bluuebunny/crossref_metadata_2025_split huggingface dataset:
Toward ecosystem-based sediment quality guidelines for polychlorinated biphenyls (PCBs)
Authors: Arblaster Jennifer , Ikonomou Michael G , Gobas Frank APC 
Published: March 2015

Abstract
To investigate whether Sediment Quality Guidelines (SQGs) for polychlorinated biphenyls (PCBs) in Canada and British Columbia achieve their objective of protecting ecosystems, we measured and compiled concentrations of PCB congeners in sediments, bivalves, crustaceans, fish, and marine mammals from 3 areas off the Pacific coast of British Columbia, Canada. The concentration data showed that whereas PCB concentrations in sediments were predominantly below the SQG of 20 µg/kg dry weight, large fractions of the PCB concentrations in fish and shellfish species exceeded the tissue residue guideline for the consumption of fish and shellfish by wildlife (i.e., 50 µg/kg wet weight [ww]) but were below the tissue residue guideline for the consumption of fish and shellfish by human populations (i.e., 2000 µg/kg ww). Also, PCB concentrations in marine mammals exceeded toxicity reference concentrations. The concentration data were used to develop species- and location-specific Biota-Sediment Accumulation Factors (BSAF = Cbiota/Csediment), that were used to estimate PCB concentrations in wildlife species that may exist if the PCB concentration in sediments are equal to the SQGs. The results show that if the PCB concentration is equal to the SQGs, then PCB concentrations in most wildlife species can be expected to exceed the tissue residue guideline for the consumption of fish and shellfish by wildlife species and by humans, as well as toxicity reference concentrations for marine mammals. A methodology for developing SQGs for PCBs that are protective of the health of different wildlife species and human consumers of fish and shellfish from general Canadian and coastal First Nations populations was developed and applied. The proposed guidelines may provide useful guidance to establish SQGs for PCBs that can account for the ecological diversity in coastal environments and that better achieve the intent of the guidelines to protect ecosystems. The proposed methodology for guideline development may also be useful in the development of SQGs for other bioaccumulative substances. Integr Environ Assess Manag 2015;X:000–000. ©2015 SETAC
Key Points
A food-web based field bioaccumulation study on the Pacific Coast shows that current sediment quality guidelines for bioaccumulative substances such as PCBs do not protect most ecological receptors (other than benthic invertebrates). A new methodology for the derivation of sediment quality guidelines is presented that aims to develop sediment quality guidelines for bioaccumulative substances that consider a range of ecological receptors and human health risk endpoints. Sediment quality guidelines to achieve various environmental and human health goals are presented for PCBs.
The RUNX2 Transcription Factor Negatively Regulates SIRT6 Expression to Alter Glucose Metabolism in Breast Cancer Cells
Authors: Choe Moran , Brusgard Jessica L. , Chumsri Saranya , Bhandary Lekhana , Zhao Xianfeng Frank , Lu Song , Goloubeva Olga G. , Polster Brian M. , Fiskum Gary M. , Girnun Geoffrey D. , Kim Myoung Sook , Passaniti Antonino 
Published: March 2015

ABSTRACTActivation of genes promoting aerobic glycolysis and suppression of mitochondrial oxidative phosphorylation is one of the hallmarks of cancer. The RUNX2 transcription factor mediates breast cancer (BC) metastasis to bone and is regulated by glucose availability. But, the mechanisms by which it regulates glucose metabolism and promotes an oncogenic phenotype are not known. RUNX2 expression in luminal BC cells correlated with lower estrogen receptor‐α (ERα) levels, anchorage‐independent growth, expression of glycolytic genes, increased glucose uptake, and sensitivity to glucose starvation, but not to inhibitors of oxidative phosphorylation. Conversely, RUNX2 knockdown in triple‐negative BC cells inhibited mammosphere formation and glucose dependence. RUNX2 knockdown resulted in lower LDHA, HK2, and GLUT1 glycolytic gene expression, but upregulation of pyruvate dehydrogenase‐A1 (PDHA1) mRNA and enzymatic activity, which was consistent with lower glycolytic potential. The NAD‐dependent histone deacetylase, SIRT6, a known tumor suppressor, was a critical regulator of these RUNX2‐mediated metabolic changes. RUNX2 expression resulted in elevated pAkt, HK2, and PDHK1 glycolytic protein levels that were reduced by ectopic expression of SIRT6. RUNX2 also repressed mitochondrial oxygen consumption rates (OCR), a measure of oxidative phosphorylation (respiration). Overexpression of SIRT6 increased respiration in RUNX2‐positive cells, but knockdown of SIRT6 in cells expressing low RUNX2 decreased respiration. RUNX2 repressed SIRT6 expression at both the transcriptional and post‐translational levels and endogenous SIRT6 expression was lower in malignant BC tissues or cell lines that expressed high levels of RUNX2. These results support a hypothesis whereby RUNX2‐mediated repression of the SIRT6 tumor suppressor regulates metabolic pathways that promote BC progression. J. Cell. Biochem. 116: 2210–2226, 2015. © 2015 Wiley Periodicals, Inc.
Delineation of homogeneous hydrometeorological regions using wavelet‐based global fuzzy cluster analysis
Authors: Bharath R. , Srinivas V. V. 
Published: March 2015

