NMR study of Y2(Co1-xFex)14B compounds

International Nuclear Information System (INIS)

Maruyama, F.; Ichinose, K.; Nagai, H.; Adachi, K.; Misawa, M.; Tsujimura, A.

1992-01-01

59 Co and 89 Y NMR of Y 2 (Co 1-x Fe x ) 14 B compounds has been measured at 4.2 K. The line positions shift rapidly to higher frequency for x≤0.3 and are almost constant for 0.3 1 and 8j 2 sites give a large contribution to the anisotropy of the 3d sublattice. (orig.)

Solid-solution stability and preferential site-occupancy in (R-R′){sub 2}Fe{sub 14}B compounds

Energy Technology Data Exchange (ETDEWEB)

Colin, C. V.; Dempsey, N. M. [CNRS, Inst NEEL, F-38000 Grenoble (France); Univ. Grenoble Alpes, Inst NEEL, F-38000 Grenoble (France); Ito, M. [CNRS, Inst NEEL, F-38000 Grenoble (France); Univ. Grenoble Alpes, Inst NEEL, F-38000 Grenoble (France); Advanced Material Engineering Div., Toyota Motor Corporation, Susono 410-1193 (Japan); Yano, M. [Advanced Material Engineering Div., Toyota Motor Corporation, Susono 410-1193 (Japan); Suard, E. [Institut Laue-Langevin, CS 20156-38042 Grenoble cedex 9 (France); Givord, D. [CNRS, Inst NEEL, F-38000 Grenoble (France); Univ. Grenoble Alpes, Inst NEEL, F-38000 Grenoble (France); Instituto de Fisica, Universidade Federal do Rio de Janeiro, 21941-972 Rio de Janeiro (Brazil)

2016-06-13

The rare-earth (R) uniaxial anisotropy of R{sub 2}Fe{sub 14}B compounds with magnetic R atoms (e.g., Nd or Pr) is at the origin of the exceptional hard magnetic properties achieved in magnets based on these compounds. The uniaxial anisotropy found in Ce{sub 2}Fe{sub 14}B is attributed mainly to the magnetism of Fe. Ce is the most abundant R element and there has been much recent effort to fabricate magnets in which Ce is partially substituted for Nd. In the present neutron study of (R{sub 1−x}Ce{sub x}){sub 2}Fe{sub 14}B (R = La or Nd), Ce is found to enter the R{sub 2}Fe{sub 14}B phase over the entire composition range. The crystallographic parameters decrease with increasing Ce content and the Ce atoms preferentially occupy the smaller 4f sites. It is concluded that Ce in these (RR′){sub 2}Fe{sub 14}B compounds essentially maintains the intermediate valence character found in Ce{sub 2}Fe{sub 14}B. It is proposed that, in this intermediate valence state, Ce weakly contributes to uniaxial anisotropy, thus making a link with the fact that significant coercivity is preserved in Ce-substituted NdFeB magnets.

Effect of Mo/B atomic ratio on the properties of Mo2NiB2-based cermets

International Nuclear Information System (INIS)

Xie, Lang; Li, XiaoBo; Zhang, Dan; Yi, Li; Gao, XiaoQing; Xiangtan Univ.

2015-01-01

Using three elementary substances, Mo, Ni, and amorphous B as raw materials, four series of Mo 2 NiB 2 -based cermets with the Mo/B atomic ratio ranging from 0.9 to 1.2 were successfully prepared via reaction sintering. The effect of Mo/B atomic ratio on the microstructure and properties was studied for the cermets. The results indicate that there is a strong correlation between the Mo/B atomic ratio and properties. The transverse rupture strength of the cermets increases with an increase in Mo/B ratio and shows a maximum value of 1 872 MPa at an Mo/B atomic ratio of 1.1 and then decreases with increasing Mo/B atomic ratio. The hardness and the corrosion resistance of the cermets increase monotonically with an increase in Mo/B atomic ratio. In Mo-rich cermets with an atomic ratio of Mo/B above 1.1, a small amount Ni-Mo intermetallic compound is found precipitated at the interface of Mo 2 NiB 2 grains.

Calculations of the magnetic properties of R2M14B intermetallic compounds (R=rare earth, M=Fe, Co)

International Nuclear Information System (INIS)

Ito, Masaaki; Yano, Masao; Dempsey, Nora M.; Givord, Dominique

2016-01-01

The hard magnetic properties of “R–M–B” (R=rare earth, M=mainly Fe) magnets derive from the specific intrinsic magnetic properties encountered in Fe-rich R 2 M 14 B compounds. Exchange interactions are dominated by the 3d elements, Fe and Co, and may be modeled at the macroscopic scale with good accuracy. Based on classical formulae that relate the anisotropy coefficients to the crystalline electric field parameters and exchange interactions, a simple numerical approach is used to derive the temperature dependence of anisotropy in various R 2 Fe 14 B compounds (R=Pr, Nd, Dy). Remarkably, a unique set of crystal field parameters give fair agreement with the experimentally measured properties of all compounds. This implies reciprocally that the properties of compounds that incorporate a mixture of different rare-earth elements may be predicted accurately. This is of special interest for material optimization that often involves the partial replacement of Nd with another R element and also the substitution of Co for Fe. - Highlights: • Anisotropy constants derived from CEF parameters of R 2 M 14 B compounds (M=Fe, Co). • Anisotropy constants of all R 2 Fe 14 B compounds using unique set of CEF parameters. • Moment non-collinearity in magnetization processes under B app along hard axis.

Schiff Bases of Benzothiazol-2-ylamine and Thiazolo[5,4-b] pyridin-2-ylamine as Anticonvulsants: Synthesis, Characterization and Toxicity Profiling.

Science.gov (United States)

Shukla, Rashmi; Singh, Ajeet P; Sonar, Pankaj K; Mishra, Mudita; Saraf, Shailendra K

2016-01-01

Schiff bases have a broad spectrum of biological activities like antiinflammatory, analgesic, antimicrobial, anticonvulsant, antitubercular, anticancer, antioxidant, anthelmintic and so forth. Thus, after a thorough perusal of literature, it was decided to conjugate benzothiazol-2-ylamine/thiazolo [5, 4-b] pyridin-2-ylamine with aromatic and heteroaromatic aldehydes to get a series of Schiff bases. Synthesis, characterization, in-silico toxicity profiling and anticonvulsant activity of the Schiff bases of Benzothiazol-2-ylamine and Thiazolo [5, 4-b] pyridin-2-ylamine. Aniline/4-aminopyridine was converted to the corresponding thiourea derivatives, which were cyclized to obtain benzothiazol-2-ylamine/thiazolo [5, 4-b] pyridin-2-ylamine. Finally, these were condensed with various aromatic and heteroaromatic aldehydes to obtain Schiff bases of benzothiazol-2-ylamine and thiazolo [5, 4-b] pyridin-2-ylamine. The synthesized compounds were characterized and screened for their anticonvulsant activity using maximal electroshock (MES) test and isoniazid (INH) induced convulsions test. In-silico toxicity profiling of all the synthesized compounds was done through "Lazar" and "Osiris" properties explorer. Majority of the compounds were more potent against MES induced convulsions than INH induced convulsions. Schiff bases of benzothiazol-2-ylamine were more effective than thiazolo [5, 4-b] pyridin-2-ylamine against MES induced convulsions. The compound benzothiazol-2-yl-(1H-indol-2-ylmethylene)-amine (VI) was the most potent member of the series against both types of convulsions. Compound VI exhibited the most significant activity profile in both the models. The compounds did not exhibit any carcinogenicity or acute toxicity in the in-silico studies. Thus, it may be concluded that the Schiff bases of benzothiazol-2-ylamine exhibit the potential to be promising and non-toxic anticonvulsant agents.

New 1,2,4-triazine bearing compounds: molecular modeling, synthesis and biotesting

Directory of Open Access Journals (Sweden)

Negrutska V. V.

2009-12-01

Full Text Available Aim. To enlarge a spectrum of biologically active compounds in the series of the 1,2,4-triazino[5,6-b] [1,4]benzothiazine (1,2,4-TBT derivatives and reveal among them efficient inhibitors of RNA synthesis Methods. The methods of structure optimization of the 3-oxo-1,2,4-TBT by fragment-oriented substitution, the molecular doking of new structures in a virtual target, the rational chemical synthesis of the theoretically predicted compounds and their testing in the system of transcription in vitro. Results. The series of 1,2,4-TBT derivatives with substituents in the benzene and triazine cycles of a base molecule were synthesized. The testing of synthesized compounds in the in vitro transcription system directed by T7 RNA polymerase revealed the structure- and concentration-dependent inhibition of the RNA synthesis by some of these compounds. The experimental and virtual screening data for all investigated compounds have a good correlation. It was found that most effective derivative is the 3-oxo-8-butyl-1,2,4-TBT which completely inhibited transcription at the concentration of 6 mg/ml. Conclusions. The biotesting results allow us to assume that the inhibition of RNA synthesis is caused by binding of the 3-oxo- 8-butyl-1,2,4-TBT to both free RNA polymerase molecules and those including in a transcriptional complex with DNA

Alloy Design Data Generated for B2-Ordered Compounds

Science.gov (United States)

Noebe, Ronald D.; Bozzolo, Guillermo; Abel, Phillip B.

2003-01-01

Developing alloys based on ordered compounds is significantly more complicated than developing designs based on disordered materials. In ordered compounds, the major constituent elements reside on particular sublattices. Therefore, the addition of a ternary element to a binary-ordered compound is complicated by the manner in which the ternary addition is made (at the expense of which binary component). When ternary additions are substituted for the wrong constituent, the physical and mechanical properties usually degrade. In some cases the resulting degradation in properties can be quite severe. For example, adding alloying additions to NiAl in the wrong combination (i.e., alloying additions that prefer the Al sublattice but are added at the expense of Ni) will severely embrittle the alloy to the point that it can literally fall apart during processing on cooling from the molten state. Consequently, alloying additions that strongly prefer one sublattice over another should always be added at the expense of that component during alloy development. Elements that have a very weak preference for a sublattice can usually be safely added at the expense of either element and will accommodate any deviation from stoichiometry by filling in for the deficient component. Unfortunately, this type of information is not known beforehand for most ordered systems. Therefore, a computational survey study, using a recently developed quantum approximate method, was undertaken at the NASA Glenn Research Center to determine the preferred site occupancy of ternary alloying additions to 12 different B2-ordered compounds including NiAl, FeAl, CoAl, CoFe, CoHf, CoTi, FeTi, RuAl, RuSi, RuHf, RuTi, and RuZr. Some of these compounds are potential high temperature structural alloys; others are used in thin-film magnetic and other electronic applications. The results are summarized. The italicized elements represent the previous sum total alloying information known and verify the computational

Magnetic structure of the magnetocaloric compound AlFe{sub 2}B{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Cedervall, Johan, E-mail: johan.cedervall@kemi.uu.se [Department of Chemistry – Ångström Laboratory, Uppsala University, Box 538, 751 21 Uppsala (Sweden); Andersson, Mikael Svante; Sarkar, Tapati [Department of Engineering Sciences, Uppsala University, Box 534, 751 21 Uppsala (Sweden); Delczeg-Czirjak, Erna K. [Department of Physics and Astronomy, Uppsala University, Box 516, 751 20 Uppsala (Sweden); Bergqvist, Lars [Department of Materials and Nano Physics and Swedish e-Science Research Centre (SeRC), Royal Institute of Technology (KTH), Electrum 229, SE-164 40 Kista (Sweden); Hansen, Thomas C. [Institut Laue-Langevin, B.P. 156, Grenoble Cedex 9, 38042 France (France); Beran, Premysl [Nuclear Physics Institute, Academy of Sciences of the Czech Republic, Rez, 25068 Czech Republic (Czech Republic); Nordblad, Per [Department of Engineering Sciences, Uppsala University, Box 534, 751 21 Uppsala (Sweden); Sahlberg, Martin [Department of Chemistry – Ångström Laboratory, Uppsala University, Box 538, 751 21 Uppsala (Sweden)

2016-04-15

The crystal and magnetic structures of AlFe{sub 2}B{sub 2} have been studied with a combination of X-ray and neutron diffraction and electronic structure calculations. The magnetic and magnetocaloric properties have been investigated by magnetisation measurements. The samples have been produced using high temperature synthesis and subsequent heat treatments. The compound crystallises in the orthorhombic crystal system Cmmm and it orders ferromagnetically at 285 K through a second order phase transition. At temperatures below the magnetic transition the magnetic moments align along the crystallographic a-axis. The magnetic entropy change from 0 to 800 kA/m was found to be −1.3 J/K kg at the magnetic transition temperature. - Graphical abstract: The magnetic structure of AlFe{sub 2}B{sub 2} has been investigated using neutron diffraction and the magnetic spins have been found to align ferromagnetically along the crystallographic a-axis. - Highlights: • The crystal and magnetic structures of AlFe{sub 2}B{sub 2} have been studied. • Orders ferromagnetically at 285 K via a second order phase transition. • The magnetic moments are found to be aligned along the crystallographic a-axis. • The magnetic entropy change from 0 to 800 kA/m was found to be −1.3 J/K kg.

Computer system organization the B5700/B6700 series

CERN Document Server

Organick, Elliott I

1973-01-01

Computer System Organization: The B5700/B6700 Series focuses on the organization of the B5700/B6700 Series developed by Burroughs Corp. More specifically, it examines how computer systems can (or should) be organized to support, and hence make more efficient, the running of computer programs that evolve with characteristically similar information structures.Comprised of nine chapters, this book begins with a background on the development of the B5700/B6700 operating systems, paying particular attention to their hardware/software architecture. The discussion then turns to the block-structured p

Electronic and magnetic structures of ferrimagnetic Mn{sub 2}Sb compound

Energy Technology Data Exchange (ETDEWEB)

Masrour, R., E-mail: rachidmasrour@hotmail.com [Laboratory of Materials, Processes, Environment and Quality, Cady Ayyed University, National School of Applied Sciences, 63 46000 Safi (Morocco); LMPHE (URAC 12), Faculty of Science, Mohammed V-Agdal University, Rabat (Morocco); Hlil, E.K. [Institut Néel, CNRS et Université Joseph Fourier, BP 166, F-38042 Grenoble Cedex 9 (France); Hamedoun, M. [Institute of Nanomaterials and Nanotechnologies, MAScIR, Rabat (Morocco); Benyoussef, A. [LMPHE (URAC 12), Faculty of Science, Mohammed V-Agdal University, Rabat (Morocco); Institute of Nanomaterials and Nanotechnologies, MAScIR, Rabat (Morocco); Hassan II Academy of Science and Technology, Rabat (Morocco); Mounkachi, O.; El moussaoui, H. [Institute of Nanomaterials and Nanotechnologies, MAScIR, Rabat (Morocco)

2015-01-15

The Self-consistent ab initio calculations, based on DFT (Density Functional Theory) approach and using FLAPW (Full potential Linear Augmented Plane Wave) method, are performed to investigate both electronic and magnetic properties of the Mn{sub 2}Sb compound. Polarized spin and spin–orbit coupling are included in calculations within the framework of the antiferromagnetic state between two adjacent Mn{sub 1} and Mn{sub 2} atoms. Magnetic moment considered to lie along (0 0 1) axes are computed. The antiferromagnetic energy of Mn{sub 2}Sb systems is obtained. Obtained data from ab initio calculations are used as input for the high temperature series expansions (HTSEs) calculations to compute other magnetic parameters. The exchange interactions between the magnetic atoms Mn{sub 1}−Mn{sub 2} in Mn{sub 2}Sb are given by using the mean field theory. The HTSEs of the magnetic susceptibility of with the magnetic moments in Mn{sub 2}Sb (m{sub Mn{sub 1}}and m{sub Mn{sub 2}}) through Ising model is given up to tenth order series in (x=J(Mn{sub 1}−Mn{sub 2})/k{sub B}T). The Néel temperature T{sub N}(K) is obtained by HTSEs applied to the magnetic susceptibility series combined with the Padé approximant method. The critical exponent γ associated with the magnetic susceptibility is deduced as well. - Highlights: • Ab initio calculations is using to investigate both electronic and magnetic properties of the Mn{sub 2}Sb compound. • Obtained data from ab initio calculations are used as input for the HTSEs. • The Néel temperature is obtained for Mn{sub 2}Sb compound.

B2 intermetallic compounds of Zr. New class of the shape memory alloys

International Nuclear Information System (INIS)

Koval, Yu.N.; Delaey, L.; Jang, W.Y.

1995-01-01

It is known that the B2 equiatomic intermetallic compounds of Zr (ZrCo-based) undergo a martensitic transformation (MT) with wide temperature hysteresis. It was found that the MT is accompanied by the perfect shape memory effect (SME) for ZrCu and ZrRh. In this report we represent the results of structural analysis, electrical resistivity, calorimetric and SME measurements for ZrCu- and ZrCo-based compounds. Interrelation between structural, thermodynamical parameters of MT and SME in this alloys will be described. The shape memory aspects of this potential alloys for the application at high temperatures will be discussed. (orig.)

RRh2Al10 (R = Ce, Yb): New intermetallic compounds in the 1 : 2 : 10 stoichiometry series

Science.gov (United States)

Strydom, A. M.; Djoumessi, R. F.; Blinova, M.; Tursina, A.; Nesterenko, S.; Avzuragova, V.

2018-05-01

The orthorhombic, space group Cmcm YbFe2Al10 structure type series of compounds are known to form with practically the entire series of rare-earth elements R, but only with the three d - electron elements Fe, Ru, and Os. The Ce-derivatives in particular have been of much interest since the first reports of their highly unusual physical properties. Classified as Kondo insulators, CeRu2Al10 and CeOs2Al10 controversially order magnetically and with uncharacteristically high Néel temperatures of ≃ 28 K. CeFe2Al10 on the other hand shows pronounced semiconducting and Kondo features but remains paramagnetic. As part of our ongoing studies into the rich physics of this class of materials we have succeeded in synthesizing new members of the 1:2:10 stoichiometry involving the chemical element Rh for the first time. CeRh2Al10 is found to crystallize in the tetragonal system with space group I41 / amd . Yb Rh2Al10 on the other hand forms in the serial Cmcm orthorhombic structure type. We discuss important similarities between the two types. At 5.310 Å the shortest Ce-Ce distance is, likewise to the situation in CeRu2Al10 and CeOs2Al10 , also well above the Hill limit of 3.40 Å. Despite the cage-like structure and large rare-earth separation distances, this study reveals the onset of long-range magnetic ordering in CeRh2Al10 at 3.9 K. The magnetic ordering develops out of an incoherent Kondo state that dominates the electrical resistivity below about 40 K.

Crystal structures of orthorhombic, hexagonal, and cubic compounds of the Sm(x)Yb(2−x)TiO5 series

International Nuclear Information System (INIS)

Aughterson, Robert D.; Lumpkin, Gregory R.; Reyes, Massey de los; Sharma, Neeraj; Ling, Christopher D.; Gault, Baptiste; Smith, Katherine L.; Avdeev, Maxim; Cairney, Julie M.

2014-01-01

A series of single phase compounds with nominal stoichiometry Sm (x) Yb (2−x) TiO 5 (x=2, 1.4, 1, 0.6, and 0) have been successfully fabricated to generate a range of crystal structures covering the most common polymorphs previously discovered in the Ln 2 TiO 5 series (Ln=lanthanides and yttrium). Four of the five samples have not been previously fabricated in bulk, single phase form so their crystal structures are refined and detailed using powder synchrotron and single crystal x-ray diffraction, neutron diffraction and transmission electron microscopy. Based on the phase information from diffraction data, there are four crystal structure types in this series; orthorhombic Pnma, hexagonal P6 3 /mmc, cubic (pyrochlore-like) Fd-3m and cubic (fluorite-like) Fm-3m. The cubic materials show modulated structures with variation between long and short range ordering and the variety of diffraction techniques were used to describe these complex crystal structure types. - Graphical abstract: A high resolution image of the compound Sm 0.6 Yb 1.4 TiO 5 showing contrast from lattice fringes and the corresponding fast Fourier transform (FFT) of the HREM image with pyrochlore related diffraction spots marked “P” and fluorite marked “F”. The crystal is oriented down the [1 1 0] zone axis based on the Fd-3m structure. The ideal crystal structure (no vacancies) of the cubic, pyrochlore-like (Sm 0.6 Yb 1.4 TiO 5 ). - Highlights: • First fabrication of bulk single-phase material with stoichiometry Sm 2 TiO 5 . • Systematic study of crystal structure types within Ln 2 TiO 5 series (Ln=lanthanides). • A novel technique using IFFT of HREM images to study cubic structures

B11 NMR in the layered diborides OsB2 and RuB2

Science.gov (United States)

Suh, B. J.; Zong, X.; Singh, Y.; Niazi, A.; Johnston, D. C.

2007-10-01

B11 nuclear magnetic resonance (NMR) measurements have been performed on B11 enriched OsB2 and RuB2 polycrystalline powder samples in an external field of 4.7T and in the temperature range, 4.2KOsB2 and RuB2 , respectively. The experimental results indicate that a p character dominates the conduction electron wave function at the B site with a negligibly small s character in both compounds.

Calculations of the magnetic properties of R{sub 2}M{sub 14}B intermetallic compounds (R=rare earth, M=Fe, Co)

Energy Technology Data Exchange (ETDEWEB)

Ito, Masaaki, E-mail: masaaki.ito@neel.cnrs.fr [CNRS, Institut Néel, 25 rue des Martyrs, BP166, 38042 Grenoble (France); University Grenoble Alpes, Institut Néel, 38042 Grenoble (France); Advanced Material Engineering Division, Toyota Motor Corporation, Susono 410-1193 (Japan); Yano, Masao [Advanced Material Engineering Division, Toyota Motor Corporation, Susono 410-1193 (Japan); Dempsey, Nora M. [CNRS, Institut Néel, 25 rue des Martyrs, BP166, 38042 Grenoble (France); University Grenoble Alpes, Institut Néel, 38042 Grenoble (France); Givord, Dominique [CNRS, Institut Néel, 25 rue des Martyrs, BP166, 38042 Grenoble (France); University Grenoble Alpes, Institut Néel, 38042 Grenoble (France); Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro (Brazil)

2016-02-15

The hard magnetic properties of “R–M–B” (R=rare earth, M=mainly Fe) magnets derive from the specific intrinsic magnetic properties encountered in Fe-rich R{sub 2}M{sub 14}B compounds. Exchange interactions are dominated by the 3d elements, Fe and Co, and may be modeled at the macroscopic scale with good accuracy. Based on classical formulae that relate the anisotropy coefficients to the crystalline electric field parameters and exchange interactions, a simple numerical approach is used to derive the temperature dependence of anisotropy in various R{sub 2}Fe{sub 14}B compounds (R=Pr, Nd, Dy). Remarkably, a unique set of crystal field parameters give fair agreement with the experimentally measured properties of all compounds. This implies reciprocally that the properties of compounds that incorporate a mixture of different rare-earth elements may be predicted accurately. This is of special interest for material optimization that often involves the partial replacement of Nd with another R element and also the substitution of Co for Fe. - Highlights: • Anisotropy constants derived from CEF parameters of R{sub 2}M{sub 14}B compounds (M=Fe, Co). • Anisotropy constants of all R{sub 2}Fe{sub 14}B compounds using unique set of CEF parameters. • Moment non-collinearity in magnetization processes under B{sub app} along hard axis.

The RMgSn{sub 2} series of compounds (R = rare earth metal). Synthesis, crystal structure, and magnetic measurements

Energy Technology Data Exchange (ETDEWEB)

Solokha, Pavlo; Minetti, Riccardo; De Negri, Serena; Saccone, Adriana [Dipartimento di Chimica e Chimica Industriale, Universita di Genova (Italy); Pereira, Laura Cristina J.; Goncalves, Antonio P. [Centro de Ciencias e Tecnologias Nucleares, Instituto Superior Tecnico, EN 10, Universidade de Lisboa, Bobadela (Portugal)

2017-06-30

The novel isostructural series of phases RMgSn{sub 2} (R = Y, La-Nd, Sm, Gd-Tm, Lu) is presented. They were prepared by direct synthesis in an induction furnace and subsequently annealed at 500 C. Their crystal structures were determined through single-crystal X-ray diffraction analysis of the Ce representative [I anti 42m, tI32-LaMgSn{sub 2}, Z = 8, a = 0.82863(3) nm, c = 1.23129(5) nm] and confirmed by powder X-ray diffraction analysis of the other members of the series. Rietveld refinements were also performed on the homologues with R = Pr, Tm, and Y. The title phases show a unique space distribution of atoms, characterized by the presence of a Sn-Sn dumbbell distanced at around 0.29 nm. Their structures are related to those of a few binary AeTt{sub 3} (Ae = alkaline earth; Tt = Si, Ge; I4/mmm, tI32-YbSi{sub 3}) compounds that are stable at high pressure, characterized by a more complex 3D covalently bonded Tt network. Compounds CeMgSn{sub 2} and TbMgSn{sub 2} were magnetically characterized; they show paramagnetic behavior with the presence of ferromagnetic interactions, more pronounced in the case of TbMgSn{sub 2}, as suggested by the Curie-Weiss temperatures, determined in the high-temperature range, of 0.96 and 27.6 K for CeMgSn{sub 2} and TbMgSn{sub 2}, respectively. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Comparison of zwitterionic N-alkylaminomethanesulfonic acids to related compounds in the Good buffer series

Directory of Open Access Journals (Sweden)

Robert D. Long

2010-04-01

Full Text Available Several N-alkyl and N,N-dialkylaminomethanesulfonic acids were synthesized (as zwitterions and/or sodium salts to be tested for utility as biological buffers at lower pH levels than existing Good buffer compounds (aminoalkanesulfonates with a minimum of two carbons between amine and sulfonic acid groups as originally described by Norman Good, and in common use as biological buffers. Our hypothesis was that a shorter carbon chain (one carbon between the amino and sulfonic acid groups should lower the ammonium ion pKa values. The alkylaminomethanesulfonate compounds were synthesized in aqueous solution by reaction of primary or secondary amines with formaldehyde/sodium hydrogensulfite addition compound. The pKa values of the ammonium ions of this series of compounds (compared to existing Good buffers was found to correlate well with the length of the carbon chain between the amino and sulfonate moeties, with a significant decrease in amine basicity in the aminomethanesulfonate compounds (pKa decrease of 2 units or more compared to existing Good buffers. An exception was found for the 2-hydroxypiperazine series which shows only a small pKa decrease, probably due to the site of protonation in this compound (as confirmed by X-ray crystal structure. X-ray crystallographic structures of two members of the series are reported. Several of these compounds have pKa values that would indicate potential utility for buffering at pH levels below the normal physiological range (pKa values in the range of 3 to 6 without aqueous solubility problems – a range that is problematic for currently available Good buffers. Unfortunately, the alkylaminomethanesulfonates were found to degrade (with loss of their buffering ability at pH levels below the pKa value and were unstable at elevated temperature (as when autoclaving – thus limiting their utility.

Compounding approach for univariate time series with nonstationary variances

Science.gov (United States)

Schäfer, Rudi; Barkhofen, Sonja; Guhr, Thomas; Stöckmann, Hans-Jürgen; Kuhl, Ulrich

2015-12-01

A defining feature of nonstationary systems is the time dependence of their statistical parameters. Measured time series may exhibit Gaussian statistics on short time horizons, due to the central limit theorem. The sample statistics for long time horizons, however, averages over the time-dependent variances. To model the long-term statistical behavior, we compound the local distribution with the distribution of its parameters. Here, we consider two concrete, but diverse, examples of such nonstationary systems: the turbulent air flow of a fan and a time series of foreign exchange rates. Our main focus is to empirically determine the appropriate parameter distribution for the compounding approach. To this end, we extract the relevant time scales by decomposing the time signals into windows and determine the distribution function of the thus obtained local variances.

The relation of the broad band with the E2g phonon and superconductivity in the Mg(B1-xCx)2 compound

International Nuclear Information System (INIS)

Parisiades, P.; Lampakis, D.; Palles, D.; Liarokapis, E.; Karpinski, J.

2007-01-01

We have carried out an extensive micro-Raman study on Mg(B 1-x C x ) 2 single crystals, for carbon concentrations up to x=0.15. The E 2g symmetry broad band for pure MgB 2 at ∼600cm -1 disappears even for small doping levels (x=0.027) and two well-defined peaks in the high-energy side of this band play a major role in the Raman spectra of the substituted compounds. We propose that a two-mode behavior of the compound might be present, induced by the coupling of the observed phonons with the electronic bands

3D-QSAR studies on CCR2B receptor antagonists: Insight into the structural requirements of (R-3-aminopyrrolidine series of molecules based on CoMFA/CoMSIA models

Directory of Open Access Journals (Sweden)

Swetha Gade

2012-01-01

Full Text Available Objective: Monocyte chemo attractant protein-1 (MCP-1 is a member of the CC-chemokine family and it selectively recruits leukocytes from the circulation to the site of inflammation through binding with the chemotactic cytokine receptor 2B (CCR2B. The recruitment and activation of selected populations of leukocytes is a key feature in a variety of inflammatory conditions. Thus MCP-1 receptor antagonist represents an attractive target for drug discovery. To understand the structural requirements that will lead to enhanced inhibitory potencies, we have carried out 3D-QSAR (quantitative structure-activity relationship studies on (R-3-aminopyrrolidine series of molecules as CCR2B receptor antagonists. Materials and Methods: Comparative molecular field analysis (CoMFA and comparative molecular similarity indices analysis (CoMSIA were performed on a series of (R-3-aminopyrrolidine derivatives as antagonists of CCR2B receptor with Sybyl 6.7v. Results: We have derived statistically significant model from 37 molecules and validated it against an external test set of 13 compounds. The CoMFA model yielded a leave one out r 2 (r 2 loo of 0.847, non-cross-validated r 2 (r 2 ncv of 0.977, F value of 267.930, and bootstrapped r 2 (r 2 bs of 0.988. We have derived the standard error of prediction value of 0.367, standard error of estimate 0.141, and a reliable external predictivity, with a predictive r 2 (r 2 pred of 0.673. While the CoMSIA model yielded an r 2 loo of 0.719, r 2 ncv of 0.964,F value of 135.666, r 2 bs of 0.975, standard error of prediction of 0.512, standard error of estimate of 0.180, and an external predictivity with an r 2 pred of 0.611. These validation tests not only revealed the robustness of the models but also demonstrated that for our models r 2 pred, based on the mean activity of test set compounds can accurately estimate external predictivity. Conclusion: The QSAR model gave satisfactory statistical results in terms of q 2 and r 2

Reactions of 3d-series metallocenes with organic cadmium compounds

International Nuclear Information System (INIS)

Razuvaev, G.A.; Mar'in, V.P.; Vyshinskaya, L.I.; Grinval'd, I.I.; Spiridonova, N.N.

1987-01-01

Interaction of organic cadmium compounds and 3d-series metallocenes, Cp 2 M (M=V, Cr, Mn, Ni, Co) has been studied. It is shown that direction of these reactions is determined by metallocene nature. Reactions of oxidizing addition leading to σ-complexes formation are characteristic for vanadium and chromium metallocenes. When reacting cobaltocene with R 2 Cd, R group introduction to cyclopentadienyl ring and elimination of cobalt diene complexes take place. Manganocene and nickelocene interaction goes through the stage of complex formation with transition metal - cadmium bond

Preparation, characterization, and thermal stability of B2O3-ZrO2

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Theresia Debora Simbolon

2017-04-01

Full Text Available Synthesis of the borate-based compound with ZrOCl2 to form B2O3-ZrO2 has been conducted. The compound was characterized by FT-IR spectrophotometer, X-ray diffraction, acidity and thermal stability test. The results showed that the FT-IR main vibration spectrum of B2O3-ZrO2 compound has appeared at wave number 401.2 cm-1 for Zr-O bonding vibration, 617.2 cm-1 for B-O-B bonding vibration and 910.4 cm-1 for B-O bonding vibration. The XRD diffraction pattern shows B2O3-ZrO2 compound has an amorphous structure. The FT-IR spectrum after saturated with ammonia and potentiometric titration indicates that the compound of B2O3-ZrO2 has acidic properties with a strong level of acidity. Thermal stability test shows that the B2O3-ZrO2 compounds have high stability on temperature with increasing crystallinity after the compound was heated at 700 °C. Keywords: B2O3-ZrO2, impregnation, thermal stability.

Hepatitis A, B, and A/B vaccination series completion among US adults: a claims-based analysis.

Science.gov (United States)

Ghaswalla, Parinaz K; Patterson, Brandon J; Cheng, Wendy Y; Duchesneau, Emilie; Macheca, Monica; Duh, Mei Sheng

2018-06-20

Hepatitis A and B disease burden persists in the US. We assessed hepatitis A and hepatitis B vaccination series completion rates among 350,240 commercial/Medicare and 12,599 Medicaid enrollees aged ≥19 years. A vaccination series was considered as completed provided that the minimum interval between doses, as defined by the CDC, and the minimum number of doses were reached. We stratified completion rates by vaccine type (i.e. monovalent or bivalent) at initial vaccination for each cohort. In the commercial/Medicare cohort, the series completion rate was 32.0% for hepatitis A and 39.6% for hepatitis B among those who initiated with a monovalent vaccine, and it was 36.2% for hepatitis A and 48.9% for hepatitis B among those who initiated with a bivalent vaccine. In the Medicaid cohort, the series completion rate was 21.0% for hepatitis A and 24.0% for hepatitis B among those who initiated with a monovalent vaccine, and it was 19.0% for hepatitis A and 24.6% for hepatitis B among those who initiated with a bivalent vaccine. In conclusion, hepatitis A and B vaccination series completion rates were low, and appeared to be lower among Medicaid than among commercial/Medicare enrollees. Commercial/Medicare enrollees who initiated with a bivalent vaccine had higher series completion rates than those who initiated with monovalent vaccines - an observation that was not made among Medicaid enrollees.

Novel series of 1,2,4-trioxane derivatives as antimalarial agents.

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Rudrapal, Mithun; Chetia, Dipak; Singh, Vineeta

2017-12-01

Among three series of 1,2,4-trioxane derivatives, five compounds showed good in vitro antimalarial activity, three compounds of which exhibited better activity against P. falciparum resistant (RKL9) strain than the sensitive (3D7) one. Two best compounds were one from aryl series and the other from heteroaryl series with IC 50 values of 1.24 µM and 1.24 µM and 1.06 µM and 1.17 µM, against sensitive and resistant strains, respectively. Further, trioxane derivatives exhibited good binding affinity for the P. falciparum cysteine protease falcipain 2 receptor (PDB id: 3BPF) with well defined drug-like and pharmacokinetic properties based on Lipinski's rule of five with additional physicochemical and ADMET parameters. In view of having antimalarial potential, 1,2,4-trioxane derivative(s) reported herein may be useful as novel antimalarial lead(s) in the discovery and development of future antimalarial drug candidates as P. falciparum falcipain 2 inhibitors against resistant malaria.

Structure of the Francisella response regulator QseB receiver domain, and characterization of QseB inhibition by antibiofilm 2-aminoimidazole-based compounds: Inhibition of response regulator QseB by antibiofilm compounds

Energy Technology Data Exchange (ETDEWEB)

Milton, Morgan E.; Allen, C. Leigh; Feldmann, Erik A.; Bobay, Benjamin G.; Jung, David K.; Stephens, Matthew D.; Melander, Roberta J.; Theisen, Kelly E.; Zeng, Daina; Thompson, Richele J.; Melander, Christian; Cavanagh, John (NCSU)

2017-08-16

With antibiotic resistance increasing at alarming rates, targets for new antimicrobial therapies must be identified. A particularly promising target is the bacterial two-component system. Two-component systems allow bacteria to detect, evaluate and protect themselves against changes in the environment, such as exposure to antibiotics and also to trigger production of virulence factors. Drugs that target the response regulator portion of two-component systems represent a potent new approach so far unexploited. Here, we focus efforts on the highly virulent bacterium Francisella tularensis tularensis. Francisella contains only three response regulators, making it an ideal system to study. In this study, we initially present the structure of the N-terminal domain of QseB, the response regulator responsible for biofilm formation. Subsequently, using binding assays, computational docking and cellular studies, we show that QseB interacts with2-aminoimidazole based compounds that impede its function. This information will assist in tailoring compounds to act as adjuvants that will enhance the effect of antibiotics.

Design and synthesis of N-(4-aminopyridin-2-yl)amides as B-Raf(V600E) inhibitors.

Science.gov (United States)

Li, Xiaokai; Shen, Jiayi; Tan, Li; Zhang, Zhang; Gao, Donglin; Luo, Jinfeng; Cheng, Huimin; Zhou, Xiaoping; Ma, Jie; Ding, Ke; Lu, Xiaoyun

2016-06-15

B-Raf(V600E) was an effective target for the treatment of human cancers. Based on a pan-Raf inhibitor TAK-632, a series of N-(4-aminopyridin-2-yl)amide derivatives were designed as novel B-Raf(V600E) inhibitors. Detailed structure-activity studies of the compounds revealed that most of the compounds displayed potent enzymatic activity against B-Raf(V600E), and good selectivity over B-Raf(WT). One of the most promising compound 4l exhibited potent inhibitory activity with an IC50 value of 38nM for B-raf(V600E), and displayed antiproliferative activities against colo205 and HT29 cells with IC50 values of 0.136 and 0.094μM, respectively. It also displayed good selectivity on both enzymatic and cellular assays over B-Raf(WT). These inhibitors may serve as lead compounds for further developing novel B-Raf(V600E) inhibitors as anticancer drugs. Copyright © 2016 Elsevier Ltd. All rights reserved.

Magnetic properties of Np2T2Sn compounds

International Nuclear Information System (INIS)

Sanchez, J.P.; Colineau, E.; Jeandey, C.; Oddou, J.L.; Rebizant, J.; Seret, A.; Spirlet, J.C.

1994-01-01

The magnetic properties of the Np 2 T 2 Sn series investigated by 237 Np Moessbauer spectroscopy are reported. Magnetic ordering is shown to occur for T = Ni, Pd, Pt, whereas the Np ions do not carry a local moment when T = Co, Ru, Rh. Comparison is made with the corresponding Np 2 T 2 In and U 2 T 2 Sn compounds. (authors). 5 refs., 3 figs

Anti-Pseudomonas aeruginosa compound, 1,2,3,4-tetrahydro-1,3,5-triazine derivative, exerts its action by primarily targeting MreB.

Science.gov (United States)

Yamachika, Shinichiro; Sugihara, Chika; Tsuji, Hayato; Muramatsu, Yasunori; Kamai, Yasuki; Yamashita, Makoto

2012-01-01

In order to find new anti-Pseudomonas agents, we carried out whole-cell based P. aeruginosa growth assay, and identified 1,2,3,4-tetrahydro-1,3,5-triazine (Compound A). This compound showed anti-Pseudomonas activity against wild as well as pumpless strain equally at a same concentration. Also, this compound was structurally very similar to A22, which is known to inhibit the bacterial actin-like protein MreB. By the analysis of resistant strains, the primary target of this compound in P. aeruginosa was definitely confirmed to be MreB. In addition, these compounds showed a bacteriostatic effect, and induced the morphology changes in P. aeruginosa from rod shape to sphere shape, which leads to be clinically favorable in terms of susceptibility to phagocytosis and release of endotoxin. These results display that Compound A is a very attractive compound which shows anti-P. aeruginosa activity based on inhibition of MreB without being affected by efflux pumps, and could provide a new step toward development of new promising anti-Pseudomonas agents, MreB inhibitors.

Isoprenylated phenolic compounds with PTP1B inhibition from Morus alba.

Science.gov (United States)

Huang, Qing-Hua; Lei, Chun; Wang, Pei-Pei; Li, Jing-Ya; Li, Jia; Hou, Ai-Jun

2017-10-01

Two new Diels-Alder adducts, albasins A and B (1 and 2), one new isoprenylated 2-arylbenzofuran, albasin C (3), one new isoprenylated flavone, albasin D (4), together with sixteen known phenolic compounds, were isolated from the root bark of Morus alba. Their structures were elucidated by extensive spectroscopic analysis, including NMR, MS, and ECD data. All the new compounds and most of the known ones showed significant inhibitory effects on PTP1B in vitro with IC 50 values ranging from 0.57 to 7.49μM. Copyright © 2017 Elsevier B.V. All rights reserved.

Metamagnetic behaviour of La1-xGdxFe12B6 compounds

International Nuclear Information System (INIS)

Li, Q.A.; Groot, C.H. de; Boer, F.R. de; Buschow, K.H.J.

1997-01-01

The magnetic properties of compounds of the type La 1-x Gd x Fe 12 B 6 have been studied in high magnetic fields at 4.2 K. LaFe 12 B 6 is a compound with Fe moments close to magnetic instability and values not larger than about 0.5 μ B . Substitution of Gd for part of the La and application of high magnetic fields enhance the Fe moments to values in excess of 2 μ B . The high-moment state in LaFe 12 B 6 is reached via a metamagnetic transition. This first-order transition is associated with an extremely large hysteresis of nearly 7 T at 4.2 K. (orig.)

Deduction of the chemical state and the electronic structure of Nd{sub 2}Fe{sub 14}B compound from X-ray photoelectron spectroscopy core-level and valence-band spectra

Energy Technology Data Exchange (ETDEWEB)

Wang, Jing; Liang, Le [School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Zhang, Lanting, E-mail: lantingzh@sjtu.edu.cn, E-mail: lmsun@sjtu.edu.cn [School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Hirano Institute for Materials Innovation, Shanghai Jiao Tong University, Shanghai 200240 (China); Sun, Limin, E-mail: lantingzh@sjtu.edu.cn, E-mail: lmsun@sjtu.edu.cn [Instrumental Analysis Center, Shanghai Jiao Tong University, Shanghai 200240 (China); Hirano, Shinichi [Hirano Institute for Materials Innovation, Shanghai Jiao Tong University, Shanghai 200240 (China)

2014-10-28

Characterization of chemical state and electronic structure of the technologically important Nd{sub 2}Fe{sub 14}B compound is attractive for understanding the physical nature of its excellent magnetic properties. X-ray photoelectron spectroscopy (XPS) study of such rare-earth compound is important and also challenging due to the easy oxidation of surface and small photoelectron cross-sections of rare-earth 4f electrons and B 2p electrons, etc. Here, we reported an investigation based on XPS spectra of Nd{sub 2}Fe{sub 14}B compound as a function of Ar ion sputtering time. The chemical state of Fe and that of B in Nd{sub 2}Fe{sub 14}B compound can be clearly determined to be 0 and −3, respectively. The Nd in Nd{sub 2}Fe{sub 14}B compound is found to have the chemical state of close to +3 instead of +3 as compared with the Nd in Nd{sub 2}O{sub 3}. In addition, by comparing the valence-band spectrum of Nd{sub 2}Fe{sub 14}B compound to that of the pure Fe, the contributions from Nd, Fe, and B to the valence-band structure of Nd{sub 2}Fe{sub 14}B compound is made more clear. The B 2p states and B 2s states are identified to be at ∼11.2 eV and ∼24.6 eV, respectively, which is reported for the first time. The contribution from Nd 4f states can be identified both in XPS core-level spectrum and XPS valence-band spectrum. Although Nd 4f states partially hybridize with Fe 3d states, Nd 4f states are mainly localized in Nd{sub 2}Fe{sub 14}B compound.

Imidazopyridine Compounds Inhibit Mycobacterial Growth by Depleting ATP Levels.

Science.gov (United States)

O'Malley, Theresa; Alling, Torey; Early, Julie V; Wescott, Heather A; Kumar, Anuradha; Moraski, Garrett C; Miller, Marvin J; Masquelin, Thierry; Hipskind, Philip A; Parish, Tanya

2018-06-01

The imidazopyridines are a promising new class of antitubercular agents with potent activity in vitro and in vivo We isolated mutants of Mycobacterium tuberculosis resistant to a representative imidazopyridine; the mutants had large shifts (>20-fold) in MIC. Whole-genome sequencing revealed mutations in Rv1339, a hypothetical protein of unknown function. We isolated mutants resistant to three further compounds from the series; resistant mutants isolated from two of the compounds had single nucleotide polymorphisms in Rv1339 and resistant mutants isolated from the third compound had single nucleotide polymorphisms in QcrB, the proposed target for the series. All the strains were resistant to two compounds, regardless of the mutation, and a strain carrying the QcrB T313I mutation was resistant to all of the imidazopyridine derivatives tested, confirming cross-resistance. By monitoring pH homeostasis and ATP generation, we confirmed that compounds from the series were targeting QcrB; imidazopyridines disrupted pH homeostasis and depleted ATP, providing further evidence of an effect on the electron transport chain. A representative compound was bacteriostatic against replicating bacteria, consistent with a mode of action against QcrB. The series had a narrow inhibitory spectrum, with no activity against other bacterial species. No synergy or antagonism was seen with other antituberculosis drugs under development. In conclusion, our data support the hypothesis that the imidazopyridine series functions by reducing ATP generation via inhibition of QcrB. Copyright © 2018 O'Malley et al.

Crystal-fields at rare-earth sites in R2Fe14B compounds

International Nuclear Information System (INIS)

Adam, S.; Adam, G.; Burzo, E.

1985-12-01

Crystal-field effects are expected to be important in R 2 Fe 14 B compounds. Within a model-independent approach, it is proved that four distinct rare-earth sites exist with respect to the crystalline electric fields, namely, R(4f; z=0), R(4f; z=0.5 c), R(4g; z=0), and R(4g; z=0.5 c), and relationships are established between the corresponding crystal-fields coefficients. Further, generalized Stevens parametrizations of the crystal field coefficients are derived at three levels of approximation for the interatomic forces inside the crystal. A crystal lattice dressing effect upon the radial electronic integrals is found to occur, the magnitude of which depends on the deviation of the interatomic forces from Coulombian. Finally, computation of crystal-field coefficients in Nd 2 Fe 14 B leads to results which raise questions about the validity of the simple Coulomb point-charge model. (author)

Design and synthesis of novel sulfonamide-containing bradykinin hB2 receptor antagonists. 2. Synthesis and structure-activity relationships of alpha,alpha-cycloalkylglycine sulfonamides.

Science.gov (United States)

Fattori, Daniela; Rossi, Cristina; Fincham, Christopher I; Caciagli, Valerio; Catrambone, Fernando; D'Andrea, Piero; Felicetti, Patrizia; Gensini, Martina; Marastoni, Elena; Nannicini, Rossano; Paris, Marielle; Terracciano, Rosa; Bressan, Alessandro; Giuliani, Sandro; Maggi, Carlo A; Meini, Stefania; Valenti, Claudio; Quartara, Laura

2007-02-08

Recently we reported on the design and synthesis of a novel class of selective nonpeptide bradykinin (BK) B2 receptor antagonists (J. Med. Chem. 2006, 3602-3613). This work led to the discovery of MEN 15442, an antagonist with subnanomolar affinity for the human B2 receptor (hB2R), which also displayed significant and prolonged activity in vivo (for up to 210 min) against BK-induced bronchoconstriction in the guinea-pig at a dose of 300 nmol/kg (it), while demonstrating only a slight effect on BK-induced hypotension. Here we describe the further optimization of this series of compounds aimed at maximizing the effect on bronchoconstriction and minimizing the effect on hypotension, with a view to developing topically delivered drugs for airway diseases. The work led to the discovery of MEN 16132, a compound which, after intratracheal or aerosol administration, inhibited, in a dose-dependent manner, BK-induced bronchoconstricton in the airways, while showing minimal systemic activity. This compound was selected as a preclinical candidate for the topical treatment of airway diseases involving kinin B2 receptor stimulation.

