bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of a discrete semi-Markov model of continuous inventory control with periodic interruptions of consumption
Authors: Shnurkov Petr V. , Ivanov Alexey V. 
Published: February 2015

AbstractWe consider a discrete stochastic model of inventory control based on a controlled semi-Markov process. Probabilistic characteristics of the semi-Markov process are found along with characteristics of a stationary cost functional connected with this process. It is proved that an optimal policy of inventory control is a deterministic one. Explicit analitical representation of stationary functional characterising the control quality is obtained. An optimal control problem is reduced to the solution of an extremal problem for a multivariate function.
N-(4-Arylpiperazinoalkyl)acetamide derivatives of 1,3- and 3,7-dimethyl-1H-purine-2,6(3H,7H)-diones and their 5-HT6, 5-HT7, and D2 receptors affinity
Authors: Żmudzki Paweł , Satała Grzegorz , Chłoń-Rzepa Grażyna , Bojarski Andrzej J. , Popik Piotr , Zajdel Paweł 
Published: February 2015

Abstract
A series of N-(arylpiperazinyl)acetamide derivatives of 1,3- and 3,7-dimethyl-1H-purine-2,6(3H,7H)-dione was synthesized and biologically evaluated in in vitro competition binding experiments for serotonin 5-HT6, 5-HT7, and dopamine D2 receptors. The structure-affinity relationships for this group of compounds allowed for determination of structural features responsible for receptor affinity. Among the investigated derivatives, compounds 5 and 12 with (2,3-dichlorophenyl)piperazine moiety were classified as potent dual 5-HT6/D2 receptors ligands, whereas compound 4, with 4-(benzo[d]isothiazol-3-yl)piperazine moiety, and compounds 8 and 15, with (2,3-dichlorophenyl)piperazine moiety, were classified as potent D2 receptor ligands.
Efficient synthesis of 6-amino-2-thiaspiro[3,3]heptane hydrochloride
Authors: Lu Yan , Wang Jin , Guo Jianyu , Tang Yihong , Zhang Suxia , Tao Jianwei , Xiong Lei , Li Xiujie , Luo Jingyi 
Published: February 2015

Abstract
A novel compound 6-amino-2-thiaspiro[3,3]heptane hydrochloride was synthesized in nine steps using 2,2-bis(bromomethyl)-1,3-propanediol as starting material, with an overall yield of 31%.
Dispersion of Particles in the Emulsion by the Electric Current
Authors: Sizonenko O.N. , Raichenko A.I. , Torpakov A.S. , Derevianko A.V. 
Published: February 2015

AbstractPossible mechanisms of metal micropowders grinding during high-voltage electric discharge processing in hydrocarbon liquid are considered in the present paper. Conditions for melting of Fe and Ti powder particles in plasma discharge channel and in microplasma channels between particles are found out. Regularities of nanopores movement and electromagnetic particle compression are evaluated. It is shown that the current density in the discharge channel is an important parameter, allowing the assessment of the efficiency of the electrodischarge dispersion of metal particles.
Robust Bayesian Sensitivity Analysis for Case–Control Studies with Uncertain Exposure Misclassification Probabilities
Authors: Mak Timothy Shin Heng , Best Nicky , Rushton Lesley 
Published: February 2015

AbstractExposure misclassification in case–control studies leads to bias in odds ratio estimates. There has been considerable interest recently to account for misclassification in estimation so as to adjust for bias as well as more accurately quantify uncertainty. These methods require users to elicit suitable values or prior distributions for the misclassification probabilities. In the event where exposure misclassification is highly uncertain, these methods are of limited use, because the resulting posterior uncertainty intervals tend to be too wide to be informative. Posterior inference also becomes very dependent on the subjectively elicited prior distribution. In this paper, we propose an alternative “robust Bayesian” approach, where instead of eliciting prior distributions for the misclassification probabilities, a feasible region is given. The extrema of posterior inference within the region are sought using an inequality constrained optimization algorithm. This method enables sensitivity analyses to be conducted in a useful way as we do not need to restrict all of our unknown parameters to fixed values, but can instead consider ranges of values at a time.
An extremal shift method for control of HIV infection dynamics
Authors: Bocharov Gennady , Kim Arkady , Krasovskii Andrey , Chereshnev Valery , Glushenkova Vera , Ivanov Alexey 
Published: February 2015

