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Abstract Eating quality (EQ) of rice has a complex nature composed of physicochemical properties. Nevertheless, breeding programs evaluating EQ through sensory test or taste-evaluation instruments have been laborious, time-consuming and inefficient. EQ is affected by both taste and aroma. However, in actual breeding programs, aroma of cooked rice has been considered the least due to lack of information. Here we identified a total of 41 volatile compounds potentially affecting the EQ of non-aromatic, cooked japonica rice, identified by GC–MS, sensory panel test, and Toyo taste-meter analyses. Partial least squares discriminant analysis demonstrated an outstanding classification effect of the identified volatile compounds on eating-quality discrimination. Several volatile compounds related to lipid oxidation and fatty acid degradation were identified to affect the EQ in japonica rice. Of them, 1-octen-3-ol, 1-ethyl-3,5-dimethylbenzene, 2,6,11-trimethyldodecane, 3-ethyloctane, 2,7,10-trimethyldodecane, methyl salicylate, 2-octanone, and heptanal were selected as important compounds. The discriminant model for the classification of the quality of cultivars was robust and accurate, an r-squared value was 0.91, a q squared value was 0.85, and an accuracy was 1.0. Overall, the results of this study characterize EQ of rice cultivars based on volatile compounds, suggesting the application of metabolite profiling data for rice breeding of high eating quality.

Floral organ number is crucial for successful seed setting and mature grain development. Although some genes and signaling pathways controlling floral organ number have been studied, the underlying mechanism is complicated and requires further investigation. In this study, a floral organ number mutant was generated by the ethyl methanesulfonate treatment of the Korean japonica rice cultivar Ilpum. In the floral organ number mutant, 37% of the spikelets showed an increase in the number of floral organs, especially stamens and pistils. Histological analysis revealed that the number of ovaries was determined by the number of stigmas; spikelets with two or three stigmas contained only one ovary, whereas spikelets with four stigmas possessed two ovaries. The floral organ number mutant showed pleiotropic phenotypes including multiple grains, early flowering, short plant height, and reduced tiller number compared with the wild-type. Genetic and MutMap analyses revealed that floral organ number is controlled by a single recessive gene located between the 8.0 and 20.0 Mb region on chromosome 8. Calculation of SNP-index confirmed Os08g0299000 as the candidate gene regulating floral organ number, which was designated as FLORAL ORGAN NUMBER7 (FON7). A single nucleotide polymorphism (G to A) was discovered at the intron splicing donor site of FON7, which caused the skipping of the entire sixth exon in the mutant, resulting in the deletion of 144 bp. Furthermore, the T-DNA-tagged line displayed the same floral organ number phenotype as the fon7 mutant. These results provide valuable insight into the mechanism of floral organ differentiation and formation in rice.

Heading date (Hd) is one of the main factors determining rice production and regional adaptation. To identify the genetic factors involved in the wide regional adaptability of rice, we conducted a genome-wide association study (GWAS) with 190 North Korean rice accessions selected for non-precocious flowering in the Philippines, a low-latitude region. Using both linear mixed models (LMM) and fixed and random model circulating probability unification (FarmCPU), we identified five significant loci for Hd in trials in 2018 and 2019. Among the five lead single nucleotide polymorphisms (SNPs), three were located adjacent to the known Hd genes, Heading date 3a (Hd3a), Heading date 5 (Hd5), and GF14-c. In contrast, three SNPs were located in novel loci with minor effects on heading. Further GWAS analysis for photoperiod insensitivity (PS) revealed no significant genes associated with PS, supporting that this North Korean (NK) population is largely photoperiod-insensitive. Haplotyping analysis showed that more than 80% of the NK varieties harbored nonfunctional alleles of major Hd genes investigated, of which a nonfunctional allele of Heading date 1 (Hd1) was observed in 66% of the varieties. Geographical distribution analysis of Hd allele combination types showed that nonfunctional alleles of floral repressor Hd genes enabled rice cultivation in high-latitude regions. In contrast, Hd1 alleles largely contributed to the wide regional adaptation of rice varieties. In conclusion, an allelic combination of Hd genes is critical for rice cultivation across wide areas.

