bluuebunny/crossref_metadata_2025_split huggingface dataset:
A multivariate time series approach to projected life tables
Authors: Lazar Dorina , Denuit Michel M. 
Published: May 2009

AbstractThe method of mortality forecasting proposed by Lee and Carter describes a time series of age‐specific log‐death rates as a sum of an independent of time age‐specific component and a bilinear term in which one of the component is a time‐varying factor reflecting general change in mortality and the second one is an age‐specific parameter. Such a rigid model structure implies that on average the mortality improvements for different age groups should be proportional, regardless of the calendar period: a single time factor drives the future death rates. This paper investigates the use of multivariate time series techniques for forecasting age‐specific death rates. This approach allows for relative speed of decline in the log death rates specific to the different ages. The dynamic factor analysis and the Johansen cointegration methodology are successfully applied to project mortality. The inclusion of several time factors allows the model to capture the imperfect correlations in death rates from 1 year to the next. The benchmark Lee–Carter model appears as a special case of these approaches. An empirical study is conducted with the help of the Johansen cointegration methodology. A vector‐error correction model is fitted to Belgian general population death rates. A comparison is performed with the forecast of life expectancies obtained from the classical Lee–Carter model. Copyright © 2009 John Wiley & Sons, Ltd.
Gene expression profiling differentiates autism case–controls and phenotypic variants of autism spectrum disorders: evidence for circadian rhythm dysfunction in severe autism
Authors: Hu Valerie W. , Sarachana Tewarit , Kim Kyung Soon , Nguyen AnhThu , Kulkarni Shreya , Steinberg Mara E. , Luu Truong , Lai Yinglei , Lee Norman H. 
Published: May 2009

AbstractAutism spectrum disorders (ASD) are neurodevelopmental disorders characterized by delayed/abnormal language development, deficits in social interaction, repetitive behaviors and restricted interests. The heterogeneity in clinical presentation of ASD, likely due to different etiologies, complicates genetic/biological analyses of these disorders. DNA microarray analyses were conducted on 116 lymphoblastoid cell lines (LCL) from individuals with idiopathic autism who are divided into three phenotypic subgroups according to severity scores from the commonly used Autism Diagnostic Interview‐Revised questionnaire and age‐matched, nonautistic controls. Statistical analyses of gene expression data from control LCL against that of LCL from ASD probands identify genes for which expression levels are either quantitatively or qualitatively associated with phenotypic severity. Comparison of the significant differentially expressed genes from each subgroup relative to the control group reveals differentially expressed genes unique to each subgroup as well as genes in common across subgroups. Among the findings unique to the most severely affected ASD group are 15 genes that regulate circadian rhythm, which has been shown to have multiple effects on neurological as well as metabolic functions commonly dysregulated in autism. Among the genes common to all three subgroups of ASD are 20 novel genes mostly in putative noncoding regions, which appear to associate with androgen sensitivity and which may underlie the strong 4:1 bias toward affected males.
Current density in a model of a human body with a conductive implant exposed to ELF electric and magnetic fields
Authors: Valič Blaž , Gajšek Peter , Miklavčič Damijan 
Published: May 2009

AbstractA numerical model of a human body with an intramedullary nail in the femur was built to evaluate the effects of the implant on the current density distribution in extremely low frequency electric and magnetic fields. The intramedullary nail was chosen because it is one of the longest high conductive implants used in the human body. As such it is expected to alter the electric and magnetic fields significantly. The exposure was a simultaneous combination of inferior to superior electric field and posterior to anterior magnetic field both alternating at 50 Hz with the values corresponding to the ICNIRP reference levels: 5000 V m−1 for electric field and 100 µT for magnetic flux density. The calculated current density distribution inside the model was compared to the ICNIRP basic restrictions for general public (2 mA m−2). The results show that the implant significantly increases the current density up to 9.5 mA m−2 in the region where it is in contact with soft tissue in the model with the implant in comparison to 0.9 mA m−2 in the model without the implant. As demonstrated the ICNIRP basic restrictions are exceeded in a limited volume of the tissue in spite of the compliance with the ICNIRP reference levels for general public, meaning that the existing safety limits do not necessarily protect implanted persons to the same extent as they protect people without implants. Bioelectromagnetics 30:591–599, 2009. © 2009 Wiley‐Liss, Inc.
A new biocatalyst: Penicillin G acylase immobilized in sol‐gel micro‐particles with magnetic properties
Authors: Bernardino Susana M. S. A. , Fernandes Pedro , Fonseca Luís P. 
Published: May 2009

