Customizing MRI-Compatible Multifunctional Neural Interfaces through Fiber Drawing

Fiber drawing enables scalable fabrication of multifunctional flexible fibers that integrate electrical, optical, and microfluidic modalities to record and modulate neural activity. Constraints on thermomechanical properties of materials, however, have prevented integrated drawing of metal electrodes with low-loss polymer waveguides for concurrent electrical recording and optical neuromodulation. Here, two fabrication approaches are introduced: 1) an iterative thermal drawing with a soft, low melting temperature (T_m) metal indium, and 2) a metal convergence drawing with traditionally non-drawable high T_m metal tungsten. Both approaches deliver multifunctional flexible neural interfaces with low-impedance metallic electrodes and low-loss waveguides, capable of recording optically-evoked and spontaneous neural activity in mice over several weeks. These fibers are coupled with a light-weight mechanical microdrive (1 g) that enables depth-specific interrogation of neural circuits in mice following chronic implantation. Finally, the compatibility of these fibers with magnetic resonance imaging is demonstrated and they are applied to visualize the delivery of chemical payloads through the integrated channels in real time. Together, these advances expand the domains of application of the fiber-based neural probes in neuroscience and neuroengineering.     

Feasibility of Using Titanium Machine Turnings in Powder Metallurgy Processes

JOM - The use of titanium machine turnings has been identified as a possible ultralow-cost method to produce titanium powder. However, very little data are available on the viability of this...     

Analytic study on structural behavior of the string bed in a tennis racket

The structural behavior of string bed of tennis rackets was investigated subjected to transverse force perpendicular to the string bed. The mathematical model developed for the string bed was implemented into a computer programming code. This code was used to conduct extensive parametric studies on the structural behavior of the string bed for various parameters, including string tension, axial rigidity of the string, string spacing and head size. The analysis results showed that while the transverse stiffness of the string bed is proportional to the string tension, the transverse stiffness of the string bed is inversely proportional to string spacing and head size. In addition, the axial rigidity of the string significantly amplifies the transverse stiffness of the string bed for relatively large transverse deflection of the string bed.     

Contributions from ethics and research that guide integrating religion into psychotherapy.

Historically ignored or “treated,” clients' religious beliefs are being incorporated into psychotherapy because they influence client and therapist thinking and have potential to heal and harm. This paper examines how professional codes of ethics and research on religion-friendly therapeutic interventions and on helpful and harmful religious beliefs and practices provide direction in dealing with religious matters in psychotherapy. Ethical codes emphasize self-determination, beneficence, and nonmaleficence, which lead to different treatment decisions depending on how they are prioritized. The informed consent process and motivational interviewing have potential to ethically reduce harm and maximize benefits from the client's religious beliefs. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Nanoparticles of CdCl2 with closed cage structures

Nanoparticles of various layered compounds having a closed cage or nanotubular structure, designated also inorganic fullerene-like (IF) materials, have been reported in the past. In this work IF-CdCl₂ nanoparticles were synthesized by two methods. In one technique, a high temperature evaporation and subsequent condensation of dried cadmium chloride powder was used. In the other method, electron beam irradiation of the source powder led to its recrystallization into closed nanoparticles with a nonhollow core. The two methods are shown to produce nanoparticles of different topologies. While mostly spherical nested structures are obtained from the high temperature process, polyhedra with hexagonal or elongated rectangular characters are obtained by the electron beam induced process. The analysis also shows that, while the source (dried) powder is orthorhombic cadmium chloride monohydrate, the crystallized IF cage consists of the anhydrous 3R polytype which is not stable as bulk material in ambient atmosphere. Consistent with previous observations, this study shows that the seamless structure of the IF materials can stabilize phases, which are otherwise unstable in ambient conditions.     

Effects of cellulosic fibre on physical and rheological properties of starch,gluten and wheat flour

In this study, we report on the effects of cellulose fibres of different particle size on changes to dough water absorption and rheology; and on effects of fibre on starch and gluten, separately, at different levels of fibre incorporation (0.1–10%). Water absorption and dough‐mixing properties were affected with fibre incorporation, with 40‐μm fibre incorporation resulting in greater absorption values. Dough stickiness and extensibility were affected by cellulose fibre particle size, and decreased with increasing fibre addition. Flour or starch and fibre mixtures were evaluated using a Micro ViscoAmlyoGraph (MVAG), and the resulting gel firmness was measured using a texture analyzer. MVAG peak and final viscosities of flour samples decreased with increasing fibre content. Starch–fibre interactions followed a similar trend as flour–fibre treatments. Gluten–fibre interactions were also measured using a Gluten Peak Tester on flour–fibre and gluten–fibre mixtures. Cellulose fibre enhanced the kinetics of gluten aggregation.     

Substrate effects on the mechanical properties and contact damage of diamond-like carbon thin films

Substrate effects on the mechanical properties and contact damage of diamond-like carbon (DLC) films have been investigated. To that end, a DLC film of 1 μm thickness was deposited on two different substrates: soda–lime glass (compliant and soft), and single-crystal silicon (stiff and hard). The elastic modulus and hardness were measured by means of nanoindentation. Quasi-static and sliding contact configurations were simulated by means of ultra-micro indentation, and surface and cross-sectional damage were assessed using a focused ion beam (FIB) miller. It was found that a compliant and soft substrate enhances crack initiation on the film surface in the form of ring/cone cracks. On the other hand, a stiff and hard substrate delays crack initiation in the film, but is more susceptible to fracture in the form of median and lateral cracks due to increased brittleness. The results have implications for the reliability of DLC-coated systems.