Metallurgy and properties of plasma spray formed materials

Understanding the fundamental metallurgy of vacuum plasma spray formed materials is the key to enhancing and developing full material properties. Investigations have shown that the microstructure of plasma sprayed materials must evolve from a powder splat morphology to a recrystallized grain structure to assure high strength and ductility. A fully, or near fully, dense material that exhibits a powder splat morphology will perform as a brittle material compared to a recrystallized grain structure for the same amount of porosity. Metallurgy and material properties of nickel, iron, and copper base alloys will be presented and correlated to microstructure

Critical Review of Theoretical Models for Anomalous Effects (Cold Fusion) in Deuterated Metals

We briefly summarize the reported anomalous effects in deuterated metals at ambient temperature, commonly known as "Cold Fusion" (CF), with an emphasis on important experiments as well as the theoretical basis for the opposition to interpreting them as cold fusion. Then we critically examine more than 25 theoretical models for CF, including unusual nuclear and exotic chemical hypotheses. We conclude that they do not explain the data.Comment: 51 pages, 4 Figure

Synthesis and characterization of hybrid organic-inorganic materials based on sulphonated polyamideimide and silica

The preparation of hybrid organic–inorganic membrane materials based on a sulphonated polyamideimide resin and silica filler has been studied. The method allows the sol–gel process to proceed in the presence of a high molecular weight polyamideimide, resulting in well dispersed silica nanoparticles (<50 nm) within the polymer matrix with chemical bonding between the organic and inorganic phases. Tetraethoxysilane (TEOS) was used as the silica precursor and the organosilicate networks were bonded to the polymer matrix via a coupling agent aminopropyltriethoxysilane (APTrEOS). The structure and properties of these hybrid materials were characterized via a range of techniques including FTIR, TGA, DSC, SEM and contact angle analysis. It was found that the compatibility between organic and inorganic phases has been greatly enhanced by the incorporation of APTrEOS. The thermal stability and hydrophilic properties of hybrid materials have also been significantly improved

An Instruction on the In Vivo Shell-Less Chorioallantoic Membrane 3-Dimensional Tumor Spheroid Model

The traditional shell chicken chorioallantoic membrane (CAM) model has been used extensively in cancer research to study tumor growth and angiogenesis. Here we present a combined in vivo tumor spheroid and shell-less CAM three-dimensional model for use in quantitative and qualitative analysis. With this model, the angiogenic and tumorigenic environments can be generated locally without exogenous growth factors. This physiological model offers a stable, static and flat environment that features a large working area and wider field of view useful for imaging and biomedical engineering applications. The short experimental time frame allows for rapid data acquisition, screening and validation of biomedical devices. The method and application of this shell-less model are discussed in detail, providing a useful tool for biomedical engineering research

Prediction of Liver-Related Events Using Fibroscan in Chronic Hepatitis B Patients Showing Advanced Liver Fibrosis

Liver stiffness measurement (LSM) using transient elastography (FibroScan®) can assess liver fibrosis noninvasively. This study investigated whether LSM can predict the development of liver-related events (LREs) in chronic hepatitis B (CHB) patients showing histologically advanced liver fibrosis.Between March 2006 and April 2010, 128 CHB patients with who underwent LSM and liver biopsy (LB) before starting nucleot(s)ide analogues and showed histologically advanced fibrosis (≥F3) with a high viral loads [HBV DNA ≥2,000 IU/mL] were enrolled. All patients were followed regularly to detect LRE development, including hepatic decompensation (variceal bleeding, ascites, hepatic encephalopathy, spontaneous bacterial peritonitis, hepatorenal syndrome) and hepatocellular carcinoma (HCC).The mean age of the patient (72 men, 56 women) was 52.2 years. During the median follow-up period [median 27.8 (12.6-61.6) months], LREs developed in 19 (14.8%) patients (five with hepatic decompensation, 13 with HCC, one with both). Together with age, multivariate analysis identified LSM as an independent predictor of LRE development [P<0.044; hazard ratio (HR), 1.038; 95% confidence interval (CI), 1.002-1.081]. When the study population was stratified into two groups using the optimal cutoff value (19 kPa), which maximized the sum of sensitivity (61.1%) and specificity (86.2%) from a time-dependent receiver operating characteristic curve, patients with LSM>19 kPa were at significantly greater risk than those with LSM≤19 kPa for LRE development (HR, 7.176; 95% CI, 2.257-22.812; P = 0.001).LSM can be a useful predictor of LRE development in CHB patients showing histologically advanced liver fibrosis

Viral Resistance in Hepatitis B: Prevalence and Management

Hepatitis B is a DNA virus affecting hundreds of millions of individuals worldwide. As the clinical sequelae of cirrhosis and hepatocellular cancer are increasingly recognized to be related to viral levels, the impetus increases to offer treatment to those previously not treated. With the development of more robust antivirals with reasonable safety profiles, long-term treatment is becoming more common. The oral nucleos(t)ide analogs have become the preferred first-line therapies for most genotypes of hepatitis B. Five are now available, all with different potencies and resistance profiles. Long-term data spanning several years are now available for most compounds in this arena. This article focuses on the common natural variants and those secondary to nucleos(t)ide therapy, as well as diagnostic methods to detect resistance

Identification of the risk for liver fibrosis on CHB patients using an artificial neural network based on routine and serum markers