ABSTRACTIdentification of homogeneous hydrometeorological regions (HMRs) is necessary for various applications. Such regions are delineated by various approaches considering rainfall and temperature as two key variables. In conventional approaches, formation of regions is based on principal components (PCs)/statistics/indices determined from time series of the key variables at monthly and seasonal scales. An issue with use of PCs for regionalization is that they have to be extracted from contemporaneous records of hydrometeorological variables. Therefore, delineated regions may not be effective when the available records are limited over contemporaneous time period. A drawback associated with the use of statistics/indices is that they do not provide effective representation of the key variables when the records exhibit non‐stationarity. Consequently, the resulting regions may not be effective for the desired purpose. To address these issues, a new approach is proposed in this article. The approach considers information extracted from wavelet transformations of the observed multivariate hydrometeorological time series as the basis for regionalization by global fuzzy c‐means clustering procedure. The approach can account for dynamic variability in the time series and its non‐stationarity (if any). Effectiveness of the proposed approach in forming HMRs is demonstrated by application to India, as there are no prior attempts to form such regions over the country. Drought severity‐area‐frequency (SAF) curves are constructed corresponding to each of the newly formed regions for the use in regional drought analysis, by considering standardized precipitation evapotranspiration index (SPEI) as the drought indicator.
Visualized absorption of anti‐atherosclerotic dipeptide, Trp‐His, in Sprague–Dawley rats by LC‐MS and MALDI‐MS imaging analyses
Authors: Tanaka Mitsuru , Hong Seong‐Min , Akiyama Sayaka , Hu Qing‐Qiang , Matsui Toshiro 
Published: March 2015

ScopeThe basic dipeptide, Trp‐His, was found to show an in vivo anti‐atherosclerotic effect when orally administered to apo E‐deficient mice. In addition, this dipeptide causes vasorelaxation in contracted rat aorta via suppression of intracellular Ca2+ signaling cascades. In this study, we attempted to determine whether Trp‐His can be absorbed after single oral administration in Sprague–Dawley (SD) rats.Methods and resultsTrp‐His and His‐Trp (10 or 50 mg/kg) was orally administered to 8‐week‐old male SD rats. Both peptides in plasma were assayed by LC‐MS/MS in combination with 2,4,6‐trinitrobenzene sulfonate derivatization technique. In vitro transport experiments using Caco‐2 cell monolayers were performed to evaluate the apparent permeability (Papp). A phytic acid‐aided MALDI‐MS imaging (MSI) was conducted to visualize the distribution of dipeptides in the rat intestinal membrane. Trp‐His was absorbed intact into SD rat blood, showing a maximal level at 1 h after administration at 10 mg/kg dose (Cmax, 28.7 ± 8.9 pmol/mL‐plasma; area under the curve, 71.3 ± 18.7 pmol·h/mL‐plasma). In contrast, His‐Trp was surprisingly not detected, although the Papp was compatible to that of Trp‐His. MSI analysis provided crucial evidence that Trp‐His was visualized in the overall intestinal membrane. The Trp‐His peptide was not visualized in the presence of Gly‐Sar, which is a model peptide that is transported via the intestinal proton‐coupled peptide transporter 1 (PepT1) transporter. The His‐Trp molecular ion was not observed at the intestinal membrane. The MSI analysis illustrated that there is no absorption of His‐Trp due to its unexpected hydrolysis by brush border proteases.ConclusionTo the best of our knowledge, this is the first study demonstrating that the vasoactive Trp‐His is preferably transported across the rat intestinal membrane by PepT1 and is absorbed intact into the circulation. However, no absorption of His‐Trp, a reverse sequence of absorbable Trp‐His, is observed owing to hydrolysis by intestinal proteases. This suggests that the bioavailability of peptides may be determined in part by their protease resistance in the intestinal membrane.
30‐GHz CMOS voltage‐controlled oscillator using drain‐gate coupled transformer to minimize the influence of parasitic components
Authors: Lee Milim , Cho Sungwoong , Park Changkun 
Published: March 2015

