228 results on '"Capillary Plasma"'
Search Results
2. High-voltage semiconductor voltage pulse generator for capillary discharge formation in soft X-ray radiation source
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Andrey A. Samokhvalov, Kirill A. Sergushichev, Stepan I. Eliseev, Artyom A. Smirnov, Maria V. Timshina, and Timur P. Bronzov
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soft x-rays ,capillary plasma ,gas-discharge source ,high-voltage generator ,voltage transformer ,capacitive storage ,computer simulation ,altium designer ,solidworks ,ltspice ,Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
The results of the development of a high-voltage semiconductor voltage generator (based on IGBT transistors) with a pulse transformer and the results of experiments on generating a capillary discharge using it on a compact gas-discharge source capable of generating pulses of soft X-ray radiation (SXR) in the area of the socalled «water window» - with wavelength in the range of 2.4...4.4 nm. Methods for designing a high-voltage pulse voltage pulse generator are described: theoretical calculations and results of modeling the electrical circuit diagram in the LTSpice software package, the developed design of a pulse transformer based on N87 ring ferrites and the generator itself is described, the results of its operation as part of a compact gas-discharge radiation source are presented and analyzed. The prospects of using such a high-voltage generator (with semiconductor transistor switches) with a pulse transformer as part of a soft X-ray radiation source are shown due to its technical and operational features: the developed generator is capable of operating from an alternating current network of 380 V/50 Hz in a frequency-burst mode (with a repetition rate of the generated voltage pulses up to 600 Hz) and charges the capillary capacitance of the SXR source to a voltage of more than 20 kV in a time of about 4 μs, has small dimensions, does not create pulsed high-frequency interference and false alarms, and also has stable output (amplitude-temporary) parameters.
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- 2023
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3. Optimization of Parameters of a Compact Soft X-Ray Source for Operation in the Wavelength Range 2–5 nm.
- Author
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Samokhvalov, A. A., Sergushichev, K. A., Eliseev, S. I., Bronzov, T. P., Bolshakov, E. P., Getman, D. V., and Smirnov, A. A.
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PULSE generators , *RADIANT intensity , *SPECTRAL lines , *MICROSCOPY , *WAVELENGTHS , *SOFT X rays - Abstract
This paper presents a compact source of soft X-ray radiation for operation in the wavelength range of 2–5 nm with a pulse repetition frequency of more than 500 Hz. The source parameters were optimized to reduce the intensity of ablation of the discharge volume wall and obtain the maximum intensity of the spectral lines of multicharged ions CV—4 nm and Ar IX—4.87 nm. The obtained results can be used in the development of a microscope for the tasks of cell transmission microscopy with nanometer resolution. [ABSTRACT FROM AUTHOR]
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- 2024
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4. Pulsed Discharge Characteristics of a Semicombustible Plasma Generator for ETC Launchers
- Author
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Yong Jin
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Stress (mechanics) ,Propellant ,Generator (circuit theory) ,Nuclear and High Energy Physics ,Materials science ,Equivalent series resistance ,Capillary Plasma ,Nuclear engineering ,Plasma ,Condensed Matter Physics ,Plasma generator ,Voltage - Abstract
A semicombustible plasma generator (SCPG), including a special tubular semicombustible medium, is introduced to improve the discharge property of the plasma generator and enhance the electrothermal–chemical (ETC) launch efficiency. The new structure of SCPG is mixed with both capillary plasma generator (CPG) and discharge rod plasma generator (DRPG). After the design and simulation, the electrical characteristics of this SCPG are discussed with both static test and dynamic tests. Results show that the SCPG is a resistive load with low inductance, which has stable and consistent electrical parameters. With the increase of discharge voltage, the peak current of SCPG is increased and the equivalent resistance of SCPG is decreased. The peak voltage is nearly 1.3 kV and the pulse current bottom width is more than 3.5 ms. Compared with the DRPG, the load characteristics of SCPG are in a stable and consistent trend during the pulsed discharge process as the same as DRPG. Also, the SCPG has longer stable working times and better stable working parameters and performance. This SCPG will promote the interaction between the plasma and propellants in the chamber.
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- 2021
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5. Pharmacokinetic studies with PET
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Bergström, Mats, Långström, Bengt, Herrling, Paul L., editor, Matter, Alex, editor, and Rudin, Markus, editor
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- 2005
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6. Capillary blood as a complementary matrix for doping control purposes. Application to the definition of the individual longitudinal profile of IGF-1.
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Stacchini, Carlotta, Botrè, Francesco, de la Torre, Xavier, and Mazzarino, Monica
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LIQUID chromatography-mass spectrometry , *CAPILLARIES , *SOMATOMEDIN C - Abstract
We present a novel procedure to monitor the fluctuations of the levels of IGF-1 in capillary blood in the framework of doping control analysis. Being an endogenous hormone, direct methods are not applicable, so the most effective way to detect the intake of the exogenous hormone would be based on the longitudinal monitoring of the athlete. We have therefore followed the individual variability, in four subjects (two males and two females), of the levels of IGF-1 in capillary blood samples collected three times per day for five days, then once a week for at least two months. Analyses were performed by liquid chromatography coupled to tandem mass spectrometry following a bottom-up approach. The whole protocol, from the sample collection to the instrumental analysis, was validated according to the World Anti-Doping Agency's guidelines and ISO17025. The analytical protocol showed to be fit for purpose in terms of sensitivity (LOD 25 ng/mL and LOI 35 ng/mL), selectivity (no interferences were detected at the retention time of IGF-1 and the internal standard), and repeatability (CV<10%). The linearity was confirmed in the range of 50–1000 ng/mL (correlation coefficient R2 >0.995, with a % relative bias of the experimental concentration of the different calibrators used for the estimation of the linearity lower than 20% for the lowest level and than 15% for the other levels). Stability studies were also performed, also to establish the optimal conditions for transport and storage: samples were stable at 4 °C for up to 72 h and at −20 °C and −80 °C for up to three months. Our preliminary results indicate that, in all subjects, the levels of IGF-1 did not present significant circadian fluctuations and remained stable during the entire period of the study (2–3 months, depending on the subject). The stability over time of IGF-1 levels in capillary blood indicates the possibility of detecting the intake of the non-endogenous hormone based on a longitudinal approach, as it is modeled in the framework of the endocrinological module of the athlete biological passport. [Display omitted] • Capillary blood sampling is proposed for the analysis in the antidoping field. • A method for quantifying IGF-1 using a bottom-up approach is presented. • The method was successfully used to quantify IGF-1 levels in volunteers. • Individual variability of IGF-1 levels in capillary plasma was measured. • Longitudinal monitoring IGF-1 levels in capillary blood can allow to detect its abuse. [ABSTRACT FROM AUTHOR]
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- 2023
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7. Performance of Capillary Plasma Source With Combustible Materials
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Nouf Almousa and Mohamed Bourham
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Nuclear and High Energy Physics ,Jet (fluid) ,Materials science ,Plasma ,Escape velocity ,Mechanics ,Condensed Matter Physics ,Kinetic energy ,Combustion ,01 natural sciences ,Energetic material ,010305 fluids & plasmas ,Heat flux ,Physics::Plasma Physics ,Capillary Plasma ,0103 physical sciences - Abstract
Application of an energetic material (EM) in a liquid or gaseous form to electrothermal (ET) plasma discharge systems can provide an energetic plasma jet that has desirable parameters for launching applications. In this energetic ET concept, the EM is basically injected into the plasma source that is operated in an ablation-free regime. The discharge and EM combustion processes have been simulated using the ETFlowCom code, which is an in-house developed energetic ET plasma model. In this article, the ETFlowCom code is used to predict the energetic plasma jet parameters such as temperature, pressure, heat flux, and exit velocity. Different computational case studies have been conducted using a variety of EM mixtures. The simulation results show that the generated energetic plasma jet has the density on the order of 10271/m3, kinetic pressure on the order of hundreds of MPa, and an exit velocity that can reach up to 6 km/s. These parameters are found to be functions of the EM type and the mixing ratio as well. The jet parameters show strong potential for launching applicability.
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- 2019
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8. Effects of Modified Arm Swing Exercise Program on Capillary Plasma Glucose and Body Composition in People with Uncontrolled Type 2 Diabetes
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Jiraporn Lininger, Sangthong Terathongkum, and Ratchanok Phonyiam
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medicine.medical_specialty ,Exercise program ,business.industry ,Arm swing ,Capillary Plasma ,Internal medicine ,Cardiology ,medicine ,Type 2 diabetes ,medicine.disease ,business - Published
- 2019
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9. Hollow electrode capillary plasma ionization source for rapid online detection of gaseous samples
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Wen Xu, Zeyue Shen, Keqi Tang, Tengyu Zhang, Huanming Wu, Jiancheng Yu, Junliang Zhang, and Chenlu Wang
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Chemical ionization ,Chemistry ,Capillary Plasma ,Ionization ,Organic Chemistry ,Analytical chemistry ,Dielectric barrier discharge ,Gas chromatography–mass spectrometry ,Mass spectrometry ,Spectroscopy ,Electron ionization ,Analytical Chemistry ,Ion - Abstract
Rationale Gas Chromatography Mass Spectrometry (GC-MS) with electron ionization (EI)is the most widely used analysis technique of gaseous samples, but it may be time-consuming for on-line monitoring of mixtures whose concentrations relatively change rapidly. On the other hand, current ionization methods, such as chemical ionization (CI) and proton transfer reaction (PTR), also have some disadvantages such as selectivity. Appropriate soft ionization sources therefore are searched for rapid on-line detection. Methods Hollow Electrode Capillary Plasma Ionization (HECPI) is based on single electrode plasma. A hollow capillary was placed as both the electrode and the inlet of the gaseous samples. The ionization source is coupled with a mass spectrometer for performance evaluation. Results Several typical compounds have been tested with HECPI-mass spectrometer. In this process, the dominant ion peaks of all compounds can be indexed as molecular ion peaks, and the product ions of HECPI are less than that of dielectric barrier discharge ionization (DBDI). Three gaseous samples (linalool, triethylamine and styrene) with various concentrations have been employed to further confirm the performance of this source, and the detection limit of linalool is as low as 10 ppb. Conclusions HECPI is simple in structure and shows good performance. The results also show that HECPI has the potential to be an effective tool for detecting on-line gaseous samples rapidly.