Synthesis and spectroscopic and structural characterization of the monomeric diborylphosphine and diphosphinoborane compounds PhP(BMes2)2 and MesB(PPh2)2 (Mes = 2,4,6-Me3C6H2)

International Nuclear Information System (INIS)

Bartlett, R.A.; Dias, H.V.R.; Power, P.P.

1988-01-01

The synthesis and spectroscopic and first x-ray structural characterization of a diborylphosphine, PhP(BMes 2 ) 2 (1), and a diphosphinoborane, MesB(PPh 2 ) 2 (2), are described. The structure of 1 has a planar core that involves the phosphorus and two boron atoms and also the five substituent carbons. In addition, the B-P bond lengths are shortened, which suggests a close structural analogy between 1 and the allyl cation. In the case of 2, although the boron remains planar, both phosphorus centers are pyramidal with slightly longer B-P bonds than in 1. Both 1 and 2 are the first examples of their respective classes of compound to be well characterized. Crystal data with Mo Kα radiation (λ = 0.71069 /angstrom/) at 130 K are as follows. 1: a = 14.302 (4) /angstrom/, b = 15.701 (3) /angstrom/, c = 16.601 (6) /angstrom/, β = 109.61 (2)/degrees/; monoclinic, space group C2/c, Z = 4, R = 0.059. 2: a = 7.815 (2) /angstrom/, b = 8.723 (2) /angstrom/, c = 40.147 (10) /angstrom/, β = 94.90 (2)/degrees/; monoclinic, space group P2 1 /n, Z = 4, R = 0.041. A listing of available 11 B and 31 P NMR data on compounds involving triply connected boron and phosphorus centers is also provided and discussed in the context of the data for 1 and 2. 25 references, 2 figures, 4 tables

Study of the CdX-B2X3-X (X=S, Se), CdTe-B-Te systems

International Nuclear Information System (INIS)

Odin, I.N.; Grin'ko, V.V.; Safronov, E.V.; Kozlovskij, V.F.

2001-01-01

Liquidus surfaces of the CdX-B 2 X 3 -X (X=S, Se), CdTe-B-Te systems are plotted for the first time. It is shown that in equilibrium solid solutions on the basis of ternary Cd 2 B 2 X 5 compounds and binary B 2 X 3 , CdX, BS 2 compounds take part with liquid phases. p gen -T and T-x projects of p-T-x phase diagram of B-S (59-100 at. % S), B-Se (59-100 at. % Se), B-Te systems are plotted . B 2 X 3 , BS 2 compounds are formed in that regions of compositions of B-X systems . In the B-Te system compounds are not formed. Ternary compounds are not formed in the CdTe-B-Te system [ru

Structure and bonding of transition metal-boryl compounds. Theoretical study of [(PH3)2(CO)ClOs-BR2] and [(PH3)2(CO)2ClOs-BR2] (BR2 = BH2, BF2, B(OH)2, B(OCH=CHO), Bcat).

Science.gov (United States)

Giju, K T; Bickelhaupt, F M; Frenking, G

2000-10-16

Quantum chemical DFT calculations using the B3LYP functionals have been carried out for the electronically unsaturated 16 VE five-coordinate osmium boryl-complexes [(PH3)2(CO)ClOs-BR2] and the 18 VE six-coordinate complexes [(PH3)2(CO)2ClOs-BR2] with BR2 = BH2, BF2, B(OH)2, B(OHC=CHO), and Bcat (cat = catecholate O2C6H4). The bonding situation of the Os-BR2 bond was analyzed with the help of the NBO partitioning scheme. The Os-B bond dissociation energies of the 16 VE complexes are very high, and they do not change very much for the different boryl ligands. The 18 VE complexes have only slightly lower bond energies than the 16 VE species. The Os-B bond in both classes of compounds is provided by a covalent sigma-bond which is polarized toward osmium and by strong charge attraction. Os-->B pi-donation is not important for the Os-B binding interactions, except for the Os-BH2 complexes. The stability of the boryl complexes [Os]-BR2 comes mainly from BB pi-donation. The intraligand charge distribution of the BR2 group changes little when the Os-B bond is formed, except for BH2. The CO ligand in [(PH3)2(CO)2ClOs-BR2] which is trans to BR2 has a relatively weak bond to the osmium atom.

Composition of the volatile compounds from Aniba canelilla (H. B. K. Mez. extracted by CO2 in the supercritical state

Directory of Open Access Journals (Sweden)

Janete H. Y. Vilegas

Full Text Available The volatile compounds obtained by SFE-CO2 (supercritical fluid extraction utilizing CO2 from the barks of Aniba canelilla (H. B. K. Mez. (Lauraceae were analyzed by HRGC-FID (high resolution gas chromatography - flame ionization detector and HRGC-MS (high resolution gas chromatography -mass spectrometry. Phenylpropanoids and lower amounts of sesquiterpenoids, representing ca. 97% of the total oil, were identified. The main compound, 2-phenylnitroethane, corresponds to 71,12% of the total oil.

Design and synthesis of novel sulfonamide-containing bradykinin hB2 receptor antagonists. 1. Synthesis and SAR of alpha,alpha-dimethylglycine sulfonamides.

Science.gov (United States)

Fattori, Daniela; Rossi, Cristina; Fincham, Christopher I; Berettoni, Marco; Calvani, Federico; Catrambone, Fernando; Felicetti, Patrizia; Gensini, Martina; Terracciano, Rosa; Altamura, Maria; Bressan, Alessandro; Giuliani, Sandro; Maggi, Carlo A; Meini, Stefania; Valenti, Claudio; Quartara, Laura

2006-06-15

We recently published the extensive in vivo pharmacological characterization of MEN 16132 (J. Pharmacol. Exp. Ther. 2005, 616-623; Eur. J. Pharmacol. 2005, 528, 7), a member of the sulfonamide-containing human B(2) receptor (hB(2)R) antagonists. Here we report, in detail, how this family of compounds was designed, synthesized, and optimized to provide a group of products with subnanomolar affinity for the hB(2)R and high in vivo potency after topical administration to the respiratory tract. The series was designed on the basis of indications from the X-ray structures of the key structural motifs A and B present in known antagonists and is characterized by the presence of an alpha,alpha-dialkyl amino acid. The first lead (17) of the series was submitted to extensive chemical work to elucidate the structural requirements to increase hB(2) receptor affinity and antagonist potency in bioassays expressing the human B(2) receptor (hB(2)R). The following structural features were selected: a 2,4-dimethylquinoline moiety and a piperazine linker acylated with a basic amino acid. The representative lead compound 68 inhibited the specific binding of [(3)H]BK to hB(2)R with a pKi of 9.4 and antagonized the BK-induced inositolphosphate (IP) accumulation in recombinant cell systems expressing the hB(2)R with a pA(2) of 9.1. Moreover, compound 68 when administered (300 nmol/kg) intratracheally in the anesthetized guinea pig, was able to significantly inhibit BK-induced bronchoconstriction for up to 120 min after its administration, while having a lower and shorter lasting effect on hypotension.

Labelled compounds. (Pt. B)

International Nuclear Information System (INIS)

Buncel, E.; Jones, J.R.

1991-01-01

Since the end of World War II there has been a tremendous increase in the number of compounds that have been synthesized with radioactive or stable isotopes. They have found application in many diverse fields, so much so, that hardly a single area in pure and applied science has not benefited. Not surprisingly it has been reflected in appearance of related publications. The early proceedings of the Symposia on Advances in Trace Methodology were soon followed by various Euratom sponsored meetings in which methods of preparing and storing labelled compounds featured prominently. In due course a resurgence of interest in stable isotopes, brought about by their greater availability (also lower cost) and partly by development of new techniques such as gas chromatography - mass spectrometry (gc-ms), led to the publication of proceedings of several successful conferences. More recently conferences dealing with the synthesis and applications of isotopes and isotopically labelled compounds have been established on a regular basis. In addition to the proceedings of conferences and journal publications individuals left their mark by producing definitive texts, usually on specific nuclides. Only the classic two volume publication of Murray and Williams (Organic syntheses with isotopes, New York 1985), now over 30 years old and out of print, attempted to do justice to several nuclides. With the large amount of work that has been undertaken since then it seems unlikely that an updated edition could be produced. The alternative strategy was to ask scientists currently active to review specific areas and this is the approach adopted in the present series of monographs. In this way it is intended to cover the broad advances that have been made in the synthesis and applications of isotopes and isotopically labelled compounds in the physical and biomedical sciences. (author). refs.; figs.; tabs

Competing anisotropies on 3d sub-lattice of YNi{sub 4–x}Co{sub x}B compounds

Energy Technology Data Exchange (ETDEWEB)

Caraballo Vivas, R. J.; Rocco, D. L.; Reis, M. S. [Instituto de Física, Universidade Federal Fluminense, Av. Gal. Milton Tavares de Souza s/n, 24210-346 Niterói, RJ (Brazil); Costa Soares, T. [Instituto de Física, Universidade Federal Fluminense, Av. Gal. Milton Tavares de Souza s/n, 24210-346 Niterói, RJ (Brazil); IF Sudeste MG Campus de Juiz de Fora-Núcleo de Física, 36080-001 Juiz de Fora, MG (Brazil); Caldeira, L. [IF Sudeste MG Campus de Juiz de Fora-Núcleo de Física, 36080-001 Juiz de Fora, MG (Brazil); Coelho, A. A. [Instituto de Física Gleb Wataghin, Universidade Estadual de Campinas-Unicamp, Caixa postal 6165, 13083-859 Campinas, SP (Brazil)

2014-08-14

The magnetic anisotropy of 3d sub-lattices has an important rule on the overall magnetic properties of hard magnets. Intermetallics alloys with boron (R-Co/Ni-B, for instance) belong to those hard magnets family and are useful objects to help to understand the magnetic behavior of 3d sub-lattice, specially when the rare earth ions R do not have magnetic nature, like YCo{sub 4}B ferromagnetic material. Interestingly, YNi{sub 4}B is a paramagnetic material and Ni ions do not contribute to the magnetic anisotropy. We focused therefore our attention to YNi{sub 4–x}Co{sub x}B series, with x = 0, 1, 2, 3, and 4. The magnetic anisotropy of these compounds is deeper described using statistical and preferential models of Co occupation among the possible Wyckoff positions into the CeCo{sub 4}B type hexagonal structure. We found that the preferential model is the most suitable to explain the magnetization experimental data.

Docking, synthesis and bioassay studies of imine derivatives as potential inhibitors for dengue NS2B/ NS3 serine protease

Directory of Open Access Journals (Sweden)

Neni Frimayanti

2017-11-01

Full Text Available Objective: To search imine derivatives as new active agents against dengue type 2 NS2B/NS3 using molecular docking, since there is no effective vaccine against flaviviral infections. Methods: In this research, molecular docking was performed for a series of imine derivatives and the information obtained from the docking studies was used to explore the binding modes of these imine derivatives with dengue type 2 NS2B/NS3 serine protease. A set of imine were synthesized and bioassay study of the inhibitory activities of these compounds was then performed. Results: The results indicated that MY8 and MY4 have the ability to inhibit DEN2 NS2B/NS3 proteolytic activity. Conclusions: These two compounds were chosen as the reference for the next stage in drug design as new inhibitor agents against NS2B/NS3.

The calculated magnetic, electronic and thermodynamic properties of Ce{sub 3}Co{sub 29}Si{sub 4}B{sub 10} compound

Energy Technology Data Exchange (ETDEWEB)

Huo, Jin-Rong [Institute of Applied Physics, Beijing University of Science and Technology, Beijing 100083 (China); Wang, Xiao-Xu [Institute of Applied Physics, Beijing University of Science and Technology, Beijing 100083 (China); Cloud Computing Department, Beijing Computing Center, Beijing 100084 (China); Hu, Yao-Wen [Department of Physics, Tsinghua University, Beijing 100084 (China); Zhang, Guo-Hua; Cheng, Hai-Xia; Li, Lu [Institute of Applied Physics, Beijing University of Science and Technology, Beijing 100083 (China); Qian, Ping, E-mail: qianping@ustb.edu.cn [Institute of Applied Physics, Beijing University of Science and Technology, Beijing 100083 (China)

2016-05-15

The magnetic moment, lattice parameter and atom fraction coordinates for Ce{sub 3}Co{sub 29}Si{sub 4}B{sub 10} are calculated by the first-principles GGA+U method, and the results indicate that the calculated and experimental values are basically accordant when U=2.6 eV. We study the interaction effect and orbital hybridization between Co and Ce atoms. The projected density of states at U=2.6 eV which provided by Co-2c, Ce-2b and Ce-4d sites are contrasted with else U values. Meanwhile the electron density of states for different sites and the distance between various atoms are exhibited. In addition, the thermodynamic properties of Ce{sub 3}Co{sub 29}Si{sub 4}B{sub 10} are evaluated by using a series of interatomic pair potentials. - Graphical abstract: Change of the total magnetic moment for Ce{sub 3}Co{sub 29}Si{sub 4}B{sub 10} along with the value of U. There is a sharply decline of the curve at U=2.6 eV and, at the moment, the total magnetic moment of the compound have a good agreement with the experimental data. - Highlights: • We research of quaternary rare earth and transition metal compounds. • We perform the calculation of magnetic moment and electronic structure by GGA+U method. • The orbital hybridization between Co and Ce atoms is displayed and analyzed. • Show the plot of projected density of states for different sites more clearly. • Calculate the thermodynamic property of rare-earth transition metal compound.

Magnetic and Moessbauer studies on GdCo3B2 and DyCo3B2

International Nuclear Information System (INIS)

Malik, S.K.; Umarji, A.M.; Shenoy, G.K.

1984-10-01

Magnetization and Moessbauer studies have been carried out on GdCo 3 B 2 and DyCo 3 B 2 . These compounds are magnetically ordered with Curie temperatures of 56 0 and 21 0 K respectively. The Co atoms are either nonmagnetic or carry a small moment in these compounds. The saturation moment of DyCo 3 B 2 at 5 0 K is smaller than the Dy 3+ free-ion value. From 161 Dy Moessbauer studies, the measured hyperfine magnetic field at the Dy site is also observed to be smaller than the free-ion value. 155 Gd Moessbauer measurements in GdCo 3 B 2 reveal the presence of large crystalline electric fields at the rare earth site. This causes the moment and the hyperfine field at the Dy site in DyCo 3 B 2 to be reduced from its free-ion value

Synthesis and SAR studies of novel 2-(6-aminomethylaryl-2-aryl-4-oxo-quinazolin-3(4H)-yl)acetamide vasopressin V1b receptor antagonists.

Science.gov (United States)

Napier, Susan E; Letourneau, Jeffrey J; Ansari, Nasrin; Auld, Douglas S; Baker, James; Best, Stuart; Campbell-Wan, Leigh; Chan, Ray; Craighead, Mark; Desai, Hema; Ho, Koc-Kan; MacSweeney, Cliona; Milne, Rachel; Richard Morphy, J; Neagu, Irina; Ohlmeyer, Michael H J; Pick, Jack; Presland, Jeremy; Riviello, Chris; Zanetakos, Heather A; Zhao, Jiuqiao; Webb, Maria L

2011-06-15

Synthesis and structure-activity relationships (SAR) of a novel series of vasopressin V(1b) antagonists are described. 2-(6-Aminomethylaryl-2-aryl-4-oxo-quinazolin-3(4H)-yl)acetamide have been identified with low nanomolar affinity for the V(1b) receptor and good selectivity with respect to related receptors V(1a), V(2) and OT. Optimised compound 16 shows a good pharmacokinetic profile and activity in a mechanistic model of HPA dysfunction. Copyright © 2011 Elsevier Ltd. All rights reserved.

Boron-substitution and defects in B2-type AlNi compound: Site-preference and influence on structural, thermodynamic and electronic properties

Energy Technology Data Exchange (ETDEWEB)

Capaz, Rodrigo B. [Instituto de Física, Universidade Federal do Rio de Janeiro, Caixa Postal 68528, Rio de Janeiro, RJ 21941-972 (Brazil); ElMassalami, M., E-mail: massalam@if.ufrj.br [Instituto de Física, Universidade Federal do Rio de Janeiro, Caixa Postal 68528, Rio de Janeiro, RJ 21941-972 (Brazil); Terrazos, L.A. [Centro de Educação e Saúde, Universidade Federal de Campina Grande, Cuité, PB 58175-000 (Brazil); Elhadi, M. [Instituto de Física, Universidade Federal do Rio de Janeiro, Caixa Postal 68528, Rio de Janeiro, RJ 21941-972 (Brazil); Takeya, H. [National Institute for Materials Science, 1-2-1, Sengen, Tsukuba, 305-0047 (Japan); Ghivelder, L. [Instituto de Física, Universidade Federal do Rio de Janeiro, Caixa Postal 68528, Rio de Janeiro, RJ 21941-972 (Brazil)

2016-06-05

Using a combination of theoretical (first-principles total-energy and electronic structure calculations) as well as experimental (structural, thermodynamics) techniques, we systematically investigated the influence of B incorporation on the structural, electronic and thermodynamic properties of a series of technologically-important B-containing AlNi matrix. Special attention was paid to calculating the energy cost of placing B at various sites within the cubic unit cell. The most energetically favorable defects were identified to be, depending on initial stoichiometry, substitutional B at Al site (B{sub Al}), Ni vacancy (V{sub Ni}), or Ni antisite (Ni{sub Al}). We show that the induced variation in the lattice parameters can be correlated with the type and concentration of the involved defects: e.g. the surge of V{sub Ni} defects leads to a stronger lattice-parameter reduction, that of Ni{sub Al} ones to a relatively weaker reduction while that of B{sub Al} defects to a much weaker influence. Both electronic band structure calculations as well as thermodynamics measurements indicate that the 3d bands of Ni are fully occupied and magnetically unpolarized and that the resulting N(E{sub F}) is very small: all studied compounds are normal conductors with no trace of superconductivity or magnetic polarization.

Complete titanium substitution by boron in a tetragonal prism: exploring the complex boride series Ti(3-x)Ru(5-y)Ir(y)B(2+x) (0 ≤ x ≤ 1 and 1 theory.

Science.gov (United States)

Fokwa, Boniface P T; Hermus, Martin

2011-04-18

Polycrystalline samples and single crystals of four members of the new complex boride series Ti(3-x)Ru(5-y)Ir(y)B(2+x) (0 ≤ x ≤ 1 and 1 X-ray diffraction as well as energy- and wavelength-dispersive X-ray spectroscopy analyses. They crystallize with the tetragonal Ti(3)Co(5)B(2) structure type in space group P4/mbm (No. 127). Tetragonal prisms of Ru/Ir atoms are filled with titanium in the boron-poorest phase (Ti(3)Ru(2.9)Ir(2.1)B(2)). Gradual substitution of titanium by boron then results in the successive filling of this site by a Ti/B mixture en route to the complete boron occupation, leading to the boron-richest phase (Ti(2)Ru(2.8)Ir(2.2)B(3)). Furthermore, both ruthenium and iridium share two sites in these structures, but a clear Ru/Ir site preference is found. First-principles density functional theory calculations (Vienna ab initio simulation package) on appropriate structural models (using a supercell approach) have provided more evidence on the stability of the boron-richest and -poorest phases, and the calculated lattice parameters corroborate very well with the experimentally found ones. Linear muffin-tin orbital atomic sphere approximation calculations further supported these findings through crystal orbital Hamilton population bonding analyses, which also show that the Ru/Ir-B and Ru/Ir-Ti heteroatomic interactions are mainly responsible for the structural stability of these compounds. Furthermore, some stable and unstable phases of this complex series could be predicted using the rigid-band model. According to the density of states analyses, all phases should be metallic conductors, as was expected from these metal-rich borides.

Nuclear magnetic resonance study of (Y[sub 1-x]R[sub x])[sub 2]Co[sub 14]B compounds (R=Gd, Tb)

Energy Technology Data Exchange (ETDEWEB)

Myojin, T. (Takamatsu National Coll. of Technology, Takamatsu (Japan)); Hayashi, M. (Takamatsu Coll. (Japan)); Ohno, T. (Faculty of Engineering, Tokushima Univ. (Japan)); Imaeda, Y. (Faculty of Engineering, Tokushima Bunri Univ., Shido (Japan)); Ushida, T. (Faculty of Engineering, Tokushima Bunri Univ., Shido (Japan)); Tsujimura, A. (Faculty of Engineering, Tokushima Bunri Univ., Shido (Japan)); Hihara, T. (Faculty of Integrated Arts and Sciences, Hiroshima Univ. (Japan))

1993-03-15

Influence of the Gd spin on the Co hyperfine field has been studied by [sup 59] Co nuclear magnetic resonance (NMR) in (Y[sub 1-x]Gd[sub x])[sub 2]Co[sub 14]B compounds. It is shown that the hyperfine coupling constants from the Gd spin for 8j[sub 1] and 8j[sub 2] sites are negative while those for 16k[sub 1] and 16k[sub 2] sites are positive. The dependence of the spin orientation temperature on the non-magnetic Y concentration in (Y[sub 1-x]Tb[sub x])[sub 2]Co[sub 14]B is also investigated by magnetization and [sup 59]Co NMR measurements. A spin phase diagram for this compound is proposed. (orig.)

Discovery of a Series of Imidazo[4,5-b]pyridines with Dual Activity at Angiotensin II Type 1 Receptor and Peroxisome Proliferator-Activated Receptor-[gamma

Energy Technology Data Exchange (ETDEWEB)

Casimiro-Garcia, Agustin; Filzen, Gary F.; Flynn, Declan; Bigge, Christopher F.; Chen, Jing; Davis, Jo Ann; Dudley, Danette A.; Edmunds, Jeremy J.; Esmaeil, Nadia; Geyer, Andrew; Heemstra, Ronald J.; Jalaie, Mehran; Ohren, Jeffrey F.; Ostroski, Robert; Ellis, Teresa; Schaum, Robert P.; Stoner, Chad (Pfizer)

2013-03-07

Mining of an in-house collection of angiotensin II type 1 receptor antagonists to identify compounds with activity at the peroxisome proliferator-activated receptor-{gamma} (PPAR{gamma}) revealed a new series of imidazo[4,5-b]pyridines 2 possessing activity at these two receptors. Early availability of the crystal structure of the lead compound 2a bound to the ligand binding domain of human PPAR{gamma} confirmed the mode of interaction of this scaffold to the nuclear receptor and assisted in the optimization of PPAR{gamma} activity. Among the new compounds, (S)-3-(5-(2-(1H-tetrazol-5-yl)phenyl)-2,3-dihydro-1H-inden-1-yl)-2-ethyl-5-isobutyl-7-methyl-3H-imidazo[4,5-b]pyridine (2l) was identified as a potent angiotensin II type I receptor blocker (IC{sub 50} = 1.6 nM) with partial PPAR{gamma} agonism (EC{sub 50} = 212 nM, 31% max) and oral bioavailability in rat. The dual pharmacology of 2l was demonstrated in animal models of hypertension (SHR) and insulin resistance (ZDF rat). In the SHR, 2l was highly efficacious in lowering blood pressure, while robust lowering of glucose and triglycerides was observed in the male ZDF rat.

75 FR 34657 - Airworthiness Directives; Bombardier, Inc. Model CL-600-2B19 (Regional Jet Series 100 & 440...

Science.gov (United States)

2010-06-18

... ``dry'' ADG [air driven generator] (Hamilton Sundstrand part number in the 761339 series), in the aft area of the strut and generator housing assembly, have been reported on CL-600-2B19 aircraft. The same... typically 45 days, which is consistent with the comment period for domestic transport ADs. We will post all...

Crystallographic, DFT and docking (cathepsin B) studies on an organotellurium(IV) compound

International Nuclear Information System (INIS)

Caracelli, Ignez; Maganhi, Stella H.; Zukerman-Schpector, Julio; Sousa Madureira, Lucas; Stefani, Helio A.; Guadagnin, Rafael C.; Tiekink, Edward R.T.

2016-01-01

Some biologically active organotellurium compounds exhibit inhibitory potency against cathepsin B. In this study, an alkyl derivative, viz. [CH 3 (CH 2 ) 2 C(I)=C(H)](nBu)TeI 2 , 1, has been structurally characterised by X-ray crystallography and shown to be coordinated within a C 2 I 2 donor set. When the stereochemically active lone pair of electrons is taken into account, a distorted trigonal bipyramidal geometry results with the iodide atoms in axial positions. Both intra- and inter-molecular Te..I interactions are also noted. If all interactions are considered, the coordination geometry is based on a Ψ-pentagonal bipyramidal geometry. An unusual feature of the structure is the curving of the functionalised C 5 chain. This feature has been explored by DFT methods and shown to arise as a result of close C-H..I interactions. A docking study (cathepsin B) was performed to understand the inhibition mechanism and to compare the new results with previous observations. Notably, 1 has the same pose exhibited by analogous biologically active compounds with aryl groups. Thus, the present study suggests that (alkyl) 2 TeX 2 compounds should also be evaluated for biological activity.

Magnetism in ordered metallic perovskite compound GdPd{sub 3}B{sub x}C{sub 1-x}

Energy Technology Data Exchange (ETDEWEB)

Pandey, Abhishek [S.N. Bose National Centre for Basic Sciences, Block-JD, Sector-III, Salt Lake, Kolkata 700098 (India); Experimental Condensed Matter Physics Division, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata 700064 (India)], E-mail: abhishek.phy@gmail.com; Mazumdar, Chandan [Experimental Condensed Matter Physics Division, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata 700064 (India)], E-mail: chandan.mazumdar@saha.ac.in; Ranganathan, R. [Experimental Condensed Matter Physics Division, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata 700064 (India); Dattagupta, S. [Indian Institute of Science Education and Research, Block-HC, Sector-III, Salt Lake, Kolkata 700106 (India)

2009-08-15

We report results of dc-magnetization, ac-susceptibility and magnetoresistance measurements on crystalline metallic-perovskite compounds GdPd{sub 3}B{sub x}C{sub 1-x} (x=0.25, 0.50, 0.75 and 1.00) and the parent cubic compound GdPd{sub 3}. The interest in these materials stems from the observation of negative temperature coefficient of resistance and negative thermal expansion in some of the members of this series. In the present study, we show that by substitution of non-magnetic elements, boron and carbon, the nature of the magnetic interaction can be varied from dominating ferromagnetic to antiferromagnetic and finally to a canted magnetic structure without altering the crystal symmetry of the compounds. The variation of magnetic interaction by modifying the lattice parameter resembles Ruderman-Kittel-Kasuya-Yosida (RKKY) oscillations.

Study of the relationship between chemical structure and antimicrobial activity in a series of hydrazine-based coordination compounds.

Science.gov (United States)

Dobrova, B N; Dimoglo, A S; Chumakov, Y M

2000-08-01

The dependence of antimicrobial activity on the structure of compounds is studied in a series of compounds based on hydrazine coordinated with ions of Cu(II), Ni(II) and Pd(II). The study has been carried out by means of the original electron-topological method developed earlier. A molecular fragment has been found that is only characteristic of biologically active compounds. Its spatial and electron parameters have been used for the quantitative assessment of the activity in view. The results obtained can be used for the antimicrobial activity prediction in a series of compounds with similar structures.

Hydrogen absorption in Zr(Alsub(x)Bsub(1-x))2 (B = Fe, Co) Laves phase compounds

International Nuclear Information System (INIS)

Jacob, I.; Shaltiel, D.

1978-01-01

The hydrogen absorption capacity of the systems Zr(Alsub(x)Fesub(1-x)) 2 and Zr(Alsub(x)Cosub(1-x)) 2 (0 = 2 (A = V, Cr, Mn; B = Fe, Co; 0 =< x =< 1). The maximum hydrogen content in both systems is achieved for x approximately 2/12 at 40 atm and 80 K. Further increase of the Al content leads, however, to a steep decrease in the hydrogen capacity. This general behaviour is well described by a phenomenological model, recently proposed by the authors, thus supporting the importance of short-range neighbouring effects for the hydrogen absorption capacity. The influence of Al on the hydrogen sorption properties in different intermetallic compounds is discussed. (author)

Intratumor heterogeneous distribution of 10B-compounds suggested by the radiobiological findings from in vivo mouse studies

International Nuclear Information System (INIS)

Masunaga, S.; Ono, K.; Sakurai, Y.; Takagaki, M.; Kobayashi, T.; Kinashi, Y.; Akaboshi, M.; Akuta, K.

2000-01-01

After continuous labeling with or without 5-bromo-2'-deoxyuridine (BrdU), SCC VII tumor-bearing mice received one of the following treatments in vivo; 1) Tumor excision right after thermal neutron irradiation following sodium borocaptate- 10 B (BSH) or p-boronophenylalanine- 10 B (BPA) administration. 2) Tumor excision 5 min through 72 h after thermal neutron or γ-ray irradiation. 3) Determination of hypoxic fraction (HF) of implanted tumors by γ-ray test irradiation 5 min through 72 h after thermal neutron or γ-ray irradiation. 4) Determination of the tumor sensitivity to γ-rays 0-24 h after thermal neutron or γ-ray irradiation. The following results were obtained; 1) BSH and BPA sensitized quiescent (Q) and total (proliferating (P) + Q) tumor cells, respectively, and the use of 10 B-compound, especially BPA, widened the sensitivity difference between Q and total cells. 2) The use of 10 B-compound, especially BPA, increased the repair capacity from potentially lethal damage (PLDR) and induced PLDR pattern like post-γ-ray irradiation. 3) Reoxygenation after thermal neutron irradiation following 10 B-compound, especially BPA, administration occurred slowly, compared with after neutron irradiation only and looked like after γ-ray irradiation. 4) The use of 10 B-compound, especially BPA, promoted sublethal damage repair (SLDR) in total cells and the recruitment from Q to P state, compared with after thermal neutron irradiation alone. All these findings suggested the difficulty in distribution of 10 B-compound, especially BPA, in Q cells and the heterogeneity in intratumor distribution of 10 B-compound. (author)

Straightforward Entry toward Highly Substituted 2,3-Dihydrobenz[ b]oxepines by Ring Expansion of Benzopyryliums with Donor-Acceptor Diazo Compounds.

Science.gov (United States)

Courant, Thibaut; Pasco, Morgane; Lecourt, Thomas

2018-05-04

Ylide-type reactivity of diazo compounds is exploited in a new way to prepare benzo[ b]oxepines thanks to the formation of three chemical bonds and two contiguous and highly substituted stereocenters in a single pot. This cationic reaction cascade first involves addition of a donor-acceptor-substituted diazo compound to a benzopyrylium. Selective 1,2 migration of the endocyclic C-C bond then results in a ring-expansion and generates a second oxocarbenium that is trapped by a nucleophile added sequentially.

Simple calculation of hybridization effects in UTX and U2T2X compounds

International Nuclear Information System (INIS)

Prokes, K.; Brueck, E.; Nakotte, H.; De Chatel, P.F.; De Boer, F.R.

1995-01-01

The band widths of several UTX and U 2 T 2 X compounds (T: transition metal, X: p-metal) are evaluated by means of a tight-binding method. The magnetism in both groups of compounds is governed by the hybridization between U f-states and transition-metal d-states. Comparing the sum of all hybridization effects, we find approximately the same hybridization effects in both groups of compounds. We also observe a decrease of the band width with increasing atomic number Z within a transition-metal series. By comparing the band width with the theoretical critical energies for the f 3 and f 2 configurations, it is in some cases possible to predict whether the ground state is magnetically ordered or not. ((orig.))

Syntheses, structures, photoluminescence and photocatalysis of 2D layered lanthanide-carboxylates with 2, 2′-dithiodibenzoic acid

Energy Technology Data Exchange (ETDEWEB)

Ding, Ling; Zhong, Jie-Cen; Qiu, Xing-Tai; Sun, Yan-Qiong, E-mail: sunyq@fzu.edu.cn; Chen, Yi-Ping

2017-02-15

Two series of lanthanide-carboxylates, [Ln(2,2′-dtba)(2,2′-Hdtba)(EtOH)]{sub n} (I:Ln=Eu(1a), Dy(1b)) and [Ln(2,2′-dtba)(2,2′-Hdtba)(4,4′-bpy){sub 0.5}]{sub n} (II:Ln=Eu(2a), Dy(2b), Tb(2c) 2,2′-H{sub 2}dtba=2,2′-dithiodibenzoic acid, 4,4′-bpy=4,4′-bipyridine) have been synthesized under hydrothermal conditions. Interestingly, the H{sub 2}dtba organic ligand was generated by in situ S–S reaction of 2-mercaptobenzoic acid. Compounds I and II possess different 2D layered structures based on similar 1D [Ln(2,2′-dtba)]{sup +} chains. Photoluminescence studies reveal that compounds I and II exhibit strong lanthanide characteristic emission bands. Remarkably, Compounds 1b and 2a both exhibit good photocatalytic activity for degradation of Rhodamine-B (Rh-B) under the simulated sunlight irradiation. - Graphical abstract: Two series of lanthanide-carboxylates have been in situ synthesized under hydrothermal conditions. The lanthanide-carboxylates exhibit strong lanthanide characteristic emission bands and good photocatalytic activity for degradation of Rhodamine-B. - Highlights: • 2D layered lanthanide-carboxylates with 2,2′-dithiodibenzoic acid. • In situ S–S reaction of 2-mercaptobenzoic acid under hydrothermal condition. • The Emission spectra of I and II exhibit the characteristic transition of lanthanide ions. • Compounds 1b and 2a exhibit good photocatalytic activity for degradation of Rhodamine-B.

Circular Cationic Compounds B3Rgn+ of Triangular Ion B3 Trapping Rare Gases

Institute of Scientific and Technical Information of China (English)

ZHANG Ruiwen; LI Anyong; LI Zhuozhe

2017-01-01

The circular cationic compounds B3Rgn+(n=1-3,Rg=He-Rn) formed by the electron-deficient aromatic ion B3+ trapping rare gases were studied theoretically.The formed B-Rg bond has large bonding energy in the range of 60--209 kJ/mol,its length is close to the stun of covalent radii of B and Rg,for Ar-Rn.The analyses based on the natural bond orbitals and electron density topology show that the B-Rg bonds for Ar-Rn have strong covalent character.The geometric structures,binding energy,bond nature and thermodynamic stability of the boron-rare gas compounds show that these species for Ar-Rn may be experimentally available.Several different theoretical studies have demonstrated that these triangular cations are aromatic.

Magnetic properties of ball-milled TbFe2 and TbFe2B

Indian Academy of Sciences (India)

Unknown

1. Introduction. The RFe2 (R = rare earth) Laves phase compounds are known to possess large cubic anisotropy (Clark et al 1972) and highest Curie temperature (TC) of all RT2 compounds. (T = transition metal). RFe2 ... TbFe2 and TbFe2B were prepared by arc melting the high pure elements (Tb and B, 99⋅9% purity; Fe, ...

New liquid crystals in the series of 1, 3, 5-triazine compounds ...

African Journals Online (AJOL)

The Series of compounds were prepared by nucleophilic addition of the primary amino nucleophile to 1,3,5-triazine electrophilic ring via alkyl spacers in presence of potassium carbonate as hydrochloride acceptor. Differencial scanning calorimetry (DSC), polarizing optical microscopy and x-ray diffraction confirmed Smectic ...

Synthesis and antimicrobial activity of some novel fused heterocyclic 1,2,4-triazolo [3,4-b][1,3,4] thiadiazine derivatives

Science.gov (United States)

Sahu, Jagdish K.; Ganguly, Swastika; Kaushik, Atul

2014-01-01

In the present investigation, the synthesis and antimicrobial evaluation of 1,2,4-triazolo [3,4-b][1,3,4] thiadiazine including different pharmacophores are aimed at. In this study, a series of 6-aryl-3- (3,4 -dialkoxyphenyl)-7H -[1,2,4]triazolo [3,4-b][1,3,4] thiadiazine (7a-7k) was synthesized by condensing 4-amino-5-(3,4-dialkoxyphenyl)-4H-[1,2,4]- triazole-3-thiol (6) with various aromatic carboxylic acids in the presence of phenacyl bromides through one-pot reaction. Eleven fused heterocyclic derivatives were successfully synthesized. The structures of these newly synthesized compounds were characterized by IR, 1H NMR and mass spectroscopic studies. All the synthesized compounds were screened for their antimicrobial evaluation. Some of the compounds exhibited promising antimicrobial activity. From the present study it may be concluded that synthesized compounds are fruitful in terms of their structural novelty and marked biological activities. These compounds could be further modified to develop potential and safer antifungal agents. PMID:24959418

Hexagonal perovskites with cationic vacancies. 33. Compounds of type Ba/sub 6-x/Sr/sub x/B/sub 2-y//sup 3 +/SE/sub y//sup 3 +/W/sub 3/vacantO/sub 18/

Energy Technology Data Exchange (ETDEWEB)

Lindner, I; Kemmler-Sack, S [Tuebingen Univ. (Germany, F.R.). Lehrstuhl fuer Anorganische Chemie 2

1982-12-01

In the series Ba/sub 6-x/Sr/sub x/Lu/sub 2-y/SE/sub y//sup 3 +/W/sub 3/vacantO/sub 18/ a substitution of Sr/sup 2 +/ for Ba/sup 2 +/ is possible. According to intensity calculations on powder data of BaSr/sub 5/Lu/sub 1.6/Ho/sub 0.4/W/sub 3/vacantO/sub 18/ the compounds crystallize in a rhombohedral 18 L type with the sequence (hhccc)/sub 3/; space group R-3m. The refined, intensity related R' value is 11.5%. The differences in properties (diffuse reflectance spectra, photoluminescence) between the hexagonal modifications Ba/sub 6/B/sub 2-y//sup 3 +/SE/sub y//sup 3 +/W/sub 3/vacantO/sub 18/ (B/sup 3 +/ = Gd, Y, Lu; SE/sup 3 +/ = Sm, Eu, Tb, Dy, Ho, Er, Tm) and the corresponding cubic HT modifications are discussed.

Enrichment of W2B5 from WO3 and B2O3 by Double SHS Method

Directory of Open Access Journals (Sweden)

Bora DERIN

2018-02-01

Full Text Available A second self-propagating high-temperature synthesis (SHS was carried out to enrich the W2B5 content in the SHS product containing a mixture of various tungsten boride compounds. In the experiment, the process called Double-SHS (D-SHS was conducted in two steps. In the first SHS reaction, an initial molar composition ratio of WO3:B2O3:Mg mixture was selected as 1:3:8. The product was then hot-leached with hydrochloric acid to eliminate MgO and Mg3B2O6 phases. The leached product, consisting of 72.6 wt.% W2B5, 16.1 wt.% WB, 8.4 wt.% W2B, and 2.9 wt.% W, was again reacted with the Mg and B2O3 mixture by second SHS. After another acid leaching step, W2B5 content in the D-SHS product was found to be 98.2 wt.%. The study showed that D-SHS is an effective method for boron enrichment in the tungsten compounds.DOI: http://dx.doi.org/10.5755/j01.ms.24.1.17834

Response of Bioluminescent Bacteria to Alkyltin Compounds.

Science.gov (United States)

1987-12-01

found in the butyltiri series of compounds; tributyltin was (’Stimes more toxic than dibutyltin and (- 50 times more toxic than (mono)butyltin. When...correlations between compounds, tributyltin was -35 tine more Kicrotxit and fish bLoessays for pure toxic than dibutyltin end -750 times More compounds and...the compounds as a decrease in toxicity (5) tributyltin compounds ea -150 tines more and a method to study synergistic andtoxic than trinethyltia

Double-edged swords as cancer therapeutics: novel, orally active, small molecules simultaneously inhibit p53-MDM2 interaction and the NF-κB pathway.

Science.gov (United States)

Zhuang, Chunlin; Miao, Zhenyuan; Wu, Yuelin; Guo, Zizhao; Li, Jin; Yao, Jianzhong; Xing, Chengguo; Sheng, Chunquan; Zhang, Wannian

2014-02-13

Simultaneous inactivation of p53 and hyperactivation of nuclear factor-κB (NF-κB) is a common occurrence in human cancer. Currently, antitumor agents are being designed to selectively activate p53 or inhibit NF-κB. However, there is no concerted effort yet to deliberately design inhibitors that can simultaneously do both. This paper provided a proof-of-concept study that p53-MDM2 interaction and NF-κB pathway can be simultaneously targeted by a small-molecule inhibitor. A series of pyrrolo[3,4-c]pyrazole derivatives were rationally designed and synthesized as the first-in-class inhibitors of p53-MDM2 interaction and NF-κB pathway. Most of the compounds were identified to possess nanomolar p53-MDM2 inhibitory activity. Compounds 5q and 5s suppressed NF-κB activation through inhibition of IκBα phosphorylation and elevation of the cytoplasmic levels of p65 and phosphorylated IKKα/β. Biochemical assay for the kinases also supported the fact that pyrrolo[3,4-c]pyrazole compounds directly targeted the NF-κB pathway. In addition, four compounds (5j, 5q, 5s, and 5u) effectively inhibited tumor growth in the A549 xenograft model. Further pharmacokinetic study revealed that compound 5q exhibited excellent oral bioavailability (72.9%).

Synthesis and properties of compounds (Ln(NO/sub 3/)/sub 2/(OP(N(CH/sub 3/)/sub 2/)/sub 3/)/sub 4/)B(C/sub 6/H/sub 5/)/sub 4/ (Ln=Y,La, Ce-Lu)

Energy Technology Data Exchange (ETDEWEB)

Skopenko, V V; Zub, Yu L; Matishinets, I M [Kievskij Gosudarstvennyj Univ. (Ukrainian SSR)

1984-01-01

From acetone solutions with the yield 75-80% compounds of the composition (Ln(NO/sub 3/)/sub 2/(OP(Nx(CN/sub 3/)/sub 2/)/sub 3/))B(C/sub 6/H/sub 5/)/sub 4/ (Ln=Y, La, Ce-Lu) have been separated. Comparing diffractograms the existence of two isostructural series with morphotropic transition at the Nd/Sm boundary has been established. Using the data of conductometry and IR spectroscopy it has been shown that the cation coordination number of the central atom is eight: four O atoms from two bidentate-cyclic nitrate groups and four O atoms from four monodentate phosphineoxide ligands. Measurement of electric conductivity of the substances separated in nitromethane has shown that the value lambdasub(M) varies inconsiderably from the value 48 Ohm/sup -1/xcm/sup 2/xmol/sup -1/.

Crystallographic, DFT and docking (cathepsin B) studies on an organotellurium(IV) compound

Energy Technology Data Exchange (ETDEWEB)

Caracelli, Ignez; Maganhi, Stella H. [Univ. Federal de Sao Carlos (Brazil). BioMat; Zukerman-Schpector, Julio; Sousa Madureira, Lucas [Univ. Federal de Sao Carlos (Brazil). Lab. de Cristalografia, Estereodinamica e Modelagem Molecular; Stefani, Helio A. [Sao Paulo Univ. (Brazil). Dept. de Farmacia; Guadagnin, Rafael C. [Univ. Federal de Sao Paulo, Diadema (Brazil). Inst. e Ciencias Mabientais, Quimicas e Farmaceuticas; Tiekink, Edward R.T. [Sunway Univ., Selangor Darul Ehsan (Malaysia). Centre for Crystalline Materials

2016-08-01

Some biologically active organotellurium compounds exhibit inhibitory potency against cathepsin B. In this study, an alkyl derivative, viz. [CH{sub 3}(CH{sub 2}){sub 2}C(I)=C(H)](nBu)TeI{sub 2}, 1, has been structurally characterised by X-ray crystallography and shown to be coordinated within a C{sub 2}I{sub 2} donor set. When the stereochemically active lone pair of electrons is taken into account, a distorted trigonal bipyramidal geometry results with the iodide atoms in axial positions. Both intra- and inter-molecular Te..I interactions are also noted. If all interactions are considered, the coordination geometry is based on a Ψ-pentagonal bipyramidal geometry. An unusual feature of the structure is the curving of the functionalised C{sub 5} chain. This feature has been explored by DFT methods and shown to arise as a result of close C-H..I interactions. A docking study (cathepsin B) was performed to understand the inhibition mechanism and to compare the new results with previous observations. Notably, 1 has the same pose exhibited by analogous biologically active compounds with aryl groups. Thus, the present study suggests that (alkyl){sub 2}TeX{sub 2} compounds should also be evaluated for biological activity.

Series of topological phase transitions in TiTe2 under strain

KAUST Repository

Zhang, Qingyun

2013-10-21

First-principles calculations are performed to investigate the topological properties of TiTe2 under hydrostatic pressure, uniaxial strain, and biaxial strain. It is found that the system is unusually accessible to strain effects and the first compound that under hydrostatic pressure (up to experimentally reasonable 30 GPa) is subject to a series of four topological phase transitions, which are related to band inversions at different points of the Brillouin zone. Therefore, TiTe2 enables experimental access to all these transitions in a single compound.

Series of topological phase transitions in TiTe2 under strain

KAUST Repository

Zhang, Qingyun; Cheng, Yingchun; Schwingenschlö gl, Udo

2013-01-01

First-principles calculations are performed to investigate the topological properties of TiTe2 under hydrostatic pressure, uniaxial strain, and biaxial strain. It is found that the system is unusually accessible to strain effects and the first compound that under hydrostatic pressure (up to experimentally reasonable 30 GPa) is subject to a series of four topological phase transitions, which are related to band inversions at different points of the Brillouin zone. Therefore, TiTe2 enables experimental access to all these transitions in a single compound.

76 FR 18960 - Airworthiness Directives; Airbus Model A300 B4-600, B4-600R, and F4-600R Series Airplanes, and...

Science.gov (United States)

2011-04-06

... B4-600, B4-600R, and F4-600R Series Airplanes, and Model C4-605R Variant F Airplanes (Collectively... July 20, 2005; have been performed in service. (2) Airbus Model A300 B4-605R, B4-622R, F4-605R, and F4... C4-600R, and A300 F4-600R series airplanes (fitted with a trim tank), all serial numbers, except...