ABSTRACTIn this study, we propose a magnetically coupled drain‐gate technique for mm‐wave CMOS voltage‐controlled oscillator (VCO) applications. To implement the proposed technique, we use a transmission line transformer. Using the proposed technique, it was possible to easily isolate the gate bias of the transistor from the drain bias of the transistor. The gate bias can then be independent of the DC bias of the drain. Accordingly, the frequency can be tuned using the gate bias, whereas the typical VCO obtains the tuning range of the operating frequency using an additional varactor. Consequently, the number of required devices for the proposed VCO decreases and, hence, the chip size is reduced compared to that of the typical VCO. To verify the feasibility of the proposed structure, we designed the VCO using 110 nm RFCMOS technology. From the measured results, we successfully obtained the required tuning range and reduced chip size of the proposed VCO. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:1025–1027, 2015
Microwave photonic filter with a tunable nonperiodic multiple passband frequency response
Authors: Chan Erwin H. W. 
Published: March 2015

ABSTRACTA microwave photonic filter that can realize a multiple nonperiodic passband frequency response is presented. It is based on stimulated Brillouin scattering in an optical fiber. The novelty of the filter is that, it has multiple passbands, which can be widely and independently tuned. The filter also has a very wide bandwidth, only limited by the system component bandwidths, as the frequency response is not periodic. Experimental results are presented demonstrating a bandpass filter with two or three widely tunable passbands. Investigations on the effects of adding or removing one passband and tuning one passband frequency to the other passbands are also presented. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:1089–1092, 2015
Novel tunable branch‐line coupler for WLAN applications
Authors: Salehi Mohamad Reza , Noori Leila , Abiri Ebrahim 
Published: March 2015

ABSTRACTIn this article, a tunable branch‐line coupler with a novel structure is designed to operate at 5.7GHz. A design method is based on miniaturization method with adjusting the resonance frequency. The proposed coupler without taped line feed structures operated at 5.62 GHz, and it has a size of 55.8 mm2 while its performance is reasonable. To improve the performance, the taped line feed structures are added. The wideband response exhibits that the proposed coupler acts properly with the spurious harmonics up to 11.4 GHz. In addition, at 5.7 GHz, the good insertion loss (2.3 dB) and coupling factor (2.6 dB) are obtained. The proposed coupler is simulated, fabricated, and measured. The results show that there is a good agreement between the simulation and measurement results. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:1081–1084, 2015
Broadband circularly polarized moon‐shaped monopole antenna
Authors: Hu Benyang , Nasimuddin  , Shen Zhongxiang 
Published: March 2015

ABSTRACTA moon‐shaped printed monopole antenna with modified ground plane is proposed for broadband circularly polarized (CP) radiation. Proposed monopole antenna consists of a moon‐shaped radiator with a microstrip feed line. The moon‐shaped radiator and its ground‐plane shaped are optimized for broadband CP radiation. Impedance matching is improved using the quarter‐wave transformer along with microstrip line. The measured results of the prototype antenna on FR4 substrate are 1.67 GHz (2.08−3.75 GHz) for 2.5‐VSWR bandwidth, 1.48 GHz (2.28–3.76 GHz) for 3‐dB axial ratio (AR) bandwidth, and gain around 1.6 dBic across the 3‐dB AR bandwidth. Overall antenna volume is 0.466λ0 × 0.70λ0 × 0.008λ0 at 3.0 GHz. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:1135–1139, 2015
General expression for tunable matching network efficiency in the case of complex impedances
Authors: Freitas Vitor , Arnould Jean‐Daniel , Ferrari Philippe 
Published: March 2015

ABSTRACTThe design of matching networks is generally based on lossless devices, hence rendering difficult to anticipate their performance when both impedances are complex. To be more predictive in terms of insertion loss and matching impedance coverage, a rigorous method is proposed for the first time to calculate the efficiency of a tunable matching network based on the quality factor of its components, with source and load complex impedances. The method allows optimizing the topology of the matching network, depending on the location of the source and loading impedances in the Smith chart. It is the first time to our knowledge that a complete analytical formulas is given to predict the matching network's efficiency in function of available components quality factors in the case of source and load complex impedance. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:1160–1166, 2014
Design trade‐off for a compact 5.8 GHz DSRC transponder front‐end
Authors: Cidronali Alessandro , Maddio Stefano , Collodi Giovanni , Manes Gianfranco 
Published: March 2015

