Effect of low concentrations of hydrogen peroxide on the contractile responses of rat detrusor smooth muscle strips

Han, J.H.,Lee, M.Y.,Lee, S.Y.,Chang, I.H.,Kim, H.J.,Kim, W.,Myung, S.C. North-Holland ; Elsevier Science Ltd 2010 european journal of pharmacology Vol.638 No.1

This study was designed to determine how the contractility of rat detrusor smooth muscle strips changes in the presence of low concentrations of hydrogen peroxide (H<SUB>2</SUB><SUB>2</SUB>. The strips were dissected from the base of Sprague-Dawley rat bladders and their contractile responses to a cumulative increase in H<SUB>2</SUB><SUB>2</SUB>concentration (3x10<SUP>-6</SUP>3x10<SUP>-2</SUP>%) were measured. How the duration of exposure to the fixed concentration of 3x10<SUP>-4</SUP>% H<SUB>2</SUB><SUB>2</SUB>affected contractility was also examined. Moreover, the effect of 3x10<SUP>-4</SUP>% H<SUB>2</SUB><SUB>2</SUB>pretreatment on the response to cumulative increases in the concentrations of phenylephrine or acetylcholine (10<SUP>-8</SUP>10<SUP>-4</SUP>) was assessed. To elucidate the mechanism by which H<SUB>2</SUB><SUB>2</SUB>induced contraction, we examined the effect of pretreatment with 10nM Y-27632, 10μM indomethacin, 10μM SQ29548, 10μM verapamil, 10μM vitamin E, or 1μM Bay-K 8644 on the contractile responses generated by cumulatively increasing the concentration of H<SUB>2</SUB><SUB>2</SUB> H<SUB>2</SUB><SUB>2</SUB>induced contractile responses in Ca<SUP>2+</SUP>free physiological solution were also examined. Low concentrations of H<SUB>2</SUB><SUB>2</SUB>increased the contractile responses of the strips in a dose-dependent manner but increasing treatment duration decreased these responses. H<SUB>2</SUB><SUB>2</SUB>pretreatment significantly augmented the contraction induced by phenylephrine (P<0.05) but had no effect on the response to acetylcholine. Pretreatment with Y-27632, indomethacin, vitamin E, verapamil, and Bay-K 8644 significantly inhibited the H<SUB>2</SUB><SUB>2</SUB>induced contraction (P<0.05). SQ 29548-pretreatment had no effect. H<SUB>2</SUB><SUB>2</SUB>could not increase the contractile responses in Ca<SUP>2+</SUP>free physiological solution. Thus, low concentrations of H<SUB>2</SUB><SUB>2</SUB>may directly affect detrusor smooth muscles and thereby induce detrusor overactivity.

A multi-virus detectable microfluidic electrochemical immunosensor for simultaneous detection of H1N1, H5N1, and H7N9 virus using ZnO nanorods for sensitivity enhancement

Han, J.H.,Lee, D.,Chew, C.H.C.,Kim, T.,Pak, J.J. Elsevier Sequoia 2016 Sensors and actuators. B Chemical Vol.228 No.-

This paper describes a multi-detectable and nano-flow immunosensor based on ZnO nanorods (NRs) grown on the inner surface of PDMS sensor region for sensing H1N1, H5N1, and H7N9 influenza viruses simultaneously using electrochemical method. Nanostructured ZnO NRs with a high isoelectric point (IEP ~9.5) tend to interact electrostatically with proteins with lower IEP such as H1N1, H5N1, and H7N9 antibodies. ZnO NRs were hydrothermally grown on the upper inner surface of the nano-flow PDMS sensor region. The forementioned three influenza viruses were successfully detected from three separate sensing regions by measuring the oxidation current of 3,3',5,5'-tetramethylbenzidine (TMB) by horseradish peroxidase (HRP) conjugated on capture antibody of those influenza viruses when proper potential was applied. The proposed immunosensors were evaluated using 1pg/ml, 10pg/ml, 100pg/ml, 1ng/ml, and 10ng/ml of H1N1, H5N1, and H7N9 antigens by amperometry. These immunosensors showed high selectivity toward H1N1, H5N1, and H7N9, which was successfully confirmed by distinguishing the target virus individually from a mixture of three virus antigens. A low limit of detection was demonstrated by detecting as low as 1pg/ml of each virus and it is believed that this was possible by enhancing the sensitivity with the ZnO NRs grown on the PDMS surface in the sensing region. The steady-state oxidation current output linearly increased with respect to the logarithm of the H1N1, H5N1, and H7N9 virus concentrations in the range of 1-10ng/ml.

