The effect of beta1-adrenergic receptor gene polymorphism on prolongation of corrected QT interval during endotracheal intubation under sevoflurane anesthesia

BACKGROUND: The hemodynamic responses to endotracheal intubation are associated with sympathoadrenal activity. Polymorphisms in the beta1-adrenergic receptor (β(1)AR) gene can alter the pathophysiology of specific diseases. The aim of this study is to investigate whether the Ser49Gly and Arg389Gly polymorphism of the β(1)AR gene have different cardiovascular responses during endotracheal intubation under sevoflurane anesthesia. METHODS: Ninety-one healthy patients undergoing general anesthesia were enrolled. Patients underwent slow inhalation induction of anesthesia using sevoflurane in 100% oxygen. Vecuronium 0.15 mg/kg was given for muscle relaxation. Endotracheal intubation was performed by an anesthesiologist. The mean arterial pressure (MAP), heart rate (HR), and the corrected QT (QTc) interval were measured before induction, before laryngoscopy, and immediately after tracheal intubation. Genomic DNA was isolated from the patients' peripheral blood and then evaluated for the β(1)AR-49 and β(1)AR-389 genes using an allele-specific polymerase chain reaction method. RESULTS: No differences were found in the baseline values of MAP, HR, and the QTc interval among β(1)AR-49 and β(1)AR-389, respectively. In the case of β(1)AR-49, the QTc interval change immediately after tracheal intubation was significantly greater in Ser/Ser genotypes than in Ser/Gly genotypes. No differences were observed immediately after tracheal intubation in MAP and HR for β(1)AR-49 and β(1)AR-389. CONCLUSIONS: We found an association between the Ser49 homozygote gene of β(1)AR-49 polymorphism and increased QTc prolongation during endotracheal intubation with sevoflurane anesthesia. Thus, β(1)AR-49 polymorphism may be useful in predicting the risk of arrhythmia during endotracheal intubation in patients with long QT syndrome.ope

Tactile Avatar: Tactile Sensing System Mimicking Human Tactile Cognition

As a surrogate for human tactile cognition, an artificial tactile perception and cognition system are proposed to produce smooth/soft and rough tactile sensations by its user's tactile feeling; and named this system as “tactile avatar”. A piezoelectric tactile sensor is developed to record dynamically various physical information such as pressure, temperature, hardness, sliding velocity, and surface topography. For artificial tactile cognition, the tactile feeling of humans to various tactile materials ranging from smooth/soft to rough are assessed and found variation among participants. Because tactile responses vary among humans, a deep learning structure is designed to allow personalization through training based on individualized histograms of human tactile cognition and recording physical tactile information. The decision error in each avatar system is less than 2% when 42 materials are used to measure the tactile data with 100 trials for each material under 1.2N of contact force with 4cm s−1 of sliding velocity. As a tactile avatar, the machine categorizes newly experienced materials based on the tactile knowledge obtained from training data. The tactile sensation showed a high correlation with the specific user's tendency. This approach can be applied to electronic devices with tactile emotional exchange capabilities, as well as advanced digital experiences. © 2021 The Authors. Advanced Science published by Wiley-VCH GmbH1

Subthreshold electrical stimulation as a low power electrical treatment for stroke rehabilitation

As a promising future treatment for stroke rehabilitation, researchers have developed direct brain stimulation to manipulate the neural excitability. However, there has been less interest in energy consumption and unexpected side effect caused by electrical stimulation to bring functional recovery for stroke rehabilitation. In this study, we propose an engineering approach with subthreshold electrical stimulation (STES) to bring functional recovery. Here, we show a low level of electrical stimulation boosted causal excitation in connected neurons and strengthened the synaptic weight in a simulation study. We found that STES with motor training enhanced functional recovery after stroke in vivo. STES was shown to induce neural reconstruction, indicated by higher neurite expression in the stimulated regions and correlated changes in behavioral performance and neural spike firing pattern during the rehabilitation process. This will reduce the energy consumption of implantable devices and the side effects caused by stimulating unwanted brain regions. © 2021, The Author(s).1

Electrical and Structural Characteristics of Excimer Laser-Crystallized Polycrystalline Si1−xGex Thin-Film Transistors