ABSTRACTThis letter introduces a method for the optimum design of a compact transponder front‐end for dedicated short range communication (DSRC) operating at 5.8 GHz band and suitable for electronic toll collection (ETC) vehicular applications. The DSRC transponder front‐end is based on a circularly polarized antenna and a RF diode, which provides both the functionalities of envelope detector and back‐scatterer. The design method is based on the characterization and optimization of the frequency conversion mechanism occurring in the front‐end during up and downlink while the best trade‐off between design parameters are identified on the base of sensitivity and back‐scatterer gain. These parameters optimize the DSRC transponder front‐end in the two links and thus leads to the maximum operative range. The methods are validated through the design of three prototypes responding to different design constraints and tested in the context of a realistic scenario of DSRC for ETC according to the ETSI EN300674 communication layers. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:1187–1191, 2015
Self‐assembled silicon‐based clusters to design efficient, fast, and controllable Fano switches
Authors: Ahmadivand Arash , Golmohammadi Saeed , Karabiyik Mustafa , Pala Nezih 
Published: March 2015

ABSTRACTIn this study, we use a nanoparticle cluster composed of silicon nanodisks in both symmetric and antisymmetric regimes to design an artificial efficient nanoswitch. Using appeared Fano dip for the antisymmetric nanocluster in the visible spectrum, we controlled the quality of Fano resonance (FR) by changing the polarization direction of the incident light source. In this method, we showed that appearing and disappearing of FR for different polarizations can be used to design an ON/OFF switch based on the behavior of Fano dip in a silicon‐based cluster. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:1242–1246, 2015
Multiresponse Optimisation Applied to the Development of a TLC Autography for the Detection of Tyrosinase Inhibitors
Authors: García Paula , Furlan Ricardo L. E. 
Published: March 2015

ABSTRACTIntroductionAutographic methods are useful tools to detect bioactive compounds in complex matrixes. Experimental design and optimisation techniques were implemented for the development of an autographic assay suitable for the detection of tyrosinase inhibitors.ObjectivesTo develop an autographic assay to detect tyrosinase inhibitors using gel entrapped enzyme, experimental design and response surface methodology (RSM) to optimise conditions with a minimum number of experiments.MethodsGel entrapment was used for the assay and the effects of four factors on the sensitivity and the detection limit for known inhibitors of the enzyme were evaluated. The factors were: tyrosinase amount (TA), L‐tyrosine amount (LTA), incubation time and incubation temperature.ResultsThe assay allowed the detection of kojic acid in an extract of Calamagrostis viridiflavescens (Poir.) Steud spiked with 0.1% w/w.ConclusionThe developed assay is able to detect tyrosinase inhibitors present in complex matrixes in a reproducible way. Copyright © 2015 John Wiley & Sons, Ltd.
Synthesis and characterization of polyaniline nanoparticles in phosphonic acid amphiphile aqueous micellar solutions for waterborne corrosion protection coatings
Authors: Perrin F. X. , Phan T. A. , Nguyen D. L. 
Published: March 2015

ABSTRACTPolyaniline (PANI) dispersions consisting of 270 to 380 nm sized particles were prepared by oxidation with ammonium peroxydisulfate (APS) in n‐decylphosphonic acid (DPA) micellar solutions. The green dispersions do not undergo macroscopic precipitation for more than a year. The synthesized DPA doped PANI exhibited enhanced electrical conductivity (3.6 S cm−1) compared with DPA‐PANI (2.3 x 10−4 S cm−1) prepared by postsynthesis treatment of the PANI‐base with DPA. It was shown that through protonation with decylphosphonic acid, polyaniline showed a significantly enhanced solubility in common organic solvents like chloroform, xylene, etc. The synthesized PANI was characterized by intrinsic viscosity, solubility, FT‐IR, conductivity, SEM, and TGA measurements. The wide‐angle X‐ray diffraction study revealed the appearance of a peak located at low angles (d = 29.4–35.3 Å) suggesting the formation of layered structure of PANI backbone separated by long alkyl side chains of DPA. The anticorrosive performance of the bilayer coatings composed of a bottom layer of DPA doped polyaniline covered with a polyvinyl butyral topcoat, have been demonstrated for steel exposed to neutral saline solutions. It was found that the inhibitive properties of DPA dopant provides further protection to the base metal through smart release when damage is produced on the surface of the coating. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 1606–1616
Facile synthesis of polyester dendrimer via combining thio‐bromo “Click” chemistry and ATNRC
Authors: Fan Xiaoshan , Hu Zhiguo , Wang Guowei 
Published: March 2015

