bluuebunny/crossref_metadata_2025_split huggingface dataset:
Steric Effects on the Stereochemistry of Old Yellow Enzyme‐Mediated Reductions of Unsaturated Diesters: Flipping of the Substrate within the Enzyme Active Site Induced by Structural Modifications
Authors: Brenna Elisabetta , Gatti Francesco G. , Manfredi Alessia , Monti Daniela , Parmeggiani Fabio 
Published: October 2012

AbstractThe ene‐reductase‐mediated reduction of the carbon‐carbon double bond of some alkyl 2‐substituted butenedioates was investigated. The stereochemical outcome of the reaction was found to be influenced by steric effects. Ethyl and butyl citraconates were converted into the corresponding alkyl (R)‐2‐methylsuccinates with excellent enantioselectivity, whereas ethyl and butyl mesaconates were completely unreactive. Methyl 2‐substituted fumarates were reduced to enantiomerically enriched methyl (S)‐2‐substituted succinates, whereas the (Z)‐stereoisomers were left unreacted by ene‐reductases. Labelling experiments were performed to investigate the mechanism of these bioreductions and explain their stereochemical outcome.
A Chemodosimetric Probe Based on a Conjugated Oxidized Bis‐Indolyl System for Selective Naked‐Eye Sensing of Cyanide Ions in Water
Authors: Kumari Namita , Jha Satadru , Bhattacharya Santanu 
Published: October 2012

AbstractA new bis‐indolyl‐based colorimetric probe has been synthesized. This allows a Michael‐type adduct formation for the detection of cyanide ions. The probe shows a remarkable color change from red to colorless upon addition of the cyanide ions in pure water. The cyanide ion reacts with the probe and removes the conjugation of the bis‐indolyl moiety of the probe with that of the 4‐substituted aromatic ring. This renders the probe colorless. The mechanism of the reaction of the probe with the cyanide ion was established by using 1H and 13C NMR spectroscopy, mass spectrometry, and kinetic studies.
Advances in the Cross‐Linguistic Study of Ideophones
Authors: Dingemanse Mark 
Published: October 2012

AbstractIdeophones are marked words that depict sensory imagery found in many of the world’s languages. They are noted for their special forms, distinct grammatical behaviour, rich sensory meanings, and interactional uses related to experience and evidentiality. This review surveys recent developments in ideophone research. Work on the semiotics of ideophones helps explain why they are marked and how they realise the depictive potential of speech. A true semantic typology of ideophone systems is coming within reach through a combination of language‐internal analyses and language‐independent elicitation tools. Documentation of ideophones in a wide variety of genres as well as sequential analysis of ideophone use in natural discourse leads to new insights about their interactional uses and about their relation to other linguistic devices like reported speech and grammatical evidentials. As the study of ideophones is coming of age, it sheds new light on what is possible and probable in human language.
Vector Space Models of Word Meaning and Phrase Meaning: A Survey
Authors: Erk Katrin 
Published: October 2012

AbstractDistributional models represent a word through the contexts in which it has been observed. They can be used to predict similarity in meaning, based on the distributional hypothesis, which states that two words that occur in similar contexts tend to have similar meanings. Distributional approaches are often implemented in vector space models. They represent a word as a point in high‐dimensional space, where each dimension stands for a context item, and a word's coordinates represent its context counts. Occurrence in similar contexts then means proximity in space. In this survey we look at the use of vector space models to describe the meaning of words and phrases: the phenomena that vector space models address, and the techniques that they use to do so. Many word meaning phenomena can be described in terms of semantic similarity: synonymy, priming, categorization, and the typicality of a predicate's arguments. But vector space models can do more than just predict semantic similarity. They are a very flexible tool, because they can make use of all of linear algebra, with all its data structures and operations. The dimensions of a vector space can stand for many things: context words, or non‐linguistic context like images, or properties of a concept. And vector space models can use matrices or higher‐order arrays instead of vectors for representing more complex relationships. Polysemy is a tough problem for distributional approaches, as a representation that is learned from all of a word's contexts will conflate the different senses of the word. It can be addressed, using either clustering or vector combination techniques. Finally, we look at vector space models for phrases, which are usually constructed by combining word vectors. Vector space models for phrases can predict phrase similarity, and some argue that they can form the basis for a general‐purpose representation framework for natural language semantics.
Human Elastin‐Based Recombinant Biopolymers Improve Mesenchymal Stem Cell Differentiation
Authors: Çelebi Betül , Cloutier Maxime , Balloni Rodrigo , Mantovani Diego , Bandiera Antonella 
Published: October 2012

