bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and Characterisation of Hydrated Calcium Pyrophosphate Phases of Biological Interest
Authors: Gras Pierre , Rey Christian , Marsan Olivier , Sarda Stéphanie , Combes Christèle 
Published: October 2013

AbstractThe details of a synthesis method for biologically relevant hydrated calcium pyrophosphates (CPPs, Ca2P2O7·nH2O) has been elucidated. Control of the pH (from 3.6 to 5.8) and the temperature (from 25 to 90 °C) during the synthesis enabled the preparation of four pure CPP phases within one hour without intermediates: monoclinic and triclinic calcium pyrophosphate dihydrate (CPPD, Ca2P2O7·2H2O), which are the two CPP phases detected in vivo in joints of arthritic patients, monoclinic tetrahydrate β (CPPT, Ca2P2O7·4H2O) and an amorphous phase (a‐CPP, Ca2P2O7·nH2O). Four domains corresponding to the four different phases of hydrated calcium pyrophosphate were identified; a‐CPP was synthesised over a very wide pH and temperature range (up to 90 °C) within the domain of synthesis conditions explored, including physiological conditions (pH 7.4 and 37 °C). The as‐synthesised hydrated CPP phases were characterised by complementary techniques (powder X‐ray diffraction, FTIR and Raman spectroscopy, scanning electron microscopy and thermogravimetry) and chemical analyses. Rietveld refinement analyses of the as‐synthesised crystalline phases were performed, and there were significant differences between the m‐CPPD X‐ray diffraction pattern observed and previously published cell parameters. Vibrational spectroscopy allowed the crystalline and amorphous phases synthesised to be clearly distinguished and identified owing to the high flexibility of the pyrophosphate anion. Chemical analyses showed that the synthesis conditions used in this study did not allow significant hydrolysis of the pyrophosphate ions into phosphate ions, and the number of water molecules associated with each synthesised CPP phase was determined by thermogravimetric analysis. Different mechanisms of dehydration were also identified. The study of the formation of synthetic and well‐characterised hydrated calcium pyrophosphate phases and their availability in large amounts in vitro could allow progress to be made on the biological role of these phases and their possible transformations. This could also aid their detection in patients suffering from disease caused by calcium salt crystals and could clarify the mechanism by which CPP crystals form and evolve in vivo.
η2‐Coordination of a Phosphaalkyne to an Amino Olefin Nickel Complex and Regioselective Catalyzed Cyclooligomerization to Dewar 1,3,5‐Triphosphabenzene
Authors: Trincado Mónica , Rosenthal Amos J. , Vogt Matthias , Grützmacher Hansjörg 
Published: October 2013

AbstractWe report herein an efficient synthesis of a Dewar‐triphosphabenzene derived from [2+2+2] cycloaddition of three phosphaalkyne molecules promoted by an amino olefin Ni0complex as the catalyst. Amino diolefin NiIcomplex1serves as a precursor complex that reacts with triphenylmethylphosphaethyne under reducing conditions at low temperature to give Ni0complex3with a coordinated phosphaalkyne in a η2‐mode. The structure of3was determined by X‐ray diffraction methods and suggests a bonding situation for the phosphaalkyne that is between a side‐on coordinated C≡P molecule and a metallaphosphacyclopropene structure. The reaction of3with a 10‐fold excess of phosphaethylene under reducing conditions at room temperature resulted in the formation of 2,4,6‐tris(triphenylmethyl)‐Dewar‐1,3,5‐triphosphabenzene (4) in good yield.
Palladium‐Catalyzed Cross‐Coupling of 2‐Chloroquinoxaline N‐Oxides with Arylboronic Acids
Authors: Maichrowski Jan , Hübner Eike G. , Kaufmann Dieter E. 
Published: October 2013

