Adaptively evolved Escherichia coli for improved ability of formate utilization as a carbon source in sugar???free conditions

Background: Formate converted from CO2 reduction has great potential as a sustainable feedstock for biological production of biofuels and biochemicals. Nevertheless, utilization of formate for growth and chemical production by microbial species is limited due to its toxicity or the lack of a metabolic pathway. Here, we constructed a formate assimilation pathway in Escherichia coli and applied adaptive laboratory evolution to improve formate utilization as a carbon source in sugar-free conditions. Results: The genes related to the tetrahydrofolate and serine cycles from Methylobacterium extorquens AM1 were overexpressed for formate assimilation, which was proved by the 13C-labeling experiments. The amino acids detected by GC/MS showed significant carbon labeling due to biomass production from formate. Then, 150 serial subcultures were performed to screen for evolved strains with improved ability to utilize formate. The genomes of evolved mutants were sequenced and the mutations were associated with formate dehydrogenation, folate metabolism, and biofilm formation. Last, 90 mg/L of ethanol production from formate was achieved using fed-batch cultivation without addition of sugars. Conclusion: This work demonstrates the effectiveness of the introduction of a formate assimilation pathway, combined with adaptive laboratory evolution, to achieve the utilization of formate as a carbon source. This study suggests that the constructed E. coli could serve as a strain to exploit formate and captured CO2

A Survey of Koreans on Sleep Habits and Sleeping Symptoms Relating to Pillow Comfort and Support

The number of people who complain of sleep disturbances is steadily increasing. An understanding of sleep-related factors is required to address sleep problems. This survey study investigated the sleep habits and sleeping symptoms relating to the comfort and support characteristics of pillows and the relationship between sleep quality and pillow design factors. The study utilized data from 332 participating Korean adults aged 20–76 years (mean age ± SD: males, 40.4 ± 15.2; females, 42.9 ± 15.4). We developed a questionnaire that evaluated sleep habits (sleep duration, bedtime, wake-up time and sleeping position); sleeping symptoms (snoring or coughing, breathing and sleepiness during waking hours) based on the Korean version of the Pittsburgh Sleep Quality Index (PSQI-K) questionnaire; and pillow-related factors (support, comfort, fatigue, height and shape) from existing pillow studies. The average sleep duration was 6.8 h, with more than half (52%) of participants sleeping in the supine position. The overall score for sleep quality was considered poor (4.84 points on a seven-point Likert scale), with some degree of sleepiness during waking hours (4.4 points on a seven-point Likert scale). Females went to bed earlier than males and were more likely to sleep in the lateral position compared to males. The number of toss and turn or waking events during sleep increased with age, and older individuals went to sleep earlier and woke up earlier. Among the symptoms of fatigue, pain, discomfort with changing position, snoring, coughing and breathing discomfort, participants reported their highest levels of discomfort due to sleepiness after waking, and they experienced the least head pain. Participants who used a regular-type pillow had poorer satisfaction on multiple comfort and support factors (support, comfort, height suitability, shape suitability) compared with those who used a functional-type pillow. Less head fatigue, less neck fatigue and less shoulder pain had significant effects on sleep quality. To reduce neck fatigue and shoulder pain, designers should consider the height for neck support in the lateral position. To reduce neck fatigue, it is desirable to use materials like latex or memory foam that provide neck support, which can improve sleep quality. The findings of this study contribute to a better understanding of sleep habits and characteristics of pillow comfort and provide practical guidelines for better pillow designs

Effect of CdSe nanoparticles in polymethylmethacrylate tunneling layeron the performance of nonvolatile organic memory device

Organic memory devices based on CdSe nanoparticles (NPs) embedded in polymethylmethacrylate (PMMA) insulating layer are demonstrated. The use of NPs/polymer blend as a tunneling layer for nonvolatile organic memory has proven to be an alternative route to manipulate and improve the device characteristics. The memory effect is adjustable upon changing the concentration of CdSe NPs within the PMMA tunneling insulator, and the tunable device performance is ascribed to the different trap densities in floating gate. The capacitance change is analyzed by monitoring the charge transport between pentacene and the CdSe NPs. Our in-depth study reveals that the increase in CdSe NPs leads to a wider memory window and better hysteresis characteristics with a maximum window of 8.6 V at VGS of 30 V for 1 s. This result demonstrates the potential application of organic/inorganic hybrid floating gate structure in organic memory devices

A Comparison of Barrier Factors between Hospitals with and without Cardiac Rehabilitation Programs in Korea: A Nation-Wide Survey Research

The percentage of patients undergoing cardiac rehabilitation programs (CRP) is very low (30–40%), and hospitals providing CRP are either insufficient or lacking, even in countries with advanced medical care; therefore, this study aims to investigate the barriers, as well as compare the differences between hospitals, with or without CRP. We conducted a survey, in which the questionnaire was distributed through post or email to 607 specialists who work at 164 hospitals performing percutaneous coronary interventions (PCI). The results were as follows: (1) of the 164 hospitals, 132 responded (response rate: 80.5%). While all 47 hospitals with CRP responded (100%), from among the 117 hospitals without CRP, 85 responded (72.7%). (2) Of the 607 specialists, 227 responded (response rate: 36.9%). The response rates according to specialties were as follows: cardiologists (28.9%), cardiac surgeons (24.5%), and physiatrists (64.1%). (3) While the specialists at hospitals with CRP identified patient referral, transportation, and cost as the major barriers, for those at hospitals without CRP, all items were considered barriers, especially the items related to equipment, space, workforce, and budget as being more serious barriers. Therefore, in order to actively promote CRP, it is suggested that governments consider the customized support system according to the performance of CRPs

Current Status of Cardiac Rehabilitation in the Regional Cardiocerebrovascular Centers in Korea

Regional Cardiocerebrovascular Centers (RCCs)—a Korean government initiative—seek to reduce medical gaps across regions, and their cardiac rehabilitation (CR) programs are expected to model post-acute care for the Korean CR program. Accordingly, this study aimed to evaluate the current status of CR programs in the RCCs. We distributed surveys on the CR condition, activity, and barriers to 12 RCCs in different provinces. The results revealed significant gaps in the annual number of acute myocardial infarction admissions, and CR candidates, capacity, and density across the 12 RCCs. The CR capacity (50–500) and density (0.42–7.36) indicated particularly large gaps. Twelve RCCs had the necessary facilities, equipment and personnel for CR assessments and management, with high CR referral (97%) and patient education (78%) rates. However, the inpatient CR exercise training (56%) participation rate was inadequate, with much lower enrollment (47%) and adherence (17%) rates to the outpatient CR program and large differences across centers. Therefore, this study’s results will provide the evidence required to establish special national health strategies to overcome the CR barriers of patient, doctor/hospital, and policy factors for activating Korean CR programs