AbstractElastin‐based polypeptides are a class of smart biopolymers representing an important model in the design of biomaterials. The combination of biomimetic materials with cells that have great plasticity provides a promising strategy for the realization of highly engineered cell‐based constructs for regenerative medicine and tissue repair applications. Two recombinant biopolymers inspired by human elastin are assessed as coating agents to prepare biomimetic surfaces for cell culture. These substrates are assayed for hBM MSC culture. The coated surfaces are also characterized with AFM to evaluate the topographical features of the deposited biopolymers. The results suggest that the elastin‐derived biomimetic surfaces play a stimulatory role on osteogenic differentiation of MSCs.magnified image
Comb‐Shaped Glycopolymer/Peptide Bioconjugates by Combination of RAFT Polymerization and Thiol‐Ene “Click” Chemistry
Authors: Wang Xiaobei , Liu Li , Luo Yan , Shi Haiting , Li Jingyi , Zhao Hanying 
Published: October 2012

AbstractComb‐shaped glycopolymer/peptide bioconjugates are constructed by grafting reduced glutathione (GSH) onto acrylate‐functional block glycocopolymers via thiol‐ene click chemistry. In aqueous solution, the glycopolymer/GSH bioconjugate self‐assembles to sugar‐installed spherical micelles. The size of micelles decreases with increasing pH, demonstrating pH‐responsive character. The isoelectric point (IEP) of the PMAGlc/GSH bioconjugate is estimated to be 3.43. The micelles show a specific interaction with the protein Concanavalin A. At endosomal pH, the PMAGlc/GSH bioconjugate can gradually degrade. These pH‐responsive glycopolymer/peptide micelles with biological recognition and degradation can be used as multifunctional nanocarriers for targeted drug delivery. magnified image
Thermoplastic Poly(urethane urea)s From Novel, Bio‐based Amorphous Polyester Diols
Authors: Tang Donglin , Noordover Bart A. J. , Sablong Rafael J. , Koning C. E. 
Published: October 2012

AbstractIn this study, two novel, bio‐based, amorphous polyester diols, namely poly(1,2‐dimethylethylene adipate) (PDMEA) and poly(1,2‐dimethylethylene succinate) (PDMES) are used to prepare thermoplastic poly(urethane urea)s (TPUUs). Interestingly, the TPUUs based on PDMEA show similar thermal and mechanical properties as their counterparts based on poly(1,2‐propylene glycol). By decreasing the hard segment length, the flow temperature (Tfl) of the TPUUs decreases. The Tfl values of the 3U series are around 170 °C, which is below their degradation temperatures. The methyl groups adjacent to the ester groups in PDMEA and PDMES may hinder the hydrolysis of the polyester soft segments in the TPUUs.
Efficient energy transfer between amphiphilic dendrimers with oligo(p‐phenylenevinylene) core branches and oligo(ethylene oxide) termini in micelles
Authors: Wook Chang Dong , Bae Seo‐Yoon , Dai Liming , Baek Jong‐Beom 
Published: October 2012

AbstractThe efficient fluorescence resonance energy transfer (FRET) between amphiphilic dendrimers with oligo(p‐phenylenevinylene) core branches and oligo(ethylene oxide) termini have been observed in micelles. All dendrimers show the critical micelle concentration and lower critical solution temperature as well as fluorescent emission. Tailoring electronic structures of the conjugated amphiphiles for FRET have been conveniently achieved by varying the branch number and/or the conjugated core structure. The Stern‐Volmer constants (KSV) for FRET were found to be 4.51 × 10−5 and 8.78 × 10−5 M for Den 30–40 and Den 50–40, respectively. The effects external stimuli such as solvent and temperature on FRET have been also investigated. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
On modifying properties of polymeric melts by nanoscopic particles
Authors: Atilgan Canan , Inanc Ibrahim , Rana Atilgan Ali 
Published: October 2012