AbstractA selection of 2‐chloro‐substituted O‐alkylquinoxaline N‐oxides, easily accessible by the one‐step annulation reaction of 4‐fluoroaniline with 1,1,2‐trichloro‐2‐nitroethylene and subsequent O‐alkylation, was arylated at the chloronitrone unit in yields up to 96 %. This first efficient Pd‐catalyzed Suzuki–Miyaura reaction of chloroquinoxaline N‐oxides with arylboronic acids led to new 2‐arylquinoxaline N‐oxides. The scope and limitations of this arylation reaction were investigated, and the role of some sterically demanding boronic acids in the cross‐coupling reaction was evaluated by means of DFT calculations. Additionally, the Pd‐catalyzed C‐arylation of the amide unit of selected quinoxalinone derivatives was accomplished.
Salt‐Solubilization and Ion‐Pair Recognition by a Quinoline‐Substituted Crown Ether
Authors: Sun Zhan‐Hu , Pan Fang‐Fang , Triyanti  , Albrecht Markus , Raabe Gerhard 
Published: October 2013

AbstractA novel quinoline‐substituted crown ether has been synthesized as a receptor for ion pairs and its binding behavior was investigated in various solvents. The binding of ion pairs in [D6]DMSO and in mixed [D6]DMSO/CD3CN/CDCl3 solvents was studied and the results revealed positive cooperativity effects. As a novel solubilizing agent, the crown ether can extract halide salts into organic media, especially chloride salts. ESI MS provided evidence for the formation of salt‐receptor complexes. A recycling experiment showed that the receptor can solubilize salts and can be recovered. This process can be performed as a cycle. This study validates the idea that a straightforward combination of a common anion receptor and a well‐studied cation complexation moiety enables the formation of ion‐pair receptors and solubilizers of salts in organic solvents.
Regioselective Oxidative Dehydrogenation under Nonenzymatic Conditions: A Synthetic Route to Gossypol
Authors: Li Ling , Liu Yuxiu , Wang Qingmin 
Published: October 2013

AbstractA practical and scalable route was developed for the total synthesis of gossypol to allow for the construction of dozens of gossypol derivatives. tBuO2Ac was found to be a highly efficient oxidant for the polymerization of hemigossypol through a biosynthetic process under nonenzymatic conditions to give gossypol. Hemigossypol was synthesized on a gram scale by starting from commercially available carvacrol and dimethyl succinate and using a Stobbe condensation, an electrophilic cyclization, and the Michael addition of ortho‐quinone methide as key steps.
Rhodium‐Catalyzed Intramolecular Difluoromethylenative Dearomatization of Phenols
Authors: Li Yajun , Zhang Lisi , Zhang Li , Wu Yongming , Gong Yuefa 
Published: October 2013

AbstractRhodium‐catalyzed intramolecular difluoromethylenative dearomatization of phenols to yield azaspirocyclohexadienones containing all‐carbon quaternary centers in good to excellent yields was developed. A variety of functional groups proved compatible with the transformation. This method could also be used for difluoromethylenative dearomatization of indoles. Preliminary mechanism studies suggest that a pure radical mechanism is not involved in this reaction.
The Anti‐Bredt Red Flag! Reassignment of Neoveratrenone
Authors: Savchenko Andrei I. , Williams Craig M. 
Published: October 2013

AbstractThe bicyclo[3.3.1]non‐1‐en‐3‐one motif, which has yet to be observed in natural products, was recently reported within the skeleton of neoveratrenone. On the basis of Bredt's rule, a plausible reassignment matching closely the C‐nor‐D‐homo steroidal ring system has been proposed herein.
Highly Ordered TiO2 Nanotubes for Electrochemical Sensing of Hair Dye Basic Brown 17
Authors: de Oliveira R. A. G. , Zanoni M. V. B. 
Published: October 2013

