bluuebunny/crossref_metadata_2025 huggingface dataset:
Potential Occurrence of MTBE and BTEX in Groundwater Resources of Amman–Zarqa Basin, Jordan
Authors: Al Kuisi Mustafa , Saffarini Ghazi , Yaseen Najal , Alawi Mahmoud
Published: July 2012

This study investigates potential occurrence, distribution, and sources of the newly added gasoline oxygenate, methyl‐tert‐butyl ether (MTBE) and the petroleum derivatives benzene, toluene, ethylbenzene, and xylenes called collectively, BTEX, in Jordan's heavily populated Amman–Zarqa Basin (AZB). It presents the first data on the levels of MTBE and BTEX in the aquifers of this basin. One hundred and seventy‐nine (179) groundwater wells were sampled near petrol service stations, oil refinery storage tanks, car wrecks, bus stations, and chemical industries at different locations in the basin. Headspace GC and purge and trap GC–MS were utilized to determine the target substances in the samples. Concentrations of BTEX varied between no‐detection (minimum) for all of them to 6.6 µg/L (maximum) for ethylbenzene. MTBE was found in few samples but none has exceeded the regulated levels; its concentrations ranged between no‐detection to 4.1 µg/L. However, though the contamination levels are very low they should be considered alarming.
Dramatic Fluorescence Enhancement of Bare Carbon Dots through Facile Reduction Chemistry
Authors: Shen Ran , Song Kai , Liu Huarong , Li Yuesheng , Liu Hewen
Published: July 2012

Reduction of bare carbon dots (CDs) in aqueous NaBH4 solution is a facile and effective approach to enhance their fluorescence without any surface coverage. CDs are treated with dilute aqueous NaBH4 solutions, enhancing their quantum yields (QYs) successfully from 1.6 % to 16 % which is comparable to semiconductive QDs in aqueous environments. If pristine CDs are treated hydrothermally prior to reduction by NaBH4, QYs reach 40.5 %. This value is among the highest QYs reported for bare CDs in the literature. The approach to enhance fluorescence through chemical reduction is generally applicable to other kinds of CDs synthesized by various methods. Alteration of the chemical structure of the CDs by NaBH4‐reduction is analyzed by 13C NMR, X‐ray photoelectron spectroscopy (XPS) and Raman spectroscopy, which demonstrate that the carbonyl group content is decreased after NaBH4‐reduction, whereas the number of sp3‐type carbon defects is increased. The valence‐band maxima (VBM) near the surface related to the surface energy bands of the CDs are estimated by XPS. VBM data show a semiconducting layer on the surface of the CDs, and the VBM of the CDs decrease with increasing NaBH4‐reduction time. The layered graphite structures in the cores of the CDs are clearly observed by transmission electron microscopy (TEM). CDs could perhaps be regarded as semiconductive surface defect layers formed by chemical erosion over conductive graphite cores. Chemical reduction by NaBH4 changes the surface‐energy bands of the CDs, thus, enhances their fluorescence. The fluorescence properties of aqueous NaBH4‐reduced CDs are also studied for possible biological applications.
On‐Bead Screens Sample Narrower Affinity Ranges of Protein–Ligand Interactions Compared to Equivalent Solution Assays
Authors: Hintersteiner Martin , Buehler Christof , Auer Manfred
Published: July 2012

Conceptually, on‐bead screening is one of the most efficient high‐throughput screening (HTS) methods. One of its inherent advantages is that the solid support has a dual function: it serves as a synthesis platform and as a screening compartment. Compound purification, cleavage and storage and extensive liquid handling are not necessary in bead‐based HTS. Since the establishment of one‐bead one‐compound library synthesis, the properties of polymer beads in chemical reactions have been thoroughly investigated. However, the characterization of the kinetics and thermodynamics of protein–ligand interactions on the beads used for screening has received much less attention. Consequently, the majority of reported on‐bead screens are based on empirically derived procedures, independent of measured equilibrium constants and rate constants of protein binding to ligands on beads. More often than not, on‐bead screens reveal apparent high affinity binders through strong protein complexation on the matrix of the solid support. After decoding, resynthesis, and solution testing the primary hits turn out to be unexpectedly weak binders, or may even fall out of the detection limit of the solution assay. Only a quantitative comparison of on‐bead binding and solution binding events will allow systematically investigating affinity differences as function of protein and small molecule properties. This will open up routes for optimized bead materials, blocking conditions and other improved assay procedures. By making use of the unique features of our previously introduced confocal nanoscanning (CONA) method, we investigated the kinetic and thermodynamic properties of protein–ligand interactions on TentaGel beads, a popular solid support for on‐bead screening. The data obtained from these experiments allowed us to determine dissociation constants for the interaction of bead‐immobilized ligands with soluble proteins. Our results therefore provide, for the first time, a comparison of on‐bead versus solution binding thermodynamics. Our data indicate that affinity ranges found in on‐bead screening are indeed narrower compared to equivalent interactions in homogeneous solution. A thorough physico‐chemical understanding of the molecular recognition between proteins and surface bound ligands will further strengthen the role of on‐bead screening as an ultimately cost‐effective method in hit and lead finding.
Phosphorylation of CRMP2 is involved in proper bifurcation of the apical dendrite of hippocampal CA1 pyramidal neurons
Authors: Niisato Emi , Nagai Jun , Yamashita Naoya , Nakamura Fumio , Goshima Yoshio , Ohshima Toshio
Published: July 2012

