bluuebunny/crossref_metadata_2025_split huggingface dataset:
Flat Resistivity in θ-Phase Charge-Transfer Salts of Selenium-Containing TMET-TTP Derivatives
Authors: Bando Yoshimasa , Ashizawa Minoru , Kawamoto Tadashi , Mori Takehiko 
Published: August 2008

Abstract
Two new tetrathiapentalene (TTP)-based donor molecules have been synthesized, in which two of the four sulfur atoms of the inner TTP-skeleton of TMET-TTP (2-[4,5-bis(methylthio)-1,3-dithiol-2-ylidene]-5-(4,5-ethylenedithio-1,3-dithiol-2-ylidene)-1,3,4,6-tetrathiapentalene) are replaced by Se atoms. Four charge-transfer salts of these donors realize θ-type structures. One of the salts shows almost temperature-independent resistivity over a wide temperature range from 50 to 200 K. The calculated highest occupied molecular orbital (HOMO) is more populated on the non-Se-substituted side. This distribution is associated with the temperature-independent resistivity.
Eigenspectral Analysis of Pendant Vertex- and Pendant Edge-Weighted Graphs of Linear Chains, Cycles, and Stars
Authors: Mandal Bholanath 
Published: August 2008

Abstract
Three classes of pendent vertex- and pendant edge-weighted graphs of linear chains (class I), stars (class II), and cycles (class III) have been presented. These graphs (particularly class I and III) represent heteroconjugated π-systems. Sometimes such graphs appear as factored subgraphs of some complicated graphs. The eigenspectra of these graphs have been found out in analytical forms. These eigenspectra have been utilized i) to calculate the band (i.e., HOMO–LUMO) gaps of such graphs, ii) to find out three classes of inversely proportional graphs (with inversely proportional pairs of eigenvalues), and iii) to express eigenspectra of some complicated graphs in analytical forms along with some subspectral relationships. In the limit of n (number of vertices) to infinity, the band gap of the graph of class I has been shown to be the same with that calculated by considering its hypothetical “cyclic dimer.” Reciprocal graphs have also been considered in this context. These graphs are not all hypothetical. A few of them have also been synthesized.
Magnetic Ordering in Organic-Radical Assemblies
Authors: Hatanaka Masashi , Shiba Ryuichi 
Published: August 2008

Abstract
Ferromagnetic interactions in three-dimensionally stacked organic-radical assemblies were deduced under periodic boundary conditions. Although the topological-linkage patterns apparently contained pentavalent carbon atomic sites due to the three dimensionalities, it was shown that the degenerate non-bonding crystal orbitals (NBCOs) were subject to orbital mixing to form Wannier-transformed NBCOs, analogous to non-Kekulé polymers. In the ferromagnetic π–π stacking modes, the NBCOs were spread over more than two adjacent unit cells. On the other hand, in the π–π antiferromagnetic stacking modes, the NBCOs were localized only at one unit cell. High-spin preferences in the ferromagnetic stacking modes were attributed to anti-parallel-spin instabilities in effective two-electron wave functions consisting of products of NBCOs (PNBCOs). Our analysis was confirmed by theoretical calculations.
Markaracter Table and Q-Conjugacy Character Table for the Non-Rigid Group 1,3,5-Trimethylbenzene
Authors: Darafsheh M R , Moghani A 
Published: August 2008

Abstract
The maturated and unmaturated groups were introduced by Shinsaku Fujita who used them in the markaracter table and the Q-conjugacy character table of a finite group. Then, he applied his results in this area of research to enumerate isomers of molecules. Using non-rigid group theory, it was shown that the full non-rigid (f-NRG) group of 1,3,5-trimethylbenzene (TMB) is isomorphic to wreath product of the cyclic group of order three and the symmetric group of order six on three letters (see Int. J. Quantum Chem.2007, 107, 340). In this paper, we will show that this group has 13 dominant classes (similarly, Q-conjugacy characters) 9 of which are unmatured (similarly, Q-conjugacy characters such that they are the sum of two irreducible characters). Then Markaracter table and Q-conjugacy character table of the unmatured full non-rigid group TMB is derived.
Photoreductive Self-Assembly from [MoVI7O24]6− to Anti-Tumoral [H2MoV12O28(OH)12(MoVIO3)4]6− in Aqueous Media
Authors: Yamase Toshihiro , Ishikawa Eri 
Published: August 2008