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- 2021
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10. Plug-and-play laser ablation-mass spectrometry for molecular imaging by means of dielectric barrier discharge ionization
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Elias Lützen, Markus Weber, Sabrina K. I. Funke, Uwe Karst, Jan-Christoph Wolf, Christoph Haisch, and Valérie A. Brückel
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Laser ablation ,Capillary action ,Chemistry ,010401 analytical chemistry ,Analytical chemistry ,02 engineering and technology ,Dielectric barrier discharge ,021001 nanoscience & nanotechnology ,Mass spectrometry ,01 natural sciences ,Biochemistry ,Mass spectrometry imaging ,Mass Spectrometry ,0104 chemical sciences ,Analytical Chemistry ,Molecular Imaging ,Capillary Plasma ,Ionization ,Environmental Chemistry ,Sample preparation ,Laser Therapy ,0210 nano-technology ,Spectroscopy - Abstract
The plug-and-play hyphenation of UV-laser ablation (LA) and mass spectrometry is presented, using dielectric barrier discharge ionization (DBDI). The DBDI source employed here is characterized by its unique geometry, being directly mounted onto the inlet capillary of a mass spectrometer. In the literature, this particular kind of DBDI source is also referred to as active capillary plasma ionization. It has been commercialized as soft ionization by chemical reaction in transfer (SICRIT) and will be addressed as DBDI in this study. LA-DBDI-MS was used for the direct, molecule-specific and spatially resolved analysis of various solid samples, such as coffee beans and pain killer tablets without extensive sample preparation. The combination of fast washout UV-laser ablation and the principle of the DBDI source used here allowed for highly efficient soft ionization as well as high spatial resolution down to 10 μm for molecular imaging.
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- 2021
11. An integrated electrochemical microsystem for real-time treatment monitoring of clozapine in microliter volume samples from schizophrenia patients
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Fang Liu, Hadar Ben-Yoav, Rajendra P. Shukla, Deanna L. Kelly, Matthew Glassman, and Crystal Rapier
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medicine.medical_treatment ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,lcsh:Chemistry ,Capillary Plasma ,In situ electroanalysis ,Microsystem ,Electrochemistry ,medicine ,Antipsychotic ,Clozapine ,Whole blood ,Detection limit ,Integrated electrochemical micro-system ,business.industry ,021001 nanoscience & nanotechnology ,medicine.disease ,0104 chemical sciences ,Point-of-care testing ,Microelectrode ,lcsh:Industrial electrochemistry ,lcsh:QD1-999 ,Schizophrenia ,Antipsychotic clozapine ,0210 nano-technology ,business ,Biomedical engineering ,medicine.drug ,lcsh:TP250-261 - Abstract
This work presents the development of an electrochemical microsystem for antipsychotic clozapine treatment monitoring in schizophrenia patients. In our previous work, we demonstrated clozapine detection directly in spiked whole blood samples of a healthy volunteer using a chitosan–carbon nanotube-modified microelectrode with external counter and reference electrodes. Here we present the miniaturization of our previous clozapine sensing approach and its clinical validation in real samples obtained from 10 schizophrenia patients. We observed a sensitivity of 0.02 ± 2.3 × 10-4 mA/cm2µM and 0.003 ± 2.6 × 10-4 mA/cm2µM and a limit of detection of 0.08 ± 9.2 × 10-4 µM and 0.45 ± 0.04 µM using chitosan–carbon nanotube-modified microelectrodes in a 20 µL volume of spiked capillary plasma and capillary whole blood. Following a calibration curve, which was obtained from spiked samples of patients prior to clozapine therapy administration, clozapine capillary plasma and whole blood levels were recovered from patients’ samples after treatment with clozapine. The developed electrochemical microsystem allows clozapine analysis in a microliter volume of finger-pricked whole blood samples of schizophrenia patients without using any pretreatment steps. By further miniaturization and integration of this sensor into a point-of-care testing device, schizophrenia treatment management can be improved.
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- 2020
12. Determination of finerenone - a novel, selective, nonsteroidal mineralocorticoid receptor antagonist - in human plasma by high-performance liquid chromatography-tandem mass spectrometry and its application to a pharmacokinetic study in venous and capillary human plasma
- Author
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Stephanie Loewen, G. Rohde, and Roland Heinig
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Adult ,Male ,Finerenone ,Clinical Biochemistry ,030226 pharmacology & pharmacy ,01 natural sciences ,Biochemistry ,High-performance liquid chromatography ,Analytical Chemistry ,Veins ,Matrix (chemical analysis) ,03 medical and health sciences ,Young Adult ,0302 clinical medicine ,Pharmacokinetics ,Capillary Plasma ,Tandem Mass Spectrometry ,Protein precipitation ,Humans ,Naphthyridines ,Renal Insufficiency, Chronic ,Chromatography, High Pressure Liquid ,Mineralocorticoid Receptor Antagonists ,Detection limit ,Chromatography ,Cross-Over Studies ,Chemistry ,010401 analytical chemistry ,Venous Plasma ,Cell Biology ,General Medicine ,Middle Aged ,0104 chemical sciences ,Capillaries - Abstract
A straightforward and rapid high-performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS) assay allowing the sensitive and selective quantitation of finerenone (BAY 94–8862) in lithium heparin human plasma is described. Finerenone is a novel, selective, nonsteroidal mineralocorticoid receptor antagonist that is in phase III clinical trials for the treatment of chronic kidney disease. Finerenone quantitation is performed after addition of its stable isotope-labelled internal standard (ISTD) by protein precipitation with acidified acetonitrile followed by HPLC–MS/MS separation and detection. The determination of finerenone concentrations was validated for a plasma volume of 0.100 mL and subsequently also for a lower plasma volume of 0.010 mL, collected e.g. in paediatric studies. The analytical range was from 0.100 µg/L (lower limit of quantification) to 200 µg/L (upper limit of quantification). Inter-day accuracy was 99.7–105.0% for the plasma volume of 0.100 mL and 101.1–104.5% for the plasma volume of 0.010 mL. Inter-day precision was ≤ 7.0%, independent of the extracted plasma volume. A moderate, concentration-independent matrix effect on ionisation was observed for both finerenone and its ISTD of 0.535–0.617, which is fully compensated by the ISTD (ISTD-normalised matrix factors were 0.98–1.03). The assay was successfully applied with both validated plasma volumes to a clinical phase I study in which the pharmacokinetics of 20 mg finerenone were compared in capillary plasma (0.010 mL) and venous plasma (0.100 mL) in a concentration range from the lower limit of quantification to 310 µg/L (capillary plasma) and 252 µg/L (venous plasma). The area under the plasma concentration versus time curve was similar in both matrices, while maximum concentrations were 37% higher in capillary plasma. In conclusion, capillary sampling should not bias pharmacokinetic exposure estimates compared with venous plasma values, if limited to sampling times in the distribution and elimination phases of finerenone.
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- 2020
13. Protein measurements in venous plasma, earlobe capillary plasma and in plasma stored on filter paper
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Thomas Pekar, Benjamin Siart, Masood Kamali-Moghaddam, Felipe Marques Souza de Oliveira, Bernard Wallner, Johan Björkesten, Qiujin Shen, Ralf Steinborn, and Alfred Nimmerichter
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Adult ,Male ,Analyte ,Extension assay ,Capillary action ,Biophysics ,Medical Biotechnology (with a focus on Cell Biology (including Stem Cell Biology), Molecular Biology, Microbiology, Biochemistry or Biopharmacy) ,Biochemistry ,Specimen Handling ,Young Adult ,03 medical and health sciences ,0302 clinical medicine ,Phlebotomy ,Venules ,Capillary Plasma ,medicine ,Humans ,Multiplex ,Medicinsk bioteknologi (med inriktning mot cellbiologi (inklusive stamcellsbiologi), molekylärbiologi, mikrobiologi, biokemi eller biofarmaci) ,Molecular Biology ,Earlobe ,030304 developmental biology ,0303 health sciences ,Chromatography ,Filter paper ,Chemistry ,Inflammation protein biomarkers ,Ear ,Venous Plasma ,Blood Proteins ,Cell Biology ,Venous blood ,Dried plasma spots ,Healthy Volunteers ,medicine.anatomical_structure ,Earlobe capillary ,Cytokines ,Biomarkers ,030217 neurology & neurosurgery - Abstract
In this study, levels of inflammatory protein biomarkers in venous plasma, plasma derived from capillary blood from the earlobe, and capillary plasma stored as dried plasma spots (DPS) were compared. Samples from 12 male individuals were assessed with a panel of 92 inflammation-related proteins using multiplex proximity extension assay. Correlations between sample types varied greatly between analytes. A high correlation of rho > 0.8 was observed between capillary plasma and DPS for 32 analytes. At this level of correlation, 13 analytes correlated between venous and capillary plasma and 5 analytes in the comparison of venous blood with DPS.
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- 2019
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14. Wake fields effects in dielectric capillary
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Enrica Chiadroni, Alessandro Cianchi, J. Scifo, Luca Ficcadenti, Maria Pia Anania, Giovanni Castorina, Marco Bellaveglia, Hesham Fares, E. Brentegani, F. Filippi, Bruno Spataro, Cristina Vaccarezza, D. Di Giovenale, Massimo Ferrario, Fabio Villa, Angelo Biagioni, G. Di Pirro, Arie Zigler, Riccardo Pompili, and Andrea Mostacci
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Accelerator Physics (physics.acc-ph) ,Deceleration ,Dielectric capillary ,Dielectric wakefield acceleration ,Transverse electric field ,Wakefield structure ,Nuclear and High Energy Physics ,Instrumentation ,FOS: Physical sciences ,02 engineering and technology ,Dielectric ,Electron ,01 natural sciences ,7. Clean energy ,Physics::Fluid Dynamics ,Acceleration ,Physics::Plasma Physics ,Capillary Plasma ,Electric field ,0103 physical sciences ,010302 applied physics ,Physics ,Settore FIS/01 - Fisica Sperimentale ,Plasma ,021001 nanoscience & nanotechnology ,Settore FIS/07 - Fisica Applicata(Beni Culturali, Ambientali, Biol.e Medicin) ,Computational physics ,Transverse plane ,Physics::Accelerator Physics ,Physics - Accelerator Physics ,0210 nano-technology ,Beam (structure) - Abstract
Plasma wake-field acceleration experiments are performed at the SPARC_LAB test facility by using a gas-filled capillary plasma source composed of a dielectric capillary. The electron can reach GeV energy in a few centimeters, with an accelerating gradient orders of magnitude larger than provided by conventional techniques. In this acceleration scheme, wake fields produced by passing electron beams through dielectric structures can determine a strong beam instability that represents an important hurdle towards the capability to focus high-current electron beams in the transverse plane. For these reasons, the estimation of the transverse wake-field amplitudes assumes a fundamental role in the implementation of the plasma wake-field acceleration. In this work, it presented a study to investigate which parameters affect the wake-field formation inside a cylindrical dielectric structure, both the capillary dimensions and the beam parameters, and it is introduced a quantitative evaluation of the longitudinal and transverse electric fields.
