Evolution of 3C-SiC islands nucleated from a liquid phase on Si face α-SiC substrates

The contact between α-SiC crystals and Si-Ge based melts provokes the nucleation of 3C-SiC islands on the crystal surface. Evolution of these islands as a function of various parameters was studied. On both 4H and 6H substrates, it was found that, after nucleation, 3C-SiC islands first enlarge and may form a complete 3C layer under certain conditions. The 3C deposit can then be dissolved by the liquid phase at high temperature or for prolonged contact at relatively moderate temperature. The graphite crucible is proposed to play a central role in these enlargement and dissolution mechanisms by providing extra carbon atoms on the seed surface (enlargement) or provoking thermal induced carbon transport toward the sidewall (dissolution). Several differences between the use of 4H and 6H substrates were also observed.     

Technological Knowledge Intensity and Entry Mode Diversity

• This paper expands the entry mode literature by referring to multiple modes exerted simultaneously in different value chain activities within and across host markets, rather than to a single entry mode at the host market level. We apply competing theoretical perspectives—internalization theory and knowledge transfer efficiency considerations on the one hand, and organizational learning theory on the other—to argue that firms’ technological knowledge intensity affect their entry mode diversity across value chain activities, across host markets, and at the overall corporate level.
• Analyzing a unique dataset we show that high technological knowledge intensity is strongly associated with high entry mode diversity across value chain activities and at the corporate level, but only weakly associated with greater entry mode diversity across geographic host markets.

     

A multivariate model of gender differences in adolescents' internalizing and externalizing problems.

Gender differences observed in interpersonal and self-critical vulnerabilities, reactivity to stressful life events, quality of relationships, and self-concepts inform a multivariate theoretical model of the moderating effects of gender on internalizing and externalizing problems in adolescence. To test this model, data were collected in a 1-year prospective study from an ethnically diverse sample of 460 middle school students. Increases in girls' internalizing symptoms, compared with boys', were partly explained by greater stability in girls' interpersonal vulnerabilities and greater magnitude in coefficients linking girls' relationships with parents and peers and internalizing problems. Boys' risks for externalizing problems, compared with girls', were partly explained by the greater stability in boys' vulnerability to self-criticism. Coefficients for most pathways in the model are similar for boys and girls. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Linear viscoelastic assessment of cold gel-like emulsions stabilized with bovine gelatin

Gel-like oil-in-water emulsions with low lipid content, stabilized with bovine gelatin of different molecular weights were analyzed. Mean droplet size and droplet size distribution of the emulsions were determined by static light scattering. The emulsions were characterized for their rheological properties using dynamic oscillatory and creep-recovery tests in the linear viscoelastic region. Most of the systems exhibited gel-like properties even the samples were not submitted to thermal treatment and the temperature was maintained below 30 °C; this viscoelastic characteristic led to a delay of the phase-separation exceeding one month. Creep-compliance data were fitted to a four parameters Burgers model. The continuous relaxation spectra were estimated from the experimental values of G′ and G″ considering the Baumgaertel - Schausberger - Winter generalized model. Discrete relaxation moduli and relaxation times were derived from the continuous spectra. The effect of molecular weight of the protein and the stability during the storage at 20 °C was analyzed in order to interpret the structural characteristics of these emulsions.     

Recent Advances in Managing Spinal Intervertebral Discs Degeneration

Low back pain (LBP) represents a frequent and debilitating condition affecting a large part of the global population and posing a worldwide health and economic burden. The major cause of LBP is intervertebral disc degeneration (IDD), a complex disease that can further aggravate and give rise to severe spine problems. As most of the current treatments for IDD either only alleviate the associated symptoms or expose patients to the risk of intraoperative and postoperative complications, there is a pressing need to develop better therapeutic strategies. In this respect, the present paper first describes the pathogenesis and etiology of IDD to set the framework for what has to be combated to restore the normal state of intervertebral discs (IVDs), then further elaborates on the recent advances in managing IDD. Specifically, there are reviewed bioactive compounds and growth factors that have shown promising potential against underlying factors of IDD, cell-based therapies for IVD regeneration, biomimetic artificial IVDs, and several other emerging IDD therapeutic options (e.g., exosomes, RNA approaches, and artificial intelligence).     

On improving normal boundary intersection method for generation of Pareto frontier

Gradient-based methods, including Normal Boundary Intersection (NBI), for solving multi-objective optimization problems require solving at least one optimization problem for each solution point. These methods can be computationally expensive with an increase in the number of variables and/or constraints of the optimization problem. This paper provides a modification to the original NBI algorithm so that continuous Pareto frontiers are obtained “in one go,” i.e., by solving only a single optimization problem. Discontinuous Pareto frontiers require solving a significantly fewer number of optimization problems than the original NBI algorithm. In the proposed method, the optimization problem is solved using a quasi-Newton method whose history of iterates is used to obtain points on the Pareto frontier. The proposed and the original NBI methods have been applied to a collection of 16 test problems, including a welded beam design and a heat exchanger design problem. The results show that the proposed approach significantly reduces the number of function calls when compared to the original NBI algorithm.     

3D Slit Scanning with Planar Constraints★

We present a planarity constraint and a novel three‐dimensional (3D) point reconstruction algorithm for a multiview laser range slit scanner. The constraint is based on the fact that all observed points on a projected laser line lie on the same plane of laser light in 3D. The parameters of the plane of laser light linearly parametrize a homography between a pair of images of the laser points. This homography can be recovered from point correspondences derived from epipolar geometry. The use of the planar constraint reduces outliers in the reconstruction and allows for the reconstruction of points seen in only one view. We derive an optimal reconstruction of points subject to the planar constraint and compare the accuracy to the suboptimal approach in prior work. We also construct a catadioptric stereo rig with high quality optical components to remove error due to camera synchronization and non‐uniform laser projection. The reconstruction results are compared to prior work that uses inexpensive optics and two cameras.     

Microvesicles and Microvesicle-Associated microRNAs Reflect Glioblastoma Regression: Microvesicle-Associated miR-625-5p Has Biomarker Potential

Glioblastoma (GB) is the most aggressive and recurrent form of brain cancer in adults. We hypothesized that the identification of biomarkers such as certain microRNAs (miRNAs) and the circulating microvesicles (MVs) that transport them could be key to establishing GB progression, recurrence and therapeutic response. For this purpose, circulating MVs were isolated from the plasma of GB patients (before and after surgery) and of healthy subjects and characterized by flow cytometry. OpenArray profiling and the individual quantification of selected miRNAs in plasma and MVs was performed, followed by target genes’ prediction and in silico survival analysis. It was found that MVs’ parameters (number, EGFRvIII and EpCAM) decreased after the surgical resection of GB tumors, but the inter-patient variability was high. The expression of miR-106b-5p, miR-486-3p, miR-766-3p and miR-30d-5p in GB patients’ MVs was restored to control-like levels after surgery: miR-106b-5p, miR-486-3p and miR-766-3p were upregulated, while miR-30d-5p levels were downregulated after surgical resection. MiR-625-5p was only identified in MVs isolated from GB patients before surgery and was not detected in plasma. Target prediction and pathway analysis showed that the selected miRNAs regulate genes involved in cancer pathways, including glioma. In conclusion, miR-625-5p shows potential as a biomarker for GB regression or recurrence, but further in-depth studies are needed.     

Flow dynamics and sediment transport in vegetated rivers:A review

The significance of riparian vegetation on river flow and material transport is not in dispute.Conveyance laws,sediment erosion and deposition,and element cycli...