AbstractWe study geometric and energetic factors that partake in modifying properties of polymeric melts via inserting well‐dispersed nanoscopic particles (NP). Model systems are cis‐1,4‐polybutadiene melts including a single atomic clusters of size varied in the range 10–150 atoms (3–7 Å in radius; 0.1–1.5% v/v). We modify the interactions between the chains and the particle by tuning attractive van der Waals interactions. Using molecular dynamics, we study equilibrium fluctuations and dynamical properties at the interface. The NPs move in the polymer matrix in two different regimes corresponding to trapped and free diffusion, depending on the NP size. Furthermore, degree of crowding around the NP by the polymer chains is quantified. Effect of NP size and interaction strength both on volume and volumetric fluctuations is manifested in mechanical properties, quantified here by bulk modulus, K. Tuning NP size and nonbonded interactions results in ∼15% enhancement in K by addition of a maximum of 1.5% v/v NP. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012
Enhancing fire risk evaluations of plant structures using finite element analysis
Authors: Reed Morgan , Peterson Eric 
Published: October 2012

AbstractAdvanced software can be used to enhance risk evaluations with fire and explosion simulations concerning the survivability of offshore drilling structures as well as major plant structures. This article focuses on simulated heat loads from fires showing structural responses due to thermal radiation fluxes, associated applied mechanical loads, and different fire protection features.Early simulation of fires (fires and their actual region of impact) allow for effective fire safety measures to be incorporated into the structure, for example, adding better passive fire protection measures where needed or substituting heavy steel with lighter alloys where local fire consequences are less severe.This article shows how three computer programs are utilized for optimizing the engineering design of structures, for example, offshore platforms, floating storage and offloading vessels, office buildings. This type of evaluation can produce significant cost savings by simulating realistic fire scenarios based on fundamental engineering principles and local conditions. © 2012 American Institute of Chemical Engineers Process Saf Prog, 2012
What risk reduction measures should be credited in process hazard analysis?
Authors: Baybutt Paul 
Published: October 2012

AbstractProcess hazard analysis (PHA) identifies existing risk reduction measures so that their contribution to reducing risk can be determined in order to decide if the risk of hazard scenarios is tolerable. Unfortunately, PHA practitioners do not follow consistent practices in crediting risk reduction measures as there are no generally accepted standards or guidelines for doing so. This situation leads to inconsistent studies and possibly erroneous results. The meaning of risk reduction measures and their relationship to process safeguards are discussed in this article, and risk reduction measures that could be credited in PHA are identified. © 2012 American Institute of Chemical Engineers Process Saf Prog, 2012.
An Investigation of Working Memory Effects on Oral Grammatical Accuracy and Fluency in Producing Questions in English
Authors: Wright Clare 
Published: October 2012

This article addresses the question of how far working memory may affect second language (L2) learners' improvement in spoken language during a period of immersion. Research is presented testing the hypothesis that individual differences in working memory (WM) capacity are associated with individual variation in improvements in oral production of questions in English. Thirty‐two Chinese adult speakers of English were tested, before and after a year's postgraduate study in the United Kingdom, to measure grammatical accuracy and fluency using a question elicitation task, and to measure WM using a battery of first language (L1) and L2 WM tests. Story recall in L1 (Mandarin) was significantly associated with individuals' improvement in oral grammatical measures (p < .05). However, there was no significant mean improvement across the cohort in grammatical accuracy, although there was for fluency. The findings suggest that WM may aid certain aspects of individuals' L2 oral proficiency during academic immersion through postgraduate study. They also indicate that academic immersion in itself can lead to improvements in oral proficiency, independent of WM capacity, but there is no general guarantee of significant grammatical change. Further research to clarify the opportunities for input and interaction available in academic immersion settings is called for.
Enzymatic Interesterification Between Pine Seed Oil and a Hydrogenated Fat to Prepare Semi‐Solid Fats Rich in Pinolenic Acid and Other Polyunsaturated Fatty Acids
Authors: Otero Cristina , Márquez Pablo , Criado Manuel , Hernández‐Martín Estela 
Published: October 2012

