bluuebunny/crossref_metadata_2025 huggingface dataset:
Cesium Carbonate‐Promoted Hydroamidation of Alkynes: Enamides, Indoles and the Effect of Iron(III) Chloride
Authors: Herrero María Teresa , de Sarralde Jokin Díaz , SanMartin Raul , Bravo Laura , Domínguez Esther
Published: November 2012

A series of enamide derivatives was prepared by a simple procedure for the hydroamidation of alkynes with amides and sulfonamides. The use of such a mild base as cesium carbonate promotes the latter transformation, and the addition of catalytic amounts of iron(III) chloride has a beneficial effect in the outcome of some of the presented hydroamidation reactions. A range of indoles was also synthesized from ortho‐alkynylanilides by both complementary procedures, which proved to be useful for the construction of the indolo[1,2‐c]quinazoline tetracyclic system from an ortho‐(2‐aminophenylalkynyl)anilide.
Acceptorless and Base‐Free Dehydrogenation of Alcohols and Amines using Ruthenium‐Hydride Complexes
Authors: Muthaiah Senthilkumar , Hong Soon Hyeok
Published: November 2012

An efficient, operatively simple, acceptorless, and base‐free dehydrogenation of secondary alcohols and nitrogen‐containing heterocyclic compounds was achieved by using readily available ruthenium hydride complexes as precatalysts. The complex RuH2(CO)(PPh3)3 (1) and Shvo’s complex (2) showed excellent activities for the dehydrogenation of secondary alcohols and nitrogen containing heterocycles. In addition to complexes 1 and 2, the complex RuH2(PPh3)4 (3) also showed moderate to excellent activity for the acceptorless dehydrogenation of nitrogen‐containing heterocyclic compounds. Kinetic studies on the oxidation reaction of 1‐phenylethanol using complex 1 were carried out in the presence and the absence of external triphenylphosphine (PPh3). External addition of PPh3 had a negative influence on the rate of the reaction, which suggested that dissociation of PPh3 occurred during the course of the reaction. Hydrogen was evolved from the oxidation reaction of 1‐phenylethanol by using 1 mol% of 1 (88%) and 2 (92%), which demonstrated the possible usage of the catalytic systems in hydrogen generation.
Novel method for targeting the optimal purification feed flow rate of hydrogen network with purification reuse/recycle
Authors: Liu Guilian , Li Hao , Feng Xiao , Deng Chun
Published: November 2012

The purification reuse/recycle is one effective resource conservation strategy. In this article, a novel conceptual method is proposed to identify the optimal purification feed flow rate (PFFR) and the corresponding maximum hydrogen utility savings (HUS) of the hydrogen network with purification reuse/recycle. In this method, the sources and sink‐tie‐lines are divided into three regions according to the purified product and purification feed. The quantitative relationship between the HUS and the PFFR is analyzed for the sink‐tie‐lines and sources of each region. With the quantitative relationship line between the HUS and the PFFR of each source plotted, the quantitative relationship diagram can be obtained and can be used to identify the pinch point and the HUS for a given PFFR. Furthermore, the optimal PFFR and the maximum HUS can be identified easily. Three cases are studied to illustrate the applicability of the proposed method. © 2012 American Institute of Chemical Engineers AIChE J, 59: 1964–1980, 2013
The stability of direct carbon fuel cells with molten Sb and Sb–Bi alloy anodes
Authors: Jayakumar Abhimanyu , Javadekar Ashay , Gissinger Jacob , Vohs John M. , Huber George W. , Gorte Raymond J.
Published: November 2012

The long‐term stability of direct carbon fuel cells, based on solid oxide fuel cells with molten Sb and Sb–Bi anodes, was examined for operation with activated charcoal, rice starch, and bio‐oil fuels at 973 K. With intermittent stirring of the fuel–metal anode interface, the anode performance was stable, and reasonable power densities (∼250 mW/cm2) were achieved for periods up to 250 h. With Sc‐stabilized zirconia, severe thinning of the electrolyte occurred in regions of high current flow. No electrolyte thinning was observed with yttria‐stabilized zirconia as the electrolyte operating at the same current densities. © 2012 American Institute of Chemical Engineers AIChE J, 59: 3342–3348, 2013
Evidence for primary laryngeal inhalant allergy: a randomized, double‐blinded crossover study
Authors: Roth Douglas F. , Abbott Katherine Verdolini , Carroll Thomas L. , Ferguson Berrylin J.
Published: November 2012

Background:

Despite anecdotal reports, no controlled studies to date link allergen exposure with a change in vocal function or dysphonia. The aim of this study was to determine whether allergen exposure in susceptible individuals impairs vocal function.

Methods:

The study was a prospective, double‐blind, placebo‐controlled study in which subjects serve as their own controls. The participants were 5 inhalant allergic adults with suspected dysphonia from allergies, without evidence of reactive lower airways based on methacholine challenge. All subjects were exposed to 2 experimental conditions in which they were challenged with (1) orally inhaled diluent placebo on 1 day, and (2) orally inhaled allergen on another day. Conditions were randomly ordered across subjects and separated by at least 48 hours. Phonatory threshold pressure (PTP) at the 80th percentile pitch was measured prior to diluent and allergen challenge, and 15 and 60 minutes postchallenge to assess potential change in vocal function after challenge testing.

Results:

A repeated measures ANOVA revealed a significant main effect for treatment (allergen vs placebo, p = 0.013) with greater PTP required post–allergen challenge compared to placebo and an effect size of 0.821.

