Whole-body fluid distribution in humans during dehydration and recovery, before and after humid-heat acclimation induced using controlled hyperthermia.

PubMed

Patterson, M J; Stocks, J M; Taylor, N A S

2014-04-01

This experiment was designed to test the hypothesis that the plasma volume is not selectively defended during exercise- and heat-induced dehydration following humid-heat acclimation. Eight physically active males were heat acclimated (39.8 °C, relative humidity 59.2%) using 17 days of controlled hyperthermia (core temperature: 38.5 °C). Inter-compartmental fluid losses and movements were tracked (radioisotopes and Evans blue dye) during progressive dehydration (cycling) in these same conditions and also during a resting recovery without fluid replacement (28 °C), before (day 1), during (day 8) and after heat acclimation (day 22). On days 8 and 22, there were significant increases in total body water, interstitial fluid and plasma volume (P < 0.05), but the intracellular compartments did not change (P > 0.05). The baseline plasma volume remained expanded throughout: 43.4 [±2.6 (day 1)], 49.1 [±2.4 (day 8); P < 0.05] and 48.9 mL kg(-1) [±3.0 (day 22); P < 0.05]. During progressive dehydration, plasma reductions of 9.0% (±0.9: day 1), 12.4% (±1.6: day 8) and 13.6% (±1.2: day 22) were observed, with day 8 and 22 losses significantly exceeding day 1 (P < 0.05). During recovery, plasma volume restoration commenced, with the intracellular fluid contribution becoming more pronounced as acclimation progressed. It is concluded that the plasma volume was not defended more vigorously following humid-heat acclimation. Indeed, a greater fluid loss may well underlie the mechanisms for enhancing plasma volume recovery when heat acclimation is induced using the controlled-hyperthermia technique. © 2013 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

21 CFR 606.122 - Circular of information.

Code of Federal Regulations, 2014 CFR

2014-04-01

... collecting the Whole Blood from each product is prepared. (e) A statement that the product was prepared from... and administration recommendations. (j) [Reserved] (k) For Red Blood Cells, the circular of information must contain: (1) Instructions to administer a suitable plasma volume expander if Red Blood Cells...

Optimizing stellarator coil winding surfaces with Regcoil

NASA Astrophysics Data System (ADS)

Bader, Aaron; Landreman, Matt; Anderson, David; Hegna, Chris

2017-10-01

We show initial attempts at optimizing a coil winding surface using the Regcoil code [1] for selected quasi helically symmetric equilibria. We implement a generic optimization scheme which allows for variation of the winding surface to allow for improved diagnostic access and allow for flexible divertor solutions. Regcoil and similar coil-solving algorithms require a user-input winding surface, on which the coils lie. Simple winding surfaces created by uniformly expanding the plasma boundary may not be ideal. Engineering constraints on reactor design require a coil-plasma separation sufficient for the introduction of neutron shielding and a tritium generating blanket. This distance can be the limiting factor in determining reactor size. Furthermore, expanding coils in other regions, where possible, can be useful for diagnostic and maintenance access along with providing sufficient room for a divertor. We minimize a target function that includes as constraints, the minimum coil-plasma distance, the winding surface volume, and the normal magnetic field on the plasma boundary. Results are presented for two quasi-symmetric equilibria at different aspect ratios. Work supported by the US DOE under Grant DE-FG02-93ER54222.

Recommendations for Improving Identification and Quantification in Non-Targeted, GC-MS-Based Metabolomic Profiling of Human Plasma

PubMed Central

Wang, Hanghang; Muehlbauer, Michael J.; O’Neal, Sara K.; Newgard, Christopher B.; Hauser, Elizabeth R.; Shah, Svati H.

