bluuebunny/crossref_metadata_2025_split huggingface dataset:
Compact, high gain, linearly polarized diversity antenna for KU band applications
Authors: Satam Vandana , Nema Shikha 
Published: October 2018

AbstractThree elements multiple input multiple output (MIMO) antenna operating in Ku band is proposed in this article. Antenna elements are fed by simple line feeding technique. Matching between feeding line and radiator is maintained by adding quarter wave transformer between them. To reduce overall size of the MIMO system, three similar antenna elements are allocated on single radiator on the top face of single substrate. Wide bandwidth is achieved by etching square slot in the elliptical shape radiator. High isolation between two antenna elements is attained by placing antenna elements λ/8 distance apart. Simulated and measured results (S11 < −10 dB, S12/S13 < −18 dB) demonstrate proposed antenna is appropriate for Ku band applications. The diversity characteristics and diversity gain are also studied by calculating envelope correlation coefficient. High gain of MIMO antenna is achieved by increasing number of elliptical radiators. Linear polarization is due to parallel orientation of all radiating antenna elements. The proposed antenna is suitable for satellite applications.
Modified Doherty combiner with adjustable phase deviation
Authors: Lee Daeung , Kim Sungmin , Jang Youna , Koo Seo , Kim In‐seon , Lim Jongsik , Cho Jeongho , Ahn Dal 
Published: October 2018

AbstractIn this paper, we propose a newly enhanced Doherty combiner by adding a 180° transmission line to the stage of the peaking amplifier of a typical Doherty combiner such that the designer can easily construct a combiner having a phase deviation to be turned on within the intended bandwidth. Given such characteristics, the proposed structure provides wider phase bandwidth and better performance with respect to power combining rate than the conventional structure does. We introduce formulas for the design variables of the added transmission line and also demonstrate its validity through circuit design and experiment.
Novel end‐fire dipole array antenna with gain and bandwidth enhancement
Authors: Ma Tianye , Shen Mengkui , Ai Jing , Joines William 
Published: October 2018

AbstractA gain and bandwidth enhanced end‐fire dipole array antenna is presented. In order to improve the bandwidth of the original dipole array antenna, 2 parasitic metallic strips are closely placed at the end‐fire direction. Three pairs of I‐shaped resonators with different lengths are placed on the broadsides of the antenna to increase the gain. The measured results show that the antenna has bandwidth of 80.3% for voltage standing wave ratio <2 and a gain of 4.72‐7.3 dBi. When compared with the original design, the presented antenna has a 9.8% wider bandwidth and a gain improvement of 4.62 dB. The gain flatness and the frequency selectivity are also improved. The presented antenna is more favorable in wireless and radar applications compared with the original design.
Transparent dual band antenna with μ‐negative material loading for smart devices
Authors: Desai Arpan , Upadhyaya Trushit 
Published: October 2018

AbstractA dual‐band optically transparent antenna having two slotted circular rings with partial ground plane is proposed for smart applications. The antenna has circular split ring resonators (SRRs) array which offers negative refractive index properties to the resonator. The antenna is fed using microstrip feed line which is matched at 50 Ω. The conducting patch, partial ground plane and two circular SRRs are made up of transparent conducting thin film AgHT‐8 having transparency of above 80%. Substrate in the form of Plexiglas is used for making the antenna structure completely transparent. Metamaterial is incorporated for achieving acceptable values of antenna gain. The patch design is engineered for antenna operation in IEEE a/b/g/n frequency bands working at 2.4 GHz and 5.5 GHz, respectively. The size of the proposed transparent antenna is 35 × 35 × 1.84 mm3 with measured impedance bandwidth of 13.27% and 5.28% achieved for lower frequency band of 2.4 GHz and the upper frequency band of 5.5 GHz, respectively. The proposed antenna is useful for smart devices communicating over WLAN frequency bands without need of extra board space due to the optical transparency of antenna.
An initial investigation of hyperpolarized gas tagging magnetic resonance imaging in evaluating deformable image registration‐based lung ventilation
Authors: Cui Taoran , Miller G. Wilson , Mugler John P. , Cates Gordon D. , Mata Jaime F. , de Lange Eduard E. , Huang Qijie , Altes Talissa A. , Yin Fang‐Fang , Cai Jing 
Published: October 2018

