bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the use of the exact exchange optimized effective potential method for static response properties
Authors: Krykunov Mykhaylo , Ziegler Tom 
Published: March 2009

AbstractIn the present work, we question the notion that the modified Kohn–Sham orbital energies and smaller HOMO‐LUMO gaps, produced from the exact exchange optimized effective potential (EXX‐OEP) method, might significantly improve the paramagnetic contribution to the NMR chemical shifts compared with the regular Hartree–Fock (HF) scheme. First of all, it is shown analytically that if there is such a local potential that produces the HF energy, and the Kohn–Sham orbitals are obtained as a result of separate rotations of the occupied and virtual HF orbitals, any static magnetic property obtained from the coupled perturbed HF method will be identical to that obtained from the EXX‐OEP approach. In fact the EXX‐OEP method is equivalent to the improved virtual orbitals (IVO) scheme in which the energies of the virtual orbitals are modified by an effective potential. It is shown that the IVO procedure leaves static response properties unchanged. To test our analysis numerically we have employed several variants of the EXX‐OEP method, based on the expansion of the local exchange potential into a linear combination of fit functions. The different EXX‐OEP schemes have been used to calculate the NMR chemical shifts for a set of small molecules containing C, H, N, O, and F atoms. Comparison of the deviation between experimental and calculated chemical shifts from the HF, the EXX‐OEP, and the common energy denominator approximation (CEDA) approximation to the EXX‐OEP methods has shown that for carbon, hydrogen, and fluorine the EXX‐OEP methods do not yield any improvement over the HF method. For nitrogen and oxygen we have found that the EXX‐OEP performs better than the HF method. However, in the limit of infinite fit basis set and, as a consequence of it, a perfect fit of the HF potential the EXX‐OEP and the HF methods would afford the same chemical shifts according to our theoretical analysis. Unfortunately, without a perfect fit the chemical shifts from the EXX‐OEP method strongly depend on the fit convergence. In our opinion, the EXX‐OEP method should not be used for response properties as it is numerically unstable. Thus, any apparent improvement of the EXX‐OEP method over the HF scheme for a finite fit basis set must be considered spurious. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
The correlation contracted Schrödinger equation: An accurate solution of the G‐particle‐hole hypervirial
Authors: Alcoba D. R. , Valdemoro C. , Tel L. M. , Pérez‐Romero E. 
Published: March 2009

AbstractThe equation obtained by mapping the matrix representation of the Schrödinger equation with the 2nd‐order correlation transition matrix elements into the 2‐body space is the so called correlation contracted Schrödinger equation (CCSE) (Alcoba, Phys Rev A 2002, 65, 032519). As shown by Alcoba (Phys Rev A 2002, 65, 032519) the solution of the CCSE coincides with that of the Schrödinger equation. Here the attention is focused in the vanishing hypervirial of the correlation operator (GHV), which can be identified with the anti‐Hermitian part of the CCSE. A comparative analysis of the GHV and the anti‐Hermitian part of the contracted Schrödinger equation (ACSE) indicates that the former is a stronger stationarity condition than the latter. By applying a Heisenberg‐like unitary transformation to the G‐particle‐hole operator (Valdemoro et al., Phys Rev A 2000, 61, 032507), a good approximation of the expectation value of this operator as well as of the GHV is obtained. The method is illustrated for the case of the Beryllium isoelectronic series as well as for the Li2 and BeH2 molecules. The correlation energies obtained are within 98.80–100.09% of the full‐configuration interaction ones. The convergence of these calculations was faster when using the GHV than with the ACSE. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Rydberg states of the helium atom
Authors: Deng Jia , Gilbert Andrew T. B. , Gill Peter M. W. 
Published: March 2009

AbstractUsing the recently introduced maximum overlap method and Hartree–Fock Perturbation Theory (HFPT), we compute Hartree–Fock (HF) wavefunctions for triplet 1s ns states of the helium atom. Comparison with near‐exact results from Nakatsuji's free ICI method reveals that HF theory provides a simple route to accurate energies of these Rydberg states, especially for large n. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Vibrational analysis of aqueous sulfuric acid: A computational study
Authors: Choe Yoong‐Kee , Tsuchida Eiji , Ikeshoji Tamio 
Published: March 2009