AbstractSelf‐organized Ti/TiO2 nanotubular array electrodes were prepared by electrochemical anodization and used to monitor the reduction of the hair dye basic brown 17 (BB17) at a potential of −0.60 V vs. Ag/AgCl. Analytical curves were obtained from 1.0×10−6 to 8.0×10−5 mol L−1 with a detection limit of 1.3×10−7 mol L−1 by using the best experimental conditions, linear scan voltammetry at pH 6, scan rate=60 mV s−1, and accumulation time=5 min. The detection system performance was not interfered by other hair dyes and successfully used to determine the dye in tap water samples.
Kinematic response of single piles to vertically incident P‐waves
Authors: Liu Qijian , Deng Fangjun , He Yibin 
Published: October 2013

SUMMARYDynamic response of single piles to seismic waves is fundamentally different from the free‐field motion because of the interaction between the pile and the surrounding soil. Considering soil–pile interaction, this paper presents a new displacement model for the steady‐state kinematic response of single piles to vertically incident P‐waves on the basis of a continuum model. The governing equations and boundary conditions of the two undetermined functions in the model are obtained to be coupled by using Hamilton's principle. Then, the two unknown functions are decoupled and solved by an iterative algorithm numerically. A parametric study is performed to investigate the effects of the properties of the soil–pile system on the kinematic response of single piles. It is shown that the effects of the pile–soil modulus ratio, the slenderness ratio of the pile, and the frequency of the incident excitations are very significant. By contrast, the influence of soil damping on the kinematics of the system is slight and can be neglected. Copyright © 2013 John Wiley & Sons, Ltd.
Application of a tenax model to assess bioavailability of polychlorinated biphenyls in field sediments
Authors: Mackenbach Elizabeth M. , Harwood Amanda D. , Mills Marc A. , Landrum Peter F. , Lydy Michael J. 
Published: October 2013

Abstract

Recent literature has shown that bioavailability-based techniques, such as Tenax extraction, can estimate sediment exposure to benthos. In a previous study by the authors, Tenax extraction was used to create and validate a literature-based Tenax model to predict oligochaete bioaccumulation of polychlorinated biphenyls (PCBs) from sediment; however, its ability to assess sediment remediation was unknown. The present study further tested the Tenax model by examining the impacts of remediation on surface sediment concentrations, Tenax extractable concentrations, and tissue concentrations of laboratory-exposed Lumbriculus variegatus. Tenax extractable concentration was an effective exposure metric to evaluate changes in Lumbriculus exposure preremediation and postremediation, with 75% of the postremediation data corresponding to the Tenax model. At nondredged sites, bioaccumulation was better predicted by the Tenax model, with 86% of the data falling within the 95% confidence intervals, than at dredged sites, for which only 64% of the data fit the Tenax model. In both pre- and postdredge conditions, when the model failed, it was conservative, predicting higher PCB concentrations than observed in the oligochaetes, particularly for the postdredge data. The present study advances understanding of the applicability of the Tenax model for use when examining systems that may have undergone significant disturbances. The Tenax model provides a unique tool for quickly quantifying potential exposure to benthic organisms. Environ Toxicol Chem 2014;33:286–292. © 2013 SETAC
Interactions between mercury and phytoplankton: Speciation, bioavailability, and internal handling
Authors: Le Faucheur Séverine , Campbell Peter G.C. , Fortin Claude , Slaveykova Vera I. 
Published: October 2013