The neural circuit in the hippocampus is important for higher brain functions. Dendrites of CA1 pyramidal neurons mainly receive input from the axons of CA3 pyramidal neurons in this neural circuit. A CA1 pyramidal neuron has a single apical dendrite and multiple basal dendrites. In wild‐type mice, most of CA1 pyramidal neurons extend a single trunk, or alternatively, the apical dendrite bifurcates into two daughter trunks at the stratum radiatum layer. We previously reported the proximal bifurcation phenotype in Sema3A−/−, p35−/−, and CRMP4−/− mice. Cdk5/p35 phosphorylates CRMP2 at Ser522, and inhibition of this phosphorylation suppressed Sema3A‐induced growth cone collapse. In this study, we analyzed the bifurcation points of the apical dendrites of hippocampal CA1 pyramidal neurons in CRMP2KI/KI mice in which the Cdk5/p35‐phosphorylation site Ser522 was mutated into an Ala residue. The proximal bifurcation phenotype was not observed in CRMP2KI/KI mice; however, severe proximal bifurcation of apical dendrites was found in CRMP2KI/KI;CRMP4−/− mice. Cultured hippocampal neurons from CRMP2KI/KI and CRMP2KI/KI;CRMP4−/− embryos showed an increased number of dendritic branching points compared to those from wild‐type embryos. Sema3A increased the number of branching points and the total length of dendrites in wild‐type hippocampal neurons, but these effects of Sema3A for dendrites were notobserved in CRMP2KI/KI and CRMP2KI/KI;CRMP4−/−hippocampal neurons. Binding of CRMP2 to tubulin increased in both CRMP2KI/KI and CRMP2KI/KI:CRMP4−/− brain lysates. These results suggest that CRMP2 and CRMP4 synergistically regulate dendritic development, and CRMP2 phosphorylation is critical for proper bifurcation of apical dendrite of CA1 pyramidal neurons. © 2012 Wiley Periodicals, Inc. Develop Neurobiol, 2013
Sequence polymorphisms in wild, weedy, and cultivated rice suggest seed‐shattering locus sh4 played a minor role in Asian rice domestication
Authors: Zhu Yongqing , Ellstrand Norman C. , Lu Bao‐Rong
Published: July 2012

The predominant view regarding Asian rice domestication is that the initial origin of nonshattering involved a single gene of large effect, specifically, the sh4 locus via the evolutionary replacement of a dominant allele for shattering with a recessive allele for reduced shattering. Data have accumulated to challenge this hypothesis. Specifically, a few studies have reported occasional seed‐shattering plants from populations of the wild progenitor of cultivated rice (Oryza rufipogon complex) being homozygous for the putative “nonshattering” sh4 alleles. We tested the sh4 hypothesis for the domestication of cultivated rice by obtaining genotypes and phenotypes for a diverse set of samples of wild, weedy, and cultivated rice accessions. The cultivars were fixed for the putative “nonshattering” allele and nonshattering phenotype, but wild rice accessions are highly polymorphic for the putative “nonshattering” allele (frequency ~26%) with shattering phenotype. All weedy rice accessions are the “nonshattering” genotype at the sh4 locus but with shattering phenotype. These data challenge the widely accepted hypothesis that a single nucleotide mutation (“G”/“T”) of the sh4 locus is the major driving force for rice domestication. Instead, we hypothesize that unidentified shattering loci are responsible for the initial domestication of cultivated rice through reduced seed shattering.
Population structure of the butternut canker fungus, Ophiognomonia clavigignenti‐juglandacearum, in North American forests
Authors: Broders K. D. , Boraks A. , Sanchez A. M. , Boland G. J.
Published: July 2012

The occurrence of multiple introduction events, or sudden emergence from a host jump, of forest pathogens may be an important factor in successful establishment in a novel environment or on a new host; however, few studies have focused on the introduction and emergence of fungal pathogens in forest ecosystems. While Ophiognomonia clavigignenti‐juglandacearum (Oc‐j), the butternut canker fungus, has caused range‐wide mortality of butternut trees in North America since its first observation in 1967, the history of its emergence and spread across the United States and Canada remains unresolved. Using 17 single nucleotide polymorphic loci, we investigated the genetic population structure of 101 isolates of Oc‐j from across North America. Clustering analysis revealed that the Oc‐j population in North America is made up of three differentiated genetic clusters of isolates, and these genetic clusters were found to have a strong clonal structure. These results, in combination with the geographic distribution of the populations, suggest that Oc‐j was introduced or has emerged in North America on more than one occasion, and these clonal lineages have since proliferated across much of the range of butternut. No evidence of genetic recombination was observed in the linkage analysis, and conservation of the distinct genetic clusters in regions where isolates from two or more genetic clusters are present, would indicate a very minimal or non‐existent role of sexual recombination in populations of Oc‐j in North America.
Investigation and improvement of torque response of control system based on direct torque control in interior permanent magnet synchronous motors
Authors: Inoue Yukinori , Morimoto Shigeo , Sanada Masayuki
Published: July 2012

