• Journal of the Korean Applied Science and Technology
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• v.27 no.3
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• pp.282-289
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• 2010

In preparation of silica aerogel-based hybrid coating materials, the combination of hydrophobic aerogel with organic polar binder material is shown to be very limited due to dissimilar surface property between two materials. Accordingly, the surface modification of the aerogel would be required to obtain compatibilized hybrid coating sols with homogeneous dispersion. In this study, the surface of silica aerogel particles was modified by using both surfactant adsorption and heat treatment methods. Four types of surfactants with different molecular weights and HLB values were used to examine the effect of chain length and hydrophilicity. The surface property of the modified aerogel was evaluated in terms of visible observation for aerogel dispersion in water, water contact angle measurement, and FT-IR analysis. In surface modification using surfactants, the effects of surfactant type and content, and mixing time as process parameter on the degree of hydrophilicity for the modified aerogel. In addition, the temperature condition in modification process via heat treatment was revealed to be significant factor to prepare aerogel with highly hydrophilic property.

• Clinical and Experimental Reproductive Medicine
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• v.46 no.3
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• pp.107-111
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• 2019

Objective: Spermatogenesis is a complex process that is regulated by a number of genes, some of which are involved in folate-dependent 1-carbon metabolism. Methionine synthase (encoded by MTR) is a key enzyme participating in this pathway. This study aimed to investigate the relationship of the MTR 2756A > G polymorphism with idiopathic male fertility in the Iranian population. Methods: The participants of this study included 100 men with idiopathic infertility and 100 healthy men as the control group. Genotyping of MTR 2756A > G was performed using the polymerase chain reaction and restriction fragment length polymorphism technique. The obtained data were analyzed using SPSS ver. 20.0 with a level of confidence of p< 0.05. Results: The frequencies of the A and G alleles at this locus were 77% and 23% in infertile patients and 84% and 16% in the control group, respectively. The frequencies of the GG, GA, and AA genotypes were 5%, 36%, and 59% in the infertile patients versus 3%, 27%, and 70% in the control group, respectively. No significant difference was observed in any genetic models. Conclusion: In general, the findings of this study suggest that the MTR 2756A > G single-nucleotide polymorphism is not a predisposing factor for idiopathic infertility in men.

• International Journal of Internet, Broadcasting and Communication
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• v.11 no.3
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• pp.34-40
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• 2019

In spatial modulation (SM), both the signal symbol and spatial symbol, i.e., the index of the antenna from which signal symbol is transmitted, carry information. To increase the number of bits carried by spatial symbols, more transmit antennas are required. In the generalized SM (GSM), the same signal symbol is transmitted from a combination of antennas, resulting in a reduction in the number of antennas required to achieve a given spectral efficiency. In this paper, we propose a rotated-symbol GSM (RGSM), in which the signal symbol is rotated with an angle corresponding to the position of the antenna index within the combination. This increases the number of spatial symbols by a factor equivalent to the length of the antenna combinations of the GSM. Numerically, SM, GSM and RGSM require 128, 17 and 12 transmit antennas to convey seven bits through the spatial symbols. Simulation results show that RGSM performs relatively close to GSM, and in several system settings, their error performances coincide.

• Korean Journal of Crystallography
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• v.7 no.1
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• pp.8-19
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• 1996

Cholestryl Methyl and Propyl Carbonate(CH3OCOOC27H45, C3H7OCOOC27H45) are monoclinic, space group P21, with a=17.014(1), b=7.682(1), c=10.612(1)Å, β=103.05(1)°, Z=2, V=1351.16Å3, Dc=1.09 g/cm3 for methyl carbonate, and with a=13.683(1), b=11.864(2), c=18.904(2)Å, β=106.30(1)°, Z=4, V=2945.4Å3, Dc=1.06 g/cm3, Dm=1.06 g/cm3 for propyl carbonate. The intensity data were collected on an Enraf-Nonius CAD-4 diffractometer with a graphite monochromated Cu-Kα radiation. The structure was solved by direct methods and refined by full matrix least-squares methods. The final R factor was 0.051 for 2323 observed reflections for methyl carbonate and 0.074 for 3323 observed reflections for propyl carbonate. Compared with other cholesteryl derivatives, the cholesteryl ring and tail region of the molecules are normal. The molecules are stacked in clearly separated layers. At center of the layer, there are cholesteryl-C(17) side chain interactions. The interface region between layers is occupied by the loosely packed methyl carbonate chains. The structure of cholesteryl propyl carbonates have two propyl carbonates have two molecules(A, B) that are not related by crystal symmetry and have their tetracyclic system almost parallel to each other. Cholesteryl-cholesteryl interactions between symmetry related A-molecules, and cholesteryl-C(17) side chain interactions between symmetry related B-molecules occur at the center of the layers and these molecules stack along 2₁ screw axes. There are also C(17)chain-carbonate chain and C(17)chain-C(17)chain interactions in the interface region between layers. There is efficient packing between cholesteryl ring systems in propyl carbonates. Temperature ranges of cholesteric mesophases of cholesteryl alkyl cargonates are narrow for methyl, pentyl and hexyl carbonates, and rather broader for ethyl and propyl carbonates. Cholesteryl-isotropic transitions change very little with chain length.

