bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Color of Influence: A Provenance Study of Hematite-Based Paints on Early Olmec Carved Pottery
Authors: Backes Clarus J. , Cheetham David , Neff Hector 
Published: April 2012

AbstractRecent research and debates regarding the origin and spread of Olmec iconography during the Early Formative have centered on provenance and stylistic analyses of carved and incised pottery. Studies by instrumental neutron activation analysis (INAA) have indicated that Gulf Coast-style carved-incised pots were exported extensively from the area of the first Olmec capital, San Lorenzo, to several other regions of Mesoamerica. More recently, excavations at the Pacific Coast site of Cantón Corralito have shown that carved-incised pottery and other Olmec-style artifacts dominate strata contemporary with Early Olmec, suggesting the site may represent a settlement enclave of Gulf Olmec peoples. In this study we provide additional evidence of exchange between the Gulf Olmec and the Pacific Coast region by using laser ablation time-of-flight inductively coupled plasma mass spectrometry (LA-TOF-ICP-MS) to characterize hematite-based paints on Olmec-style pottery from Cantón Corralito, and to compare these paints to raw hematite recovered from Cantón Corralito and San Lorenzo. When examined in combination with sherd provenance data, the LA-TOF-ICP-MS data demonstrate that Olmec vessels were decorated in the San Lorenzo region before being exported to the Pacific Coast, and that Gulf Coast hematite was exported to Cantón Corralito, where it was used to enhance Olmec-style symbolism on locally produced vessels.
Photochemistry
Authors: Pfoertner Karl‐Heinz , Oppenländer Thomas 
Published: April 2012

AbstractThe article contains sections titled:1.Introduction2.Primary Photophysical Processes2.1.The Laws of Photochemistry2.2.Quantum Yield3.Performance of Photochemical Reactions3.1.Photoreactor Design3.2.Light Sources3.3.Materials3.4.Scale‐up and Scale‐down (Micro‐Photoreactors)3.5.Economic Considerations4.Light‐Induced Chain Reactions4.1.Photohalogenation4.2.Photosulfochlorination4.3.Photosulfoxidation4.4.Type I Photooxidation4.5.Photopolymerization5.Quasi‐Stoichiometric Photoreactions5.1.Photonitrosation5.2.Photosynthesis of Previtamin D5.3.Photoreactions in Supercritical Fluids6.Photosensitized Reactions6.1.(E/Z)‐Isomerization of Tachysterol6.2.Type II Photooxidation7.Selected Useful Photoreactions7.1.Enamide Cyclization7.2.Cyclobutane Formation7.3.Oxetane Formation7.4.Oxadi‐π‐Methane Rearrangement7.5.1,3‐Dipolar Cycloaddition8.Environmental Applications8.1.Advanced Oxidation Technologies (AOTs)8.2.Photocatalysis8.3.UV‐Disinfection
Polyoxymethylenes
Authors: Haubs Michael , Kurz Klaus , Sextro Guenter 
Published: April 2012

Abstract

The article contains sections titled:

1.

Introduction

2.

Physical and Chemical Properties

2.1.

Morphology

2.2

Mechanical Properties

2.3.

Thermal Properties

2.4.

Chemical Stability

2.5.

UV and Weather Resistance

2.6.

Permeability

2.7.

Fire Behavior

2.8.

Optical Properties

2.9.

Electrical Properties

3.

Production

3.1.

Polymerization of Formaldehyde and Trioxane

3.2.

Homopolymers

3.3.

Copolymers

3.3.1.

Polymerization of Trioxane

3.3.1.1.

Initiation

3.3.1.2.

Chain Propagation

3.3.1.3.

Chain Termination by Chain Transfer

3.4.

Additives

3.4.1.

Stabilizers

4.4.2.

Nucleation Agents

3.4.3.

Release Agents

3.5.

Impact‐Resistant Types

3.6.

Low VOC‐Grades

3.7.

High Strength POM Copolymer

4.

Economic Aspects

5.

Quality Specifications and Analysis

6.

Product Range and Processing

7.

Uses

8.

Recycling

9.