AbstractOptimal control problems for mathematical models describing HIV infection dynamics in a human body are considered in the paper. An overview of current approaches to solution of control problems for models of HIV dynamics is presented for techniques related to construction of optimal programme (open loop) or positional (feedback) controls for various criteria of control process quality and is based on the Pontryagin’s maximum principle and the Bellman’s theory of dynamic programming, respectively. In the framework of the theory of positional differential games of Krasovskii, there are constructive and efficient methods of synthesis of controls for different classes of dynamical systems. In this paper we present a formalization of a control problem for HIV infection considered as a corresponding positional differential game. The control algorithm based on the method of extremal shift is applied to the ODEs model of HIV infection. The numerical implementation of the extremal shift method is developed to construct the control taking the system to a neighbourhood of a given trajectory using the information on the dynamics of the guides or leaders.
Bis-und Tris[μ-nitrido-bis(diorganylphoshinato-O,O′)]- element( 1+)-Kationen / Bis- and Tris[μ-nitrido-bis(diorganylphosphinato-O,O′)]-element(1+) Cations
Authors: Jirjahn Burkhard , Hildebrandt Henry , Heller Gert 
Published: February 2015

The following compounds have been prepared and characterized by crystal structure analyses:
Two modifications of bis[μ-nitrido-bis(diphenylphosphinato-O,O′)]boronium (1+) triiodide (A and B): A (monoclinic, P21/c; a = 1908.8, b = 1652.7, and c = 1719.4 pm; β = 109.54°; Z = 4; = 10.3%) and B (triclinic, P 1̄, a = 981.8, b = 1148.9, and c = 2353.7 pm; α = 80,91°, β = 81.09°, γ = 74.58°, Z = 2, wR = 7.4%).
Tris[μ-nitrido-bis(diphenylphosphinato-O,O′)]aluminium( 1 +) triiodide (C) and tris[μ-imidobis(diphenylphosphinato-O,O′)]aluminium (1+)bis(hydrogenphosphate) dioxane adduct (D): C (monoclinic, P21/n ,a = 1332.4, b = 4087.6, an d c = 1368.1 pm; β = 93.17°; Z = 4; R = 10.4%) and D (orthorhombic, Pc21b, a = 1798.7, b = 2151.1, and c = 1948.7 pm; Z = 4; R = 12,8%).
Two modifications of tris[μ-nitrido-bis(diphenylphosphinato-O,O′)]stannium (1+) perchlorate (E and F): E (triclinic, P 1̄, a = 1468.7, b = 1480.2, and c = 1629.8 pm; α = 99.75°, β = 90.77°, and γ = 92,65°, Z = 2, wR = 6,0%) and F (hexagonal, a = 1224 and c = 2110 pm). Bis[μ-nitridobis(diethylphosphinato-O,O′)]boronium (1+) triiodide has been characterized by IR, FIR, 1H - and 31P NMR, as well as by mass spectra
Structure and Magnetic Properties of a Dinuclear Copper(II) Complex
Authors: Elmali Ayhan , Elerman Yalcin , Svoboda Ingrid , Fuess Hartmut , Griesar Klaus , Haase Wolfgang 
Published: February 2015

Abstract
[Cu2L] (L=N-2-hydroxy-4-methylphenyl-4-oxo-2-pentalketimine) was synthesized and its crystal structure determined. C24H26Cu2N2O4 monoclinic space group P21/n with a= 10.978(2), 17.045(3), c= 11.958(2) Å, β = 101.89(1)°, V = 2189.6(7) Å3,Z = 4. Two copper(II) atoms in a distorted square-planar coordination are bridged by two oxygen atoms to form a dinuclear unit. The copper(II) centers are separated by 3.025(1) Å and antiferromagnetically coupled (J =-222.3 cm-1 ), which follows from temperature-dependent magnetic susceptibility measurements in the range 4.2 to 300 K.
Über die Reaktion von SbPh3 mit S3N2Cl2 Kristallstrukturen von [xxx] und [(Ph3SbCl2)2·S4N4]/ On the Reaction of SbPh3 with S3N2Cl2. Crystal Structures of [xxx] and [(Ph3SbCl2)2· S4N4]
Authors: Kunkel Frank , Harms Klaus , Kang Hak-Chul , Massa Werner , Dehnicke Kurt 
Published: February 2015

