bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structure–Property Relationships of Random Aromatic Copolyamide Membranes by the Partial N‐Methylation of Amide Linkages
Authors: Aiba Motohiro , Ito Kenji , Tokuyama Takahiro , Tomioka Hiroki , Higashihara Tomoya , Ueda Mitsuru , Matsumoto Hidetoshi 
Published: January 2018

AbstractThe internal and surface structures and transport properties of partially N‐methylated aromatic random copolyamides are reported. The results from positron annihilation lifetime spectroscopy demonstrate that the N‐methylation of the amide linkages in the polymer backbone increases the size of the free volume in the membrane. The time‐resolved water contact angle measurements also indicate that the N‐methylation of the amide linkages increases the chain mobility at the membrane surfaces and consequently enhances the water‐induced surface reorganization. The partial N‐methylation of aromatic copolyamides can be used to control the internal and surface structures of the membranes. In particular, the size of the free volume can be tuned by suppressing the hydrogen bonding between the polymer chains, improving the transport properties through the membranes.
Electrospun Antimicrobial PVDF‐DTAB Nanofibrous Membrane for Air Filtration: Effect of DTAB on Structure, Morphology, Adhesion, and Antibacterial Properties
Authors: Capkova Pavla , Kormunda Martin , Kolska Zdenka , Trögl Josef , Munzarova Marcela , Rysanek Petr 
Published: January 2018

AbstractAntimicrobial polyvinylidene fluoride (PVDF) membrane modified by dodecyltrimethyl ammonium bromide (DTAB) has been electrospun using simple one‐step technology, where the modifying agent DTAB is dissolved in spinning solution. X‐ray photoelectron spectroscopy and electrokinetic analysis confirm reliably the presence of DTAB on the nanofibers surfaces; electrokinetic analysis shows the changes of zeta potential due to modification by DTAB. X‐ray diffraction shows that electrospinning converts the part of α phase (≈40%) present in PVDF powder into β phase with all trans (TTT) zigzag chains conformation in PVDF electrospun membrane. Surface modification does not affect the phase composition of PVDF nanofibers, just only leads to lower crystallinity (smaller size of crystallites) in PVDF nanofibers. DTAB causes the curling of fibers and their aggregation, what completely changed the membrane structure. DTAB‐modified membrane exhibits antibacterial properties against Staphylococcus aureus subsp. Aureus. Concentration of 0.5 wt% DTAB in spinning solution causes partial inhibition of bacterial growth only, while 1.0 wt% concentration leads to complete inhibition.
Rapid, Regioselective Living Ring‐Opening Metathesis Polymerization of Bio‐Derivable Asymmetric Tricyclic Oxanorbornenes
Authors: Naguib Mohamed , Schiller Tara L. , Keddie Daniel J. 
Published: January 2018

AbstractThe synthesis of a range of alkyl esters (methyl, n‐butyl, and n‐decyl) prepared via Steglich esterification of the thermodynamically controlled exo, exo Diels–Alder adduct of furfuryl alcohol and maleic anhydride is reported. Subsequent ring‐opening metathesis polymerization of these bio‐derivable tricyclic oxanorbornene analogs delivers polymers with targeted molar mass and low molar mass dispersity. The polymerizations are rapid with complete monomer conversion achieved within 15 min. Significantly, the presence of the cyclic lactone at the bridgehead of these monomers leads to polymers with high regioregularity (>85% head‐to‐tail) and high stereoregularity (>75% trans). The resultant polymers display both high thermal stability and high glass transition temperatures. This new class of oxanorbornene monomer, accessed from bio‐derivable furfuryl alcohol and maleic anhydride, may be further tailored to incorporate a range of functional moieties. Furthermore, the exceptional properties of the derived polymers indicate potential in a range of applications.
Fluid Flow and Distributive Mixing Analysis in the Cavity Transfer Mixer
Authors: Grosso Giovanna , Hulsen Martien A. , Overend Andrew , Anderson Patrick D. 
Published: January 2018