We investigated the characteristics of excimer laser-annealed polycrystalline silicon–germanium (poly-Si1−xGex) thin film and thin-film transistor (TFT). The Ge concentration was increased from 0% to 12.3% using a SiH4 and GeH4 gas mixture, and a Si1−xGex thin film was crystallized using different excimer laser densities. We found that the optimum energy density to obtain maximum grain size depends on the Ge content in the poly-Si1−xGex thin film; we also confirmed that the grain size of the poly-Si1−xGex thin film is more sensitive to energy density than the poly-Si thin film. The maximum grain size of the poly-Si1−xGex film was 387.3 nm for a Ge content of 5.1% at the energy density of 420 mJ/cm2. Poly-Si1−xGex TFT with different Ge concentrations was fabricated, and their structural characteristics were analyzed using Raman spectroscopy and atomic force microscopy. The results showed that, as the Ge concentration increased, the electrical characteristics, such as on current and sub-threshold swing, were deteriorated. The electrical characteristics were simulated by varying the density of states in the poly-Si1−xGex. From this density of states (DOS), the defect state distribution connected with Ge concentration could be identified and used as the basic starting point for further analyses of the poly-Si1−xGex TFTs

Practical Performance Analysis of a Bifacial PV Module and System

Bifacial photovoltaic (PV) modules can take advantage of rear-surface irradiance, enabling them to produce more energy compared with monofacial PV modules. However, the performance of bifacial PV modules depends on the irradiance at the rear side, which is strongly affected by the installation setup and environmental conditions. In this study, we experiment with a bifacial PV module and a bifacial PV system by varying the size of the reflective material, vertical installation, temperature mismatch, and concentration of particulate matter (PM), using three testbeds. From our analyses, we found that the specific yield increased by 1.6% when the reflective material size doubled. When the PV module was installed vertically, the reduction of power due to the shadow effect occurred, and thus the maximum current was 14.3% lower than the short-circuit current. We also observed a maximum average surface temperature mismatch of 2.19 °C depending on the position of the modules when they were composed in a row. Finally, in clear sky conditions, when the concentration of PM 10 changed by 100 µg/m3, the bifacial gain increased by 4%. In overcast conditions, when the concentration of PM 10 changed by 100 µg/m3, the bifacial gain decreased by 0.9%

Electrical and Structural Characteristics of Excimer Laser-Crystallized Polycrystalline Si_1−xGe_x Thin-Film Transistors

We investigated the characteristics of excimer laser-annealed polycrystalline silicon−germanium (poly-Si1−xGex) thin film and thin-film transistor (TFT). The Ge concentration was increased from 0% to 12.3% using a SiH4 and GeH4 gas mixture, and a Si1−xGex thin film was crystallized using different excimer laser densities. We found that the optimum energy density to obtain maximum grain size depends on the Ge content in the poly-Si1−xGex thin film; we also confirmed that the grain size of the poly-Si1−xGex thin film is more sensitive to energy density than the poly-Si thin film. The maximum grain size of the poly-Si1−xGex film was 387.3 nm for a Ge content of 5.1% at the energy density of 420 mJ/cm2. Poly-Si1−xGex TFT with different Ge concentrations was fabricated, and their structural characteristics were analyzed using Raman spectroscopy and atomic force microscopy. The results showed that, as the Ge concentration increased, the electrical characteristics, such as on current and sub-threshold swing, were deteriorated. The electrical characteristics were simulated by varying the density of states in the poly-Si1−xGex. From this density of states (DOS), the defect state distribution connected with Ge concentration could be identified and used as the basic starting point for further analyses of the poly-Si1−xGex TFTs

Performance Analysis of Bifacial PV Modules with Transparent Mesh Backsheet

Due to their transparent rear side, bifacial modules can take advantage of rear side irradiance as opposed to monofacial modules. Glass or transparent backsheets are conventionally used as rear side encapsulation material. To increase coupling gains achieved through internal reflection at the module rear side, a white or reflecting mesh structure can be applied in the areas between the cells on the rear side material. In this study, an existing optical model based on a simplified ray tracing approach is extended to describe the effects achieved though this mesh structure. The model is further integrated into a complete cell-to-module loss and gain analysis. The performance of the mesh backsheet concept is assessed under varying parameters. The impact of mesh reflectance, bifaciality of the cell and width of the mesh compared to the cell spacing are investigated. Losses due to increased module temperature and gains due to internal reflection gains are compared. We confirm that the optimal power gain can be achieved when the width of the mesh is the same as the spacing between the cells. We find that the power gain due to the improved internal reflection outweighs the power loss due to increased module temperature