Multiple heterologous M2 extracellular domains presented on virus-like particles confer broader and stronger M2 immunity than live influenza A virus infection

Kim, M.C.,Lee, J.S.,Kwon, Y.M.,O, E.,Lee, Y.J.,Choi, J.G.,Wang, B.Z.,Compans, R.W.,Kang, S.M. Elsevier/North-Holland 2013 Antiviral research Vol.99 No.3

The influenza M2 ectodomain (M2e) is poorly immunogenic and has some amino acid changes among isolates from different host species. We expressed a tandem repeat construct of heterologous M2e sequences (M2e5x) derived from human, swine, and avian origin influenza A viruses on virus-like particles (M2e5x VLPs) in a membrane-anchored form. Immunization of mice with M2e5x VLPs induced protective antibodies cross-reactive to antigenically different influenza A viruses and conferred cross protection. Anti-M2e antibodies induced by heterologous M2e5x VLPs showed a wider range of cross reactivity to influenza A viruses at higher levels than those by live virus infection, homologous M2e VLPs, or M2e monoclonal antibody 14C2. Fc receptors were found to be important for mediating protection by immune sera from M2e5x VLP vaccination. The present study provides evidence that heterologous recombinant M2e5x VLPs can be more effective in inducing protective M2e immunity than natural virus infection and further supports an approach for developing an effective universal influenza vaccine.

Groundwater Dynamics and Balance in the Western Part of Greater Kushtia District of Bangladesh

M. Nozibul Haque,Mumnunul Keramat,Shamsuddin Shahid,Morteza Mohsenipour,Xiao-Jun Wang 대한토목학회 2017 KSCE JOURNAL OF CIVIL ENGINEERING Vol.21 No.5

Groundwater dynamics and balance have been studied for the assessment of groundwater abstraction status in the western part of grater Kushtia district, Bangladesh using data from 28 groundwater level monitoring wells, 180 lithologs, and one rainfall station for the period 2001-2007. The groundwater levels in the study area were found to vary at a depth between 0.0 m and 9.34 m. During peak season of groundwater abstraction (pre-monsoon), the maximum and minimum groundwater level with respect to mean sea level (MSL) were found to vary from 9.36 to 11.3 m and 2.3 to 4.9 m, respectively, whereas in post-monsoon these values were found to vary from 13.2 to 15.6 m and 7.6 to 9.6 m, respectively. The groundwater flow in the area was driven by topography, directed from the northwest to the southeast. This study revealed a declining trend in groundwater table both in pre- and post-monsoon seasons in the area. It has also been noticed that the rate of declination is increasing with time. The volumetric analysis of groundwater also showed a net negative balance, which indicates overexploitation of groundwater. The study concluded that the unsustainable utilization of groundwater resources in the study area has caused depletion in groundwater table.

Graphene/M_xWO₃ (M=Na, K) nanohybrids with excellent electrical properties

Liu, B.,Yin, S.,Wu, X.,Wang, Y.,Huang, Y.,Wu, J.,Sekino, T.,Matsushita, J.,Lee, S.W.,Kobayashi, M.,Kakihana, M.,Sato, T. Pergamon Press ; Elsevier Science Ltd 2015 Carbon Vol.94 No.-

Graphene/M<SUB>x</SUB>WO<SUB>3</SUB> (M=Na, K) nanocomposites with different weight ratios were successfully synthesized using MBH<SUB>4</SUB> as a reducing agent in aqueous solution, followed by crystallization of amorphous precursors under calcination in H<SUB>2</SUB> (5vol.%)/N<SUB>2</SUB> atmosphere at 600<SUP>o</SUP>C. The coupled samples showed good shielding properties in NIR wavelength range together with certain visible lights transparency. The as-prepared tungsten bronze nanoparticles are homogeneously anchored on graphene sheets, and the graphene/tungsten bronze nanocomposite showed an enhanced electrical conductivity with good shielding properties in the NIR range together with certain visible lights transparency. With the increment of graphene amount in the composites, the contact between the graphene sheets was enhanced, and the M<SUB>x</SUB>WO<SUB>3</SUB> might enhance the charge transport properties of graphene by generating the short conductive path for electrons over the remained oxygenated functional groups. The synergistic effects could be observed in the composites. When 5wt.% or more graphene were composed into M<SUB>x</SUB>WO<SUB>3</SUB>, the hybrid composite showed the higher electrical conductivity than those of uncoupled graphene and tungsten bronze alone.

