42,589 research outputs found
Reply to comments on 'EPR study of He-implanted Si' by P. Pivac, B. Rakvin, R. Tonini, F. Corni, G. Ottaizani, Published in Mater. Sci. Eng. B73 (2000) 60-63 - Written by M. Kakazey, M. Vlasova, and J.G. Gonzalez-Rodriguez - Reply to discussion
No full textReply to comments on 'EPR study of He-implanted Si' by P. Pivac, B. Rakvin, R. Tonini, F. Corni, G. Ottaizani, Published in Mater. Sci. Eng. B73 (2000) 60-63 - Written by M. Kakazey, M. Vlasova, and J.G. Gonzalez-Rodriguez - Reply to discussio
Genetic predisposition and chromosome instability in neuroblastoma
No full textNeuroblastoma (NB) is a pediatric tumor of embryonic origin. About 1–2% of all NBs are familial cases, and genetic predisposition is suspected for the remaining cases. During the last decade, genome-wide association studies (GWAS) and high-throughput sequencing approaches have been used to identify associations among common and rare genetic variants and NB risk. Substantial data has been produced by large patient cohorts that implicate various genes in NB tumorigenesis, such as CASC15, BARD1, CHEK2, LMO1, LIN28B, AXIN2, BRCA1, TP53, SMARCA4, and CDK1NB. NB, as well as other pediatric cancers, has few recurrent mutations but several copy number variations (CNVs). Almost all NBs show both numerical and structural CNVs. The proportion between numerical and structural CNVs differs between localized and metastatic tumors, with a greater prevalence of structural CNVs in metastatic NB. This genomic chaos frequently identified in NBs suggests that chromosome instability (CIN) could be one of the major actors in NB oncogenesis. Interestingly, many NB-predisposing variants occur in genes involved in the control of genome stability, mitosis, and normal chromosome separation. Here, we discuss the relationship between genetic predisposition and CIN in NB
Lambda CDM halo density profiles: where do actual halos converge to NFW ones?
No full textAims. We present an analysis of 37 high-quality extended rotation curves that highlights the existence of a new discrepancy (or a new aspect of an old discrepancy) between the density profiles predicted by the Lambda Cold Dark Matter (LambdaCDM) theory and the actual distribution of dark matter in galaxies.
Methods. We compare the predicted face-value density vs. enclosed mass relationship, at large distances, to the observational data at the last measured radii of the rotation curves and in two whole rotation curves of high quality. A further analysis is performed by studying a relation, inbuilt in LambdaCDM, that links at radius R, the enclosed halo mass M(R) and its density rho(R) in a way that is independent of the mass of the virialised object.
Results. We find that the predicted density vs. enclosed mass relationship has a systematic offset with respect to the observational data. In test case extended rotation curves, at their last measured point, the predicted NFW densities are up to a factor 3 lower than those derived from the kinematics. Moreover, the abovementioned relation, inbuilt in LambdaCDM, does not hold for the objects of our sample. Such a new outer discrepancy is different and maybe complementary with respect to the core/cusp issue, for which the NFW densities turn out to be higher than those observed and it seems to imply a global mass rearrangement of a pristine NFW-LambdaCDM halo
Impact of interleukin-6 -174 G>C gene promoter polymorphism on neuroblastoma.
No full textBACKGROUND: Common variants in DNA may predispose to onset and progression of neuroblastoma (NB). The genotype GG of single nucleotide polymorphism (SNP) rs1800795 (-174 G>C) in interleukin (IL)-6 promoter has been associated with lower survival of high-risk NB.
RESULT: To evaluate the impact of IL-6 SNP rs1800795 on disease risk and phenotype, we analyzed 326 Italian NB patients and 511 controls. Moreover, we performed in silico and quantitative Real Time (qRT)-PCR analyses to evaluate the influence of the SNP on gene expression in 198 lymphoblastoid cell lines (LCLs) and in 31 NB tumors, respectively. Kaplan-Meier analysis was used to verify the association between IL-6 gene expression and patient survival. We found that IL-6 SNP is not involved in susceptibility to NB development. However, our results show that a low frequency of genotype CC is significantly associated with a low overall survival, advanced stage, and high-risk phenotype. The in silico (p = 2.61 × 10(-5)) and qRT-PCR (p = 0.03) analyses showed similar trend indicating that the CC genotype is correlated with increased level of IL-6 expression. In report gene assay, we showed that the -174 C variant had a significantly increased transcriptional activity compared with G allele (p = 0.0006). Moreover, Kaplan-Meier analysis demonstrated that high levels of IL-6 are associated with poor outcome in children with NB in two independent gene expression array datasets.
CONCLUSIONS: The biological effect of SNP IL-6-174 G>C in relation to promotion of cancer progression is consistent with the observed decreased survival time. The present study suggests that SNP IL-6-174 G>C may be a useful marker for NB prognosis
Prognostic impact of VEGF, CD31, CD34, and CD105 expression and tumour vessel invasion after radical surgery for IB-IIA non-small cell lung cancer
No full textAims: To evaluate the prognostic impact of tumour angiogenesis assessed by vascular endothelial growth factor (VEGF), microvessel density (MVD), and tumour vessel invasion in patients who had undergone radical resection for stage IB-IIA non-small cell lung cancer (NSCLC). Methods: Fifty one patients (42 men, nine women; mean age, 62.3 years; SD, 6.9) undergoing complete surgical resection (35 lobectomy, 16 pneumonectomy) of pathological stage IB (n = 43) and IIA (n = 8) NSCLC were evaluated retrospectively. No patient underwent postoperative chemotherapy or neoadjuvant treatment. Tumour specimens were stained for VEGF and specific MVD markers: CD31, CD34, and CD105. Results: VEGF expression significantly correlated with high CD105 expression (p < 0.0001) and tumour vessel invasion (p = 0.04). Univariate analysis showed that those patients with VEGF overexpression (p = 0.0029), high MVD by CD34 (p = 0.0081), high MVD by CD105 (p = 0.0261), and tumour vessel invasion (p = 0.0245) have a shorter overall survival. Furthermore, multivariate Cox regression analysis showed that MVD by CD34 (p = 0.007), tumour vessel invasion (p = 0.024), and VEGF expression (p = 0.042) were significant predictive factors for overall survival. Finally, the presence of both risk factors, tumour vessel invasion and MVD by CD34, was highly predictive of poor outcome (odds ratio, 3.4; 95% confidence interval, 1.7 to 6.5; p = 0.0002). Conclusions: High MVD by CD34 and tumour vessel invasion are more closely related to poor survival than the other neoangiogenetic factors in stage IB-IIA NSCLC. This may be because these factors are more closely related to the metastatic process
Introduction to Constitutive Equations
No full textWhen the conservation equations for mass, chemical species, momentum and energy were derived in the previous chapter, it became soon evident that the number of unknown functions was far larger than that of the equations. To allow the closure of the problem some quantities need to be related to others and to the properties of matter, and these are the diffusive mass fluxes, j(p), the deviatoric stress tensor, τjk, the internal energy per unity of mass, u^ (or the specific enthalpy, h^ ) and the heat flux, q. The laws that describe these quantities are known as constitutive equations, and in thermo-fluids they are inherently empirical, although they must satisfy some requirement based upon first principles, like the condition of material objectivity (material properties must be independent of observer), the symmetry properties of a material body and the law of thermodynamics (particularly, the entropy inequality)
Determination of functional viral titer by drug-resistance colony assay, expression of green fluorescent protein, and beta-galactoside staining
No full textRetroviral and lentiviral vector titration by the analysis of the activity of viral reverse transcriptase
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