bluuebunny/crossref_metadata_2025_split huggingface dataset:
Palladium‐Catalyzed Diorganozinc Conjugate Additions to Enones: Preparative and Computational Studies
Authors: Lorenzo Paula , Aurrecoechea José M. , de Lera Angel R. , Álvarez Rosana 
Published: March 2013

AbstractThe Pd‐catalyzed conjugate addition of diorganozinc reagents to α,β‐unsaturated carbonyl compounds has been applied to a variety of enone substrates, both cyclic and acyclic, encompassing various combinations of aryl and alkyl substitution, in combination with diorganozinc reagents incorporating alkyl (Me, linear and branched) or Ph groups. While both Pd0 and PdII complexes have been found to be competent precatalysts, reaction yields are strongly dependent on the relative amounts of Pd to phosphane ligand. Thus, a 1:1 Pd/P ratio is well tolerated, but going to Pd/P = 1:2 leads to poor conversions and yields. A calculated Pd0‐mediated pathway involving an unusual oxidative addition step with simultaneous transmetalation, followed by reductive elimination, has been found to be compatible with the observed phosphane effect.
Stannylene‐Mediated Regioselective 6‐O‐Glycosylation of Unprotected Phenyl 1‐Thioglycopyranosides
Authors: Maggi Agnese , Madsen Robert 
Published: March 2013

AbstractA straightforward procedure is described for the synthesis of (1→6)‐linked saccharides by regioselective glycosylation of unprotected glycosyl acceptors. Phenyl 1‐thioglycopyranosides derived from D‐glucose, D‐galactose and D‐mannose were treated with dibutyltin oxide to introduce a stannylene acetal, and then subjected to selective glycosylation at the 6‐position with the Koenigs–Knorr protocol. Peracylated glycosyl bromides of D‐glucose, D‐galactose, D‐mannose and D‐glucosamine were employed as the donors to give the corresponding (1→6)‐linked disaccharides in moderate to good yields. The best results were obtained with glycosyl donors and acceptors derived from D‐glucose and D‐galactose. Fully acylated disaccharide thioglycosides could also serve as glycosyl donors for the regioselective coupling. Brominolysis and subsequent Koenigs–Knorr coupling with the stannylene acetal of phenyl 1‐thio‐β‐D‐glucopyranoside gave rise to the corresponding (1→6)‐linked trisaccharides in moderate yields.
Electrochemically Predicting Phenolic Substrates’ Suitability for Detection by Amperometric Laccase Biosensors
Authors: Fogel Ronen , Limson Janice L. 
Published: March 2013

AbstractIn this article, a rapid, simple method of electrochemically predicting a given phenolic substrate’s ability to be detected via amperometric laccase biosensors is proposed. Ten selected substrates were analysed by cyclic voltammetry and the relevant electrochemical parameters compared to biosensor kinetic parameters produced through amperometric detection of these substrates. The two major findings of this study were that biosensor detection sensitivities were found to correlate to: (1) peak oxidation potential of a substrate at unmodified electrodes and (2) the apparent MichaelisMenten constant, Km, of the biosensor‐substrate system, once corrections accounting for the relative differences in electroreducible product yield are made.
EXPLAINING HEALTH CARE EXPENDITURE VARIATION: LARGE‐SAMPLE EVIDENCE USING LINKED SURVEY AND HEALTH ADMINISTRATIVE DATA
Authors: Ellis Randall P. , Fiebig Denzil G. , Johar Meliyanni , Jones Glenn , Savage Elizabeth 
Published: March 2013

