全文获取类型
收费全文 | 1541篇 |
免费 | 86篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 19篇 |
儿科学 | 86篇 |
妇产科学 | 25篇 |
基础医学 | 170篇 |
口腔科学 | 27篇 |
临床医学 | 158篇 |
内科学 | 273篇 |
皮肤病学 | 34篇 |
神经病学 | 124篇 |
特种医学 | 210篇 |
外科学 | 248篇 |
综合类 | 17篇 |
一般理论 | 1篇 |
预防医学 | 94篇 |
眼科学 | 18篇 |
药学 | 61篇 |
肿瘤学 | 64篇 |
出版年
2023年 | 7篇 |
2022年 | 9篇 |
2021年 | 17篇 |
2020年 | 8篇 |
2019年 | 17篇 |
2018年 | 29篇 |
2017年 | 23篇 |
2016年 | 31篇 |
2015年 | 27篇 |
2014年 | 41篇 |
2013年 | 57篇 |
2012年 | 92篇 |
2011年 | 86篇 |
2010年 | 82篇 |
2009年 | 65篇 |
2008年 | 65篇 |
2007年 | 66篇 |
2006年 | 61篇 |
2005年 | 58篇 |
2004年 | 41篇 |
2003年 | 41篇 |
2002年 | 29篇 |
2001年 | 27篇 |
2000年 | 29篇 |
1999年 | 30篇 |
1998年 | 43篇 |
1997年 | 50篇 |
1996年 | 50篇 |
1995年 | 45篇 |
1994年 | 23篇 |
1993年 | 27篇 |
1992年 | 24篇 |
1991年 | 25篇 |
1990年 | 23篇 |
1989年 | 32篇 |
1988年 | 36篇 |
1987年 | 37篇 |
1986年 | 34篇 |
1985年 | 17篇 |
1984年 | 8篇 |
1983年 | 7篇 |
1981年 | 14篇 |
1980年 | 7篇 |
1979年 | 6篇 |
1978年 | 10篇 |
1977年 | 14篇 |
1976年 | 5篇 |
1975年 | 9篇 |
1972年 | 8篇 |
1965年 | 6篇 |
排序方式: 共有1629条查询结果,搜索用时 15 毫秒
11.
Berbaum KS; el-Khoury GY; Franken EA Jr; Kathol M; Montgomery WJ; Hesson W 《Radiology》1988,168(2):507-511
The effect of knowledge of localizing symptoms and signs in the detection of fractures was studied. Forty radiographs of the extremities were examined twice by seven radiologists; the sessions were separated by 4 months. In 26 cases, a subtle fracture was present; 14 cases were normal. In half of the cases at each session, the precise location of pain, tenderness, or swelling was provided. The observer was asked to determine if the case was normal or abnormal (provide the exact location of the fracture) and to indicate the degree of confidence in the diagnosis. Responses were converted to a numeric scale for analysis. Analysis of receiver operator characteristic parameters indicates that clues regarding location of trauma facilitate detection of fractures. The improvement is based largely on an increased true-positive rate without an increased false-positive rate, regardless of the decision criteria of the radiologist (overall willingness to "overread" or "underread"). This has direct clinical applicability and reinforces the plea of radiologists for precise clinical information. 相似文献
12.
Two males suffering from Pelizaeus-Merzbacher disease were examined, one at the age of 1 year 4 months and at the age of 7 years, and the other at the age of 7 years 8 months. The former had spontaneous vertical pendular nystagmus. He also showed horizontal "micronystagmus", present only at the age of 1 year, which might be similar to "voluntary nystagmus". Both males had jerky bilateral gaze-evoked nystagmus, defective smooth pursuit and optokinetic responses and a hyporeactive vestibulo-ocular reflex (VOR). All three obligate carriers exhibited typical VOR disinhibition in the two horizontal nystagmus directions, which may be a distinctive feature. This feature was also found in one of the 7 possible carriers examined and was not observed in the 3 non-affected males, who had normal oculomotor responses. 相似文献
13.
