bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation and properties of cotton stalk bark fibers using combined steam explosion and laccase treatment
Authors: Hou Xiuliang , Zhang Li , Wizi Jakpa , Liao Xiangru , Ma Bomou , Yang Yiqi 
Published: May 2017

ABSTRACTCotton stalk bark fibers (CSBF) were prepared using combined steam explosion and laccase treatment (explosion–laccase). CSBF have been applied to reinforce thermoplastic composites, but were difficult to be spun into yarns due to their inferior fineness and high stiffness. In order to improve the fineness and flexibility with a green method, explosion–laccase treatment was used to separate bark of cotton stalks. The results indicated that steam explosion at 1.7 MPa for 3 min effectively facilitated laccase penetration into the lignocellulose complex to enhance delignification without negative effects on activity of laccase. Compared with CSBF after explosion, CSBF after explosion–laccase had better fineness (31 dtex), higher aspect ratio (1110), higher tensile strength (2.81 cN/dtex), higher flexibility (321 twist/(m·dtex)), and better thermal stability, which meets the requirement of textile fibers. CSBF had higher water retention (127%) and moisture regain (10.3%) than cotton. Explosion–laccase is an effective and eco‐friendly method of preparing CSBF for textiles. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45058.
Impact of fluidic agitation on human pluripotent stem cells in stirred suspension culture
Authors: Nampe Daniel , Joshi Ronak , Keller Kevin , zur Nieden Nicole I. , Tsutsui Hideaki 
Published: May 2017

ABSTRACTThe success of human pluripotent stem cells (hPSCs) as a source of future cell therapies hinges, in part, on the availability of a robust and scalable culture system that can readily produce a clinically relevant number of cells and their derivatives. Stirred suspension culture has been identified as one such promising platform due to its ease of use, scalability, and widespread use in the pharmaceutical industry (e.g., CHO cell‐based production of therapeutic proteins) among others. However, culture of undifferentiated hPSCs in stirred suspension is a relatively new development within the past several years, and little is known beyond empirically optimized culture parameters. In particular, detailed characterizations of different agitation rates and their influence on the propagation of hPSCs are often not reported in the literature. In the current study, we systematically investigated various agitation rates to characterize their impact on cell yield, viability, and the maintenance of pluripotency. Additionally, we closely examined the distribution of cell aggregates and how the observed culture outcomes are attributed to their size distribution. Overall, our results showed that moderate agitation maximized the propagation of hPSCs to approximately 38‐fold over 7 days by keeping the cell aggregates below the critical size, beyond which the cells are impacted by the diffusion limit, while limiting cell death caused by excessive fluidic forces. Furthermore, we observed that fluidic agitation could regulate not only cell aggregation, but also expression of some key signaling proteins in hPSCs. This indicates a new possibility to guide stem cell fate determination by fluidic agitation in stirred suspension cultures. Biotechnol. Bioeng. 2017;114: 2109–2120. © 2017 Wiley Periodicals, Inc.
Development and validation of a liquid chromatography tandem mass spectrometry method for the measurement of urinary catecholamines in diagnosis of pheochromocytoma
Authors: Shen Ying , Cheng Liming , Guan Qing , Li Huijun , Lu Jie , Wang Xu 
Published: May 2017

AbstractThe measurement of catecholamines in human body fluids is requested frequently for the differential diagnosis and monitoring of pheochromocytoma. The methods in most clinical laboratories focus on high‐performance liquid chromatography coupled with electrochemical detection, which suffers from high background noise, low sensitivity, and poor separation. We reported and developed a robust high‐throughput liquid chromatography tandem mass spectrometry method in routine clinical laboratories for the measurement of urinary catecholamines for diagnosis of pheochromocytoma. The method was validated for consistent linearity, good recovery (88–112%), excellent stability and low carryover. Intra‐ and inter‐assay precision values for catecholamines were all below 3.35 and 4.83% respectively. Dilution linearity was investigated with satisfactory linearly dependent coefficients (r > 0.9988). The reference intervals were obtained from 310 results derived from patients in which the diagnosis of pheochromocytoma was excluded. This method was successfully used in our laboratory. The clinical characteristics of patients have been explored with satisfactory sensitivity and specificity. Therefore, we have developed a reliable assay for the liquid chromatography tandem mass spectrometry measurement of catecholamines in a routine clinical laboratory. The assay requires a small volume of urine, and all analytes are measured simultaneously. The assay is rapid and reliable to be executed, offering the potential for routine clinical laboratories.
PC‐based control and simulation of an electro‐hydraulic system
Authors: Erzan Topçu Elif 
Published: May 2017