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- 2018
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15. Plasma temperature measurements using black-body radiation from spectral lines emitted by a capillary discharge
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Erik Wagenaars, G.J. Tallents, T. Page, Sarah Wilson, and J. Branson
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Radiation ,Materials science ,genetic structures ,Opacity ,Plasma parameters ,business.industry ,Plasma ,01 natural sciences ,Temperature measurement ,Atomic and Molecular Physics, and Optics ,Spectral line ,010309 optics ,Wavelength ,Optics ,Physics::Plasma Physics ,Capillary Plasma ,0103 physical sciences ,Black-body radiation ,sense organs ,010306 general physics ,business ,Spectroscopy - Abstract
Optically thick spectral line emssion from plasmas is often difficult to use for the diagnosis of plasma parameters. We demonstrate a technique for temperature measurement using the peak intensity of optically thick lines as their intensities approach a black-body distribution. Recording optical emission in the wavelength range 300–1000 nm from a plasma formed by radio-frequency heating and electrical discharges in a 0.2 m long capillary plasma, we show that the high wavelength Rayleigh-Jeans form of the black-body emission can be fitted to the most intense spectral lines to give a measurement of plasma temperatures in the 1–1.5 eV range. The temperature measurement technique should have wider applicability in diagnosing plasmas with optically thick spectral lines.
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- 2018
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16. Numerical Models for Interactions of Ablating-Capillary Plasma With Air and Bulk-Loaded Liquid
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Qi Zhang, Shanshan Mang, and Yonggang Yu
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Propellant ,Nuclear and High Energy Physics ,Jet (fluid) ,animal structures ,Materials science ,Capillary action ,02 engineering and technology ,Plasma ,Mechanics ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,complex mixtures ,01 natural sciences ,010305 fluids & plasmas ,Arc (geometry) ,Physics::Plasma Physics ,Capillary Plasma ,Ionization ,0103 physical sciences ,Dynamic pressure ,0210 nano-technology ,human activities - Abstract
The jet expansion behaviors of ablating-capillary plasma used in the liquid propellant electrothermal chemical gun were investigated. A pulsed power system was built up to drive the arc plasma generator by high-voltage discharge in polyethylene capillary. The temporal evolutions of the arc plasma jet in both open air and bulk-loaded liquid were analyzed with high-speed imaging and dynamic pressure measurements. The arc plasma jet exhibited rapid axial expansion and strongly turbulent mixing with the ambient fluids. Experiments conducted with different discharge voltages showed that the voltage had a significant effect on the axial expanding speed of the arc plasma jet. A 2-D magneto-hydrodynamic model, which consisted of several submodels, such as the capillary ablation model, the species ionization model, the high-temperature radiation model, and the turbulent model, was developed to describe the generation and evolution of arc plasma jet. Good agreements between calculations and experiments in the aspects of jet contours and pressure histories indicated that the current model had the capacity to capture the major physical features of the ablating-capillary arc plasma jet.
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- 2018
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17. Discharge Characteristics of a Gas-Filled Capillary Plasma for Laser Wakefield Acceleration.
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Kim, M. S., Jang, D. G., Uhm, H. S., Hwang, S. W., Lee, I. W., and Suk, H.
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ELECTRIC discharges , *CAPILLARITY , *PLASMA gases , *POTENTIAL theory (Physics) , *PLASMA accelerators , *INTERFEROMETERS , *HEAT equation , *GAS lasers - Abstract
A gas-filled capillary plasma source for potential use in conjunction with laser wakefield acceleration is developed, and its discharge characteristics are presented here. In the capillary, helium or hydrogen gas ( \sim150 torr in pressure) is injected, and a pulsed high voltage (\sim25 kV) is applied for electrical discharge and plasma production. The discharge properties of the helium and hydrogen gases are compared. The plasma densities inside the capillary hole are measured with a Mach–Zehnder interferometer and are obtained separately by a simple analysis using the diffusion equation and measured current profiles. [ABSTRACT FROM AUTHOR]
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- 2011
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18. Macroscopic Description of a Discharge Current in a Capillary Discharge System.
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Uhm, H. S., Kim, M. S., Nam, I. H., Lee, I. W., Oh, S. Y., and Suk, H.
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CAPILLARITY , *ELECTRIC discharges , *BREAKDOWN voltage , *PLASMA accelerators , *ELECTRIC wave damping , *PLASMA density , *TEMPERATURE measurements , *ELECTRIC inductance - Abstract
Based on a simple circuit model, the global properties of the electrical discharge in a capillary discharge system are investigated by analyzing the breakdown electron temperature in terms of the applied voltage. The electrical charge and current flowing through the capillary hole are calculated from a theoretical model and compared with experimental observations, providing valuable information pertaining to system inductance, discharge-plasma resistivity in terms of the applied voltage, the breakdown temperature of electrons, and the time-averaged plasma density. The response time of the electrical breakdown in the capillary hole is expressed in terms of the electron temperature and the applied voltage. [ABSTRACT FROM AUTHOR]
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- 2010
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19. Investigation of the breakdown temperature in capillary discharge plasmas
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Oh, Seong Y., Uhm, Han S., Kim, Min-Seok, Sohn, Ik-Bu, and Suk, Hyyong
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PLASMA diagnostics , *ELECTRON temperature , *ELECTRIC breakdown , *ELECTRONS , *BREAKDOWN voltage , *THERMODYNAMIC equilibrium - Abstract
Abstract: We developed a simple way to estimate the breakdown temperature of plasma electrons in a capillary, which is based on measurement of the electrical breakdown voltage . The result shows that the breakdown temperature decreases with increasing pressure. The thermal equilibrium electron temperature in the capillary plasma after the electrical discharge is also measured by using the optical emission spectroscopy method. [ABSTRACT FROM AUTHOR]
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- 2010
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20. Plasmochemical degradation of volatile organic compounds (VOC) in a capillary discharge plasma Reactor.
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Koutsospyros, Agamemnon D., Yin, Shu-Min, Christodoulatos, Christos, and Becker, Kurt
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VOLATILE organic compounds , *PLASMA displays , *ELECTRODES , *ELECTRIC discharges , *ORGANIC compounds - Abstract
We report the results of parametric and kinetic studies of the plasmochemical degradation of volatile organic compounds (VOCs) present in respirable atmospheres using a nonthermal ambient-pressure plasma generated in a pin-to-plate capillary plasma electrode (CPE) discharge reactor. Parameters studied included the reactor volume, contaminant residence time, energy density, and influent contaminant concentration. A kinetic model was developed based on a plug-flow regime and a second-order kinetic expression with respect to the reactive plasma species and contaminant concentration. Experimental data were fitted to the proposed model using nonlinear regression techniques, and plasmochemical degradation rate constants were determined for toluene, ethylbenzene, and m-xylene as model compounds. [ABSTRACT FROM PUBLISHER]
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- 2005
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21. Destruction of hydrocarbons in non-thermal, ambient-pressure, capillary discharge plasmas
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Koutsospyros, A., Yin, S.-M., Christodoulatos, C., and Becker, K.
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HYDROCARBONS , *IONIZATION (Atomic physics) , *ATMOSPHERIC pressure , *DIFFUSION - Abstract
This present work investigates the effectiveness of non-thermal diffuse plasmas for the destruction of environmental contaminants that are present in trace concentrations in respirable atmospheres. Parametric studies were carried out using three atmospheric-pressure capillary plasma reactors of varying geometry. Volatile aliphatic and aromatic hydrocarbons, at concentrations of up to several hundred parts per million (ppm), were used as prototypical compounds for these studies. Parameters studied included the reactor volume, the species residence time, the specific energy input, and the influent contaminant concentration. Moreover, the dependence of the overall destruction efficiency on specific energy, contaminant type, and presence of other contaminants in well-defined contaminant mixtures was evaluated. By-product formation during the plasma chemical destruction was assessed by monitoring the concentration of gaseous nitrogen and carbon oxides, namely, NOx (NO, NO2) and COx (CO, CO2). Carbon mass balances were used to assess the possibility of complete contaminant destruction leading to mineralization. Systematic trends are highlighted and show that the destruction efficiency increases with specific energy, but tends to level off at values of specific energy that are compound dependent. An inverse relationship between the maximum destruction efficiency of a particular compound and its ionization energy was found for chemically similar compounds. [Copyright &y& Elsevier]
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- 2004
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22. Determination of piperaquine concentration in human plasma and the correlation of capillary versus venous plasma concentrations
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Francesca T. Aweeka, Richard Kajubi, Vincent Cheah, Norah Mwebaza, Liusheng Huang, Grant Dorsey, Erika Wallender, Philip J. Rosenthal, Camilla Forsman, Florence Marzan, and Schallig, Henk DFH
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Physiology ,medicine.medical_treatment ,Maternal Health ,030226 pharmacology & pharmacy ,Biochemistry ,0302 clinical medicine ,Mathematical and Statistical Techniques ,Pregnancy ,Medicine and Health Sciences ,030212 general & internal medicine ,Child ,Multidisciplinary ,Chemistry ,Statistics ,Obstetrics and Gynecology ,Venous Plasma ,Blood proteins ,Body Fluids ,Blood ,Infectious Diseases ,Physical Sciences ,Quinolines ,Medicine ,Regression Analysis ,Female ,Anatomy ,Research Article ,Adult ,Analyte ,Coefficient of determination ,General Science & Technology ,Science ,Dihydroartemisinin ,Linear Regression Analysis ,Research and Analysis Methods ,Blood Plasma ,Veins ,03 medical and health sciences ,Pharmacokinetics ,Capillary Plasma ,Clinical Research ,Piperaquine ,medicine ,Parasitic Diseases ,Humans ,Statistical Methods ,Pharmacology ,Chromatography ,Plasma Proteins ,Biology and Life Sciences ,Proteins ,Tropical Diseases ,Malaria ,Capillaries ,Cardiovascular Anatomy ,Linear Models ,Blood Vessels ,Women's Health ,Mathematics - Abstract
Background: A considerable challenge in quantification of the antimalarial piperaquine in plasma is carryover of analyte signal between assays. Current intensive pharmacokinetic studies often rely on the merging of venous and capillary sampling. Drug levels in capillary plasma may be different from those in venous plasma, Thus, correlation between capillary and venous drug levels needs to be established.Methods: Liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) was used to develop the method. Piperaquine was measured in 205 pairs of capillary and venous plasma samples collected simultaneously at ≥24hr post dose in children, pregnant women and non-pregnant women receiving dihydroartemisinin-piperaquine as malaria chemoprevention. Standard three-dose regimen over three days applied to all participants with three 40mg dihydroartemisinin/320mg PQ tablets per dose for adults and weight-based dose for children. Correlation analysis was performed using the program Stata® SE12.1. Linear regression models were built using concentrations or logarithm transformed concentrations and the final models were selected based on maximal coefficient of determination (R2) and visual check.Results: An LC-MS/MS method was developed and validated, utilizing methanol as a protein precipitation agent, a Gemini C18 column (50x2.0mm, 5μm) eluted with basic mobile phase solvents (ammonium hydroxide as the additive), and ESI+ as the ion source. This method had a calibration range of 10-1000 ng/mL and carryover was negligible. Correlation analysis revealed a linear relationship: Ccap = 1.04×Cven+4.20 (R2 = 0.832) without transformation of data, and lnCcap = 1.01×lnCven+0.0125, (R2 = 0.945) with natural logarithm transformation. The mean ratio (±SD) of Ccap/Cven was 1.13±0.42, and median (IQR) was 1.08 (0.917, 1.33).Conclusions: Capillary and venous plasma PQ measures are nearly identical overall, but not readily exchangeable due to large variation. Further correlation study accounting for disposition phases may be necessary.