Conclusion:

A primary causal relationship between allergen exposure and impaired vocal function, as assessed by PTP, was observed in adults with documented allergy independent of asthma or nasal exposure. The current design establishes a safe model for laryngeal inhalant allergen challenge. © 2013 ARS–AAOA, LLC.
Identifying clinical symptoms for improving the symptomatic diagnosis of chronic rhinosinusitis
Authors: Hsueh Wayne D. , Conley David B. , Kim Haena , Shintani‐Smith Stephanie , Chandra Rakesh K. , Kern Robert C. , Tan Bruce K.
Published: November 2012

Background

Current symptom criteria for identifying patients with chronic rhinosinusitis (CRS) has poor specificity. The objective of this study was to test the hypothesis that symptoms drawn from the Task Force on Rhinosinusitis (RSTF) criteria and the International Headache Society (IHS) criteria for primary headaches can differentiate CRS patients from those with CRS‐symptoms but no evidence for inflammation (non‐CRS).

Methods

A retrospective cohort study from a total of 140 charts of patients who received a diagnostic computed tomography (CT) scan for CRS symptoms in a tertiary care clinic. The study was conducted in 2 phases: (1) using a retrospective review of otolaryngologist‐documented symptoms (ODS) in the medical record; and (2) using patient‐reported symptoms (PRS) on a prospectively collected customized review of systems form from a separate cohort. A radiographic gold standard differentiated CRS from non‐CRS patients.

Results

Subjects in the CRS and non‐CRS group were matched for age and race and almost universally met symptomatic criteria as defined by the RSTF in both study phases. In both study phases, facial pain, but not facial pressure, was negatively predictive for CRS (p < 0.05). Similarly, hyposmia was positively predictive, whereas facial pain of a pulsating quality and photophobia were negatively predictive (p < 0.05), although analysis of PRS was significant only when symptom frequency was considered. Nonetheless, significant overlap exists between the prevalence and frequency of symptoms in both groups.

Conclusion

The symptom‐based diagnosis of CRS is challenging but symptoms of hyposmia is positively predictive while facial pain, a throbbing quality, headaches and photophobia are negatively predictive and show promise for improving the specificity of CRS diagnosis. Further validation studies are needed.
Nanobasierte Energiegewinnung in autarken Mikro‐/Nanosystemen
Authors: Wang Zhong Lin , Wu Wenzhuo
Published: November 2012

Gesundheit, Infrastruktur oder Umweltüberwachung sowie Vernetzungs‐ und Verteidigungstechnologien sind nur einige der potenziellen Anwendungsbereiche für Mikro‐/Nanosysteme (MNS). Dabei sollten die MNS unabhängig von einer externen Stromversorgung arbeiten, und ihre Energie aus der Umgebung beziehen, in der sie eingesetzt werden. Dieser Aufsatz beschäftigt sich mit verschiedenen Ansätzen zur Energiegewinnung, um der zukünftigen Nachfrage nach autarken MNS gerecht zu werden.
Copper hexacyanoferrate–polymer composite beads for cesium ion removal: Synthesis, characterization, sorption, and kinetic studies
Authors: Dwivedi Charu , Kumar Amar , Singh Krishan Kant , Juby Ajish K. , Kumar Manmohan , Wattal Piaray Kishen , Bajaj Parma Nand
Published: November 2012

A novel synthetic method for the preparation of different sorbent–polymer composite beads has been developed under simple laboratory conditions. Copper hexacyanoferrate was synthesized, and its composite beads of required size were synthesized by phase‐inversion technique, using polyethersulfone as the polymer matrix. Suitable size and mechanical stability, along with their spherical shape, make these composite beads most appropriate for column operation. The efficiency of these composite beads was tested for the removal of cesium, using radioanalytical techniques, in batch conditions. The effect of pH, the initial metal ion concentration, and contact time was also investigated. The synthesized beads perform best in the pH range 5–9. Different sorption isotherm models were applied to the experimental data. Equilibrium data are represented well by the Langmuir isotherm equation, with a monolayer sorption capacity of 1.56 mg g−1 for the swollen beads. Kinetic modeling analysis, by fitting the data in the pseudo first‐order, pseudo second‐order, and intraparticle diffusion equations, shows that the pseudo second‐order equation is the most appropriate model for the description of sorption of cesium ions onto the composite beads. The process mechanism is found to be complex, consisting of both intraparticle diffusion and film diffusion. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Potassium methyl siliconate‐treated pulp fibers and their effects on wood plastic composites: Water sorption and dimensional stability
Authors: Piao Cheng , Cai Zhiyong , Stark Nicole M. , Monlezun Charles J.
Published: November 2012

Potassium methyl siliconate (PMS) was investigated as a new nano modifier of wood fiber and wood flour to improve the compatibility between the fiber/flour and the plastic matrix in fiber reinforced plastic composites. Before injection molding, bleached and brown pulp fibers and mixed species wood flour were pretreated in PMS solutions. The morphology of the treated and untreated fiber and flour, the compatibility of PMS‐treated fiber and flour with polyethylene (PE), and the water sorption and volumetric swell of PMS‐treated fiber/flour plastic composites in a long‐term soaking test were evaluated. Fiber and flour treated with PMS increased the compatibility between the fiber/flour and the PE matrix. The increased compatibility of PMS‐treated fiber and flour with the matrix contributed to the reduction of water sorption and, thus, increased dimensional stability. For all composites, water sorption and volumetric swell of fiber/four plastic composites decreased as the ratio of fiber to flour increased. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Patterns and impacts of fish bycatch in a scallop dredge fishery
Authors: Craven Helen R. , Brand Andrew R. , Stewart Bryce D.
Published: November 2012

Dredging for marine bivalves can cause considerable damage to benthic invertebrates and habitats. However, it is largely unknown how dredging affects fish communities. In this study patterns and impacts of fish bycatch in scallop dredges around the Isle of Man, in the north Irish Sea, were investigated by analysing data from fisheries‐independent surveys conducted between 1992 and 2005.

