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51.
Monochorionic monozygotic twins frequently suffer complications from the presence of vascular anastomoses in their monochorionic placentas. Also, sharing of perfusion zones may be unequal, leading to marked growth discordance. This paper analyzes four measures of perinatal outcome (gestational age at delivery, perinatal mortality, birth weight discordance, and presence/absence of hydramnios) according to the vascular patterns of the monochorionic placentas. The worst clinical outcomes were associated with arteriovenous anastomoses in the absence of arterio-arterial and veno-venous anastomoses. The vascular patterns of monochorionic placentas cause significant fetal environmental differences within pairs of monochorionic monozygotic twins. These differences may cause life-long discordance for several phenotypic traits that are not genetically based, and which cause monochorionic monozygotic twins to be “non-identical.” © 1996 Wiley-Liss, Inc.  相似文献   
52.
Human coronavirus (HCoV) is a known cause of influenza‐like illness (ILI). In a multisite, observational, longitudinal study of ILI among otherwise healthy adolescents and adults, 12% of subjects were PCR‐positive for HCoV. The distribution of species was as follows: HCoV‐OC43 (34%), HCoV‐229E (28%), HCoV‐NL63 (22%), and HCoV‐HKU1 (16%). We did not observe species‐specific differences in the clinical characteristics of HCoV infection, with the exception of HCoV‐HKU1, for which the severity of gastrointestinal symptoms trended higher on the fourth day of illness.  相似文献   
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Cancers expressing mutant RAS are associated with a weaker response to chemotherapy and a shorter overall patient survival. We have demonstrated that the irreversible inhibitor of ERBB1/2/4, neratinib, inhibits ERBB1/2/4 and causes their internalization and autolysosomal degradation. Fellow-traveler membrane proteins with RTKs, including mutant K-/N-RAS, were also degraded. We discovered that the CDK4/6 inhibitor palbociclib increased autophagosome and then autolysosome levels in a time dependent fashion, did not reduce mTOR activity, and interacted with temsirolimus to kill. Neratinib and palbociclib interacted in a greater than additive manner to increase autophagosome and then autolysosome levels in a time dependent fashion, and to cause tumor cell killing. Killing required the expression of ATM and AMPKα, Beclin1 and ATG5, BAX and BAK and of AIF, but not of caspase 9. In some cells over-expression of BCL-XL was protective whereas in others it was ineffective. The lethality of [neratinib + palbociclib] was modestly enhanced by the PDE5 inhibitor sildenafil and strongly enhanced by the HDAC inhibitor sodium valproate. This was associated with K-RAS degradation and a greater than additive increase in autophagosome and autolysosome levels. Killing by the three-drug combination required ATM and AMPKα, and, to a greater extent, Beclin1 and ATG5. In vivo, [valproate + palbociclib] and [neratinib + valproate + palbociclib] interacted to suppress the growth of a carboplatin/paclitaxel resistant PDX ovarian tumors that express a mutant N-RAS. Our data support performing a future three-drug trial with these agents.  相似文献   
55.
Phenotypic manifestations of copy number variation in chromosome 16p13.11   总被引:1,自引:0,他引:1  
The widespread clinical utilization of array comparative genome hybridization, has led to the unraveling of many new copy number variations (CNVs). Although some of these CNVs are clearly pathogenic, the phenotypic consequences of others, such as those in 16p13.11 remain unclear. Whereas deletions of 16p13.11 have been associated with multiple congenital anomalies, the relevance of duplications of the region is still being debated. We report detailed clinical and molecular characterization of 10 patients with duplication and 4 patients with deletion of 16p13.11. We found that patients with duplication of the region have varied clinical features including behavioral abnormalities, cognitive impairment, congenital heart defects and skeletal manifestations, such as hypermobility, craniosynostosis and polydactyly. These features were incompletely penetrant. Patients with deletion of the region presented with microcephaly, developmental delay and behavioral abnormalities as previously described. The CNVs were of varying sizes and were likely mediated by non-allelic homologous recombination between low copy repeats. Our findings expand the repertoire of clinical features observed in patients with CNV in 16p13.11 and strengthen the hypothesis that this is a dosage sensitive region with clinical relevance.  相似文献   
56.