- Published
- 2020
23. Expanding access to SARS-CoV-2 IgG and IgM serologic testing using fingerstick whole blood, plasma, and rapid lateral flow assays
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Gavin A. Cloherty, James N. Moy, Russell H. Taylor, Ana Vallari, Mark C Anderson, and Vera Holzmayer
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0301 basic medicine ,medicine.medical_specialty ,Fingerstick ,030106 microbiology ,Antibodies, Viral ,Sensitivity and Specificity ,Gastroenterology ,Asymptomatic ,Article ,Antibodies ,Serology ,Microtainer ,03 medical and health sciences ,COVID-19 Testing ,0302 clinical medicine ,Seroepidemiologic Studies ,Capillary Plasma ,Virology ,Internal medicine ,medicine ,Humans ,030212 general & internal medicine ,COVID-19 Serotherapy ,Whole blood ,Rapid Diagnostics ,biology ,SARS-CoV-2 ,business.industry ,fungi ,Immunization, Passive ,COVID-19 ,Reproducibility of Results ,Venous Plasma ,Dried Blood Spots ,Dried blood spot ,Infectious Diseases ,Immunoglobulin M ,Immunoglobulin G ,biology.protein ,Sample collection ,Antibody ,medicine.symptom ,business - Abstract
Serologic testing for SARS-CoV-2 antibodies can be used to confirm diagnosis, estimate seroprevalence, screen convalescent plasma donors, and assess vaccine efficacy. Several logistical and infrastructure challenges limit access to SARS-CoV-2 serologic testing. Dried blood spot (DBS) samples have been used for serology testing of various diseases in resource-limited settings. We examined the use of DBS samples and capillary blood (fingerstick) plasma collected in Microtainer tubes for SARS-CoV-2 testing with the automated Abbott ARCHITECT™ SARS-CoV-2 IgG (List 6R86) and IgM assays and use of venous whole blood with a prototype PANBIO™ rapid point-of-care lateral flow SARS-CoV-2 IgG assay. The ARCHITECT™ SARS-CoV-2 IgG assay was initially optimized for use with DBS, venous and capillary plasma, and venous whole blood collected from patients with symptoms and PCR-confirmed COVID-19 and negative asymptomatic controls. Assay linearity and reproducibility was confirmed with 3 contrived DBS samples, with sample stability and signal recovery after 14 days at room temperature. ARCHITECT™ SARS-CoV-2 IgG and IgM assay results showed high concordance between fingerstick DBS and venous DBS samples, and between fingerstick DBS and venous whole blood samples (n=61). Discordant results were seen in 3 participants (2 IgG, 1 IgM) who were in the process of seroreversion at the time of sample collection and had results near the assay cutoff. Use of fingerstick plasma collected in Microtainer tubes (n=109) showed 100% concordant results (R2=0.997) with matched patient venous plasma on the ARCHITECT™ SARS-CoV-2 IgG assay. High concordance of assay results (92.9% positive, 100% negative) was also observed for the PANBIO™ SARS-CoV-2 IgG assay compared to the ARCHITECT™ SARS-CoV-2 IgG assay run with matched venous plasma (n=61). Fingerstick DBS and plasma samples are easy and inexpensive to collect and, along with the use of rapid point-of-care testing platforms, will expand access to SARS-CoV-2 serology testing, particularly in resource-limited areas.
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- 2021
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24. Low jitter parabolic profile low density plasma channel in 3D printed gas filled capillary
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Costa Gemma, Arie Zigler, Riccardo Pompili, Maria Pia Anania, Yoav Raz, Mario Galletti, Ehud Behar, Angelo Biagioni, and Yair Ferber
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Nuclear and High Energy Physics ,3d printed ,Settore FIS/03 ,Materials science ,business.industry ,Capillary action ,Settore FIS/07 ,Condensed Matter Physics ,Nuclear Energy and Engineering ,Capillary Plasma ,Low jitter ,Low density ,Optoelectronics ,Plasma channel ,business - Published
- 2021
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25. Investigation of Geometry and Current Density Effects in a Pulsed Electrothermal Plasma Source Using a 2-D Simulation Model
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M. J. Esmond and A. Leigh Winfrey
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Nuclear and High Energy Physics ,Materials science ,Plasma parameters ,Projectile ,Capillary action ,Magnetic confinement fusion ,Geometry ,Plasma ,Condensed Matter Physics ,01 natural sciences ,010305 fluids & plasmas ,Physics::Plasma Physics ,Capillary Plasma ,Electric field ,0103 physical sciences ,010306 general physics ,Current density - Abstract
Electrothermal (ET) plasma discharges have application to mass acceleration technologies relevant to military ballistics and magnetic confinement fusion reactor operation. ET plasma discharges are initiated in capillary geometries by passing large currents (order of tens of kiloamperes) along the capillary axis. A partially ionized plasma then forms and radiates heat to the capillary walls inducing ablation. Ablated particles enter the capillary plasma source and cause a pressure surge that can propel pellets to velocities exceeding 2 km/s. These devices present several advantages over other mass accelerator technologies due to their simple design and ability to achieve high projectile launch frequencies. In order to investigate the operation of ET plasma discharges in more detail than previously possible, a 2-D, multifluid model has been developed to simulate the plasma-fluid dynamics that develop in these devices during operation. In this paper, the 2-D simulation model is used to investigate the effect of source geometry and current density on discharge characteristics. Peak pressure and electric field magnitudes for pulsed discharge operation are shown to scale well with theoretical and empirical scaling laws for steady-state discharge operation. The pulse shape of the source internal pressure is shown to change significantly with increasing source radius. The behavior of other plasma parameters is investigated. In addition, observations of the departure from the ablation-controlled arc regime are presented. This analysis suggests that, for the current pulse length investigated, source radii higher than 4 mm require significantly more current density in order to produce sufficient ablation to stabilize the plasma discharge.
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- 2017
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26. Study on a New Ignition Method of the Spark Gap Based on Plasma Ejection in Air
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Lanjun Yang, J.B. Ma, Wei Wang, Dong Huang, Weidong Ding, P. Huo, and Shuai Liu
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010302 applied physics ,Resistive touchscreen ,Materials science ,Spark gap ,Mechanics ,Plasma ,Condensed Matter Physics ,01 natural sciences ,010305 fluids & plasmas ,law.invention ,Ignition system ,Physics::Plasma Physics ,law ,Capillary Plasma ,0103 physical sciences ,Electric spark ,Trigatron ,Plasma channel - Abstract
A new ignition method of the spark gap based on plasma ejection is proposed in this paper, as the conventional trigatron spark gap performs poorly under the low working coefficient (the ratio of the charging voltage to the self-breakdown voltage) in air. The plasma is generated by the capillary discharge, which has high pressure, high temperature and high velocity. The capillary discharge device is placed inside the low voltage electrode. As long as the triggering signal is sent to the device, a column of the plasma flow is ejected in axial direction and develops rapidly towards the high voltage electrode. Subsequently, the gap is broken down and a high resistive channel is formed, where the thermal ionization takes place and the arc across the whole gap is generated and develops into a well conductive channel. The process of the thermal ionization of the high resistive channel varies with the change of the spark gap distance. The breakdown delay and the delay jitter of the spark gap increase with the spark gap distance, as both parameters are mainly determined by the developing process of the plasma ejection. The characteristics of the plasma flow determine the possibility of the breakdown of the spark gap under the low working coefficient. The ignition method based on capillary plasma ejection has been proved by the preliminary experiments, which indicate that under the gap length of 8 cm and the working coefficient of less than 3%, the effective ignition is still achievable.
