bluuebunny/crossref_metadata_2025_split huggingface dataset:
Luminescence and laser Raman studies on gamma‐irradiated RbI:Sm3+ crystals
Authors: Manimozhi P. K. , Muralidharan G. 
Published: August 2007

AbstractThis paper reports results of the photoluminescence (PL), thermoluminescence (TL) optical absorption and laser Raman scattering (LRS) studies on RbI:Sm3+ crystals. Sm when doped in the RbI crystals is found to enter in the trivalent state. Interestingly, it is found that the samarium ions act as electron traps and as electron donors as well on gamma irradiation. TL emission studies confirm this interesting be‐havior. The PL spectrum exhibits the characteristic red/orange emission of the Sm ions corresponding to 4G5/2 → 6H9/2 (red) and 4G5/2 → 6H7/2 (orange) transitions. The TL glow indicates that the process is due to two different kinds of traps. Z3 centers are observed on optical treatment and a TL glow peak attributable to them is identified. Aggregation of V centers during the TL process is observed. Laser Raman scattering (LRS) of gamma‐irradiated crystals contains two lines at 111 cm–1 and at 150 cm–1 attributable to I–3 (ions). On prolonged irradiation to γ‐rays, RbI:Sm3+ crystals exhibit a strong line at 180 cm–1, which is attributable to I–5 (ions). TL emission spectra contain the Sm3+ emissions. From PSL and TL emission studies, the TL process is identified to be due to the thermal release of F electrons and their recombination with their counterparts. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Study of molecular dynamics and phase transitions in trimethylammonium trichlorogermanate using 1H NMR and DSC measurements
Authors: Mallikarjunaiah K. J. , Ramesh K. P. , Damle R. 
Published: August 2007

Abstract(CH3)3NHGeCl3 is prepared, characterized and studied by 1H NMR and differential scanning calorimetry to understand the molecular dynamics and phase transitions. The proton spin lattice relaxation time (T1) is measured at 20.53 MHz in the temperature range 391–5.2 K employing a home‐made pulsed NMR spectrometer. The T1 results show that (CH3)3NHGeCl3 undergoes several phase transitions in the temperature range 391–50 K. Both T1 data and DSC thermograms support the occurrence of phase transitions at 272 K and around 323 K. T1 data are analyzed in three temperature regions using standard models. The T1 variations in the intermediate temperature region 272–100 K are attributed to the hindered reorientations of symmetric groups (CH3 and (CH3)3NH). A broad asymmetric T1 minimum in the temperature region 45–20 K is attributed to quantum rotational tunneling of the methyl groups. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Dielectric nonlinear properties of pyridinium tetrafluoroborate single crystal near the ferroelectric phase transition
Authors: Jamiński J. , Czapla Z. , Dacko S. , Cach R. 
Published: August 2007

AbstractPyridinium tetrafluoroborate (PyBF4) single crystals have been grown and their dielectric properties around the ferroelectric phase transition at 237.3 K were studied. The electric permittivity was measured as a function of temperature as the dc electric field ranged between 0 and 1100 kV/m. The electric permittivity was also measured at constant temperature as a function of the electric field intensity, which was changed slowly in the range 0–650 kV/m. Detailed measurements of spontaneous polarization were done by means of a Sawyer–Tower circuit and a pyroelectric method. The results of the experimental studies were analyzed in the framework of the classical dielectric state equation and the nonlinearity coefficient B was estimated. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The difficult and ubiquitous problems of multiplicities
Authors: Berry Donald A. 
Published: August 2007

AbstractMultiplicities are ubiquitous. They threaten every inference in every aspect of life. Despite the focus in statistics on multiplicities, statisticians underestimate their importance. One reason is that the focus is on methodology for known multiplicities. Silent multiplicities are much more important and they are insidious. Both frequentists and Bayesians have important contributions to make regarding problems of multiplicities. But neither group has an inside track. Frequentists and Bayesians working together is a promising way of making inroads into this knotty set of problems. Two experiments with identical results may well lead to very different statistical conclusions. So we will never be able to use a software package with default settings to resolve all problems of multiplicities. Every problem has unique aspects. And all problems require understanding the substantive area of application. Copyright © 2007 John Wiley & Sons, Ltd.
Combiningp‐values in large‐scale genomics experiments
Authors: Zaykin Dmitri V. , Zhivotovsky Lev A. , Czika Wendy , Shao Susan , Wolfinger Russell D. 
Published: August 2007