In this study, we investigate the torque response of a control system that is based on the direct torque control (DTC) principle for an interior permanent magnet synchronous motor (IPMSM). We also propose a gain‐scheduling method for improving the torque response. Reference flux vector calculation (RFVC) DTC is used in this study. In RFVC DTC, a PI controller is used for torque control; this is in contrast to the use of the hysteresis comparator and switching table in basic DTC. In this paper, we present the relationship between the torque response and the gain of the PI controller. This relationship is derived by using the transfer function of the torque control loop. We also examine the difference between the torque responses of two motors that have different machine parameters. The proposed method can be used to realize a torque response that is independent of the operating torque. The simulation results and experimental results presented in this paper show the validity of the derived relationship as well as the effectiveness of the proposed method. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 181(2): 55–65, 2012; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.21198
A small‐size self‐propelled Stewart platform
Authors: Torii Akihiro , Banno Masaaki , Ueda Akiteru , Doki Kae
Published: July 2012

This paper describes a self‐propelled Stewart platform. The Stewart platform usually consists of a base platform, a moving platform, and linear actuators connecting the platforms. We use six stacked‐type piezoelectric actuators as linear actuators. Mechanical joints connected the linear actuators and both of the platforms. We inserted electromagnets between the linear actuators and the base platform instead of the mechanical joints. This structure enables the Stewart platform to move on a surface by using the principle of inchworm motion. While the electromagnets fix the linear actuators on the base platform, the proposed Stewart platform realizes a precise 6‐DOF motion. Control signals are designed for small displacement based on inverse kinematics, and for a wide working area based on the principle of inchworm motion. The position and orientation of the moving platform are measured, and experimental results indicate the feasibility of the proposed mechanism. The mechanism is effective for a precise position system which has unlimited working space. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 181(2): 37–46, 2012; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.21261
Influence of surface‐conductivity nonuniformity on charge accumulation of GIS downsized model spacer under DC field application
Authors: Iwabuchi Hiroyuki , Donen Taiki , Matsuoka Shigeyasu , Kumada Akiko , Hidaka Kunihiko , Hoshina Yoshikazu , Takei Masafumi
Published: July 2012

When a DC voltage is applied to an insulating spacer, the electric field distribution around it is determined by the resistivity of the material. Consequently, charges are accumulated on the surface of the insulator, and its breakdown voltage may become low. In this paper, the charge density distribution of the insulator is measured. The measured data indicate that the surface conductance is the main factor in charge accumulation. Therefore, the conductivity of the insulator is also measured, and the influence of the surface conductivity on charge accumulation is examined both experimentally and by numerical computation. It is confirmed that nonuniformity of surface conductivity is responsible for charge accumulation and the conductivity of the insulator in atmospheric‐pressure SF6 is estimated to be $\sigma = 1 \times 10^{-18} \Omega^{-1}$. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 181(2): 29–36, 2012; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.22272
A multiagent‐based cooperative voltage and reactive power control
Authors: Ishida Masato , Nagata Takeshi , Saiki Hiroshi , Shimada Ikuhiko , Hatano Ryousuke
Published: July 2012

In order to maintain the system voltage within the optimal range and to prevent voltage instability phenomena before they occur, a variety of phase modifying equipment are installed in optimal locations throughout the power system network and a variety of methods of voltage reactive control are employed. The proposed system divides the traditional method of controlling voltage and reactive power into two subproblems: “voltage control” to adjust the secondary bus voltage of substations, and “reactive power control” to adjust the primary bus voltage. In this system, two types of agents are installed in substations in order to coordinate voltage control and reactive power control. In order to verify the performance of the proposed method, it was applied to a model network system. The results confirm that our proposed method is able to control violent fluctuations in load. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 181(2): 20–28, 2012; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.22286
System identification of power network for coordinated setting of PSSs
Authors: Murayama Dai , Mitsumoto Kenji , Takagi Yasuo , Uemura Youichi , Sato Koji , Shirasaki Takashi , Sakamoto Kunio
Published: July 2012

The PSS is a reasonable controller to stabilize the intertie and local oscillations of power networks. PSSs are usually set with the one‐machine infinite‐bus system model. The coordinated setting of the multiple PSSs considering the characteristics of the network is expected to improve stability. For this purpose, the Modal Performance Measure method is used to adjust the PSS parameters. The model is identified by the N4SID identification method. In this paper, the conditions of identification and validation of identification are presented. Identified models are validated by comparison of vector diagrams, impulse response, and so on. Identification of a power network that consists of many generators is successful. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 181(2): 10–19, 2012; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.22287
Bis‐Ylide Ligands from Acyclic Proximal Diphosphonium Precursors
Authors: Maaliki Carine , Abdalilah Mohammed , Barthes Cécile , Duhayon Carine , Canac Yves , Chauvin Remi
Published: July 2012

1,2‐ or 1,3‐Phenylene‐diphosphonium bis‐ylides have been prepared and their stabilities compared by analysis of the effects of the substitution pattern of the phenylene bridge and the steric hindrance of the P‐alkyl substituents in the diphosphonium precursors RPh2P+(C6H4)+PPh2R′ (R,R′ = Me, Et). In the o‐phenylene series, the vicinity of the phosphorus centers allows the distal P+/C– charge separation of the mono‐ylide intermediate to be canceled by the formation of a cyclic ylidophosphorane. The ring strain in the latter was released through phenylene–P(σ5) bond cleavage to afford relaxed diphosphonium bis‐ylides, which were isolated as carbodiphosphorane, or protonated in situ to form bis‐phosphonium ylides depending on the bulkiness of the P‐alkyl substituents. In the m‐phenylene series (with R,R′ = Me), the amplified distal P+/C– charge separation proved sufficient to stabilize the corresponding diphosphonium bis‐ylide as a chelating ligand of an RhI(CO)2 center, in a complex where the effective σ‐donation of the ligand was confirmed by comparison of the IR carbonyl stretching frequencies with those of the isostructural complex previously described in the o‐phenylene series.
Singlet Carbenes Derived from Ferrocene and Closely Related Sandwich Complexes (Eur. J. Inorg. Chem. 22/2012)
Authors: Siemeling Ulrich
Published: July 2012

