全文获取类型
收费全文 | 25118篇 |
免费 | 2065篇 |
国内免费 | 38篇 |
专业分类
耳鼻咽喉 | 404篇 |
儿科学 | 733篇 |
妇产科学 | 727篇 |
基础医学 | 3239篇 |
口腔科学 | 640篇 |
临床医学 | 3080篇 |
内科学 | 4275篇 |
皮肤病学 | 213篇 |
神经病学 | 1814篇 |
特种医学 | 914篇 |
外科学 | 3734篇 |
综合类 | 593篇 |
一般理论 | 13篇 |
预防医学 | 2958篇 |
眼科学 | 435篇 |
药学 | 1748篇 |
1篇 | |
中国医学 | 64篇 |
肿瘤学 | 1636篇 |
出版年
2021年 | 353篇 |
2020年 | 228篇 |
2019年 | 366篇 |
2018年 | 419篇 |
2017年 | 306篇 |
2016年 | 299篇 |
2015年 | 384篇 |
2014年 | 508篇 |
2013年 | 770篇 |
2012年 | 1134篇 |
2011年 | 1121篇 |
2010年 | 643篇 |
2009年 | 558篇 |
2008年 | 1033篇 |
2007年 | 1121篇 |
2006年 | 972篇 |
2005年 | 962篇 |
2004年 | 997篇 |
2003年 | 919篇 |
2002年 | 864篇 |
2001年 | 878篇 |
2000年 | 867篇 |
1999年 | 723篇 |
1998年 | 383篇 |
1997年 | 355篇 |
1996年 | 342篇 |
1995年 | 326篇 |
1994年 | 233篇 |
1993年 | 199篇 |
1992年 | 605篇 |
1991年 | 521篇 |
1990年 | 510篇 |
1989年 | 501篇 |
1988年 | 492篇 |
1987年 | 438篇 |
1986年 | 471篇 |
1985年 | 462篇 |
1984年 | 369篇 |
1983年 | 305篇 |
1982年 | 213篇 |
1981年 | 194篇 |
1980年 | 218篇 |
1979年 | 347篇 |
1978年 | 239篇 |
1977年 | 224篇 |
1975年 | 189篇 |
1974年 | 227篇 |
1973年 | 204篇 |
1972年 | 199篇 |
1969年 | 198篇 |
排序方式: 共有10000条查询结果,搜索用时 11 毫秒
121.
J. Dennis Wilson Geoff Moore 《The Australian & New Zealand journal of obstetrics & gynaecology》1995,35(1):100-101
Summary: A case of successful pregnancy in a patient with the complete DIDMOAD syndrome is described. Attention is drawn to the need to monitor fluid balance carefully during and after pregnancy in this condition. The current literature in the area is reviewed. 相似文献
122.
Margaret Comerford Freda RN EdD FAAN Mary Lou Moore RN PhD FAAN 《Journal of nursing scholarship》1995,27(1):61-64
Interdisciplinary collaboration between nursing and medicine is a valued goal, but one which is difficult to achieve. Two nurses who are faculty members in medical schools reflect on their unique roles and how these encompass interdisciplinary research, teaching, and practice. 相似文献
123.
Bilaterality in anterior cruciate ligament injuries: associated intercondylar notch stenosis 总被引:8,自引:0,他引:8
Nonsimultaneous, bilateral ACL injuries are not uncommon. We studied a group of patients with these injuries to determine possible predisposing factors that could aid in early detection and prevention of contralateral ACL injury. Retrospective analysis of 1,120 patients with ACL ruptures who were treated between 1983 and 1987 revealed 45 patients with bilateral ruptures. Complete follow-up data were available for 41 of these patients. We examined age at initial injury, sex, interval between initial and contralateral ACL injury, mechanism of injury, activity at injury, medical and family histories, treatment of initial injury, and radiographic measurement of intercondylar notch width. The overall incidence of bilaterality was 4.01% in the 28 male and 13 female patients. Their average age was 19 years and 10 months. The average interval between initial and contralateral injury was 47 months. A noncontact cutting maneuver was the most common mechanism of injury. We devised a method to measure and compare intercondylar notch widths on plain radiographs. We compared the mean notch width index (NWI) of the bilateral group to the mean NWI of a group of 50 consecutive patients with "normal" knees and to the mean NWI of 50 consecutive patients with acute ACL ruptures. The mean NWI for the normal group was .2338, for the acute ACL group, .2248, and for the bilateral group, .1961. We noted a statistically significant difference when we compared the bilateral group to the normal and acute groups (P less than 0.0001, respectively). There was no statistically significant difference between the NWI of the normal and acute ACL groups.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
124.