Almost all (97.6%) tows of the survey gear generated fish bycatch, with a total of approximately 50 species recorded. Cuckoo ray (Leucoraja naevus) and monkfish (Lophius piscatorius) dominated the bycatch, accounting for 46.82% of the total. Three other species of particular commercial or ecological interest; lemon sole (Microstomus kitt), plaice (Pleuronectes platessa) and lesser spotted dogfish (Scyliorhinus caniculus), were also abundant. Most of the cuckoo ray, monkfish and plaice captured were juveniles, whereas lesser spotted dogfish and lemon sole were a mixture of juveniles and adults.

In general, rates of fish bycatch appeared low, but this may be at least partly because background fish densities around the Isle of Man were also low. There was considerable spatial, temporal, and species‐specific variation in fish bycatch, and the finer meshed dredges traditionally used to catch queen scallops (Aequipecten opercularis), caught significantly more fish than the great scallop (Pecten maximus) dredges.

The density of lesser spotted dogfish bycatch increased significantly over the 14 years of the study whereas the density of monkfish decreased significantly. These patterns appear to reflect differences in the susceptibility of the two species to capture and damage by scallop dredging, and/or have been caused by regional trends in stock levels. An assessment of the impact of the local great scallop dredge fishery indicated that it may be catching substantial numbers of monkfish.

Given the recent expansion of scallop dredging around the UK, such effects should be factored into ecosystem‐based management plans.

Copyright © 2012 John Wiley & Sons, Ltd.
TFPI‐2 Downregulates Multidrug Resistance Protein in 5‐FU‐Resistant Human Hepatocellular Carcinoma BEL‐7402/5‐FU Cells
Authors: Lu Fei , Hou Yong‐Qiang , Song Ying , Yuan Zheng‐Jiang
Published: November 2012

Tissue factor pathway inhibitor‐2 (TFPI‐2) is known to induce apoptosis and to suppress tumor metastasis in several types of cancer cells. However, there is little known about its reversal effect on chemoresistant tumor cells. This study investigated the effect of TFPI‐2 in 5‐fluorouracil (5‐FU)‐resistant human hepatocellular cancer BEL‐7402/5‐FU cells in vitro. We constructed TFPI‐2 overexpression BEL‐7402/5‐FU cell lines and explored resistance index (RI) of 5‐FU, function of the P‐glycoprotein (P‐gp) efflux pump, and the mRNA and protein expression of drug resistance gene, including multidrug resistance gene (MDR1), lung‐resistance protein (LRP), multidrug resistance‐associated protein (MRP1), glutathione‐S‐transferase‐π (GST‐π), excision repair cross‐complementing gene 1 (ERCC1), and p38 phosphorylation. We found that TFPI‐2 improved the RI of 5‐FU and inhibited P‐gp function. Western blotting and real‐time PCR revealed that TFPI‐2 also decreased mRNA and protein expression of MDR1, LRP, MRP1, GST‐π, and ERCC1, whereas p38 phosphorylation was increased. We considered that TFPI‐2 reduces 5‐FU resistance in BEL‐7402/5‐FU cells, and the mechanism appears to involve p38‐mediated downregulation of drug resistance gene expression such as MDR1, LRP, MRP1, GST‐π, and ERCC1. Anat Rec, 2013. © 2012 Wiley Periodicals, Inc.
Entwicklung eines Prüfplans für Bewehrungen für Textilbeton
Authors: Eckers Vera , Gries Thomas
Published: November 2012

Beim Bauen mit dem ressourcenschonenden Werkstoff Textilbeton werden gitterartige Textilstrukturen als Bewehrung eingesetzt. Es existieren bereits zahlreiche praktische Anwendungsbeispiele sowohl im Bereich der Bauwerkssanierung als auch für Neubauten mit Textilbeton [1–7]. Die Wahl der Bewehrung hängt hierbei von der Bauteilgeometrie, der Belastung und der Art der Bauteilherstellung ab. Je nach Fall sind unterschiedliche Kennwerte der Materialien notwendig, um die richtige Auswahl des Textils treffen zu können. Weiterhin werden zusätzliche Kennwerte relevant, wenn die Textilien für die Bauteilbemessung oder die Abbildung in numerischen Simulationen verwendet werden sollen. In diesem Artikel werden die verschiedenen textilen Prüfungen, die sowohl für die Qualitätssicherung im Handel als auch für die Simulation notwendig werden können, beschrieben und es wird der Nutzen der jeweiligen Kenngröße erläutert. In dem vorgeschlagenen Prüfplan werden durchzuführende Prüfungen empfohlen und geeignete Prüfparameter genannt.

Development of a test plan for concrete reinforcements

When building with the resource conserving material textile reinforced concrete, open meshed structures are used. Several examples of use exist both in the field of rehabilitation and in new construction [1–7]. The choice of the reinforcement depends on the geometry of the part, the loading and the manufacturing method. Different geometries and manufacturing methods require textiles with different characteristics. Furthermore, additional textile characteristic properties are required for the dimensioning and for computer‐based simulation. In this article different textile characterization test methods are presented that can be important for both, quality assurance and simulation. The benefit of each characteristic is explained. The proposed test plan not only outlines the test methods to be conducted but also includes appropriate test parameters.
Digitale Nahbereichsphotogrammetrie im bautechnischen Versuchswesen
Authors: Maas Hans‐Gerd
Published: November 2012

Der Beitrag stellt die Grundprinzipien der Nahbereichsphotogrammetrie und einige Anwendungsbeispiele im bautechnischen Versuchswesen vor. Das Ziel der Photogrammetrie ist die messtechnische Auswertung von Bilddaten mit hoher Genauigkeit und Zuverlässigkeit. Ein entscheidender Vorteil des Einsatzes photogrammetrischer Verfahren liegt in der Möglichkeit simultaner Messungen an einer großen Anzahl von Messpunkten. Durch stereoskopische Aufnahme können aus mehreren Aufnahmen eines Objekts dreidimensionale Informationen gewonnen werden, und durch die Anwendung von Bildverarbeitungsverfahren lassen sich Messabläufe weitestgehend automatisieren. Dank Subpixeloperatoren der Bildverarbeitung in Kombination mit einer strengen geometrischen Modellierung können auch beim Einsatz preiswerter Kameras hohe Genauigkeiten in vollautomatischen Messsystemen erzielt werden.