Cytoplasmic male sterility (CMS) is a maternally inherited trait that inhibits plants from producing or releasing viable pollen. CMS is caused by mitochondrial-nuclear interaction, and can be rescued by introducing functional nuclear restorer-of-fertility (Rf) gene. The Tetep-CMS/Rf lines were developed through successive inter-subspecific backcrosses between indica and japonica rice accessions. Phenotypic characterization of Tetep-CMS lines revealed abnormal anther dehiscence and the inability to release, while possessing functional pollen. Transverse sections of developing anthers collected from CMS plants showed connective tissue deformities and aberrant dehydration of endothecium and epidermis. Fine mapping of Rf-Tetep using a series of segregating populations, delimited the candidate region to an approximately 109 kb genomic interval between M2099 and FM07 flanking markers. Nanopore long-read sequencing and genome assembly, proceeded by gene prediction and annotation revealed 11 open reading frames (ORFs) within the candidate region, and suggest ORF6 annotated as pentatricopeptide repeat motif containing gene 1 (PPR1), as a possible candidate gene responsible for fertility restoration. This study suggests that tissue-specific abnormalities in anthers are responsible for indehiscence-based sterility, and propose that the functional Rf gene is derived from allelic variation between inter-subspecies in rice.

Abstract Background Although embryo accounts for only 2–3% of the total weight of a rice grain, it is a good source of various nutrients for human health. Because enlarged embryo size causes increase of the amount of nutrients and bioactive compounds stored within rice grain, giant embryo mutants of rice (Oryza sativa L.) are excellent genetic resources for improving the nutritional value of rice grains. Results Three giant embryo mutants, including large embryo (le), giant embryo (ge) and super-giant embryo (ge s ), with variable embryo size were used in this study. We investigated whether genes controlling embryo size in these mutants (le, ge and ge s ) were allelic to each other. Although ge and ge s was allelic to GIANT EMBRY (GE), le was not allelic to ge and ge s in allelism test. The GE gene carried a unique nucleotide substitution in each of the two mutants (ge and ge s ), resulting in non-synonymous mutations in exon 2 of GE in both mutants. However, the GE gene of the le mutant did not carry any mutation, suggesting that the enlarged embryo phenotype of le was governed by another gene. Using map-based cloning, we mapped the LE gene to the short arm of chromosome 3. The le mutant showed mild enlargement in embryo size, which resulted from an increase in the size of scutellar parenchyma cells. The LE encodes a C3HC4-type RING finger protein and was expressed to relatively high levels in seeds at a late developmental stage. Knockdown of LE expression using RNA interference increased the embryo size of rice grains, confirming the role of LE in determining the embryo size. Conclusion Overall, we identified a new gene controlling embryo size in rice. Phenotypic and molecular characterization results suggest that the le mutant will serve as a valuable resource for developing new rice cultivars with large embryos and nutrient-dense grains.

Moderate leaf rolling is considered optimal for the ideal plant type in rice (Oryza sativa L.), as it improves photosynthetic efficiency and, consequently, grain yield. Determining the genetic basis of leaf rolling via the identification of quantitative trait loci (QTLs) could facilitate the development of high-yielding varieties. In this study, we identified three stable rice QTLs, qARO1, qARO5, and qARO9, which control adaxial leaf rolling in a recombinant inbred line (RIL) population derived from a cross between Tong 88-7 (T887) and Milyang 23 (M23), using high-density SNP markers. These QTLs controlled the rolling phenotype of both the flag leaf (FL) and secondary leaf (SL), and different allelic combinations of these QTLs led to a wide variation in the degree of leaf rolling. Additive gene actions of qARO1 and qARO9 on leaf rolling were observed in a backcross population. In addition, qARO1 (markers: 01id4854718 and 01asp4916781) and qARO9 (markers: 09id19650402 and 09id19740436) were successfully fine-mapped to approximately 60- and 90-kb intervals on chromosomes 1 and 9, respectively. Histological analysis of near-isogenic lines (NILs) revealed that qARO1 influences leaf thickness across the small vein, and qARO9 affects leaf thickness in the entire leaf and bulliform cell area, thus leading to adaxial leaf rolling. The results of this study advance our understanding of the genetic and molecular bases of adaxial leaf rolling, and this information can be used for the development of rice varieties with the ideal plant type.