분만 후 모돈의 행동적 회복과 포유자돈의 행동적 발달

전중환,김동주,한지훈,연성찬,장홍희 한국동물자원과학회 2003 한국축산학회지 Vol.45 No.6

We investigated postpartum behaviors of sows and their litters. The aim of this study was to determine the behavioral recovery of sows and behavioral development of their piglets postpartum. Five multiparous sows(Landrace × Yorkshire) and their litters were studied over a period of 5 days postpartum. The litter size varied from 8 to 13 with a mean of 11.2 piglets. The behaviors of sows and their piglets were recorded using five CCD cameras, a multiplexer and a time lapsed VCR. The videotapes were scanned every 2 min to obtain an instantaneous behavioral sample. In the behaviors of sows, ?Lying ventrally? increased from 1h postpartum to 26g postpartum, then decreased gradually, and stabilized after 80h postpartum. ?Lying ventrally? decreased from 1h postpartum to 26h postpartum and stabilized after 80h postpartum. ?Standing, drinking and feeding? increased from 1h postpartum to 23h postpartum, then decreased gradually, and increased again from 60h postpartum. ?Sitting? increased from 1h postpartum to 46h postpartum and then decreased. In the behaviors of piglets, ?Lying? increased rapidly from 1h postpartum to 45h postpartum, and then was maintained at an almost constant level. ?Massaging and Suckling? decreased rapidly from 1h postpartum to 36g postpartum, and then was maintained at an almost constant level. ?Walking? increased from 1h postpartum to 21h postpartum, then decreased gradually. These results suggest that the behavioral recovery of the sow is almost completed at 80h postpartum and that the behavioral development of the piglet is almost completed at 45h postpartum.

Urinary concentration of transforming growth factor-&bgr;-inducible gene-h3(&bgr;ig-h3) in patients with Type 2 diabetes mellitus

Cha, D. R.,Kim, I. S.,Kang, Y. S.,Han, S. Y.,Han, K. H.,Shin, C.,Ji, Y. H.,Kim, N. H. Blackwell Science Ltd 2005 Diabetic medicine Vol.22 No.1

<P>Abstract</P><P>Aims </P><P>The expression of TGF&bgr;-inducible gene h3(&bgr;ig-h3) has been used to assess the biological activity of TGF&bgr; in the kidney. In this study, we investigated whether the urinary concentration of &bgr;ig-h3 is associated with diabetic nephropathy in patients with Type 2 diabetes mellitus. We also evaluated the relationship between the urinary concentration of &bgr;ig-3 and proteinuria and microalbuminuria (AER) in a normal healthy population and in Type 2 diabetes patients.</P><P>Methods </P><P>Four hundred and seventy-nine Type 2 diabetic patients without non-diabetic kidney diseases and 528 healthy control subjects were enrolled. The study subjects were divided into five groups: a non-diabetic healthy control group with normal ACR (<I>n</I> = 443), a non-diabetic healthy control group with microalbuminuria (<I>n</I> = 85), a normoalbuminuric diabetic group (<I>n</I> = 198), a microalbuminuric diabetic group (<I>n</I> = 155) and an overt proteinuria group (<I>n</I> = 126). Urinary levels of &bgr;ig-h3 were measured by enzyme-linked immunosorbent assay.</P><P>Results </P><P>(i) Urinary excretion of &bgr;ig-h3 was significantly higher in the diabetic groups than in the controls, even in the normoalbuminuric stage (25.02 ± 8.84 vs. 18.67 ± 6.56, <I>P</I> = 0.03). In diabetic patients, urinary &bgr;ig-h3 levels increased significantly as diabetic nephropathy advanced (25.02 ± 8.84 vs. 34.06 ± 24.55 vs. 169.63 ± 57.33, <I>P</I> < 0.001). (ii) Proteinuria was found to be significantly correlated with urinary &bgr;ig-h3 (healthy control; <I>r</I> = 0.137, <I>P</I> = 0.019, diabetic patients; <I>r</I> = 0.604, <I>P</I> < 0.001). ACR was also found to be significantly related with urinary &bgr;ig-h3 in diabetic patients (<I>r =</I> 0.383, <I>P</I> = 0.006). (iii) In diabetic patients, urinary &bgr;ig-h3 was significantly related with systolic and diastolic blood pressure (systolic blood pressure: <I>r</I> = 0.436, <I>P</I> = 0.024; diastolic blood pressure, <I>r</I> = 0.365, <I>P</I> = 0.042), total cholesterol and HbA<SUB>1c</SUB> (cholesterol: <I>r</I> = 0.169, <I>P</I> = 0.03, HbA<SUB>1c</SUB>; <I>r</I> = 0.387, <I>P</I> = 0.044). Logistic regression analyses showed that urinary &bgr;ig-h3 was associated with a significant increase in the risk of microalbuminuria and proteinuria in diabetic patients.</P><P>Conclusions </P><P>Longitudinal monitoring of urinary &bgr;ig-h3 may improve the likelihood of detecting diabetic nephropathy at an earlier stage and &bgr;ig-h3 could be a sensitive marker of diabetic kidney disease progression.</P>