AbstractIn the polymer industry good mixing is essential to guarantee the characteristics of finished products. However, optimizing mixing devices is often difficult because mixing mechanisms are the result of the complex interaction between the moving elements and the non‐Newtonian fluids used. Full 3D simulations are computationally expensive and the complexity of the problem is often split into approximated subproblems. The present work focuses on a simplified 2D model of the Cavity Transfer Mixer, investigating stretching and folding mixing actions. Several geometrical and functioning parameters, such as cavity speed, cavity shape, intercavity distance, rotor–stator clearance, and fluid rheology are varied. Mixing is analyzed in terms of Poincaré maps and by simulating the evolution of fluid blobs. The intercavity distance is found to play a major role, enabling and governing the stretching actions inside the mixing device.
The effects of low levels of trivalent ions on a standard strain of Escherichia coli (ATCC 11775) in aqueous solutions
Authors: Deng Can , Li Xinpeng , Xue Xinkai , Pashley Richard M. 
Published: January 2018

AbstractConsidering the ever‐growing usage of trivalent salts in water treatment, for example, lanthanum salts in rare earth, AlCl3 and FeCl3, the effects of different trivalent cations on the bacterium Escherichia coli (E. coli) ATCC 11775 strain have been studied in aqueous solutions. From colony incubation studies, the colony‐forming unit (CFU) densities were found to decrease significantly in the presence of even low levels (10−5 mol/L) of lanthanum chloride. This level of reduction in CFU number is comparable to the results obtained using the known bacteriocidal cationic surfactant, C14TAB. By comparison, exposure of the cells to low levels of trivalent ion, aluminum and chromium ion solutions produced only modest reductions in CFU density. The results from the incubation studies suggest that the bacteriostatic mechanism of La3+ ions has similarities to that of the cationic surfactant, and different to that of the other trivalent ions. Size distribution and zeta potential measurements of E. coli cells and phospholipid vesicles in the presence of trivalent cations solutions suggested significant cell shrinkage probably caused by membrane disruption.
Tuning Bis(imino)pyridyl Iron‐Catalyzed Ethylene Oligomerization by Modification of MAO with p‐BrPhOH
Authors: Zhang Wei , Ye Jian , Jiang Binbo , Wang Jingdai , Liao Zuwei , Huang Zhengliang , Yang Yongrong , Ye Zhibin 
Published: January 2018

AbstractTo reduce the simultaneous production of insoluble polymers during the bis(imino)pyridyl iron‐catalyzed ethylene oligomerization, in this study, p‐BrPhOH (4‐bromophenol) has been chosen as the most optimal modifier for the production of linear α‐olefins. It is found that the polymer share in the total products is largely reduced with the use of p‐BrPhOH as the modifier. The catalytic system also possesses a high activity with the liquid production maintained high level of linearity. Moreover, the introduction of p‐BrPhOH promoted the high‐temperature stability of the catalytic system, leading to the enhanced oligomerization activity as the catalytic system can catalyze ethylene oligomerization at higher temperatures. A characterization of the catalytic system with electron paramagnetic resonance shows that introduction of p‐BrPhOH significantly inhibits the formation of ferric ions, which can be the main active centers responsible for generating undesired insoluble polymers, thus this can largely retard the production of insoluble polymers during ethylene oligomerization.
Improved liver mapping by pixel‐wise curve fitting with adaptive neighborhood regularization
Authors: Wang Changqing , Zhang Xinyuan , Liu Xiaoyun , He Taigang , Chen Wufan , Feng Qianjin , Feng Yanqiu 
Published: January 2018

PurposeTo improve liver
mapping by incorporating adaptive neighborhood regularization into pixel‐wise curve fitting.MethodsMagnetic resonance imaging
mapping remains challenging because of the serial images with low signal‐to‐noise ratio. In this study, we proposed to exploit the neighboring pixels as regularization terms and adaptively determine the regularization parameters according to the interpixel signal similarity. The proposed algorithm, called the pixel‐wise curve fitting with adaptive neighborhood regularization (PCANR), was compared with the conventional nonlinear least squares (NLS) and nonlocal means filter‐based NLS algorithms on simulated, phantom, and in vivo data.ResultsVisually, the PCANR algorithm generates
maps with significantly reduced noise and well‐preserved tiny structures. Quantitatively, the PCANR algorithm produces
maps with lower root mean square errors at varying
values and signal‐to‐noise‐ratio levels compared with the NLS and nonlocal means filter‐based NLS algorithms. For the high
values under low signal‐to‐noise‐ratio levels, the PCANR algorithm outperforms the NLS and nonlocal means filter‐based NLS algorithms in the accuracy and precision, in terms of mean and standard deviation of
measurements in selected region of interests, respectively.ConclusionsThe PCANR algorithm can reduce the effect of noise on liver
mapping, and the improved measurement precision will benefit the assessment of hepatic iron in clinical practice. Magn Reson Med 80:792–801, 2018. © 2018 International Society for Magnetic Resonance in Medicine.
Interleaved susceptibility‐weighted and FLAIR MRI for imaging lesion‐penetrating veins in multiple sclerosis
Authors: Gabr Refaat E. , Pednekar Amol S. , Kamali Arash , Lincoln John A. , Nelson Flavia M. , Wolinsky Jerry S. , Narayana Ponnada A. 
Published: January 2018