Highly nutritious rice production will be benefited with the improvement of amino acid content (AAC) and protein content (PC). The identification of quantitative trait loci (QTLs) associated with the PC and AAC of rice grains could provide a basis for improving the nutritional value of rice grains. Here, we conducted QTL analyses using recombinant inbred lines from the cross between indica (Milyang 23 or M23) and japonica (Tong 88-7 or T887) rice varieties, afterward employing genotyping-by-sequencing to obtain a high-density genetic map. A total of 17 and 3 QTLs were detected for AAC and PC, respectively. Among them, two QTLs associated with more than 10 AACs, qAAC6.1 and qAAC7.1, were identified for the first time in this study. Each favorable allele that increased the AAC of the two QTLs was derived from M23 and T887, respectively. Allelic combination of qAAC6.1M23 and qAAC7.1T887 showed significantly higher content of associated amino acids (AAs) than other allelic combinations. Near-isogenic line (NIL) possessing qAAC7.1T887 with M23 genetic background had significantly higher AACs than both parents. These results indicate that the pyramiding of QTLs would be useful in developing brown rice with a high AA and protein content.

Abstract Background Balancing panicle-related traits such as panicle length and the numbers of primary and secondary branches per panicle, is key to improving the number of spikelets per panicle in rice. Identifying genetic information contributes to a broader understanding of the roles of gene and provides candidate alleles for use as DNA markers. Discovering relations between panicle-related traits and sequence variants allows opportunity for molecular application in rice breeding to improve the number of spikelets per panicle. Results In total, 142 polymorphic sites, which constructed 58 haplotypes, were detected in coding regions of ten panicle development gene and 35 sequence variants in six genes were significantly associated with panicle-related traits. Rice cultivars were clustered according to their sequence variant profiles. One of the four resultant clusters, which contained only indica and tong-il varieties, exhibited the largest average number of favorable alleles and highest average number of spikelets per panicle, suggesting that the favorable allele combination found in this cluster was beneficial in increasing the number of spikelets per panicle. Conclusions Favorable alleles identified in this study can be used to develop functional markers for rice breeding programs. Furthermore, stacking several favorable alleles has the potential to substantially improve the number of spikelets per panicle in rice.

Rice yield is a complex trait that is strongly affected by environment and genotype × environment interaction (GEI) effects. Consideration of GEI in diverse environments facilitates the accurate identification of optimal genotypes with high yield performance, which are adaptable to specific or diverse environments. In this study, multiple environment trials were conducted to evaluate grain yield (GY) and four yield-component traits: panicle length, panicle number, spikelet number per panicle, and thousand-grain weight. Eighty-nine rice varieties were cultivated in temperate, subtropical, and tropical regions for two years. The effects of both GEI (12.4–19.6%) and environment (23.6–69.6%) significantly contributed to the variation of all yield-component traits. In addition, 37.1% of GY variation was explained by GEI, indicating that GY performance was strongly affected by the different environmental conditions. GY performance and genotype stability were evaluated using simultaneous selection indexing, and 19 desirable genotypes were identified with high productivity and broad adaptability across temperate, subtropical, and tropical conditions. These optimal genotypes could be recommended for cultivation and as elite parents for rice breeding programs to improve yield potential and general adaptability to climates.

Abstract Background Starch biosynthesis is one of the most important pathways that determine both grain quality and yield in rice (Oryza sativa L.). Sugary endosperm, sugary-1 (sug-1), is a mutant trait for starch biosynthesis. Rice plants carrying sug-1 produce grains that accumulate water-soluble carbohydrates instead of starch, even after maturity. Although this trait enhances the diversity of grain quality, sugary endosperm rice has hardly been commercialized due to the severely wrinkled grains and subsequent problems in milling. This study was conducted to identify the genes responsible for the sug-h phenotype through a map-based cloning technology. Results We induced a mild sugary mutant, sugary-h (sug-h) through the chemical mutagenesis on the Korean japonica cultivar Hwacheong. Grains of the sug-h mutant were translucent and amber-colored, and the endosperm appeared less wrinkled than sug-1, whereas the soluble sugar content was fairly high. These characteristics confer greater marketability to the sug-h mutant. Genetic analyses indicated that the sug-h mutant phenotype was controlled by a complementary interaction of two recessive genes, Isoamylase1 (OsISA1), which was reported previously, and Starch branching enzyme IIa (OsBEIIa), which was newly identified in this study. Complementation tests indicated that OsBEIIa regulated the properties of sugary endosperm. Conclusions Complementary interactions between the starch biosynthesis genes OsISA1 and OsBEIIa determine the mild sugary endosperm mutant, sugary-h, in rice. Our finding may facilitate the breeding of sugaryendosperm rice for commercial benefit.

