Manufacturing and analyses of wet-laid nonwoven consisting of carboxymethyl cellulose fibers

Carboxymethyl cellulose (CMC) is a cellulose derivative having water-soluble property, biodegradability, and biocompatibility. It has been used in various medical applications as forms of gel, film, membrane, or powder. In this study, composite CMC nonwovens were produced, by a wet-laid nonwoven process, to improve the wet strength of carboxymethyl cellulose nonwovens. Followed by preparing the CMC fibers from cotton fiber, the composite CMC nonwovens composed of CMC fibers and PE/PP bicomponent fibers were manufactured by using 85/15 % v/v of ethanol/water solution as a dispersion medium. Structural analyses of CMC fibers, such as XRD, TGA, FT-IR, and degree of substitution indicated that CMC fibers were successfully produced. The wet strength of CMC nonwoven was dramatically increased by blending with the PE/PP fibers without sacrificing the key properties for wound dressing materials such as liquid absorption, gel blocking and liquid retention. It is expected that the composite CMC nonwovens will be a good candidate for wound dressing materials for mild exudate condition.     

Ca2+ Cascade and Meiotic Resumption of the Caprine Primary Oocyte

In this study, we investigated the fluctuations of concentration of intracytoplasmic free Ca(2+) during in vitro maturation of caprine primary oocytes and its role in meiotic resumption. Oocytes that were extracted from caprine ovaries were cultured and allowed to mature in vitro to determine their developmental stages including germinal vesicle (GV), germinal vesicle breakdown (GVBD), metaphase of the first meiotic division (MI) and metaphase of the second meiotic division (MII). Intracytoplasmic free Ca(2+) turnovers of caprine oocytes at these different developmental stages were measured using the calcium fluorescent probe Fura-2/AM (C(44)H(47)N(3)O(24)) to investigate the dynamics of cytosolic free Ca(2+) during in vitro maturation of oocytes and the role of Ca(2+) in inducing the initiation of meiotic resumption of oocytes. Moreover, the oocytes were cultured in Ca(2+) culture medium and Ca(2+)-free culture medium to examine the effect of extracellular Ca(2+) on the oocyte maturation. The results indicated that Ca(2+) concentrations at GV, GVBD, MI and MII stages were 78.06, 147.41, 126.97 and 97.73 nmol/l, respectively, and that 86.30% of oocytes remained at the GV stage and no oocyte developed to MII in Ca(2+)-free culture medium, and 1.1% of oocytes stayed at the GV stage and 83.5% of oocytes developed to MII in Ca(2+) culture medium. These results suggest that the occurrence of GVBD and cell cycle progression to MI and MII stages are closely related to Ca(2+), and that extracellular Ca(2+) performs a specific function for the initiation of meiotic resumption in caprine oocytes.     

Change in weed control studies of rice paddy fields in Korea

This paper was reviewed on the research status of weed control according to cultivating patterns of rice in Korea. Weed control study in a nursery bed was chiefly carried out to control the species of barnyardgrass at the times of machine transplanting. Propanil and nitrofen were applied successfully in wet-nursery beds, and chlornitrofen and pyrazolate/butachlor were also successfully applied in protected semi-irrigated rice nursery beds in the 1970s. Sequential application of herbicides in the mid-1980s has resulted in the end of hand weeding. In machine transplanting, basic research such as the selection of herbicides was conducted in the early 1970s, and its related research including crop injury, seedling age, and reaction of cultivars were done in the late 1970s to early 1980s. Effects of the continuous application of herbicides and its methods of labor saving for rice cultivation were studied in the mid to late 1980s. When the rice planting methods were newly established, such as transplanting when seedlings were 10-days-old and direct seeding from the early 1990s, weed control research relating to herbicides was carried out (e.g. herbicide registration, crop injury, water management, appropriate application time, and neighboring application with insecticide). Weed control for the dill seeding of fields in wetted and reclaimed saline land have been experimented with, particularly in terms of the physio-ecological characteristics and the control of problematic weeds, and the resistance of weeds to herbicides was also investigated systematically.     