Fabrication of highly permeable thin-film nanocomposite forward osmosis membranes <i>via</i> the design of novel freestanding robust nanofiber substrates

Obaid, M.,Kang, Yesol,Wang, Sungrok,Yoon, Myung-Han,Kim, Chang-Min,Song, Jun-ho,Kim, In S. The Royal Society of Chemistry 2018 Journal of Materials Chemistry A Vol.6 No.25

<P>Although forward osmosis (FO) technology is considered to be a sustainable solution for the water and energy shortage, it has not been commercialized yet due to a few factors. Internal concentration polarization (ICP) is one of the most important barriers preventing the commercialization of the technology. To overcome the ICP obstacle, novel high-performance thin-film nanocomposite (TFN) membranes were successfully fabricated <I>via</I> interfacial polymerization on robust freestanding graphene oxide (GO) incorporated polyvinylidene fluoride (PVDF) nanofiber substrates. Compared to the pristine PVDF nanofiber substrate, the incorporation of GO (ranging from 0.1-15 wt%) significantly alters the chemical structure, porosity, wettability, morphology, and mechanical properties of the substrate, leading to an enhancement in the TFN membrane performance. The results showed that TFN5 (containing 5% GO) membrane possesses the lowest structural parameter of 85.5 μm (one of the best values in the literature), indicating a low internal concentration polarization (ICP) effect, resulting in a remarkably heightened water permeability (<I>A</I>; 2.96 L m<SUP>−2</SUP> h<SUP>−1</SUP> bar<SUP>−1</SUP>, enhanced by 167% compared to TFC). As a result, the membrane achieved the highest FO water flux at all draw solution concentrations (0.5-2 M NaCl), and the maximum FO water flux was 80.9 L m<SUP>−2</SUP> h<SUP>−1</SUP> (LMH) with a comparable specific salt flux (<I>J</I>s/<I>J</I>v) of 0.41 g L<SUP>−1</SUP> in the active layer facing the deionized feed water (AL-FS) when 2 M NaCl was applied as a draw solution. Interestingly, TFN5 was found to be the strongest material, with outstanding flexibility and strength over that of the TFC membrane. Furthermore, it showed high stability and durability during long-term FO operation. More importantly, the interaction mechanism between PVDF and GO was proposed schematically. Overall, the obtained results show highly efficient and promising TFN membranes that may overcome the drawbacks of the aforementioned FO membranes.</P>

Is iron unique in promoting electrical conductivity in MOFs?

Sun, L.,Hendon, C.,Park, S.,Tulchinsky, Y.,Wan, R.,Wang, F.,Walsh, A.,Dinca, M. Royal Society of Chemistry 2017 Chemical Science Vol.8 No.6

<P>Identifying the metal ions that optimize charge transport and charge density in metal-organic frameworks is critical for systematic improvements in the electrical conductivity in these materials. In this work, we measure the electrical conductivity and activation energy for twenty different MOFs pertaining to four distinct structural families: M-2(DOBDC)(DMF)(2) (M = Mg2+, Mn2+, Fe2+, Co2+, Ni2+, Cu2+, Zn2+); H4DOBDC = 2,5-dihydroxybenzene-1,4-dicarboxylic acid; DMF = N, N-dimethylformamide), M-2(DSBDC)(DMF)(2) (M = Mn2+, Fe2+; H4DSBDC = 2,5-disulfhydrylbenzene-1,4-dicarboxylic acid), M2Cl2(BTDD)(DMF)(2) (M = Mn2+, Fe2+, Co2+, Ni2+; H2BTDD = bis(1H-1,2,3-triazolo[4,5-b],[40,50-i]dibenzo[1,4]dioxin), and M(1,2,3-triazolate)(2) (M = Mg2+, Mn2+, Fe2+, Co2+, Cu2+, Zn2+, Cd2+). This comprehensive study allows us to single-out iron as the metal ion that leads to the best electrical properties. The iron-based MOFs exhibit at least five orders of magnitude higher electrical conductivity and significantly smaller charge activation energies across all different MOF families studied here and stand out materials made from all other metal ions considered here. We attribute the unique electrical properties of iron-based MOFs to the high-energy valence electrons of Fe2+ and the Fe3+/2+ mixed valency. These results reveal that incorporating Fe2+ in the charge transport pathways of MOFs and introducing mixed valency are valuable strategies for improving electrical conductivity in this important class of porous materials.</P>