Abstract
The long-term photolysis of [iPrNH3]6[Mo7O24]·3H2O in aqueous solutions at pH 5–6 is found to provide the formation of anti-tumoral [H2MoV12O28(OH)12(MoVIO3)4]6− species (1a), the core of which is a well-known ε-isomer ({ε-MoV12}) of the Keggin anion showing edge-shared MoVO6 octahedra in the arrangement of six diamagnetic MoV2-pairs with a MoV–MoV bond distance of 2.6 Å. To obtain structural insight of 1a in aqueous solutions from a viewpoint of the pharmaceutical mechanism, 95Mo NMR, electronic absorption, IR, and electrospray ionization mass (ESI-MS) spectrometries of 1a are investigated and indicate that the {ε-MoV12} core remains intact at pH 5–9 and that a detachment of the MoVIO3 unit from 1a proceeds at high pH level with an accompanying increase in the electronic transition of the MoV2 pairs. Highly positive and negative potentials (0.8–0.9 and −1.1– −1.2 V) of oxidation and reduction current peaks for the MoV2 pairs of 1a assist the structural stability of the ε-Keggin {MoV12} framework in aerobic solutions. A plausible mechanism of the photoreductive self-assembly of [MoVI7O24]6− to 1a through two- and four-electron reduction species, [MoV2Mo5O22(OH)2]6− ({MoV2MoVI5}) and [MoV4Mo3O20(OH)4]6− ({MoV4MoVI3}), is proposed in terms of the formation of a half molecule ([HMoV6O18(OH)6(MoVIO3)2]11−) of 1a, which is suggested by ESI-MS spectrometry of the photolytes.
Three-Dimensional Manganese Octacyanoniobate-Based Pyroelectric Ferrimagnet
Authors: Kosaka Wataru , Hashimoto Kazuhito , Ohkoshi Shin-ichi 
Published: August 2008

Abstract
A novel pyroelectric ferrimagnet, [{MnII(pyrazine)(H2O)2}{MnII(H2O)2}{NbIV(CN)8}]·4H2O, is synthesized. The crystal consists of an NbIV–CN–MnII linked three-dimensional network, which has an electric polarization along the b axis. This compound exhibits ferrimagnetism with a Curie temperature of 48 K due to the antiparallel ordering of magnetic spins on NbIV (S=1⁄2) and those on MnII (S=5⁄2).
Regioselective Synthesis of Antipodal β-Tetrabrominated meso-Tetraarylporphyrins
Authors: Bhyrappa Puttaiah , Velkannan Veerapandian , Karunanithi Karuppaiah , Varghese Babu , Harikrishna  
Published: August 2008

Abstract
A series of meso-tetraarylporphyrins bearing electron-donor or electron-withdrawing substituents at the meso-phenyl groups were examined for antipodal β-pyrrole tetrabromination using different brominating agents. Porphyrins bearing electron-donor substituents undergo bromination at moderate temperatures with N-bromosuccinimide as the brominating agent while the electron-deficient porphyrins require liq. Br2 at room temperature. The brominated porphyrins were isolated in moderate to very good yields. Synthesized compounds were characterized by electronic absorption, 1H NMR, and mass spectroscopic methods. Regioselectivity of an electron-deficient porphyrin, 2,3,12,13-tetrabromo-5,10,15,20-tetrakis(4-methoxycarbonylphenyl)porphyrin was examined by single-crystal X-ray structure analysis and showed antipodal β-pyrrole bromo substitution.
Facile Preparation of Polytopic Azoles: Synthesis, Characterization, and X-ray Powder Diffraction Studies of 1,4-Bis(pyrazol-4-yl)- and 1,4-Bis(tetrazol-5-yl)benzene
Authors: Maspero Angelo , Galli Simona , Masciocchi Norberto , Palmisano Giovanni 
Published: August 2008

Abstract
Two polytopic azoles, 1,4-bis(pyrazol-4-yl)benzene and 1,4-bis(tetrazol-5-yl)benzene, were prepared in sizable amounts by high yield syntheses employing, in mild conditions, cheap reactants and, whenever possible, aqueous solutions. The two species were characterized by 1H and 13C NMR spectroscopy and by thermal analyses, the latter evidencing their high chemical and thermal stability. X-ray powder diffraction methods disclosed their non isomorphous crystal structures, in which individual molecules interact via hydrogen bonds to form two-dimensional sheets.
XAFS Analysis of Ti and Ni Dissolution from Pure Ti, Ni–Ti Alloy, and SUS304 in Soft Tissues
Authors: Uo Motohiro , Asakura Kiyotaka , Tamura Kazuchika , Totsuka Yasunori , Abe Shigeaki , Akasaka Tsukasa , Watari Fumio 
Published: August 2008

