Hydroxyl end-functionalized poly(2-isopropyl oxazoline)s used as nano-sized colloidal templates for preparation of hollow polymeric nanocapsules

Hollow polymeric nanocapsules with a thermosensitive membrane are prepared and characterized. They reversibly change their dimensions during temperature variations below and above the transition of the membrane. The nanocapsules were prepared by three steps: (i) well-defined mesoglobules prepared from an LCST polymer (hydroxyl end functionalized poly(2-isopropyl-2-oxazoline), PiPOZ-OH) were coated with a thermo-sensitive cross-linked shell formed via seeded radical copolymerization of N-isopropylacrylamide (NIPAM) and N,N′-bis-methylene acrylamide to produce core–shell nanoparticles (ii), which were subjected to extensive dialysis below the LCSTs of both the core-forming PiPOZ-OH and shell-forming PNIPAM to remove the core (iii). The use of a core-forming polymer of low molecular weight (<8900 g mol⁻¹), narrow dispersity (<1.15) and relatively low T_g (52–68 °C) is beneficial as far as the effectiveness of the removal of the cores is concerned. The inherent immiscibility between PiPOZ-OH and PNIPAM as well as the specific raspberry-like structure of the core–shell particles also contributed for enhancement of the core removal effectiveness.     

The bending of silicon wafers by thin polycrystalline silicon film deposition and by film doping using boron diffusion

The existence of stress at the interface between a monocrystalline silicon substrate and a thin (under 1 μm) polycrystalline silicon film was demonstrated using X-ray topography. The wafer-bending direction was studied for a polycrystalline film doped by boron prediffusion and by prediffusion followed by drive-in diffusion. Wafer bending in the presence of SiO₂ thermal growth between the monocrystalline substrate and the polycrystalline film was also investigated. The causes of the wafer bending and its change during polycrystalline film doping are discussed.     

Self-organizing maps for texture classification

A further investigation of our intelligent machine vision system for pattern recognition and texture image classification is discussed in this paper. A data set of 335 texture images is to be classified into several classes, based on their texture similarities, while no a priori human vision expert knowledge about the classes is available. Hence, unsupervised learning and self-organizing maps (SOM) neural networks are used for solving the classification problem. Nevertheless, in some of the experiments, a supervised texture analysis method is also considered for comparison purposes. Four major experiments are conducted: in the first one, classifiers are trained using all the extracted features without any statistical preprocessing; in the second simulation, the available features are normalized before being fed to a classifier; in the third experiment, the trained classifiers use linear transformations of the original features, received after preprocessing with principal component analysis; and in the last one, transforms of the features obtained after applying linear discriminant analysis are used. During the simulation, each test is performed 50 times implementing the proposed algorithm. Results from the employed unsupervised learning, after training, testing, and validation of the SOMs, are analyzed and critically compared with results from other authors.     

Artificial neural networks applied to fetal monitoring in labour

Birth asphyxia can result in death or permanent brain damage. To prevent it, the fetal heart rate (FHR) is recorded in labour on a paper strip. In clinical practice, the complicated FHR patterns are assessed by eye, which is error-prone, inconsistent and unreliable. Objective alternatives are needed and thus we investigated the applicability of feed-forward artificial neural networks (ANNs) for FHR analysis. Six FHR features were extracted and combined with six clinical parameters to form a feature space of 12 dimensions. The feature space was reduced to six dimensions by principal component analysis. Subsequently, a network committee of ten ANNs was trained with the data of 124 patients (a balanced set of 62 adverse, coded 1, and 62 normal outcomes, coded 0). The ANN committee was tested on another balanced set of 252 patients obtaining misclassification rate of 36%. Finally, the committee was tested on a large dataset of 7,568 patients (non-balanced). As the committee output continuously increased from 0 to 1, there was a consistent growth of the adverse outcome rate (from 0.26 to 5.3%) and the low umbilical pH rate (from 2.6 to 16.7%.) Based on this correlation between the committee output and the risk of compromise, we concluded that ANNs can be successfully applied to FHR monitoring in labour. However, extensive further work is necessary, for which we outline our plans. To our knowledge, this is the first time that an automated method for FHR diagnostic analysis has been tested on a database of this size.     

Über die Aufkohlungskinetik von Eisen-Zink-Legierungen

Untersuchung der Aufkohlungskinetik von zwischen 870 und 1107 °C ferritischen und austenitischen Eisen-Zink-Legierungen. Mikrohärtemessungen und Untersuchungen der Kohlenstoffverteilung innerhalb der Aufkohlungsschicht mit der Röntgenmikrosonde. Ermittlung der Wachstumskinetik der Schicht und Erörterung der Ergebnisse im Zusammenhang mit der Diffusion des Kohlenstoffs in den Legierungen.     

Electrospun polylactide‐based materials for curcumin release: Photostability,antimicrobial activity,and anticoagulant effect

New microfibrous materials from polylactide and polyvinylpyrrolidone or polyethylene glycol loaded with the natural polyphenolic compound curcumin have been prepared by one‐pot electrospinning. The incorporation of curcumin in the fibers contributes to shielding curcumin from photodestruction and to enhancement of the mechanical properties of the fibers. Moreover, the formation of hydrogen bonds between curcumin and polyvinylpyrrolidone or polyethylene glycol facilitates the drug release. Curcumin release provides for the antibacterial and anticoagulant activity of the curcumin‐loaded mats and prevents adhesion and aggregation of platelets onto the surface of the mats. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 42940.     

Materials from Nanosized ZnO and Polyacrylonitrile: Properties Depending on the Design of Fibers (Electrospinning or Electrospinning/Electrospraying)

New hybrid fibrous materials from polyacrylonitrile (PAN) and nanosized zinc oxide have been prepared by electrospinning or by combining electrospinning and electrospraying techniques. Electrospinning of PAN/nanosized zinc oxide dispersion leads to the production of mats with nanofiller distributed mainly in the bulk of the fibers. Electrospinning of PAN solution performed in conjunction with electrospraying of nanosized zinc oxide dispersion enables the preparation of fibers decorated with zinc oxide particles. The incorporation of zinc oxide in the fibers leads to enhancement of the mechanical properties of the mats. The fibrous materials having zinc oxide particles situated on the fibers surface exhibit better photocatalytic activity in respect to photo-induced degradation of the model dye methylene blue and greater antibacterial activity against the pathogenic microorganism Staphylococcus aureus.     

Bilateral tubo-ovarian actinomycosis and rheumatoid arthritis

It's a lot cheaper to develop a compliance plan than fight fraud charges. Trouble is, off-the-shelf wisdom is hard to come by. Here's sage advice from compliance pros on how to put your plan in motion.     

Association between polyether–polyamine block-copolymers and low molecular weight polyacids in solution

An ABA block-copolymer in which A is a poly(N-tert-butylimino-ethylene) segment and B a poly(oxytetramethylene) segment has been prepared. The salt form of this polymer, obtained with low molecular weight polycarboxylic acids such as citric acid or benzene-1,3,5-tricarboxylic acid, was found to form ionic networks in organic solvents of low or medium polarity, when the concentration of the polymeric salt exceeded a critical concentration, between 2 and 4wt%. The viscosities of the polymeric salt solutions were strongly pseudoplastic, showing a yield point and thixotropic behaviour.