Spatio-Temporal Images of Single Streamer Propagation in Dielectric Barrier Discharge

One-dimensional time-dependent numerical simulations are presented to find the discharge mechanism and illustrate the spatio-temporal images of a single streamer in the dielectric barrier discharge (DBD). Calculated results reveal that the three discharge phases of avalanche, streamer, and decay are distinguished depending on the external voltage applied to the electrodes in the DBD. At different over-voltage conditions, the time evolutions of discharge currents show distinct profiles which adequately explain the spatio-temporal variations of the single streamer in the DBD

ESTpass: a web-based server for processing and annotating expressed sequence tag (EST) sequences

We present a web-based server, called ESTpass, for processing and annotating sequence data from expressed sequence tag (EST) projects. ESTpass accepts a FASTA-formatted EST file and its quality file as inputs, and it then executes a back-end EST analysis pipeline consisting of three consecutive steps. The first is cleansing the input EST sequences. The second is clustering and assembling the cleansed EST sequences using d2_cluster and CAP3 programs and producing putative transcripts. From the CAP3 output, ESTpass detects chimeric EST sequences which are confirmed through comparison with the nr database. The last step is annotating the putative transcript sequences using RefSeq, InterPro, GO and KEGG gene databases according to user-specified options. The major advantages of ESTpass are the integration of cleansing and annotating processes, rigorous chimeric EST detection, exhaustive annotation, and email reporting to inform the user about the progress and to send the analysis results. The ESTpass results include three reports (summary, cleansing and annotation) and download function, as well as graphic statistics. They can be retrieved and downloaded using a standard web browser. The server is available at http://estpass.kobic.re.kr/

Electrochemically Controlled Reconstitution of Immobilized Ferritins for Bioelectronic Applications

Site-specific reconstituted nanoparticles were fabricated via electrochemically-controlled biomineralization through the immobilization of biomolecules. The work reported herein includes the immobilization of ferritin with various surface modifications, the electrochemical biomineralization of ferritins with different inorganic cores, and the electrocatalytic reduction of oxygen on the reconstituted Pt-cored ferritins. Protein immobilization on the substrate is achieved by anchoring ferritins with dithiobis-N-succinimidyl propionate (DTSP). A reconstitution process of site-specific electrochemical biomineralization with a protein cage loads ferritins with different core materials. The ferritin acts as a nano-scale template, a biocompatible cage, and a separator between the nanoparticles. This first demonstration of electrochemically controlled site-specific reconstitution of biomolecules provides a new tool for biomineralization and opens the way to produce the bio-templated nanoparticles by electrochemical control. The nanosized platinum-cored ferritins on gold displayed good catalytic activity for the electrochemical reduction of oxygen, which is applicable to biofuel cell applications. This results in a smaller catalyst loading on the electrodes for fuel cells or other bioelectronic devices

Gas Temperature Effect on Discharge-Mode Characteristics of Atmospheric-Pressure Dielectric Barrier Discharge in a Helium–Oxygen Mixture

For a better understanding of gas temperature effects on plasma characteristics, a numerical study has been carried out for a dielectric barrier discharge (DBD) with a helium–oxygen mixture at atmospheric pressure. A one-dimensional time-dependent simulation code has been developed to solve continuity equations for plasma species and Poisson's equation for electric field calculation for a parallel-plate DBD reactor. To include temperature effects, gas heating by enthalpy change and Joule heating with ionic current movement are considered in the helium–oxygen plasma including 13 species reacting with one another according to 34 reactions depending on the gas temperature. Varying the ambient temperature from 300 K to 500 K, the plasma characteristics are calculated for the temporal variations and spatial distributions of electric field and species densities in the DBD region, and the different features of discharge modes are described by the voltage–current characteristic curves. A glowlike mode, which typically shows the formation of cathode fall, Faraday dark space, negative glow, and positive column in the spatial distributions of electric field and plasma density, is found in the discharge at a low ambient temperature, while a Townsend discharge mode with moderate electric field intensity and lower electron density is characterized at higher ambient temperatures. The temperature-dependent reactions strongly influence the generation and loss of species in the DBD plasma, and the decomposition of O3 into O or O2 and the quenching of metastable helium by the resultant O or O2 play an important role in determining the distinct discharge mode in the DBD of a He-O2 mixture. Furthermore, it is understood that the discharge-mode transition is controllable by the coupled effects of oxygen additive concentration, frequency, and gas temperature. A small amount of O2 additive or a high-frequency operation exhibits a glow mode in a specific range of ambient temperature, of which reason can be explained by density variation and quenching of helium metastable species caused by the produced oxygen-related species