2017-01-01

The field of metabolomics as applied to human disease and health is rapidly expanding. In recent efforts of metabolomics research, greater emphasis has been placed on quality control and method validation. In this study, we report an experience with quality control and a practical application of method validation. Specifically, we sought to identify and modify steps in gas chromatography-mass spectrometry (GC-MS)-based, non-targeted metabolomic profiling of human plasma that could influence metabolite identification and quantification. Our experimental design included two studies: (1) a limiting-dilution study, which investigated the effects of dilution on analyte identification and quantification; and (2) a concentration-specific study, which compared the optimal plasma extract volume established in the first study with the volume used in the current institutional protocol. We confirmed that contaminants, concentration, repeatability and intermediate precision are major factors influencing metabolite identification and quantification. In addition, we established methods for improved metabolite identification and quantification, which were summarized to provide recommendations for experimental design of GC-MS-based non-targeted profiling of human plasma. PMID:28841195

The Geopause

NASA Technical Reports Server (NTRS)

Moore, T. E.; Delcourt, D. C.

1995-01-01

Coupled to the Earth and protected by the geomagnetic field, terrestrial matter in the plasma state dominates a larger region of space than was suspected when the 'space age' began, a region we refer to as the geosphere. Accelerated and heated by solar wind energy, this matter expands in size and increases in mass density in response to the Sun's ultraviolet spectrum, heliospheric conditions, and the occurrence of severe space storms. Such storms regularly damage spacecraft, interfere with communications, and trigger power grid interruptions or failures. They occur within the geopause region, that is, the volume defined by the limits of the instantaneous boundary between plasmas that are primarily heliospheric and geospheric. The geopause is analogous in some ways to the heliopause but also resembles the terrestrial air-sea interface. It is the boundary layer across which the supersonically expanding solar plasma delivers momentum and energy to the terrestrial plasma and gas, exciting them into motion, 'evaporating' them into space, and dissipating considerable amounts of power in thermal forms, while generating energetic particles through repeated storage and explosive release of electromagnetic energy. The intensity of the solar wind and the orientation of its magnetic field jointly control the strength of the coupling between solar and terrestrial plasmas and hence the occurrence of severe storms in the geopause region.

Formulation and development of plasma volume expander using natural and modified starch from Solanum tuberosum

PubMed Central

Thombre, Nilima A.; Vishwakarma, Ajit V.; Jadhav, Trupti S.; Kshirsagar, Sanjay J.

2016-01-01

Background: To formulation and development of plasma volume expander (PVE) by using natural and modified starch from Solanum tuberosum. The function of blood circulation is to provide the needs of the body tissues and to maintain an appropriate environment in all tissue fluids of the body for the optimal survival and functions of the cells. Rapid restoration of the blood volume is necessary to decrease reduction in the amount of the blood. The PVEs are isotonic colloidal solutions, act by increasing the osmotic pressure of the intravascular compartment, which leads to the influx of the interstitial fluids through the capillary pore which, in turn, leads to the increase in the volume of the blood. Therefore, there is a need to discover the PVE with less side effects. The main aim of the present study is to use amylopectin as PVEs, fractionated from natural and modified starch obtained from S. tuberosum. Methods: The starch extracted from the normal grains and the tubers of potatoes was selected for the production of starch. Statistical analysis includes in vitro characterization that involves viscosity studies, plasma–product interaction, osmotic pressure detection, molecular weight–viscosity relationship, determination of weight average molecular weight, enzymatic interaction, and in vivo characterization such as toxicity studies and the effect of the products on the blood coagulation. The isolated starch and fractionated amylopectin were analyzed for the physicochemical characteristics. Result and Conclusion: The amylopectin fractionated from isolated starch from grains and tubers of potatoes can be used as PVE, as per the outcome of the study. PMID:28123990

