Effects of Addition Level and Chemical Type of Propionate Precursors in Dicarboxylic Acid Pathway on Fermentation Characteristics and Methane Production by Rumen Microbes In vitro

Li, X.Z.,Yan, C.G.,Choi, S.H.,Long, R.J.,Jin, G.L.,Song, Man K. Asian Australasian Association of Animal Productio 2009 Animal Bioscience Vol.22 No.1

Two in vitro experiments were conducted to examine the effects of propionate precursors in the dicarboxylic acid pathway on ruminal fermentatation characteristics, $CH_4$ production and degradation of feed by rumen microbes. Fumarate or malate as sodium salts (Exp. 1) or acid type (Exp. 2) were added to the culture solution (150 ml, 50% strained rumen fluid and 50% artificial saliva) to achieve final concentrations of 0, 8, 16 and 24 mM, and incubated anaerobically for 0, 1, 3, 6, 9 and 12 h at $39^{\circ}C$. For both experiments, two grams of feed consisting of 70% concentrate and 30% ground alfalfa (DM basis) were prepared in a nylon bag, and were placed in a bottle containing the culture solution. Addition of fumarate or malate in both sodium salt and acid form increased (p<0.0001) pH of culture solution at 3, 6, 9 and 12 h incubations. The pH (p<0.0001) and total volatile fatty acids (VFA, p<0.05) were enhanced by these precursors as sodium salt at 3, 6 and 9 h incubations, and pH (p<0.001) and total VFA (p<0.01) from fumarate or malate in acid form were enhanced at a late stage of fermentation (9 h and 12 h) as the addition level increased. pH was higher (p<0.001) for fumarate than for malate as sodium salt at 3 h and 6 h incubations. Propionate ($C_3$) proportion was increased (p<0.0001) but those of $C_2$ (p<0.05) and $C_4$ (p<0.01 - p<0.001) were reduced by the addition of sodium salt precursors from 3 h to 12 incubation times while both precursors in acid form enhanced (p<0.011 - p<0.0001) proportion of $C_3$ from 6h but reduced (p<0.018 - p<0.0005) $C_4$ proportion at incubation times of 1, 3, 9 and 12 h. Proportion of $C_3$ was increased (p<0.05 - p<0.0001) at all incubation times by both precursors as sodium salt while that of $C_3$ was increased (p<0.001) from 6h but $C_4$ proportion was decreased by both precursors in acid form as the addition level increased. Proportion of $C_3$ was higher (p<0.01 - p<0.001) for fumarate than malate as sodium salt from 6 h incubation but was higher for malate than fumarate in acid form at 9 h (p<0.05) and 12 h (p<0.01) incubation times. Increased levels (16 and 24 mM) of fumarate or malate as sodium salt (p<0.017) and both precursors in acid form (p<0.028) increased the total gas production, but no differences were found between precursors in both chemical types. Propionate precursors in both chemical types clearly reduced (p<0.0001 - p<0.0002) $CH_4$ production, and the reduction (p<0.001 - p<0.0001) was dose dependent as the addition level of precursors increased. The $CH_4$ generated was smaller (p<0.01 - p<0.0001) for fumarate than for malate in both chemical types. Addition of fumarate or malate as sodium type reduced (p<0.004) dry matter degradation while both precursors in both chemical types slightly increased neutral detergent fiber degradability of feed in the nylon bag.

K _Ca 3.1 upregulation preserves endothelium‐dependent vasorelaxation during aging and oxidative stress

Choi, Shinkyu,Kim, Ji Aee,Li, Hai&#x2010,yan,Shin, Kyong&#x2010,Oh,Oh, Goo Taeg,Lee, Yong&#x2010,Moon,Oh, Seikwan,Pewzner&#x2010,Jung, Yael,Futerman, Anthony H.,Suh, Suk Hyo BLACKWELL PUBLISHING 2016 AGING CELL Vol.15 No.5

