Cost-effective production of bioplastic polyhydroxybutyrate via introducing heterogeneous constitutive promoter and elevating acetyl-Coenzyme A pool of rapidly growing cyanobacteria.

Bioplastic production using cyanobacteria can be an effective strategy to cope with environmental problems caused by using petroleum-based plastics. Synechococcus elongatus UTEX 2973 with heterogeneous phaCAB can produce bioplastic polyhydroxybutyrate (PHB) with a high CO2 uptake rate. For cost-effective production of PHB in S. elongatus UTEX 2973, phaCAB was expressed by the constitutive Pcpc560, resulting in the production of 226 mg/L of PHB by only photoautotrophic cultivation without the addition of inducer. Several culture conditions were applied to increase PHB productivity, and when acetate was supplied at a concentration of 1 g/L as an organic carbon source, productivity significantly increased resulting in 607.2 mg/L of PHB and additive cost reduction of more than 300 times was achieved compared to IPTG. Consequently, these results suggest the possibility of cyanobacteria as an agent that can economically produce PHB and as a solution to the problem of petroleum-based plastics.

Distinct plasma phosphorylated-tau proteins profiling for the differential diagnosis of mild cognitive impairment and Alzheimer's disease by plasmonic asymmetric nanobridge-based biosensor.

The differential diagnosis between mild cognitive impairment (MCI) and Alzheimer's disease (AD) has been highly demanded for its effectiveness in preventing and contributing to early diagnosis of AD. To this end, we developed a single plasmonic asymmetric nanobridge (PAN)-based biosensor to differentially diagnose MCI and AD by quantitative profiling of phosphorylated tau proteins (p-tau) in clinical plasma samples, which revealed a significant correlation with AD development and progression. The PAN was designed to have a conductive junction and asymmetric structure, which was unable to be synthesized by the traditional thermodynamical methods. For its unique morphological characteristics, PAN features high electromagnetic field enhancement, enabling the biosensor to achieve high sensitivity, with a limit of detection in the attomolar regime for quantitative analysis of p-tau. By introducing support vector machine (SVM)-based machine learning algorithm, the improved diagnostic system was achieved for prediction of healthy controls, MCI, and AD groups with an accuracy of 94.47 % by detecting various p-tau species levels in human plasma. Thus, our proposed PAN-based plasmonic biosensor has a powerful potential in clinical utility for predicting the onset of AD progression in the asymptomatic phase.

Korean Clinical Guideline for Autism Spectrum Disorder - Clinical Features, Course, Epidemiology, and Cause.

Autism spectrum disorder (ASD) is a heterogeneous developmental disorder characterized by impairments in two core areas: 1) social communication and interaction and 2) restricted and repetitive patterns of behaviors and interests. In general, ASD is known to be a lifelong disorder. Follow-up studies from childhood to adulthood have reported that the severity of the key symptoms ASD decreases over time. However, chronic health problems including mental health occur in many patients with ASD. The prevalence of ASD has increased from around 0.04% in the 1970s to 2.8% at present. The average age of diagnosis in developed countries is 38-120 months of age. Recent evidence suggests that biological factors which include genetic, congenital, immunological, neuroanatomical, biochemical, and environmental ones are important in causing autism. Until now, early signs and various risk factors of ASD have been suggested.

Enhancement of microalgal biomass productivity through mixotrophic culture process utilizing waste soy sauce and industrial flue gas.

Wastewater treatment plants are indispensable facilities, which emit a massive amount of greenhouse gases. To boost CO2 mitigation and wastewater treatment performance, mixotrophic microalgae cultivation using wastewater has recently been proposed. In this study, food industry wastewater (waste soy sauce) was applied to Chlorella sorokiniana UTEX 2714 cultivation. By using a medium with 20% (v/v) of 10-fold diluted soy sauce, the biomass and fatty acid methyl ester (FAME) productivity enhanced by 1.93 and 1.76 times, respectively. Biomass productivity increased up to 5.2 times when using medium with high soy sauce content under high-intensity light that inhibits cell growth in photoautotrophic environments. Furthermore, industrial flue gas treatment with wastewater was demonstrated by outdoor semi-continuous cultivation with 42% improved biomass production. Consequently, these results suggest that mixotrophic microalgal cultivation has great potential to address both climate change and water pollution while producing valuable products and can contribute to building a sustainable society.

