Microgel electrospinning: A novel tool for the fabrication of nanocomposite fibers

We demonstrate for the first time herein that electrospinning of soluble crosslinked polymer particles (microgels) is feasible and that it can be used to obtain micron-sized fibers from these macromolecules. Most notably, the electrospinning approach is found to be successful also in the case of microgels bearing metal nanoclusters, and allows to prepare composite fibers containing a homogeneous dispersion of metal nanoparticles without alterations in the nanoparticle size and size distribution. Given the broad applicability of microgels as exotemplates and stabilisers for inorganic nanoparticles, the proposed preparation method stands out as a novel, general approach for the synthesis of potentially useful composite fibers containing inorganic nanoparticles.     

从结构主义到想象艺术

正家具最早出现在人类生活中时,是作为提高生活效率的"器具"使用的,它具备基础的功能性,外型和整体架构都十分简单。随着人类社会的不断演变,家具的存在早已被附上一层又一层的定义,设计师们的想象力通过家具的外型得以展现;而它的内部结构,成为展示制造工艺的最好平台;它的质感与视觉效果,通过材料的异同展现出不一样的姿态。荷兰设计师Oato所设计的Stuck Chair映射了工     

Cleanability of Surfaces from Active Pharmaceutical Ingredient Surrogate Riboflavin by Falling Film

Falling films in wash down process are of major interest for pharmaceutical isolators, which are used for processing of highly potent pharmaceutical products. In this study multiple process parameters were examined with common materials of isolator systems. The importance of material and surface finish in respect of cleanability and complete wetting as well as a combination of process parameters are presented and discussed. For cleaning validation an effect of high interest was discovered: swab sampling areas changed their properties over many repeated cycles and showed decreased cleanability.     

Patulin in apple-based foods: occurrence and safety evaluation

Patulin is a mycotoxin produced by certain species of Penicillium and Aspergillus, often detectable in mouldy fruits and their derivatives. On the basis of a PMTDI of 0.4 mu g/kg bw, limit values of 50 mu g/kg or 50 mu g/l of patulin have been set in fruit derivatives. To estimate the quantity of patulin that can be taken in with the diet, we analysed by HPL C samples of apples and apple derivatives which are most likely to be contaminated with patulin. In apple juices and in homogenized babyfoods, the mycotoxin concentration was always below the established limits, while in some samples of juice with pulp the mycotoxin content exceeded the safe levels. In rotten apples, not only was the amount of patulin extraordinarily high in the rotten area, but the mycotoxin had also spread to the part unaffected by mould. The data presented in this study indicate that the intake of patulin with apple derivatives is usually below the tolerable level of 0.4 mu g/kg bw/day, but since the patulin content in apples can vary considerably, the quality of fruits used in the production of apple derivatives should be strictly controlled in order not to exceed the safe limits.     

Exploitation of Polyphenolic Extracts from Grape Marc as Natural Antioxidants by Encapsulation in Lipid-Based Nanodelivery Systems

Phenolic compounds were extracted from grape marc by means of high pressure and temperature extraction. In order to increase their dispersability in the aqueous phase, the polyphenolic extracts were encapsulated at a final concentration of 0.1 % (w/w) in nanoemulsion-based delivery systems, which were formulated with natural ingredients, using either a liquid (sunflower oil) or a solid (palm oil) lipid phase, as well as the combination of a hydrophilic and hydrophobic emulsifier, and were produced by high-pressure homogenization. The delivery systems were characterized in terms of physicochemical stability under accelerated ageing (storage at 4 °C, 30 °C, and 55 °C for 14 days), by recording the evolution of the mean droplet size, the creaming index as well as the UV–vis absorption spectra of the encapsulated polyphenols. The antioxidant activity of the encapsulated extracts was measured with two different chemical assays (FRAP and ORAC) and a cellular antioxidant assay. Sunflower oil-based nanoemulsions resulted to be the most physically and chemically stable, with no significant variation of the mean droplet size and no degradation of the encapsulated compounds under the different conditions tested. The FRAP and ORAC assays showed that the antioxidant compounds, when encapsulated, are as available as unencapsulated polyphenols in scavenging the peroxyl radicals (ORAC), but are less available in reducing the ferric tripyridyltriazine complexes (FRAP). Remarkably, the cellular antioxidant activity was significantly higher for the encapsulated grape marc polyphenols than for the unencapsulated ones, suggesting the fundamental role of the nanoemulsions in favoring the delivery through the biological membranes.     

Tape cast porosity-graded piezoelectric ceramics

In this work a functionally graded porous Nb-doped PZT material (PZTN) was produced by tape casting. Each step of the production process (slurry formulation, lamination and thermal treatments) was thoroughly investigated. Tapes with different carbon black (CB) amounts were produced. The conditions necessary to laminate 6 layers of different CB concentration were optimized by tailoring the binder to plasticizer volume ratio of each single green layer. Cracks and delaminations were eliminated by gradually increasing CB content and adjusting the binder burn-out procedure. The optimization process led to a well developed, crack-free porosity-graded multilayer, less than 400 μm thick and with porosity along the thickness ranging from 10 to 30 vol.%. The application of a load during the heating treatments was absolutely required to obtain warpage-free planar multilayer specimens.     

Mycotoxins produced by Fusarium genus in maize: determination by screening and confirmatory methods based on liquid chromatography tandem mass spectrometry

A confirmatory method for fusariotoxin analysis in maize meal, based on liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS), was developed, and compared with a previously published screening method, based on the same technique. By eluting selectively from a Carbograph-4 clean-up cartridge trichothecenes, fumonisins and macrocyclic lactones, and optimizing LC–MS/MS conditions for every chemical class, a sensitive and reliable determination was performed. Method quantification limits for confirmatory and screening methods were in the range 0.001–0.019 mg/kg and 0.003–0.125 mg/kg, respectively.     

Xylitol crystallization from culture media fermented by yeasts

Among sugar substitutes, an important role is played by xylitol, an aliphatic pentitol provided with some interesting properties which make it a high value product for pharmaceutical, odontological and food industries. Its production by biotechnological methods is based on fermentation of agro-industrial residues and could potentially compete with the traditional chemical way. However, crystallization is an important stage of xylitol production, since in many respects it determines the yield and quality of the target product. In the present work tests were made in order to determine the best conditions to clarify fermented media, which were then subjected to isothermal crystallization in the presence or in the absence of residual xylose and varying xylitol concentration as well as cooling temperature (−10 ≤ T_c ≤ 15 °C). Besides, the kinetics of xylitol crystallization from fermented solutions was investigated as function of the initial solution supersaturation and cooling temperature. The effect of the presence of residual xylose on the rate of crystallization was also evaluated. The best clarifying treatment was found to be 20 g l⁻¹ activated charcoal at room temperature for 1 h. The study of xylitol crystallization revealed the positive effect of the presence of residual xylose, which ensured a 1.6-fold increase in the crystallization yield (from 0.27 to 0.42).