A Highly Selective and Sensitive H2S Gas Sensor Based on Novel Nanostructure Core–Shell FeCr2O4@ZnO@MgO

Journal of Inorganic and Organometallic Polymers and Materials - Gas detection is significant for controlling industrial and vehicle emission, house equipment security and environmental monitoring....     

Ultrastructure of collagen thermally denatured by microsecond domain pulsed carbon dioxide laser

BACKGROUND: Clinical improvement in photodamaged skin after carbon dioxide (CO2) laser resurfacing is thought to result in part from thermal collagen shrinkage. The presence of such collagen has not been unequivocally demonstrated. To identify and characterize the morphological features of collagen after CO2 laser exposure, we irradiated ex vivo human facial skin and bovine calcaneus tendon with microsecond domain pulsed CO2 laser energy and examined specimens for histopathological and ultrastructural changes in collagen. OBSERVATIONS: In dermis and tendon, 3 zones of collagen structure were apparent on electron microscopy. The first, most superficial zone demonstrated loss of collagen structure. The second zone consisted of admixed normal collagen fibers and thickened collagen fibers. Zone 3 consisted of normal-appearing collagen fibers. CONCLUSIONS: Ultrastructural examination of irradiated collagen revealed distinct morphological zones of denatured collagen fibers. Partially denatured fibers had an increased diameter consistent with lineal shrinkage. Zonal distinction was undetectable by light microscopy. Ultrastructurally, the zones of denatured collagen located above the normal fibers correlated with the zone of altered material seen on light microscopy. These findings suggest that collagen fiber shrinkage does occur after pulsed CO2 laser irradiation and that this phenomenon contributed, at least in part, to the immediate tissue contraction observed clinically.     

Oxidative dehydrogenation of ethane over Dy2O3/MgO supported LiCl containing eutectic chloride catalysts

The catalytic oxidative dehydrogenation of ethane with alkali and alkaline earth metal chloride modified LiCl supported on Dy₂O₃/MgO (MD) was studied. Eutectic mixtures of alkali and alkaline earth metal chloride with LiCl are formed on the support surface decreasing so the melting point of pure LiCl to temperatures as low as 366 °C (Li-K-MD). All samples had weak basicity decreasing in the order: Li-K-MD < Li-Sr-MD Li-Ba-MD < Li-Na-MD < Li-MD. Physisorbed and chemisorbed CO₂ species are identified for all materials studied by in situ IR spectroscopy. Bidentate carbonate species are the most abundant on Li-MD, while on modified samples bi- and unidentate carbonate species exist. The catalyst activity increases with decreasing basicity. Catalyst selectivity increases with increasing reaction temperature and is constant above a threshold temperature. The maximum ethene selectivity is directly correlated with the melting point of the eutectic melt on the catalyst support.     

An automated slide scanning system for membrane filter imaging in diagnosis of urogenital schistosomiasis

Traditionally, automated slide scanning involves capturing a rectangular grid of field-of-view (FoV) images which can be stitched together to create whole slide images, while the autofocusing algorithm captures a focal stack of images to determine the best in-focus image. However, these methods can be time-consuming due to the need for X-, Y- and Z-axis movements of the digital microscope while capturing multiple FoV images. In this paper, we propose a solution to minimise these redundancies by presenting an optimal procedure for automated slide scanning of circular membrane filters on a glass slide. We achieve this by following an optimal path in the sample plane, ensuring that only FoVs overlapping the filter membrane are captured. To capture the best in-focus FoV image, we utilise a hill-climbing approach that tracks the peak of the mean of Gaussian gradient of the captured FoVs images along the Z-axis. We implemented this procedure to optimise the efficiency of the Schistoscope, an automated digital microscope developed to diagnose urogenital schistosomiasis by imaging Schistosoma haematobium eggs on 13 or 25 mm membrane filters. Our improved method reduces the automated slide scanning time by 63.18% and 72.52% for the respective filter sizes. This advancement greatly supports the practicality of the Schistoscope in large-scale schistosomiasis monitoring and evaluation programs in endemic regions. This will save time, resources and also accelerate generation of data that is critical in achieving the targets for schistosomiasis elimination.     

Synthesis and Characterization of Novel CoCr2O4@GeO2@ZnO Core–Shell Nanostructure: Focus on Electrical Conductivity and Gas Sensing Properties

Journal of Inorganic and Organometallic Polymers and Materials - An effort has been made to develop and synthesize novel CoCr2O4@GeO2@ZnO core–shell nanostructure gas sensor via sol–gel...