Fabrication and evaluation of physical properties and cytotoxicity of zein-based polyurethanes

Polyurethane prepolymer (PUP) was first synthesized from polycaprolactone diol and isophorone diisocyanate; and then a series of zein-based polyurethane (ZEPU) sheets was fabricated from PUP and zein (ZE) using a hot press and moulding process without addition of other additives. Effects of ZE content (W_ZE) on the structure and properties of the resultant ZEPU sheets were investigated by Fourier transform infrared spectroscopy, scanning electron microscopy, dynamic mechanical analysis, tensile testing, and dissolubility testing in alcohol. The results indicated that cross-linking and grafting reactions occurred between ZE and PUP to form new polyurethane showing a higher thermal stability, flexibility, and alcohol-resistance than the neat ZE sheets. For example, the elongation at break of ZEPU with 50 % W_ZE was 211.2 %, which was 47 times higher than that of neat ZE sheet. ZE molecules acted as both cross-linkers and polymer fillers in ZEPU sheets. The cytotoxicity and cytocompatibility of ZEPU sheets were evaluated by cell culture in vitro. The ZEPU sheets showed non- or low-cytotoxicity, and L929 cells grew and expanded well on the surfaces of the sheets with W_ZE over 50 %. Undoubtedly, the fabrication of ZE-based polyurethanes without toxic additives such as catalysts, cross-linkers and chain extenders improved the physical properties and cytocompatibility of zein, thus widening the possible range of applications for zein-based biomaterials.     

802．11n将取代802．11g

9月17日,博通公司的无线连接集团高级总监Rahul Patel先生接受了本刊记者关于802．11n相关问题的采访。在采访中,Rahul Patel首先向记者介绍了Wi—Fi技术的发展情况以及Wi—Fi联盟目前的工作进展。他介绍说：“做为互联网世界的必然衍生产物,在过去4、5年中,Wi—Fi逐渐地集成到基于尖端通信半导体的消费类电子产品当中,其作用也开始显现。     

First order random forests: Learning relational classifiers with complex aggregates

In relational learning, predictions for an individual are based not only on its own properties but also on the properties of a set of related individuals. Relational classifiers differ with respect to how they handle these sets: some use properties of the set as a whole (using aggregation), some refer to properties of specific individuals of the set, however, most classifiers do not combine both. This imposes an undesirable bias on these learners. This article describes a learning approach that avoids this bias, using first order random forests. Essentially, an ensemble of decision trees is constructed in which tests are first order logic queries. These queries may contain aggregate functions, the argument of which may again be a first order logic query. The introduction of aggregate functions in first order logic, as well as upgrading the forest’s uniform feature sampling procedure to the space of first order logic, generates a number of complications. We address these and propose a solution for them. The resulting first order random forest induction algorithm has been implemented and integrated in the ACE-ilProlog system, and experimentally evaluated on a variety of datasets. The results indicate that first order random forests with complex aggregates are an efficient and effective approach towards learning relational classifiers that involve aggregates over complex selections. Editor: Rui Camacho     

Dielectrophoretic segregation of different human cell types on microscope slides

A new method for preparing cells for microscopic examination is presented in which cell mixtures are fractionated by dielectrophoretic forces and simultaneously collected into characteristic zones on slides. The method traps cells directly from the suspending medium onto the slide, reducing cell loss. Furthermore, it exploits differences in the dielectric properties of the cells, which sensitively reflect their morphology. Because different cell types are trapped in characteristic zones on the slide, the technique represents an advance over existing methods for slide preparation, such as centrifugation and smears where cells are randomly distributed. In particular, the new method should aid in the detection of rare and anomalous cell subpopulations that might otherwise go unnoticed against a high background of normal cells. As well as being suitable for traditional microscopic examination and automated slide scanning approaches, it is compatible with histochemical and immunochemical techniques, as well as emerging molecular and proteomic methods. This paper describes the rationale and design of this so-called electrosmear instrumentation and shows experimental results that verify the theory and applicability of the method with model cell lines and normal peripheral blood subpopulations.     

The use of vascular access audit and infections in home hemodialysis

Vascular access‐related infection is an important adverse event in home hemodialysis (HHD). We hypothesize that errors in self‐cannulation or manipulation of dialysis vascular access are associated with increased incidence of access‐related infection. We conducted a retrospective cohort study of all prevalent HHD patients at the University Health Network. All vascular access‐related infections were recorded from 2006 to 2013. Errors in dialysis access were ascertained by nurse‐administered vascular access checklist. Ninety‐two patients had completed at least one vascular access audit. Median HHD vintage was 2.3 (0.9–5.0) years in patients with appropriate vascular access technique and 5.8 (1.5–9.4) years in patients with erroneous vascular access technique. The overall rate of infection between patients with and without appropriate vascular access technique was similar (0.27 and 0.28 infections per year, P = 0.166). Among patients who were identified with errors in dialysis access manipulation, patients with five or more errors were associated with higher rate of access‐related infection (mean of 0.47 vs. 0.16 infection per patient‐year, P < 0.001). The use of vascular access audit is a feasible strategy, which can identify errors in vascular access technique. Patients with a longer median HHD vintage are associated with higher risk of inappropriate vascular access technique. Patients with multiple errors in vascular access technique are associated with a higher risk of dialysis access‐related infection. Prospective evaluation of the impact of vascular access audit on adverse vascular access events is warranted.     

Outlier detection in relational data: A case study in geographical information systems

Geographical information systems are commonly used for a variety of purposes. Many of them make use of a large database of geographical data, the correctness of which strongly influences the reliability of the system. In this paper, we present an approach to quality maintenance that is based on automatic discovery of non-perfect regularities in the data. The underlying idea is that exceptions to these regularities (‘outliers’) are considered probable errors in the data, to be investigated by a human expert. A case study shows how the tool can be used for extracting valuable knowledge about outliers in real-world geographical data, in an adaptive manner to the evolving data model supporting it. While the tool aims specifically at geographical information systems, the underlying approach is more broadly applicable for quality maintenance in data-rich intelligent systems.     

External Design for Reputation,Perspective and Exposure

This paper analyses why and how design‐centred industrial firms with internal design teams contract external designers. This research is based on an exploratory multiple case study methodology, with a sample of five highly reputable design‐centred industrial firms, operating in hypercompetitive industries. While some results challenge the mainstream literature on design management, others expand the existing literature, highlighting that not all firms extract the same benefits from external designers; neither do all external designers bring the same benefits to firms. The paper shows that firms with internal design teams contract external design for (1) reputation (external designers sign products and bring their reputation to the product and to the firm), (2) perspective (external designers bring a different perspective, especially when they come from a different industry from the firm), and (3) exposure (external designers bring exposure that enriches internal design teams).     

Automatic high-dynamic range image generation for dynamic scenes.

Automatic high-dynamic range image generation from low-dynamic range images offers a solution to conventional methods, which require a static scene. The method consists of two modules: a camera-alignment module and a movement detector, which removes the ghosting effects in the HDRI created by moving objects.