Evidence for a Humoral Mechanism in Volume Expansion Natriuresis

PubMed Central

Kaloyanides, George J.; Azer, Maher

1971-01-01

The role of a humoral mechanism in the natriuresis induced by volume expansion was evaluated using an isolated dog kidney perfused by a second dog which had been pretreated with desoxycorticosterone acetate (DOCA). Expansion of the perfusion dog with an equilibrated volume of blood from a reservoir, resulted in an increase in UnaV (sodium excretion) from 153.6±27.9 (sem) to 345.5±57.8 μEq/min, P<0.001. FEna (fractional sodium excretion) increased from 3.4±0.6 to 8.1±1.2%, P<0.01. The natriuresis occurred in the face of a significant decrease in Cin, RBF, and renal arterial pressure, and in the absence of any change in plasma protein concentration or packed cell volume. In a control group of experiments, sodium excretion did not change when the perfusion dog was not volume expanded, although Cin (inulin clearance) and RBF (renal blood flow) decreased to the same degree as in the expanded group. These data support the conclusion that volume expansion of the perfusion dog either stimulated the release of a natriuretic factor or suppressed the release of an antinatriuretic factor which was manifested by an increase in sodium excretion in the isolated kidney. PMID:5097568

Glycerol-induced hyperhydration

NASA Technical Reports Server (NTRS)

Riedesel, Marvin L.; Lyons, Timothy P.; Mcnamara, M. Colleen

1991-01-01

Maintenance of euhydration is essential for maximum work performance. Environments which induce hypohydration reduce plasma volume and cardiovascular performance progressively declines as does work capacity. Hyperhydration prior to exposure to dehydrating environments appears to be a potential countermeasure to the debilitating effects of hypohydration. The extravascular fluid space, being the largest fluid compartment in the body, is the most logical space by which significant hyperhydration can be accomplished. Volume and osmotic receptors in the vascular space result in physiological responses which counteract hyperhydration. Our hypothesis is that glycerol-induced hyperhydration (GIH) can accomplish extravascular fluid expansion because of the high solubility of glycerol in lipid and aqueous media. A hypertonic solution of glycerol is rapidly absorbed from the gastrointestinal tract, results in mild increases in plasma osmolality and is distributed to 65 percent of the body mass. A large volume of water ingested within minutes after glycerol intake results in increased total body water because of the osmotic action and distribution of glycerol. The resulting expanded extravascular fluid space can act as a reservoir to maintain plasma volume during exposure to dehydrating environments. The fluid shifts associated with exposure to microgravity result in increased urine production and is another example of an environment which induces hypohydration. Our goal is to demonstrate that GIH will facilitate maintenance of euhydration and cardiovascular performance during space flight and upon return to a 1 g environment.

Ways to improve the efficiency and reliability of radio frequency driven negative ion sources for fusion.

PubMed

Kraus, W; Briefi, S; Fantz, U; Gutmann, P; Doerfler, J

2014-02-01

Large RF driven negative hydrogen ion sources are being developed at IPP Garching for the future neutral beam injection system of ITER. The overall power efficiency of these sources is low, because for the RF power supply self-excited generators are utilized and the plasma is generated in small cylindrical sources ("drivers") and expands into the source main volume. At IPP experiments to reduce the primary power and the RF power required for the plasma production are performed in two ways: The oscillator generator of the prototype source has been replaced by a transistorized RF transmitter and two alternative driver concepts, a spiral coil, in which the field is concentrated by ferrites, which omits the losses by plasma expansion and a helicon source are being tested.

Three-dimensional imaging of the ultracold plasma formed in a supersonic molecular beam

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schulz-Weiling, Markus; Grant, Edward