Comparative effects of norepinephrine and vasopressin on internal thoracic arterial graft flow after off-pump coronary artery bypass grafting

ObjectiveVasoconstrictors such as norepinephrine and vasopressin are commonly used to raise the blood pressure during myocardial revascularization. The internal thoracic artery is commonly used for coronary artery grafting because of its long-term patency. However, the internal thoracic artery is a living conduit that responds to vasoactive substances. The objective of this study was to measure change in internal thoracic arterial flow after infusion of norepinephrine or vasopressin.MethodsForty-one patients undergoing elective off-pump coronary artery bypass grafting participated in this study. After the median sternotomy, the left internal thoracic artery was dissected with a pedicle and grafted to the left anterior descending artery. After all anastomoses were performed and hemodynamic parameters were stable, the grafted internal thoracic arterial blood flow was measured by transit time flowmeter on the distal portion of the graft as a baseline. Norepinephrine or vasopressin was then infused until mean arterial pressure was increased to 20% of baseline. Graft flow and hemodynamic variables were measured when mean arterial pressure reached the intended level.ResultsBaseline grafted internal thoracic arterial flows were similar (norepinephrine 57.1 ± 17.7 mL min−1, vasopressin 66.0 ± 34.3 mL min−1). With norepinephrine, flow increased significantly relative to baseline (77.2 ± 31.0 mL min−1); with vasopressin, it remained unchanged (68.3 ± 37.0 mL min−1).ConclusionsFor patients needing vasopressor support after coronary artery bypass grafting, norepinephrine appeared superior to vasopressin because of increased internal thoracic arterial flow

Effect of Output Conditions on Microstructure and Properties of SKD61 Laser Cladding

This study investigated the effect of cladding on tool steel (SKD61) by using 5%Cr-1.5%Mo-Fe powder (SKD61), which is expected to be economically effective when used to manufacture and mend die-casting parts. The cladding conditions were as follows: the distance between the coaxial powder supply head and the substrate surface was 20 mm, and Ar was used as the supply gas. The laser outputs applied in the cladding procedure were 3, 4, and 5 kW. The microstructure of the heat-affected zone in the processed specimens was analyzed, and the macrostructure and morphology of the substrate material were studied. Specimen hardness measurements were performed at intervals of 0.1 mm from the substrate surface to the core. As the laser output increased from 3 to 4 and 5 kW, the dilution rate increased from 10.6% to 11.8 and 13.2%. It was confirmed that the fraction of carbides increased as the laser output increased from 3 kW to 5 kW

Intraoperative blood loss during different stages of scoliosis surgery: A prospective study

<p>Abstract</p> <p>Background</p> <p>There are a number of reasons for intraoperative blood loss during scoliosis surgery based on the type of approach, type of disease, osteopenia, and patient blood profile. However, no studies have investigated bleeding patterns according to the stage of the operation. The objective of this prospective study was to identify intraoperative bleeding patterns in different stages of scoliosis surgery.</p> <p>Methods</p> <p>We prospectively analyzed the estimated blood loss (EBL) and operation time over four stages of scoliosis surgery in 44 patients. The patients were divided into three groups: adolescent idiopathic (group 1), spastic neuromuscular (group 2) and paralytic neuromuscular (group 3). The per-level EBL and operation times of the groups were compared on a stage-by-stage basis. The bone marrow density (BMD) of each patient was also obtained, and the relationship between per-level EBL and BMD was compared using regression analysis.</p> <p>Results</p> <p>Per-level operation time was similar across all groups during surgical stage (p > 0.05). Per-level EBL was also similar during the dissection and bone-grafting states (p > 0.05). However, during the screw insertion stage, the per-level EBL was significantly higher in groups 2 and 3 compared to group 1 (p < 0.05). In the correction stage, per-level EBL was highest in group 3 (followed in order by groups 2 and 1) (p < 0.05). Preoperative BMD indicated that group 3 had the lowest bone quality, followed by groups 2 and 1 (in order), but the preoperative blood indices were similar in all groups. The differences in bleeding patterns in the screw insertion and correction stages were attributed to the poor bone quality of groups 2 and 3. Group 3 had the lowest bone quality, which caused loosening of the bone-screw interface during the correction stage and led to more bleeding. Patients with a T-score less than -2.5 showed a risk for high per-level EBL that was nine times higher than those with scores greater than -2.5 (p = 0.003).</p> <p>Conclusions</p> <p>We investigated the blood loss patterns during different stages of scoliosis surgery. Patients with poor BMD showed a risk of blood loss nine times higher than those with good BMD.</p