Inhibitory mechanism of chroman compound on LPS-induced nitric oxide production and nuclear factor-κB activation

International Nuclear Information System (INIS)

Kim, Byung Hak; Reddy, Alavala Matta; Lee, Kum-Ho; Chung, Eun Yong; Cho, Sung Min; Lee, Heesoon; Min, Kyung Rak; Kim, Youngsoo

2004-01-01

6-Hydroxy-7-methoxychroman-2-carboxylic acid phenylamide (KL-1156) is a novel chemically synthetic compound. In the present study, the chroman KL-1156 compound was found to inhibit lipopolysaccharide (LPS)-induced nitric oxide production in macrophages RAW 264.7. KL-1156 compound attenuated LPS-induced synthesis of both mRNA and protein of inducible nitric oxide synthase (iNOS), in parallel, and inhibited LPS-induced iNOS promoter activity, indicating that the chroman compound down-regulated iNOS expression at transcription level. As a mechanism of the anti-inflammatory action shown by KL-1156 compound, suppression of nuclear factor (NF)-κB has been documented. KL-1156 compound exhibited a dose-dependent inhibitory effect on LPS-induced NF-κB transcriptional activity in macrophages RAW 264.7. Furthermore, the compound inhibited LPS-induced nuclear translocation of NF-κB p65 and DNA binding activity of NF-κB complex, in parallel, but did not affect IκBα degradation. Taken together, this study demonstrated that chroman KL-1156 compound interfered with nuclear translocation step of NF-κB p65, which was attributable to its anti-inflammatory action

Group 1B organometallic chemistry XXIX. Synthetic and structural aspects of polynuclear arylcopperlithium compounds Ar4Cu2Li2 ('arylcuprates') and interaggregate exchange phenomena in Ar4Cu4/Ar4Li4/Ar4Cu2Li2 systems

NARCIS (Netherlands)

Koten, G. van; Noltes, J.G.

1979-01-01

The thermally stable arylmetal-IB-lithium compounds (2-Me{2}NCHZC{6}H{4}){4}M{2}Li{2} (M = Cu, Ag or Au; Z = H or Me) and (2-Me{2}NC{6}H{4}){4}M{2}Li{2} have been prepared by a 21 molar reaction of the aryllithium compounds with the corresponding metal-IB halide (Cu or Ag) or metal-lB halide

Superconductivity in Ti3P-type compounds

International Nuclear Information System (INIS)

Wills, J.O.; Hein, R.A.; Waterstrat, R.M.

1978-01-01

A study of 12 intermetallic A 3 B compounds which crsytallize in the tetragonal Ti 3 P-type structure has revealed five new superconductors with transition temperatures below 1 K: Zr 3 Si, Zr 3 Ge, Zr 3 P, V 3 P, and Nb 3 Ge (extrapolated from the alloy series Nb-Ge-As). In addition, two compounds, Zr 3 Sb and Ta 3 Ge, having the Ni 3 P structure type are found to be superconducting below 1 K. Within the Ti 3 P-type compounds, those with the lighter ''B'' elements in a given column of the Periodic Table have the higher transition temperatures. Critical-magnetic-field and electrical-resistivity data are reported for the superconducting Ti 2 P-type compound Nb 3 P, which permit one to estimate the Ginzburg-Landau kappa parameter and the electronic-specific-heat coefficient γ. The kappa value of 8.4 indicates that this material is type II, and the γ value of 1.3 mJ/mole K 2 for Nb 3 P is probably related to its low transition temperature relative to many A15 compounds

Superconducting properties of Zr1+xNi2-xGa and Zr1-xNi2+xGa Heusler compounds

Directory of Open Access Journals (Sweden)

Saad Alzahrani

2017-05-01

Full Text Available The superconducting properties of a series of Zr1+xNi2-xGa and Zr1-xNi2+xGa compounds have been investigated by x-ray diffraction, electrical resistivity, dc magnetization, and ac susceptibility measurements. While the parent compound, ZrNi2Ga, exhibited the cubic L21 Heusler structure, multiple non-cubic structures formed in the Zr and Ni rich doped materials. For x ≤ 0.3, all Zr1-xNi2+xGa compounds demonstrated superconducting behavior, but no superconductivity was observed in the Zr1+xNi2-xGa alloys for x > 0.2. The magnetization data revealed that all materials in both Zr1+xNi2-xGa and Zr1-xNi2+xGa series exhibited type-II superconductivity. With increasing doping concentration x, the paramagnetic ordering were enhanced in both systems while the superconducting properties were found to weaken. The observations are discussed considering the structural disorders in the systems.

Effects of UV-B radiation on growth, photosynthesis, UV-B-absorbing compounds and NADP-malic enzyme in bean (Phaseolus vulgaris L.) grown under different nitrogen conditions.

Science.gov (United States)

Pinto, M E; Casati, P; Hsu, T P; Ku, M S; Edwards, G E

1999-02-01

The effects of UV-B radiation on growth, photosynthesis, UV-B-absorbing compounds and NADP-malic enzyme have been examined in different cultivars of Phaseolous vulgaris L. grown under 1 and 12 mM nitrogen. Low nitrogen nutrition reduces chlorophyll and soluble protein contents in the leaves and thus the photosynthesis rate and dry-matter accumulation. Chlorophyll, soluble protein and Rubisco contents and photosynthesis rate are not significantly altered by ambient levels of UV-B radiation (17 microW m-2, 290-320 nm, 4 h/day for one week). Comparative studies show that under high nitrogen, UV-B radiation slightly enhances leaf expansion and dry-matter accumulation in cultivar Pinto, but inhibits these parameters in Vilmorin. These results suggest that the UV-B effect on growth is mediated through leaf expansion, which is particularly sensitive to UV-B, and that Pinto is more tolerant than Vilmorin. The effect of UV-B radiation on UV-B-absorbing compounds and on NADP-malic enzyme (NADP-ME) activity is also examined. Both UV-B radiation and low-nitrogen nutrition enhance the content of UV-B-absorbing compounds, and among the three cultivars used, Pinto exhibits the highest increases and Arroz the lowest. The same trend is observed for the specific activity and content of NADP-ME. On a leaf-area basis, the amount of UV-B-absorbing compounds is highly correlated with the enzyme activity (r2 = 0.83), suggesting that NADP-ME plays a key role in biosynthesis of these compounds. Furthermore, the higher sensitivity of Vilmorin than Pinto to UV-B radiation appears to be related to the activity of NADP-ME and the capacity of the plants to accumulate UV-B-absorbing compounds.

Synthesis, biological evaluation and in silico studies of 5-(3-methoxybenzylidene)thiazolidine-2,4-dione analogues as PTP1B inhibitors.

Science.gov (United States)

Mahapatra, Manoj Kumar; Kumar, Rajnish; Kumar, Manoj

2017-04-01

PTP1B (protein tyrosine phosphatase 1B) dephosphorylates the insulin receptor substrate and thus acts as a negative regulator of the insulin and leptin signalling pathway. Recently, it has been considered as a new therapeutic target of intervention for the treatment of type2 diabetes. A series of aryl/alkylsulfonyloxy-5-(3-methoxybenzylidene)thiazolidine-2,4-dione derivatives were synthesized, screened in vitro for their PTP1B inhibitory activity and in vivo for anti-hyperglycaemic activity. Docking results further helped in understanding the nature of interactions governing the binding mode of ligands inside the active site of PTP1B. Among the synthesized compounds, 13 and 16 were found to be potent PTP1B inhibitors having IC 50 of 7.31 and 8.73μM respectively. Significant lowering of blood glucose level was observed in some of the synthesized compounds in in vivo study. Copyright © 2017 Elsevier Inc. All rights reserved.

Synthesis and biological activity of novel series of 4-methoxy, and 4,9-dimethoxy-5-substituted furo[2,3-g]-1,2,3-benzoxathiazine-7,7-dioxide derivatives.

Science.gov (United States)

El-Sawy, Eslam R; Ebaid, Manal S; Abo-Salem, Heba M; El-Hallouty, Salwa; Kassem, Emad M; Mandour, Adel H

2014-05-01

A novel series of 4-methoxy, and 4,9-dimethoxy-5-substituted furo[2,3-g]-1,2,3-benzoxathiazine-7,7-dioxide derivatives 3a,b, 10a-g and 11a-g were prepared in good yields via the reaction of 4-methoxy (1a) and 4,7-dimethoxy-5-acetyl-6-hydroxybenzofurans (1b) and their α,β-unsaturated keto derivatives 6a-g and 7a-g with chlorosulfonyl isocyanate (CSI). On the other hand, N-chlorosulfonyl carbamate derivatives 4a,b, 12a,b and 13a,b were prepared and allowed to react with piperidine to give the corresponding N-piperidinosulfonyl carbamate derivatives 5a,b, 14a,b and 15a,b, respectively. Sixteen new target compounds 3a,b, 10a-g, and 11a-g were tested for their DPPH radical-scavenging, and in vitro antiproliferative activity against A-549, MCF7 and HCT-116 cancer cell lines. Compounds 10a, 11c, 11e, and 11g showed moderate DPPH radical-scavenging activity compared to ascorbic acid at 100 μg/mL. 4,9-Dimethoxy-5-substituted styrylfuro[3,2-g]-1,2,3-benzoxathiazine-7,7-dioxides 11a, 11b, and 11c were found to be highly active against A-549 and HCT-116 cancer cell lines with IC50 values ranging from 0.02 to 0.08 μmol/mL compared to doxorubicin with IC50 = 0.04 and 0.06 μmol/mL, respectively.

Antiferromagnetic ordering of Er2NiSi3 compound

International Nuclear Information System (INIS)

Pakhira, Santanu; Mazumdar, Chandan; Ranganathan, R.

2014-01-01

Ternary intermetallics of the stoichiometric composition R 2 TX 3 , where, R = rare earth element, T = d-electron transition metal and X= p-electron element, crystallizes in hexagonal A1B 2 type crystal structure with space group P6/mmm. We report here the synthesis and basic magnetic properties of the compound Er 2 NiSi 3 . Paramagnetic to antiferromagnetic phase change occurs below 5.4 K for this compound. (author)

Synthesis and Cytotoxic Evaluation of 1H-1,2,3-Triazol-1-ylmethyl-2,3-dihydronaphtho[1,2-b]furan-4,5-diones

Directory of Open Access Journals (Sweden)

INGRID C. CHIPOLINE

2018-02-01

Full Text Available ABSTRACT The 1,2-naphthoquinone compound was previously considered active against solid tumors. Moreover, glycosidase inhibitors such as 1,2,3-1H triazoles has been pointed out as efficient compounds in anticancer activity studies. Thus, a series of eleven 1,2-naphthoquinones tethered in C2 to 1,2,3-1H-triazoles 9a-k were designed, synthesized and their cytotoxic activity evaluated using HCT-116 (colon adenocarcinoma, MCF-7 (breast adenocarcinoma and RPE (human nontumor cell line from retinal epithelium. The chemical synthesis was performed from C-3 allylation of lawsone followed by iodocyclization with subsequent nucleophilic displacement with sodium azide and, finally, the 1,3-dipolar cycloaddition catalyzed by Cu(I with terminal alkynes led to the formation of 1H-1,2,3-Triazol-1-ylmethyl-2,3-dihydronaphtho[1,2-b]furan-4,5-diones in good yields. Compounds containing aromatic group linked to 1,2,3-triazole ring (9c, 9d, 9e, 9i presented superior cytotoxic activity against cancer cell lines with IC50 in the range of 0.74 to 4.4 µM indicating that the presence of aromatic rings substituents in the 1,2,3-1H-triazole moiety is probably responsible for the improved cytotoxic activity.

Self-consistent electronic structure of the refractory metal ZrB2, a pseudographite intercalation compound

International Nuclear Information System (INIS)

Johnson, D.L.; Harmon, B.N.; Liu, S.H.

1980-01-01

The self-consistent band structure of ZrB 2 has been evaluated using the KKR method. It is noted that a large charge transfer is not necessary to explain many of the experimental results which can be understood in terms of the band structure and the bonding nature of the wave functions. X-ray photoemission spectra and optical reflectance measurements are compared with the calculated density of states and joint density of states, respectively. The calculations are also discussed with reference to nuclear quadrupole experiments, Hall effect measurements, and the electronic specific heat. The similarities to intercalated graphite and related compounds are discussed and the strong bonding as reflected in the hardness and high melting point is considered

Synthesis, characterization and anti cancer activity of some fluorinated 3,6-diaryl-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazoles

Directory of Open Access Journals (Sweden)

Deepak Chowrasia

2017-05-01

Full Text Available A series of fluorinated 3,6-diaryl-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazoles (2a–2i was synthesized by condensation of various substituted 4-amino-5-phenyl-4H-1,2,4-triazole-3-thiols (1a–1i with penta fluoro benzoic acid in good yields (60–80%. The synthesized compounds were screened for anticancer activity against three cancerous cell lines MCF7 (human breast cancer, SaOS-2 (human osteosarcoma and K562 (human myeloid leukemia. The compounds showed moderate to good antiproliferative potency against the studied cell lines. Among these, compound 2b showed higher antiproliferative activity (IC50 22.1, 19 and 15 μM against MCF7, SaOS-2 and K562, respectively while 2a exhibited least antiproliferative activity (IC50 30.2, 39 and 29.4 μM against MCF7, SaOS-2 and K562 cells, respectively. Therefore, the present study demonstrates that fluorine substituted 3,6-diaryl-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazoles would be a better prospective in the development of anticancer drugs.

Perovskites Ba/sub 2/Bsub(1/2)sup(I)Bsub(1/2)sup(III)Usup(VI)O/sub 6/

Energy Technology Data Exchange (ETDEWEB)

Roller, H; Kemmler-Sack, S [Tuebingen Univ. (Germany, F.R.). Inst. fuer Chemie

1978-11-01

Compounds of type Ba/sub 2/Lisub(1/2)Bsub(1/2)sup(III)Usup(VI)O/sub 6/ and Ba/sub 2/Nasub(1/2)Bsub(1/2)sup(III)Usup(VI)O/sub 6/ are formed with Bsup(III) = La, Nd, Sm, Gd, Y, In as red to reddish brown perovskites. They are for Bsup(III) = La, Nd and Sm polymorphic. With Bsup(III) = La both HT-forms crystallize cubic. In the Li series the HT-modifications with Bsup(III) = Nd, Sm are monoclinic (a < c/..sqrt..2 < b) and in the Na series rhombic (c/..sqrt..2 < a < b); the corresponding Gd, Y, and In compounds have the same structure. The transformation HT ..-->.. TT is reversible. The TT modifications crystallize monoclinic (a < b < c/..sqrt..2). Unlike the HT forms an increase of c and a decrease of a and b is observed, the cell volumina rested nearly unchanged. The origin for the transformation are order disorder phenomena.

Synthesis of Novel Heterocyclic Compounds Incorporate 4,5,6,7-Tetrahydrobenzo[b]thiophene Together with Their Cytotoxic Evaluations.

Science.gov (United States)

Abdallah, Amira Elsayed Mahmoud; Mohareb, Rafat Milad; Khalil, Eid Metwally; Elshamy, Menna Alla Mohamed Abd Elaleem

2017-01-01

The 2-amino-3-cyano-4,5,6,7-tetrahydrobenzo[b]thiophene was the key starting compound used to synthesize new thiazole, pyrimidine, pyran, pyridine and thiazine derivatives. The cytotoxicity of the synthesized compounds was studied towards the three cancer cell lines namely MCF-7 (breast adenocarcinoma), NCI-H460 (non-small cell lung cancer) and SF-268 (central nervous system (CNS) cancer) in addition to the normal cell line (WI-38) using doxorubicin as the reference drug. The study showed that compounds 5, 9a, 15b, 17c, 18 and 21b were the most potent compounds.

Lattice Thermal Conductivity from Atomistic Simulations: ZrB2 and HfB2

Science.gov (United States)

Lawson, John W.; Daw, Murray S.; Bauschlicher, Charles W.

2012-01-01

Ultra high temperature ceramics (UHTC) including ZrB2 and HfB2 have a number of properties that make them attractive for applications in extreme environments. One such property is their high thermal conductivity. Computational modeling of these materials will facilitate understanding of fundamental mechanisms, elucidate structure-property relationships, and ultimately accelerate the materials design cycle. Progress in computational modeling of UHTCs however has been limited in part due to the absence of suitable interatomic potentials. Recently, we developed Tersoff style parameterizations of such potentials for both ZrB2 and HfB2 appropriate for atomistic simulations. As an application, Green-Kubo molecular dynamics simulations were performed to evaluate the lattice thermal conductivity for single crystals of ZrB2 and HfB2. The atomic mass difference in these binary compounds leads to oscillations in the time correlation function of the heat current, in contrast to the more typical monotonic decay seen in monoatomic materials such as Silicon, for example. Results at room temperature and at elevated temperatures will be reported.

Analysis of Photosynthetic Characteristics and UV-B Absorbing Compounds in Mung Bean Using UV-B and Red LED Radiation

Directory of Open Access Journals (Sweden)

Fang-Min Li

2014-01-01

Full Text Available Mung bean has been reported to have antioxidant, antidiabetic, anti-inflammatory, and antitumor activities. Various factors have important effects on the types and contents of plant chemical components. In order to study quality of mung bean from different light sources, mung bean seedlings were exposed to red light-emitting diodes (LEDs and ultraviolet-B (UV-B. Changes in the growth parameters, photosynthetic characteristics, the concentrations of chlorophyll a and chlorophyll b and the content of UV-B absorbing compounds were measured. The results showed that photosynthetic characteristics and chlorophyll a and chlorophyll b concentrations were enhanced by red LEDs. The concentrations of UV-B absorbing compounds were enhanced by UV-B on the 20th day, while photosynthetic characteristics, plant length, and the concentrations of chlorophyll a and chlorophyll b were reduced by UV-B on the 40th day; at the same time the values of the stem diameter, plant fresh weight, dry weight, and the concentrations of UV-B absorbing compounds were enhanced. It is suggested that red LEDs promote the elongation of plant root growth and photosynthetic characteristics, while UV-B promotes horizontal growth of stems and the synthesis of UV-B absorbing compounds.

Evolution of the orbitals Dy-4f in the DyB2 compound using the LDA, PBE approximations, and the PBE0 hybrid functional

Science.gov (United States)

Rasero Causil, Diego; Ortega López, César; Espitia Rico, Miguel

2018-04-01

Computational calculations of total energy based on density functional theory were used to investigate the structural, electronic, and magnetic properties of the DyB2 compounds in the hexagonal structure. The calculations were carried out by means of the full-potential linearized augmented plane wave (FP-LAPW) method, employing the computational Wien2k package. The local density approximation (LDA) and the generalized gradient approximation (GGA) were used for the electron-electron interactions. Additionally, we used the functional hybrid PBE0 for a better description the electronic and magnetic properties, because the DyB2 compound is a strongly-correlated system. We found that the calculated lattice constant agrees well with the values reported theoretically and experimentally. The density of states (DOS) calculation shows that the compound exhibits a metallic behavior and has magnetic properties, with a total magnetic moment of 5.47 μ0/cell determined mainly by the 4f states of the rare earth elements. The functional PBE0 shows a strong localization of the Dy-4f orbitals.

Blood-brain transfer of Pittsburgh compound B in humans

DEFF Research Database (Denmark)

Gjedde, Albert; Aanerud, Joel; Braendgaard, Hans

2013-01-01

-brain barrier is held to be high but the permeability-surface area product and extraction fractions in patients or healthy volunteers are not known. We used PET to determine the clearance associated with the unidrectional blood-brain transfer of [(11)C]PiB and the corresponding cerebral blood flow rates...... with the observation that numerically, but insignificantly, unidirectional blood-brain clearances are lower and extraction fractions higher in the patients. The evidence of unchanged permeability-surface area products in the patients implies that blood flow changes can be deduced from the unidirectional blood......In the labeled form, the Pittsburgh compound B (2-(4'-{N-methyl-[(11)C]}methyl-aminophenyl)-6-hydroxy-benzothiazole, [(11)C]PiB), is used as a biomarker for positron emission tomography (PET) of brain β-amyloid deposition in Alzheimer's disease (AD). The permeability of [(11)C]PiB in the blood...

Identification of the stereochemical requirements in the 4-aryl-2-cycloalkylidenhydrazinylthiazole scaffold for the design of selective human monoamine oxidase B inhibitors.

Science.gov (United States)

D'Ascenzio, Melissa; Carradori, Simone; Secci, Daniela; Mannina, Luisa; Sobolev, Anatoly P; De Monte, Celeste; Cirilli, Roberto; Yáñez, Matilde; Alcaro, Stefano; Ortuso, Francesco

2014-05-15

Exploring the effect that substituents on the cycloaliphatic ring had on the inhibitory activity against human monoamine oxidase B of a series of 4-aryl-2-cycloalkylidenhydrazinylthiazoles led to the synthesis of a new series of 2-methylcyclopentyl and 3-methylcyclopentyl derivatives which were tested in vitro as mixtures of diastereoisomers. In fact, due to the presence of a chiral center on the cycloaliphatic ring and a trisubstituted CN bond, they exist as four diastereoisomers ((E)-(R), (E)-(S), (Z)-(R), (Z)-(S)). 4-(2,4-Difluorophenyl)-2-(2-(3-methylcyclopentylidene)hydrazinyl)thiazole was chosen as a model to investigate the influence of stereochemical requirements on the inhibitory activity against hMAO-B of these derivatives after a stereoconservative synthesis and semi-preparative HPLC diastereoseparation. (R)-(Z) isomer of this compound was endowed with a potent and selective hMAO-B inhibition higher than that of reference drugs as also corroborated by molecular modeling studies. Copyright © 2014 Elsevier Ltd. All rights reserved.

Synthesis, Structure, Bonding, and Reactivity of Metal Complexes Comprising Diborane(4) and Diborene(2): [{Cp*Mo(CO)2 }2 {μ-η2 :η2 -B2 H4 }] and [{Cp*M(CO)2 }2 B2 H2 M(CO)4 ], M=Mo,W.

Science.gov (United States)

Mondal, Bijan; Bag, Ranjit; Ghorai, Sagar; Bakthavachalam, K; Jemmis, Eluvathingal D; Ghosh, Sundargopal

2018-04-26

The reaction of [(Cp*Mo) 2 (μ-Cl) 2 B 2 H 6 ] (1) with CO at room temperature led to the formation of the highly fluxional species [{Cp*Mo(CO) 2 } 2 {μ-η 2 :η 2 -B 2 H 4 }] (2). Compound 2, to the best of our knowledge, is the first example of a bimetallic diborane(4) conforming to a singly bridged C s structure. Theoretical studies show that 2 mimics the Cotton dimolybdenum-alkyne complex [{CpMo(CO) 2 } 2 C 2 H 2 ]. In an attempt to replace two hydrogen atoms of diborane(4) in 2 with a 2e [W(CO) 4 ] fragment, [{Cp*Mo(CO) 2 } 2 B 2 H 2 W(CO) 4 ] (3) was isolated upon treatment with [W(CO) 5 ⋅thf]. Compound 3 shows the intriguing presence of [B 2 H 2 ] with a short B-B length of 1.624(4) Å. We isolated the tungsten analogues of 3, [{Cp*W(CO) 2 } 2 B 2 H 2 W(CO) 4 ] (4) and [{Cp*W(CO) 2 } 2 B 2 H 2 Mo(CO) 4 ] (5), which provided direct proof of the existence of the tungsten analogue of 2. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis and antiproliferative activity of novel polynuclear heterocyclic compounds derived from 2,3-diaminophenazine.

Science.gov (United States)

Mahran, Asma M; Ragab, Sherif Sh; Hashem, Ahmed I; Ali, Mamdouh M; Nada, Afaf A

2015-01-27

2,3-Diaminophenazine 1 was used as a precursor for the preparation of some novel phenazine derivatives such as imidazo[4,5-b]phenazine-2-thione 2, its methylthio 3, ethyl 1-aryl-3H-[1,2,4]triazolo[2,3-a]imidazo[4,5-b]phenazines 8a-c, ethyl (2Z)-[3-aminophenazin-2-yl)amino](phenylhydrazono)ethanoate 9, pyrazino[2,3-b]phenazine derivatives 10, 12, 15-17, [1,4]diazepino[2,3-b]phenazine derivatives 13, 14, 2,3-dibenzoylaminophenazine 18, 1H-Imidazo[4,5-b]phenazine derivatives 20, 23a-c, 24, 25 and 4-[(E)-(3-amino phenazin-2-yl)diazenyl] derivatives 27-29. All compounds were tested as inhibitors of the proliferation of human lung carcinoma and colorectal cancer cell lines through inhibition of Tyrosine Kinases. Most of compounds exert good activity against the two cancer cell lines. Five compounds (1, 2, 3, 25 and 28) were found to possess the same activity as the standard drug Cisplatin. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Structural, electronic and magnetic properties of layered REB{sub 2}C compounds (RE=Dy, Tm, Lu)

Energy Technology Data Exchange (ETDEWEB)

Babizhetskyy, Volodymyr, E-mail: v.babizhetskyy@googlemail.com [Max-Planck-Institut fuer Festkoerperforschung, Heisenbergstrasse 1, D-70569 Stuttgart (Germany); Department of Inorganic Chemistry, Ivan Franko National University of L' viv, Kyryla and Mefodiya Str. 6, UA-79005 Lviv (Ukraine); Simon, Arndt; Hoch, Constantin [Max-Planck-Institut fuer Festkoerperforschung, Heisenbergstrasse 1, D-70569 Stuttgart (Germany); Hiebl, Kurt [Arbeitsgruppe Neue Materialien, Universitaet Wien, Waehringerstrasse 42, A-1090 Wien (Austria); Le Polles, Laurent [Sciences Chimiques de Rennes, UMR 6226 CNRS, Ecole Nationale Superieure de Chimie de Rennes, Universite de Rennes 1, Avenue du General Leclerc, F-35042 Rennes Cedex (France); Gautier, Regis, E-mail: rgautier@ensc-rennes.fr [Sciences Chimiques de Rennes, UMR 6226 CNRS, Ecole Nationale Superieure de Chimie de Rennes, Universite de Rennes 1, Avenue du General Leclerc, F-35042 Rennes Cedex (France); Halet, Jean-Francois, E-mail: halet@univ-rennes1.fr [Sciences Chimiques de Rennes, UMR 6226 CNRS, Ecole Nationale Superieure de Chimie de Rennes, Universite de Rennes 1, Avenue du General Leclerc, F-35042 Rennes Cedex (France)

2012-07-15

The crystal structure of LuB{sub 2}C has been determined from single crystal and powder X-ray diffraction data. It crystallizes in the orthorhombic space group Pbam (a=6.7429(1) A, b=6.7341(1) A, c=3.5890(1) A, Z=4, R1=0.024 (wR2=0.059) for 436 reflections with I{sub o}>2{sigma}(I{sub o})). The compounds REB{sub 2}C (RE=Y, Tb-Lu) are isotypic. The boron and carbon atoms form infinite, planar two-dimensional nets which alternate with sheets of rare-earth metal atoms. Inside the nonmetal atom nets, a coloring with fused B{sub 2}C{sub 2} rhombuses and B{sub 5}C{sub 2} heptagons is proposed, supported by NMR experiments and density functional theory calculations. The calculated density of states of LuB{sub 2}C indicates this compound to be metallic. The magnetic properties of the isotypic compound TmB{sub 2}C, has been measured in the temperature range 2 KB=7 T. The sample undergoes an antiferromagnetic (AFM) transition at T{sub N}=12 K, and at fields B>3 T a metamagnetic transition is encountered. The temperature dependence of the electrical resistivity proves the metallic character of the TmB{sub 2}C compound as well as the AFM ordering. - Graphical abstract: The crystal structure of LuB{sub 2}C has been determined from single crystal and powder X-ray diffraction data. It crystallizes in the orthorhombic space group Pbam. The compounds REB{sub 2}C (RE=Y, Tb-Lu) are isotypic. The boron and carbon atoms form infinite, planar two-dimensional nets which alternate with sheets of rare-earth metal atoms. Inside the nonmetal atom nets, a coloring with fused B{sub 2}C{sub 2} rhombuses and B{sub 5}C{sub 2} heptagons is proposed, supported by NMR experiments and density functional theory calculations. The magnetic properties of the isotypic compound TmB{sub 2}C, has been measured in the temperature range 2 KB=7 T. The sample undergoes an antiferromagnetic (AFM) transition at T{sub N}=12

Raman spectra of Cu{sub 2}B{sup II}C{sup IV}X{sub 4}{sup VI} magnetic quaternary semiconductor compounds with tetragonal stannite type structure

Energy Technology Data Exchange (ETDEWEB)

Rincón, C., E-mail: crincon@ula.ve; Quintero, M.; Power, Ch.; Moreno, E.; Quintero, E.; Morocoima, M. [Centro de Estudios de Semiconductores, Departamento de Física, Facultad de Ciencias, Universidad de Los Andes, Mérida (Venezuela, Bolivarian Republic of); Henao, J. A.; Macías, M. A. [Grupo de Investigación en Química Estructural, Facultad de Ciencias, Escuela de Química, Universidad Industrial de Santander, Apartado Aéreo 678, Bucaramanga (Colombia)

2015-05-28

A comparative study of the Raman spectra of Cu{sub 2}B{sup II}C{sup IV}S{sub 4}{sup VI} and Cu{sub 2}B{sup II}C{sup IV}Se{sub 4}{sup VI}(where B = Mn or Fe) magnetic quaternary semiconductor compounds with stannite-type structure (I4{sup ¯}2m) has been done. Most of the fourteen Raman lines expected for these materials were observed in the spectra. The two strongest lines observed have been assigned to the IR inactive A{sub 1}{sup 1} and A{sub 1}{sup 2} stannite modes that originated from the motion of the S or Se anion around the Cu and C{sup IV} cations remaining at rest. The shift in the frequency of these two lines of about 150 cm{sup −1} to lower energies observed in Cu{sub 2}B{sup II}C{sup IV}Se{sub 4}{sup VI} compounds as compared to those in Cu{sub 2}B{sup II}C{sup IV}S{sub 4}{sup VI} ones, can then be explained as due to the anion mass effect. Based on the fact that values of these frequencies depend mainly on anion mass and bond-stretching forces between nearest-neighbor atoms, the vibrational frequencies v{sup ¯}(A{sub 1}{sup 2}) and v{sup ¯}(A{sub 1}{sup 2}) of both modes for several Cu{sub 2}B{sup II}C{sup IV}X{sub 4}{sup VI} stannite compounds (where X = S, Se, or Te) very close to the experimental data reported for these materials were calculated from a simple model that relates these stretching forces to the anion-cation bond-distances.

Cs[FeSe{sub 2}], Cs{sub 3}[FeSe{sub 2}]{sub 2}, and Cs{sub 7}[Fe{sub 4}Se{sub 8}]. Missing links of known chalcogenido ferrate series

Energy Technology Data Exchange (ETDEWEB)

Stueble, Pirmin; Roehr, Caroline [Institut fuer Anorganische und Analytische Chemie, Universitaet Freiburg (Germany)

2017-11-17

The three cesium selenido ferrate title compounds with an Se:Fe ratio of 2:1 were synthesized from stoichiometric samples reacting elemental Cs either (A) with Fe and Se in a double-crucible setup (Cs[FeSe{sub 2}], Cs{sub 3}[FeSe{sub 2}]{sub 2}) or (B) with previously prepared FeSe{sub 2} (Cs{sub 3}[FeSe{sub 2}]{sub 2}, Cs{sub 7}[Fe{sub 4}S{sub 8}]) (T{sub max} = 800-1000 C). The pure Fe{sup III} ferrate Cs[FeSe{sub 2}] crystallizes in the Tl[FeSe{sub 2}] type [monoclinic, space group C2/m, a = 1392.95(10), b = 564.43(3), c = 737.44(6) pm, β = 119.163(5) , Z = 4, R{sub 1} = 0.0550]. It is thus not isotypic to all other alkali ferrates(III) A[FeS{sub 2}] and A[FeSe{sub 2}] containing chains of edge-sharing tetrahedra, but crystallizes in a t2 subgroup of the Immm structure of Cs[FeS{sub 2}]. The mixed-valent chain compound Cs{sub 3}[FeSe{sub 2}]{sub 2} is isotypic to its sulfido analogue [orthorhombic, space group Pnma, a = 777.88(6), b = 1151.02(6), c = 1341.61(7) pm, Z = 4, R{sub 1} = 0.0470]. In contrast to the isopunctal Na{sub 3}[FeSe{sub 2}]{sub 2} type K/Rb compounds the chains are only slightly corrugated. The monoclinic, likewise mixed-valent Fe{sup II/III} selenido ferrate Cs{sub 7}[Fe{sub 4}Se{sub 8}] [monoclinic, space group C2/c, a = 1953.79(10), b = 879.71(5), c = 1717.03(10) pm, β = 117.890(2) , Z = 4, R{sub 1} = 0.0816] is isostructural both to the cesium sulfido and tellurido compound. The structure contains oligomeric moieties of four edge sharing [FeSe{sub 4}] tetrahedra forming slightly distorted tetrahedral clusters [Fe{sub 4}Se{sub 8}]{sup 7-}, which are surrounded by a cube of 26 Cs cations. Based on a structure map, the crystal chemistry of the three title compounds is discussed together with all chain/cluster ferrates of the general series A{sub 1+x}[Fe{sup III}{sub 1-x}Fe{sup II}{sub x}Q{sub 2}] (x = 0-1; A = Na, K, Rb, Cs; Q = S, Se, Te). (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

A Cross-Talk Between NFAT and NF-κB Pathways is Crucial for Nickel-Induced COX-2 Expression in Beas-2B Cells

Science.gov (United States)

Cai, T.; Li, X.; Ding, J.; Luo, W.; Li, J.; Huang, C.

2013-01-01

Cyclooxygenase-2 (COX-2) is a critical enzyme implicated in chronic inflammation-associated cancer development. Our studies have shown that the exposure of Beas-2B cells, a human bronchial epithelial cell line, to lung carcinogenic nickel compounds results in increased COX-2 expression. However, the signaling pathways leading to nickel-induced COX-2 expression are not well understood. In the current study, we found that the exposure of Beas-2B cells to nickel compounds resulted in the activation of both nuclear factor of activated T cell (NFAT) and nuclear factor-κB (NF-κB). The expression of COX-2 induced upon nickel exposure was inhibited by either a NFAT pharmacological inhibitor or the knockdown of NFAT3 by specific siRNA. We further found that the activation of NFAT and NF-κB was dependent on each other. Since our previous studies have shown that NF-κB activation is critical for nickel-induced COX-2 expression in Beas-2B cells exposed to nickel compounds under same experimental condition, we anticipate that there might be a cross-talk between the activation of NFAT and NF-κB for the COX-2 induction due to nickel exposure in Beas-2B cells. Furthermore, we showed that the scavenging of reactive oxygen species (ROS) by introduction of mitochondrial catalase inhibited the activation of both NFAT and NF-κB, and the induction of COX-2 due to nickel exposure. Taken together, our results defining the evidence showing a key role of the cross-talk between NFAT and NF-κB pathways in regulating nickel-induced COX-2 expression, further provide insight into the understanding of the molecular mechanisms linking nickel exposure to its lung carcinogenic effects. PMID:21486220

Thermal stability of polyoxometalate compound of Keggin K8[2-SiW11O39]∙nH2O supported with SiO2

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Yunita Sari M A

2017-06-01

Full Text Available Synthesis through sol-gel method and characterization of polyoxometalate compound of K8[b2-SiW11O39]∙nH2O supported with SiO2 have been done. The functional groups of polyoxometalate compound  was characterized by FT-IR spectrophotometer for the fungtional groups and the degree’s of crystalinity  using XRD. The acidity of K8[b2-SiW11O39]∙nH2O/SiO2 was determined qualitative analysis using ammonia and pyridine adsorption and the quantitative analysis using potentiometric titration method. The results of FT-IR spectrum of K8[b2-SiW11O39]∙nH2O appeared at  wavenumber 987.55 cm-1 (W=O, 864.11 cm-1 (W-Oe-W, 756.1 cm-1 (W-Oc-W, 3425.58 cm-1 (O-H, respectively and spectrum of  K8[b2-SiW11O39]SiO2 appeared at wavenumber  956.69 cm-1 (W=O, 864.11 cm-1 (W-Oe-W, 3448.72 cm-1 (O-H, respectively. The diffraction of XRD pattern of K8[b2-SiW11O39]∙nH2O and K8[b2-SiW11O39]∙nH2O/SiO2 compounds show high crystalinity. The acidic properties showed K8[b2-SiW11O39]∙nH2O/SiO2 more acidic compared to K8[b2-The SiW11O39]∙nH2O. The qualitative analysis showed pyridine compound adsorbed more of polyoxometalate compound of K8[b2-SiW11O39]∙nH2O/SiO2. Analysis of stability showed that the K8[b2-SiW11O39]∙nH2O/SiO2 at temperature 500°C has structural changes compare to 200-400oC which was indicated from vibration at wavenumber 800-1000 cm-1. Keywords : K8[b2-SiW11O39]∙nH2O, polyoxometalate, SiO2.

AgLnSb/sub 2/O/sub 7/ compounds with weberite structure

Energy Technology Data Exchange (ETDEWEB)

Lopatin, S S; Aver' yanova, L N; Belyaev, I N; Zvyagintsev, B I; Dyatlov, Eh V [Rostovskij-na-Donu Gosudarstvennyj Univ. (USSR)

1982-11-01

The interaction between AgSbO/sub 3/ and LnSbO/sub 4/ in the solid phase at 1100-1150 deg C has been investigated. AgLnSb/sub 2/O/sub 7/ compounds with weberite crystal structure are formed in Ln=La, Pr, Nd, Sm cases but in Ln=Eu, Cd, Dy, Er cases the formation of termary oxides of the indicated composition has not been observed. Inasmuch as compounds of the general formula A/sub 2/B/sub 2/O/sub 7/ with average cation radii Rsub(B) >0.60 A and 1.65 <= Rsub(A)/Rsub(B) <= 2.20 can crystallize in weberite, pyrochlore and laminated perovskite-like structurer, conditions of the existence of the above mentioned structures depending on A and B dimensions and electronegativity are discussed.

Ordered perovskites with cationic vacancies. 4. Compounds of type Ba/sub 6/B/sub 2/sup(III)vacantTe/sub 3/sup(VI)O/sub 18/

Energy Technology Data Exchange (ETDEWEB)

Schittenhelm, H J; Kemmler-Sack, S [Tuebingen Univ. (Germany, F.R.). Lehrstuhl fuer Anorganische Chemie 2

1979-07-01

Compounds of the composition Ba/sub 6/B(III)/sub 2/vacantTe(VI)/sub 3/O/sub 18/ equivalent to Ba/sub 2/Ba(III)sub(2/3)vacantsub(1/3)Te(VI)O/sub 6/, with B(III) = Pr, Nd, Sm-Lu, Y crystallize with a cubic perovskite lattice. The cell parameters diminish as the size of B(III) falls (B(III) = Pr: a = 8.52 A; Lu: a = 8.33 A). In contrast to the corresponding perovskites with U(VI) and W(VI) no polymorphism is observed.

Searching for Multi-Targeting Neurotherapeutics against Alzheimer’s: Discovery of Potent AChE-MAO B Inhibitors through the Decoration of the 2H-Chromen-2-one Structural Motif

Directory of Open Access Journals (Sweden)

Leonardo Pisani

2016-03-01

Full Text Available The need for developing real disease-modifying drugs against neurodegenerative syndromes, particularly Alzheimer’s disease (AD, shifted research towards reliable drug discovery strategies to unveil clinical candidates with higher therapeutic efficacy than single-targeting drugs. By following the multi-target approach, we designed and synthesized a novel class of dual acetylcholinesterase (AChE-monoamine oxidase B (MAO-B inhibitors through the decoration of the 2H-chromen-2-one skeleton. Compounds bearing a propargylamine moiety at position 3 displayed the highest in vitro inhibitory activities against MAO-B. Within this series, derivative 3h emerged as the most interesting hit compound, being a moderate AChE inhibitor (IC50 = 8.99 µM and a potent and selective MAO-B inhibitor (IC50 = 2.8 nM. Preliminary studies in human neuroblastoma SH-SY5Y cell lines demonstrated its low cytotoxicity and disclosed a promising neuroprotective effect at low doses (0.1 µM under oxidative stress conditions promoted by two mitochondrial toxins (oligomycin-A and rotenone. In a Madin-Darby canine kidney (MDCKII-MDR1 cell-based transport study, Compound 3h was able to permeate the BBB-mimicking monolayer and did not result in a glycoprotein-p (P-gp substrate, showing an efflux ratio = 0.96, close to that of diazepam.

Isolation and Characterization of Protein Tyrosine Phosphatase 1B (PTP1B Inhibitory Polyphenolic Compounds From Dodonaea viscosa and Their Kinetic Analysis

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Zia Uddin

2018-03-01

Full Text Available Diabetes mellitus is one of a major worldwide concerns, regulated by either defects in secretion or action of insulin, or both. Insulin signaling down-regulation has been related with over activity of protein tyrosine phosphatase 1B (PTP1B enzyme, which has been a promising target for the treatment of diabetes mellitus. Herein, activity guided separation of methanol extract (95% of Dodonaea viscosa aerial parts afforded nine (1-9 polyphenolic compounds, all of them were identified through spectroscopic data including 2D NMR and HREIMS. Subsequently, their PTP1B inhibitory potentials were evaluated, in which all of the isolates exhibited significant dose-dependent inhibition with IC50 13.5–57.9 μM. Among them, viscosol (4 was found to be the most potent compound having IC50 13.5 μM. In order to unveil the mechanistic behavior, detailed kinetic study was carried out, in which compound 4 was observed as a reversible, and mixed type I inhibitor of PTP1B with inhibitory constant (Ki value of 4.6 μM. Furthermore, we annotated the major metabolites through HPLC-DAD-ESI/MS analysis, in which compounds 3, 6, 7, and 9 were found to be the most abundant metabolites in D. viscosa extract.

Isolation and characterization of protein tyrosine phosphatase 1B (PTP1B) inhibitory polyphenolic compounds from Dodonaea viscosa and their kinetic analysis

Science.gov (United States)

Uddin, Zia; Song, Yeong Hun; Ullah, Mahboob; Li, Zuopeng; Kim, Jeong Yoon; Park, Ki Hun

2018-03-01

Diabetes mellitus is one of a major worldwide concerns, regulated by either defects in secretion or action of insulin, or both. Insulin signaling down-regulation has been related with over activity of protein tyrosine phosphatase 1B (PTP1B) enzyme, which has been a promising target for the treatment of diabetes mellitus. Herein, activity guided separation of methanol extract (95%) of Dodonaea viscosa aerial parts afforded nine (1-9) polyphenolic compounds, all of them were identified through spectroscopic data including 2D NMR and HREIMS. Subsequently, their PTP1B inhibitory potentials were evaluated, in which all of the isolates exhibited significant dose-dependent inhibition with IC50 13.5-57.9 μM. Among them, viscosol (4) was found to be the most potent compound having IC50 13.5 μM. In order to unveil the mechanistic behavior, detailed kinetic study was carried out, in which compound 4 was observed as a reversible, and mixed type I inhibitor of PTP1B with inhibitory constant (Ki) value of 4.6 μM. Furthermore, we annotated the major metabolites through HPLC-DAD-ESI/MS analysis, in which compounds 3, 6, 7 and 9 were found to be the most abundant metabolites in D.viscosa extract.

Studies on structure and covalence effects on hyperfine interactions of AFeO sub(2) and BFeS sub(2) compounds by Moessbauer spectroscopy (A= Na, Cu, Ag, B= K, Rb, Cs, Na)

International Nuclear Information System (INIS)

Taft, C.A.

1975-01-01

The compounds AFeO sub(2) and BFeS sub(2) (A = Na, Cu, Ag, B = K, Rb, Cs, Na) were investigated by Moessbauer spectroscopy. The spectra were registered at temperature range from 4.2 sup(0) to 300 sup(0)K and magnetic transitions were observed determining correspondent temperatures by variation of hyperfine field. The electric field gradient of these compounds and perovskite type compounds (Pb sub(1-x) - Ba sub(x)) Zr O sub(3) were calculated and experimental part were determined by perturbed angular correlation, taking in account the effects of covalence, crystal lattice parameters and dipolar contributions. (M.C.K.)

Evolution of the Sunspot Number and Solar Wind B Time Series

Science.gov (United States)

Cliver, Edward W.; Herbst, Konstantin

2018-03-01

The past two decades have witnessed significant changes in our knowledge of long-term solar and solar wind activity. The sunspot number time series (1700-present) developed by Rudolf Wolf during the second half of the 19th century was revised and extended by the group sunspot number series (1610-1995) of Hoyt and Schatten during the 1990s. The group sunspot number is significantly lower than the Wolf series before ˜1885. An effort from 2011-2015 to understand and remove differences between these two series via a series of workshops had the unintended consequence of prompting several alternative constructions of the sunspot number. Thus it has been necessary to expand and extend the sunspot number reconciliation process. On the solar wind side, after a decade of controversy, an ISSI International Team used geomagnetic and sunspot data to obtain a high-confidence time series of the solar wind magnetic field strength (B) from 1750-present that can be compared with two independent long-term (> ˜600 year) series of annual B-values based on cosmogenic nuclides. In this paper, we trace the twists and turns leading to our current understanding of long-term solar and solar wind activity.

Pittsburgh compound B (PiB) PET imaging of meningioma and other intracranial tumors.

Science.gov (United States)

Johnson, Derek R; Hunt, Christopher H; Nathan, Mark A; Parisi, Joseph E; Boeve, Bradley F; Murray, Melissa E; Knopman, David S; Jack, Clifford R; Petersen, Ronald C; Lowe, Val J; Johnson, Geoffrey B

2018-01-01

Meningiomas are the most common intracranial tumors. Diagnosis by MRI is generally straightforward, but lack of imaging specificity can present a diagnostic dilemma, particularly in patients with cancer. We report our experience with meningioma identification on Pittsburgh compound B (PiB) PET/CT. Patients who underwent PiB PET/CT from 2006 to 2015 were reviewed to identify those with intracranial tumors. Tumor types were classified by MR appearance, or by pathology when available. Maximum standardized uptake value (SUVmax) measurements of tumor PiB activity were compared across tumor types. 2472 patients underwent PiB PET/CT in the period of interest; 45 patients (1.8%) had probable or definite intracranial tumor. Tumor types were meningioma (29/45, 64%), vestibular schwannoma (7/45, 16%), pituitary macroadenoma (4/45, 9%), metastatic disease (2/45, 4%), and others (3/45, 7%). In patients with meningioma, the mean lesion SUVmax was 2.05 (SD 1.37), versus 1.00 (SD 0.42) in patients with non-meningioma tumors (p < 0.01). A receiver operating curve was created for lesion:cerebellum SUVmax ratio, with an area under the curve of 0.91 for a value of 1.68. At or above this ratio, specificity for meningioma was 100% (95% CI 79-100%) and sensitivity was 76% (95% CI 57-90%). PiB PET activity within an intracranial tumor is a highly specific and reasonably sensitive marker of meningioma. Further prospective evaluation is warranted to validate this result as well as to assess the performance of commercially available beta-amyloid radiotracers in meningioma identification.

Synthesis and serotonergic activity of substituted 2, N-benzylcarboxamido-5-(2-ethyl-1-dioxoimidazolidinyl)-N, N-dimethyltryptamine derivatives: novel antagonists for the vascular 5-HT(1B)-like receptor.