BACKGROUND. Currently available noninvasive techniques for measuring blood flow velocities are constrained by limited view orientations (Doppler ultrasound) or limited time resolution (magnetic resonance imaging, MRI). We describe an MRI technique for measuring flow velocities in real time at arbitrary orientations within a cylindrical volume or "beam": V-mode nuclear magnetic resonance (NMR). METHODS AND RESULTS. The technique was implemented on a standard 1.5-T clinical NMR imager with no special hardware and was tested on phantoms and human volunteers. The beam can be fired at rates up to 60 times per second, allowing measurements on a time scale that is appropriate for ungated cardiac studies. In phantoms, steady flow velocities were measured with the beam aligned along the direction of flow, and the measured velocities correlated well with the actual velocities (r > 0.99). The radial distribution of velocities in phantoms under constant flow conditions was also determined. In humans, flow of blood in the descending aortas of normal and aortic insufficiency subjects was measured. Distinctive backflow of blood because of aortic insufficiency was readily apparent. CONCLUSIONS. The V-mode NMR technique is capable of acquiring clinically relevant real-time blood flow information from any desired angle of view with no attenuation at bone or air-tissue interfaces. 相似文献
125.
126.
An association between variants in the IGF2 gene and Beckwith-Wiedemann syndrome: interaction between genotype and epigenotype 总被引:5,自引:0,他引:5
Murrell A Heeson S Cooper WN Douglas E Apostolidou S Moore GE Maher ER Reik W 《Human molecular genetics》2004,13(2):247-255
Beckwith-Wiedemann syndrome (BWS) is a fetal overgrowth disorder involving the deregulation of a number of genes, including IGF2 and CDKN1C, in the imprinted gene cluster on chromosome 11p15.5. In sporadic BWS cases the majority of patients have epimutations in this region. Loss of imprinting of the IGF2 gene is frequently observed in BWS, as is reduced CDKN1C expression related to loss of maternal allele-specific methylation (LOM) of the differentially methylated region KvDMR1. The causes of epimutations are unknown, although recently an association with assisted reproductive technologies has been described. To date the only genetic mutations described in BWS are in the CDKN1C gene. In order to screen for other genetic predispositions to BWS, the conserved sequences between human and mouse differentially methylated regions (DMRs) of the IGF2 gene were analyzed for variants. Four single nucleotide polymorphisms (SNPs) were found in DMR0 (T123C, G358A, T382G and A402G) which occurred in three out of 16 possible haplotypes: TGTA, CATG and CAGA. DNA samples from a cohort of sporadic BWS patients and healthy controls were genotyped for the DMR0 SNPs. There was a significant increase in the frequency of the CAGA haplotype and a significant decrease in the frequency of the CATG haplotype in the patient cohort compared to controls. These associations were still significant in a BWS subgroup with KvDMR1 LOM, suggesting that the G allele at T382G SNP (CAGA haplotype) is associated with LOM at KvDMR1. This indicates either a genetic predisposition to LOM or interactions between genotype and epigenotype that impinge on the disease phenotype. 相似文献
127.
Effect of a CCR5 inhibitor on viral loads in macaques dual-infected with R5 and X4 primate immunodeficiency viruses 总被引:2,自引:0,他引:2
Wolinsky SM Veazey RS Kunstman KJ Klasse PJ Dufour J Marozsan AJ Springer MS Moore JP 《Virology》2004,328(1):19-29
Human immunodeficiency virus type 1 (HIV-1) fusion with its target cells is initiated by sequential interactions between its envelope glycoprotein, CD4, and a co-receptor, usually CCR5 or CXCR4. Small molecules that bind to CCR5 and prevent its use by R5 HIV-1 strains are now being developed clinically as antiviral drugs. To test whether a block to CCR5 promotes the replication of viruses that enter cells via CXCR4 and are associated with accelerated disease progression, we administered a small molecule CCR5 inhibitor, CMPD 167, to three macaques dual-infected with both R5 (SIVmac251) and X4 (SHIV-89.6P) viruses. CMPD 167 caused a rapid and substantial (on average, 50-fold) suppression of R5 virus replication in each animal. In two of the animals, but not in the third, a rapid, transient, 8- to 15-fold increase in the amount of plasma X4 virus occurred. In neither animal was the increase in X4 viral load sustained throughout therapy, however. These observations may have relevance for the development of CCR5 inhibitors for treatment of HIV-1 infection of humans. 相似文献
128.