A tiller number is the key determinant of rice plant architecture and panicle number and consequently controls grain yield. Thus, it is necessary to optimize the tiller number to achieve the maximum yield in rice. However, comprehensive analyses of the genetic basis of the tiller number, considering the development stage, tiller type, and related traits, are lacking. In this study, we sequence 219 Korean rice accessions and construct a high-quality single nucleotide polymorphism (SNP) dataset. We also evaluate the tiller number at different development stages and heading traits involved in phase transitions. By genome-wide association studies (GWASs), we detected 20 significant association signals for all traits. Five signals were detected in genomic regions near known candidate genes. Most of the candidate genes were involved in the phase transition from vegetative to reproductive growth. In particular, HD1 was simultaneously associated with the productive tiller ratio and heading date, indicating that the photoperiodic heading gene directly controls the productive tiller ratio. Multiple linear regression models of lead SNPs showed coefficients of determination (R2) of 0.49, 0.22, and 0.41 for the tiller number at the maximum tillering stage, productive tiller number, and productive tiller ratio, respectively. Furthermore, the model was validated using independent japonica rice collections, implying that the lead SNPs included in the linear regression model were generally applicable to the tiller number prediction. We revealed the genetic basis of the tiller number in rice plants during growth, By GWASs, and formulated a prediction model by linear regression. Our results improve our understanding of tillering in rice plants and provide a basis for breeding high-yield rice varieties with the optimum the tiller number.

Abstract Background Chuna manual therapy (CMT), a Korean manual therapy technique predominantly used for treating low back pain (LBP) and related disorders, lacks well-conceived research focusing on its comparative effectiveness, safety, and economic evaluation, particularly with respect to complex CMT with established CMT diagnostic algorithms. This study aims to illustrate a protocol for a randomized clinical study for comparative effectiveness and cost-effectiveness of complex CMT with simple CMT and usual care. Methods This is a protocol for a three-armed, multicenter, assessor-blinded, pragmatic, randomized controlled trial study. A total of 81 patients suffering from non-acute LBP with pelvic biomechanical lesions (PBL), characterized by a pain duration of at least two weeks and a Numeric Rating Scale (NRS) score of 5 or higher, will be recruited from two Korean medicine hospitals. These participants will be randomly assigned to one of three groups: complex CMT plus usual care (UC; n = 27), simple CMT plus UC (n = 27), or UC groups (n = 27). They will undergo treatment for 4 weeks, and follow-up assessments will be performed 8 weeks after treatment completion. The primary outcome will be the NRS score of LBP, and secondary outcomes will include the Oswestry Disability Index, Patient Global Impression of Change, credibility and expectancy questionnaire, three-dimensional posture analysis indicators, quality of life assessment, economic evaluation, and safety assessments. Discussion This will be the first study to assess the comparative effectiveness, safety, and cost-effectiveness of complex CMT compared to UC and simple/complex CMT in patients with LBP and PBL. We will also analyze useful diagnostic methods to help in clinical practice for CMT diagnosis. Trial registration Clinical Research Information Service (CRIS), KCT0009210. Registered on February 28, 2024.

Purpose To investigate the form and level of daily caffeine intake recommended above 400 mg in medical students expected to consume caffeinated beverages to enhance their performance. Methods From May to June 2023, freshman through senior medical students at a medical school in Korea were administered a seven-item questionnaire designed to measure the amount of caffeine-containing foods consumed, the weekly interval between consumption, the reason for consumption, and the level of caffeine-induced symptoms experienced. Results Out of 443 students, 361 responded (81.5%). The most commonly consumed caffeine beverages were coffee (79.2%), followed by soda (33.2%), tea (27.4%), chocolate (25.2%), and energy drinks (20.5%). The estimated (average±standard deviation) daily intake was estimated to 274.6±276.5 mg, and they consumed caffeine on an average of 4.25±2.26 days per week. Students who consumed 400 mg or more of caffeine daily consumed 19.9%. The primary motivation for caffeine intake was “to improve academic performance” (60.9%) and “preferred food” (51.8%). Among the responders, 98% of them replied they had symptoms that could be caused by caffeine, in order of palpitations (47.4%), frequent urination (42.9%), anxiety (27.1%), indigestion (17.5%), and excitement (17.5%). A total of 45.7% reported two symptoms, and 24.7% reported three or more. Conclusion Caffeinated beverage consumption was routine among current medical students, with 20% consuming more than the recommended daily amount. Most students experienced at least one caffeine-induced symptom, with two symptoms in half, suggesting the need for policy measures and warnings about caffeine-containing foods.

