bluuebunny/crossref_metadata_2025_split huggingface dataset:
Engineered enzymes for chemical production
Authors: Luetz Stephan , Giver Lori , Lalonde James 
Published: August 2008

AbstractIn order to enable competitive manufacturing routes, most biocatalysts must be tailor‐made for their processes. Enzymes from nature rarely have the combined properties necessary for industrial chemical production such as high activity and selectivity on non‐natural substrates and toleration of high concentrations of organic media over the wide range of conditions (decreasing substrate, increasing product concentrations, solvents, etc.,) that will be present over the course of a manufacturing process. With the advances in protein engineering technologies, a variety of enzyme properties can be altered simultaneously, if the appropriate screening parameters are employed. Here we discuss the process of directed evolution for the generation of commercially viable biocatalysts for the production of fine chemicals, and how novel approaches have helped to overcome some of the challenges. Biotechnol. Bioeng. 2008;101: 647–653. © 2008 Wiley Periodicals, Inc.
Emulating human perception of motion similarity
Authors: Tang Jeff K. T. , Leung Howard , Komura Taku , Shum Hubert P. H. 
Published: August 2008

AbstractEvaluating the similarity of motions is useful for motion retrieval, motion blending, and performance analysis of dancers and athletes. Euclidean distance between corresponding joints has been widely adopted in measuring similarity of postures and hence motions. However, such a measure does not necessarily conform to the human perception of motion similarity. In this paper, we propose a new similarity measure based on machine learning techniques. We make use of the results of questionnaires from subjects answering whether arbitrary pairs of motions appear similar or not. Using the relative distance between the joints as the basic features, we train the system to compute the similarity of arbitrary pair of motions. Experimental results show that our method outperforms methods based on Euclidean distance between corresponding joints. Our method is applicable to content‐based motion retrieval of human motion for large‐scale database systems. It is also applicable to e‐Learning systems which automatically evaluates the performance of dancers and athletes by comparing the subjects' motions with those by experts. Copyright © 2008 John Wiley & Sons, Ltd.
Supramolecular Domains in Mixed Peptide Self‐Assembled Monolayers on Gold Nanoparticles
Authors: Duchesne Laurence , Wells Geoff , Fernig David G. , Harris Sarah A. , Lévy Raphaël 
Published: August 2008

AbstractSelf‐organization in mixed self‐assembled monolayers of small molecules provides a route towards nanoparticles with complex molecular structures. Inspired by structural biology, a strategy based on chemical cross‐linking is introduced to probe proximity between functional peptides embedded in a mixed self‐assembled monolayer at the surface of a nanoparticle. The physical basis of the proximity measurement is a transition from intramolecular to intermolecular cross‐linking as the functional peptides get closer. Experimental investigations of a binary peptide self‐assembled monolayer show that this transition happens at an extremely low molar ratio of the functional versus matrix peptide. Molecular dynamics simulations of the peptide self‐assembled monolayer are used to calculate the volume explored by the reactive groups. Comparison of the experimental results with a probabilistic model demonstrates that the peptides are not randomly distributed at the surface of the nanoparticle, but rather self‐organize into supramolecular domains.
Stereoselective Synthesis of 4‐Dehydroxydiversonol Employing Enantioselective Palladium‐Catalysed Domino Reactions
Authors: Tietze Lutz F. , Spiegl Dirk A. , Stecker Florian , Major Julia , Raith Christian , Große Christian 
Published: August 2008

AbstractThe stereoselective synthesis of 4‐dehydroxydiversonol (4) employing enantioselective palladium‐catalysed domino processes such as the domino Wacker–Heck and the domino Wacker‐carbonylation reaction for the formation of the central chroman moiety is described. Thus, reaction of 8 with palladium(II) trifluoroacetate [Pd(OTFA)2] in the presence of carbon monoxide, methanol and the 2,2′‐ bis(oxazolin‐2‐yl)‐1,1'‐binaphthyl (BOXAX) ligand 17 led to 19 in 80 % yield and 96 % ee. Similarly, the chroman 7 was prepared using 8 and methyl acrylate (9) as starting material. Hydrogenation of the double bond, oxidation of the benzylic methylene group and intramolecular acylation of chromanone 6 provided the tetrahydroxanthenone core 5, from which the synthesis of 4 was completed. The relative configuration of 4 could be established by crystal structure analysis.
Enantioselective recognitions of chiral molecular tweezers containing imidazoliums for amino acids
Authors: Su Xiaoyu , Luo Kui , Xiang Qingxiang , Lan Jingbo , Xie Rugang 
Published: August 2008