ABSTRACTExplaining individual, regional, and provider variation in health care spending is of enormous value to policymakers but is often hampered by the lack of individual level detail in universal public health systems because budgeted spending is often not attributable to specific individuals. Even rarer is self‐reported survey information that helps explain this variation in large samples. In this paper, we link a cross‐sectional survey of 267 188 Australians age 45 and over to a panel dataset of annual healthcare costs calculated from several years of hospital, medical and pharmaceutical records. We use this data to distinguish between cost variations due to health shocks and those that are intrinsic (fixed) to an individual over three years. We find that high fixed expenditures are positively associated with age, especially older males, poor health, obesity, smoking, cancer, stroke and heart conditions. Being foreign born, speaking a foreign language at home and low income are more strongly associated with higher time‐varying expenditures, suggesting greater exposure to adverse health shocks. Copyright © 2013 John Wiley & Sons, Ltd.
Synthesis of Isoindolo[2,1‐a]quinazoline‐5,11‐dione Derivatives via the Reductive One‐Pot Reaction of N‐Substituted 2‐Nitrobenzamides and 2‐Formylbenzoic Acids
Authors: Mahdavi Mohammad , Najafi Ramin , Saeedi Mina , Alipour Eskandar , Shafiee Abbas , Foroumadi Alireza 
Published: March 2013

AbstractVarious isoindolo[2,1‐a]quinazoline‐5,11‐dione derivatives 3 were synthesized in good yields by means of the reductive reaction of N‐substituted 2‐nitrobenzamides 1 and 2‐formylbenzoic acids 2 in the presence of SnCl2⋅2 H2O under reflux in EtOH (Scheme, Table). The procedure needed two steps, the reduction of the nitro group of the 2‐nitrobenzamide and ring closure by nucleophilic addition of the NH2 group to both the formyl and carboxylic acid CO groups.
Synthesis of PhospholipidRibavirin Conjugates
Authors: Oleynikova Ilona A. , Kulak Tamara I. , Bolibrukh Dmitry A. , Kalinichenko Elena N. 
Published: March 2013

AbstractNew conjugates of antiviral nucleoside Ribavirin (=1‐(β‐D‐ribofuranosyl)‐1H‐1,2,4‐triazole‐3‐carboxamide; 1) with 1,2‐ and 1,3‐diacyl glycerophosphates have been synthesized by the phosphoramidite method. A combination of 2′,3′‐phenylboronate protecting group for the sugar moiety of the ribonucleoside 1 and 2‐cyanoethyl protection for the phosphate fragment ensured the preparation of the desired compounds with reasonable yields via a small number of synthetic steps.
A Novel and Efficient Synthesis of 3‐[(4,5‐Dihydro‐1H‐pyrrol‐3‐yl)carbonyl]‐2H‐chromen‐2‐ones (=3‐[(4,5‐Dihydro‐1H‐pyrrol‐3‐yl)carbonyl]‐2H‐1‐benzopyran‐2‐ones)
Authors: Alizadeh Abdolali , Ghanbaripour Rashid 
Published: March 2013

AbstractAn efficient one‐pot synthesis of 3‐[(4,5‐dihydro‐1H‐pyrrol‐3‐yl)carbonyl]‐2H‐chromen‐2‐one (=3‐[(4,5‐dihydro‐1H‐pyrrol‐3yl)carbonyl]‐2H‐1‐benzopyran‐2‐one) derivatives 4 by a four‐component reaction of a salicylaldehyde 1, 4‐hydroxy‐6‐methyl‐2H‐pyran‐2‐one, a benzylamine 2, and a diaroylacetylene (=1,4‐diarylbut‐2‐yne‐1,4‐dione) 3 in EtOH is reported. This new protocol has the advantages of high yields (Table), and convenient operation. The structures of these coumarin (=2H‐1‐benzopyran‐2‐one) derivatives, which are important compounds in organic chemistry, were confirmed spectroscopically (IR, 1H‐ and 13C‐NMR, and EI‐MS) and by elemental analyses. A plausible mechanism for this reaction is proposed (Scheme 2).
An Efficient One‐Pot Four‐Component Synthesis of Functionalized Imidazo[1,2‐a]pyridines
Authors: Kazemi Movahed Siyavash , Dabiri Minoo , Bazgir Ayoob 
Published: March 2013

