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Abstract Background Industrial biomanufacturing of value-added products using CO2 as a carbon source is considered more sustainable, cost-effective and resource-efficient than using common carbohydrate feedstocks. Cupriavidus necator H16 is a representative H2-oxidizing lithoautotrophic bacterium that can be utilized to valorize CO2 into valuable chemicals and has recently gained much attention as a promising platform host for versatile C1-based biomanufacturing. Since this microbial platform is genetically tractable and has a high-flux carbon storage pathway, it has been engineered to produce a variety of valuable compounds from renewable carbon sources. In this study, the bacterium was engineered to produce resveratrol autotrophically using an artificial phenylpropanoid pathway. Results The heterologous genes involved in the resveratrol biosynthetic pathway—tyrosine ammonia lyase (TAL), 4-coumaroyl CoA ligase (4CL), and stilbene synthase (STS) —were implemented in C. necator H16. The overexpression of acetyl-CoA carboxylase (ACC), disruption of the PHB synthetic pathway, and an increase in the copy number of STS genes enhanced resveratrol production. In particular, the increased copies of Vv STS derived from Vitis vinifera resulted a 2-fold improvement in resveratrol synthesis from fructose. The final engineered CR-5 strain produced 1.9 mg/L of resveratrol from CO2 and tyrosine via lithoautotrophic fermentation. Conclusions To the best of our knowledge, this study is the first to describe the valorization of CO2 into polyphenolic compounds by engineering a phenylpropanoid pathway using the lithoautotrophic bacterium C. necator H16, demonstrating the potential of this strain a platform for sustainable chemical production.

This study investigated whether coding (computer programming) and horticultural activities alone and combined have psychophysiological and psychological effects. Compulsory computer programming has been required in elementary schools in South Korea since 2018. A total of 34 participants, who were students between the ages of 11 and 16 years were involved in the study. Participants undertook the following activities in random order: connecting components, coding, horticultural activities, and combining coding and horticultural activities (run program, horticultural activities, and coding modifications). Brain waves were measured during the activity, and a subjective self-report evaluation was conducted at the end of each activity. In a spectral edge frequency of 50% of the alpha spectrum band, which indicates a comfortable, stable, and relaxed state, there was a significant difference in the left prefrontal pole when participants performed a combination of coding and horticultural activities (P < 0.001). In addition, there were significant differences in the coding activities based on horticultural activities (P < 0.05, P < 0.001), with a relatively low beta, indicating attention and alertness; relative mid beta, indicating active awareness; ratio of SMR to theta, indicating focused attention; and the ratio of mid beta to theta, indicating concentrated focus. It is judged that activities involving plant engagement can contribute to comfort, stability, focused attention, and positive effects in response to active stimuli. As a result of a subjective evaluation, it was found that horticultural activities had a positive effect on participants’ emotions (P < 0.01). This study demonstrates that horticulture-based coding activities have a positive impact on physiological relaxation and cognitive enhancement, and are also associated with subjectively reported positive emotions.

Abstract Background A representative hydrogen-oxidizing bacterium Cupriavidus necator H16 has attracted much attention as hosts to recycle carbon dioxide (CO2) into a biodegradable polymer, poly(R)-3-hydroxybutyrate (PHB). Although C. necator H16 has been used as a model PHB producer, the PHB production rate from CO2 is still too low for commercialization. Results Here, we engineer the carbon fixation metabolism to improve CO2 utilization and increase PHB production. We explore the possibilities to enhance the lithoautotrophic cell growth and PHB production by introducing additional copies of transcriptional regulators involved in Calvin Benson Bassham (CBB) cycle. Both cbbR and regA-overexpressing strains showed the positive phenotypes for 11% increased biomass accumulation and 28% increased PHB production. The transcriptional changes of key genes involved in CO2—fixing metabolism and PHB production were investigated. Conclusions The global transcriptional regulator RegA plays an important role in the regulation of carbon fixation and shows the possibility to improve autotrophic cell growth and PHB accumulation by increasing its expression level. This work represents another step forward in better understanding and improving the lithoautotrophic PHB production by C. necator H16.

Background: The purpose of this study was to analyze research trends in articles published in the Journal of Dental Hygiene Science over the past decade.Methods: From 2011 to 2020, 653 studies were reviewed using a keyword analysis. Contents such as academic classification, research type, research method, research topic, data collection method, data analysis method, and financial support were analyzed.Results: Analysis by school type showed 34.2% of clinical dental hygiene studies, 23.3% of educational dental hygiene studies, 22.8% of basic dental hygiene studies, 10.0% of other field studies, and 9.8% of social dental hygiene studies. By type of study, quantitative studies were the most common at 69.5%. Regarding data collection methods, 45.8% of the studies that used surveys were the most common. The subjects of the study were 20.1% experimental studies, 15.6% general adults, and 15.0% dental hygienists. Regarding the data analysis method, 49.3% of the studies that conducted frequency analysis were the most common. The total number of keywords was 2,390, with 107 (4.48%) being ‘dental hygienists.’ Next, oral health was the most common with 67 (2.80%) articles, followed by 31 for the elderly (1.30%), 25 for dental hygiene students (1.05%), and 24 for stress (1.00%).Conclusion: For academic development of dental hygiene, it is necessary to explore the diversity of academic topics based on the results of this study. It is necessary to find a way to spread the research results so that the published research can be used for the academic development of dental hygiene.