On the potential of photogrammetric techniques in civil engineering material testing

Photogrammetry is a technique to derive metric information from images with high precision and reliability. The paper presents the fundamentals and some application examples of close range photogrammetry in civil engineering material testing. A clear advantage of photogrammetric techniques is in the fact that it allows for simultaneous measurements at a large number of positions in an image. Processing stereoscopic images, 3D object information can be obtained. Subpixel accuracy image processing operators together with strict geometric sensor modeling allows for obtaining high accuracies in fully automatic measurement systems based on off‐the‐shelf camera components.
Zyklisch belastete Betonstrukturen
Authors: Urban Susanne , Strauss Alfred , Macho Werner , Bergmeister Konrad , Dehlinger Christian , Reiterer Michael
Published: November 2012

Bei Ermüdungsnachweisen von Betonstrukturen, vor allem im Bereich Offshore, wird die schrittweise Degradation von Materialparametern oftmals nicht berücksichtigt. Eine Auswirkung dieser Schädigung des Materials in Teilbereichen des Betonquerschnitts in Abhängigkeit des Belastungszustands ist eine Spannungsumlagerung innerhalb des Querschnitts und somit die Verlängerung der theoretischen Nutzungsdauer der Betonstruktur. Beton wird in seinen Eigenschaften mithilfe von Materialparametern näher bestimmt. Ein sehr wichtiger Materialparameter ist der E‐Modul, auch Elastizitätskoeffizient genannt. Ein Weg, die Schädigung des Materials in einer FE‐Analyse zu berücksichtigen, ist die schrittweise Anpassung und Minimierung des E‐Moduls. Um ein Bauwerk zu bemessen, seinen internen Spannungsverlauf oder sein Verformungsverhalten vorherzusagen, ist es somit von großer Wichtigkeit, diesen Parameter genau zu bestimmen, seine Veränderung mit der Zeit und aufgrund seiner Belastungshistorie zu kennen. In diesem Beitrag wird zusätzlich zur Robustheits‐ und Redundanz‐Definition auch eine Lebenszeitberechnung des Strabag‐Testfundaments in Cuxhaven nach Model Code 1990 für die geplanten Ermüdungsversuche mit realistisch verändertem E‐Modul ausgeführt. An der Fallstudie Cuxhaven wird mithilfe eines linearen, iterativen Modellbildungsprozesses die Nutzung der Robustheit des Systems für die Verlängerung der verbleibenden Nutzungsdauer gezeigt.

Concrete structures under cyclic loading – robustness and redundancy considerations for residual lifetime optimization

Concerning fatigue analysis of concrete structures, especially in offshore areas, the continuous degradation of material parameters is not taken into account. One effect of the damaged material structure in parts of the concrete cross section is the stress redistribution from highly loaded (damaged) areas to low loaded (undamaged) areas and therefore an elongation of the theoretical residual service life. Concrete is described by the use of material parameters. A very important parameter is the E‐modulus, also called the modulus of elasticity. A possibility to consider the degradation process within the material concrete is the gradual adaption and minimization of the E‐modulus. In order to analyze and dimension a structure, to predict the internal stress distribution and deflection behavior, it is very important to specify this parameter and to know the variation according loading history and time.

In addition to robustness and redundancy definition given in this article, a life time calculation of the Strabag gravity base test foundation in Cuxhaven according Model Code 1990 for the planned fatigue tests with realistic reduction of E‐Modulus is performed. Concerning the case study “Cuxhaven” the use of system robustness in order to extend the residual service life is been demonstrated by means of a linear iterative modeling process.
Textilbeton – Ausgeführte Projekte im Überblick
Authors: Ehlig Daniel , Schladitz Frank , Frenzel Michael , Curbach Manfred
Published: November 2012

In den vergangenen 15 Jahren lag im deutschen Bauwesen ein Forschungsschwerpunkt auf dem Verbundmaterial Textilbeton. 2011 endete die Finanzierung der durch die Deutsche Forschungsgemeinschaft (DFG) geförderten Sonderforschungsbereiche an der TU Dresden (SFB 528) und an der RWTH Aachen (SFB 532). Im Zuge dieser Forschungsarbeiten entstanden bereits erste Pilotbauwerke, die das hohe Potenzial von Textilbeton demonstrieren. Besonders im Bereich filigraner Neubauteile und der Verstärkung bestehender Tragwerke konnten mit dünnen Schichten aus Textilbeton unter Ausnutzung seiner hohen Zugtragfähigkeit Ansätze für eine wirtschaftliche Alternative zu konventionellen Bauweisen aufgezeigt werden. Um die Verbundwerkstoffe für ein breites Anwendungsfeld nutzbar zu machen, lag der Fokus in den vergangenen Jahren auf der anwendungsorientierten Forschung in Zusammenarbeit mit Firmen der Bauwirtschaft. So sind beispielsweise im Bereich der Fassadenelemente kleinformatige Platten aus Textilbeton heute bereits Stand der Technik. Auch für Brückenkonstruktionen, Tragwerksverstärkungen und großformatige Bauteile wie Balkonbodenplatten oder tragende Schalenkonstruktionen konnte die hohe Leistungsfähigkeit von Textilbeton ausgenutzt werden.