The cover picture shows the molecular structure of an N‐heterocyclic carbene with a ferrocene‐based backbone. This unique blend of the ferrocene and carbene motifs gives rise to compounds of fantastic reactivity, completely unprecedented for diaminocarbenes. With its ferrocene‐like orange colour the cover picture stresses that the properties of carbenes have been changed dramatically through combining them with ferrocene‐based moieties. The Microreview by U. Siemeling on p. 3523 ff. systematically addresses the different ways of ferrocene–carbene combination, together with the sometimes spectacular achievements in this area. The cover picture also underlines that results that may appear like revolutionary progress are mostly due to an evolutionary scientific process.

magnified image
Refined hazard characterization of 3‐MCPD using benchmark dose modeling
Authors: Rietjens Ivonne M. C. M. , Scholz Gabriele , Berg Iekje , Schilter Benoit , Slob Wout
Published: July 2012

3‐Monochloropropane‐1,2‐diol (3‐MCPD)‐esters represent a newly identified class of food‐borne process contaminants of possible health concern. Due to hydrolysis 3‐MCPD esters constitute a potentially significant source of free 3‐MCPD exposure and their preliminary risk assessment was based on toxicological data on free 3‐MCPD. 3‐MCPD is a non‐genotoxic carcinogen and a (provisional maximum) tolerable daily intake ((PM)TDI) of 2 µg/kg bodyweight per day was established by the Scientific Committee on Food and the Joint FAO/WHO Expert Committee on Food Additives. Both committees derived the TDI from a lowest observed adverse effect level, not a no observed adverse effect level, for renal tubular hyperplasia, using an uncertainty factor of 500. When using the Benchmark Dose (BMD) approach and a BMDL10 value as point of departure, part of this uncertainty factor of 500 would no longer be needed. The present study presents a BMD analysis of the currently available chronic data on 3‐MCPD mediated induction of tubular hyperplasia in rats as the most sensitive endpoint. The results indicate a (model‐averaged) BMDL10 value of 0.72 mg/kg bw/day. The TDI that would be derived based on this BMDL10 value will depend on the uncertainty factor chosen. Using the default uncertainty factor of 100 for inter‐ and intraspecies extrapolation would result in a TDI of 7 µg/kg bw/day.

See commentary by Abraham et al. [p. 1225–1226]
Chemical and sensorial changes of Croatian monovarietal olive oils during ripening
Authors: Brkić Bubola Karolina , Koprivnjak Olivera , Sladonja Barbara , Škevin Dubravka , Belobrajić Ivana
Published: July 2012

The aim of this investigation was to determine the impact of fruit ripening on chemical and sensorial changes in monovarietal olive oils obtained from two important olive cultivars grown in Croatia, Buža and Črna. In Buža oils peroxide value, K232 and K270 increased during ripening, while no differences among three ripening stages in Črna oils were observed. Oils of both cultivars at the later ripening stages had higher free acidity level and lower sensory score followed by mild loss in almost all positive sensory characteristics. Total phenols and antioxidant capacity decreased in Buža oils during fruit ripening, while in Črna oils reached maximum level in purple stage and then progressively decreased in the black ripening stage. Oleic acid level slightly increased during ripening in both cultivar oils. Linoleic acid decreased in Buža oils obtained from black fruits while palmitic acid decreased in Črna oils during ripening. In both monovarietal oils chlorophyll and carotenoids concentrations decreased during ripening. The two cultivars had different course of total aldehydes, total esters and total ketones during ripening, while total alcohols were the highest in oils from purple ripening stage and then decreased as ripening progress.

Practical applications: During the ripening, the chemical composition of olive fruit changes influencing the quality grade, oxidative stability, sensory characteristics and nutritional value of the obtained products. The cultivars characterized by a similar trend of ripening process could have different course of chemical and sensorial changes in oil during fruit ripening. Therefore, knowledge about these changes is important for determination of proper harvest time of single cultivar to achieve optimum of its potential regarding desirable characteristics of obtained oil.
Vegetable‐based building‐blocks for the synthesis of thermoplastic renewable polyurethanes and polyesters
Authors: More Arvind S. , Maisonneuve Lise , Lebarbé Thomas , Gadenne Benoit , Alfos Carine , Cramail Henri
Published: July 2012

Fatty acid derivatives, viz, methyl oleate and methyl 10‐undecenoate were systematically explored to obtain a set of monomers with defined functionality. More specifically, AB‐type self‐condensable monomers containing hydroxyl‐acyl azide functionality and diols with pre‐formed ester linkage were synthesized. A series of polyurethanes was prepared using two methods: (i) AB‐type self‐polycondensation reaction of hydroxyl‐acyl azide moiety, and (ii) polymerization of diols with isophorone diisocyanate and methylene diphenyl diisocyanate. The diols were also reacted with a bio‐sourced diester using organocatalyst to obtain a set of polyesters. The obtained polyurethanes and polyesters were thoroughly analyzed with fourier‐transformed infrared, nuclear magnetic resonance, size exclusion chromatography, differential scanning calorimetry and thermogravimetric analysis experiments. The polymers displayed amorphous to semi‐crystalline behaviors with regard to the structure of the monomers. Both, polyurethanes and polyesters displayed a good thermal stability with no significant weight loss below 200°C.
Modular Synthesis of Core Fucosylated N‐Glycans
Authors: Ott Dimitri , Seifert Joachim , Prahl Ingo , Niemietz Mathäus , Hoffman Joanna , Guder Janna , Mönnich Manuel , Unverzagt Carlo
Published: July 2012

