STATIC BENDING STRENGTH PERFORMANCES OF CROSS-LAMINATED WOOD PANELS MADE WITH SIX SPECIES

In this study, with the view to using effectively Korean small and medium diameter woods as structural materials, the cross-laminated wood panels were manufactured by using six species of Korean softwoods and hardwoods, and static bending strength performances were investigated for each species. The static bending strength performances of parallel- and cross-laminated wood panels increased in proportion to the density of species on the whole. The static bending strength performances perpendicular to the grain were improved by cross-laminating the longitudinal direction lamina in the core, the extent of the increase was higher in softwoods than in hardwoods. The measured modulus of elasticity (MOE) of parallel-laminated wood panels and cross-laminated wood panels perpendicular to the grain of face laminae had a little difference with those calculated from true MOEs of individual laminae. However, the measured MOEs of cross-laminated woods parallel to the grain of face laminae were much lower than the estimated MOEs owing to the effect of deflection caused by shear force. The percentage of deflection caused by shear force versus total deflection (Ys) showed high values of 9.8%~34.0%, and the cross-laminated wood panels made with softwoods were found to be markedly higher than those made with hardwoods

Calcium Oxalate Crystals and the Optimal Growing Conditions for Actinidia arguta

The presence, distribution, and morphology of calcium oxalate (CaC2O4, CaOx) crystals were observed in the stunted bodies of Actinidia arguta (A. arguta) vines, and their ability of microorganisms to degrade CaOx crystals was analyzed. Leaves, branches, and roots of stunted A. arguta vines were collected. In the roots, CaOx crystal bundles were distributed in the form of dotted lines. In the branches, CaOx crystal bundles were observed blocking and accumulating in the vessels. In the leaves, CaOx crystal bundles were observed in a net-like entanglement. Therefore, CaOx crystals present in the roots, branches, and leaves hinder the growth. A hydroponic cultivation with different calcium (Ca) concentrations showed that the growth of A. arguta was best at a Ca concentration of 1 cmol+/kg; at a Ca concentration of 2 cmol+/kg, the edges of the leaves began to dry out after 7 days; and at a Ca concentration of 4 cmol+/kg, the entire leaves died within 14 days. From this study, it was concluded that CaOx crystals hindered the growth of A. arguta, and the Acinetobacter calcoaceticus (A. calcoaceticus) strain was effective in degrading CaOx crystals. Therefore, the Ca concentration in the soil of the cultivation site should be managed at less than 2 cmol+/kg

Shedding and extensive and prolonged environmental contamination of goat farms of Q fever patients by Coxiella burnetii

Abstract Background A majority (>70%) of Q fever patients in South Korea do not have a history of animal contact. Therefore, unconscious environmental exposure is suspected. The aim of this study was to investigate exposure of Q fever patients to environmental contamination and animal shedding. Methods Two goat farmers were enrolled. One was diagnosed with Q fever 3 years ago (Farm 1). Among 20 goats on Farm 1, five were tested randomly and found to be Q fever PCR‐positive. Three of the five were Q fever ELISA‐positive. Two of five environmental samples taken in 2015 were PCR‐positive. In 2018, 17 of 18 environmental samples were PCR‐positive. On Farm 2, 54 of the 77 goats were PCR‐positive, and 63 were ELISA‐positive. Twelve of 14 environmental samples were PCR‐positive. Repeat administration of oxytetracycline to goats led to a gradual reduction in PCR‐positive tests over a 5‐month period. However, PCR‐positivity of the farm environment persisted for 5 months. Conclusion The environment on farms owned by Q fever patients was contaminated extensively and persistently, even after antibiotic treatment of goats and environmental decontamination. Undetected environmental contamination can be a major source of sporadic Q fever infection in South Korea

Inter-observer agreement on the interpretation of capsule endoscopy findings based on capsule endoscopy structured terminology: A multicenter study by the Korean Gut Image Study Group

Objective. Capsule endoscopy (CE) is a novel investigation for the diagnosis of small-bowel disease but its interpretation is highly subjective. We studied the inter-observer agreement and accuracy of the interpretation of CE findings based on capsule endoscopy structured terminology (CEST). Material and methods. Fifty-six CE video clips were collected from eight university hospitals in South Korea and were independently reviewed by 13 gastroenterology experts and 10 trainees. All investigators recorded their findings based on CEST. To determine the accuracy of individual viewers, we defined the `gold standard` as a joint review by four experts. Results. The 56 CE video clips included five normal cases, 19 cases of protruding lesions, 21 cases of depressed lesions, three cases of flat lesions, one case of abnormal mucosa, six cases with blood in the lumen, and one case of stenotic lumen. The overall mean accuracies for the experts and trainees were 74.3% +/- 22.6% and 61.7% +/- 25.4%, respectively. The overall accuracy for the trainee group was significantly lower than that for the expert group (P < 0.001), especially in normal, tumor, venous structure, and ulcer cases. The accuracies of the two groups varied with the CE findings. The accuracies were higher in cases with more prominent intraluminal changes (e.g. active small-bowel bleeding, ulcer, tumor, stenotic lumen). In contrast, subtle mucosal lesions, such as erosion, angioectasia, and diverticulum, had lower accuracies. The mean kappa values for the experts and trainees were 0.61 (range 0.39-0.97) and 0.46 (range 0.17-0.66), respectively. Conclusions. Our results showed that there was substantial agreement between experts and moderate agreement between trainees. In order to achieve higher accuracies and better inter-observer agreement, we need not only more experience with CE but also consensus regarding CEST terminology.Lai LH, 2006, EUR J GASTROEN HEPAT, V18, P283Chen GC, 2006, WORLD J GASTROENTERO, V12, P1249Niv Y, 2005, DIGEST DIS SCI, V50, P2121, DOI 10.1007/s10620-005-3017-7Petroniene R, 2005, AM J GASTROENTEROL, V100, P685, DOI 10.1111/j.1572-0241.2005.41069.xAdler DG, 2004, GASTROINTEST ENDOSC, V59, P492Levinthal GN, 2003, AM J GASTROENTEROL, V98, P2669, DOI 10.1016/j.amjgastroenterol.2003.06.001Lewis BS, 2002, GASTROINTEST ENDOSC, V56, P349, DOI 10.1067/mge.2002.126906Ell C, 2002, ENDOSCOPY, V34, P685Hahne M, 2002, ENDOSCOPY, V34, P588Iddan G, 2000, NATURE, V405, P417FOUTCH PG, 1990, GASTROINTEST ENDOSC, V36, P337RABE FE, 1981, RADIOLOGY, V140, P47LANDIS JR, 1977, BIOMETRICS, V33, P159