Science.gov (United States)

Moloney, G P; Martin, G R; Mathews, N; Milne, A; Hobbs, H; Dodsworth, S; Sang, P Y; Knight, C; Williams, M; Maxwell, M; Glen, R C

1999-07-15

The synthesis and vascular 5-HT(1B)-like receptor activity of a novel series of substituted 2, N-benzylcarboxamido-5-(2-ethyl-1-dioxoimidazolidinyl)-N, N-dimethyltryptamine derivatives are described. Modifications to the 5-ethylene-linked heterocycle and to substituents on the 2-benzylamide side chain have been explored. Several compounds were identified which exhibited affinity at the vascular 5-HT(1B)-like receptor of pK(B) > 7.0, up to 100-fold selectivity over alpha(1)-adrenoceptor affinity and 5-HT(2A) receptor affinity, and which exhibited a favorable pharmacokinetic profile. N-Benzyl-3-[2-(dimethylamino)ethyl]-5-[2-(4,4-dimethyl-2, 5-dioxo-1-imidazolidinyl)ethyl]-1H-indole-2-carboxamide (23) was identified as a highly potent, silent (as judged by the inability of angiotensin II to unmask 5-HT(1B)-like receptor-mediated agonist activity in the rabbit femoral artery), and competitive vascular 5-HT(1B)-like receptor antagonist with a plasma elimination half-life of approximately 4 h in dog plasma and with good oral bioavailability. The selectivity of compounds from this series for the vascular 5-HT(1B)-like receptors over other receptor subtypes is discussed as well as a proposed mode of binding to the receptor pharmacophore. It has been proposed that the aromatic ring of the 2, N-benzylcarboxamide group can occupy an aromatic binding site rather than the indole ring. The resulting conformation allows an amine-binding site to be occupied by the ethylamine nitrogen and a hydrogen-bonding site to be occupied by one of the hydantoin carbonyls. The electronic nature of the 2,N-benzylcarboxamide aromatic group as well as the size of substituents on this aromatic group is crucial for producing potent and selective antagonists. The structural requirement on the 3-ethylamine side chain incorporating the protonatable nitrogen is achieved by the bulky 2, N-benzylcarboxamide group and its close proximity to the 3-side chain.

Magnetic anisotropy of (Sm, Y)2Fe17Ny compounds

International Nuclear Information System (INIS)

Lu, Y.; Tegus, O.; Li, Q.A.; Tang, N.; Yu, M.J.; Zhao, R.W.; Kuang, J.P.; Yang, F.M.; Zhou, G.F.; Li, X.; Boer, F.R. de

1992-01-01

A study of the crystal structure and the magnetic properties, especially the magnetocrystalline anisotropy of (Sm 1-x Y x ) 2 Fe 17 N y compounds (x = 0, 0.2, 0.4, 0.6, 0.8, and 1.0, 2 2 Zn 17 - or Th 2 Ni 17 -type structure as the original compounds. The Curie temperatures decrease from 750 to 700 K as x increases from 0 to 1. The anisotropy field decreases linearly with increasing yttrium content. The spin reorientation has been investigated by means of high field magnetization measurements, AC-susceptibility measurements and thermomagnetic analysis, combined with X-ray diffraction. The anisotropy constants K 1 , K 2 and K 3 were derived by a phenomenological analysis, using magnetization curves measured in high fields, applied perpendicular to the alignment direction of the powder samples. A tentative spin phase diagram of the series is presented. (orig.)

Synthesis of new dithiacobaltaborane clusters derived from arachno-6,8-S2B7H9

International Nuclear Information System (INIS)

Kang, S.O.; Sneddon, L.G.

1988-01-01

A series of air-stable dithiacobaltaborane clusters has been isolated from either the reaction of the arachno-S 2 B 7 H 8 - anion with cobalt chloride and pentamethylcyclopentadienide or the reaction of neutral arachno-6,8-S 2 B 7 H 9 with cobalt atoms and pentamethylcyclopentadiene. Thus, the reaction of arachno-S 2 B 7 H 8 - with CoCl 2 and C 5 (CH 3 ) 5 - in THF gave, as the major products, the triple-decker compound nido-4,6-η-C 5 (CH 3 ) 52 Co 2 -3,5-S 2 B 2 H 2 (I) and the 11-vertex cluster nido-8,10(η-C 5 (CH 3 ) 5 ) 2 Co 2 -7,9-S 2 B 7 H 7 (III). Also isolated in smaller amounts were a chloride derivative of I, nido-1-Cl-4,6-(η-C 5 (CH 3 ) 5 ) 2 Co 2 -3,5-S 2 B 2 H (II), two isomers of III, nido-3,10-(η-C 5 (CH 3 ) 5 ) 2 Co 2 -7,9-S 2 B 7 H 7 (IV) and nido-3,5-(η-C 5 (CH 3 ) 5 ) 2 Co 2 -7,9-S 2 B 7 H 7 (V), and the eight-boron cluster nido-8-(η-C 5 (CH 3 ) 5 )Co-7,9-S 2 B 8 H 8 (VI). Other trace products of the reaction included the six-boron clusters nido-5,8-(η-C 5 (CH 3 ) 5 ) 2 Co 2 -6,9-S 2 B 6 H 6 (VII) and arachno-7-(η-C 5 (CH 3 ) 5 )Co-6,8-S 2 B 6 H 8 (VIII). Compound III was found to isomerize at 250 degree C to IV, which could then be converted to V at 300 degree C. The reaction of cobalt atoms with arachno-6,8-S 2 B 7 H 9 in the presence of pentamethylcyclopentadiene gave VIII as the major product; however, a number of other clusters including I, V, VI, and [(η-C 5 (CH 3 ) 5 ) 2 Co] + [(SB 10 H 10 ) 2 Co] - were isolated in trace amounts. 16 references, 6 figures, 3 tables

Coordination compound of vanadyl with meta-nitrobenzoilgydrozine and polyedric closo-borate anions B11H11CH

International Nuclear Information System (INIS)

Safarov, Sh.S; Kayumov, A.; Mirsaidov, U.M.

2005-01-01

The new complex compound [V O(m-NBzH) 4 (H 2 O)](B 1 1H 1 1CH) 2 C 2 H 5 OH have been synthesised and their properties have investigated. The compound of medetomidine of meta-nitronbenzoilgydrazinum with the nitroge nium of amine group and external sphere of clozo-borate anions was defined by analysis of IR-spectra

Tyrphostin AG-related compounds attenuate H2O2-induced TRPM2-dependent and -independent cellular responses.

Science.gov (United States)

Yamamoto, Shinichiro; Toda, Takahiro; Yonezawa, Ryo; Negoro, Takaharu; Shimizu, Shunichi

2017-05-01

TRPM2 is a Ca 2+ -permeable channel that is activated by H 2 O 2 . TRPM2-mediated Ca 2+ signaling has been implicated in the aggravation of inflammatory diseases. Therefore, the development of TRPM2 inhibitors to prevent the aggravation of these diseases is expected. We recently reported that some Tyrphostin AG-related compounds inhibited the H 2 O 2 -induced activation of TRPM2 by scavenging the intracellular hydroxyl radical. In the present study, we examined the effects of AG-related compounds on H 2 O 2 -induced cellular responses in human monocytic U937 cells, which functionally express TRPM2. The effects of AG-related compounds on H 2 O 2 -induced changes in intracellular Ca 2+ concentrations, extracellular signal-regulated kinase (ERK) activation, and CXCL8 secretion were assessed using U937 cells. Ca 2+ influxes via TRPM2 in response to H 2 O 2 were blocked by AG-related compounds. AG-related compounds also inhibited the H 2 O 2 -induced activation of ERK, and subsequent secretion of CXCL8 mediated by TRPM2-dependent and -independent mechanisms. Our results show that AG-related compounds inhibit H 2 O 2 -induced CXCL8 secretion following ERK activation, which is mediated by TRPM2-dependent and -independent mechanisms in U937 cells. We previously reported that AG-related compounds blocked H 2 O 2 -induced TRPM2 activation by scavenging the hydroxyl radical. The inhibitory effects of AG-related compounds on TRPM2-independent responses may be due to scavenging of the hydroxyl radical. Copyright © 2017 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

Design and synthesis of new potent PTP1B inhibitors with the skeleton of 2-substituted imino-3-substituted-5-heteroarylidene-1,3-thiazolidine-4-one: Part I.

Science.gov (United States)

Meng, Ge; Zheng, Meilin; Wang, Mei; Tong, Jing; Ge, Weijuan; Zhang, Jiehe; Zheng, Aqun; Li, Jingya; Gao, Lixin; Li, Jia

2016-10-21

A new series of 2-substituted imino-3-substituted-5- heteroarylidene-1,3-thiazolidine-4-ones as the potent bidentate PTP1B inhibitors were designed and synthesized in this paper. All of the new compounds were characterized and identified by spectra analysis. The biological screening test against PTP1B showed that some of these compounds have the positive inhibitory activity against PTP1B. The activity of the compounds with 5-substituted pyrrole on 5-postion of 1,3-thiazolidine-4-one are more potent than that of those compounds with 5-substituted pyridine group. Compound 14b, 14h and 14i showed IC50 values of 8.66 μM, 6.83 μM and 6.09 μM against PTP1B, respectively. Docking analysis of these active compounds with PTP1B showed the possible interaction modes of these biheterocyclic compounds with the active sites of PTP1B. The inhibition tests against oncogenetic CDC25B were also conducted on this set of compounds to evaluate the selectivity and possible anti-neoplastic activity. Compound 14b also showed the lowest IC50 of 1.66 μM against CDC25B among all the possible inhibitors, including 14g, 14h, 14i and 15c. Some pharmacological parameters including VolSurf, steric and electric descriptors of all the compounds were calculated to give some hints about the relative relationship with the biological activity. The result of this study might give some light on designing the possible anti-cancer drugs targeting at phosphatases. The most active compound 14i might be used as the lead compound for further structure modification of the new low molecular weight PTP1B inhibitors with the N-containing heterocyclic skeleton. Copyright © 2016. Published by Elsevier Masson SAS.

New Approaches for the Synthesis, Cytotoxicity and Toxicity of Heterocyclic Compounds Derived from 2-Cyanomethylbenzo[c]imidazole.

Science.gov (United States)

Mohareb, Rafat M; Mohamed, Abeer A; Abdallah, Amira E M

2016-01-01

The reaction of ethyl cyanoacetate with o-phenylenediamine gave the 2-cyanomethylbenzo[c]imidazole (1). The latter compound was used as the key starting material to synthesise biologically active heterocyclic derivatives. Thus, the reaction of 1 with cyclohexanone and either of benzaldehyde, 4-methoxybenzaldehyde or 4-chlorobenzaldehyde gave the annulated derivatives 2a-c, respectively. The antitumor evaluations of the newly synthesized products against the three cancer cell lines MCF-7 (breast adeno-carcinoma), NCI-H460 (non-small cell lung cancer) and SF-268 (CNS cancer) showed that compounds 2b, 6, 11b, 11c, 12b, 16a, 16b and 18a exhibited optimal cytotoxic effect against cancer cell lines, with IC50 values in the nM range. Bioactive compounds are often toxic to shrimp larvae. Thus, in order to monitor these chemicals in vivo lethality to shrimp larvae (Artemia salina), Brine-Shrimp Lethality Assay was used. Compounds 11b, 12b and 16b showed no toxicity against the tested organisms.

Superconductivity in MgB{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Muranaka, Takahiro; Akimitsu, Jun [Aoyama Gakuin Univ., Kanagawa (Japan). Dept. of Physics and Mathematics

2011-07-01

We review superconductivity in MgB{sub 2} in terms of crystal and electronic structure, electron-phonon coupling, two-gap superconductivity and application. Finally, we introduce the development of new superconducting materials in related compounds. (orig.)

Discovery of estrogen receptor α modulators from natural compounds in Si-Wu-Tang series decoctions using estrogen-responsive MCF-7 breast cancer cells.

Science.gov (United States)

Liu, Li; Ma, Hongyue; Tang, Yuping; Chen, Wenxing; Lu, Yin; Guo, Jianming; Duan, Jin-Ao

2012-01-01

The binding between the estrogen receptor α (ER-α) and a variety of compounds in traditional Chinese formulae, Si-Wu-Tang (SWT) series decoctions, was studied using a stably-transfected human breast cancer cell line (MVLN). In 38 compounds tested from SWT series decoctions, the estrogen-like activity of 22 compounds was above 60% in 20 μg mL(-1). Furthermore, theoretical affinity of these compounds was certificated using the functional virtual screen of ER-α modulators by FlexX-Pharm. The accuracy of functional virtual screening of ER-α modulators could reach to 77.27%. The results showed that some compounds, such as organic acids and flavones in SWT series decoctions could be used as selective estrogen receptor modulators (SERMs) and could be selected for further development as potential agents for estrogen related diseases. Copyright © 2011 Elsevier Ltd. All rights reserved.

The interplay of magnetic order and superconductivity in GdxY1-xNi2B2C

International Nuclear Information System (INIS)

Drzazga, Z.; Fuchs, G.; Handstein, A.; Nenkov, K.; Mueller, K.-H.

2003-01-01

Resistivity, ac susceptibility and magnetization measurements are reported for polycrystalline samples of the Gd x Y 1-x Ni 2 B 2 C series as a function of temperature and magnetic field. The magnetic Gd impurities cause an almost linear decrease of the superconducting transition temperature T c with increasing Gd content in the range of x c have been observed. The effect of the 4f local moments manifests in a complete suppression of superconductivity for x≥0.3 and in antiferromagnetic ordering for x>0.3. In zero applied magnetic field, a distinct concentration region around x∼0.3 has been revealed separating superconductivity and antiferromagneting ordering. A metamagnetic transition has been observed in the compound with x=0.5 at a magnetic field of 0.8 T

Benzoquinones and terphenyl compounds as phosphodiesterase-4B inhibitors from a fungus of the order Chaetothyriales (MSX 47445).

Science.gov (United States)

El-Elimat, Tamam; Figueroa, Mario; Raja, Huzefa A; Graf, Tyler N; Adcock, Audrey F; Kroll, David J; Day, Cynthia S; Wani, Mansukh C; Pearce, Cedric J; Oberlies, Nicholas H

2013-03-22

Three bioactive compounds were isolated from an organic extract of an ascomycete fungus of the order Chaetothyriales (MSX 47445) using bioactivity-directed fractionation as part of a search for anticancer leads from filamentous fungi. Of these, two were benzoquinones [betulinan A (1) and betulinan C (3)], and the third was a terphenyl compound, BTH-II0204-207:A (2). The structures were elucidated using a set of spectroscopic and spectrometric techniques; the structure of the new compound (3) was confirmed via single-crystal X-ray diffraction. Compounds 1-3 were evaluated for cytotoxicity against a human cancer cell panel, for antimicrobial activity against Staphylococcus aureus and Candida albicans, and for phosphodiesterase (PDE4B2) inhibitory activities. The putative binding mode of 1-3 with PDE4B2 was examined using a validated docking protocol, and the binding and enzyme inhibitory activities were correlated.

New ternary tantalum borides containing boron dumbbells: Experimental and theoretical studies of Ta2OsB2 and TaRuB

Science.gov (United States)

Mbarki, Mohammed; Touzani, Rachid St.; Rehorn, Christian W. G.; Gladisch, Fabian C.; Fokwa, Boniface P. T.

2016-10-01

The new ternary transition metal-rich borides Ta2OsB2 and TaRuB have been successfully synthesized by arc-melting the elements in a water-cooled crucible under an argon atmosphere. The crystal structures of both compounds were solved by single-crystal X-ray diffraction and their metal compositions were confirmed by EDX analysis. It was found that Ta2OsB2 and TaRuB crystallize in the tetragonal Nb2OsB2 (space group P4/mnc, no. 128) and the orthorhombic NbRuB (space group Pmma, no. 51) structure types with lattice parameters a=5.878(2) Å, c=6.857(2) Å and a=10.806(2) Å, b=3.196(1) Å, c=6.312(2) Å, respectively. Furthermore, crystallographic, electronic and bonding characteristics have been studied by density functional theory (DFT). Electronic structure relaxation has confirmed the crystallographic parameters while COHP bonding analysis indicates that B2-dummbells are the strongest bonds in both compounds. Moreover, the formation of osmium dumbbells in Ta2OsB2 through a Peierls distortion along the c-axis, is found to be the origin of superstructure formation. Magnetic susceptibility measurements reveal that the two phases are Pauli paramagnets, thus confirming the theoretical DOS prediction of metallic character. Also hints of superconductivity are found in the two phases, however lack of single phase samples has prevented confirmation. Furthermore, the thermodynamic stability of the two modifications of AMB (A=Nb, Ta; M =Ru, Os) are studied using DFT, as new possible phases containing either B4- or B2-units are predicted, the former being the most thermodynamically stable modification.

Synthesis and magnetic properties of layered MnPSxSe3-x (0 < x < 3) and corresponding intercalation compounds of 2,2'-bipyridine

International Nuclear Information System (INIS)

Yan, Xiaobing; Chen, Xingguo; Qin, Jingui

2011-01-01

Graphical abstract: A series of new layered MnPS x Se 3-x (0 x Se 3-x exhibited antiferromagnetism similar to MnPS 3 or MnPSe 3 , but the intercalation of 2,2'-bipyridine can dramatically change the properties of MnPS x Se 3-x slab. Research highlights: → A series of new MnPS x Se 3-x are designed and synthesized for the first time and their layered structure has been determined. → The intercalation chemistry has been initially studied via the intercalation of 2,2'-bipyridine with MnPS x Se 3-x . → The magnetic properties of the series MnPS x Se 3-x and the corresponding intercalation compounds of 2,2'-bipydine have been studied. And the relationship between the structure and the magnetic propertied has been primarily explored. -- Abstract: In this work, we synthesize a series of new MnPS x Se 3-x (0 1-y PS x Se 3-x (bipy) 4y , x = 1.2, 1.8 and 2.4) via the intercalation of 2,2'-bipyridine with MnPS x Se 3-x . XRD results confirm that MnPS x Se 3-x compounds show the layered structure and can be regarded as the solid solution of MnPS 3 and MnPSe 3 . Magnetic measurements indicate that MnPS x Se 3-x compounds exhibit paramagnetism with negative Weiss constant in the paramagnetic temperature region, and an antiferromagnetic phase transition occurs at the Neel temperature. It is found that the magnetic properties of MnPS x Se 3-x slab are dramatically changed after the intercalation of 2,2'-bipyridine, which is close related to the relative ratio of S and Se atom as well as the intralayered Mn 2+ vacancies of MnPS x Se 3-x slab.

Toward the identification of a reliable 3D-QSAR model for the protein tyrosine phosphatase 1B inhibitors

Science.gov (United States)

Wang, Fangfang; Zhou, Bo

2018-04-01

Protein tyrosine phosphatase 1B (PTP1B) is an intracellular non-receptor phosphatase that is implicated in signal transduction of insulin and leptin pathways, thus PTP1B is considered as potential target for treating type II diabetes and obesity. The present article is an attempt to formulate the three-dimensional quantitative structure-activity relationship (3D-QSAR) modeling of a series of compounds possessing PTP1B inhibitory activities using comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) techniques. The optimum template ligand-based models are statistically significant with great CoMFA (R2cv = 0.600, R2pred = 0.6760) and CoMSIA (R2cv = 0.624, R2pred = 0.8068) values. Molecular docking was employed to elucidate the inhibitory mechanisms of this series of compounds against PTP1B. In addition, the CoMFA and CoMSIA field contour maps agree well with the structural characteristics of the binding pocket of PTP1B active site. The knowledge of structure-activity relationship and ligand-receptor interactions from 3D-QSAR model and molecular docking will be useful for better understanding the mechanism of ligand-receptor interaction and facilitating development of novel compounds as potent PTP1B inhibitors.

Discovery of 1-[2-(2,4-dimethylphenylsulfanyl)phenyl]piperazine (Lu AA21004): a novel multimodal compound for the treatment of major depressive disorder.

Science.gov (United States)

Bang-Andersen, Benny; Ruhland, Thomas; Jørgensen, Morten; Smith, Garrick; Frederiksen, Kristen; Jensen, Klaus Gjervig; Zhong, Huailing; Nielsen, Søren Møller; Hogg, Sandra; Mørk, Arne; Stensbøl, Tine Bryan

2011-05-12

The synthesis and structure-activity relationship of a novel series of compounds with combined effects on 5-HT(3A) and 5-HT(1A) receptors and on the serotonin (5-HT) transporter (SERT) are described. Compound 5m (Lu AA21004) was the lead compound, displaying high affinity for recombinant human 5-HT(1A) (K(i) = 15 nM), 5-HT(1B) (K(i) = 33 nM), 5-HT(3A) (K(i) = 3.7 nM), 5-HT(7) (K(i) = 19 nM), and noradrenergic β(1) (K(i) = 46 nM) receptors, and SERT (K(i) = 1.6 nM). Compound 5m displayed antagonistic properties at 5-HT(3A) and 5-HT(7) receptors, partial agonist properties at 5-HT(1B) receptors, agonistic properties at 5-HT(1A) receptors, and potent inhibition of SERT. In conscious rats, 5m significantly increased extracellular 5-HT levels in the brain after acute and 3 days of treatment. Following the 3-day treatment (5 or 10 (mg/kg)/day) SERT occupancies were only 43% and 57%, respectively. These characteristics indicate that 5m is a novel multimodal serotonergic compound, and 5m is currently in clinical development for major depressive disorder.

Structural instability and ground state of the U_2Mo compound

International Nuclear Information System (INIS)

Losada, E.L.; Garcés, J.E.

2015-01-01

This work reports on the structural instability at T = 0 °K of the U_2Mo compound in the C11_b structure under the distortion related to the C_6_6 elastic constant. The electronic properties of U_2Mo such as density of states (DOS), bands and Fermi surface (FS) are studied to understand the source of the instability. The C11_b structure can be interpreted as formed by parallel linear chains along the z-directions each one composed of successive U–Mo–U blocks. Hybridization due to electronic interactions inside the U–Mo–U blocks is slightly modified under the D_6 distortion. The change in distance between chains modifies the U–U interaction and produces a split of f-states. The distorted structure is stabilized by a decrease in energy of the hybridized states, mainly between d-Mo and f-U states, together with the f-band split. Consequently, an induced Peierls distortion is produced in U_2Mo due to the D_6 distortion. It is important to note that the results of this work indicate that the structure of the ground state of the U_2Mo compound is not the assumed C11_b structure. It is suggested for the ground state a structure with hexagonal symmetry (P6 #168), ∼0.1 mRy below the energy of the recently proposed Pmmn structure. - Highlights: • Structural instability of the C11b compound due to the D6 deformation. • Induced Peierls distortion due to the D6 deformation. • Distorted structure is stabilized by hybridization and split of f-Uranium state. • P6 (#168) suggested ground state for the U_2Mo compound.

2-arylureidobenzoic acids

DEFF Research Database (Denmark)

Valgeirsson, Jon; Nielsen, Elsebet Ø; Peters, Dan

2003-01-01

A series of 2-arylureidobenzoic acids (AUBAs) was prepared by a short and effective synthesis, and the pharmacological activity at glutamate receptors was evaluated in vitro and in vivo. The compounds showed noncompetitive antagonistic activity at the kainate receptor subtype GluR5. The most potent...... on the benzoic acid moiety (ring A), whereas ring B tolerated a variety of substituents, but with a preference for lipophilic substituents. The most potent compounds had a 4-chloro substituent on ring A and 3-chlorobenzene (6b), 2-naphthalene (8h), or 2-indole (8k) as ring B and had IC(50) values of 1.3, 1...

Production and characterization of compounds based on MgB4O7 for application in dosimetry

International Nuclear Information System (INIS)

Souza, Luiza Freire de

2016-01-01

Many materials with luminescent properties are used for ionizing radiation dosimetry through the thermoluminescence (TL) and optically stimulated luminescence (OSL) techniques. Detectors based on lithium fluoride (LiF), calcium sulphate (CaSO 4 ) and aluminum oxide (Al 2 O 3 ), doped or codoped with various elements, are the TL or OSL commercial dosimeters most widely used currently. However, several researches are focused to the development of new TL /OSL materials in intention to enhance the dosimetric properties, in view that no TL/OSL dosimeter has all the ideal characteristics for monitoring the radiation. In this context, magnesium tetraborate (MgB 4 O 7 ), which has been presented in the literature as a material for dosimetry TL, was investigated in this work. As there are no reports on the structural characterization of this material or regarding to its applicability on OSL dosimetry, the proposal of the present work was to develop compounds based on MgB 4 O 7 , with different doping, by solid state synthesis. It was made the structural, optical, TL and OSL characterization of the compound to verify it feasibility for application on radiation dosimetry. Initially, it was determined the calcination temperature and time for MgB 4 O 7 formation, with the use of thermal analyses and x ray diffraction. The ideal calcination was found at 900 °C for 7 hours. It were produced , in powder form, the compounds: MgB 4 O 7 , MgB 4 O 7 :Dy, MgB 4 O 7 :Dy,Li, MgB 4 O 7 :Ce, MgB 4 O 7 :Ce,Li, MgB 4 O 7 :Nd and MgB 4 O 7 :Nd,Li. For TL and OSL analyses it were produced pellets sintering at 950 °C for 2 hours. The radioluminescence (RL) analyses of MgB 4 O 7 :Dy and MgB 4 O 7 :Dy,Li shows wavelength emissions at 490, 590, 670 and 760 nm. For MgB 4 O 7 :Ce and MgB 4 O 7 :Ce,Li RL was observed wide emission band in the ultraviolet region. For the MgB 4 O 7 :Nd and MgB 4 O 7 :Nd,Li RL were not observed emission from the ultraviolet to infrared. With the results obtained from

New silicate-germanate Cs2Pb2[(Si0.6Ge0.4)2O7] from the series A2Pb2[B2O7], A = K, Cs, B = Si, Ge with the umbrella-like [PbO3]4- group

Science.gov (United States)

Belokoneva, Elena L.; Morozov, Ivan A.; Volkov, Anatoly S.; Dimitrova, Olga V.; Stefanovich, Sergey Yu.

2018-04-01

New silicate-germanate Cs2Pb2[(Si0.6Ge0.4)2O7] was synthesized in multi-components hydrothermal solution with 20 w.% concentration of Cs2CO3 mineralizer, pH = 10. Novel mixed compound belongs to the structure type A2Pb2[B2O7] previously indicated for powders with A = K, B=Si or Ge. Singe crystal structure determination of Cs2Pb2[(Si0.6Ge0.4)2O7] revealed the need for the correction of the space group of the earlier suggested structural model from P-3 to P-3m1, as well as for the splitting of the Pb-atom position. Umbrella-like groups [PbO3]4- are located between [(Si,Ge)O4]4- tetrahedra in mica-like honeycomb layers and play the role of tetrahedra with the Pb-lone-pair as the forth apex. Crystal chemical comparison revealed similarities and differences with the classical structure type of α-celsian Ba[Al2Si2O8] with the tetrahedral double layer. Recently investigated nonlinear optical acentric borates Pb2(BO3)(NO3) and Pb2(BO3)Cl are both related to this structural type, possessing umbrella-like groups [PbO3]4- and honeycomb layers [Pb2(BO3)]+ with the BO3-triangles on the tetrahedral positions.

Synthesis and structure elucidation of a series of pyranochromene chalcones and flavanones using 1D and 2D NMR spectroscopy and X-ray crystallography.

Science.gov (United States)

Pawar, Sunayna S; Koorbanally, Neil A

2014-06-01

A series of novel pyranochromene chalcones and corresponding flavanones were synthesized. This is the first report on the confirmation of the absolute configuration of chromene-based flavanones using X-ray crystallography. These compounds were characterized by 2D NMR spectroscopy, and their assignments are reported herein. The 3D structure of the chalcone 3b and flavanone 4g was determined by X-ray crystallography, and the structure of the flavanone was confirmed to be in the S configuration at C-2. Copyright © 2014 John Wiley & Sons, Ltd.

Antagonism at the NR2B subunit of NMDA receptors induces increased connectivity of the prefrontal and subcortical regions regulating reward behavior.

Science.gov (United States)

Gass, Natalia; Becker, Robert; Sack, Markus; Schwarz, Adam J; Reinwald, Jonathan; Cosa-Linan, Alejandro; Zheng, Lei; von Hohenberg, Christian Clemm; Inta, Dragos; Meyer-Lindenberg, Andreas; Weber-Fahr, Wolfgang; Gass, Peter; Sartorius, Alexander

2018-04-01

Evidence indicates that ketamine's rapid antidepressant efficacy likely results from its antagonism of NR2B-subunit-containing NMDA receptors (NMDAR). Since ketamine equally blocks NR2A- and NR2B-containing NMDAR, and has affinity to other receptors, NR2B-selective drugs might have improved therapeutic efficiency and side effect profile. We aimed to compare the effects of (S)-ketamine and two different types of NR2B-selective antagonists on functional brain networks in rats, in order to find common circuits, where their effects intersect, and that might explain their antidepressant action. The experimental design comprised four parallel groups of rats (N = 37), each receiving (S)-Ketamine, CP-101,606, Ro 25-6981 or saline. After compound injection, we acquired resting-state functional magnetic resonance imaging time series. We used graph theoretical approach to calculate brain network properties. Ketamine and CP-101,606 diminished the global clustering coefficient and small-worldness index. At the nodal level, all compounds induced increased connectivity of the regions mediating reward and cognitive aspects of emotional processing, such as ventromedial prefrontal cortex, septal nuclei, and nucleus accumbens. The dorsal hippocampus and regions involved in sensory processing and aversion, such as superior and inferior colliculi, exhibited an opposite effect. The effects common to ketamine and NR2B-selective compounds were localized to the same brain regions as those reported in depression, but in the opposite direction. The upregulation of the reward circuitry might partially underlie the antidepressant and anti-anhedonic effects of the antagonists and could potentially serve as a translational imaging phenotype for testing putative antidepressants, especially those targeting the NR2B receptor subtype.

Identification of novel candidate compounds targeting TrkB to induce apoptosis in neuroblastoma

International Nuclear Information System (INIS)

Nakamura, Yohko; Suganami, Akiko; Fukuda, Mayu; Hasan, Md Kamrul; Yokochi, Tomoki; Takatori, Atsushi; Satoh, Shunpei; Hoshino, Tyuji; Tamura, Yutaka; Nakagawara, Akira

2014-01-01

Neuroblastoma (NB) is one of the most frequent solid tumors in children and its prognosis is still poor. The neurotrophin receptor TrkB and its ligand brain-derived neurotrophic factor (BDNF) are expressed at high levels in high-risk NBs and are involved in defining the poor prognosis of the patients. However, the TrkB targeting therapy has never been realized in the clinic. We performed an in silico screening procedure utilizing an AutoDock/grid computing technology in order to identify novel small chemical compounds targeting the BDNF-binding domain of TrkB. For the first screening, a library of three million synthetic compounds was screened in silico and was ranked according to the Docking energy. The top-ranked 37 compounds were further functionally screened for cytotoxicity by using NB cell lines. We have finally identified seven compounds that kill NB cells with the IC 50 values of 0.07–4.6 μmol/L. The terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay showed that these molecules induce apoptosis accompanied by p53 activation in NB cell lines. The candidate compounds and BDNF demonstrated an antagonistic effect on cell growth, invasion, and colony formation, possibly suggesting competition at the BDNF-binding site of TrkB. The candidate compounds had tumor-suppressive activity in xenograft and in vivo toxicity tests (oral and intravenous administrations) using mice, and did not show any abnormal signs. Using in silico Docking screening we have found new candidate TrkB inhibitors against high-risk NBs, which could lead to new anti-cancer drugs

Fused Heterocyclic Compounds as Potent Indoleamine-2,3-dioxygenase 1 Inhibitors.

Science.gov (United States)

Panda, Subhankar; Roy, Ashalata; Deka, Suman Jyoti; Trivedi, Vishal; Manna, Debasis

2016-12-08

Uncontrolled metabolism of l-tryptophan (l-Trp) in the immune system has been recognized as a critical cellular process in immune tolerance. Indoleamine 2,3-dioxygenase 1 (IDO1) enzyme plays an important role in the metabolism of a local l-Trp through the kynurenine pathway in the immune systems. In this regard, IDO1 has emerged as a therapeutic target for the treatment of diseases that are associated with immune suppression like chronic infections, cancer, and others. In this study, we synthesized a series of pyridopyrimidine, pyrazolopyranopyrimidine, and dipyrazolopyran derivatives. Further lead optimizations directed to the identification of potent compounds, 4j and 4l (IC 50 = 260 and 151 nM, respectively). These compounds also exhibited IDO1 inhibitory activities in the low nanomolar range in MDA-MB-231 cells with very low cytotoxicity. Stronger selectivity for the IDO1 enzyme (>300-fold) over tryptophan 2,3-dioxygenase (TDO) enzyme was also observed for these compounds. Hence, these fused heterocyclic compounds are attractive candidates for the advanced study of IDO1-dependent cellular function and immunotherapeutic applications.

RE{sub 2}B{sub 8}O{sub 15} (RE = La, Pr, Nd). Syntheses of three new rare earth borates isotypic to Ce{sub 2}B{sub 8}O{sub 15}

Energy Technology Data Exchange (ETDEWEB)

Glaetzle, Matthias; Hoerder, Gregor J.; Huppertz, Hubert [Innsbruck Univ. (Austria). Inst. fuer Allgemeine, Anorganische und Theoretische Chemie

2016-08-01

The rare earth borates RE{sub 2}B{sub 8}O{sub 15} (RE = La, Pr, Nd) were synthesized in a Walker-type multianvil apparatus under conditions of 5.5 GPa and 1100 C. Starting from the corresponding rare earth oxides and boron oxide, the syntheses yielded crystalline products of all new compounds that allowed crystal structure analyses based on single-crystal X-ray diffraction data for La{sub 2}B{sub 8}O{sub 15} and Nd{sub 2}B{sub 8}O{sub 15}. The compound Pr{sub 2}B{sub 8}O{sub 15} could be characterized via X-ray powder diffractometry. The results show that the new compounds crystallize isotypically to Ce{sub 2}B{sub 8}O{sub 15} in the monoclinic space group P2/c. The infrared spectra of RE{sub 2}B{sub 8}O{sub 15} (RE = La, Pr, Nd) have also been studied.

Co-existence of long-range order and spin fluctuation in a new geometric frustration series M2(OH)3Cl

International Nuclear Information System (INIS)

Zheng, X.G.; Hagihala, Masato; Toriyi, Takato

2007-01-01

Recently, we observed the co-existence of a long-range magnetic order and spin fluctuation in a clean compound of clinoatacamite, Cu 2 (OH) 3 Cl (PRL95 (2005) 057201). The present work reports magnetic studies on other compounds of this transition metal series M 2 (OH) 3 Cl, where M represents three-dimensional (3D)-electron magnetic ions of Co 2+ , Fe 2+ , etc., respectively. The present study shows that this co-existence is a common feature of the M 2 Cl(OH) 3 series, no matter whether it is anti-ferromagnetic, as in the case of Fe 2 (OH) 3 Cl (T N =15 K), or ferromagnetic, as in the case of Co 2 (OH) 3 Cl (T C =10.5 K). These compounds show a 3D network of corner-sharing tetrahedrons for the magnetic ions. The tetrahedron is slightly tilted with roughly 10% longer distance between the M-M bonded by Cl than those bonded by O and this distortion is suspected to be responsible for the partial order. This research suggests that the transition metal hydroxyhalide M 2 Cl(OH) 3 series are new geometric frustration system on tetrahedral lattice for d-electron spins

AAg2M[VO4]2 (A=Ba,Sr; M=Co,Ni): A series of ferromagnetic insulators

Science.gov (United States)

Möller, Angela; Amuneke, Ngozi E.; Daniel, Phillip; Lorenz, Bernd; de la Cruz, Clarina R.; Gooch, Melissa; Chu, Paul C. W.

2012-06-01

AAg2M[VO4]2 with A=Sr2+ or Ba2+ present a series of layered compounds featuring a triangular lattice of transition metal cations, M = Co2+ or Ni2+, connected via nonmagnetic ortho-vanadates, which provide the magnetic superexchange within the layers. For this series of insulating compounds, ferromagnetic long-range order below 10 K is suggested by magnetization and specific heat measurements and confirmed by neutron diffraction experiments. We have investigated the impact of the spacer size of A2+ separating the layers leading to a tilting of the vanadates and consequently inducing a change in the effective magnetic correlations. Magnetization and specific heat measurements corroborate the important dependence of the magnetic superexchange on the orientation of the vanadates and the respective spin system. Furthermore, the ground state properties of the spin systems, S=1 (Ni2+) and S=3/2 (Co2+) in their respective octahedral coordination of oxygen, are evaluated. Calculated magnetic moments of the single ion complexes agree well with the magnetic structure. We, furthermore, report the dependence of Tc on applied isotropic pressure suggestive of a pressure effect on the effective ferromagnetic exchange coupling constants. In addition spectroscopic investigations probing the electronic structure of the [MO6] complexes and the vibrational structure of the [VO4] units are given.

B_2S_2O_9. A boron sulfate with phyllosilicate topology

International Nuclear Information System (INIS)

Logemann, Christian; Wickleder, Mathias S.

2013-01-01

The condensation of [BO_4] and [SO_4] tetrahedra in the first binary boron sulfate B_2S_2O_9, leads to a structure with typical layered phyllosilicate topology. The compound is obtained from the hydrolysis of B(OH)_3 and HSO_3Cl. (Copyright copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Characterization of Fumonisin A-Series by High-Resolution Liquid Chromatography-Orbitrap Mass Spectrometry

Directory of Open Access Journals (Sweden)

Masayoshi Tamura

2014-08-01

Full Text Available Fumonisin A-series (FAs in a reference material of corn sample that was naturally contaminated with fumonisins was characterized using high-resolution liquid chromatography-Orbitrap mass spectrometry (LC-Orbitap MS. Peaks for fumonisin B1 (FB1, fumonisin B2 (FB2, and fumonisin B3 (FB3, in addition to three peaks corresponding to unknown compounds I, II, and III, were detected in the chromatogram for the corn sample. Fragment ion analysis for FB1, FB2, and FB3 showed that while the ions formed at m/z values of 200–800 were similar to those formed by the cleavage of the tricarballylic acids and the hydroxyl groups, the fragmentation patterns at m/z values of 50–200 varied depending on the hydroxyl group locations in the compounds. Fragment ion analysis of compounds I–III revealed structural similarities to FBs, only differing by an additional C2H2O in the unknown compounds. Using these results and by comparing the product ion mass spectra of compound I with fumonisin A1 (FA1 synthesized from FB1 standards, compounds I–III were hypothesized to be N-acetyl analogs of FBs: fumonisins A1 (FA1, A2 (FA2, and A3 (FA3. The method for determining concentrations was validated with FA1, FB1, FB2, and FB3 standards and applied to analyze the reference material. The FB1, FB2, and FB3 analytical levels were within acceptance limits and the amount of FA1 in the material was ~15% of FB1 amount at 4.2 mg/kg.

Characterization of fumonisin A-series by high-resolution liquid chromatography-orbitrap mass spectrometry.

Science.gov (United States)

Tamura, Masayoshi; Mochizuki, Naoki; Nagatomi, Yasushi; Toriba, Akira; Hayakawa, Kazuichi

2014-08-21

Fumonisin A-series (FAs) in a reference material of corn sample that was naturally contaminated with fumonisins was characterized using high-resolution liquid chromatography-Orbitrap mass spectrometry (LC-Orbitap MS). Peaks for fumonisin B1 (FB1), fumonisin B2 (FB2), and fumonisin B3 (FB3), in addition to three peaks corresponding to unknown compounds I, II, and III, were detected in the chromatogram for the corn sample. Fragment ion analysis for FB1, FB2, and FB3 showed that while the ions formed at m/z values of 200-800 were similar to those formed by the cleavage of the tricarballylic acids and the hydroxyl groups, the fragmentation patterns at m/z values of 50-200 varied depending on the hydroxyl group locations in the compounds. Fragment ion analysis of compounds I-III revealed structural similarities to FBs, only differing by an additional C2H2O in the unknown compounds. Using these results and by comparing the product ion mass spectra of compound I with fumonisin A1 (FA1) synthesized from FB1 standards, compounds I-III were hypothesized to be N-acetyl analogs of FBs: fumonisins A1 (FA1), A2 (FA2), and A3 (FA3). The method for determining concentrations was validated with FA1, FB1, FB2, and FB3 standards and applied to analyze the reference material. The FB1, FB2, and FB3 analytical levels were within acceptance limits and the amount of FA1 in the material was ~15% of FB1 amount at 4.2 mg/kg.

Peniciadametizine A, a Dithiodiketopiperazine with a Unique Spiro[furan-2,7'-pyrazino[1,2-b][1,2]oxazine] Skeleton, and a Related Analogue, Peniciadametizine B, from the Marine Sponge-Derived Fungus Penicillium adametzioides

Directory of Open Access Journals (Sweden)

Yang Liu

2015-06-01

Full Text Available Peniciadametizine A (1; a new dithiodiketopiperazine derivative possessing a unique spiro[furan-2,7'-pyrazino[1,2-b][1,2]oxazine] skeleton, together with a highly oxygenated new analogue, peniciadametizine B (2; as well as two known compounds, brasiliamide A (3; and viridicatumtoxin (4, were isolated and identified from Penicillium adametzioides AS-53, a fungus obtained from an unidentified marine sponge. The unambiguous assignment of the relative and absolute configuration for the spiro center C-2 of compound 1 was solved by the combination of NMR and ECD measurements with Density-Functional Theory (DFT conformational analysis and Time-Dependent Density-Functional Theory-Electronic Circular Dichroism (TDDFT-ECD calculations. The spiro[furan-2,7'-pyrazino[1,2-b][1,2]oxazine] skeleton of 1 has not been reported yet among natural products and the biosynthetic pathway for 1 and 2 was discussed. Compounds 1 and 2 showed inhibitory activity against the pathogenic fungus Alternaria brassicae.

Synthesis, antimicrobial and cytotoxic activities of 5-benzylidene-2-[(pyridine-4-ylmethylenehydrazono]-thiazolidin-4-one and 2-[(pyridine-4-ylmethylene hydrazono]-thiazolidin-4-one derivatives

Directory of Open Access Journals (Sweden)

Danniel Delmondes Feitoza

2012-01-01

Full Text Available A new series of 5-benzylidene-2-[(pyridine-4-ylmethylenehydrazono]-thiazolidin-4-ones 4a-l have been synthesized. These compounds were designed by a molecular hybridization approach. 2-[(Pyridine-4-ylmethylenehydrazono]-thiazolidin-4-ones 3a-d were also obtained and used as intermediates to give the target compounds. The in vitro antimicrobial and cytotoxic activities were evaluated for both series. The intermediate 3b showed considerable antibiotic activity against B. subtilis and C. albicans. In the cytotoxic activity compounds 3b (IC50= 4.25 ± 0.36 µg/mL and 4l (IC50= 1.38 ± 0.04 µg/mL were effective for inhibition of human erythromyeloblastoid leukemia (K-562 and human lung carcinoma (NCI-H292 cell lines, respectively.

Stochastic B-series and order conditions for exponential integrators

DEFF Research Database (Denmark)

Arara, Alemayehu Adugna; Debrabant, Kristian; Kværnø, Anne

2018-01-01

We discuss stochastic differential equations with a stiff linear part and their approximation by stochastic exponential integrators. Representing the exact and approximate solutions using B-series and rooted trees, we derive the order conditions for stochastic exponential integrators. The resulting...

Synthesis and biological evaluation of novel bis-aromatic amides as novel PTP1B inhibitors.

Science.gov (United States)

Wang, Wen-Long; Huang, Chao; Gao, Li-Xin; Tang, Chun-Lan; Wang, Jun-Qing; Wu, Min-Chen; Sheng, Li; Chen, Hai-Jun; Nan, Fa-Jun; Li, Jing-Ya; Li, Jia; Feng, Bainian

2014-04-15

A series of bis-aromatic amides was designed, synthesized, and evaluated as a new class of inhibitors with IC50 values in the micromolar range against protein tyrosine phosphatase 1B (PTP1B). Among them, compound 15 displayed an IC50 value of 2.34±0.08 μM with 5-fold preference over TCPTP. More importantly, the treatment of CHO/HIR cells with compound 15 resulted in increased phosphorylation of insulin receptor (IR), which suggested extensive cellular activity of compound 15. These results provided novel lead compounds for the design of inhibitors of PTP1B as well as other PTPs. Copyright © 2014 Elsevier Ltd. All rights reserved.

The Sr2.75Ce0.25Co2O7-δ oxide, n=2 member of the Ruddlesden-Popper series: Structural and magnetic evolution depending on oxygen stoichiometry

International Nuclear Information System (INIS)

Demont, A.; Hebert, S.; Pelloquin, D.; Maignan, A.

2008-01-01

The second member of the Ruddlesden-Popper series, n=2 in Sr n+1 Co n O 3n+1 , has been stabilized by substituting cerium for strontium leading to the pure compound Sr 2.75 Ce 0.25 Co 2 O 7-δ . The oxygen vacancies of this phase can be partially filled by a post-annealing oxidizing treatment with δ decreasing from 1.1 to 0.3 for the as-prepared and oxidized phases, respectively. As the samples are oxidized from δ∼1.1 to 0.3, the a and b unit cell parameters decrease from 3.836 to 3.815 A and from 20.453 to 20.047 A, respectively. Despite the average value of the cobalt valence state, V Co ∼+3.5, obtained in the oxidized Sr 2.75 Ce +4 0.25 Co 2 O 6.7 phase, a clear ferromagnetic state wit T C =175 K and M S =0.8 μB/Co is reached. - Graphical abstract: Temperature dependence of the magnetic susceptibility of as-prepared and PO 2 annealing Sr 2.75 Ce 0.25 Co 2 O 7-δ RP2-type structures

Lead optimization of 2-(piperidin-3-yl)-1H-benzimidazoles: identification of 2-morpholin- and 2-thiomorpholin-2-yl-1H-benzimidazoles as selective and CNS penetrating H₁-antihistamines for insomnia.

Science.gov (United States)

Ravula, Satheesh Babu; Yu, Jinghua; Tran, Joe A; Arellano, Melissa; Tucci, Fabio C; Moree, Wilna J; Li, Bin-Feng; Petroski, Robert E; Wen, Jianyun; Malany, Siobhan; Hoare, Samuel R J; Madan, Ajay; Crowe, Paul D; Beaton, Graham

2012-01-01

The structure-activity relationships of 2-(piperidin-3-yl)-1H-benzimidazoles, 2-morpholine and 2-thiomorpholin-2-yl-1H-benzimidazoles are described. In the lead optimization process, the pK(a) and/or logP of benzimidazole analogs were reduced either by attachment of polar substituents to the piperidine nitrogen or incorporation of heteroatoms into the piperidine heterocycle. Compounds 9a and 9b in the morpholine series and 10g in the thiomorpholine series demonstrated improved selectivity and CNS profiles compared to lead compound 2 and these are potential candidates for evaluation as sedative hypnotics. Copyright © 2011 Elsevier Ltd. All rights reserved.