Abstract
Ti, a Ni–Ti alloy, and stainless steel (SUS304) were implanted in rat soft tissues for 6 months. The chemical states of the component elements contained in the tissues surrounding those metallic implants were analyzed by fluorescence X-ray absorption fine structure (XAFS). Titanium oxide and a nickel aquo complex, which would be caused by the erosion of Ti and Ni, were detected in the surrounding tissues. The concentrations of Ti and Ni in the tissues were 1–3 and 300 ppm, respectively. Thus, the dissolved conditions and concentrations of those practical metallic materials in vivo were successfully confirmed.
Quenching and Recovery of Fluorescence of Azobenzenes by Acid–Base Reactions
Authors: Yoshino Junro , Kano Naokazu , Kawashima Takayuki 
Published: August 2008

Abstract
2-[Bis(pentafluorophenyl)boryl]-4′-(dimethylamino)azobenzene was synthesized as a hybrid of the intensely fluorescent 2-borylazobenzene and the pH-responsive 4-(dimethylamino)azobenzene. Quenching and recovery of fluorescence of this azobenzene were reversibly performed by addition of trifluoroacetic acid and triethylamine, respectively. The reason of fluorescence quenching was investigated by theoretical calculations.
Efficient Entry to the Pyrroloquinoline Core of Martinella Alkaloids via Novel Base-catalyzed Mukaiyama–Mannich Reaction
Authors: Ikeda Shuhei , Shibuya Masatoshi , Kanoh Naoki , Iwabuchi Yoshiharu 
Published: August 2008

Abstract
An efficient enantiocontrolled entry to Martinella alkaloids was achieved based on the unexpected discovery that a catalytic amount of KH/dicyclohexyl-18-crown-6 induced an intramolecular Mukaiyama–Mannich reaction of imine 3, leading to a cascade sequence involving a novel silyl group migration to furnish the pyrroloquinoline core 6.
Drastic Enhancement of Cycle Lifetime of Electrochromic Devices Using Polysilsesquioxane as an Anchoring Agent
Authors: Imae Ichiro , Takenaka Youichi , Tokita Daisuke , Ooyama Yousuke , Komaguchi Kenji , Harima Yutaka 
Published: August 2008

Abstract
Polysilsesquioxanes were obtained by hydrolysis of viologens having one or two triethoxysilyl groups, followed by their polycondensation, and anchored on the surface of an ITO electrode. The electrochromic properties of the polysilsesquioxanes were investigated and its component was optimized to enhance the cycle lifetime.
Heptanuclear Nickel(II) Wheel with Eight Redox Active Ferrocenyl Groups
Authors: Mitsumoto Kiyotaka , Nihei Masayuki , Shiga Takuya , Oshio Hiroki 
Published: August 2008

Abstract
The reaction of Ni(ClO4)2·6H2O with 3-ferrocenyl-5-(2-pyridyl)pyrazole (Hfcpp) and Et3N in acetonitrile yielded a pentadecanuclear heterometallic complex of [Ni7(fcpp)8(OH)4](ClO4)2·6CH3CN (1). Complex 1 has a heptanuclear wheel core composed of seven NiII ions, and eight ferrocenyl groups are attached to the core through pyrazolyl groups. Magnetic susceptibility measurements for 1 revealed that overall antiferromagnetic interactions are operative within the heptanuclear core.
Extraction of Electrons from H2 with a NiIRuI Catalyst
Authors: Matsumoto Takahiro , Kure Bunsho , Ogo Seiji 
Published: August 2008

Abstract
The mechanism of extraction of electrons from H2 catalyzed by hydrogenases has proven challenging to elucidate. Catalytic extraction of electrons from H2 has been achieved by use of a low-valent NiIRuI complex [NiI(μ-SR)2RuI(η6-C6Me6)]{(μ-SR)2 = N,N′-dimethyl-N,N′-bis(2-mercaptoethyl)-1,3-propanediamine} as the active catalyst with evolution of H2 under ambient conditions. The electrons extracted from H2 have been used for a catalytic reduction of Cu2+ to Cu0 with the NiRu complexes.
Life expectancy estimation in cerebral palsy – a paediatrician's approach
Authors: Miles Richard 
Published: August 2008