AbstractIn large‐scale genomics experiments involving thousands of statistical tests, such as association scans and microarray expression experiments, a key question is: Which of theLtests represent true associations (TAs)? The traditional way to control false findings is via individual adjustments. In the presence of multiple TAs,p‐value combination methods offer certain advantages. Both Fisher's and Lancaster's combination methods use an inverse gamma transformation. We identify the relation of the shape parameter of that distribution to the implicit threshold value;p‐values below that threshold are favored by the inverse gamma method (GM). We explore this feature to improve power over Fisher's method whenLis large and the number of TAs is moderate. However, the improvement in power provided by combination methods is at the expense of a weaker claim made upon rejection of the null hypothesis – that there are some TAs among theLtests. Thus, GM remains a global test. To allow a stronger claim about a subset ofp‐values that is smaller thanL, we investigate two methods with an explicit truncation: the rank truncated product method (RTP) that combines the firstK‐orderedp‐values, and the truncated product method (TPM) that combinesp‐values that are smaller than a specified threshold. We conclude that TPM allows claims to be made about subsets ofp‐values, while the claim of the RTP is, like GM, more appropriately about allLtests. GM gives somewhat higher power than TPM, RTP, Fisher, and Simes methods across a range of simulations. Copyright © 2007 John Wiley & Sons, Ltd.
A unifying approach to non‐inferiority, equivalence and superiority tests via multiple decision processes
Authors: Hirotsu Chihiro 
Published: August 2007

AbstractTwo approaches of multiple decision processes are proposed for unifying the non‐inferiority, equivalence and superiority tests in a comparative clinical trial for a new drug against an active control. One is a method of confidence set with confidence coefficient 0.95 improving the conventional 0.95 confidence interval in the producer's risk and also the consumer's risk in some cases. It requires to include 0 within the region as well as to clear the non‐inferiority margin so that a trial with somewhat large number of subjects and inappropriately large non‐inferiority margin for proving non‐inferiority of a drug that is actually inferior should be unsuccessful. The other is the closed testing procedure which combines the one‐ and two‐sided tests by applying the partitioning principle and justifies the switching procedure by unifying the non‐inferiority, equivalence and superiority tests. In particular regarding the non‐inferiority, the proposed method justifies simultaneously the old Japanese Statistical Guideline (one‐sided 0.05 test) and the International Guideline ICH E9 (one‐sided 0.025 test). The method is particularly attractive, changing the strength of the evidence of relative efficacy of the test drug against a control at five levels according to the achievement of the clinical trial. The meaning of the non‐inferiority test and also the rationale of switching from it to superiority test will be discussed. Copyright © 2007 John Wiley & Sons, Ltd.
Activity against drug resistant‐tuberculosis strains of plants used in Mexican traditional medicine to treat tuberculosis and other respiratory diseases
Authors: Camacho‐Corona María del Rayo , Ramírez‐Cabrera Mónica A. , Santiago Omar González‐ , Garza‐González Elvira , Palacios Isidoro de Paz , Luna‐Herrera Julieta 
Published: August 2007

