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BackgroundA microbial cell factory with high yield and productivity are prerequisites for an economically feasible bio-based chemical industry. However, cell factories that show a kinetic imbalance between glycolysis and product formation pathways are not optimal. Glycolysis activity is highly robust for survival in nature, but is not optimized for chemical production.ResultsHere, we propose a novel approach to balance glycolytic activity with the product formation capacity by precisely controlling expression level of ptsG (encoded glucose transporter) through UTR engineering. For various heterologous pathways with different maximum production rates, e.g., n-butanol, butyrate, and 2,3-butanediol, glycolytic fluxes could be successfully modulated to maximize yield and productivity, while minimizing by-product formation in Escherichia coli.ConclusionsThese results support the application of this simple method to explore the maximum yield and productivity when designing optimal cell factories for value-added products in the fields of metabolic engineering and synthetic biology.

Introduction: This study examines the prevalence experience of traumatic dental injuries (TDIs) due to workplace safety accidents by occupation among Korean workers. Furthermore, identify occupation-specific risk factors, providing essential data for formulating workplace safety policies and TDI prevention strategies. Methods: Data from Korea National Health and Nutrition Examination Survey VII and VIII (2016–2020) were analyzed for 16,588 adults aged 19–54 years, selected from 39,738 participants to represent the active working population in Korea. Analyses were adjusted for sociodemographic factors and covariates. Results: Thirteen percent of participants reported TDIs, with 7.3% attributed to work-related accidents. Manual laborers, particularly plant and machine operators and assemblers, had the highest TDI rate (odds ratio [OR] = 1.56, 95% confidence interval [CI] = 1.20–1.94). Significant disparities in work-related TDIs were observed between agriculture, forestry, and fishery workers compared to industrial plant workers. Among manual laborers, plant and machine operators and assemblers showed an adjusted OR of 1.53 (95% CI = 1.20–1.94). Moreover, the level of education was found to be a significant contributing factor to the previously mentioned differences in experience rates. Conclusion: Manual workers exhibit a higher vulnerability to experiencing TDIs in workplace compared to nonmanual workers, and this association is significantly impacted by their educational attainment. Therefore, to enhance the oral health of workers confronting economic and time restrictions, policies and interventions targeting the enhancement of their working conditions should be implemented. [ABSTRACT FROM AUTHOR]

The vehicle route choice has great impact on the vehicle operating conditions, but it has rarely been used as a way to create desired vehicle operation and benefit automotive control. This paper presents a route planning algorithm which generates a route that meets the requirement of high-speed driving time from the diesel particulate filter controller for an active diesel particulate filter regeneration. Real-time traffic information is considered when designing the route. A new routing algorithm based on the unconstrained Dijkstra algorithm is developed to approximately solve this consecutive-highway-time-constrained shortest-path problem. A correctness proof of the algorithm is given based on an augmented graph. Examples are provided to show the scenarios in which the proposed routes can facilitate the diesel particulate filter regeneration control without adding too much travel time cost. [ABSTRACT FROM AUTHOR]

The most common complication of implant ball attachments is loss of retention via structural wear. Hence, parallel placement of implants was identified as a prerequisite for long-term success. In this case, although severe angulation was formed between implants due to severe alveolar bone resorption, parallel ball attachments on the implants could be fabricated using computer-aided design/computer-assisted manufacture. This procedure can be a solution when implants are placed with angulation and offers additional advantages such as long-term stability. [ABSTRACT FROM AUTHOR]

ABSTRACT Butyrate pathway was constructed in recombinant Escherichia coli using the genes from Clostridium acetobutylicum and Treponema denticola. However, the pathway constructed from exogenous enzymes did not efficiently convert carbon flux to butyrate. Three steps of the productivity enhancement were attempted in this study. First, pathway engineering to delete metabolic pathways to by-products successfully improved the butyrate production. Second, synthetic scaffold protein that spatially co-localizes enzymes was introduced to improve the efficiency of the heterologous pathway enzymes, resulting in threefold improvement in butyrate production. Finally, further optimizations of inducer concentrations and pH adjustment were tried. The final titer of butyrate was 4.3 and 7.2 g/L under batch and fed-batch cultivation, respectively. This study demonstrated the importance of synthetic scaffold protein as a useful tool for optimization of heterologous butyrate pathway in E. coli. Biotechnol. Bioeng. 2013;110: 2790-2794. © 2013 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Computational studies of heavy-duty diesel engine reactivity controlled compression ignition combustion employing both high pressure common rail diesel and low pressure gasoline direct injection were conducted to examine the benefits of using gasoline direct injection compared to port injected gasoline in improving engine performance. In the current study, multi-dimensional modeling using a discrete multi-component fuel vaporization version of the KIVA-3V code was used to examine gasoline direct injection strategies to improve CO and unburned hydrocarbon emissions while maintaining low indicated specific fuel consumption. For a 9 bar indicated mean effective pressure, 1300 r/min operating condition the engine-out CO and unburned hydrocarbonons were reduced by 27.1% and 7.1%, respectively, while engine-out NOx and soot emissions were maintained low. The predicted indicated specific fuel consumption was 159 g/kW h and the maximum pressure rise rate was 6.1 bar/°, which are comparable to or lower than those of the port injected reactivity controlled compression ignition combustion case. Although further study is needed to find optimum injection strategies to improve the combustion efficiency of reactivity controlled compression ignition combustion using gasoline direct injection, the current results show that direct-injecting both high and low reactivity fuels has the potential to reduce CO and unburned hydrocarbon emissions without sacrificing the thermal efficiency benefit of reactivity controlled compression ignition. Moreover, the reduced maximum pressure and pressure rise rate indicates the possibility of improved brake efficiency in reactivity controlled compression ignition combustion and lowered exhaust gas recirculation requirements. The study also explored the use of a low pressure gasoline direct injection injector for the diesel fuel and found that similar results were obtained to those with the high pressure common rail injector. This indicates that reactivity controlled compression ignition combustion is controlled by the global equivalence ratio and fuel reactivity stratification rather than by the location of the stratification in the combustion chamber. This indicates that the complexity and cost of the injection system can be reduced considerably. [ABSTRACT FROM AUTHOR]

The most common complication of implant ball attachments is loss of retention via structural wear. Hence, parallel placement of implants was identified as a prerequisite for long-term success. In this case, although severe angulation was formed between implants due to severe alveolar bone resorption, parallel ball attachments on the implants could be fabricated using computer-aided design/computer-assisted manufacture. This procedure can be a solution when implants are placed with angulation and offers additional advantages such as long-term stability.