The mechanism of hydrogen embrittlement in intercritically annealed medium Mn TRIP steel

Han, J.,Nam, J.H.,Lee, Y.K. Elsevier Science 2016 Acta materialia Vol.113 No.-

<P>The objective of this study was to investigate the mechanisms of hydrogen embrittlement (HE) in intercritically annealed medium Mn steel. For this purpose, both hot-rolled and cold-rolled Fe-7Mn-0.1C-0.5Si (wt.%) steels were annealed at 640 degrees C for 30 min. The annealed specimens had a dual-phase microstructure of retained austenite (gamma R) and ferrite (alpha) with different morphologies; a lath shape for the hot-rolled and annealed (HRA) specimen and a globular shape for the cold-rolled and annealed (CRA) specimen. Although the difference in microstructural morphology did not influence the H permeation, it significantly affected the HE behavior. The H-charged HRA (HRA(H)) specimen was fractured by inter granular cracking occurring along the boundaries of prior gamma grains by the H-enhanced decohesion (HEDE) mechanism. The intergranular cracking leaved both flat and rugged facets, which appeared at the prior gamma grain boundaries without and with gamma R, respectively. The H-charged CRA (CRA(H)) specimen was fractured to leave both dimples filled with grains and empty dimples at the fractured surface. The dimples filled with grains were generated by intergranular cracking occurring along the boundaries of gamma R grains by the HEDE mechanism. The empty dimples were made by intragranular cracking occurring inside the alpha grains by the H-enhanced local plasticity (HELP) mechanism. The CRA(H) specimen exhibited a smaller elongation loss than the HRA(H) specimen because cracks were propagated by frequently changing their direction along the boundaries of nano-sized gamma R grains or into alpha grains. (C) 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.</P>

Photocatalytic H2 production on trititanate nanotubes coupled with CdS and platinum nanoparticles under visible light: revisiting H2 production and material durability

Park, H.,Ou, H. H.,Kim, M.,Kang, U.,Han, D.,Hoffmann, M. Royal Society of Chemistry 2017 Faraday discussions Vol.198 No.-

<P>The photocatalytic production of molecular hydrogen (H-2) on ternary composites of Pt, CdS, and sodium trititanate nanotubes (NaxH2-xTi3O7, TNTs) is examined in an aqueous 2-propanol (IPA) solution (typically 5 vol%) at a circum-neutral pH under visible light (lambda > 420 nm). The H-2 production rates are dependent on the Pt-loading level, and the optimum production rate in the Pt/CdS/TNTs is approximately six times higher than that in Pt/CdS/TiO2. A D2O solution containing 5 vol% IPA leads only to the production of D-2 molecules, whereas increasing the IPA amount to 30 vol% leads to the production of DH molecules. This indicates that the Pt/CdS/TNTs composites enable H-2 production via true water splitting under our typical experimental conditions. X-ray photoelectron spectroscopy (XPS) analyses of the as-synthesized Pt/CdS/TNTs and those used for 6 and 12 h show that metallic Pt on the CdS/TNTs is less susceptible to oxidation than Pt on CdS/TiO2. In addition, photocorrosion of CdS (i.e., sulfate formation) is significantly inhibited during the photocatalytic H-2 production reactions in the Pt/CdS/TNTs because of the efficient charge transfer via the TNTs framework. The Pt/CdS/TNTs samples are thermally more stable than Pt/CdS/TiO2 and CdS/TNTs, effectively inhibiting the formation of CdO during the thermal synthesis. Detailed surface characterizations of the as-synthesized ternary composites are performed using Xray diffraction, transmission electron microscopy, energy dispersive spectroscopy, and XPS.</P>