Toxicology and Occupational Health
Antipsychotics
Authors: Kleemann Axel 
Published: April 2012

AbstractThe article contains sections titled:1.Introduction2.Phenothiazines2.1.Phenothiazines with Aliphatic Side Chains2.2.Phenothiazines Substituted by Piperazines2.3.Phenothiazines Substituted by Piperidines3.Butyrophenones4.Indole Derivatives5.Thioxanthene Derivatives6.Diphenylbutylpiperidine Derivatives7.Diazepines, Oxazepines, and Thiazepines8.Sulfonylbenzamide Derivatives9.Other Antipsychotics
Zeolites
Authors: Broach Robert W. , Jan Deng‐Yang , Lesch David A. , Kulprathipanja Santi , Roland Eckehart , Kleinschmit Peter 
Published: April 2012

AbstractThe article contains sections titled:1.Introduction2.Nomenclature3.History4.Structure, Composition, and Properties4.1.Framework Structure4.2.Nonframework Cations4.3.Chemical and Physical Properties4.3.1.Physical Properties4.3.2.Chemical Properties5.Characterization6.Occurrence, Mining, and Processing of Natural Zeolites7.Production of Synthetic Zeolites7.1.Chemistry of Zeolite Synthesis7.2.Composition of Reaction Mixtures7.3.Raw Materials7.3.1.Synthesis Conditions7.3.2.Examples of Industrial Zeolite Syntheses7.3.3.Post Synthesis Treatments7.3.4.Environmental Aspects8.Commercial Applications and Importance8.1.Natural Zeolites8.2.Synthetic Zeolites8.2.1.Adsorption8.2.2.Membranes8.2.3.Catalysis8.2.4.Other Uses9.ToxicologyZeolites are hydrated aluminosilicates with a three‐dimensional framework structure constructed of SiO4and AlO4tetrahedra linked through oxygen atoms. They contain regular channels or interlinked voids whose aperture diameters are in the micropore range. The regular nature of the channels and apertures, whose dimensions are of the same order of magnitude as molecular diameters, enables the zeolites to function as molecular sieves and gives them value as selective adsorbents for separating substances and as shape‐selective catalysts. This article gives an overview of history, structure, properties, occurrence, production, and applications of zeolites.
Nanoscale Ferroelectricity in Crystalline γ‐Glycine
Authors: Heredia Alejandro , Meunier Vincent , Bdikin Igor K. , Gracio José , Balke Nina , Jesse Stephen , Tselev Alexander , Agarwal Pratul K. , Sumpter Bobby G. , Kalinin Sergei V. , Kholkin Andrei L. 
Published: April 2012

AbstractFerroelectrics are multifunctional materials that reversibly change their polarization under an electric field. Recently, the search for new ferroelectrics has focused on organic and bio‐organic materials, where polarization switching is used to record/retrieve information in the form of ferroelectric domains. This progress has opened a new avenue for data storage, molecular recognition, and new self‐assembly routes. Crystalline glycine is the simplest amino acid and is widely used by living organisms to build proteins. Here, it is reported for the first time that γ‐glycine, which has been known to be piezoelectric since 1954, is also a ferroelectric, as evidenced by local electromechanical measurements and by the existence of as‐grown and switchable ferroelectric domains in microcrystals grown from the solution. The experimental results are rationalized by molecular simulations that establish that the polarization vector in γ‐glycine can be switched on the nanoscale level, opening a pathway to novel classes of bioelectronic logic and memory devices.
Thinning and Shaping Solid Films into Functional and Integrative Nanomembranes
Authors: Huang Gaoshan , Mei Yongfeng 
Published: April 2012

AbstractConventional solid films on certain substrates play a crucial role in various applications, for example in flat panel displays, silicon technology, and protective coatings. Recently, tremendous attention has been directed toward the thinning and shaping of solids into so‐called nanomembranes, offering a unique and fantastic platform for research in nanoscience and nanotechnology. In this Review, a conceptual description of nanomembranes is introduced and a series of examples demonstrate their great potential for future applications. The thinning of nanomembranes indeed offers another strategy to fabricate nanomaterials, which can be integrated onto a chip and exhibit valuable properties (e.g. giant persistent photoconductivity and thermoelectric property). Furthermore, the stretching of nanomembranes enables a macroscale route for tuning the physical properties of the membranes at the nanoscale. The process by which nanomembranes release from a substrate presents several approaches to shaping nanomembranes into three‐dimensional architectures, such as rolled‐up tubes, wrinkles, and the resulting channels, which can provide fascinating applications in electronics, mechanics, fluidics, and photonics. Nanomembranes as a new type of nanomaterial promise to be an attractive direction for nanoresearch.
Conversion of Methanol to Hydrocarbons: How Zeolite Cavity and Pore Size Controls Product Selectivity
Authors: Olsbye Unni , Svelle Stian , Bjørgen Morten , Beato Pablo , Janssens Ton V. W. , Joensen Finn , Bordiga Silvia , Lillerud Karl Petter 
Published: April 2012