AbstractThe present work focuses on the development and basic characterization of a new magnetic biocatalyst, namely penicillin G acylase (PGA), immobilized in sol‐gel matrices with magnetic properties, ultimately aimed for application in cephalexin (CEX) synthesis. A mechanically stable carrier, based on porous xerogels silica matrixes starting from tetramethoxysilane (TMOS), was prepared leading to micro‐carriers with medium sized particles of 30 μm, as determined by scanning electron microscopy. An immobilization yield of 95–100% and a recovered activity of 50–65% at 37°C, as determined by penicillin G (PG) hydrolysis (pH STAT method), were observed. These results clearly exceed those reported in a previous work on PGA immobilization in sol‐gel, where only 10% of activity was recovered. The values of activity were kept constant for 6 months. Immobilized PGA (682 U/gdry weight) retained high specific activity throughout ten consecutive runs for PG hydrolysis, suggesting adequate biocatalyst stability. The CEX synthesis was performed at 14°C, using the free and immobilized PGA in aqueous medium. Phenylglycine methyl ester was used as acyl donor at 90 mM and 7‐aminodeacetoxycephalosporanic acid was the limiting substrate at 30 mM. The CEX stoichiometric yield after 1‐h reaction was close to 68% (23 mM CEX/h) and 65% (19 mM CEX/h), respectively.
Cell‐free synthesis of functional aquaporin Z in synthetic liposomes
Authors: Hovijitra Norman T. , Wuu Jessica J. , Peaker Boris , Swartz James R. 
Published: May 2009

AbstractThe challenges involved in producing sufficient quantities of aquaporins for precise biophysical characterization have limited our knowledge of this important class of molecules. This article describes a cell‐free protein synthesis method for producing high concentrations of the E. coli water transporter, aquaporin Z (AqpZ), in synthetic liposomes. To our knowledge, this is the first report of in vitro synthesis of a membrane protein directly into synthetic liposomes with verified function, (i.e., transport activity and selectivity). Titration of DOPC lipid vesicles added to the cell‐free reaction show that production yields of active AqpZ are dependent on the concentration of DOPC lipid vesicles added to the cell‐free reaction, with 224 ± 24 lipids required per aquaporin monomer. Supplementation of the signal recognition particle receptor (FtsY) to the cell‐free reaction increases production of vesicle‐associated AqpZ but not active AqpZ. Cell‐free reactions using 7 mg/mL lipids that were not supplemented with FtsY produced 507 ± 11 µg/mL of vesicle‐associated AqpZ that exhibited a specific water transport activity of (2.2 ± 0.3) × 10−14 cm3 s−1 monomer−1. Proteinase K protection, activation energy determination, and selectivity against glycerol and urea transport also confirmed the production of correctly folded AqpZ. This technique is capable of producing milligram quantities of aquaporin that can be readily assayed for function, facilitating biophysical characterization and high‐throughput analysis. Biotechnol. Bioeng. 2009; 104: 40–49 © 2009 Wiley Periodicals, Inc.
Bioproduction of the aroma compound 2‐Phenylethanol in a solid–liquid two‐phase partitioning bioreactor system by Kluyveromyces marxianus
Authors: Gao Fang , Daugulis Andrew J. 
Published: May 2009