BackgroundDeformable image registration (DIR)‐based lung ventilation mapping is attractive due to its simplicity, and also challenging due to its susceptibility to errors and uncertainties. In this study, we explored the use of 3D Hyperpolarized (HP) gas tagging MRI to evaluate DIR‐based lung ventilation.Method and MaterialThree healthy volunteers included in this study underwent both 3D HP gas tagging MRI (t‐MRI) and 3D proton MRI (p‐MRI) using balanced steady‐state free precession pulse sequence at end of inhalation and end of exhalation. We first obtained the reference displacement vector fields (DVFs) from the t‐MRIs by tracking the motion of each tagging grid between the exhalation and the inhalation phases. Then, we determined DIR‐based DVFs from the p‐MRIs by registering the images at the two phases with two commercial DIR algorithms. Lung ventilations were calculated from both the reference DVFs and the DIR‐based DVFs using the Jacobian method and then compared using cross correlation and mutual information.ResultsThe DIR‐based lung ventilations calculated using p‐MRI varied considerably from the reference lung ventilations based on t‐MRI among all three subjects. The lung ventilations generated using Velocity AI were preferable for the better spatial homogeneity and accuracy compared to the ones using MIM, with higher average cross correlation (0.328 vs 0.262) and larger average mutual information (0.528 vs 0.323).ConclusionWe demonstrated that different DIR algorithms resulted in different lung ventilation maps due to underlining differences in the DVFs. HP gas tagging MRI provides a unique platform for evaluating DIR‐based lung ventilation.
Monitoring daily routine performance in quantitative NMR (qNMR) spectroscopy: Is the system suitability test necessary?
Authors: Monakhova Yulia B. , Diehl Bernd W.K. 
Published: October 2018

AbstractNuclear magnetic resonance spectrometry (NMR) finds numerous applications in pharmacy, cosmetic, and food control as well as in developing tools for “big data” analysis. However, there remains a need for automated tools to assess instrument system suitability in real time for each particular routine sample.An automated procedure has been introduced to monitor a number of characteristics (resolution, symmetry, and half width) in real time after the measurement of two samples distributed by the vendor (0.3% CHCl3 in acetone‐d6 with tetramethylsilane and 2 mM sucrose in H2O‐D2O). The results over 11 months were discussed in terms of average values, standard deviations, and spectrometer variability. Moreover, multivariate statistical procedure was implemented to evaluate metrics generated from three NMR spectrometers. Performance of three NMR spectrometers (500 MHz with BBO Prodigy Cryoprobe, 500 MHz with BBFOPLUS SmartProbe, and 600 MHz with BBO Cryoprobe) differed significantly.The developed routine was also applied to calculate the performance characteristics during routine quantitative NMR experiments. The procedure was evaluated for NMR spectra of 659 active pharmaceutical ingredients dissolved in CDCl3, DMSO, and CH3OD. This test is more preferable than the routine procedure using standard solutions because the performance is estimated separately for each matrix at the specific time point of measurements.Our automated routine is the ideal tool for any NMR laboratory. In full automation, the NMR data are validated directly for each sample, making unnecessary daily measurements of standard solutions and manual evaluation to their NMR spectra.
An efficient runtime mesh smoothing technique for 3D explicit Lagrangian free‐surface fluid flow simulations
Authors: Meduri S. , Cremonesi M. , Perego U. 
Published: October 2018

SummaryA fast runtime mesh smoothing algorithm for explicit Lagrangian simulations of 3D weakly compressible viscous fluid flows, implemented in conjunction with the particle finite element method (PFEM), is proposed. The formulation for weakly compressible fluids allows for the use of an explicit time integration scheme. Explicit solvers are appealing for large‐scale engineering problems characterized by fast dynamics and/or a high degree of nonlinearity. However, the conditional stability of these schemes requires the use of small time increments, proportional to the size of the element in the mesh with the worst geometrical quality. The Lagrangian description of the PFEM requires an efficient and robust runtime mesh generator algorithm, such as the Delaunay tessellation, to create new meshes during the analysis, whenever the current ones get too distorted because of the motion of the mesh nodes. When 3D problems are considered, a computationally effective mesh‐improving algorithm is also required because, in 3D, the Delaunay tessellation loses some of its optimality properties holding in 2D so that badly shaped tetrahedra are frequently included in the triangulation, leading to unacceptably small stable time step sizes for the explicit solver. To this purpose, a novel and efficient mesh smoothing technique is here proposed, exploiting an elastic analogy that allows for the use of the same explicit and parallelizable architecture of the fluid solver. This smoothing algorithm has been specifically designed to ensure reasonably large critical time step sizes at an acceptable computational cost. This is particularly appealing for the application of explicit Lagrangian PFEM in large‐scale 3D engineering problems, but it could be conveniently applied also to regularize the mesh and improve the solution of implicit solvers.
Discovery of Novel Molecular Frameworks of Farnesoid X Receptor Modulators by Ensemble Machine Learning
Authors: Merk Daniel , Grisoni Francesca , Schaller Kay , Friedrich Lukas , Schneider Gisbert 
Published: October 2018