The Difference in the Quality of Life of Korean Children With Attention-Deficit/Hyperactivity Disorder Between Before and After COVID-19.

Objectives: This study aimed to compare the quality of life (QoL) of children with attention-deficit/hyperactivity disorder (ADHD) before and during coronavirus disease-2019 (COVID-19) and to examine how their QoL is affected by emotional and environmental factors during COVID-19. Methods: Participants in the pre-COVID-19 (n=43) and COVID-19 (n=36) groups were recruited from the same university hospital. The Pediatric Quality of Life Inventory (PedsQL) 4.0 Child Self-report, the Children's Depression Inventory (CDI), the Revised Children's Manifest Anxiety Scale (RCMAS), the PedsQL 4.0 Parent Proxy Report, and the Conners' Parent Rating Scale (CPRS) were employed. Independent t-tests, Pearson's correlation analysis, and multiple regression analysis were conducted. Results: Caregivers assessed the children's QoL more negatively than the children themselves in both groups. Children with ADHD evaluated their physical function more negatively and anxiety was significantly higher in the COVID-19 group. In the COVID-19 group, the PedsQL child self-report was significantly predicted by the CPRS, the CDI, and environmental factors (i.e., relation to child and monthly household income). Conclusion: Children with ADHD in the COVID-19 group had a numerically lower QoL and significantly higher anxiety. To improve QoL, it is important to deal with not only depression but also ADHD symptoms and environmental factors.

Development of a limitless scale-up photobioreactor for highly efficient photosynthesis-based polyhydroxybutyrate (PHB)-producing cyanobacteria.

Photosynthetic polyhydroxybutyrate (PHB) production is an attractive technology for realizing a sustainable society by simultaneously producing useful biodegradable plastics and mitigating CO2. It is necessary to establish an economical large-scale photobioreactor (PBR) capable of effectively cultivating photosynthetic microorganisms such as cyanobacteria. A roll-to-roll winding machine/heat-sealer hybrid system for fabricating an easy-to-scale-up PBR was developed in the present study. The baffle design was optimized to facilitate mass transfer within the PBR, and the operating conditions of the gas sparger were investigated to maximize the CO2 transfer efficiency. The newly developed PBR was able to produce biomass of PHB content 10.7 w/w% at a rate of 6.861 g m-2 d-1, 21 % improved biomass productivity compared with the existing PBR. It was confirmed that biomass productivity was maintained even when PBR was scaled up to 2 tons. Consequently, the newly developed PBR is expected to improve the feasibility of photosynthetic PHB production.

Kinetic analysis of microalgae cultivation utilizing 3D-printed real-time monitoring system reveals potential of biological CO2 conversion.

The microalgae-based bioconversion process is a promising carbon utilization technology because it can upgrade CO2 into valuable substances, but a multiplex monitoring system required for process control to maximize biomass productivity has not been well established. Herein, a 3D printed real-time optical density monitoring device (RTOMD) combined platform was presented. This platform enables precise kinetics analysis by maintaining high accuracy (over 95 %) under raucous outdoor conditions. Through RTOMD-based high-frequency measurements, it was observed that maximum biomass productivity of 4.497 g L-1 d-1 was reached, which greatly exceeds the requirements for a feasible microalgae process. We discovered that the CO2 fixation efficiency could be achieved to 70.75 %, indicating the potential of a bioconversion process to realize a carbon-neutral society. Consequently, the RTOMD system can contribute to promoting microalgae cultivation as an attractive carbon mitigation technology based on an improved understanding of the photosynthetic CO2 fixation kinetics.

