A study of nerve agent model organophosphonate binding with manganese-A₂B-corrole and -A₂B₂-porphyrin systems

Kim, K.,Kim, I.,Maiti, N.,Kwon, S.J.,Bucella, D.,Egorova, O.A.,Lee, Y.S.,Kwak, J.,Churchill, D.G. Pergamon Press 2009 Polyhedron Vol.28 No.12

Herein the synthesis and binding studies of novel trans-A<SUB>2</SUB>B-corrole and trans-A<SUB>2</SUB>B<SUB>2</SUB>-porphyrin derivatives are presented in comparing manganese(III)-organophosphonate (OP) binding (e.g., M<SUP>n+</SUP>←O?PR(OR)<SUB>2</SUB>) capabilities. H<SUB>3</SUB>(PFP-VC) [PFP-VC=5,15-di(pentafluorophenyl)-10-(3-vinylphenyl)corrolate] was synthesized by way of literature procedures and was characterized by a variety of 2-D NMR spectroscopic techniques and single-crystal X-ray diffraction. These compounds represent the first example of 3-vinyl-phenyl-containing meso-substituted corroles or porphyrins. Mn(PFP-VC) (3) was treated separately with (CH<SUB>3</SUB>CH<SUB>2</SUB>O)<SUB>2</SUB>P?O(C<SUB>3</SUB>H<SUB>6</SUB>NMe<SUB>2</SUB>), (C<SUB>4</SUB>H<SUB>9</SUB>O)<SUB>2</SUB>P?O(Me), (C<SUB>2</SUB>H<SUB>5</SUB>O)<SUB>2</SUB>P?O(CH<SUB>2</SUB>COCH<SUB>3</SUB>), (CH<SUB>3</SUB>CH<SUB>2</SUB>O)<SUB>2</SUB>P?O(Me), to give 1:1 adducts, as determined by UV-Vis spectroscopy (Job Plot), giving a red shift; Ph<SUB>3</SUB>P?O, was also found to bind, but very weakly. The trans-A<SUB>2</SUB>B<SUB>2</SUB>-porphyrin analogue Mn(PFP-VP) (4) was also prepared by way of a literature procedure; related binding studies gave 1:1 organophosphonate-Mn(PFP-VP) adducts (Job Plot). A clean blue shift occurred for the Mn-porphyrins at higher organophosphonate loadings (K<SUB>a</SUB> values: 6.7 (0.9)-11.9 (0.4)M<SUP>-1</SUP>). DFT geometry optimizations of O?P(OMe)<SUB>2</SUB>Me binding and formal Mn-O or P-O cleavage products in the unsubstituted neutral Mn-corrolato and -porphyrinato systems with a range of metal-based spin states revealed greatest stability in formal phosphoryl oxygen binding (energies: 11-13kcal/mol) for the Mn-corrole (singlet); the Mn-porphyrin (sextet) was also quite stable.

Growth and characterisation of n- and p-type ZnTe thin films for applications in electronic devices

O.I. Olusola,M.L. Madugu,N.A. Abdul-Manaf,I.M. Dharmadasa 한국물리학회 2016 Current Applied Physics Vol.16 No.2

The growth of n- and p-type ZnTe thin films have been achieved intrinsically by potentiostatic electrodeposition method using a 2-electrode system. Cyclic voltammogram have been used to obtain range of growth voltages required to form stoichiometric thin films of ZnTe. The ZnTe thin films have been electrodeposited (ED) on glass/fluorine-doped tin oxide (FTO) conducting substrates in aqueous solutions of ZnSO4$7H2O and TeO2. The films have been characterised for their structural, electrical, morphological, compositional and optical properties by using X-ray diffraction (XRD), Raman spectroscopy, Photoelectrochemical (PEC) cell measurements, DC conductivity measurements, Scanning electron microscopy (SEM), Atomic force microscopy (AFM), energy-dispersive X-ray analysis (EDX) and Optical absorption techniques. The XRD results reveal that the electroplated films are polycrystalline and have hexagonal crystal structure with the preferred orientation along (002) plane. UVeVisible spectrophotometer has been used for the bandgap determination of as-deposited and heat-treated ZnTe layers. The bandgap of the heat-treated ZnTe films are in the range (1.90e2.60) eV depending on the deposition potential. PEC cell measurements show that the ED-ZnTe films have both n- and p-type electrical conductivity. The DC conductivity measurements revealed that the average resistivity of n-ZnTe and p-ZnTe layers of equal thickness is of the order of 104 Ucm; the magnitude of the electrical resistivity of p-ZnTe is almost five times greater than that of the n-ZnTe layer. Using the n- and p-type ZnTe layers, p-n homo-junction diodes with device structure of glass/FTO/n-ZnTe/p-ZnTe/Au were fabricated. The fabricated diodes showed rectification factor of 102, reverse saturation current of ~10.0 nA and potential barrier height greater than 0.77 eV indicating electronic device quality of these layers.

