Nonuniformity of phase structure in immiscible polymer blends

This article is focused on the phase structure development in immiscible polymer blends during melt mixing. Nonuniformity of the phase structure, i.e., the coexistence of areas containing particles with markedly different size distribution, was detected in quenched and compression molded samples of a number of various blends prepared by long and intensive mixing in the chamber of a Plasticorder. The same effect was found also for polystyrene/polyamide blends prepared in a twin‐screw extruder. It was shown that neglecting nonuniformity of the phase structure can lead to considerable error in evaluation of the effect of system parameters on the blend morphology. The reasons for the effect were discussed and it was found that inhomogeneous flow field in mixers is a plausible explanation of the nonuniform phase structure. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers     

secG and temperature modulate expression of azide-resistant and signal sequence suppressor phenotypes of Escherichia coli secA mutants

SecA is a dynamic protein that undergoes ATP-dependent membrane cycling to drive protein translocation across the Escherichia coli inner membrane. To understand more about this process, azide-resistant (azi) and signal sequence suppressor (prlD) alleles of secA were studied. We found that azide resistance is cold sensitive because of a direct effect on protein export, suggesting that SecA-membrane interaction is regulated by an endothermic step that is azide inhibitable. secG function is required for expression of azide-resistant and signal sequence suppressor activities of azi and prlD alleles, and in turn, these alleles suppress cold-sensitive and export-defective phenotypes of a secG null mutant. These remarkable genetic observations support biochemical data indicating that SecG promotes SecA membrane cycling and that this process is dependent on an endothermic change in SecA conformation.     

Internal Reduction of Chromium-Doped α-Alumina

(Al,Cr)₂O₃ single crystals and polycrystals were internally reduced at 1873 K in an Al/Al₂O₃ buffer for periods of time ranging from 1 to 100 h. The growth kinetics of the reduction scale were measured. The microstructure of the reduction scale was investigated by SEM and TEM. As a result of the reduction, two types of discrete chromium precipitates developed inside the alumina matrix (inside the single crystal or the polycrystalline grains), each one being characterized by a particular morphology (needle or spheroid) and a low-energy orientation relationship with respect to the alumina matrix. In addition, larger precipitates without special orientation relationship developed along the grain boundaries and at the triple junctions of the polycrystais. In the first part of this paper, the precipitate morphology and size are described in terms of the crystallography of the interface between the two crystal structures in relation to the reduction mechanism. In the second part, the global reduction scale growth is analyzed in terms of point defect fluxes across the reduction scale.     

Classification of hyperspectral remote sensing image via rotation-invariant local binary pattern-based weighted generalized closest neighbor

The Journal of Supercomputing - In this article, the authors suggested a rotation-invariant local binary pattern-based weighted generalized closest neighbor (RILBP-WGCN) method for HSI...     

Polymorphisms in EGFR Gene Predict Clinical Outcome in Unresectable Non-Small Cell Lung Cancer Treated with Radiotherapy and Platinum-Based Chemoradiotherapy

For non-small cell lung cancer (NSCLC), radiotherapy (RT) and platinum-based chemotherapy (CHT) are among the main treatment options. On the other hand, radioresistance and cytotoxic drug resistance are common causes of failure. The epidermal growth factor receptor (EGFR) plays an important role in radioresponse and therapy resistance. We hypothesized that single nucleotide polymorphisms (SNPs) in the EGFR gene might affect individual sensitivity to these treatments, and thus, therapy outcome and prognosis. The association between functional EGFR SNPs and overall (OS), locoregional recurrence-free (LFRS), and metastasis-free (MFS) survival was examined in 436 patients with unresectable NSCLC receiving RT and platinum-based CHTRT. In a multivariate analysis, the rs712830 CC homozygotes showed reduced OS in the whole group (p = 0.039) and in the curative treatment subset (p = 0.047). The rs712829 TT genotype was strongly associated with decreased LRFS (p = 0.006), and the T-C haplotype was a risk factor for locoregional recurrence in our patients (p = 0.003). The rs2227983 GG alone and in combination with rs712829 T was an indicator of unfavorable LRFS (p = 0.028 and 0.002, respectively). Moreover, significant independent effects of these SNPs on OS, LRFS, and MFS were observed. Our results demonstrate that inherited EGFR gene variants may predict clinical outcomes in NSCLC treated with DNA damage-inducing therapy.     