Background: The purpose of this study was to identify the differences in the importance of oral pathology learning objectives for instructors and clinical dental hygienists and provide basic data that can guide learning objectives for acquiring practically necessary basic knowledge in the clinical field.Methods: Through the first-stage expert meeting, 27 items with less than four points out of 129 learning objectives in 15 detailed areas were deleted, 12 additional opinions were reflected, 114 learning objectives were set, and a survey was conducted with 253 people.Results: There were statistically significant differences in 92 items after examining the difference between professors and clinical dental hygienists. Among the areas of inflammation and repair, “Can explain the five symptoms of inflammation” had the highest with a score at 4.76 in the case of the professors. Among the areas of tooth damage, “Can explain abrasion” had the highest with a score at 4.61 in the case of the clinical dental hygienists.Conclusion: I would like to propose the existing 15 detail areas and 129 learning objectives as 14 detail areas and 98 learning objectives and strengthen the job competency of dental hygienists in the future. First, you need to develop competencies that are highly relevant to your work. Second, it is necessary to develop related textbooks and educational materials based on revised learning objectives and competencies. Third, based on revised learning objectives, the dental hygienist national examination should be improved. Through these changes in education, the education of oral and maxillofacial disease subjects should strengthen job competencies among dental hygienists with learning objectives that can be applied to actual clinical practice based on basic knowledge rather than knowledge orientation. In addition, it is possible to improve the quality of dental hygiene studies.

Various kinds of plastics have been developed over the past century, vastly improving the quality of life. However, the indiscriminate production and irresponsible management of plastics have led to the accumulation of plastic waste, emerging as a pressing environmental concern. To establish a clean and sustainable plastic economy, plastic recycling becomes imperative to mitigate resource depletion and replace non-eco-friendly processes, such as incineration. Although chemical and mechanical recycling technologies exist, the prevalence of composite plastics in product manufacturing complicates recycling efforts. In recent years, the biodegradation of plastics using enzymes and microorganisms has been reported, opening a new possibility for biotechnological plastic degradation and bio-upcycling. This review provides an overview of microbial strains capable of degrading various plastics, highlighting key enzymes and their role. In addition, recent advances in plastic waste valorization technology based on systems metabolic engineering are explored in detail. Finally, future perspectives on systems metabolic engineering strategies to develop a circular plastic bioeconomy are discussed.

Background: Stress as a cause of mental health problems is known to be more prevalent in women than in men and has a negative effect on several aspects of physical health, such as the composition of blood and saliva. This study investigated the relationship of perceived stress with blood cell counts, saliva flow rate, and saliva factors.Methods: We recruited women in their 20s with a high prevalence of stress. Stress was evaluated using the Korean version of the perceived stress scale. Blood tests included white blood cell, hemoglobin, and platelet. We then examined the saliva flow rate and cariogenic bacteria level, acidity, occult blood, buffer capacity, leukocyte level, protein level, and ammonia level using rinse water with the SILL-HaⓇ saliva test system.Results: In a total of 70 participants, the average age was 21.64 years old, the average perceived stress score was 16.96±4.32, and high levels of stress were reported by 80% of the participants (n=56). The high-stress group had lower hemoglobin levels. In addition, the high-stress group showed a lower saliva flow rate than the low-stress group, and there was a difference in the salivary acidity and buffer capacity. The total perceived stress score showed a positive correlation with acidity and negative correlation with buffer capacity and the hemoglobin level.Conclusion: This study found that stress in female college students might affect the composition of blood and saliva. High levels of stress were positively correlated with the hemoglobin level, saliva flow rate, and acidity and negatively correlated with the buffer capacity.