Abstract
Triphenylantimony reacts with S3N2Cl2 in dichloromethane solution to give yellow crystals of the cyclostibathiazene derivative [xxx], As a by-product orange single crystals of [(Ph3SbCl2)2·S4N4] were isolated, in which the molecular compounds Ph3SbCl2 and S4N4 only form van der Waals contacts with one another. Both compounds are characterized by crystal structure determinations.
[xxx]: Space group P21/n, Z = 4; lattice dimensions at -80°C: a = 759.4(1), b = 1448.5(3); c = 1557.6(2) pm; β = 91.09(1)°, R = 0.026. The complex has a molecular structure in which the Sb atom is coordinate in a distorted trigonal-bipyramidal fashion with one phenyl group and one of the nitrogen atoms of the planar [xxx] ring in the apical positions.
[(Ph3SbCL)2·S4N4]: Space group C2/c, Z = 8 ; lattice dimensions at -60°C: a = 1549.3(1), b = 1017.7(1), c = 2623.9(1) pm, β = 105.56(2)°, R = 0.050.
2-(Diphenylphosphino)-pyridine as an Ambidentate Ligand in Homo-and Hetero-binuclear Complexes of Copper, Silver, and Gold
Authors: Olmos M. Elena , Schier Annette , Schmidbaur Hubert 
Published: February 2015

Abstract
The reaction of 2-diphenylphosphino-pyridine (1) with AgBF4 in an equimolar ratio affords the cyclic, dinuclear complex 2 with mixed P,N-coordination of the metal atoms. With two equivalents of 1 the 2:1 complexes 4a,b are formed which have the metal atoms solely Pcoordinated. The previously reported gold complex (3), an analogue of 2, or [Au(tht)2]ClO4 (tht = tetrahydrothiophen) also give the 2:1 complexes (5a,b) when treated with an excess of ligand 1. Addition of AgClO4 to a solution of 5a in acetone, or treatment of 4a with [Au(tht)2]ClO4 in dichloromethane, give the same mixed-metal complex 6, where the Au atoms are exclusively P-coordinated, while the Ag atoms are coordinated by the two pyridine nitrogen atoms. In the crystal there are also weak interactions of the perchlorate counterions with the silver atom. Addition of [Cu(MeCN)4]BF4 to compound 5b gives the Cu/Au-complex with P,P-coordinated gold and N,N-bonded copper centers. All products were characterized by standard analytical and spectroscopic techniques; the crystal structure of complex 6 was determined in a single crystal X-ray diffraction study.
Gold(I) Complexes of Open-chain and Cyclic Di-secondary Amines
Authors: López-de-Luzuriaga José M. , Söldner Marcus , Schier Annette , Schmidbaur Hubert 
Published: February 2015

Abstract
Treatment of N,N′-diisopropyl-ethylenediamine or 1,4-piperazine with two equivalents of [(Ph3P)Au]+ BF4
- leads to binuclear complexes of the diamines:
{[(Ph3P)Au]HN(iPro)NCH2-}2
2+ 2 BF4
- (1) and {[(Ph3P)Au]HNCH2CH2}2
2+ 2 BF4
- (2), respectively. In the products each quaternary ammonium center bears one gold ligand, one hydrogen atom and two alkyl substituents. The crystal structures of both compounds have been determined. Compound 1 contains discrete ion-triples. The ethylene bridge in the dications is in an unfolded conformation, with a crystallographic center of inversion, and allows for weak hydrogen bonding N-H--F [2.085 Å; N-H--F 169.2°] between the NH functions and the counterions. The existing distant contacts F--Au [3.599 Å] are probably less significant for the aggregation of the ion triples, but will contribute through Coulomb forces. Compound 2 crystallizes with two solvent molecules CH2CI2. The dication has a crystallographic center of inversion with the piperazine ring in a chair conformation and the gold atoms in equatorial positions. There are hydrogen bonds N-H--F [2.076 and 2.457 Å] between the dication and the anions which lead to the formation of ion-triples, with further contacts between the BF4
- anions and the solvent molecules [C-H--F 2.340 and 2.446 Å].
Photoreactivity of Coordinated Phenylhydrazine. Intraligand Excitation of ReCl(CO)3(PhNH-NH2)2
Authors: Kunkely Horst , Vogler Amd 
Published: February 2015