OBJECTIVE: This autopsy-based study was designed to evaluate sonographic and neuropathologic findings of fetuses diagnosed prenatally with Dandy-Walker malformation complex. METHODS: The retrospective study encompassed a series of 44 autopsy cases from 2 tertiary referral centers with a prenatal ultrasound diagnosis of Dandy-Walker malformation complex between 1995 and 2003. Ultrasound and pathology data from the cases and from age-matched controls were reviewed in a blinded manner. An unequivocal diagnosis of Dandy-Walker malformation complex from ultrasonography or pathology archival images required significant hypoplasia or aplasia of the cerebellar vermis. RESULTS: Neuropathologic examination failed to confirm the prenatal diagnosis of Dandy-Walker malformation complex in 59% (26/44, 95% confidence interval [CI] 44-72) of the cases. After standardized reevaluation of high quality archival sonograms and pathology images, concordance remained poor at 55% (6/11 cases, 95% CI 28-79). Sonographic features that favored concordance included marked enlargement of the cisterna magna (> or = 10 mm), complete aplasia of the vermis, and a trapezoid-shaped gap between the cerebellar hemispheres. This latter finding contrasted with a keyhole-shaped gap in fetuses with no cerebellar neuropathology. CONCLUSION: Correlation between a prenatal ultrasound diagnosis of Dandy-Walker malformation complex and autopsy neuropathology findings is poor. Unequivocal prenatal sonographic diagnosis of Dandy-Walker malformation complex should be reserved for cases with the classic findings of Dandy-Walker malformation, including enlargement of the cisterna magna, aplasia of the vermis, and a trapezoid-shaped, rather than keyhole-shaped, interhemispheric gap. LEVEL OF EVIDENCE: III.  相似文献   
57.
Based on a review of the medical literature (PubMed database, keywords: medical information, informed consent), the authors analyse the main medicolegal aspects concerning the patient information that must be provided in France prior to any invasive diagnostic or therapeutic medical procedures in otorhinolaryngology head and neck surgery, as well as the patient's perception and recall of the information provided, the quality of the information provided and problems encountered in providing this information. In the light of this review, several solutions are recommended to improve this essential phase prior to obtaining the patient's informed consent.  相似文献   
58.
Chromosome 15q11q13 is among the least stable regions in the genome due to its highly complex genomic architecture. Low copy repeat elements at 15q13.3 facilitate recurrent copy number variants (CNVs), with deletions established as pathogenic and CHRNA7 implicated as a candidate gene. However, the pathogenicity of duplications of CHRNA7 is unclear, as they are found in affected probands as well as in reportedly healthy parents and unaffected control individuals. We evaluated 18 children with microduplications involving CHRNA7, identified by clinical chromosome microarray analysis (CMA). Comprehensive phenotyping revealed high prevalence of developmental delay/intellectual disability, autism spectrum disorder, and attention deficit/hyperactivity disorder. As CHRNA7 duplications are the most common CNVs identified by clinical CMA, this study provides anticipatory guidance for those involved with care of affected individuals.  相似文献   
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60.
Human MUC1 mucin is a high-molecular-weight transmembrane glycoprotein, which is apically expressed in the majority of glandular epithelia. During embryonic development, changes in the pattern of MUC1 mucin expression coincide with the onset of glandular differentiation. This mucin is also frequently overexpressed and aberrantly glycosylated in carcinomas. To investigate the potential role of MUC1 mucin in morphogenesis, a full length MUC1 cDNA was transfected into murine mammary adenocarcinoma (410.4) and Madin-Darby canine kidney (MDCK) cells. This generated four clonal cell lines. Western blotting, FACS analysis, and immunohistochemistry confirmed expression of MUC1. All four MUC1-expressing clones demonstrated altered morphogenesis when cultured in three-dimensional type I collagen gels. While parental and vector control 410.4 cells formed compact spherical structures, the MUC1-expressing clones formed complex branching structures. Similarly, while parental and vector control MDCK cells formed small circumscribed colonies with a central lumen, the MUC1-expressing clones formed elongated tubules. MUC1 expression was also associated with reduced cellular cohesion and enhanced migration on type I collagen-coated surfaces for all except one of the clones, which expressed only low levels of MUC1 on the cell surface. These results show that MUC1 expression stimulates morphogenetic changes in two distinct epithelial cell lines. Taken together with previous observations on MUC1 expression in embryonic development and carcinomas, this finding suggests that MUC1 may induce changes in tissue architecture in both normal development and cancer.  相似文献   
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