bluuebunny/crossref_metadata_2025_split huggingface dataset:
Photochemical and microbial transformation of emerging flame retardants: Cause for concern?
Authors: Chen Da , Hale Robert C. , Letcher Robert J. 
Published: March 2015

Abstract

Among anthropogenic chemicals, flame retardants have attracted mounting environmental concerns. In recent years, an increasing number of studies have been conducted worldwide to investigate flame-retardant sources, environmental distribution, wildlife and human exposure, and toxicity. Data generated have demonstrated that some flame-retardant substances such as polybrominated diphenyl ethers (PBDE) are persistent, bioaccumulative, and toxic to exposed organisms. However, comparatively much less attention has been paid to the mechanisms and products of environmental transformation of flame retardants. This lack of information undermines our understanding of the environmental behavior and fate of flame retardants, as well as the associated risks to environmental and human health. Photochemical and microbial transformation of flame retardants in various matrices and environmental compartments can elevate the toxicological significance of flame retardant exposure, via the formation of, for example, lesser halogenated but more bioaccumulative degradation products and toxic radicals. Such pathways raise concerns related to the environmental safety of some alternative flame retardants that are presumably safe and used to replace PBDEs. To fully assess the environmental risks, more research is needed to investigate the environmental transformation potential of emerging flame retardants including polymeric flame retardants. Enhanced analytical efforts are needed to better characterize transformation products and transient radicals. Additional mesocosm and field studies are needed to elucidate transformation kinetics and consequences under environmentally relevant conditions. Environ Toxicol Chem 2015;34:687–699. © 2015 SETAC
On the approximate zeroth and first‐order consistency in the presence of 2‐D irregular boundaries in SPH obtained by the virtual boundary particle methods
Authors: Fourtakas Georgios , Vacondio Renato , Rogers Benedict D. 
Published: March 2015

AbstractIn this paper, a new method to impose 2‐D solid wall boundary conditions in smoothed particle hydrodynamics is presented. The wall is discretised by means of a set of virtual particles and is simulated by a local point symmetry approach. The extension of a previously published modified virtual boundary particle (MVBP) method guarantees that arbitrarily complex domains can be readily discretised guaranteeing approximate zeroth and first‐order consistency. To achieve this, three important new modifications are introduced: (i) the complete support is ensured not only for particles within one smoothing length distance, h, from the boundary but also for particles located at a distance greater than h but still within the support of the kernel; (ii) for a non‐uniform fluid particle distribution, the fictitious particles are generated with a uniform stencil (unlike the previous algorithms) that can maintain a uniform shear stress on a particle‐moving parallel to the wall in a steady flow; and (iii) the particle properties (density, mass and velocity) are defined using a local point of symmetry to satisfy the hydrostatic conditions and the Cauchy boundary condition for pressure. The extended MVBP model is demonstrated for cases including hydrostatic conditions for still water in a tank with a wedge and for curved boundaries, where significant improved behaviour is obtained in comparison with the conventional boundary techniques. Finally, the capability of the numerical scheme to simulate a dam break simulation is also shown. Copyright © 2015 John Wiley & Sons, Ltd.
A boundary element method for the solution of finite mobility ratio immiscible displacement in a Hele‐Shaw cell
Authors: Jackson S. J. , Stevens D. , Power H. , Giddings D. 
Published: March 2015

SummaryIn this paper, the interaction between two immiscible fluids with a finite mobility ratio is investigated numerically within a Hele‐Shaw cell. Fingering instabilities initiated at the interface between a low‐viscosity fluid and a high‐viscosity fluid are analysed at varying capillary numbers and mobility ratios using a finite mobility ratio model.The present work is motivated by the possible development of interfacial instabilities that can occur in porous media during the process of CO2 sequestration but does not pretend to analyse this complex problem. Instead, we present a detailed study of the analogous problem occurring in a Hele‐Shaw cell, giving indications of possible plume patterns that can develop during the CO2 injection.The numerical scheme utilises a boundary element method in which the normal velocity at the interface of the two fluids is directly computed through the evaluation of a hypersingular integral. The boundary integral equation is solved using a Neumann convergent series with cubic B‐Spline boundary discretisation, exhibiting sixth‐order spatial convergence. The convergent series allows the long‐term nonlinear dynamics of growing viscous fingers to be explored accurately and efficiently.Simulations in low‐mobility ratio regimes reveal large differences in fingering patterns compared with those predicted by previous high‐mobility ratio models. Most significantly, classical finger shielding between competing fingers is inhibited. Secondary fingers can possess significant velocity, allowing greater interaction with primary fingers compared with high‐mobility ratio flows. Eventually, this interaction can lead to base thinning and the breaking of fingers into separate bubbles. Copyright © 2015 John Wiley & Sons, Ltd.
The Function of Twisted Gastrulation in Regulating Osteoclast Differentiation is Dependent on BMP Binding
Authors: Huntley Raphael , Davydova Julia , Petryk Anna , Billington Charles J. , Jensen Eric D. , Mansky Kim C. , Gopalakrishnan Rajaram 
Published: March 2015

