Band gap engineering for improved photocatalytic performance of CuS/TiO2 composites under solar light irradiation

ABSTRACT. Nanoparticles of CuS, TiO2 and CuS/TiO2 composites were prepared by template free hydrothermal method. Prepared nanoparticles were characterized by X-ray diffraction (XRD) and electron dispersive X-ray spectroscopy to confirm the formation of nanoparticles. Field emission scanning electron microscopy (FESEM) was applied to investigate the morphology and particle size of the nanoparticles which were measured in the range of 30–40 nm. Photocatalytic performance of CuS, TiO2 and Cus/TiO2 were measured by degradation of methyl orange (MO) under solar light irradiation. Coupling of n-type TiO2 (3.2 eV) with p-type CuS (1.9 eV) showed efficient degradation of the contaminants under the solar light irradiation. Photocatalytic performance of CuS/TiO2 composite improves 1.4 times than CuS for the degradation of methyl orange (MO) under solar light irradiation.               KEY WORDS: CuS/TiO2 composites, Photocatalytic performance, Hydrothermal growth, Solar light, Irradiation Bull. Chem. Soc. Ethiop. 2019, 33(3), 561-571.        DOI: https://dx.doi.org/10.4314/bcse.v33i3.1

Evaluation Method, Dataset Size or Dataset Content: How to Evaluate Algorithms for Image Matching?

Most vision papers have to include some evaluation work in order to demonstrate that the algorithm proposed is an improvement on existing ones. Generally, these evaluation results are presented in tabular or graphical forms. Neither of these is ideal because there is no indication as to whether any performance differences are statistically significant. Moreover, the size and nature of the dataset used for evaluation will obviously have a bearing on the results, and neither of these factors are usually discussed. This paper evaluates the effectiveness of commonly used performance characterization metrics for image feature detection and description for matching problems and explores the use of statistical tests such as McNemar’s test and ANOVA as better alternatives

Using a population-based approach to prevent hepatocellular cancer in New South Wales, Australia: effects on health services utilisation

<p>Abstract</p> <p>Background</p> <p>Australians born in countries where hepatitis B infection is endemic are 6-12 times more likely to develop hepatocellular cancer (HCC) than Australian-born individuals. However, a program of screening, surveillance and treatment of chronic hepatitis B (CHB) in high risk populations could significantly reduce disease progression and death related to end-stage liver disease and HCC. Consequently we are implementing the <it>B Positive </it>pilot project, aiming to optimise the management of CHB in at-risk populations in south-west Sydney. Program participants receive routine care, enhanced disease surveillance or specialist referral, according to their stage of CHB infection, level of viral load and extent of liver injury. In this paper we examine the program's potential impact on health services utilisation in the study area.</p> <p>Methods</p> <p>Estimated numbers of CHB infections were derived from Australian Bureau of Statistics data and applying estimates of HBV prevalence rates from migrants' countries of birth. These figures were entered into a Markov model of disease progression, constructing a hypothetical cohort of Asian-born adults with CHB infection. We calculated the number of participants in different CHB disease states and estimated the numbers of GP and specialist consultations and liver ultrasound examinations the cohort would require annually over the life of the program.</p> <p>Results</p> <p>Assuming a 25% participation rate among the 5,800 local residents estimated to have chronic hepatitis B infection, approximately 750 people would require routine follow up, 260 enhanced disease surveillance and 210 specialist care during the first year after recruitment is completed. This translates into 5 additional appointments per year for each local GP, 25 for each specialist and 420 additional liver ultrasound examinations.</p> <p>Conclusions</p> <p>While the program will not greatly affect the volume of local GP consultations, it will lead to a significant increase in demand for specialist services. New models of CHB care may be required to aid program implementation and up scaling the program will need to factor in additional demands on health care utilisation in areas of high hepatitis B sero-prevalence.</p

Strontium substituted bioactive glasses for tissue engineered scaffolds: the importance of octacalcium phosphate