A modular synthesis of complex‐type N‐glycans containing the core fucosyl motif was optimized. The core trisaccharide building block was protected by a methoxyphenyl group for convenient core fucosylation. The trisaccharide was obtained on a large scale from the glycosylation of the corresponding chitobiosyl azide with a glucosyl donor followed by intramolecular inversion. Improved methods were established for the synthesis of the monosaccharide building blocks and for their couplings. The inversion to the β‐mannoside was accompanied by previously unnoticed side‐reactions resulting in the hydrolytic ring‐opening of the iminocarbonate intermediate. The benzylidene‐protected core trisaccharide was elongated into a biantennary N‐glycan heptasaccharide by two regio‐ and stereoselective couplings. The final fucosylation also gave some of the β anomer, which could be removed by HPLC to give an α1,6‐fucosylated N‐glycan octasaccharide.
Synthesis of Piperazinones, Piperazines, Tetrahydropyrazines, and Dihydropyrazinones from Polymer‐Supported Acyclic Intermediates via N‐Alkyl‐ and N‐Acyl­iminiums
Authors: Vaňková Barbora , Brulíková Lucie , Wu Boyuan , Krchňák Viktor
Published: July 2012

Trisubstituted piperazinones, piperazines, tetrahydropyrazines, and dihydropyrazinones were prepared in a one‐step procedure from easily accessible polymer‐supported acyclic precursors containing either a masked aldehyde or ketone group. Acid‐mediated unmasking of the aldehyde triggered cyclic iminium formation followed by reduction with triethylsilane present in the cleavage cocktail. The effect of the substituent at the iminium‐forming nitrogen was evaluated: whereas complete conversion to the target compounds was observed with N‐alkyl, aryl, and phenylsulfonamido derivatives, the N‐acyl compound suffered from a partial reduction of the aldehyde to an alcohol. Similarly, ketones readily provided cyclic iminiums with N‐alkyl compounds, whereas their cyclization with N‐acyl precursors proceeded unwillingly. Interestingly, cleavage of the resin‐bound acyclic precursor at 60 °C in the presence of triethylsilane resulted in the decomposition of the amide bond and formation of a lactone. An analogous synthetic route was also successfully used for the preparation of piperazines and tested as an alternative route for the synthesis of diazepanones.
Highly Selective Activation of Vinyl C–S Bonds Over Aryl C–S Bonds in the Pd‐Catalyzed Coupling of (E)‐(β‐Trifluoromethyl)vinyldiphenylsulfonium Salts: Preparation of Trifluoromethylated Alkenes and Dienes
Authors: Lin Hao , Dong Xicheng , Li Yuxue , Shen Qilong , Lu Long
Published: July 2012

We describe the Suzuki coupling reaction of (E)‐(β‐trifluoromethyl)vinyldiphenylsulfonium salts with arylboronic acid. The highly efficient and selective reaction provides a useful and mild method for the synthesis of trifluoromethylated alkenes and dienes. Subsequent DFT studies showed that the oxidative addition transition state of the vinyl C–S bond is much more favorable (11.7 kcal mol–1) than that of the aryl C–S bond.
Decarboxylative Allylation of Glyoxylic Acids with Diallyl Carbonate
Authors: Manjolinho Filipe , Grünberg Matthias F. , Rodríguez Nuria , Gooßen Lukas J.
Published: July 2012

A catalyst system consisting of Pd(PPh3)4 and P(pTol)3 was found to effectively promote the intermolecular decarboxylative coupling of α‐oxocarboxylic acids with diallyl carbonate to give α,β‐unsaturated ketones. The key advantage of the new reaction protocol is that preformation of the allyl esters is not required. The reaction is believed to proceed via phosphane‐mediated decarboxylation of the α‐oxocarboxylates, leading to acyl anion equivalents that are allylated within the coordination sphere of the palladium catalyst. Under the reaction conditions, the double bond then migrates into conjugation with the carbonyl group.
Cylindrospermopsin determination in water by LC-MS/MS: Optimization and validation of the method and application to real samples
Authors: Guzmán-Guillén Remedios , Prieto Ana I. , González A. Gustavo , Soria-Díaz M. Eugenia , Cameán Ana M.
Published: July 2012

A new method for determining dissolved cylindrospermopsin (CYN) in waters using solid-phase extraction (SPE) with graphitized carbon cartridges and quantification by liquid chromatography coupled with tandem mass spectrometry is described and discussed. The method has been suitably validated: the linear range covered is from 0.900 to 125 µg CYN/L. Limits of detection and quantification were 0.5 and 0.9 µg CYN/L, respectively, and allow CYN determination at concentrations below the guideline proposed of 1 µg CYN/L in natural waters. The method exhibits mean recoveries from 83 to 95%, and intermediate precision (relative standard deviation (%)) values from 5 to 12%, ensuring adequacy against the Association of Official Analytical Chemists guidelines. The method is robust against the following three influential factors considered in the cleanup stage: the batch of the graphitized carbon cartridges, the flow rate of the water sample through the cartridge, and the final redissolved water volume after SPE treatment. The method has been successfully applied to detection and quantification of CYN in water samples from aquaria of a toxicological in vivo laboratory experiment. Environ. Toxicol. Chem. 2012; 31: 2233–2238. © 2012 SETAC
Risk management: Uncovering hidden insights from VaR simulation data for financial performance
Authors: Henderson Phil
Published: July 2012