AbstractTuberculosis (TB) kills about 3 million people per year worldwide. Furthermore, TB is an infectious disease associated with HIV patients, and there is a rise in multidrug‐resistant TB (MDR‐TB) cases around the world. There is a need for new anti‐TB agents. The study evaluated the antimycobacterial activity of nine plants used in Mexican traditional medicine to treat tuberculosis and other respiratory diseases. Nasturtium officinale showed the best activity (MIC = 100 µg/mL) against the sensitive Mycobacterium tuberculosis. The following plants were active also but at 200 µg/mL: Citrus sinensis, Citrus aurantifolia, Foeniculum vulgare, Larrea tridentata, Musa acuminata and Olea europaea. Contrary to the above data, activity against drug‐resistant variants of M. tuberculosis was more evident, e.g. N. officinale was the most potent (MIC ≤ 100 µg/mL) against the four mono‐resistant variants tested; F. vulgare and O. europaea were active against all the resistant variants (MICs ≤ 100 µg/mL). The most susceptible variant was the isoniazid resistant, being inhibited by C. aurantifolia, C. sinensis and O. europaea (MIC = 25 µg/mL). These data point to the importance of biological testing of extracts against drug‐resistant M. tuberculosis isolates, and the bioguided assay of these extracts for the identification of lead compounds against MDR‐TB isolates. Copyright © 2007 John Wiley & Sons, Ltd.
Antiinflammatory activity of Lindera erythrocarpa fruits
Authors: Wang Sheng‐Yang , Lan Xing‐Yu , Xiao Jun‐Hong , Yang Jeng‐Chung , Kao Yi‐Ting , Chang Shang‐Tzen 
Published: August 2007

AbstractIn this study, in vitro and in vivo antiinflammatory activities of fruits from Lindera erythrocarpa Makino were evaluated. The ethyl acetate soluble fraction derived from the ethanol extract of L. erythrocarpa fruits inhibited significantly nitric oxide (NO) production in lipopolysaccharide (LPS) induced NO in the murine macrophage cell line (RAW264.7) assay, the EC50 being 16.35 µg/mL. Four compounds, including lucidone (1), cis/trans‐methylludicone (2), methyl linderone (3) and linderone (4) were identified from the active fraction based on the bioactivity‐guided fractionation procedure. Of these lucidone possessed the strongest NO inhibitory activity with an EC50 value of 4.22 µg/mL. Furthermore, results from the protein expression assay demonstrated that lucidone suppressed iNOS and COX‐2 protein expression in a dose‐dependent manner. Lucidone also provided antiinflammatory activity in the croton oil‐induced ear edema assay. When it was applied topically at a dosage of 0.5 and 1 mg per ear, the percent edema reduction in treated mice was 44% and 25%, respectively. The results obtained in this study indicated that lucidone has a good potential to be developed as an antiinflammation agent. Copyright © 2007 John Wiley & Sons, Ltd.
Synthesizing SoS concepts for use in cost modeling
Authors: Lane Jo Ann , Valerdi Ricardo 
Published: August 2007

AbstractToday's need for more complex, capable systems in a short timeframe is leading many organizations towards the integration of existing systems into network‐centric, knowledge‐based system‐of‐systems (SoS). This presents new acquisition challenges in the area of cost estimation because of the lack of commonly accepted definitions and roles. Software and system cost models to date have focused on the software and system development activities of a single system. When viewing the new SoS architectures, one finds that the cost associated with the design and integration of these SoSs is not handled well, if at all, in current cost models. This paper looks at commonly cited definitions of SoS, then evaluates these definitions to determine if they adequately describe and converge on a set of SoS characteristics in the areas of product, development process, and development personnel that can be used to define boundaries and key parameters for an initial SoS cost model. Sixteen SoS definitions are synthesized to provide reasonable coverage for different properties of SoSs. Two examples are used to illustrate key characteristics relevant to cost modeling. © 2007 Wiley Periodicals, Inc. Syst Eng 10: 297–308, 2007
Modification of the Hydrogen Bonds Network in a Hydroxyl Functionalized Dithiolene Ligand by HgX2 Complexation
Authors: Ndiaye Amadou L. , Guyon Fabrice , Knorr Michael , Huch Volker , Veith Michael 
Published: August 2007

AbstractLigand L (4,5‐bis[(2′‐hydroxyethyl)thio]1,3‐dithiole‐2‐thione) which crystallizes in the monoclinic system (P21/n) displays a 1‐D network generated by a succession of intra‐molecular and inter‐molecular hydrogen bonds. Weak π‐π and S···S interactions are also observed in the supramolecular structure. Reaction of L with one equivalent of mercury(II) iodide affords the adduct [HgI2L] (1a). The crystal structure of this complex shows that coordination occurs exclusively via the sulfur atom of the thione function (C=S). The ligation on HgI2 induces a change of the hydrogen bond pattern generated by the hydroxyl substituents: only intermolecular hydrogen bonds are present, organizing the adduct 1a in form of centrosymmetrical dimers in the solid state. The propensity of HgI2 to build‐up chains via μ2‐iodo ligand may be at the origin of the modification of the hydrogen bond network.
New Complexes with a Sterically Hindered Thiourea: Syntheses and Crystal Structures of [Co(dchtu)2Cl2], [Zn(dchtu)2(NCS)2] and [Pb(dchtu)6](SCN)2·2C2H5OH (dchtu = N,N′‐dicyclohexylthiourea)
Authors: Jia Ding‐Xian , Zhu, Ai‐Mei , Deng Jie , Zhang Yong 
Published: August 2007

