Effect of self-learning media based on 360° virtual reality for learning periodontal instrument skills.

INTRODUCTION: Of 360° Virtual Reality (VR) is possibly produced and sufficiently effective as a consumer-friendly VR learning medium. Therefore, it is also expected to be useful in the dental practice field, as a self-learning medium for non-face-to-face skill training during the ongoing pandemic (COVID-19). Accordingly, this study was conducted to assess 360° VR self-learning media for a periodontal instrument operation. MATERIALS AND METHODS: We recruited 30 participants who had never experienced instrument training. We offered basic education and initial assessment (IA), then divided them into three groups: 1) PAPER: trained only with paper handouts; 2) 2D: trained with 2D video; 3) VR: trained with 360° VR. Each group performed self-learning and mid-term assessment (MA). Subjects then implemented home self-learning with the same media for one week, which was then followed by a final assessment (FA). RESULT: Analysis of IA-to-FA improvement scores showed that VR and 2D video were significantly higher than the PAPER groups. Meanwhile, analysis of MA-to-FA improvement scores showed that only VR was substantially higher than the PAPER group. Although VR and 2D video groups were not considerably different, VR scores were numerically higher than 2D video in all improvement score analyses. DISCUSSION: Both 2D video and 360° VR training were helpful to participants for an effective self-learning and also had good portability and accessibility as online-based learning methods. 360° VR showed higher learning efficiency than regular 2D video, possibly due to its autonomy, 360° visual information and physical and immersive characteristics, which positively affected self-training. CONCLUSION: Our findings showed the potential of 360° VR learning media and, further, suggest its usefulness as a novel self-learning method in future dental education.

Changes of ultrasonographic pattern of the spleen examined with a high-frequency linear transducer during growth in puppies.

A normal spleen is a homogeneous, finely textured, and hyperechoic organ. The development of high-frequency transducers has enabled the examination of the structural features of the spleen. Thus, the spleen can appear mildly mottled, even in normal dogs, and this could be misinterpreted as an abnormality. The purpose of this prospective, longitudinal, descriptive study was to describe the ultrasonographic pattern of the splenic parenchyma using a high-frequency transducer in puppies. The study included nine, normal, client-owned puppies that were born healthy. Transabdominal ultrasonographic examination was performed from 4 to 60 weeks serially every 4 weeks. Ultrasonographic patterns of the spleen were graded as follows: granular, mild reticulonodular, moderate reticulonodular, and marked reticulonodular pattern. The examinations were performed by one veterinary clinician, and the grades of the ultrasonographic patterns were determined by two veterinary clinicians experienced in ultrasonography, based on consensus. Differences and associations between time and the grade of the splenic parenchyma were determined using the paired t-test and scatter plots. There was a strong quadratic relationship between time and the grade of the splenic parenchyma. It was found that the splenic parenchymal patterns changed with increasing age, with a granular appearance initially at 4 weeks, followed by a reticulonodular pattern with well-defined hypoechoic nodules-most marked between 28 and 36 weeks, after which this pattern decreased until there was a homogeneous granular pattern again at 60 weeks. These findings should not be misinterpreted as being indicative of a disease in normal puppies, particularly those aged between 28 and 36 weeks.

Cone beam CT findings of retromolar canals in a Korean population.

PURPOSE: The identification of the variation involving the mandibular canal is important during surgical procedures in the mandible. This study aims to investigate the incidence, course, width, and location of retromolar canals in a Korean population using cone beam CT. METHODS: The cross-sectional, sagittal, and three dimensional images from volumetric cone beam CT data of 446 patients were reconstructed using imaging analysis software for the presence of a retromolar canal. Retromolar canals were classified into three types according to the courses. The width and location (distance from the second molar) of retromolar canals were evaluated. RESULTS: A retromolar canal was observed in 8.5 % of patients (38/446). Most retromolar canals had vertically curved courses (Type 1, 66.7 %), followed by horizontally curved courses (Type 2, 20 %). Type 3 retromolar canals, which run independently from separate foramina in the mandibular ramus, were rare (13.3 %). The mean width of a retromolar canal was 1.13 mm (SD ± 0.38, 0.60-2.00), and the mean distance to the second molar was 14.08 mm (SD ± 3.85, 8.50-24.00). CONCLUSIONS: The incidence of retromolar canals in the Korean population was lower than that reported in the investigated ethnic groups. In the presence of a retromolar canal, local anesthesia may be ineffective. The damage to a retromolar canal may be unavoidable during surgical procedures involving the mandible and may result in paresthesia, excessive bleeding, postoperative hematoma, or traumatic neuroma.

Seed coat color and seed weight contribute differential responses of targeted metabolites in soybean seeds.