MgB2 superconducting wires basics and applications

CERN Document Server

2016-01-01

The compendium gives a complete overview of the properties of MgB2 (Magnesium Diboride), a superconducting compound with a transition temperature of Tc = 39K, from the fundamental properties to the fabrication of multifilamentary wires and to the presentation of various applications. Written by eminent researchers in the field, this indispensable volume not only discusses superconducting properties of MgB2 compounds, but also describes known preparation methods of thin films and of bulk samples obtained under high pressure methods. A unique selling point of the book is the detailed coverage of various applications based on MgB2, starting with MRI magnets and high current cables, cooled by Helium (He) vapor. High current cables cooled by liquid hydrogen are also highlighted as an interesting alternative due to the shrinking He reserves on earth. Other pertinent subjects comprise permanent magnets, ultrafine wires for space applications and wind generator projects.

Thermal expansion and magnetostriction in Pr(n+2)(n+1)Nin(n-1)+2Sin(n+1) compounds

International Nuclear Information System (INIS)

Jiles, D.C.; Song, S.H.; Snyder, J.E.; Pecharsky, V.K.; Lograsso, T.A.; Wu, D.; Pecharsky, A.O.; Mudryk, Ya.; Dennis, K.W.; McCallum, R.W.

2006-01-01

Thermal expansion and magnetostriction of members of a homologous series of compounds based on the alloy series Pr (n+2)(n+1) Ni n(n-1)+2 Si n(n+1) have been measured. The crystal structures of these compounds are closely interrelated because they form trigonal prismatic columns in which the number of trigonal prisms that form the base of the trigonal columns is determined by the value of n in the chemical formula. Two compositions were investigated, Pr 5 Ni 2 Si 3 and Pr 15 Ni 7 Si 10 , corresponding to n=3 and n=4, respectively. The results were analyzed and used to determine the location of magnetic phase transitions by calculating the magnetic contribution to thermal expansion using the Gruneisen-Debye theory. This allowed more precise determination of the magnetic transition temperatures than could be achieved using the total thermal expansion. The results show two phase transitions in each material, one corresponding to the Curie temperature and the other at a lower temperature exhibiting characteristics of a spin reorientation transition

Preparation of a radioactive boron compound (B-I-131-lipiodol) for neutron capture therapy of hepatoma

International Nuclear Information System (INIS)

Chou, F.I.; Chung, H.P.; Chung, R.J.; Wen, H.W.; Wei, Y.Y.; Kai, J.J.; Lui, W.Y.; Chi, C.W.

2000-01-01

In our research, a radioactive boron compound, B-I-131-lipiodol, that can be selectively retained in hepatoma cells was prepared. Combining the effect of α particles produced by boron neutron capture reaction with the β particles released by radionuclides in the radioactive boron compounds will produce a synergistic killing effect on cancer cells. Human hepatoma HepG2 cell cultures were used to examine the stability and the intracellular distribution of the radioactive boron drug. Microscopes were used to examine the interaction and retention of B-I-131-lipiodol globules in the individual hepatoma cell. Moreover, ICP-AES and NaI scintillation counter were performed to determine boron concentrations and I-131 radioactivity, respectively. Results showed that B-I-131-lipiodol with a boron concentration and a specific radioactivity ranged from 500-2000 ppm and 0.05-10 mCi/mL respectively was stably retained in serum. The radiochemical purity of B-I-131-lipiodol was 98%. After supplement with a medium containing B-I-131-lipiodol, the HepG2 cells had intracellular B-I-131-lipiodol globules in the cytoplasm as seen by inverted light microscope, the I-131 and boron can be stably retained in HepG2 cells. (author)

Synthesis and characterization of one- to three-dimensional compounds composed of paradodecatungstate-B cluster and transition metals as linkers

International Nuclear Information System (INIS)

Sun Chunyan; Liu Shuxia; Xie Linhua; Wang Chunling; Gao Bo; Zhang Chundan; Su Zhongmin

2006-01-01

Three new extended frameworks built from paratungstate and transition metals have been synthesized and characterized. In the compound Na 8 [{Cd (H 2 O) 2 }(H 2 W 12 O 42 )].32H 2 O (1), two neighboring paratungstate-B ions [H 2 W 12 O 42 ] 10- are linked by [Cd(H 2 O) 2 ] 2+ units, leading to the formation of infinite one-dimensional (1D) anion chain [{Cd(H 2 O) 2 }(H 2 W 12 O 42 )] n 8n- . The anion [{Co(H 2 O) 3 }{Co(H 2 O) 4 }(H 2 W 12 O 42 )] n 6n- of the compound Na 6 [{Co(H 2 O) 3 }{Co(H 2 O) 4 }(H 2 W 12 O 42 )].29H 2 O (2) shows a layer-like (2D) structure in which paratungstate-B units are linked by CoO 6 octahedra, while the anion [{Co(H 2 O) 3 } 3 (H 2 W 12 O 42 )] n 4n- of the compound (H 3 O + ) 3 [{Na(H 2 O) 4 }{Co(H 2 O) 4 } 3 (H 2 W 12 O 42 )].24.5H 2 O (3) is a three-dimensional (3D) anionic polymer that consists of paratungstate-B units linked by CoO 6 octahedra. Compound 3 can reversibly adsorb and desorb water molecules leading to the color reversibly change from pink to violet. The preliminary magnetic measurement and electrochemical properties of compounds are performed. The crystal structure of unexpected product Na 4 [NiW 6 O 24 H 6 ].13H 2 O (4) is described here for the rare report of crystal structure information on the Anderson-type polyoxotungstate which has nickel as a heteroatom. - Graphical abstract: Three new compounds with one- to three-dimensional extended frameworks built from [H 2 W 12 O 42 ] 10- anion and transition metals have been synthesized and characterized by elemental analyses, X-ray single-crystal analyses, magnetic measurement, XRPD, and cyclic voltammetry measurements. The cobalt containing compound exhibits interesting reversible sorption/desorption of water molecules

Synthesis, Leishmanicidal Activity and Theoretical Evaluations of a Series of Substituted bis-2-Hydroxy-1,4-Naphthoquinones

Directory of Open Access Journals (Sweden)

Morgana V. de Araújo

2014-09-01

Full Text Available A series of eight substituted bis-2-hydroxy-1,4-naphthoquinone derivatives was synthesized through lawsone condensation with various aromatic and aliphatic aldehydes under mild acidic conditions. The title compounds were evaluated for antileishmanial activity in vitro against Leishmania amazonensis and Leishmania braziliensis promastigotes; six compounds showed good activity without significant toxic effects. The compound with the highest activity was used for an in vivo assay with Leishmania amazonensis.

2-(2-Oxo-1,4-dihydro-2H-quinazolin-3-yl)- and 2-(2,2-dioxo-1,4-dihydro-2H-2lambda6-benzo[1,2,6]thiadiazin-3-yl)-N-hydroxy-acetamides as potent and selective peptide deformylase inhibitors.

Science.gov (United States)

Apfel, C; Banner, D W; Bur, D; Dietz, M; Hubschwerlen, C; Locher, H; Marlin, F; Masciadri, R; Pirson, W; Stalder, H

2001-06-07

Potent, selective, and structurally new inhibitors of the Fe(II) enzyme Escherichia coli peptide deformylase (PDF) were obtained by rational optimization of the weakly binding screening hit (5-chloro-2-oxo-1,4-dihydro-2H-quinazolin-3-yl)-acetic acid hydrazide (1). Three-dimensional structural information, gathered from Ni-PDF complexed with 1, suggested the preparation of two series of related hydroxamic acid analogues, 2-(2-oxo-1,4-dihydro-2H-quinazolin-3-yl)-N-hydroxy-acetamides (A) and 2-(2,2-dioxo-1,4-dihydro-2H-2lambda(6)-benzo[1,2,6]thiadiazin-3-yl)-N-hydroxy-acetamides (B), among which potent PDF inhibitors (37, 42, and 48) were identified. Moreover, two selected compounds, one from each series, 36 and 41, showed good selectivity for PDF over several endoproteases including matrix metalloproteases. However, these compounds showed only weak antibacterial activity.

Molecular dinamics of tetrahedral clelate compounds of Cd(2) in solutions

International Nuclear Information System (INIS)

Nivorozhkin, L.E.; Minkin, V.I.; Borisenko, N.I.; Konstantinovskij, L.E.; Korobov, M.S.; Olekhnovich, R.Ya.

1981-01-01

Interconversion kinetics of enantiomers of tetrahedral intracomplex compounds of metals (ICM) on the base of unsymmetric ligands in solu-- tions is studied for several series of compounds according to the temperature dependence of the shape of line of prochiral substituents using the methods of the dynamic NMR (DNMR). The use of tetracoordinated ICM in the solutions of synthesized compounds of Cd(2) with the inclusion of magnetic isotope 111 Cd(S=1/2) to study molecular dynamics and the application of the corresponding methods of calculation of the DNMR signal forms permitted to clearly separate the mechanisms of digonal twist and degenerated ligand exchange. In ICM solutions the low-barrier transformations, connected with intramolecular digonal twist, take place as well as high-barrier processes of degenerated ligand exchange. The technique suggested can be applied to the studies of ICM molecular dynamics with other magnetic isotopes of metals ( 207 Pb, 199 Hg, etc.) and rapid non-degenerated ligand exchanges [ru

Synthesis, antimicrobial and cytotoxic activities of 5-benzylidene-2-[(pyridine-4-ylmethylene)hydrazono]-thiazolidin-4-one and 2-[(pyridine-4-ylmethylene) hydrazono]-thiazolidin-4-one derivatives

Energy Technology Data Exchange (ETDEWEB)

Feitoza, Danniel Delmondes; Alves, Antonio Jose; Lima, Jose Gildo de, E-mail: jgildolima@gmail.com [Departamento de Ciencias Farmaceuticas, Universidade Federal de Pernambuco, Recife - PE (Brazil); Araujo, Janete Magali; Aguiar, Jaciana Santos; Rodrigues, Maria do Desterro; Silva, Teresinha Goncalves; Nascimento, Silene Carneiro do; Goes, Alexandre Jose da Silva [Departamento de Antibioticos, Universidade Federal de Pernambuco, Recife - PE (Brazil)

2012-07-01

A new series of 5-benzylidene-2-[(pyridine-4-ylmethylene)hydrazono]-thiazolidin-4-ones 4a-l have been synthesized. These compounds were designed by a molecular hybridization approach. 2-[(Pyridine-4-ylmethylene)hydrazono]-thiazolidin-4-ones 3a-d were also obtained and used as intermediates to give the target compounds. The in vitro antimicrobial and cytotoxic activities were evaluated for both series. The intermediate 3b showed considerable antibiotic activity against B. subtilis and C. albicans. In the cytotoxic activity compounds 3b (IC{sub 50} = 4.25 +- 0.36 {mu}g/mL) and 4l (IC{sub 50} = 1.38 +- 0.04 {mu}g/mL) were effective for inhibition of human erythromyeloblastoid leukemia (K-562) and human lung carcinoma (NCI-H292) cell lines, respectively. (author)

Ce2Co3Ge5: a new U2Co3Si5 - type valance fluctuating compound

International Nuclear Information System (INIS)

Layek, Samar; Hossain, Zakir

2010-01-01

Poly crystalline sample of Ce 2 Co 3 Ge 5 have been prepared by arc melting and consequently annealing at 1100 deg C. Rietveld refinement of XRD shows that it crystallize in the orthorhombic U 2 Co 3 Si 5 structure (space group Ibam) with crystal parameters a= 9.802A, b= 11.777A and c= 5.941A and unit cell volume V= 684.8 A 3 The unit cell volume of Ce 2 Co 3 Ge 5 is seen clearly to deviate from that expected on the basis of lanthanide contraction. From susceptibility measurement, effective magnetic moment of this compound μ eff = 0.95 μ B which is lower than magnetic moment free for Ce 3+ ions (2.54 μB) but higher than that of non-magnetic Ce 4+ state (0 μ B ). All these results clearly indicated Ce 2 Co 3 Ge 5 to be a mixed valance compound. (author)

Three series of quaternary rare-earth transition-metal pnictides with CaAl{sub 2}Si{sub 2}-type structures: RECuZnAs{sub 2}, REAgZnP{sub 2}, and REAgZnAs{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Stoyko, Stanislav S.; Ramachandran, Krishna K.; Blanchard, Peter E.R. [Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2 (Canada); Rosmus, Kimberly A.; Aitken, Jennifer A. [Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA 15282 (United States); Mar, Arthur, E-mail: arthur.mar@ualberta.ca [Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2 (Canada)

2014-05-01

Three series of quaternary rare-earth transition-metal pnictides REMM′Pn{sub 2} (M=Cu, Ag; M′=Zn; Pn=P, As) have been prepared by reaction of the elements at 800 °C, with crystal growth promoted through the addition of iodine. The extent of RE substitution is broad in these series: RECuZnAs{sub 2} (RE=Y, La-Nd, Sm, Gd–Lu), REAgZnP{sub 2} (RE=La–Nd, Sm, Gd–Dy), and REAgZnAs{sub 2} (RE=La-Nd, Sm, Gd-Dy). Powder and single-crystal X-ray diffraction analysis revealed that they adopt the trigonal CaAl{sub 2}Si{sub 2}-type structure (space group P3{sup ¯}m1, Z=1), in which Cu or Ag atoms are disordered with Zn atoms over the unique tetrahedrally coordinated transition-metal site. Magnetic measurements indicated Curie–Weiss behavior for several members of the RECuZnAs{sub 2} and REAgZnP{sub 2} series. Core-line X-ray photoelectron spectra (XPS) collected on some RECuZnAs{sub 2} members corroborate the charge assignment deduced by the Zintl concept for these compounds, (RE{sup 3+})(M{sup 1+})(Zn{sup 2+})(Pn{sup 3−}){sub 2}. Optical diffuse reflectance spectra and valence band XPS spectra established that these compounds are small band-gap semiconductors (up to ∼0.8 eV in REAgZnP{sub 2}) or semimetals (RECuZnAs{sub 2}). Band structure calculations also support this electronic structure and indicate that the band gap can be narrowed through appropriate chemical substitution (RE=smaller atoms, M=Cu, and Pn=As). - Graphical abstract: Cu or Ag atoms are disordered with Zn atoms over the tetrahedral site within relatively rigid [M{sub 2}Pn{sub 2}] slabs in three series of quaternary pnictides adopting the CaAl{sub 2}Si{sub 2}-type structure. - Highlights: • Three series (comprising 25 compounds) of pnictides REMM'Pn{sub 2} were prepared. • Cu or Ag atoms are disordered with Zn atoms within relatively rigid [M{sub 2}Pn{sub 2}] slabs. • They are semimetals or small band-gap semiconductors. • RECuZnAs{sub 2} and REAgZnP{sub 2} are generally

2-[1-(Methylsulfanylnaphtho[2,1-b]furan-2-yl]acetic acid

Directory of Open Access Journals (Sweden)

Uk Lee

2008-02-01

Full Text Available The title compound, C15H12O3S, was prepared by alkaline hydrolysis of ethyl 2-{1-(methylsulfanylnaphtho[2,1-b]furan-2-yl}acetate. The crystal structure is stabilized by CH2—H...π interactions between the methyl H atoms of the methylsulfanyl substituent and the central benzene ring of the naphthofuran system, and by inversion-related intermolecular O—H...O hydrogen bonds between the carboxyl groups.

MgB{sub 2} superconductors for applications

Energy Technology Data Exchange (ETDEWEB)

Glowacki, B A; Majoros, M; Eisterer, M; Toenies, S; Weber, H W; Fukutomi, M; Komori, K; Togano, K

2003-05-01

The paper presents up to date results on MgB{sub 2} filamentary conductors and coated conductors from the point of view of their possible applications. Basic physical parameters of MgB{sub 2} compound relevant to conductor design are introduced. The correlation between the slope of the irreversibility line, critical temperature and critical current density is discussed with respect to the conductor performance and applicability. The possible origin of the observed anomalous decrease of ac susceptibility at 50 K in copper clad in situ powder-in-tube MgB{sub 2} wires is presented. Some numerical results on critical currents, thermal stability and ac losses of the MgB{sub 2} multifilamentary and coated conductors with magnetic cladding of their filaments are given.

Synthesis and antimalarial testing of neocryptolepine analogues: addition of ester function in SAR study of 2,11-disubstituted indolo[2,3-b]quinolines.

Science.gov (United States)

Lu, Wen-Jie; Wicht, Kathryn J; Wang, Li; Imai, Kento; Mei, Zhen-Wu; Kaiser, Marcel; El Sayed, Ibrahim El Tantawy; Egan, Timothy J; Inokuchi, Tsutomu

2013-06-01

This report describes the synthesis, and in vitro and in vivo antimalarial evaluations of certain ester-modified neocryptolepine (5-methyl-5H-indolo[2,3-b]quinoline) derivatives. The modifications were carried out by introducing ester groups at the C2 and/or C9 position on the neocryptolepine core and the terminal amino group of the 3-aminopropylamine substituents at the C11 position with a urea/thiourea unit. The antiplasmodial activities of our derivative agents against two different strains (CQS: NF54, and CQR: K1) and the cytotoxic activity against normal L6 cells were evaluated. The test results showed that the ester modified neocryptolepine derivatives have higher antiplasmodial activities against both strains and a low cytotoxic activity against normal cells. The best results were achieved by compounds 9c and 12b against the NF54 strain with the IC50/SI value as 2.27 nM/361 and 1.81 nM/321, respectively. While against K1 strain, all the tested compounds showed higher activity than the well-known antimalarial drug chloroquine. Furthermore, the compounds were tested for β-haematin inhibition and 12 were found to be more active than chloroquine (IC50 = 18 μM). Structure activity relationship studies exposed an interesting linear correlation between polar surface area of the molecule and β-haematin inhibition for this series. In vivo testing of compounds 7 and 8a against NF54 strain on Plasmodium berghei female mice showed that the introduction of the ester group increased the antiplasmodial activity of the neocryptolepine core substantially. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

B1 to B2 structural phase transition in LiF under pressure

Science.gov (United States)

Jain, Aayushi; Dixit, R. C.

2018-05-01

In the last few decades the alkali halides emerged as crystals with useful applications and their high-pressure behaviour is the most intensively studied subject in high-pressure physics/chemistry, material science, and geosciences. Most alkali halides follow the B1 (NaCl-type)→B2 (CsCl-type) phase-transition route under pressure. In the present paper, we have investigated the characteristics of structural phase transition that occurred in Lithium Florid compound under high pressure. The transition pressure of B1-B2 was calculated using an effective interionic interaction potential (EIOP). The changes of the characteristics of crystals like, Gibbs free energy, cohesive energy, volume collapse, and lattice constant are calculated for the B1 and B2 structures. These data were compared with the available experimental and theoretical data.

On possibility origination of superconductivity in MgB sub 2 compound

CERN Document Server

Zajtsev, R O

2001-01-01

The mechanism of originating superconductivity in the MgB sub 2 is studied on the basis of the Hubbard generalized model. The possibility of existence of the Cooper instability in the system with jumps between the cations and anions of the nontransient elements is established with application of the notion on the strong interaction. Filling of the boron four electron p-shell and the magnesium two-electron 3s sup 2 shell is considered with an account of the hexagonal symmetry of the MgB sub 2 elementary cell. The phase diagram of existing the superconductivity in dependence on the filling rate of the (n sub p)p sup 6 and (n sub s)s sup 2 -shells of the nontransient elements is plotted

Readily-accessible oxidation of d0 organozirconium compounds: The electronic structure of (η5-C5H5)3ZrX compounds

International Nuclear Information System (INIS)

Strittmatter, R.J.; Bursten, B.E.; Rhodes, L.F.; Morris, D.E.; Rogers, R.D.

1990-01-01

In an effort to obtain a comparison between organotransition metal and organoactinide complexes, a series of Cp 3 ZrX compounds have been synthesized. A single crystal X-ray crystallographic study of Cp 3 ZrCl reveals that all three Cp ligands are bound in an η 5 fashion. Electrochemical investigations of this series show a first oxidation of these d 0 compounds approximately one volt less positive than the d 0 Cp 2 ZrX 2 compounds and approximately one-half volt less positive than the d 0 f 0 Cp 3 ThCl compound. These results will be presented along with a discussion of the electronic structure of this series, as determined by Xα-SW and Fenske-Hall calculations

Synthesis and investigation of aluminium uranium-containing compounds of Al[B5UO6]2[OH]·nH2O (B5=P, As) composition

International Nuclear Information System (INIS)

Chernorukov, N.G.; Sulejmanov, E.V.; Barch, S.V.

2001-01-01

The technique of synthesis of hydroxyuranophosphate and hydroxyuranoarsenate of aluminium is developed. Hydroxyuranophosphates and hydroxyuranoarsenates of aluminium are prepared by reaction of interaction of aqueous solutions of orthophosphoric (orthoarsenic) acid (0.05 mol/l), uranyl nitrate (0.05 mol/l) and aluminium nitrate (0.1 mol/l) at 20 Deg C. Peculiarities of the structure and thermal degradation reactions are studied by the methods of x-ray diffraction, IR spectroscopy, thermography. It is shown that in dependence on outer conditions in the systems Al[PUO 6 ] 2 ·[OH]·nH 2 O and Al[AsUO 6 ] 2 ·[OH]·nH 2 O crystal hydrates with hydrate numbers n=3-11(13) and anhydrous compounds form. The compounds have laminated type of lattice. Two-dimensional layers of [P(As)UO 6 ] ∞ n- are the basis of anion sublattice of these compounds. Aluminium in coordination surrounding of hydroxy groups and water molecules forms cationic sublattice [ru

Structural instability and ground state of the U{sub 2}Mo compound

Energy Technology Data Exchange (ETDEWEB)

Losada, E.L., E-mail: losada@cab.cnea.gov.ar [SIM" 3, Centro Atómico Bariloche, Comisión Nacional de Energía Atómica (Argentina); Garcés, J.E. [Gerencia de Investigación y Aplicaciones Nucleares, Comisión Nacional de Energía Atómica (Argentina)

2015-11-15

This work reports on the structural instability at T = 0 °K of the U{sub 2}Mo compound in the C11{sub b} structure under the distortion related to the C{sub 66} elastic constant. The electronic properties of U{sub 2}Mo such as density of states (DOS), bands and Fermi surface (FS) are studied to understand the source of the instability. The C11{sub b} structure can be interpreted as formed by parallel linear chains along the z-directions each one composed of successive U–Mo–U blocks. Hybridization due to electronic interactions inside the U–Mo–U blocks is slightly modified under the D{sub 6} distortion. The change in distance between chains modifies the U–U interaction and produces a split of f-states. The distorted structure is stabilized by a decrease in energy of the hybridized states, mainly between d-Mo and f-U states, together with the f-band split. Consequently, an induced Peierls distortion is produced in U{sub 2}Mo due to the D{sub 6} distortion. It is important to note that the results of this work indicate that the structure of the ground state of the U{sub 2}Mo compound is not the assumed C11{sub b} structure. It is suggested for the ground state a structure with hexagonal symmetry (P6 #168), ∼0.1 mRy below the energy of the recently proposed Pmmn structure. - Highlights: • Structural instability of the C11b compound due to the D6 deformation. • Induced Peierls distortion due to the D6 deformation. • Distorted structure is stabilized by hybridization and split of f-Uranium state. • P6 (#168) suggested ground state for the U{sub 2}Mo compound.

New ternary tantalum borides containing boron dumbbells: Experimental and theoretical studies of Ta2OsB2 and TaRuB

International Nuclear Information System (INIS)

Mbarki, Mohammed; Touzani, Rachid St.; Rehorn, Christian W.G.; Gladisch, Fabian C.; Fokwa, Boniface P.T.

2016-01-01

The new ternary transition metal-rich borides Ta 2 OsB 2 and TaRuB have been successfully synthesized by arc-melting the elements in a water-cooled crucible under an argon atmosphere. The crystal structures of both compounds were solved by single-crystal X-ray diffraction and their metal compositions were confirmed by EDX analysis. It was found that Ta 2 OsB 2 and TaRuB crystallize in the tetragonal Nb 2 OsB 2 (space group P4/mnc, no. 128) and the orthorhombic NbRuB (space group Pmma, no. 51) structure types with lattice parameters a=5.878(2) Å, c=6.857(2) Å and a=10.806(2) Å, b=3.196(1) Å, c=6.312(2) Å, respectively. Furthermore, crystallographic, electronic and bonding characteristics have been studied by density functional theory (DFT). Electronic structure relaxation has confirmed the crystallographic parameters while COHP bonding analysis indicates that B 2 -dummbells are the strongest bonds in both compounds. Moreover, the formation of osmium dumbbells in Ta 2 OsB 2 through a Peierls distortion along the c-axis, is found to be the origin of superstructure formation. Magnetic susceptibility measurements reveal that the two phases are Pauli paramagnets, thus confirming the theoretical DOS prediction of metallic character. Also hints of superconductivity are found in the two phases, however lack of single phase samples has prevented confirmation. Furthermore, the thermodynamic stability of the two modifications of AMB (A=Nb, Ta; M =Ru, Os) are studied using DFT, as new possible phases containing either B 4 - or B 2 -units are predicted, the former being the most thermodynamically stable modification. - Graphical abstract: The two new ternary tantalum borides, Ta 2 OsB 2 and TaRuB, have been discovered. Their crystal structures contain boron dumbbells, which are the strongest bonds. Peirls distortion is found responsible for Os 2 -dumbbells formation in Ta 2 OsB 2 . Ta 2 OsB 2 and TaRuB are Pauli paramagnet and potential superconductors. - Highlights: �

Case series: toxicity from 25B-NBOMe--a cluster of N-bomb cases.

Science.gov (United States)

Gee, Paul; Schep, Leo J; Jensen, Berit P; Moore, Grant; Barrington, Stuart

2016-01-01

Background A new class of hallucinogens called NBOMes has emerged. This class includes analogues 25I-NBOMe, 25C-NBOMe and 25B-NBOMe. Case reports and judicial seizures indicate that 25I-NBOMe and 25C-NBOMe are more prevalently abused. There have been a few confirmed reports of 25B-NBOMe use or toxicity. Report Observational case series. This report describes a series of 10 patients who suffered adverse effects from 25B-NBOMe. Hallucinations and violent agitation predominate along with serotonergic/stimulant signs such as mydriasis, tachycardia, hypertension and hyperthermia. The majority (7/10) required sedation with benzodiazepines. Analytical method 25B-NBOMe concentrations in plasma and urine were quantified in all patients using a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. Peak plasma levels were measured between 0.7-10.1 ng/ml. Discussion The NBOMes are desired by users because of their hallucinogenic and stimulant effects. They are often sold as LSD or synthetic LSD. Reported cases of 25B- NBOMe toxicity are reviewed and compared to our series. Seizures and one pharmacological death have been described but neither were observed in our series. Based on our experience with cases of mild to moderate toxicity, we suggest that management should be supportive and focused on preventing further (self) harm. High doses of benzodiazepines may be required to control agitation. Patients who develop significant hyperthermia need to be actively managed. Conclusions Effects from 25B-NBOMe in our series were similar to previous individual case reports. The clinical features were also similar to effects from other analogues in the class (25I-NBOMe, 25C-NBOMe). Violent agitation frequently present along with signs of serotonergic stimulation. Hyperthermia, rhabdomyolysis and kidney injury were also observed.

Insight into π-hole interactions containing the inorganic heterocyclic compounds S2N2/SN2P2.

Science.gov (United States)

Lu, Bo; Zhang, Xueying; Meng, Lingpeng; Zeng, Yanli

2017-08-01

Similar to σ-hole interactions, the π-hole interaction has attracted much attention in recent years. According to the positive electrostatic potentials above and below the surface of inorganic heterocyclic compounds S 2 N 2 and three SN 2 P 2 isomers (heterocyclic compounds 1-4), and the negative electrostatic potential outside the X atom of XH 3 (X = N, P, As), S 2 N 2 /SN 2 P 2 ⋯XH 3 (X = N, P, As) complexes were constructed and optimized at the MP2/aug-cc-pVTZ level. The X atom of XH 3 (X = N, P, As) is almost perpendicular to the ring of the heterocyclic compounds. The π-hole interaction energy becomes greater as the trend goes from 1⋯XH 3 to 4⋯XH 3 . These π-hole interactions are weak and belong to "closed-shell" noncovalent interactions. According to the energy decomposition analysis, of the three attractive terms, the dispersion energy contributes more than the electrostatic energy. The polarization effect also plays an important role in the formation of π-hole complexes, with the contrasting phenomena of decreasing electronic density in the π-hole region and increasing electric density outside the X atom of XH 3 (X = N, P, As). Graphical abstract Computed density difference plots for the complexes 3⋯NH 3 (a 1 ), 3⋯PH 3 (b 1 ), 3⋯AsH 3 (c 1 ) and electron density shifts for the complexes 3⋯NH 3 (a 2 ), 3⋯PH 3 (b 2 ),3⋯AsH 3 (c 2 ) on the 0.001 a.u. contour.

EXERGY AND CARBON CREDITS FOR SERIES CONNECTED N PHOTOVOLTAIC THERMAL - COMPOUND PARABOLIC CONCENTRATOR (PVT-CPC) COLLECTOR: AT CONSTANT OUTLET TEMPERATURE

OpenAIRE

Rohit Tripathi 1,*, G. N. Tiwari 2

2017-01-01

In the present study, overall energy and exergy performance of partially covered N photovoltaic thermal - compound parabolic concentrators (PVT-CPC) (25% covered by glass to glass PV module) collector connected in series have been carried out at constant outlet temperature mode. Further, comparison in performance for partially covered N photovoltaic thermal - compound parabolic concentrators (PVT-CPC) [case (i)] and N compound parabolic concentrators (CPC) collector [case (ii)] connected in s...

2-Arylbenzo[b]furan derivatives as potent human lipoxygenase inhibitors.

Science.gov (United States)

Lang, Li; Dong, Ningning; Wu, Deyan; Yao, Xue; Lu, Weiqiang; Zhang, Chen; Ouyang, Ping; Zhu, Jin; Tang, Yun; Wang, Wei; Li, Jian; Huang, Jin

2016-01-01

Human lipoxygenases (LOXs) have been emerging as effective therapeutic targets for inflammatory diseases. In this study, we found that four natural 2-arylbenzo[b]furan derivatives isolated from Artocarpus heterophyllus exhibited potent inhibitory activities against human LOXs, including moracin C (1), artoindonesianin B-1 (2), moracin D (3), moracin M (4). In our in vitro experiments, compound 1 was identified as the most potent LOX inhibitor and the moderate subtype selective inhibitor of 12-LOX. Compounds 1 and 2 act as competitive inhibitors of LOXs. Moreover, 1 significantly inhibits LTB4 production and chemotactic capacity of neutrophils, and is capable of protecting vascular barrier from plasma leakage in vivo. In addition, the preliminary structure-activity relationship analysis was performed based on the above four naturally occurring (1-4) and six additional synthetic 2-arylbenzo[b]furan derivatives. Taken together, these 2-arylbenzo[b]furan derivatives, as LOXs inhibitors, could represent valuable leads for the future development of therapeutic agents for inflammatory diseases.

Novel series of potent, nonsteroidal, selective androgen receptor modulators based on 7H-[1,4]oxazino[3,2-g]quinolin-7-ones.

Science.gov (United States)

Higuchi, Robert I; Arienti, Kristen L; López, Francisco J; Mani, Neelakhanda S; Mais, Dale E; Caferro, Thomas R; Long, Yun Oliver; Jones, Todd K; Edwards, James P; Zhi, Lin; Schrader, William T; Negro-Vilar, Andrés; Marschke, Keith B

2007-05-17

Recent interest in orally available androgens has fueled the search for new androgens for use in hormone replacement therapy and as anabolic agents. In pursuit of this, we have discovered a series of novel androgen receptor modulators derived from 7H-[1,4]oxazino[3,2-g]quinolin-7-ones. These compounds were synthesized and evaluated in competitive binding assays and an androgen receptor transcriptional activation assay. A number of compounds from the series demonstrated single-digit nanomolar agonist activity in vitro. In addition, lead compound (R)-16e was orally active in established rodent models that measure androgenic and anabolic properties of these agents. In this assay, (R)-16e demonstrated full efficacy in muscle and only partially stimulated the prostate at 100 mg/kg. These data suggest that these compounds may be utilized as selective androgen receptor modulators or SARMs. This series represents a novel class of compounds for use in androgen replacement therapy.

Bi∼3.785Cd∼3.575Cu∼1.5(PO4)3.5O5.5, a new arrangement of double (n=2) and triple (n=3) [M4Bi2n-2O2n]x+ polycationic ribbons in the bismuth-transition metal oxy-phosphate series

International Nuclear Information System (INIS)

Colmont, Marie; Huve, Marielle; Abraham, Francis; Mentre, Olivier

2004-01-01

This work is dedicated to investigation of new disordered bismuth-containing oxy-phosphates compounds with an original structure type. As previously observed in this series, they are formed of [M 4 Bi 2n-2 O 2n ] x+ polycationic ribbons of width n O(Bi,M) 4 tetrahedra, surrounded by PO 4 groups. In the new crystal structure type, double (=D), triple (=T) and tunnels (=t) alternate along a common axis obeying the TtDtTtDt/TTtTTt sequence in respect to a nomenclature previously described and recalled in this work. The existence this new polymorph has first been detected by electron diffraction in a multi-phased sample. Then, the crystal structure type, i.e., the TtDtTtDt/TTtTTt sequence, has been deduced from HREM images help to a contrast-interpreting code available for these series of polycations-formed compounds. The subsequent compounds formulation leads to a number of new materials that verify the general formula: [Bi 2 (Bi,M) 4 O 4 ] 2 [Bi 4 (Bi,M) 4 O 6 ] 6 (PO 4 ) 28 M x , with x= 2+ , Cd 2+ cations. Single crystals of the nominal [O6Bi 4.57 Cd 3.43 ] 4 +8.57 [O 6 Bi 4 Cd 4 ] 2 +8 [O 4 Bi 2 Cd 3.56 Cu 0.44 ] 2 +6 (PO 4 ) 28 Cu 10.86 have been prepared in a further stage and confirms the predicted crystal structure, Bi ∼3.785 Cd ∼3.575 Cu ∼1.5 (PO 4 ) 3.5 O 5.5 , a=11.506(8)A, b=5.416(4)A, c=53.94 (4)A, β=90.10(1) o , RF=0.0835, RwF=0.0993, SG=A2/m, Z=8. As already observed for other elements of this family such as Bi ∼1.2 M ∼1.2 O 1.5 (PO 4 ), Bi ∼6.2 Cu ∼6.2 O 8 (PO 4 ) 5 or Bi ∼3 Cd ∼3.72 M ∼1.28 O 5 (PO 4 ) 3 (M=Cu, Co, Zn), this compound shows an additional example of PO 4 disorder due to the presence of mixed Bi 3+ /M 2+ sites at the edges of ribbons. The origin and consequence of this so-called disorder mostly occurring on PO 4 configurations is intensively discussed and has been characterized by infrared spectroscopy and by neutron diffraction on similar compounds. It is noticeable that the great number of antagonist PO 4

Electronic structure of MgB 2

Indian Academy of Sciences (India)

Results of ab initio electronic structure calculations on the compound MgB2 using the FPLAPW method employing GGA for the exchange-correlation energy are presented. Total energy minimization enables us to estimate the equilibrium volume, / ratio and the bulk modulus, all of which are in excellent agreement with ...

Electronic structure of MgB2

Indian Academy of Sciences (India)

Abstract. Results of ab initio electronic structure calculations on the compound MgB2 using the. FPLAPW method employing GGA for the exchange-correlation energy are presented. Total energy minimization enables us to estimate the equilibrium volume, c/a ratio and the bulk modulus, all of which are in excellent ...

Magnetic properties for the Mn{sub 2}GeTe{sub 4} compound

Energy Technology Data Exchange (ETDEWEB)

Quintero, M. [Departamento de Fisica, Facultad de Ciencias, Centro de Estudios de Semiconductores, Universidad de los Andes, Merida 5101 (Venezuela, Bolivarian Republic of)], E-mail: mquinter@ula.ve; Quintero, E.; Caldera, D.; Moreno, E.; Morocoima, M.; Grima, P.; Ferrer, D.; Marchan, N.; Bocaranda, P. [Departamento de Fisica, Facultad de Ciencias, Centro de Estudios de Semiconductores, Universidad de los Andes, Merida 5101 (Venezuela, Bolivarian Republic of); Delgado, G.E. [Laboratorio de Cristalografia, Departamento de Quimica, Facultad de Ciencias, Universidad de Los Andes, Merida 5101 (Venezuela, Bolivarian Republic of); Henao, J.A.; Macias, M.A.; Pinto, J.L. [Grupo de Investigacion en Quimica Estructural (GIQUE), Centro de Investigacion en Biomoleculas (CIBIMOL), Facultad de Ciencias, Escuela de Quimica, Universidad Industrial de Santander, Apartado aereo 678, Bucaramanga (Colombia); Ponce, C.A. [Facultad de Ciencias Exactas y Naturales y Agrimensura, Universidad Nacional del Nordeste, Corrientes 3400 (Argentina)

2009-02-15

Measurements of magnetic susceptibility {chi}, in the temperature range from 2 to 300 K, and of magnetization M vs. applied magnetic field B, up to 5 T, at various temperatures were made on polycrystalline samples of the Mn{sub 2}GeTe{sub 4} compound. It was found that Mn{sub 2}GeTe{sub 4} has a Neel temperature T{sub N} of about 135 K, shows mainly antiferromagnetic behavior with a very weak superimposed ferromagnetic component that is attributed to spin canting. Also, the magnetic results suggest that a possible spin-glass transition takes place at T{sub f}{approx}45 K. The spin-glass order parameter q(T), determined from the susceptibility data, was found to be in agreement with the prediction of conventional spin-glass theory. The M vs. B results indicated that bound magnetic polarons (BMPs) occur in the compound, and that the effects from BMPs disappear at approximately 80 K. The M vs. B curves were well fitted by a Langevin type of equation, and the variation of the fitting parameters determined as a function of temperature. Using a simple spherical model, the radius of the BMP in the material was found to be about 27 A; this value is similar to the effective Bohr radius for an acceptor in the II-IV-V{sub 2} and I-III-VI{sub 2} ternary semiconductor compounds.

Multimodal imaging Gd-nanoparticles functionalized with Pittsburgh compound B or a nanobody for amyloid plaques targeting.

Science.gov (United States)

Pansieri, Jonathan; Plissonneau, Marie; Stransky-Heilkron, Nathalie; Dumoulin, Mireille; Heinrich-Balard, Laurence; Rivory, Pascaline; Morfin, Jean-François; Toth, Eva; Saraiva, Maria Joao; Allémann, Eric; Tillement, Olivier; Forge, Vincent; Lux, François; Marquette, Christel

2017-07-01

Gadolinium-based nanoparticles were functionalized with either the Pittsburgh compound B or a nanobody (B10AP) in order to create multimodal tools for an early diagnosis of amyloidoses. The ability of the functionalized nanoparticles to target amyloid fibrils made of β-amyloid peptide, amylin or Val30Met-mutated transthyretin formed in vitro or from pathological tissues was investigated by a range of spectroscopic and biophysics techniques including fluorescence microscopy. Nanoparticles functionalized by both probes efficiently interacted with the three types of amyloid fibrils, with K D values in 10 micromolar and 10 nanomolar range for, respectively, Pittsburgh compound B and B10AP nanoparticles. Moreover, they allowed the detection of amyloid deposits on pathological tissues. Such functionalized nanoparticles could represent promising flexible and multimodal imaging tools for the early diagnostic of amyloid diseases, in other words, Alzheimer's disease, Type 2 diabetes mellitus and the familial amyloidotic polyneuropathy.

Electronic Properties and Photovoltaic Performances of a Series of Oligothiophene Copolymers Incorporating Both Thieno[3,2-b]thiophene and 2,1,3-Benzothiadiazole Moieties.

Science.gov (United States)

Biniek, Laure; Chochos, Christos L; Hadziioannou, Georges; Leclerc, Nicolas; Lévêque, Patrick; Heiser, Thomas

2010-04-06

A series of donor-acceptor alternated conjugated copolymers, composed of thiophene, bithiophene, thieno[3,2-b]thiophene, and 2,1,3-benzothiadiazole units and differing from each other by the nature and the number of 3-alkylthiophene in the backbone, have been synthesized by Stille cross-coupling polymerization. The material's optical and electrochemical properties, in solution and in thin films, have been investigated using UV-Visible absorption and cyclic voltammetry. Bulk heterojunction solar cells using blends of the newly synthesized copolymers, as electron donor, and C60-PCBM or C70-PCBM, as electron transporting material, have been elaborated. A maximum power conversion efficiency of 1.8% is achieved with a 1:4 PPBzT(2) -C12:C70-PCBM weight ratio. Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Structural and Biochemical Characterization of Organotin and Organolead Compounds Binding to the Organomercurial Lyase MerB Provide New Insights into Its Mechanism of Carbon–Metal Bond Cleavage

Energy Technology Data Exchange (ETDEWEB)

Wahba, Haytham M. [Département; Faculty; Stevenson, Michael J. [Department; Mansour, Ahmed [Département; Sygusch, Jurgen [Département; Wilcox, Dean E. [Department; Omichinski, James G. [Département

2017-01-03

The organomercurial lyase MerB has the unique ability to cleave carbon–Hg bonds, and structural studies indicate that three residues in the active site (C96, D99, and C159 in E. coli MerB) play important roles in the carbon–Hg bond cleavage. However, the role of each residue in carbon–metal bond cleavage has not been well-defined. To do so, we have structurally and biophysically characterized the interaction of MerB with a series of organotin and organolead compounds. Studies with two known inhibitors of MerB, dimethyltin (DMT) and triethyltin (TET), reveal that they inhibit by different mechanisms. In both cases the initial binding is to D99, but DMT subsequently binds to C96, which induces a conformation change in the active site. In contrast, diethyltin (DET) is a substrate for MerB and the SnIV product remains bound in the active site in a coordination similar to that of HgII following cleavage of organomercurial compounds. The results with analogous organolead compounds are similar in that trimethyllead (TML) is not cleaved and binds only to D99, whereas diethyllead (DEL) is a substrate and the PbIV product remains bound in the active site. Binding and cleavage is an exothermic reaction, while binding to D99 has negligible net heat flow. These results show that initial binding of organometallic compounds to MerB occurs at D99 followed, in some cases, by cleavage and loss of the organic moieties and binding of the metal ion product to C96, D99, and C159. The N-terminus of MerA is able to extract the bound PbVI but not the bound SnIV. These results suggest that MerB could be utilized for bioremediation applications, but certain organolead and organotin compounds may present an obstacle by inhibiting the enzyme.

Design and optimization of a series of 1-sulfonylpyrazolo[4,3-b]pyridines as selective c-Met inhibitors.

Science.gov (United States)

Ma, Yuchi; Sun, Guangqiang; Chen, Danqi; Peng, Xia; Chen, Yue-Lei; Su, Yi; Ji, Yinchun; Liang, Jin; Wang, Xin; Chen, Lin; Ding, Jian; Xiong, Bing; Ai, Jing; Geng, Meiyu; Shen, Jingkang

2015-03-12

c-Met has emerged as an attractive target for targeted cancer therapy because of its abnormal activation in many cancer cells. To identify high potent and selective c-Met inhibitors, we started with profiling the potency and in vitro metabolic stability of a reported hit 7. By rational design, a novel sulfonylpyrazolo[4,3-b]pyridine 9 with improved DMPK properties was discovered. Further elaboration of π-π stacking interactions and solvent accessible polar moieties led to a series of highly potent and selective type I c-Met inhibitors. On the basis of in vitro and in vivo pharmacological and pharmacokinetics studies, compound 46 was selected as a preclinical candidate for further anticancer drug development.

Synthesis and SAR study of a novel series of dopamine receptor agonists

DEFF Research Database (Denmark)

Risgaard, R.; Jensen, M.; Jørgensen, M.

2014-01-01

The synthesis of a novel series of dopamine receptor agonists are described as well as their in vitro potency and efficacy on dopamine D and D receptors. This series was designed from pergolide and (4aR,10aR)-1-propyl-1,2,3,4,4a,5,10,10a-octahydro-benzo[g]quinolin-6-ol (PHBQ) and resulted in the ...... in the synthesis of (2R,4aR,10aR)-2-methylsulfanylmethyl-4-propyl-3,4,4a,5,10,10a-hexahydro-2H-naphtho[2,3-b][1,4]oxazin-9-ol (compound 27), which has a D and D receptor profile similar to that of the most recently approved drug for Parkinson's disease, rotigotine.......The synthesis of a novel series of dopamine receptor agonists are described as well as their in vitro potency and efficacy on dopamine D and D receptors. This series was designed from pergolide and (4aR,10aR)-1-propyl-1,2,3,4,4a,5,10,10a-octahydro-benzo[g]quinolin-6-ol (PHBQ) and resulted...

PRECIPITATION HARDENING IN B2-ORDERED NiAl BY Ni2AlTiCOMPOUND

Institute of Scientific and Technical Information of China (English)

W.H. Tian; K. Ohishi; M. Nemoto

2001-01-01

Microstructural variations and correlated hardness changes in B2-ordered NiAl containing fine precipitation of Ni2AlTi have been investigated by means of transmission electron microscopy (TEM) and hardness tests. The amount of age hardening is not large as compared to the large microstructural variations during aging. TEM observations have revealed that the L21-type Ni2AlTi precipitates keep a lattice coherency with the NiAl matrix at the beginning of aging. By longer periods of aging Ni2AlTi precipitates lose their coherency and change their morphology to the globular ones surrounded by misfit dislocations. The temperature dependence of the yield strength of precipitate-containing B2-ordered NiAl was investigated by compression tests over the temperature range of 873-1273K. The fine precipitation of Ni2AlTi was found to enhance greatly the yield strength and the high-temperature strength is comparison with that of superalloy Mar-M200.``

Potential antimicrobial agents from triazole-functionalized 2H-benzo[b][1,4]oxazin-3(4H)-ones.

Science.gov (United States)

Bollu, Rajitha; Banu, Saleha; Bantu, Rajashaker; Reddy, A Gopi; Nagarapu, Lingaiah; Sirisha, K; Kumar, C Ganesh; Gunda, Shravan Kumar; Shaik, Kamal

2017-12-01

A series of substituted triazole functionalized 2H-benzo[b][1,4]oxazin-3(4H)-ones were synthesized by employing click chemistry and further characterized based on 1 H NMR, 13 C NMR, IR and mass spectral studies. All the synthesized derivatives were screened for their in vitro antimicrobial activities. Further, molecular docking studies were accomplished to explore the binding interactions between 1,2,3-triazol-4-yl-2H-benzo[b][1,4]oxazin-3(4H)-one and the active site of Staphylococcus aureus (CrtM) dehydrosqualene synthase (PDB ID: 2ZCS). These docking studies revealed that the synthesized derivatives showed high binding energies and strong H-bond interactions with the dehydrosqualene synthase validating the observed antimicrobial activity data. Based on antimicrobial activity and docking studies, the compounds 9c, 9d and 9e were identified as promising antimicrobial leads. Copyright © 2017 Elsevier Ltd. All rights reserved.

Structural aspects of B2O3-substituted (PbO)0.5(SiO2)0.5 glasses

International Nuclear Information System (INIS)

Sudarsan, V.; Kulshreshtha, S.K.; Shrikhande, V.K.; Kothiyal, G.P.