AbstractAn efficient one‐pot four‐component protocol for the synthesis of imidazo[1,2‐a]pyridines was developed by condensing ethane‐1,2‐diamine (2), 1,1‐bis(methylthio)‐2‐nitroethene (1), aldehydes 3, and activated methylene compounds in EtOH under reflux conditions (Tables 1–3). The features of this procedure are operational simplicity, good yields of products, in situ preparation of heterocyclic ketene aminals (HKA), and catalyst‐free conditions.
Stereoselective Total Synthesis of Passifloricin A
Authors: Reddy Cheruku Ravindra , Veeranjaneyulu Boyapati , Nagendra Siddavatam , Das Biswanath 
Published: March 2013

AbstractThe stereoselective total synthesis of passifloricin A (1), a naturally occurring dihydropyranone with leishmanicidal and antiprotozoal activities, has been accomplished starting from protected glyceraldehyde using Maruoka asymmetric allylation, diastereoselective iodo‐carbonate cyclization, and Grubbs' olefin metathesis reactions as the key steps.
Organic Stereochemistry. Part 3
Authors: Testa Bernard 
Published: March 2013

AbstractThis review continues a general presentation of the principles of stereochemistry with special reference to medicinal compounds. Here, we discuss further stereogenic elements other than the stereogenic centers presented in Part 2. These are the axis of chirality, the plane of chirality, helicity, and (E,Z)‐diastereoisomerism (stereoisomerism about double bonds). Some of these elements of stereoisomerism are not always well understood, and they raise specific convention issues. Isomerization reactions will also be discussed. As far as possible, the examples we present have biochemical and mainly medicinal relevance; a systematic overview concerning biosystems will be presented in Parts 5–8.
Evaluation of Taiwan's National Health Insurance policy: an importance–satisfaction analysis
Authors: Liu I‐Chun 
Published: March 2013

SUMMARYThe hypothesis that policy performance affects citizens' satisfaction with public policies could be considered a well‐worn topic. However, this paper shows that the extant literature has not adequately conceptualized nor addressed the relationship, which could exist between citizens' satisfaction and importance of the evaluation's indicators. The findings of most previous studies reflect elite perspectives on Taiwan's National Health Insurance (NHI) policy evaluation, and the importance of the evaluation's indicators may not be recognized by the public. In addition, previous satisfaction studies have not provided information on the level of evaluative indicator importance. This study utilized importance–satisfaction analysis to examine public preferences of the NHI policy and assigned weights for NHI policy evaluation indicators by administering a national phone survey in October 2009. A total of 1103 telephone interviews were conducted with people aged 20 years and older, comprising a sample that was representative of the Taiwanese population according to age, gender, and area of residence. Furthermore, to explore the difference between expected importance and perceived satisfaction, this study calculated a reconceptualized performance gap. To obtain the gap value for an indicator, the mean value for importance was subtracted from the mean value for satisfaction. The findings imply that public recognition and support constitute the premise for the successful operation and reform of the NHI policy. The study concludes that policy adjustment is needed in several areas where importance outweighed satisfaction, including access to medical care services and NHI efficiency. The results suggest public recognition of and satisfaction with the evaluation indicators in use and the need for policy adjustment in areas where importance outweighs satisfaction. Copyright © 2013 John Wiley & Sons, Ltd.
SENSITIVITY TO CHANGING CONTINGENCIES IN AN IMPULSIVITY TASK
Authors: Young Michael E. , Webb Tara L. , Rung Jillian M. , Jacobs Eric A. 
Published: March 2013

AbstractUsing a video‐game‐based escalating interest task, participants repeatedly encountered a reward that gradually increased in value over a 10‐second interval. Responding early in the interval netted less immediate reward than responding later in the interval. Each participant experienced four different reward contingencies for waiting. These contingencies were changed three times as the experiment proceeded. Behavior tracked these changing contingencies, but wait times reflected long‐term carryover from the previously assigned contingencies. Both the tendency to respond slowly and the optimality of behavior were affected by the order of contingencies experienced. Demographic variables only weakly predicted behavior, and delay discounting rate in a hypothetical money choice task predicted choice only when the contingencies in the game were weaker.
Turning Experiments into Objects: The Cognitive Processes Involved in the Design of a Lab‐on‐a‐Chip Device
Authors: Aurigemma Joshua , Chandrasekharan Sanjay , Nersessian Nancy J. , Newstetter Wendy 
Published: March 2013