Double-resonant excitation of nitric oxide in a seeded supersonic molecular beam forms a state-selected Rydberg gas that evolves to form an ultracold plasma. This plasma travels with the propagation of the molecular beam in z over a variable distance as great as 600 mm to strike an imaging detector, which records the charge distribution in the dimensions, x and y. The ω{sub 1} + ω{sub 2} laser crossed molecular beam excitation geometry convolutes the axial Gaussian distribution of NO in the molecular beam with the Gaussian intensity distribution of the perpendicularly aligned laser beam to create an ellipsoidal volume of Rydbergmore » gas. Detected images describe the evolution of this initial density as a function of selected Rydberg gas initial principal quantum number, n{sub 0}, ω{sub 1} laser pulse energy (linearly related to Rydberg gas density, ρ{sub 0}) and flight time. Low-density Rydberg gases of lower principal quantum number produce uniformly expanding, ellipsoidal charge-density distributions. Increase either of n{sub 0} or ρ{sub 0} breaks the ellipsoidal symmetry of plasma expansion. The volume bifurcates to form repelling plasma volumes. The velocity of separation depends on n{sub 0} and ρ{sub 0} in a way that scales uniformly with ρ{sub e}, the density of electrons formed in the core of the Rydberg gas by prompt Penning ionization. Conditions under which this electron gas drives expansion in the long axis dimension of the ellipsoid favours the formation of counter-propagating shock waves.« less

Re-appraisal and extension of the Gratton-Vargas two-dimensional analytical snowplow model of plasma focus. II. Looking at the singularity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Auluck, S. K. H., E-mail: skhauluck@gmail.com

2015-11-15

The Gratton-Vargas snowplow model, recently revisited and expanded [S. K. H. Auluck, Phys. Plasmas 20, 112501 (2013)], has given rise to significant new insights into some aspects of the Dense Plasma Focus (DPF), in spite of being a purely kinematic description having no reference to plasma phenomena. It is able to provide a good fit to the experimental current waveforms in at least 4 large facilities. It has been used for construction of a local curvilinear frame of reference, in which conservation laws for mass, momentum, and energy can be reduced to effectively-one-dimensional hyperbolic conservation law equations. Its utility inmore » global parameter optimization of device parameters has been demonstrated. These features suggest that the Gratton-Vargas model deserves a closer look at its supposed limitations near the singular phase of the DPF. This paper presents a discussion of its development near the device axis, based on the original work of Gratton and Vargas, with some differences. It is shown that the Gratton-Vargas partial differential equation has solutions for times after the current singularity, which exhibit an expanding bounded volume (which can serve as model of an expanding plasma column) and decreasing dynamic inductance of the discharge, in spite of having no built-in hydrodynamics. This enables the model to qualitatively reproduce the characteristic shape of the current derivative in DPF experiments without reference to any plasma phenomena, such as instabilities, anomalous resistance, or reflection of hydrodynamic shock wave from the axis. The axial propagation of the solution exhibits a power-law dependence on the dimensionless time starting from the time of singularity, which is similar to the power-law relations predicted by theory of point explosions in ideal gases and which has also been observed experimentally.« less

Vascular and renal effects of dopamine during extracellular volume expansion: Role of nitric oxide pathway.

PubMed

Costa, María A; Elesgaray, Rosana; Loria, Analía; Balaszczuk, Ana María; Arranz, Cristina

2006-02-28

The aim of the study was to determine the possible role of NO-system activation in vascular and renal effects of the dopaminergic system and the probable interaction between both systems during acute volume expansion in rats. Expanded (10% bw) and non-expanded anaesthetized male Wistar rats were treated with haloperidol, a DA receptor antagonist (3 mg/kg bw, ip). Mean arterial pressure, diuresis, natriuresis, renal plasma flow, glomerular filtration rate, nitrites and nitrates excretion (NOx) were determined. NADPH diaphorase activity was measured using a histochemistry technique in kidney, aorta and renal arteries. NOS activity in kidney and aorta from expanded and non-expanded animals was determined with L-[U14C]-arginine substrate, in basal conditions and after DA (1 microM) administration. The hypotensive effect of L-arg and hypertension induced by L-NAME were not modified by haloperidol. This blocker reverted the increase in diuresis, natriuresis and RPF induced by L-arg in both groups. Dopaminergic blockade induced a decrease in NOx excretion and in NADPH-diaphorase activity in glomeruli, proximal tubule and medullar collecting duct and in endothelium and vascular smooth muscle of renal arteries. DA induced an increase in NOS activity in renal medulla and cortex in both groups, but no changes in the aorta were observed. Our results suggest that renal DA would be associated with the renal response induced by NO during extracellular volume expansion. NO-system activation would be one of the mechanisms involved in renal DA activity during saline load, but NO appears not to be involved in DA vascular effects.