Introduction: False memory, observed as intrusion errors or false positives (FPs), is prevalent in patients with Alzheimer’s disease, but has yet to be thoroughly investigated in patients with amnestic mild cognitive impairment (a-MCI) with Alzheimer’s disease pathology (ADP). We analyzed false versus veridical memory in individuals with a-MCI and measured the utility of false memory for ADP discrimination. Methods: Patients with a-MCI who received neuropsychological testing and amyloid PET were included. Patients were categorized into “with” and “without ADP” groups according to PET results. Memory tests assessed veridical and false memory, and the verity of patient responses was analyzed. A logistic regression model was used to evaluate false memory efficiency in discriminating ADP, and the sensitivity and specificity at the optimal level were estimated using the receiver-operating characteristic curve. Results: Thirty-seven ADP and 46 non-ADP patients were enrolled. The ADP group made more FPs in the recognition tests, and their response verity was significantly lower in every delayed memory test. No group difference, however, was observed in the veridical memory. The logistic regression analysis demonstrated that as the FPs increased, the risk of ADP increased 1.31 and 1.36 times in the verbal and visual recognition tests, respectively. The discriminatory accuracy of the FPs was estimated “low” to “moderate” in the visual and verbal recognition, respectively, with an optimal cutoff above 2.5. Conclusion: Increased false memory was the only feature to discriminate ADP from non-ADP in individuals with a-MCI. Further studies regarding false memory and its mechanism are warranted.

Abstract Barley is a major cereal crop with a wide ecological range, and its lignocellulosic residues have the potential to be used as a feedstock for various purposes, including biofuel production. Lignocellulosic biomass is an abundant renewable source of carbon energy. However, its heterogeneous properties and intrinsic recalcitrance caused by cell wall lignification have lowered the biorefinery efficiency. The reduced lignin content and/or altered lignin structure have been desirable traits for lignocellulosic feedstock. We report the reduction of lignin content in barley by CRISPR/Cas9‐mediated mutagenesis of caffeic acid O‐methyltransferase 1 (HvCOMT1), the lignin biosynthetic gene responsible for lignin syringyl unit formation. The transgene‐free, homozygous HvCOMT1 mutant was generated and analyzed for its cell wall composition, saccharification efficiency, and bioethanol production performance. The mutant had 14% lower total lignin content and 34% higher fermentable glucose recovery rate, compared to the wild‐type (WT). The bioethanol concentration and yield from the hydrolysates of the mutant biomass were 14.3 g/L and 0.46 g/g total sugar, respectively. This result was 34% and 12% higher than those obtained from WT (10.7 g/L and 0.41 g/g total sugar). Under controlled environmental conditions, the overall growth performance of the HvCOMT1 mutant was similar to WT, with no distinct morphological variations between them. The HvCOMT1 mutant barley could offer improved quality lignocellulosic feedstock for efficient lignocellulosic biofuel production.

The production of hexanol from syngas by acetogens has gained attention as a replacement for petroleum-derived hexanol, which is widely used in the chemical synthesis and plastic industries. However, acetogenic bacteria generally produce C2 compounds (e.g., acetate and ethanol) as the main products. In this study, the gas fermentation conditions favorable for hexanol production were investigated at different temperatures (30–37°C) and CO gas contents (30–70%) in batch gas fermentation. Hexanol production increased from 0.02 to 0.09 g/L when the cultivation temperature was lowered from 37 to 30°C. As the CO content increased from 30 to 70%, the CO consumption rate and hexanol production (yield, titer, and ratio of C6 compound to total products) increased with the CO content. When 70% CO gas was repeatedly provided by flushing the headspace of the bottles at 30°C, the total alcohol production increased to 4.32 g/L at the expense of acids. Notably, hexanol production (1.90 g/L) was higher than that of ethanol (1.20 g/L) and butanol (1.20 g/L); this is the highest level of hexanol produced in gas fermentation to date and the first report of hexanol as the main product. Hexanol production was further enhanced to 2.34 g/L when 2 g/L ethanol was supplemented at the beginning of 70% CO gas refeeding fermentation. Particularly, hexanol productivity was significantly enhanced to 0.18 g/L/day while the supplemented ethanol was consumed, indicating that the conversion of ethanol to acetyl-CoA and reducing equivalents positively affected hexanol production. These optimized culture conditions (gas fermentation at 30°C and refeeding with 70% CO gas) and ethanol supplementation provide an effective and sustainable approach for bio-hexanol production.

Background: The objective of this study is to investigate the needs and importance of basic core competencies required for future society by dental hygienists’ viewpoints who are working in the clinical practices and to provide the fundamental data to develop the educational programs based on the competencies in the 21st century so as to enhance their working capability.Methods: A total of 38 questionnaires were used in this study, 3 questionnaires on the general characteristics (age, service years, main job functions) and those in 11 sub-factors of basic core competencies including 4 questionnaires on creativity, 3 on collaboration, 3 on communication, 3 on interpersonal relationship, 3 on problem-solving, 4 on resource control, 4 on self- control and development, 2 on vocational ethics, 3 on knowledge information utilization, 3 on global mind, and 3 on emotional intelligence. Self-reported survey was conducted in the dental hygienists who were working in Seoul and Gyeonggi Province and a total of 195 data were analyzed.Results: Vocational ethics, communication, and collaboration showed the highest on both importance and needs with 4.49 points and 4.34; 4.41 and 4.28; and 4.39 and 4.22, respectively, while global mind showed the lowest with 3.51 and 3.59. Upon Importance-Performance Analysis, 7 items were defined to require maintain the status including vocational ethics, communication, collaboration, interpersonal relationship, self-control, emotional intelligence, and problem-solving while 4 items with lower priority were resource control and development, knowledge information utilization, creativity, and global mind.Conclusion: Based on this study results that suggested the basic core competencies of dental hygienists in alignment with their jobs in the future society, competitive dental hygienists should be developed with the educational programs applied with these competencies.

