bluuebunny/crossref_metadata_2025_split huggingface dataset:
Azadipyrromethene‐Based Near‐Infrared Dyes: Effect of Thienylethynyl Substitution at the Distal and Proximal Phenyl Groups
Authors: Daddario Cassie M. , Han Qi , Zeller Matthias , Sauvé Geneviève 
Published: June 2015

AbstractAzadipyrromethene (ADP) ligands substituted with thienylethynyl substituents either at the distal phenyl groups H(CD1) or the proximal phenyl groups H(CD2) were synthesized and characterized. The thienyl groups have a hexyl group at the third position to improve solubility in organic solvents and prevent homocoupling of the ethynylthiophene reactants. To further tune the opto‐electronic properties, the substituted ADPs were coordinated with BF2+ and ZnII. Absorption spectroscopy shows that the thienylethynyl substitutions redshift the absorption spectra of the dyes, with a larger shift when the substituents are added on the proximal phenyl groups. Cyclic voltammetry experiments show that the substitutions stabilize the anion and dianion. The reduction potentials for the modified ligands (or zinc chelates) were not affected by the placement of the thienylethynyl groups. Preliminary studies of blends of the new molecules with poly(3‐hexylthiophene) (P3HT) suggest that the zinc(II) chelates have potential as electron acceptors for organic solar cells.
Reversible Phase Transitions and Dielectric Properties in [(CH3)4P]2[Cr2O7] and ­[Et4P]2[Cr3O10]
Authors: Shi Ping‐Ping , Ye Qiong , Wang Hui‐Ting , Li Qiang , Fu Da‐Wei , Zhang Yi 
Published: June 2015

AbstractTetramethylphosphonium dichromate ([(CH3)4P]2[Cr2O7], 1) undergoes a reversible phase transition at around 221 K. The results of the variable‐temperature single‐crystal X‐ray structural analyses and the rotational potential energy calculations suggest that the phase transition is probably related to the order–disorder transition of the [Cr2O7]2– anion. The change of the space group from Pa‐3 at room temperature to Pbca at low temperature is reflected in the peak‐like dielectric response. Tetraethylphosphonium trichromate ([Et4P]2[Cr3O10], 2) crystallizes in the monoclinic space group P21/c at room temperature. Upon cooling and heating, the step‐like dielectric anomalies observed at around 270 K indicate a reversible phase transition. Moreover, the rotational potential energy calculations certify the potential motion of the [Cr3O10]2– anion, being related to the phase transition. These findings open a new approach to the design of complexes that show phase transitions coupled with unusual dielectric properties.
Trinuclear Heterobimetallic Complexes by Stepwise Metalation of a Macrocyclic Tetraimidazolium Salt
Authors: Schulte to Brinke Christian , Hahn F. Ekkehardt 
Published: June 2015

AbstractA series of trinuclear heterobimetallic AuI/M2 (M = RhIII, IrIII, RuII) complexes were prepared by the stepwise and selective metalation of a rigid cyclic tetraimidazolium salt. Reaction of the tetraimidazolium salt with exactly 1 equivalent of silver oxide and transmetalation of the dicarbene ligand to AuI yielded selectively a mononuclear AuI complex. This complex features an CNHC–Au–CNHC unit obtained by coordination of two N‐heterocyclic carbene (NHC) donors placed in diagonal positions within the macrocycle and two non‐metalated imidazolium moieties. Subsequent metalation of these imidazolium groups yielded heterobimetallic complexes (AuI/RhIII2, AuI/IrIII2, and AuI/RuII2) with Au···M separations shorter than 5.5 Å.
Endocrine-disrupting effect of the ultraviolet filter benzophenone-3 in zebrafish, Danio rerio
Authors: Kinnberg Karin L. , Petersen Gitte I. , Albrektsen Mette , Minghlani Mita , Awad Suad Mohamud , Holbech Bente F. , Green John W. , Bjerregaard Poul , Holbech Henrik 
Published: June 2015

