bluuebunny/crossref_metadata_2025_split huggingface dataset:
Highly Functionalised Enantiopure 4‐Hydroxypyridine Derivatives by a Versatile Three‐Component Synthesis
Authors: Eidamshaus Christian , Reissig Hans‐Ulrich 
Published: May 2009

Abstractmagnified imageThe scope of a novel alkoxyallene‐based pyridine synthesis was expanded to enantiopure carboxylic acids and nitriles as starting materials. The enantiomeric purity of the chiral α‐secondary carboxylic acids and nitriles was completely preserved during this reaction sequence thus allowing the one‐pot preparation of a whole range of 4‐hydroxypyridines or their 4‐pyridinone tautomers in good yields.
Use of the Chiral Pool – Practical Asymmetric Organocatalytic Strecker Reaction with Quinine
Authors: Reingruber Rüdiger , Baumann Thomas , Dahmen Stefan , Bräse Stefan 
Published: May 2009

Abstractmagnified imageAn efficient, organocatalytic enantioselective synthesis of N‐arylsulfonyl α‐amino nitriles from the corresponding α‐amido sulfones has been developed. This quinine‐catalyzed Strecker reaction provides the corresponding cyanated products in good yields and enantioselectivities.
Enantioselective Copper‐Catalyzed Allylic Substitution Reaction with Aminohydroxyphosphine Ligand
Authors: Yoshikai Naohiko , Miura Kotaro , Nakamura Eiichi 
Published: May 2009

Abstractmagnified imageA proline‐derived aminohydroxyphosphine ligand induced excellent regio‐ and enantioselectivities (SN2′:SN2>94:6, 94–97% ee) in the copper‐catalyzed substitution reaction of cinnamyl phosphates with Et2Zn. A computational modelling study of the reaction pathway suggests that the displacement of the leaving group takes place in an ordered, anti‐fashion through simultaneous copper–olefin and zinc–oxygen interactions, which is critical for the enantioselection.
Terephthalic acid synthesis at higher concentrations in high‐temperature liquid water. 2. Eliminating undesired byproducts
Authors: Osada Mitsumasa , Savage Phillip E. 
Published: May 2009

AbstractWe synthesized terephthalic acid (TPA) from p‐xylene at an initial concentration above its solubility limit in high‐temperature liquid water (HTW). The nominal p‐xylene loading at the reaction conditions was 0.4 mol L−1, which is the highest reported to date for generation of high TPA yields (>70 mol %) in HTW. The presence of two liquid phases during the reaction did not appear to accelerate the rate, unlike behavior reported for some other organic reactions done “on water” at lower temperatures. Adding oxygen gas in a large increment during synthesis produced a black liquid and a black solid byproduct, which is a previously undocumented problem. Adding oxygen in smaller increments prevented formation of the liquid and solid byproducts and also provided high selectivities (90 mol %) and yields (>70 mol %) of TPA. These results demonstrate the feasibility of HTW as a medium for TPA synthesis at p‐xylene concentrations even higher than its solubility limit. © 2009 American Institute of Chemical Engineers AIChE J, 2009
Theoretical analysis of the effects of asymmetric membrane structure on fouling during microfiltration
Authors: Li Weiyi , Duclos‐Orsello Chase , Ho Chia‐Chi 
Published: May 2009

AbstractThere is a growing interest in the use of both asymmetric and composite membranes for microfiltration and ultrafiltration processes. This includes particle removal applications in the semiconductor industry and virus clearance in biopharmaceutical applications. Filter fouling plays an important role in these processes. Although flux decline models have been developed for homogeneous membranes, the effects of asymmetric membrane structure on flux decline behavior remain poorly understood on a fundamental level. Here, we develop a theoretical model to describe the effects of asymmetric membrane structure on flux decline. The asymmetric structure was described by the spatial variation in Darcy permeability in the directions normal to and parallel to the membrane surface. The velocity profile and flux decline because of pore blockage were described using Darcy's law and a pore blockage and cake filtration model. Flux decline data were obtained using pseudocomposite membranes with highly interconnected polyvinylidene fluoride membranes (PVDF) and straight through pore polycarbonate track‐etched membranes (PCTE). Model composite membranes were formed by layering PCTE or PVDF membranes with different pore sizes on top of each other. Flux decline data for the composite membrane were in good agreement with model calculations. The results provide important insights into the effects of asymmetric membrane pore structures on flux decline. © 2009 American Institute of Chemical Engineers AIChE J, 2009
Description of the mutual solubilities of fatty acids and water with the CPA EoS
Authors: Oliveira M. B. , Pratas M. J. , Marrucho I. M. , Queimada A. J. , Coutinho J. A. P. 
Published: May 2009