AbstractLiquid hydrocarbon fuels play an essential part in the global energy chain, owing to their high energy density and easy transportability. Olefins play a similar role in the production of consumer goods. In a post‐oil society, fuel and olefin production will rely on alternative carbon sources, such as biomass, coal, natural gas, and CO2. The methanol‐to‐hydrocarbons (MTH) process is a key step in such routes, and can be tuned into production of gasoline‐rich (methanol to gasoline; MTG) or olefin‐rich (methanol to olefins; MTO) product mixtures by proper choice of catalyst and reaction conditions. This Review presents several commercial MTH projects that have recently been realized, and also fundamental research into the synthesis of microporous materials for the targeted variation of selectivity and lifetime of the catalysts.
Simulation-based training and learning curves in laparoscopic Roux-en-Y gastric bypass
Authors: Zevin B , Aggarwal R , Grantcharov T P 
Published: April 2012

AbstractBackgroundEx vivo simulation-based technical skills training has been shown to improve operating room performance and shorten learning curves for basic laparoscopic procedures. The application of such training for laparoscopic Roux-en-ϒ gastric bypass (LRYGBP) has not been reviewed.MethodsRelevant studies were identified by one author from a search of MEDLINE and Embase databases from 1 January 1994 to 30 November 2010. Studies examining the learning curves and ex vivo training methods for LRYGBP were included; all other types of bariatric operations were excluded. A manual search of the references was also performed to identify additional potentially relevant papers.ResultsTwelve studies (5 prospective and 7 retrospective case series) were selected for review. The learning curve for LRYGBP was reported to be 50–100 procedures. Bench-top laparoscopic jejunojejunostomy, anaesthetized animals and Thiel human cadavers made up the bulk of the reported models for ex vivo training. Most studies were of relatively poor quality. An evidence-based ex vivo training curriculum for LRYGBP is currently lacking.ConclusionBetter quality studies are needed to define the learning curve for LRYGBP. Future studies should focus on the design and validation of training models, and a comprehensive curriculum for training and assessment of cognitive, technical and non-technical components of competency for laparoscopic bariatric surgery.
Use of a green (bio) solvent – limonene – as extractant and immiscible diluent for large volume injection in the RPLC‐tandem MS assay of statins and related metabolites in human plasma
Authors: Medvedovici Andrei , Udrescu Stefan , David Victor 
Published: April 2012

ABSTRACTLimonene, considered a green solvent, was successfully used to extract simvastatin, lovastatin, and their hydroxy‐acid metabolites from human plasma samples. The extraction process was followed by the direct injection of a large volume aliquot (100 μL) from the limonene layer into a Zorbax SB‐C18 Rapid Resolution chromatographic column (50 mm length × 4.6 mm i.d. × 1.8 µm d.p.), operated under gradient elution reversed‐phase separation mechanism. Tandem mass spectrometry operated under the multiple reaction monitoring mode was used for detection, providing low quantitation limits in the 0.25–0.5 ng/mL concentration interval. This method was validated and used for quantitation of simvastatin and its hydroxy acid metabolite in incurred plasma samples obtained from two volunteers participating in a bioequivalence study, using lovastatin and its hydroxy analog as internal standards. The results were statistically compared with those produced by means of an alternative RPLC‐tandem MS using protein precipitation with acetonitrile. The quality attributes of the two methods are comparatively discussed. The agreement between the quality characteristics of the two methods and the experimental results obtained on real samples may be considered as a consistent basis for the simultaneous use of limonene as extraction medium and injection diluent for hydrophobic compounds in bioanalytical approaches. Copyright © 2012 John Wiley & Sons, Ltd.
Authenticity as meaning validation: An empirical investigation of iconic and indexical cues in a context of “green” products
Authors: Ewing Douglas R. , Allen Chris T. , Ewing Randall L. 
Published: April 2012