AbstractVibrational spectrum of aqueous sulfuric acid has been investigated theoretically by means of the first‐principles molecular dynamics simulations employing the PBE functional for exchange‐correlation functionals and norm‐conserving pseudopotentials. For better understanding of vibrational features of aqueous sulfuric acid, we have also undertaken vibrational analyses on sulfuric acid and its hydrate using standard quantum chemical methods including the effects of anharmonicity. The combination of such calculations allows us to interpret complex vibrational features of aqueous sulfuric acid. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Two component calculations of Pt2 with relativistic effective core potential including spin‐orbit operator
Authors: Lee Dong‐Ki , Jeung Gwang‐Hi , Lee Yoon Sup 
Published: March 2009

AbstractThe Kramers restricted two‐component ab initio calculations were performed for the eight lowest electronic states of Pt2 using the relativistic effective core potential with the spin‐orbit operator at the multireference first‐order configuration interaction level of theory employing two‐component molecular spinors as one‐electron basis. The dominant role of the spin‐orbit effects are mainly accounted for by using two‐component spinors as one‐electron wave function, and the importance of the dynamic and the nondynamic electron correlation effects are shown by employing configuration interaction and coupled cluster methods to obtain reliable spectroscopic data for this molecule. The two‐component molecular spinors were generated from Kramers restricted Hartree–Fock calculations for the average configuration and used in the multireference Kramers restricted configuration interaction method to account for nondynamic correlation effect. Effect of dynamic correlations was investigated with the Kramers restricted coupled‐cluster (KRCC) method. Spectroscopic constants calculated at the KRCC level are in good agreement with the most recent experimental values. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Infrared spectra of water molecule encapsulated inside fullerene studied by instantaneous vibrational analysis
Authors: Yagi Kiyoshi , Watanabe Daichi 
Published: March 2009

AbstractInstantaneous vibrational analysis (IVA) is proposed for computing the infrared spectrum of dynamically fluctuating system, and applied to a water molecule encapsulated into fullerene (H2O@C60). A molecular dynamics simulation is first carried out to generate an ensemble of configurations averaging the rotational and translational motion of H2O inside fullerene. At each configuration, instantaneous vibrational frequencies of the water molecule are computed by the vibrational configuration interaction method, which are then employed to construct the line‐shape of the spectrum. The vibrational spectrum in the OH stretching region is computed at a temperature of 10 and 100 K based on a direct potential energy surface incorporating the electronic structure theory. It is found that the vibrational frequency of the symmetric stretching mode is blue‐shifted compared to that of isolated water, whereas that of the asymmetric stretching mode exhibits no shift in average. The relation between IVA and instantaneous normal mode analysis is presented, and their performances are compared. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
The S and G transformations for computing three‐center nuclear attraction integrals
Authors: Slevinsky Richard Mikael , Safouhi Hassan 
Published: March 2009

AbstractIt is now well established that nonlinear transformations can be extremely useful in the case of oscillatory integrals. In previous work, we could show that the G transformation, which is not so well known among those interested in the numerical evaluation of highly oscillatory integrals, works very well for the extremely challenging integral called Twisted Tail. In this work, we demonstrate that these techniques also apply to three‐center nuclear attraction integrals over exponential type functions. The accurate and rapid evaluation of these integrals is required in ab initio molecular structure calculations and density functional theory. Using a basis set of B functions and profiting from their relatively simple Fourier representation, these integrals are formulated as analytical expressions involving highly oscillatory spherical Bessel integral functions. In the present work, we implement two highly accurate algorithms for three‐center nuclear attraction integrals. The first algorithm is based on the G transformation and the second is based on a combination of the S and G transformations. The application of these transformations is largely due to the properties of special functions that allow the computation of higher order derivatives of the integrands with exceptional simplicity. The numerical results illustrate the accuracy of these algorithms applied to three‐center nuclear attraction integrals over exponential type functions with a miscellany of different parameters. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Privacy‐preserving rental services using one‐show anonymous credentials
Authors: Yang Yanjiang , Deng Robert H. , Bao Feng 
Published: March 2009