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- 2016
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27. Comparison of Capillary and Venous Plasma Drug Concentrations After Repeated Administration of Risperidone, Paliperidone, Quetiapine, Olanzapine, or Aripiprazole
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Jay Ariyawansa, Bart Remmerie, Marc De Meulder, and Adam Savitz
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Olanzapine ,Adult ,Male ,capillary concentrations ,Adolescent ,olanzapine ,Aripiprazole ,Pharmaceutical Science ,Original Manuscript ,Pharmacology ,030226 pharmacology & pharmacy ,Veins ,Fingers ,03 medical and health sciences ,Benzodiazepines ,Quetiapine Fumarate ,Young Adult ,0302 clinical medicine ,Capillary Plasma ,Paliperidone Palmitate ,medicine ,Humans ,Pharmacology (medical) ,Paliperidone ,Blood Specimen Collection ,Risperidone ,risperidone ,business.industry ,Venous Plasma ,Venous blood ,Articles ,quetiapine ,Middle Aged ,030227 psychiatry ,Capillaries ,antipsychotics ,Anesthesia ,Schizophrenia ,Quetiapine ,Female ,antipsychotic drug monitoring ,business ,venous concentrations ,paliperidone ,medicine.drug ,Antipsychotic Agents ,Half-Life - Abstract
Quantification of blood levels of antipsychotic drugs may be useful for managing medication therapy. This open‐label, parallel‐group study was performed to compare finger‐stick‐based capillary with corresponding venous plasma concentrations for risperidone, paliperidone, quetiapine, olanzapine, and aripiprazole and their major metabolites after repeated dosing in patients with schizophrenia or related illnesses. Finger‐stick‐based capillary and venous blood samples were collected at various times within a dosing interval. All drug concentration measurements in the derived plasma samples were performed with validated liquid chromatography–tandem mass spectrometry methods. Finger‐stick‐based capillary and venous plasma drug concentrations after repeated dosing were generally similar. Olanzapine capillary plasma concentrations, however, were on average approximately 20% higher than venous concentrations, with a trend for a relatively greater difference occurring shortly after dosing. In addition, smaller capillary–venous differences were observed for extended‐release and long‐acting intramuscular formulations and for aripiprazole, a drug with a long half‐life, compared with drugs administered as an immediate‐release formulation (risperidone, olanzapine). After repeated dosing, plasma derived from finger‐stick‐based blood was observed to be predictive of the venous concentrations. Capillary sampling may be an appropriate alternative to venous sampling to readily evaluate systemic drug concentrations.
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- 2016
28. Diagnostic accuracy of a fully automated multiplex celiac disease antibody panel for serum and plasma
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Subo Perampalam, Jeff Terryberry, Detlef Schuppan, Stefano Guandalini, Eric Brouwer, Russ Peloquin, and Jani Tuomi
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Adult ,Male ,medicine.medical_specialty ,Adolescent ,Clinical Biochemistry ,Diagnostic accuracy ,Enzyme-Linked Immunosorbent Assay ,Disease ,Gastroenterology ,03 medical and health sciences ,Automation ,Young Adult ,0302 clinical medicine ,Capillary Plasma ,Predictive Value of Tests ,Internal medicine ,Biopsy ,medicine ,Humans ,Multiplex ,030212 general & internal medicine ,Child ,Autoantibodies ,biology ,medicine.diagnostic_test ,business.industry ,Biochemistry (medical) ,General Medicine ,Middle Aged ,Response to treatment ,Celiac Disease ,Fully automated ,Child, Preschool ,biology.protein ,030211 gastroenterology & hepatology ,Female ,Antibody ,business ,Blood Chemical Analysis - Abstract
Background An automated multiplex platform using capillary blood can promote greater throughput and more comprehensive studies in celiac disease (CD). Diagnostic accuracy should be improved using likelihood ratios for the post-test probability of ruling-in disease. Methods The Ig_plex™ Celiac Disease Panel on the sqidlite™ automated platform measured IgA and IgG antibodies to tTG and DGP in n = 224 CD serum or plasma samples. Diagnostic accuracy metrics were applied to the combined multiplex test results for several CD populations and compared to conventional single antibody ELISA tests. Results With multiple positive antibody results, the post-test probability for ruling-in untreated and treated CD increased to over 90%. The number of samples positive for more than one antibody also increased in untreated CD to ≥90%. Measurement of all four CD antibodies generate cut-off dependent accuracy profiles that can monitor response to treatment with the gluten-free diet (GFD). Higher positive tTG and DGP antibodies are seen more frequently in confirmed CD without (81%–94%) than with GFD treatment (44%–64%). In CD lacking biopsy confirmation, overall agreement of plasma to serum was ≥98% for all antibodies, and 100% for venous to capillary plasma. Conclusions The Ig_plex Celiac Disease Panel increases the likelihood of confirming CD based on the post-test probability of disease results for multi-reactive markers. Specific positivity profiles and cut-off intervals can be used to monitor GFD treatment and likely disease progression. Using serum, venous and capillary plasma yield comparable and accurate results.
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- 2018
29. Microexplosions initiated by a microwave capillary torch on a metal surface at atmospheric pressure
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A. M. Davydov, I. A. Kossyi, and S. I. Gritsinin
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Torch ,Argon ,Materials science ,Physics and Astronomy (miscellaneous) ,Atmospheric pressure ,Capillary action ,chemistry.chemical_element ,Plasma ,Condensed Matter Physics ,law.invention ,chemistry ,Physics::Plasma Physics ,law ,Plasma torch ,Capillary Plasma ,Atomic physics ,Microwave - Abstract
The interaction of the plasma of a microwave capillary argon torch with a metal surface was studied experimentally. It is shown that the interaction of the plasma jet generated by the capillary plasma torch with the metal in atmospheric-pressure air leads to the initiation of microexplosions (sparks) on the metal surface. As a result, the initially smooth surface acquires a relief in the form of microtips and microcraters. The possibility of practical application of the observed phenomenon is discussed.
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- 2015
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30. Hyper Jet Focused-Injection Tapered Capillary Plasma Source Concept
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A. Leigh Winfrey, Shawn Mittal, and Mohamed A. Abd Al-Halim
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Nuclear and High Energy Physics ,Jet (fluid) ,Range (particle radiation) ,Materials science ,business.industry ,Capillary action ,Tapering ,Plasma ,Condensed Matter Physics ,Kinetic energy ,Ion ,Optics ,Capillary Plasma ,Atomic physics ,business - Abstract
The concept of tapered capillary is introduced as a method of injecting focused plasma jet into the breach of bulk-loaded electrothermal-chemical (ETC) launcher. Tapered capillaries will operate in the confined controlled arc regime, and they can provide the advantage of producing focused hyper plasma jets useful for ignition of ETC systems at controlled plasma temperatures and pressures. The concept is also useful for focused implantation of plasma ions on substrates with desired patterns. Such tapered capillaries can inject plasmas at peak kinetic temperatures in the range of 14000-21000 K (~1.2-1.8 eV) and considerable jet pressures of 10-70 MPa for an input discharge current of 20-30 kA over a short pulselength of 100-150 μs. A tapered geometry made of Lexan polycarbonate with 16.8-mm inlet and 8.8-mm outlet radii produces a plasma jet with a plasma temperature of 14253 K (1.23 eV) at a peak bulk velocity of 4.027 km/s with a 10.38-MPa exit pressure, and a total ablated mass of 10.56 mg. Reducing the tapering to 12.6-mm inlet and 6.6-mm outlet radii produces a plasma jet with a plasma temperature of 16382-K (1.411 eV) at a bulk velocity of 4.34 km/s and a total of 23.27-mg ablated mass. Further reduction in the tapering to 8.4-mm inlet and 4.4-mm outlet radii produces a plasma jet with a plasma temperature of 20954 K (1.8 eV) at a bulk velocity of 4.89 km/s with a 70.78-MPa exit pressure, and a total ablated mass of 15.09 mg. The preliminary study shows that the narrow tapering angle produces higher pressure, temperature, velocity, and more ablated mass. Radiant heat flux at the taper exit varies from 2.2 GW/m 2 for the wider tapers to 6.24 GW/m 2 for the narrower ones.
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- 2015
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31. Closed Vessel Investigation of Propellant Ignition Process with Using Capillary Plasma Generator
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Jakub Michalski and Zbigniew Leciejewski
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internal ballistics ,Propellant ,Materials science ,lcsh:Electronics ,Process (computing) ,lcsh:TK7800-8360 ,lcsh:TP155-156 ,General Medicine ,Mechanics ,Plasma generator ,Automotive engineering ,plasma generator ,law.invention ,Generator (circuit theory) ,Ignition system ,Internal ballistics ,closed vessel test ,law ,Capillary Plasma ,lcsh:Chemical engineering - Abstract
Previous published results of closed vessel investigations indicated that classical primers (electric or percussion with black powder bedding) when used with LOVA propellants cause unstable burning, deflagration or even lack of ignition. Capillary Plasma Generator is one of the most reliable ignition sources which make possible a reduction of temperature gradient effect and control combustion process. Comparable tests of black powder and plasma ignition in closed vessel with conventional NC propellant were done. Shorter ignition time while using plasma was achieved.
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- 2015
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32. Atmospheric Plasma Jet-Enhanced Anodization and Nanoparticle Synthesis
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Igor Levchenko, Kostya Ostrikov, and Jinghua Fang
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Nuclear and High Energy Physics ,Jet (fluid) ,Materials science ,Nanoporous ,Anodizing ,technology, industry, and agriculture ,Nanoparticle ,Nanotechnology ,Atmospheric-pressure plasma ,equipment and supplies ,Condensed Matter Physics ,Electric arc ,Chemical engineering ,Capillary Plasma ,Electrode - Abstract
Atmospheric-pressure discharge in the tubular capillary plasma jet was studied to reveal the possibility to accelerate anodization of aluminum foils and fabricate alumina nanoparticles in liquid acids. Two different positions of the atmospheric pressure plasma jet relatively to the acid electrolyte and aluminum electrode were studied. Whereas at larger distances, only slight oxidation was obtained, the nanoporous surface and alumina nanoparticles were produced at closer (3–5 mm) distances. The mode with arcing (sparking) resulted in the film of alumina nanoparticles. The obtained results could be useful for the cheap and convenient synthesis of nanoparticles and nanostructured surfaces for various applications, including medical, biological, energy conversion, and nanoelectronic devices.