AbstractThe rose‐like aroma compound 2‐phenylethanol (2‐PE) is an important fragrance and flavor ingredient. Several yeast strains are able to convert l‐phenylalanine (l‐phe) to 2‐PE among which Kluyveromyces marxianus has shown promising results. The limitation of this process is the low product concentration and productivity primarily due to end product inhibition. This study explored the possibility and benefits of using a solid–liquid Two‐Phase Partition Bioreactor (TPPB) system as an in situ product removal technique. The system applies polymer beads as the sequestering immiscible phase to partition 2‐PE and reduce the aqueous 2‐PE concentration to non‐inhibitory levels. Among six polymers screened for extracting 2‐PE, Hytrel® 8206 performed best with a partition coefficient of 79. The desired product stored in the polymer was ultimately extracted using methanol. A 3 L working volume solid–liquid batch mode TPPB using 500 g Hytrel® as the sequestering phase generated a final overall 2‐PE concentration of 13.7 g/L, the highest reported in the current literature. This was based on a polymer phase concentration of 88.74 g/L and aqueous phase concentration of 1.2 g/L. Even better results were achieved via contact with more polymers (approximately 900 g) with the aqueous phase applying a semi‐continuous reactor configuration. In this system, a final 2‐PE concentration (overall) of 20.4 g/L was achieved with 1.4 g/L in the aqueous and 97 g/L in the polymer phase. The overall productivities of these two reactor systems were 0.38 and 0.43 g/L h, respectively. This is the first report in the literature of the use of a polymer sequestering phase to enhance the bioproduction of 2‐PE, and exceeds the performance of two‐liquid phase systems in terms of productivity as well as ease of operation (no emulsions) and ultimate product recovery. Biotechnol. Bioeng. 2009; 104: 332–339 © 2009 Wiley Periodicals, Inc.
Reversal of coenzyme specificity of 2,3‐butanediol dehydrogenase from Saccharomyces cerevisae and in vivo functional analysis
Authors: Ehsani Maryam , Fernández Maria R. , Biosca Josep A. , Dequin Sylvie 
Published: May 2009

AbstractSaccharomyces cerevisiae NAD(H)‐dependent 2,3‐butanediol dehydrogenase (Bdh1), a medium chain dehydrogenase/reductase is the main enzyme catalyzing the reduction of acetoin to 2,3‐butanediol. In this work we focused on altering the coenzyme specificity of Bdh1 from NAD(H) to NADP(H). Based on homology studies and the crystal structure of the NADP(H)‐dependent yeast alcohol dehydrogenase Adh6, three adjacent residues (Glu221, Ile222, and Ala223) were predicted to be involved in the coenzyme specificity of Bdh1 and were altered by site‐directed mutagenesis. Coenzyme reversal of Bdh1 was obtained with double Glu221Ser/Ile222Arg and triple Glu221Ser/Ile222Arg/Ala223Ser mutants. The performance of the triple mutant for NADPH was close to that of native Bdh1 for NADH. The three engineered mutants were able to restore the growth of a phosphoglucose isomerase deficient strain (pgi), which cannot grow on glucose unless an alternative NADPH oxidizing system is provided, thus demonstrating their in vivo functionality. These mutants are interesting tools to reduce the excess of acetoin produced by engineered brewing or wine yeasts overproducing glycerol. In addition, they represent promising tools for the manipulation of the NADP(H) metabolism and for the development of a powerful catalyst in biotransformations requiring NADPH regeneration. Biotechnol. Bioeng. 2009; 104: 381–389 © 2009 Wiley Periodicals, Inc.
Anatomical variations of the upper thoracic sympathetic chain
Authors: Zhang Bensi , Li Zhuang , Yang Xinwen , Li Guangzhong , Wang Yong , Cheng Jiamao , Tang Ximin , Wang Fan 
Published: May 2009

AbstractThe aim is to clearly delineate the upper thoracic sympathetic chains and neural connections between the chains and ventral rami of the thoracic nerves, and to provide an anatomical foundation for successful upper thoracic sympathicotomy for treating upper essential hyperhidrosis. The upper thoracic sympathetic chains, upper five intercostal nerves, and neural connections between them in 50 halves of 25 adult cadavers have been dissected, measured, and mapped. The stellate ganglion had an incidence of 80%. The second to the fourth thoracic sympathetic ganglia were commonly located in the corresponding intercostal spaces with the presence of 92%, 68%, and 50%, respectively. The incidence of the first and second intercostal rami was 40% and 6%, and that of the ascending or descending rami from the second, third and fourth ganglia was 54%, 24%, and 14%, respectively. Additional rami communicantes joined the ventral ramus of the 1st thoracic nerve proximal to the point where the latter gave a branch to the brachial plexus. The farthest horizontal distance from the sympathetic chain to the junction between the additional rami communicantes and the second to the fourth intercostal nerves was 29.1 mm. Only 16% of cadavers had similar anatomy bilaterally. Anatomical variations of the upper thoracic sympathetic trunk in relation to intercostal nerves, which may be one of the causes resulting in surgical failures and recurrences, were striking. Attention should be given to such anatomical variations when planning thoracic sympathicotomy. Clin. Anat. 22:595–600, 2009. © 2009 Wiley‐Liss, Inc.
Dealing with dynamic changes in time critical decision‐making for MOUT simulations
Authors: Ting Shang‐Ping , Zhou Suiping 
Published: May 2009

