Effect of Board Type on Some Properties of Bamboo Strandboard

The objective of this study was to evaluate the properties of bamboo strandboard (OSB) by comparing different board types and strand-lengths. Bamboo  strandboards with nominal dimensions of 37 mm by 37 mm by 12 mm and target density 0.65 g/cm3 were manufactured using moso bamboo (Pyllostachys pubescent Mezel) and MDI resin to produce two types of strandlength. Two types of strand length and MDI resin were used to produce three types of strandboard. The bending properties and dimensional stability of the strandboards were evaluated according to the Japanese Industrial Standard (JIS) for particleboard. The results of this experiment indicate that the bending properties and internal bond strength were affected by both board type and strand-length. The distribution of resin inside the 80 mm strandboard was less homogenous than in the 50 mm strandboard, which affects the internal bond strength. Thickness swelling of the RAND board was the highest and linear stability was affected substantially by strand alignment. The RAND board and cross-oriented 3LAY board effectively restrained linear expansion in the direction perpendicular to the strand alignment. A cross-oriented core may be the most effective way to reduce dimensional change and bending property values in perpendicular directions

Effect of Furnish on Temperature and Vapor Pressure Behavior in the Center of Mat Panels during Hot Pressing

Particleboard achieves its overall performance characteristics during hot pressing process. As this process is influenced by several factors, particularly temperature and pressure, it is very important to understand the behavior of both. This study investigates the effects of furnish materials on temperature and vapor pressure behavior inside particleboard mat panels during hot pressing. Strand type particles from hinoki and ring-flaker recycled wood particles were used as furnish for laboratory-scale particleboard panels with a target density of 0.76 g/cm³. Mat panels with a moisture content of about 10% were hot pressed at a platen temperature of 180°C and an initial pressure of 3 MPa until the mat center reached the same temperature as the platen. A press monitoring device (PressMAN Lite) was used for detecting the temperature and vapor pressure change in the center of the mat panels. The study showed that the furnish type affected the temperature and vapor behavior inside the mat panels. Particleboard made of hinoki strand resulted in a longer plateau time, a higher plateau temperature and a higher gas pressure generated during hot pressing than those of ring-flaker recycled wood particles. Mixed board resulted in values between those of the two other furnish materials

Preparation of partial-thickness burn wounds in rodents using a new experimental burning device

Objective: The manual application of hot water or hot metal to an animal's skin surface is often used to prepare burn wound models. However, manual burn creation is subject to human variability.We developed a new device that can control the temperature, time, and pressure of contact to produce precise and reproducible animal burn wounds and investigated the conditions required to prepare various burn wounds using our new device. Methods: We prepared burnwounds on F344 rats using 3 contact times 2, 4, and 10 seconds using a stamp heated to 80C. We observed the wound-healing process macroscopically and histologically and evaluated the burn depth using a laser speckle contrast-imaging device, which evaluated the blood flow of the wound. Results: The changes in the burned area over time, tissue perfusion of the burn wounds, histological evaluation of the burn depth by hematoxylin-eosin and azocarmine and aniline blue staining, and the epithelialization rate (the ratio of the epithelialized area to the wound length) were evaluated on histological sections. Results indicated that the burn wounds prepared with contact times of 2, 4, and 10 seconds corresponded to superficial dermal burns, deep dermal burns, and full-thickness burns, respectively. Conclusions: We demonstrated that partial-and full-thickness burn wounds can be precisely and reproducibly created with our new automated burning device

Cultured Human Epidermis Combined With Meshed Skin Autografts Accelerates Epithelialization and Granulation Tissue Formation in a Rat Model