Changes in blood product utilization in a seven-hospital system after the implementation of a patient blood management program: A 9-year follow-up.

PubMed

Verdecchia, Nicole M; Wisniewski, Mary Kay; Waters, Jonathan H; Triulzi, Darrell J; Alarcon, Louis H; Yazer, Mark H

2016-09-01

To analyze changes in red blood cell (RBC), platelet (PLT), and plasma transfusion volumes 9 years after the implementation of a multifaceted patient blood management (PBM) program across multiple hospitals. Between fiscal years 2007 and 2015, the annual transfusion volumes for seven hospitals in a regional healthcare system were analyzed by hospital, and between 2014 and 2015, by four service lines including emergency department, intensive care unit (ICU), medical/surgical ward, and operating room at each hospital. The number of units of RBCs administered to transfused recipients on the wards and in ICUs was also enumerated. For these seven hospitals combined, there was a 29.9% reduction in the number of RBCs transfused between 2007 and 2015, a 24.8% reduction in plasma units, and a 25.7% reduction in PLT units. The two largest hospitals saw some of the largest reductions in RBC transfusions (40.1, 25.1%), and plasma transfusions (26.1, 33.8%), and one of those hospitals had a 49.5% reduction in PLT transfusions. Smaller-sized hospitals also had reductions in transfusion volumes, while some volumes increased at hospitals when new or expanded clinical services were introduced. The number of RBC units per transfused recipient was generally between 1.5 and 2 units on the wards and slightly higher in the ICUs. Although the overall volume of transfusions has generally decreased at each hospital site over time, the appropriateness of the administered transfusions cannot be evaluated by these data. The system-wide implementation of a PBM program has reduced transfusion volumes.

Performance of the BATMAN RF source with a large racetrack shaped driver

NASA Astrophysics Data System (ADS)

Kraus, W.; Schiesko, L.; Wimmer, C.; Fantz, U.; Heinemann, B.

2017-08-01

In the negative ion sources in neutral beam injection systems (NBI) of future fusion reactors the plasma is generated in up to eight cylindrical RF sources ("drivers") from which it expands into the main volume. For these large sources, in particular those used in the future DEMO NBI, a high RF efficiency and operational reliability is required. To achieve this it could be favorable to substitute each pair of drivers by one larger one. To investigate this option the cylindrical driver of the BATMAN source at IPP Garching has been replaced by a large source with a racetrack shaped base area and tested using the same extraction system. The main differences are a five times larger source volume and another position of the Cs oven which is mounted onto the driver`s back plate and not onto the expansion volume. The conditioning characteristics and the plasma symmetry in front of the plasma grid were very similar. The extracted H- current densities jex are comparable to that achieved with the small driver at the same power. Because no saturation of jex occurred at 0.6 Pa at high power and the source allows high power operation, a maximum value 45.1 mA/cm2 at 103 kW has been reached. Sputtered Cu from the walls of the expansion volume affected the performance at low pressure, particularly in deuterium. The experiments will be therefore continued with Mo coating of all inner walls.

Measurement of Debye length in laser-produced plasma.

NASA Technical Reports Server (NTRS)

Ehler, W.

1973-01-01

The Debye length of an expanded plasma created by placing an evacuated chamber with an entrance slit in the path of a freely expanding laser produced plasma was measured, using the slab geometry. An independent measurement of electron density together with the observed value for the Debye length also provided a means for evaluating the plasma electron temperature. This temperature has applications in ascertaining plasma conductivity and magnetic field necessary for confinement of the laser produced plasma. Also, the temperature obtained would be useful in analyzing electron-ion recombination rates in the expanded plasma and the dynamics of the cooling process of the plasma expansion.