ABSTRACTProper regulation of osteoclast (OCL) function is critical for normal bone homeostasis. Bone morphogenetic protein (BMP) signaling and its regulation have been shown to have direct effects on OCL differentiation and activity. One of the major modulators of BMP signaling in the extracellular space is the secreted protein twisted gastrulation (TWSG1), which can inhibit BMP signaling and OCL differentiation. In this study we examine specific N‐terminal regions of TWSG1 protein that have been previously proposed as BMP binding sites to determine whether TWSG1 binding to BMPs is required for its inhibitory effects on OCLs. We demonstrate that overexpression of wild type TWSG1 suppresses osteoclastogenesis, while overexpression of mutant TWSG1 proteins (W66A and N80Q/N146Q mutants), which cannot bind BMPs, leads to increased BMP signaling, enhanced osteoclastogenesis, increased resorptive activity, and expression of OCL‐specific genes. Our results show that BMP binding is required for TWSG1‐mediated inhibition of OCL formation and function, and validate the critical functional regions within the TWSG1 protein for these interactions. J. Cell. Biochem. 116: 2239–2246, 2015. © 2015 Wiley Periodicals, Inc.
Silver oxide‐containing hydroxyapatite coating supports osteoblast function and enhances implant anchorage strength in rat femur
Authors: Eto Shuichi , Miyamoto Hiroshi , Shobuike Takeo , Noda Iwao , Akiyama Takayuki , Tsukamoto Masatsugu , Ueno Masaya , Someya Shinsuke , Kawano Shunsuke , Sonohata Motoki , Mawatari Masaaki 
Published: March 2015

ABSTRACTAntibacterial silver with hydroxyapatite (Ag–HA) is a promising coating material for imparting antibacterial properties to implants. We previously reported that 3% (w/w) silver with HA (3% Ag–HA) has both antibacterial activity and osteoconductivity. In this study, we investigated the effects of Ag–HA on the in vitro osteoblast function and the in vivo anchorage strength and osteoconductivity of implants. Production of the osteoblast marker alkaline phosphatase, but not cytotoxicity, was observed in cells of the osteoblast cell line MC3T3‐E1 cultured on the 3% Ag–HA‐coated surface. These results were similar to those observed with silver‐free HA coating. In contrast, a significant high level of cytotoxicity was observed when the cells were cultured on a 50% Ag–HA‐coated surface. The anchorage strength of implants inserted into the femur of Sprague–Dawley (SD) rats was enhanced by coating the implants with 3% Ag–HA. On the 3% Ag–HA‐coated surface, both metaphyseal and diaphyseal areas were largely covered with new bone and had adequate osteoconductivity. These results suggest that 3% Ag–HA, like conventional HA, promotes osteogenesis by supporting osteoblast viability and function and thereby contributes to sufficient anchorage strength of implants. Application of 3% Ag–HA, which combines the osteoconductivity of HA and the antibacterial activity of silver, to prosthetic joints will help prevent postoperative infections. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1391–1397, 2015.
Combined free flaps with arteriovenous loops for reconstruction of extensive thoracic defects after sternal osteomyelitis
Authors: Taeger Christian D. , Horch Raymund E. , Arkudas Andreas , Schmitz Marweh , Stübinger Axel , Lang Werner , Meyer Alexander , Seitz Timo , Weyand Michael , Beier Justus P. 
Published: March 2015

