Showing papers by "Kyungpook National University published in 2006"

A strong dose-response relation between serum concentrations of persistent organic pollutants and diabetes: results from the National Health and Examination Survey 1999-2002

Abstract: OBJECTIVE —Low-level exposure to some persistent organic pollutants (POPs) has recently become a focus because of their possible link with the risk of diabetes. RESEARCH DESIGN AND METHODS —Cross-sectional associations of the serum concentrations of POPs with diabetes prevalence were investigated in 2,016 adult participants in the National Health and Nutrition Examination Survey 1999–2002. Six POPs (2,2′,4,4′,5,5′-hexachlorobiphenyl, 1,2,3,4,6,7,8-heptachlorodibenzo- p -dioxin, 1,2,3,4,6,7,8,9-octachlorodibenzo- p -dioxin, oxychlordane, p,p ′-dichlorodiphenyltrichloroethane, and trans -nonachlor) were selected, because they were detectable in ≥80% of participants. RESULTS —Compared with subjects with serum concentrations below the limit of detection, after adjustment for age, sex, race and ethnicity, poverty income ratio, BMI, and waist circumference, diabetes prevalence was strongly positively associated with lipid-adjusted serum concentrations of all six POPs. When the participants were classified according to the sum of category numbers of the six POPs, adjusted odds ratios were 1.0, 14.0, 14.7, 38.3, and 37.7 ( P for trend < 0.001). The association was consistent in stratified analyses and stronger in younger participants, Mexican Americans, and obese individuals. CONCLUSIONS —There were striking dose-response relations between serum concentrations of six selected POPs and the prevalence of diabetes. The strong graded association could offer a compelling challenge to future epidemiologic and toxicological research.

Search for neutral MSSM Higgs bosons at LEP

Abstract: The four LEP collaborations, ALEPH, DELPHI, L3 and OPAL, have searched for the neutral Higgs bosons which are predicted by the Minimal Supersymmetric standard model (MSSM). The data of the four collaborations are statistically combined and examined for their consistency with the background hypothesis and with a possible Higgs boson signal. The combined LEP data show no significant excess of events which would indicate the production of Higgs bosons. The search results are used to set upper bounds on the cross-sections of various Higgs-like event topologies. The results are interpreted within the MSSM in a number of “benchmark” models, including CP-conserving and CP-violating scenarios. These interpretations lead in all cases to large exclusions in the MSSM parameter space. Absolute limits are set on the parameter cosβ and, in some scenarios, on the masses of neutral Higgs bosons.

Link between isoprene and secondary organic aerosol (SOA): Pyruvic acid oxidation yields low volatility organic acids in clouds

Abstract: [1] Aqueous-phase oxidation (in clouds and aerosols) is a potentially important source of organic aerosol and could explain the atmospheric presence of oxalic acid. Methylglyoxal, a water-soluble product of isoprene, oxidizes further in the aqueous phase to pyruvic acid. Discrepancies in the literature regarding the aqueous-phase oxidation of pyruvic acid create large uncertainties in the in-cloud yields of secondary organic aerosol (SOA) and oxalic acid. Resolving the fate of aqueous-phase pyruvic acid is critical to understanding SOA formation through cloud processing of water-soluble products of isoprene, other alkenes and aromatics. In this work, aqueous-phase photochemical reactions of pyruvic acid and hydrogen peroxide at pH values typical of clouds were conducted and demonstrated that photochemical oxidation of pyruvic acid yields glyoxylic, oxalic, acetic and formic acids. Oxalic and glyoxylic acids remain mostly in the particle phase upon droplet evaporation. Thus isoprene is an important precursor of in-cloud SOA formation.

