PRELIMINARY FINDINGS THAT KEROSENE ALTERS THE DISTRIBUTION OF TOPICALLY APPLIED BENZO[A]PYRENE IN MICE

The dermal route is important in occupational exposure to polycyclic aromatic compounds (PACs), but other organs may be affected. We reported that kerosene-cleaning following treatment with used engine oil increased DNA adducts in the lungs of mice viz. animals treated with used oil alone. To determine the mechanism we topically applied ³ H-BAP(100 nmol in 25 μL acetone) and washed half the mice with 25 μL kerosene 1 h after carcinogen application. Groups of four mice were sacrificed from 1 to 72 h after treatment. Lung, liver, and skin were harvested. The fraction of the radiolabel remaining in the skin of animals treated with benzo[a]pyrene (BAP) and washed with kerosene was significantly less than those not washed, beginning at 24 h (p < .05). Fractional distribution to the lungs and livers of these animals became significantly elevated. Kerosene increased transdermal water loss. Kerosene treatment compromises dermal barrier function, enhances carcinogen absorption, and alters organ distribution.     

河内博物馆

穿过园林景观来访者可从四个方向进入博物馆。在正方形的建筑体中庭内,一座圆形的挑空大厅将入口层面于其上的三层展览空间连接起来。如同倒置的金字塔般,中庭向上呈阶梯状展开。来访者向外望去,仿佛"漂浮"于主题公园景观之上。盘旋上升的坡道作为极富表现力的空间元素,将人们吸引至建筑顶部,并且实现了展览空间与中庭的视线交流。由于展览空间全部安排在建筑的首层至三层,会议、科研中心,办公空间以     

Platinum(II) phenanthroimidazoles for targeting telomeric G-quadruplexes

A rationally designed progression of phenanthroimidazole platinum(II) complexes were examined for their ability to target telomere-derived intramolecular G-quadruplex DNA. Through the use of circular dichroism, fluorescence displacement assays, and molecular modeling we show that these complexes template and stabilize G-quadruplexes from sequences based on the human telomeric repeat (TTAGGG)(n). The greatest stabilization was observed for the p-chlorophenyl derivative 6((G4)DC(50) =0.31 μM). We also show that the G-quadruplex binding complexes are able to inhibit telomerase activity through a modified telomerase repeat amplification protocol (TRAP-LIG assay). Preliminary cell studies show that complex 6 is preferentially cytotoxic toward cancer over normal cell lines, indicating its potential use in cancer therapy.     

The role of surface barrier oxidation on AlGaN/GaN HEMTs reliability

Reliability of AlGaN/GaN HEMTs processed with different surface oxidation levels was studied using electrical and optical methods. It was found that HEMTs with more surface oxide content are more susceptible to degradation in terms of gate leakage and trapping characteristics, although this oxide layer initially passivates surface traps. In the degraded devices, trap level with activation energy of 0.45–0.47 eV was observed and attributed to surface related traps. This indicates that oxygen may play a crucial role for AlGaN/GaN HEMT reliability.     

Core Histones Are Constituents of the Perinuclear Theca of Murid Spermatozoa: An Assessment of Their Synthesis and Assembly during Spermiogenesis and Function after Gametic Fusion

The perinuclear theca (PT) of the eutherian sperm head is a cytoskeletal-like structure that houses proteins involved in important cellular processes during spermiogenesis and fertilization. Building upon our novel discovery of non-nuclear histones in the bovine PT, we sought to investigate whether this PT localization was a conserved feature of eutherian sperm. Employing cell fractionation, immunodetection, mass spectrometry, qPCR, and intracytoplasmic sperm injections (ICSI), we examined the localization, developmental origin, and functional potential of histones from the murid PT. Immunodetection localized histones to the post-acrosomal sheath (PAS) and the perforatorium (PERF) of the PT but showed an absence in the sperm nucleus. MS/MS analysis of selectively extracted PT histones indicated that predominately core histones (i.e., H3, H3.3, H2B, H2A, H2AX, and H4) populate the murid PT. These core histones appear to be de novo-synthesized in round spermatids and assembled via the manchette during spermatid elongation. Mouse ICSI results suggest that early embryonic development is delayed in the absence of PT-derived core histones. Here, we provide evidence that core histones are de novo-synthesized prior to PT assembly and deposited in PT sub-compartments for subsequent involvement in chromatin remodeling of the male pronucleus post-fertilization.     

