Intrapancreatic ectopic splenic tissue found in a cloned miniature pig     

Ok Jae Koo  Seung-Kwon Ha  Sol Ji Park  Hee Jung Park  Su Jin Kim  Daekee Kwon  Jung Taek Kang  Joon Ho Moon  Eun Jung Park  Goo Jang  Byeong Chun Lee 《Journal of veterinary science (Suw?n-si, Korea)》2015,16(2):241-244

Somatic cell nuclear transfer (SCNT) is a cost-effective technique for producing transgenic pigs. However, abnormalities in the cloned pigs might prevent use these animals for clinical applications or disease modeling. In the present study, we generated several cloned pigs. One of the pigs was found to have intrapancreatic ectopic splenic tissue during histopathology analysis although this animal was grossly normal and genetically identical to the other cloned pigs. Ectopic splenic tissue in the pancreas is very rare, especially in animals. To the best of our knowledge, this is the first such report for cloned pigs.  相似文献   

Surface modification of silk fibroin nanofibrous mat with dextran for wound dressing     

Moo Kon Kim  Hyo Won Kwak  Hyung Hwan Kim  Tae Rin Kwon  So Young Kim  Beom Joon Kim  Young Hwan Park  Ki Hoon Lee 《Fibers and Polymers》2014,15(6):1137-1145

In this study, we examined the effects of a dextran-modified silk fibroin nanofibrous mat (D-SFNM) on wound healing. To increase the hydrophilicity of silk fibroin (SF), the SF nanofibrous mat (SFNM) was modified with oxidized dextran. The D-SFNM absorbed water faster than the SFNM, and the swelling ratio was increased by approximately 80 % compared with the SFNM. An in vitro cell (NIH3T3) test revealed that fewer cells attached to the D-SFNM than the SFNM, but the proliferation of cells was not significantly affected by the presence of dextran. An in vivo wound healing test with mice indicated that the D-SFNM resulted in a good wound recovery effect similar to a commercial wound dressing material. The increased hydrophilicity of the D-SFNM might balance the moist environment at the wound site, which improves the wound healing compared with the SFNM.  相似文献   

A New Benzofuran Glycoside and Indole Alkaloids from a Sponge-Associated Rare Actinomycete,Amycolatopsis sp.     

Yun Kwon  Seong-Hwan Kim  Yoonho Shin  Munhyung Bae  Byung-Yong Kim  Sang Kook Lee  Ki-Bong Oh  Jongheon Shin  Dong-Chan Oh 《Marine drugs》2014,12(4):2326-2340

Three new secondary metabolites, amycofuran (1), amycocyclopiazonic acid (2), and amycolactam (3), were isolated from the sponge-associated rare actinomycete Amycolatopsis sp. Based on combined spectroscopic analyses, the structures of 1–3 were determined to be a new benzofuran glycoside and new indole alkaloids related to cyclopiazonic acids, a class that has previously only been reported in fungi. The absolute configurations of 1 and 3 were deduced by ECD calculations, whereas that of 2 was determined using the modified Mosher method. Amycolactam (3) displayed significant cytotoxicity against the gastric cancer cell line SNU638 and the colon cancer cell line HCT116.  相似文献   

Target region amplification polymorphism (TRAP) for assessing genetic diversity and marker-trait associations in chickpea (Cicer arietinum L.) germplasm     

Yogesh Kumar  Soon Jae Kwon  Clarice J. Coyne  Jinguo Hu  Michael A. Grusak  Theodore J. Kisha  Rebecca J. McGee  Ashutosh Sarker 《Genetic Resources and Crop Evolution》2014,61(5):965-977