Functional rice giant embryo and Aranghyangchal reduce blood glucose level and enhance antioxidative defense status in high fat-fed mice

The effect of functional rice giant embryo and Aranghyangchal on the glucose metabolism and antioxidative defense status in high fat-fed C57BL/6N mice were investigated. The animals were randomly divided into four dietary groups: normal control (NC), high fat (HF), and high fat supplemented with giant embryo rice (HF-GE) or Aranghyangchal rice (HF-AR). After 8 weeks of feeding them with experimental diets, the HF mice exhibited a marked increase in the blood glucose concentration, plasma insulin level, and lipid peroxidation and a significant decrease in the hepatic glycogen level relative to the NC group. On the other hand, diet supplementation of the rice samples suppressed this high fat diet-induced hyperglycemia and oxidative stress through inhibition of the glucose-regulating enzymes and activation of the antioxidant enzymes. These findings demonstrate that the giant embryo and Aranghyangchal rice may be beneficial as biomaterials in the development of functional food with hypoglycemic and antioxidative properties.     

Histopathological retrospective study of canine renal disease in Korea, 2003~2008

Renal disease includes conditions affecting the glomeruli, tubules, interstitium, pelvis, and vasculature. Diseases of the kidney include glomerular diseases, diseases of the tubules and interstitium, diseases of renal pelvis, and developmental abnormalities. Renal tissue samples (n = 70) submitted to the Department of Veterinary Pathology of Konkuk University from 2003 to 2008 were included in this study. Tissue histopathology was performed using light microscopy with hematoxylin and eosin stains. Masson''s trichrome, Congo Red, and Warthin starry silver staining were applied in several individual cases. Glomerular diseases (22.9%), tubulointerstitial diseases (8.6%), neoplastic diseases (8.6%), conditions secondary to urinary obstruction (24.3%), and other diseases (35.7%) were identified. Glomerulonephritis (GN) cases were classified as acute proliferative GN (5.7%), membranous GN (4.3%), membranoproliferative GN (4.3%), focal segmental GN (2.9%), and other GN (4.2%). The proportion of canine GN cases presently identified was not as high as the proportions identified in human studies. Conversely, urinary obstruction and end-stage renal disease cases were relatively higher in dogs than in human populations.     

Estimation of the international virtual water flow of grain crop products in Korea

The Korean 2008 self-sufficiency rate for grain was only 26.2%. Because of this, the quantity virtual water (VW) for crop product imports is much greater than that of other countries. International VW trade is especially important to Korea due to its dependency on foreign imports to maintain food security and to establish an agricultural water resource policy. Using international crop products trade statistics during 2003?C2007, this study analyzed the virtual water content (VWC) and international virtual water flow (VWF) of major crops. The national water savings and global water savings were also estimated. Major grain products, including 28 products made from 13 crops, were selected for the analysis, based on the net import and export of products totaling more than 10,000 tons. VWCs were computed for the selected major crop products using the VWC of the primary crop of Korea. International VWFs were estimated using the VWC of each crop products. The amount of imported VW was 16,804 and 226?M?m³ was exported, so that the net imported VW was 16,578?M?m³. VW import is concentrated in wheat, rice, maize (corn), and soybean crops. A small number of countries, including the USA, China, Brazil, etc., account for over 96% of the imported VW, indicating Korea??s heavy dependence on these countries. The average national water savings for Korea and the average global water savings according to crop were estimated using VW flow from international crop products trade during 2003?C2007. The estimate of national water savings was 23,870.3?M?m³. Three major crops, namely wheat, maize and soybean, account for 95.3% of this total VW saving. Global water savings from the VW trade amounted to 7,253.0?M?m³. Korea depends heavily on VW imports concentrated in specific crops and which are primarily imported from a particular set of countries. This indicates that Korea is vulnerable to disruptions in the international grain harvest such as those caused by natural disasters such as floods and drought. Any such disruption could easily become a critical issue for governmental planners who establish food and water supply policies for Korea.     

Specific labeling of neurogenic, endothelial, and myogenic differentiated cells derived from human amniotic fluid stem cells with silica-coated magnetic nanoparticles

Stem cell based cell therapies offer significant potential for the field of regenerative medicine. Human amniotic fluid stem cells (hAFSCs) are an attractive source for lineage-specific differentiated stem cell therapy since they have properties that are able to differentiate into cells representing all three germ layers. To better understand the fate and location of implanted hAFSCs, a means to monitor cells in living subjects is essential. Here, we showed that differentiated cells, such as neurogenic, endothelial, and myogenic cells, derived from hAFSCs can be effectively labeled by the FITC-incorporated silica-coated nanoparticles, MNPs@SiO2 (FITC), although the labeling efficacy and cytotoxicity were distinct depending on the differentiated cell type. In addition, we observed that MNPs@SiO2-labeled cells provided sufficient signals for detection by optical and confocal microscope imaging when transplanted into the mice. These results suggest that the fluorescent dye incorporated MNPs@SiO2 are a useful tool for the cell labeling and in vivo tracking of differentiated cells derived from hAFSCs.