Verb Use in Parkinson\u27s Disease

Verb-specific impairments in their use and comprehension are well documented in persons with Parkinson’s disease (PD). The grammatical and the motor theories have been proposed as possible explanations for verb impairments. The purpose of this study is to describe the use of low-motion and high-motion content verbs in PD in everyday conversation and to determine which theory best supports these findings. In this cross-sectional prospective study, conversation samples were collected and analyzed from participants with PD and their spouses in a mealtime context. Results indicated that total verb use on a proportional basis was not significantly different between persons with PD vs. control participants. Participants with PD produced significantly fewer high-motion verbs compared to low-motion content verbs. However, control participants also produced significantly fewer high-motion verbs compared to low-motion content verbs. The findings do not support the motor theory or the grammatical theory of verb processing in participants with PD

Effect of Dietary Protein Quality on the Biochemical Adaptation to High Altitude

The usefulness of a particular type of dietary protein for a quicker acclimatization to simulated high altitude stress was investigated in albino rats, by studying the changes occurring in the levels of urea cycle enzymes in liver. A good quality protein in (egg) and a commonly used dal protein (arhar dal, Cajanus cajan) were studied.Liver arginase levels increased on starvation in the two groups of rats fed with egg and dal diets, the increase being less and gradual in the dal diet fed group. Exposure to the simulated altitude stress for various periods further increased the enzyme levels, greater changes being seen in egg diet fed group only. Similar observations were made with liver ornithine transcarbamylase which is a mitochondrial enzyme. Urea cycle enzymes were affected more in the exposed animals maintained on the egg diet than those on the dal diet. Moreover, the enzymic parameters of the latter group tended to return to the normal level much earlier than the former. It is, therefore, suggested that not-so-well-balanced dietary proteins may be well suited to overcome the initial problem of metabolic adaptation faced by subjects exposed to high altitude stress

Microfabrication of passive electronic components with printed graphene-oxide deposition

Flexible electronic circuitry is an emerging technology that will significantly impact the future of healthcare and medicine, food safety inspection, environmental monitoring, and public security. Recent advances in drop-on-demand printing technology and electrically conductive inks have enabled simple electronic circuits to be fabricated on mechanically flexible polymers, paper, and bioresorbable silk. Research has shown that graphene, and its derivative formulations, can be used to create low-cost electrically conductive inks. Graphene is a one atom thick two-dimensional layer composed of carbon atoms arranged in a hexagonal lattice forming a material with very high fracture strength, high Young's Modulus, and low electrical resistance. Non-conductive graphene-oxide (GO) inks can also be synthesized from inexpensive graphite powders. Once deposited on the flexible substrate the electrical conductivity of the printed GO microcircuit traces can be restored through thermal reduction. In this paper, a femtosecond laser with a wavelength of 775nm and pulse width of 120fs is used to transform the non-conductive printed GO film into electrically conductive oxygen reduced graphene-oxide (rGO) passive electronic components by the process of laser assisted thermal reduction. The heat affected zone produced during the process was minimized because of the femtosecond pulsed laser. The degree of conductivity exhibited by the microstructure is directly related to the laser power level and exposure time. Although rGO films have higher resistances than pristine graphene, the ability to inkjet print capacitive elements and modify local resistive properties provides for a new method of fabricating sensor microcircuits on a variety of substrate surfaces. \ua9 2014 SPIE.Peer reviewed: YesNRC publication: Ye

Graphene-based inkjet printing of flexible bioelectronic circuits and sensors

Bioelectronics involves interfacing functional biomolecules or living cells with electronic circuitry. Recent advances in electrically conductive inks and inkjet printing technologies have enabled bioelectronic devices to be fabricated on mechanically flexible polymers, paper and silk. In this research, non-conductive graphene-oxide (GO) inks are synthesized from inexpensive graphite powders. Once printed on the flexible substrate the electrical conductivity of the micro-circuitry can be restored through thermal reduction. Laser irradiation is one method being investigated for transforming the high resistance printed GO film into conductive oxygen reduced graphene-oxide (rGO). Direct laser writing is a precision fabrication process that enables the imprinting of conductive and resistive micro-features on the GO film. The mechanically flexible rGO microcircuits can be further biofunctionalized using molecular self-assembly techniques. Opportunities and challenges in exploiting these emerging technologies for developing biosensors and bioelectronic cicruits are briefly discussed. \ua9 2013 Copyright SPIE.Peer reviewed: YesNRC publication: Ye