<P><B>Summary</B></P><P>Endothelial oxidative stress develops with aging and reactive oxygen species impair endothelium‐dependent relaxation (EDR) by decreasing nitric oxide (NO) availability. Endothelial K<SUB>Ca</SUB>3.1, which contributes to EDR, is upregulated by H<SUB>2</SUB>O<SUB>2</SUB>. We investigated whether K<SUB>Ca</SUB>3.1 upregulation compensates for diminished EDR to NO during aging‐related oxidative stress. Previous studies identified that the levels of ceramide synthase 5 (CerS5), sphingosine, and sphingosine 1‐phosphate were increased in aged wild‐type and CerS2 mice. In primary mouse aortic endothelial cells (MAECs) from aged wild‐type and CerS2 null mice, superoxide dismutase (SOD) was upregulated, and catalase and glutathione peroxidase 1 (GPX1) were downregulated, when compared to MAECs from young and age‐matched wild‐type mice. Increased H<SUB>2</SUB>O<SUB>2</SUB> levels induced Fyn and extracellular signal‐regulated kinases (ERKs) phosphorylation and K<SUB>Ca</SUB>3.1 upregulation. Catalase/GPX1 double knockout (catalase<SUP>−/−</SUP>/GPX1<SUP>−/−</SUP>) upregulated K<SUB>Ca</SUB>3.1 in MAECs. NO production was decreased in aged wild‐type, CerS2 null, and catalase<SUP>−/−</SUP>/GPX1<SUP>−/−</SUP>MAECs. However, K<SUB>Ca</SUB>3.1 activation‐induced, NG‐nitro‐<SMALL>L</SMALL>‐arginine‐, and indomethacin‐resistant EDR was increased without a change in acetylcholine‐induced EDR in aortic rings from aged wild‐type, CerS2 null, and catalase<SUP>−/−</SUP>/GPX1<SUP>−/−</SUP> mice. CerS5 transfection or exogenous application of sphingosine or sphingosine 1‐phosphate induced similar changes in levels of the antioxidant enzymes and upregulated K<SUB>Ca</SUB>3.1. Our findings suggest that, during aging‐related oxidative stress, SOD upregulation and downregulation of catalase and GPX1, which occur upon altering the sphingolipid composition or acyl chain length, generate H<SUB>2</SUB>O<SUB>2</SUB> and thereby upregulate K<SUB>Ca</SUB>3.1 expression and function via a H<SUB>2</SUB>O<SUB>2</SUB>/Fyn‐mediated pathway. Altogether, enhanced K<SUB>Ca</SUB>3.1 activity may compensate for decreased NO signaling during vascular aging.</P>

Effect of alendronate on healing of extraction sockets and healing around implants

Kim, J&#x2010,H,Park, Y&#x2010,B,Li, Z,Shim, J&#x2010,S,Moon, H&#x2010,S,Jung, H&#x2010,S,Chung, M&#x2010,K Blackwell Publishing Ltd 2011 Oral diseases Vol.17 No.7

<P><I>Oral Diseases</I> (2011) <B>17</B>, 705–711</P><P><B>Objectives: </B> The purpose of this study was to evaluate the effect of alendronates on healing of extraction sockets and healing around implants in the maxilla of rats.</P><P><B>Materials and Methods: </B> Twenty‐four Sprague–Dawley rats were used. The rats in bisphosphonate group were subcutaneously injected with alendronate (5.0 mg kg<SUP>‐‐1</SUP>) three times a week for 4 weeks. Both sides of the maxillary first molars were extracted, and customized titanium implants (Ø1.5 × 2.0 mm) were placed immediately into one side. Rats were killed at 3, 7, 14, or 28 days following surgery.</P><P><B>Results: </B> New bone formation in extraction sockets, bone area around the implant site, and bone–implant contact were not delayed in the bisphosphonate group. The tartrate‐resistant acid phosphatase positive cell count did not differ between bisphosphonate and control groups; however, empty lacunae were observed significantly more in bisphosphonate group. The differences in empty lacunae were shown at different time points between the implant sites and extraction sites: at 7 days after extraction, and at 14 and 28 days after implantation.</P><P><B>Conclusions: </B> Alendronates seemed to decrease bone resorption but not to decrease bone formation. Empty lacunae were observed significantly more at later time points in implant sites compared to extraction sockets.</P>

Altering sphingolipid composition with aging induces contractile dysfunction of gastric smooth muscle via KC _a 1.1 upregulation

Choi, Shinkyu,Kim, Ji Aee,Kim, Tae Hun,Li, Hai&#x2010,yan,Shin, Kyong&#x2010,Oh,Lee, Yong&#x2010,Moon,Oh, Seikwan,Pewzner&#x2010,Jung, Yael,Futerman, Anthony H.,Suh, Suk Hyo BLACKWELL PUBLISHING 2015 AGING CELL Vol.14 No.6