Value at Risk (VaR) is a widely used risk measure to examine the risk of loss on a specific portfolio of financial assets. In fact, it has become “best practice” for companies to report VaR of their derivative portfolio in their annual financial statements. As a result, in the natural gas and power industries, VaR has evolved to a simplistic calculation largely adapted for reporting purposes and often misunderstood, yet less employed to business performance and capital adequacy.
Natural gas matters: Gas‐Electric interaction steps up a notch
Authors: Smead Richard G.
Published: July 2012

In April, in this space, I discussed the effort undertaken by the North American Energy Standards Board (NAESB), in response to the National Petroleum Council (NPC), to address “gas‐electric harmonization,” a rationalization of the interaction between the business structures of the natural gas and electric power industries. Since that time, there have been a number of developments as the NAESB effort has moved forward. First, in June Federal Energy Regulatory Commission (FERC) Chairman Jon Wellinghoff announced a series of five regional conferences designed to provide input to the commission on the same issues. The chairman's statement was really pretty short and to the point, the key paragraph being the following:
Stimulation of murine biliary cholesterol secretion by thyroid hormone is dependent on a functional ABCG5/G8 complex
Authors: Bonde Ylva , Plösch Torsten , Kuipers Folkert , Angelin Bo , Rudling Mats
Published: July 2012

Secretion of cholesterol into bile is important for the elimination of cholesterol from the body. Thyroid hormone (TH) increases biliary cholesterol secretion and hepatic gene expression of adenosine triphosphate (ATP)-binding cassette, subfamily G (WHITE), member 5 (ABCG5) and ATP-binding cassette, subfamily G (WHITE), member 8 (ABCG8), two half-transporters that act as a heterodimeric complex promoting sterol secretion. In addition, nuclear liver x receptor-alpha (LXRa), also regulated by TH, induces gene expression of ABCG5/G8. We here investigated if the TH-induced stimulation of biliary cholesterol secretion is mediated by the ABCG5/G8 complex

in vivo

, and if so, whether LXRa is involved. Mice homozygous for disruption of

Abcg5

(

Abcg5

−/−) or

Lxra

(

Lxra

−/−) and their wild-type counterparts were treated with triiodothyronine (T3) for 14 days and compared to untreated mice of corresponding genetic backgrounds. Bile was collected by gallbladder cannulation, and liver samples were analyzed for gene expression levels. Basal biliary cholesterol secretion in

Abcg5

−/− mice was 72% lower than in

Abcg5

+/+ mice. T3 treatment increased cholesterol secretion 3.1-fold in

Abcg5

+/+ mice, whereas this response was severely blunted in

Abcg5

−/− mice. In contrast, biliary cholesterol secretion in T3-treated

Lxra

+/+ and

Lxra

−/− mice was increased 3.5- and 2.6-fold, respectively, and did not differ significantly.

Conclusions :

TH-induced secretion of cholesterol into bile is largely dependent on an intact ABCG5/G8 transporter complex, whereas LXRa is not critical for this effect.
Human liver stem cells improve liver injury in a model of fulminant liver failure
Authors: Herrera Maria Beatriz , Fonsato Valentina , Bruno Stefania , Grange Cristina , Gilbo Nicholas , Romagnoli Renato , Tetta Ciro , Camussi Giovanni
Published: July 2012

Liver transplantation is currently the only effective therapy for fulminant liver failure, but its use is limited by the scarcity of organs for transplantation, high costs, and lifelong immunosuppression. Here we investigated whether human liver stem cells (HLSCs) protect from death in a lethal model of fulminant liver failure induced by intraperitoneal injection of D-galactosamine and lipopolysaccharide in SCID mice. We show that injection of HLSCs and of HLSC-conditioned medium (CM) significantly attenuates mouse mortality in this model. Histopathological analysis of liver tissue showed reduction of liver apoptosis and enhancement of liver regeneration. By optical imaging we observed a preferential localization of labeled HLSCs within the liver. HLSCs were detected by immunohistochemistry in large liver vessels (at 24 hours) and in the liver parenchyma (after day 3). Fluorescence in situ hybridization analysis with the human pan-centromeric probe showed that positive cells were cytokeratin-negative at 24 hours. Coexpression of cytokeratin and human chromosome was observed at 7 and, to a lesser extent, at 21 days. HLSC-derived CM mimicked the effect of HLSCs in vivo. Composition analysis of the HLSC-CM revealed the presence of growth factors and cytokines with liver regenerative properties. In vitro experiments showed that HLSC-CM protected human hepatocytes from apoptosis and enhanced their proliferation. Conclusion: These data suggest that fulminant liver failure may potentially benefit from treatment with HLSCs or HLSC-CM. (Hepatology 2013)
Stromal Interactions as Regulators of Tumor Growth and Therapeutic Response: A Potential Target for Photodynamic Therapy?
Authors: Celli Jonathan P.
Published: July 2012