Antihyperglycemic and Antioxidant Properties of Caffeic Acid in db/db Mice

Abstract: This study investigated the blood glucose-lowering effect and antioxidant capacity of caffeic acid in C57BL/KsJ-db/db mice. Caffeic acid induced a significant reduction of the blood glucose and glycosylated hemoglobin levels than the control group. The plasma insulin, C-peptide, and leptin levels in caffeic acid group were significantly higher than those of the control group, whereas the plasma glucagon level was lower. Increased plasma insulin by caffeic acid was attributable to an antidegenerative effect on the islets. Caffeic acid also markedly increased glucokinase activity and its mRNA expression and glycogen content and simultaneously lowered glucose-6-phosphatase and phosphoenolpyruvate carboxykinase activities and their respective mRNA expressions, accompanied by a reduction in the glucose transporter 2 expression in the liver. In contrast to the hepatic glucose transporter 2, adipocyte glucose transporter 4 expression was greater than the control group. In addition, caffeic acid significantly increased superoxide dismutase, catalase, and glutathione peroxidase activities and their respective mRNA levels, while lowering the hydrogen peroxide and thiobarbituric acid reactive substances levels in the erythrocyte and liver of db/db mice. These results indicate that caffeic acid exhibits a significant potential as an antidiabetic agent by suppressing a progression of type 2 diabetic states that is suggested by an attenuation of hepatic glucose output and enhancement of adipocyte glucose uptake, insulin secretion, and antioxidant capacity.

Multiple Crack Detection of Concrete Structures Using Impedance-based Structural Health Monitoring Techniques

Abstract: This paper presents a feasibility study for practical applications of an impedance-based real-time health monitoring technique applying PZT (Lead–Zirconate–Titanate) patches to concrete structures. First, comparison between experimental and analytical studies for damage detection on a plain concrete beam is made. In the experimental study, progressive surface damage inflicted artificially on the plain concrete beam is assessed by using both lateral and thickness modes of the PZT patches. Then, an analytical study based on finite element (FE) models is carried out to verify the validity of the experimental result. Secondly, multiple (shear and flexural) cracks incurred in a reinforced concrete (RC) beam under a third point bending test are monitored continuously by using a sensor array system composed of the PZT patches. In this study, a root mean square deviation (RMSD) in the impedance signatures of the PZT patches is used as a damage indicator.

Sequence-Level Analysis of the Diploidization Process in the Triplicated FLOWERING LOCUS C Region of Brassica rapa

Abstract: Strong evidence exists for polyploidy having occurred during the evolution of the tribe Brassiceae. We show evidence for the dynamic and ongoing diploidization process by comparative analysis of the sequences of four paralogous Brassica rapa BAC clones and the homologous 124-kb segment of Arabidopsis thaliana chromosome 5. We estimated the times since divergence of the paralogous and homologous lineages. The three paralogous subgenomes of B. rapa triplicated 13 to 17 million years ago (MYA), very soon after the Arabidopsis and Brassica divergence occurred at 17 to 18 MYA. In addition, a pair of BACs represents a more recent segmental duplication, which occurred ∼0.8 MYA, and provides an exception to the general expectation of three paralogous segments within the B. rapa genome. The Brassica genome segments show extensive interspersed gene loss relative to the inferred structure of the ancestral genome, whereas the Arabidopsis genome segment appears little changed. Representatives of all 32 genes in the Arabidopsis genome segment are represented in Brassica, but the hexaploid complement of 96 has been reduced to 54 in the three subgenomes, with compression of the genomic region lengths they occupy to between 52 and 110 kb. The gene content of the recently duplicated B. rapa genome segments is identical, but intergenic sequences differ.

Synthesis of metal (Fe or Pd)/alloy (Fe–Pd)‐nanoparticles‐embedded multiwall carbon nanotube/sulfonated polyaniline composites by γ irradiation