PurposeTo simultaneously image brain lesions and veins in multiple sclerosis.MethodsAn interleaved sequence was developed to simultaneously acquire 3‐dimensional
‐weighted (or susceptibility‐weighted (SW)) and fluid‐attenuated inversion recovery (FLAIR) images on a 3T MRI system. The pulse sequence parameters were calculated to minimize signal perturbation from steady state while maintaining acceptable image contrast and scan time. Fifteen multiple sclerosis patients were enrolled in this prospective study and underwent a standard multiple sclerosis imaging protocol. In addition, SW and FLAIR images were acquired separately and also in an interleaved manner. The SW and FLAIR images were combined into one image to visualize lesions and penetrating veins. The contrast ratios between white matter lesions and penetrating veins were compared between the interleaved sequence and the individual noninterleaved acquisitions.ResultsInterleaved scanning of the FLAIR and the SW pulse sequences was achieved, producing aligned images, and with similar image contrast as in the noninterleaved images. A total of 1076 lesions were identified in all patients on the combined SW‐FLAIR image, of which 968 lesions (90%) had visible penetrating veins. Lesion‐to‐vein contrast ratio was 32.7 ± 17.9 (mean ± standard deviation) for the interleaved sequence compared with 28.1 ± 13.7 using the separate acquisitions (P < 0.001).ConclusionThe feasibility of interleaved acquisition of SW and FLAIR images was demonstrated. This sequence provides self‐registered images and facilitates the visualization of veins in brain lesions. Magn Reson Med 80:1132–1137, 2018. © 2018 International Society for Magnetic Resonance in Medicine.
Characterization of mouse neuro‐urological dynamics in a novel decerebrate arterially perfused mouse (DAPM) preparation
Authors: Ito Hiroki , Drake Marcus J. , Fry Christopher H. , Kanai Anthony J. , Pickering Anthony E. 
Published: January 2018

AimTo develop the decerebrate arterially perfused mouse (DAPM) preparation, a novel voiding model of the lower urinary tract (LUT) that enables in vitro‐like access with in vivo‐like neural connectivity.MethodsAdult male mice were decerebrated and arterially perfused with a carbogenated, Ringer's solution to establish the DAPM. To allow distinction between central and peripheral actions of interventions, experiments were conducted in both the DAPM and in a “pithed” DAPM which has no brainstem or spinal cord control.ResultsFunctional micturition cycles were observed in response to bladder filling. During each void, the bladder showed strong contractions and the external urethral sphincter (EUS) showed bursting activity. Both the frequency and amplitude of non‐voiding contractions (NVCs) in DAPM and putative micromotions (pMM) in pithed DAPM increased with bladder filling. Vasopressin (>400 pM) caused dyssynergy of the LUT resulting in retention in DAPM as it increased tonic EUS activity and basal bladder pressure in a dose‐dependent manner (basal pressure increase also noted in pithed DAPM). Both neuromuscular blockade (vecuronium) and autonomic ganglion blockade (hexamethonium), initially caused incomplete voiding, and both drugs eventually stopped voiding in DAPM. Intravesical acetic acid (0.2%) decreased the micturition interval. Recordings from the pelvic nerve in the pithed DAPM showed bladder distention‐induced activity in the non‐noxious range which was associated with pMM.ConclusionsThis study demonstrates the utility of the DAPM which allows a detailed characterization of LUT function in mice.
Enrollment in early‐phase clinical trials in pediatric oncology: The experience at Institut Curie
Authors: Surun Aurore , Dujaric Marie‐Églantine , Aerts Isabelle , Orbach Daniel , Jiménez Irène , Pacquement Hélène , Schleiermacher Gudrun , Bourdeaut Franck , Michon Jean , Dupont Jean‐Claude K. , Doz François 
Published: January 2018