Sustainable production of polyhydroxybutyrate from autotrophs using CO2 as feedstock: Challenges and opportunities.

Due to industrialization and rapid increase in world population, the global energy consumption has increased dramatically. As a consequence, there is increased consumption of fossil fuels, leading to a rapid increase in CO2 concentration in the atmosphere. This accumulated CO2 can be efficiently used by autotrophs as a carbon source to produce chemicals and biopolymers. There has been increasing attention on the production of polyhydroxybutyrate (PHB), a biopolymer, with focus on reducing the production cost. For this, cheaper renewable feedstocks, molecular tools, including metabolic and genetic engineering have been explored to improve microbial strains along with process engineering aspects for scale-up of PHB production. This review discusses the recent advents on the utilization of CO2 as feedstock especially by engineered autotrophs, for sustainable production of PHB. The review also discusses the innovations in cultivation technology and process monitoring while understanding the underlying mechanisms for CO2 to biopolymer conversion.

Significant Domains of Life Satisfaction That Affect Suicidal Behavior in Adolescents.

OBJECTIVES: Adolescent suicide is a serious national issue in Korea. Recently, life satisfaction has been recognized as a major factor related to this issue. The main purpose of this study was to identify the domains of life satisfaction that affect suicidal behavior in adolescence. METHODS: Data were collected from eight middle schools in Incheon, Korea. A total of 1297 students answered questions regarding their demographic characteristics, happiness, self-related life satisfaction domains (appearance, leisure time, physical health, and mental health), depressive symptoms, and suicidal behavior. RESULTS: In the Spearman correlation analysis, female sex, perceived socioeconomic status (SES), happiness, and all four self-related satisfaction scores showed significant correlations with depression and suicidality. Multivariate regression analysis suggested that suicidality was significantly affected by perceived SES, satisfaction with appearance, mental health satisfaction, and depression. Finally, depression was identified as a partial mediator of the association between mental health satisfaction and suicidality, and a complete mediator of the association between female sex and suicidality. CONCLUSION: Perceived SES, satisfaction with appearance, and mental health satisfaction significantly affected students' suicidality, with or without the effect of depression. Health authorities, educators, and family members must be aware of this to identify adolescents at suicide risk earlier.

Robust cyst germination induction in Haematococcus pluvialis to enhance astaxanthin productivity in a semi-continuous outdoor culture system using power plant flue gas.

The microalgae Haematococcus pluvialis biologically converts CO2 into natural astaxanthin that possesses a strong antioxidant activity; its low carbon footprint and economic viability have allowed it to garner great attention. However, low efficiency of the cultivation process is a major hurdle in its commercial production. Here, additional nitrogen was provided to fully grown cells to induce efficient cyst germination, thereby rapidly increasing the number of cells containing astaxanthin. After germination, these cells were rapidly converted from zooids to cysts by nitrogen depletion, while maintaining a steady astaxanthin content of 5.5%. Consequently, a 2.1-fold increase in astaxanthin productivity in comparison with that in a batch culture was achieved. Moreover, the germination-based semi-continuous process yielded 2.6 times higher astaxanthin productivity in a large-scale culture using power plant flue gas and a polymeric photobioreactor. This study provides a promising cultivation strategy for the commercial mass production of natural astaxanthin.

Purcell-enhanced photoluminescence of few-layer MoS2 transferred on gold nanostructure arrays with plasmonic resonance at the conduction band edge.

