Shrinkage vector determination of dental composite by μCT images

Hypotheses about contraction patterns of light-curing dental composites are controversial. The purpose of this study was to develop a method to determine the direction and extent of polymerization shrinkage. Cavities were restored with a modified composite that contained traceable particles, and digitized before and after light-curing with micro-computed tomography (μCT). The resulting displacement vector fields based on the elastic registration of μCT images (uncured vs. cured) were examined and used to calculate the changes. In unbonded restorations, the displacement vectors pointed inward, but not perfectly, to the center of mass. Bonded restorations exhibited two contraction patterns: either toward one side of the cavity or toward the top-surface of the restoration, and showed significant higher deformation than unbonded group (p < 0.01). The total vector length histogram also indicated the boundary condition is critical to the pattern of polymerization shrinkage. This method has great potential in validating current models of shrinkage.     

Enhancing development team flexibility in IS projects

Information system development projects face tremendous challenges because of business changes and technology changes. Research has shown that software team flexibility has a positive effect on project outcomes, but specific requirements for enhancing flexibility are lacking. Drawing from the input-mediator-outcome (IMO) team effectiveness framework, this research investigates the contextual inputs and team processes that lead to development team flexibility and how well team flexibility improves project outcomes. A survey was developed to consider a model derived from the IMO framework. One hundred fourteen members of information systems development project teams in China responded to the survey. Partial least squares analysis was used served to analyze the data. Results indicate that a participatory culture and cooperative norms are an effective foundation for improving required processes that include project coordination of the project and knowledge sharing activities. In turn, the improved process performance extends responses to changes in technology and the business climate. The improved flexibility in meeting change is predictive of outcomes related to project performance and quality of the final product.     

Investigation of the friction induced conformational change of protein and wear of UHMWPE by a wear process with microfabricated surfaces

An accelerated wear testing procedure was developed to carry out an articulation process between UHWMPE and microfabricated surfaces with controlled asperities. By such a design, the effect of lubricant on wear of UHMWPE can be scaled-up and measured within a short duration of the test. The most abundant composition of the synovial fluid–human serum albumin was employed as a lubricant. Analysis of the albumin protein structure by a circular dichroism (CD) spectroscopy was proceeded to detect the conformational change during a tribological process. We observed that the thinner and fibril-like wear particles were found in biological lubricants than the particle generated in water. Our results also indicated that the content of α-helix structure of albumin was decreased after the tribological process. The denatured albumin solution resulted in the decrease of UHMWPE wear rate. It may be due to the decrease of the contact angle of unfolding albumin protein on articulating surfaces. It implies a larger coverage of the lubricating molecules on the UHMWPE surface. The relevance of the tribological process induced conformational change and wear of UHWMPE were discussed in this study.     

Applying spray pyrolysis to synthesize MnOx for decomposing isopropyl alcohol in ozone- and thermal-catalytic oxidation

Manganese oxides (MnO _x ) were prepared by spray pyrolysis methods (Mn _S ) and calcination at 600 and 1,000 °C (Mn₆₀₀ and Mn₁₀₀₀) in this study. Further, the efficiencies of oxidizing isopropanol (IPA) by these MnO _x utilizing ozone (OZCO) and thermal catalytic oxidation (TCO) were compared. The results indicated that Mn _S , which are characterized by larger surface areas, processed gas hourly space velocity of 42,000 h⁻¹ and inlet IPA concentration of 400 ppm performing IPA decomposition efficiencies approaching 100%, and the reaction temperature was operated at only 85 °C for OZCO. The reaction temperature of TCO operated above 270 °C decomposed IPA at the same efficiency.     