Decomposition of hydrogen sulfide (H₂S) on Ni(100) and Ni₃Al(100) surfaces from first-principles

Hernandez, J.M.,Lim, D.H.,Nguyen, H.V.P.,Yoon, S.P.,Han, J.,Nam, S.W.,Yoon, C.W.,Kim, S.K.,Ham, H.C. Pergamon Press ; Elsevier Science Ltd 2014 International journal of hydrogen energy Vol.39 No.23

Spin-polarized density functional theory studies of hydrogen sulfide (H<SUB>2</SUB>S) adsorption and decomposition on Ni(100) and Ni<SUB>3</SUB>Al(100) surfaces were conducted to understand the aluminum (Al) alloying effect on H<SUB>2</SUB>S dissociation. For such purpose, we first determined the near surface structure of fully ordered Ni<SUB>3</SUB>Al alloy along the [100] direction by calculating the Al segregation energy to the surface and then examined the adsorption energies of the adsorbates (H<SUB>2</SUB>S, HS, S, and H) and the activation barriers for the H<SUB>2</SUB>S and HS decomposition by using Climbing Image-Nudged Elastic Band method. We found that regardless of the way to terminate the surface, Al atom in bimetallic Ni<SUB>3</SUB>Al(100) tends to exist in the first surface layer, rather than in the second or third layer, and the Ni<SUB>3</SUB>Al(100) surface can substantially retard the H<SUB>2</SUB>S decomposition by reducing the adsorption energy of sulfur compounds compared to the pure Ni(100) case. Finally, we presented how the Al in Ni<SUB>3</SUB>Al modifies the activity of surface Ni atoms toward the sulfur compounds by calculating the local density of states and charge distribution in alloying components. This work hints the importance of knowing how to properly tailor the reactivity of Ni based materials to enhance the resistance for sulfur poisoning.

A new linking ligand with pyridyl-carboxylate terminals and its coordination polymers: Synthesis, structures, and properties of HL, [AgL]_∼, {[CdL₂](CH₃OH)(H₂O)}_∼, and [MnL₂(CH<sub>3</sub

Han, S.H.,Lee, S.W. Pergamon Press 2012 Polyhedron Vol.31 No.1

A new linking ligand with pyridyl-carboxylate terminals {HL=(3-py)-CH?N-CH<SUB>2</SUB>-C<SUB>6</SUB>H<SUB>4</SUB>-COOH} was prepared from 3-pyridinecarboxaldehyde and 4-(aminomethyl)benzoic acid by Schiff-base condensation. Under solvothermal conditions in methanol, the ligand reacted with AgBF<SUB>4</SUB>, Cd(NO<SUB>3</SUB>)<SUB>2</SUB>.4H<SUB>2</SUB>O, and Mn(OAc)<SUB>2</SUB>.4H<SUB>2</SUB>O to produce a 3-D Ag coordination polymer [AgL]<SUB>∼</SUB> (1), a 2-D Cd coordination polymer {[CdL<SUB>2</SUB>](CH<SUB>3</SUB>OH)(H<SUB>2</SUB>O)}<SUB>∼</SUB> (2), and a 2-D Mn coordination polymer [MnL<SUB>2</SUB>(CH<SUB>3</SUB>OH)]<SUB>∼</SUB> (3), respectively. In all coordination polymers, both the terminal pyridyl and terminal carboxylate groups in the ligand coordinate to metal ions to form coordination polymers. The central imine nitrogen in the ligand coordinates to the metal ion (Ag<SUP>+</SUP>) in coordination polymer 1, but it does not coordinate to the metal ions in coordination polymers 2 and 3. Coordination polymer 2 contains guest molecules (water and methanol molecules), whereas coordination polymers 1 and 3 do not.