Characteristics and composition of atmospheric aerosols in Phimai, central Thailand during BASE-ASIA

Li, C.,Tsay, S.C.,Hsu, N.C.,Kim, J.Y.,Howell, S.G.,Huebert, B.J.,Ji, Q.,Jeong, M.J.,Wang, S.H.,Hansell, R.A.,Bell, S.W. Pergamon Press ; Elsevier [distribution] 2013 Atmospheric environment Vol.78 No.-

Comprehensive measurements of atmospheric aerosols were made in Phimai, central Thailand (15.183<SUP>o</SUP>N, 102.565<SUP>o</SUP>E, elevation: 206 m) during the BASE-ASIA field experiment from late February to early May in 2006. The observed aerosol loading was sizable for this rural site (mean aerosol scattering: 108 +/- 64 Mm<SUP>-1</SUP>; absorption: 15 +/- 8 Mm<SUP>-1</SUP>; PM<SUB>10</SUB> concentration: 33 +/- 17 μg m<SUP>-3</SUP>), and dominated by submicron particles. Major aerosol compounds included carbonaceous (OC: 9.5 +/- 3.6 μg m<SUP>-3</SUP>; EC: 2.0 +/- 2.3 μg m<SUP>-3</SUP>) and secondary species (SO<SUB>4</SUB><SUP>2-</SUP>: 6.4 +/- 3.7 μg m<SUP>-3</SUP>, NH<SUB>4</SUB><SUP>+</SUP>: 2.2 +/- 1.3 μg m<SUP>-3</SUP>). While the site was seldom under the direct influence of large forest fires to its north, agricultural fires were ubiquitous during the experiment, as suggested by the substantial concentration of K<SUP>+</SUP> (0.56 +/- 0.33 μg m<SUP>-3</SUP>). Besides biomass burning, aerosols in Phimai during the experiment were also strongly influenced by industrial and vehicular emissions from the Bangkok metropolitan region and long-range transport from southern China. High humidity played an important role in determining the aerosol composition and properties in the region. Sulfate was primarily formed via aqueous phase reactions, and hygroscopic growth could enhance the aerosol light scattering by up to 60%, at the typical morning RH level of 85%. The aerosol single scattering albedo demonstrated distinct diurnal variation, ranging from 0.86 +/- 0.04 in the evening to 0.92 +/- 0.02 in the morning. This experiment marks the first time such comprehensive characterization of aerosols was made for rural central Thailand. Our results indicate that aerosol pollution has developed into a regional problem for northern Indochina, and may become more severe as the region's population and economy continue to grow.

Expression of Each Cistron in the <i>gal</i> Operon Can Be Regulated by Transcription Termination and Generation of a <i>galK</i>-Specific mRNA, mK2

Wang, Xun,Ji, Sang Chun,Yun, Sang Hoon,Jeon, Heung Jin,Kim, Si Wouk,Lim, Heon M. American Society for Microbiology 2014 Journal of Bacteriology Vol.196 No.14

<P>The <I>gal</I> operon of <I>Escherichia coli</I> has 4 cistrons, <I>galE</I>, <I>galT</I>, <I>galK</I>, and <I>galM</I>. In our previous report (H. J. Lee, H. J. Jeon, S. C. Ji, S. H. Yun, H. M. Lim, J. Mol. Biol. <B>378:</B>318–327, 2008), we identified 6 different mRNA species, mE1, mE2, mT1, mK1, mK2, and mM1, in the <I>gal</I> operon and mapped these mRNAs. The mRNA map suggests a gradient of gene expression known as natural polarity. In this study, we investigated how the mRNAs are generated to understand the cause of natural polarity. Results indicated that mE1, mT1, mK1, and mM1, whose 3′ ends are located at the end of each cistron, are generated by transcription termination. Since each transcription termination is operating with a certain frequency and those 4 mRNAs have 5′ ends at the transcription initiation site(s), these transcription terminations are the basic cause of natural polarity. Transcription terminations at <I>galE-galT</I> and <I>galT-galK</I> junctions, making mE1 and mT1, are Rho dependent. However, the terminations to make mK1 and mM1 are partially Rho dependent. The 5′ ends of mK2 are generated by an endonucleolytic cleavage of a pre-mK2 by RNase P, and the 3′ ends are generated by Rho termination 260 nucleotides before the end of the operon. The 5′ portion of pre-mK2 is likely to become mE2. These results also suggested that <I>galK</I> expression could be regulated through mK2 production independent from natural polarity.</P>