Paediatricians involved in providing reports for cerebral palsy litigation are often asked to give an opinion on life expectancy and this article outlines the approach taken by one paediatrician. The article describes how statistical data is available, particulary from America, to guide the clinician and the Court. This data acts as the starting point. The two factors that affect life expectancy most of all in the data are mobility and feeding ability, hence tables and survival curves are provided within the publications cited so that additional years of survival can be assessed for individuals in the different functional groups. The article describes how it is the clinicians' role to assess the individual's functional capabilities and any relevant clinical issues and ‘interpret’ the data accordingly.
Experimental Estimation of Mutation Rates in a Wheat Population With a Gene Genealogy Approach
Authors: Raquin Anne-Laure , Depaulis Frantz , Lambert Amaury , Galic Nathalie , Brabant Philippe , Goldringer Isabelle 
Published: August 2008

Abstract
Microsatellite markers are extensively used to evaluate genetic diversity in natural or experimental evolving populations. Their high degree of polymorphism reflects their high mutation rates. Estimates of the mutation rates are therefore necessary when characterizing diversity in populations. As a complement to the classical experimental designs, we propose to use experimental populations, where the initial state is entirely known and some intermediate states have been thoroughly surveyed, thus providing a short timescale estimation together with a large number of cumulated meioses. In this article, we derived four original gene genealogy-based methods to assess mutation rates with limited bias due to relevant model assumptions incorporating the initial state, the number of new alleles, and the genetic effective population size. We studied the evolution of genetic diversity at 21 microsatellite markers, after 15 generations in an experimental wheat population. Compared to the parents, 23 new alleles were found in generation 15 at 9 of the 21 loci studied. We provide evidence that they arose by mutation. Corresponding estimates of the mutation rates ranged from 0 to 4.97 × 10−3 per generation (i.e., year). Sequences of several alleles revealed that length polymorphism was only due to variation in the core of the microsatellite. Among different microsatellite characteristics, both the motif repeat number and an independent estimation of the Nei diversity were correlated with the novel diversity. Despite a reduced genetic effective size, global diversity at microsatellite markers increased in this population, suggesting that microsatellite diversity should be used with caution as an indicator in biodiversity conservation issues.
Exchangeable Models of Complex Inherited Diseases
Authors: Slatkin Montgomery 
Published: August 2008

AbstractA model of unlinked diallelic loci affecting the risk of a complex inherited disease is explored. The loci are equivalent in their effect on disease risk and are in Hardy–Weinberg and linkage equilibrium. The goal is to determine what assumptions about dependence of disease risk on genotype are consistent with data for diseases such as schizophrenia, bipolar disorder, autism, and multiple sclerosis that are relatively common (0.1–2% prevalence) and that have high concordance rates for monozygotic twins (30–50%) and high risks to first-degree relatives of affected individuals (risk ratios exceeding 4). These observations are consistent with a variety of models, including generalized additive, multiplicative, and threshold models, provided that disease risk increases rapidly for a narrow range of numbers of causative alleles. If causative alleles are in relatively high frequency, then the combined effects of numerous causative loci are necessary to substantially elevate disease risk.
Localization of the Genetic Determinants of Meiosis Suppression in Daphnia pulex
Authors: Lynch Michael , Seyfert Amanda , Eads Brian , Williams Emily 
Published: August 2008

Abstract
Although ∼1 in 10,000 animal species is capable of parthenogenetic reproduction, the evolutionary causes and consequences of such transitions remain uncertain. The microcrustacean Daphnia pulex provides a potentially powerful tool for investigating these issues because lineages that are obligately asexual in terms of female function can nevertheless transmit meiosis-suppressing genes to sexual populations via haploid sperm produced by environmentally induced males. The application of association mapping to a wide geographic collection of D. pulex clones suggests that sex-limited meiosis suppression in D. pulex has spread westward from a northeastern glacial refugium, conveyed by a dominant epistatic interaction among the products of at least four unlinked loci, with one entire chromosome being inherited through males in a nearly nonrecombining fashion. With the enormous set of genomic tools now available for D. pulex, these results set the stage for the determination of the functional underpinnings of the conversion of meiosis to a mitotic-like mode of inheritance.
A Complex Genetic Basis to X-Linked Hybrid Male Sterility Between Two Species of House Mice
Authors: Good Jeffrey M , Dean Matthew D , Nachman Michael W 
Published: August 2008