AbstractThe present review describes and discusses key interactions between mercury (Hg) and phytoplankton to highlight the role of phytoplankton in the biogeochemical cycle of Hg and to understand direct or indirect Hg effects on phytoplankton. Phytoplankton are exposed to various Hg species in surface waters. Through Hg uptake, phytoplankton affect the concentration, speciation, and fate of Hg in aquatic systems. The mechanisms by which phytoplankton take up Hg are still not well known, but several studies have suggested that both facilitated transport and passive diffusion could be involved. Once internalized, Hg will impact several physiological processes, including photosynthesis. To counteract these negative effects, phytoplankton have developed several detoxification strategies, such as the reduction of Hg to elemental Hg or its sequestration by intracellular ligands. Based on the toxicological studies performed so far in the laboratory, Hg is unlikely to be toxic to phytoplankton when they are exposed to environmentally relevant Hg concentrations. However, this statement should be taken with caution because questions remain as to which Hg species control Hg bioavailability and about Hg uptake mechanisms. Finally, phytoplankton are primary producers, and accumulated Hg will be transferred to higher consumers. Phytoplankton are a key component in aquatic systems, and their interactions with Hg need to be further studied to fully comprehend the biogeochemical cycle of Hg and the impact of this ubiquitous metal on ecosystems. Environ Toxicol Chem 2014;33:1211–1224. © 2013 SETAC
Oxidative stress responses of gulf killifish exposed to hydrocarbons from the Deepwater Horizon oil spill: Potential implications for aquatic food resources
Authors: Crowe Kristi M. , Newton Joseph C. , Kaltenboeck Bernhard , Johnson Calvin 
Published: October 2013

Abstract

Ecosystem effects of polycyclic aromatic hydrocarbons (PAHs) remain under investigation following the Gulf of Mexico Deepwater Horizon oil spill. Fundulus grandis, an established indicator of aquatic ecosystem health, was investigated because this species shares genes and biochemical pathways with higher trophic–level fish and plays an important role in the gulf food chain. Oxidative stress responses including hepatic cytochrome P4501A (CYP1A) and serum antioxidant capacity were evaluated in fish exposed to PAHs. Fish were exposed to water-accommodated fractions (WAFs) of crude oil (7.0  ± 0.10 mg/L C6-C28) after which solutions were diluted below the level of detection over 8 h using 15 ppt aerated artificial seawater. Before euthanasia, fish remained in aquaria for 12 h, 24 h, or 48 h. Three replicate experiments were conducted at each time point using unexposed fish as experimental controls. Significant differences (p &lt; 0.05) in CYP1A induction were observed in exposed versus control fish at 24 h. Expression of CYP1A increased by 25%, 66%, and 23% in exposed fish at 12 h, 24 h, and 48 h, respectively. Significant increases were observed in antioxidant capacity of nonenzymatic antioxidants in exposed versus control fish at each time point. Given the activity of CYP1A, radicals formed during PAH detoxification likely resulted in increased oxidant load requiring elevated antioxidant defenses. Research is needed to determine the duration of oxidative stress responses considering the potential for lipid oxidation in exposed fish or species feeding on exposed fish. Environ Toxicol Chem 2014;33:370–374. © 2013 SETAC
A molecular method for assessing the effects of potential contaminants on the rate of zebrafish (Danio rerio) development
Authors: Beasley Amy , Graham Chris , Otter Ryan , Elrod-Erickson Matthew 
Published: October 2013

Abstract

Monitoring expression of the developmentally regulated genes shh, sox2, and tnnt1 by reverse transcriptase polymerase chain reaction (RT-PCR) allows determination of the rate of embryogenesis in zebrafish (Danio rerio) embryos without direct visual observation. The utility of combining this approach and morphological methods during toxicity studies was demonstrated with embryos developing at either 28.5 °C or 24.5 °C and with embryos exposed to sublethal doses of silver nanoparticles. Environ Toxicol Chem 2014;33:238–242. © 2013 SETAC
SOCIAL WITHDRAWAL BEHAVIOR IN INFANCY: A HISTORY OF THE CONCEPT AND A REVIEW OF PUBLISHED STUDIES USING THE ALARM DISTRESS BABY SCALE
Authors: Guedeney Antoine , Matthey Stephen , Puura Kaija 
Published: October 2013