Abstract

The chemical ultraviolet (UV) filter benzophenone-3 (BP-3) is suspected to be an endocrine disruptor based on results from in vitro and in vivo testing. However, studies including endpoints of endocrine adversity are lacking. The present study investigated the potential endocrine-disrupting effects of BP-3 in zebrafish (Danio rerio) in the Fish Sexual Development Test (Organisation for Economic Co-operation and Development TG 234) and a 12-d adult male zebrafish study. In TG 234, exposure from 0 d to 60 d posthatch caused a monotone dose-dependent skewing of the phenotypic sex ratio toward fewer males and more female zebrafish (no observed effect concentration [NOEC]: 191 μg/L, lowest observed effect concentration [LOEC]: 388 μg/L). Besides, gonad maturation was affected in both female fish (NOEC 191 μg/L, LOEC 388 μg/L) and male fish (NOEC 388 μg/L, LOEC 470 μg/L). Exposure to BP-3 did not affect the vitellogenin concentration in TG 234. After 12 d exposure of adult male zebrafish, a slight yet significant increase in the vitellogenin concentration was observed at 268 μg/L but not at 63 μg/L and 437 μg/L BP-3. Skewing of the sex ratio is a marker of an endocrine-mediated mechanism as well as a marker of adversity, and therefore the conclusion of the present study is that BP-3 is an endocrine-disrupting chemical in accordance with the World Health Organization's definition. Environ Toxicol Chem 2015;34:2833–2840. © 2015 SETAC
Species-specific mercury bioaccumulation in a diverse fish community
Authors: Donald David B. , Wissel Björn , Anas M.U. Mohamed 
Published: June 2015

Abstract

Mercury bioaccumulation models developed for fish provide insight into the sources and transfer of Hg within ecosystems. Mercury concentrations were assessed for 16 fish species of the western reach of Lake Diefenbaker, Saskatchewan, Canada. For top predators (northern pike, Esox Lucius; walleye, Sander vitreum), Hg concentrations were positively correlated to δ15N, and δ15N to fish age, suggesting that throughout life these fish fed on organisms with increasingly higher trophic values and Hg concentrations. However, fish mass and/or age were the principal parameters related to Hg concentrations for most species. For 9 common species combined, individual variation in Hg concentration was explained in declining order of importance by fish mass, trophic position (δ15N), and fish age. Delta 15N value was not the leading variable related to Hg concentration for the assemblage, probably because of the longevity of lower­–trophic-level species (3 species ≥ 20 yr), substantial overlap in Hg concentration and δ15N values for large-bodied fish up to 3000 g, and complex relationships between Hg concentration and δ15N among species. These results suggest that the quantity of food (and Hg) consumed each year and converted to fish mass, the quantity of Hg bioaccumulated over years and decades, and trophic position were significant determinants of Hg concentration in Lake Diefenbaker fish. Environ Toxicol Chem 2015;34:2846–2855. © 2015 SETAC
Effect of brick kiln emissions on commonly used vegetables of Kashmir Valley
Authors: Skinder Bhat M. , Sheikh Afeefa Q. , Pandit Ashok K. , Ganai Bashir A. , Kuchy Aashiq H. 
Published: June 2015

AbstractTo study the impact of brick kiln emissions on plant growth and productivity, a study was conducted on various biochemical parameters of three main vegetables Brassica oleracea L., Phaseolus vulgaris L., and Solanum melongena L. cultivated in the vicinity of the brick kiln area of the Panzan village of district Budgam (J&K). Plants in the vicinity of brick kilns are direct recipients of emissions and therefore important materials for assessing potential effects of kiln pollutants. The biochemical values of all the three vegetables of the brick kiln site when compared to the control site are significantly (P ≤ 0.05) different. The findings of the present work depict that the brick kilns are the prime reason for the deterioration of important consumable vegetables, which could lead to chaos in the food security of the area in concern besides a threat to local people in terms of health if proper pollution control devices or the replacement of brick kilns are not put in place with new technology.
Comparison of sequential drug release in vitro and in vivo
Authors: Sundararaj Sharath C. , Al‐Sabbagh Mohanad , Rabek Cheryl L. , Dziubla Thomas D. , Thomas Mark V. , Puleo David A. 
Published: June 2015