Plasmonic coupling of metallic nanostructures with two-dimensional molybdenum disulfide (MoS2) atomic layers is an important topic because it provides a pathway to manipulate the optoelectronic properties and to overcome the limited optical cross-section of the materials. Plasmonic enhanced light-matter interaction of a MoS2 layer is known to be mainly governed by optical field enhancement and the Purcell effect, while the discrimination of the contribution from each mechanism to the plasmonic enhancement is challenging. Here, we investigate photoluminescence (PL) enhancement from few-layer MoS2 transferred on Au nanostructure arrays with controlled localized surface plasmon resonance (LSPR) spectral positions that were detuned from the excitation wavelengths. Two distinctive regimes in LSPR mode-dependent PL enhancement were revealed showing a maximum enhancement (∼40-fold) with zero detuning and a modest enhancement (∼10-fold) with the red-shift detuned LSPR from the excitation wavelength, which were attributed to LSPR-induced optical field enhancement and the Purcell effect, respectively. By applying the experimental parameters into the Purcell effect formalism, an effective mode volume of ∼0.016λ03 was estimated. Our work provides an insight into how to utilize few-layer MoS2 as a base material for optoelectronics by harnessing Purcell-enhanced optical responsivity.

Fabrication of plasmonic arrays of nanodisks and nanotriangles by nanotip indentation lithography and their optical properties.

Fabrication of plasmonic nanostructures in a precise and reliable manner is a topic of huge interest because their structural details significantly affect their plasmonic properties. Herein, we present nanotip indentation lithography (NTIL) based on atomic force microscopy (AFM) indentation for the patterning of plasmonic nanostructures with precisely controlled size and shape. The size of the nanostructures is controlled by varying the indentation force of AFM tips into the mask polymer; while their shapes are determined to be nanodisks (NDs) or nanotriangles (NTs) depending on the shapes of the AFM tip apex. The localized surface plasmon resonance of the NDs is tailored to cover most of the visible-wavelength regime by controlling their size. The NTs show distinct polarization-dependent plasmon modes consistent with full-wave optical simulations. For the demonstration of the light-matter interaction control capability of NTIL nanostructures, we show that photoluminescence enhancement from MoS2 layers can be deliberately controlled by tuning the size of the nanostructures. Our results pave the way for the AFM-indentation-based fabrication of plasmonic nanostructures with a highly precise size and shape controllability and reproducibility.

Improved CO2-derived polyhydroxybutyrate (PHB) production by engineering fast-growing cyanobacterium Synechococcus elongatus UTEX 2973 for potential utilization of flue gas.

Industrial application of cyanobacterial poly-ß-hydroxybutyrate (PHB) production from CO2 is currently challenged by slow growth rate and low photoautotrophic PHB productivity of existing cyanobacteria species. Herein, a novel PHB-producing cyanobacterial strain was developed by harnessing fast-growing cyanobacteria Synechococcus elongatus UTEX 2973 with introduction of heterologous phaCAB genes. Under photoautotrophic condition, the engineered strain produced 420 mg L-1 (16.7% of dry cell weight) with the highest specific productivity of 75.2 mg L-1 d-1. When compared with a native PHB producer Synechocystis PCC 6803 under nitrogen deprivation, the engineered strain exhibited 2.4-fold higher PHB productivity. The performance of the engineered strain was further demonstrated in large scale cultivation using photobioreactor and outdoor cultivation employing industrial flue gas as the sole carbon source. This study can provide a promising solution to address petroleum-based plastic waste and contribute to CO2 mitigation.

Variables Affecting Attitudes Toward Suicide Among the Adolescent Population.

Past research has supported the positive association between prosuicide attitudes and suicidal behavior. The aim of the present study was to determine the factor structure of adolescents' attitudes toward suicide and to explore correlates associated with their attitudes. A questionnaire was distributed to 1292 adolescents at eight middle schools to assess their demographic information, clinical variables, and attitudes toward suicide. After factor analysis, we reached a four-factor solution of the attitudes toward suicide. Significantly more females, nonreligious adolescents, those with a lower socioeconomic status, those with higher levels of depressive symptoms, and those with a history of suicidal ideation/plans had more understanding attitudes toward suicide. Depressive adolescents were also more permissive and believed that suicides were unpreventable and that loneliness led to suicide. In conclusion, adolescents' attitudes toward suicide were significantly associated with not only various sociodemographic correlates but also the severity of depressive symptoms and their own experiences of suicidality.

Two Novel Mutations of ANKRD11 Gene and Wide Clinical Spectrum in KBG Syndrome: Case Reports and Literature Review.