Abstract
The complex of ReCl(CO)3(PhNH-NH2)2 shows an absorption band at λmax = 272 nm which is assigned to an IL (intraligand) transition of the coordinated phenylhydrazine. Upon IL excitation the complex undergoes a decomposition with ϕ = 0.03 at λirr = 280 nm.
Zinn(IV)-Komplexe mit diaciden Azo(hydrazono)verbindungen. Kristallstruktur von Bis[4-(2′-hydroxyphenylazo)-3-methyl-lphenyl- pyrazol-5-onato(2-)]zinn(IV)/ Tin(IV) Complexes with Diacidic Azo(hydrazono) Compounds. Crystal Structure of Bis[4-(2′-hydroxyphenylazo)-3-methyl-l-phenyl-pyrazol-5-onato(2-)]tin(IV)
Authors: Banße Wolfgang , Jäger Norbert , Ludwig Eberhard , Schilde Uwe , Uhlemann Erhard , Lehmann Andreas , Mehner Hartmut 
Published: February 2015

Abstract
Tin(IV) complexes of diacidic azo and hydrazono compounds were synthesized by the reaction of these ligands with SnCl2acac2 and SnCl2 · 2H2O , respectively. The complexes were further characterized by Mössbauer spectroscopy.
For bis[4-(2′-hydroxyphenylazo)-3-methyl-l-phenyl-pyrazol-5-onato(2-)]tin(IV) force field calculations have been performed and the crystal structure was determined by X-ray analysis.
Synthesen, Kristallstrukturen und Eigenschaften von Trisilber-und Trikalium-tri-μ-imido-cyclotriphosphat, Ag3(PO2NH)3 und K3(PO2NH)3 / Syntheses, Crystal Structures, and Properties of Trisilver and Tripotassium Tri-μ-im ido Cyclotriphosphate, Ag3(PO2NH)3 and K3(PO2NH)3
Authors: Stock N. , Schnick W. 
Published: February 2015

Abstract
Coarse crystalline Ag3(PO2NH)3 (1) and K3(PO2NH)3 (2) are obtained by addition of an aqueous solution of AgNO3 to an acidified solution of Na3(PO2NH)3 · 4H2O and by diffusion controlled addition of ethanol to a solution of K3(PO2NH)3 in water, respectively. The crystal structures of 1 and 2 have been determined by single crystal X-ray methods (Ag3(PO2NH)3: P21/c; a = 1166.6(1), b = 786.4(1), c = 997.8(1) pm, β = 106.91(1)°; Z = 4. K3(PO2NH)3: R3̄; a = 1271.4(2), c = 1017.9(2) pm, Z = 6). In Ag3(PO2NH)3 the cyclic anion is markedly distorted because of interactions between Ag+ and one nitrogen atom of the anion. In K3(PO2NH)3 the trimetaphosphimate ring shows a chair conformation and two cyclic anions are connected to each other by hydrogen bonds. DTA/TG investigations show thermal decomposition above 275 and 250 °C for 1 and 2, respectively.
Kristallstruktur von Bromnitrat BrONO2 / Crystal Structure of Bromine Nitrate BrONO2
Authors: Minkwitz Rolf , Hertel Thomas 
Published: February 2015

Abstract
The crystal structure of bromine nitrate BrONO2 has been determined on a single crystal with MoKα radiation at -83°C. The structure is orthorhombic, space group P212121, Z = 4, and the cell dimensions are a = 403.2(2), b = 684.9(4), c = 1201.4(5) pm. An intermolecular Br.....O contact leads to the formation of chains within the crystal. Attempts to synthesize a bromine(III)-nitrate by oxidizing CF3Br and CF3Br with ClONO2 were not successful.
Prediction of Dissociation Constants of Ammonium Ion in 20 Mass % Ethanol + Water Mixed Solvent Solutions Containing Sodium Chloride
Authors: Maeda Masunobu , Iwata Chisako 
Published: February 2015

