Dual polarity open circuit voltage in triboelectric nanogenerators originated from two states series impedance.

Experimental and simulation studies demonstrated that the initial voltage setting significantly influences the open-circuit voltage (VOC) in triboelectric nanogenerators (TENGs). Utilizing diode configurations, we consistently observed two distinct VOCs independent of the initial settings. A lower VOC corresponded to the surface voltage (VSurface), while a higher VOC was amplified by the product of the VSurface and the TENG's characteristic impedance ratio. Notably, a lower measurement system capacitance provided a more precise representation of the inherent characteristics of the TENG. Conversely, an increase in system impedance led to a convergence of the two VOCs and a reduction in their magnitudes relative to VSurface. These findings suggest that optimizing the initial/repeated charge balancing and minimizing capacitive loads are crucial for maximizing TENG output power in practical applications.

Radon concentration and affecting environmental conditions in water-curtain heated cultivation facilities.

Farmers cultivate plants in the winter using water curtain cultivation (WCC) facilities by spraying groundwater to keep them warm. In this study, the WCC facilities exhibited high radon concentrations during winter. The risk varied significantly depending on the facility operation, peaking in the early morning and then decreasing upon ventilation. At all measurement sites, radon concentrations were low when groundwater was not used. Even during the period of facility groundwater use, if water vapor condensation does not occur, there is no significant difference from soil-only emissions. However, once water vapor condensation occurs, radon accumulates rapidly, depending on the degree of radon contamination in the groundwater. Because groundwater contamination varies according to dilution by regional rainfall or inflow from other regions due to groundwater movement, abnormal changes in radon content occur. We found that in the absence of water vapor condensation in the facility, all the radon emitted from the soil and groundwater quickly escaped to the atmosphere, resulting in significantly lower indoor radon concentrations. These findings pave the way for the development of new methods to mitigate radon in WCC facilities.

Asymmetric voltage amplification using a capacitive load energy management circuit in a triboelectric nanogenerator.

We investigated the polarity dependence of a capacitive energy management circuit in a triboelectric nanogenerator (TENG) power system. In a half-wave rectifying circuit, the Simulation Program with Integrated Circuit Emphasis and analytical models show that the charge dump to the load varied depending on the polarity of the rectifying circuit even with the same charge output from TENG. Depending on the polarity of the rectifying circuit, a fast saturation of the direct current (DC) output voltage or a high DC output voltage was obtained. Experiments with a half-wave rectifier and Bennet doubler confirmed our simulation and theoretical results. The charge dump from the minimum capacitance of the separated TENG to the load capacitance and the charge dump from the maximum capacitance of the contacted TENG to the load resulted in asymmetric charging behavior. We concluded that it is necessary to analyze the TENG and the capacitive energy management circuit as a single system rather than considering them as independent units in the rectifying circuit of the TENG. This work can provide insights for the design of triboelectric energy harvesting systems.

Engineered Escherichia coli cell factory for anthranilate over-production.

Anthranilate is a key platform chemical in high demand for synthesizing food ingredients, dyes, perfumes, crop protection compounds, pharmaceuticals, and plastics. Microbial-based anthranilate production strategies have been developed to overcome the unstable and expensive supply of anthranilate via chemical synthesis from non-renewable resources. Despite the reports of anthranilate biosynthesis in several engineered cells, the anthranilate production yield is still unsatisfactory. This study designed an Escherichia coli cell factory and optimized the fed-batch culture process to achieve a high titer of anthranilate production. Using the previously constructed shikimate-overproducing E. coli strain, two genes (aroK and aroL) were complemented, and the trpD responsible for transferring the phosphoribosyl group to anthranilate was disrupted to facilitate anthranilate accumulation. The genes with negative effects on anthranilate biosynthesis, including pheA, tyrA, pabA, ubiC, entC, and trpR, were disrupted. In contrast, several shikimate biosynthetic pathway genes, including aroE and tktA, were overexpressed to maximize glucose uptake and the intermediate flux. The rationally designed anthranilate-overproducing E. coli strain grown in an optimized medium produced approximately 4 g/L of anthranilate in 7-L fed-batch fermentation. Overall, rational cell factory design and culture process optimization for microbial-based anthranilate production will play a key role in complementing traditional chemical-based anthranilate production processes.

Outcome predictors affecting the efficacy of clonazepam therapy for the management of burning mouth syndrome (BMS).

BMS is a common condition characterized by chronic oral mucosal pain condition and primarily affects elderly women. Although clonazepam therapy has been widely used due to its efficacy, it is not always effective because of the complexity of BMS pathogenesis. In this study, we have investigated outcome predictors of clonazepam therapy in patients with BMS. One hundred patients with BMS (7 men and 93 women, mean age 58.5 ± 10.8 years) were instructed to take 0.5mg of clonazepam once or twice daily for 4 weeks. The patients were sub-grouped according to psychological status, salivary flow rate, presence of psychiatric medications, symptom area and duration, symptom severity, presence of oral parafunctions, and accompanying oral complaints. The changes in symptoms were analyzed and compared between the sub-groups. Subjects with T-scores ≤50 for each psychological symptom dimension, a greater degree of initial symptoms (visual analog scale (VAS)≥5), and accompanying oral complaints, such as xerostomia and taste disturbance, displayed greater decreases in symptoms compared with their counterparts. In conclusion, psychological status, initial symptom severity, and the presence of xerostomia and/or taste disturbance can serve as outcome predictors of clonazepam therapy for patients with BMS.

Outcome predictors of initial treatment with topical lubricant and parafunctional habit control in burning mouth syndrome (BMS).

Burning mouth syndrome (BMS) is a common chronic pain condition which mainly affects elderly women. The concomitant prescription of topical lubricants with oral parafunctional habit control has been reported as an effective initial approach for patients with BMS. In this study, we have investigated outcome predictors of this initial treatment in patients with BMS. One hundred forty patients with BMS (12 men and 128 women, mean age 59.9±10.7 years) were instructed to avoid oral parafunctions and to use topical lubricant for 2 weeks. The patients were sub-grouped according to psychological status, salivary flow rate, presence of psychiatric medications, symptom area and duration, symptom severity, presence of oral parafunctions, and accompanying oral complaints. The changes in symptoms were analyzed and compared between sub-groups. Subjects with T-scores≤50 for each psychological symptom dimension, a flow rate of stimulated whole saliva (SWS)>0.5 ml/min, no psychiatric medications, and a greater degree of initial symptoms (VAS≥5) displayed greater decreases in symptoms compared with their counterparts. In conclusion, psychological status, psychiatric medications, flow rate SWS, and initial symptom severity can be outcome predictors of the initial treatment approach for patients with BMS.