AbstractThe X chromosome plays a central role in the evolution of reproductive isolation, but few studies have examined the genetic basis of X-linked incompatibilities during the early stages of speciation. We report the results of a large experiment focused on the reciprocal introgression of the X chromosome between two species of house mice, Mus musculus and M. domesticus. Introgression of the M. musculus X chromosome into a wild-derived M. domesticus genetic background produced male-limited sterility, qualitatively consistent with previous experiments using classic inbred strains to represent M. domesticus. The genetic basis of sterility involved a minimum of four X-linked factors. The phenotypic effects of major sterility QTL were largely additive and resulted in complete sterility when combined. No sterility factors were uncovered on the M. domesticus X chromosome. Overall, these results revealed a complex and asymmetric genetic basis to X-linked hybrid male sterility during the early stages of speciation in mice. Combined with data from previous studies, we identify one relatively narrow interval on the M. musculus X chromosome involved in hybrid male sterility. Only a handful of spermatogenic genes are within this region, including one of the most rapidly evolving genes on the mouse X chromosome.
Cut Thy Neighbor: Cyclic Birth and Death of Recombination Hotspots via Genetic Conflict
Authors: Friberg Urban , Rice William R 
Published: August 2008

Abstract
Most recombination takes place in numerous, localized regions called hotspots. However, empirical evidence indicates that nascent hotspots are susceptible to removal due to biased gene conversion, so it is paradoxical that they should be so widespread. Previous modeling work has shown that hotspots can evolve due to genetic drift overpowering their intrinsic disadvantage. Here we synthesize recent theoretical and empirical results to show how natural selection can favor hotspots. We propose that hotspots are part of a cycle of antagonistic coevolution between two tightly linked chromosomal regions: an inducer region that initiates recombination during meiosis by cutting within a nearby region of DNA and the cut region itself, which can evolve to be resistant to cutting. Antagonistic coevolution between inducers and their cut sites is driven by recurrent episodes of Hill–Robertson interference, genetic hitchhiking, and biased gene conversion.
Defective Break-Induced Replication Leads to Half-Crossovers inSaccharomyces cerevisiae
Authors: Deem Angela , Barker Krista , VanHulle Kelly , Downing Brandon , Vayl Alexandra , Malkova Anna 
Published: August 2008

AbstractBreak-induced replication (BIR) is an important process of DNA metabolism that has been implicated in the restart of collapsed replication forks, as well as in various chromosomal instabilities, including loss of heterozygosity, translocations, and alternative telomere lengthening. Therefore, knowledge of how BIR is carried out and regulated is important for better understanding the maintenance of genomic stability in eukaryotes. Here we present a new yeast experimental system that enables the genetic control of BIR to be investigated. Analysis of mutations selected on the basis of their sensitivity to various DNA-damaging agents demonstrated that deletion of POL32, which encodes a third, nonessential subunit of polymerase δ, significantly reduced the efficiency of BIR, although some POL32-independent BIR was still observed. Importantly, the BIR defect in pol32Δ cells was associated with the formation of half-crossovers. We propose that these half-crossovers resulted from aberrant processing of BIR intermediates. Furthermore, we suggest that the half-crossovers observed in our system are analogous to nonreciprocal translocations (NRTs) described in mammalian tumor cells and, thus, our system could represent an opportunity to further study the NRT mechanism in yeast.
Bayesian Quantitative Trait Loci Mapping for Multiple Traits
Authors: Banerjee Samprit , Yandell Brian S , Yi Nengjun 
Published: August 2008

AbstractMost quantitative trait loci (QTL) mapping experiments typically collect phenotypic data on multiple correlated complex traits. However, there is a lack of a comprehensive genomewide mapping strategy for correlated traits in the literature. We develop Bayesian multiple-QTL mapping methods for correlated continuous traits using two multivariate models: one that assumes the same genetic model for all traits, the traditional multivariate model, and the other known as the seemingly unrelated regression (SUR) model that allows different genetic models for different traits. We develop computationally efficient Markov chain Monte Carlo (MCMC) algorithms for performing joint analysis. We conduct extensive simulation studies to assess the performance of the proposed methods and to compare with the conventional single-trait model. Our methods have been implemented in the freely available package R/qtlbim (http://www.qtlbim.org), which greatly facilitates the general usage of the Bayesian methodology for unraveling the genetic architecture of complex traits.