bluuebunny/crossref_metadata_2025_split huggingface dataset:
Surface‐Selective Grafting of Crosslinking Layers on Hydrogel Surfaces via Two Different Mechanisms of Photopolymerization for Site‐Controllable Release
Authors: Zhang Jiaojiao , Nie Jun , Zhu Xiaoqun 
Published: May 2018

AbstractThis study reports an effective method for controlling substance‐release sites of hydrogel. Glycidyl methacrylate, which contains two functional groups, namely, double‐bond acrylate and epoxide, is photografted on a hydrogel surface through hydrogen abstraction photopolymerization due to the existence of a hydrogen donor, such as an amine, in the hydrogel matrix. The remaining epoxide group crosslinks the polymer chain of polyglycidyl methacrylate. Substance release of hydrogel is changed due to the altered surface texture of hydrogel. Rate and site‐controlled substance release are achieved by controlling the thickness and site of surface grafting and the extent of epoxide ring opening. This study may provide a novel method for achieving hydrogel function or modified performance of other biomaterials to meet biological activity requirements.
Exploiting the Versatility of Polydopamine‐Coated Nanoparticles to Deliver Nitric Oxide and Combat Bacterial Biofilm
Authors: Adnan Nik Nik. M. , Sadrearhami Zahra , Bagheri Ali , Nguyen Thuy‐Khanh , Wong Edgar H. H. , Ho Kitty K. K. , Lim May , Kumar Naresh , Boyer Cyrille 
Published: May 2018

AbstractIn this study, an antimicrobial platform in the form of nitric oxide (NO) gas‐releasing polydopamine (PDA)‐coated iron oxide nanoparticles (IONPs) is developed for combating bacterial biofilms. NO is bound to the PDA‐coated IONPs via the reaction between NO and the secondary amine moieties on PDA to form N‐diazeniumdiolate (NONOate) functionality. To impart colloidal stability to the nanoparticles in aqueous solutions (e.g., phosphate buffered saline (PBS) and bacteria cell culture media M9), a polymer bearing hydrophilic and amine pendant groups, P(OEGMA)‐b‐P(ABA), is synthesized via reversible addition‐fragmentation chain transfer (RAFT) polymerization and is subsequently grafted onto the PDA‐coated IONPs by employing the Schiff base/Michael addition reaction between o‐quinone and a primary amine. These nanoparticles are able to effectively disperse Pseudomonas aeruginosa biofilms (up to 79% dispersal) at submicromolar NO concentrations. In addition, the nanoparticles demonstrate excellent bactericidal activity toward P. aeruginosa planktonic and biofilm cells (up to 5‐log10 reduction).
Poly(vinyl diaminotriazine): From Molecular Recognition to High‐Strength Hydrogels
Authors: Liu Bo , Liu Wenguang 
Published: May 2018

AbstractPoly(2‐vinyl‐4,6‐diamino‐1,3,5‐triazine), (PVDT) with diaminotriazine residues is found to form not only intramolecular hydrogen bonds, but also three robust, complementary hydrogen bonds with nucleobases such as thymine and uracil. Taking advantage of the three complementary hydrogen bonds, molecular recognition of a nucleic acid base has been investigated in previous work. Over the past few years, the use of PVDT has been extended to the construction of gene delivery vectors and nonswellable, high‐strength hydrogels by copolymerization with a hydrophilic monomer and/or crosslinker. In particular, many fascinating properties, such as excellent mechanical properties, stimuli responsiveness, the shape memory effect, and biodegradability, have emerged in PVDT‐based hydrogels. In this article, the molecular recognition and self‐assembly of diaminotriazine are introduced first, and then a particular focus is placed on the development of PVDT‐based high performance hydrogels, especially their biorelated applications.
Cyclodextrin‐Based Star‐Like Amphiphilic Cationic Polymer as a Potential Pharmaceutical Carrier in Macrophages
Authors: Cheng Hongwei , Fan Xiaoshan , Wu Caisheng , Wang Xiaoyuan , Wang Li‐Juan , Loh Xian Jun , Li Zibiao , Wu Yun‐Long 
Published: May 2018