• Journal of Global Scholars of Marketing Science
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• v.17 no.1
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• pp.51-75
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• 2007

Dongdaemun fashion market has been successfully positioned as a main hub for non-brand fashion product distribution in Korea. One of important competitive advantages of Dongdaemun market often quoted by retail researchers is an efficiently managed network system among supply chain members. This study aimed to examine the importance of buyer-supplier relationship elements and supplier properties from buyers' perspectives (small & very small-sized fashion stores in Dongdaemun market), and to identify the determinants of the relationship length between suppliers and buyers. Survey responses of 233 stores were analyzed using EQS 6.1 for Window and SPSSWIN 10.0. The findings could be summarized as follows: First, fashion stores perceived that right delivery as the most important factor, and geographically closeness, design capability, quality, and lower price followed in order. Second, the characteristics of stores such as location, wholesaling versus retailing focusing, monthly sales, and total business length all affected the perceived importance of buyer-supplier relationship. Third, design capacity, communication, power was identified as determinants of actual relationship length with a supplier, while communication and trust were found to be determinants of future expected relationship length.

• Clinical and Experimental Pediatrics
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• v.52 no.4
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• pp.476-480
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• 2009

Purpose : The purpose of this study was to investigate the polymorphisms of the TNF-alpha promotor gene, its susceptibility to Kawasaki disease (KD) and to assess whether the TNF-alpha promotor gene polymorphism was related the risk of coronary artery lesions (CALs). Methods : From January 2003 to January 2007, 51 children (30 boys and 21 girls) with KD and 48 children forming an age-matched control group were studied. DNA from the peripheral blood of all the children was sampled, and the DNA polymorphisms of the 5' flanking regions of the TNF-alpha promoter gene at position -308 [guanine (G) to adenine (A)] were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Then, the relationship between KD and the TNF-alpha promotor gene polymorphisms was evaluated. Results : The A allele frequency of the -308 site of the TNF-alpha promotor gene was 17.6% (9/51) for children with KD and 6.8% (3/48) for the control group children, but this result was not statistically significant. Twenty-four patients experienced CALs within 60 days after the onset of symptoms. KD children with TNF-alpha -308 A allele had lower frequencies of CALs (12.5% versus 22.2%, P>0.05). Conclusion : The DNA polymorphism of the -308 site TNF-alpha gene was not associated with susceptibility to KD and a risk of CALs. Multicenter, large-scale randomized controlled trials are needed for further study.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.5
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• pp.606-612
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• 2012

Insulin-like growth factor-binding protein-5 (IGFBP-5) is one of the six members of IGFBP family, important for cell growth, apoptosis and other IGF-stimulated signaling pathways. In order to explore the significance of IGFBP-5 in cells of the Inner Mongolian Cashmere goat (Capra hircus), IGFBP-5 gene complementary DNA (cDNA) was amplified by reverse transcription polymerase chain reaction (RT-PCR) from the animal's fetal fibroblasts and tissue-specific expression analysis was performed by semi-quantitative RT-PCR. The gene is 816 base pairs (bp) in length and includes the complete open reading frame, encoding 271 amino acids (GenBank accession number JF720883). The full cDNA nucleotide sequence has a 99% identity with sheep, 98% with cattle and 95% with human. The amino acids sequence shares identity with 99%, 99% and 99%, respectively. The bioinformatics analysis showed that IGFBP-5 has an insulin growth factor-binding protein homologues (IB) domain and a thyroglobulin type-1 (TY) domain, four protein kinase C phosphorylation sites, five casein kinase II phosphorylation sites, three prenyl group binding sites (CaaX box). The IGFBP-5 gene was expressed in all the tested tissues including testis, brain, liver, lung, mammary gland, spleen, and kidney, suggesting that IGFBP-5 plays an important role in goat cells.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.39 no.2
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• pp.127-132
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• 2013