AbstractThe bile acid activated transcription factor farnesoid X receptor (FXR) has revealed therapeutic potential as a molecular drug target for the treatment of hepatic and metabolic disorders. Despite strong efforts in FXR ligand development, the structural diversity among the known FXR modulators is limited. Only four molecular frameworks account for more than 50 % of the FXR modulators annotated in ChEMBL. Here, we leverage machine learning methods to expand the chemical space of FXR‐targeting small molecules by employing an ensemble of three complementary machine learning approaches. A counter‐propagation artificial neural network, a k‐nearest neighbor learner, and a three‐dimensional pharmacophore descriptor were combined to retrieve novel FXR ligands from a collection of more than 3 million compounds. The ensemble machine learning model identified six new FXR modulators among ten top‐ranked candidates. These active hits comprise both FXR activators and antagonists with micromolar potencies. With four novel FXR ligand scaffolds, these computationally identified bioactive compounds appreciably expand the chemical space of known FXR modulators and may serve as starting points for hit‐to‐lead expansion.
Spaced TiO2 Nanotubes Enable Optimized Pt Atomic Layer Deposition for Efficient Photocatalytic H2 Generation
Authors: Ozkan Selda , Yoo JeongEun , Nguyen Nhat Truong , Mohajernia Shiva , Zazpe Raul , Prikryl Jan , Macak Jan M. , Schmuki Patrik 
Published: October 2018

AbstractIn the present work, we report the use of TiO2 nanotube (NT) layers with a regular intertube spacing that are decorated by Pt nanoparticles through the atomic layer deposition (ALD) of Pt. These Pt‐decorated spaced (SP) TiO2 NTs are subsequently explored for photocatalytic H2 evolution and are compared to classical close‐packed (CP) TiO2 NTs that are also decorated with various amounts of Pt by using ALD. On both tube types, by varying the number of ALD cycles, Pt nanoparticles of different sizes and areal densities are formed, uniformly decorating the inner and outer walls from tube top to tube bottom. The photocatalytic activity for H2 evolution strongly depends on the size and density of Pt nanoparticles, driven by the number of ALD cycles. We show that, for SP NTs, a much higher photocatalytic performance can be achieved with significantly smaller Pt nanoparticles (i.e. for fewer ALD cycles) compared to CP NTs.
The Effect of Lower Transaction Costs on Social Security Disability Insurance Application Rates and Participation
Authors: Foote Andrew , Grosz Michel , Rennane Stephanie 
Published: October 2018

AbstractTransaction costs pose significant barriers to participation in public programs. We analyze how Social Security Disability Insurance (SSDI) application behavior was affected by iClaim, a 2009 innovation that streamlined the online application process. We use a difference‐in‐differences design to compare application rates before and after 2009 across counties with varying degrees of access to high‐speed internet. We estimate that counties with internet connectivity one standard‐deviation above the mean experienced a 1.6 percent increase in SSDI applications, and a 2.8 percent increase in appeals after the reform. We estimate that the increase in applications due to iClaim can explain 15 percent of the overall increase in applications between 2008 and 2011. Higher exposure to the online application led to a slightly larger increase in SSDI awards, meaning there was a small but significant increase in the overall award rate. Application rates increased the most in rural areas, while appeals and awards had more significant increases in urban areas. These results suggest that the online application reduced transaction costs to applicants, and the lower costs improved the overall targeting efficiency of the application process.
Design, Synthesis and Biological Evaluation of 2 (((5‐aryl‐1,2,4‐oxadiazol‐3‐yl)methyl)thio)benzo[d]oxazoles: New Antiinflammatory and Antioxidant Agents
Authors: Yatam Satyanarayana , Jadav Surender Singh , Gundla Rambabu , Gundla Krishna Prasadh , Reddy Gangireddy Madhusudhana , Ahsan Mohamed Jawed , Chimakurthy Jithendra 
Published: October 2018