AbstractEffective delivery of therapeutic genes or small molecular drugs into macrophages is important for cell based immune therapy, but it remains a challenge due to the intracellular reactive oxygen species and endosomal degradation of therapeutics inside immune cells. In this report, the star‐like amphiphilic biocompatible β‐cyclodextrin‐graft‐(poly(ε‐caprolactone)‐block‐poly(2‐(dimethylamino) ethyl methacrylate)x (β‐CD‐g‐(PCL‐b‐PDMAEMA)x) copolymer, consisting of a biocompatible cyclodextrin core, hydrophobic poly(ε‐caprolactone) PCL segments and hydrophilic PDMAEMA blocks with positive charge, is optimized to achieve high efficiency gene transfection with enhanced stability, due to the micelle formation by hydrophobic PCL segments. In comparison with lipofetamine, a currently popular nonviral gene carrier, β‐CD‐g‐(PCL‐b‐PDMAEMA)x copolymer, shows better transfection efficiency of plasmid desoxyribose nucleic acid in RAW264.7 macrophages. More interestingly, this delivery platform by β‐CD‐g‐(PCL‐b‐PDMAEMA)x not only shows low toxicity but also better dexamethasone delivery efficiency, which might indicate its great potential in immunotherapy.
Wurster‐Type Anthanthrene Polyradicaloid Cations
Authors: Desroches Maude , Morin Jean‐François 
Published: May 2018

Abstract4,10‐dibromoanthanthrone, a highly robust building block, is used to synthesize a bis(triarylamine) polymer. The polymer can be oxidized twice to form a polycationic macromolecule showing magnetic properties by electron paramagnetic resonance spectroscopy. In its dicationic state, the presence of isolated radicals is possible because of the interrupted conjugation between the diphenylamine with the anthanthrone core. The high steric hindrance prevents the planarity of the adjacent groups resulting in a polyradical cationic polymer. The oxidized polymer has a strong absorption in the near‐infrared region along with reversible redox stages.
Gut Glucosinolate Metabolism and Isothiocyanate Production
Authors: Narbad Arjan , Rossiter John Trevor 
Published: May 2018

AbstractThe glucosinolate‐myrosinase system in plants has been well studied over the years while relatively little research has been undertaken on the bacterial metabolism of glucosinolates. The products of myrosinase‐based glucosinolate hydrolysis in the human gut are important to health, particularly the isothiocyanates, as they are shown to have anticancer properties as well as other beneficial roles in human health. This review is concerned with the bacterial metabolism of glucosinolates but is not restricted to the human gut. Isothiocyanate production and nitrile formation are discussed together with the mechanisms of the formation of these compounds. Side chain modification of the methylsulfinylalkyl glucosinolates is reviewed and the implications for bioactivity of the resultant products are also discussed.
Design and development of a nonrigid phantom for the quantitative evaluation of DIR‐based mapping of simulated pulmonary ventilation
Authors: Miyakawa Shin , Tachibana Hidenobu , Moriya Shunsuke , Kurosawa Tomoyuki , Nishio Teiji , Sato Masanori 
Published: May 2018

PurposeThe validation of deformable image registration (DIR)‐based pulmonary ventilation mapping is time consuming and prone to inaccuracies and is also affected by deformation parameters. In this study, we developed a nonrigid phantom as a quality assurance (QA) tool that simulates ventilation to evaluate DIR‐based images quantitatively.MethodsThe phantom consists of an acrylic cylinder filled with polyurethane foam designed to simulate pulmonic alveoli. A polyurethane membrane is attached to the inferior end of the phantom to simulate the diaphragm. In addition, tracheobronchial‐tree‐shaped polyurethane tubes are inserted through the foam and converge outside the phantom to simulate the trachea. Solid polyurethane is also used to model arteries, which closely follow the model airways. Two three‐dimensional (3D) CT scans were performed during exhalation and inhalation phases using xenon (Xe) gas as the inhaled contrast agent. The exhalation 3D‐CT image is deformed to an inhalation 3D‐CT image using our in‐house program based on the NiftyReg open‐source package. The target registration error (TRE) between the two images was calculated for 16 landmarks located in the simulated lung volume. The DIR‐based ventilation image was generated using Jacobian determinant (JD) metrics. Subsequently, differences in the Hounsfield unit (HU) values between the two images were measured. The correlation coefficient between the JD and HU differences was calculated. In addition, three 4D‐CT scans are performed to evaluate the reproducibility of the phantom motion and Xe gas distribution.ResultsThe phantom exhibited a variety of displacements for each landmark (range: 1–20 mm). The reproducibility analysis indicated that the location differences were <1 mm for all landmarks, and the HU variation in the Xe gas distribution was close to zero. The mean TRE in the evaluation of spatial accuracy according to the DIR software was 1.47 ± 0.71 mm (maximum: 2.6 mm). The relationship between the JD and HU differences had a large correlation (R = −0.71) for the DIR software.ConclusionThe phantom implemented new features, namely, deformation and simulated ventilation. To assess the accuracy of the DIR‐based mapping of the simulated pulmonary ventilation, the phantom allows for simulation of Xe gas wash‐in and wash‐out. The phantom may be an effective QA tool, because the DIR algorithm can be quickly changed and its accuracy evaluated with a high degree of precision.
Libration of phenyl groups detected by VT‐SSNMR: Comparison with X‐ray crystallography
Authors: Nieto Carla I. , Cabildo Pilar , García M. Ángeles , Claramunt Rosa M. , Elguero José , Alkorta Ibon 
Published: May 2018