The distribution and variation of targeted metabolites in soybean seeds are affected by genetic and environmental factors. In this study, we used 192 soybean germplasm accessions collected from two provinces of Korea to elucidate the effects of seed coat color and seeds dry weight on the metabolic variation and responses of targeted metabolites. The effects of seed coat color and seeds dry weight were present in sucrose, total oligosaccharides, total carbohydrates and all measured fatty acids. The targeted metabolites were clustered within three groups. These metabolites were not only differently related to seeds dry weight, but also responded differentially to seed coat color. The inter-relationship between the targeted metabolites was highly present in the result of correlation analysis. Overall, results revealed that the targeted metabolites were diverged in relation to seed coat color and seeds dry weight within locally collected soybean seed germplasm accessions.

The characterization of caffeine and nine individual catechins in the leaves of green tea (Camellia sinensis L.) by near-infrared reflectance spectroscopy.

Near-infrared reflectance spectroscopy (NIRS) was used to determine the contents of caffeine and nine individual catechins in tea leaves. A total of 665 samples were scanned by NIRS, and also by high performance liquid chromatography coupled to a diode array detector to determine the contents of caffeine and nine individual catechins. The calibration models for caffeine, EGC, C, EGCG, EC, ECG, and total catechins had high r(2) (more than 0.90) and RSP (the ratio of standard deviation of reference data to SEP(C) in the external validation set) values (more than 4.1), indicating a good correlation between reference values and NIRS predicted values. In contrast, the calibration models of GC and EGCG-3Me had low r(2) and RSP values (below 0.8 and 2.0). Therefore, these results suggest that NIRS could be applied for the rapid determination of the contents of caffeine, EGC, C, EGCG, EC, ECG, and total catechins in tea leaves for breeding programs that develop high-quality tea plants.

Differential responses of B vitamins in black soybean seeds.

This study was aimed to determine the contents and the association of B vitamins from seeds of 10 black and one yellow soybean (Glycine max (L.) Merr.) varieties with either green or yellow cotyledon. Thiamine, flavin adenine dinucleotide (FAD), riboflavin and total riboflavin were found highest in 'Chengjakong', while flavin mononucleotide (FMN) was greatest in 'Mirang'. Nicotinic acid and total vitamin B3 were highest in 'Shingi' as a yellow soybean variety but pantothenic acid and pyridoxine contents were greatest in 'Tawon' and 'Mirang', respectively. These content variations of B vitamins directly reflected the wide segregation of soybean varieties on the principal component analysis (PCA) scores plot, indicating that these 4 soybean varieties appeared to be least associated with other soybean varieties based on the different responses of B vitamins. The results of cluster and correlation analyses presented that the cotyledon colour of soybean seed contributed to a variation of B vitamin contents. Overall, the results suggest that a wide range of B vitamin contents would be affected by genotypic factors alongside the difference of cotyledon colour.

Seed maturity differentially mediates metabolic responses in black soybean.

The soybean seed is placed in the middle of the morphological and developmental alterations, such as changes in seed size, weight, and colour, and alteration of the composition and contents of metabolites during maturation. In this study, we used black soybean seeds to investigate the effect of maturity on metabolite levels at different maturity stages. Seeds were sorted into five maturity categories, from M1 to M5, based on seed size and external pigmentation. Maturity stages M1, M3, and M5 are equivalent to R6, R7, and R8 on the soybean reproductive growth stage scale, indicating full seed, beginning maturity, and full maturity, respectively. As seed maturation progressed, the seed size decreased and the water soluble extract changed, indicating that a change of seed pigmentation occurred. At the same time, numerous metabolites responded differentially to seed maturation. The partial least squares (PLS) scores plot indicated that the metabolic alteration during maturation was clearly visible. Furthermore, isoflavones were highly associated with seed maturity on the PLS loading plot while fatty acids, glucose, fructose, and sucrose were less linked with seed maturity, indicating that those metabolites responded less to seed maturation. Overall, the results indicate that each category of metabolites is mediated differentially during maturation in black soybean seeds.

Metabolic alterations of lutein, ß-carotene and chlorophyll a during germination of two soybean sprout varieties.

The metabolic changes of lutein, ß-carotene and chlorophyll a during germination of the soybean (Glycine max (L.) Merr.) sprout varieties, 'Pungsannamulkong' and 'Bosug', have been studied. Seeds were germinated at 20 °C with 80% humidity in the darkness and sampled at 2 day intervals for 10 days. Partial least squares (PLS) scores plot showed that the responses of three metabolites during germination were linearly linked with each other except for day 2 in both varieties. PLS loading plots indicated that lutein content in whole sprout and cotyledon was closely associated with germination in 'Pungsannamulkong' while the chlorophyll a content in whole sprouts was highly linked with germination in 'Bosug'. Heatmap analyses revealed that lutein and ß-carotene levels, but not those of chlorophyll a, accumulated in whole soybean sprouts and cotyledon. While hypocotyls did not accumulate lipophilic pigments during germination, the accumulation of lutein and ß-carotene in the cotyledons was greater in 'Pungsannamulkong' than in 'Bosug' sprouts. In addition, the contents of lutein, ß-carotene and chlorophyll a increased from those in the seeds. Overall, the metabolic changes of lutein, ß-carotene and chlorophyll a during germination are affected not only by variety but also by organ type.