AbstractRental services play an important part in our daily life and the trend has been towards digital transactions. Rental records contain lots of sensitive information on individuals, so if abused by rental service providers, users' privacy could be jeopardized. To mitigate this concern, we present privacy‐preserving rental services where interests of both the users and the service provider are protected. Specifically, our system enables normal users to engage in a rental service in an anonymous manner, whereas users with overdue items are subject to anonymity revocation by the rental service provider; moreover, the rental service provider enforces a rental limit which caps the number of rentals per user under a prescribed limit. We propose a novel one‐show anonymous credential scheme to realize the above design objectives. While this scheme is tailored to the scenario of online credential issuing in the proposed rental services, we believe that it is of independent interest and may find its use in other applications. Copyright © 2009 John Wiley & Sons, Ltd.
A theory of optimized resource allocation from systems perspectives
Authors: Xiong Ying , S. Chaudhry Sohail 
Published: March 2009

AbstractA construction project is an example of a complex systems engineering problem. In this paper, we have characterized a construction project in the context of the theory of six forces on the factors of production. This new approach was defined by giving consideration to the characteristics of the construction project's resource allocation. An economic efficiency index was also used to assess resource allocation of a construction project. Based on this approach, a theory of optimized resource allocation of the construction project is proposed. Copyright © 2009 John Wiley & Sons, Ltd.
Downregulation of APE1/Ref-1 Is Involved in the Senescence of Mesenchymal Stem Cells
Authors: Heo Jun-Young , Jing Kaipeng , Song Kyoung-Sub , Seo Kang-Sik , Park Ji-Hoon , Kim Jong-Seok , Jung Yeon-Joo , Hur Gang-Min , Jo Deog-Yeon , Kweon Gi-Ryang , Yoon Wan-Hee , Lim Kyu , Hwang Byung-Doo , Jeon Byeong Hwa , Park Jong-Il 
Published: March 2009

Abstract
The senescence of human mesenchymal stem cells (hMSCs) causes disruption of tissue and organ maintenance, and is thus an obstacle to stem cell-based therapies for disease. Although some researchers have studied changes in the characteristics of hMSCs (decreases in differentiation ability and self-renewal), comparing young and old ages, the mechanisms of stem cell senescence have not yet been defined. In this study, we developed a growth curve for human bone marrow derived MSCs (hBMSCs) which changes into a hyperbolic state after passage number 7. Senescence associated β-galactosidase (SA β-gal) staining of hBMSCs showed 10% in passage 9 and 45% in passage 11. We detected an increase in endogenous superoxide levels during senescence that correlated with senescence markers (SA β-gal, hyperbolic growth curve). Interestingly, even though endogenous superoxide increased in a replicative senescence model, the expression of APE1/Ref-1, which is sensitive to intracellular redox state, decreased. These effects were confirmed in a stress-induced senescence model by exogenous treatment with H2O2. This change is related to the p53 activity that negatively regulates APE1/Ref-1. p21 expression levels, which represent p53 activity, were transiently increased in passage 9, meaning that they correlated with the expression of APE1/Ref-1. Overexpression of APE1/Ref-1 suppressed superoxide production and decreased SA β-gal in hBMSCs. In conclusion, intracellular superoxide accumulation appears to be the main cause of the senescence of hBMSCs, and overexpression of APE1/Ref-1 can rescue cells from the senescence phenotype. Maintaining characteristics of hBMSCs by regulating intracellular reactive oxygen species production can contribute to tissue regeneration and to improved cell therapy.
Disclosure of potential conflicts of interest is found at the end of this article.
cAMP Response Element Binding Protein Is Required for Mouse Neural Progenitor Cell Survival and Expansion
Authors: Dworkin Sebastian , Malaterre Jordane , Hollande Frédéric , Darcy Phillip K. , Ramsay Robert G. , Mantamadiotis Theo 
Published: March 2009

