• The Korea Journal of Herbology
• /
• v.20 no.3
• /
• pp.9-18
• /
• 2005

Objectives : The purpose of this study is to investigate characteristics of cell morphology of two different agar woods (Aquilaria agallocha Roxburgh (AAR) and imitative agar wood (IAW)) using microscopic techniques. Methods : Both light and scanning electron microscopes were used to observe morphological and histological features of the cell of agar woods collected from commercial products in the market. Results : The cell morphology and tissue arrangements of AAR depending on either the adsorption of resin into vessels or no adsorption of resin were observed to compare these features with those of both IAW and Aquilaria sinensis Gilb (ASG). Conclusions : As a result, the vessels of AAR with the resin adsorption was packed with lots of yellow-brownish materials, which were quite different from those of IAW and ASG. The cell walls were thick, and had well-developed traumatic parenchyma tissues with squared cells of the same height and width, which appeared as a clump of small grains packed.

• Journal of the Korean Wood Science and Technology
• /
• v.44 no.2
• /
• pp.172-183
• /
• 2016

Densification of the inner part of oil palm trunk (OPT) by the close system compression (CSC) method was performed in this study. The effects of the compression temperature and time on the anatomical, physical and mechanical properties of OPT were evaluated. The inner part of OPT with an initial average density of $0.3g/cm^3$ was used as samples. Oven-dried samples were immersed in water and vacuumed until fully saturated and then compressed by CSC at 120, 140, 160 or $180^{\circ}C$ for 10, 20, 30 or 40 min. The anatomical characteristics of transverse and radial sections before and after compression were compared by optical microscopy. The physical and mechanical properties, including the density, recovery of set (RS), modulus of elasticity (MOE), modulus of rupture (MOR), and compression parallel to grain were examined. It was observed that the anatomical characteristic of the inner part of OPT (i.e., vascular bundles, vessels, and parenchyma tissue) became flattened, fractured, and collapsed after compression by CSC. The RS decreased with increasing compression temperature and time. The lower RS indicated high dimensional stability. The physical and mechanical properties (i.e., density, MOR, MOE, and compressive strength) of the inner part of OPT increased with increasing compression temperature and time. Compression by the CSC method at $160^{\circ}C$ for 40 min was the optimum treatment.

• Journal of Plant Biology
• /
• v.34 no.1
• /
• pp.67-75
• /
• 1991

Anatomical study of the secondary xylem in Malvales plants, including four families, five genera and ten species grown in Korea, was carried out to elucidate relationship among genera or families in the order. Wood of Elaeocarpus is diffuse porous and shows angular vessels in radial multiples of 2-14 cells and a few apotracheal or paratracheal parenchyma. Tiliaceous genera have diffuse porous wood, vessels in solitary distribution and apotracheal parenchyma of sinuous scalariform uniseriate band. In the family, Tilia shows angular vessel. noded and tile-like cell in ray and storied tissue but Grewia has circular vessel. Hibiscus shows ring porous wood, circular solitary vessel and biseriate band of apotracheal and paratracheal parenchyma. Firmiana shows ring porous wood, circular solitary vessel and confluent parenchyma. Many starch grains appear in ray and axial parenchyma. Judging from arrangement, shape, length and diameter of vessel element and angle of end wall to vessel axis, and arrangement and shape of axial parenchyma, the lines of specialization in these genera are from primitive Elaeocarpaceae through less primitive Tiliaceae and less advanced Malvaceae to advanced Sterculiaceae.iaceae.