Textile concrete – an overview of executed projects

In Germany, a research focus was on the composite material textile reinforced concrete (TRC) in the last 15 years. In 2011 two Collaborative Research Centres (SFBs), SFB 528 at the TU Dresden and the SFB 532 at the RWTH Aachen, funded by the Deutsche Forschungsgemeinschaft (DFG) were successfully completed. Within the research projects, pilot buildings have already been developed to demonstrate the high potential of textile reinforced concrete. Particularly in the field of strengthening of existing structures and thin walled new components, thin constructions with a high tensile bearing capacity provide a cost‐effective alternative to conventional construction methods. With the aim of applying the material in a wide range of fields, numerous different research projects were realised in collaboration with companies from the construction industry in the last years. For instance small‐sized slabs made of textile reinforced concrete are already the state‐of‐the‐art in the field of facade panels. Furthermore, the high effectiveness of textile reinforced concrete could be shown for the strengthening of existing structures, bridge constructions and large‐sized components such as balcony floor slabs or bearing shell structures.
The limbal epithelium of the eye – A review of limbal stem cell biology, disease and treatment
Authors: Osei‐Bempong Charles , Figueiredo Francisco C. , Lako Majlinda
Published: November 2012

The limbus is a narrow band of tissue that encircles the cornea, the transparent ‘window’ into the eye. The outermost layer of the cornea is the epithelium, which is necessary for clear vision. The limbus acts as a ‘reservoir’ for limbal stem cells which maintain and regenerate the corneal epithelium. It also functions as a barrier to the conjunctiva and its blood vessels. Limbal stem cell deficiency is a general term for diseases which are characterised by the impairment of the limbus, limbal stem cells and their ability to replenish the corneal epithelium through proliferation and differentiation. Consequently, sufferers experience chronic pain and progressive blindness. This paper will highlight the salient milestones of limbal stem cell biology and potential future treatments for limbal stem cell deficiency.
THE EFFECTS OF FUNCTIONAL ANALYSIS TEST SESSIONS ON SUBSEQUENT RATES OF PROBLEM BEHAVIOR IN THE NATURAL ENVIRONMENT
Authors: Shabani Daniel B. , Carr James E. , Pabico Ryan S. , Sala Antonio P. , Lam Wing Yan , Oberg Traci L.
Published: November 2012

The present study was conducted to determine whether elevated response rates that occurred in an experimental functional analysis were correlated with higher post‐session response rates in the natural environment. Functional analyses indicated that the problem behavior of four children with developmental disabilities was maintained by common sources of reinforcement. Observational assessment in the natural environment showed no differences in post‐session rates compared with pre‐session rates for three participants, and the data for the fourth participant were equivocal. Overall, no convincing evidence was found to suggest that functional analyses might worsen post‐session problem behavior in the natural environment. Copyright © 2012 John Wiley & Sons, Ltd.
Revisiting flow‐chemiluminescence techniques: pharmaceutical analysis
Authors: Iranifam Mortaza
Published: November 2012

The state of the art in flow‐chemiluminescence (flow‐CL) technique for automated pharmaceutical analysis is reviewed. Flow‐CL approaches have become powerful and promising tools for pharmaceutical screening in recent years due to their simplicity, low cost and high sensitivity. Because of these advantages, these methods have been widely used for pharmaceutical analysis in recent years. The literature reviewed covers papers of analytical interest that appeared between 2007 and mid‐2012 and have been divided into several sections based on fundamental types of CL systems employed. Furthermore, entries have been summarized alphabetically in tabular form giving details of analytical figures of merit of the methods. Copyright © 2012 John Wiley & Sons, Ltd.
Total Synthesis of (−)‐Doliculide, Structure–Activity Relationship Studies and Its Binding to F‐Actin
Authors: Matcha Kiran , Madduri Ashoka V. R. , Roy Sayantani , Ziegler Slava , Waldmann Herbert , Hirsch Anna K. H. , Minnaard Adriaan J.
Published: November 2012

Actin, an abundant protein in most eukaryotic cells, is one of the targets in cancer research. Recently, a great deal of attention has been paid to the synthesis and function of actin‐targeting compounds and their use as effective molecular probes in chemical biology. In this study, we have developed an efficient synthesis of (−)‐doliculide, a very potent actin binder with a higher cell‐membrane permeability than phalloidin. Actin polymerization assays with (−)‐doliculide and two analogues on HeLa and BSC‐1 cells, together with a prediction of their binding mode to F‐actin by unbiased computational docking, show that doliculide stabilizes F‐actin in a similar way to jasplakinolide and chondramide C.
A Gene‐Fusion Approach to Enabling Plant Cytochromes P450 for Biocatalysis
Authors: Schückel Julia , Rylott Elizabeth L. , Grogan Gideon , Bruce Neil C.
Published: November 2012

Cytochromes P450 from plants have the potential to be valuable catalysts for industrial hydroxylation reactions, but their application is hindered by poor solubility, the lack of suitable expression systems and the requirement of P450s for auxiliary redox‐transport proteins for the delivery of reducing equivalents from NAD(P)H. In the interests of enabling useful P450 activity from plants, we have developed a suite of vectors for the expression of plant P450s as non‐natural genetic fusions with reductase proteins. First, we have fused the P450 isoflavone synthase (IFS) from Glycine max with the bacterial P450 reductase domain (Rhf‐RED) from Rhodococcus sp., by using our LICRED vector developed previously (F. Sabbadin, R. Hyde, A. Robin, E.‐M. Hilgarth, M. Delenne, S. Flitsch, N. Turner, G. Grogan, N. C. Bruce, ChemBioChem 2010, 11, 987–994) creating the first active bacterial–plant fusion P450 enzyme. We have then created a complementary vector, ACRyLIC for the fusion of selected plant P450 enzymes to the P450 reductase ATR2 from Arabidopsis thaliana. The applicability of this vector to the creation of active P450 fusion enzymes was demonstrated using both IFS1 and the cinnamate‐4‐hydroxylase (C4H) from A. thaliana. Overall the fusion vector systems will allow the rapid creation of libraries of plant P450s with the aim of identifying enzyme activities with possible applications in industrial biocatalysis.
Biocatalysis: Key to Selective Oxidations
Authors: Schulz Sebastian , Girhard Marco , Urlacher Vlada B.
Published: November 2012