Theoretical analysis and experimental measurement for resonant vibration of piezoceramic circular plates

Based on the electroelastic theory for piezoelectric plates, the vibration characteristics of piezoceramic disks with free-boundary conditions are investigated in this work by theoretical analysis, numerical simulation, and experimental measurement. The resonance of thin piezoceramic disks is classified into three types of vibration modes: transverse, tangential, and radial extensional modes. All of these modes are investigated in detail. Two optical techniques, amplitude-fluctuation electronic speckle pattern interferometry (AF-ESPI) and laser Doppler vibrometer (LDV), are used to validate the theoretical analysis. Because the clear fringe patterns are shown only at resonant frequencies, both the resonant frequencies and the corresponding mode shapes are obtained experimentally at the same time by the proposed AF-ESPI method. Good quality of the interferometric fringe patterns for both the transverse and extensional vibration mode shapes are demonstrated. The resonant frequencies of the piezoceramic disk also are measured by the conventional impedance analysis. Both theoretical and experimental results indicate that the transverse and tangential vibration modes cannot be measured by the impedance analysis, and only the resonant frequencies of extensional vibration modes can be obtained. Numerical calculations based on the finite element method also are performed, and the results are compared with the theoretical analysis and experimental measurements. It is shown that the finite element method (FEM) calculations and the experimental results agree fairly well for the resonant frequencies and mode shapes. The resonant frequencies and mode shapes predicted by theoretical analysis and calculated by finite element method are in good agreement, and the difference of resonant frequencies for both results with the thickness-to-diameter (h/D) ratios, ranging from 0.01 to 0.1, are presented.     

Cytokine Signature of Dengue Patients at Different Severity of the Disease

Clinical presentations of dengue fever (DF) are diverse and non-specific, causing unpredictable progression and outcomes. Its progression and severity have been associated with cytokine levels alteration. In this study, dengue patients were classified into groups following the 2009 WHO dengue classification scheme to investigate the cytokine signature at different severity of the disease: dengue without warning sign symptoms (A); dengue with warning signs (B); severe dengue (C); other fever (OF) and healthy (Healthy). We analyzed 23 different cytokines simultaneously, namely IL-1b, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, IL-17A, IL-33, CD14, CD54, CD62E, CD62L, CD62p, CD106, CD121b, CD154, CD178, GM-CSF, IFN-g, MIF, ST2 and TNF from patients admitted to National Cheng Kung University Hospital during the 2015 Taiwan dengue outbreak. Cytokines TNF, CD54, CD62E, CD62L, CD62P, GM-CSF, IL-1b, IL-2, IL-6, IL-8, IL-10, IL-12p70, IL-17A, INF-g and MIF were elevated while CD106, CD154, IL-4 and L-33 were decreased when compared to the control. IL-10 demonstrated to be a potential diagnostic marker for DF (H and A group; AUC = 0.944, H and OF group; AUC = 0.969). CD121b demonstrated to be predictive of the SD (A and B group; AUC = 0.744, B and C group; AUC = 0.775). Our results demonstrate the cytokine profile changes during the progression of dengue and highlight possible biomarkers for optimizing effective intervention strategies.     

High-Throughput Cellular Heterogeneity Analysis in Cell Migration at the Single-Cell Level

Cancer cell migration represents an essential step toward metastasis and cancer deaths. However, conventional drug discovery focuses on cytotoxic and growth-inhibiting compounds rather than inhibitors of migration. Drug screening assays generally measure the average response of many cells, masking distinct cell populations that drive metastasis and resist treatments. Here, this work presents a high-throughput microfluidic cell migration platform that coordinates robotic liquid handling and computer vision for rapidly quantifying individual cellular motility. Using this innovative technology, 172 compounds were tested and a surprisingly low correlation between migration and growth inhibition was found. Notably, many compounds were found to inhibit migration of most cells while leaving fast-moving subpopulations unaffected. This work further pinpoints synergistic drug combinations, including Bortezomib and Danirixin, to stop fast-moving cells. To explain the observed cell behaviors, single-cell morphological and molecular analysis were performed. These studies establish a novel technology to identify promising migration inhibitors for cancer treatment and relevant applications.