Abstract Lignocellulosic biomass shows high potential as a renewable feedstock for use in biodiesel production via microbial fermentation. Yarrowia lipolytica, an emerging oleaginous yeast, has been engineered to efficiently convert xylose, the second most abundant sugar in lignocellulosic biomass, into lipids for lignocellulosic biodiesel production. Yet, the lipid yield from xylose or lignocellulosic biomass remains far lower than that from glucose. Here we developed an efficient xylose‐utilizing Y. lipolytica strain, expressing an isomerase‐based pathway, to achieve high‐yield lipid production from lignocellulosic biomass. The newly developed xylose‐utilizing Y. lipolytica, YSXID, produced 12.01 g/L lipids with a maximum yield of 0.16 g/g, the highest ever reported, from lignocellulosic hydrolysates. Consequently, this study shows the potential of isomerase‐based xylose‐utilizing Y. lipolytica for economical and sustainable production of biodiesel and oleochemicals from lignocellulosic biomass.

Label-free trapping of nanoparticles via dielectophoretic forces is traditionally done with electrodes in a horizontal gap layout. Here, the authors present a vertical nanogap architecture, which allows for precise capture and spatiotemporal manipulation of nanoparticles and molecular assemblies.

Abstract Backgrounds Despite the advances of rheumatoid arthritis (RA) therapeutics, several patients do not receive adequate treatment due to the toxicity and/or insufficient response of drugs. The aim of this study is to design photothermally controlled drug release from multifunctional nanoparticles (MNPs) at a near-infrared (NIR) irradiated site to improve therapeutic efficacy for RA and reduce side effects. Methods Au film was deposited onto methotrexate (MTX)-loaded poly(ethylene glycol)-poly(lactic-co-glycolic acid) (PLGA) nanoparticles, resulting in MTX-loaded MNPs. The synergistic effects of MTX-loaded MNPs with NIR irradiation were investigated using RA fibroblast-like synoviocytes (FLSs) and collagen-induced arthritis (CIA) mice. Results Upon NIR irradiation, NIR resonance of the Au half-shell generated heat locally, accelerating MTX release from PLGA nanoparticles. In vivo NIR images of MTX-loaded MNPs indicated effective delivery of the MNPs to the inflamed joints. Moreover, in collagen-induced arthritis mice, MTX-loaded MNPs containing 1/1400 of MTX solution (repeated-dose administration) had therapeutic effects comparable to conventional treatment with MTX solution. In vitro experiments showed higher therapeutic efficacy of MTX-loaded MNPs with NIR irradiation than that of chemotherapy alone. Conclusions A combination therapy of MTX-loaded MNP and NIR irradiation showed durable and good treatment efficacy for the suppression of arthritis in a single administration of small dose of MTX. Our results demonstrate that the treatment modality using drug-loaded MNP with NIR irradiation may be a promising therapeutic strategy for the treatment of RA and allow in vivo NIR optical imaging.

Abstract Background Lignocellulosic biorefinery offers economical and sustainable production of fuels and chemicals. Saccharomyces cerevisiae, a promising industrial host for biorefinery, has been intensively developed to expand its product profile. However, the sequential and slow conversion of xylose into target products remains one of the main challenges for realizing efficient industrial lignocellulosic biorefinery. Results In this study, we developed a powerful mixed-sugar co-fermenting strain of S. cerevisiae, XUSEA, with improved xylose conversion capacity during simultaneous glucose/xylose co-fermentation. To reinforce xylose catabolism, the overexpression target in the pentose phosphate pathway was selected using a DNA assembler method and overexpressed increasing xylose consumption and ethanol production by twofold. The performance of the newly engineered strain with improved xylose catabolism was further boosted by elevating fermentation temperature and thus significantly reduced the co-fermentation time by half. Through combined efforts of reinforcing the pathway of xylose catabolism and elevating the fermentation temperature, XUSEA achieved simultaneous co-fermentation of lignocellulosic hydrolysates, composed of 39.6 g L−1 glucose and 23.1 g L−1 xylose, within 24 h producing 30.1 g L−1 ethanol with a yield of 0.48 g g−1. Conclusions Owing to its superior co-fermentation performance and ability for further engineering, XUSEA has potential as a platform in a lignocellulosic biorefinery toward realizing a more economical and sustainable process for large-scale bioethanol production.