Grain Refinement of an Extruded Mg Alloy via Na Microalloying

The effect of 0.3 wt pct Na on the microstructure of extruded alloy Mg-2Sn-1Zn is examined. We report that Na stabilizes the Mg₂Sn phase, resulting in its precipitation during extrusion under conditions where a solid solution is otherwise expected. This effect appears to be thermodynamic in nature and is different from the kinetic enhancement of low- temperature aging reported by Mendis et al. [Phil. Mag. Letters, 86 (2006), 443]. The precipitates of the current study enable useful refinement of the grain size.     

Molecular insights for the optimization of solvent‐based selective extraction of ethanol from fermentation broths

Simulations and experiments were carried out to explore the solvent extraction of ethanol from aqueous solution using a series of seven 10‐carbon alcohols. It is shown that configurational‐bias Monte Carlo simulations in the Gibbs ensemble coupled with the TraPPE‐UA force field can be utilized for predictive screening of the different extraction abilities (in terms of capacity factor and selectivity) of these alcohols. Analysis of the simulation trajectories indicates that extraction capacity is connected to the stabilization of larger ethanol/water cluster in the organic solvent, whereas selectivity is improved when smaller ethanol/water clusters are more prevalent. © 2013 American Institute of Chemical Engineers AIChE J, 59: 3065–3070, 2013     

Potassium methyl siliconate‐treated pulp fibers and their effects on wood plastic composites: Water sorption and dimensional stability

Potassium methyl siliconate (PMS) was investigated as a new nano modifier of wood fiber and wood flour to improve the compatibility between the fiber/flour and the plastic matrix in fiber reinforced plastic composites. Before injection molding, bleached and brown pulp fibers and mixed species wood flour were pretreated in PMS solutions. The morphology of the treated and untreated fiber and flour, the compatibility of PMS‐treated fiber and flour with polyethylene (PE), and the water sorption and volumetric swell of PMS‐treated fiber/flour plastic composites in a long‐term soaking test were evaluated. Fiber and flour treated with PMS increased the compatibility between the fiber/flour and the PE matrix. The increased compatibility of PMS‐treated fiber and flour with the matrix contributed to the reduction of water sorption and, thus, increased dimensional stability. For all composites, water sorption and volumetric swell of fiber/four plastic composites decreased as the ratio of fiber to flour increased. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Self‐segregating hyperbranched polymer/silver nanoparticle hybrids in thermoplastic polyurethane films

Self‐segregating hyperbranched polymer (HBP) additives have been utilized to concentrate silver nanoparticles (AgNPs) at the air interface of polyurethane films. The limited spontaneous surface migration of the AgNPs was enhanced through the addition of appropriately functionalized HBPs. Both amine and thiol terminated additives were employed to allow interaction of the HBP with the nanoparticles. Both types of additives increased surface concentration of silver modestly, though the thiol‐terminated HBPs demonstrated nearly a seven‐fold enhancement of surface migration. It was also found that wholly‐aliphatic HBPs demonstrated only slightly reduced ability to bias AgNP concentration as compared to HBPs functionalized with perfluorinated chains. In addition, films containing 1% total silver concentration were tested for antimicrobial activity using the ASTM‐E 2180 protocol. Significant reduction of the microorganisms was observed for all samples, 6‐log reduction was achieved for the gram‐negative bacteria P. aeruginosa, the gram‐positive bacteria S. aureus, and the fungi C. albicans. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Effective dispersion model for flow-through catalytic membrane reactors combining axial dispersion and pore size distribution

In a flow-through catalytic membrane reactor, catalyst is immobilized in the pores of a membrane, which is convectively passed by the reaction mixture, allowing for high catalytic activity and a potentially narrow residence time distribution (RTD). As the membrane geometry prevents measurement of a meaningful RTD, a residence time distribution model is introduced, which accounts for deviations from ideal plug flow behavior induced by a non-ideal pore size distribution and by axial molecular diffusion. Both effects are combined to an effective dispersion model with a single dimensionless parameter, which is a function of pore geometry, axial velocity and molecular diffusion coefficient. As a result of the developed model, recommendations for optimum reactor operation are given.