AbstractThe oxadiazole linked benzoxazoles derivatives were designed using scaffold hopping approach and their molecular level interactions with both isoforms of cyclooxygenases, Cyclo OXygenase‐1 (COX‐1) and CycloOXygenase‐2 (COX‐2), were carried out using docking protocols. Mini library of oxadiazole linked benzoxazoles derivatives were synthesized and tested for their COX inhibitory activity by in vitro enzyme assay. The results indicated that compound 2‐(((5‐(2,4‐dichlorophenyl)‐1,2,4‐oxadiazol‐3‐yl)methyl)thio)benzo[d]oxazole (5 h), 2‐(((5‐(4‐nitrophenyl)‐1,2,4‐oxadiazol‐3‐yl)methyl)thio)benzo[d]oxazole (5 j) and 2‐(((5‐(4‐(trifluoromethyl)phenyl)‐1,2,4‐oxadiazol‐3‐yl)methyl)thio)benzo[d]oxazole (5 k) selectively inhibited COX‐2 enzyme. The compound 5 j exhibited strong selective COX‐2 inhibition (IC50=4.83 μM) followed by compound 5 h (IC50=5.10 μM) and 5 k (IC50=6.70 μM). The in vivo anti‐inflammatory activity of compound 5 j was found to have better efficiency than the standard drug Ibuprofen at both 3 h and 5 h intervals. The significant molecular level interactions with respect to position of benzoxazole, 1,2,4‐oxadiazole and substituted aryl groups in both COX‐1 and COX‐2 active sites were discussed. Subsequently, 2,2‐diphenyl‐2‐picrylhydrazyl (DPPH) anti‐oxidant activity was also checked for all the compounds and the compound 5 j was found to be good anti‐oxidant among the series with an IC50 of 34.5 μM.
Tetranuclear Copper(II) Complexes with Simultaneous Phenoxo and Azido Bridges ‐ Synthesis, Structural and Magnetic Studies
Authors: Pandey Priyanka , Dwivedi Nidhi , Cosquer Goulven , Yamashita Masahiro , Sunkari Sailaja 
Published: October 2018

AbstractTetradentate Schiff base ligands with multiple coordinaton sites are one of the best choice for the construction of multinuclear metal complexes. Coupled with auxiliary ligands under self assembling conditions, the scope for generating new structures increases manifold due to various structure directing factors in operation. Though, phenoxo or azido bridged copper(II) systems have been investigated thoroughly from structural and magnetic aspects, the literature is scanty with combined phenoxo and azido bridged systems. In a study on the effect of synthetic conditions on the structures generated and associated magnetic properties, two new tetranuclear copper complexes, viz., [Cu4(L1)2(μ‐N3)2(N3)2] (1) and [Cu4(L2)2(μ‐N3)2(N3)2] (2) where L1=N,N′‐Bis(salicylidene)diaminopropane (salpn) and L2=N,N′‐Bis(salicylidene)diaminobenzene (salophen) with both phenoxo and azido bridges are reported. The tetranuclear cluster is made of two inversion related dimers built of phenoxo bridged Cu1 and Cu2 with distorted square planar and square pyramidal geometries respectively. These dimers are bridged by symmetrically bridging azides leading to a tetranuclear core. The contrasting magnetic behavior inspite of same coordination environments, antiferromagnetic in 1 (J1=−2.17 cm−1; J2=−28.15 cm−1) and ferromagnetic in 2 (J1=−74.7 cm−1; J2=146.5 cm−1), is understood in terms of lower bridge angles and closer separation between copper centers in 2 than in 1.
Iron‐Dicyano Dichloro Quinone Primary Battery
Authors: Ramavath Janraj Naik , Ramachandra Chinmaya , Ramanujam Kothandaraman 
Published: October 2018

AbstractA Iron/2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone (Fe‐DDQ) primary battery operating in neat methanesulfonic acid (MSA) is explored. As it involves abundant Fe and renewable materials such as DDQ and MSA, it is expected to be cost effective powering system for single use applications. Stainless steel (SS‐304) is used as Fe source (anode) and DDQ in MSA used as cathode. Oxidation characteristics of SS‐304 in neat MSA, 14 M and 12 M MSA were explored. As reactivity of SS with MSA is controllable without any rapid H2 evolution while comparing with that of Fe granules, making/demonstration of SS‐DDQ based battery system is possible. Moreover, neat MSA does not allow formation of passive layer on SS, thereby allowing continuous operation of battery. As a proof of concept, we have demonstrated a two‐cell stack powering a light emitting diode (LED).
Molecular Characteristics of Shenfu Coal Characterized by Mass Spectrometers with Three Ion Sources
Authors: Fan Xing , Yu Guo , Zhao Yun‐Peng , Wang Rui‐Yu , Wei Xian‐Yong , Ma Feng‐Yun , Liu Jing‐Mei , Zhang Xiao‐Yun , Zhao Wei 
Published: October 2018