AbstractDevelopment of drug‐delivery devices typically involves characterizing in vitro release performance with the inherent assumption that this will closely approximate in vivo performance. Yet, as delivery devices become more complex, for instance with a sequential drug release pattern, it is important to confirm that in vivo properties correlate with the expected “programming” achieved in vitro. In this work, a systematic comparison between in vitro and in vivo biomaterial erosion and sequential release was performed for a multilayered association polymer system comprising cellulose acetate phthalate and Pluronic F‐127. After assessing the materials during incubation in phosphate‐buffered saline, devices were implanted supracalvarially in rats. Devices with two different doses and with different erosion rates were harvested at increasing times post‐implantation, and the in vivo thickness loss, mass loss, and the drug release profiles were compared with their in vitro counterparts. The sequential release of four different drugs observed in vitro was successfully translated to in vivo conditions. Results suggest, however, that the total erosion time of the devices was longer and that release rates of the four drugs were different, with drugs initially released more quickly and then more slowly in vivo. Many comparative studies of in vitro and in vivo drug release from biodegradable polymers involved a single drug, whereas this research demonstrated that sequential release of four drugs can be maintained following implantation. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1302–1310, 2016.
Methylenetetrahydrofolate Reductase CpG Islands: Epigenotyping
Authors: Wei Loo Keat , Sutherland Heidi , Au Anthony , Camilleri Emily , Haupt Larisa M , Gan Siew Hua , Griffiths Lyn R 
Published: June 2015

BackgroundDetermination of the differential DNA methylation patterns of methylenetetrahydrofolate reductase (MTHFR) that are associated with differential MTHFR activity is important to understand the pathogenesis of ischemic stroke. However, to date, no data are available on the differential DNA methylation profiles of Kelantanese Malays. Therefore, we developed a rapid and efficient serial pyrosequencing assay to determine differential DNA methylation profiles of MTHFR, which help to further our understanding of the pathogenesis of ischemic stroke. The developed assay also served as the validation platform for our previous computational epigenetic research on MTHFR.MethodsPolymerase chain reaction primers were designed and validated to specifically amplify the cytosine that is followed by guanine residues (CpGs) A and B regions. Prior epigenotyping on 110 Kelantanese Malays, the serial pyrosequencing assays for the CpGs A and B regions were validated using five validation controls. The mean values of the DNA methylation profiles of CpGs A and B were calculated.ResultsThe mean DNA methylation levels for CpGs A and B were 0.984 ± 0.582 and 2.456 ± 1.406, respectively. The CpGs 8 and 20 showed the highest (5.581 ± 4.497) and the lowest (0.414 ± 2.814) levels of DNA methylation at a single‐base resolution.ConclusionWe have successfully developed and validated a pyrosequencing assay that is fast and can yield high‐quality pyrograms for DNA methylation analysis and is therefore applicable to high throughput study. Using this newly developed pyrosequencing assay, the MTHFR DNA methylation profiles of 110 Kelantanese Malays were successfully determined. It also validated our computational epigenetic research on MTHFR.
In vivo breath‐hold 1H MRS simultaneous estimation of liver proton density fat fraction, and T1 and T2 of water and fat, with a multi‐TR, multi‐TE sequence
Authors: Hamilton Gavin , Middleton Michael S. , Hooker Jonathan C. , Haufe William M. , Forbang Nketi I. , Allison Matthew A. , Loomba Rohit , Sirlin Claude B. 
Published: June 2015

PurposeTo examine the intra‐examination repeatability of proton density fat fraction (PDFF) and T1 and T2 of liver water and fat as estimated by a novel multi‐repetition time (TR)‐echo time (TE) 1H magnetic resonance spectroscopy (MRS)‐stimulated echo acquisition mode (STEAM) sequence that acquires 32 spectra for a range of TRs and TEs in single breath‐hold.Materials and MethodsSixty‐seven subjects undergoing liver MRI examinations at 3T had three multi‐TR‐TE sequences acquired consecutively in a single session. This sequence was designed to allow accurate estimation of T1 and T2 of both water and fat, as well as PDFF, in a single breath‐hold. A standard long‐TR, multi‐TE sequence was also acquired to allow comparison of estimated PDFF. Regression and interclass correlation (ICC) analyses were performed.ResultsThere was strong agreement between PDFF estimated by the multi‐TR‐TE and long‐TR, multi‐TE sequences (slope 0.997; intercept −0.03; R = 0.997). The multi‐TR‐TE sequence had high repeatability for estimating PDFF (ICC = 0.999), water T2 (ICC = 0.920), water T1 (ICC = 0.845), and fat T2 (ICC = 0.760), and moderate repeatability for estimating fat T1 (ICC = 0.556).ConclusionA novel multi‐TR‐TE sequence can estimate PDFF and water and fat T1 and T2 in a single breath‐hold. Refinement may be needed to improve repeatability for fat T1 estimation. J. MAGN. RESON. IMAGING 2015;42:1538–1543.
Reactivity change of IgE to buckwheat protein treated with high‐pressure and enzymatic hydrolysis
Authors: Lee Chaeyoon , In Sooyeon , Han Youngshin , Oh Sangsuk 
Published: June 2015

