Modelling of spheroidal drop evaporation with non-uniform temperature conditions

[EN] The heating and evaporation of single component spherical and spheroidal drops in gaseous quiescent environment are predicted, accounting for the effect of a non-uniform distribution of the temperature at the drop surface. The analytical solution of the species conservation equations in the proper coordinate system (spherical/spheroidal) is implemented to numerically solve the energy equation in a rectangular domain. The effect of temperature non-uniformity on the local Nusselt number and global heat and evaporation rates is calculated for different species, drop deformation and gaseous temperature.Cossali, G.; Ravasio, S.; Tonini, S. (2017). Modelling of spheroidal drop evaporation with non-uniform temperature conditions. En Ilass Europe. 28th european conference on Liquid Atomization and Spray Systems. Editorial Universitat Politècnica de València. 75-82. https://doi.org/10.4995/ILASS2017.2017.4721OCS758

Transcribed-ultra conserved region expression profiling from low-input total RNA

<p>Abstract</p> <p>Background</p> <p>Ultra Conserved Regions (UCRs) are a class of 481 noncoding sequences located in both intra- and inter-genic regions of the genome. The recent findings that they are significantly altered in adult chronic lymphocytic leukemias, carcinomas, and pediatric neuroblastomas lead to the hypothesis that UCRs may play a role in tumorigenesis.</p> <p>Results</p> <p>We present a novel application of Ribo-SPIA™ isothermal linear amplification of minute RNA quantities for quantifying Transcribed-UCR (T-UCR) expression by quantitative PCR. Direct comparison of non-amplified with amplified cDNA in two neuroblastoma cell lines showed that the amplification approach increases sensitivity and repeatability in T-UCR quantification. It is noteworthy that the Ribo-SPIA™ step allowed us to analyze all 481 T-UCRs by using 150 ng of RNA, while introducing a minimal bias and preserving the magnitude of relative expression. Only the less abundant T-UCRs have high intra-assay variability, consistently with the Poisson distribution statistics and stochastic effects on PCR repeatability.</p> <p>Conclusions</p> <p>We demonstrated that the quantification procedure shown here is an accurate and reliable technique for genome-wide non coding gene (i.e., UCRs) profiling using small amounts of RNA. This issue is particularly important because studies of transcription regulation are increasingly conducted in small homogeneous samples, such as laser capture microdissected or sorted cell populations.</p

Prenatal Exposure to BPA: The Effects on Hepatic Lipid Metabolism in Male and Female Rat Fetuses

Bisphenol A (BPA) is an organic chemical compound widely used for manufacturing plastics. BPA exposure originates principally from the diet, but it can also originate from dermal contact. In over 90% of individuals, including pregnant women, BPA is detectable in several body fluids. The effects of this exposure on the fetus are under active investigation in several research laboratories. The aim of our work was to study the impact of prenatal exposure to BPA in the liver of rat fetuses from a sex-dependent point of view. We particularly investigated the effects of prenatal BPA exposure on hepatic lipids because of their crucial role, not only for the liver, but also for the whole-body functions. Our results demonstrate that the liver of rat fetuses, in utero exposed to a very low dose of BPA (2.5 µg/kg/day), displays significant modulations with regard to proteins involved in cholesterol and fatty acid biosynthesis and trafficking. Moreover, an impact on inflammatory process has been observed. All these effects are dependent on sex, being observable only in female rat fetuses. In conclusion, this work demonstrates that maternal exposure to BPA compromises hepatic lipid metabolism in female offspring, and it also reveals the perspective impact of BPA on human health at doses currently considered safe

Identification of low intratumoral gene expression heterogeneity in neuroblastic tumors by genome-wide expression analysis and Game Theory

BACKGROUND. Neuroblastic tumors (NTs) are largely comprised of neuroblastic (Nb) cells with various quantities of Schwannian stromal (SS) cells. NTs show a variable genetic heterogeneity. NT gene expression profiles reported so far have not taken into account the cellular components. The authors reported the genome-wide expression analysis of whole Minors and microdissected Nb and SS cells. METHODS. The authors analyzed gene expression profiles of 10 stroma-poor NTs (NTs-SP) and 9 stroma-rich NTs (NTS-SR) by microarray technology. Nb and SS cells were. isolated by laser microdissection from NTs-SP and NTs-SR and probed with microarrays. Gene expression data were analyzed by the Significance Analysis of Microarrays (SAM) and Game Theory (GT) methods, the latter applied for the first time to microarray data evaluation. RESULTS. SAM identified 84 genes differentially expressed between NTs-SP and NTs-SR, whereas 50 were found by GT. NTs-SP mainly express genes associated with cell replication, nervous system development, and antiapoptotic pathways, whereas NTs-SR express genes of cell-cell communication and apoptosis. Combining SAM and GT, the authors found 16 common genes driving the separation between NTs-SP and NTs-SR. Five genes overexpressed in NTs-SP encode for nuclear proteins (CENPE, EYA1, PBK TOP2A, TFAP2B), whereas only 1 of 11 highly expressed genes in NTs-SR encodes for a nuclear receptor (NR4A2). CONCLUSIONS. The results showed that NT-SP and NT-SR gene signatures differ for a set of genes involved in distinct pathways, and the authors demonstrated a low intratumoral heterogeneity at the mRNA level in both NTs-SP and NTs-SR. The combination of SAM and GT methods may help to better identify gene expression profiling in NTs