BackgroundVarious local flaps have been described for patients suffering from sternal osteomyelitis and are regarded as a standard procedure for defect reconstruction. In contrast, the use of microsurgical free flaps has been reported anecdotally only. We present our experiences with the combination of an arteriovenous loop and a free flap transfer in defects larger than half of the sternum.MethodsBetween January 2012 and October 2014, eight patients with a mean age of 68 years who suffered from extensive deep sternal osteomyelitis were operated in a consecutive series. After radical surgical debridement, the defect size comprised all three thirds of the sternum. Defect reconstruction was achieved by means of free flap transplantation using the vastus lateralis myocutaneous flap, rectus abdominis, and bipedicled latissimus dorsi/parascapular flap. As local recipient vessels were depleted in all patients, the pedicle of the flap was anastomosed to a high‐flow and short‐length subclavian arteriovenous loop as recipient vessel in all cases.ResultsThe immediate postoperative course in all patients was uneventful despite one axonal injury to the femoral nerve at the donor site. There was no partial or total flap loss. During a mean follow‐up of 9 months, one patient suffered from a local infection at the donor site. In all patients, a successful defect reconstruction could be achieved.ConclusionDepletion of local recipient vessels as an obstacle for free flap reconstruction can be overcome by creating an arteriovenous loop. Even extensive defects are adequate for defect reconstruction using a single or, in extreme cases, bipedicled free flap. © 2015 Wiley Periodicals, Inc. Microsurgery 36:121–127, 2016.
Analysis of spatial/polarization diversity using a broadband slot‐coupled patch antenna for the WLAN 802.11A/B/G/N access point
Authors: Yeom Insu , Kim Hyungrak , Jung Jihak , Jung Chang Won 
Published: March 2015

ABSTRACTA broad dual‐band slot‐coupled patch antenna is proposed for the wireless local area network band. The basic antenna element consists of two radiators on three layers. To enhance the bandwidth, a coupled feeding was used in the first radiator, and a parasitic patch was used in the second radiator. The peak gain of the single antenna element was more than 6 dBi at 2.4 GHz and more than 8 dBi at 5 GHz. We simulated and measured the extended antenna to four elements using a common reflector, and the spatial and polarization diversity of the proposed antenna were analyzed according to the isolation and the diversity gain. The isolation is below −15 dB at the operating frequency when the distance between the proposed antennas is more than 0.67λ (80 mm). The orthogonal polarization of the proposed antenna obviously improves the performance of the diversity antenna system. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:1042–1048, 2015
Acrylic substrate based low profile wearable button antenna with FSS layer for WLAN and Wi‐Fi applications
Authors: Mandal Bappaditya , Chatterjee Ayan , Parui Susanta Kumar 
Published: March 2015

ABSTRACTIn this letter, a low profile circularly polarized wearable antenna with the appearance of a button on clothing for Wi‐Fi and WLAN applications is presented. The radiating elements of the antenna are made of copper sheet while a transparent acrylic fiber sheet material is used as substrate and fed by a coaxial line through the ground plane. The proposed antenna is simulated by Ansoft high frequency structure synthesis finite element method‐based (HFSS FEM)‐based EM simulator and has been optimized to operate within the Wi‐Fi and WLAN frequency bands (5250–5850 MHz) with center frequency of 5.25 GHz. A split ring‐shaped slot‐based frequency selective surface (FSS) is designed to enhance the gain of the proposed antenna. The peak gain of the antenna is found to increase from the conventional antenna gain of 2.1 to 5.1 dBi with the superstrate along with a bandwidth enhancement of 290 MHz. The composite FSS antenna is fabricated and the maximum measured gain of 5.1 dBi matches well with theoretical value. The antenna gets miniaturized around 34% by the slits with its circular polarization characteristic well maintained. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:1033–1038, 2015
Tri‐band HIS backed spiral antenna for wireless LAN applications
Authors: Mohamad Sarah , Cahill Robert , Fusco Vincent 
Published: March 2015