ABSTRACTAuthenticity judgments involve how individuals distinguish what appears to be real versus fake, genuine versus phony. In this investigation, we bring authenticity into the laboratory to assess it in a manner quite different from most extant approaches. Taking a Peircian semiotic view in a context of environmentally conscious consumption, we develop and test a set of hypotheses concerning the effects of indexical and iconic cues to an authentic “green” product meaning. Results suggest that effects of these indicators of authenticity can be induced in a controlled manner with products being assessed as more or less “green” on the basis of particular cue arrangements. Furthermore, the effectiveness of these semiotic cues is moderated by a basic distinction among products. Taken together, the results provide evidence supporting a meaning validation process as the basis of authenticity judgments and suggest new directions for theory building in a domain where there is substantial practitioner interest. Copyright © 2012 John Wiley & Sons, Ltd.
A “modified crossover technique” for vascular access management in high‐risk patients undergoing transfemoral transcatheter aortic valve implantation
Authors: Buchanan Gill Louise , Chieffo Alaide , Montorfano Matteo , Maccagni Davide , Maisano Francesco , Latib Azeem , Covello Remo Daniel , Grimaldi Antonio , Alfieri Ottavio , Colombo Antonio 
Published: April 2012

ObjectivesTo describe results from our “modified crossover technique” for vascular access management during transcatheter aortic valve implantation (TAVI).BackgroundVascular access management remains a major cause of complications following TAVI due to the large bore sheaths required.MethodsAll suitable patients undergoing TAVI in our center, between June and August 2011, underwent our “modified crossover technique,” which enables the passage of a balloon through left radial access and inflation in the proximal iliac to allow percutaneous closure in a clean field.ResultsIn total, 15 patients were included: the logistic EuroSCORE was 19.7 ± 12.1% and STS score 5.7 ± 5.6%. The mean therapeutic femoral access site diameter was 8.1 ± 1.0 mm. Ten (66.7%) patients received Edwards SAPIEN™ XT (two using the new E‐sheath) and five (33.3%) patients a Medtronic CoreValve ReValving System® device. The “modified crossover technique” was used successfully in all patients. There were three vascular complications occurring at the therapeutic access site: one rupture of the external iliac artery, one Prostar failure, and one pseudoaneurysm of the right common femoral artery. All complications were successfully treated percutaneously with covered stent implantation via access from the contralateral femoral artery. In view of the balloon inflation from the left radial artery, the complications could be treated in a clean field with minimal blood loss.ConclusionsOur “modified crossover technique” using the left radial artery as the diagnostic site for balloon inflation appears a helpful adjunct in managing TAVI vascular access sites. © 2012 Wiley Periodicals, Inc.
Complete interventional heart repair of multiple concomitant cardiac pathologies in a staged approach
Authors: Puls Miriam , Seipelt Ralf , Schillinger Wolfgang 
Published: April 2012

Objectives and BackgroundThe evidence of multiple percutaneous cardiac procedures in patients with numerous concomitant cardiac pathologies is limited.Methods and ResultsWe report on the case of a 90‐year‐old male patient presenting with advanced heart failure because of degenerative aortic valve stenosis and degenerative mitral valve regurgitation. Moreover, significant coronary artery disease and intolerance of anticoagulation in atrial fibrillation were present. The patient was rejected from surgery because of age and frailty and underwent a staged interventional procedure with percutaneous coronary intervention, followed by transfemoral aortic valve implantation with Edwards Sapien XT, percutaneous mitral valve repair with MitraClip, and left atrial appendage closure with Amplatzer Cardiac Plug. The last procedure was complicated by pericardial tamponade necessitating pericardial drainage. Eight weeks later, the patient reported on the absence of dyspnea in activities of daily living and a significant gain in quality of live.ConclusionsThe case demonstrates feasibility of a staged interventional approach in a select high‐risk patient. © 2012 Wiley Periodicals, Inc.
Significance of the structure of data in partial least squares regression predictions involving both natural and human experimental design
Authors: Rinnan Åsmund , Munck Lars 
Published: April 2012

