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Over the past decade, infections linked to duodenoscopes have become a significant concern, primarily due to the intricate design of the elevator mechanism. Currently, there is limited evidence regarding the bacterial contamination level of the elevator mechanism after clinical use and throughout its various reprocessing stages. This study utilized the swab culture technique to examine the bacterial contamination on the duodenoscope elevator mechanism after clinical use and after 3 reprocessing stages at a Center of tertiary hospital. Our findings revealed severe bacterial contamination after clinical usage, emphasizing that the effectiveness of manual cleaning greatly influences the subsequent high-level disinfection quality. • Recent reports about endoscopy-related infections have spotlighted the elevator mechanism at the distal end of the duodenoscope as a critical reservoir for pathogenic microorganisms. • Our investigation showed that after clinical utilization of duodenoscope, the peak bacterial contamination observed for the elevator and recess were 5.95 × 108 cfu/piece and 9.15 × 108 cfu/piece respectively. • Our findings revealed sever bacterial contamination after clinical usage, emphasizing that the effectiveness of manual cleaning greatly influences the subsequent high-level disinfection quality. [ABSTRACT FROM AUTHOR]

The trade-off between sensitivity and linearity has been the major problem in designing the piezoresistive pressure sensors for low pressure ranges. To resolve the problem, a novel peninsula-structured diaphragm with specially designed piezoresistors was proposed. Finite element method (FEM) was adopted for analyzing the sensor performance as well as comparisons with other sensor structures. In comparison to flat diaphragm, the proposed sensor design could achieve a sensitivity increase by 11.4%, nonlinearity reduction of 60% and resonance frequency increase of 41.8%. In addition, the modified peninsula-structured diaphragms featuring a center boss have been optimized to achieve ultra-low nonlinearities of 0.018%FFS and 0.07%FFS for the 5 kPa and 3 kPa pressure ranges respectively with higher sensitivities as compared to the CBM (cross beam membrane) and hollow stiffening structures. In accordance with the FEM results, the fabricated pressure sensor with the peninsula-structured diaphragm showed a sensitivity of 18.4 mV/V full-scale output and a nonlinearity error of 0.36%FSS in the pressure range 0-5 kPa. The proposed sensor structure is potentially a better choice for designing low pressure sensors. [ABSTRACT FROM AUTHOR]

Toxic particulate elements present in cigarette smoke pose health threats to the life of smokers due to direct inhalation and at the same time increase health risks to non-smokers present in the vicinity of smokers because of their exposure. This study conducted a series of experiments using a controlled experimental chamber, equipped with simulated smoking conditions for characterization of particulate trace elements in mainstream and sidestream cigarette smoke. Four popular commercial cigarette brands available in Singapore market were used in this study. The target elements for extraction and analysis were Al, As, B, Ba, Be, Bi, Ca, Cd, Co, Cr, Cs, Cu, Fe, Ga, Hg, K, Li, Mg, Mn, Na, Ni, Pb, Rb, Se, Sn, Sr, Te, Tl and Zn of both water-soluble and total constituents. The human health risk assessment results showed that the sidestream smoke had higher concentrations of toxic elements than those in the mainstream smoke. However, risk assessment analysis revealed that the sidestream smoke resulted in less human health risks compared to the mainstream smoke due to the influence of dilution of particulate emissions in sidestream smoke prior to inhalation exposure experienced by non-smokers. The cumulative non-cancer and cancer risks of toxic elements varied from 2.0 to 3.1 and from 398.4×10−6 to 626.1×10−6 due to inhalation of cigarette smoke by an active smoker. In the case of non-smokers, the risks were estimated under three possible cases of exposure. The cumulative cancer risks under three different cases were greater than the permissible limits. Therefore, it could be concluded that the toxic particulate elements present in cigarette smoke have significant carcinogenic and non-carcinogenic health effects due to inhalation exposure in the environment. [ABSTRACT FROM AUTHOR]

Abstract: Using the fixed bed (ϕ=72mm) packing with micro glass beads to simulate a small sack in the catalyst-bundles. A dispersion model was established at the stable state point source tracing condition, and it''s analytic and numerical solution were obtained. The stable state point source tracer technique and reducing pressure sampling were used to measure the concentration profile of tracer under different liquid flow rate and different height of fixed bed. The results indicated that the coefficient of radial diffusion decreased with the increasing of the packing height, on the contrary the coefficient of radial diffusion increased with the increasing of the liquid flow rate and the diameter of the micro beads. The influence of axial diffusion coefficient on the radial diffusion coefficient was also discussed and the relationship between Per with ln(Re) was obtained by data regression. [Copyright &y& Elsevier]