The effective utilization of crop diversity held in genebanks depends on our knowledge of useful traits and available markers associated with the target traits. Target region amplification polymorphism (TRAP) was used to evaluate the genetic diversity and underlying relationships among 263 accessions of chickpea landraces maintained by the USDA-ARS Western Regional Plant Introduction Station in Pullman, WA, USA. Two-hundred sixty-two TRAP markers were amplified by eight primer combinations. Altogether, 110 (42 %) markers were polymorphic, the other 152 (58 %) displayed no variation. These polymorphic markers revealed important differences among the accessions, with an estimated, mean pair-wise genetic distance of 25.82 %, ranging from 2.8 to 50.0 %. Genetic distance analysis divided the accessions into two major groups, with 113 and 150 accessions each, and substantial association between molecular diversity and geographic origin was evident. Bayesian analysis of population structure revealed two groups (K = 2) with evidence for six sub-groups. Additionally, the population structure of a subset of 110 lines was determined (K = 3) for testing marker-trait associations (MTAs). Phenotypic traits included the concentrations of protein and nine mineral elements in the seeds. Two MTAs were significant (p < 0.01) for concentrations of Ca and K, and three MTAs were significant for Cu and Ni concentrations. The results indicate that this population is useful for genome-wide association studies on other economic traits given the level of genetic diversity uncovered and the marker-trait associations in seed minerals discovered.  相似文献   

Thermal properties of copolyetherester/silica nanocomposites     

Doo Hyun Baik  Hae Young Kim  Sun Jin Kwon  Myung Hyun Kwon  Han Sup Lee  Ji Ho Youk  Seung Won Seo 《Fibers and Polymers》2006,7(4):367-371

Thermal properties of copolyetherester/silica nanocomposites were examined by using DSC and TGA. The segmented block copolyetheresters with various hard segment structures and hard segment contents (HSC) were synthesized and their silica nanocomposite films were prepared by solution casting method. The nano-sized fumed silica particles were found to act as a nucleating agent of the copolyetheresters. The nanocomposites always showed reduced degree of supercooling or faster crystallization than the corresponding copolyetheresters. The nanocomposites also showed increased hard segment crystallinity except HSC 35 sample which had short hard segment length. In case of 2GT [poly(ethylene terephthalate)] copolyetheresters, which were not developed commercially because of their low crystallization rate, the hard segment crystallinity increased considerably. The copolyetherester/silica nanocomposites showed better thermal stability than copolyetheresters.  相似文献   

Prediction and measurement of residual stresses in injection molded parts     

Young Il Kwon  Tae Jin Kang  Kwansoo Chung  Jae Ryoun Youn 《Fibers and Polymers》2001,2(4):203-211

Residual stresses were predicted by a flow analysis in the mold cavity and residual stress distribution in the injection molded product was measured. Flow field was analyzed by the hybrid FEM/FDM method, using the Hele Shaw approximation. The Modified Cross model was used to determine the dependence of the viscosity on the temperature and the shear rate. The specific volume of the polymer melt which varies with the pressure and temperature fields was calculated by the Tait’s state equation. Flow analysis results such as pressure, temperature, and the location of the liquid-solid interface were used as the input of the stress analysis. In order to calculate more accurate gap-wise temperature field, a coordinate transformation technique was used. The residual stress distribution in the gap-wise direction was predicted in two cases, the free quenching and the constrained quenching, under the assumption that the shrinkage of the injection molded product occurs within the mold cavity and that the solid polymer is elastic. Effects of the initial flow rate, packing pressure, and mold temperature on the residual stress distribution was discussed. Experimental results were also obtained by the layer removal method for molded polypropylene.  相似文献   

Seasonal variations of fatty acid compositions in various Korean shellfish     

Surh J  Ryu JS  Kwon H 《Journal of agricultural and food chemistry》2003,51(6):1617-1622

Seasonal variations of fatty acids in various Korean shellfish were investigated in relation to the changes in total fatty acids contents, the ratio of polyunsaturated fatty acids to saturated fatty acids (P/S), and that of n-3 fatty acids to n-6 fatty acids (n-3/n-6). A distinct seasonal pattern was found in total fatty acids contents with maximal values in early summer and minimal values in late summer. The percentage of monounsaturated fatty acids was lowest in most species throughout the year. In summer months, the proportion of polyunsaturated fatty acids decreased while that of saturated fatty acids increased. The major contributing factor to the seasonal variation of polyunsaturated fatty acids was n-3 fatty acids. These results led to the lowest levels of P/S and n-3/n-6 in summer. Nevertheless, the data suggest that bivalve shellfish would be excellent sources of n-3 fatty acids, especially eicosapentaenoic acid and docosahexaenoic acid.  相似文献   