Selective oxidations of readily available organic molecules can lead directly to high‐value chiral compounds. Although modern chemical catalysts have significantly been improved toward the selective hydroxylation of nonactivated CH bonds, cytochrome P450 monooxygenases still remain unsurpassed in their regio‐, chemo‐, and stereoselectivity. The exploitation of new P450 enzymes discovered through genome mining provides sought‐after fine chemicals, drugs, drug metabolites, and vitamins and has already been proven superior to classical chemical synthesis in many cases. Here, we provide examples for highly selective oxidations achieved through the exploitation of naturally occurring (wild‐type) P450 monooxygenases. We summarize recent achievements in the area of P450 biocatalysis and present examples for applications of P450s in industrial synthetic chemistry.
Molecular Ionics in Supramolecular Assemblies with Channel Structures Containing Lithium Ions
Authors: Moriya Makoto , Kitaguchi Hiro , Nishibori Eiji , Sawa Hiroshi , Sakamoto Wataru , Yogo Toshinobu
Published: November 2012

A novel trilithium compound, Li3[B(C6H4O2){O(CH2CH2O)3CH3}2][N(SO2CF3)2]2 (1‐2.0), with solid‐state ionic conductivity was synthesized. The crystal structure of 1‐2.0 consists of the one‐dimensional ionic conduction paths. The paths were afforded as a result of the self‐assembled stacking of the component molecules of 1‐2.0 with channel structures containing lithium ions. In this supramolecule, one lithium ion holds the component molecules in specific positions to construct a supramolecular structure with thermally stable ionic conduction paths and the others behave as carrier ions exhibiting selective lithium‐ion conductivity. Owing to the existence of both roles for the lithium ions, this electrolyte shows selective lithium‐ion conductivity.
Multivalent Design of Apoptosis‐Inducing Bid‐BH3 Peptide–Oligosaccharides Boosts the Intracellular Activity at Identical Overall Peptide Concentrations
Authors: Richter Martin , Chakrabarti Alokta , Ruttekolk Ivo R. , Wiesner Burkhard , Beyermann Michael , Brock Roland , Rademann Jörg
Published: November 2012

Multivalent peptide–oligosaccharide conjugates were prepared and used to investigate the multivalency effect concerning the activity of Bid‐BH3 peptides in live cells. Dextran oligosaccharides were carboxyethylated selectively in the 2‐position of the carbohydrate units and activated for the ligation of N‐terminally cysteinylated peptides. Ligation through maleimide coupling was found to be superior to the native chemical ligation protocol. Monomeric Bid‐BH3 peptides were virtually inactive, whereas pentameric peptide conjugates induced apoptosis up to 20‐fold stronger at identical peptide concentrations. Comparison of lowly multivalent and highly multivalent peptide dextrans proved a multivalency effect in life cells which was specific for the BH3 peptide sequence.
In Situ Gel‐to‐Crystal Transition and Synthesis of Metal Nanoparticles Obtained by Fluorination of a Cyclic β‐Aminoalcohol Gelator
Authors: Xu Yang , Kang Chuanqing , Chen Yu , Bian Zheng , Qiu Xuepeng , Gao Lianxun , Meng Qingxin
Published: November 2012

A new fluorinated version of a cyclic β‐aminoalcohol gelator derived from 1,2,3,4‐tetrahydroisoquinoline is presented. The gelator is able to gel various nonprotic solvents through OH⋅⋅⋅N hydrogen bonds and additional CH⋅⋅⋅F interactions due to the introduction of fluorine. A bimolecular lamellar structure is formed in the gel phase, which partly preserves the pattern of molecular organization in the single crystal. The racemate of the chiral gelator shows lower gelation ability than its enantiomer because of a higher tendency to form microcrystals, as shown by X‐ray diffraction analysis. The influence of fluorination on the self‐assembly of the gelator and the properties of the gel was investigated in comparison to the original fluorine‐free gel system. The introduction of fluorine brings two new features. The first is good recognition of o‐xylene by the gelator, which induces an in situ transition from gels of o‐xylene and of an o‐xylene/toluene mixture to identical single crystals with unique tubular architecture. The second is the enhanced stability of the toluene gel towards ions, including quaternary ammonium salts, which enables the preparation of a stable toluene gel in the presence of chloroaurate or chloroplatinate. The gel system can be used as a template for the synthesis of spherical gold nanoparticles with a diameter of 5 to 9 nm and wormlike platinum nanostructures with a diameter of 2 to 3 nm and a length of 5 to 12 nm. This is the first example of a synthesis of platinum nanoparticles in an organogel medium. Therefore, the appropriate introduction of a fluorine atom and corresponding nonbonding interactions into a known gelator to tune the properties and functions of a gel is a simple and effective tactic for design of a gel system with specific targets.
Self‐Assembly of a Mononuclear [FeIII(L)(EtOH)2] Complex Bearing an n‐Dodecyl Chain on Solid Highly Oriented Pyrolytic Graphite Surfaces
Authors: Ako Ayuk M. , Alam Mohammad Sahabul , Rahman Mostafizur , Hill Jonathan P. , Sanchez‐Ballester Noelia M. , Ariga Katsuhiko , Buth Gernot , Anson Christopher E. , Powell Annie K.
Published: November 2012