ABSTRACTThis article reports on developing an efficient synthesis approach to aliphatic polyester dendrimer, poly(thioglycerol‐2‐propionate) (PTP), by combination of thio‐bromo “Click” chemistry with atom transfer nitroxide radical coupling (ATNRC). Through the one‐pot two‐step method, linear polystyrene with hydroxyl end groups (l‐PS‐2OH) was obtained by first atom transfer radical polymerization of styrene and following termination using 4‐(2,3‐dihydroxypropoxy)‐TEMPO (DHP‐TEMPO) to capture the PS macroradicals via ATNRC method. Using l‐PS‐2OH as support, the dendritic repeating units divergently were grown from the hydroxyl end groups via esterification and thio‐bromo “Click” reaction two‐step process. In every generation, the resulting intermediates l‐PS‐d‐PTP (G1‐G4) can be easily isolated from the excessive unreacted monomers by simple precipitation in ethanol without help of time, labor and solvent consuming column chromatographic purification. At last, cleavage of the alkoxyamine group between the PS support and dendrimer at elevated temperature (125 °C) provided the targeted polyester dendrimer PTP up to the fourth generation. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 1762–1768
Mechanism of Catalytic Effects on AMMO/HMX Composite Propellants Combustion Rates
Authors: Oyumi Yoshio , Mitarai Yoshiaki , Anan Toshiyuki 
Published: March 2015

AbstractMechanismus der katalytischen Wirkung auf die Abbrandgeschwindigkeit von AMMO/HMX‐KomposittreibstoffenDie thermische Zersetzung und die Abbrandeigenschaften von AMMO/HMX‐Treibstoffen wurden untersucht. Die bei der AMMO‐Zersetzung freiwerdende Wärme initiierte und beschleunigte die thermische Zersetzung von HMX, die Reaktion zwischen den Zersetzungsprodukten von AMMO und HMX war abhängig von der Aufheizgeschwindigkeit. Der geschwindigkeitsbestimmende Schritt für den Reaktionsverlauf war verschieden je nach höherer oder niedriger Aufheizgeschwindigkeit. Zusatz von 2,2‐Bis(ethylferrocenyl)propan (CFe) und Kupferchromit (CuC) veränderte den Mechanismus der thermischen Zersetzung und die Abbrandeigenschaften sichtbar. CFe zeigte eine Zunahme der Abbrandgeschwindigkeit mit leichtem Anstieg des Druckexponenten, dagegen lieferte CuC höhere Werte für den Druckexponenten. Die Kombination beider Zusätze erbrachte die höchste Abbrandgeschwindigkeit mit dem niedrigsten Druckexponenten. Der Einfluß des CuC auf den Druckexponenten verschwand bei Kombination mit CFe. Obwohl CFe und der kombinierte Zusatz die Zündfähigkeit der Treibstoffe verbesserte, war es schwierig, den Treibstoff bei Zusatz von CuC zu zünden aufgrund des geringen Wärmerückflusses und/oder der geringen freiwerdenden Wärme bei der Zersetzung.
Calculation of Reduced Second Virial Coefficient Parameters for Angle Independent Intermolecular Potential Energy Functions
Authors: Jones David E.G. , Phelps Brian F. 
Published: March 2015

AbstractBerechnung des reduzierten zweiten Virialkoeffizienten für winkelunabhängige intermolekulare PotentialenergiefunktionenEs wird eine Rechenverfahren beschrieben, mit dem der zweite Virialkoeffizient und seine Ableitungen in Bezug auf die reduzierte Temperatur für alle winkelunabhängigen intermolekularen Potentialenergiefunktionen bestimmt werden können. Dieses Verfahren ist allgemeiner und liefert genauere Ergebnisse als alle anderen gegenwärtig gebräuchlichen Methoden. Ergebnisse für reduzierte zweite Virialkoeffizienten für die exp n‐6 Potentialenergiefunktion bezogen auf den Bereich 0,4 bis 400 der reduzierten Temperatur und für n = 12 bis 15 werden in Tabellenform angegeben.