AbstractThis article addresses the development of a control system design methodology to make control courses easier to understand. The methodology can be handled in four stages: Modeling, controller design and tuning of the controller gains, simulation, and experimental studies. A PC‐based control system environment is chosen to help students/researchers understand the control system both theoretically and experimentally. An electro‐hydraulic system is used for training. Such fluid power systems are widely used in the industrial area and combine different engineering system properties. First, a system is defined by a mathematical model and simulated using the MATLAB/Simulink environment. An easy to use toolbox, Simscape/Simhydraulics, is used to facilitate the modeling phase in simulation of the hydraulic system. Next, the design of the feedback controller is proposed. Basic controllers in control education, such as proportional + derivative + integral (PID) and a Fuzzy Logic Controller (FLC), are utilized, and the gains of the controllers are tuned with a simplified method according to the given design criteria. The proposed tuning method can also be useful for overdamped or first‐order systems. Time and frequency responses of the system are obtained and evaluated. The experimental studies are conducted on a hydraulic control system at the Automatic Control Laboratory of the Mechanical Engineering Department of Uludağ University. This work aims to train engineering students/researchers both theoretically and practically regarding PC‐based control system design and fluid power systems.
Acute and midterm results following perventricular device closure of muscular ventricular septal defects: A multicenter PICES investigation
Authors: Gray Robert G. , Menon Shaji C. , Johnson Joyce T. , Armstrong Aimee K. , Bingler Michael A. , Breinholt John P. , Kenny Damien , Lozier John , Murphy Joshua J. , Sathanandam Shyam K. , Taggart Nathaniel W. , Trucco Sara M. , Goldstein Bryan H. , Gordon Brent M. 
Published: May 2017

ObjectivesTo describe acute and mid‐term results of hybrid perventricular device closure of muscular ventricular septal defects (mVSDs).BackgroundPerventricular device closure of mVSDs can mitigate technical limitations of percutaneous closure and need for cardiopulmonary bypass or ventriculotomy with a surgical approach.MethodsThis is a multicenter retrospective cohort study of patients undergoing hybrid perventricular mVSD device closure from 1/2004 to 1/2014. Procedural details, adverse events, outcomes, and follow‐up data were collected. Patients were divided into two groups: (1) simple (mVSD closure alone) and (2) complex (mVSD closure with concomitant cardiac surgery).ResultsForty‐seven patients (60% female) underwent perventricular mVSD device closure at a median age of 5.2 months (IQR 1.8–8.9) and weight of 5.1 kg (IQR 4.0–6.9). Procedural success was 91% [100% (n = 22) simple and 84% (n = 21/25) complex]. Adverse events occurred in 19% (9/47) [9% (2/22) simple and 28% (7/25) complex]. Hospital length of stay (LOS) was shorter in the simple vs. complex group (4 vs. 14 days, P < 0.01). At mid‐term follow‐up of 19.2 months (IQR 2.3–43) 90% of pts had complete mVSD closure; none developed late heart block, increased atrioventricular (AV) valve insufficiency or ventricular dysfunction.ConclusionsPerventricular device closure of simple mVSD was associated with a high rate of procedural success, few adverse events, and short hospital LOS. Procedural adverse events were associated with the presence of concomitant complex surgery. Residual mVSD, AV valve insufficiency, or ventricular dysfunction were uncommon at mid‐term follow‐up. © 2017 Wiley Periodicals, Inc.
A High‐Throughput Composite Catalyst based on Nickel Carbon Cubes for the Hydrogenation of 5‐Hydroxymethylfurfural to 2,5‐Dimethylfuran
Authors: Mani Christian Mbaya , Braun Max , Molinari Valerio , Antonietti Markus , Fechler Nina 
Published: May 2017

AbstractA high‐throughput composite catalyst is prepared from porous carbon with an unconventional nanocube morphology decorated with nickel nanoparticles. Owing to the advantageous properties of the designed carbon support, the composite combines a high surface area and a hierarchical pore structure with high functionality. Furthermore, the regularly shaped nanocubes allow for a good packing of a fixed‐bed flow reactor, in which the internal transport pores cannot be blocked and stay open for efficient column performance. The composite is employed as a catalyst in the hydrogenation of 5‐hydroxymethylfurfural (HMF) to 2,5‐dimethylfuran (DMF), showing good catalytic performance and overcoming the conventional problem of column blocking.
A Novel Experimental Setup for Kinetic Studies of Toluene Oxidation in the Homogeneous Liquid Phase
Authors: Gast Sebastian , Matthies Jörn H. , Tuttlies Ute S. , Nieken Ulrich 
Published: May 2017