The structure activity relationship of polyhydroxylated benzamide derivatives for whitening effects was examined. The adamantyl benzamide derivatives with catechol (3,4-dihydroxyphenyl) of B-ring part showed good anti-melanogenesis activity, but the inhibitory activity of mono-hydroxyphenyl (3-OH or 4-OH) or 3,4-dimethoxyphenyl substituted derivatives was decreased or lost. Therefore the catechol unit was appeared to be the crucial factor for the inhibition of melanogenesis. And the existence of 2-OH of A-ring part had minor influence on the activity, the length of carbon chain between A-ring and B-ring was also not the major factor for the anti-melanogenesis activity.

• Environmental Analysis Health and Toxicology
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• v.25 no.3
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• pp.229-240
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• 2010

During the last decade, perfluorinated compounds (PFCs) have gained more attention due to their toxicity and global distribution. The aim of this study was to examine the distribution and bioaccumulation of perfluorinated compounds (PFCs) in aquatic wildlife effected from a sewage treatment plant. The concentrations of 12 PFCs were determined in water, sediment and fish samples. PFOS were predominantly detected in both ambient environment and fish. In fish, the concentration of PFCs in blood was the highest (i.e., 112.47 ng/mL wet-wt. PFOS) in comparison to other tissues. However, PFOA and PFHpS were highly detected in gonad as 3.87 and 4.58 ng/g wet-wt., respectively. The bioconcentration factor (BCF) of PFCs was greatest in the blood > liver${\cong}$gonad > kidney > gill, and lowest in the muscle tissue. The BCFs of PFUnDA (39,000), PFDA (2,700) and PFOS (1,100) were rated as high values based on wet weight concentration. BCFs increased with increasing the length of the perfluoralkyl chain.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.23
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• pp.10209-10215
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• 2015

To assess the contribution of tumor necrosis factor $(TNF){\beta}$ +252 polymorphisms to risk and prognosis of hepatocellular carcinoma (HCC), we enrolled 150 pairs of sex- and age-matched patients with HCC, patients with cirrhosis alone, and unrelated healthy controls. $TNF{\beta}$ +252 genotypes were determined by polymerase chain reaction with restriction fragment length polymorphism. Multivariate analysis indicated that $TNF{\beta}$ G/G genotype [odds ratio (OR), 3.64; 95%CI, 1.49-8.91], hepatitis B surface antigen (OR, 16.38; 95%CI, 8.30-32.33), and antibodies to hepatitis C virus (HCV) (OR, 39.11; 95%CI, 14.83-103.14) were independent risk factors for HCC. There was an additive interaction between $TNF{\beta}$ G/G genotype and chronic hepatitis B virus (HBV)/HCV infection (synergy index=1.15). Multivariate analysis indicated that factors associated with $TNF{\beta}$ G/G genotype included cirrhosis with Child-Pugh C (OR, 4.06; 95%CI, 1.34-12.29), thrombocytopenia (OR, 6.55; 95%CI, 1.46-29.43), and higher serum ${\alpha}$-fetoprotein concentration (OR, 2.53; 95%CI, 1.14-5.62). Patients with $TNF{\beta}$ G/G genotype had poor cumulative survival (p=0.005). Cox proportional hazard model indicated that $TNF{\beta}$ G/G genotype was a biomarker for poor HCC survival (hazard ratio, 1.70; 95%CI, 1.07-2.69). In conclusion, there are independent and additive effects between $TNF{\beta}$ G/G genotype and chronic HBV/HCV infection on risk for HCC. It is a biomarker for poor HCC survival. Carriage of this genotype correlates with disease severity and advanced hepatic fibrosis, which may contribute to a higher risk and poor survival of HCC. Chronic HBV/HCV infected subjects with this genotype should receive more intensive surveillance for early detection of HCC.