Mathematical modelling of heating and evaporation of a spheroidal droplet

Most of the currently used models for droplet heating and evaporation are based on the assumption that droplets are perfect spheres. At the same time the shapes of many observed droplets in engineering applications are far from spherical. We have studied the influence of droplet non-sphericity on their heating and evaporation, approximating droplet shapes as prolate and oblate spheroids. The previously developed exact solutions to the heat and mass transfer equations for the gas phase surrounding a spheroidal droplet have been used as boundary conditions for the solutions to these equations in the liquid phase. The temperature gradients inside and at the surface of the droplets, and the changes in their shape during the heating and evaporation process have been taken into account. The effects of surface tension and droplet motion on droplet heating and evaporation are ignored. The results are applied to the analysis of heating and evaporation of an n-dodecane fuel droplet in Diesel engine-like conditions. The effect of droplet non-sphericity is shown to be relatively small for the evaporation time of these droplets with initial eccentricities 2/3⩽ε⩽1.52/3⩽ε⩽1.5

Genome analysis and gene expression profiling of neuroblastoma and ganglioneuroblastoma reveal differences between neuroblastic and Schwannian stromal cells

Neuroblastic tumours are a group of paediatric cancers with marked morphological heterogeneity. Neuroblastoma (Schwannian stroma-poor) (NB-SP) is composed of undifferentiated neuroblasts. Ganglioneuroblastoma intermixed (Schwannian stroma-rich) (GNBi-SR) is predominantly composed of Schwannian stromal (SS) and neuroblastic (Nb) cells. There are contrasting reports suggesting that SS cells are non-neoplastic. In the present study, laser capture microdissection (LCM) was employed to isolate SS and Nb cells. Chromosome 1p36 deletion and MYCN gene amplification were found to be associated in two out of seven NB-SPs, whereas no abnormalities were observed in five GNBi-SRs. In some cases, loss of heterozygosity (LOH) at 1p36 loci was detected in Nb cells but not in the bulk tumour by LCM; furthermore, LOH was also identified in both SS and tumour tissue of a GNBi-SR. DNA gain and loss studied by comparative genomic hybridization were observed at several chromosome regions in NB-SP but in few regions of GNBi-SR. Finally, gene expression profiles studied using an oligo-microarray technique displayed two distinct signatures: in the first, 32 genes were expressed in NB-SP and in the second, 14 genes were expressed in GNBi-SR. The results show that NB-SP is composed of different morphologically indistinguishable malignant cell clones harbouring cryptic mutations that are detectable only after LCM. The degree of DNA imbalance is higher in NB-SP than in GNBi-SR. However, when the analysis of chromosome 1p36 is performed at the level of microdissection, LOH is also observed in SS cells. These data provide supportive evidence that SS cells have a less aggressive phenotype and play a role in tumour maturation. Copyright © 2005 Pathological Society of Great Britain and Ireland

Impiego degli Inibitori della Pompa protonica (IPP) in Piemonte: indagine sulle abitudini prescrittive dei Medici di Medicina Generale

Proton Pump Inhibitors (PPIs) (Omeprazole, Lansoprazole, Pantoprazole, Rabeprazole and Esomeprazole), one of the most commonly prescribed classes of medications in the primary care setting, are considered a major advance in the treatment of acid-peptic diseases. In Italy PPIs are reimbursed by National Health Service on the basis of CUF (Commissione Unica del Farmaco) 1 and 48 Notes. In 2002 and 2003 a significant increase in PPIs consumption and expenditure have been documented, showing differences between regions. The aim of this study is to investigate and monitor, at regional level, type and entity of PPIs use through a drug utilization study, evaluating prescribing behaviour and compliance of PPIs treatments with CUF Notes indications. The study has been carried out on a sample of 436 General Practitioners belonging to 22 Piemonte's ASL (Aziende Sanitarie Locali). The data analysis shows that acid-related pathologies are significantly more common in patients with at least 50 years of age and the most frequent condition is represented by gastroesophageal reflux disease. Despite the general conditions of PPIs use by General Practitioners in terms of duration and dosage of therapy result in most cases (from 49% to 80% for duration and from 54% to 97% for dosage) compliant with what proposed by CUF Notes, in some cases the same CUF Notes indications seem to be not observed. Consequently the Piemonte Region has decided to plan a guideline on PPIs rational use. Such guideline, expected to be introduced in the regional area, may also be considered as an instrument able to lead to a more appropriate expenditure for this drug class. Moreover, in order to control PPIs expenditure, pharmacoeconomic methodologies can be applied allowing to identify the most cost - effective active substance and therapeutic scheme, overcoming CUF Notes which consider all PPIs use under the same reimbursement conditions