AbstractGenerating realistic behaviors for the non‐player characters (also known as bots) is an important task for Military Operations on Urban Terrain (MOUT) simulations. Most of the current bots reasoning models are based on complete rational analysis of all alternatives. However, such models may not be adequate in time critical and uncertain situations. In such situations, due to time constraints and incomplete information, humans rely mainly on experience rather than some structured analysis of the given situation to make decisions. In our previous work, we have developed SNAP, a time critical decision‐making framework which aims to imitate human decision‐making processes for MOUT simulations. A major limitation that we found about SNAP is its difficulty in dealing with dynamic changes in MOUT simulations. In this paper, we propose to address this problem by incorporating a novel feature of expectations into SNAP. The effectiveness of this new feature is assessed with Twilight City, a virtual environment for MOUT simulations. Experimental results show that our expectation model works well in dealing with dynamic changes in MOUT. Copyright © 2009 John Wiley & Sons, Ltd.
Real‐time dynamics for geometric textures in shell
Authors: Huang Jin , Sun Hanqiu , Zhou Kun , Bao Hujun 
Published: May 2009

AbstractEmbedding geometric textures in a shell space around an arbitrary surface has been a popular way to add highly detailed geometric details and enhance visual richness in graphics community, but the dynamic effects of geometric textures have not been modeled and simulated. In this paper, we introduce an efficient algorithm for deforming geometric textures with dynamic effects. The algorithm consists of two steps. First, it computes a deformed shell space by optimizing a material related energy function, which is then used to evaluate the equilibrium position of the geometric texture. Second, an explicit time integration scheme is applied for vibrating the geometric texture around its equilibrium position. Users can deform the geometric textures by dragging its vertices directly, and the dynamic behavior of the geometric textures can be changed by adjusting several material parameters. The dynamic simulation of geometric textures can be easily implemented on GPU and runs at real‐time rates. Copyright © 2009 John Wiley & Sons, Ltd.
Performance‐driven motion choreographing with accelerometers
Authors: Liang Xiubo , Li Qilei , Zhang Xiang , Zhang Shun , Geng Weidong 
Published: May 2009

AbstractLive performance is an intuitive way to naturally draft the desired motion in the choreographer's mind. In this paper we present a novel approach to choreographing motions by live performance captured with degree of freedom (3‐DOF) accelerometers. The process begins by placing the accelerometers on the user's limbs according to the pre‐specified positions. The computer then recognizes the performed actions using Hidden Markov Model (HMM), which is pre‐trained by the acceleration data samples automatically generated from a pre‐segmented motion capture database. At last, the captured actions are further synthesized with motion retiming and exaggeration based on the acceleration signals from the accelerometers. This method can intuitively rapid‐prototype the choreographed motions for pre‐production of animation, the avatar control in virtual reality and game‐like scenarios, etc. The experimental results show that it can effectively recognize actions with spatial‐time variance, and is easy‐to‐use especially for a novice with little experience. Copyright © 2009 John Wiley & Sons, Ltd.
Functionalization of Boron Dipyrrin (BODIPY) Dyes through Iridium and Rhodium Catalysis: A Complementary Approach to α‐ and β‐Substituted BODIPYs
Authors: Chen Jinping , Mizumura Masatoshi , Shinokubo Hiroshi , Osuka Atsuhiro 
Published: May 2009