AbstractBackgroundThe European Paediatric Regulation was introduced in 2007 to facilitate access to new medicines for children. Our study explored accessibility of early‐phase trials in pediatric oncology, in line with the European Paediatric Regulation, to identify the reasons for not inviting patients to participate, parents’ refusal, or inclusion failure.ProcedureWe conducted a retrospective chart review at Institut Curie, Paris, for all pediatric patients whose cancer progressed despite known effective treatments between July 2010 and December 2013.ResultsOut of 100 patients in the palliative phase, 52 received one or more invitations to participate in early‐phase trials. Twenty parents declined the invitation, mainly prioritizing quality of life or fearing constraints. Fourteen inclusions failed despite parental approval, mostly due to rapid clinical deterioration. Five patients received no invitations because no early‐phase trials were available. Major reasons for noninclusion in the 43 remaining patients were presence of exclusion criteria or other physical factors, preference for conventional treatment, constraints, psychological factors, and follow‐up in another hospital after moving.ConclusionsThe Paediatric Regulation has led to increased availability of early‐phase trials. Better timing of the proposal, designing less constraining early‐phase trials, reducing waiting lists, and improving information for parents and children would facilitate pediatric access to new medicines.
Improved efficiencies of hybrid organic light‐emitting diodes using efficient electron injection layer
Authors: Jayabharathi Jayaraman , Nethaji Pavadai , Thanikachalam Venugopal , Jeeva Palanivel , Ramya Ramaiyan 
Published: January 2018

AbstractHybrid organic‐inorganic light‐emitting diodes were developed with pristine ZnO (2.0 wt%) and Cu‐doped ZnO (2.0 wt%) as electron injection layer and iridium(III)‐bis‐2‐(4‐fluorophenyl)‐1‐(naphthalen‐1‐yl)‐1H‐phenanthro[9,10‐d]imidazole (acetylacetonate) [Ir(fpnpi)2 (acac)] as green emissive layer (521 nm). The pristine ZnO and Cu‐doped ZnO are deposited at indium tin oxide cathode and emissive layer interface. The electroluminescent performances increased by electron injection layer–Cu‐doped ZnO compared with ZnO‐based device because Cu‐doped ZnO injects electron efficiently result in balanced h+ − e− recombination in emissive layer than ZnO‐based device. The Cu‐doped ZnO (2.0 %) device shows luminance (L) of 10 982 cd/m2 at 23.0 V (ZnO, 1450 cd/m2 at 23.0 V).
Factors affecting the dimerization of persistent nitrogen‐centered 1‐phenyl urazole radicals to tetrazanes
Authors: Breton Gary W. 
Published: January 2018

Abstract1‐Phenyl urazole radicals are persistent air‐stable nitrogen‐centered radicals that engage in an equilibrium with the corresponding N―N tetrazane dimers in solution. While the equilibrium typically weakly favors the dimer form, for some 1‐phenyl urazole radicals bearing substituents at the ortho position of the benzene ring, the equilibrium instead strongly favors the dimer form. With the recent surge of interest in the properties and potential applications of heterocyclic radicals, the factors that affect this equilibrium are important to determine. We examined the effect of the extent of ortho substitution (none, 1, or 2 substituents) on the equilibrium by experimentally using variable temperature 1H nuclear magnetic resonance and UV‐visible spectroscopy in addition to supporting computational investigations at the (U)B3LYP/6‐311G(d,p) level of theory. We confirmed that the equilibrium generally favored the dimer in all cases. However, the equilibrium was more favorable towards dimer formation for urazole radicals substituted with 1 and 2 ortho substituents on the aromatic ring. The activation enthalpies for dissociation of singly substituted dimers were greater than that for dimers without ortho substituents, but lower than that for doubly substituted dimers. The greater preference for dimer formation for the ortho‐substituted urazole radicals is attributed to a greater enthalpic advantage for N―N bond formation. This advantage may be traced to a higher concentration of spin density on the urazole unit of the radicals and a lesser deformation energy required for N―N bond formation.
Insert Zn Nanoparticles into the 3D Porous Carbon Ultrathin Films as a Superior Anode Material for Lithium Ion Battery
Authors: Wu Xuan , Xing Zheng , Zhao Yulong , Qi Xiujun , Wang Hong , Zhao Wei , Cui Yongli , Ju Zhicheng 
Published: January 2018