<p>Abstract</p> <p>Background</p> <p>Liver fibrosis progression is commonly found in patients with CHB. Liver biopsy is a gold standard for identifying the extent of liver fibrosis, but has many draw-backs. It is essential to construct a noninvasive model to predict the levels of risk for liver fibrosis. It would provide very useful information to help reduce the number of liver biopsies of CHB patients.</p> <p>Methods</p> <p>339 chronic hepatitis B patients with HBsAg-positive were investigated retrospectively, and divided at random into 2 subsets with twice as many patients in the training set as in the validation set; 116 additional patients were consequently enrolled in the study as the testing set. A three-layer artificial neural network was developed using a Bayesian learning algorithm. Sensitivity and ROC analysis were performed to explain the importance of input variables and the performance of the neural network.</p> <p>Results</p> <p>There were 329 patients without significant fibrosis and 126 with significant fibrosis in the study. All markers except gender, HB, ALP and TP were found to be statistically significant factors associated with significant fibrosis. The sensitivity analysis showed that the most important factors in the predictive model were age, AST, platelet, and GGT, and the influence on the output variable among coal miners were 22.3-24.6%. The AUROC in 3 sets was 0.883, 0.884, and 0.920. In the testing set, for a decision threshold of 0.33, sensitivity and negative predictive values were 100% and all CHB patients with significant fibrosis would be identified.</p> <p>Conclusions</p> <p>The artificial neural network model based on routine and serum markers would predict the risk for liver fibrosis with a high accuracy. 47.4% of CHB patients at a decision threshold of 0.33 would be free of liver biopsy and wouldn't be missed.</p

Trends in all cause and viral liver disease-related hospitalizations in people with hepatitis B or C: a population-based linkage study

<p>Abstract</p> <p>Background</p> <p>Previous studies have reported an excess burden of cancer and mortality in populations with chronic hepatitis B (HBV) or C (HCV), but there are limited data comparing hospitalization rates. In this study, we compared hospitalization rates for all causes and viral liver disease in people notified with HBV or HCV in New South Wales (NSW), Australia.</p> <p>Methods</p> <p>HBV and HCV notifications were linked to their hospital (July 2000-June 2006), HIV and death records. Standardized hospitalization ratios (SHRs) were calculated using rates for the NSW population. Random effects Poisson regression was used to examine temporal trends.</p> <p>Results</p> <p>The SHR for all causes and non alcoholic liver disease was two-fold higher in the HCV cohort compared with the HBV cohort (SHRs 1.4 (95%CI: 1.4-1.4) v 0.6 (95%CI: 0.6-0.6) and 14.0 (95%CI: 12.7-15.4) v 5.4 (95%CI: 4.5-6.4), respectively), whilst the opposite was seen for primary liver cancer (SHRs 16.2 (95%CI: 13.8-19.1) v 29.1 (95%CI: 24.7-34.2)). HIV co-infection doubled the SHR except for primary liver cancer in the HCV/HIV cohort. In HBV and HCV mono-infected cohorts, all cause hospitalization rates declined and primary liver cancer rates increased, whilst rates for non alcoholic liver disease increased by 9% in the HCV cohort but decreased by 14% in the HBV cohort (<it>P </it>< 0.001).</p> <p>Conclusion</p> <p>Hospital-related morbidity overall and for non alcoholic liver disease was considerably higher for HCV than HBV. Improved treatment of advanced HBV-related liver disease may explain why HBV liver-related morbidity declined. In contrast, HCV liver-related morbidity increased and improved treatments, especially for advanced liver disease, and higher levels of treatment uptake are required to reverse this trend.</p

Hydrophobically Modified Sulfobetaine Copolymers with Tunable Aqueous UCST through Postpolymerization Modification of Poly(pentafluorophenyl acrylate)

Polysulfobetaines, polymers carrying highly polar zwitterionic side chains, present a promising research field by virtue of their antifouling properties, hemocompatibility, and stimulus-responsive behavior. However, limited synthetic approaches exist to produce sulfobetaine copolymers comprising hydrophobic components. Postpolymerization modification of an activated ester precursor, poly(pentafluorophenyl acrylate), employing a zwitterionic amine, 3-((3-aminopropyl)dimethylammonio)propane-1-sulfonate, ADPS, is presented as a novel, one-step synthetic concept toward sulfobetaine (co)polymers. Modifications were performed in homogeneous solution using propylene carbonate as solvent with mixtures of ADPS and pentylamine, benzylamine, and dodecylamine producing a series of well-defined statistical acrylamido sulfobetaine copolymers containing hydrophobic pentyl, benzyl, or dodecylacrylamide comonomers with well-controllable molar composition as evidenced by NMR and FT-IR spectroscopy and size exclusion chromatography.This synthetic strategy was exploited to investigate, for the first time, the influence of hydrophobic modification on the upper critical solution temperature (UCST) of sulfobetaine copolymers in aqueous solution. Surprisingly, incorporation of pentyl groups was found to increase solubility over a wide composition range, whereas benzyl groups decreased solubility—an effect attributed to different entropic and enthalpic contributions of both functional groups. While UCST transitions of polysulfobetaines are typically limited to higher molar mass samples, incorporation of 0–65 mol % of benzyl groups into copolymers with molar masses of 25.5–34.5 kg/mol enabled sharp, reversible transitions from 6 to 82 °C in solutions containing up to 76 mM NaCl, as observed by optical transmittance and dynamic light scattering. Both synthesis and systematic UCST increase of sulfobetaine copolymers presented here are expected to expand the scope and applicability of these smart materials