Hydrophilic and flexible polyurethane foams using sodium alginate as polyol: Effects of PEG molecular weight and cross-linking agent content on water absorbency     

Oh-Jin Kwon  Seung-Taek Oh  Sang-Do Lee  Na-Ri Lee  Chang-Hoon Shin  Jong-Shin Park 《Fibers and Polymers》2007,8(4):347-355

Hydrophilic and flexible polyurethane foams were prepared using sodium alginate as a polyol, and characterized by optical microscopy, FT-IR spectroscopy, density measurements, volume swelling, and water absorbency. Optical microscopy revealed that the resulting cells were closed with round and elongated shapes. FT-IR confirmed that the urethane linkages were formed between the isocyanate and sodium-alginate. As an indirect measurement of porosity, the apparent density indicated an initial decrease followed by an increase with increasing glycerin content. The volume-swelling ratio was initially constant, followed by a gradual decrease with glycerin content. The volume swelling ratio increased with PEG molecular weight. The water absorbency initially increased, followed by a decrease with increasing glycerin content. The correlation-ships between water absorbency, density, and volume-swelling ratio indicated that the absorbency was predominantly influenced by density when the PEG molecular weight was low and was greatly affected by the volume-swelling ratio when the PEG molecular weight was relatively high.  相似文献   

Seasonal Variation of Phenolic Antioxidant-mediated α-glucosidase Inhibition of <Emphasis Type="Italic">Ascophyllum nodosum</Emphasis>     

Apostolidis E  Karayannakidis PD  Kwon YI  Lee CM  Seeram NP 《Plant foods for human nutrition (Dordrecht, Netherlands)》2011,66(4):313-319

Ascophyllum nodosum is a brown seaweed that grows abundantly in the US Northeast coastal region. This study examined the seasonal variation of A. nodosum in phenolic contents and subsequent antioxidant, α-glucosidase and α-amylase inhibitory activities. A. nodosum was harvested monthly and extracted in hot water and the resulting extracts were spray-dried. The results indicate a clear seasonal variation in terms of phenolic content, with June and July being the highest (36.4 and 37 mg/g, respectively) and May the lowest (21.8 mg/g). The antioxidant activities, in terms of 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity, correlated with the phenolic contents observed (r = 0.81), with the month of July being the highest (58%) and April the lowest (26%). Similarly in terms of Trolox equivalent, July had the highest activity (15.53 μM) and April and May the lowest (8.40 and 8.27 μM, respectively). α-glucosidase inhibitory activity exhibited a pattern similar to the phenolic contents observed with July having the highest inhibitory activity (IC₇₀ 2.23 μg) and April the lowest (IC₇₀ 26.13 μg), resulting in an inverse correlation between IC₇₀ values and total phenolic content (r = −0.89). Such seasonal variation is believed to be caused by temperature-related stress considering that A. nodosum is a cold water species.  相似文献   

Association analysis of physicochemical traits on eating quality in rice (Oryza sativa L.)     

Wei-Guo Zhao  Jong-Wook Chung  Soon-Wook Kwon  Jeong-Heui Lee  Kyung-Ho Ma  Yong-Jin Park 《Euphytica》2013,191(1):9-21

Improvement of rice eating quality is an important objective in current breeding programs. In this study, 130 rice accessions of diverse origin were genotyped using 170 SSR markers to identify marker–trait associations with physicochemical traits on eating quality. Analysis of population structure revealed four subgroups in the population. Linkage disequilibrium (LD) patterns and distributions are of fundamental importance for genome-wide mapping associations. The mean r ² value for all intrachromosomal loci pairs was 0.0940. LD between linked markers decreased with distance. Marker–trait associations were investigated using the unified mixed-model approach, considering both population structure (Q) and kinship (K). In total, 101 marker–trait associations (p < 0.05) were identified using 52 different SSR markers covering 12 chromosomes. The results suggest that association mapping in rice is a viable alternative to quantitative trait loci mapping, and detection of new marker–trait associations associated with rice eating quality will also provide important information for marker-assisted breeding and functional analysis of rice grain quality.  相似文献