AbstractData for the mutual solubilities of fatty acid + water mixtures are scarce and so measurements for seven fatty acid (C5‐C10, C12) + water systems were carried out. This new experimental data was successfully modelled with the cubic plus association EoS. Using data from C6 to C10 and the Elliot's cross‐associating combining rule a correlation for the kij binary interaction parameter, as a function of the acid chain length, is proposed. The mutual solubilities of water and fatty acids can be adequately described with average deviations inferior to 6% for the water rich phase and 30% for the acid rich phase. Furthermore, satisfactory predictions of solid‐liquid equilibria of seven fatty acids (C12‐C18) + water systems were achieved based only on the kij correlation obtained from liquid–liquid equilibria data. © 2009 American Institute of Chemical Engineers AIChE J, 2009
Women's fertility and mortality in late mid life: A comparison of three contemporary populations
Authors: Grundy Emily 
Published: May 2009

AbstractEvolutionary theory suggests a trade‐off between reproduction and somatic maintenance implying a negative relationship between parity and longevity, at least in natural fertility populations. In populations in which fertility control is usual, there are also a number of mechanisms that may link reproductive careers and later mortality, but evidence of associations between women's fertility patterns and their later life health has been judged inconclusive due to varying controls for socio‐economic characteristics and marital status. Here, we build on three recent studies that followed a common framework to investigate associations between women's parity and timing of first and last birth with mortality in late middle age in three contemporary developed counties, Norway, England and Wales, and the USA. Data were drawn from whole population registers (Norway); a large census‐based record linkage study (England and Wales), and a nationally representative survey linked to death records (USA). Results show that teenage childbirth was associated with higher mortality risks in late middle age in all three countries. Risks of death were significantly raised among nulliparous women in Norway and England and Wales, and also raised (although not significantly so) for childless US women. However, although higher parity was associated with a slight mortality disadvantage in England and Wales and the USA, the reverse seemed the case in Norway. These finding suggest that in populations in which fertility control is usual, contextual factors influencing the relative costs and benefits of childbearing may influence associations between fertility histories and later mortality. Am. J. Hum. Biol., 2009. © 2009 Wiley‐Liss, Inc.
An fMRI study of working memory in persons with bipolar disorder or at genetic risk for bipolar disorder
Authors: Thermenos Heidi W. , Goldstein Jill M. , Milanovic Snezana M. , Whitfield‐Gabrieli Susan , Makris Nikos , LaViolette Peter , Koch Jennifer K. , Faraone Stephen V. , Tsuang Ming T. , Buka Stephen L. , Seidman Larry J. 
Published: May 2009

AbstractFirst‐degree relatives of persons with bipolar disorders (BDs) carry elevated risk for the illness, and manifest deficits in attention and memory (possible “endophenotypes”). However, there is only one published functional magnetic resonance imaging (fMRI) study of candidate endophenotypes in BD. We used fMRI to examine brain function in BD and in first‐degree relatives performing a 2‐back working memory (WM) task, and correlated brain activity with mood measures taken at the scanning session. Subjects (age 32–46) were 19 persons with BD, 18 unmedicated, non‐psychotic first‐degree relatives (RELs) of persons with BD, and 19 matched controls, ascertained from a long‐term follow‐up of a prenatal cohort study in New England. fMRI signal during 2‐back and 0‐back WM tasks was measured on a Siemens 1.5T MR scanner. fMRI data were analyzed using SPM‐2. Persons with BD and RELs failed to suppress activation in the left anterior insula (BA 13) during WM, whereas controls suppressed activation. Compared to controls, RELs also failed to suppress activation in the orbitofrontal cortex (OFC) and superior parietal cortex. Controls and RELs exhibited greater activation than BD individuals in the left frontopolar cortex (BA 10) during WM. Results remained significant after controlling for confounders except for mild attenuation of OFC findings. Significant correlations between brain activity, mood, and WM suggest that activity in WM circuits is affected by activity in emotion‐regulatory circuits. Persons with BD and RELs exhibit altered activity in the frontopolar cortex and insula, which may represent biomarkers of genetic risk for BD. © 2009 Wiley‐Liss, Inc.
The dangers of multi‐male groupings: trauma and healing in cercopithecoid monkeys from Cameroon
Authors: Chapman Tara J. , Legge Scott S. 
Published: May 2009

