Synthesis method of nanomaterials by pulsed plasma in liquid

A new synthesis method of nanomaterials using pulsed plasma in liquid by the low voltage spark discharge is presented. The fullerene C60 and TiO nanopowder were for the first time synthesized by electric discharge method in liquid. The purity of C60 was >99%, which is much higher than those by the conventional arc plasma in inert gas methods (less than 80% C60 and 20% C70 and other fullerenes). Copper nanoparticles prepared by this method were smaller than those by arc method by a factor of >5. The pulsed plasma in liquid enables us to quench from plasma state, by which we can synthesize nanomaterials, metastable materials, etc. In addition, the applied power is 100 times smaller than those of arc discharge.     

Long-Term Administration of Cod Liver Oil Ameliorates Cognitive Impairment Induced by Chronic Stress in Rats

Cod liver oil (CLO) is a rich source of omega-3 fatty acids (FA), especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The existing data suggest that EPA and DHA are the active agents of fish oil. In this study, we tested a hypothesis that the active constituents of CLO alleviate the negative impact of prolonged restraint stress on cognitive functions of male Wistar rats. Specifically, we attempted to characterize the preventive action of long-lasting treatment with CLO [0.375 ml/100 g body weight (equivalent to a dose of 300 mg/kg DHA and 225 mg/kg EPA), p.o. for 21 days] against an impairment caused by chronic restraint stress (2 h daily for 21 days) on recall as tested in a passive avoidance situation and on the spatial reference and working memory tested in a Barnes maze as well as on locomotor activity and anxiety behavior tested respectively in an open field and elevated plus-maze. We found that CLO administration statistically significantly (p < 0.01, both) prevented the deleterious effects of chronic restraint stress on recall and the spatial memory.     

Onion-like carbon-encapsulated Co,Ni, and Fe magnetic nanoparticles with low cytotoxicity synthesized by a pulsed plasma in a liquid

We synthesized onion-like carbon-encapsulated Co, Ni, and Fe (Co–C, Ni–C, and Fe–C) magnetic nanoparticles with low cytotoxicity using pulsed plasma in a liquid. The pulsed plasma is induced by a low-voltage spark discharge submerged in a dielectric liquid. The face-centered cubic Co and Ni, and body-centered cubic Fe core nanoparticles showed good crystalline structures with an average size between 20 and 30 nm were encapsulated in onion-like carbon coatings with a thickness of 2–10 nm. Vibrating-sample magnetometer measurements revealed the ferromagnetic properties of as-synthesized samples at room temperature (Co–C = 360 Oe, Fe–C = 380 Oe, and Ni–C = 211 Oe). Raman-spectroscopy analysis found onion-like carbon shells composed of well-organized graphitic structures. Thermal gravimetric analysis showed a high stability of the as-synthesized samples under thermal treatment and oxidation. Cytotoxicity measurements showed higher cancer cell viability than samples synthesized by different methods.     

Design of magneto-optical system for imaging of magnetic flux created during a conductor-superconductor phase transition

According to the Kibble-Zurek model, flux lines are spontaneously created during a fast conductor-superconductor phase transition. The model predicts both the spatial density and the correlations of the flux array. We present the design of a magneto-optical system with a projected single-flux-line resolution. Such a system can allow detailed measurements of the distribution of flux created spontaneously during a conductor-superconductor phase transition.     

Parameter selection methods for axisymmetric flame tomography through Tikhonov regularization

Deconvolution of optically collected axisymmetric flame data is equivalent to solving an ill-posed problem subject to severe error amplification. Tikhonov regularization has recently been shown to be well suited for stabilizing this deconvolution, although the success of this method hinges on choosing a suitable regularization parameter. Incorporating a parameter selection scheme transforms this technique into a reliable automatic algorithm that outperforms unregularized deconvolution of a smoothed data set, which is currently the most popular way to analyze axisymmetric data. We review the discrepancy principle, L-curve curvature, and generalized cross-validation parameter selection schemes and conclude that the L-curve curvature algorithm is best suited to this problem.     

Addressing professional competence problems in trainees: Some ethical considerations.

Psychologists working as graduate student educators and clinical supervisors often encounter trainees who manifest problems of professional competence. At times, faculty members and supervisors may experience role conflict, ambiguity, and anxiety about how to respond to trainee competence problems. Psychologists engaged in the education, training, and credentialing of trainees are ethically and professionally obligated to balance their developmental and gatekeeping roles with respect to trainees. A discussion of several systemic concerns related to psychology's approach to competence problems is presented along with 3 expert commentaries that further elucidate the core issues from the vantage point of education, training, and licensure. Several recommendations for enhancing cooperation and excellent practice among psychologists who train and credential are offered. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Scattering of light from quasi-homogeneous sources by quasi-homogeneous media

The field generated by scattering of light from a quasi-homogeneous source on a quasi-homogeneous, random medium is investigated. It is found that, within the accuracy of the first-order Born approximation, the far field satisfies two reciprocity relations (sometimes called uncertainty relations). One of them implies that the spectral density (or spectral intensity) is proportional to the convolution of the spectral density of the source and the spatial Fourier transform of the correlation coefficient of the scattering potential. The other implies that the spectral degree of coherence of the far field is proportional to the convolution of the correlation coefficient of the source and the spatial Fourier transform of the strength of the scattering potential. While the case we consider might seem restrictive, it is actually quite general. For instance, the quasi-homogeneous source model can be used to describe the generation of beams with different coherence properties and different angular spreads. In addition, the quasi-homogeneous scattering model adequately describes a wide class of turbulent media, including a stratified, turbulent atmosphere and confined plasmas.     

Region of interest reconstruction from truncated data in circular cone-beam CT

The circular scanning trajectory is one of the most widely adopted data-acquisition configurations in computed tomography (CT). The Feldkamp, Davis, Kress (FDK) algorithm and its various modifications have been developed for reconstructing approximately three-dimensional images from circular cone-beam data. When data contain transverse truncations, however, these algorithms may reconstruct images with significant truncation artifacts. It is of practical significance to develop algorithms that can reconstruct region-of-interest (ROI) images from truncated circular cone-beam data that are free of truncation artifacts and that have an accuracy comparable to that obtained from nontruncated cone-beam data. In this work, we have investigated and developed a backprojection-filtration (BPF)-based algorithm for ROI-image reconstruction from circular cone-beam data containing transverse truncations. Furthermore, we have developed a weighted BPF algorithm to exploit "redundant" information in data for improving image quality. In an effort to validate and evaluate the proposed BPF algorithms for circular cone-beam CT, we have performed numerical studies by using both computer-simulation data and experimental data acquired with a radiotherapy cone-beam CT system. Quantitative results in these studies demonstrate that the proposed BPF algorithms for circular cone-beam CT can reconstruct ROI images free of truncation artifacts.