Error estimates for some quadrature rules with maximal trigonometric degree of exactness

In this paper, we give error estimates for quadrature rules with maximal trigonometric degree of exactness with respect to an even weight function on ( ? π,π) for integrand analytic in a certain domain of complex plane. Copyright © 2013 John Wiley & Sons, Ltd.     

Model reduction and dynamic iteration for coupled nonlinear systems

The dynamical behavior of coupled systems is determined by different interconnected subsystems that are usually governed by entirely different physical laws and often act in different time and space scales. We discuss the simulation of coupled nonlinear systems using dynamic iteration combined with model order reduction. We also study the convergence of this approach and derive error estimates for approximate solutions. (© 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

A Hot‐Segment‐Based Approach for the Design of Cross‐Amyloid Interaction Surface Mimics as Inhibitors of Amyloid Self‐Assembly

The design of inhibitors of protein–protein interactions mediating amyloid self‐assembly is a major challenge mainly due to the dynamic nature of the involved structures and interfaces. Interactions of amyloidogenic polypeptides with other proteins are important modulators of self‐assembly. Here we present a hot‐segment‐linking approach to design a series of mimics of the IAPP cross‐amyloid interaction surface with Aβ (ISMs) as nanomolar inhibitors of amyloidogenesis and cytotoxicity of Aβ, IAPP, or both polypeptides. The nature of the linker determines ISM structure and inhibitory function including both potency and target selectivity. Importantly, ISMs effectively suppress both self‐ and cross‐seeded IAPP self‐assembly. Our results provide a novel class of highly potent peptide leads for targeting protein aggregation in Alzheimer’s disease, type 2 diabetes, or both diseases and a chemical approach to inhibit amyloid self‐assembly and pathogenic interactions of other proteins as well.     

New β-carotene-xylan complexes: preparation and characterization

Cellulose - The study aimed to propose a new system based on xylan for β-carotene delivery into aqueous environments. The xylan fraction of low molecular weight of...     

The existence of a positive solution for nonlinear fractional differential equations with integral boundary value conditions

In this paper, first, we consider the existence of a positive solution for the nonlinear fractional differential equation boundary value problem where 0≤λ < 1,^CD^α is the Caputo's differential operator of order α, and f:[0,1] × [0,∞)→[0,∞) is a continuous function. Using some cone theoretic techniques, we deduce a general existence theorem for this problem. Then, we consider two following more general problems for arbitrary α, 1≤n < α≤n + 1: Problem 1: where , 0≤λ < k + 1; Problem 2: where 0≤λ≤α and D^α is the Riemann–Liouville fractional derivative of order α. For these problems, we give existence results, which improve recent results in the literature. Copyright © 2016 John Wiley & Sons, Ltd.     

Luminescent N-isopropylacrylamide–surfmer copolymer hydrogels prepared upon electrostatic self-assembly of 1-pyrenesulfonate

The preparation of luminescent hydrogels based on the electrostatic self-assembly of 1-pyrenesulfonate (PyS) anions in a positively charged N-isopropylacrylamide (NiPAAm)/surfmer copolymer gel is described. The hydrogels were prepared from a micellar aqueous solution of 11-acryloyloxyundecyltrimethylammonium bromide and NiPAAm upon ⁶⁰Co-gamma irradiation. For assembly of PyS, the gel was shrunken at 50 °C and re-swollen at 20 °C in an aqueous solution of sodium 1-pyrenesulfonate. Re-swelling was accompanied by electrostatic assembly of PyS anions within the gel. Subsequently, the excess non-bound PyS ions were removed by repeatedly swelling and shrinking the gel in pure water at 20 °C and 50 °C, respectively. Incorporation of PyS ions in the hydrogel was studied using UV/Vis spectroscopy and energy dispersive x-ray (EDX) measurements. The amount of electrostatically adsorbed PyS was found to be proportional to the amount of copolymerized surfmer. EDX studies indicated that 20% of the bromide counterions were replaced for PyS. The PyS counterions could be released again if the functionalized hydrogel was immersed in acidified water. At a pH of 1, an almost complete release of PyS was found after 250 h. The preparation method can be used to introduce a variety of functional properties in thermoresponsive charged copolymer gels.     

Quantitative Structure—Retention Relationships Study of the Retention Data of 5,5-Disubstituted Hydantoins

JPC – Journal of Planar Chromatography – Modern TLC - The behavior of 5,5-disubstituted hydantoin derivatives has been studied using four chromatographic systems, two normal-phase...     

Certification of reference materials for ochratoxin A analysis in coffee and wine

Mycotoxins are important non-anthropogenic food and feed contaminants, which can be present on almost every agricultural commodity. Effective consumer protection therefore essentially depends on food surveillance by reliable quantitative analysis enabled by appropriate quality control. Certified (matrix) reference materials (CRMs) are versatile tools to support quality assurance. However, in the case of ochratoxin A (OTA), a hepato- and nephrotoxic mycotoxin, which is regulated in various foods, there is a lack of suitable CRMs. This lack has now been overcome by the development of two European Reference Materials (ERM^?) for the determination of OTA in roasted coffee (ERM^?-BD475) and red wine (ERM^?-BD476). This article discusses the material preparation process as well as the results of homogeneity and stability testing. Furthermore, the results of the in-house certification studies carried out at BAM Federal Institute for Materials Research and Testing are presented and discussed. Interlaboratory comparison studies involving selected expert laboratories with documented expertise in the field of mycotoxin analysis were conducted to confirm the certified values determined by BAM. The certified ochratoxin A values and their corresponding expanded uncertainties (k?=?2) were assigned in full compliance with the requirements of ISO Guide 35 and are as follows: (6.0?±?0.6)???g?kg^?1 for roasted coffee, ERM^?-BD475, and (0.52?±?0.11)???g?L^?1 for red wine, ERM^?-BD476.