Abstract: Composites of multiwall carbon nanotubes (MWCNTs) and sulfonated polyaniline (SPAN) were prepared through the oxidative polymerization of a mixture of aniline, 2,5-diaminobenzene sulfonic acid, and MWCNTs. Fe, Pd, or Fe–Pd alloy nanoparticles were embedded into the MWCNT–SPAN matrix by the reduction of Fe, Pd, or a mixture of Fe and Pd ions with γ radiation. Sulfonic acid groups and the emeraldine form of backbone units in SPAN served as the source for the reduction of the metal ions in the presence of γ radiation. The existence of metallic/alloy particles in the MWCNT–SPAN matrix was further ascertained through characterization by high-resolution transmission electron microscopy (HRTEM), Fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, thermogravimetric analysis, and conductivity measurements. HRTEM pictures clearly revealed the existence of Fe, Pd, and Fe–Pd nanoparticles of various sizes in the MWCNT–SPAN matrices. There were changes in the electronic properties of the MWCNT–SPAN–M composites due to the interaction between the metal nanoparticles and MWCNT–SPAN. Metal-nanoparticle-loaded MWCNT–SPAN composites (MWCNT–SPAN–M; M = Fe, Pd, or Fe–Pd alloy) showed better thermal stability than the pristine polymers. The conductivity of the MWCNT–SPAN–M composites was approximately 1.5 S cm−1, which was much higher than that of SPAN (2.46 × 10−4 S cm−1). Metal/alloy-nanoparticle-embedded, MWCNT-based composite materials are expected to find applications in molecular electronics and other fields. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3355–3364, 2006

Randomized clinical trial of splenectomy versus splenic preservation in patients with proximal gastric cancer.

Abstract: Background: Preservation or removal of the spleen during total gastrectomy for proximal gastric cancer is a matter of debate. Methods: A randomized clinical trial included patients with gastric adenocarcinoma who underwent total gastrectomy either with (104 patients) or without (103) splenectomy. Postoperative outcome in the two groups was compared, including morbidity, mortality and survival. Results: Gastrectomy combined with splenectomy tended to be associated with slightly higher morbidity and mortality rates, a slightly greater incidence of lymph node metastasis at the splenic hilum and along the splenic artery, and marginally better survival, but there were no statistically significant differences between the groups. Splenectomy had no impact on survival in patients with metastatic lymph nodes at the hilum of the spleen or in those with metastatic lymph nodes along the splenic artery. Conclusion: These results do not support the use of prophylactic splenectomy to remove macroscopically negative lymph nodes near the spleen in patients undergoing total gastrectomy for proximal gastric cancer. Copyright © 2006 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.

Serum gamma-glutamyltransferase predicts non-fatal myocardial infarction and fatal coronary heart disease among 28 838 middle-aged men and women

Abstract: Aims Serum gamma-glutamyltransferase (GGT) concentration may be involved in atherosclerosis. This study examined if serum GGT predicted coronary heart disease (CHD), especially differentiating non-fatal myocardial infarction (MI) and fatal CHD event, among the general population or participants with type-2 diabetes. Methods and results A prospective study of 28 838 Finnish men and women aged 25–74 years was performed (1467 incident CHD cases; a median follow-up time of 11.9 years). Serum GGT cutpoints were the 25th, 50th, 75th, and 90th sex-specific percentiles. After adjustment for known cardiovascular risk factors, compared with the lowest GGT category, hazard ratios (HR) were 1.15, 1.25, 1.27, and 1.57 among men and 1.03, 1.22, 1.32, and 1.44 among women in other four GGT categories ( P for trend <0.01, respectively). However, stronger associations were observed among subjects aged <60 and among alcohol drinkers. The strength of association was similar for non-fatal MI and for fatal CHD. Among subjects with type-2 diabetes, the corresponding adjusted HRs were 1.29, 1.57, 1.88, and 1.78 ( P trend=0.03, men and women combined). Conclusion This study suggests an independent mechanism linking serum GGT to CHD among general population. Even though the strength of association appeared to be modest among all subjects, stronger associations were observed among subjects aged <60 and among alcohol drinkers. Especially, measurement of serum GGT among type-2 diabetics may be helpful to predict the future risk of CHD.

Cell-permeable and biocompatible polymeric nanoparticles for apoptosis imaging.

Abstract: Here, we report for the first time cell-permeable and biocompatible polymeric nanoparticles consisting of a polymer conjugated to a near-infrared (NIR) fluorescence (Cy5.5)-linked effector caspase-specific peptide. The close spatial proximity of the NIR fluorochromes in polymeric nanoparticles results in an autoquenched state, but polymer nanoparticles give rise to strong NIR fluorescence signal under apoptotic cells. Thus, the smart polymeric nanoparticle developed here is an attractive probe for real-time imaging of apoptosis in single cells.