AbstractThe X‐ray crystal structure of 2‐benzyl‐1H‐benzimidazole, 2BnBzIm, was determined at 293 K showing no dynamic phenomena (disorder) of any class. On the other hand, some 13C NMR signals were absent in the CPMAS spectrum (100 MHz, 300 K). We decided to carry out variable‐temperature SSNMR and discovered that the missing signals are ortho and meta carbons of the phenyl ring of the benzyl group. Line‐shape analysis and the Eyring equation were used to determine the barrier, which was compared with the calculated DFT for the gas phase that it is much lower.
Estimation of Polymerization Rate Constants Using Experimental Residence Time Studies in Industrial Pilot Plant Equipment
Authors: Karjala Thomas W. , Kolthammer Brian W. S. , Zhang Min , Jain Pradeep 
Published: May 2018

AbstractEstimation of polymerization rate constants is industrially important for reactor design, reactor control, and evaluation of the productivity and product properties of new catalyst systems. Propagation and catalyst deactivation rate constants are particularly important as they control how a given catalyst system will behave in a given reactor. Pilot scale reactors are used to investigate the kinetics of solution ethylene polymerization of several catalyst systems; a heterogeneous Ziegler–Natta (Ti/MgCl2) and two constrained‐geometry molecular catalysts. A model is developed to estimate the propagation and first order catalyst deactivation rate constants through carefully conducted residence time experiments. D‐optimal experimental design criteria is used to determine the appropriate experimental conditions. Analysis shows that the observed propagation rate constant is confounded by catalyst poisons while the catalyst deactivation rate constant is independent of these factors. This helps explain how to obtain significantly larger propagation rate constants than have been previously reported in the literature.
Association between overactive bladder treatment and falls among older adults
Authors: Jayadevappa Ravishankar , Chhatre Sumedha , Newman Diane K. , Schwartz Jerome Sanford , Wein Alan J. 
Published: May 2018

AimsTo analyze the risk of falls associated with Overactive bladder (OAB), and the effects of OAB treatment on falls among older adult Medicare fee‐for‐service enrollees.MethodsPopulation based retrospective longitudinal cohort design study using 5% Medicare claims between 2006 and 2010. Patients with a diagnosis of OAB (ICD 9: 596.51); Urinary Incontinence (ICD 9: 788.3); Urinary incontinence, unspecified (ICD 9: 788.30); Urge incontinence (ICD 9: 788.31); Mixed incontinence (male, female) (ICD 9: 788.33); Urinary frequency (ICD 9: 788.41); Nocturia (ICD 9: 788.43); or Urgency of urination (ICD 9: 788.63) were identified and followed retrospectively for 2 years. Falls was the main outcome of the study. Using logistic regressions, we analyzed the association between OAB and falls; and the protective effect of OAB treatment on falls. Propensity score and instrumental variable were used to minimize bias.ResultsWe identified 33 631 Medicare enrollees (mean age = 77.8 years, sd = 7.6) with OAB. Higher proportion of OAB patients had falls, compared to those without OAB (11% vs 7%, P < 0.001). Diagnosis of OAB was associated with higher odds of falls (OR = 1.59; 95% CI = 1.53, 1.65) compared to those without OAB. Fourteen percent of OAB patients received OAB treatment. Treatment for OAB was associated with lower odds of falls (OR = 0.88; 95% CI = 0.80, 0.98) compared to those OAB patients who were not treated.ConclusionsOlder adults with OAB experience increased risk of falls. Treatment for OAB may reduce this risk. These findings emphasize the need to effectively identify and treat OAB in older adults.
Electronic health record (EHR) based postmarketing surveillance of adverse events associated with pediatric off‐label medication use: A case study of short‐acting beta‐2 agonists and arrhythmias
Authors: Czaja Angela S. , Ross Michelle E. , Liu Weiwei , Fiks Alexander G. , Localio Russell , Wasserman Richard C. , Grundmeier Robert W. , Adams William G. ,   for the Comparative Effectiveness Research through Collaborative Electronic Reporting (CER) Consortium
Published: May 2018