Fucoidan protects mesenchymal stem cells against oxidative stress and enhances vascular regeneration in a murine hindlimb ischemia model

Han, Y.s.,Lee, J.H.,Jung, J.S.,Noh, H.,Baek, M.J.,Ryu, J.M.,Yoon, Y.M.,Han, H.J.,Lee, S.H. Elsevier/North-Holland Biomedical Press 2015 INTERNATIONAL JOURNAL OF CARDIOLOGY Vol.198 No.-

Background: Mesenchymal stem cells (MSCs) have the potential to differentiate into multiple cell lineages. Given this potential for tissue regeneration, MSC-based therapeutic applications have been considered in recent years. However, ischemia-induced apoptosis has been reported to be one of the main causes of MSC death following transplantation. The primary objective of this study was to determine whether a natural antioxidant, fucoidan, could protect MSCs from ischemia-induced apoptosis in vitro and in vivo. Furthermore, we investigated the mechanism of action of fucoidan's anti-ischemic effect in MSCs. Methods and result: Pre-treatment with fucoidan (10μg/mL) suppressed the increase in H<SUB>2</SUB>O<SUB>2</SUB>-induced reactive oxygen species (ROS) levels and drastically reduced apoptotic cell death in MSCs. Fucoidan inhibited the activation of the pro-apoptotic proteins p38-mitogen-activated protein kinase (MAPK), Jun N-terminal kinase (JNK), and caspase-3, and augmented the expression of the anti-apoptosis protein cellular inhibitor of apoptosis (cIAP). Moreover, fucoidan significantly increased manganese superoxide dismutase (MnSOD) expression and decreased cellular ROS levels via the Akt pathway, resulting in enhanced cell survival. In a murine hindlimb ischemia model, transplanted fucoidan-treated MSCs showed significantly enhanced cell survival and proliferation in ischemic tissues. Functional recovery and limb salvage also remarkably improved in mice injected with fucoidan-stimulated MSCs compared with mice injected with non-stimulated MSCs. Conclusion: Taken together, these results show that fucoidan protects MSCs from ischemia-induced cell death by modulation of apoptosis-associated proteins and cellular ROS levels through regulation of the MnSOD and Akt pathways, suggesting that fucoidan could be powerful therapeutic adjuvant for MSC-based therapy in ischemic diseases.

Tuning microcavities in thermally rearranged polymer membranes for CO₂ capture

Han, S. H.,Kwon, H. J.,Kim, K. Y.,Seong, J. G.,Park, C. H.,Kim, S.,Doherty, C. M.,Thornton, A. W.,Hill, A. J.,Lozano, Á,. E.,Berchtold, K. A.,Lee, Y. M. The Royal Society of Chemistry 2012 Physical Chemistry Chemical Physics Vol.14 No.13

<P>Microporous materials have a great importance in catalysis, delivery, storage and separation in terms of their performance and efficiency. Most microporous materials are comprised of inorganic frameworks, while thermally rearranged (TR) polymers are a microporous organic polymer which is tuned to optimize the cavity sizes and distribution for difficult separation applications. The sub-nano sized microcavities are controlled by <I>in situ</I> thermal treatment conditions which have been investigated by positron annihilation lifetime spectroscopy (PALS). The size and relative number of cavities increased from room temperature to 230 °C resulting in improvements in both permeabilities and selectivities for H<SUB>2</SUB>/CO<SUB>2</SUB> separation due to the significant increase of gas diffusion and decrease of CO<SUB>2</SUB> solubility. The highest performance of the well-tuned TR-polymer membrane was 206 Barrer for H<SUB>2</SUB> permeability and 6.2 of H<SUB>2</SUB>/CO<SUB>2</SUB> selectivity, exceeding the polymeric upper bound for gas separation membranes.</P> <P>Graphic Abstract</P><P>Thermally rearranged polybenzoxazoles with tuned cavities for hydrogen purification and carbon dioxide separation even at high temperature were developed to apply for a syn gas separation. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c2cp23729f'> </P>