<P><B>Summary</B></P><P>KC<SUB>a</SUB>1.1 regulates smooth muscle contractility by modulating membrane potential, and age‐associated changes in KC<SUB>a</SUB>1.1 expression may contribute to the development of motility disorders of the gastrointestinal tract. Sphingolipids (SLs) are important structural components of cellular membranes whose altered composition may affect KC<SUB>a</SUB>1.1 expression. Thus, in this study, we examined whether altered SL composition due to aging may affect the contractility of gastric smooth muscle (GSM). We studied changes in ceramide synthases (CerS) and SL levels in the GSM of mice of varying ages and compared them with those in young CerS2‐null mice. The levels of C16‐ and C18‐ceramides, sphinganine, sphingosine, and sphingosine 1‐phosphate were increased, and levels of C22, C24:1 and C24 ceramides were decreased in the GSM of both aged wild‐type and young CerS2‐null mice. The altered SL composition upregulated KC<SUB>a</SUB>1.1 and increased KC<SUB>a</SUB>1.1 currents, while no change was observed in KC<SUB>a</SUB>1.1 channel activity. The upregulation of KC<SUB>a</SUB>1.1 impaired intracellular Ca2+ mobilization and decreased phosphorylated myosin light chain levels, causing GSM contractile dysfunction. Additionally, phosphoinositide 3‐kinase, protein kinase C<SUB>ζ</SUB>, c‐Jun N‐terminal kinases, and nuclear factor kappa‐B were found to be involved in KC<SUB>a</SUB>1.1 upregulation. Our findings suggest that age‐associated changes in SL composition or CerS2 ablation upregulate KC<SUB>a</SUB>1.1 via the phosphoinositide 3‐kinase/protein kinase C<SUB>ζ</SUB>/c‐Jun N‐terminal kinases/nuclear factor kappa‐B‐mediated pathway and impair Ca2+ mobilization, which thereby induces the contractile dysfunction of GSM. CerS2‐null mice exhibited similar effects to aged wild‐type mice; therefore, CerS2‐null mouse models may be utilized for investigating the pathogenesis of aging‐associated motility disorders.</P>

<i>Swift</i>,<i>XMM</i>-<i>Newton</i>, and<i>NuSTAR</i>Observations of PSR J2032+4127/MT91 213

Li, K. L.,Kong, A. K. H.,Tam, P. H. T.,Hou, X.,Takata, J.,Hui, and C. Y. American Astronomical Society 2017 The Astrophysical journal Vol.843 No.2

<P>We report our recent Swift, NuSTAR, and XMM-Newton X-ray and Lijiang optical observations on PSR J2032 + 4127/MT91 213, the gamma-ray binary candidate with a period of 45-50 years. The coming periastron of the system was predicted to be in 2017 November, around which high-energy flares from keV to TeV are expected. Recent studies with Chandra and Swift X-ray observations taken in 2015/2016 showed that its X-ray emission has been brighter by a factors of similar to 10 than that before 2013, probably revealing some ongoing activities between the pulsar wind and the stellar wind. Our new Swift/XRT lightcurve shows no strong evidence of a single vigorous brightening trend, but rather several strong X-ray flares on weekly to monthly timescales with a slowly brightening baseline, namely the low state. The NuSTAR and XMM-Newton observations taken during the flaring and the low states, respectively, show a denser environment and a softer power-law index during the flaring state, implying that the pulsar wind interacted with the stronger stellar winds of the companion to produce the flares. These precursors would be crucial in studying the predicted giant outburst from this extreme gamma-ray binary during the periastron passage in late 2017.</P>

Deliquescence and efflorescence behavior of individual NaCl and KCl mixture aerosol particles

Li, X.,Gupta, D.,Eom, H.J.,Kim, H.,Ro, C.U. Pergamon Press ; Elsevier [distribution] 2014 Atmospheric environment Vol.82 No.-

The hygroscopic behavior of laboratory-generated, micrometer sized NaCl and KCl mixture aerosol particles in nine mixing ratios (mole fractions of KCl (X<SUB>KCl</SUB>) = 0.1-0.9) was investigated systematically to observe their deliquescence and efflorescence behavior, obtain experimental phase diagrams for their deliquescence and efflorescence, and understand the efflorescence mechanism. Aerosol particles with a eutonic composition of X<SUB>KCl</SUB> = 0.3 showed only one phase transition during the humidifying process at the mutual deliquescence relative humidity (MDRH) of 72.3(+/-0.5)%, whereas the aerosol particles with other mixing ratios showed two distinct deliquescence transitions. First, the eutonic component dissolved at the MDRH and second, the remainder in the solid phase dissolved completely at various DRHs, resulting in a phase diagram composed of four different phases. During the dehydration process, droplets at all mixing ratios showed a single transition at their efflorescence RHs (ERHs), resulting in a phase diagram composed of two different phases. The minimum ERH of 43.7-43.2% was observed for X<SUB>KCl</SUB> = 0.4. This suggests that short-range ionic interactions and the common-ion effect may substantially affect the mutual solubility of NaCl and KCl at high ionic-strengths, and hence the supersaturation of the salts. Elemental X-ray mapping of the effloresced NaCl-KCl mixture particles at all mixing ratios suggests that more supersaturated salt nucleated homogeneously to crystallize in the center, and the other salt underwent the heterogeneous crystallization on the former.