AbstractTwo kinds of novel chiral molecular tweezers containing imidazoliums were synthesized from L‐alanine, L‐phenylalanine, and L‐glutamic acid. They are constructed by the chiral imidazolium pincers and two different spacers which are 1,3‐bis (bromomethyl)benzene and 2,6‐bis(bromomethyl)pyridine, respectively. The enantioselective recognition of L‐ and D‐amino acid derivatives by these molecular tweezers was investigated by UV spectroscopic titration experiments and good enantioselectivities were obtained, which are highly sensitive to whether the spacer has the binding site and the pincers has the other aromatic rings besides imidazolium ring. The host molecular 3b.2PF6− showed remarkable enantioselectivity for N‐Boc protected histidine methyl ester, affording KL/KD of 5.10. Chirality, 2009. © 2008 Wiley‐Liss, Inc.
Racial disparities in recurrence among patients with early‐stage endometrial cancer
Authors: Maxwell G. Larry , Tian Chunqiao , Risinger John I. , Hamilton Chad A. , Barakat Richard R. 
Published: August 2008

AbstractBACKGROUND.Population‐based studies suggest that, because of inequalities in treatment, black women with localized endometrial cancer have shorter survival compared with white women. The objective of the current investigation was to determine whether there is a racial disparity in outcome between black patients and white patients with early‐stage endometrial cancer treated similarly in a clinical trial setting.METHODS.A retrospective review of 110 black patients and 1049 white patients with stage I and II endometrial cancer (graded according to the International Federation of Gynecology and Obstetrics grading system) was performed using data from a randomized, placebo‐controlled trial performed by the Gynecologic Oncology Group that evaluated postoperative estrogen replacement therapy (ERT) and the risk of cancer recurrence. Demographic, pathologic, treatment, and outcome‐related data were collected and analyzed using regression and survival analysis.RESULTS.Estimates of recurrence‐free survival suggested that black patients may be more likely to have disease recurrence, particularly those receiving ERT. Within a median follow‐up of 3 years, 5 of 56 black patients with endometrial cancer in the ERT group were identified with recurrent disease compared with only 8 of 521 white patients. Adjusted for age, body mass index, and tumor grade, the relative risk of recurrence among blacks in the ERT group was 11.2 (95% confidence interval, 2.86‐43.59; P = .0005).CONCLUSIONS.The findings of the current study suggested that recurrence‐free survival may be shorter among black women with stage I endometrial cancer, even in a clinical trials setting in which patients receive similar treatment and follow‐up. This increased risk of recurrence appeared to be most evident in black women with endometrial cancer who maintained ERT after primary treatment. Cancer 2008. Published 2008 by the American Cancer Society.
Psychologists' judgements of diagnostic activities: deviations from a theoretical model
Authors: Groenier Marleen , Pieters Jules M. , Hulshof Casper D. , Wilhelm Pascal , Witteman Cilia L. M. 
Published: August 2008

AbstractIn this article, we describe an investigation into the diagnostic activities of practicing clinical psychologists. Two questionnaires were filled in by 313 psychologists. One group of psychologists (N = 175) judged the necessity of diagnostic activities; the other group (N = 138) selected the activities they would actually perform. Results showed that more participants thought that diagnostic activities were necessary than there were participants who intended to actually perform those activities. Causal analysis, by generating and testing diagnostic hypotheses to form an integrated client model with an explanation for the problem, was judged least necessary and would not be performed. We conclude that a discrepancy exists between the number and types of activities psychologists judged to be necessary and they intend to actually perform. The lack of attention for causal analysis is remarkable as causal explanations are crucial to effective treatment planning. Copyright © 2008 John Wiley & Sons, Ltd.
Flow cytometric investigations of diploid and tetraploid plants and in vitro cultures of Datura stramonium and Hyoscyamus niger
Authors: Weber Jost , Georgiev Vasil , Pavlov Atanas , Bley Thomas 
Published: August 2008