AbstractThis study examines the potential linkage between social organization and trauma in a sample of cercopithecids from Cameroon. Skeletal trauma is described in a museum collection of eight sympatric monkey species. Macroscopic analysis was carried out on a total of 139 complete skeletons of mangabeys, colobines and guenons. Species in multi‐male groups were found to have higher fracture frequencies than those in uni‐male groups. These higher frequencies may be related to intra‐specific male–male aggression; however, similarities in fracture patterning between males and females in multi‐male groups suggest that other factors may be involved. Although fracture etiology may not be identified with certainty, this study suggests that predation may indirectly be a cause of traumatic injuries in those species of cercopithecid monkeys displaying multi‐male social organizations. The data presented also highlight the utility of museum collections as an additional resource in analyses of primate behavior, demonstrating that behavioral information does not die when the animal does. Am. J. Primatol. 71:567–573, 2009. © 2009 Wiley‐Liss, Inc.
Molecular Photoacoustic Tomography with Colloidal Nanobeacons
Authors: Pan Dipanjan , Pramanik Manojit , Senpan Angana , Yang Xinmai , Song Kwang H. , Scott Mike J. , Zhang Huiying , Gaffney Patrick J. , Wickline Samuel A. , Wang Lihong V. , Lanza Gregory M. 
Published: May 2009

AbstractErkennung von Engpässen: Goldhaltige Kolloidpartikel wie die abgebildeten GNBs („gold nanobeacons“) eignen sich als exogene Kontrastmittel zur Erkennung von Fibrin, einem biochemischen Anzeiger der Thrombenbildung. Fibrinbindende GNBs ergaben eine zehnfache Signalverstärkung bei der photoakustischen Tomographie im Nah‐IR‐Bereich und könnten daher für diagnostische Bildgebungsverfahren interessant sein.magnified image
Linearer Aufbau eines reinen Glykoenzyms
Authors: Davis Benjamin G. 
Published: May 2009

AbstractAus Liebe zur Sache: Die Synthese der aktiven reinen Glykoform eines Enzyms (RNase) durch native chemische Ligation eines (Glyko)Peptids mit Peptidthioester‐Fragmenten erforderte eine Reihe mühsamer Schritte: Optimierung der Strategie, Gewinnung aktiver Inteine, Feinabstimmung von Redoxbedingungen und die Synthese der Glykoaminosäuren‐Bausteine.magnified image
A Microreactor with Thousands of Subcompartments: Enzyme‐Loaded Liposomes within Polymer Capsules
Authors: Städler Brigitte , Chandrawati Rona , Price Andrew D. , Chong Siow‐Feng , Breheney Kerry , Postma Almar , Connal Luke A. , Zelikin Alexander N. , Caruso Frank 
Published: May 2009

AbstractVollgeladen: Durch nichtkovalente Verankerung von Liposomen auf mehrschichtigen Polymerfilmen mit Cholesterin‐modifizierten Polymeren gelingt die Herstellung von Kapsosomen – Polymerkapseln mit Liposom‐Kompartimenten (siehe Bild). Eine quantitative enzymatische Reaktion bestätigte das Vorliegen einer aktiven eingelagerten Spezies in den Kapsosomen und diente zur Bestimmung der Zahl an Kompartimenten im neuen biomedizinischen Trägersystem.magnified image
Molecular Photoacoustic Tomography with Colloidal Nanobeacons
Authors: Pan Dipanjan , Pramanik Manojit , Senpan Angana , Yang Xinmai , Song Kwang H. , Scott Mike J. , Zhang Huiying , Gaffney Patrick J. , Wickline Samuel A. , Wang Lihong V. , Lanza Gregory M. 
Published: May 2009

AbstractSpotting clots: Vascularly constrained colloidal gold nanobeacons (GNBs; see picture) can be used as exogenous photoacoustic contrast agents for the targeted detection of fibrin, a major biochemical feature of thrombus. Fibrin‐targeted GNBs provide a more than tenfold signal enhancement in photoacoustic tomography in the near‐IR wavelength window, indicating their potential for diagnostic imaging.magnified image
The Linear Assembly of a Pure Glycoenzyme
Authors: Davis Benjamin G. 
Published: May 2009

AbstractA labor of love: The synthesis of an active pure enzyme (RNase) glycoform by the native chemical ligation of a (glyco)peptide and peptide thioester fragments required numerous painstaking steps: the strategy was optimized, active inteins accessed, redox conditions fine‐tuned, and glycoamino acid building blocks synthesized.magnified image
A Microreactor with Thousands of Subcompartments: Enzyme‐Loaded Liposomes within Polymer Capsules
Authors: Städler Brigitte , Chandrawati Rona , Price Andrew D. , Chong Siow‐Feng , Breheney Kerry , Postma Almar , Connal Luke A. , Zelikin Alexander N. , Caruso Frank 
Published: May 2009