2002-01-01

Lead borosilicate glasses having general formulae (PbO) 0.5-x (SiO 2 ) 0.5 (B 2 O 3 ) x with 0.0≤x≤0.4 and (PbO) 0.5 (SiO 2 ) 0.5-y (B 2 O 3 ) y with 0.0≤y≤0.5 have been prepared by a conventional melt-quench method and characterized by 29 Si, 11 B magic angle spinning (MAS) NMR techniques and infrared spectroscopy, as regards their structural features. From 29 Si NMR results, it has been inferred that with increasing concentration of boron oxide, (PbO) 0.5-x (SiO 2 ) 0.5 (B 2 O 3 )x glasses exhibit a systematic increase in the number of Q 4 structural units of Si at the expense of Q 2 structural units, along with the formation of Si-O-B linkages. On the other hand, for (PbO) 0.5 (SiO 2 ) 0.5-y (B 2 O 3 ) y glasses, there is no direct interaction between SiO 2 and B 2 O 3 in the glass network, as revealed by the 29 Si MAS NMR studies. Boron exists in both trigonal and tetrahedral configurations for these two series of glasses and for the (PbO) 0.5 (SiO 2 ) 0.5-y (B 2 O 3 ) y series of glasses; the relative concentration of these two structural units remains almost constant with increasing B 2 O 3 concentration. In contrast, for (PbO) 0.5-x (SiO 2 ) 0.5 (B 2 O 3 ) x glasses, there is a slight increase in the number of BO 3 structural units above x = 0.2, as there is a competition between SiO 2 and B 2 O 3 for interaction with Pb 2+ , thereby leading to the formation of BO 3 structural units. For both series of glasses, the thermal expansion coefficient is found to decrease with increasing B 2 O 3 concentration, the effect being more pronounced for the (PbO) 0.5-x (SiO 2 ) 0.5 (B 2 O 3 ) x series of glasses due to the increased concentration of Q 4 structural units of silicon and better cross-linking as a result of the formation of Si-O-B-type linkages. (author)

75 FR 28480 - Airworthiness Directives; Airbus Model A300 Series Airplanes; Model A300 B4-600, B4-600R, F4-600R...

Science.gov (United States)

2010-05-21

... Airworthiness Directives; Airbus Model A300 Series Airplanes; Model A300 B4-600, B4-600R, F4-600R Series..., B4-622, B4- 605R, B4-622R, F4-605R, F4-622R, and C4-605R Variant F airplanes; and Model A310-203...

Lethality of cytochalasin B and other compounds isolated from fungus Aspergillus sp. (Trichocomaceae) endophyte of Bauhinia guianensis (Fabaceae).

Science.gov (United States)

Feitosa, André de O; Dias, Amanda Cristina S; Ramos, Gisele da C; Bitencourt, Heriberto R; Siqueira, José Edson S; Marinho, Patrícia Santana B; Barison, Andersson; Ocampos, Fernanda M M; Marinho, Andrey Moacir do R

Endophytic fungi are fungi that colonize internal tissues of plants; several biologically active compounds have been isolated from these fungi. There are few studies of compounds isolated from endophytic fungi of Amazon plants. Thus, this study aimed the isolation and structural identification of ergosterol (1), ergosterol peroxide (2), mevalonolactone (3), cytochalasin B (4) and cytochalasin H (5) from Aspergillus sp. EJC 04, an endophytic fungus from Bauhinia guianensis. The cytochalasin B (4) and the diacetate derivative of cytochalasin B (4a) showed high lethality in the brine shrimp assay. This is the first occurrence of cytochalasins in Amazonian endophytic fungi from B. guianensis. Copyright © 2016 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

Anti-proliferative, Cytotoxic and NF-ĸB Inhibitory Properties of Spiro(Lactone-Cyclohexanone) Compounds in Human Leukemia.

Science.gov (United States)

Bouhenna, Mustapha M; Orlikova, Barbora; Talhi, Oualid; Schram, Ben; Pinto, Diana C G A; Taibi, Nadia; Bachari, Khaldoun; Diederich, Marc; Silva, Artur M S; Mameri, Nabil

2017-09-01

NF-ĸB affects most aspects of cellular physiology. Deregulation of NF-ĸB signaling is associated with inflammatory diseases and cancer. In this study, we evaluated the cytotoxic and NF-ĸB inhibition potential of new spiro(lactone-cyclohexanone) compounds in two different human leukemia cell lines (U937 and K562). The anti-proliferative effects of the spiro(lactone-cyclohexanone) compounds on human K562 and U937 cell lines was evaluated by trypan blue staining, as well as their involvement in NF-kB regulation were analyzed by luciferase reporter gene assay, Caspase-3/7 activities were evaluated to analyze apoptosis induction. Both spiro(coumarin-cyclohexanone) 4 and spiro(6- methyllactone-cyclohexanone) 9 down-regulated cancer cell viability and proliferation. Compound 4 inhibited TNF-α-induced NF-ĸB activation in a dose-dependent manner and induced caspase-dependent apoptosis in both leukemia cell lines. Results show that compound 4 and compound 9 have potential as anti-cancer agents. In addition, compound 4 exerted NF-kB inhibition activity in leukemia cancer cells. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

75 FR 60611 - Airworthiness Directives; Airbus Model A300 B4-600, B4-600R, and F4-600R Series Airplanes, and...

Science.gov (United States)

2010-10-01

... Airworthiness Directives; Airbus Model A300 B4-600, B4-600R, and F4-600R Series Airplanes, and Model A300 C4...; Model A300 B4-601, B4- 603, B4-620, B4-622, B4-605R, B4-622R, F4-605R, F4-622R, and C4-605R Variant F...-- Dated-- A300 series airplanes......... A300-32A0447..... April 22, 2004. A300 B4-600, B4-600R, and F4...

High-pressure synthesis and characterization of the effective pseudospin S =1 /2 XY pyrochlores R2P t2O7 (R =Er ,Yb )

Science.gov (United States)

Cai, Y. Q.; Cui, Q.; Li, X.; Dun, Z. L.; Ma, J.; dela Cruz, C.; Jiao, Y. Y.; Liao, J.; Sun, P. J.; Li, Y. Q.; Zhou, J. S.; Goodenough, J. B.; Zhou, H. D.; Cheng, J.-G.

2016-01-01

We report on the high-pressure syntheses and detailed characterizations of two effective pseudospin S =1 /2 XY pyrochlores E r2P t2O7 and Y b2P t2O7 via x-ray/neutron powder diffraction, dc and ac magnetic susceptibility, and specific-heat measurements down to 70 mK. We found that both compounds undergo long-range magnetic transitions at TN ,C≈0.3 K , which are ascribed to an antiferromagnetic- and ferromagnetic-type order for E r2P t2O7 and Y b2P t2O7 , respectively, based on the field dependence of their transition temperatures as well as the systematic comparisons with other similar pyrochlores R2B2O7 (R =Er ,Yb ;B =Sn ,Ti ,Ge ). The observed TN of E r2P t2O7 is much lower than that expected from the relationship of TN versus the ionic radius of B4 + derived from the series of E r2B2O7 , while the TC of Y b2P t2O7 is the highest among the series of ferromagnetic compounds Y b2B2O7 (B =Sn ,Pt ,Ti ). Given the monotonic variation of the lattice constant as a function of the B -cation size across these two series of R2B2O7 (R =Er ,Yb ), the observed anomalous values of TN ,C in the Pt-based XY pyrochlores imply that another important factor beyond the nearest-neighbor R -R distance is playing a role. In light of the anisotropic exchange interactions Jex={Jz z,J±,J±±,Jz ± } for the S =1 /2 XY pyrochlores, we have rationalized these observations by considering a weakened (enhanced) antiferromagnetic planar J± (ferromagnetic Ising-like Jz z) due to strong Pt 5 d -O 2 p hybridization within the plane perpendicular to the local [111] direction.

Comparative fate of an organochlorine, chlordecone, and a related compound, chlordecone-5b-hydro, in soils and plants.

Science.gov (United States)

Clostre, Florence; Cattan, Philippe; Gaude, Jean-Marie; Carles, Céline; Letourmy, Philippe; Lesueur-Jannoyer, Magalie

2015-11-01

We address the problem of the comparative environmental fate of a pesticide, chlordecone (CLD), and a related compound, chlordecone-5b-hydro (CLD-5b-hydro). We used a large database including data from two types of contaminated volcanic soils, andosol and nitisol, and thirteen crops grown in the French West Indies in historically polluted soils. We performed in-depth statistical analysis of the effect of different parameters (soil type, crop, organ, etc.) on the ratio of CLD-5b-hydro to CLD in both soils and plants. The environmental fate of the two compounds differed depending on the type of soil. Proportionally, more CLD-5b-hydro than CLD was measured in nitisols than in andosols. Compared to CLD, we also found a preferential transfer of CLD-5b-hydro from the soil to the plant. Finally, mobilization of the two compounds differed according to the species of crop but also within the plant, with increasing ratios from the roots to the top of the plant. The properties of the compound played a key role in the underlying processes. Because CLD-5b-hydro is more soluble in water and has a lower K(ow) than CLD, CLD-5b-hydro (1) was more easily absorbed from soils by plants, (2) was less adsorbed onto plant tissues and (3) was transported in greater quantities through the transpiration stream. Due to the amounts of CLD-5b-hydro we measured in some plant parts such as cucurbit fruits, an assessment of the toxicity of this CLD monodechlorinated product is recommended. Copyright © 2015 Elsevier B.V. All rights reserved.

One pot synthesis, X-ray crystal structure of 2-(2‧-hydroxyphenyl)oxazolo[4,5-b]pyridine derivatives and studies of their optical properties

Science.gov (United States)

Briseño-Ortega, Horacio; Juárez-Guerra, Lizbeth; Rojas-Lima, Susana; Mendoza-Huizar, Luis Humberto; Vázquez-García, Rosa A.; Farfán, Norberto; Arcos-Ramos, Rafael; Santillan, Rosa; López-Ruiz, Heralio

2018-04-01

A series of five 2-(2-hydroxyphenyl)oxazolo [4,5-b]pyridines (HPOP) (3a-e), where four are novel, were synthesized by a mild, one pot, phenylboronic acid-NaCN catalyzed reaction. Spectroscopic characterization and photophysical properties of these compounds are reported. Absorption and excitation spectra of the compounds were dependent on the substituents in the phenyl ring. Fluorescence quantum yields (0.009-0.538) were associated with the donor strength and the position of the substituents. Also, DFT analysis allowed us to determine the contribution of diethylamino and methoxy moieties to the π-system, which is in agreement with the experimental data analyzed in solution and by cyclic voltammetry. The results obtained in the solid state by single-crystal X-ray diffraction experiments indicate that, the quasi-planarity envisioned for the explored compounds is present, supporting the hypothesis that both the H-bonding of a hydroxyl group to the Cdbnd N moiety and a donor groups such as diethylamino and methoxy moieties favor an electronic communication. Due to the facile synthesis and their photophysical properties, the novel HPOP 3a-e have potential application as organic semiconductors.

Investigation of pinning in MgB2 superconductors

International Nuclear Information System (INIS)

Mohammad, S.; Reissner, M.; Steiner, W.; Bauer, E.; Giovannini, M.

2006-01-01

Full text: The pinning behaviour of bulk MgB 2 superconductors is peculiar in many respects. Pinning seems to be stronger than in classical high T C materials and there seems to be no weak link problem in these compounds, giving hope to produce bulk samples and wires with current densities appropriate for technical applications. But, although many studies concerning the pinning behaviour in this compound appeared in recent years, the results are still contradictory. In the present work we present results of an investigation of the pinning behaviour by magnetic relaxation measurements of three MgB 2 samples: a pure one, a sample with 8 at% Al substitution and a sample with 10 wt% of SiC admixture. A comparison of different analyses methods is given. (author)

Atomistic simulation of radiation-induced amorphization of the B2 ordered intermetallic compound NiTi

International Nuclear Information System (INIS)

Sabochick, M.J.

1990-12-01

Amorphization of the B2 intermetallic compound NiTi under electron irradiation has been investigated using molecular dynamics. The effect of irradiation was simulated using two processes: (1) Ni and Ti atoms were exchanged, resulting in chemical disorder, and (2) Frenkel pairs were introduced, leading to the formation of stable point defects and also chemical disorder upon mutual recombination of interstitials and vacancies. After ∼0.4 exchanges per atom, the first process resulted in an energy increase of approximately 0.11 eV/atom and a volume increase of 1.91%. On the other hand, after introducing ∼0.5 Frenkel pairs per atom, the second process led to smaller increases of 0.092 eV/atom in energy and 1.43% in volume. The calculated radial distribution functions (RDFs) were essentially identical to each other and to the calculated RDF of a quenched liquid. The structure factor, however, showed that long-range order was still present after atom exchanges, while the introduction of Frenkel pairs resulted in the loss of long-range order. It was concluded that point defects are necessary for amorphization to occur in NiTi, although chemical disorder alone is capable of storing enough energy to make the transition possible. 18 refs., 3 figs

SensL B-Series and C-Series silicon photomultipliers for time-of-flight positron emission tomography

Energy Technology Data Exchange (ETDEWEB)

O' Neill, K., E-mail: koneill@sensl.com; Jackson, C., E-mail: cjackson@sensl.com

2015-07-01

Silicon photomultipliers from SensL are designed for high performance, uniformity and low cost. They demonstrate peak photon detection efficiency of 41% at 420 nm, which is matched to the output spectrum of cerium doped lutetium orthosilicate. Coincidence resolving time of less than 220 ps is demonstrated. New process improvements have lead to the development of C-Series SiPM which reduces the dark noise by over an order of magnitude. In this paper we will show characterization test results which include photon detection efficiency, dark count rate, crosstalk probability, afterpulse probability and coincidence resolving time comparing B-Series to the newest pre-production C-Series. Additionally we will discuss the effect of silicon photomultiplier microcell size on coincidence resolving time allowing the optimal microcell size choice to be made for time of flight positron emission tomography systems.

2. Intermetallic compounds with lanthanides

International Nuclear Information System (INIS)

Elemans, J.B.A.A.

1975-01-01

Theoretical considerations are given concerning the structures of intermetallic compounds of the lanthanides and thorium (R) on the one hand, and with Fe, Co or Ni (M) on the other. They all derive from the parent composition RM 5 with the CaCu 5 hexagonal structure. This consists of alternate layers in which the M atoms are distinguished as M 1 and M 2 . The other compounds whose structures are studied are obtained by systematic replacement of R by M, or vice versa. In the first type, every third R is replaced by two M's yielding R 2 M 17 compounds. The substitution may be truly random or structured in two ways: so that either the hexagonal structure is maintained or that it is converted into a rhombihedral one. In the second type, one M (in a M 1 position) out of every five is replaced by one R, giving rise to RM 2 compounds which form Laves phases. In the third type, the M 1 's are replaced by R's, resulting in compounds RM 3 . In the fourth type, every third M is replaced by R, yielding R 2 M 7 compounds. With M = Co and R a light lanthanide, the compounds are ferromagnets; with R yttrium, thorium, or a heavy lanthanide, they are ferrimagnets. The preparation of the compounds in an arc-melting apparatus under an Ar-atmosphere followed by annealing is described

Pharmacophore modeling and in silico / in vitro screening for human cytochrome P450 11B1 & cytochrome P450 11B2 inhibitors

Science.gov (United States)

Akram, Muhammad; Waratchareeyakul, Watcharee; Haupenthal, Joerg; Hartmann, Rolf W.; Schuster, Daniela

2017-12-01

Cortisol synthase (CYP11B1) is the main enzyme for the endogenous synthesis of cortisol and its inhibition is a potential way for the treatment of diseases associated with increased cortisol levels, such as Cushing’s syndrome, metabolic diseases, and delayed wound healing. Aldosterone synthase (CYP11B2) is the key enzyme for aldosterone biosynthesis and its inhibition is a promising approach for the treatment of congestive heart failure, cardiac fibrosis, and certain forms of hypertension. Both CYP11B1 and CYP11B2 are structurally very similar and expressed in the adrenal cortex. To facilitate the identification of novel inhibitors of these enzymes, ligand-based pharmacophore models of CYP11B1 and CYP11B2 inhibition were developed. A virtual screening of the SPECS database was performed with our pharmacophore queries. Biological evaluation of the selected hits lead to the discovery of three potent novel inhibitors of both CYP11B1 and CYP11B2 in the submicromolar range (compounds 8-10), one selective CYP11B1 inhibitor (Compound 11, IC50 = 2.5 µM), and one selective CYP11B2 inhibitor (compound 12, IC50 = 1.1 µM), respectively. The overall success rate of this prospective virtual screening experiment is 20.8% indicating good predictive power of the pharmacophore models.

Lattice Thermal Conductivity of Ultra High Temperature Ceramics (UHTC) ZrB2 and HfB2 from Atomistic Simulations

Science.gov (United States)

Lawson, John W.; Daw, Murray S.; Bauschlicher, Charles W.

2012-01-01

Ultra high temperature ceramics (UHTC) including ZrB2 and HfB2 have a number of properties that make them attractive for applications in extreme environments. One such property is their high thermal conductivity. Computational modeling of these materials will facilitate understanding of fundamental mechanisms, elucidate structure-property relationships, and ultimately accelerate the materials design cycle. Progress in computational modeling of UHTCs however has been limited in part due to the absence of suitable interatomic potentials. Recently, we developed Tersoff style parameterizations of such potentials for both ZrB2 and HfB2 appropriate for atomistic simulations. As an application, Green-Kubo molecular dynamics simulations were performed to evaluate the lattice thermal conductivity for single crystals of ZrB2 and HfB2. The atomic mass difference in these binary compounds leads to oscillations in the time correlation function of the heat current, in contrast to the more typical monotonic decay seen in monoatomic materials such as Silicon, for example. Results at room temperature and at elevated temperatures will be reported.

New compounds from acid hydrolyzed products of the fruits of Momordica charantia L. and their inhibitory activity against protein tyrosine phosphatas 1B.

Science.gov (United States)

Zeng, Ke; He, Yan-Ni; Yang, Di; Cao, Jia-Qing; Xia, Xi-Chun; Zhang, Shi-Jun; Bi, Xiu-Li; Zhao, Yu-Qing

2014-06-23

Four new cucurbitane-type triterpene sapogenins, compounds 1-4, together with other eight known compounds were isolated from the acid-hydrolyzed fruits extract of Momordica charantia L. Their chemical structures were established by NMR, mass spectrometry and X-ray crystallography. Compounds 1-7 and 9-12 were evaluated for their inhibitory activities toward protein tyrosine phosphatase 1B (PTP1B), a tyrosine phosphatase that has been implicated as a key target for therapy against type II diabetes. Compounds 1, 2, 4, 7 and 9 were shown inhibitory activities of 77%, 62%, 62% 60% and 68% against PTP1B, respectively. All of these tested compounds were exhibited higher PTP1B inhibition activities than that of the Na3VO4, a known PTP1B inhibitor used as positive control in present study. Structure activity relationship (SAR) analysis indicated that the inhibition activity of PTP1B was associated with the presence and number of -OH groups. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Effect of UV-B Radiation and Desiccation Stress on Photoprotective Compounds Accumulation in Marine Leptolyngbya sp.

Science.gov (United States)

Joshi, Devika; Mohandass, C; Dhale, Mohan

2018-01-01

Increased awareness regarding the harmful effects of ultraviolet (UV)-B radiation has led to the search for new sources of natural UV-B protecting compounds. Mycosporine-like amino acids are one of such promising compounds found in several organisms. Cyanobacteria are ideal organisms for isolation of these compounds due to their compatibility and adaptability to thrive under harsh environmental conditions. In the following investigation, we report the production of shinorine in Leptolyngbya sp. isolated from the intertidal region. Based on the spectral characteristics and liquid chromatography-mass spectrometry analysis, the UV-absorbing compound was identified as shinorine. To the best of our knowledge, this is the first report on the occurrence of shinorine in Leptolyngbya sp. We also investigated the effect of artificial UV-B radiation and periodic desiccation on chlorophyll-a, total carotenoids, and mycosporine-like amino acids (MAAs) production. The UV-B radiation had a negative effect on growth and chlorophyll concentration, whereas it showed an inductive effect on the production of total carotenoids and MAAs. Desiccation along with UV-B radiation led to an increase in the concentration of photoprotective compounds. These results indicate that carotenoids and MAAs thus facilitate cyanobacteria to avoid and protect themselves from the deleterious effects of UV-B and desiccation.

New Benzimidazole-1,2,4-Triazole Hybrid Compounds: Synthesis, Anticandidal Activity and Cytotoxicity Evaluation

Directory of Open Access Journals (Sweden)

Hülya Karaca Gençer

2017-03-01

Full Text Available Owing to the growing need for antifungal agents, we synthesized a new series 2-((5-(4-(5-substituted-1H-benzimidazol-2-ylphenyl-4-substituted-4H-1,2,4-triazol-3-ylthio-1-(substitutedphenylethan-1-one derivatives, which were tested against Candida species. The synthesized compounds were characterized and elucidated by FT-IR, 1H-NMR, 13C-NMR and HR-MS spectroscopies. The synthesized compounds were screened in vitro anticandidal activity against Candida species by broth microdiluation methods. In vitro cytotoxic effects of the final compounds were determined by MTT assay. Microbiological studies revealed that compounds 5m, 5o, 5r, 5t, 5y, 5ab, and 5ad possess a good antifungal profile. Compounds 5w was the most active derivative and showed comparable antifungal activity to those of reference drugs ketoconazole and fluconazole. Cytotoxicity evaluation of compounds 5m, 5o, 5r, 5w, 5y, 5ab and 5ad showed that compounds 5w and 5ad were the least cytotoxic agents. Effects of these two compounds against ergosterol biosynthesis were observed by LC-MS-MS method, which is based on quantification of ergosterol level in C. albicans. Compounds 5w and 5d inhibited ergosterol biosynthesis concentration dependently. A fluorescence microscopy study was performed to visualize effect of compound 5w against C. albicans at cellular level. It was determined that compound 5w has a membrane damaging effect, which may be related with inhibition of biosynthesis of ergosterol.

Synthesis and antimicrobial activity of chromone-linked 2-pyridone fused with 1,2,4-triazoles, 1,2,4-triazines and 1,2,4-triazepines ring systems

International Nuclear Information System (INIS)

Ali, Tarik El-Sayed; Ibrahim, Magdy Ahmed

2010-01-01

Three series of novel fused nitrogen heterocyclic systems such as 1,2,4-triazolo[1,5-a ] pyridines (5-7 and 9), pyrido[1,2-b][1,2,4]triazines (10, 11, 13 and 15), and pyrido[1,2-b][1,2,4]triazepines (17, 18, 20 and 22) linked with a chromone moiety were synthesized from the key intermediate 1,6-diamino-(6-chloro-4-oxo-4H-chromen-3-yl)-2-oxo-1,2-dihydropyridine-3,5- dicarbonitrile (4) with some electrophilic reagents. The structures of the novel compounds were established by elemental analyses and spectral data. All the products were also screened in vitro for their antimicrobial activity. Compounds 7, 9 and 15 showed the highest activities when compared with the reference drugs. (author)

Synthesis and biological evaluation of novel thiadiazole amides as potent Cdc25B and PTP1B inhibitors.

Science.gov (United States)

Li, Yingjun; Yu, Yang; Jin, Kun; Gao, Lixin; Luo, Tongchuan; Sheng, Li; Shao, Xin; Li, Jia

2014-09-01

A series of novel thiadiazole amide derivatives have been synthesized and evaluated for inhibitory activities against Cdc25B and PTP1B. Most of them showed inhibitory activities against Cdc25B (IC50=1.18-8.01 μg/mL) and PTP1B (IC50=0.85-8.75 μg/mL), respectively. Moreover, compounds 5b and 4l were most potent with IC50 values of 1.18 and 0.85 μg/mL for Cdc25B and PTP1B, respectively, compared with reference drugs Na3VO4 (IC50=0.93 μg/mL) and oleanolic acid (IC50=0.85 μg/mL). The results of selectivity experiments showed that the target compounds were selective inhibitors against PTP1B and Cdc25B. Enzyme kinetic experiments demonstrated that compound 5k was a specific inhibitor with the typical characteristics of a mixed inhibitor. Copyright © 2014 Elsevier Ltd. All rights reserved.

K2-60b and K2-107b. A Sub-Jovian and a Jovian Planet from the K2 Mission

International Nuclear Information System (INIS)

Eigmüller, Philipp; Csizmadia, Szilard; Smith, Alexis M. S.; Cabrera, Juan; Erikson, Anders; Gandolfi, Davide; Barragán, Oscar; Persson, Carina M.; Fridlund, Malcolm; Donati, Paolo; Cusano, Felice; Korth, Judith; Grziwa, Sascha; Prieto-Arranz, Jorge; Nespral, David; Deeg, Hans J.; Saario, Joonas; Cochran, William D.; Endl, Michael; Guenther, Eike W.

2017-01-01

We report the characterization and independent detection of K2-60b, as well as the detection and characterization of K2-107b, two transiting hot gaseous planets from the K2 space mission. We confirm the planetary nature of the two systems and determine their fundamental parameters combining the K2 time-series data with FIES@NOT and HARPS-N@TNG spectroscopic observations. K2-60b has a radius of 0.683 ± 0.037 R Jup and a mass of 0.426 ± 0.037 M Jup and orbits a G4 V star with an orbital period of 3.00267 ± 0.00006 days. K2-107b has a radius of 1.44 ± 0.15 R Jup and a mass of 0.84 ± 0.08 M Jup and orbits an F9 IV star every 3.31392 ± 0.00002 days. K2-60b is among the few planets at the edge of the so-called “desert” of short-period sub-Jovian planets. K2-107b is a highly inflated Jovian planet orbiting an evolved star about to leave the main sequence.

K2-60b and K2-107b. A Sub-Jovian and a Jovian Planet from the K2 Mission

Energy Technology Data Exchange (ETDEWEB)

Eigmüller, Philipp; Csizmadia, Szilard; Smith, Alexis M. S.; Cabrera, Juan; Erikson, Anders [Institute of Planetary Research, German Aerospace Center, Rutherfordstrasse 2, D-12489 Berlin (Germany); Gandolfi, Davide; Barragán, Oscar [Dipartimento di Fisica, Universitá di Torino, via P. Giuria 1, I-10125 Torino (Italy); Persson, Carina M.; Fridlund, Malcolm [Department of Earth and Space Sciences, Chalmers University of Technology, Onsala Space Observatory, SE-439 92 Onsala (Sweden); Donati, Paolo; Cusano, Felice [INAF—Osservatorio Astronomico di Bologna, Via Ranzani, 1, I-40127, Bologna (Italy); Korth, Judith; Grziwa, Sascha [Rheinisches Institut für Umweltforschung an der Universität zu Köln, Aachener Strasse 209, D-50931 Köln (Germany); Prieto-Arranz, Jorge; Nespral, David; Deeg, Hans J. [Instituto de Astrofísica de Canarias, E-38205 La Laguna, Tenerife (Spain); Saario, Joonas [Nordic Optical Telescope, Apartado 474, E-38700, Santa Cruz de La Palma (Spain); Cochran, William D.; Endl, Michael [Department of Astronomy and McDonald Observatory, University of Texas at Austin, 2515 Speedway, Stop C1400, Austin, TX 78712 (United States); Guenther, Eike W. [Thüringer Landessternwarte Tautenburg, Sternwarte 5, D-07778 Tautenberg (Germany); and others

2017-03-01

We report the characterization and independent detection of K2-60b, as well as the detection and characterization of K2-107b, two transiting hot gaseous planets from the K2 space mission. We confirm the planetary nature of the two systems and determine their fundamental parameters combining the K2 time-series data with FIES@NOT and HARPS-N@TNG spectroscopic observations. K2-60b has a radius of 0.683 ± 0.037 R {sub Jup} and a mass of 0.426 ± 0.037 M {sub Jup} and orbits a G4 V star with an orbital period of 3.00267 ± 0.00006 days. K2-107b has a radius of 1.44 ± 0.15 R {sub Jup} and a mass of 0.84 ± 0.08 M {sub Jup} and orbits an F9 IV star every 3.31392 ± 0.00002 days. K2-60b is among the few planets at the edge of the so-called “desert” of short-period sub-Jovian planets. K2-107b is a highly inflated Jovian planet orbiting an evolved star about to leave the main sequence.

Performance of Partially Covered N Number of Photovoltaic Thermal (PVT) - Compound Parabolic Concentrator (CPC) Series Connected Water Heating System

OpenAIRE

Rohit Tripathi; Sumit Tiwari; G. N. Tiwari

2016-01-01

In present study, an approach is adopted where photovoltaic thermal flat plate collector is integrated with compound parabolic concentrator. Analytical expression of temperature dependent electrical efficiency of N number of partially covered Photovoltaic Thermal (PVT) - Compound Parabolic Concentrator (CPC) water collector connected in series has been derived with the help of basic thermal energy balance equations. Analysis has been carried for winter weather condition at Delhi location, Ind...

Whole-body voxel phantoms of paediatric patients—UF Series B

Science.gov (United States)

Lee, Choonik; Lee, Choonsik; Williams, Jonathan L.; Bolch, Wesley E.

2006-09-01

Following the previous development of the head and torso voxel phantoms of paediatric patients for use in medical radiation protection (UF Series A), a set of whole-body voxel phantoms of paediatric patients (9-month male, 4-year female, 8-year female, 11-year male and 14-year male) has been developed through the attachment of arms and legs from segmented CT images of a healthy Korean adult (UF Series B). Even though partial-body phantoms (head-torso) may be used in a variety of medical dose reconstruction studies where the extremities are out-of-field or receive only very low levels of scatter radiation, whole-body phantoms play important roles in general radiation protection and in nuclear medicine dosimetry. Inclusion of the arms and legs is critical for dosimetry studies of paediatric patients due to the presence of active bone marrow within the extremities of children. While the UF Series A phantoms preserved the body dimensions and organ masses as seen in the original patients who were scanned, comprehensive adjustments were made for the Series B phantoms to better match International Commission on Radiological Protection (ICRP) age-interpolated reference body masses, body heights, sitting heights and internal organ masses. The CT images of arms and legs of a Korean adult were digitally rescaled and attached to each phantom of the UF series. After completion, the resolutions of the phantoms for the 9-month, 4-year, 8-year, 11-year and 14-year were set at 0.86 mm × 0.86 mm × 3.0 mm, 0.90 mm × 0.90 mm × 5.0 mm, 1.16 mm × 1.16 mm × 6.0 mm, 0.94 mm × 0.94 mm × 6.00 mm and 1.18 mm × 1.18 mm × 6.72 mm, respectively.

First principle study on generalized-stacking-fault energy surfaces of B2-AlRE intermetallic compounds

Science.gov (United States)

Li, Shaorong; Wang, Shaofeng; Wang, Rui

2011-12-01

First-principles calculations are used to predict the generalized-stacking-fault energy (GSFE) surfaces of AlRE intermetallics. The calculations employ the projector augmented-wave (PAW) method within the generalized gradient approximation (GGA) using the density functional theory (DFT). GSFE curves along {1 1 0} direction, {1 1 0} direction and {1 1 0} direction have been calculated. The fitted GSFE surfaces have been obtained from the Fourier series based on the translational symmetry. In order to illuminate the reasonable of our computational accuracy, we have compared our theoretical results of B2 intermetallics YCu with the previous calculated results. The unstable-stacking-fault energy (γus) on the {1 1 0} plane has the laws of AlPr, and directions. For the antiphase boundary (APB) energy, that of AlSc is the lowest in the calculated AlRE intermetallics. So the superdislocation with the Burgers vector along direction of AlSc will easily split into two superpartials.

Electronic structure of magnesium diboride and related compounds

International Nuclear Information System (INIS)

Paduani, C.

2003-01-01

The electronic structure of AlB 2 -type diborides and related compounds has been investigated in first-principles calculations with the molecular cluster discrete variational method. For MgB 2 was studied the effect of the lattice relaxation on the total density of states at the Fermi energy (N(ε F )). The results indicated that a contraction of about 2% in the lattice spacings a and c can lead to a slight increase of N(ε F ) for boron. In the MB 2 diborides, M=Al, Ti, V, Cr, Zr, Nb, Mo and Ta, the largest contributions to N(ε F ) is observed for Cr, Mo and Nb. TiB 2 possess the highest chemical stability in the series. The electronic specific heat coefficient γ also is calculated for the diborides. The method is employed to obtain the partial B2p contribution to the total DOS at the Fermi level with the introduction of a monolayer of solute atoms as a substitution for Mg atoms of Na, Al, Ca, Ti, V, Cr, Zr, Nb, Mo and Ta in layered superstructures.. /M/B 2 /Mg/B 2 /.. A stronger covalent bonding between boron atoms is identified in these cases. (copyright 2003 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Crystallographic and Mössbauer investigations on Np1- xPuxB2

Science.gov (United States)

Chipaux, R.; Bonnisseau, D.; Bogé, M.; Larroque, J.

1988-08-01

The diborides of neptunium and plutonium and their solid solutions Np 1- xPu xB 2 have been synthesized by direct reaction with a good purity. The lattice parameters follow Vegard's law. The magnetic properties of the samples containing neptunium have been investigated by Mössbauer spectrometry. The isomer shift is almost constant in all compounds (-14.5 (0.2) mm/s resp. to NpAl 2), suggesting tetravalent Np ions. At high temperatures, a large quadrupolar interaction, clearly connected to the crystal structure, is observed in all compounds, decreasing slowly with the neptunium concentration. At low temperature, magnetic patterns appear for x ⩽ 0.5. The magnetic moments are ordered perpendicular to the c-axis and equal to 0.57μ B for x = 0. In Np 0.5Pu 0.5B 2 and, in less degree in Np 0.7Pu 0.3B 2 and Np 0.33Pu 0.67B 2, magnetic fluctuations are detec ted.

Structural, electronic and elastic properties of heavy fermion YbRh2 Laves phase compound

Science.gov (United States)

Pawar, Harsha; Shugani, Mani; Aynyas, Mahendra; Sanyal, Sankar P.

2018-05-01

The structural, electronic and elastic properties of YbRh2 Laves phase intermetallic compound which crystallize in cubic (MgCu2-type) structure have been investigated using ab-initio full potential linearized augmented plane wave (FP- LAPW) method with LDA and LDA+U approximation. The calculated ground state properties such as lattice parameter (a0), bulk modulus (B) and its pressure derivative (B') are in good agreement with available experimental and theoretical data. The electronic properties are analyzed from band structures and density of states. Elastic constants are predicted first time for this compound which obeys the stability criteria for cubic system.

High field magnetization process of (Sm, Nd)2Fe17Ny compounds

International Nuclear Information System (INIS)

Yu, M.J.; Tang, N.; Liu, Y.L.; Tegus, O.; Lu, Y.; Kuang, J.P.; Yang, F.M.; Li, X.; Zhou, G.F.; Boer, F.R. de

1992-01-01

The crystal structure and high-field magnetization process of (Sm 1-x Nd x ) 2 Fe 17 N y compounds (x = 0.0, 0.1, ..., 1.0, 2 1-x Nd x ) 2 Fe 17 N y compounds were found to crystallize in the rhombohedral Th 2 Zn 17 structure. As x increases, the Curie temperature decreases. The anisotropy fields and easy magnetization direction were investigated from 1.5 K to room temperature by means of high-field magnetization measurements and AC-susceptibility measurements, combined with X-ray diffraction on random and magnetically aligned powder samples. The anisotropy field decreases with increasing x and approaches a minimum value at about x = 0.6, then increases again. A tentative spin phase diagram for the (Sm 1-x Nd x ) 2 Fe 17 N y series is presented. At room temperature, the easy magnetization direction remains along the c-axis up to x = 0.6. (orig.)

Synthesis, urease inhibition, antioxidant and antibacterial studies of some 4-amino-5-aryl-3H-1,2,4-triazole-3-thiones and their 3,6-disubstituted 1,2,4-triazolo[3,4-b]1,3,4-thiadiazole derivatives

International Nuclear Information System (INIS)

Hanif, Muhammad; Saleem, Muhammad; Rama, Nasim Hasan; Hussain, Muhammad Tahir; Zaib, Sumera; Aslam, Muhammad Adil M.; Iqbal, Jamshed; Jones, Peter G.

2012-01-01

A new series of 4-amino-5-aryl-3H-1,2,4-triazole-3-thiones, bearing various methoxybenzyl- and methoxyphenethyl groups, was synthesized by refluxing potassium hydrazinecarbodithioate salts in dilute aqueous solution of hydrazine hydrate. These salts were formed by the reaction of acid hydrazides and carbon disulfide in methanolic potassium hydroxide solution at 0-5 deg C. 4-Amino- 5-aryl-3H-1,2,4-triazole-3-thiones were condensed with different substituted aromatic acids to yield 3,6-disubstituted-1,2,4-triazolo[3,4-b]1,3,4-thiadiazoles. The structures of the synthesized compounds were characterized by infrared (IR), 1 H and 13 C nuclear magnetic resonance (NMR), elemental analysis and mass spectrometric (MS) studies. All the synthesized compounds were screened for their urease inhibition, antioxidant and antibacterial activities. Some compounds showed excellent urease inhibition activity, more than the standard drug. Others exhibited potent antioxidant activity. All the compounds showed significant antibacterial activities as compared to the standard drug. (author)

Preliminary antifungal and cytotoxic evaluation of synthetic cycloalkyl[b]thiophene derivatives with PLS-DA analysis.

Science.gov (United States)

Souza, Beatriz C C; De Oliveira, Tiago B; Aquino, Thiago M; de Lima, Maria C A; Pitta, Ivan R; Galdino, Suely L; Lima, Edeltrudes O; Gonçalves-Silva, Teresinha; Militão, Gardênia C G; Scotti, Luciana; Scotti, Marcus T; Mendonça, Francisco J B

2012-06-01

A series of 2-[(arylidene)amino]-cycloalkyl[b]thiophene-3-carbonitriles (2a-x) was synthesized by incorporation of substituted aromatic aldehydes in Gewald adducts (1a-c). The title compounds were screened for their antifungal activity against Candida krusei and Criptococcus neoformans and for their antiproliferative activity against a panel of 3 human cancer cell lines (HT29, NCI H-292 and HEP). For antiproliferative activity, the partial least squares (PLS) methodology was applied. Some of the prepared compounds exhibited promising antifungal and proliferative properties. The most active compounds for antifungal activity were cyclohexyl[b]thiophene derivatives, and for antiproliferative activity cycloheptyl[b]thiophene derivatives, especially 2-[(1H-indol-2-yl-methylidene)amino]- 5,6,7,8-tetrahydro-4H-cyclohepta[b]thiophene-3-carbonitrile (2r), which inhibited more than 97 % growth of the three cell lines. The PLS discriminant analysis (PLS-DA) applied generated good exploratory and predictive results and showed that the descriptors having shape characteristics were strongly correlated with the biological data.

Magnetic behaviour of a new compound, Eu{sub 2}CuSi{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Majumdar, Subham; Mallik, R; Sampathkumaran, E V [Tata Institute of Fundamental Research, Mumbai (India)

1999-07-01

As a part of our program to synthesize new ternary Eu compounds, we report here the formation of Eu{sub 2}CuSi{sub 3} for the first time and its magnetic behaviour by magnetic susceptibility, electrical-resistivity and heat-capacity measurements. This compound is found to crystallize in an AlB{sub 2}-derived hexagonal structure. The results establish that Eu ions are divalent, undergoing long-range ferromagnetic-ordering below 38 K. (author)

Calculation of the magnetic properties of pseudo-ternary R2M14B intermetallic compounds (R = rare earth, M = Fe, Co

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Gabriel Gómez Eslava

2016-06-01

Full Text Available The extrinsic properties of NdFeB-based magnets can be tuned through partial substitution of Nd by another rare-earth element and Fe by Co, as such substitution leads to a modification in the intrinsic properties of the main phase. Optimisation of a magnet's composition through trial and error is time consuming and not straightforward, since the interplay existing between magnetocrystalline anisotropy and coercivity is not completely understood. In this paper we present a model to calculate the intrinsic magnetic properties of pseudo-ternary Nd2Fe14B-based compounds. As concrete examples, which are relevant for the optimisation of NdFeB-based high-performance magnets used in (hybrid electric vehicles and wind turbines, we consider partial substitution of Nd by Dy or Tb, and Fe by Co.

Pharmacophore Modeling and in Silico/in Vitro Screening for Human Cytochrome P450 11B1 and Cytochrome P450 11B2 Inhibitors.

Science.gov (United States)

Akram, Muhammad; Waratchareeyakul, Watcharee; Haupenthal, Joerg; Hartmann, Rolf W; Schuster, Daniela

2017-01-01

Cortisol synthase (CYP11B1) is the main enzyme for the endogenous synthesis of cortisol and its inhibition is a potential way for the treatment of diseases associated with increased cortisol levels, such as Cushing's syndrome, metabolic diseases, and delayed wound healing. Aldosterone synthase (CYP11B2) is the key enzyme for aldosterone biosynthesis and its inhibition is a promising approach for the treatment of congestive heart failure, cardiac fibrosis, and certain forms of hypertension. Both CYP11B1 and CYP11B2 are structurally very similar and expressed in the adrenal cortex. To facilitate the identification of novel inhibitors of these enzymes, ligand-based pharmacophore models of CYP11B1 and CYP11B2 inhibition were developed. A virtual screening of the SPECS database was performed with our pharmacophore queries. Biological evaluation of the selected hits lead to the discovery of three potent novel inhibitors of both CYP11B1 and CYP11B2 in the submicromolar range (compounds 8 - 10 ), one selective CYP11B1 inhibitor (Compound 11 , IC 50 = 2.5 μM), and one selective CYP11B2 inhibitor (compound 12 , IC 50 = 1.1 μM), respectively. The overall success rate of this prospective virtual screening experiment is 20.8% indicating good predictive power of the pharmacophore models.

Pharmacophore Modeling and in Silico/in Vitro Screening for Human Cytochrome P450 11B1 and Cytochrome P450 11B2 Inhibitors

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Muhammad Akram

2017-12-01

Full Text Available Cortisol synthase (CYP11B1 is the main enzyme for the endogenous synthesis of cortisol and its inhibition is a potential way for the treatment of diseases associated with increased cortisol levels, such as Cushing's syndrome, metabolic diseases, and delayed wound healing. Aldosterone synthase (CYP11B2 is the key enzyme for aldosterone biosynthesis and its inhibition is a promising approach for the treatment of congestive heart failure, cardiac fibrosis, and certain forms of hypertension. Both CYP11B1 and CYP11B2 are structurally very similar and expressed in the adrenal cortex. To facilitate the identification of novel inhibitors of these enzymes, ligand-based pharmacophore models of CYP11B1 and CYP11B2 inhibition were developed. A virtual screening of the SPECS database was performed with our pharmacophore queries. Biological evaluation of the selected hits lead to the discovery of three potent novel inhibitors of both CYP11B1 and CYP11B2 in the submicromolar range (compounds 8–10, one selective CYP11B1 inhibitor (Compound 11, IC50 = 2.5 μM, and one selective CYP11B2 inhibitor (compound 12, IC50 = 1.1 μM, respectively. The overall success rate of this prospective virtual screening experiment is 20.8% indicating good predictive power of the pharmacophore models.

Synthesis and magnetic structure of the YbMn{sub 2}Sb{sub 2} compound

Energy Technology Data Exchange (ETDEWEB)

Morozkin, A.V. [Department of Chemistry, Moscow State University, Leninskie Gory, House 1, Building 3, GSP-2, Moscow 119992 (Russian Federation)]. E-mail: morozkin@general.chem.msu.ru; Isnard, O. [Institute Laue-Langevin, 6 Rue J. Horowitz, 38042 Grenoble (France); Henry, P. [Institute Laue-Langevin, 6 Rue J. Horowitz, 38042 Grenoble (France); Granovsky, S. [Physics Department, Moscow State University, GSP-2, 119899 Moscow (Russian Federation); Nirmala, R. [Indian Institute of Science, Bangalore (India); Manfrinetti, P. [Dipartimento di Chimica, Universita di Genova, Via Dodecaneso 31, 16146 Genova (Italy)

2006-08-31

A neutron diffraction investigation has been carried out on the trigonal La{sub 2}O{sub 3}-type (hP5, space group P3-bar ml, No. 164; also CaAl{sub 2}Si{sub 2}-type) YbMn{sub 2}Sb{sub 2} intermetallic. A two-step synthesis route has been tried in this work, and successfully utilised to prepare single phase samples of this compound. This study shows that YbMn{sub 2}Sb{sub 2} presents antiferromagnetic ordering below 120K. The magnetic structure of this intermetallic consists of antiferromagnetically coupled magnetic moments of the manganese atoms, in the Mn1 (1/3, 2/3, Z{sub Mn}) and Mn2 (2/3, 1/3, 1-Z{sub Mn}) sites; the direction of magnetic moments of manganese atoms forming a {phi} and a {theta} angle, respectively with the X- and the Z-axis. At 4K the magnetic moment of the Mn1 atom is {mu}{sub Mn}=3.6(1) {mu}{sub B}, with {phi}=0{sup o} and {theta}=62(4){sup o}, whilst the Mn2 atom has a magnetic moment {mu}{sub Mn}=3.6(1) {mu}{sub B}, with {phi}=0{sup o} and {theta}=242(4){sup o}. On the other hand, in this compound no local moment was detected on the Yb site.

2-{[(2-Methoxynaphthalen-1-ylmethyl]amino}phenol

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Sara Mahdjoub

2016-07-01

Full Text Available The asymmetric unit of the title compound, C18H17NO2, contains two independent molecules (A and B. The dihedral angle between the naphthalene ring system and the benzene ring is 74.67 (10° in molecule A and 78.81 (9° in molecule B. In the crystal, molecules are linked by a series of C—H...π interactions, forming sheets parallel to the ab plane.

Rational Design of Glycomimetic Compounds Targeting the Saccharomyces cerevisiae Transglycosylase Gas2.

Science.gov (United States)

Delso, Ignacio; Valero-González, Jessika; Marca, Eduardo; Tejero, Tomás; Hurtado-Guerrero, Ramón; Merino, Pedro

2016-02-01

The transglycosylase Saccharomyces cerevisiae Gas2 (ScGas2) belongs to a large family of enzymes that are key players in yeast cell wall remodeling. Despite its biologic importance, no studies on the synthesis of substrate-based compounds as potential inhibitors have been reported. We have synthesized a series of docking-guided glycomimetics that were evaluated by fluorescence spectroscopy and saturation-transfer difference (STD) NMR experiments, revealing that a minimum of three glucose units linked via a β-(1,3) linkage are required for achieving molecular recognition at the binding donor site. The binding mode of our compounds is further supported by STD-NMR experiments using the active site-mutants Y107Q and Y244Q. Our results are important for both understanding of ScGas2-substrate interactions and setting up the basis for future design of glycomimetics as new antifungal agents. © 2015 John Wiley & Sons A/S.

Modelling approach to limit aflatoxin B1 contamination in dairy cattle compound feed

NARCIS (Netherlands)

Bouzembrak, Y.; Fels-Klerx, van der H.J.