AbstractAccurate measurements of gas‐liquid reactions are difficult and often impossible to obtain owing to the effects of mass transfer, mixing, and a high risk of explosion in cases when oxygen is involved. In this work, a novel reactor concept is introduced that allows the accurate determination of gas‐liquid reaction kinetics in a homogeneous liquid phase without the influence of mass transport or mixing effects. Both effects can be bypassed, and the risk of explosion minimized, through the instant dissolution of gaseous oxygen by using a strongly elevated pressure. This work presents an experimental proof of concept of this system with the example of the oxidation of toluene.
Co‐reactant Electrogenerated Chemiluminescence of Iridium(III) Complexes Containing an Acetylacetonate Ligand
Authors: Chen Lifen , Doeven Egan H. , Wilson David J. D. , Kerr Emily , Hayne David J. , Hogan Conor F. , Yang Wenrong , Pham Tien T. , Francis Paul S. 
Published: May 2017

AbstractWe examine the electrogenerated chemiluminescence (ECL) of three Ir(
)2(acac) complexes, where acac=acetylacetonate anion and
=2‐phenylpyridine (ppy), 2‐phenylbenzothiazole (bt), or 2‐phenylquinoline (pq) anions, with tri‐n‐propylamine co‐reactant in acetonitrile under a range of chemical and instrumental conditions; this follows somewhat conflicting recent claims of the ECL intensities from complexes of this type. Relevant electrochemical, spectroscopic, and ECL properties are evaluated in direct comparison with those of Ir(ppy)3 and [Ru(bpy)3](PF6)2, as well as data from previous publications. DFT calculations on the Ir(
)2(acac) complexes show the HOMOs to be composed of both the metal and the
ligand, and the LUMOs almost exclusively on the
ligand. The ECL intensities of the Ir(
)2(acac) complexes (relative to [Ru(bpy)3](PF6)2) were dependent on experimental conditions and, in some cases, the ECL intensities reported for iridium complexes may have been derived using conditions that unintentionally disadvantaged the reference electrochemiluminophore.
Tandem Tetrahydroisoquinoline‐4‐carboxylic Acid/β‐Alanine as a New Construct Able To Induce a Flexible Turn
Authors: Bucci Raffaella , Bonetti Andrea , Clerici Francesca , Contini Alessandro , Nava Donatella , Pellegrino Sara , Tessaro Davide , Gelmi Maria Luisa 
Published: May 2017

AbstractTetrahydroisoquinoline‐4‐carboxylic acid, a constrained β2‐amino acid named β‐TIC, was synthesised for the first time in enantiopure form. The biocatalytic route applied herein represents one of the few successful examples of enzymatic resolution of β2‐amino acids. Model tetrapeptides, namely, Fmoc‐l‐Ala‐β‐TIC‐β‐Ala‐l‐Val‐OBn (Fmoc=fluorenylmethyloxycarbonyl, Bn=benzyl), containing both isomers of β‐TIC, were prepared. Both computational and NMR spectroscopy studies were performed. A reverse‐turn conformation was observed in the case of (R)‐β‐TIC enantiomer that was obtained in 99 % enantiomeric excess by enzymatic resolution. The β‐TIC/β‐Ala construct represents the first example of a flexible turn mimetic containing a cyclic and an acyclic β‐amino acid. Furthermore, the presence of an aromatic ring of β‐TIC could facilitate non‐covalent interactions to increase the potential of this scaffold for the preparation of protein–protein interaction modulators.
Solvent Geometry Regulated Cooperative Supramolecular Polymerization
Authors: Kar Haridas , Ghosh Goutam , Ghosh Suhrit 
Published: May 2017