AbstractBACKGROUNDBuckwheat is a popular food material in eastern Asian countries that can cause allergenic response. This study was conducted to evaluate the effects of hydrolysis with papain and high‐pressure (HP) treatment of buckwheat protein (BWP) on reactivity of immunoglobulin E (IgE) and its secondary structure.RESULTSReactivity of IgE was examined by enzyme‐linked immunosorbent assay (ELISA) with serum samples from 16 patients allergic to buckwheat. Reactivity of IgE to hydrolysate of BWP with papain showed a maximum decrease of 79.8%. After HP treatment at 600 MPa for 1 min, reactivity of IgE to BWP decreased by up to 55.1%. When extracted, BWP was hydrolyzed with papain overnight following HP treatment at 600 MPa which the reactivity of IgE decreased significantly by up to 87.1%. Significant changes in secondary structure of BWP were observed by circular dichroism (CD) analysis after hydrolysis with papain following HP treatment.CONCLUSIONReduction of reactivity of IgE showed a correlation with changes in secondary structure of BWP, which may cause changes in conformational epitopes. This suggests the possibility of decreasing the reactivity of IgE to BWP using combined physical and enzymatic treatments. © 2015 Society of Chemical Industry
Polarization‐free directional coupling of surface plasmon polaritons
Authors: Chen Jianjun , Sun Chengwei , Rong Kexiu , Li Hongyun , Gong Qihuang 
Published: June 2015

AbstractSurface plasmon polaritons (SPPs) have sparked enormous interest on nanophotonics beyond the diffraction limit for their remarkable capabilities of subwavelength confinements and strong enhancements. Due to the inherent polarization sensitivity of the SPPs [transverse‐magnetic (TM) polarization], it is a great challenge to couple the s‐polarized free‐space light to the SPPs. Here, an ultrasmall defect aperture (<λ2/2) is designed to directionally couple both the p‐ and s‐polarized incident beams to the single SPP mode in a broad bandwidth, which is guided by a subwavelength plasmonic waveguide. Simulations show that hot spots emerge at the sharp corners of the defect aperture when the incident beams illuminate it from the back side. The strong radiative fields from the hot spots are directionally coupled to the SPP mode because of the symmetry breaking of the defect aperture. By adjusting the structural parameters, both the unidirectional and bidirectional SPP coupling from the two orthogonal linear‐polarization incident beams are experimentally demonstrated. The polarization‐free coupling of the SPPs is of importance in circuits for fully optical processing of information with a deep‐subwavelength footprint.
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One‐Pot Formation of ZnO‐graft‐Poly(d,l‐Lactide) Hybrid Systems via Microwave‐Assisted Polymerization of d,l‐Lactide in the Presence of ZnO Nanoparticles
Authors: Rodríguez‐Tobías Heriberto , Morales Graciela , Olivas Amelia , Grande Daniel 
Published: June 2015

The surface modification of inorganic nanoparticles by polymer grafting is generally required for obtaining well dispersed polymer‐based (bio)nanocomposites, and the in situ polymerization of corresponding monomers is considered to be a versatile approach to this purpose. In this work, the microwave‐assisted ring‐opening polymerization of d,l‐lactide in the presence of zinc oxide (ZnO) nanoparticles affords an original and straightforward method for generating ZnO‐graft‐poly(d,l‐lactide) hybrid systems. The influence of ZnO particle size and concentration on polymerization kinetics and molar masses of free poly(d,l‐lactide) (PLA) chains is analyzed. Several physico‐chemical techniques, including proton nuclear magnetic resonance (1H NMR), Fourier‐transform infrared spectroscopy, X‐ray photoelectron spectroscopy, and thermogravimetric analysis, are used to characterize intermediates and/or reaction products. Taking into account the kinetic and spectroscopic investigation, competitive chemical pathways based on grafting from and grafting onto reactions are proposed for the one‐pot formation of PLA‐grafted ZnO nanoparticles.
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Degenerated shell element with composite implicit time integration scheme for geometric nonlinear analysis
Authors: Zhang Jie , Liu Donghuan , Liu Yinghua 
Published: June 2015