AbstractNew complexes of a sterically hindered thiourea, [M(dchtu)2Cl2] (M = Co 1, Ni 2), [Zn(dchtu)2(NCS)2] (3) and [Pb(dchtu)6](SCN)2·2C2H5OH (4) (dchtu = N,N′‐dicyclohexylthiourea), have been synthesized and characterized. The single crystal structures of 1, 3 and 4 have been determined by single crystal X‐ray diffraction analyses. CoII, NiII, and ZnII form 1: 2 compounds with dchtu even if molar excesses of dchtu is used, while PbII forms 1:6 compound under the same conditions. The dchtu acts as a monodenate S‐donor ligand in all the complexes. CoII and ZnII atoms are tetrahedrally coordinated with two dchtu ligands, and two chloride or isothiocyanate ions, respectively. The PbII ion in 4 forms an octahedral coordination sphere with six dchtu ligands. The structures of the complexes are stabilized by a system of intermolecular H‐bonding.
Rich Magnetic Chemistry of Cobalt(II) Complexes with N‐Phosphorylthioureas. Crystal Structure and Solution 1H NMR Spectral Properties
Authors: Safin Damir A. , Mlynarz Piotr , Sokolov Felix D. , Kubiak Maria , Hahn F. Ekkehardt , Babashkina Maria G. , Zabirov Nail G. , Galezowska Joanna , Kozlowski Henryk 
Published: August 2007

AbstractStructure and magnetic properties of CoII complexes with N‐phosphorylthiourea derivatives {RC(S)NHP(O)(OiPr)2} (HL) [Co{Et2NC(S)NP(O)(OiPr)2}2] (1), [Co{iPrNHC(S)NP(O)(OiPr)2}2] (2), [Co{[tBuNHC(S)NP(O)(OiPr)2}2] (3), [Co{p‐MeOC6H4NHC(S)NP(O)(OiPr)2}2] (4), [Co{p‐BrC6H4NHC(S)NP(O)(OiPr)2}2] (5) were investigated. Paramagnetic shifts in the 1H NMR spectrum were observed for high‐spin CoII complexes with HL, incorporating amidophosphate moiety C(S)NP(O). The thermal dependence of the magnetic susceptibility has shown that the extended materials 2, 3 and 5 show ferromagnetic exchange between distorted tetrahedral metal atoms, while in complex 4 antiferromagnetic behavior takes place. Compound 1 behaves as a spin‐canted ferromagnet, an antiferromagnetic ordering taking place below a critical temperature, Tc = 175 K. Complex 2 was investigated by single crystal X‐ray diffraction. The cobalt(II) atom in complex 2 is in distorted tetrahedral CoO2S2 environment formed by the C=S sulfur atoms and the P=O oxygen atoms of two deprotonated ligands.
Synthesis and Structural Characterization of Two Aluminium Malate Complexes
Authors: Happel Oliver , Harms Klaus , Seubert Andreas 
Published: August 2007

