Probing the physiology of ASH neuron in Caenorhabditis elegans using electric current stimulation

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98694/1/ApplPhysLett_99_053702.pd

Imaging Oxygen Defects and their Motion at a Manganite Surface

Manganites are technologically important materials, used widely as solid oxide fuel cell cathodes: they have also been shown to exhibit electroresistance. Oxygen bulk diffusion and surface exchange processes are critical for catalytic action, and numerous studies of manganites have linked electroresistance to electrochemical oxygen migration. Direct imaging of individual oxygen defects is needed to underpin understanding of these important processes. It is not currently possible to collect the required images in the bulk, but scanning tunnelling microscopy could provide such data for surfaces. Here we show the first atomic resolution images of oxygen defects at a manganite surface. Our experiments also reveal defect dynamics, including oxygen adatom migration, vacancy-adatom recombination and adatom bistability. Beyond providing an experimental basis for testing models describing the microscopics of oxygen migration at transition metal oxide interfaces, our work resolves the long-standing puzzle of why scanning tunnelling microscopy is more challenging for layered manganites than for cuprates.Comment: 7 figure

Synthesis of N-arylpyridinium salts bearing a nitrone spin trap as potential mitochondria-targeted antioxidants

The generation of excess reactive oxygen species (ROS) in mitochondria is responsible for much of the oxidative stress associated with ageing (aging), and mitochondrial dysfunction is part of the pathology of neurodegeneration and type 2 diabetes. Lipophilic pyridinium ions are known to accumulate in mitochondria and this paper describes a general route for the preparation of nitrone-containing N-arylpyridinium salts having a range of lipophilicities, as potential therapeutic antioxidants. The compatibility of nitrones with the Zincke reaction is the key to their synthesis. Their trapping of carbon-centred radicals and the EPR spectra of the resulting nitroxides are reported

Endothelial Function in Systemic Lupus Erythematosus: Relationship to Disease Activity, Cardiovascular Risk Factors, Corticosteroid Therapy, and Coronary Calcification

Elizabeth Turner2, Victor Dishy1, Cecilia P Chung2, Paul Harris4, Rosanna Pierce5, Yu Asanuma1, Annette Oeser1, Tebeb Gebretsadik3, Ayumi Shintani3, Paolo Raggi6, C Michael Stein1,21Division of Clinical Pharmacology, 2Division of Rheumatology, 3Department of Medicine; Center of Health Services Research, Department of Biostatistics; 4General Clinical Research Center; 5Department of Vascular Surgery, Vanderbilt University School of Medicine, Nashville, TN, USA; 6Section of Cardiology, Tulane University School of Medicine, New Orleans, LA, USAObjectives: Endothelial dysfunction is frequently present in patients with systemic lupus erythematosus and may increase their risk of premature coronary artery disease. In this pilot study we have characterized the relationship between endothelial function, measures of disease activity, and cardiovascular risk factors in patients with lupus.Methods: Clinical characteristics and cardiovascular risk factors were evaluated in 20 patients with lupus. Flow-mediated dilation of the brachial artery was measured using high resolution ultrasound and the presence or absence of coronary calcification determined by electronbeam computed tomography. The relationship between these variables and flow-mediated dilation was determined using Spearman correlation coefficients (RHO) and Mann Whitney-Wilcoxon tests.Results: Twenty patients (17 female) median age (interquartile range) 42.5 (32.0–47.5) years were studied. The median flow-mediated vasodilation was 3.6% (1.7%–7.7%). In patients with coronary calcification (n = 6), flow-mediated dilation was 2.1% (–0.42%–3.6%) compared with 4.0% (3.5%–8.3%) in those without (p = 0.12). There was no significant relationship between flow-mediated dilation and markers of disease activity, duration of disease, and cardiovascular risk factors. Lower flow-mediated dilation was associated with duration of corticosteroid therapy (RHO = –0.44, p = 0.05).Conclusions: In these preliminary results, endothelial dysfunction is associated with longterm exposure to corticosteroids.Keywords: flow-mediated dilation, endothelium, inflammation, atherosclerosis, systemic lupus erythematosu

Broadly tunable, high-power terahertz radiation up to 73 K from a stand-alone Bi2Sr2CaCu2O8+delta mesa

High-power, continuous, broadly tunable THz radiation from 0.29 to 1.06 THz, was obtained from the outer current-voltage characteristic (IVC) branch of a single stand-alone mesa of the high-transition temperature T-c superconductor Bi2Sr2CaCu2O8+delta. The particular metallic film structures placed both beneath and atop the mesas resulted in more efficient heat dissipation, higher allowed applied dc voltages, larger IVC loops, wider emission temperature ranges, and much broader emission frequency tunability than obtained previously

Computed tomography image using sub-terahertz waves generated from a high-T-c superconducting intrinsic Josephson junction oscillator

A computed tomography (CT) imaging system using monochromatic sub-terahertz coherent electromagnetic waves generated from a device constructed from the intrinsic Josephson junctions in a single crystalline mesa structure of the high-T-c superconductor Bi2Sr2CaCu2O8+delta was developed and tested on three samples: Standing metallic rods supported by styrofoam, a dried plant (heart pea) containing seeds, and a plastic doll inside an egg shell. The images obtained strongly suggest that this CT imaging system may be useful for a variety of practical applications

Diminished Alveolar Microvascular Reserves in Type 2 Diabetes Reflect Systemic Microangiopathy

OBJECTIVE—Alveolar microvascular function is moderately impaired in type 1 diabetes, as manifested by restriction of lung volume and diffusing capacity (DLCO). We examined whether similar impairment develops in type 2 diabetes and defined the physiologic sources of impairment as well as the relationships to glycemia and systemic microangiopathy

AMSR2 Soil Moisture Product Validation

The Advanced Microwave Scanning Radiometer 2 (AMSR2) is part of the Global Change Observation Mission-Water (GCOM-W) mission. AMSR2 fills the void left by the loss of the Advanced Microwave Scanning Radiometer Earth Observing System (AMSR-E) after almost 10 years. Both missions provide brightness temperature observations that are used to retrieve soil moisture. Merging AMSR-E and AMSR2 will help build a consistent long-term dataset. Before tackling the integration of AMSR-E and AMSR2 it is necessary to conduct a thorough validation and assessment of the AMSR2 soil moisture products. This study focuses on validation of the AMSR2 soil moisture products by comparison with in situ reference data from a set of core validation sites. Three products that rely on different algorithms were evaluated; the JAXA Soil Moisture Algorithm (JAXA), the Land Parameter Retrieval Model (LPRM), and the Single Channel Algorithm (SCA). Results indicate that overall the SCA has the best performance based upon the metrics considered