ABSTRACTThis article reviews the studies using or validating the Alarm Distress Baby Scale (ADBB; A. Guedeney & J. Fermanian, ) within different countries, different populations, and different settings. After a brief summary of the theoretical backgrounds of infant social behavior, the results of the main controlled and methodologically comparable studies are summarized and discussed. Second, the results of some observational studies as well as different models of factor analysis are presented. The modified, five‐item ADBB (m‐ADBB) Scale is described. Finally, perspectives for future research and training are presented.
Assessment of the genotoxic and carcinogenic potentials of 3‐aminothiophene derivatives using in vitro and in silico methodologies
Authors: Lepailleur Alban , Bureau Ronan , Halm‐Lemeille Marie‐Pierre , Bouquet Michel , Pecquet Régis , Paris‐Soubayrol Christine , Goff Jérémie Le. , André Véronique , Lecluse Yannick , Lebailly Pierre , Maire Marie‐Aline , Vasseur Paule 
Published: October 2013

ABSTRACTThiophene derivatives, a class of compounds widely used in products such as pharmaceuticals, agrochemicals or dyestuffs, represent chemicals of concern. Indeed, the thiophene ring is often considered as a structural moiety that may be involved in toxic effects in humans. We primarily focus on the genotoxic/mutagenic and carcinogenic potentials of the methyl 3‐amino‐4‐methylthiophene‐2‐carboxylate (1), a precursor of the articaine local anesthetic (4) which falls within the scope of the European REACH (Registration, Evaluation, Authorisation and restriction of CHemicals) legislation. To discern some structure–toxicity relationships, we also studied two related compounds, namely the 3‐amino 4‐methylthiophene (2) and the 2‐acetyl 4‐chlorothiophene (3). Techniques employed to assess mutagenic and DNA‐damaging effects involved the Salmonella mutagenicity assay (or Ames test) and the single‐cell gel electrophoresis assay (or Comet assay). In the range of tested doses, none of these derivatives led to a positive response in the Ames tests and DNA damage was only observed in the Comet assay after high concentration exposure of 2. The study of their carcinogenic potential using the in vitro SHE (Syrian Hamster Embryo) cell transformation assay (CTA) highlighted the activity of compound 2. A combination of experimental data with in silico predictions of the reactivity of thiophene derivatives towards cytochrome P450 (CYP450), enabled us to hypothesize possible pathways leading to these toxicological profiles. Copyright © 2013 John Wiley & Sons, Ltd.
Interdependence of Muscle Atrophy and Bone Loss Induced by Mechanical Unloading
Authors: Lloyd Shane A , Lang Charles H , Zhang Yue , Paul Emmanuel M , Laufenberg Lacee J , Lewis Gregory S , Donahue Henry J 
Published: October 2013

ABSTRACT

Mechanical unloading induces muscle atrophy and bone loss; however, the time course and interdependence of these effects is not well defined. We subjected 4-month-old C57BL/6J mice to hindlimb suspension (HLS) for 3 weeks, euthanizing 12 to 16 mice on day (D) 0, 7, 14, and 21. Lean mass was 7% to 9% lower for HLS versus control from D7–21. Absolute mass of the gastrocnemius (gastroc) decreased 8% by D7, and was maximally decreased 16% by D14 of HLS. mRNA levels of Atrogin-1 in the gastroc and quadriceps (quad) were increased 99% and 122%, respectively, at D7 of HLS. Similar increases in MuRF1 mRNA levels occurred at D7. Both atrogenes returned to baseline by D14. Protein synthesis in gastroc and quad was reduced 30% from D7–14 of HLS, returning to baseline by D21. HLS decreased phosphorylation of SK61, a substrate of mammalian target of rapamycin (mTOR), on D7–21, whereas 4E-BP1 was not lower until D21. Cortical thickness of the femur and tibia did not decrease until D14 of HLS. Cortical bone of controls did not change over time. HLS mice had lower distal femur bone volume fraction (−22%) by D14; however, the effects of HLS were eliminated by D21 because of the decline of trabecular bone mass of controls. Femur strength was decreased approximately 13% by D14 of HLS, with no change in tibia mechanical properties at any time point. This investigation reveals that muscle atrophy precedes bone loss during unloading and may contribute to subsequent skeletal deficits. Countermeasures that preserve muscle may reduce bone loss induced by mechanical unloading or prolonged disuse. Trabecular bone loss with age, similar to that which occurs in mature astronauts, is superimposed on unloading. Preservation of muscle mass, cortical structure, and bone strength during the experiment suggests muscle may have a greater effect on cortical than trabecular bone. © 2014 American Society for Bone and Mineral Research.
First Clinical Experience With TRV130: Pharmacokinetics and Pharmacodynamics in Healthy Volunteers
Authors: Soergel David G. , Ann Subach Ruth , Sadler Brian , Connell John , Marion Alan S. , Cowan Conrad L. , Violin Jonathan D. , Lark Michael W. 
Published: October 2013