BACKGROUND: KBG syndrome (OMIM #148050) is a rare, autosomal dominant inherited genetic disorder caused by heterozygous mutations in the ankyrin repeat domain-containing protein 11 (ANKRD11) gene or by microdeletion of chromosome 16q24.3. It is characterized by macrodontia of the upper central incisors, distinctive facial dysmorphism, short stature, vertebral abnormalities, hand anomaly including clinodactyly, and various degrees of developmental delay. KBG syndrome presents with variable clinical feature and severity among individuals. Here, we report two KBG patients who have different novel heterozygous mutations of ANKRD11 gene with wide range of clinical manifestations. CASE PRESENTATION: Two novel heterozygous mutations of ANKRD11 gene were identified in two unrelated Korean patients with variable clinical presentations. The first patient presented with short stature and early puberty and was treated with growth hormone and gonadotropin-releasing hormone agonist without adverse effects. He had mild intellectual disability. In targeted exome sequencing, a novel de novo frameshift variant was identified in ANKRD11, c.5889del, and p. (Ile1963MetfsX9). The second patient had severe intellectual disability with epilepsy. He had normal height and prepubertal stage at the age of 11 years. He had behavioral problems such as autism-like features, anxiety, and stereotypical movements. Whole exome sequencing (WES) was performed, and the novel heterozygous mutation, c3310dup, p. (Glu110GlyfsTer5) in ANKRD11 was identified. CONCLUSION: KBG syndrome is often underdiagnosed because of its non-specific features and phenotypic variability. Performing a next-generation sequencing panel, including the ANKRD11 gene for cases of developmental delay with/without short stature may be helpful to identify hitherto undiagnosed KBG syndrome patients.

Association between Perceived Parenting Style and Adolescents' Attitudes toward Suicide.

OBJECTIVES: Adolescent suicide, a major cause of adolescent death, is affected by various factors, including attitudes toward suicide. This study investigated the association between parenting style and adolescents' attitudes toward suicide and the mediating role of attitude toward suicide between parenting style and suicidal ideation. METHODS: We surveyed 1,071 adolescents from eight middle schools in Incheon, Korea. The survey included sociodemographic information, attitudes toward suicide, perception of parenting style, depression severity, and suicidality. RESULTS: Students in the authoritarian parenting group had a more permissive attitude toward suicide compared with the democratic and permissive parenting groups. These students considered that suicide is justified in certain situations and that choosing suicide is an individual's right. They also had a negative attitude toward talking about suicide or intervening in others' suicide. This association remained statistically significant after adjusting for the impact of confounding factors that could affect attitudes toward suicide, except for suicidal processes and preparedness to prevent suicide. In the mediation analysis, we observed that some factors of the attitudes toward suicide mediated between authoritarian parenting attitudes and suicidal ideation, namely, suicide as a right, preventability, suicide as normal/common, preparedness to prevent suicide, and resignation. CONCLUSION: This study revealed the significant impact of parenting style on children's attitudes toward suicide. Educating parents about the appropriate parenting attitudes-sympathetic and rational-can help prevent youth suicide.

Scalable Cultivation of Engineered Cyanobacteria for Squalene Production from Industrial Flue Gas in a Closed Photobioreactor.

Economically feasible photosynthetic cultivation of microalgal and cyanobacterial strains is crucial for the biological conversion of CO2 and potential CO2 mitigation to challenge global warming. To overcome the economic barriers, the production of value-added chemicals was desired by compensating for the overall processing cost. Here, we engineered cyanobacteria for photosynthetic squalene production and cultivated them in a scalable photobioreactor using industrial flue gas. First, an inducer-free gene expression system was developed for the cyanobacteria to lower production const. Then, the recombinant cyanobacteria were cultivated in a closed photobioreactor (100 L) using flue gas (5% CO2) as the sole carbon source under natural sunlight as the only energy source. Seasonal light intensities and temperatures were analyzed along with cyanobacterial cell growth and squalene production in August and October 2019. As a result, the effective irradiation hours were the most critical factor for the large-scale cultivation of cyanobacteria. Thus, an automated photobioprocess system will be developed based on the regional light sources.

