Somatization is known to be more prevalent in Asian than in Western populations. Using a South Korean adolescent and young adult twin sample (N = 1754; 367 monozygotic male, 173 dizygotic male, 681 monozygotic female, 274 dizygotic female and 259 opposite-sex dizygotic twins), the present study aimed to estimate heritability of somatization and to determine common genetic and environmental influences on somatization and hwabyung (HB: anger syndrome). Twins completed self-report questionnaires of the HB symptoms scale and the somatization scale via a telephone interview. The results of the general sex-limitation model showed that 43% (95% CI [36, 50]) of the total variance of somatization was attributable to additive genetic factors, with the remaining variance, 57% (95% CI [50, 64]), being due to individual-specific environmental influences, including measurement error. These estimates were not significantly different between the two sexes. The phenotypic correlation between HB and somatization was .53 (p < .001). The bivariate model-fitting analyses revealed that the genetic correlation between the two symptoms was .68 (95% CI [.59, .77]), while the individual-specific environmental correlation, including correlated measurement error, was .41 (95% CI [.34, .48]). Of the additive genetic factors of 43% that influence somatization, approximately half (20%) were associated with those related to HB, with the remainder being due to genes unique to somatization. A substantial part (48%) of individual environmental variance in somatization was unrelated to HB; only 9% of the environmental variance was shared with HB. Our findings suggest that HB and somatization have shared genetic etiology, but environmental factors that precipitate the development of HB and somatization may be largely independent from each other.

Residual stress is generally evaluated using indentation by comparing the indentation curves of stressed and stress-free states. Here, we suggest a new method that can evaluate surface residual stress without indentation testing on stress-free specimen using stress-independent indentation parameters and an analysis of indentation contact morphology for the stress-free state. We found that several indentation parameters are independent of the stress by Vickers indentation testing on various stress states. The indentation contact morphology can be represented by indentation parameters including stress-independent ones, and by applying the stress-independent parameters obtained from the stressed state to the indentation contact depth function, we can estimate an indentation curve for stress-free state. The estimated curve matches well with the experimental stress-free indentation curve, and it was also confirmed that the applied stress values evaluated by comparing the estimated curve with the stressed indentation curve agree well with the reference values obtained from strain gauge.

Clonorchis sinensis (C. sinensis), a trematode parasite that invades the hypoxic hepatobiliary tract of vertebrate hosts requires a considerable amount of oxygen for its sexual reproduction and energy metabolism. However, little is known regarding the molecular mechanism of C. sinensis involved in the adaptation to the hypoxic environments. In this study, we investigated the molecular structures and induction patterns of hypoxia-inducible factor-1α (HIF-1α) and other basic helix–loop–helix and Per–Arnt–Sim (bHLH–PAS) domain-containing proteins such as HIF-1β, single-minded protein and aryl hydrocarbon receptor, which might prompt adaptive response to hypoxia, in C. sinensis. These proteins possessed various bHLH–PAS family-specific domains. Expression of C. sinensis HIF-1α (CsHIF-1α) was highly induced in worms which were either exposed to a hypoxic condition or co-incubated with human cholangiocytes. In addition to oxygen, nitric oxide and nitrite affected the CsHIF-1α expression depending on the surrounding oxygen concentration. Treatment using a prolyl hydroxylase-domain protein inhibitor under 20%-oxygen condition resulted in an increase in the CsHIF-1α level. Conversely, the other bHLH–PAS genes were less responsive to these exogenous stimuli. We suggest that nitrite and nitric oxide, as well as oxygen, coordinately involve in the regulation of HIF-1α expression to adapt to the hypoxic host environments in C. sinensis.

The present study aimed to estimate heritability of Hwabyung (HB) symptoms in adolescent and young adult twins in South Korea. The sample included 1,601 twins consisting of 143 pairs of monozygotic male (MZM), 67 pairs of dizygotic male (DZM), 295 pairs of monozygotic female (MZF), 114 pairs of dizygotic female (DZF), and 117 pairs of opposite-sex dizygotic (OSDZ) twins and 129 twins with non-participating co-twins (mean age = 19.1 ± 3.1 years; range: 12–29 years). An HB symptom questionnaire was given to twins via a telephone interview. Consistent with the literature of HB, the mean level of HB was significantly higher in females than in males. Maximum likelihood twin correlations for HB were 0.31 (95% CI [0.16, 0.45]) for MZM, 0.19 (95% CI [-0.05, 0.41]) for DZM, 0.50 (95% CI [0.41, 0.58]) for MZF, 0.28 (95% CI [0.11, 0.44]) for DZF, and 0.23 (95% CI [0.05, 0.40]) for OSDZ twins. These patterns of twin correlations suggested the presence of additive genetic influences on HB. Model-fitting analysis showed that additive genetic and individual-specific environmental influences on HB were 44% (95% CI [37, 51]) and 56% (95% CI [49, 63]), respectively. Shared environmental influences were not significant. These parameter estimates were not significantly different between two sexes, and did not change significantly with age in the present sample, suggesting that genetic and environmental influences on HB in both sexes are stable across adolescence and young adulthood.