AbstractThis article discloses hydrogen‐bonding driven supramolecular polymerization of a core‐substituted naphthalene‐diimide derivative NDI‐1, which exhibits J‐aggregation in all tested hydrocarbon solvents; however, spontaneous gelation was noticed only in linear alkanes in contrast to free flowing solution in their cyclic analogs. Mechanistic investigation by variable‐temperature UV/Vis studies and analyzing the data by using an appropriate model(s) elucidates a highly cooperative self‐assembly pathway in linear hydrocarbons (heptane, octane, nonane, or decane) in sharp contrast to cyclohexane or methylcyclohexane in which an ill‐defined polymerization was noticed. This is attributed to the direct participation of linear alkanes in the nucleation process by favorable mixing with the peripheral alkyl chains of the NDI monomer, which appears not to be the case for cyclic alkanes owing to geometry mismatch. Although all tested linear hydrocarbons induced nucleation–elongation growth, the thermodynamic parameters were found to depend on the chain length of the alkane. The morphology of the self‐assembled polymer was strongly dependent on the growth mechanism as we noticed fibrillar networks and short‐length rods, respectively, in decane and methylcyclohexane (MCH). However, in the presence of a small amount of additive (preformed fiber in decane; added in situ or post self‐assembly) a fibrillar structure was noticed also in MCH, corroborating the self‐assembly in solution, which adopted a cooperative mechanism similar to linear alkanes.
Photocatalytic CO2 Reduction by Periodic Mesoporous Organosilica (PMO) Containing Two Different Ruthenium Complexes as Photosensitizing and Catalytic Sites
Authors: Kuramochi Yusuke , Sekine Masato , Kitamura Kyohei , Maegawa Yoshifumi , Goto Yasutomo , Shirai Soichi , Inagaki Shinji , Ishida Hitoshi 
Published: May 2017

AbstractA periodic mesoporous organosilica (PMO) containing 2,2′‐bipyridine (bpy) ligands within the framework (BPy‐PMO) has great potential for designing novel catalysts by modifying metal complexes. A photosensitizing site (Ru(PS)) was introduced by treating cis‐[Ru(bpy)2(dimethylsulfoxide)Cl]Cl with BPy‐PMO. Then a catalytic site (Ru(Cat)) was brought in Ru(PS)x‐BPy‐PMO by reaction with a ruthenium polymer [Ru(CO)2Cl2]n. The stepwise modification of BPy‐PMO successfully affords a novel photocatalyst Ru(PS)x‐Ru(Cat)y‐BPy‐PMO. The molar fractions (x, y) of Ru(PS) and Ru(Cat) were determined by energy dispersive X‐ray (EDX) measurement and quantification of the amount of CO emitted in the photo‐decarbonylation of Ru(Cat), respectively. Photochemical CO2 reduction (λex>430 nm) by Ru(PS)x‐Ru(Cat)y‐BPy‐PMO in a CO2‐saturated N,N‐dimethylacetamide/water solution containing 1‐benzyl‐1,4‐dihydronicotinamide catalytically produced CO and formate. The total turnover frequency of CO and formate reached more than 162 h−1 on x=0.11 and y=0.0055. The product selectivity (CO/formate) became large when the ratio of Ru(PS)‐to‐Ru(Cat) (x/y) was increased. The photocatalysts can be recycled at least three times without losing their catalytic activity, demonstrating that the Ru(PS) and Ru(Cat) units were strongly immobilized on the BPy‐PMO framework.
Catalytically Active Silicon Oxide Nanoclusters Stabilized in a Metal–Organic Framework
Authors: Rimoldi Martino , Gallington Leighanne C. , Chapman Karena W. , MacRenaris Keith , Hupp Joseph T. , Farha Omar K. 
Published: May 2017

AbstractPost‐synthetic modification of the zirconium‐based metal–organic framework (MOF) NU‐1000 by atomic layer deposition (ALD), using tetramethoxysilane (Si(OMe)4) as a precursor, led to the incorporation and stabilization of silicon oxide clusters composed of only a few silicon atoms in the framework's pores. The resulting SiOx functionalized material (Si‐NU‐1000) was found to be catalytically active despite the inactivity of related bulk silicon dioxide (SiO2), thus demonstrating the positive effects of having nanosized clusters of SiOx. Moreover, Si‐NU‐1000 showed activity greater than that found for aluminum oxide based catalysts—oxides known for their high acidity—such as an aluminum oxide functionalized MOF (Al‐NU‐1000) and bulk γ‐Al2O3. X‐ray photoelectron spectroscopy and infrared spectroscopy measurements unmasked the electron donating nature of Si‐NU‐1000, explaining the unusual electronic properties of the nanosized SiOx clusters and supporting their high catalytic activity.
Design of functional macromonomer derivatives of poly(isobutylene‐co‐isoprene)
Authors: Rodrigo Antonio C. , Shanmugan Karthik Vikram Siva , Whitney Ralph A. , Parent J. Scott 
Published: May 2017