AbstractFully loaded: Noncovalent anchoring of liposomes into polymer multilayered films with cholesterol‐modified polymers allows the preparation of capsosomes—liposome‐compartmentalized polymer capsules (see picture). A quantitative enzymatic reaction confirmed the presence of active cargo within the capsosomes and was used to determine the number of subcompartments within this novel biomedical carrier system.magnified image
Implementation of Design of Experiments projects in industry
Authors: Tanco Martín , Viles Elisabeth , Ilzarbe Laura , Alvarez María Jesus 
Published: May 2009

AbstractAlthough design of experiments (DoE) is a common feature of statistics and quality literature, it is insufficiently used in industry. Surveys and numerous articles alike have verified that a gap exists between theoretical development and its effective application in industry. Therefore, we have developed a complete, friendly and easy‐to use methodology, from an engineering point of view, to ease the implementation of DoE in companies. Our approach presents a framework for the experimentation process that follows the traditional DMAIC steps of ‘Six Sigma’ as a generic problem solving methodology. We aim to present a complete overview of the experimentation process useful for those engineers, statisticians and scientists who are not experts in DoE. Copyright © 2009 John Wiley & Sons, Ltd.
Leukocyte depletion for safe blood transfusion
Authors: Singh Shikha , Kumar Ashok 
Published: May 2009

AbstractLeukocytes have ability to distinguish between self cells (body own cells) and foreign (allogenic) cells on the basis of human leukocyte antigen (HLA) proteins that are present on the cell membrane and are effectively unique to a person. During allogenic blood transfusion a person receives large number of allogenic donor leukocytes and these are recognized as foreign cells by the recipient immune system which leads to several adverse reactions. To avoid such leukocyte‐mediated adverse reactions leukodepleted blood transfusion is required. Leukocytes can be separated on the basis of size, dielectric properties, by affinity separation, freeze‐thawing and centrifugation but all these methods are time consuming and costly. Filtration is another method for leukocyte depletion that is comparatively less expensive and more efficient as it gives more than 90% leukodepletion of blood along with minimal cell loss. However, present filtration procedures also have some limitations as they work efficiently with blood components but not with whole blood and show non‐specific adhesion of large number of platelets and red blood cells along with leukocytes. All the currently available filters are costly, which has been a major reason for their limited application. Therefore, demand for a more efficient and cost‐effective filter is high in medical community and scientists are attenpting to improve the efficiency of currently available filters. The present review gives an overview of the significance of leukodepleted blood transfusion and focuses on different methods for leukocyte depletion and challenges involved in all these technologies.
Substrate and water adsorption phenomena in a gas/solid enzymatic reactor
Authors: Dimoula Kerasina , Pohl Martina , Büchs Jochen , Spiess Antje C. 
Published: May 2009

AbstractThe adsorption of water and substrates to dry deposited alcohol dehydrogenase from Lactobacillus brevis (LBADH) is studied in a continuous enzymatic gas/solid reactor. This work is aiming at obtaining a deeper and more thorough understanding of the enzyme microenvironment in the gas/solid system of acetophenone reduction with concomitant oxidation of 2‐propanol. Extensive water adsorption studies showed that the effect of sucrose in the enzyme preparation on the water adsorption isotherm is significant for water activities exceeding 0.5 and reaches a factor 2 with respect to bead mass at water activity of 0.9. Significant hysteresis during water desorption is identified, resulting in up to 0.6 mgwater/mgprotein, for lyophilized enzyme preparation and up to 10 mgwater/mgprotein for deposited enzyme preparation. The adsorption of the substrates is quantified here for the first time. Whereas the adsorption of the main substrate, acetophenone, may reach a significant level of up to 6 mg/mgprotein, at an acetophenone activity of 0.32, the secondary substrate, 2‐propanol is not adsorbed at a detectable degree. The presence of water leads to a decrease of the adsorbed amount of acetophenone, by approximately 25%, at a water activity of 0.54.
Synthesis of alkyl esters by cutinase in miniemulsion and organic solvent media
Authors: de Barros Dragana P. C. , Fonseca Luís P. , Cabral Joaquim M. S. , Weiss Clemens K. , Landfester Katharina 
Published: May 2009