Porous bioactive glasses are attractive for use as bone scaffolds. There is increasing interest in strontium containing bone grafts, since strontium ions are known to up-regulate osteoblasts and down regulate osteoclasts. This paper investigates the influence of partial to full substitution of strontium for calcium on the dissolution and phase formation of a multicomponent high phosphate content bioactive glass. The glasses were synthesised by a high temperature melt quench route and ground to a powder of <38 microns. The dissolution of this powder and its ability to form apatite like phases after immersion in Tris buffer (pH 7.4) and simulated body fluid (SBF) was followed by inductively coupled plasma optical emission spectroscopy (ICP), Fourier transform infra red spectroscopy (FTIR), X-ray powder diffraction (XRD) and (31)P solid state nuclear magnetic resonance spectroscopy up to 42 days of immersion. ICP indicated that all three glasses dissolved at approximately the same rate. The all calcium (SP-0Sr-35Ca) glass showed evidence of apatite like phase formation in both Tris buffer and SBF, as demonstrated after 3 days by FTIR and XRD analysis of the precipitate that formed during the acellular dissolution bioactivity studies. The strontium substituted SP-17Sr-17Ca glass showed no clear evidence of apatite like phase formation in Tris, but evidence of an apatite like phase was observed after 7 days incubation in SBF. The SP-35Sr-0Ca glass formed a new crystalline phase termed “X Phase” in Tris buffer which FTIR indicated was a form of crystalline orthophosphate. The SP-35Sr-0Ca glass appeared to support apatite like phase formation in SBF by 28 days incubation. The results indicate that strontium substitution for calcium in high phosphate content bioactive glasses can retard apatite like phase formation. It is proposed that apatite formation with high phosphate bioactive glasses occurs via an octacalcium phosphate (OCP) precursor phase that subsequently transforms to apatite. The equivalent octa-strontium phosphate does not exist and consequently in the absence of calcium, apatite formation does not occur. The amount of strontium that can be substituted for calcium in OCP probably determines the amount of strontium in the final apatite phase and the speed with which it forms

Hepatitis C virus re-treatment in the era of direct-acting antivirals: projections in the USA

BACKGROUND: The introduction of oral direct-acting antivirals (DAAs) has dramatically changed the landscape of HCV treatment. However, a small percentage of patients fail to achieve sustained virologic response (SVR). Understanding the number of people who fail on DAAs and require re-treatment is important for budget impact and disease burden projections. AIM: To quantify the number of HCV patients who fail to achieve SVR on oral DAAs (NS5A vs. non-NS5A) and require re-treatment. METHODS: We used a mathematical model to simulate clinical management of HCV in the USA, which included the implementation of HCV screening, treatment, and disease progression. We simulated different waves of DAA treatment and used real-world data to extract SVR rates and market shares of available therapies. RESULTS: Our model projected that the number of people living without viraemia (i.e. cured) would increase from 0.70 million in 2014 to 1.78 million by 2020. Between 2014 and 2020, 1.50 million people would receive treatment with DAAs, of whom 124 000 (8.3%) are projected to fail to achieve SVR. Among those treatment failures, 66 600 (53.7%) patients would fail treatment with NS5A inhibitors and 69 600 (56.1%) would have cirrhosis. During the same period, 34 200 people would progress to decompensated cirrhosis and 27 300 would develop hepatocellular carcinoma after failing to achieve SVR. CONCLUSIONS: Even in the era of highly effective DAAs, a significant number of patients will fail to achieve SVR and will require re-treatment options. Timely and effective re-treatment is essential to prevent the long-term sequelae of HCV

Establishment and optimization of callus-to-plant regeneration system using mature and immature embryos of maize (Zea mays)

Two experiments were conducted to develop an efficient maize regeneration system using mature and immature embryos of four maize elite lines (Agaiti-85, Golden, Soneri and Sultan). The comparative studies revealed that all maize lines were responsive to callus and plant regeneration from mature and immature embryos. The culture medium Chu\u27s N6 was used in both experiments. Immature embryos efficiently produced callus and regenerated plants therefore, when cultured on medium supplemented with 2,4-D, kinetin, 6-BAP and IBA at concentrations of 2 mL L-1, 0.2, 0.2 and 0.3 g L-1, respectively. However, callus-to-plant regeneration system for mature embryos required these growth regulators at higher concentrations (5 mL L-1, 0.4 g L-1, 0.5 g L-1 and 0.6 g L-1, respectively). The regeneration frequencies ranged from 40 to 75% using immature embryos, compared to 55 to 80% from immature embryos of all elite lines of maize under study