When predicting the chemical composition of food samples from near‐infrared spectroscopy using partial least squares regression, deep knowledge of the origin of the information is not present. We are aiming at opening a Pandora's box of how the prediction of protein proceeds in a unique set of chemically diverse barley mutant samples. An external validation of the sources of co‐variation in nature that are exploited by chemometric models would give a framework for manipulating the deciding information to make expensive calibration more economical. The barley samples were supplemented by two designed data sets: one mirroring the coarse composition of the barley samples by mixing six main chemical components and one set where the biological covariance between the six chemical components had been reduced.The three original data sets give remarkably comparable prediction models, albeit their regression coefficients are quite different. The origin of the prediction ability of the data is elucidated by splitting the natural barley samples into two parts: one based on simulated biology extracted from a set of chemical mixtures, and the residual after the chemistry has been removed from the raw data. As much as 98.1% of the spectral information in the natural barley data is explained through the simulated biology, leaving as little as 1.9% of the spectral information for the unexplained biological variation and noise. However, unexplained biological variation still gives a fair prediction of protein (RMSECV = 1.23 andr2 = 0.80, compared with RMSECV = 0.46 andr2 = 0.97 for the natural data), and it gives a clear principal component analysis separation of the three genotype classes. The results were interpreted by conducting spectral inspection on the origin of the unique covariate patterns appearing in self‐organised biological systems that should motivate researchers and industry to investigate the compressive effect that the model has on the essential deterministic biological data. Copyright © 2012 John Wiley & Sons, Ltd.
An Amine‐Catalyzed Enantioselective [3+2] Cycloaddition of Azomethine Ylides and α,β‐Unsaturated Aldehydes: Applications and Mechanistic Implications
Authors: Reboredo Silvia , Reyes Efraím , Vicario Jose L. , Badía Dolores , Carrillo Luisa , de Cózar Abel , Cossío Fernando P. 
Published: April 2012

AbstractThe catalytic enantioselective [3+2] cycloaddition between azomethine ylides and α,β‐unsaturated aldehydes catalyzed by α,α‐diphenylprolinol has been studied in detail. In particular, the reaction has been extended to the use of 2‐alkenylidene aminomalonates generated in situ as azomethine ylide precursors. These reactions lead to the formation of pyrrolidines containing a 5‐alkenyl side chain with potential for chemical manipulation. Moreover, a detailed and concise computational study has been carried out to understand the exact nature of the mechanism of this reaction and especially the consequences derived from the incorporation of the chiral secondary amine catalyst on the reaction pathway.
Quantifying Homo‐ and Heteromolecular Hydrogen Bonds as a Guide for Adduct Formation
Authors: Delori Amit , Galek Peter T. A. , Pidcock Elna , Jones William 
Published: April 2012

AbstractAn investigation into the predictability of molecular adduct formation is presented by using the approach of hydrogen bond propensity. Along with the predictions, crystallisation reactions (1a–1j) were carried out between the anti‐malarial drug pyrimethamine (1) and the acids oxalic (a), malonic (b), acetylenedicarboxylic (c), adipic (d), pimelic (e), suberic (f), azelaic acids (g), as well as hexachlorobenzene (h), 1,4‐diiodobenzene (i), and 1,4‐diiodotetrafluorobenzene (j); seven (1a to 1g) of these successfully formed salts. Five of these seven salts were found to be either hydrated or solvated. Hydrogen bond propensity calculations predict that hydrogen bonds between 1 and acids a–g are more likely to form rather than the H bonds involved in self‐association, providing a rationale for the observation of the seven new salts. In contrast, propensity of hydrogen bonds between 1 and h–j is much smaller as compared to other bonds predicted for self‐association/solvate formation, in agreement with the observed unsuccessful reactions.
Preparation of Carbohydrate Arrays by Using Diels–Alder Reactions with Inverse Electron Demand
Authors: Beckmann Henning S. G. , Niederwieser Andrea , Wiessler Manfred , Wittmann Valentin 
Published: April 2012

AbstractCarbohydrate microarrays are an emerging tool for the high‐throughput screening of carbohydrate–protein interactions that represent the basis of many biologically and medicinally relevant processes. The crucial step in the preparation of carbohydrate arrays is the attachment of carbohydrate probes to the surface. We examined the Diels–Alder reaction with inverse‐electron‐demand (DARinv) as an irreversible, chemoselective ligation reaction for that purpose. After having shown the efficiency of the DARinv in solution, we prepared a series of carbohydrate–dienophile conjugates that were printed onto tetrazine‐modified glass slides. Binding experiments with fluorescently labeled lectins proved successful and homogeneous immobilization was achieved by the DARinv. For immobilization of nonfunctionalized reducing oligosaccharides we developed a bifunctional chemoselective linker that enabled the attachment of a dienophile tag to the oligosaccharides through oxime ligation. The conjugates obtained were successfully immobilized on glass slides. The presented strategies for the immobilization of both synthetic carbohydrate derivatives and unprotected reducing oligosaccharides facilitate the preparation of high‐quality carbohydrate microarrays by means of the chemoselective DARinv. This concept can be readily adapted for the preparation of other biomolecule arrays.