AbstractThe main objective of this work was studying and testing the nature and influence of reaction media (organic solvent vs. miniemulsion system) on the synthesis of alkyl esters catalyzed by Fusarium solani pisi cutinase. Ester synthesis and cutinase selectivity for different chain length of acids and alcohols (ethyl and hexyl) were evaluated. In iso‐octane, after 1 h of reaction, cutinase exhibits rates of esterification between 0.24 μmol x mg–1 x min–1 for ethyl oleate and 1.15 μmol x mg–1 x min–1 for ethyl butyrate, while in a miniemulsion system the rates were from 0.05 for ethyl heptanoate to 0.76 μmol x mg–1 x min–1 for ethyl decanoate. The reaction rate for the synthesis of hexyl esters in a miniemulsion system was from 0.19 for hexyl heptanoate to 1.07 μmol x mg–1 x min–1 for hexyl decanoate. High conversion yields of 95% at equilibrium after 8 h of reaction in iso‐octane for pentanoic acid (C5) with ethanol at equimolar concentration (0.1 M) was achieved. Additionally, this work showed that a significant and unexpected shift in cutinase selectivity occurred towards longer chain length carboxylic acids (C8–C10) in miniemulsion system as compared to organic solvent (iso‐octane) and previous studies in reverse micellar systems. The possibility of working with higher concentration of substrates, without inhibitory effect on the enzyme, was another advantage of the miniemulsion system.
Visualization of biomass solubilization and cellulose regeneration during ionic liquid pretreatment of switchgrass
Authors: Singh Seema , Simmons Blake A. , Vogel Kenneth P. 
Published: May 2009

AbstractAuto‐fluorescent mapping of plant cell walls was used to visualize cellulose and lignin in pristine switchgrass (Panicum virgatum) stems to determine the mechanisms of biomass dissolution during ionic liquid pretreatment. The addition of ground switchgrass to the ionic liquid 1‐n‐ethyl‐3‐methylimidazolium acetate resulted in the disruption and solubilization of the plant cell wall at mild temperatures. Swelling of the plant cell wall, attributed to disruption of inter‐ and intramolecular hydrogen bonding between cellulose fibrils and lignin, followed by complete dissolution of biomass, was observed without using imaging techniques that require staining, embedding, and processing of biomass. Subsequent cellulose regeneration via the addition of an anti‐solvent, such as water, was observed in situ and provided direct evidence of significant rejection of lignin from the recovered polysaccharides. This observation was confirmed by chemical analysis of the regenerated cellulose. In comparison to untreated biomass, ionic liquid pretreated biomass produces cellulose that is efficiently hydrolyzed with commercial cellulase cocktail with high sugar yields over a relatively short time interval. Biotechnol. Bioeng. 2009; 104: 68–75 Published 2009 Wiley Periodicals, Inc.
Metabolomics for biotransformations: Intracellular redox cofactor analysis and enzyme kinetics offer insight into whole cell processes
Authors: Schroer Kirsten , Zelic Bruno , Oldiges Marco , Lütz Stephan 
Published: May 2009

AbstractFor redox reactions catalyzed by microbial cells the analysis of involved cofactors is of special interest since the availability of cofactors such as NADH or NADPH is often limiting and crucial for the biotransformation efficiency. The measurement of these cofactors has usually been carried out using spectrophotometric cycling assays. Today LC‐MS/MS methods have become a valuable tool for the identification and quantification of intracellular metabolites. This technology has been adapted to measure all four nicotinamide cofactors (NAD, NADP, NADH, and NADPH) during a whole cell biotransformation process catalyzed by recombinant Escherichia coli cells. The cells overexpressing an alcohol dehydrogenase from Lactobacillus brevis were used for the reduction of methyl acetoacetate (MAA) with substrate‐coupled cofactor regeneration by oxidation of 2‐propanol. To test the reliability of the measurement the data were evaluated using a process model. This model was derived using the measured concentrations of reactants and cofactors for initiation as well as the kinetic constants from in vitro measurements of the isolated enzyme. This model proves to be highly effective in the process development for a whole cell redox biotransformation in predicting both the right concentrations of cofactors and reactants in a batch and in a CSTR process as well as the right in vivo expression level of the enzyme. Moreover, a sensitivity analysis identifies the cofactor regeneration reaction as the limiting step in case for the reduction of MAA to the corresponding product (R)‐methyl 3‐hydroxybutyrate. Using the combination of in vitro enzyme kinetic measurements, measurements of cofactors and reactants and an adequate model initiated by intracellular concentrations of all involved reactants and cofactors the whole cell biotransformation process can be understood quantitatively. Biotechnol. Bioeng. 2009; 104: 251–260 © 2009 Wiley Periodicals, Inc.