AbstractPlant in vitro systems are valuable sources for the production of biological active substances. However, changed profiles of secondary metabolites, and low, variable yields possibly caused by genetic instabilities complicate their industrial implementation. DNA profiling of plant in vitro cultures may provide data for the selection of highly producing in vitro cultures. Diploid and tetraploid Datura stramonium and Hyoscyamus niger plant as well as calli, and hairy root lines derived from them were analyzed by flow cytometry. Plant in vitro cultures undergo several cycles of endoreduplication more than the explants from which they were obtained. The highest cycle values were observed in calli (e.g. 1.19 for diploid H. niger) possibly induced by the growth factors. However, hairy roots cultivated without growth factor exhibited significant degrees of endoreduplication (cycle value 0.88 for diploid H. niger). Sets of five hairy root lines from each plant and ploidy level showed consistent within‐set ploidy patterns. The ploidy profiles of investigated plant in vitro and in vivo differ. For the first time we report that hairy roots of two Solanaceae species undergo endoreduplication. Theploidy profiles of in vitro cultures (hairy roots and calli) seem to be influenced by the genome size, the growth factors applied, and the type of in vitro culture. The transformation of several hairy root lines showed no differences in the ploidy patterns. © 2008 International Society for Advancement of Cytometry
An energy‐efficient localized topology control algorithm for wirelessad hocand sensor networks
Authors: Liu Haitao , Zhang Baoxian , Zheng Jun , Mouftah Hussein T. 
Published: August 2008

AbstractTopology control plays an important role in the design of wirelessad hocand sensor networks and has demonstrated its high capability in constructing networks with desirable characteristics such as sparser connectivity, lower transmission power, and smaller node degree. However, the enforcement of a topology control algorithm in a network may degrade the energy‐draining balancing capability of the network and thus reduce the network operational lifetime. For this reason, it is important to take into account energy efficiency in the design of a topology control algorithm in order to achieve prolonged network lifetime. In this paper, we propose a localized energy‐efficient topology control algorithm for wirelessad hocand sensor networks with power control capability in network nodes. To achieve prolonged network lifetime, we introduce a concept called energy criticality avoidance and propose an energy criticality avoidance strategy in topology control and energy‐efficient routing. Through theoretical analysis and simulation results, we prove that the proposed topology control algorithm can maintain the global network connectivity with low complexity and can significantly prolong the lifetime of a multi‐hop wireless network as compared with existing topology control algorithms with little additional protocol overhead. Copyright © 2008 John Wiley & Sons, Ltd.
Robust blind PIC with adaptive despreader and improved interference estimator
Authors: Shakya Indu , Ali Falah H. , Stipidis Elias 
Published: August 2008

AbstractAn effective design of multistage parallel interference cancellation (PIC) receiver using blind adaptive (BA) despreader and pre‐respreader interference estimator for uplink CDMA is proposed and analysed. A novel algorithm is designed, which exploits constant modulus (CM) property of the users' transmitted signals and inherent channel condition to perform adaptive despreading based on minimum error variance criteria. This is carried out by BA weighting of each chip signal for accurate tracking of the desired user's signal power and hence for more improved data detection at the output of each stage of PIC. Furthermore, the despreader weights are used within the adaptive pre‐respreader interference estimation and cancellation to obtain online scaling factors during every symbol period, without any knowledge of users' channels or the use of training sequences. It is found that this way of estimation is optimal in minimum mean squared error sense, and hence, significant reduction in interference and noise variance is observed in detection and estimation of the desired users' signals compared with conventional PIC. Bit error probability of the proposed PIC is obtained using Gaussian Approximation method. Extensive simulation results are shown, which demonstrate impressive performance advantage in fading environments, high system loading, and severe near far conditions. Copyright © 2008 John Wiley & Sons, Ltd.
Quantitative analysis of microtubule dynamics during adhesion‐mediated growth cone guidance
Authors: Lee Aih Cheun , Suter Daniel M. 
Published: August 2008