AbstractA flexible strategy is exploited to insert Zn nanoparticles into the pores of highly stable 3D network of carbon ultrathin films (P‐Zn/C) that can effectively localize the postformed Zn nanoparticles, thereby solving the problem of structural degradation, and thus achieve improved anode performance. A maximum capacity of 657.3 mA h g−1 at a current density of 200 mA g−1 after 50 cycles is achieved for P‐Zn/C. Even at a high current density of 2 A g−1, a capacity of 653 mA h g−1 is maintained after 1000 cycles, indicating that it could be a promising anode for lithium ion batteries. By comparing the capacitive and diffusion contribution qualitatively and quantitatively, the result reveals that the enhanced electrochemical performance mainly originates from the pseudocapacitance storage mechanism.
An impulsive‐switched‐system approach to aperiodic sampled‐data systems with time‐delay control
Authors: Ma Weiwei , Jia Xinchun , Yang Fuwen , Zhang Dawei 
Published: January 2018

SummaryThis paper devotes to the stability of aperiodic sampled‐data systems with time‐delay control, where the delays can impose a positive effect on the stability of the systems. The systems are modeled as impulsive switched systems with fixed switching laws. A novel separation theorem is presented to determine the Schur property of a matrix product and then used to obtain a less conservative stability criterion for the impulsive switched systems with fixed switching laws. By the separation theorem and a loop‐functional approach, some new stability and stabilization criteria for aperiodic sampled‐data systems with time‐delay control are provided in terms of linear matrix inequalities. Finally, the stability and stabilization results are tested on some classical numerical examples to illustrate the efficiency of the proposed method.
Efficient routing redundancy design over lossy networks
Authors: Smarra Francesco , Di Benedetto Maria Domenica , D'Innocenzo Alessandro 
Published: January 2018

SummaryIn this paper, a wireless networked control system is made robust with respect to packet losses by exploiting routing redundancy. Multiple copies of sensing and actuation data are sent via different routing paths, associated to possibly different delays. Similar to linear network coding, such data are recombined as a weighted linear combination. A MIMO output‐feedback architecture is considered. A methodology that takes into account both the network parameters and the plant dynamics is proposed to set up an optimization problem to design network weights to satisfy a robustness metric based on the notion of asymptotic mean‐square stability. Such metric induces either an objective or a constraint function that is nonlinear. For this reason, an efficient suboptimal design methodology is also proposed. Finally, the solutions are compared with the optimal choice from the communication designer point of view, which is based on the minimization of the quadratic error induced by the network on the actuation signal. The suboptimal methodology is shown, by means of a nontrivial example, to give results extremely close to the optimum with a strongly reduced computation time. It is also shown that the optimal choice from the communication design point of view, which neglects the plant dynamics, does not guarantee stochastic stability.
Necessary and sufficient conditions for distributed constrained optimal consensus under bounded input
Authors: Qiu Zhirong , Liu Shuai , Xie Lihua 
Published: January 2018

SummaryIn this paper, we study a distributed constrained optimal consensus problem for discrete‐time first‐order integrator systems under bounded input. Each agent is assigned with a local convex cost function, and all agents are required to achieve consensus at the minimum of the aggregate cost over a common convex constraint set, which is only accessible by part of the agents. A 2‐step control protocol is designed to solve the problem under bounded input. Firstly, at each time step, each agent moves a bounded step of the subgradient descent from an individual cost and another one along the projection direction if it can access the constraint. The second movement is then given by a bounded average of the relative positions to neighbors. Specifically, to coordinate the subgradient step within the network without using global information, we introduce an estimate of the upper bound of all agents' subgradients, which is updated by a unilateral consensus mechanism. Under the given control protocol, we obtain the necessary and sufficient conditions to achieve the constrained optimal consensus for a fixed topology. Under similar conditions, we also solve the problem for switching topologies and conduct a convergence rate analysis for strongly convex costs.