• Journal of Plant Biology
• /
• v.35 no.3
• /
• pp.211-217
• /
• 1992

In order to elucidate the formation of reaction tissues during the transition from primary to secondary growth, the developmental anatomy was conducted in the first internode of Acer sacchan'num seedling in horizontal position. During the transition from primary to secondary growth, tension wood(gelatinous fiber) was gradually developed on the upper side only, And the tension wood formation in the upper side of the horizontal first internode proceeds acropetally from base to apical portion. Some of the anatomical features of tension wood start to be in the primary vascular tissue and a typical tension wood show during the secondary growth, Therefore, the procambium seems to respond to the gravity as well as vascular cambium. For this reason, both procambium and vascular cambium has to regard as the same meristem, On the other hand, the upper side vessels were longer than those of the lower side in the horizontal first internode. The lateral-wall pitting of vessel elements, however, showed no differences between upper and lower sides which have alternate type. The width and height of rayon the upper side of horizontal first internode was larger as compared with the lower side.r side.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2004.10a
• /
• pp.1038-1041
• /
• 2004

In this study, developed a micro-level experimental setup to measure pore pressure and poroelastic modulus in various strain and strain rate about a stress in micro-structure of bone tissue. It is essential device in the development of the model to analysis the interstitial bone fluid flow of the lacuno-canalicular system to be known that would effect on the bone remodeling. The constitution of the experimental setup is as follows, microscopic image processing system; actuator control unit; load measurement system. A pilot study was used an artificial chemical wood to have similar poroelastic property of bone matrix and conducted to validate the suitability of the measurement system.

• 보존과학연구
• /
• s.33
• /
• pp.99-108
• /
• 2012

The white-rot fungus (Trametes versicolor) and brown-rot fungus (Tyromyces palustris), which cause damage to a variety of wooden cultural properties and buildings, such as drying of the wood tissue, decay and cracks, sponge, and discoloration, give rise to serious structural and aesthetic problems. Moreover, pest termites (Reticulitermes speratus kyushuensis Morimoto) can cause damages like hollowing the outdoor beams or pillars of wooden buildings and finally causing such buildings to collapse due to the termites' destruction of the inside of the beams or pillars, leaving only a thin layer on their surfaces. This study was conducted to determine the impact of the wood-decay fungus, a representative damage-causing microorganism, and of insects and termites on the termite ecology. The damage ratio was calculated as the weight of the timber, and the overall total mass was reduced from two kinds of rot fungi. The white-rot fungi reduced the total wood mass, but the brown-rot fungi were observed to have had an increasing tendency to do so. The wood mass was measured after drying to determine the destruction capacity of termites. As a result, the wood mass consumed by the brown-rot fungi was shown to be greater.

• Clinical and Experimental Reproductive Medicine
• /
• v.47 no.2
• /
• pp.94-100
• /
• 2020

The inverse correlation between maternal age and pregnancy rate represents a major challenge for reproductive endocrinology. The high embryo ploidy error rate in failed in vitro fertilization (IVF) cycles reflects genetic misfires accumulated by older oocytes over time. Despite the application of different follicular recruitment protocols during IVF, gonadotropin modifications are generally futile in addressing such damage. Even when additional oocytes are retrieved, quality is frequently poor. Older oocytes with serious cytoplasmic and/or chromosomal errors are often harvested from poorly perfused follicles, and ovarian vascularity and follicular oxygenation impact embryonic chromosomal competency. Because stimulation regimens exert their effects briefly and immediately before ovulation, gonadotropins alone are an ineffective antidote to long-term hypoxic pathology. In contrast, the tissue repair properties (and particularly the angiogenic effects) of platelet-rich plasma (PRP) are well known, with applications in other clinical contexts. Injection of conventional PRP and/or its components (e.g., isolated platelet-derived growth factors as a cell-free substrate) into ovarian tissue prior to IVF has been reported to improve reproductive outcomes. Any derivative neovascularity may modulate oocyte competence by increasing cellular oxygenation and/or lowering concentrations of intraovarian reactive oxygen species. We propose a mechanism to support intrastromal angiogenesis, improved follicular perfusion, and, crucially, embryo ploidy rescue. This last effect may be explained by mRNA upregulation coordinated by PRP-associated molecular signaling, as in other tissue systems. Additionally, we outline an intraovarian injection technique for platelet-derived growth factors and present this method to help minimize reliance on donor oocytes and conventional hormone replacement therapy.