AbstractBackgroundIncreasingly, modern engineers are designing miniature devices that integrate complex activities, actions, processes, or operations involving many steps, persons, and equipment; a good example is a microfluidic lab‐on‐a‐chip device. The design of such devices is cognitively demanding and requires the generation of multiple model representations, which are used in an iterative fashion to analyze and improve prototype designs.PurposeThis study addresses two questions: How are various representations and prototypes used in the iterative design and building of a microfluidic lab‐on‐a‐chip device in a systems biology laboratory? In this design process, what cognitive functions did the representations serve?Design/MethodThis case study employed mixed methods. We utilized the standard ethnographic methods of participant observation, open‐ended interviewing of participants, and artifact collection in an integrated systems biology research lab. Data were analyzed using open and axial coding. We also used cognitive‐historical analysis to collect and analyze data from traditional historical sources (publications, grant proposals, laboratory notebooks, and technological artifacts) to recover how the salient representational, methodological, and reasoning practices were developed and used by the researchers.ResultsThe device design involved complex interactions among mental models, computational models, and building and testing prototypes; tagging and visualizations were used to query and validate the prototypes as well as the computational models; all these were integrated to meet stringent experimental and fabrication constraints. Integration takes place across many different kinds of representations. The building of external representations helped not just to off‐load cognitive load but also to add detail and constraints to the mental model.ConclusionsRepresentational fluency and flexibility are required to manage the complexity of modern bioengineered devices. To support the development of such fluency and flexibility, engineering students must understand the function and the use of such representations, an instructional goal that has implication for new models of learning.
The Effects of Temperature and Activity on Intraspecific Scaling of Metabolic Rates in a Lungless Salamander
Authors: GIFFORD MATTHEW E. , CLAY TIMOTHY A. , PETERMAN WILLIAM E. 
Published: March 2013

AbstractThe scaling of metabolic rate with body mass holds substantial predictive power as many biological processes depend on energy. A significant body of theory has been developed based on the assumption that metabolic rate scales with body mass as a power function with an exponent of 0.75, and that this scaling relationship is independent of temperature. Here we test this hypothesis at the intraspecific level in a lungless salamander using data on both standard and maximal metabolic rates (SMR and MMR, respectively). We also address a recently proposed alternative explanation that predicts systematic variation in this mass‐scaling exponent, the metabolic level boundaries hypothesis (MLB). Consistent with predictions of the metabolic theory of ecology the mass scaling of SMR and MMR were independent of temperature, however, we find evidence that the mass‐scaling exponent for SMR and MMR differ significantly from 0.75. Further, our data do not provide strong support for MLB. Mass‐scaling exponents for MMR generally exceed those for SMR, although these differences are rarely statistically significant. J. Exp. Zool. 319A:230–236, 2013. © 2013 Wiley Periodicals, Inc.
Serotonin in Testes of Bat Myotis velifer During Annual Reproductive Cycle: Expression, Localization, and Content Variations
Authors: JIMÉNEZ‐TREJO FRANCISCO , LEÓN‐GALVÁN MIGUEL ÁNGEL , MARTÍNEZ‐MÉNDEZ LUIS ANTONIO , TAPIA‐RODRÍGUEZ MIGUEL , MENDOZA‐RODRÍGUEZ C. ADRIANA , GONZÁLEZ‐SANTOYO ISAAC , LÓPEZ‐WILCHIS RICARDO , VELA‐HINOJOSA CRISTIÁN , BARANDA‐AVILA NOEMI , CERBÓN MARCO 
Published: March 2013