Abstract Lignocellulosic biomass has considerable potential for the production of fuels and chemicals as a promising alternative to conventional fossil fuels. However, the bioconversion of lignocellulosic biomass to desired products must be improved to reach economic viability. One of the main technical hurdles is the presence of inhibitors in biomass hydrolysates, which hampers the bioconversion efficiency by biorefinery microbial platforms such as Saccharomyces cerevisiae in terms of both production yields and rates. In particular, acetic acid, a major inhibitor derived from lignocellulosic biomass, severely restrains the performance of engineered xylose‐utilizing S. cerevisiae strains, resulting in decreased cell growth, xylose utilization rate, and product yield. In this study, the robustness of XUSE, one of the best xylose‐utilizing strains, was improved for the efficient conversion of lignocellulosic biomass into bioethanol under the inhibitory condition of acetic acid stress. Through adaptive laboratory evolution, we successfully developed the evolved strain XUSAE57, which efficiently converted xylose to ethanol with high yields of 0.43–0.50 g ethanol/g xylose even under 2–5 g/L of acetic stress. XUSAE57 not only achieved twofold higher ethanol yields but also improved the xylose utilization rate by more than twofold compared to those of XUSE in the presence of 4 g/L of acetic acid. During fermentation of lignocellulosic hydrolysate, XUSAE57 simultaneously converted glucose and xylose with the highest ethanol yield reported to date (0.49 g ethanol/g sugars). This study demonstrates that the bioconversion of lignocellulosic biomass by an engineered strain could be significantly improved through adaptive laboratory evolution for acetate tolerance, which could help realize the development of an economically feasible lignocellulosic biorefinery to produce fuels and chemicals.

Efficient xylose catabolism in engineered Saccharomyces cerevisiae enables more economical lignocellulosic biorefinery with improved production yields per unit of biomass. Yet, the product profile of glucose/xylose co-fermenting S. cerevisiae is mainly limited to bioethanol and a few other chemicals. Here, we introduced an n-butanol-biosynthesis pathway into a glucose/xylose co-fermenting S. cerevisiae strain (XUSEA) to evaluate its potential on the production of acetyl-CoA derived products. Higher n-butanol production of glucose/xylose co-fermenting strain was explained by the transcriptomic landscape, which revealed strongly increased acetyl-CoA and NADPH pools when compared to a glucose fermenting wild-type strain. The acetate supplementation expected to support acetyl-CoA pool further increased n-butanol production, which was also validated during the fermentation of lignocellulosic hydrolysates containing acetate. Our findings imply the feasibility of lignocellulosic biorefinery for producing fuels and chemicals derived from a key intermediate of acetyl-CoA through glucose/xylose co-fermentation.

Yeasts are promising industrial hosts for sustainable production of fuels and chemicals. Apart from efficient bioethanol production, yeasts have recently demonstrated their potential for biodiesel production from renewable resources. The fuel-oriented product profiles of yeasts are now expanding to include non-native chemicals with the advances in synthetic biology. In this review, current challenges and opportunities in yeast engineering for sustainable production of non-native chemicals will be discussed, with a focus on the comparative evaluation of a bioethanol-producing Saccharomyces cerevisiae strain and a biodiesel-producing Yarrowia lipolytica strain. Synthetic pathways diverging from the distinctive cellular metabolism of these yeasts guide future directions for product-specific engineering strategies for the sustainable production of non-native chemicals on an industrial scale.

Yarrowia lipolytica, the non-conventional yeast capable of high lipogenesis, is a microbial chassis for producing lipid-based biofuels and chemicals from renewable resources such as lignocellulosic biomass. However, the low tolerance of Y. lipolytica against furfural, a major inhibitory furan aldehyde derived from the pretreatment processes of lignocellulosic biomass, has restricted the efficient conversion of lignocellulosic hydrolysates. In this study, the furfural tolerance of Y. lipolytica has been improved by supporting its endogenous detoxification mechanism. Specifically, the endogenous genes encoding the aldehyde dehydrogenase family proteins were overexpressed in Y. lipolytica to support the conversion of furfural to furoic acid. Among them, YALI0E15400p (FALDH2) has shown the highest conversion rate of furfural to furoic acid and resulted in two-fold increased cell growth and lipid production in the presence of 0.4 g/L of furfural. To our knowledge, this is the first report to identify the native furfural detoxification mechanism and increase furfural resistance through rational engineering in Y. lipolytica. Overall, these results will improve the potential of Y. lipolytica to produce lipids and other value-added chemicals from a carbon-neutral feedstock of lignocellulosic biomass.