AbstractThe crystalline aluminium‐malate‐complex, (NH4)6[Al4(D‐C4H3O5)3(L‐C4H3O5)3]·6H2O (1), can be isolated from solutions containing a ratio of 1:2 aluminium to DL‐malic acid in a pH‐range of 5–6. Complex 1 crystallizes in space group $P{\bar 1}$, with a = 9.974(1) Å, b = 10.721(1) Å, c = 12.332(1) Å, α = 102.51(1)°, β = 112.16(1)°, γ = 104.44(1)°, V = 1109.5(2) Å3, and Z = 1. A second crystalline aluminium‐malate‐complex, (C3N2H5)2[Al4(L‐C4H3O5)4(OH)2 (H2O)4]·7H2O (2b), is available from solutions with pH 3 containing a ratio of 1:1 aluminium to L‐malic acid. Complex 2b crystallizes in space group P21, with a = 7.7596(5) Å, b = 25.290(1) Å, c = 10.5393(7) Å, β = 104.855(5)°, V = 1999.1(2) Å3, and Z = 2. A third structure with the same complex anion as it was found in complex 2a is available using aqueous ammonia for pH‐adjustment. The presence of pronounced disorder affecting the positions of the nitrate ion and solvent molecules prohibited a complete structure determination in this case. The two new crystallized complex anions can be used as a powerful tool for aluminium speciation with malic acid ligands. The solution chemistry of the dissolved malate complexes is investigated by NMR spectroscopy.
Syntheses, Crystal Structures and Magnetic Properties of Three Low‐Dimensional Materials Constructed from [Cu2(dmpzpo)2]2+ and [M(CN)2/4]–/2– (M = Ag or Ni) Precursors (Hdmpzpo = 1,3‐bis(3,5‐dimethylpyrazol‐1‐yl)propan‐2‐ol)
Authors: Zhang Guo‐Fang , Zhou Qiu‐Ping , Dou Yin‐Li , Wang Yao , Wu Li‐Ping 
Published: August 2007

AbstractThe syntheses, X‐ray structures of three novel low‐dimensional assemblies, the molecules [Cu2(dmpzpo)2][Ag(CN)2]2 (1), [Cu2(dmpzpo)2][Ni(CN)4]·2CH3OH (2·2CH3OH) and [Cu2(dmpzpo)2][Ni(CN)4]·DMF·3H2O (2·DMF·3H2O), are presented. The temperature‐dependent susceptibility of 2·2CH3OH and 2·DMF·3H2O is determined. The structure of compound 1 consists of one dicopper(II) moiety and two Ag(CN)2− units, each being coordinated to different copper atoms of the dicopper(II) moiety with trans arrangement. Compound 1 has an inversion center located the middle of the Cu2O2 plane. The structures of 2·2CH3OH and 2·DMF·3H2O are isostructural, consisting of {Cu2Ni} repeating units connected through Cu‐NC‐Ni‐CN‐Cu linkages to form an one‐dimensional infinite chain. The magnetic studies on the compounds 2·2CH3OH and 2·DMF·3H2O showed that both compounds exhibit an overall antiferromagnetic behavior.
Arylphosphanide Complexes of the Heavy Alkaline Earth Metals Calcium, Strontium and Barium of the Formula (thf)nM[P(R)Aryl]2
Authors: Gärtner Martin , Görls Helmar , Westerhausen Matthias 
Published: August 2007

AbstractThe metathesis reaction of CaI2 with KPPh2 in THF yields (thf)4Ca(PPh2)2 (1). A metallation of HPPh2 with alkaline earth metals succeeds with strontium and barium and gives (thf)4Sr(PPh2)2 (2) and (thf)5Ba(PPh2)2 (3). From crystal structure determinations of 1 and 2 Ca‐P and Sr‐P bond lengths of 298.65(6) and 314.29(9) pm, respectively, were obtained. Extremely large Ba‐P distances of 332.8(2) and 334.5(2) pm were found for 3. In order to investigate the influence of the bulkiness of the phosphanides on the molecular structure, (thf)4Ba[P(Mes)2]2 (4) and (thf)2Ba[P(Et)Ph]2 (5) were prepared in a similar manner. Derivative 4 is monomeric with Ba‐P distances of 318.72(9) pm, whereas 5 crystallizes as a one‐dimensional polymer with bridging ethyl(phenyl)phosphanide groups with Ba‐P bond lengths between 324.8(1) and 336.0(1) pm.
The Electrophilic Character of Bunsen's Cacodyl Disulfide, Me2As(S)‐S‐AsMe2
Authors: Ioannou Panayiotis V. , Vachliotis Dimitris G. , Sideris Theodore D. 
Published: August 2007