It has become increasingly widely recognized that the stroma plays several vital roles in tumor growth and development and that tumor‐stroma interactions can in many cases account for poor therapeutic response. Inspired by an emerging body of literature, we consider the potential role of photodynamic therapy (PDT) in targeting interactions with stromal fibroblasts and mechanosensitive signaling with the extracellular matrix as a means to drive tumors toward a more therapeutically responsive state and synergize with other treatments. This concept is particularly relevant for cancer of the pancreas, which is characterized by tumors with a profoundly dense, rigid fibrous stroma. Here we introduce new in vitro systems to model interactions between pancreatic tumors and their mechanical microenvironment and restore signaling with stromal fibroblasts. Using one such model as a test bed it is shown here that PDT treatment is able to destroy fibroblasts in an in vitro 3D pancreatic tumor‐fibroblast coculture. These results and the literature suggest the further development of PDT as a potential modality for stromal depletion.
Exploring Maternal Representations During Pregnancy in Normal and At‐Risk Samples: The Use of the Interview of Maternal Representations During Pregnancy
Authors: Ammaniti Massimo , Tambelli Renata , Odorisio Flaminia
Published: July 2012

The purpose of this study is to evaluate the potentiality of the Interview of Maternal Representations during Pregnancy‐Revised Version (IRMAG‐R; M. Ammaniti & R. Tambelli, 2010) in exploring maternal representations in at‐risk and nonrisk conditions. Maternal representations were assessed during the last trimester of pregnancy in 411 nonrisk women and in 255 depressed and/or psychosocially at‐risk women. The results showed a prevalence of Integrated/Balanced representations in nonrisk women and a higher frequency of Not Integrated/Ambivalent representations in at‐risk women. Data obtained confirm that the IRMAG‐R is a valid instrument for exploring maternal representation during the last trimester of pregnancy in both the absence and presence of risk conditions.
In vitro characterizations of mesoporous hydroxyapatite as a controlled release delivery device for VEGF in orthopedic applications
Authors: Poh Chye Khoon , Ng Suxiu , Lim Tee Yong , Tan Hark Chuan , Loo Joachim , Wang Wilson
Published: July 2012

Following bone implant surgery, prolonged ischemic conditions at the implant site often result in postsurgical complications like failure of osseointegration at the bone‐implant interface which can lead to implant failure. Thus, restoration of the vascular supply is paramount to the proper development of the bone. High surface area mesostructured materials have been shown to be attractive candidates for bone regeneration to enhance cell adhesion and cell proliferation. This study uses hydroxyapatite, a naturally occurring mineral in the bone, fabricated to a range of suitable pore sizes, infused with vascular endothelial growth factor (VEGF), to be progressively released to stimulate revascularization. In this study, several characterizations including nitrogen adsorption analysis, Fourier‐transformed infrared spectroscopy, X‐ray diffraction, field emission scanning electron microscope, and transmission electron microscope were used to evaluate the synthesized mesoporous hydroxyapatite (MHA). The results showed that MHA can gradually release VEGF for enhancing revascularization, which is beneficial for orthopedic applications. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 100A:3143–3150, 2012.
Bioactive TiO2fiber films prepared by electrospinning method
Authors: Chen S. J. , Yu H. Y. , Yang B. C.
Published: July 2012

Electrospining method was used to prepare bioactive TiO2fibers films in this study. The acetic acid/ethanol/tetrabutyl titanate/polyvinylpyrrolidone (PVP) solvent system was used as precursor for the electrospining. The TiO2fiber structures (including its fiber diameter, morphology, and phase composition) could be controlled by changing feeding rate, PVP concentration and sinter temperature. The fiber films were subjected to simulated body fluid soaking experiments and MG63 cells culture experiments to study their bioactivity. According to the X‐ray diffraction and MTT assay results, the fiber containing with anatase showed better apatite formation ability than that without anatase at the early stage, while cell proliferated on anatase‐rutile TiO2fiber was better than that on other samples (p< 0.05).Some string beads in the fiber were beneficial for apatite formation, while the cell proliferated best on the fiber film without string beads (p< 0.05). The fiber with a diameter of 200 nm had the best apatite formation ability and osteoblast compatibility (p< 0.05). The results showed that the TiO2fiber film structure had great influence on its bioactivity. It indicated that the electronspining method is an effective way to prepare bioactive titania fiber films, and it is possible to control the structure of the films in the spinning process to optimize the bioactivity of TiO2fiber. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 101A:64–74, 2013.
Laser microfabricated poly(glycerol sebacate) scaffolds for heart valve tissue engineering
Authors: Masoumi Nafiseh , Jean Aurélie , Zugates Jeffrey T. , Johnson Katherine L. , Engelmayr George C.
Published: July 2012