Indigofera koreana is an endemic species to Korea, yet its phylogenetic position remains unresolved. In this study, we sequenced and analyzed plastid genomes (plastomes) to clarify the phylogenetic standing of I. koreana. We produced next-generation sequencing data for I. koreana and its close relative, Indigofera kirilowii. The plastomes of both species were successfully assembled, measuring 159,517 bp for I. kirilowii and 159,459 bp for I. koreana. Both species shared the same number of 128 intact genes and had identical 35.7% guanine–cytosine content. Phylogenetic analyses utilizing complete plastome and coding sequence–only data, along with 20 other Indigofera plastomes, were conducted to elucidate their evolutionary relationships. Our findings indicate that I. koreana forms a monophyletic group with Indigofera decora, Indigofera carlesii, and I. kirilowii, supported by maximum bootstrap values. Specifically, the phylogenetic tree derived from complete plastome data strongly suggests that I. koreana is most closely related to I. kirilowii. While these results are in line with previously suggested infra-generic classifications, they highlight the need for more comprehensive genomic studies to further unravel the evolutionary dynamics within the Indigofera genus, especially considering the role of polyploidization in species diversification.

Direct-seeded rice is one of the solutions against the issues of limited labor and time in the rice cropping system. Improved useful traits, such as fertilizer uptake and anaerobic germination, are needed to increase yield and efficiency in the direct seeding system in rice. Pup1 (Phosphorous uptake1) containing PSTOL1 is useful in improving the phosphate uptake under rainfed/upland conditions. OsTPP7 is the major gene of AG1 (Anaerobic Germination), which shows anaerobic germination. IR64-Pup1-AG1 (I-PA) was developed by pyramiding Pup1 and AG1. Around 20% of the chromosomal segments from the donor remained in I-PA. Phenotypic analysis revealed that I-PA showed better phenotypic performance under low and normal P conditions by enhancing the root system and tiller numbers during the early stage. Significantly better P uptake capacity of I-PA was observed upon a P-supplied soil condition. The coleoptile length and germination rate of I-PA showed tolerance under anaerobic-germinated conditions. PSTOL1 and OsTPP7 were independently expressed under different P conditions of soils, as well as anaerobic conditions. The newly developed breeding lines, I-PA, showed early vigor capacity through a high number of tillers, better P uptake, and germination in low-oxygen conditions. It will be a useful and improved breeding line for direct seeding rice breeding programs.

Tiller angle is an important influencing factor in rice plant architecture that affects planting density and yield per unit area. Molecular tools to predict tiller angle contribute to breeding programs, which aim at optimizing rice plant architecture. In this study, several single-nucleotide polymorphism (SNP) markers related to tiller angle were developed and used with a model population to define a linear regression model for the prediction of tiller angle in rice. The resulting linear regression model, consisting of eight SNP markers as independent variables, was assessed using an independent test population. Overall, the regression model achieved an adjusted R2 of 0.51 and exhibited consistent predictive accuracy with an R2 of 0.61. Three of the eight independent variables, namely, PIN2-1, LIC1-1, and TAC1, contributed substantially to the linear regression model. These three major effect markers were also major determinants of tiller angle in the independent test population. Allelic combinations of the three major effect markers modulated tiller angle in the range of 5.6–19°. The DNA markers and linear regression model developed in this study will facilitate rice breeding programs for improving plant architecture.

Lesion mimic mutants (LMMs) commonly exhibit spontaneous cell death similar to the hypersensitive defense response that occurs in plants in response to pathogen infection. Several lesion mimic mutants have been isolated and characterized, but their molecular mechanisms remain largely unknown. Here, a spotted leaf sheath (sles) mutant derived from japonica cultivar Koshihikari is described. The sles phenotype differed from that of other LMMs in that lesion mimic spots were observed on the leaf sheath rather than on leaves. The sles mutant displayed early senescence, as shown, by color loss in the mesophyll cells, a decrease in chlorophyll content, and upregulation of chlorophyll degradation-related and senescence-associated genes. ROS content was also elevated, corresponding to increased expression of genes encoding ROS-generating enzymes. Pathogenesis-related genes were also activated and showed improved resistance to pathogen infection on the leaf sheath. Genetic analysis revealed that the mutant phenotype was controlled by a single recessive nuclear gene. Genetic mapping and sequence analysis showed that a single nucleotide substitution in the sixth exon of LOC_Os07g25680 was responsible for the sles mutant phenotype and this was confirmed by T-DNA insertion line. Taken together, our results revealed that SLES was associated with the formation of lesion mimic spots on the leaf sheath resulting early senescence and defense responses. Further examination of SLES will facilitate a better understanding of the molecular mechanisms involved in ROS homeostasis and may also provide opportunities to improve pathogen resistance in rice.