Depression of lymphocyte response to phytohaemagglutinin in the presence of plasma from children with acute protein energy malnutrition. 下载免费PDF全文
Phytohaemagglutinin-induced lymphocyte transformation of four healthy adults and a child with kwashiorkor was performed in the presence of plasma from nineteen patients with protein energy malnutrition and a nutritionally normal child. Marked inhibition occurred in the presence of plasma from six patients who subsequently died, moderate inhibition occurred in six other patients in the acute stage and in two of these six in the convalescent stage, whilst in the remaining seven there was no effect. Reduction in response did not appear to be due to plasma cytotoxicity. Plasma factors in some cases of malnutrition, associated with certain infections appear to inhibit the lymphocyte response and this may have prognostic implications. 相似文献
129.
Pelosi G Scarpa A Veronesi G Spaggiari L Del Curto B Moore PS Maisonneuve P Sonzogni A Masullo M Viale G 《Virchows Archiv : an international journal of pathology》2005,447(6):969-977
Nuclear translocation of β-catenin has been correlated with epidermal growth factor receptor (EGFR) overexpression/activation
in nonsmall cell lung cancer. Less is known on β-catenin transactivation in high-grade pulmonary neuroendocrine tumors and
on the status of β-catenin activating EGFR and human epidermal growth factor receptor 2 (HER-2) or β-catenin target genes
cyclin D1 and matrix metalloproteinase-7 (MMP-7). β-catenin immunoreactivity was evaluated in 51 large-cell neuroendocrine
carcinomas (LCNEC) and 45 small-cell lung carcinomas (SCLC). Nineteen cases were assessed for β-catenin gene exon 3 mutations, expression of MMP-7, and expression/gene amplification of EGFR, HER-2, and cyclin D1. β-catenin was
expressed in all 96 high-grade neuroendocrine tumors, the vast majority (94%) showing >50% immunopositive cells. A disarrayed
immunoreactivity, however, was commonly encountered consisting in variably altered membrane-associated patterns of staining
along with progressive accumulation of cytoplasmic immunoreactivity. In LCNEC, but not in SCLC, the disarrayed patterns correlated
with EGFR and HER-2 protein expression. β-catenin nuclear accumulation was found in nine tumors, including seven LCNEC and
two SCLC, and was always associated with disarrayed immunoreactivity and increased MMP-7, but not cyclin D1 expression. These
cases, however, did not show β-catenin gene mutations or EGFR and HER-2 gene amplification or expression. No association was found between nuclear β-catenin and
any clinicopathological variable including patients' survival. The subcellular compartmentalization of β-catenin is profoundly
altered in high-grade pulmonary neuroendocrine tumors. A minor subset of these tumors shows β-catenin nuclear accumulation
in association with increased expression of MMP-7, but not of cyclin D1, independent of EGFR and HER-2 gene amplification
or expression.
The authors have no significant financial or other relationship with the manufacturers of any commercial products or commercial
services presented in this paper 相似文献
130.
Mutations in the retinal guanylate cyclase (RETGC-1) gene in dominant cone-rod dystrophy 总被引:3,自引:0,他引:3
Kelsell RE; Gregory-Evans K; Payne AM; Perrault I; Kaplan J; Yang RB; Garbers DL; Bird AC; Moore AT; Hunt DM 《Human molecular genetics》1998,7(7):1179-1184
The dominant cone-rod dystrophy gene CORD6 has previously been mapped to
within an 8 cM interval on chromosome 17p12-p13. The retinal- specific
guanylate cyclase gene (RETGC-1), which maps to within this genetic
interval and previously was implicated in Leber's congenital amaurosis, was
screened for mutations within this family and in a panel of small families
and individuals with various cone and cone- rod dystrophy phenotypes. A
missense mutation (E837D) was identified in affected members of the CORD6
family, as well as a second missense mutation (R838C) in three other
families with dominant cone-rod dystrophy. RETGC-1 is only the fourth gene
to be implicated in cone-rod dystrophy and this is the first report of
dominant mutations in this gene.
相似文献