Resource loss, resource gain, and psychological resilience and dysfunction following cancer diagnosis: A growth mixture modeling approach.

Objective: This study investigated trajectories of psychological distress and their relationships with change in psychosocial resources in the year following cancer diagnosis. Design: Chinese colorectal cancer (CRC) patients (n = 234) were assessed within 12 weeks of diagnosis (T1) and again at 3-month (T2) and 12-month (T3) follow-ups. Growth mixture modeling was used to analyze the longitudinal data. Main Outcome Measures: Psychological distress was measured at the three time-points using Hospital Anxiety and Depression Scale (HADS). Results: Growth mixture models identified four classes: chronic distress (7–9%), delayed distress (10–13%), recovery (13–16%), and resilient (65–67%). People in chronic distress were more likely to demonstrate loss in physical functioning and social relational quality than those in delayed distress, and loss in physical functioning, optimism, and hope than those in recovery, but more likely to demonstrate stability/gain in optimistic personalities than those in delayed distress and resilient. People in resilient were more likely to report stability/gain in optimistic personalities than those in delayed distress but not those in recovery. Conclusion: Understanding differential outcome trajectories and associated change in coping resources has implications for developing ongoing psychological services for cancer patients during the diagnosis and treatment process. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Numerical and experimental study of the influence of CO2 dilution on burning characteristics of syngas/air flame

In this study, effect of carbon dioxide dilution on explosive behavior of syngas/air mixture was investigated numerically and experimentally. Explosion in a 3-D cylindrical geometry model with dimensions identical to the chamber used in the experiment was simulated using ANSYS Fluent. The simulated results showed that after ignition, the flame front propagated outward spherically until it touched the wall, like the propagating flame observed in the experiment. Both experimental and simulated results presented a same trend of decreasing the maximum explosion pressure and prolonging the explosion time with CO₂ dilution. The results showed that for CO₂ additions, the maximum explosion pressure decreased linearly and the explosion time increased linearly, while the maximum rate of pressure rise decreased nonlinearly, which can be correlated to an exponential equation. In addition, both results showed a good agreement for syngas/air flame with CO₂ addition up to 20% in volume. However, larger discrepancies were observed for higher levels of CO₂ dilutions. Of the three diluents tested, carbon dioxide displayed the strongest effect in reducing explosion hazard of syngas/air flame compared to helium and nitrogen. Chemical kinetic analysis results showed that maximum concentration of major radicals and net reaction rates of important reactions drastically decreased with CO₂ addition, causing a reduction of laminar flame speed.     

A novel near-infrared fluorescence sensor for detection of thrombin activation in blood

Thrombosis is an important pathophysiologic component of many cardiovascular diseases. Thrombin, a serine protease, plays a central role in thrombosis formation. Detection and imaging of thrombin activity may thus be of considerable biomedical interest. The goal of this study was to design, synthesize, and characterize a novel thrombin-activated near-infrared fluorescence (NIRF) probe. The probe consisted of a thrombin-cleavable peptide spacer (...D-Phe-Pip-Arg...; Pip=pipecolic acid) and contained a terminal fluorescence reporter which was quenched when conjugated to a biocompatible delivery vehicle. A control peptide spacer was synthesized that differed by one amino acid. Following thrombin addition, the probe was activated within minutes. The NIRF signal increased by a factor of 27-fold within 20 minutes, and was inhibited by hirudin, a specific thrombin inhibitor. NIRF optical imaging experiments confirmed rapid activation of the probe in both buffer and human blood. The control probe showed minimal activation in all experiments. In addition to potentially furthering our understanding of thrombin regulation in vivo, the thrombin-activated near-infrared probe may have broad clinical application to the diagnosis of arterial and venous thrombosis.     

Probabilistic evaluations of economic merit of water resource projects

The presence of uncertainties in assessing benefits and costs detracts from deterministic economic evaluation. This paper examines three probabilistic economic evaluation procedures: stochastic dominance, expected gain-confidence limit, and Hurwicz criterion. Their relative performances are evaluated through an example. Furthermore, the paper investigates the effects of (1) distributional assumptions of benefit and cost items, (2) uncertainty in project life, and (3) distribution of net present value on the project selection.     

Molecular weight distributions of standard polystyrene samples by GPC and by sedimentation velocity analysis

In precision gel permeation chromatographic (GPC) work, the spreading (zone spreading) characteristics of the instrument must be calibrated. Standard samples of anionic polystyrene have been used for this purpose. The molecular weight distributions of these standard samples, nevertheless, have not been determined carefully. In this work, several standard polystyrene samples obtained from Pressure Chemical Company were examined by GPC and by sedimentation velocity analysis. The results show that (1) the high molecular weight polystyrene samples have skewed molecular weight distributions as has been suspected and that (2) the present data treatment technique for GPC is effective for these very narrow-distribution samples.     

A study of magnetic coupling in GdT2Si2 compounds (T=transition metal)

The magnetic coupling in the GdT₂Si₂ (T=transition metal) antiferromagnetic compounds is studied by means of DC susceptibility and high-field free-powder (HFFP) measurements. In most compounds, the experimental results can be described in the framework of a two-sublattice model without anisotropy. From this analysis, an intrasublattice exchange coupling constant, n₁₁, and an intersublattice exchange coupling constant, n₁₂, are obtained. The exchange couplings are discussed in terms of the change of the lattice parameters, the volume V and the filling of the transition metal electron band. The apparently reduced value of the moment per Gd atom in the forced ferromagnetic configuration is attributed to a reduction of the on-site 5d-moment and a possible negative polarisation of the other non-4f electrons.     

Mechanism-based fluorescent reporter for protein kinase A detection

A novel mechanism-based fluorescent reporter was designed for the detection of protein kinase A (PKA), which is known to mediate a variety of cellular responses in most eukaryotic cells. The probe consists of a specific binding peptide sequence, LRRRRFAFC, conjugated with 2'-thioethyl-5-(or -6)-carboxyfluoresceinamide (FAMS; 2) and 5-(or 6-)carboxytetramethylrhodamine (TAMRA) at the cysteine and leucine residues, respectively. In the absence of PKA, the two fluorophores associate by hydrophobic interactions, forming an intramolecular ground-state dimer; this results in fluorescein quenching (>93 %). Upon PKA addition, the reporter reacts with the sulfhydryl functionality at Cys199 through a disulfide-exchange mechanism. FAMS is subsequently released, resulting in significant fluorescence amplification. The remaining peptide sequence, which acts as an inhibitor, is attached covalently to the enzyme. Our results suggest that this type of sensors could have far-reaching applications in the molecular sensing of enzymes.     

Indexation de modèles 3D par graphe de Reeb multirésolution augmenté

This article presents an indexing method for 3D mesh models applied to shape and appearance similarity retrieval in database of 3D objects. The approach relies on the multi-resolution Reeb graph matching method proposed by Hilaga et al. in 2001 [1]. In our framework, we consider 3D mesh models of various geometrical complexity, different resolution, and sometimes textured. The original approach, based on the 3D object topology, is not accurate enough to obtain satisfying matching. Therefore we propose to reinforce the topological consistency conditions of the matching and to merge within the graph geometrical and visual information to improve the matching and the calculation of the similarity between models. Besides, all these new attributes can be freely weighted to fit the user requirements for object retrieval. We obtain a flexible multiresolutional and multicriteria representation that we called augmented Multiresolution Reeb Graph (aMrg). The approach has been tested and compared with other methods. It reveals very performant for the retrieval and the classification of similar 3D shapes.