Evidence of the purely leptonic decay B-→τ-ν̄τ

Abstract: We present the first evidence of the decay B-→τ-ντ, using 414fb-1 of data collected at the Υ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. Events are tagged by fully reconstructing one of the B mesons in hadronic modes. We detect the signal with a significance of 3.5 standard deviations including systematics and measure the branching fraction to be B(B-→τ-ντ)=(1.79-0.49+0.56(stat) -0.51+0.46(syst))×10-4. This implies that fB=0.229-0.031+0.036(stat)-0. 037+0.034(syst)GeV and is the first direct measurement of this quantity. © 2006 The American Physical Society.

Differential cross sections for gamma plus p -> K++ Y for Lambda and Sigma(0) hyperons

Abstract: High-statistics cross sections for the reactions {gamma}+p{yields}K{sup +}+{lambda} and {gamma}+p{yields}K{sup +}+{sigma}{sup 0} have been measured using CLAS at Jefferson Lab for center-of-mass energies W between 1.6 and 2.53 GeV, and for -0.85

Measurement of two- and three-nucleon short-range correlation probabilities in nuclei

Abstract: The ratios of inclusive electron scattering cross sections of {sup 4}He, {sup 12}C, and {sup 56}Fe to {sup 3}He have been measured at 1 1.4 GeV{sup 2}, the ratios exhibit two separate plateaus, at 1.5 2.25. This pattern is predicted by models that include 2- and 3-nucleon short-range correlations (SRC). Relative to A=3, the per-nucleon probabilities of 3-nucleon SRC are 2.3, 3.1, and 4.4 times larger for A=4, 12, and 56. This is the first measurement of 3-nucleon SRC probabilities in nuclei.

Observation of new states decaying into Λc+K-π+ and Λc+KS0π

Abstract: Reference EPFL-ARTICLE-154577doi:10.1103/PhysRevLett.97.162001View record in Web of Science Record created on 2010-11-05, modified on 2017-05-12

Observation of a χc2′ candidate in γγ→DD̄ production at belle

Abstract: We report on a search for new resonant states in the process gamma gamma -> D (D) over bar. A candidate C-even charmonium state is observed in the vicinity of 3.93 GeV/c(2). The production rate and the angular distribution in the gamma gamma center-of-mass frame suggest that this state is the previously unobserved chi(')(c2), the 2(3)P(2) charmonium state.

The office candy dish: proximity's influence on estimated and actual consumption

Abstract: Although there is increasing interest in how environmental factors influence food intake, there are mixed results and misunderstandings of how proximity and visibility influence consumption volume and contribute to obesity. The objective of this paper is to examine two questions: first, how does the proximity and salience of a food influence consumption volume? Second, are proximate foods consumed more frequently because they are proximate, or are they consumed more frequently because people lose track of how much they eat? The 4-week study involved the chocolate candy consumption of 40 adult secretaries. The study utilized a 2 × 2 within-subject design where candy proximity was crossed with visibility. Proximity was manipulated by placing the chocolates on the desk of the participant or 2 m from the desk. Visibility was manipulated by placing the chocolates in covered bowls that were either clear or opaque. Chocolates were replenished each evening, and placement conditions were rotated every Monday. Daily consumption was noted and follow-up questionnaires were distributed and analyzed. There were main effects for both proximity and visibility. People ate an average of 2.2 more candies each day when they were visible, and 1.8 candies more when they were proximately placed on their desk vs 2 m away. It is important to note, however, that there was a significant tendency for participants to consistently underestimate their daily consumption of proximately placed candies (−0.9) and overestimate their daily consumption of less proximately placed candies (+0.5). These results show that the proximity and visibility of a food can consistently increase an adult's consumption of it. In addition, these results suggest that people may be biased to overestimate the consumption of foods that are less proximate, and to underestimate those that are more proximate. Knowing about these deviation tendencies is important for those attempting effectively monitor their consumption of fat and sugar.