Severe traumatic brain injury management and clinical outcome using the Lund concept.

PubMed

Koskinen, L-O D; Olivecrona, M; Grände, P O

2014-12-26

This review covers the main principles of the Lund concept for treatment of severe traumatic brain injury. This is followed by a description of results of clinical studies in which this therapy or a modified version of the therapy has been used. Unlike other guidelines, which are based on meta-analytical approaches, important components of the Lund concept are based on physiological mechanisms for regulation of brain volume and brain perfusion and to reduce transcapillary plasma leakage and the need for plasma volume expanders. There have been nine non-randomized and two randomized outcome studies with the Lund concept or modified versions of the concept. The non-randomized studies indicated that the Lund concept is beneficial for outcome. The two randomized studies were small but showed better outcome in the groups of patients treated according to the modified principles of the Lund concept than in the groups given a more conventional treatment. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

Diagnostic study of multiple double layer formation in expanding RF plasma

NASA Astrophysics Data System (ADS)

Chakraborty, Shamik; Paul, Manash Kumar; Roy, Jitendra Nath; Nath, Aparna

2018-03-01

Intensely luminous double layers develop and then expand in size in a visibly glowing RF discharge produced using a plasma source consisting of a semi-transparent cylindrical mesh with a central electrode, in a linear plasma chamber. Although RF discharge is known to be independent of device geometry in the absence of magnetic field, the initiation of RF discharge using such a plasma source results in electron drift and further expansion of the plasma in the vessel. The dynamics of complex plasma structures are studied through electric probe diagnostics in the expanding RF plasma. The measurements made to study the parametric dependence of evolution of double layer structures are analyzed and presented here. The plasma parameter measurements suggest that the complex potential structures initially form with low potential difference between the layers and then gradually expand producing burst oscillations. The present study provides interesting information about the stability of plasma sheath and charge particle dynamics in it that are important to understand the underlying basic sheath physics along with applications in plasma acceleration and propulsion.

Haemodilution for acute ischaemic stroke

PubMed Central

Chang, Timothy S; Jensen, Matthew B

2014-01-01

Background Ischaemic stroke interrupts the flow of blood to part of the brain. Haemodilution is thought to improve the flow of blood to the affected areas of the brain and thus reduce infarct size. Objectives To assess the effects of haemodilution in acute ischaemic stroke. Search methods We searched the Cochrane Stroke Group Trials Register (February 2014), the Cochrane Central Register of Controlled Trials (Issue 1, 2014), MEDLINE (January 2008 to October 2013) and EMBASE (January 2008 to October 2013). We also searched trials registers, scanned reference lists and contacted authors. For the previous version of the review, the authors contacted manufacturers and investigators in the field. Selection criteria Randomised trials of haemodilution treatment in people with acute ischaemic stroke. We included only trials in which treatment was started within 72 hours of stroke onset. Data collection and analysis Two review authors assessed trial quality and one review author extracted the data. Main results We included 21 trials involving 4174 participants. Nine trials used a combination of venesection and plasma volume expander. Twelve trials used plasma volume expander alone. The plasma volume expander was plasma alone in one trial, dextran 40 in 12 trials, hydroxyethyl starch (HES) in five trials and albumin in three trials. Two trials tested haemodilution in combination with another therapy. Evaluation was blinded in 14 trials. Five trials probably included some participants with intracerebral haemorrhage. Haemodilution did not significantly reduce deaths within the first four weeks (risk ratio (RR) 1.10; 95% confidence interval (CI) 0.90 to 1.34). Similarly, haemodilution did not influence deaths within three to six months (RR 1.05; 95% CI 0.93 to 1.20), or death and dependency or institutionalisation (RR 0.96; 95% CI 0.85 to 1.07). The results were similar in confounded and unconfounded trials, and in trials of isovolaemic and hypervolaemic haemodilution. No statistically significant benefits were documented for any particular type of haemodiluting agents, but the statistical power to detect effects of HES was weak. Six trials reported venous thromboembolic events. There was a tendency towards reduction in deep venous thrombosis or pulmonary embolism or both at three to six months’ follow-up (RR 0.68; 95% CI 0.37 to 1.24). There was no statistically significant increased risk of serious cardiac events among haemodiluted participants. Authors’ conclusions The overall results of this review showed no clear evidence of benefit of haemodilution therapy for acute ischaemic stroke. These results are compatible with no persuasive beneficial evidence of haemodilution therapy for acute ischaemic stroke. This therapy has not been proven to improve survival or functional outcome. PMID:25159027