Studies of N-Doped p-ZnO Layers Grown on c-Sapphire by Radical Source Molecular Beam Epitaxy

S. V. Ivanov,A. El-Shaer,M. Al-Suleiman,A. Bakin,A. Waag,O. G. Lyublinskaya,N. M. Shmidt,S. B. Listoshin,R. N. Kyutt,V. V. Ratnikov,A. Ya. Terentyev,B. Ya. Ber,T. A. Komissarova,L. I. Ryabova,D. R. Kh 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.5

We report on the fabrication of p-type ZnO:N layers using radical-source molecular beam epitaxy and post-growth annealing of the samples. Plasma-activated oxygen and nitrogen fluxes are supplied via a single plasma cell. The combination of low growth temperature (350 − 400 ℃), slightly O-rich conditions, and post-growth annealing in the range of 650 − 800 ℃ results in efficient nitrogen pdoping with Hall hole concentration 3 × 1017 cm−3. The details of the structural and the electrical characterizations of the films are discussed. We report on the fabrication of p-type ZnO:N layers using radical-source molecular beam epitaxy and post-growth annealing of the samples. Plasma-activated oxygen and nitrogen fluxes are supplied via a single plasma cell. The combination of low growth temperature (350 − 400 ℃), slightly O-rich conditions, and post-growth annealing in the range of 650 − 800 ℃ results in efficient nitrogen pdoping with Hall hole concentration 3 × 1017 cm−3. The details of the structural and the electrical characterizations of the films are discussed.

A DFT study of electronic structure and optical properties of the pure, doped and co-doped CaZrO3 perovskite for photovoltaic applications

El Badraoui A.,Dahbi S.,Tahiri N.,El Bounagui O.,Ez-Zahraouy H. 한국세라믹학회 2023 한국세라믹학회지 Vol.60 No.4

The present study investigates the effects, of V and/or N-doped CaZrO 3 on the electronic and optical properties using spin-polarized density functional theory calculations. It was found that the obtained results of the pure CaZrO 3 are in complete agreement with the experimental data. Moreover, the V and N impurities decrease and transform the sizeable electronic band gap from an indirect insulator (4.964 eV for the pure CaZrO 3) to a direct semiconductor (1.369 eV for CaZr0.8750V0.1250O2.9584N0.0416). Hence, the absorption coefficient of CaZr 0.8750V0.1250O2.9584N0.0416 structure is enhanced in the visible region which is quite remarkable for solar cells. In addition, the calculated enthalpies of formation confi rm that all studied structures are thermodynamically stable.

Pedobacter oryzae sp. nov., isolated from rice paddy soil

Jeon, Y.,Kim, J. M.,Park, J. H.,Lee, S. H.,Seong, C.-N.,Lee, S.-S.,Jeon, C. O. Microbiology Society 2009 International journal of systematic and evolutiona Vol.59 No.10

<P>A Gram-stain-negative, strictly aerobic bacterium, designated strain N7(T), was isolated from a rice paddy in South Korea. Cells of strain N7(T) were non-motile, non-spore-forming rods. Growth was observed at 15-35 degrees C (optimum of 25-30 degrees C) and between pH 6.0 and 8.0 (optimum of pH 6.5-7.5). The predominant isoprenoid quinone was menaquinone-7. The major cellular fatty acids of strain N7(T) were summed feature 3 (comprising C(16 : 1)omega7c and/or iso-C(15 : 0) 2-OH), iso-C(15 : 0), anteiso-C(15 : 0), C(15 : 0) and iso-C(16 : 0). The G+C content of the genomic DNA was 37.7 mol%. Comparative 16S rRNA gene sequence analyses showed that strain N7(T) formed a distinct phyletic line within the genus Pedobacter. Phylogenetic distances from strains of other Pedobacter species with validly published names were greater than 5.0 % (i.e. <95.0 % 16S rRNA gene sequence similarities). On the basis of phenotypic and molecular data, it is clear that strain N7(T) represents a novel species within the genus Pedobacter, for which the name Pedobacter oryzae sp. nov. is proposed. The type strain is N7(T) (=KACC 12821(T) =DSM 19973(T)).</P>