Many transgenic domestic animals have been developed to produce therapeutic proteins in the mammary gland, and this approach is one of the most important methods for agricultural and biomedical applications. However, expression and secretion of a protein varies because transgenes are integrated at random sites in the genome. In addition, distal enhancers are very important for transcriptional gene regulation and tissue-specific gene expression. Development of a vector system regulated accurately in the genome is needed to improve production of therapeutic proteins. The objective of this study was to develop a knock-in system for expression of human fibroblast growth factor 2 (FGF2) in the bovine β-casein gene locus. The F2A sequence was fused to the human FGF2 gene and inserted into exon 3 of the β-casein gene. We detected expression of human FGF2 mRNA in the HC11 mouse mammary epithelial cells by RT-PCR and human FGF2 protein in the culture media using western blot analysis when the knock-in vector was introduced. We transfected the knock-in vector into bovine ear fibroblasts and produced knock-in fibroblasts using the clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 system. Moreover, the CRISPR/Cas9 system was more efficient than conventional methods. In addition, we produced knock-in blastocysts by somatic cell nuclear transfer using the knock-in fibroblasts. Our knock-in fibroblasts may help to create cloned embryos for development of transgenic dairy cattle expressing human FGF2 protein in the mammary gland via the expression system of the bovine β-casein gene.

Despite recent reports regarding the biology of cytosine methylation in Schistosoma mansoni, the impact of the regulatory machinery remains unclear in diverse platyhelminthes. This ambiguity is reinforced by discoveries of DNA methyltransferase 2 (DNMT2)-only organisms and the substrate specificity of DNMT2 preferential to RNA molecules. Here, we characterized a novel DNA methyltransferase, named CsDNMT2, in a liver fluke Clonorchis sinensis. The protein exhibited structural properties conserved in other members of the DNMT2 family. The native and recombinant CsDNMT2 exhibited considerable enzymatic activity on DNA. The spatiotemporal expression of CsDNMT2 mirrored that of 5-methylcytosine (5 mC), both of which were elevated in the C. sinensis eggs. However, CsDNMT2 and 5 mC were marginally detected in other histological regions of C. sinensis adults including ovaries and seminal receptacle. The methylation site seemed not related to genomic loci occupied by progenies of an active long-terminal-repeat retrotransposon. Taken together, our data strongly suggest that C. sinensis has preserved the functional DNA methylation machinery and that DNMT2 acts as a genuine alternative to DNMT1/DNMT3 to methylate DNA in the DNMT2-only organism. The epigenetic regulation would target functional genes primarily involved in the formation and/or maturation of eggs, rather than retrotransposons.

We present experimental evidence of enhancement of thermoelectric properties in tellurium (Te) nanoparticle-embedded bismuth antimony telluride (BiSbTe) alloys. Bi0.5Sb1.5Te3 films with a high density of Te particles of 10–20 nm size were prepared by growth of alternating multilayers of ultrathin Te and Bi0.5Sb1.5Te3. As the amount of Te nanoinclusions increased up to ∼15%, the Seebeck coefficient and thermoelectric power factor were increased. Based on the concept of band bending at heterointerfaces as a carrier energy filter, the energy relaxation calculation was made to confirm that the Te nanoinclusions result in a carrier energy filtering effect in p-type bismuth antimony telluride. In addition, thermal conductivities were reduced in the Te-embedded samples, permitting possible further enhancement of the thermoelectric figure of merit. The advantages of Te nanoinclusions in p-type Bi0.5Sb1.5Te3alloys on thermoelectric performance are experimentally realized by both electron- and phonon scattering.

Oxidative stress may be affected by lead exposure as well as antioxidants, yet little is known about the interaction between dietary antioxidants and blood lead levels (BLL) on oxidative stress level. We investigated the interaction between dietary antioxidants and BLL on oxidative stress level. As part of the Biomarker Monitoring for Environmental Health conducted in Seoul and Incheon, Korea, between April and December 2005, we analysed data from 683 adults (female = 47·4 %, mean age 51·4 (sd 8·4) years) who had complete measures on BLL, dietary intakes and oxidative stress marker (urinary 8-hydroxy-2′-deoxyguanosine (8-OHdG)). Dietary intakes were assessed by a validated semi-quantitative FFQ, BLL was measured using atomic absorption spectrophotometry, and 8-OHdG by ELISA. Multivariate linear regression analyses were used to evaluate the influence of BLL on the association between dietary antioxidants and 8-OHdG. Geometric means of BLL and 8-OHdG concentrations were 4·1 (sd 1·5) μg/dl and 5·4 (sd 1·9) μg/g creatinine, respectively. Increases of vitamins C and E were significantly associated with the decrease of log10 8-OHdG in the adults from the lowest quartile of the BLL group ( ≤ 3·18 μg/dl, geometric mean = 2·36 μg/dl) than those of the highest quartile BLL group (>5·36 μg/dl, geometric mean = 6·78 μg/dl). Regarding antioxidant-related foods, vegetables excluding kimchi showed a higher inverse relationship with 8-OHdG in the lowest quartile BLL group than the highest group. These findings suggest a rationale for lowering the BLL and increasing the intake of dietary antioxidants in the urban population in Korea.

