paternal
transmission than in that of maternal transmission and 7.4-fold (95% CI:
2.4-23.3) higher in the case of transmission from a parent with the
[expanded (CAG)n-CGG]/[normal (CAG)n-GGG] haplotypes than in that of
transmission from a parent with the [expanded (CAG)n-CGG]/[normal
(CAG)n-CGG] or [expanded (CAG)n- GGG]/[normal (CAG)n-GGG] haplotypes. The
combination of paternal transmission and the [expanded (CAG)n-CGG]/[normal
(CAG)n-GGG] haplotypes resulted in a 75.2-fold (95% CI: 9.0-625.0) increase
in the relative risk compared with that of maternal transmission and the
[expanded (CAG)n-CGG]/[normal (CAG)n-CGG] or [expanded (CAG)n- GGG]/[normal
(CAG)n-GGG] haplotypes. The results suggest that an inter- allelic
interaction is involved in the intergenerational instability of the
expanded CAG repeat.
相似文献
13.
Functional consequences of ROMK mutants linked to antenatal Bartter's syndrome and implications for treatment 总被引:4,自引:0,他引:4
The antenatal variant of Bartter's syndrome is an autosomal recessive
kidney disease characterized by polyhydramnios, premature delivery,
hypokalemic alkalosis and hypercalciuria. It is genetically heterogeneous,
having been linked recently to mutations in an ATP- sensitive, renal outer
medullary K+channel, ROMK, and earlier to mutations in the Na-K-2Cl
co-transporter, NKCC2. We characterized four of the mutations reported in
three heterozygous ROMK variants of antenatal Bartter's and found that each
expressed a distinct phenotype in Sf9 cells. One mutation expressed normal
function and appears to be an allelic polymorphism. The other three
mutations produced channels with significantly reduced K+fluxes. However,
the mechanisms in each case were different and reflected abnormalities in
phosphorylation, proteolytic processing or protein trafficking. The
different mechanisms may be important in the design of appropriate therapy
for patients with this disease.
相似文献
14.
Detecting pre-ovulatory luteinizing hormone surges in urine 总被引:2,自引:1,他引:2
Kesner JS; Knecht EA; Krieg EF Jr; Wilcox AJ; O'Connor JF 《Human reproduction (Oxford, England)》1998,13(1):15-21
The study objectives were to determine (i) if pre-ovulatory luteinizing
hormone (LH) surges, undetected in urine by two immunoradiometric assays
(IRMA), were detectable by an ultrasensitive immunofluorometric assay
(IFMA) and (ii) the influence of creatinine adjustment on the detection and
timing of the urinary LH surges. Daily urine specimens were contributed by
healthy 25-36 year old volunteers during 14 ovulatory menstrual cycles for
an epidemiological study conducted in 1983-1985. Specimens were selected as
having been previously assayed by two IRMA without consistently detecting
LH surges. These urine specimens were remeasured using an IFMA and adjusted
for creatinine concentration. IFMA measurements revealed unambiguous LH
surges in all cycles. Adjusting IRMA urinary LH values for creatinine
concentrations revealed previously undetected LH surges in four of eight
cycles. Creatinine adjustment also altered the timing of IRMA and IFMA LH
surges by 1-5 days. These results demonstrate an IFMA that detects pre-
ovulatory LH surges in unpreserved, frozen urine from cycles where such
surges were previously undetectable. Further, creatinine adjustment can
markedly affect detection and timing of the onset and peak of the urinary
LH surge. While our analysis suggests that this adjustment improves the
validity of the LH measure, this requires further investigation.
相似文献
15.
16.
17.
18.
19.
Edward Gologorsky Ernesto A. Pretto Kyota Fukazawa 《Journal of clinical anesthesia》2013,25(8):618-623
Study ObjectiveTo determine the distribution of coronary artery disease (CAD) and its risk factors across the various etiologies of end-stage liver disease, and to elucidate the relationship between severe alcohol consumption and CAD.DesignRetrospective multicenter study analysis.SettingNational Standard Transplant Analysis and Research file data.MeasurementsData from all primary adult orthotopic liver transplant recipients during the period from 2004 through 2006 were studied. Data were divided into 5 groups according to each patient’s etiology of end-stage liver disease. The prevalence of CAD and the distribution of its risk factors were compared among groups.Main results17,482 cases were studied. The incidence of CAD was highest in nonalcoholic hepatic steatosis (7.4%) and lowest in biliary cirrhosis (1.7%). No difference in prevalence of CAD and its risk factors was noted between the viral and alcoholic etiologies (Hepatitis C 2.7%, Hepatitis B 2.3%, and alcoholic cirrhosis 2.9%).ConclusionsPrevalence of CAD and the distribution of CAD risk factors in patients with severe alcohol consumption were similar to patients with viral hepatitis. CAD was most prevalent in patients with hepatic steatosis. This study argues against the notion of decreased expression and progression of CAD in patients with alcoholic cirrhosis presenting for liver transplantation. 相似文献
20.
Membrane-associated sickle hemoglobin: a major determinant of sickle erythrocyte rigidity 总被引:1,自引:0,他引:1
Micropipette aspiration tests on single erythrocytes have previously shown that the static rigidity (membrane shear modulus) of oxygenated sickle cells increased with increasing hemoglobin concentration, whereas the rigidity of normal cells was independent of hemoglobin concentration. Moreover, it was observed that after mechanical extension, sickle cells exhibited persistent deformation more frequently and to a greater extent than normal cells. To ascertain if differences in association of normal and sickle hemoglobin with the membrane could account for these observations, we measured rheologic properties of normal membranes reconstituted with sickle hemoglobin and sickle membranes reconstituted with normal hemoglobin. The static rigidity of normal ghosts reloaded with sickle hemoglobin was higher than those of either normal ghosts reloaded with normal hemoglobin or native normal cells. On the other hand, the increased rigidity of native sickle cells decreased to near-normal values following reconstitution with normal hemoglobin. Furthermore, we observed that normal ghosts reconstituted with sickle hemoglobin exhibited persistent bumps after mechanical extension, but no bumps formed on normal ghosts reconstituted with normal hemoglobin. Moreover residual bumps were not produced on sickle cells reloaded with normal hemoglobin. Since mechanical characteristics peculiar to sickle cells could be induced in normal cells by incorporation of sickle hemoglobin, and since normal characteristics could be restored to sickle cells by incorporation of normal hemoglobin, we suggest that the interaction of sickle hemoglobin with the cell membrane is responsible for augmented static rigidity of oxygenated sickle erythrocytes. 相似文献