Numerical Investigation of Diffusion Flame in Transonic Flow with Large Pressure Gradient

A finite-volume method for the steady, compressible, reacting, turbulent Navier-Stokes equations is developed and implemented by using a novel splitting scheme for the stiff source terms in chemical reaction. The laminar and turbulent reacting flows in a mixing layer with large streamwise pressure gradient are studied and compared to the boundary-layer solutions. The influence of chemical reaction on the turbulent transport in the mixing layer is analyzed. The influence of vitiated air on the combustion process and aerodynamic performance is also investigated for the cases of turbulent mixing layer and turbine cascade.Comment: 21 pages, 20 figure

Low-dose rectal inoculation of rhesus macaques by SIVsmE660 or SIVmac251 recapitulates human mucosal infection by HIV-1

We recently developed a novel strategy to identify transmitted HIV-1 genomes in acutely infected humans using single-genome amplification and a model of random virus evolution. Here, we used this approach to determine the molecular features of simian immunodeficiency virus (SIV) transmission in 18 experimentally infected Indian rhesus macaques. Animals were inoculated intrarectally (i.r.) or intravenously (i.v.) with stocks of SIVmac251 or SIVsmE660 that exhibited sequence diversity typical of early-chronic HIV-1 infection. 987 full-length SIV env sequences (median of 48 per animal) were determined from plasma virion RNA 1–5 wk after infection. i.r. inoculation was followed by productive infection by one or a few viruses (median 1; range 1–5) that diversified randomly with near starlike phylogeny and a Poisson distribution of mutations. Consensus viral sequences from ramp-up and peak viremia were identical to viruses found in the inocula or differed from them by only one or a few nucleotides, providing direct evidence that early plasma viral sequences coalesce to transmitted/founder viruses. i.v. infection was >2,000-fold more efficient than i.r. infection, and viruses transmitted by either route represented the full genetic spectra of the inocula. These findings identify key similarities in mucosal transmission and early diversification between SIV and HIV-1, and thus validate the SIV–macaque mucosal infection model for HIV-1 vaccine and microbicide research

An Insight into the Sorption Behavior of 2,3,7,8-Tetrachlorodibenzothiophene on the Sediments and Paddy Soil from Chaohu Lake Basin

Considering the frequent detection of polychlorinated dibenzothiophenes (PCDTs) in various environmental matrices and the potential ecological health risks, the environmental behavior of such compounds needs to be elucidated further. In this work, the sorption behavior of 2,3,7,8-tetrachlorodibenzothiophene (2,3,7,8-TCDT) onto three sediments and paddy soil from Chaohu Lake were investigated via batch equilibration experiments. From the perspective of sorption kinetics and isotherms, the sorption characteristics and mechanism of 2,3,7,8-TCDT on the above four carriers were compared, and the relationship between their structural characteristics and soil sorption capacity was discussed. Results suggested that rapid sorption played the primary role during the sorption process of 2,3,7,8-TCDT and the corresponding sorption isotherms were well fitted using the Freundlich logarithmic model. Moreover, the effects of pH and dissolved organic matter (DOM) on the sorption of 2,3,7,8-TCDT were investigated. The maximum sorption capacity of 2,3,7,8-TCDT on sediment was under acidic pH condition (pH = 4.0). Meanwhile, DOM at a low level promoted the sorption capacity of sediment toward 2,3,7,8-TCDT, while the high concentration of DOM inhibited this effect. In addition, the values of logKoc were obtained using high-performance liquid chromatography (HPLC) and did not show any significant correlation with organic carbon (OC) contents, thereby indicating that the partition effect was the dominating influencing factor for the sorption of 2,3,7,8-TCDT both on sediments and soil. This work provides useful data to understand the sorption behavior of 2,3,7,8-TCDT on sediments and soil and assess its potential environmental risk

Blood-Brain Barrier Permeable Chitosan Oligosaccharides Interfere with beta-Amyloid Aggregation and Alleviate beta-Amyloid Protein Mediated Neurotoxicity and Neuroinflammation in a Dose- and Degree of Polymerization-Dependent Manner

It is proven that beta-amyloid (A beta) aggregates containing cross-beta-sheet structures led to oxidative stress, neuroinflammation, and neuronal loss via multiple pathways. Therefore, reduction of A beta neurotoxicity via inhibiting aggregation of A beta or dissociating toxic A beta aggregates into nontoxic forms might be effective therapeutic methods for Alzheimer's disease (AD) treatment. This study was designed to explore interference of chitosan oligosaccharides (COS) on beta-(1-42)-amyloid protein (A beta 42) aggregation and A beta 42-induced cytotoxicity. Here it was demonstrated that COS showed good blood-brain barrier (BBB) penetration ability in vitro and in vivo. The experimental results showed that COS efficiently interfered with A beta 42 aggregation in dose- and degree of polymerization (DP)-dependent manners, and COS monomer with DP6 showed the best effect on preventing conformational transition into beta-sheet-rich structures. Based on the binding affinity analysis by microscale thermophoresis (MST), it was confirmed that COS could directly bind with A beta 42 in a DP-dependent manner. Our findings demonstrated that different performance of COS monomers with different DPs against A beta 42 assembly was, to some extent, attributable to their different binding capacities with A beta 42. As a result, COS significantly ameliorated A beta 42-induced cytotoxicity. Taken together, our studies would point towards a potential role of COS in treatment of AD