Abstract
Development of the mammalian brain relies on the coordinated expansion of neural cells in a relatively short time, spanning for a period of only a few days in mice. The molecular networks regulating neural cell birth and expansion, termed neurogenesis, are still unresolved, although many studies using genetically modified mice have revealed a growing number of genes that are involved in regulating these processes. The cAMP response element binding protein (CREB) lies at the hub of a diverse array of intracellular signaling pathways and is a major transcriptional regulator of numerous functions in adult neural cells, including learning and memory and neuronal survival. Recent studies have shown that activated CREB is highly expressed in immature dividing cells in adult mouse and zebrafish brains and that CREB regulates neural stem/progenitor cells (NSPCs) proliferation in embryonic zebrafish brain. Using genetically modified mice, we show that deletion of CREB, without the concomitant loss of the related compensating factor cAMP response element modifier, leads to defects in neural progenitor cell expansion and survival. Cultured primary CREB−/− NSPCs exhibited decreased expression of several target genes important for neuronal survival and growth, including brain-derived neurotrophic factor and neural growth factor and showed that the survival and growth defect can be rescued by the addition of wild-type NSPC-conditioned medium. This is the first study showing a specific role for CREB in mammalian embryonic neurogenesis. This role appears to be mediated via the expression of factors important for NSPC survival and growth and suggests that CREB is an important signaling regulator within the developing neurogenic niche.
Disclosure of potential conflicts of interest is found at the end of this article.
Results of a second survey to assess the reproductive status of female Asian and African elephants in North America
Authors: Proctor Christine M. , Freeman Elizabeth W. , Brown Janine L. 
Published: March 2009

AbstractSurveys are being conducted to monitor the reproductive health of elephants managed by the TAG/SSP. This study summarizes results of a 2005 survey and compares data to one conducted in 2002. Surveys were returned for 100% and 79.0% of Asian and African elephants, respectively. Of those, 79.3% of Asian and 92.1% of African elephants had weekly progestagen data to assess ovarian cyclicity. For Asian elephants, acyclicity rates were similar between the 2002 and 2005 surveys (13.3% versus 10.9%), whereas irregular cycling increased in 2005 (2.6% versus 7.6%), respectively. For African elephants, the percentages of both acyclicity (22.0% versus 31.2%) and irregular cycling females (5.2% versus 11.8%) increased. In both species, ovarian inactivity was more prevalent in the older age categories (>30 years of age), but for African elephants also occurred in the reproductive aged groups. Reproductive tract pathologies did not account for the majority of acyclicity problems. Several females changed cyclicity status between the two surveys, including from noncycling to cycling, suggesting this is not an irreversible condition. However, seven African females went from cycling to abnormal or no cyclic activity. In summary, the incidence of ovarian acyclicity in Asian elephants is low and stable, but appears to be increasing in African females. These findings reinforce the need for long‐term reproductive monitoring programs and continuous reproductive surveys, even for females not being considered for breeding. With more data we hope to determine what factors are related to changes in ovarian status and how to reverse the trend towards acyclicity. Zoo Biol 29:127–139, 2010. © 2009 Wiley‐Liss, Inc.
A rigorous methodology for specification and verification of business processes
Authors: Masalagiu Cristian , Chin Wei-Ngan , Andrei Ştefan , Alaiba Vasile 
Published: March 2009

