Electrospinning piezoelectric fibers for biocompatible devices

The field of nanotechnology has been gaining great success due to its potential in developing new generations of nanoscale materials with unprecedented properties and enhanced biological responses. This is particularly exciting using nanofibers, as their mechanical and topographic characteristics can approach those found in naturally occurring biological materials. Electrospinning is a key technique to manufacture ultrafine fibers and fiber meshes with multifunctional features, such as piezoelectricity, to be available on a smaller length scale, thus comparable to subcellular scale, which makes their use increasingly appealing for biomedical applications. These include biocompatible fiber-based devices as smart scaffolds, biosensors, energy harvesters, and nanogenerators for the human body. This paper provides a comprehensive review of current studies focused on the fabrication of ultrafine polymeric and ceramic piezoelectric fibers specifically designed for, or with the potential to be translated toward, biomedical applications. It provides an applicative and technical overview of the biocompatible piezoelectric fibers, with actual and potential applications, an understanding of the electrospinning process, and the properties of nanostructured fibrous materials, including the available modeling approaches. Ultimately, this review aims at enabling a future vision on the impact of these nanomaterials as stimuli-responsive devices in the human body

The Consensus from the Mycobacterium avium ssp. paratuberculosis (MAP) Conference 2017.

On March 24 and 25, 2017 researchers and clinicians from around the world met at Temple University in Philadelphia to discuss the current knowledge of Mycobacterium avium ssp. paratuberculosis (MAP) and its relationship to human disease. The conference was held because of shared concern that MAP is a zoonotic bacterium that poses a threat not only to animal health but also human health. In order to further study this problem, the conferees discussed ways to improve MAP diagnostic tests and discussed potential future anti-MAP clinical trials. The conference proceedings may be viewed on the www.Humanpara.org website. A summary of the salient work in this field is followed by recommendations from a majority of the conferees

Nonlinearity of Diffusion Resistors at High-density Current

The paper presents the results of an experimental study of the current dependence of the resistance of diffusion resistors (DR) produced by the "silicon with dielectric insulation" technology, with different geometric characteristics, in particular, length and thickness, with a current density of 105 A/cm2. The analysis of the obtained results is carried out and three areas on the dependence of resistance on current R(I) are determined. The first region is an ohmic plot, on which the resistance value of the diffusion resistor is linearly dependent on the current value. The second region of the curve R(I) is characterized by the presence of strong nonlinearity, jumps and a sharp increase in the resistance of the DR, which happen due to the emergence of a high electric field in the DR. The third region on R(I) is characterized by a decrease in the value of the current resistance: the thicker the DR, the lower the peak value of the resistance. It is shown that the change in the length and the decrease in the thickness of the diffusion resistors lead to a change in the length of the linear region on R(I): the smaller the length, the lower the resistance of the sample and the longer the area of stable differential resistance. The region of the linearity of the diffusion resistor is determined on the basis of the differential resistance on the current dependence. The linearity of the resistance was defined as the region where the change in the differential resistance did not exceed 10 % of its value at some small electric field: the largest region of the linearity of the resistor is present in a specimen with a length of 2.4 μm and a thickness of 8.4 μm. The revealed characteristics of the behavior of the resistance of the diffusion resistor are due to the change in its physical characteristics as a result of significant self-heating

Properties of Electrochromic Cell with WO3 and NiO: the Influence of Ionic Conductor

The electrochromic WO3 and NiO films were deposited by magnetron sputtering on indium tin oxides coated glass. The structural properties of the films were investigated by scanning electron microscopy and X-ray diffractometery techniques. The electrochromic properties of the films were investigated by means cyclic voltammetry using different types of ionic conductors. The use of water electrolytes and electrolytes which are based on propylene carbonate leads to the destruction of electrochromic cells. The stable working electrochromic cell with WO3 and NiO films was obtained using ionic liquid as the ionic conductor. The coloration efficiency of electrochromic cell which is based on amorphous WO3 film and crystalline NiO film is 28.7 cm2 /C. Keywords: tungsten oxide, nickel oxide, electrochromic cell, ion conductor