A GHz Silicon-Based Width Extensional Mode MEMS Resonator with <i>Q</i> over 10,000

This work presents a silicon-based capacitively transduced width extensional mode (WEM) MEMS rectangular plate resonator with quality factor (Q) of over 10,000 at a frequency of greater than 1 GHz. The Q value, determined by various loss mechanisms, was analyzed and quantified via numerical calculation and simulation. The energy loss of high order WEMs is dominated by anchor loss and phonon-phonon interaction dissipation (PPID). High-order resonators possess high effective stiffness, resulting in large motional impedance. To suppress anchor loss and reduce motional impedance, a novel combined tether was designed and comprehensively optimized. The resonators were batch fabricated based on a reliable and simple silicon-on-insulator (SOI)-based fabrication process. The combined tether experimentally contributes to low anchor loss and motional impedance. Especially in the 4th WEM, the resonator with a resonance frequency of 1.1 GHz and a Q of 10,920 was demonstrated, corresponding to the promising f × Q product of 1.2 × 1013. By using combined tether, the motional impedance decreases by 33% and 20% in 3rd and 4th modes, respectively. The WEM resonator proposed in this work has potential application for high-frequency wireless communication systems

EP300 single nucleotide polymorphism rs20551 correlates with prolonged overall survival in diffuse large B cell lymphoma patients treated with R-CHOP

Abstract Background Rituximab combined with cyclophosphamide, doxorubicin, vincristine and prednisone (CHOP) is used as standard frontline regimen for diffuse large B-cell lymphoma (DLBCL). The landscape of somatic mutations in DLBCL revealed that inactivation of EP300 plays an important role in lymphomagenesis. A common EP300 single nucleotide polymorphism (SNP) rs20551 results in the substitution of valine for isoleucine at codon 997 close to the Bromodomain. However, the association between SNP rs20551 and clinical prognosis in DLBCL patients treated with R-CHOP is unknown. Methods In this study we analyzed the EP300 SNP rs20551 and prognosis of 226 DLBCL patients who treated with R-CHOP or R-CHOP-like regimes from 2002 to 2013. Determination of the EP300 SNP rs20551 from genomic DNA was obtained by Sanger chain termination sequencing. Result In this study, the frequency of the A and G allele of the EP300 SNP rs20551 in 226 patients were 92.5 and 7.5%, respectively. We did not observe obvious correlation between patients’ disease features and the EP300 SNP rs20551. But the patients with genotype AA had a higher 5-year overall survival rate than those with genotype GA (77.0% vs. 64.7%, p = 0.045). Furthermore, multivariate Cox regression analysis showed that the GA genotype of EP300 SNP rs20551 was an independent poor prognostic factor for DLBCL patients treated with Rituximab-chemotherapy (p = 0.009, HR 2.956, 95% CI 1.315–6.645). Conclusion This study suggests that EP300 SNP rs20551 might be a useful biomarker to predict the long-term outcome of R-CHOP in DLBCL patients

TP53 Arg72 as a favorable prognostic factor for Chinese diffuse large B-cell lymphoma patients treated with CHOP

Abstract Background TP53 Arg72Pro (SNP rs1042522) is associated with risk of non-Hodgkin lymphoma (NHL). Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of NHL. However, the relationship between this SNP and prognosis of DLBCL in Asians is unknown. Methods Genotyping of TP53 Arg72Pro was done in 425 Chinese DLBCL patients. Two hundred and eighty-nine patients were treated with R-CHOP, and 136 patients received CHOP or CHOP-like as frontline regimen. Three hundred and ninety-six patients were assessable for the efficacy. Results Patients with Arg/Arg and Arg/Pro at codon 72 of TP53 had a higher complete response rate (61% vs. 44%, P = 0.007) than those with Pro/Pro. In the subgroup treated with CHOP or CHOP-like therapy, patients with Arg/Arg and Arg/Pro showed a higher 5-year overall survival (OS) rate than those with Pro/Pro (68.8% vs. 23.2%, P = 0.001). Multivariate Cox regression analysis revealed TP53 Arg72 as a favorable prognostic factor in this group. However, the combination of rituximab with CHOP significantly increased the 5-year OS rate of patients with Pro/Pro to 63%. Conclusion This study revealed TP53 Arg72 as a favorable prognostic factor for Chinese DLBCL patients treated with CHOP or CHOP-like as frontline therapy