Boron adsorption mechanism of a hybrid gel derived from tetraethoxysilane and bis(trimethoxysilylpropyl)amine

Liu, H.,Qing, B.,Ye, X.,Guo, M.,Li, Q.,Wu, Z.,Lee, K.,Lee, D.,Lee, K. 한국물리학회 2009 Current Applied Physics Vol.9 No.4_SUP

An organic/inorganic hybrid gel was prepared with tetraethoxysilane (TEOS) and bis(trimethoxysilylpropyl)amine (TSPA) as precursors. The adsorption of boron on the hybrid gel in aqueous solutions was investigated comprehensively by varying the initial boron concentration, pH, ionic strength, and temperature. The equilibrium adsorption amount of boron increases with the increase in initial boron concentration and ionic strength, but decreases with the increase in temperature. The adsorption amount exhibits a maximum at initial pH of 4-10. Boron appears to be adsorbed in both H<SUB>3</SUB>BO<SUB>3</SUB> and B(OH)<SUB>4</SUB><SUP>-</SUP> forms through the hydrogen bonding, electrostatic and hydrophobic attractions.

A Damage Model for Assessing Pipeline Safety in Corrosion Environments

Zhao, X. W.,Luo, J. H.,Zheng, M.,Lu, M.X.,Li, H.L 대한금속학회 2002 METALS AND MATERIALS International Vol.8 No.5

Considering such practical pipeline service conditions in the petroleum transportation field as corrosion from harmful media (H_2S, CO_2 etc.) and load from the pressure of flowing petroleum as key factors, the degradation of the mechanical properties of pipeline steels and the corresponding variations in stress states are studied. A damage variable is introduced to reflect the degradation in the mechanical properties of the pipeline due to corrosion. A diluted solution approach is proposed to model the corrosion process of harmful media within the pipeline and the distribution of the damage variable along the radial direction of the pipeline is derived. An approach to the safety evaluation of damaged pipeline is proposed by comparing the instant properties of pipeline steels with servicing conditions.

Preparation, surface characteristic and photoactive activitiesof Ni₂FeV₃O₁₁ semiconductor nanoparticles

Qiao, X.,Yang, L.,Li, Y.,Wan, Y.,Huang, Y.,Cheng, H.,Seo, H.J. North-Holland 2016 Materials letters Vol.163 No.-

Ni<SUB>2</SUB>FeV<SUB>3</SUB>O<SUB>11</SUB> nanorods were prepared by the sol-gel method via film-coating and subsequent heating. The sample was conducted by the crystal structure refinement confirming a pure triclinic phase with space group P-1. The surface characteristics were investigated by the measurements such as scanning electron microscope (SEM), transmission electron microscopy (TEM), specific surface area, and energy-dispersive X-ray spectroscopy (EDX). The photo-physical properties of Ni<SUB>2</SUB>FeV<SUB>3</SUB>O<SUB>11</SUB> nanorods were measured by the UV-vis absorption spectrum, and the photodegradation for methylene blue solutions (MB). This vanadate semiconductor has band-gap energy of 1.85eV and presents an efficient photocatalytic activity driven by visible-light. Moreover, the nanorods are magnetically recoverable after the photocatalysis.

The Influence of Side‐Chain Position on the Optoelectronic Properties of a Red‐Emitting Conjugated Polymer

Lu, Li Ping,Finlayson, Chris E.,Kabra, Dinesh,Albert&#x2010,Seifried, Sebastian,Song, Myoung Hoon,Havenith, Remco W. A.,Tu, Guoli,Huck, Wilhelm T. S.,Friend, Richard H. WILEY‐VCH Verlag 2013 Macromolecular chemistry and physics Vol.214 No.9

<P><B>Abstract</B></P><P>A study of the organic semiconductor F8TBT is presented, directly comparing a conventional form (F8TBT‐out) with a form with varied alkyl side‐chain position (F8TBT‐in), in terms of optical properties and device performance in light‐emitting‐diodes (LEDs). Computational simulations of the side‐chain position with respect to the TBT unit reveal geometrical differences between F8TBT‐out and F8TBT‐in. π–π conjugation on the backbone of F8TBT‐in is interrupted by a distortion of the benzothiadiazole ring, leading to a blue‐shift of the absorption spectrum and increased photoluminescence quantum efficiency. Both conventional and hybrid LEDs demonstrate that devices with F8TBT‐in show improved performance, as compared to F8TBT‐out, illustrating how tuning the optoelectronic properties of conjugated polymers by varying the placement of side chains has an important role in device optimization.</P>