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A torrefaction treatment process followed by ethanol extraction was applied for extracting antioxidant components from oak wood. Response surface methodology (RSM) was applied to optimize the ethanol extraction conditions of antioxidant compounds from torrefied oak wood (severity factor R o = 4.23). Response values were assessed such as total polyphenol content, total flavonoid content, and DPPH radical scavenging activity. Optimal extraction conditions were found as follows: ethanol concentration 69.15 %, extraction temperature 71.60 °C and processing time 70.15 min for total polyphenol content; ethanol concentration 66.93 %, extraction temperature 69.52 °C and time 66.09 min for total flavonoids content; ethanol concentration 68.18 %, extraction temperature 51.77 °C and time 74.22 min for DPPH radical scavenging activity. The experimental values agreed with those predicted within a 95 % confidence interval indicating the suitability of RSM in optimizing the ethanol extraction of antioxidant compounds from the torrefied oak wood. However, no significant correlation was found between antioxidant activity (DPPH), neither with total polyphenol content nor with total flavonoid content.

To expand the potential of cork composite wood flooring as an interior material, this study investigated the bending performance of sandwich-structured cork composite wood flooring. The cork composite wood flooring was composed of temperate and tropical wood species as face layer and a cork board reinforced with metal, glass fiber, or carbon fiber placed between two cork boards as the core layer. The MOE value of wood flooring with merbau (M) had the highest value (6.71 GPa) and that of larch (La) had the lowest value (5.40 GPa). Overall, the MOE value of wood flooring with tropical wood species had higher value than those with temperate wood species, which had lower densities. According to the core reinforcements, the CM (cork board-metal) type showed a higher MOE value than the CG (cork board-glass fiber) and CC (cork board-carbon fiber) types. However, within the specific MOE, the order was CG > CC > CM. The ratio measured to calculated MOE ranged from 1.0 to 1.1, it showed a similar or slightly higher value than the measured MOE. The MOR of wood flooring had the highest value (51.0 MPa) in that with teak (T) and had the lowest value (34.9 MPa) in that with larch (La). The specific MOR of the wood floorings with cork board reinforced with glass fiber and carbon fiber was 20 to 40% higher than those reinforced with metal. Stable fracture behavior was observed for the cork composite wood flooring reinforced with metal, glass fiber, or carbon fiber.

In a detailed study of the relation between the deflection caused by shear force and the constitution of a laminated material beam, we derived an equation for calculating the shear modulus of a laminated material beam from the shear moduli of individual laminae. The validity of the derived equation was investigated using cross-laminated wood beams made with five species. The calculated shear moduli parallel to the grain of face laminae ranged from 48.3 MPa to 351 MPa, while those perpendicular to the grain of face laminae ranged from 58.0 MPa to 350 MPa. The calculated shear moduli increased markedly with increasing shear modulus in a cross section of perpendicular-direction lamina of a cross-laminated wood beam. The calculated apparent modulus of elasticity (MOE) of cross-laminated wood beams agreed fairly well with the measured apparent MOE values. This fact indicated that the apparent MOE of cross-laminated wood beam was able to be calculated from the true MOE values and shear moduli of individual laminae. The percentage of deflection caused by shear force obtained from the calculated apparent MOE (Ysub(sc)) was close to that obtained from the measured apparent MOE (Ysub(s)) and there was a high correlation between both values. From the above results, it was concluded that the derived equation had high validity in calculation of shear modulus of a cross-laminated wood beam.

This paper deals with flexural vibration techniques as a means of predicting modulus of rupture (MOR) and static modulus of elasticity (MOE) of finger-jointed wood specimens made with Sitka spruce (Picea sitchensis Carr.) and red pine (Pinus densiflora S. et Z.). Dynamic MOE was calculated from resonance frequencies obtained from forced vibrations induced in the two species of finger-jointed wood specimens by a magnetic driver and a tapping hammer. The dynamic MOE was well correlated to the static bending MOE and its value also showed a reasonable correlation with bending MOR, although the correlation coefficient was lower than that between the dynamic MOE and static bending MOE. It was found that the correlation of the dynamic MOE to MOR was higher in the magnetic driver with both ends free condition than in the tapping hammer condition. For both methods, red pine finger-jointed wood specimens showed higher correlation coefficients to the MOR than Sitka spruce finger-jointed wood specimens. The correlation coefficient values for the magnetic driver and tapping hammer methods were almost equal to or slightly lower than those for static MOE and MOR for red pine and Sitka spruce finger-jointed wood specimens. It can be concluded that the two flexural vibration techniques are useful for predicting the MOR and static MOE of finger-jointed wood specimens. [PUBLICATION ABSTRACT]