Anthropogenic land use within watersheds has substantial effects on aquatic habitats and biological communities. From September 2006 to December 2008, we investigated the effects of land use on benthic macroinvertebrate communities by comparing Song Stream and Odae Stream, two adjacent mountain streams in Korea whose watersheds have different land use patterns. Song Stream is significantly disturbed by agricultural activities in the watershed, whereas Odae Stream is relatively undisturbed and is surrounded by a well-conserved forest area. Song Stream had significantly higher levels of all nutrients and sediment-related factors due to the adjacent agricultural area. As a result, Song Stream had markedly lower species community indices, such as taxa richness and abundance. In Song Stream, macroinvertebrate scrapers and predators were most adversely affected, whereas collector-gatherers became a dominant group. Based on correlation and multivariate analyses, total dissolved solids had the strongest negative relationship with macroinvertebrate assemblages, followed by electrical conductivity, total nitrogen, and pH. The proportion of cobble in stream substrate was positively related to the richness and abundance of macroinvertebrates. Our results indicate that disturbances caused by agricultural land use, particularly sand deposition, had significant adverse effects on macroinvertebrate habitats and on the biotic integrity of benthic macroinvertebrate communities.

We investigated the pressure dependence of the inductive coupled plasma (ICP) oxidation on the electrical characteristics of the thin oxide films. Activation energies and electron temperatures with different pressures were estimated. To demonstrate the pressure effect on the plasma oxide quality, simple N type metal-oxide-semiconductor (NMOS) transistors were fabricated and investigated in a few electrical properties. At higher pressure than 200mTorr, plasma oxide has a slightly higher on-current and a lower interfacial trap density. The on-current gain seems to be related to the field mobility increase and the lower defective interface to the electron temperature during oxidation.

Permeable pavement systems to alleviate urban heat island phenomena are suitable for a variety of residential, commercial and industrial applications, yet are confined to light duty and infrequent usage. And Most of study for the permeable pavement is limited to asphalt pavement. Also, immense quantities of coal combustion by-products are produced every year, but only a small fraction of them are currently utilized, particularly bottom ash which is used in this study. In this study, we aimed at the development of new permeable and water absorbing pavement blocks. Optimum conditions for compressive strength and water absorption, volume of water retention and porosity characteristics were investigated for production of the pavement blocks from bottom ash. In addition, removal efficiencies of pollutants in road runoff by the pavement blocks were compared under various conditions. Experimental results showed that the compressive strengths and water absorption after 7 and 28days for blocks were 12˜15MPa and 18%, respectively. Also, turbidity and heavy metals in rainwater were successfully removed. So, further study on the durability test such as the effect of surface fouling by dust is possibly needed prior to use the new bricks as construction materials.

Highly (100) oriented Pb(Zr,Ti)O3 [PZT] films were fabricated using lanthanum nitrate/nickel acetate double layers as a buffer layer, regardless of the other deposition conditions, such as the pyrolysis temperature, pyrolysis time, annealing temperature, and heating rate. The buffer layer was also acted as a very effective barrier against Pb-Si interdiffusion, thus allowing for the direct deposition of PZT films on Si, SiO2/Si, and glass substrates. The strong orientation was attributed to the formation of a crystalline intermediate phase between the PZT and lanthanum nitrate during annealing. The lanthanum nitrate/nickel acetate double layers became a lanthanum nickel oxide (LaNiO3), which shows good electrical conductivity, after an annealing process at 650°C. The nature and the role of lanthanum nitrate buffer as a layer for the growth of highly (100) oriented PZT films have been studied. The dielectric, ferroelectric, piezoelectric and electrooptic properties of the highly (100) oriented PZT films with a lanthanum nitrate/nickel acetate buffer layer were measured and compared with the values measured from the (111) and (100) oriented PZT films deposited without buffer layer.

NiCr films were thermally evaporated on the Mn-Ni-Co-O thick-film substrates. The NiCr/Mn-Ni-Co-O bi-layer systems were tested in a thermal shock chamber with three temperature differences of 150, 175 and 200°C. The systems were considered to have failed when the sheet resistance of NiCr films changed by 30% relative to an initial value. As the cyclic repetition of thermal shock increased, the sheet resistance of NiCr coatings increased. The Coffin-Manson equation was applied to the failure mechanism of cracking of NiCr coatings and the SEM observation of cracks and delamination in NiCr coatings due to thermal cycling agreed well with the failure mechanism.