Purpose This study aimed to evaluate the level of professional ethics awareness and medical ethics competency in order to assess the potential need for ethics items to be included on the Korean Dental Hygienist Licensing Examination. Methods In total, 358 clinical dental hygienists and dental hygiene students completed a structured questionnaire to evaluate their level of ethical awareness and medical ethics competency. The sub-factors of medical ethics were classified into relationships with patients, medical and social relations, and individual specialized fields. Results Only 32.1% of participants indicated that they had taken a course on professional ethics in the university curriculum, but 95.2% of respondents considered professional ethics to be important. The overall score for medical ethics competency was average (3.37 out of 5). The score for relationships with patients was 3.75 points, followed by medical and social relations (3.19 points) and individual specialized fields (3.16 points). The level of professional ethics awareness was higher among participants who had taken a course on professional ethics than among those who had not done so or who did not remember whether they had done so. Conclusion Dental hygienists were aware of the importance of professional ethics, but their medical ethics competency was moderate. Therefore, medical ethics should be treated as a required subject in the university curriculum, and medical ethics competency evaluations should be strengthened by adding ethics items to the Korean Dental Hygienist Licensing Examination.

Abstract Background Engineered strains of Saccharomyces cerevisiae have significantly improved the prospects of biorefinery by improving the bioconversion yields in lignocellulosic bioethanol production and expanding the product profiles to include advanced biofuels and chemicals. However, the lignocellulosic biorefinery concept has not been fully applied using engineered strains in which either xylose utilization or advanced biofuel/chemical production pathways have been upgraded separately. Specifically, high-performance xylose-fermenting strains have rarely been employed as advanced biofuel and chemical production platforms and require further engineering to expand their product profiles. Results In this study, we refactored a high-performance xylose-fermenting S. cerevisiae that could potentially serve as a platform strain for advanced biofuels and biochemical production. Through combinatorial CRISPR–Cas9-mediated rational and evolutionary engineering, we obtained a newly refactored isomerase-based xylose-fermenting strain, XUSE, that demonstrated efficient conversion of xylose into ethanol with a high yield of 0.43 g/g. In addition, XUSE exhibited the simultaneous fermentation of glucose and xylose with negligible glucose inhibition, indicating the potential of this isomerase-based xylose-utilizing strain for lignocellulosic biorefinery. The genomic and transcriptomic analysis of XUSE revealed beneficial mutations and changes in gene expression that are responsible for the enhanced xylose fermentation performance of XUSE. Conclusions In this study, we developed a high-performance xylose-fermenting S. cerevisiae strain, XUSE, with high ethanol yield and negligible glucose inhibition. Understanding the genomic and transcriptomic characteristics of XUSE revealed isomerase-based engineering strategies for improved xylose fermentation in S. cerevisiae. With high xylose fermentation performance and room for further engineering, XUSE could serve as a promising platform strain for lignocellulosic biorefinery.

Background : For phosphate control, patient education is essential due to the limited clearance of phosphate by dialysis. However, well-designed randomized controlled trials about dietary and phosphate binder education have been scarce. Methods : We enrolled maintenance hemodialysis patients and randomized them into an education group (n = 48) or a control group (n = 22). We assessed the patients' drug compliance and their knowledge about the phosphate binder using a questionnaire. Results : The primary goal was to increase the number of patients who reached a calcium-phosphorus product of lower than 55. In the education group, 36 (75.0%) patients achieved the primary goal, as compared with 16 (72.7%) in the control group (P = 0.430). The education increased the proportion of patients who properly took the phosphate binder (22.9% vs. 3.5%, P = 0.087), but not to statistical significance. Education did not affect the amount of dietary phosphate intake per body weight (education vs. control: -1.18 ± 3.54 vs. -0.88 ± 2.04 mg/kg, P = 0.851). However, the dietary phosphate-to-protein ratio tended to be lower in the education group (-0.64 ± 2.04 vs. 0.65 ± 3.55, P = 0.193). The education on phosphate restriction affected neither the Patient-Generated Subjective Global Assessment score (0.17 ± 4.58 vs. -0.86 ± 3.86, P = 0.363) nor the level of dietary protein intake (-0.03 ± 0.33 vs. -0.09 ± 0.18, P = 0.569). Conclusion : Education did not affect the calcium-phosphate product. Education on the proper timing of phosphate binder intake and the dietary phosphate-to-protein ratio showed marginal efficacy.

Abstract Background The construction of microbial cell factories requires cost-effective and rapid strain development through metabolic engineering. Recently, RNA-guided CRISPR technologies have been developed for metabolic engineering of industrially-relevant host. Results To demonstrate the application of the CRISPR interference (CRISPRi), we developed two-plasmid CRISPRi vectors and applied the CRISPRi in Corynebacterium glutamicum to repress single target genes and double target genes simultaneously. Four-different single genes (the pyc, gltA, idsA, and glgC genes) repressions were successfully performed using the CRISPRi vectors, resulting significant mRNA reductions of the targets compared to a control. Subsequently, the phenotypes for the target gene-repressed strains were analyzed, showing the expected cell growth behaviors with different carbon sources. In addition, double gene repression (the idsA and glgC genes in a different order) by the CRISPRi resulted in an independent gene repression to each target gene simultaneously. To demonstrate an industrial application of the CRISPRi, citrate synthase (CS)-targeting DM1919 (l-lysine producer) strains with a sgRNA-gltA-r showed reduced CS activity, resulting in the improvement of l-lysine yield by 1.39-fold than the parental DM1919 (a lysine producer). Conclusions Single or double gene repression were successfully performed using the CRISPRi vectors and sequence specific sgRNAs. The CRISPRi can be applied for multiplex metabolic engineering to enhanced lysine production and it will promote the further rapid development of microbial cell factories of C. glutamicum.