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
14.
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
15.
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
16.
Partial characterization of a Hantavirus isolated from a Clethrionomys glareolus captured in Belgium 总被引:1,自引:0,他引:1
G van der Groen G Beelaert G Hoofd H Leirs R Verhagen H Yamanishi E A Tkachenko A P Ivanov 《Acta virologica》1987,31(2):180-184
A Hantavirus was isolated in Vero-E6 cells from lungs of a free living bank vole (Clethrionomys glareolus) captured in Turnhout, Province of Antwerp--Northern part of Belgium. With help of monoclonal antibodies the Belgian Hantavirus isolate could be clearly differentiated from Hantaan virus strain 76-118, Prospect Hill virus strain PH1 and SR11, a Hantavirus isolated from laboratory Wistar rat in Japan, but not from the nephropathia epidemica virus strain H?lln?s. 相似文献
17.
A common ancestor for COCH related cochleovestibular (DFNA9) patients in Belgium and The Netherlands bearing the P51S mutation 总被引:6,自引:0,他引:6 下载免费PDF全文
18.
19.
Han C.G. Kemper E.A.L.M. Verhagen D. Milo G.B. Post F. Van Lenthe W van Mechelen J.W.R. Twisk W W de Vente 《American journal of human biology》2002,14(4):448-456
In the Amsterdam Growth and Health Longitudinal Study (AGAHLS), a group of apparently healthy males and females (n = 200) were interviewed about their physical activities on eight separate occasions over a period of 20 years between 13 and 33 years of age (multi‐measured group: MM). Information about their health was given based on their personally measured lifestyle (activity, diet, smoking) and biological risk characteristics for chronic diseases (medical check‐ups). A comparable group of boys and girls (n = 200) was only measured on two occasions (bi‐measured group: BM): at 13 and 33 years. Physical activity was estimated with a structured interview. Total physical activity and sports activity were estimated in three intensity levels (light, moderate, and heavy). It was hypothesized that the eight repeated medical check‐ups with health information in the MM group would result in a healthier lifestyle with respect to the determinants and levels of habitual physical activity compared to the BM group. Contrary to the hypothesis, males and females in the BM group showed a significantly higher increase or a lower decrease in physical activities compared to the MM group. This negative effect on the physical activity pattern at 33 years in the MM group may have been caused by more underreporting of physical activities than in the BM group. In conclusion, there does not appear to be a significant effect of long‐term (multi‐measured) health information with medical check‐ups during adolescence and young adulthood on level of physical activity in males and females at 33 years of age. Am. J. Hum. Biol. 14:448–456, 2002. © 2002 Wiley‐Liss, Inc. 相似文献
20.
Escutenaire S Chalon P Verhagen R Heyman P Thomas I Karelle-Bui L Avsic-Zupanc T Lundkvist A Plyusnin A Pastoret P 《Virus research》2000,67(1):91-107
Dynamics of hantavirus infection and population densities in rodents were investigated from 1996 to 1999 in southern Belgium. Evidence of Puumala infection was restricted to Clethrionomys glareolus. Although the serotype was not determined, antibodies against hantavirus were also found in eight Apodemus sylvaticus. In fall 1996, the seroprevalence in C. glareolus was high (20.1%, 37 of 184) and the infection was widely distributed in the area studied whereas a focal occurrence of positive rodents and lower seroprevalence rates were recorded in spring 1997 (14.3%, six of 42), fall 1997 (6. 6%, 11 of 166), spring 1998 (6.4%, three of 47) and fall 1998 (6.7%, 11 of 165). A pullulation of rodents was observed in spring 1999 and was associated with a markedly higher seroprevalence in C. glareolus (47.7%, 189 of 396). In all seasons, infection rates in adults were higher than in juveniles and subadults. No significant difference of prevalence was recorded between males and females. In two trapping sites, the temporary disappearance of positive animals after a crash in rodent populations suggests that a threshold in density is necessary for the maintenance of the enzootic cycle. 相似文献