SummaryA degenerated shell element with composite implicit time integration scheme is developed in the present paper to solve the geometric nonlinear large deformation and dynamics problems of shell structures. The degenerated shell element is established based on the eight‐node solid element, where the nodal forces, mass matrices, and stiffness matrices are firstly obtained upon virtual velocity principle and then translated to the shell element. The strain field is modified based on the mixed interpolation of tensorial components method to eliminate the shear locking, and the constitutive relation is modified to satisfy the shell assumptions. A simple and practical computational method for nonlinear dynamic response is developed by embedding the composite implicit time integration scheme into the degenerated shell element, where the composite scheme combines the trapezoidal rule with the three‐point backward Euler method. The developed approach can not only keep the momentum and energy conservation and decay the high frequency modes but also lead to a symmetrical stiffness matrix. Numerical results show that the developed degenerated shell element with the composite implicit time integration scheme is capable of solving the geometric nonlinear large deformation and dynamics problems of the shell structures with momentum and energy conservation and/or decay. Copyright © 2015 John Wiley & Sons, Ltd.
Lithium Insertion Mechanism in Iron‐Based Oxyfluorides with Anionic Vacancies Probed by PDF Analysis
Authors: Dambournet Damien , Chapman Karena W. , Duttine Mathieu , Borkiewicz Olaf , Chupas Peter J. , Groult Henri 
Published: June 2015

AbstractThe mechanism of lithium insertion that occurs in an iron oxyfluoride sample with a hexagonal–tungsten–bronze (HTB)‐type structure was investigated by the pair distribution function. This study reveals that upon lithiation, the HTB framework collapses to yield disordered rutile and rock salt phases followed by a conversion reaction of the fluoride phase toward lithium fluoride and nanometer‐sized metallic iron. The occurrence of anionic vacancies in the pristine framework was shown to strongly impact the electrochemical activity, that is, the reversible capacity scales with the content of anionic vacancies. Similar to FeOF‐type electrodes, upon de‐lithiation, a disordered rutile phase forms, showing that the anionic chemistry dictates the atomic arrangement of the re‐oxidized phase. Finally, it was shown that the nanoscaling and structural rearrangement induced by the conversion reaction allow the in situ formation of new electrode materials with enhanced electrochemical properties.
c‐Met identifies a population of matrix metalloproteinase 9‐producing monocytes in peritumoural stroma of hepatocellular carcinoma
Authors: Zhao Lan , Wu Yan , Xie Xu‐Dong , Chu Yi‐Fan , Li Jin‐Qing , Zheng Limin 
Published: June 2015

AbstractMacrophages (Mϕ) are prominent components of solid tumours and exhibit distinct phenotypes in different microenvironments. Previously, we found that tumours could alter the normal developmental process of Mϕ to trigger transient activation of monocytes in the peritumoural stroma of human hepatocellular carcinoma (HCC). In the present study, we showed that a fraction of monocytes in the peritumoural stroma, but not in HCC cancer nests, expressed surface c‐Met molecules. Monocytes exposed to tumours strongly expressed c‐Met proteins with kinetics similar to their activation status, and significant correlations were found between c‐Met levels and HLA‐DR expression on tumour‐infiltrating monocytes. NF‐κB‐mediated autocrine TNF‐α stimulated the expression of c‐Met on activated monocytes, and by interacting with its ligand hepatocyte growth factor (HGF), c‐Met increased the motility and matrix metalloproteinase (MMP) 9‐producing capacity of tumour‐associated monocytes. The intensity of c‐Met expression on tumour‐infiltrating monocytes was associated with high mortality and reduced survival of patients with HCC. Therefore, the expression of c‐Met on activated monocytes/Mϕ may represent a novel mechanism by which a tumour actively and precisely regulates the distribution and functions of these cells to facilitate disease progression. Copyright © 2015 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.