AbstractEnzyme catalyzed interesterification (EIE) of pine seed oil (PSO) and a fully hydrogenated soybean oil (FHSBO) were studied in batch reactors in solvent‐free media to prepare different semisolid fats rich in polyunsaturated fatty acids (PUFA). Optimal operation conditions found were: 10 % (w/w) enzyme loading, 75 °C and magnetic agitation at 300 rpm. Quasi‐equilibrium conditions were reached after 2, 3 and 6 h, when immobilized lipases from Thermomyces lanuginosus (Lipozyme® TL IM),Candida antarctica B. (Novozym® 435) and Rhizomucor miehei (Lipozyme® RM IM) from Novozymes A/S (Bagsvaerd, Denmark) were employed, respectively. Similar distributions of unsaturated to saturated fatty acid (UFA/SFA) residues along the glycerol backbone of the fat products were obtained with both non‐selective and sn‐1(3) regioselective lipases due to significant spontaneous acyl migration during the reaction. The products had higher UFA/SFA ratios at the sn‐2 position (2.4–2.5, 1.4–1.7, and 0.5–0.8 for the trials involving 20, 40 and 70 % FHSBO, w/w, respectively) than the corresponding physical blends (0.8, 0.4 and 0.5, respectively). Fat products containing 3.1–11.6 % (w/w) pinolenic acid (Pn) and 16.1–35.7 % (w/w) linoleic acid (L) at the sn‐2 position were prepared. The free acid contents of EIE products prepared with Lipozyme® TL IM and Novozym® 435 were 6.1–6.4 and 2.5–2.6, respectively. Residual activities of Lipozyme® TL IM and Novozym® 435 diminish by ca. 20 % after 9 reaction cycles.
Direct numerical simulation of a spatially developing compressible plane mixing layer: flow structures and mean flow properties
Authors: Zhou Qiang , He Feng , Shen M. Y. 
Published: October 2012

AbstractThe spatially developing compressible plane mixing layer with a convective Mach number of 0.7 is investigated by direct numerical simulation. A pair of equal and opposite oblique instability waves is introduced to perturb the mixing layer at the inlet. The full evolution process of instability, including formation of $ \mrm{\Lambda} $-vortices and hairpin vortices, breakdown of large structures and establishment of self-similar turbulence, is presented clearly in the simulation. In the transition process, the flow fields are populated sequentially by $ \mrm{\Lambda} $-vortices, hairpin vortices and ‘flower’ structures. This is the first direct evidence showing the dominance of these structures in the spatially developing mixing layer. Hairpin vortices are found to play an important role in the breakdown of the flow. The legs of hairpin vortices first evolve into sheaths with intense vorticity then break up into small slender vortices. The later flower structures are produced by the instability of the heads of the hairpin vortices. They prevail for a long distance in the mixing layer until the flow starts to settle down into its self-similar state. The preponderance of slender inclined streamwise vortices is observed in the transversal middle zone of the transition region after the breakup of the hairpin legs. This predominance of streamwise vortices also persists in the self-similar turbulent region, though the vortices there are found to be relatively very weak. The evolution of both the mean streamwise velocity profile and the Reynolds stresses is found to have close connection to the behaviour of the large vortex structures. High growth rates of the momentum and vorticity thicknesses are observed in the transition region of the flow. The growth rates in the self-similar turbulence region decay to a value that agrees well with previous experimental and numerical studies. Shocklets occur in the simulation, and their formation mechanisms are elaborated and categorized. This is the first three-dimensional simulation that captures shocklets at this low convective Mach number.
Forecasting the number of extreme daily events out to a decade ahead
Authors: Eade Rosie , Hamilton Emily , Smith Doug M. , Graham Richard J. , Scaife Adam A. 
Published: October 2012