Abstract Excessive clotting or abnormal platelet accumulation can lead to serious cardiovascular disorders such as atherosclerosis, stroke, and thrombosis. Therefore, it is imperative to identify compounds capable of controlling or impeding platelet aggregation to prevent the onset of cardiovascular diseases. Arteanoflavone, a compound extracted from Artemisia iwayomogi, has not garnered scientific recognition for its potential health benefits, recent studies have substantiated its anti-inflammatory, antioxidant, and anti-allergic properties. However, the precise mechanisms by which arteanoflavone influences platelet aggregation and blood clot formation have not been conclusively established. This research investigates arteanoflavone’s role in these processes, particularly in platelets induced by collagen. The study reveals a significant increase in the production of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) correlating with the administered dosage of arteanoflavone. Concurrently, a noticeable escalation is observed in substrates of cAMP-dependent kinase and cGMP-dependent kinase, specifically VASP and inositol 1,4,5-trisphosphate receptor (IP3R). Arteanoflavone demonstrates its ability to limit Ca2+ movement in the dense tubular system through IP3R phosphorylation. Moreover, phosphorylated VASP inhibits the binding of fibrinogen to αIIb/β3, thus suppressing platelet activity. Arteanoflavone also stimulates the phosphorylation of PI3K/Akt, a protein linked to platelet granule release, and MAPK (ERK, JNK, and p38) protein, associated with both platelet granule release and TXA2 production. Lastly, arteanoflavone impedes collagen-induced platelet aggregation and blood clot formation by inhibiting fibrin production in thrombin-induced platelets. Hence, it is suggested that arteanoflavone could be valuable as an agent that effectively deters platelet inhibition and blood clot formation through antiplatelet mechanisms.

Introduction: The coronavirus disease 2019 (COVID-19) pandemic may have influenced the prevalence and seasonality of acute respiratory viral infections. The aim of the study was to investigate the prevalence of all viruses causing acute viral respiratory infections before and after social distancing measures were lifted. Methods: Cross-sectional study where outpatients and inpatients at Kyunghee University Hospital were examined. From January 2021 to December 2022, respiratory samples were analyzed using multiplex reverse transcriptase real-time polymerase chain reaction. Results: Of 3953 samples obtained, 412 (10.42%) were positive for acute respiratory viral infection, and 502 viruses were detected. The number of viral infections increased from 184 in 2021 to 318 in 2022. Human metapneumovirus was detected from August to November 2022. Human bocavirus (HBoV) was frequently detected from April to June 2021; however, in 2022, HBoV was frequently detected from July to October. Human parainfluenza virus 3 was rarely detected after its initial frequent detection from October to December 2021 but was continuously observed after frequent detection in September 2022. Co-infection occurred in 78 (18.9%) cases. The most common combination of simultaneous infections was human rhinovirus–HBoV (n = 30, 38.5%). Conclusions: During the COVID-19 pandemic, the incidence of acute respiratory viral infection decreased significantly but increased in 2022 when measures were lifted. The prevalence and seasonality of respiratory viral infections have changed since the pandemic. Our findings contribute to the prediction of an effective response to changes in the prevalence of respiratory viruses.

Suicide among the older population is a significant public health concern in South Korea. As the older individuals have long considered suicide before committing suicide trials, it is important to analyze the suicidal ideation that precedes the suicide attempt for intervention. In this study, six machine learning algorithms were employed to construct a predictive model for suicidal thinking and identify key variables. A traditional logistic regression analysis was supplementarily conducted to test the robustness of the results of machine learning. All analyses were conducted using a hierarchical approach to compare the model fit of each model in both machine learning and logistic regression. Three models were established for analysis. In Model 1, socioeconomic, residential, and health behavioral factors were incorporated. Model 2 expanded upon Model 1 by integrating physical health status, and Model 3 further incorporated mental health conditions. The results indicated that the gradient boosting algorithm outperformed the other machine learning techniques. Furthermore, the household income quintile was the most important feature in Model 1, followed by subjective health status, oral health, and exercise ability in Model 2, and anxiety and depression in Model 3. These results correspond to those of the hierarchical logistic regression. Notably, economic and residential vulnerabilities are significant factors in the mental health of the older population with higher instances of suicidal thoughts. This hierarchical approach could reveal the potential target population for suicide interventions.