Mitochondria are essential organelles that are not only responsible for energy production but are also involved in cell metabolism, calcium homeostasis, and apoptosis. Targeting mitochondria is a key strategy for bacteria to subvert host cells’ physiology and promote infection. Helicobacter (H.) pylori targets mitochondria directly. However, mitochondrial genome (mtDNA) polymorphism (haplogroup) is not yet considered an important factor for H. pylori infection. Here, we clarified the association of mitochondrial haplogroups with H. pylori prevalence and the ability to perform damage. Seven mtDNA haplogroups were identified among 28 H. pylori-positive subjects. Haplogroup B was present at a higher frequency and haplotype D at a lower one in the H. pylori population than in that of the H. pylori-negative one. The fibroblasts carrying high-frequency haplogroup displayed a higher apoptotic rate and diminished mitochondrial respiration following H. pylori infection. mtDNA mutations were accumulated more in the H. pylori-positive population than in that of the H. pylori-negative one in old age. Among the mutations, 57% were located in RNA genes or nonsynonymous protein-coding regions in the H. pylori-positive population, while 35% were in the H. pylori-negative one. We concluded that gastric disease caused by Helicobacter virulence could be associated with haplogroups and mtDNA mutations.

Background/Aims: Cyclooxygenase-2 (COX-2), 15-hydroxyprostaglandin dehydrogenase (15-PGDH), and microsomal prostaglandin E synthase-1 (mPGEs-1) regulate prostaglandin E₂ (PGE₂) expression and are involved in colon carcinogenesis. We investigated the expression of PGE₂ and its regulating genes in sporadic human colon tumors and matched normal tissues.Methods: Twenty colonic adenomas and 27 colonic adenocarcinomas were evaluated. COX-2 and 15-PGDH expression was quantified by real-time polymerase chain reaction. The expression of PGE₂ and mPGEs-1 was measured using enzyme-linked immunosorbent assay and Western blotting, respectively.Results: The expression of COX-2, mPGEs-1, and PGE₂ did not differ between the adenomas and matched distant normal tissues. 15-PGDH expression was lower in adenomas than in the matched normal colonic tissues (P

Background/Aim. In Korea, the rate of Helicobacter pylori (H. pylori) eradication has declined steadily as a result of increasing resistance to antibiotics, especially dual resistance to clarithromycin and metronidazole. However, microbiological culture data on drug-resistant H. pylori is lacking. This study evaluated the antimicrobial efficacy of candidate antibiotics against resistant H. pylori strains. Methods. After retrospectively reviewing the data from the Helicobacter Registry in Gil Medical Center (GMC) and Asan Medical Center (AMC), along with 4 reference strains, we selected the 31 single- or multidrug-resistant strains. The susceptibility of the H. pylori strains to seven antibiotics (clarithromycin, metronidazole, levofloxacin, amoxicillin, tetracycline, rifabutin, and furazolidone) and minimum inhibitory concentration were tested using the broth microdilution technique. Results. Among 31 antibiotic resistance strains for H. pylori, there were no strains resistant to rifabutin or furazolidone, which had MICs of

Purpose This study aimed to investigate current issues and areas for improvement in the Korean Dental Hygienist National Licensing Examination (KDHNLE) through an expert Delphi survey. Methods A Delphi survey was conducted from May through August 2016 in Korea. This Delphi survey included 20 persons representing the field of dental hygiene (7 groups from various dental hygiene-related organizations). The Delphi survey was administered through e-mail as 3 rounds of questionnaire surveys regarding the issues facing the KDHNLE and potential solutions to those challenges. The primary Delphi survey was an open questionnaire. In each round, subjects’ responses were categorized according to the detailed themes of their responses. The minimum value of the content validity ratio of the survey results was determined by the number of panels participating in the Delphi survey. Results Issues facing the KDHNLE were identified from the results of the Delphi survey. The following 4 items had an average importance score of 4.0 or higher and were considered as important by over 85% of the panels: the failure of the practical test to reflect actual clinical settings, the focus of the practical test on dental scaling, the gap between the items evaluated on the national examination and actual practical work, and insufficiency in strengthening the expertise of licensed dental hygienists. The following items were suggested for improvement: more rigorous rater training, adjustment of the difficulty of the licensing examination, the introduction of a specialized dental hygienist system, and more rigorous refresher training for licensed dental hygienists. Conclusion Based on the above results, the KDHNLE should be improved according to the core competencies of dental hygienists, including on-site clinical practice experience.