AbstractThe development of new peroxide‐curable poly(isobutylene‐co‐isoprene) (IIR) elastomers is described, wherein pendant oligomerizable C=C groups are introduced in combination with a range of serviceable functional groups. Ring‐opening of itaconic anhydride with functional alcohols or amines, followed by esterification of the resulting acids with brominated IIR, yield macromonomers that crosslink efficiently under the action of dicumyl peroxide alone. More importantly, the additional graft functionality improves the physical and chemical properties of the resulting thermosets. The introduction of fluorocarbon functionality is shown to lower surface energy and improve the material's extrusion characteristics, and trialkoxysilane functionality is used to improve filler dispersion within silica‐reinforced composites. This strategy is extended to prepare thermosets bearing polymer‐bound phenolic antioxidant. Details of macromonomer production are followed by demonstrations of their utility as engineering materials.
Prognostic impact of diastolic dysfunction in systolic heart failure—A cross‐project analysis from the German Competence Network Heart Failure
Authors: Lüers Claus , Edelmann Frank , Wachter Rolf , Pieske Burkert , Mende Meinhard , Angermann Christiane , Ertl Georg , Düngen Hans‐Dirk , Störk Stefan 
Published: May 2017

BackgroundWe investigated the modifying role and prognostic importance of diastolic dysfunction (DD) in patients with heart failure and systolic dysfunction (SD).HypothesisThe echocardiographic evaluation of diastolic function in patients with SD provides further prognostic information.MethodsFrom the German Competence Network Heart Failure, 1046 heart failure patients with reduced left ventricular ejection fraction (LVEF; <50%) were echocardiographically studied and followed for a median of 5 years. SD was subdivided into nonsevere (LVEF 36%–49%) and severe (LVEF ≤35%); DD was subdivided into nonsevere (E/E′ <15) and severe (E/E′ ≥15).ResultsIn general, severe SD was associated with higher hazard ratios (HRs; 2‐fold to 3.5‐fold) for all endpoints (all‐cause death, cardiac death, cardiovascular hospitalization, duration of hospitalization). Patients with severe SD had a 2.5‐fold risk of death (95% confidence interval [CI]: 1.84‐3.47, P < 0.001), and patients with severe DD showed a 1.8‐fold risk (95% CI: 1.17‐2.61, P = 0.004). Furthermore, we observed a strong interaction of SD and DD: concomitant severe DD in patients with moderate SD increased risk substantially (HR: 1.73, 95% CI: 1.16‐2.6, P = 0.007); by contrast, in patients with severe SD, additional presence of severe DD added little or no risk (HR for interaction: 0.5–1.2).ConclusionsIn heart failure patients with reduced LVEF, the evaluation of diastolic function provides additional prognostic information. Although severe SD generally increased the risk for all endpoints, the degree of DD and its impact as a prognostic marker for overall and cardiovascular mortality appeared of particular relevance in subjects with nonsevere SD.
On the Finite‐Time Blowup of a One‐Dimensional Model for the Three‐Dimensional Axisymmetric Euler Equations
Authors: Choi Kyudong , Hou Thomas Y. , Kiselev Alexander , Luo Guo , Sverak Vladimir , Yao Yao 
Published: May 2017

AbstractIn connection with the recent proposal for possible singularity formation at the boundary for solutions of three‐dimensional axisymmetric incompressible Euler's equations (Luo and Hou, Proc. Natl. Acad. Sci. USA (2014)), we study models for the dynamics at the boundary and show that they exhibit a finite‐time blowup from smooth data. © 2017 Wiley Periodicals, Inc.
Entropy, Chaos, and Weak Horseshoe for Infinite‐Dimensional Random Dynamical Systems
Authors: Huang Wen , Lu Kening 
Published: May 2017

AbstractIn this paper, we study the complicated dynamics of infinite‐dimensional random dynamical systems that include deterministic dynamical systems as their special cases in a Polish space. Without assuming any hyperbolicity, we prove if a continuous random map has a positive topological entropy, then it contains a topological horseshoe. We also show that the positive topological entropy implies the chaos in the sense of Li‐Yorke. The complicated behavior exhibited here is induced by the positive entropy but not the randomness of the system.© 2017 Wiley Periodicals, Inc.