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- 2015
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33. Determination of finerenone – a novel, selective, nonsteroidal mineralocorticoid receptor antagonist – in human plasma by high-performance liquid chromatography-tandem mass spectrometry and its application to a pharmacokinetic study in venous and capillary human plasma
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Rohde, Gabriele, Loewen, Stephanie, and Heinig, Roland
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- *
LIQUID chromatography-mass spectrometry , *MINERALOCORTICOID receptors , *BLOOD volume , *PHARMACOKINETICS , *MATRIX effect - Abstract
• Sensitive clinical determination of finerenone in human plasma samples by HPLC–MS/MS. • Quantification of finerenone concentrations in plasma volumes as low as 10 µL. • Application of HPLC–MS/MS to pharmacokinetics in venous and capillary human plasma. • Similar area under the concentration vs time curve in venous and capillary plasma. • Subtle differences in the absorption phase with higher capillary concentrations. A straightforward and rapid high-performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS) assay allowing the sensitive and selective quantitation of finerenone (BAY 94–8862) in lithium heparin human plasma is described. Finerenone is a novel, selective, nonsteroidal mineralocorticoid receptor antagonist that is in phase III clinical trials for the treatment of chronic kidney disease. Finerenone quantitation is performed after addition of its stable isotope-labelled internal standard (ISTD) by protein precipitation with acidified acetonitrile followed by HPLC–MS/MS separation and detection. The determination of finerenone concentrations was validated for a plasma volume of 0.100 mL and subsequently also for a lower plasma volume of 0.010 mL, collected e.g. in paediatric studies. The analytical range was from 0.100 µg/L (lower limit of quantification) to 200 µg/L (upper limit of quantification). Inter-day accuracy was 99.7–105.0% for the plasma volume of 0.100 mL and 101.1–104.5% for the plasma volume of 0.010 mL. Inter-day precision was ≤ 7.0%, independent of the extracted plasma volume. A moderate, concentration-independent matrix effect on ionisation was observed for both finerenone and its ISTD of 0.535–0.617, which is fully compensated by the ISTD (ISTD-normalised matrix factors were 0.98–1.03). The assay was successfully applied with both validated plasma volumes to a clinical phase I study in which the pharmacokinetics of 20 mg finerenone were compared in capillary plasma (0.010 mL) and venous plasma (0.100 mL) in a concentration range from the lower limit of quantification to 310 µg/L (capillary plasma) and 252 µg/L (venous plasma). The area under the plasma concentration versus time curve was similar in both matrices, while maximum concentrations were 37% higher in capillary plasma. In conclusion, capillary sampling should not bias pharmacokinetic exposure estimates compared with venous plasma values, if limited to sampling times in the distribution and elimination phases of finerenone. [ABSTRACT FROM AUTHOR]
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- 2021
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34. High-throughput screening of PAHs and polar trace contaminants in water matrices by direct solid-phase microextraction coupled to a dielectric barrier discharge ionization source
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Mario F. Mirabelli, Anna Katarina Huba, and Renato Zenobi
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Dopant ,Chemistry ,010401 analytical chemistry ,Analytical chemistry ,Dielectric barrier discharge ,Wastewater ,Contamination ,010402 general chemistry ,Solid-phase microextraction ,01 natural sciences ,Biochemistry ,Dielectric Barrier Discharge Ionization ,0104 chemical sciences ,Analytical Chemistry ,Capillary Plasma ,Ionization ,Polycyclic Aromatic Hydrocarbons ,High-Throughput Screening ,Environmental Chemistry ,Polar ,Sample preparation ,Spectroscopy - Abstract
Analytica Chimica Acta, 1030, ISSN:0003-2670, ISSN:1873-4324
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- 2018
35. Strong correlation of lumefantrine concentrations in capillary and venous plasma from malaria patients
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Liusheng Huang, Sunil Parikh, Richard Kajubi, Norah Mwebaza, Camilla Forsman, Francesca T. Aweeka, Florence Marzan, and Marinho, Claudio Romero Farias
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0301 basic medicine ,RNA viruses ,Time Factors ,Physiology ,Maternal Health ,lcsh:Medicine ,HIV Infections ,Pathology and Laboratory Medicine ,chemistry.chemical_compound ,0302 clinical medicine ,Mathematical and Statistical Techniques ,Immunodeficiency Viruses ,Pregnancy ,Tandem Mass Spectrometry ,Medicine and Health Sciences ,030212 general & internal medicine ,lcsh:Science ,Child ,Chromatography ,Liquid ,Multidisciplinary ,Coinfection ,Obstetrics and Gynecology ,Venous Plasma ,3. Good health ,Body Fluids ,Linear relationship ,Blood ,Medical Microbiology ,Viral Pathogens ,Physical Sciences ,Viruses ,Regression Analysis ,Female ,Sample collection ,Drug Monitoring ,Anatomy ,Pathogens ,Infection ,Statistics (Mathematics) ,Research Article ,medicine.medical_specialty ,General Science & Technology ,030106 microbiology ,Urology ,Linear Regression Analysis ,Lumefantrine ,Research and Analysis Methods ,Microbiology ,Uncomplicated malaria ,Blood Plasma ,03 medical and health sciences ,Antimalarials ,Rare Diseases ,Capillary Plasma ,Retroviruses ,medicine ,Parasitic Diseases ,Humans ,Adults ,Pharmacokinetics ,Statistical Methods ,Microbial Pathogens ,Finger prick ,Pharmacology ,Extramural ,business.industry ,lcsh:R ,Lentivirus ,Organisms ,Biology and Life Sciences ,HIV ,Tropical Diseases ,Malaria ,Capillaries ,Orphan Drug ,chemistry ,Age Groups ,People and Places ,Cardiovascular Anatomy ,Women's Health ,Blood Vessels ,lcsh:Q ,Population Groupings ,business ,Mathematics ,Chromatography, Liquid - Abstract
Background Lumefantrine is a long-acting antimalarial drug with an elimination half-life of over 3 days and protein binding of 99 percent. Correlation of lumefantrine concentrations from capillary plasma via fingerprick (Cc) versus venous plasma (Cv) remains to be defined. Methods Venous and capillary plasma samples were collected simultaneously from children, pregnant women, and non-pregnant adults at 2, 24, 120hr post last dose of a standard 3-day artemether-lumefantrine regimen they received for uncomplicated malaria. Some of the enrolled children and pregnant women were also HIV-infected. Samples were analyzed via liquid chromatography tandem mass spectrometry. Linear regression analysis was performed using the program Stata® SE12.1. Results In children, the linear regression equations for Cc vs Cv at 2, 24, and 120hr (day 7) post dose are [Cc] = 1.05*[Cv]+95.0 (n = 142, R2 = 0.977), [Cc] = 0.995*[Cv]+56.7 (n = 147, R2 = 0.990) and [Cc] = 0.958*[Cv]+18.6 (n = 139, R2 = 0.994), respectively. For pregnant women, the equations are [Cc] = 1.04*[Cv]+68.1 (n = 43, R2 = 0.990), [Cc] = 0.997*[Cv]+37.3 (n = 43, R2 = 0.993) and [Cc] = 0.941*[Cv]+11.1 (n = 41, R2 = 0.941), respectively. For non-pregnant adults, the equations are [Cc] = 1.05*[Cv]-117 (n = 32, R2 = 0.958), [Cc] = 0.962*[Cv]+9.21 (n = 32, R2 = 0.964) and [Cc] = 1.04*[Cv]-40.1 (n = 32, R2 = 0.988), respectively. In summary, a linear relationship with a slope of ~1 was found for capillary and venous lumefantrine levels in children, pregnant women and non-pregnant adults at 2hr, 24hr and 120hr post last dose, representing absorption, distribution, and elimination phases. Conclusions Capillary and venous plasma concentration of lumefantrine can be used interchangeably at 1:1 ratio. Capillary sampling method via finger prick is a suitable alternative for sample collection in clinical studies.
- Published
- 2017
36. P213 Comparison of transcutaneous with capillary plasma bilirubin measurement for neonates. the experience of our paediatricclinic
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Maria G Gianniki, Kyriaki N Velali, Anastasia Anastasiou-Katsiardani, Theodoros V Tsikrikas, Eleni Atmatzidou, Vasileios Vlachopoulos, and Sofia-Dimitra Bampalitsa
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business.industry ,Bilirubin ,Serum bilirubin measurement ,Jaundice ,Term neonates ,Bilirubin measurement ,chemistry.chemical_compound ,Transcutaneous method ,chemistry ,Capillary Plasma ,Anesthesia ,medicine ,Statistical analysis ,medicine.symptom ,business - Abstract
Introduction Neonatal jaundice is one of the most frequent diagnostic and therapeutic problems. It is estimated that 60% of term neonates and 80% of premature neonates present jaundice in their first week of life. Often, everyday measurements of bilirubin are needed, for early diagnosis and treatment. There are three methods of bilirubin measurement: the serum bilirubin measurement, the capillary and the transcutaneoust. Transcutaneous method is referred to be reliable related to other invasive methods of measurement, at least for low bilirubin prices. Aim The comparison of measurement results of non-invasive transcutaneous method with capillary plasma bilirubin method. Methods All the bilirubin measurements during the time period from 25/01/2016 to 18/02/2016 in the neonates of our Clinic. Results There were 59 bilirubin measurements in 49 newborns. At first, the capillary method was used and then the transcutaneous. The statistical analysis showed that the two methods have normal distribution. The capillary method highlighted a price range of 3,90 mg/dl- 13,20 mg/dl (SD=2,03) and the transcutaneous method showed a range from 4,3 mg/dl to 15,5 mg/dl (SD=2,45). The Pearson Correlation coefficcient of the two methods was 0,903, showing a positive significant correlation (p Conclusion Transcutaneous method can replace the capillary method, in order to have an everyday, non- invasive method of bilirubin measurement. However, in bilirubin prices>15 mg/dl, or when a therapeutic intervention is needed, the laboratory measurement is necessary.
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- 2017
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37. P210 Comparison of transcutaneous with capillary plasma bilirubin measurement for neonates. the experience of our paediatricclinic
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Vasileios Vlachopoulos, Theodoros V Tsikrikas, Sofia-Dimitra Bampalitsa, Eleni Atmatzidou, Anastasia Anastasiou-Katsiardani, Maria G Gianniki, and Kyriaki N Velali
- Subjects
Serum bilirubin measurement ,business.industry ,Bilirubin ,Jaundice ,Term neonates ,Bilirubin measurement ,chemistry.chemical_compound ,Transcutaneous method ,chemistry ,Capillary Plasma ,Anesthesia ,Medicine ,Statistical analysis ,medicine.symptom ,business - Abstract
Introduction Neonatal jaundice is one of the most frequent diagnostic and therapeutic problems. It is estimated that 60% of term neonates and 80% of premature neonates present jaundice in their first week of life. Often, everyday measurements of bilirubin are needed, for early diagnosis and treatment. There are three methods of bilirubin measurement: the serum bilirubin measurement, the capillary and the transcutaneoust. Transcutaneous method is referred to be reliable related to other invasive methods of measurement, at least for low bilirubin prices. Aim The comparison of measurement results of non-invasive transcutaneous method with capillary plasma bilirubin method. Methods All the bilirubin measurements during the time period from 25/01/2016 to 18/02/2016 in the neonates of our Clinic. Results There were 59 bilirubin measurements in 49 newborns. At first, the capillary method was used and then the transcutaneous. The statistical analysis showed that the two methods have normal distribution. The capillary method highlighted a price range of 3,90 mg/dl- 13,20 mg/dl (SD=2,03) and the transcutaneous method showed a range from 4,3 mg/dl to 15,5 mg/dl (SD=2,45). The Pearson Correlation coefficcient of the two methods was 0,903, showing a positive significant correlation (p Conclusion Transcutaneous method can replace the capillary method, in order to have an everyday, non- invasive method of bilirubin measurement. However, in bilirubin prices>15 mg/dl, or when a therapeutic intervention is needed, the laboratory measurement is necessary.