ABSTRACTThis study reports the performance of an Archimedean spiral antenna, which exhibits unidirectional circularly polarized radiation patterns with a peak gain >8 dBic in the lower (2.4–2.485 GHz) and upper (5.15–5.35 and 5.725–5.875 GHz) Wireless local area network frequency bands. The required backlobe suppression and impedance match are obtained by placing a multiresonant high impedance surface (HIS) in close proximity to the radiating aperture. Simulated and measured radiation patterns are shown at the center frequency of all three channels and a comparison of the key performance metrics is made with free space and metal backed antenna arrangements to demonstrate the enhancements which are attributed to the HIS reflector. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:1116–1121, 2015
A new multipassband filter with multiple transmission zeros based on quarter‐wavelength resonators in wireless communication systems
Authors: Cao Xin , Tang Zongxi , Wang Fei , Wu Yunqiu , Zhang Biao 
Published: March 2015

ABSTRACTIn this article, a new multipassband filter with multiple transmission zeros (TZs) based on quarter‐wavelength resonators (QWRs) is proposed. Three pairs of QWRs are utilized to produce three passbands and three TZs, and the center frequencies of the passbands can be flexibly controlled by changing the length and width of the corresponding resonators without major influence on the other passbands. It is proved from the simulated and measured results that the proposed filter has some excellent properties such as low in‐band insertion loss, great out‐band rejection and compact size. The designed filter has the working frequencies of 1.9 GHz (Global System for Mobile Communication), 2.6 GHz (4G Communication), and 5.2 GHz (Worldwide Interoperability for Microwave Access) and can be applied in the multiprotocol wireless communication systems. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:1105–1107, 2015
Physically symmetric wideband waveguide T‐junction with equal‐phase and unequal‐power division
Authors: Huang Guan‐Long , Chio Tan‐Huat , Hui Hon‐Tat , Yeo Tat‐Soon 
Published: March 2015

ABSTRACTAn H‐plane wideband rectangular waveguide T‐junction divider with an equal‐phase and an unequal‐power‐division is proposed. This T‐junction has an intrinsic hallmark of symmetry, namely, the lengths of two output branches being maintained equally with reference to the input port. Numerical analysis results are compared with the measured ones to verify the design idea. This device has a potential application in array feeding network designs where equal‐phase and unequal‐power division are to be achieved by equal‐length feeding lines. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:1216–1219, 2015
Rotational circular split ring resonator array loaded CPW for dual notch and wide bandstop applications
Authors: Saha Chinmoy , Siddiqui Jawad Y. , Shaik Latheef A. , Antar Yahia M. M. 
Published: March 2015

ABSTRACTA compact design of a wide bandstop and dual notch filter using an array of circular split ring resonators (SRR) on a coplanar waveguide is proposed in this article. The band rejection is determined by the resonance frequencies of the loaded SRRs. The resonance frequencies of the SRRs are optimized by gradual angular rotation of the inner rings of the SRRs. The dual notch is achieved with dual SRR pairs with two different angular orientations of (0°–60° and 0°–90°). A wideband rejection is achieved by an array of eight pairs of SRRs with gradually changing angular orientation from 0° to 90°. Good agreement is achieved between the simulated and the measured results. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:1204–1209, 2015
A CPW‐fed wideband circularly polarized slot antenna with FSS for enhanced gain
Authors: Ramkrishna RVS , Kumar Raj 
Published: March 2015

ABSTRACTA CPW fed slot antenna is proposed. The slot is rectangular in shape and is excited by a two step feed terminated on a circular disc which protrudes into the slot center. Perturbations in the form of metallic L‐shape strips are attached at two opposite corners of the slot while the other two slot corners are blended with circular arcs. Further, slant narrow rectangular slits are cut on the circular disc. The frequency selected surface (FSS) designed to improve the gain and the Circular Polarization (CP) of the antenna is an array of rectangular metallic patches printed on one side of a substrate. The antenna—FSS combination achieves an impedance bandwidth of 2.3–12.0 GHz (136%, measured). The 3‐dB axial ratio bandwidth (ARBW) achieved by the combination is from 4.3–6.9 GHz (46.4%, measured). The measured peak gain is 7–8 dBi over much of the band which is an enhancement of about 4 dBi when compared to the antenna without the FSS. The antenna along with the FSS can be useful for CP applications such as in ground penetrating radar and vehicular radar where high gain is additionally required. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:1199–1204, 2015
A coupled line bandpass filter using a novel SIR with intentional coupled length
Authors: Kim In‐Seon , Shin Imseob , Lee Byeong‐Nam 
Published: March 2015