The predictability of daily temperature and precipitation extremes is assessed out to a decade ahead using the Met Office Decadal Prediction System. Extremes are defined using a simple percentile based counting method applied to daily gridded observation data sets and corresponding model forecasts. We investigate moderate extremes, with a 10% probability of occurrence, ensuring they are frequent enough for robust skill analysis while having sizable impacts. We quantify the predictability of extremes, assess the impact of initialization, and compare with the predictability of the mean climate. We find modest but significant skill for seasonal predictions of temperature extremes in most regions (global area‐average correlation of 0.3) and for precipitation extremes over the USA (area‐average correlation of 0.2). The skill of both temperature and European rainfall extremes improves for multiyear forecast periods, as longer averaging periods reduce the impact of unpredictable short‐term variations, capitalizing on predictable trends from external forcings. For 5 year periods out to a decade ahead, root‐mean square temperature errors are reduced by 20% compared to use of climatology in most regions, apart from the southeastern USA. Initialization improves forecast skill for temperature and precipitation extremes on seasonal timescales in most regions. However, there is little improvement beyond the first year suggesting that skill then arises largely from external forcings. The skill for extremes is generally similar to, but slightly lower than, that for the mean. However, extremes can be more skillful than the mean, for example, USA cold nights, where trends in extremes are greater than for the mean.
Formation of high-molecular-weight angiotensinogen during pregnancy is a result of competing redox reactions with the proform of eosinophil major basic protein
Authors: Kløverpris Søren , Skov Louise L. , Glerup Simon , Pihl Kasper , Christiansen Michael , Oxvig Claus 
Published: October 2012

The plasma concentration of the placentally derived proMBP (proform of eosinophil major basic protein) increases in pregnancy, and three different complexes containing proMBP have been isolated from pregnancy plasma and serum: a 2:2 complex with the metalloproteinase, PAPP-A (pregnancy-associated plasma protein-A), a 2:2 complex with AGT (angiotensinogen) and a 2:2:2 complex with AGT and complement C3dg. In the present study we show that during human pregnancy, all of the circulating proMBP exists in covalent complexes, bound to either PAPP-A or AGT. We also show that the proMBP–AGT complex constitutes the major fraction of circulating HMW (high-molecular weight) AGT in late pregnancy, and that this complex is able to further associate with complement C3 derivatives post-sampling. Clearance experiments in mice suggest that complement C3-based complexes are removed faster from the circulation compared to monomeric AGT and the proMBP–AGT complex. Furthermore, we have used recombinant proteins to analyse the formation of the proMBP–PAPP-A and the proMBP–AGT complexes, and we demonstrate that they are competing reactions, depending on the same cysteine residue of proMBP, but differentially on the redox potential, potentially important for the relative amounts of the complexes in vivo. These findings may be important physiologically, since the biochemical properties of the proteins change as a consequence of complex formation.
Current Status of Adult Spinal Deformity
Authors: Youssef J. A. , Orndorff D. O. , Patty C. A. , Scott M. A. , Price H. L. , Hamlin L. F. , Williams T. L. , Uribe J. S. , Deviren V. 
Published: October 2012

Purpose To review the current literature for the nonoperative and operative treatment for adult spinal deformity. Recent Findings With more than 11 million baby boomers joining the population of over 60 years of age in the United States, the incidence of lumbar deformity is greatly increasing. Recent literature suggests that a lack of evidence exists to support the effectiveness of nonoperative treatment for adult scoliosis. In regards to operative treatment, current literature reports a varying range of improved clinical outcomes, curve correction, and complication rates. The extension of fusion to S1 compared with L5 and lower thoracic levels compared with L1 remains a highly controversial topic among literature. Summary Most adult deformity patients never seek nonoperative or operative treatment. Of the few that seek treatment, many can benefit from nonoperative treatment. However, in selected patients who have failed nonoperative treatment and who are candidates for surgical intervention, the literature reflects positive outcomes related to surgical intervention as compared with nonoperative treatment despite varying associated ranges in morbidity and mortality rates. If nonoperative therapy fails in addressing a patient's complaints, then an appropriate surgical procedure that relieves neural compression, corrects excessive sagittal or coronal imbalance, and results in a solidly fused, pain-free spine is warranted.