AbstractTwo series of BODIPY dyes with substituents either in the α positions or in the β positions and different conjugation lengths were synthesized by means of iridium‐catalyzed borylation and rhodium‐catalyzed Heck‐type addition (see scheme). The α‐ and β‐substituted series show completely different photophysical properties. BODIPY=boron dipyrrin.magnified imageIridium‐catalyzed direct borylation has been applied to meso‐substituted dipyrromethane and boron dipyrrin (BODIPY) dyes. Borylation is highly regioselective and complementary: it occurs exclusively at the α position for meso‐mesityldipyrromethane and at the β positions for meso‐mesityl BODIPY dye. This regioselective borylation enables a variety of α‐ and β‐substituted BODIPY dyes to be synthesized. Introduction of α,β‐enoate and α,β,γ,δ‐dienoate functions into BODIPY dyes at the α or β positions was achieved by rhodium‐catalyzed Heck‐type addition of the borylated compounds to acrylate and 2,4‐pentadienoate esters. This functionalization has a significant effect on the electronic properties of BODIPY dyes, as seen in substantial redshift of the absorption and emission spectra. Comparative studies showed that the α‐ and β‐substituted series of BODIPY dyes show substantially different photophysical properties, and thus the importance of the position to be functionalized is highlighted.
Bonding or Nonbonding? Description or Explanation? “Confinement Bonding” of He@adamantane
Authors: Wang Shu‐Guang , Qiu Yi‐Xiang , Schwarz W. H. Eugen 
Published: May 2009

AbstractInsight into bonding phenomenadepends on whether one analyzes the whole bond‐formation process or just the final product. Examination of the formation of the inclusion complex He@adamantane by energy partitioning reveals that the high energy cost of “He bonding” originates in strong HeC Pauli repulsions. The postulate of attractive HeC bonds requires a very specific view.magnified imageDifferent insights into chemical phenomena are obtained by analyzing the whole process (comparing three or more points, thereby explaining the atomistic mechanism) or only the final product (yielding an interesting fingerprint of the result). The viewpoint depends also on whether one analyzes the wavefunctions according to notions grounded in chemical experience or along physically well‐defined formal concepts. Bond energies can only be understood upon comparing both ends of the formation process from fragments to molecule. We examine the formation of the inclusion complex He@adamantane. The large antibonding energy expense is partitioned into four physical contributions according to chemical concepts. Introduction of the He atom into an undeformed adamantane cage leads to a large increase of Pauli repulsion; this is partly moderated by electrostatic overlap attraction and by electronic and nuclear relaxations. The IUPAC definition of bonding comprises this antibonding interaction, since a (meta)stable complex is formed. We call it “confinement bonding”. Single‐point analyses of the bond‐formation product can only yield one‐sided characterizations. Any analysis depends on its prescription, which should always be specified in order to avoid controversies based on a mix up of unlike concepts.
Controlled Assembly of Au, Ag, and Pt Nanoparticles with Chitosan
Authors: Hong Min , Wu Linlin , Tian Liangfei , Zhu Jin 
Published: May 2009

AbstractWorking on the chain gang: A simple method for the controlled assembly of metal nanoparticles (Au, Ag, and Pt) into 1D chains (see figure) has been developed based on the electrostatic interaction of negatively charged carboxylic groups on the citrate ions surrounding the NPs and the positively charged chitosan polymer.magnified imageA simple method for the controlled assembly of metal nanoparticles into one‐dimensional chains has been developed. The chain‐formation process could be accounted for by the electrostatic interaction of the negatively charged carboxylic groups on the citrate ions surrounding metal nanoparticles and the positively charged chitosan polymer. Three representative types of nanoparticles comprising Au, Ag, and Pt, respectively, have been used to illustrate the generic applicability of the proposed methodology. Facile control of the chain length of the nanoparticle assembly could be achieved by adjusting the concentrations of negatively or positively charged species. We anticipate the ready adaptability of the methodology to nanoparticles of more complex compositions.
Lithium Diisopropylamide‐Mediated Carbolithiation Reactions of Vinylidenecyclopropanes and Further Transformations of the Adducts
Authors: Lu Jian‐Mei , Shi Min 
Published: May 2009

AbstractSynthetic methods: Lithium diisopropylamide‐mediated highly selective carbolithiation reactions of vinylidenecyclopropanes are described and further transformations of these adducts were performed in the presence of Lewis or Brønsted acids (see scheme for sample reactions).magnified imageHighly stereo‐ and regioselective carbolithiation reactions of vinylidenecyclopropanes 1 were realized by treatment with lithium diisopropylamide (LDA) in THF and by quenching with various electrophiles such as aryl or aliphatic aldehydes, ketones, enones or propargyl bromide. Transformation of these adducts such as vinylcyclopropenes and allenols was also performed in the presence of Lewis acid or Brønsted acid to provide the fused and conjugated aromatic products in good to high yields under mild conditions.