AbstractTRV130 is a G protein‐biased ligand at the µ‐opioid receptor. In preclinical studies it was potently analgesic while causing less respiratory depression and gastrointestinal dysfunction than morphine, suggesting unique benefits in acute pain management. A first‐in‐human study was conducted with ascending doses of TRV130 to explore its tolerability, pharmacokinetics, and pharmacodynamics in healthy volunteers. TRV130 was well‐tolerated over the dose range 0.15 to 7 mg administered intravenously over 1 hour. TRV130 geometric mean exposure and Cmax were dose‐linear, with AUC0–inf of 2.52 to 205.97 ng h/mL and Cmax of 1.04 to 102.36 ng/mL across the dose range tested, with half‐life of 1.6–2.7 hours. A 1.5 mg dose of TRV130 was also well‐tolerated when administered as 30, 15, 5, and 1 minute infusions. TRV130 pharmacokinetics were modestly affected by CYP2D6 phenotype: clearance was reduced by 53% in CYP2D6 poor metabolizers.TRV130 caused dose‐ and exposure‐related pupil constriction, confirming central compartment µ‐opioid receptor engagement. Marked pupil constriction was noted at 2.2, 4, and 7 mg doses. Nausea and vomiting observed at the 7 mg dose limited further dose escalation. These findings suggest that TRV130 may have a broad margin between doses causing µ‐opioid receptor‐mediated pharmacology and doses causing µ‐opioid receptor‐mediated intolerance.
Desulfurization activity of metal oxides blended into walnut shell based activated carbons
Authors: Guo Jia‐Xiu , Fan Lu , Peng Jian‐Fei , Chen Jie , Yin Hua‐Qiang , Jiang Wen‐Ju 
Published: October 2013

AbstractBACKGROUNDWalnut shell, a nutshell waste, was used to prepare activated carbons (AC) for desulfurization. Titanium ore (TO), TiO2 or Fe2O3 was blended into the resulting carbonized powders, which were extruded into cylinders and activated under CO2 atmosphere. The desulfurization activity of samples was evaluated in a fixed bed under a simulated gaseous mixture from coal combustion.RESULTSWalnut shell can be used to prepare activated carbons (AC) for desulfurization, giving an AC surface area of 401.2 m2 g−1. When TO, TiO2 or Fe2O3 were added into the AC, the surface area of ACTO2, ACT2 and ACF2 increased to 937.1, 661.8 and 791.0 m2 g−1. Ti and Fe in TO are changed into anatase TiO2 and Fe2O3 in ACTOx, and TiO2 and Fe2O3 exist in ACTx and ACFx, respectively. The optimum additive dosage of ACTOx, ACTx and ACFx is 2%. The breakthrough sulfur capacity of ACT2 is higher than that of ACTO2 and ACF2, but other ACTOx is better than ACTx and ACFx, indicating that TiO2 and Fe2O3 have synergistic effects in ACTOx.CONCLUSIONPore structure and metal oxides are the main factors which influence the desulfurization performance of catalysts. © 2013 Society of Chemical Industry