Screening of oleaginous algal strains from Chlamydomonas reinhardtii mutant libraries via density gradient centrifugation.

Microalgae have a high potential to be utilized as feedstock for biofuels because they have high growth rates and do not compromise food production. Commercialized algae-based biofuel production relies on the development of strains with high lipid content. Based on the relatively low density of lipids compared to other cellular components, density gradient centrifugation was used to isolate high lipid content algal strains from Chlamydomonas reinhardtii mutant libraries. The correlation between cell density and lipid content was confirmed by analysis of Nile red fluorescence intensity, total lipids, and total fatty acid methyl ester content. A strain isolated by this screening method had 50% higher lipid content and 7% lower cell density than the parent wild-type strain. Consequently, we demonstrated that screening of algal strains with low cell density via continuous density gradient centrifugation allows simple, rapid, and inexpensive screening for high lipid content strains.

The Influence of Depression and School Life on the Quality of Life of Korean Child and Adolescent Patients with Attention-Deficit/Hyperactivity Disorder:A Comparison of the Perspectives of the Patients and Their Caregivers.

OBJECTIVES: This study aimed to compare the quality of life reported by patients with attention-deficit/hyperactivity disorder (ADHD) to the patients' quality of life as reported by their caregivers. In addition, it aimed to examine how emotional problems, including depression and anxiety, and the severity of the symptoms affect the quality of life reported by the patients and their caregivers. METHODS: The patients' quality of life and their degree of depression and anxiety were measured using the Pediatric Quality of Life Inventory (PedsQL) 4.0 Child Self-Report, the Children's Depression Inventory (CDI), and the Revised Children's Manifest Anxiety Scale, respectively. The caregivers' perception of the patients' quality of life and severity of the ADHD symptoms were measured using the PedsQL 4.0 Parent Proxy Report and the Conners' Parent Rating Scale (CPRS), respectively. A total of 66 participants completed the survey. The independent-samples t-test, Pearson's correlation analysis, and multiple regression analysis were conducted. RESULTS: The mean score of the PedsQL 4.0 Child Self-Report was significantly higher than the mean score of the PedsQL 4.0 Parent Proxy Report. However, for school function, the PedsQL 4.0 Child Self-Report score was significantly lower than that of Parent Proxy Report. The correlation between the PedsQL 4.0 Child Self-Report and PedsQL 4.0 Parent Proxy Report scores was significant only for emotional function and social function. The multiple regression analysis showed that the PedsQL 4.0 Child Self-Report and PedsQL 4.0 Parent Proxy Report scores were significantly predicted by the CDI and CPRS scores, respectively. CONCLUSION: Our results demonstrate that there are clear differences between the quality of life reported by the patient themselves and that reported by their caregivers. In addition, the findings suggest that it is critical to treat the patients' accompanying depressive symptoms.

Performance and potential appraisal of various microalgae as direct combustion fuel.

Direct combustion of biomass is considered the most effective and simple means to contribute to CO2 reduction. In this context, the life-cycle potential of microalgal solid fuel, which has been overlooked so far, was comprehensively scrutinized ranging from cultivation to direct combustion. According to the quantitative data, using the raw fuel was confirmed to offer great benefits over the conventional lipid-targeted microalgal fuel systems through exploiting all of the biomass' energy potential, thereby being able to significantly increase the energy yield from biomass. The solid fuel is shown to exhibit diverse positive aspects owing to its remarkable calorific value, productivity and CO2 fixation ability. The combustion test reveals coal-microalgae co-combustion brings beneficial consequences on combustibility and environmental impacts with no notable thermal efficiency drop. This holistic appraisal shows microalgae patently possess high potential as a direct combustion fuel, even outperforming that of extensively used woody fuels.