AbstractThe mechanism of reproduction in mammals is very complex and in some cases is quite particular. For example in some bat species, the male presents a reproductive mechanism characterized by an annual testicular cycle that goes from recrudescence to regression (spermatogenesis to inactivity period, respectively). After recrudescence, the spermatozoa arrive at epididymis and wait to be expelled at the time of ejaculation during the mating period, which occurs some months later. Because serotonin (5‐HT) has gained reproductive importance in the last years, the aim of the present study was to analyze the expression of this indolamine and both tryptophan hydroxylase and monoamine oxidase isoform A—enzymes involved in its metabolism—in Myotis velifer testes, a seasonal reproductive bat species that shows temporal asynchrony in its sexual cycle, across the principal periods of their reproductive cycle. By using both Falck–Hillarp histochemistry and immunofluorescence techniques, we found serotonin in vesicles of Leydig cells and probably Sertoli cells too; interestingly, both intracellular localization and concentration was variable across the different stages of the reproductive cycle, being lower during spermatogenesis phase and increasing during the mating phase. These results suggest that 5‐HT is present in bat testes and it could play an important role in testicular function during their reproductive cycle. J. Exp. Zool. 319A:249–258, 2013. © 2013 © 2013 Wiley Periodicals, Inc.
Therapeutic concentrations of anti‐epileptic drugs do not inhibit the activity of the oncolytic adenovirus Delta24‐RGD in malignant glioma
Authors: de Jonge Jonas , Berghauser Pont Lotte M. E. , Idema Sander , Kloezeman Jenneke J. , Noske David , Dirven Clemens M. F. , Lamfers Martine L. M. 
Published: March 2013

AbstractBackgroundThe oncolytic adenovirus Delta24‐RGD is currently being tested in phase I trials for the treatment of glioblastoma (GBM). Literature suggests that frequently prescribed anticonvulsants for these patients, phenytoin (PHE), valproic acid (VPA) and levetiracetam (LEV), may interfere with cellular mechanisms of cancer or oncolytic virus activity. We therefore investigated the direct effects of these drugs on Delta24‐RGD infection and oncolytic activity.MethodsThe anticonvulsants PHE, VPA, and LEV were combined with Delta24‐RGD treatment in established glioma cell lines as well as on a panel of patient‐derived GBM cultures. Effects on infection efficiency were assessed using luciferase‐encoding adenoviral vectors. Oncolytic activity was determined by WST‐1 assay and viral progeny production was quantified by dilution titration.ResultsIC50 values of the anti‐epileptic drugs on the four glioma cell lines were far above clinically‐relevant concentrations. At therapeutic concentrations, the anti‐epileptics generally did not alter the infection efficiency of RGD‐modified adenovirus, nor affect progeny production or oncolytic activity of Delta24‐RGD. The only exception was found in U373 cells, where VPA slightly antagonised the oncolytic effect of Delta24‐RGD (from 29% to 55% viability, p<0.01) as well as viral progeny production (60% decrease, p<0.01). Oncolysis by Delta24‐RGD was not inhibited by the anti‐epileptics in any of the patient‐derived glioma cultures (n=6). In fact, in one culture a slight enhancement of viral oncolysis by PHE and LEV was found, from 89.7% viability to 76% and 62.4%, respectively (p<0.01)ConclusionsTherapeutic levels of valproic acid, phenytoin and levetiracetam do not negatively interfere with the infection efficiency or oncolytic activity of Delta24‐RGD in patient‐derived GBM cells. Therefore, there is no indication that the choice of anticonvulsant for seizure control in glioma patients should take treatment with Delta24‐RGD into account. Copyright © 2013 John Wiley & Sons, Ltd.
Multi‐body simulation of various falling scenarios for determining resulting loads at the prosthesis interface of transfemoral amputees with osseointegrated fixation
Authors: Welke Bastian , Schwarze Michael , Hurschler Christof , Calliess Tilman , Seehaus Frank 
Published: March 2013