AbstractA coal sample was extracted at 300 oC sequentially with cyclohexane, acetone and methanol to obtain three filtrates. Mass spectrometers coupled with various commercial ion sources such as electron ionization (EI), electrospray ionization (ESI) or atmospheric pressure photoionization (APPI) were used to acquire a full view of molecular information for the coal and build up the analytical strategy for aromatics. Phenols, furans and ketones were the most abundant products in the filtrates of cyclohexane, acetone and methanol, respectively, which were obtained by mass spectrometer with EI source. ESI well ionized compounds with high polarity and high molecular weight (900 Da), but not for aromatics with ring number over 2. APPI enhanced the ionization efficiency for compounds with both high molecular weight and high aromatic ring size, which is the best one for the analysis of aromatics.
Lipase from Porcine Pancreas: An Efficient Biocatalyst for the Synthesis of ortho‐Aminocarbonitriles
Authors: Dalal Kiran S. , Padvi Swapnil A. , Wagh Yogesh B. , Dalal Dipak S. , Chaudhari Bhushan L. 
Published: October 2018

AbstractEnzymatic processes are highly specific, green, operate at mild conditions and reduce environmental pollution in comparison to conventional hazardous chemical processes. Herein, we describe a new strategy for the synthesis of ortho‐aminocarbonitriles by a multicomponent reaction of aromatic aldehydes, cyclohexanone and two equivalents of malononitrile at 40 °C. A new six‐membered ring was constructed by breaking seven bonds while four new bonds were formed. The solvent, lipase quantity and reaction conditions were optimized. The advantages of this biocatalyst mediated synthesis of ortho‐aminocarbonitriles comprised a one‐pot procedure with simple operations and higher yields, which were reported for the first time by biocatalysis.
Diffusion‐Ordered NMR Spectroscopy of Guest Molecules in DNA Hydrogels and Related Matrices
Authors: Nöll Tanja , Wenderhold‐Reeb Sabine , Bourdeaux Florian , Paululat Thomas , Nöll Gilbert 
Published: October 2018

AbstractDiffusion‐ordered NMR spectroscopy was used to monitor the diffusion of guest molecules in DNA hydrogels and related DNA matrices. As guest molecule the highly symmetric hollow‐spherical flavoprotein dodecin was studied. Thermoresponsive hydrogels were formed by self‐assembly via hybridization of linear double‐stranded DNA building blocks of 30 base pairs equipped with sticky ends, i. e. additional overhangs of 15 bases on both ends, which were complementary to each other. This resulted in hydrogels, in which dodecin was freely diffusing. When in contrast self‐assembly was performed with rather short building blocks (9 base pairs + sticky ends of 6 bases), the diffusion of the guest molecule was hampered, but as hybridization was reversible within the timescale of the experiment, the resulting DNA matrix did not behave as a true gel. Apparently true DNA hydrogels with small mesh size can be obtained only, when self‐assembly of short DNA building blocks via hybridization is combined with enzymatic ligation leading to a covalently linked network. In that case, the minimum achievable mesh size should be limited by the diameter of the ligase. While DNA hydrogels are an ideal matrix to host rather large molecules or even living cells, it is a challenge to design pristine DNA hydrogels with mesh sizes sufficiently small to capture guest molecules such as drugs or enzymes in the size of only a few nm.
Acidochromic Turn‐on 2,4‐Diarylpyrano[2, 3‐b]indole Luminophores with Solubilizing Groups for A Broad Range of Polarity
Authors: Wilcke Tobias , Glißmann Tobias , Lerch Arne , Karg Matthias , Müller Thomas J. J. 
Published: October 2018

AbstractAcidochromic turn‐on 2,4‐diarylpyrano[2, 3‐b]indole luminophores with different solubilizing groups are readily synthesized in a two‐step process, consisting of a Pd−Cu‐catalyzed domino insertion‐coupling‐cycloisomerization reaction of alkynoyl ortho‐iodo anilides and terminal arylacetylenes furnishing the chromophore, and a desilylation‐alkylation sequence of the 2‐TMS‐ethylthio functionality for introducing solubilizing moieties, i. e. polar and aliphatic swallowtails as well as propylsulfonate potassium. These title compounds are able to cover a broad spectrum of solubility in nonpolar to polar and even aqueous solvent systems. Indeed, the turn‐on fluorescence can be shown to proceed without precipitation in aqueous solvent systems. In addition, a selected pyrano[2, 3‐b]indole forms clusters of 127 nm diameter at high water concentrations as determined by dynamic light scattering.