Background: The prevalence of sexually transmitted infections (STIs) remains high worldwide. Despite the worldwide increase in the incidence of STIs every year, there are few reports on the frequency of STIs with different pathogens according to age and gender. Accordingly, a study was conducted to determine trends in co-infection with STIs by age and gender in Cheonan, South Korea from 2017 to 2021. Objectives: To identify trends by age or sex in co-infection of STIs in this region. Design: A retrospective study was conducted on clinical samples examined at Dankook University Hospital from January 2017 to November 2021. A total of 3297 specimens were collected from patients visiting Dankook University Hospital (Cheonan, Korea), and statistical analysis was performed on patients ranging in age from 1 day to 93 years. Methods: Multiplex polymerase chain reaction, the most efficient method to diagnose a bacterial infection, was performed using an MJ Research PTC-200 Thermal Cycler (Marshall Scientific, Richmond, VA, USA) and a Seeplex STD Detection Kit (Seegene, Seoul, Republic of Korea). The co-infection rate with STI pathogens was analyzed according to age and sex. Results: Of the 3297 clinical samples, 1017 (30.9%) tested positive for sexually transmitted pathogens, ranging from one to six co-infections. Analysis of the co-infection rate by age revealed that the average age gradually decreased as the total number of co-infection pathogens increased. The co-infection percentage and age distribution of STIs differed according to sex. Co-infection was more prevalent in female patients. Furthermore, co-infection in male patients occurred frequently in the 30–39-year-old group, while those in female patients occurred in the 20–29- and 30–39-year-old groups. Conclusion: Our statistical analysis showed that STI co-infections were more common among younger than older people. Therefore, it helps in recognizing STIs at a young age and provides possible indicator data to prevent STIs at a young age. In addition, further research is needed on co-infection in other regions.

Atopic dermatitis (AD) is a prevalent inflammatory skin disease characterized by epidermal barrier dysfunction and Th2-skewed inflammation. Campanula takesimana (C. takesimana), a Korean endemic plant grown on Ulleng Island, has long been associated with a traditional alternative medicine for asthma, tonsillitis, and sore throat. In this study, we reported the effect of C. takesimana callus extract on upregulating epidermal barrier-related proteins dysregulated by Th2 cytokines. C. takesimana callus extract induced the expression of skin barrier proteins, such as filaggrin, claudin-1, and zonula occludens-1, in both human primary keratinocytes and Th2-induced AD-like skin-equivalent models. Additionally, RNA sequencing analysis demonstrated that C. takesimana callus extract partially restored Th2 cytokine-induced dysregulation of the epidermal development and lipid metabolic pathways. Considering the advantages of callus as a sustainable eco-friendly source of bioactive substances, and its effect on skin barrier proteins and lipid metabolic pathways, C. takesimana callus extracts can possibly be utilized to improve the integrity of the skin barrier.

BACKGROUND Using a thread for wound closure promotes healing and minimizes contamination by foreign substances. Threads have also been employed in esthetic surgery; however, functional threads that can improve wrinkles and rejuvenate the skin are required. OBJECTIVE To evaluate the suitability of polydioxanone threads coated with polyethylene glycol, hyaluronic acid, and amino acids for use in the medical field because such formulations are expected to promote regeneration and collagen synthesis. MATERIALS AND METHODS Physical properties (diameter [n = 20], tensile strength [n = 20], strength retention rate [n = 10], and scanning electron microscopy images) and cytotoxicity (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide and lactate dehydrogenase assays) of polydioxanone threads coated with polyethylene glycol, hyaluronic acid, and amino acids were assessed and compared with those of uncoated polydioxanone threads. Analyses were performed using IBM SPSS Statistics (Statistical significance; p values,.05). RESULTS The size standards for tensile strength ($63.5 N) and diameter (average 0.570-0.610 mm) were met. There were no differences in the physical properties of the coated and uncoated threads; however, the biocompatibility of coated threads was high owing to low cytotoxicity. CONCLUSION Threads coated with materials that can promote regeneration are suitable for use in the medical field. [ABSTRACT FROM AUTHOR]