• Journal of the Korean Wood Science and Technology
• /
• v.27 no.1
• /
• pp.105-114
• /
• 1999

Antimicrobial activities of the organosoluble extracts, seperated fractions and isolated lignans from the leaves tissue of Magnolia kobus DC. var. borealis Sarg. were investigated. The results are summarized as follows : 1. The inhibitory components against the spore growing test were concentrated on light petroleum ether and diethyl ether soluble fractions. The light petroleum ether solubles of the leaves tissue had terpenes compound, so, that they caused growing inhibition. These appearance showed high values of Rf on TLC bioautography and GC analyses with monoterpenes. 2. In the lignans, syringaresinol(X III), medioresinol(VI), phillygenin(VIII), kobusinol A(X) showed relatively high inhibitory effects in the spore growing test, and these are all showed structural characteristic of the phenolic hydroxyl group of guaiacyl and syringyl skelecton. 3. The light petroleum ether soluble fraction showed the strongest inhibitory effect against the antimicrobial activity in the seperated fractions. 4. The inhibitory effects of the lignans against the bacteria showed not so pronounced independantly, but the extracts and separated fractions contained with these lignans showed something synergism.

• Journal of the Korean Wood Science and Technology
• /
• v.34 no.2
• /
• pp.68-77
• /
• 2006

The heartwood of cengal (Neobalanocarpus heimii) is known to have a high degree of decay resistance by virtue of its high extractive content. After 30 years in ground contact an utility pole of this tropical hardwood was found to be degraded only in the surface layers by cavity-forming soft rot fungi. The present work was undertaken 1) to characterize the degradation of cengal heartwood from the aspect of ultrastructure and chemistry and 2) to investigate the correlation between soft rot decay and its extractive microdistribution in wood tissues. The chemical analysis of cengal heartwood revealed the presence of a high amount of extractives as well as lignin. The wood contained a relatively high amount of condensed lignin and the guaiacyl units. Microscopic observations revealed that vessels, fibers and parenchyma cells (both ray and axial parenchyma) all contained extractives in their lumina, but in variable amounts. The lumina of fibers and most axial parenchyma were completely or almost completely filled with the extractives. TEM micrographs showed that cell walls were also impregnated with extractives and that pit membranes connecting parenchyma cells were well coated and impregnated with extractives. However, fungal hyphae were present in the extractive masses localized in cell lumina, and indications were that the extractives did not completely inhibit fungal growth. The extent of cell wall degradation varied with tissue types. The fibers appeared to be more susceptible to decay than vessels and parenchyma. Middle lamella was the only cell wall region which remained intact in all cell types which were severely degraded. The microscopic observations suggested a close correlation between extractive microdistribution and the pattern and extent of cell wall degradation. In addition to the toxicity to fungi, the physical constraint of the extractive material present in cengal heartwood cells is likely to have a profound effect on the growth and path of invasion of colonizing fungi, thus conferring protection to wood by restricting fungal entry into cell walls. The presence of relatively high amount of condensed lignin is also likely to be a factor in the resistance of cengal heartwood to soft rot decay.

• Journal of the Korean Wood Science and Technology
• /
• v.51 no.4
• /
• pp.309-319
• /
• 2023

Bamboo culm is in the form of a tube/pipe, composed of internodes which are bounded by a partition/diaphragm (node). Anatomically, bamboo is composed of vascular bundles and parenchyma ground tissue. One of the constituents of vascular bundles is fibers that are grouped to form a fiber sheath. The anatomical structure of the nodes and internodes is thought to influence the strength of bamboo strips, including tensile strength. This study aimed to determine the characteristics of vascular bundles (distribution and fiber percentage) and their effects on the density and tensile strength of Gigantochloa apus bamboo strips with and without nodes. The bamboo culms were divided into three parts (outer, middle, and inner) along the radial direction. The results showed that the distribution of vascular bundles and percentage of fiber sheaths decreased significantly from the outer to the inner layer. This also had a significantly decreased density and tensile strength. Furthermore, the number of vascular bundles (in the transverse plane) was greater in the internodes than in the nodes. Anatomically, the orientation of the vascular bundles at irregular nodes is observed in the radial and tangential planes, where the direction is not only in the axial direction, but also in the radial and tangential directions. This caused the tensile strength of the G. apus bamboo strips to be lower at the nodes than at the internodes.