Thirty types of three-ply parallel- and cross-laminated woods were prepared from five species, and their static bending strength performance were investigated. The modulus of elasticity (MOE), proportional limit stress, and modulus of rupture (MOR) perpendicular to the grain were increased by cross-laminating, and the extent of the increase increased with decreasing density of the species. The measured values of MOE parallel and perpendi-cular to the grain of parallel-laminated woods and perpendicular to the grain of face laminae of cross-laminated woods were approximately equal to those calculated from true MOEs of individual laminae. However, the MOE parallel to the grain of face laminae of cross-laminated woods was much lower than the calculated MOE owing to the effect of the deflection caused by shear force on the MOE. The percentage of deflection caused by shear force versus total deflection (Ys) showed high values, from 16.1% (buna) to 40.5% (sugi), and it decreased linearly with increasing shear modulus in the cross section of the core. In addition, there was an extremely high positive correlation between the MOR and the measured MOE parallel to the grain of face laminae of cross-laminated woods. The MOR was also highly dependent on the shear modulus in cross section of the core.

Chemical therapeutics targeted against H. pylori may lead to host toxicity and pathogen eradication failures. In this study, ethanolic extracts from five Lespedeza sp. plants were shown to inhibit the gastric-pathogen H. pylori and to modulate cytokine production. Disc agar diffusion assays showed that Lespedeza sp. ethanol extracts possess potent anti-H. pylori activity. Among the five plant extracts, the extracts from L. cyrtobotrya demonstrated the highest anti-H. pylori effect. The growth inhibitory effect against H. pylori was initiated after six h of treatment with plant extracts and the effect remained for a continuous period of 48 h. Incubation of the gastric cells infected with H. pylori with 1.25 to 50 mg/mL of Lespedeza sp. plant extracts resulted in a reduction of the production of cytokine IL-8. The plant ethanol extracts generally had little influence on AGS cell viability, indicating their safety for the treatment of bacterial infections. Three active fractions of L. cyrtobotrya also demonstrated similar anti- H. pylori and immuno-modulatory effects. Taken together, these results provide evidence that Lespedeza sp. plant extracts might be potential sources of new host friendly anti-H. pylori agents.

As the use of drones grows, so too does the demand for physical protection against drone damage resulting from collisions and falls. In addition, as the flight environment becomes more complicated, a shock absorption system is required, in which the protective structure can be deformed based on the circumstances. Here, we present an origami- and kirigami-based structure that provides protection from various directions. This research adds a deformation capacity to existing fixed-shape guards; by using shape memory alloys, the diameter and height of the protective structure are controlled. We present three protective modes (1: large diameter/low height; 2: small diameter/large height; and 3: lotus shaped) that mitigate drone falls and side collisions. From the result of the drop impact test, mode 2 showed a 78.2% reduction in the maximum impact force at side impact. We incorporated kirigami patterns into the origami structures in order to investigate the aerodynamic effects of the hollow patterns. Airflow experiments yielded a macro understanding of flow-through behaviors on each kirigami pattern. In the wind speed experiment, the change in airflow velocity induced by the penetration of the kirigami pattern was measured, and in the force measurement experiment, the air force applied to the structure was determined.

Excess exogenous supplementation of d -galactose ( d -gal), a monosaccharide and reducing sugar, generates reactive oxygen species (ROS), leading to cell damage and death. ROS accumulation is critical in aging. Therefore, d -gal-induced aging mouse models are used in aging studies. Herein, we evaluated d -gal’s effect on neonatal testis development using an in vitro organ culture method. Mouse testicular fragments (MTFs) derived from neonatal testes (postnatal day 5) were cultured with 500 mM d -gal for 5 days. d -gal-treated MTFs showed a significantly increased and decreased expression of undifferentiated and differentiated germ cell markers, respectively, with a substantial reduction in meiotic cells. In d -gal-exposed MTFs, expression levels of Sertoli cell markers (Sox9 and Wt1) increased, while those of StAR and 17β-HSD3, whose expressions are abundant in d -Gal treated adult Leydig cells, decreased. Additionally, the enzyme 3 β-HSD1, essential for steroidogenesis in Leydig cells, was significantly reduced in d -gal-exposed MTFs compared to that in controls. d -gal significantly increased the expression of Bad, Bax, and cleaved caspase-3 and -8. Via oxidative stress in MTF. Overall, d -gal negatively regulates germ cell and Leydig cell development in neonatal testes through pro-apoptotic mechanisms and ROS.