The Effect of High CO₂ Treatment and MA Packaging on Asparagus Quality and Shelf Life during Cold Storage

( Wang,L. X. ),( I. L. Choi ),( J. H. Lee ),( H. M. Kang ) 강원대학교 농업생명과학연구원(구 농업과학연구소) 2019 강원 농업생명환경연구 Vol.31 No.2

Oxygen transmission rate (OTR) films of 1,300 and 10,000 cc/m²/day/atm, perforated (P), micro-perforated (MP), and vacuum (V) films were investigated for suitability in maintaining the quality and prolonging shelf life of asparagus during cold storage. An additional investigation using 60% (v/v) carbon dioxide treatment (V + 60% CO₂) was also performed. All samples lost fresh weight over time, P and V + 60% CO₂ had the highest and lowest fresh weight loss rate by the last day. Only 1,300 cc and 10,000 cc OTR films kept the asparagus at a marketable value, the least off-odor was detected in P, and the worst was in V + 60% CO₂ in final day. The V + 60% CO₂ resulted in lower firmness in asparagus tips, and the V resulted in the lowest firmness in stems. Although, little color changes happened in all treatments, the V + 60% CO₂ treatment had greater soluble solids content and hue angle. The highest ethylene concentration was detected in the V film. The CO₂ and O₂ levels of the 1,300 cc and 10,000 cc OTR treatments were more suitable for asparagus storage. In general, based on the visual quality, 1,300 cc and 10,000 cc OTR films were more effective for asparagus cold storage. To some extent, high CO₂ treatment exhibited a positive effect on maintaining internal quality, fresh weight and color of asparagus.

Activation of Neuronal Nitric Oxide Synthase by M2 Muscarinic Receptors Associated with a Small Increase in Intracellular Calcium

Wang, Shou-Zhen,Lee, Seok-Yong,Zhu, Sheng-Zu,Wotta, Diane R.,Parsons, Ann M.,El-Fakahany, Esam E. 성균관대학교 약학연구소 1998 成均藥硏論文集 Vol.10 No.1

We investigated the coupling of the M2 muscarinic acetylcholine receptors expressed in Chinese hamster ovary cells to activation of neuronal nitric oxide(NO) synthase. Stimulation of guanylate cyclase activity in detector neuroblastoma cells was used as an indirect measure of the generation of NO in Chinese hamster ovary cells. The muscarinic agonist carbachol induced marked time-and concentration-dependent enhancement of the activity of NO synthase. Activation of neuronal NO synthase by M2 muscarinic receptors was associated with a small increase in the concentration of intracellular Ca^2+. These data suggest the presence of alternate mechanisms of activation of neuronal NO synthase which might be operative in the absence of large changes in the concentration of cellular Ca^2+. These findings help to understand the mechanisms of activation of NO synthase.

Effect of magnesium carbonate on microstructure and rolling behaviors of AZ31 alloy

Wang, L.,Kim, Y.M.,Lee, J.,You, B.S. Elsevier Sequoia 2011 Materials science & engineering. properties, micro Vol.528 No.3

The present study aims at investigating grain refinement and rolling behavior of a magnesium carbonate (MgCO<SUB>3</SUB>) added AZ31 alloy. MgO particles produced by decomposition of MgCO<SUB>3</SUB> in an AZ31 melt act as effective heterogeneous nuclei, and decrease the grain size of the ingot from 310 to 117μm. Grain refinement alters the hot deformation mechanism of AZ31 alloy from TDRX-dominance to CDRX-dominance. The twinned regions provide easy crack propagation routes and thus deteriorate workability. As a result, workability in hot rolling especially up to the intermediate stage is improved.