bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bis‐Ylide Ligands from Acyclic Proximal Diphosphonium Precursors
Authors: Maaliki Carine , Abdalilah Mohammed , Barthes Cécile , Duhayon Carine , Canac Yves , Chauvin Remi 
Published: July 2012

Abstract1,2‐ 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

AbstractThe 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

Abstract3‐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

AbstractThe 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

AbstractFatty 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

AbstractA 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

AbstractTrisubstituted 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

AbstractWe 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

AbstractA 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

Abstract
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

AbstractValue 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

AbstractIn 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:
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

Abstract
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

AbstractIt 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

AbstractThe 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

AbstractFollowing 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

AbstractElectrospining 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

AbstractMicrofabricated 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.