The synthesis and structures of the N‐[(2‐hydroxy‐3‐methyl‐5‐dodecylphenyl)methyl]‐N‐(carboxymethyl)glycine disodium salt (HL) ligand and its neutral mononuclear complex [FeIII(L)(EtOH)2] (1) are reported. Structural and electronic properties of 1 were investigated by using scanning tunneling microscopy (STM) and current imaging tunneling spectroscopy (CITS) techniques. These studies reveal that molecules of 1 form well‐ordered self‐assemblies when deposited on a highly oriented pyrolytic graphite (HOPG) surface. At low concentrations, single or double chains (i.e., nanowires) of the complex were observed, whereas at high concentration the complex forms crystals and densely packed one‐dimensional structures. In STM topographies, the dimensions of assemblies of 1 found on the surface are consistent with dimensions obtained from X‐ray crystallography, which indicates the strong similarities between the crystal form and surface assembled states. Double chains are attributed to hydrogen‐bonding interactions and the molecules align preferentially along graphite defects. In the CITS image of complex 1 a strong tunneling current contrast at the positions of the metal ions was observed. These data were interpreted and reveal that the bonds coordinating the metal ions are weaker than those of the surrounding ligands; therefore the energy levels next to the Fermi energy of the molecule should be dominated by metal‐ion orbitals.
Modeling lightness perception—a response to Kuehni
Authors: Carter Robert C. , Brill Michael H.
Published: November 2012

We agree with the main point of Rolf Kuehni's letter; time is ripe to improve the standard lightness metric L*. We discuss items he raised: scientific literature supporting both log and power laws of lightness, the relation of math theory and curve fitting, crispening, different models of lightness for different situations, and “who cares?” © 2012 Wiley Periodicals, Inc. Col Res Appl, 39, 105–106, 2014
Shifts in the ESR Spectra of Alkali‐Metal Atoms (Li, Na, K, Rb) on Helium Nanodroplets
Authors: Hauser Andreas W. , Gruber Thomas , Filatov Michael , Ernst Wolfgang E.
Published: November 2012

He‐droplet‐induced changes of the hyperfine structure constants of alkali‐metal atoms are investigated by a combination of relativistically corrected ab initio methods with a simulation of the helium density distribution based on He density functional theory. Starting from an accurate description of the variation of the hyperfine structure constant in the M–He diatomic systems (M=Li, Na, K, Rb) as a function of the interatomic distance we simulate the shifts induced by droplets of up to 10 000 4He atoms. All theoretical predictions for the relative shifts in the isotropic hyperfine coupling constants of the alkali‐metal atoms attached to helium droplets of different size are then tied to a single, experimentally derived parameter of Rb.
The effects of vitamin D3 during pregnancy and lactation on offspring physiology and behavior in Sprague–Dawley rats
Authors: Pan Pauline , Jin Daniel H.S. , Chatterjee‐Chakraborty Munmun , Halievski Katherine , Lawson Daeria , Remedios David , Smetka Cassandra , Pinto Vania , Parra Esteban , Fleming Alison S.
Published: November 2012

Recent findings show that developmental vitamin D deficiency leads to altered brain morphology and behavioral development in the rat offspring. We examined the effects of different dietary vitamin D levels in rat dams on behavior and biochemistry of the offspring. Females were divided into five conditions and received diets containing 0, 1,5, 3.3, 6.0, or 10.0 IU/g of vitamin D3 from mating to weaning. Offspring were tested as juveniles and as adults for anxiety, social learning and behavior, and locomotion. Results show that both deficient and excessive levels of vitamin D3 in juveniles lead to altered physiology and behavior. In juveniles but not adults, variations in vitamin D were related to variations in measures of anxiety and marginally, activity levels. For social behaviors, both juveniles and adults were affected by mothers' diets. In general, offspring of animals receiving abnormal concentrations of vitamin D showed the most deficits. © 2012 Wiley Periodicals, Inc. Dev Psychobiol 56: 12–22, 2014.
Ephrin‐B stimulation of calvarial bone formation
Authors: Benson M. Douglas , Opperman Lynne A. , Westerlund Jan , Fernandez Claudia R. , San Miguel Symone , Henkemeyer Mark , Chenaux George
Published: November 2012

Introduction: Ephrin‐B2 on osteoclasts was reported to promote bone formation as part of homeostasis by activating the EphB4 tyrosine kinase receptor on osteoblasts. Little is known about the role of ephrin‐B signaling to EphBs in developmental bone formation. Results: We observed expression of an ephrin‐B2 LacZ chimeric allele in the periosteum, sutural bone fronts, and dura mater of embryonic and neonatal mice. Expression in the adult skull was confined to sutures, but was heavily upregulated at sites of bone injury. Culture of embryonic calvariae with soluble recombinant ephrin‐B2/Fc doubled their bone content without altering suture width or overall skull morphology. Ephrin‐B2/Fc also stimulated osteoblast marker gene expression in cultured MC3T3 preosteoblastic cells without the need for type 1 collagen‐induced differentiation. EphB4 was absent in embryonic and adult skulls. However, EphB1 and EphB2, both physiological receptors for ephrin‐Bs, were expressed at sites of osteogenesis, and EphB1 knockout mice displayed a reduction in calvarial bone content compared to controls. Conclusions: These data support a role for ephrin‐B2 in the development and healing of bone through activation of osteoblast‐specific gene expression. EphB1 and EphB2 are likely candidates receptors for the ephrin‐B2 in bone. Developmental Dynamics, 2012. © 2012 Wiley Periodicals, Inc.
The interactions of the flow regime and the terrestrial ecology of the Mana floodplains in the middle Zambezi river basin
Authors: Ncube Sikhululekile , Beevers Lindsay , Hes Edwin M. A.
Published: November 2012