AN X-RAY STUDY OF SUPERNOVA REMNANT N49 AND SOFT GAMMA-RAY REPEATER 0526-66 IN THE LARGE MAGELLANIC CLOUD

Park, Sangwook,Hughes, John P.,Slane, Patrick O.,Burrows, David N.,Lee, Jae-Joon,Mori, Koji IOP Publishing 2012 The Astrophysical journal Vol.748 No.2

<P>We report on the results from our deep Chandra observation (120 ks) of the supernova remnant (SNR) N49 and soft gamma-ray repeater (SGR) 0526-66 in the Large Magellanic Cloud. We firmly establish the detection of an ejecta 'bullet' beyond the southwestern boundary of N49. The X-ray spectrum of the bullet is distinguished from that of the main SNR shell, showing significantly enhanced Si and S abundances. We also detect an ejecta feature in the eastern shell, which shows metal overabundances similar to those of the bullet. If N49 was produced by a core-collapse explosion of a massive star, the detected Si-rich ejecta may represent explosive O-burning or incomplete Si-burning products from deep interior of the SN. On the other hand, the observed Si/S abundance ratio in the ejecta may favor Type Ia origin for N49. We refine the Sedov age of N49, tau(Sed) similar to 4800 yr, with the explosion energy E-0 similar to 1.8 x 10(51) erg. Our blackbody (BB) + power law (PL) model for the quiescent X-ray emission from SGR 0526-66 indicates that the PL photon index (Gamma similar to 2.5) is identical to that of PSR 1E1048.1-5937, the well-known candidate transition object between anomalous X-ray pulsars and SGRs. Alternatively, the two-component BB model implies X-ray emission from a small (R similar to 1 km) hot spot(s) (kT similar to 1 keV) in addition to emission from the neutron star's cooler surface (R similar to 10 km, kT similar to 0.4 keV). There is a considerable discrepancy in the estimated column toward 0526-66 between BB+PL and BB+BB model fits. Discriminating these spectral models would be crucial to test the long-debated physical association between N49 and 0526-66.</P>

Astrochemical Properties of Planck Cold Clumps

Tatematsu, Ken’ichi,Liu, Tie,Ohashi, Satoshi,Sanhueza, Patricio,Nguyê,̃,n Lu’o’, Quang,Hirota, Tomoya,Liu, Sheng-Yuan,Hirano, Naomi,Choi, Minho,Kang, Miju,A.Thompson, Mark,Fuller, Gary,Wu, Y Published by the University of Chicago Press for t 2017 The Astrophysical journal Supplement series Vol.228 No.2

<P>We observed 13 Planck cold clumps with the James Clerk Maxwell Telescope/SCUBA-2 and with the Nobeyama 45 m radio telescope. The N2H+ distribution obtained with the Nobeyama telescope is quite similar to SCUBA-2 dust distribution. The 82 GHz HC3N, 82 GHz CCS, and 94 GHz CCS emission are often distributed differently with respect to the N2H+ emission. The CCS emission, which is known to be abundant in starless molecular cloud cores, is often very clumpy in the observed targets. We made deep single-pointing observations in DNC, (HNC)-C-13, N2D+, and cyclic-C3H2 toward nine clumps. The detection rate of N2D+ is 50%. Furthermore, we observed the NH3 emission toward 15 Planck cold clumps to estimate the kinetic temperature, and confirmed that most targets are cold (less than or similar to 20 K). In two of the starless clumps we observed, the CCS emission is distributed as it surrounds the N2H+ core (chemically evolved gas), which resembles the case of L1544, a prestellar core showing collapse. In addition, we detected both DNC and N2D+. These two clumps are most likely on the verge of star formation. We introduce the chemical evolution factor (CEF) for starless cores to describe the chemical evolutionary stage, and analyze the observed Planck cold clumps.</P>

Diabetes augments cognitive dysfunction in chronic cerebral hypoperfusion by increasing neuronal cell death: Implication of cilostazol for diabetes mellitus-induced dementia

Kwon, K.J.,Lee, E.J.,Kim, M.K.,Kim, S.Y.,Kim, J.N.,Kim, J.O.,Kim, H.J.,Kim, H.Y.,Han, J.S.,Shin, C.Y.,Han, S.H. Blackwell Science ; Academic Press 2015 Neurobiology of disease Vol.73 No.-