Abstract
Dissociation constants of amonium ion (Ka= [H +][NH3]/[NH4+], where [ ] denotes the con­centration) in 20 mass % ethanol + water mixtures with different concentrations of sodium chloride were determined by means of a glass electrode. The dissociation constants in pKa units (on molarity and molality bases) increase linearly with increasing ionic strength. Activ­ity coefficients of ammonia in the ethanol + water mixtures were determined by a transpiration method. The observed dissociation constants on the molality scale were compared with those calculated from the Pitzer equations modified on the basis of the principles of corre­sponding states. The observed values agreed with the calculated ones almost within experi­mental uncertainties.
ab initio MO Optimization of Molecular Structures of Fluoro- and Chloro-Substituted Dibenzo-p-dioxines and the Effect of Halogen Substitution at the 2,3,7,8-Positions on Metabolic Attack
Authors: Weber Roland , Kühn Till , Hagenmaier Hanspaul , Häfelinger Günter 
Published: February 2015

Full ab initio optimizations were performed on the molecular structures of 24 fluorinated and chlorinated dibenzodioxines (PFDD/PCDD ) and dibenzofurans (PFDF/PCDF). Reasonable agreement was found by comparing the geometries of four calculated structures with known X-ray data from the literature. For the fluorine substituent, calculated electron densities (Mulliken total charges and π-electron charges) clearly demonstrate the opposite influence of the inductive (I) and mesomeric (M) effect. The changes in π-densities at carbons in ortho-, meta- and para-position are constant for each fluorine substituent (independent of degree, pattern, and position of substitution). It is thus possible to calculate the π-densities of the substituted dioxines by increments starting from dibenzodioxine. π-Charges from quantum mechanical calculations and the increment system show good agreement even for OctaFDD (O8FDD ), where eight substituent effects are acting additively. Compared with fluorine, the chlorine substituent exercises a smaller -I-effect and a clearly weaker +M-effect.
The HOMO coefficients of the unsubstituted dibenzodioxine and dibenzofuran, extracted from ab initio calculations, yield a good explanation for the observed regioselective metabolic attack at the 2,3,7,8-positions. The squares of the HOMO-coefficients of the 2,3,7,8-positions in dibenzodioxine (DD ) are about ten times greater than those of the 1,4,6,9-positions. These HOMO coefficients are practically unaffected by halide substitution. But halogen substitution reduces strongly the electron density at the halogen-bound carbon, which, however, is a necessary prerequisite for the electrophilic oxygen transfer during metabolism. One would therefore expect halogen substitution of dibenzodioxine and dibenzofuran (DF) at the 2,3,7,8-position to hinder metabolism, as is indeed found. This provides a plausible explanation for the highly selective tissue retention of 2,3,7,8-substituted PCDDs and PCDFs.
Our ab initio calculations of five tetra CDDs (T4CDDs) confirm the postulate of Kobayashi et al. [1 ] who, using semiempirical calculations, found a correlation between the toxicity of a dioxine congener and its absolute molecular hardness. The 2,3,7,8-T4CDD also exhibits the smallest absolute hardness (derived from the HOMO-LUMO energy gap) in our calculations.
Metall(II)-Diazin Komplexe: Kristallstrukturen von Cd(pyrazin)Br2, Cd(pyrazin)I2, Cu(pyrazin)Cl2 und Cd(pyrimidin)(NO3)2·2H2O/ Metal(II) Diazine Complexes: Crystal Structures of Cd(pyrazine)Br2, Cd(pyrazine)I2, Cu(pyrazine)Cl2, and Cd(pyrimidine)(NO3)2·2H2O.
Authors: Pickardt Joachim , Staub Benedikt 
Published: February 2015

Abstract
Single crystals of the compounds Cd(pyrazine)Br2, Cd(pyrazine)I2, Cu(pyrazine)Cl2 and Cd(pyrimidine)(NO3)2·2H2O were obtained by crystallisation from aqueous solutions of the metal salts and solutions of the respective diazine in an organic solvent.
The structures of the pyrazine complexes consist of “supramolecular” networks of -M-pyrazine-M-and -M -(μ2-Hal)2-M-chains. The pyrimidine complex shows a three dimensional network due to -M-pyrimidine-M-chains connected via hydrogen bonds between H(H2O) and O(ONO2).
Quaternary Equiatomic Compounds LnZnSbO (Ln = La - Nd, Sm) with ZrCuSiAs-Type Structure
Authors: Wollesen Petra , Kaiser Joachim W. , Jeitschko Wolfgang 
Published: February 2015