2016-01-01

Feeding dairy cattle with safe compound feed helps farmers to ensure food safety. However, several ingredients often used in compound feed production can be contaminated with aflatoxin B1 (AFB1), which may result into milk contaminated with aflatoxin M1. Given the number of ingredients and their

Standard enthalpies of formation of selected Rh2YZ Heusler compounds

International Nuclear Information System (INIS)

Yin, Ming; Nash, Philip

2015-01-01

The standard enthalpies of formation (Δ f H°) of selected ternary Rh-based Rh 2 YZ (Y = Cu, Fe, Mn, Ni, Ru, Ti, V; Z = Al, Ga, In, Si, Ge, Sn) compounds were measured using high temperature direct reaction calorimetry. The measured standard enthalpies of formation (in kJ/mol of atoms) are, for the Heusler compound Rh 2 MnSn (−40.1 ± 3.6), for the B2-structured compounds: Rh 2 FeAl (−48.5 ± 2.9); Rh 2 MnAl (−72.4 ± 2.7); Rh 2 MnGa (−55.3 ± 2.0); Rh 2 MnIn (−35.3 ± 1.9), for the tetragonal compounds: Rh 2 FeSn (−28.9 ± 1.3); Rh 2 TiAl (−97.6 ± 2.2); Rh 2 TiGa (−79.0 ± 1.8); Rh 2 TiSn (−74.7 ± 3.1). Values are compared with those from first principles calculations in published papers and the Open Quantum Materials Database (OQMD). Lattice parameters of these compounds are determined using X-ray diffraction analysis (XRD). Microstructures were characterized using scanning electron microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). - Highlights: • Standard enthalpies of formation of Rh 2 YZ were measured using a drop calorimeter. • Measured enthalpies agree with first principles data in general. • Lattice parameters and related phase relationships were consistent with literature data. • Rh 2 TiSn of tI8 structure were reported for the first time.

New heterocyclic compounds: Synthesis and antitrypanosomal properties.

Science.gov (United States)

Pomel, S; Dubar, F; Forge, D; Loiseau, P M; Biot, C

2015-08-15

Three new series of quinoline, quinolone, and benzimidazole derivatives were synthesized and evaluated in vitro against Trypanosoma brucei gambiense. In the quinoline series, the metallo antimalarial drug candidate (ferroquine, FQ) and its ruthenium analogue (ruthenoquine, RQ, compound 13) showed the highest in vitro activities with IC50 values around 0.1 μM. Unfortunately, both compounds failed to cure Trypanosoma brucei brucei infected mice in vivo. The other heterocyclic compounds were active in vitro with IC50 values varying from 0.8 to 34 μM. One of the most interesting results was a fluoroquinolone derivative (compound 2) that was able to offer a survival time of 8 days after a treatment at the single dose of 100 μmol/kg by intraperitoneal route. Although no clear-cut structure-activity relationships emerged, further pharmacomodulations are worth to be developed in this series. Copyright © 2015 Elsevier Ltd. All rights reserved.

Influence on the interaction by functional groups in some series of bicyclo (2,2,1) heptane derivatives

International Nuclear Information System (INIS)

Gagnaire, Genevieve

1971-01-01

In connection with investigations involving the interactions of substituted groups in the bicyclo (2,2,1) heptane molecules, the chemical reactivity and some physical properties of polyfunctional compounds have been studied. A new method for preparation of β-fenchylic derivatives is presented, the first described terpenic nitroxide radical have been prepared from oxazolidinic compounds. The stereochemistry of the base induced elimination reaction of 6-exo tosyl and 6-endo tosyl oxy epi-camphor is dependent of the geometry of these compounds. On the other hand, the results indicate that the most important part of the structure is the position of the carbonyl group. Tricyclenic and camphenic derivatives are obtained with different rates. An explanation for these results involve several possible basic abstractions of acid protons, and the competition between these different reactions. The oxazolidinic compounds are obtained by reacting 2-amino 2-methyl 1-propanol with norcamphor and norbornane-2,5 dione. The geometrical configuration of the different stereoisomers is deduced from the measured dipolar interaction parameter D. The cotton effects of the γ-diketones do not show any interaction between the two carbonyl groups, in the fenchylic and bornylic series. The two carbonyl bond angles of the substituted α-diketones do not seem to be sensitive to any substitution of an alkoxy group. So, a new quadrant rule is proposed; compatible results are obtained, except for a methyl group in the α position. At least, PMR studies of terpenic polyfunctional compounds demonstrate the influence of the substitution on the geometry of the carbon skeleton. A new coupling constant 4 J HH is examined. (author) [fr

Crystal Growth, Structures, and Properties of the Complex Borides, LaOs ₂ Al ₂ B and La ₂ Os ₂ AlB ₂

Energy Technology Data Exchange (ETDEWEB)

Bugaris, Daniel E.; Han, Fei; Im, Jino; Chung, Duck Young; Freeman, Arthur J.; Kanatzidis, Mercouri G.

2015-08-17

Single crystals of two novel quaternary metal borides, LaOs2Al2B and La2Os2AlB2, have been grown from La/Ni eutectic fluxes. LaOs2Al2B crystallizes in tetragonal space group P4/mmm with the CeCr2Si2C-type structure, and lattice parameters a = 4.2075(6) angstrom and c = 5.634(1) angstrom. La2Os2AlB2 exhibits a new crystal structure in monoclinic space group C2/c with lattice parameters a = 16.629(3) angstrom, b = 6.048(1) angstrom, c = 10.393(2) angstrom, and beta = 113.96(3)degrees. Both structures are three-dimensional frameworks with unusual coordination (for solid-state compounds) of the boron atoms by transition metal atoms. The boron atom is square planar in LaOs2Al2B, whereas it exhibits linear and T-shaped geometries in La2Os2AlB2. Electrical resistivity measurements reveal poor metal behavior (rho(30)0 (K) similar to 900 mu Omega cm) for La2Os2AlB2, consistent with the electronic band structure calculations, which also predict a metallic character for LaOs2Al2B.

Detection of organic compound signatures in infra-red, limb emission spectra observed by the MIPAS-B2 balloon instrument

Directory of Open Access Journals (Sweden)

J. J. Remedios

2007-01-01

Full Text Available Organic compounds play a central role in troposphere chemistry and increasingly are a viable target for remote sensing observations. In this paper, infra-red spectral features of three organic compounds are investigated in thermal emission spectra recorded on a flight on 8 May 1998 near Aire sur l'Adour by a balloon-borne instrument, MIPAS-B2, operating at high spectral resolution. It is demonstrated, for the first time, that PAN and acetone can be detected in infra-red remote sensing spectra of the upper troposphere; detection results are presented at tangent altitudes of 10.4 km and 7.5 km (not acetone. In addition, the results provide the first observation of spectral features of formic acid in thermal emission, as opposed to solar occultation, and confirm that concentrations of this gas are measurable in the mid-latitude upper troposphere, given accurate spectroscopic data. For PAN, two bands are observed centred at 794 cm−1 and 1163 cm−1. For acetone and formic acid, one band has been detected for each so far with band centres at 1218 cm−1 and 1105 cm−1 respectively. Mixing ratios inferred at 10.4 km tangent altitude are 180 pptv and 530 pptv for PAN and acetone respectively, and 200 pptv for formic acid with HITRAN 2000 spectroscopy. Accuracies are on the order of 15 to 40%. The detection technique applied here is verified by examining weak but known signatures of CFC-12 and HCFC-22 in the same spectral regions as those of the organic compounds, with results confirming the quality of both the instrument and the radiative transfer model. The results suggest the possibility of global sensing of the organic compounds studied here which would be a major step forward in verifying and interpreting global tropospheric model calculations.

New ternary tantalum borides containing boron dumbbells: Experimental and theoretical studies of Ta{sub 2}OsB{sub 2} and TaRuB

Energy Technology Data Exchange (ETDEWEB)

Mbarki, Mohammed; Touzani, Rachid St.; Rehorn, Christian W.G.; Gladisch, Fabian C. [Institute of Inorganic Chemistry, RWTH Aachen University, D-52056 Aachen (Germany); Fokwa, Boniface P.T., E-mail: bfokwa@ucr.edu [Institute of Inorganic Chemistry, RWTH Aachen University, D-52056 Aachen (Germany); Department of Chemistry, University of California Riverside (UCR), Riverside, CA 92521 (United States)

2016-10-15

The new ternary transition metal-rich borides Ta{sub 2}OsB{sub 2} and TaRuB have been successfully synthesized by arc-melting the elements in a water-cooled crucible under an argon atmosphere. The crystal structures of both compounds were solved by single-crystal X-ray diffraction and their metal compositions were confirmed by EDX analysis. It was found that Ta{sub 2}OsB{sub 2} and TaRuB crystallize in the tetragonal Nb{sub 2}OsB{sub 2} (space group P4/mnc, no. 128) and the orthorhombic NbRuB (space group Pmma, no. 51) structure types with lattice parameters a=5.878(2) Å, c=6.857(2) Å and a=10.806(2) Å, b=3.196(1) Å, c=6.312(2) Å, respectively. Furthermore, crystallographic, electronic and bonding characteristics have been studied by density functional theory (DFT). Electronic structure relaxation has confirmed the crystallographic parameters while COHP bonding analysis indicates that B{sub 2}-dummbells are the strongest bonds in both compounds. Moreover, the formation of osmium dumbbells in Ta{sub 2}OsB{sub 2} through a Peierls distortion along the c-axis, is found to be the origin of superstructure formation. Magnetic susceptibility measurements reveal that the two phases are Pauli paramagnets, thus confirming the theoretical DOS prediction of metallic character. Also hints of superconductivity are found in the two phases, however lack of single phase samples has prevented confirmation. Furthermore, the thermodynamic stability of the two modifications of AMB (A=Nb, Ta; M =Ru, Os) are studied using DFT, as new possible phases containing either B{sub 4}- or B{sub 2}-units are predicted, the former being the most thermodynamically stable modification. - Graphical abstract: The two new ternary tantalum borides, Ta{sub 2}OsB{sub 2} and TaRuB, have been discovered. Their crystal structures contain boron dumbbells, which are the strongest bonds. Peirls distortion is found responsible for Os{sub 2}-dumbbells formation in Ta{sub 2}OsB{sub 2}. Ta{sub 2}OsB{sub 2} and

Development of Pharmacophore Model for Indeno[1,2-b]indoles as Human Protein Kinase CK2 Inhibitors and Database Mining

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Samer Haidar

2017-01-01

Full Text Available Protein kinase CK2, initially designated as casein kinase 2, is an ubiquitously expressed serine/threonine kinase. This enzyme, implicated in many cellular processes, is highly expressed and active in many tumor cells. A large number of compounds has been developed as inhibitors comprising different backbones. Beside others, structures with an indeno[1,2-b]indole scaffold turned out to be potent new leads. With the aim of developing new inhibitors of human protein kinase CK2, we report here on the generation of common feature pharmacophore model to further explain the binding requirements for human CK2 inhibitors. Nine common chemical features of indeno[1,2-b]indole-type CK2 inhibitors were determined using MOE software (Chemical Computing Group, Montreal, Canada. This pharmacophore model was used for database mining with the aim to identify novel scaffolds for developing new potent and selective CK2 inhibitors. Using this strategy several structures were selected by searching inside the ZINC compound database. One of the selected compounds was bikaverin (6,11-dihydroxy-3,8-dimethoxy-1-methylbenzo[b]xanthene-7,10,12-trione, a natural compound which is produced by several kinds of fungi. This compound was tested on human recombinant CK2 and turned out to be an active inhibitor with an IC50 value of 1.24 µM.

Mixed valence and metamagnetism in a metal flux grown compound Eu2Pt3Si5

International Nuclear Information System (INIS)

Sarkar, Sumanta; Subbarao, Udumula; Joseph, Boby; Peter, Sebastian C.

2015-01-01

A new compound Eu 2 Pt 3 Si 5 with plate shaped morphology has been grown from excess In flux. The compound crystallizes in the orthorhombic U 2 Co 3 Si 5 structure type, Ibam space group and the lattice parameters are a=10.007(2) Å, b=11.666(2) Å and c=6.0011(12) Å. The crystal structure of this compound can be conceived as inter-twinned chains of [Pt 2 Si 2 ] and [PtSi 3 ] tetrahedra connected along [100] direction to give rise to a complex three dimensional [Pt 3 Si 5 ] network. Temperature dependent magnetic susceptibility data suggests that Eu 2 Pt 3 Si 5 undergoes a strong antiferromagnetic ordering (T N =19 K) followed by a weak ferromagnetic transition (T C =5.5 K). The effective magnetic moment/Eu obtained from susceptibility data is 6.78 μ B accounts mixed valent Eu with almost 85% divalent Eu, which is supported by X-ray absorption near edge spectroscopy. The compound undergoes a metamagnetic transition under applied magnetic field through a probable spin flop mechanism. - Graphical abstract: Eu 2 Pt 3 Si 5 , a new member in the U 2 Co 3 Si 5 (Ibam) family undergoes metamagnetic transition at high magnetic field and Eu is in mixed valence state. - Highlights: • A new compound Eu 2 Pt 3 Si 5 has been synthesized using indium as an inactive metal flux. • The compound undergoes metamagnetic transition at higher field. • Eu in this compound resides in a mixed valence state

Synthesis of novel 3-cyclohexylpropanoic acid-derived nitrogen heterocyclic compounds and their evaluation for tuberculostatic activity.

Science.gov (United States)

Gobis, Katarzyna; Foks, Henryk; Bojanowski, Krzysztof; Augustynowicz-Kopeć, Ewa; Napiórkowska, Agnieszka

2012-01-01

A series of novel 3-cyclohexylpropanoic acid derivatives and 3-cyclohexylpropanoic acid-derived nitrogen heterocyclic compounds (1-8) have been synthesized and evaluated for tuberculostatic activity. Compounds 1a, 1c, 1e and 1f bearing benzimidazole or benzimidazole-like systems showed the most potent tuberculostatic activity against Mycobacterium tuberculosis strains with MIC values ranging from 1.5 to 12.5μg/mL. More importantly 1a (6-chloro-2-(2-cyclohexylethyl)-4-nitro-1H-benzo[d]imidazole) and 1f (2-(2-cyclohexylethyl)-1H-imidazo[4,5-b]phenazine) appeared selective for M. tuberculosis as compared with eukaryotic cells (human fibroblasts), and other antimicrobial strains. These compounds may thus represent a novel, selective class of antitubercular agents. Additionally compound 1a stimulated type I collagen output by fibroblasts, in vitro. Copyright © 2011 Elsevier Ltd. All rights reserved.

Exploration of the anti-enterovirus activity of a series of pleconaril/pirodavir-like compounds.

Science.gov (United States)

Bernard, Angela; Lacroix, Céline; Cabiddu, Maria G; Neyts, Johan; Leyssen, Pieter; Pompei, Raffaello

2015-04-01

The Enterovirus genus of the Picornaviridae is represented by several viral pathogens that are associated with human disease, namely Poliovirus 1, Enterovirus 71 and Rhinoviruses. Enterovirus 71 has been associated with encephalitis, while Rhinoviruses are a major cause of asthma exacerbations and chronic obstructive pulmonary disease. Based on the structure of both pleconaril and pirodavir, we previously synthesized some original compounds as potential inhibitors of Rhinovirus replication. These compounds were explored for in vitro antiviral potential on other human pathogenic Enteroviruses, namely Enterovirus 71 on rhabdo-myosarcoma cells, Coxsackievirus B3 on Vero cells, Poliovirus 1 and Echovirus 11 on BGM cells. Activity was confirmed for compound against Rhinovirus 14. Furthermore, few compounds showed a cell-protective effect on Enterovirus 71, presented a marked improvement as compared to the reference drug pleconaril for inhibitory activity on both Enterovirus 71 and Poliovirus 1. The most striking observation was the clear cell protective effect for the set of analogues in a virus-cell-based assay for Echovirus 11 with an effective concentration (EC50) as low as 0.3 µM (Selectivity index or SI = 483), and selectivity indexes greater than 857 (EC50 = 0.6 µM) and 1524 (EC50 = 0.33 µM). Some of the evaluated compounds showed potent and selective antiviral activity against several enterovirus species, such as Enterovirus 71 (EV-A), Echovirus 11 (EV-B), and Poliovirus 1 (EV-C). This could be used as a starting point for the development of other pleconaril/pirodavir-like enterovirus inhibitors with broad-spectrum activity and improved effects as compared to the reference drugs. © The Author(s) 2015.

Structure and microstructure of the high pressure synthesised misfit layer compound [Sr2O2][CrO2]1.85

International Nuclear Information System (INIS)

Castillo-Martinez, E.; Schoenleber, A.; Smaalen, S. van; Arevalo-Lopez, A.M.; Alario-Franco, M.A.

2008-01-01

The strontium chromium oxide [Sr 2 O 2 ][CrO 2 ] 1.85 misfit layer compound has been synthesised at high-pressure and high-temperature conditions. Electron diffraction patterns and high-resolution transmission electron microscopy images along [001] show the misfit character of the different layers composing the structure with a supercell along the incommensurate parameter b∼7b 1 ∼13b 2 . The modulated crystal structure has been refined within the superspace formalism against single-crystal X-ray diffraction data, employing the (3+1)-dimensional superspace group C'nmb(0σ 2 0)0 0 s. The compound has a composite structure with lattice parameters a 1 =5.182(1) A, b 1 =5.411(1) A, c 1 =18.194(3) A for the first, SrO, subsystem and the same a and c, but with b 2 =2.925(1) A for the second, CrO 2 , subsystem. The layer stacking is similar to that of orthorhombic PbS(TiS 2 ) 1.18 , but with a much stronger intersubsytem bonding in the case of the oxide. The intersubsystem lattice mismatch is mainly handled by displacement modulations of the Sr atoms, correlated with modulations of the valence, the coordination and the anisotropic displacement parameters. - Graphical abstract: A strontium chromium oxide, [Sr 2 O 2 ][CrO 2 ] 1.85 , with an orthorhombic misfit layer structure has been synthesised under high pressure. Mainly modulations on the Sr position, ADPs and coordination save the subsystems lattice mismatch

Synthesis of Tetrasubstituted Thieno[3,2-b]pyridin-5(4H)-one Derivatives as a Heterocyclic Scaffold for Multisite-specific Fluorous Fluorescent Tagging and Fluorous Solid-Phase Extraction

Energy Technology Data Exchange (ETDEWEB)

Jeon, Moon-Kook; Yi, Su-Jin [Korea Research Institute of Chemical Technology, Daejeon (Korea, Republic of); Son, Seung Uk [Sungkyunkwan University, Suwon (Korea, Republic of)

2016-08-15

Tetrasubstituted thieno[3,2-b]pyridin-5(4H)-one derivatives were selected as a highly functionalized heterocyclic scaffold for a multisite-specific tagging process utilizing a previously devised fluorous fluorescent tag system. A suitable synthetic method was established for the 7-alkoxy-2,4,6-risubstituted-thieno[3,2-b] pyridin-5(4H)-one derivatives, and incorporating t-butoxycarbonyl-functionalized building blocks into the reaction sequence produced precursors that could be used in the tagging process. Fluorous solid-phase extraction facilitated the purification of the tagged target compounds after a series of reactions, including t-Bu deprotection/N-hydroxysuccinimidyl ester formation/amidation.

Synthesis of Tetrasubstituted Thieno[3,2-b]pyridin-5(4H)-one Derivatives as a Heterocyclic Scaffold for Multisite-specific Fluorous Fluorescent Tagging and Fluorous Solid-Phase Extraction

International Nuclear Information System (INIS)

Jeon, Moon-Kook; Yi, Su-Jin; Son, Seung Uk

2016-01-01

Tetrasubstituted thieno[3,2-b]pyridin-5(4H)-one derivatives were selected as a highly functionalized heterocyclic scaffold for a multisite-specific tagging process utilizing a previously devised fluorous fluorescent tag system. A suitable synthetic method was established for the 7-alkoxy-2,4,6-risubstituted-thieno[3,2-b] pyridin-5(4H)-one derivatives, and incorporating t-butoxycarbonyl-functionalized building blocks into the reaction sequence produced precursors that could be used in the tagging process. Fluorous solid-phase extraction facilitated the purification of the tagged target compounds after a series of reactions, including t-Bu deprotection/N-hydroxysuccinimidyl ester formation/amidation.

Half-metallic magnetism in Ti3Co5-xFexB2

Directory of Open Access Journals (Sweden)

Rohit Pathak

2017-05-01

Full Text Available Bulk alloys and thin films of Fe-substituted Ti3Co5B2 have been investigated by first-principle density-functional calculations. The series, which is of interest in the context of alnico magnetism and spin electronics, has been experimentally realized in nanostructures but not in the bulk. Our bulk calculations predict paramagnetism for Ti3Co5B2, Ti3Co4FeB2 and Ti3CoFe4B2, whereas Ti3Fe5B2 is predicted to be ferromagnetic. The thin films are all ferromagnetic, indicating that moment formation may be facilitated at nanostructural grain boundaries. One member of the thin-film series, namely Ti3CoFe4B2, is half-metallic and exhibits perpendicular easy-axis magnetic anisotropy. The half-metallicity reflects the hybridization of the Ti, Fe and Co 3d orbitals, which causes a band gap in minority spin channel, and the limited equilibrium solubility of Fe in bulk Ti3Co5B2 may be linked to the emerging half-metallicity due to Fe substitution.

Singlet ground state in the spin-1/2 weakly coupled dimer compound NH4[ (V2O3)2(4,4'-b p y ) 2(H2PO4)(PO4)2] .0.5 H2O

Science.gov (United States)

Arjun, U.; Kumar, Vinod; Anjana, P. K.; Thirumurugan, A.; Sichelschmidt, J.; Mahajan, A. V.; Nath, R.

2017-05-01

We present the synthesis and a detailed investigation of structural and magnetic properties of polycrystalline NH4[(V2O3)2(4,4'-b p y ) 2(H2PO4) (PO4)2] .0.5 H2O by means of x-ray diffraction, magnetic susceptibility, electron spin resonance, and 31P nuclear magnetic resonance measurements. Temperature-dependent magnetic susceptibility could be described well using a weakly coupled spin-1/2 dimer model with an excitation gap Δ /kB≃26.1 K between the singlet ground state and triplet excited states and a weak interdimer exchange coupling J'/kB≃4.6 K. A gapped chain model also describes the data well with a gap of about 20 K. The electron spin resonance intensity as a function of temperature traces the bulk susceptibility nicely. The isotropic Landé g factor is estimated to be about g ≃1.97 , at room temperature. We are able to resolve the 31P NMR signal as coming from two inequivalent P sites in the crystal structure. The hyperfine coupling constant between 31P nucleus and V4 + spins is calculated to be Ahf(1 ) ≃2963 Oe/μB and Ahf(2 ) ≃1466 Oe/μB for the P(1) and P(2) sites, respectively. Our NMR shift and spin-lattice relaxation rate for both the 31P sites show an activated behavior at low temperatures, further confirming the singlet ground state. The estimated value of the spin gap from the NMR data measured in an applied field of H =9.394 T is consistent with the gap obtained from the magnetic susceptibility analysis using the dimer model. Because of a relatively small spin gap, NH4[(V2O3)2(4,4'-b p y ) 2(H2PO4) (PO4)2] .0.5 H2O is a promising compound for further experimental studies under high magnetic fields.

Full elastic tensor of a crystal of the superhard compound ReB{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Levine, J.B. [Department of Chemistry and Biochemistry and California NanoSystems Institute, University of California, Los Angeles, CA 90095-1569 (United States); Betts, J.B. [National High Magnetic Field Laboratory, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Garrett, J.D. [Brockhouse Institute for Materials Research, McMaster University, Hamilton, Ontario, L8S 4M1 (Canada); Guo, S.Q. [Composites Group, National Institute for Materials Science, Tsukuba 3050047 (Japan); Eng, J.T. [Department of Chemistry and Biochemistry and California NanoSystems Institute, University of California, Los Angeles, CA 90095-1569 (United States); Migliori, A., E-mail: migliori@cybermesa.com [National High Magnetic Field Laboratory, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Kaner, R.B., E-mail: kaner@chem.ucla.edu [Department of Chemistry and Biochemistry and California NanoSystems Institute, University of California, Los Angeles, CA 90095-1569 (United States)] [Department of Materials Science and Engineering, University of California, Los Angeles, CA 90095-1595 (United States)

2010-03-15

The search for superhard materials, driven by their widespread use in industrial applications, highlights one of the most difficult problems in the field of materials science: the accurate characterization of a material's intrinsic physical properties. This paper reports on the full elastic tensor of two polycrystalline isotropic specimens and one specimen of ReB{sub 2} consisting of highly oriented grains. The high-monocrystal bulk modulus value extracted from the grain-oriented specimen, measured by resonant ultrasound spectroscopy, validates the ultra-incompressibility of ReB{sub 2}. An observed hardness of 40 GPa and a Debye temperature of 731 K were calculated for the ReB{sub 2} crystal, confirming its superhard and super-stiff properties. All the measured moduli of the ReB{sub 2} grain-oriented crystal exceed the comparable ones for the polycrystal by amounts that cannot be explained by averaging over direction, which may reveal why recent measurements reported on ReB{sub 2} containing excess boron yield values that are not as hard or incompressible as the crystal.

PRECIPITATION BEHAVIOR OF Co PHASES IN B2-ORDERED(Ni,Co)Al COMPOUND

Institute of Scientific and Technical Information of China (English)

W.H. Tian; A.L. Fan; M. Nemoto

2002-01-01

The precipitation behavior of Co phases in B2-ordered (Ni, Co)Al has been investigatedin terms of transmission electron microscopy. Fine precipitation off cc-Co occurs in(Ni, Co)Al by aging at temperature over 973K. The orientation relationship betweenthe fcc-Co precipitates and the B2-(Ni, Co)Al matrix follows the Kurdjumow-Sachs(K-S) orientation relation. But when the aging temperature is under 873K the Coprecipitates have a hcp crystal structure. The orientation relationship between thehcp-Co precipitates and the B2-(Ni, Co)Al matrix follows the Burgers orientation re-lation. (Ni, Co)Al is hardened appreciably by the fine precipitation of both the fcc-Coand hcp-Co phases. The temperature dependence of the yield strength of precipitate-containing B2-ordered (Ni, Co)Al was investigated by compression tests over the rangeof 298-1273K. The fine precipitation of Co phases enhances greatly the low and in-termediate temperature yield strength. When the deformation temperature was over873K, the strength of precipitate-containing (Ni, Co)Al is comparable to ternary dual-phase (Ni, Co)Al+Ni3Al alloy.

Magnetic phase diagram of ErNi2B2C

DEFF Research Database (Denmark)

Jensen, A.; Toft, K.N.; Abrahamsen, A.B.

2004-01-01

The magnetic phase diagram of the superconductor ErNi2B2C (T-c = 11 K and T-N = 6 K) has been studied by neutron diffraction as a function of temperature and magnetic field applied along the symmetry directions [010], [110] and [001] of the tetragonal crystal structure. A series of commensurate...... magnetic structures, consistent with a transversely polarized spin-density wave with modulation vectors Q = n/ma* (0.55 less than or equal to n/m field model that has been established from...... an analysis of bulk magnetization and zero-field neutron diffraction data. The model accounts for most of the observed features but fails to explain the occurrence of a small component Qdelta approximate to -0.005b* observed close to H-c2 when the field is applied along [110]. (C) 2004 Elsevier B.V. All...

Synthesis and biological evaluation of 3,6-dialkylsubstituted-[1,2,4 ...

Indian Academy of Sciences (India)

VIJAYENDAR VENEPALLY

2018-02-16

Feb 16, 2018 ... A series of 3,6-dialkyl-[1,2,4] triazolo[3,4-b][1,3,4]thiadiazole (10) analogues were ... Cytotoxicity data revealed that most of the tested compounds revealed cytotoxic ...... jary B 2003 Synthesis characterization and anticancer.

Crystallographic characterization of divalent organosamarium compound (C5H5)2Sm(THF)2

International Nuclear Information System (INIS)

Jagannatha Swamy, S.

2002-01-01

The single pot reaction between SmX 2 (X = Cl - , I - ) and BuLi in THF at -40 degC, followed by the addition of C 5 H 5 - Na + results in a dark red solution. Leaving the concentrated reaction mixture at -25 degC for two days in a deep freezer results in the formation of the crystals of the compound, (C 5 H 5 ) 2 ; Sm(THF) 2 . The compound is insoluble in any solvent and it has been characterized by conventional methods. The crystals are monoclinic with space group C2/c, and a = 13.416(1), b = 9.644(1), c = 14.129(2) pm, β109.873(9) 0 and z = 4 for ρcalcd = 1.64 g cm -3 . Least squares refinement on the basis of 1804 observed reflections has led to a final R value of 0.037 and R w = 0.054. (author)

First-principles investigation of Cr-doped Fe2B: Structural, mechanical, electronic and magnetic properties

Science.gov (United States)

Wei, Xiang; Chen, Zhiguo; Zhong, Jue; Wang, Li; Wang, Yipeng; Shu, Zhongliang

2018-06-01

The structural, mechanical, electronic and magnetic properties of Fe8-xCrxB4 (x = 0, 0.25, 0.5, 1, 2, 3, 4, 5, 6, 7 and 8) have been investigated by first-principles calculation. It was found that the calculated structural parameters are well consistent with available experimental data. Moreover, all studied compounds are thermodynamically stable phases. On the whole, the moduli of the compounds firstly increase and then decrease with the increase of Cr concentration, whereas the variation of hardness exhibits more fluctuations. All Cr-doped Fe2B have better ductility than Fe2B except Fe2Cr6B4 and Fe5Cr3B4. Interestingly, Fe4Cr4B4 is of not only the slightly larger hardness, but also much better ductility than Fe2B. As the Cr concentration is lower than 20 wt%, the hardness of Cr-doped Fe2B slightly decreases with increasing Cr, whereas the sharply increased hardness of (Fe, Cr)2B in Fe-B alloys or boriding layer should be attributed to the multiple alloying effects resulting from Cr and the other alloying elements. The electronic structures revealed that the Fe-B and/or Cr-B bonds are mainly responsible for their mechanical properties, and the M-N (M = Fe or Cr, N = Fe or Cr) bonds in 〈2 2 0〉 and 〈1 1 3〉 orientations show covalent character. Additionally, the magnetic moments (Ms) of the compounds do not monotonically decrease with increasing Cr.

Crystal structure of the new ternary indide CePt{sub 2}In{sub 2} and the isostructural compounds RPt{sub 2}In{sub 2} (R=La,Pr,Nd)

Energy Technology Data Exchange (ETDEWEB)

Zaremba, V.; Galadzhun, Y.; Kalychak, Y. [I. Franko Lviv State Univ. (Ukraine). Inorganic Chem. Dept.; Kaczorowski, D.; Stepien-Damm, J. [W. Trzebiatowski Institute of Low Temperature and Structural Research, Polish Academy of Sciences, Okolna Str. 2, 50-950, Wroclaw (Poland)

2000-01-10

The title compounds have been synthesized by arc melting of the elemental components and subsequent annealing at 870 K. The crystal structure of CePt{sub 2}In{sub 2} was determined from single-crystal X-ray data (R=0.0437 for 1439 F values and 62 variables). It represents a new structure type of intermetallic compounds: P2{sub 1}/m, mP20, a=10.189(6), b=4.477(4), c=10.226(6) A, {beta}=117.00(5) , V=416.1(1) A{sup 3}, Z=4. Isostructural compounds have been found also for La,Pr, and Nd. (orig.)

Electronic structure of magnesium diboride and related compounds

Energy Technology Data Exchange (ETDEWEB)

Paduani, C. [Departamento de Fisica, Universidade Federal de Santa Catarina, UFSC, Florianopolis, CEP 88040-900, SC (Brazil)

2003-11-01

The electronic structure of AlB{sub 2}-type diborides and related compounds has been investigated in first-principles calculations with the molecular cluster discrete variational method. For MgB{sub 2} was studied the effect of the lattice relaxation on the total density of states at the Fermi energy (N({epsilon}{sub F})). The results indicated that a contraction of about 2% in the lattice spacings a and c can lead to a slight increase of N({epsilon}{sub F}) for boron. In the MB{sub 2} diborides, M=Al, Ti, V, Cr, Zr, Nb, Mo and Ta, the largest contributions to N({epsilon}{sub F}) is observed for Cr, Mo and Nb. TiB{sub 2} possess the highest chemical stability in the series. The electronic specific heat coefficient {gamma} also is calculated for the diborides. The method is employed to obtain the partial B2p contribution to the total DOS at the Fermi level with the introduction of a monolayer of solute atoms as a substitution for Mg atoms of Na, Al, Ca, Ti, V, Cr, Zr, Nb, Mo and Ta in layered superstructures.. /M/B{sub 2}/Mg/B{sub 2}/.. A stronger covalent bonding between boron atoms is identified in these cases. (copyright 2003 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Arohynapenes A and B, new anticoccidial agents produced by Penicillium sp. Taxonomy, fermentation, and structure elucidation.

Science.gov (United States)

Masuma, R; Tabata, N; Tomoda, H; Haneda, K; Iwai, Y; Omura, S

1994-01-01

Penicillium sp. FO-2295, a water isolate, was found to produce a series of new anticoccidial compounds. Two active compounds, designated arohynapenes A and B, were isolated from the fermentation broth of the producing strain by solvent extration and preparative HPLC. Arohynapene A was deduced to be (2E,4E)-5-(5-hydroxy-2,6,8-trimethyl-5,6,7,8-tetrahydronaphtale ne)-2,4- pentadienoic acid, and arohynapene B was (2E,4E)-5-(2-hydroxymethyl-6,8-dimethyl-5,6,7,8-tetrahydronapht alene)-2,4- pentadienoic acid. Arohynapenes inhibited the growth of Eimeria tenella in an in vitro assay using BHK-21 cells as a host. No schizont in the cells was observed at concentrations ranging above 35.0 microM and 7.0 microM for arohynapenes A and B, respectively.

Valence behavior of Eu-ions in intermetallic compound Ce{sub 0.5}Eu{sub 0.5}Pd{sub 3}B{sub 0.5}

Energy Technology Data Exchange (ETDEWEB)

Pandey, Abhishek, E-mail: apandey@ameslab.gov [Experimental Condensed Matter Physics Division, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata 700064 (India); S.N. Bose National Centre for Basic Sciences, Block-JD, Sector-III, Salt Lake, Kolkata 700098 (India); Mazumdar, Chandan, E-mail: chandan.mazumdar@saha.ac.in [S.N. Bose National Centre for Basic Sciences, Block-JD, Sector-III, Salt Lake, Kolkata 700098 (India); Ranganathan, R. [S.N. Bose National Centre for Basic Sciences, Block-JD, Sector-III, Salt Lake, Kolkata 700098 (India); Raghavendra Reddy, V.; Gupta, Ajay [UGC-DAE Consortium for Scientific Research, University Campus, Khandawa Road, Indore (India)

2011-12-15

We have studied the valence behavior of rare-earth ions, in particular Eu-ions, in a cubic intermetallic compound Ce{sub 0.5}Eu{sub 0.5}Pd{sub 3}B{sub 0.5} which is a homogeneous solid solution of two mixed-valent compounds CePd{sub 3} and EuPd{sub 3}B. Results of {sup 151}Eu Moessbauer spectroscopic measurements show that two different valence states, i.e., divalent- and trivalent-like states of Eu-ions exist in the compound. The possible reason for the observed heterogeneous valency vis-a-vis the variation in the chemical environment and the number of nearest-neighbor B atoms surrounding the Eu-ions has been discussed. Our results demonstrate that B incorporation in such Eu-based cubic intermetallic compounds leads to a situation where heterogeneous-valence state of Eu-ions is an energetically favorable ground state. - Highlights: > Intermetallic compound Ce{sub 0.5}Eu{sub 0.5}Pd{sub 3}B{sub 0.5} crystallizes in a single phase. > Eu-ions in Ce{sub 0.5}Eu{sub 0.5}Pd{sub 3}B{sub 0.5} are charge-ordered compared to +2.3 valency in Ce{sub 0.5}Eu{sub 0.5}Pd{sub 3}. > B incorporation makes charge-ordered state of Eu-ions energetically more favorable. > Nearest-neighbor chemical environment affects the Eu valency.

In Vitro Antifungal Activities of a Series of Dication-Substituted Carbazoles, Furans, and Benzimidazoles

Science.gov (United States)

Del Poeta, Maurizio; Schell, Wiley A.; Dykstra, Christine C.; Jones, Susan K.; Tidwell, Richard R.; Kumar, Arvind; Boykin, David W.; Perfect, John R.

1998-01-01

Aromatic dicationic compounds possess antimicrobial activity against a wide range of eucaryotic pathogens, and in the present study an examination of the structures-functions of a series of compounds against fungi was performed. Sixty-seven dicationic molecules were screened for their inhibitory and fungicidal activities against Candida albicans and Cryptococcus neoformans. The MICs of a large number of compounds were comparable to those of the standard antifungal drugs amphotericin B and fluconazole. Unlike fluconazole, potent inhibitory compounds in this series were found to have excellent fungicidal activities. The MIC of one of the most potent compounds against C. albicans was 0.39 μg/ml, and it was the most potent compound against C. neoformans (MIC, ≤0.09 μg/ml). Selected compounds were also found to be active against Aspergillus fumigatus, Fusarium solani, Candida species other than C. albicans, and fluconazole-resistant strains of C. albicans and C. neoformans. Since some of these compounds have been safely given to animals, these classes of molecules have the potential to be developed as antifungal agents. PMID:9756748

ENDF-201 Supplement 1. ENDF/B-V.2 summary documentation. Third edition

International Nuclear Information System (INIS)

Magurno, B.A.; Young, P.G.

1985-01-01

The purpose of the present publication is to provide the summary documentation for Revision 2 of the General Purpose File of ENDF/B-V. Revision 2 embodies a series of updates for important materials in the ENDF/B-V libraries in advance of the more comprehensive changes that will accompany a complete version change to ENDF/B, Verison VI. The summary documents for the evaluations that were completely or extensively modified during Revision 2 are provided. Less extensive changes made to other evaluations are also documented. Modifications made to the fission energy release parameters for fissionable nuclei are described. Finally, a series of modifications made to the covariance files of the major fissionable nuclei, including cross correlation information, is summarized

B{sub 2}S{sub 2}O{sub 9}. A boron sulfate with phyllosilicate topology

Energy Technology Data Exchange (ETDEWEB)

Logemann, Christian; Wickleder, Mathias S. [Carl von Ossietzky University, Institute for Chemistry, Oldenburg (Germany)

2013-12-23

The condensation of [BO{sub 4}] and [SO{sub 4}] tetrahedra in the first binary boron sulfate B{sub 2}S{sub 2}O{sub 9}, leads to a structure with typical layered phyllosilicate topology. The compound is obtained from the hydrolysis of B(OH){sub 3} and HSO{sub 3}Cl. (Copyright copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

2-acetylphenol analogs as potent reversible monoamine oxidase inhibitors

Directory of Open Access Journals (Sweden)

Legoabe LJ

2015-07-01

Full Text Available Lesetja J Legoabe,1 Anél Petzer,1 Jacobus P Petzer1,21Centre of Excellence for Pharmaceutical Sciences, 2Department of Pharmaceutical Chemistry, School of Pharmacy, North-West University, Potchefstroom, South AfricaAbstract: Based on a previous report that substituted 2-acetylphenols may be promising leads for the design of novel monoamine oxidase (MAO inhibitors, a series of C5-substituted 2-acetylphenol analogs (15 and related compounds (two were synthesized and evaluated as inhibitors of human MAO-A and MAO-B. Generally, the study compounds exhibited inhibitory activities against both MAO-A and MAO-B, with selectivity for the B isoform. Among the compounds evaluated, seven compounds exhibited IC50 values <0.01 µM for MAO-B inhibition, with the most selective compound being 17,000-fold selective for MAO-B over the MAO-A isoform. Analyses of the structure–activity relationships for MAO inhibition show that substitution on the C5 position of the 2-acetylphenol moiety is a requirement for MAO-B inhibition, and the benzyloxy substituent is particularly favorable in this regard. This study concludes that C5-substituted 2-acetylphenol analogs are potent and selective MAO-B inhibitors, appropriate for the design of therapies for neurodegenerative disorders such as Parkinson’s disease.Keywords: monoamine oxidase, MAO, inhibition, 2-acetylphenol, structure–activity relationship

Novel Anthra[1,2-c][1,2,5]Thiadiazole-6,11-Diones as Promising Anticancer Lead Compounds: Biological Evaluation, Characterization & Molecular Targets Determination.

Directory of Open Access Journals (Sweden)

Ahmed Atef Ahmed Ali

Full Text Available The novel compounds NSC745885 and NSC757963 developed at our laboratory were tested against a panel of 60 cancer cell lines at the National Cancer Institute, USA, and a panel of 39 cancer cell lines at the Japanese Foundation of Cancer Research. Both compounds demonstrated selective unique multi-log differential patterns of activity, with GI50 values in the sub-micro molar range against cancer cells rather than normal cardiac cells. NSC757963 showed high selectivity towards the leukemia subpanel. Activities of both compounds strongly correlated to expression of NFKB1 and CSNK2B genes, implying that they may inhibit the NF-κB pathway. Immunocytochemical microscopy of OVCAR-3 cells showed clear cytosolic accumulation of the NF-κB p65 subunit following treatment. Western blotting showed dose dependent inhibition of the nuclear expression of the NF-κB p65 subunit with subsequent accumulation in the cytosol following treatment. Docking experiments showed binding of both compounds to the NF-κB activator IKKβ subunit preventing its translocation to the nucleus. Collectively, these results confirm the ability of our compounds to inhibit the constitutively active NF-κB pathway of OVCAR-3 cells. Furthermore, COMPARE analysis indicated that the activity of NSC757963 is similar to the antituberculosis agent rifamycin SV, this was confirmed by testing the antimycobacterial activity of NSC757963 against Mycobacterium tuberculosis, results revealed potent activity suitable for use in clinical practice. Molecular properties and Lipinski's parameters predicted acceptable bioavailability properties with no indication of mutagenicity, tumorigenicity, irritability and reproductive effects. Oral absorption experiments using the human Caco-2 model showed high intestinal absorption of NSC745885 by passive transport mechanism with no intestinal efflux or active transport mechanisms. The unique molecular characterization as well as the illustrated anticancer

Hydrothermal synthesis and structural analysis of new mixed oxyanion borates: Ba11B26O44(PO4)2(OH)6, Li9BaB15O27(CO3) and Ba3Si2B6O16

Science.gov (United States)

Heyward, Carla; McMillen, Colin D.; Kolis, Joseph

2013-07-01

Several new borate compounds, Ba11B26O44(PO4)2(OH)6 (1), Li9BaB15O27(CO3) (2), and Ba3Si2B6O16 (3) were synthesized containing other hetero-oxyanion building blocks in addition to the borate frameworks. They were all prepared under hydrothermal conditions and characterized by single crystal and powder X-ray diffraction, and IR spectroscopy. Crystal data: For 1; space group P21/c, a=6.8909 (14) Å, b=13.629 (3) Å, c=25.851 (5) Å, β=90.04 (3)°; For 2; space group P-31c, a=8.8599 (13) Å, c=15.148 (3) Å; For 3; space group P-1, a=5.0414 (10) Å, b=7.5602 (15) Å, c=8.5374 (17) Å, α=77.15 (3)°, β=77.84 (3)°, γ=87.41 (3)° for 3. Compounds 1 and 2 contain isolated oxyanions [PO4]3- and [CO3]2- respectively, sitting in channels created by the borate framework, while structure 3 has the [SiO4]4- groups directly bonded to the borate groups creating a B-O-Si framework.

β1-adrenergic receptor stimulation by agonist Compound 49b restores insulin receptor signal transduction in vivo

Science.gov (United States)

Jiang, Youde; Zhang, Qiuhua; Ye, Eun-Ah

2014-01-01

Purpose Determine whether Compound 49b treatment ameliorates retinal changes due to the lack of β2-adrenergic receptor signaling. Methods Using retinas from 3-month-old β2-adrenergic receptor-deficient mice, we treated mice with our novel β1-/β2-adrenergic receptor agonist, Compound 49b, to assess the effects of adrenergic agonists acting only on β1-adrenergic receptors due to the absence of β2-adrenergic receptors. Western blotting or enzyme-linked immunosorbent assay (ELISA) analyses were performed for β1- and β2-adrenergic receptors, as well as key insulin resistance proteins, including TNF-α, SOCS3, IRS-1Ser307, and IRTyr960. Analyses were also performed on key anti- and proapoptotic proteins: Akt, Bcl-xL, Bax, and caspase 3. Electroretinogram analyses were conducted to assess functional changes, while histological assessment was conducted for changes in retinal thickness. Results A 2-month treatment of β2-adrenergic receptor-deficient mice with daily eye drops of 1 mM Compound 49b, a novel β1- and β2-adrenergic receptor agonist, reversed the changes in insulin resistance markers (TNF-α and SOCS3) observed in untreated β2-adrenergic receptor-deficient mice, and concomitantly increased morphological integrity (retinal thickness) and functional responses (electroretinogram amplitude). These results suggest that stimulating β1-adrenergic receptors on retinal endothelial cells or Müller cells can compensate for the loss of β2-adrenergic receptor signaling on Müller cells, restore insulin signal transduction, reduce retinal apoptosis, and enhance retinal function. Conclusions Since our previous studies with β1-adrenergic receptor knockout mice confirmed that the reverse also occurs (β2-adrenergic receptor stimulation can compensate for the loss of β1-adrenergic receptor activity), it appears that increased activity in either of these pathways alone is sufficient to block insulin resistance–based retinal cell apoptosis. PMID:24966659

Synthesis, reactions and biological activity of some new bis-heterocyclic ring compounds containing sulphur atom

Science.gov (United States)

2013-01-01

Background The derivatives of thieno[2,3-b]thiophene belong to a significant category of heterocyclic compounds, which have shown a wide spectrum of medical and industrial application. Results A new building block with two electrophilic center of thieno[2,3-b]thiophene derivatives 2 has been reported by one-pot reaction of diketone derivative 1 with Br2/AcOH in excellent yield. A variety of heteroaromatics having bis(1H-imidazo[1,2a] benzimidazole), bis(1H-imidazo[1,2-b][1,2,4]triazole)-3-methyl-4-phenylthieno[2,3-b]thiophene derivatives, dioxazolo-, dithiazolo-, and 1H-imidazolo-3-methyl-4-phenylthieno[2,3-b]thiophene derivatives as well pyrrolo, thiazolo -3-methyl-4-phenylthieno[2,3-b]thiophene derivatives have been designed, synthesized, characterized, and evaluated for their biological activity. Compounds 3–9 showed good bioassay result. These new derivatives were evaluated for anti-cancer activity against PC-3 cell lines, in vitro antioxidant potential and β-glucuronidase and α-glucosidase inhibitory activities. Compound 3 (IC50 = 56.26 ± 3.18 μM) showed a potent DPPH radical scavenging antioxidant activity and found to be more active than standard N-acetylcystein (IC50 = 105.9 ± 1.1 μM). Compounds 8a (IC50 = 13.2 ± 0.34 μM) and 8b (IC50 = 14.1 ± 0.28 μM) found as potent inhibitor of α-glucusidase several fold more active than the standard acarbose (IC50 = 841 ± 1.73 μM). Most promising results were obtained in β-glucuronidase enzyme inhibition assay. Compounds 5 (IC50 = 0.13 ± 0.019 μM), 6 (IC50 = 19.9 ± 0.285 μM), 8a (IC50 = 1.2 ± 0.0785 μM) and 9 (IC50 = 0.003 ± 0.09 μM) showed a potent inhibition of β-glucuronidase. Compound 9 was found to be several hundred fold more active than standard D-Saccharic acid 1,4-lactone (IC50 = 45.75 ± 2.16 μM). Conclusions Synthesis, characterization, and in vitro biological activity of a series of

[Distribution and sources of oxygen and sulfur heterocyclic aromatic compounds in surface soil of Beijing, China].