AbstractConventionally, transfemoral amputees are treated with a shaft prosthesis fitted over the residual limb. To improve the quality of life of such patients, in particular those with complications relating to conventional attachment (e.g., skin irritation, stump ulcers, and poor motor‐control with short stumps), osseointegrated prosthesis fixation implants have been developed and implanted in a limited population of patients. To assess possible damage to the implant/prosthesis during falling scenarios, the loads in high‐risk situations were estimated using a multi‐body simulation of motion. Five falling scenarios were identified and performed by healthy volunteer wearing safety equipment. Kinematic data and ground reaction forces were captured as input for the inverse‐dynamics‐based simulations, from which the forces and moments at a typical implant‐prosthesis interface location were computed. The estimated peak loads in all five scenarios were of a magnitude that could lead to bone fracture. The largest peak force observed was 3274 ± 519 N, with an associated resultant moment of 176 ± 55 Nm on the prosthesis‐implant interface. A typical femur is prone to fracture under this load, thus illustrating the need for a safety‐release element in osseointegrated prosthesis fixation. © 2013 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 31:1123–1129, 2013
Leichter, schneller, kostengünstiger mit dem Laser
Authors: Brockmann Rüdiger , Andreev Andrey , Müllerschön Oliver , Fritz Michael 
Published: March 2013

AbstractDie Lasermaterialbearbeitung ist in der Automobilindustrie etabliert. Sie hilft die Abläufe zu flexibilisieren und zu beschleunigen, Kosten zu sparen, an Effizienz zu gewinnen oder schlicht Anwendungen zu ermöglichen, die mit konventionellen Verfahren nicht realisierbar wären. Dazu gehören die Herstellung warmumgeformter Bauteile für den Leichtbau, das Entschichten mit Kurzpulslasern für die Schweiß‐ und Klebevorbereitung sowie das Remoteschweißen für schnelle und exakte Schweißnähte. TRUMPF bietet für alle diese Anwendungen Lösungen und forscht darüber hinaus an künftigen Leichtbauszenarien, wie beispielsweise der industriellen Bearbeitung von Faserverbundwerkstoffen.
Schneiden, Schweißen und Bohren — „All‐in‐One”︁
Authors: Fassbind Eduard 
Published: March 2013

AbstractUltrakurzpulslaser sind in vielerlei Hinsicht ideale Werkzeuge für die Mikrobearbeitung. Das volle Potenzial dieser Laserklasse lässt sich aber nur durch anwendungsgerechte und industrietaugliche Gesamtsysteme erschließen. Ein besonders kompaktes System hat Swisstec Micromachining auf der Lasys in Stuttgart als Weltneuheit vorgestellt.
Programmierbare Strahlqualität
Authors: Kimme Thomas , Ochlich Hans‐Michael 
Published: March 2013

AbstractModerne Faserlaser bieten Strahlqualitäten „höchster Güte“. Für die Laserquelle ist damit üblicherweise eine Fokussierbarkeit bis nahe an das theoretisch erreichbare Minimum gemeint. In praktischen Anwendungen mit toleranzbehafteten Bauteilen, Lagefehlern, dem Bedarf moderater Temperaturgradienten im Bauteil oder ähnlichen Randbedingungen ist diese „höchste Güte“ oftmals nicht das Optimum. Ziel der hier vorgestellten Arbeit ist daher eine bedarfsgerechte und in Echtzeit programmierbare, synchrone Beeinflussung der folgenden Größen:· Strahlqualität am Bauteil,· Laserleistung der Strahlquelle,· Lage innerhalb der Bearbeitungsbahn bzw. ToolCenterPoint (TCP)‐Bahngeschwindig­keit.Zur Umsetzung wurde ein streng synchron betriebenes Steuerungssystem aus NC, Strahlformungssteuerung (realisiert am Beispiel Einachsscanner) und Laser­parameter­vorgabe (realisiert am Beispiel Laserleistungsvorgabe) geschaffen, welches in Frequenzen bis 40 kHz arbeiten kann. Die realisierte Lösung wird in den wichtigsten Eigenschaften vorgestellt ebenso wie Ergebnisse beim Einsatz der Technik in den Verfahren Laserschweißen, Laserhärten und Laser‐Pulver‐Auftragschweißen.