ObjectivesThe purpose of this study was to review evaluation studies of nursing management information systems (NMISs) and their outcome measures to examine system effectiveness.MethodsFor the systematic review, a literature search of the PubMed, CINAHL, Embase, and Cochrane Library databases was conducted to retrieve original articles published between 1970 and 2014. Medical Subject Headings (MeSH) terms included informatics, medical informatics, nursing informatics, medical informatics application, and management information systems for information systems and evaluation studies and nursing evaluation research for evaluation research. Additionally, manag* and admin*, and nurs* were combined. Title, abstract, and full-text reviews were completed by two reviewers. And then, year, author, type of management system, study purpose, study design, data source, system users, study subjects, and outcomes were extracted from the selected articles. The quality and risk of bias of the studies that were finally selected were assessed with the Risk of Bias Assessment Tool for Non-randomized Studies (RoBANS) criteria.ResultsOut of the 2,257 retrieved articles, a total of six articles were selected. These included two scheduling programs, two nursing cost-related programs, and two patient care management programs. For the outcome measurements, usefulness, time saving, satisfaction, cost, attitude, usability, data quality/completeness/accuracy, and personnel work patterns were included. User satisfaction, time saving, and usefulness mostly showed positive findings.ConclusionsThe study results suggest that NMISs were effective in time saving and useful in nursing care. Because there was a lack of quality in the reviewed studies, well-designed research, such as randomized controlled trials, should be conducted to more objectively evaluate the effectiveness of NMISs.

Biological production of 2,3-butandiol (2,3-BD) has received great attention as an alternative to the petroleum-based 2,3-BD production. In this study, a high production of 2,3-BD in fed-batch fermentation was investigated with a newly isolated bacterium designated as Raoultella ornithinolytica B6. The isolate produced 2,3-BD as the main product using hexoses (glucose, galactose, and fructose), pentose (xylose) and disaccharide (sucrose). The effects of temperature, pH-control schemes, and agitation speeds on 2,3-BD production were explored to optimize the fermentation conditions. Notably, cell growth and 2,3-BD production by R. ornithinolytica B6 were higher at 25°C than at 30°C. When three pH control schemes (no pH control, pH control at 7, and pH control at 5.5 after the pH was decreased to 5.5 during fermentation) were tested, the best 2,3-BD titer and productivity along with reduced by-product formation were achieved with pH control at 5.5. Among different agitation speeds (300, 400, and 500 rpm), the optimum agitation speed was 400 rpm with 2,3-BD titer of 68.27 g/L, but acetic acid was accumulated up to 23.32 g/L. Further enhancement of the 2,3-BD titer (112.19 g/L), yield (0.38 g/g), and productivity (1.35 g/L/h) as well as a significant reduction of acetic acid accumulation (9.71 g/L) was achieved by the overexpression of homologous budABC genes, the 2,3-BD-synthesis genes involved in the conversion of pyruvate to 2,3-BD. This is the first report presenting a high 2,3-BD production by R.ornithinolytica which has attracted little attention with respect to 2,3-BD production, extending the microbial spectrum of 2,3-BD producers.

The number of breast cancer women has increased dramatically in Korea. The cause is perceived to stem from adaptation to a westernized life style which increases body mass index (BMI). However, there are no meta-analysis data available that could help in understanding the relationship between Korean females' BMI and breast cancer occurrence. Method: All the published articles that investigated the relationship of Korean women's BMI with breast cancer prevalence between 1950 and 2007 were included in this study, based on a screen of the comput- erized databases that search for these articles (MEDLINE, RISS4U and KMBase). The commercial software Comprehensive Meta Analysis was used for the analysis. Results: The high BMI score group presented a higher prevalence of breast cancer on both a fixed-effects model [odds ratio (OR) = 1.282; 95% confidence interval (CI) = 1.209, 1.361] and a random-effects model (OR = 1.388; 95% CI = 1.129, 1.706). In addition, a high BMI score on pre- and postmenopausal groups was found to have a significantly higher prevalence of breast cancer on both a fixed-effects model (OR = 1.467; 95% CI = 1.268, 1.698, OR = 1.614; 95% CI = 1.360, 1.917, pre- and postmenopausal, respectively) and a random-effects model (OR = 1.387; 95% CI = 1.134, 1.696, OR = 1.681; 95% CI = 1.149, 2.461, pre- and postmenopausal, respectively). Conclusion: This meta-analysis of Korean women showed that a high BMI was related to a higher inci- dence rate of breast cancer. This study used a subgroup analysis of pre- and postmenopausal groups; the high BMI subset in both the pre- and postmenopausal groups was shown to have a higher incidence rate of breast cancer. [Asian Nursing Research 2009;3(1):31–40]