AbstractThe behaviour of Bunsen's cacodyl disulfide, Me2As(S)‐S‐AsMe2 towards Lewis bases of group 15 of the Periodic Table was studied mainly by 1H NMR. While Ph3N did not react, 4‐dimethylaminopyridine and triethylamine isomerized the disulfide to Me2AsSSAsMe2. Ph3P, (PhO)3P, (MeO)3P, (EtO)3P and Ph3As desulfurized the disulfide to Me2AsSAsMe2. (PhS)3P also desulfurized the disulfide but Me2As‐S‐SPh was also produced. Me2As‐S‐SPh was the main product with (PhS)3As nucleophile. In most systems, cationic and anionic species were formed. The results are best interpreted by initial attack of the nucleophile on the electrophilic As=S sulfur.
A Pressure Range in the Synthesis of the RuSr2RECu2O8 Family
Authors: Ruiz‐Bustos R. , Dos Santos‐García A. J. , Alario‐Franco M. Á 
Published: August 2007

AbstractThe family of compounds RuSr2RECu2O8 (RE = Yb, Tm, Er, Ho, Dy, Tb, Gd, Eu, Sm, Nd, Pr, Ce and La) has been prepared. At normal pressure, Sm, Eu and Gd seem to be the only RE elements that accept to enter into the structure of RuSr2RECu2O8. High pressures and temperatures are needed in order to obtain the rest of the members. We describe here the search for the optimum synthesis conditions. The variation of the pressure needed to stabilize each compound show a remarkable gaussian correlation with the rare earth ion size and do not follow the classic lanthanide contraction so often observed in the chemistry of those elements.
Copper Complexes with Sulfonamides Derivatives of Natural Amino Acids as Chemical Nucleases
Authors: Macías Benigno , Villa María V. , Sánchez‐Mesonero Laura , Sanz Francisca , Borrás Joaquín , González‐Álvarez Marta 
Published: August 2007

AbstractThree new coordination compounds have been prepared by reacting copper salts with sulfonamides derived from amino acids. Their molecular structures have been determined with the aid of single crystal X‐ray diffraction. The copper cations are four‐coordinated in all cases and the local environment is almost planar. Compound [Cu(ts‐gly)(NH3)2]·H2O (1) crystallizes in monoclinic space group P21/c (no 14) with Z = 4 and with unit cell parameters a = 6.0490(12) Å, b = 24.719(5) Å, c = 9.159(2) Å, α = γ = 90°, and β = 94.69(3)°. Compound [Cu(ts‐isoleu)(NH3)2] (2) crystallizes in monoclinic space group C2/c (no 8) with Z = 15 and with unit cell parameters a = 30.800(6) Å, b = 6.5510(13) Å, c = 15.830(3) Å, α = γ = 90°, and β = 100.19(3)°. Compound Na[Cu(ts‐gly)(gly)]·2H2O (3) crystallizes in triclinic space group P‐1 (no 2) with Z = 2 and with unit cell parameters a = 5.6220(11) Å, b = 7.775(2) Å, c = 18.704(4) Å, α = 94.61(3)°, β = 98.32(3)°, and γ = 98.29(3)°. The study of nuclease activity with plasmid pUC18 shows that all three compounds act as chemical nucleases, although complex Na[Cu(ts‐gly)(gly)]·2H2O is more efficient in splitting the DNA chains than the other two compounds.
Minority Business Development: Where do we go from Here?
Authors: Chen Gavin M. 
Published: August 2007

It is the contention here that the development of secondary markets to add liquidity to minority and small business equity and investors will greatly increase the flow of investment funds to institutions that originate those assets. While that may be true, investment originators can also create derivatives to contain the risk or to speculate in those markets. Also, investment originators can issue bonds or certificates using their minority C&I assets as securities. It is clear that a number of avenues already exist to enhance liquidity and investment flow to investors in minority and small businesses. Why then are they not being used? The primary reason for the exclusion of such assets from the derivative and secondary markets is the risk perception. It is felt that some form of guaranty or portfolio discount would be necessary to attract investors to these markets. That would mean governmental interference and regulation. However, the government is not willing to add “full faith and credit” to another financial intermediary, especially one where the downside risk is perceptively large.