The flow regime of a river is the main driver of the processes that make up a floodplain ecosystem. Changes in a flow regime will therefore result in changes in the floodplain. The Mana floodplains in the middle Zambezi river basin have been impacted by the construction of the Kariba dam as indicated by the decline in the population of mature, Faidherbia albida (F. albida) trees and the absence young trees. However, the relationship between the effects of the river impoundment, some 50 years ago, and the current ecological state of the floodplain is not well understood. Hence, this study is aimed at describing the historic (pre‐Kariba and post‐Kariba dam) and the current terrestrial ecological state of the Mana floodplains. Data was gathered through review of literature, archival records and hydrological records. Furthermore, vegetation plots were set up to measure diameter at breast height (dbh) of F. albida trees and hence describe the current F. albida stand structure. Results from this study show that the Kariba dam altered the peak mean monthly flows by about 60%. The frequency distribution of the dbh sizes of the current F. albida trees depicted an even‐aged stand structure (mean dbh of 103 cm). There was no evidence of growth of young F. albida trees as there were no trees with smaller (less than 40 cm) dbh sizes. The dry season densities of elephants, (Loxodonta africana) on the Mana floodplains have been increasing since the 1990s, and these also seem to have impacted on the F. albida stand structure. This perhaps partially has to do with the increased length of the dry season as a result of the changed river flows. Therefore, the influence of the altered flow regime and the impact of wildlife have acted interdependently in influencing the noted detectable changes to the ecology of the Mana floodplains. Copyright © 2012 John Wiley & Sons, Ltd.
Protein‐Directed In Situ Synthesis of Gold Nanoparticles on Reduced Graphene Oxide Modified Electrode for Nonenzymatic Glucose Sensing
Authors: Liu Yang , Dong Yongqiang , Guo Chun Xian , Cui Zhiming , Zheng Lianxi , Li Chang Ming
Published: November 2012

A novel nonenzymatic glucose sensor was developed based on well‐dispersed gold nanoparticles, which were in situ grown under direction of protein on a reduced graphene oxide modified electrode. This electrode exhibited high electrocatalytic activity towards glucose oxidation without use of any enzyme or mediator. In application for the amperometric detection of glucose, a wide linear range of 0.02–16.6 mM, low detection limit of 5 µM and good selectivity were obtained. The attractive analytical performances of the proposed glucose sensor, coupled with the facile preparation method, provide a promising electrochemical platform for the development of effective nonenzymatic sensors.
Climatic catastrophes in Earth history: two great Proterozoic glacial episodes
Authors: Young Grant M.
Published: November 2012

Near the beginning and end of the Proterozoic Eon (2.5 Ga–542 Ma) the Earth went through dramatic climatic perturbations. The Palaeoproterozoic (Huronian) glaciations are best known from the Canadian Shield where there is evidence of at least three such episodes. Glacial deposits of comparable age are also known from Fennoscandia, South Africa and Western Australia. In the type area, the Huronian glacial deposits are preserved in an ancient rift system that preceded break‐up of the supercraton, Kenorland, whereas those in the southern hemisphere may have been deposited in a foreland basin setting. Detailed correlations between the two hemispheres must await more geochronological data. Following a long period (~1.5 Ga) with little evidence of glaciation, the climatic upheavals of the Neoproterozoic Era began. The two most widespread glacial events are known as the Sturtian and Marinoan. The Neoproterozoic glaciations also took place on a supercontinent (Rodinia). Some were accompanied by unexpected rock types such as dolomitic cap carbonates and iron formations, both of which show evidence of hydrothermal influence. Major influences on surface temperatures on Earth include solar luminosity (increasing throughout geological history) and the concentration of atmospheric greenhouse gases such as CO2 (generally diminishing with time). It is suggested that the two great Proterozoic climatic oscillation periods resulted from perturbations of the balance between these two variables, triggered by drawdown of atmospheric CO2 during intensive weathering of supercontinents. A weathering‐related negative feedback loop resulted in multiple glaciations with intervening warm periods. Climatic stability only returned after the supercontinent broke apart and reduced continental freeboard moderated continental weathering. Copyright © 2012 John Wiley & Sons, Ltd.
Functional connectivity networks associated with chronic musculoskeletal pain in old age
Authors: Duke Han S. , Buchman Aron S. , Arfanakis Konstantinos , Fleischman Debra A. , Bennett David A.
Published: November 2012

Objective

Musculoskeletal disorders are common and often lead to chronic pain in older adults. Because the efficacy of interventions varies with the duration of pain, the identification of early biomarkers for chronic pain would have important public health consequences. Imaging of functional connectivity differences between brain regions might identify some of the earliest functional consequences of a disease process. We tested the hypothesis that chronic musculoskeletal pain in older persons is associated with changes in functional brain connectivity.

Method

We used resting‐state functional magnetic resonance imaging and a spherical seed‐based region of interest approach to assess functional connectivity of brain regions on a sample of 128 (64 who reported chronic musculoskeletal pain and 64 demographically matched, pain free) nondemented older adults from the Memory and Aging Project, a clinical‐pathological cohort study of aging and dementia.

Results

Older adults with chronic pain showed greater functional connectivity between the posterior cingulate and left insula, left superior temporal gyrus, and left cerebellum.

Conclusion

Chronic musculoskeletal pain is associated with a specific pattern of functional connectivity between brain regions among older adults. Copyright © 2012 John Wiley & Sons, Ltd.