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- 2017
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38. Nitrogen capillary plasma as a source of intense monochromatic radiation at 2.88 nm
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S. V. Zakharov, Miroslava Vrbová, V. S. Zakharov, Alexandr Jancarek, Michal Nevrkla, and Pavel Vrba
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Radiation ,Capillary action ,Chemistry ,Plasma ,Condensed Matter Physics ,Atomic and Molecular Physics, and Optics ,Spectral line ,Electronic, Optical and Magnetic Materials ,Ray tracing (physics) ,Wavelength ,Capillary Plasma ,Electron temperature ,Physical and Theoretical Chemistry ,Atomic physics ,Spectroscopy - Abstract
Capillary discharge plasma related to our laboratory device is modeled and the results are compared with experimental data. Time dependences of selected plasma quantities (e.g. plasma mass density, electron temperature and density and emission intensities) evaluated by 2D Radiation-Magneto-Hydro-Dynamic code Z* describe plasma evolution. The highest output pulse energy at 2.88 nm wavelength is achieved for nitrogen filling pressure ∼100 Pa. The estimated output energy of monochromatic radiation 5.5 mJ sr −1 (∼10 14 photons sr −1 ) corresponds properly to observe experimental value ∼3 × 10 13 photons sr −1 . Ray tracing inspection along the capillary axis proves an influence of radiation self-absorption for the investigated wavelength. The spectra, evaluated using the FLY code, agree to the measured ones.
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- 2014
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39. Direct measurement of cell-free DNA from serially collected capillary plasma during incremental exercise
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Carlos Magallanes, Björn Sterzing, Perikles Simon, Sarah Breitbach, and Suzan Tug
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Adult ,Male ,Anaerobic Threshold ,Physiology ,Kinetics ,Analytical chemistry ,Cardiovascular System ,Running ,Incremental exercise ,Young Adult ,chemistry.chemical_compound ,Oxygen Consumption ,Heart Rate ,Capillary Plasma ,Physiology (medical) ,Humans ,Exercise ,Chromatography ,Cell-Free System ,Chemistry ,Plasma dna ,DNA ,Capillaries ,Cell-free fetal DNA ,Exercise Test ,Lactates ,Energy Metabolism - Abstract
To investigate the kinetics of cell-free DNA (cfDNA) due to exercise, we established a direct real-time PCR for the quantification of cfDNA from unpurified capillary plasma by amplification of a 90- and a 222-bp multilocus L1PA2 sequence. Twenty-six male athletes performed an incremental treadmill test. For cfDNA measurement, capillary samples were collected serially from the fingertip preexercise, during, and several times postexercise. Venous blood was drawn before and immediately after exercise to compare capillary and venous cfDNA values. To elucidate the strongest association of cfDNA accumulations with either cardiorespiratory or metabolic function during exercise, capillary cfDNA values were correlated with standard measures like heart rate, oxygen consumption, or lactate concentrations. The venous cfDNA concentrations were significantly higher compared with the capillary plasma, but in both fractions cfDNA increased 9.8-fold and the values correlated significantly ( r = 0.796). During incremental treadmill running, the capillary cfDNA concentrations increased nearly parallel to the lactate values. The values correlated best with heart rate and energy expenditure, followed by oxygen consumption, Borg values, and lactate levels (0.710 ≤ r ≥ 0.808). With this article, we present a sensitive procedure for the direct quantification of cfDNA in unpurified capillary plasma instead of purified venous plasma. Further studies should investigate the differences between capillary and venous cfDNA that might mirror different physiological mechanisms. Enhanced cardiorespiratory function during exercise might lead to the accumulation of cfDNA via the release of stress hormones that already increase at intensities below the anaerobic threshold. Furthermore, cfDNA might be released by neutrophil extracellular traps.
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- 2014
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40. Capillary plasma gun for a high-current plasma-filled diode
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N. N. Pedin, B.M. Kovalchuk, and A. A. Zherlitsyn
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Optics ,Materials science ,Dense plasma focus ,Capillary Plasma ,business.industry ,Capillary action ,Plasma channel ,Plasma ,Electron ,Current (fluid) ,business ,Instrumentation ,Diode - Abstract
A capillary-type plasma gun designed for generating a plasma channel with a characteristic diameter of ≈10 mm in a high-current relativistic electron diode has been tested. The dynamics of ion flow propagation and the effect of the plasma source parameters on the current amplitude of the low-resistance phase of the plasma-filled diode have been studied. A low-resistance phase duration of ≈120 ns has been attained at a current of ≈185 kA in the diode based on a unit gun with a 0.4-mm-diameter capillary. The possibility of increasing the diode current by using several capillaries in a gun is demonstrated.
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- 2014
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41. Is erythrocyte sedimentation rate a useful inflammatory marker independently of the hematocrit? Comparison results with plasma viscosity
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Oscar Fuster, José Todolí, Begoña Laiz, Cristina Giménez, José L. Hernández, and Amparo Vayá
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Male ,medicine.medical_specialty ,Physiology ,Blood Sedimentation ,Hematocrit ,Fibrinogen ,AutoAnalyzer ,Gastroenterology ,Capillary Plasma ,Physiology (medical) ,Inflammatory marker ,Internal medicine ,medicine ,Humans ,Plasma viscosity ,Hematologic Tests ,medicine.diagnostic_test ,Chemistry ,Hematology ,Blood Viscosity ,Red blood cell ,medicine.anatomical_structure ,Erythrocyte sedimentation rate ,Female ,Cardiology and Cardiovascular Medicine ,Biomarkers ,medicine.drug - Abstract
Plasma viscosity (PV) and erythrocyte sedimentation rate (ESR) are tests which can be used as inflammation and tissue injury markers [2, 11]. ESR usage is more extended than PV in clinical laboratories. However ESR may be haematocrit (Ht) dependent and is related with red blood cell (RBC) rheological properties [1], whereas RBC are not involved in PV. We aimed to evaluate retrospectively the impact of Ht on ESR as an inflammatory marker and compare the results with those of PV in 333 outand in-patients at our hospital. Our study is a human non-interventional retrospective review and written consent is not required for human non-interventional studies. We evaluated both markers in two patient groups of i.e., the first one did not present other inflammatory components measured as C-reactive protein (CRP) below 10 mg/L and fibrinogen below 450 mg/dL (n= 211). The second one presented CRP over 10 mg/L and/or fibrinogen values higher than 450 mg/dL (n= 122). PV and ESR were determined in a capillary plasma viscosimeter (Fresenius GmbH, Germany) at 37◦C and using a Ves matic 30 Plus Analyzer (Diesse Diagnostica Senese, Siena, Italy), respectively. CRP was determined by immunoturbidity in an AU5430 autoanalyzer (Beckman Coulter, Lexington, KY, USA) and fibrinogen analysis was performed in an ACL-TOP 700 autoanalyzer (Instrumentation Laboratory, Bedford, MA, USA).
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- 2014
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42. Calculation of Plasma Radiation in Electrothermal-Chemical Launcher
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Baoming Li and Yong Jin
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Propellant ,Physics ,animal structures ,musculoskeletal, neural, and ocular physiology ,Monte Carlo method ,Radiant energy ,macromolecular substances ,Injector ,Mechanics ,Plasma ,Condensed Matter Physics ,law.invention ,Ignition system ,Physics::Plasma Physics ,law ,Capillary Plasma ,Physics::Space Physics ,Atomic physics ,Absorption (electromagnetic radiation) - Abstract
A numerical model of radiation has been adopted for electrothermal-chemical (ETC) launcher, in which Monte Carlo method and statistical physics are employed to simulate the process of a capillary plasma source in an ETC launcher. The effect on propellant grains with different average absorption coefficients is discussed. The plasma-propellant interaction is also discussed when combined with a thermal model. Results show that the strong instantaneous radiation is responsible for the transmission of energy to the propellant grains leading to ignition. The efficiency of energy absorption in the propellant bed always maintains a high level. Radiant energy caused by plasma is concentrated around the plasma injector. And the "hot zone" efficiency is mainly affected by the properties of propellant grains within a small field around the plasma injector.
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- 2014
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43. Plasma Pulse Jet—Zero-Dimension Modeling Versus Experiments
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D. Aberg and Patrik Hermansson
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Physics ,Nuclear and High Energy Physics ,Dense plasma focus ,Mechanics ,Plasma ,Condensed Matter Physics ,Plasma window ,Physics::Plasma Physics ,Capillary Plasma ,Electrical measurements ,Black-body radiation ,Plasma diagnostics ,Inductively coupled plasma ,Atomic physics - Abstract
This paper presents a zero-dimension model of a capillary plasma pulse jet generator governed by wall ablation feed of plasma. Experiments are made and electrical measurements compared with model simulations. Spectral measurements are performed to validate the assumption of radiation from black body radiation with a gray factor.
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- 2013
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44. Pulsed microwave discharge in a capillary filled with atmospheric-pressure gas
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Evgenii Ivanov, A. M. Davydov, Pavel A. Gushchin, I. A. Kossyi, and S. I. Gritsinin
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Argon ,Materials science ,Physics and Astronomy (miscellaneous) ,Atmospheric pressure ,Capillary action ,chemistry.chemical_element ,Dielectric barrier discharge ,Plasma ,Condensed Matter Physics ,chemistry ,Physics::Plasma Physics ,Capillary Plasma ,Coaxial ,Atomic physics ,Microwave - Abstract
A pulsed microwave coaxial capillary plasma source generating a thin plasma filament along the capillary axis in an atmospheric-pressure argon flow is described. The dynamics of filament formation is studied, and the parameters of the gas and plasma in the contraction region are determined. A physical model of discharge formation and propagation is proposed. The model is based on the assumption that, under the conditions in which the electric fields is substantially below the threshold value, the discharge operates in a specific form known as a self-sustained-non-self-sustained (SNS) microwave discharge.