Abstract
The five compounds LnZnSbO (Ln = La - Nd, Sm) were prepared by annealing cold-pressed pellets of the lanthanoids, zinc oxide, and antimony, or by reacting these components in a NaCl/KCl flux. They crystallize with the tetragonal ZrCuSiAs type structure, which was refined from single-crystal X-ray data of CeZnSbO : P 4/nmm, a = 419.76(4), c = 947.4(1) pm, Z = 2, R = 0.022 for 165 structure factors and 12 variable parameters. Chemical bonding in this and the formally isotypic compound CeZn1-xSb2 is briefly discussed.
Physiological Significance of Overproduced Carotenoids in Transformants of the Cyanobacterium Synechococcus PCC7942
Authors: Karapetyan Navassard V. , Windhövel Ute , Holzwarth Alfred R. , Böger Peter 
Published: February 2015

Abstract
The functional location of carotenoids in the photosynthetic apparatus of -crtB and -pys transformants of the cyanobacterium Synechococcus PCC7942 was studied and compared with a control strain -pFP 1-3. These transformants overproduce carotenoids due to the insertion of an additional foreign phytoene synthase gene. A higher carotenoid content was found for -crtB and -pys transformants both in whole cells and isolated membranes; the -crtB transformant was also enriched with chlorophyll. 77-K fluorescence emission and excitation spectra of the phycobilin-free membranes were examined for a possible location of overproduced carotenoids in pigment-protein complexes in situ. A similar ratio of the amplitudes of fluorescence bands at 716 and 695 nm emitted by photosystems I and II, found for the three strains, indicates that the stoichiometry between photosystems of the transformants was not changed. Overproduced carotenoids are not located in the core antenna of photosys­ tem I, since 77-K fluorescence excitation spectra for photosystem I of isolated membranes from the studied strains do not differ in the region of carotenoid absorption. When illuminated with light of the same intensity but different quality, absorbed preferentially by either carotenoids, chlorophylls or phycobilins, respectively, oxygen evolution was found always higher in the transformants -crtB and -pys than in -pFP 1-3 control cells. Identical kinetics of fluorescence induction of all strains under carotenoid excitation did not reveal a higher activity of photosystem II in cells enriched with carotenoids. It is suggested that overproduced carotenoids of the transformants are not involved in photosynthetic light-harvesting; rather they may serve to protect the cells and its membranes against photodestruction.
Mitogen-Activated Protein Kinase and Cell Cycle Progression During Mouse Egg Activation Induced by Various Stimuli
Authors: Sun Q. Y. , Lax Y. , Rubinstein S. , Chen D. Y. , Breitbart H. 
Published: February 2015

Abstract
A very sensitive method was established for detecting the activity of mitogen-activated protein (MAP) kinase in mouse eggs, and used to follow temporal changes of this kinase during fertilization and sponatenous or chemically-induced parthenogenic activation. MAP kinase activity increased between 1 and 2.5 h post-insemination, at which time the second polar body was emitted and sperm chromatin was dispersed; its activity decreased sharply at 8 h, when pronuclei were formed. Both calcium ionophore A23187 and ethanol simulta­ neously induced pronuclear formation and MAP kinase inactivation in aged eggs 8 h after incubation but less effectively in fresh eggs. The protein kinase inhibitor staurosporine in­duced pronuclear formation and MAP kinase inactivation more quickly than other treat­ ments, with MAP kinase inactivation occurring slightly proceeding pronuclear formation. Okadaic acid, a specific inhibitor of protein phosphatase 1 and 2A , induced increase in MAP kinase activity, and overcame pronuclear formation induced by various stimuli. MAP kinase inactivation preceded pronuclear formation in eggs spontaneously activated by aging in vitro, perhaps due to cytoplasmic degeneration and thus delayed response of nuclear envelope precursors to MAP kinase inactivation. These data suggest that MAP kinase is a key protein kinase regulating the events of mouse egg activation. Increased MAP kinase activity is temporally correlated with the second polar body emission and sperm chromatin decondensation. Although different stimuli (including sperm) may initially act through different mechanisms, they finally inactivate MAP kinase, probably by allowing the action of protein phosphatase, and thus induces the transition to interphase.