The Co-Culture of Staphylococcal Biofilm and Fibroblast Cell Line: The Correlation of Biological Phenomena with Metabolic NMR1 Footprint

Staphylococcus aureus is one of the most prevalent pathogens associated with several types of biofilm-based infections, including infections of chronic wounds. Mature staphylococcal biofilm is extremely hard to eradicate from a wound and displays a high tendency to induce recurring infections. Therefore, in the present study, we aimed to investigate in vitro the interaction between S. aureus biofilm and fibroblast cells searching for metabolites that could be considered as potential biomarkers of critical colonization and infection. Utilizing advanced microscopy and microbiological methods to examine biofilm formation and the staphylococcal infection process, we were able to distinguish 4 phases of biofilm development. The analysis of staphylococcal biofilm influence on the viability of fibroblasts allowed us to pinpoint the moment of critical colonization—12 h post contamination. Based on the obtained model we performed a metabolomics analysis by ¹H NMR spectroscopy to provide new insights into the pathophysiology of infection. We identified a set of metabolites related to the switch to anaerobic metabolism that was characteristic for staphylococcal biofilm co-cultured with fibroblast cells. The data presented in this study may be thus considered a noteworthy but preliminary step in the direction of developing a new, NMR-based tool for rapid diagnosing of infection in a chronic wound.     

Verlauf der Hydrierung pflanzlicher Öle - Makrokinetische Einflüsse

Course of Hydrogenation of Vegetable Oils-Macrokinetic Influence. Hydrogenation of vegetable oils is a complicated process whose course is not only influenced by the nature and properties of the catalyst and of the oil, which is to be hardened, of the temperature and pressure, but also by physical-chemical processes as adsorption, desorption and diffusion. During exploration of microkinetic phenomena, especially the way of formation of hydrogen dispersion in the reaction mixture and its influence on the curse of hydrogenation were investigated. Tne velocity and the character of hydrogenation were investigated. The velocity and the character of hydrogenation are significantly influenced by material transfer whose data are essentially changed by the shape of the stirrer, the rotation velocity and the way of the hydrogen supply. By increase of the efficiency of the flushing of Ni-catalyst particles with hydrogen the reaction velocity increases nearly in one scale of magnitude. Simultaneously the selectivity in dependence on the way of stirring of the reaction mixture and the hydrogen distribution was expressed.     

Nomadic Work: Romance and Reality. A Response to Barbara Czarniawska’s ‘Nomadic Work as Life-Story Plot’

This article takes departure in Barbara Czarniawska’s discussion of ‘Nomadic Work as Life-Story Plot’. It contextualises her analysis of actors’ interpretations of nomadic work with a bi-focal review of the ambiguous realities of these phenomena. Firstly, an examination of key aspects of the socio-economic and political context of nomadic work in global neoliberal economies reveals precarious conditions that cloud romantic interpretations of nomadicity. Secondly, a review of studies of everyday practices of nomadic work shows how neoliberal, but also alternative futures are enacted through creative appropriation of collaborative technologies. One example is the work of digital ‘disaster deck’ volunteers and its potential for the mobilization of ‘rapid, highly localized assistance’ through closer collaboration between a distributed crowd, local communities, and official emergency responders (Starbird and Palen 2013). This and other examples suggest emergent new practices and politics of dwelling in mobility that are focused on sociality and collaboration, straddling virtual and physical commons. The twin critique developed in this response can augment narrative analysis to inform more integrated CSCW innovation that challenges the ‘brave new world of work’.