AbstractDuring adhesion‐mediated neuronal growth cone guidance microtubules undergo major rearrangements. However, it is unknown whether microtubules extend to adhesion sites because of changes in plus‐end polymerization and/or translocation dynamics, because of changes in actin–microtubule interactions, or because they follow the reorganization of the actin cytoskeleton. Here, we used fluorescent speckle microscopy to directly quantify microtubule and actin dynamics in Aplysia growth cones as they turn towards beads coated with the cell adhesion molecule apCAM. During the initial phase of adhesion formation, dynamic microtubules in the peripheral domain preferentially explore apCAM‐beads prior to changes in growth cone morphology and retrograde actin flow. Interestingly, these early microtubules have unchanged polymerization rates but spend less time in retrograde translocation due to uncoupling from actin flow. Furthermore, microtubules exploring the adhesion site spend less time in depolymerization. During the later phase of traction force generation, the central domain advances and more microtubules in the peripheral domain extend because of attenuation of actin flow and clearance of F‐actin structures. Microtubules in the transition zone and central domain, however, translocate towards the adhesion site in concert with actin arcs and bundles, respectively. We conclude that adhesion molecules guide neuronal growth cones and underlying microtubule rearrangements largely by differentially regulating microtubule–actin coupling and actin movements according to growth cone region and not by controlling plus‐end polymerization rates. © 2008 Wiley Periodicals, Inc. Develop Neurobiol, 2008
IR Laser‐Induced Carbothermal Reduction of Silica
Authors: Urbanová Markéta , Pokorná Dana , Bakardjieva Snejana , Šubrt Jan , Bastl Zdeněk , Pola Josef 
Published: August 2008

AbstractPulsed IR‐laser irradiation of silica in the presence of gaseous hydrocarbons (benzene or ethyne) results in carbothermal reduction of silica by hydrocarbon decomposition products and allows deposition of amorphous solids which were analyzed by FTIR, Raman, X‐ray photoelectron and Auger spectra and by electron microscopy and revealed as nanosized carbon–silicon oxycarbide composites containing crystalline silica domains. The reported IR laser‐induced process is the first approach to deposition of nanosized carbon–silicon oxycarbide composites. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Cell adhesion and proliferation are reduced on stainless steel coated with polysaccharide‐based polymeric formulations
Authors: Vicario Pasquale P. , Lu Zichun , Grigorian Irina , Wang Zheng , Schottman Tom 
Published: August 2008

AbstractHydromer's polymeric formulations F200™ and F202™ were evaluated after application to a synthetic substrate for effects on cell adhesion and proliferation. A significant reduction in cell adhesion was observed when cells grown on medical‐grade stainless steel coated with these polymers were stained and examined under a fluorescence microscope. This reduction in cell adhesion/proliferation was confirmed when cells were isolated and analyzed by the MTS cell proliferation assay. The rate of growth of cells on F200‐ and F202‐coated stainless steel monitored over a period of 7 days was significantly less than that observed on uncoated stainless steel, suggesting that the rate of growth of cells was reduced. The adhesion/proliferation of human umbilical vein endothelial cells (HUVEC) to coated substrates was also decreased significantly, indicating that the reduction in cell adhesion/proliferation is not restricted to only fibroblasts. Additional studies have indicated that the adhesion/proliferation of murine fibroblasts and human endothelial cells to stainless coated with a modified formulation exhibiting a high degree of lubricity was also significantly reduced. This lubricious formulation was also observed to be effective in reducing platelet adhesion, data supporting the view that lubricity also contributes to a reduction in cell and platelet adhesion. The application of these polymeric coatings on devices designed for medical implantation may not only prevent thrombus formation but may also retard the process of restenosis. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Predictors of grief following the death of one's child: the contribution of finding meaning
Authors: Keesee Nancy J. , Currier Joseph M. , Neimeyer Robert A. 
Published: August 2008