AbstractPurposeUse electronic health record (EHR) data to (1) estimate the risk of arrhythmia associated with inhaled short‐acting beta‐2 agonists (SABA) in pediatric patients and (2) determine whether risk varied by on‐label versus off‐label prescribing.MethodsRetrospective cohort study of 335 041 children ≤18 years using EHR primary care data from 2 pediatric health systems (2011‐2013). A series of monthly pseudotrials were created, using propensity score methodology to balance baseline characteristics between SABA‐exposed (identified by prescription) and SABA‐unexposed children. Association between SABA and subsequent arrhythmia for each health system was estimated through pooled logistic regression with separate estimates for children initiating under and over 4 years old (off‐label and on‐label, respectively).ResultsEleven percent of the cohort received a SABA prescription, 57% occurred under the age of 4 years (off‐label). During the follow‐up period, there were 283 first arrhythmia events, most commonly atrial tachyarrhythmias and premature ventricular/atrial contractions. In 1 health system, adjusted risk for arrhythmia was increased among exposed children (OR 1.89, 95% CI 1.31‐2.73) without evidence of interaction between label status and risk. The absolute adjusted rate difference was 3.6/10 000 person‐years of SABA exposure. The association between SABA exposure and arrhythmias was less strong in the second system (OR 1.26, 95% CI 0.30‐5.33).ConclusionUsing EHR data, we could estimate the risk of a rare event associated with medication use and determine difference in risk related to on‐label versus off‐label status. These findings support the value of EHR‐based data for postmarketing drug studies in the pediatric population.
Organic tandem solar cells: How impedance analyses can improve the quality of external quantum efficiency measurements
Authors: Bahro Daniel , Wilck Manfred , Mertens Adrian , Ebenhoch Bernd , von Hauff Elizabeth , Colsmann Alexander 
Published: May 2018

AbstractTandem architectures are one of the most promising concepts towards superior power conversion efficiencies of organic solar cells. An accurate determination of the power conversion efficiency requires correction of the spectral mismatch and thus relies on accurate external quantum efficiency (EQE) spectra. Due to the series connection of 2 subcells in the tandem architecture, the EQE of the tandem solar cell reproduces the EQE of one subcell if an appropriate bias light is chosen to selectively illuminate and hence forward bias the other subcell. The resulting internal voltage drop is then compensated by applying an external voltage to the tandem solar cell. In this work, we use impedance spectroscopy to accurately predict the minimum bias light intensity and the external voltage to enable accurate EQE measurements on both subcells. We exemplify this procedure on organic tandem solar cells comprising spectrally complementary absorbers and suggest an extended protocol for future measurements of the EQE.
Passivating electron‐selective contacts for silicon solar cells based on an a‐Si:H/TiOx stack and a low work function metal
Authors: Cho Jinyoun , Melskens Jimmy , Debucquoy Maarten , Recamán Payo Maria , Jambaldinni Shruti , Bearda Twan , Gordon Ivan , Szlufcik Jozef , Kessels W.M.M. , Poortmans Jef 
Published: May 2018

AbstractIn this work, the ATOM (intrinsic a‐Si:H/TiOx/low work function metal) structure is investigated to realize high‐performance passivating electron‐selective contacts for crystalline silicon solar cells. The absence of a highly doped Si region in this contact structure is meant to reduce the optoelectrical losses. We show that a low contact resistivity (ρc) can be obtained by the combined effect of a low work function metal, such as calcium (Φ 2.9 eV), and Fermi‐level depinning in the metal‐insulator‐semiconductor contact structure (where in our case TiOx acts as the insulator on the intrinsic a‐Si:H passivating layer). TiOx grown by ALD is effective to achieve not only a low ρc but also good passivation properties. As an electron contact in silicon heterojunction solar cells, inserting interfacial TiOx at the i‐a‐Si:H/Ca interface significantly enhances the solar cell conversion efficiency. Consequently, the champion solar cell with the ATOM contact achieves a VOC of 711 mV, FF of 72.9%, JSC of 35.1 mA/cm2, and an efficiency of 18.2%. The achievement of a high VOC and reasonable FF without the need for a highly doped Si layer serves as a valuable proof of concept for future developments on passivating electron‐selective contacts using this structure.
High‐performance low bandgap thin film solar cells for tandem applications
Authors: Elanzeery Hossam , Babbe Finn , Melchiorre Michele , Werner Florian , Siebentritt Susanne 
Published: May 2018