AbstractBoth specification and verification of business processes are gaining more and more attention in the field. Most of the existing works in the last years are dealing with important, yet very specialized, issues. Among these, we can enumerate compensation constructs to cope with exceptions generated by long running business transactions, fully programmable fault and compensation handling mechanism, web service area, scope-based compensation and shared-labels for synchronization, and so on. The main purpose of this paper is to present a semi-automatized framework to describe and analysebusiness processes. Business analysts can now use a simple specification language (e.g.,BPMN[Obj06]) to describe any type of activity in a company, in aconcurrentandmodularfashion. The associated programs (e.g.,BPDs [Obj06]) have to be executed in an appropriate language (e.g.,BPEL4WS[ACD+03]). Much more, they have to beconfirmed to be sound, via some prescribed (a priori) conditions. We suggest how all the issues can be embedded in aunifying computer tool. We link our work with similar approaches and we justify our particular choices (besidesBPMNandBPD): theTLA+ language for expressing the imposed behavioural conditions andPetri Nets([EB87], [EB88]) to describe an intermediate semantics. In fact, we want to manage in an appropriate way the general relationship diagram (Fig. 1). Examples and case studies are provided.
Type II Gaucher disease manifesting as haemophagocytic lymphohistiocytosis
Authors: Sharpe L.‐R. , Ancliff P. , Amrolia P. , Gilmour K. C. , Vellodi A. 
Published: March 2009

SummaryHaemophagocytic lymphohistiocytosis (HLH) is a rare and rapidly progressive disease which, untreated, invariably leads to death. Gaucher disease is a rare lysosomal storage disorder. The acute neuronopathic variant; type II, is also rapidly progressive. We report an infant with Gaucher disease type II manifesting as HLH. Immunoblot revealed a deficiency of Munc 13‐4, an intracellular protein responsible for docking of secretory lysosomes. This, and other possible pathogenetic mechanisms to explain the link are discussed.
Comprehensive description of the phenotype of the first case of congenital disorder of glycosylation due to RFT1 deficiency (CDG In)
Authors: Clayton P. T. , Grunewald S. 
Published: March 2009

SummaryVery recently, Haeuptle and colleagues described a new glycosylation defect due to RFT1 deficiency (CDG In). Accumulation of intracellular DolPP‐GlcNAc2Man5 with absence of cytosolic GlcNAc2Man5 resembled the profile of a yeast mutant deficient in RFT1, a protein that is thought to have a role as a flippase. This is the first detailed description of the clinical phenotype of this patient. It was a severe disorder affecting intrauterine development and movement, and leading to intrauterine growth retardation. The child was born with several musculoskeletal abnormalities including arthrogryposis. Postnatally, severe reflux and irregular bowl movements contributed to failure to thrive. The patient showed very little development and no vision and suffered from drug‐resistant epilepsy. Abnormal coagulation resulted in thrombosis and the patient died at the age of 4 years from a pulmonary embolus.
Synthesis of Novel Porphyrin and its Complexes Covalently Linked to Multi-Walled Carbon Nanotubes and Study of their Spectroscopy
Authors: Jin Jun , Dong Zhengping , He Jianguo , Li Rong , Ma Jiantai 
Published: March 2009

Abstract
Novel covalent porphyrin and its complexes (Co2+, Zn2+) functionalized multi-walled carbon nanotubes (MWNTs) have been successfully synthesized by the reaction of the carboxyl on the surface of MWNTs which was synthesized to use carbon radicals generated by the thermal decomposition of azodiisobutyronitrile (AIBN) with 5-p-hydroxyphenyl-10,15,20-triphenyl-porphyrin and its complexes (Co2+, Zn2+). Three resulting nanohybrids were characterized by spectroscopy (FT-IR, Raman, and UV-vis), TGA, and TEM. The quality of porphyrin attached to the MWNTs was determined from thermogravimeric analysis (TGA) of the MWNTs, which showed a weight loss of about 60%. The Raman and absorption spectroscopy data showed that the electronic properties of modified MWNTs were mostly retained, without damaging their one-dimensional electronic properties. From fluorescence measurements, it was observed that the porphyrin and its complexes (Co2+, Zn2+) were nearly quenched by MWNTs, indicating that this covalently modified mode facilitated the effective energy or electron transfer between the excited porphyrin moiety and the extended π-system of MWNTs.