Science.gov (United States)

He, Guang-Xiu; Zhang, Zhi-Huan; Peng, Xu-Yang; Zhu, Lei; Lu, Ling

2011-11-01

62 surface soil samples were collected from different environmental function zones in Beijing. Sulfur and oxygen heterocyclic aromatic compounds were detected by GC/MS. The objectives of this study were to identify the composition and distribution of these compounds, and discuss their sources. The results showed that the oxygen and sulfur heterocyclic aromatic compounds in the surface soils mainly contained dibenzofuran, methyl- and C2-dibenzofuran series, dibenzothiophene, methyl-, C2- and C3-dibenzothiophene series and benzonaphthothiophene series. The composition and distribution of the oxygen and sulfur heterocyclic aromatic compounds in the surface soil samples varied in the different environmental function zones, of which some factories and the urban area received oxygen and sulfur heterocyclic aromatic compounds most seriously. In Beijing, the degree of contamination by oxygen and sulfur heterocyclic aromatic compounds in the north surface soil was higher than that in the south. There were preferable linear correlations between the concentration of dibenzofuran series and fluorene series, as well as the concentration of dibenzothiophene series and dibenzofuran series. The oxygen and sulfur heterocyclic aromatic compounds in the surface soil were mainly derived from combustion products of oil and coal and direct input of mineral oil, etc. There were some variations in pollution sources of different environmental function zones.

Organic high ionic strength aqueous two-phase solvent system series for separation of ultra-polar compounds by spiral high-speed counter-current chromatography

Science.gov (United States)

Zeng, Yun; Liu, Gang; Ma, Ying; Chen, Xiaoyuan; Ito, Yoichiro

2011-01-01

Existing two-phase solvent systems for high-speed countercurrent chromatography cover the separation of hydrophobic to moderately polar compounds, but often fail to provide suitable partition coefficient values for highly polar compounds such as sulfonic acids, catecholamines and zwitter ions. The present paper introduces a new solvent series which can be applied for the separation of these polar compounds. It is composed of 1-butanol, ethanol, saturated ammonium sulfate and water at various volume ratios and consists of a series of 10 steps which are arranged according to the polarity of the solvent system so that the two-phase solvent system with suitable K values for the target compound(s) can be found in a few steps. Each solvent system gives proper volume ratio and high density difference between the two phases to provide a satisfactory level of retention of the stationary phase in the spiral column assembly. The method is validated by partition coefficient measurement of four typical polar compounds including methyl green (basic dye), tartrazine (sulfonic acid), tyrosine (zwitter ion) and epinephrine (a catecholamine), all of which show low partition coefficient values in the polar 1-butanol-water system. The capability of the method is demonstrated by separation of three catecholamines. PMID:22033108

Transport properties of RCo_2B_2C with R = Dy, Ho, and Pr single

Science.gov (United States)

Duran, Alejandro; Escudero, Roberto

2002-03-01

Single crystals of (Dy, Ho, Pr)Co_2B_2C have been grown by a cold copper crucible method. Metallurgical and structural studies indicate that this borocarbide family melts incongruently and crystallizes as a derivative structure of the ThCr_2Si_2. The family accepts rare earth atoms depending on the type of transition metals used to form the compound. For instance with Ni atoms, all lanthanides ranging from the large lanthanum to lutetium ions are reported to form RNi_2B_2C single crystals, so far no single crystals have been obtained when changing Ni by Cobalt. A comparison of the structural parameters of the RCo_2B_2C with the RNiHo, Pr) compounds indicate that the atomic distance between transition metal atoms contracts with the insertion of the Co ion, resulting in an increasing of the c parameter and decreasing volume. Several recent reports published in the current literature related on the physical properties of RCo_2B_2C (R = rare earth metals and Y) have been only performed on polycrystalline samples, they commonly contain small amounts of second phases. High quality single crystals are necessaries in order to better understand the physical properties, such as anisotropy in the transport and in the magnetic properties. In this report we show magnetic susceptibility and resistivity measurements performed in single crystals in the ab-plane and c direction for 2 - 320 K temperature range for the three single crystals of (Dy, Ho, Pr)Co_2B_2C.

Targeting Sulfotransferase (SULT) 2B1b as a regulator of Cholesterol Metabolism in Prostate Cancer

Science.gov (United States)

2016-10-01

associated with de novo androgen synthesis will be addressed based on the hypothesis that SULT2B1b promotes PCa proliferation by impacting the...evaluation of sulfonation activity on other sterols using in vitro assays. Seven thousand (7,000) compounds were screened after computational...stim- ulation, and previous studies have demonstrated that cholesterol canbeused as a precursor for androgen synthesis (6, 26). Thus, the impact of

OxymaPure/DIC: An Efficient Reagent for the Synthesis of a Novel Series of 4-[2-(2-Acetylaminophenyl-2-oxo-acetylamino] Benzoyl Amino Acid Ester Derivatives

Directory of Open Access Journals (Sweden)

Ayman El-Faham

2013-11-01

Full Text Available OxymaPure (ethyl 2-cyano-2-(hydroxyiminoacetate was tested as an additive for use in the carbodiimide (DIC approach for the synthesis of a novel series of α-ketoamide derivatives (4-[2-(2-acetylaminophenyl-2-oxo-acetylamino]benzoyl amino acid ester derivatives. OxymaPure showed clear superiority to HOBt/DIC or carbodiimide alone in terms of purity and yield. The title compounds were synthesized via the ring opening of N-acylisatin. First, N-acetylisatin was reacted with 4-aminobenzoic acid under conventional heating as well as microwave irradiation to afford 4-(2-(2-acetamidophenyl-2-oxoacetamidobenzoic acid. This α-ketoamide was coupled to different amino acid esters using OxymaPure/DIC as a coupling reagent to afford 4-[2-(2-acetylaminophenyl-2-oxo-acetylamino]benzoyl amino acid ester derivatives in excellent yield and purity. The synthesized compounds were characterized using FT-IR, NMR, and elemental analysis.

Mixed nickel-gallium tellurides Ni{sub 3−x}GaTe{sub 2} as a matrix for incorporating magnetic cations: A Ni{sub 3−x}Fe{sub x}GaTe{sub 2} series

Energy Technology Data Exchange (ETDEWEB)

Kuznetsov, Alexey N., E-mail: alexei@inorg.chem.msu.ru [Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1-3, GSP-1, 119991 Moscow (Russian Federation); N.S. Kurnakov Institute of General and Inorganic Chemistry, RAS, Leninsky pr. 31, GSP-1, 119991 Moscow (Russian Federation); Stroganova, Ekaterina A.; Zakharova, Elena Yu; Solopchenko, Alexander V.; Sobolev, Alexey V.; Presniakov, Igor A. [Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1-3, GSP-1, 119991 Moscow (Russian Federation); Kirdyankin, Denis I.; Novotortsev, Vladimir M. [N.S. Kurnakov Institute of General and Inorganic Chemistry, RAS, Leninsky pr. 31, GSP-1, 119991 Moscow (Russian Federation)

2017-06-15

Using a high-temperature ampoule technique, a series of mixed nickel-iron-gallium metal-rich tellurides with layered structures, Ni{sub 3-x}Fe{sub x}GaTe{sub 2}, were prepared and characterized based on X-ray powder diffraction, energy-dispersive spectroscopy, and {sup 57}Fe Mössbauer spectroscopy data. These compounds may be regarded as a result of partial substitution of nickel by iron in the recently reported ternary Ni{sub 3-x}GaTe{sub 2} series, which are based on NiAs/Ni{sub 2}In type of structure. The compositional boundary for the substitution was found to be at x~1. According to the Mössbauer spectroscopy data, the substitution is not statistical, and iron atoms with the increase in x tend to preferentially occupy those nickel positions that are partially vacant in the initial ternary compound. Magnetic measurements data for the Ni{sub 3-x}Fe{sub x}GaTe{sub 2} series show dramatic change in behavior from temperature-independent paramagnetic properties of the initial matrix to a low-temperature (~75 K) ferromagnetic ordering in the Ni{sub 2}FeGaTe{sub 2}. - Graphical abstract: Ordered substitution of nickel by iron in the Ni{sub 3−x}GaTe{sub 2} series leading to ferromagnetic ordering. - Highlights: • A series of Ni{sub 3−x}Fe{sub x}GaTe{sub 2} compounds were synthesized. • They adopt the NiAs/Ni{sub 2}In type of structure with ordered iron distribution. • The distribution of iron was studied using {sup 57}Fe Mössbauer spectroscopy. • An increase in iron content leads to the strong ferromagnetic coupling.

Impurity induced antiferromagnetic order in Haldane gap compound SrNi2-xMgxV2O8

International Nuclear Information System (INIS)

Pahari, B.; Ghoshray, K.; Ghoshray, A.; Samanta, T.; Das, I.

2007-01-01

The effect of nonmagnetic Mg 2+ doping in SrNi 2 V 2 O 8 , a Haldane gap system with a disordered ground state, was investigated using DC magnetic susceptibility and heat capacity measurements in polycrystalline samples of SrNi 2-x Mg x V 2 O 8 with x=0.03, 0.05, 0.07, 0.1 and 0.14. The results clearly reveal that the substitution of Ni 2+ (S=1) ion by Mg 2+ (S=0) ion induces a magnetic phase transition with the ordering temperatures lying in the range 3.4-4.3K, for the samples with lowest and highest value of x. The intrachain exchange constant (J/k B ) and the Haldane gap (Δ) for all the compounds were estimated to be ∼98+/-2 and 25K, respectively, which are close to that of the undoped compound. The magnetization data further suggest that the compounds exhibit metamagnetic behavior below T N , supporting a picture of antiferromagnet with significant magnetic anisotropy and competing intrachain and interchain interactions

cis- and trans-2,3,3a,4,5,9b-Hexahydro-1H-benz[e]indoles: synthesis and evaluation of dopamine D2, and D3 receptor binding affinity

DEFF Research Database (Denmark)

Song, Xiaodong; Crider, Michael A.; Cruse, Sharon F.

1999-01-01

cis- and trans-2,3,3a,4,5,9b-hexahydro-1H-benz [e]indoles were synthesized as conformationally rigid analogues of 3-phenylpyrrolidine and evaluated for dopamine (DA) D2S and D3 receptor binding affinity. The tricyclic benz[e]indole nucleus was constructed by a previously reported reductive...... configuration. These novel ligands may be useful tools for gaining additional information about the DA D3 receptor. Copyright Elsevier, Paris.dopamine / D2S receptor / D3 receptor / cis- and trans-2,3,3a,4,5,9b-hexahydro-1H-benz[e]indoles / receptor binding affinity....... receptors was shown by compounds substituted with N-n-propyl or N-allyl groups. The cis-(+-)-N-allyl derivative 21e demonstrated a D2S/D3 selectivity of 290. Resolution of cis-(+-)-5 and trans-(+-)- 21c into individual enantiomers showed that in both series the more active isomer had 3aR absolute...

Electronic structure and superconductivity of MgB 2

Indian Academy of Sciences (India)

Results of ab initio electronic structure calculations on the compound, MgB2, using the FPLAPW method employing GGA for the exchange–correlation energy are presented. Total energy minimization enables us to estimate the equilibrium volume, / ratio and the bulk modulus, all of which are in excellent agreement with ...

Valence, magnetism and conduction in the intermediate valence compounds: the case SmB6

International Nuclear Information System (INIS)

Derr, J.

2006-09-01

In some rare earth based compounds, the 4f level is situated so close to the Fermi level that the valence of the compound can become intermediate between two integer values. The so called 'intermediate valence' compound of Samarium hexaboride (SmB 6 ) is one typical example of the exciting physics which can result from this quantum equilibrium between two valence configurations. The first configuration (Sm 2+ ) corresponds to an insulating and non magnetic state whereas the second one (Sm 3+ ) would theoretically give a magnetic and metallic ground state. This dissertation deals with the influence of pressure on this equilibrium. Specific heat measurements under pressure evidenced a new long range magnetic ordering for pressures higher than p c ∼ 10 GPa. On another hand, transport measurements measured for the first time in good conditions of hydrostatics found a reliable and reproducible critical pressure for the insulator to metal transition equal to p c . The phase diagram of SmB 6 is now well known and the observation for the first time of a magnetic anomaly in the high pressure resistivity curves certifies that the onset of the magnetic phase really coincide with the closure of the gap. This change at the critical pressure p c is discussed in a general frame taking into account the Kondo lattice temperature as a key parameter for the renormalization of the wavefunction from one integer configuration to the other whereas the valence itself is still intermediate. This general idea seems to be valid also for other systems studied in this dissertation like SmS or TmSe and could even be valid for more general cases (Ytterbium, Cerium). In the same time, resistivity measurements under uniaxial stress were undertaken. The result is a strong anisotropy effect observed on the pressure dependence of the residual resistivity in the compound SmB 6 . The comparison with the transport under hydrostatic conditions enables us to consider a new idea for the nature of the gap

Influence of lambda-carrageenan on the release of systematic series of volatile flavor compounds from viscous food model systems

DEFF Research Database (Denmark)

Bylaite, Egle; Ilgunaite, Z.; Meyer, Anne Boye Strunge

2004-01-01

-liquid partition coefficients K (37degreesC) of a total of 43 aroma compounds were determined in pure water and in the lambda-carrageenan solutions by static headspace gas chromatography. Mass transfer of the aroma compounds in water and in the thickened lambda-carrageenan solutions which had a wide viscosity...... range was assessed by dynamic headspace gas chromatography. K(37degreesC) increased as the carbon chain increased within each homologous series. Esters exhibited the highest volatility, followed by aldehydes, ketones, and alcohols. Under equilibrium, no overall effect of lambda-carrageenan was found...

Discovery of novel, high potent, ABC type PTP1B inhibitors with TCPTP selectivity and cellular activity.

Science.gov (United States)

Liu, Peihong; Du, Yongli; Song, Lianhua; Shen, Jingkang; Li, Qunyi

2016-08-08

Protein tyrosine phosphatase 1B (PTP1B) as a key negative regulator of both insulin and leptin receptor pathways has been an attractive therapeutic target for the treatment of type 2 diabetes mellitus (T2DM) and obesity. With the goal of enhancing potency and selectivity of the PTP1B inhibitors, a series of methyl salicylate derivatives as ABC type PTP1B inhibitors (P1-P7) were discovered. More importantly, compound P6 exhibited high potent inhibitory activity (IC50 = 50 nM) for PTP1B with 15-fold selectivity over T-cell PTPase (TCPTP). Further studies on cellular activities revealed that compound P6 could enhance insulin-mediated insulin receptor β (IRβ) phosphorylation and insulin-stimulated glucose uptake. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Exploring high-pressure FeB{sub 2}: Structural and electronic properties predictions

Energy Technology Data Exchange (ETDEWEB)

Harran, Ismail [School of Physical Science and Technology, Key Laboratory of Advanced Technologies of Materials, Ministry of Education of China, Southwest Jiaotong University, Chengdu, 610031 (China); Al Fashir University (Sudan); Wang, Hongyan [School of Physical Science and Technology, Key Laboratory of Advanced Technologies of Materials, Ministry of Education of China, Southwest Jiaotong University, Chengdu, 610031 (China); Chen, Yuanzheng, E-mail: cyz@calypso.org.cn [School of Physical Science and Technology, Key Laboratory of Advanced Technologies of Materials, Ministry of Education of China, Southwest Jiaotong University, Chengdu, 610031 (China); Jia, Mingzhen [School of Physical Science and Technology, Key Laboratory of Advanced Technologies of Materials, Ministry of Education of China, Southwest Jiaotong University, Chengdu, 610031 (China); Wu, Nannan [School of Mathematics, Physics and Biological Engineering, Inner Mongolia University of Science & Technology, Baotou, 014010 (China)

2016-09-05

The high pressure (HP) structural phase of FeB{sub 2} compound is investigated by using first-principles crystal structure prediction based on the CALYPSO technique. A thermodynamically stable phase of FeB{sub 2} with space group Imma is predicted at pressure above 225 GPa, which is characterized by a layered orthorhombic structure containing puckered graphite-like boron layers. Its electronic and mechanical properties are identified and analyzed. The feature of band structures favors the occurrence of superconductivity, whereas, the calculated Pugh's ratio reveals that the HP Imma structure exhibits ductile mechanical property. - Highlights: • The high pressure structural phase of FeB{sub 2} compound is firstly investigated by the CALYPSO technique. • A thermodynamically stable Imma phase of FeB{sub 2} is predicted at pressure above 225 GPa. • The Imma structure is characterized by a 2D boron network containing puckered graphite-like boron layers. • The band feature of Imma structure favors the occurrence of superconductivity. • The calculated Pugh's ratio suggests that the Imma structure exhibits ductile mechanical property.

Alteration of sensitivity of intratumor quiescent and total cells to γ-rays following thermal neutron irradiation with or without 10B-compound

International Nuclear Information System (INIS)

Masunaga, Shin-ichiro; Ono, Koji; Suzuki, Minoru; Sakurai, Yoshinori; Kobayashi, Tooru; Takagaki, Masao; Kinashi, Yuko; Akaboshi, Mitsuhiko

2000-01-01

Purpose: Changes in the sensitivity of intratumor quiescent (Q) and total cells to γ-rays following thermal neutron irradiation with or without 10 B-compound were examined. Methods and Materials: 5-Bromo-2'-deoxyuridine (BrdU) was injected to SCC VII tumor-bearing mice intraperitoneally 10 times to label all the proliferating (P) tumor cells. As priming irradiation, thermal neutrons alone or thermal neutrons with 10 B-labeled sodium borocaptate (BSH) or dl-p-boronophenylalanine (BPA) were administered. The tumor-bearing mice then received a series of γ-ray radiation doses, 0 through 24 h after the priming irradiation. During this period, no BrdU was administered. Immediately after the second irradiation, the tumors were excised, minced, and trypsinized. Following incubation of tumor cells with cytokinesis blocker, the micronucleus (MN) frequency in cells without BrdU labeling (= Q cells at the time of priming irradiation) was determined using immunofluorescence staining for BrdU. The MN frequency in the total (P + Q) tumor cells was determined from the tumors that were not pretreated with BrdU before the priming irradiation. To determine the BrdU-labeled cell ratios in the tumors at the time of the second irradiation, each group also included mice that were continuously administered BrdU until just before the second irradiation using mini-osmotic pumps which had been implanted subcutaneously 5 days before the priming irradiation. Results: In total cells, during the interval between the two irradiations, the tumor sensitivity to γ-rays relative to that immediately after priming irradiation decreased with the priming irradiation ranking in the following order: thermal neutrons only > thermal neutrons with BSH > thermal neutrons with BPA. In contrast, in Q cells, during that time the sensitivity increased in the following order: thermal neutrons only 10 B-compound, especially BPA, in thermal neutron irradiation causes the recruitment from the Q to P population

Segmentation algorithm for non-stationary compound Poisson processes. With an application to inventory time series of market members in a financial market

Science.gov (United States)

Tóth, B.; Lillo, F.; Farmer, J. D.

2010-11-01

We introduce an algorithm for the segmentation of a class of regime switching processes. The segmentation algorithm is a non parametric statistical method able to identify the regimes (patches) of a time series. The process is composed of consecutive patches of variable length. In each patch the process is described by a stationary compound Poisson process, i.e. a Poisson process where each count is associated with a fluctuating signal. The parameters of the process are different in each patch and therefore the time series is non-stationary. Our method is a generalization of the algorithm introduced by Bernaola-Galván, et al. [Phys. Rev. Lett. 87, 168105 (2001)]. We show that the new algorithm outperforms the original one for regime switching models of compound Poisson processes. As an application we use the algorithm to segment the time series of the inventory of market members of the London Stock Exchange and we observe that our method finds almost three times more patches than the original one.

Neutron diffraction from HoNi₂B₂C

DEFF Research Database (Denmark)

Tomy, C.V.; Chang, L.J.; Paul, D.M.

1995-01-01

RENi(2)B(2)C (RE = rare-earth) are quaternary compounds which exhibit a considerable degree of interaction between their superconducting and magnetic properties. The Ho variant is found to become superconducting at T-c = 9 K, but anomalous behaviour is observed in the low-field magnetic properties...... at T demonstrate that at low temperatures (T

Electronic structure and magnetic properties of the ThCo4B compound

International Nuclear Information System (INIS)

Benea, D.; Pop, V.; Isnard, O.

2008-01-01

Detailed theoretical investigations of the electronic and magnetic properties of the newly discovered ThCo 4 B compound have been performed. The influence of the local environment on the magnitude of the Co magnetic moments is discussed by comparing the magnetic and electronic properties in the ThCo 4 B, YCo 4 B and ThCo 5 systems. All theoretical investigations of the electronic and magnetic properties have been done using the Korringa-Kohn-Rostoker (KKR) band-structure method in the ferromagnetic state. Very good agreement of the calculated and the experimental magnetic moments is obtained. Larger exchange-splitting is observed on the 2c site which carries by far the largest magnetic moment. Comparison of the band structure calculation for ThCo 5 and ThCo 4 B reveals that the presence of boron in the Co 6i site environment induces a broadening of the electronic bands as well as a significant reduction of the exchange-splitting and a diminution of the DOS at the Fermi level. These differences are attributed to the hybridization of the boron electronic states to the cobalt 3d ones. The calculated magnetic moment is 1.94μ B /formula unit. A large difference on the magnetic moment magnitude of the two Co sites is observed since 1.30 and 0.27μ B /atom are calculated for the 2c and 6i sites, respectively. The orbital contribution is found to differ by almost an order of magnitude on both cobalt sites. The Co magnetic moment is much smaller in the ThCo 4 B than in the YCo 4 B or RCo 4 B (where R is a rare earth) isotypes evidencing the major role played by the Th-Co bands on the electronic properties

Peierls-distorted Ru-chains and boron dumbbells in Nb{sub 2}RuB{sub 2} and Ta{sub 2}RuB{sub 2} from first-principles calculations and experiments

Energy Technology Data Exchange (ETDEWEB)

Touzani, Rachid S.; Mbarki, Mohammed; Chen, Ximeng [Institute of Inorganic Chemistry, RWTH Aachen University (Germany); Fokwa, Boniface P.T. [Institute of Inorganic Chemistry, RWTH Aachen University (Germany); Department of Chemistry, University of California Riverside (UCR), Riverside, CA (United States)

2016-09-15

Nb{sub 2}RuB{sub 2} and Ta{sub 2}RuB{sub 2} phases were recently predicted by GGA-VASP structure optimization to crystallize in the Nb{sub 2}OsB{sub 2}-type structure. Although the Fe-based (Mo{sub 2}FeB{sub 2} type) and Os-based (Nb{sub 2}OsB{sub 2} type, superstructure variant of Mo{sub 2}FeB{sub 2} type) analogues have been synthesized and characterized successfully, the Ru-based phases remained unknown. Crystal structure prediction of Nb{sub 2}RuB{sub 2} and Ta{sub 2}RuB{sub 2} phases, using an evolutionary algorithm, led to the AlMn{sub 2}B{sub 2}-type structure in contrast to the aforementioned optimization; however, phonon calculations showed that the Nb{sub 2}OsB{sub 2}-type phases are dynamically more stable than the AlMn{sub 2}B{sub 2}-type phases. A slightly modified synthetic strategy finally led to the successful preparation of the predicted phases. The extremely quick arc-melting procedure, under argon atmosphere, not only led to a quantitative amount of the phases but also to single crystals suitable for structure determination. Powder and single-crystal X-ray diffraction as well as EDX analysis of the metal ratio have confirmed the GGA-VASP structure optimization: Nb{sub 2}RuB{sub 2} and Ta{sub 2}RuB{sub 2} compounds indeed crystallize isotypically with Nb{sub 2}OsB{sub 2} structure, a superstructure variant of Mo{sub 2}FeB{sub 2} type, in which B-dumbbells and Peierls-distorted Ru-chains are found. Susceptibility measurements on a Ta{sub 2}RuB{sub 2} single crystal reveal no superconducting transition down to 2 K, even though some features in the band structures of both phases, similar to those reported in superconducting NbRuB, hinted at possible superconductivity. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Synthesis and crystal structures of 2-methyl-4-aryl-5-oxo-5H-indeno [1,2-b] pyridine carboxylate derivatives

DEFF Research Database (Denmark)

Pandian, Ramesh; Naushad, Edayadulla; Vijayakumar, Vinodhkumar

2014-01-01

pyridine derivatives through oxidation. Consequently, the interest in this aromatization reaction, investigation of a wide range of 1, 4-DHPs continues to attract the attention of researchers. Herein, we report the preparation of pyridine derivatives and the crystal structures determined by X......-ray crystallographic methods.Results: The crystal structures and conformational studies of two organic compounds, namely ethyl 2-methyl-4-phenyl-5-oxo-5H-indeno [1,2-b] pyridine-3-carboxylate (I) and ethyl 2-methyl-4-(4 chlorophenyl)-5-oxo-5H-indeno [1,2-b] pyridine-3-carboxylate (II) are reported. The terminal ethyl......) dimer running along 011 direction.Conclusion: The crystal structures ethyl 2-methyl-4-phenyl-5-oxo-5H-indeno [1,2-b] pyridine-3-carboxylate and ethyl 2-methyl-4-(4 chlorophenyl)-5-oxo-5H-indeno [1,2-b] pyridine-3-carboxylate have been investigated in detail. The terminal ethyl group of compound I...

Standard enthalpies of formation of selected Rh{sub 2}YZ Heusler compounds

Energy Technology Data Exchange (ETDEWEB)

Yin, Ming, E-mail: myin1@hawk.iit.edu; Nash, Philip

2015-11-25

The standard enthalpies of formation (Δ{sub f}H°) of selected ternary Rh-based Rh{sub 2}YZ (Y = Cu, Fe, Mn, Ni, Ru, Ti, V; Z = Al, Ga, In, Si, Ge, Sn) compounds were measured using high temperature direct reaction calorimetry. The measured standard enthalpies of formation (in kJ/mol of atoms) are, for the Heusler compound Rh{sub 2}MnSn (−40.1 ± 3.6), for the B2-structured compounds: Rh{sub 2}FeAl (−48.5 ± 2.9); Rh{sub 2}MnAl (−72.4 ± 2.7); Rh{sub 2}MnGa (−55.3 ± 2.0); Rh{sub 2}MnIn (−35.3 ± 1.9), for the tetragonal compounds: Rh{sub 2}FeSn (−28.9 ± 1.3); Rh{sub 2}TiAl (−97.6 ± 2.2); Rh{sub 2}TiGa (−79.0 ± 1.8); Rh{sub 2}TiSn (−74.7 ± 3.1). Values are compared with those from first principles calculations in published papers and the Open Quantum Materials Database (OQMD). Lattice parameters of these compounds are determined using X-ray diffraction analysis (XRD). Microstructures were characterized using scanning electron microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). - Highlights: • Standard enthalpies of formation of Rh{sub 2}YZ were measured using a drop calorimeter. • Measured enthalpies agree with first principles data in general. • Lattice parameters and related phase relationships were consistent with literature data. • Rh{sub 2}TiSn of tI8 structure were reported for the first time.

Synthesis and evaluation of a series of 2-substituted-5-thiopropylpiperazine (piperidine)-1,3,4-oxadiazoles derivatives as atypical antipsychotics.

Science.gov (United States)

Chen, Yin; Xu, Xiangqing; Liu, Xin; Yu, Minquan; Liu, Bi-Feng; Zhang, Guisen

2012-01-01

It is important to develop novel antipsychotics that can effectively treat schizophrenia with minor side-effects. The aim of our work is to develop novel antipsychotics that act on dopamine D(2) and D(3), serotonin 5-HT(1A) and 5-HT(2A) receptors with low affinity for the serotonin 5-HT(2C) and H(1) receptors, which can effectively cure positive symptoms, negative symptoms and cognitive impairment without the weight gain side-effect. A series of 2-substituted-5-thiopropylpiperazine (piperidine) -1,3,4-oxadiazoles derivatives have been synthesized and the target compounds were evaluated for binding affinities to D(2), 5-HT(1A) and 5-HT(2A) receptors. Preliminary results indicated that compounds 14, 16 and 22 exhibited high affinities to D(2), 5-HT(1A) and 5-HT(2A) receptors among these compounds. Further binding tests showed that compound 22 had high affinity for D(3) receptor, and low affinity for serotonin 5-HT(2C) and H(1) receptors. In addition, compound 22 inhibited apomorphine-induced climbing behavior and MK-801-induced hyperactivity with no extrapyramidal symptoms liability in mice. Moreover, compound 22 exhibited acceptable pharmacokinetic properties. Compound 22 showed an atypical antipsychotic activity without liability for extrapyramidal symptoms. We anticipate compound 22 to be useful for developing a novel class of drug for the treatment of schizophrenia.

75 FR 27956 - Airworthiness Directives; Airbus Model A300 B4-600, B4-600R, and F4-600R Series Airplanes, and...

Science.gov (United States)

2010-05-19

... B4-600, B4-600R, and F4-600R Series Airplanes, and Model C4-605R Variant F Airplanes (Collectively...-203, and B4-203 airplanes; Model A300 B4-601, B4- 603, B4-620, B4-622, B4-605R, B4-622R, F4-605R, F4...

[Chloroquine analogues from benzofuro- and benzothieno[3,2-b]-4-pyridone-2-carboxylic acid esters].

Science.gov (United States)

Gölitzer, K; Meyer, H; Jomaa, H; Wiesner, J

2004-08-01

The amides 7 were synthesized from the annulated methyl 4-pyridone-2-carboxylates 4 via the carboxylic acids 5 and their acid chlorides by reacting with the novaldiamine base 6. The alcohol 8b, obtained from DIBAH reduction of the ester 4b, was transformed to the chloromethyl derivative 9 which reacted with 6 and 18-crown-6 leading to the 2-novaldiaminomethyl-4-pyridone 10. Compound 10 was obtained with higher yield from DIBAH reduction of the amide 7b. The substances 7 and 10 were inactive when tested against the chloroquine resistant Plasmodium falciparum strain Dd2.

Animal experiments and clinical studies on the role of the vitamins B1, B2, and B6 in radiation protection

International Nuclear Information System (INIS)

Schmidt, W.; Wulff, K.; Grimm, U.

1988-01-01

The effects of ionizing radiation on erythrocytic transketolase, glutathion reductase, and aspartate-aminotransferase activities with and without addition of coenzymes were studied in 152 Wistar rats, six beagles, and 225 carcinoma patients, as a measure for vitamin B 1 , B 2 , and B 6 supplies. Examinations of 108 patients with mammary carcinoma and 117 patients with cervical, corpus, and ovarian carcinomas were undertaken prior to, during, and after termination of radiotherapy. Two check-up series were run, the first without vitamin B complex therapy, and the second with three daily applications of one dragee each, beginning on the first day of irradiation. The TPP effects recorded indicated no impairment of vitamin B 1 supply. FAD and PLP effects, on the other hand, were significantly increased, which suggested B 2 and B 6 deficits. Vitamin B 2 metabolism was causally impaired by radiation, while the disordes in vitamin B 6 metabolism were attributed to tumour-related causes. The results obtained revealed that both types of disorders can be avoided by prophylactic vitamin B complex treatment. (author)

Vitamin B6 in Health Supplements and Neuropathy: Case Series Assessment of Spontaneously Reported Cases.

Science.gov (United States)

van Hunsel, Florence; van de Koppel, Sonja; van Puijenbroek, Eugène; Kant, Agnes

2018-05-08

In the literature, vitamin B 6 has been linked to the development of polyneuropathy. Most often, these complaints were seen when taking high doses of vitamin B 6 for a long time. Evidence as to whether a lower dosage range of vitamin B 6 (< 50 mg/day) can also induce neuropathy is scarce. We aim to comprehensively describe the cases of neuropathy associated with vitamin B 6 received by the Netherlands Pharmacovigilance Centre Lareb and to assess the case series concerning the use of vitamin B 6 and neuropathic complaints. We describe the number and nature of the reported cases, including suspect product, dosage, duration of use, and vitamin B 6 serum levels. In addition, we describe the causality for the individual cases (Naranjo Probability Scale) and for the entire case series (Bradford Hill criteria). In total, 90 reports on products containing vitamin B 6 included at least one adverse drug reaction in the standardized Medical Dictionary for Regulatory Activities (MedDRA ® ) query (SMQ; broad) 'peripheral neuropathy'. The amount of vitamin B 6 in the products varied between 1.4 and 100 mg per tablet. The serum vitamin B 6 level was known in 36 cases (88-4338 nmol/l), and the mean serum vitamin B 6 level was 907 nmol/l. However, no statistical correlation between dosage and vitamin B 6 blood levels was found. Causality assessment of the case series of 90 reports to Lareb shows it is plausible for the vitamin B 6 supplements to have caused complaints such as neuropathies. This is especially the case with higher dosages and prolonged use, but dosages < 50 mg/day also cannot be excluded.

New hydride compounds of 1,4-diazabicyclo[2.2.2]octane and its dication with borine and tetrahydridoborate anion and products of their transformations

International Nuclear Information System (INIS)

Shevchenko, Yu.N.; Yashina, N.I.; Markova, O.Z.; Trachevskij, V.V.

1996-01-01

New compounds [dabcoH 2 ](BH 4 ) 2 , dabco(BH 3 ) 2 2H 2 , [dabco(BH 3 ) 2 H 2 ] n have been synthesized by means of interaction between dihydrochloride of 1,4-diazobicyclo[2.2.2] octane (dabco) and NaBH 4 in the medium of nonaqueous solvents (glyme, diglyme, tetrahydrofuran, dimethylsulfoxide) and identified by the methods of element analysis, conductometry, 1 H, 11 B, 14 N NMR, IR spectroscopy and thermal analysis. A mechanism is suggested and the conditions are defined for mutual transformations of the compounds studied. Their ability to bind reversibly molecular hydrogen has been revealed for the first time. 19 refs.; 3 figs.; 1 tab

Quinolactacins A, B and C: novel quinolone compounds from Penicillium sp. EPF-6. II. Physico-chemical properties and structure elucidation.

Science.gov (United States)

Takahashi, S; Kakinuma, N; Iwai, H; Yanagisawa, T; Nagai, K; Suzuki, K; Tokunaga, T; Nakagawa, A

2000-11-01

Three novel quinolone compounds, quinolactacins A (1), B (2) and C (3), have been found from the fermentation broth of Penicillium sp. EPF-6, a fungus isolated from the larvae of mulberry pyralid (Margaronia pyloalis Welker). The molecular formulas of 1, 2 and 3 were determined to be C16H18N2O2, C15H16N2O2 and C16H18N2O3, respectively by FAB-MS and NMR spectral analyses. The structures of these compounds have a novel quinolone skeleton with a gamma-lactam ring consisting of C12H8N2O2 as the common chromophore.

NMR study of Gd2(Co1-xFex)14B compounds

International Nuclear Information System (INIS)

Hayashi, M.; Myojin, T.; Kasamatsu, Y.; Imaeda, Y.; Ushida, T.; Tsujimura, A.; Hihara, T.

1992-01-01

59 Co NMR measurements in Gd 2 (Co 1-x Fe x ) 14 B have been carried out at 4.2 K. The resonance line corresponding to each site of the Co atoms shifts gradually to a higher frequency region as the value of x increases, and when the value exceeds 0.3 the resonance line seems to be disturbed. (orig.)

Synthesis, crystal structure and biological activity of a novel 1,2,3-thidiazole compound

International Nuclear Information System (INIS)

Ke, W.

2013-01-01

A new 1,2,3-thiadiazole compound was synthesized and characterized by 1H NMR, MS and HRMS. The crystal structure of the title compound (C/sub 12/H/sub 11/ClN/sub 2/O/sub 4/S/sub 2/, Mr = 346.80) has been determined by single-crystal X-ray diffraction. The crystal is of triclinic, space group P-1 with a = 8.4425(17) A, b = 8.9801(18) A, c = 9.859(2) A, alpha = 84.36(3) degree, beta = 86.71(3)degree, lambda = 83.25(3) degree, V = 737.9(3)A3, Z 2, F(000) = 356, Dc = 1.561 g/cm/sup 3/, mu = 0.557 mm-1, the final R1 0.0380 and wR2 = 0.0982 for 2160 observed reflections with I > 2sigma(I). A total of 12585 reflections were collected, of which 2601 were independent (Rint 0.0364). The herbicidal activity of title compound was determined, the results showed the title compound displayed excellent herbicidal activity against Brassica campestris. (author)

3-Amino-thieno[2,3-b]pyridines as microtubule-destabilising agents: Molecular modelling and biological evaluation in the sea urchin embryo and human cancer cells.

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Eurtivong, Chatchakorn; Semenov, Victor; Semenova, Marina; Konyushkin, Leonid; Atamanenko, Olga; Reynisson, Jóhannes; Kiselyov, Alex

2017-01-15

A series of 3-amino-thieno[2,3-b]pyridines was prepared and tested in a phenotypic sea urchin embryo assay to identify potent and specific molecules that affect tubulin dynamics. The most active compounds featured a tricyclic core ring system with a fused cycloheptyl or cyclohexyl substituent and unsubstituted or alkyl-substituted phenyl moiety tethered via a carboxamide. Low nano-molar potency was observed in the sea urchin embryos for the most active compounds (1-5) suggestive of a microtubule-destabilising effect. The molecular modelling studies indicated that the tubulin colchicine site is inhibited, which often leads to microtubule-destabilisation in line with the sea urchin embryo results. Finally, the identified hits displayed a robust growth inhibition (GI 50 of 50-250nM) of multidrug-resistant melanoma MDA-MB-435 and breast MDA-MB-468 human cancer cell lines. This work demonstrates that for the thieno[2,3-b]pyridines the most effective mechanism of action is microtubule-destabilisation initiated by binding to the colchicine pocket. Copyright © 2016 Elsevier Ltd. All rights reserved.

Novel maturity parameters for mature to over-mature source rocks and oils based on the distribution of phenanthrene series compounds

Directory of Open Access Journals (Sweden)

Zixiang Wang

2016-03-01

Two additional novel and an optimized maturation parameters based on the distribution of phenanthrene series compounds are proposed and their relationships to EasyRo% (x are established: log(MPs/P = 0.19x + 0.08 (0.9% < EasyRo% < 2.1%; log(MPs/P = 0.64x − 0.86 (2.1% < EasyRo% < 3.4%; log(DMPs/TMPs = 0.71x − 0.55 (0.9% < EasyRo% < 3.4%; log(MTR = 0.84x − 0.75 (0.9% < EasyRo% < 3.4%. These significant positive correlations are strong argument for using log(MPs/P, log(DMPs/TMPs and log(MTR as maturity parameters, especially for mature to over-mature source rocks.

Design and synthesis of novel chalcones as potent selective monoamine oxidase-B inhibitors.

Science.gov (United States)

Hammuda, Arwa; Shalaby, Raed; Rovida, Stefano; Edmondson, Dale E; Binda, Claudia; Khalil, Ashraf

2016-05-23

A novel series of substituted chalcones were designed and synthesized to be evaluated as selective human MAO-B inhibitors. A combination of either methylsulfonyl or trifluoromethyl substituents on the aromatic ketone moiety with a benzodioxol ring on the other end of the chalcone scaffold was investigated. The compounds were tested for their inhibitory activities on both human MAO-A and B. All compounds appeared to be selective MAO-B inhibitors with Ki values in the micromolar to submicromolar range. Molecular modeling studies have been performed to get insight into the binding mode of the synthesized compounds to human MAO-B active site. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Synthesis of Symmetrical and Asymmetrical Azines Encompassing Naphtho[2,1-b]furan by a Novel Approach

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K. Veena

2011-01-01

Full Text Available The starting material 3-nitro-2-acetylnaphtho[2,1-b]furan (2 was obtained by nitration of 2-acetylnaphtho[2,1-b] furan (1, under mild condition. The compound 1 was synthesized by the reaction of 2-hydroxy-1-naphthaldehyde with chloroacetone, where in both condensation and cyclization took place in single step. The reaction of 3-nitro-2-acetylnaphtho[2,1-b]furan (2 with hydrazine hydrate produced corresponding hydrazone (3 in excellent yield, which on treatment with various aromatic aldehydes under different reaction conditions resulted in the formation of symmetrical azines (4a-e and unsymmetrical azines (5a-e. All the newly synthesized compounds have been characterized by analytical and spectral studies and were screened for antibacterial antibacterial activity against Bacillus subtilus and Alcaligenes fecalies and antifungal activity against Aspergillus nidulans, Aspergillus parasiticus and Aspergillus terrus. The Second Harmonic Generation (SHG efficiency of some of the synthesized compounds was measured by powder technique using Nd:YAG laser.

Reduced binding of Pittsburgh Compound-B in areas of white matter hyperintensities

Directory of Open Access Journals (Sweden)

A.E. Goodheart

2015-01-01

Full Text Available The amyloid imaging agent, Pittsburgh Compound-B, binds with high affinity to β-amyloid (Aβ in the brain, and it is well established that PiB also shows non-specific retention in white matter (WM. However, little is known about retention of PiB in areas of white matter hyperintensities (WMH, abnormalities commonly seen in older adults. Further, it is hypothesized that WMH are related to both cognitive dysfunction and Aβ deposition. The goal of the present study was to explore PiB retention in both normal-appearing WM (NAWM and WMH in a group of elderly, cognitively normal individuals. In a group of cognitively normal elderly (n = 64; 86.5 ± 2.6 years two analyses were applied: (1 ROIs were placed over periventricular areas in which WMH caps are commonly seen on all subjects, regardless of WMH burden or size. (2 Subject-specific maps of NAWM and WMH were co-registered with the PiB-PET images and mean SUVR values were calculated in these NAWM and WMH maps. PiB retention was significantly reduced in the ROIs of subjects with high WMH compared to subjects with low WMH. Additionally, in subjects with high WMH, there was significantly lower PiB retention in subject-specific maps of WMH compared to NAWM, which was not observed in subjects with low WMH, likely because of the small size of WMH maps in this group. These data suggest that WM in areas of WMH binds PiB less effectively than does normal WM. Further exploration of this phenomenon may lead to insights about the molecular basis of the non-specific retention of amyloid tracers in white matter.

Passive sampling as a tool for identifying micro-organic compounds in groundwater.

Science.gov (United States)

Mali, N; Cerar, S; Koroša, A; Auersperger, P

2017-09-01

The paper presents the use of a simple and cost efficient passive sampling device with integrated active carbon with which to test the possibility of determining the presence of micro-organic compounds (MOs) in groundwater and identifying the potential source of pollution as well as the seasonal variability of contamination. Advantage of the passive sampler is to cover a long sampling period by integrating the pollutant concentration over time, and the consequently analytical costs over the monitoring period can be reduced substantially. Passive samplers were installed in 15 boreholes in the Maribor City area in Slovenia, with two sampling campaigns covered a period about one year. At all sampling sites in the first series a total of 103 compounds were detected, and 144 in the second series. Of all detected compounds the 53 most frequently detected were selected for further analysis. These were classified into eight groups based on the type of their source: Pesticides, Halogenated solvents, Non-halogenated solvents, Domestic and personal, Plasticizers and additives, Other industrial, Sterols and Natural compounds. The most frequently detected MO compounds in groundwater were tetrachloroethene and trichloroethene from the Halogenated solvents group. The most frequently detected among the compound's groups were pesticides. Analysis of frequency also showed significant differences between the two sampling series, with less frequent detections in the summer series. For the analysis to determine the origin of contamination three groups of compounds were determined according to type of use: agriculture, urban and industry. Frequency of detection indicates mixed land use in the recharge areas of sampling sites, which makes it difficult to specify the dominant origin of the compound. Passive sampling has proved to be useful tool with which to identify MOs in groundwater and for assessing groundwater quality. Copyright © 2017 Elsevier B.V. All rights reserved.

Magnetic properties of the compound Zn(Mnsub(0.98)Fesub(0.02)2O4

International Nuclear Information System (INIS)

Wautelet, M.; Gerard, A.

1975-01-01

Moessbauer spectra were measured of the compound Zn(Mnsub(0.98)Fesub(0.02)) 2 O 4 at several temperatures between 4.2 and 77 K. Evaluation of the spectra showed that the Neel temperature of ZnMn 2 O 4 does not exceed 50 K; the magnetic structure seems to be the same as that of Mn 3 O 4 with predominant B-B interactions. (A.K.)

Synthesis and biological characterization of (3R,4R)-4-(2-(benzhydryloxy)ethyl)-1-((R)-2-hydroxy-2-phenylethyl)-piperidin-3-ol and its stereoisomers for activity toward monoamine transporters.

Science.gov (United States)

Kharkar, Prashant S; Batman, Angela M; Zhen, Juan; Beardsley, Patrick M; Reith, Maarten E A; Dutta, Aloke K

2009-07-01

A novel series of optically active molecules based on a 4-(2-(benzhydryloxy)ethyl)-1-((R)-2-hydroxy-2-phenylethyl)-piperidin-3-ol template were developed. Depending on stereochemistry, the compounds exhibit various degrees of affinity for three dopamine, serotonin, and norepinephrine transporters. These molecules have the potential for treating several neurological disorders such as drug abuse, depression, and attention deficit hyperactivity disorder.Herein we describe the synthesis and biological evaluation of a series of asymmetric 4-(2-(benzhydryloxy)ethyl)-1-((R)-2-hydroxy-2-phenylethyl)-piperidin-3-ol-based dihydroxy compounds in which the hydroxy groups are located on both the piperidine ring and the N-phenylethyl side chain. In vitro uptake inhibition data of these molecules indicate high affinity for the dopamine transporter (DAT) in addition to moderate to high affinity for the norepinephrine transporter (NET). Interestingly, compounds 9 b and 9 d exhibit affinities for all three monoamine transporters, with highest potency at DAT and NET, and moderate potency at the serotonin transporter (SERT) (K(i): 2.29, 78.4, and 155 nM for 9 b and 1.55, 14.1, and 259 nM for 9 d, respectively). Selected compounds 9 a, 9 d, and 9 d' were tested for their locomotor activity effects in mice and for their ability to occasion the cocaine-discriminative stimulus in rats. These test compounds generally exhibit a much longer duration of action than cocaine for elevating locomotor activity, and completely generalize the cocaine-discriminative stimulus in a dose-dependent manner.