AbstractThin film tandem solar cells provide a promising approach to achieve high efficiencies. These tandem cells require at least a bottom low bandgap and an upper high bandgap solar cell. In this contribution, 2 high‐performance Cu(In,Ga)Se2 cells with bandgaps as low as 1.04 and 1.07 eV are presented. These cells have shown certified efficiencies of 15.7% and 16.6% respectively. Measuring these cells under a 780‐nm longpass filter, corresponding to the bandgap of a typical top cell in tandem applications (1.57 eV), they achieved efficiencies of 7.9% and 8.3%. Admittance measurements showed no recombination active deep defects. One additional high‐performance CuInSe2 thin film solar cell with bandgap of 0.95 eV and efficiency of 14.1% is presented. All 3 cells have the potential to be integrated as bottom low bandgap cells in thin film tandem applications achieving efficiencies around 24% stacked with an efficient high bandgap top cell.
Dynamic and Reversible Accumulation of Plasmonic Core‐Satellite Nanostructures in a Light‐Induced Temperature Gradient for In Situ SERS Detection
Authors: Kang Chia‐Yu , Li Jr‐Jie , Wu Li‐An , Wu Chia‐Cheng , Chen Yih‐Fan 
Published: May 2018

AbstractA surface‐enhanced Raman spectroscopy (SERS) detection method that allows dynamic on‐demand generation of SERS substrates at locations of interest for in situ molecular sensing is demonstrated. Thermal convection and thermophoresis, which are both generated in a laser‐induced temperature gradient, are used to accumulate suspended plasmonic nanostructures to form 3D SERS substrate. Raman signals of melamine, which is used as a model analyte, increase to ≈117‐fold within 2 min of laser irradiation because of the accumulation. In addition, it is demonstrated that the accumulation of the nanostructures is reversible, and that reproducible SERS effects can be obtained during a repeated heating and cooling process. Because of the capability of on‐demand generation of a high density of SERS hot spots at different locations in solution, this particle manipulation and SERS detection method is applicable to monitor temporal and spatial variations of the concentrations of molecules. The complexity of the detection system remains the same when using this method since all the measurements are performed with a conventional Raman system and simple fluid channels. The required temperature gradient is generated by the laser used to excite Raman signals, and no nanofabricated substrates and complicated microfluidic or optical components are needed.
Ionothermal Synthesis of Hollow Aluminophosphate Molecular Sieves
Authors: Feng Jie , Wang Jianfeng , Wang Zheng , Lu Tianliang , Wang Baishun , Xu Jun , Zhan Yuzhong , Han Li 
Published: May 2018

AbstractHollow AlPO4‐5 spheres (E‐AP and B‐AP) are synthesized ionothermally in tri‐substituted imidazolium bromide ionic liquids (ILs), that is, 1‐ethyl‐2,3‐dimethylimidazolium bromide and 1‐butyl‐2,3‐dimethylimidazolium bromide, respectively. Moreover, the morphologies of the hollow AlPO4‐5 particles vary with the type of ILs and the amounts of ILs, phosphoric acid, amine, and hydrofluoric acid. The thicknesses of the shells of the hollow spheres are substantially affected by the length of the alkyl chain on the imidazole ring of the ILs. The shell thicknesses significantly increase from 300–500 nm to 4–5 µm as the alkyl chain length increases, and solid AlPO4‐5 spheres (H‐AP) are generated in 1‐hexyl‐2,3‐dimethylimidazolium bromide IL. Furthermore, the experimental results suggest that the formation of hollow AlPO4‐5 spheres in an IL is consistent with Ostwald ripening theory. In addition, compared with ordinary solid AlPO4‐5 (S‐AP) prepared by hydrothermal methods, the hollow E‐AP particles are small and spherical. Moreover, the Co‐loaded hollow AlPO4‐5 (Co/E‐AP) catalyst exhibits excellent catalytic activities in the selective oxidation of tetralin. The reaction conversions are 73.5 and 5.7% over the Co/E‐AP catalyst and Co‐loaded solid AlPO4‐5 (Co/S‐AP) catalyst, respectively, which means that the hollow structure facilitates the mass transfer of the reactants and products in the catalytic reaction.