Many patients with diabetes are at increased risk of cognitive dysfunction and dementia. Diabetes mellitus is a vascular risk factor that may increase the risk of dementia through its associations with vascular dementia. We tested whether cognitive impairment could be exacerbated in combined injury using a rat model of chronic cerebral hypoperfusion with diabetes. We also determined whether a potent inhibitor of type III phosphodiesterase could prevent the cognitive decline caused by this combined injury. We used Otsuka Long-Evans Tokushima Fatty (OLETF) rats as a model of type II diabetes (T2DM) and Long-Evans Tokushima Otsuka (LETO) rats as a control. Chronic cerebral hypoperfusion was modeled by permanent bilateral common carotid artery occlusion (BCCAO). At 24weeks, the non-diabetic and T2DM rats were randomly assigned into groups for the following experiments: analysis I (1) sham non-diabetic rats (n=8); (2) hypoperfused non-diabetic rats (n=9); (3) sham T2DM rats (n=8); (4) hypoperfused T2DM rats (n=9); analysis II- (1) sham T2DM rats without treatment (n=8); (2) cilostazol-treated T2DM rats (n=8); (3) hypoperfused T2DM rats (n=9); and (4) hypoperfused T2DM rats and cilostazol treatment (n=9). The rats were orally administered cilostazol (50mg/kg) or vehicle once a day for 2weeks after 24weeks. Rats performed Morris water maze tasks, and neuronal cell death and neuroinflammation were investigated via Western blots and histological investigation. Spatial memory impairment was exacerbated synergistically in the hypoperfused T2DM group compared with the hypoperfused non-diabetic group and sham T2DBM group (P<0.05). Compared with the control group, neuronal cell death was increased in the hippocampus of the hypoperfused T2DM group. Cilostazol, a PDE-3 inhibitor, improved the memory impairments through inhibition of neuronal cell death, activation of CREB phosphorylation and BDNF expression in the hypoperfused T2DM group. Our experimental results support the hypothesis that there are deleterious interactions between chronic cerebral hypoperfusion and T2DM. That is, metabolic diseases such as diabetes may exacerbate cognitive impairment in a rat model of vascular dementia. We also suggest that surprisingly, the phosphodiesterase III inhibitor, cilostazol may be useful for the treatment of cognitive impairment in diabetes mellitus-induced dementia. In conclusion, diabetes can aggravate cognitive dysfunction in vascular dementia, and PDE-3 inhibitors, such as cilostazol, may form the basis of a novel therapeutic strategy for diabetes-associated cognitive impairment or vascular dementia.

MEASUREMENTS OF THE RELATIVE ABUNDANCES OF HIGH-ENERGY COSMIC-RAY NUCLEI IN THE TeV/NUCLEON REGION

Ahn, H. S.,Allison, P. S.,Bagliesi, M. G.,Barbier, L.,Beatty, J. J.,Bigongiari, G.,Brandt, T. J.,Childers, J. T.,Conklin, N. B.,Coutu, S.,DuVernois, M. A.,Ganel, O.,Han, J. H.,Jeon, J. A.,Kim, K. C.,L IOP Publishing 2010 The Astrophysical journal Vol.715 No.2

<P>We present measurements of the relative abundances of cosmic-ray nuclei in the energy range of 500-3980 GeV/nucleon from the second flight of the Cosmic Ray Energetics And Mass balloon-borne experiment. Particle energy was determined using a sampling tungsten/scintillating-fiber calorimeter, while particle charge was identified precisely with a dual-layer silicon charge detector installed for this flight. The resulting element ratios C/O, N/O, Ne/O, Mg/O, Si/O, and Fe/O at the top of atmosphere are 0.919 +/- 0.123(stat) +/- 0.030(syst), 0.076 +/- 0.019(stat) +/- 0.013(syst), 0.115 +/- 0.031(stat) +/- 0.004(syst), 0.153 +/- 0.039(stat) +/- 0.005(syst), 0.180 +/- 0.045(stat) +/- 0.006(syst), and 0.139 +/- 0.043(stat) +/- 0.005(syst), respectively, which agree with measurements at lower energies. The source abundance of N/O is found to be 0.054 +/- 0.013(stat) +/- 0.009(-0.017)(syst+0.010esc). The cosmic-ray source abundances are compared to local Galactic (LG) abundances as a function of first ionization potential and as a function of condensation temperature. At high energies the trend that the cosmic-ray source abundances at large ionization potential or low condensation temperature are suppressed compared to their LG abundances continues. Therefore, the injection mechanism must be the same at TeV/nucleon energies as at the lower energies measured by HEAO-3, CRN, and TRACER. Furthermore, the cosmic-ray source abundances are compared to a mixture of 80% solar system abundances and 20% massive stellar outflow (MSO) as a function of atomic mass. The good agreement with TIGER measurements at lower energies confirms the existence of a substantial fraction of MSO material required in the similar to TeV per nucleon region.</P>

양파검은무늬병균의 포자발아에 미치는 물리적 요인

O,P,베르마,V,N,파닥,R,B,L,굽타 한국식물병리학회 1985 한국식물보호학회지 Vol.24 No.3