INTRODUCTION: As the take rate of cultured epidermal autografts in burn wound treatment is variable, widely expanded meshed auto skin grafts are often used in combination with cultured epidermal autograft to increase the take rate and achieve definitive wound coverage. However, a long time (3–4 weeks) required to prepare a cultured epidermis sheet is a disadvantage. Allogeneic cultured epidermis can be prepared in advance and cryopreserved to be used in combination with auto meshed skin grafts for treating third-degree burns. Nevertheless, the human cultured epidermis (hCE) has not been proved to accelerate wound healing after meshed skin grafting. Here, we investigated the effect of hCE on wound healing in a rat model of meshed skin grafting. MATERIALS AND METHODS: Human cultured epidermis was prepared from human neonatal foreskin and assessed by the release of growth factors into the culture medium using enzyme-linked immunosorbent assay. Skin wounds were inflicted on male F344 rats and treated by the application of widely meshed (6:1 ratio) autogenous skin grafts with or without hCE (n = 8 rats per group). Wound area, neoepithelium length, granulation tissue formation, and neovascularization were evaluated on day 7 postgrafting. RESULTS: Human cultured epidermis secreted IL-1α, Basic fibroblast growth factor, platelet-derived growth factor-AA, TGF-α, TGF-β1, and vascular endothelial growth factor in vitro. In rats, hCE accelerated wound closure (P = 0.003), neoepithelium growth (P = 0.019), and granulation tissue formation (P = 0.043), and increased the number of capillaries (P = 0.0003) and gross neovascularization area (P = 0.008) compared with the control group. CONCLUSIONS: The application of hCE with meshed grafts promoted wound closure, possibly via secretion of growth factors critical for cell proliferation and migration, suggesting that hCE can enhance the healing effect of widely expanded skin autografts.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal

Mass Spectra-Based Framework for Automated Structural Elucidation of Metabolome Data to Explore Phytochemical Diversity

A novel framework for automated elucidation of metabolite structures in liquid chromatography–mass spectrometer metabolome data was constructed by integrating databases. High-resolution tandem mass spectra data automatically acquired from each metabolite signal were used for database searches. Three distinct databases, KNApSAcK, ReSpect, and the PRIMe standard compound database, were employed for the structural elucidation. The outputs were retrieved using the CAS metabolite identifier for identification and putative annotation. A simple metabolite ontology system was also introduced to attain putative characterization of the metabolite signals. The automated method was applied for the metabolome data sets obtained from the rosette leaves of 20 Arabidopsis accessions. Phenotypic variations in novel Arabidopsis metabolites among these accessions could be investigated using this method

Does respiratory drive modify the cerebral vascular response to changes in end‐tidal carbon dioxide?

What is the central question of this study? An interaction exists between the regulatory systems of respiration and cerebral blood flow (CBF), because of the same mediator (carbon dioxide, CO ) for both physiological systems. The present study examined whether the traditional method for determining cerebrovascular reactivity to CO (cerebrovascular reactivity; CVR) is modified by changes in respiration. What is the main finding and its importance? CVR was modified by voluntary changes in respiration during hypercapnia. This finding suggests that an alteration in the respiratory system may under- or over-estimate CVR determined by traditional methods in healthy adults.The cerebral vasculature is sensitive to changes in the arterial partial pressure of carbon dioxide (CO ). This physiological mechanism has been well established as a cerebrovascular reactivity to CO (CVR). However, arterial CO may not be an independent variable in the traditional method to assess CVR since the cerebral blood flow (CBF) response is partly affected by the activation of respiratory drive or higher centers in the brain. We hypothesized that CVR is modified by changes in respiration. To test our hypothesis, in the present study, ten young healthy subjects performed hyper- or hypo-ventilation to change end-tidal CO (P CO ) under different concentrations of CO gas inhalation (0, 2.0, 3.5%). We measured middle cerebral artery mean blood flow velocity (MCAVm) by transcranial Doppler to identify the CBF response to change in P CO during each condition. At each F CO condition, P CO was significantly altered by changes in ventilation, and MCA Vm changed accordingly. However, the relationship between changes in MCV Vm and P CO as a response curve of CVR was reset upwards and downwards by hypo- and hyper-ventilation, respectively, compared with CVR during normal-ventilation. The findings of the present study may provide the possibility that an alteration in respiration under- or over-estimates CVR determined by the traditional methods