ABSTRACTA novel stepped impedance resonator (SIR) and its design formulas for the coupled line bandpass filter (BPF) are proposed. The proposed SIR can provide tight coupling by intentionally extending the length of a coupled line. In addition, it forms the second passband much farther away compared to the conventional SIR. To show the validity of the proposed SIR and its application to the coupled line BPF, the three‐pole SIR BPF is designed and fabricated. The measured and simulated results are in very good agreement. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:1259–1262, 2015
XD‐GRASP: Golden‐angle radial MRI with reconstruction of extra motion‐state dimensions using compressed sensing
Authors: Feng Li , Axel Leon , Chandarana Hersh , Block Kai Tobias , Sodickson Daniel K. , Otazo Ricardo 
Published: March 2015

PurposeTo develop a novel framework for free‐breathing MRI called XD‐GRASP, which sorts dynamic data into extra motion‐state dimensions using the self‐navigation properties of radial imaging and reconstructs the multidimensional dataset using compressed sensing.MethodsRadial k‐space data are continuously acquired using the golden‐angle sampling scheme and sorted into multiple motion‐states based on respiratory and/or cardiac motion signals derived directly from the data. The resulting undersampled multidimensional dataset is reconstructed using a compressed sensing approach that exploits sparsity along the new dynamic dimensions. The performance of XD‐GRASP is demonstrated for free‐breathing three‐dimensional (3D) abdominal imaging, two‐dimensional (2D) cardiac cine imaging and 3D dynamic contrast‐enhanced (DCE) MRI of the liver, comparing against reconstructions without motion sorting in both healthy volunteers and patients.ResultsXD‐GRASP separates respiratory motion from cardiac motion in cardiac imaging, and respiratory motion from contrast enhancement in liver DCE‐MRI, which improves image quality and reduces motion‐blurring artifacts.ConclusionXD‐GRASP represents a new use of sparsity for motion compensation and a novel way to handle motions in the context of a continuous acquisition paradigm. Instead of removing or correcting motion, extra motion‐state dimensions are reconstructed, which improves image quality and also offers new physiological information of potential clinical value. Magn Reson Med 75:775–788, 2016. © 2015 Wiley Periodicals, Inc.
Morphological changes in the salivary acini after in vivo cholinergic stimulation
Authors: Hassan Sherif S. , Rachakatla Raja , McGarvey Terence , Youakeem Magdy F. 
Published: March 2015

AimsOveractive bladder syndrome treated by muscarinic receptor antagonists may be complicated by reduced salivation. Cholinergic agonists may reverse this effect. The aim of the present study was to determine the antagonizing effect of a cholinergic agonist (carbachol) on a muscarinic receptor antagonist (oxybutynin) in the submandibular acini in a rat model.MethodsForty male Sprague Dawley rats were divided into three groups: Group I (control), Group II (vehicle), and Group III (treatment). Group III was subdivided so Group IIIa was treated with a muscarinic receptor antagonist (oxybutynin) for 1 week, Group IIIb was treated with oxybutynin for 3 weeks, and Group IIIc was treated with oxybutynin for 1 week and oxybutynin and a cholinergic agonist (carbachol) for 2 weeks. Histological and ultrastructural studies were performed on submandibular glands.ResultsGroup IIIa showed moderate atrophic changes in the serous acini and ducts. Group IIIb showed serous acini with distorted wall, widening of the inter‐lobar space, and deposition of mononuclear cells in the connective tissue. Group IIIc had serous acini similar to Group I, with mildly dilated inter‐lobar ducts, but some serous acini revealed double nuclei and the inter‐lobar duct showed luminal vacuolations. Ultrastructural studies confirmed histological results.ConclusionsMuscarinic receptor antagonist administration led to changes in the submandibular gland of rats, while concomitant administration of cholinergic agonists seemed to counteract these atrophic changes. Additional studies should assess carbachol as a cholinergic agonist in treating dry mouth in patients with overactive bladder syndrome who are taking the muscarinic receptor. Neurourol. Urodynam. 35:574–581, 2016. © 2015 Wiley Periodicals, Inc.