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- 2013
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45. Gas-filled Capillaries for Plasma-Based Accelerators
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Arie Zigler, Riccardo Pompili, E. Brentegani, S. Romeo, Angelo Biagioni, Alessandro Cianchi, Maria Pia Anania, F. Filippi, Massimo Ferrario, and Enrica Chiadroni
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010302 applied physics ,History ,Electron density ,Materials science ,Capillary action ,02 engineering and technology ,Mechanics ,Plasma ,Electron ,021001 nanoscience & nanotechnology ,01 natural sciences ,Computer Science Applications ,Education ,Accelerator Physics ,03 Novel Particle Sources and Acceleration Techniques ,Capillary Plasma ,Physics::Plasma Physics ,Ionization ,0103 physical sciences ,Particle ,0210 nano-technology ,Beam (structure) - Abstract
Plasma Wakefield Accelerators are based on the excitation of large amplitude plasma waves excited by either a laser or a particle driver beam. The amplitude of the waves, as well as their spatial dimensions and the consequent accelerating gradient depend strongly on the background electron density along the path of the accelerated particles. The process needs stable and reliable plasma sources, whose density profile must be controlled and properly engineered to ensure the appropriate accelerating mechanism. Plasma confinement inside gas filled capillaries have been studied in the past since this technique allows to control the evolution of the plasma, ensuring a stable and repeatable plasma density distribution during the interaction with the drivers. Moreover, in a gas filled capillary plasma can be pre-ionized by a current discharge to avoid ionization losses. Different capillary geometries have been studied to allow the proper temporal and spatial evolution of the plasma along the acceleration length. Results of this analysis obtained by varying the length and the number of gas inlets will be presented., Proceedings of the 8th Int. Particle Accelerator Conf., IPAC2017, Copenhagen, Denmark
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- 2017
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46. Acute Effects of Pomegranate Extract on Postprandial Lipaemia, Vascular Function and Blood Pressure
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Sarah Berry, Gabriella M. Capel-Williams, Aarati Susan Mathew, and Wendy L. Hall
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Adult ,Blood Glucose ,Male ,Adolescent ,Blood Pressure ,Hyperlipidemias ,Diet, High-Fat ,Placebo ,Cardiovascular Physiological Phenomena ,Young Adult ,Capillary Plasma ,Humans ,Single-Blind Method ,Food science ,Pulse ,Triglycerides ,Lythraceae ,Meal ,Cross-Over Studies ,Plant Extracts ,Chemistry ,Area under the curve ,Polyphenols ,Venous Plasma ,Postprandial Period ,Crossover study ,Hydrolyzable Tannins ,Cholesterol ,Postprandial ,Blood pressure ,Chemistry (miscellaneous) ,Food Science - Abstract
We investigated whether a test drink enriched in pomegranate polyphenols, consumed with a high-fat meal, can reduce postprandial lipaemia and improve vascular function and blood pressure compared to placebo. Nineteen young, healthy men completed a randomized, controlled crossover trial. The active drink (containing a pomegranate extract) was consumed during a high-fat meal (ET-DUR) or 15 min before (ET-PRE), and the placebo drink (no pomegranate extract) was consumed during the high-fat meal (CONTROL). Postprandial lipaemia was assessed by venous plasma TAG 0-2 h, and capillary plasma TAG 0-4 h. Blood pressure and digital volume pulse, to measure reflection index (DVP-RI) and stiffness index (DVP-SI), were monitored at baseline, 2 and 4 h. There was no inhibition of postprandial lipaemia by the active drink compared to CONTROL. ET-PRE caused a greater increase in the venous plasma TAG at 2 h compared to CONTROL and ET-DUR (treatment effect P = 0.001). The incremental area under the curve 0-4 h for capillary plasma TAG was not significantly different between treatments. Systolic blood pressure (SBP) increased in the ET-PRE and ET-DUR groups to a lesser extent than the CONTROL group (treatment effect P = 0.041). There were no treatment effects for DVP-RI, DVP-SI or diastolic blood pressure. In conclusion, the consumption of a single drink containing ET-rich pomegranate extract did not decrease postprandial plasma TAG concentrations, but suppressed the postprandial increase in SBP following the high-fat meal.
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- 2012
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47. Critical Parameters of the Pumping Scheme of Ar+8Lasers Excited by Z Pinches in Long Capilaries
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I. Santa, S.V. Kukhlevsky, M. Kiss, Sándor Szatmári, and József Attila Szász
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Inductance ,Materials science ,Capillary Plasma ,law ,Excited state ,Atomic physics ,Condensed Matter Physics ,Laser ,Excitation ,Marx generator ,Water capacitor ,Voltage ,law.invention - Abstract
The present study is focused on the demonstration of the most critical parameters of the pumping scheme of a table-top Ar+8-laser excited by discharges with relatively low current and voltage (I ≤ 20 kA, U ≤ 200 kV) in long (L ∼ 0.5 m) capillaries. The most critical parameters of the pumping scheme were analyzed and then adjusted experimentally. The table-top size is attributed to the use of a low-inductance co-axial discharge configuration that decreases the voltage and current necessary for laser excitation. Low inductance is achieved by using a capillary, water-capacitor and water spark-gap placed into a chamber filled with deionized water. The capillary z-pinch is produced by the water capacitor, which is pulse-charged by a six-stage Marx generator, optimized for the low-inductance discharge configuration. Optimization is performed by adjusting the value of the charging inductance and the peak charging voltage with a water spark-gap. At the optimal conditions laser pulses with a Gaussian-like intensity distribution and divergence angle ∼ 1 mrad and energy ∼ 10 μJ are generated. The physical method for generation of a laser beam with such parameters is based on the use of a long (L = 0.45 m) capillary plasma (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
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- 2012
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48. Active capillary plasma source for ambient mass spectrometry
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Renato Zenobi, Liang Zhu, and Maryia M. Nudnova
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Desorption electrospray ionization ,Chromatography ,Capillary action ,Chemistry ,Organic Chemistry ,Analytical chemistry ,Dielectric barrier discharge ,Plasma ,Mass spectrometry ,Mass spectrometry imaging ,Analytical Chemistry ,Capillary Plasma ,Ionization ,Spectroscopy - Abstract
RATIONALE Imaging mass spectrometry with high spatial resolution has become a rapidly developing area of mass spectrometric research. Many scientific and industrial problems deal with mass spectrometric analysis at ambient pressures. This requires efficient transport and ionization of small amounts of substance. METHODS An active sampling capillary based on a dielectric barrier discharge was constructed for ambient mass spectrometry. The capillary serves as an ionization source as well as an atmospheric interface of the mass spectrometer. The analyzed samples are transported through the sampling capillary due to the pressure difference between the atmospheric environment and the vacuum in the mass spectrometer. Ionization of the transported samples is provided by a low-temperature dielectric barrier discharge. This active capillary was shown to work in a robust fashion for ionizing both gas-phase and laser-ablated solid-phase samples. RESULTS The geometry of the electrodes was found to play a crucial role in ionization efficiency. The capillary was optimized in order to perform surface analysis of solid samples. Sensitivity tests were carried out to characterize different active capillary constructions. The sensitivity of the constructed active capillary was 0.1 ppb (relative concentration of a gaseous sample in ambient air). The active capillary was able to detect samples evaporated from a solid surface. With the active capillary source, it was possible to detect anthracene traces evaporated from a surface located 3 cm from the capillary inlet. CONCLUSIONS A plasma-based active capillary ionization source was constructed. This concept of an active sample inlet should broaden the range of applications of ambient mass spectrometry. Copyright © 2012 John Wiley & Sons, Ltd.
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- 2012
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49. Investigating paracetamol pharmacokinetics using venous and capillary blood and saliva sampling
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Andrew J. McLachlan and Anneliese Rittau
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Adult ,Analyte ,Saliva ,Pharmaceutical Science ,Pharmacology ,High-performance liquid chromatography ,Veins ,Young Adult ,Pharmacokinetics ,Reference Values ,Capillary Plasma ,Humans ,Protein precipitation ,Chromatography, High Pressure Liquid ,Acetaminophen ,Chromatography ,Chemistry ,Reproducibility of Results ,Venous Plasma ,Reversed-phase chromatography ,Middle Aged ,Capillaries ,Area Under Curve ,Female - Abstract
Objective The aim of this study was to develop, validate and apply a high performance liquid chromatography (HPLC) assay for analysis of paracetamol, paracetamol glucuronide and paracetamol sulfate in plasma (venous and capillary) and saliva to study paracetamol pharmacokinetics in healthy volunteers. Methods Samples were prepared using protein precipitation and analysed using reverse phase HPLC with UV detection. This assay was applied to venous and capillary plasma and saliva samples from 20 healthy volunteers after paracetamol 1 g four times daily for three days. Key findings The HPLC assay for paracetamol and its metabolites was found to be sensitive and selective in plasma and saliva samples over the range 0.05–50 mg/l with an inter- and intraday precision and accuracy within 11.2% and 11.1%, respectively. Mean recoveries for all analytes were > 88%. A study of paracetamol pharmacokinetics in healthy volunteers found close agreement between the sampling matrices for paracetamol and metabolites (metabolites were not detected in saliva). The value for area under the concentration–time curve over the 6 h dosing interval of venous plasma (45.3 ± 12.9 mg/l.h) was significantly higher than that observed for capillary plasma (33.8 ± 12.9 mg/l.h) or saliva (35.1 ± 9.4 mg/l.h; P > 0.01). Conclusions Capillary blood and saliva collection were found to be reliable sampling matrices for the evaluation of paracetamol pharmacokinetics, although paracetamol metabolites were not detected in saliva.
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- 2012
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50. Wakefield Resonant Excitation by Intense Laser Pulse in Capillary Plasma
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Suyun Zhou, Xiao Yuan, and Mingping Liu
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Capillary action ,Chemistry ,Resonance ,Plasma ,Condensed Matter Physics ,Laser ,law.invention ,Pulse (physics) ,Condensed Matter::Soft Condensed Matter ,Physics::Fluid Dynamics ,Amplitude ,Physics::Plasma Physics ,law ,Capillary Plasma ,Physics::Space Physics ,Physics::Accelerator Physics ,Atomic physics ,Excitation - Abstract
The laser-induced plasma wakefield in a capillary is investigated on the basis of a simple two-dimensional analytical model. It is shown that as an intense laser pulse reshaped by the capillary wall propagates in capillary plasma, it resonantly excites a strong wakefield if a suitable laser pulse width and capillary radius are chosen for a certain plasma density. The dependence of the laser width and capillary radius on the plasma density for resonance conditions is considered. The wakefield amplitude and longitudinal scale of bubbles in capillary plasma are much larger than those in unbounded plasma, so the capillary guided plasma wakefield is more favorable to electron acceleration.
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- 2012
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