Polymer micromolds with near optical quality surface finishes

Disposable microfluidic systems are used to avoid sample contamination in a variety of medical and environmental monitoring applications. A contactless hot intrusion (HI) process for fabricating reusable polymer micromolds with near "optical quality" surface finishes is described in this paper. A metallic hot intrusion mask with the desired microchannels and related passive components is first machined using a tightly focused beam from a diode-pumped solid-state (DPSS) laser. The polymer mold master is then created by pressing the 2D metallic mask onto a polymethylmethacrylate (PMMA) substrate. Since it is a contactless fabrication process the resultant 3D micro-reliefs have near optical quality surface finishes. Unfortunately, the desired micro-relief dimensions (height and width) are not easily related to the hot intrusion process parameters of pressure, temperature, and time exposure profile. A finite element model is introduced to assist the manufacturing engineer in predicting the behavior of the PMMA substrate material as it deforms under heat and pressure during micromold manufacture. The FEM model assumes that thermo-plastics like PMMA become "rubber like" when heated to a temperature slightly above the glass transition temperature. By controlling the material temperature and maintaining its malleable state, it is possible to use the stress-strain relationship to predict the profile dimensions of the imprinted microfeature. Examples of curved microchannels fabricated using PMMA mold masters are presented to illustrate the proposed methodology and verify the finite element model. In addition, the non-contact formation of the micro-reliefs simplifies the demolding process and helps to preserve the high quality surface finishes. \ua9 2012 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).Peer reviewed: YesNRC publication: Ye

Laser micromachining of oxygen reduced graphene-oxide films

Non-conductive graphene-oxide (GO) inks can be synthesized from inexpensive graphite powders and deposited on functionalized flexible substrates using inkjet printing technology. Once deposited, the electrical conductivity of the GO film can be restored through laser assisted thermal reduction. Unfortunately, the inkjet nozzle diameter ( 3c40\u3bcm) places a limit on the printed feature size. In contrast, a tightly focused femtosecond pulsed laser can create precise micro features with dimensions in the order of 2 to 3 \u3bcm. The smallest feature size produced by laser microfabrication is a function of the laser beam diameter, power level, feed rate, material characteristics and spatial resolution of the micropositioning system. Laser micromachining can also remove excess GO film material adjacent to the electrode traces and passive electronic components. Excess material removal is essential for creating stable oxygen-reduced graphene-oxide (rGO) printed circuits because electron buildup along the feature edges will alter the conductivity of the non-functional film. A study on the impact of laser ablation on the GO film and the substrate are performed using a 775nm, 120fs pulsed laser. The average laser power was 25mW at a spot size of 3c 5\u3bcm, and the feed rate was 1000-1500mm/min. Several simple microtraces were fabricated and characterized in terms of electrical resistance and surface topology. \ua9 2014 SPIE.Peer reviewed: YesNRC publication: Ye

Trimming phase and birefringence errors in planar lightwave circuits with deep ultraviolet femtosecond laser

A deep ultraviolet femtosecond laser was employed to trim phase and birefringence errors in silica planar lightwave circuits. A permanent refractive index change of ∼3.8 × 10-4 and a birefringence change of 1.0 × 10-4 were induced in hydrogen-free Mach-Zehnder planar waveguide circuits. The ultrafast laser enhances the ultraviolet photo-sensitivity response in silica waveguides by two orders of magnitude greater than that of a nanosecond 248 nm KrF excimer laser

Deep ultraviolet femtosecond laser tuning of fiber Bragg gratings

A deep ultraviolet femtosecond laser operating at wavelength 258 nm was demonstrated to be effective in trimming fiber Bragg gratings in telecommunication fibers. A smooth tunable resonance wavelength shift of up to 0.52 nm has been observed, corresponding to a refractive index change of ∼5 × 10-4 after an accumulated laser fluence of 63.3 kJ/cm 2 at a single pulse fluence of 124 mJ/cm2. The ultrafast laser enhancement of ultraviolet photosensitivity response and modification of anisotropic index profile in silica fiber is a powerful technique to precise control of the performance of fiber Bragg grating devices for applications in optical filtering and polarization mode dispersion management. Crown Copyright © 2005 Published by Elsevier B.V. All rights reserved