Microfabricated poly(glycerol sebacate) (PGS) scaffolds may be applicable to tissue engineering heart valve leaflets by virtue of their controllable microstructure, stiffness, and elasticity. In this study, PGS scaffolds were computationally designed and microfabricated by laser ablation to match the anisotropy and peak tangent moduli of native bovine aortic heart valve leaflets. Finite element simulations predicted PGS curing conditions, scaffold pore shape, and strut width capable of matching the scaffold effective stiffnesses to the leaflet peak tangent moduli. On the basis of simulation predicted effective stiffnesses of 1.041 and 0.208 MPa for the scaffold preferred (PD) and orthogonal, cross‐preferred (XD) material directions, scaffolds with diamond‐shaped pores were microfabricated by laser ablation of PGS cured 12 h at 160°C. Effective stiffnesses measured for the scaffold PD (0.83 ± 0.13 MPa) and XD (0.21 ± 0.03 MPa) were similar to both predicted values and peak tangent moduli measured for bovine aortic valve leaflets in the circumferential (1.00 ± 0.16 MPa) and radial (0.26 ± 0.03 MPa) directions. Scaffolds cultivated with fibroblasts for 3 weeks accumulated collagen (736 ± 193 μg/g wet weight) and DNA (17 ± 4 μg/g wet weight). This study provides a basis for the computational design of biomimetic microfabricated PGS scaffolds for tissue‐engineered heart valves. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 101A:104–114, 2013.
Consistent quasistatic and acoustic elasticity determination of poly‐L‐lactide‐based rapid‐prototyped tissue engineering scaffolds
Authors: Luczynski Krzysztof W. , Brynk Tomasz , Ostrowska Barbara , Swieszkowski Wojciech , Reihsner Roland , Hellmich Christian
Published: July 2012

This paper is concerned with reliable and physically sound elasticity determination of rapid‐prototyped tissue engineering scaffolds made of poly‐L‐lactide (PLLA), with and without small portions of tricalcium phosphate (TCP) inclusions. At the level of overall scaffolds, that is, that of several millimeters, multiple uniaxial loading–unloading (quasistatic) tests were performed, giving access to the scaffolds' Young's moduli, through stress–strain characteristics during unloading. In addition, acoustic tests with 0.05 MHz frequency delivered an independent access to elastic properties, in terms of the normal components of the scaffolds' stiffness tensors. The latter strongly correlate, in a linear fashion, with the Young's moduli from the unloading tests, revealing porosity independence of Poisson's ratio. The magnitude of the latter is in full agreement with literature data on polymers. Both of these facts underline that both ultrasound tests and quasistatic unloading tests reliably provide the elastic properties of tissue engineering scaffolds. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 101A:138–144, 2013.
Developing Rural Tourism: the PAT Program and ‘Nong jia le’ Tourism in China
Authors: Su Baoren
Published: July 2012

Despite the fact that the last three decades have witnessed the rapid development of rural tourism (RT) in China, which is being promoted by the Chinese government as an important new type of tourism due to its special role in revitalizing China's rural economy, there is still little knowledge about the economic impacts of RT on Chinese rural communities in terms of socio‐economic development and regeneration. Accordingly, this study represents an attempt to address this issue by examining the Poverty Alleviation through Tourism program and ‘Nong jia le’ (Happy Farmer Home) tourism within the Chinese context. The findings not only confirm the widely held importance of RT, as expected, but also identify the problems and challenges relating to the sustainable development of RT in the future. Copyright © 2012 John Wiley & Sons, Ltd.
The impact of intimate partner violence and additional traumatic events on trauma symptoms and PTSD in preschool‐aged children
Authors: Graham‐Bermann Sandra A. , Castor Lana E. , Miller Laura E. , Howell Kathryn H.
Published: July 2012

Children exposed to intimate partner violence (IPV) are at increased risk for developing traumatic stress symptoms and posttraumatic stress disorder (PTSD). Unfortunately, children who witness IPV are often exposed to additional traumatic events. Previous research has indicated that approximately one third of children experience 2 or more direct victimizations each year, and that exposure to one type of victimization places children at risk for exposure to additional types of victimization. Yet little is known about the impact of these additional traumas on children's functioning. For a sample of 120 preschool children (age 4–6 years) exposed to IPV in the past 2 years, 38% were exposed to additional traumatic events, including sexual assaults by family members, physical assaults, serious accidents, and/or life‐threatening illnesses. Those exposed to both IPV and additional traumatic events had higher rates of PTSD diagnoses, traumatic stress symptoms (d = 0.96), and internalizing (d = 0.86) and externalizing behavior (d = 0.47) problems, than those exposed to IPV alone. We also compared DSM‐IV diagnostic criteria to proposed criteria for evaluating traumatic stress in preschool‐aged children. Results revealed the importance of conducting a complete assessment of traumatic events prior to treating children exposed to IPV.
Influence of kinship on donors' mental burden in living donor liver transplantation
Authors: Erim Yesim , Beckmann Mingo , Kroencke Sylvia , Sotiropoulos Georgios C. , Paul Andreas , Senf Wolfgang , Schulz Karl-Heinz
Published: July 2012

In the context of living donor liver transplantation (LDLT), German transplantation law stipulates that donor candidates should primarily be relatives of the recipients or persons with distinct and close relationships. In this study, we investigated the influence of the relationship between the donor and the recipient on the donor's emotional strain before transplantation. Donors were categorized according to the following subgroups: (1) parents donating for their children, (2) children donating for their parents, (3) siblings, (4) spouses, (5) other relatives, and (6) nonrelatives. The sample consisted of 168 donor candidates. Anxiety (F = 2.8, P = 0.02), depression (F = 2.6, P = 0.03), and emotional quality of life (F = 3.1, P = 0.01) differed significantly according to the relationship between the donor and the recipient. In comparison with healthy controls, parents donating for their children were significantly less stressed before LDLT and demonstrated fewer anxiety (P < 0.01) and depression symptoms (P < 0.05). Adult children donating for their parents demonstrated the highest mental burden and the lowest emotional quality of life. However, this was not due to the responsibility of these children for their own families because differences between donors with children and donors without children could not be ascertained. This group should be given special attention before LDLT and during follow-up visits, and psychological help should be provided when it is necessary. Liver Transpl, 2012. © 2012 AASLD.