AbstractThis study examined the relative contribution of objective risk factors and meaning‐making to grief severity among 157 parents who had lost a child to death. Participants completed the Core Bereavement Items (CBI; Burnett, Middleton, Raphael, & Martinek, 1997), Inventory of Complicated Grief (ICG; Prigerson et al., 1995), questions assessing the process and degree of sense‐making and benefit‐finding, and the circumstances surrounding their losses. Results showed that the violence of the death, age of the child at death, and length of bereavement accounted for significant differences in normative grief symptoms (assessed by the CBI). Other results indicated that the cause of death was the only objective risk factor that significantly predicted the intensity of complicated grief (assessed by the ICG). Of the factors examined in this study, sense‐making emerged as the most salient predictor of grief severity, with parents who reported having made little to no sense of their child's death being more likely to report greater intensity of grief. Implications for clinical work are discussed. © 2008 Wiley Periodicals, Inc. J Clin Psychol 64:1–19, 2008.
Skull anatomy of the miniaturized gecko Sphaerodactylus roosevelti (Squamata: Gekkota)
Authors: Daza Juan D. , Abdala Virginia , Thomas, Richard , Bauer Aaron M. 
Published: August 2008

AbstractA detailed description of the skull and jaw of the gecko Sphaerodactylus roosevelti is presented. The bones are described articulated and isolated with special consideration given to the type of suture among joining elements. S. roosevelti was compared with 109 gekkotan species to evaluate the osteological variation and to find characters for cladistic analysis. Changes in the skull associated with the miniaturization process are discussed within the sphaerodactylid geckos. A noticeable increase of overlapping sutures was observed in the snout of the smallest sphaerodactylids compared to other gekkotans. This pattern is convergent with that in miniaturized pygopodids and may be attributed to adaptations for decreasing mechanical resistance of the cranium during feeding or burrowing. New cranial characters support Sphaerodactylinae as a monophyletic group and should be useful for resolving questions such as their relationship with other gekkotans. J. Morphol. 269:1340–1364, 2008. © 2008 Wiley‐Liss, Inc.
A kinetic study of guest displacement reactions on a host–guest complex with a photoswitchable calixarene
Authors: Letzel Matthias C. , Schäfer Christian , Novara Francesca R. , Speranza Maurizio , Rozhenko Alexander B. , Schoeller Wolfgang W. , Mattay Jochen 
Published: August 2008

AbstractThe displacement processes of several guests, incorporated in a calixarene host system, were investigated in the gas phase by electrospray ionization‐Fourier transform‐ion cyclotron resonance (ESI‐FT‐ICR) mass spectrometry. The complexes resulting from a resorcin[4]arene host with ammonia and sec‐butylamine guests were isolated in an ICR‐cell, separately using both states of the photoswitch as well as two reference systems for the open and closed forms of the photoswitchable host. The isolated complexes were forced to exchange the guest by using methylamine, ethylamine and sec‐butylamine, resulting in different reaction rates for all the measured systems. Especially, the reaction rates of both states of the photoswitch are dependent on the provided guest. Potential side effects like proton exchanges were examined by an H/D‐exchange experiment. The results were investigated and supported by quantum chemical calculations (DFT). Copyright © 2008 John Wiley & Sons, Ltd.
Oscore: a combined score to reduce false negative rates for peptide identification in tandem mass spectrometry analysis
Authors: Shao Chen , Sun Wei , Li Fuxin , Yang Ruifeng , Zhang Ling , Gao Youhe 
Published: August 2008

AbstractTandem mass spectrometry (MS/MS) has been widely used in proteomics studies. Multiple algorithms have been developed for assessing matches between MS/MS spectra and peptide sequences in databases. However, it is still a challenge to reduce false negative rates without compromising the high confidence of peptide identification. In this study, we developed the score, Oscore, by logistic regression using SEQUEST and AMASS variables to identify fully tryptic peptides. Since these variables showed complicated association with each other, combining them together rather than applying them to a threshold model improved the classification of correct and incorrect peptide identifications. Oscore achieved both a lower false negative rate and a lower false positive rate than PeptideProphet on datasets from 18 known protein mixtures and several proteome‐scale samples of different complexity, database size and separation methods. By a three‐way comparison among Oscore, PeptideProphet and another logistic regression model which made use of PeptideProphet's variables, the main contributor for the improvement made by Oscore is discussed. Copyright © 2008 John Wiley & Sons, Ltd.