Plasma volume status predicts prognosis in patients with acute heart failure syndromes.

PubMed

Yoshihisa, Akiomi; Abe, Satoshi; Sato, Yu; Watanabe, Shunsuke; Yokokawa, Tetsuro; Miura, Shunsuke; Misaka, Tomofumi; Sato, Takamasa; Suzuki, Satoshi; Oikawa, Masayoshi; Kobayashi, Atsushi; Yamaki, Takayoshi; Kunii, Hiroyuki; Saitoh, Shu-Ichi; Takeishi, Yasuchika

2017-01-01

The intravascular compartment is known as the plasma volume, and the extravascular compartment represents fluid within the interstitial space. Plasma volume expansion is a major symptom of heart failure. The aim of the current study was to investigate the impact of plasma volume status on the prognosis of acute heart failure syndromes. We analyzed 1115 patients with acute heart failure syndromes who were admitted to our hospital. These patients were divided into three groups based on their plasma volume status at admission: first tertile (plasma volume status <41.9%, n = 371), second tertile (41.9%⩽ plasma volume status <49.0%, n = 372), and third tertile (49.0%⩽ plasma volume status, n = 372). Plasma volume status was defined as follows: actual plasma volume = (1 - hematocrit) × [ a + ( b × body weight)] ( a=1530 in males and a=864 in females, b=41.0 in males and b=47.9 in females); ideal plasma volume = c × body weight ( c=39 in males and c=40 in females); and plasma volume status = [(actual plasma volume - ideal plasma volume)/ideal plasma volume] × 100 (%). In the Kaplan-Meier analysis, all-cause mortality, cardiac mortality and cardiac events increased progressively from the first to third tertile ( p <0.001, respectively). In the Cox proportional hazard analysis, after adjusting for potential confounding factors, plasma volume status was an independent predictor of all-cause mortality (hazard ratio 1.429, p < 0.001), cardiac mortality (hazard ratio 1.416, p = 0.001) and cardiac events (hazard ratio 1.207, p = 0.004). Increased congestion is associated with increased morbidity and mortality in heart failure patients. Plasma volume status, which represents intravascular compartment and congestion, can identify poor prognosis in patients with acute heart failure syndromes.

Extending laser plasma accelerators into the mid-IR spectral domain with a next-generation ultra-fast CO 2 laser

DOE PAGES

Pogorelsky, I. V.; Babzien, M.; Ben-Zvi, I.; ...

2016-01-20

Here we discuss how expanding the scope of relativistic plasma research to wavelengths longer than λ/≈0.8₋1.1μm covered by conventional mode-locked solid-state lasers would offer attractive opportunities due to the quadratic scaling of the ponderomotive electron energy and critical plasma density with λ. Answering this quest, a next-generation mid-IR laser project is being advanced at the BNL ATF as a part of the user facility upgrade. We discuss the technical approach to this conceptually new 100 TW, 100 fs, λ=9₋11 μm CO 2 laser BESTIA (Brookhaven Experimental Supra-Terawatt Infrared at ATF) that encompasses several innovations applied for the first time tomore » molecular gas lasers. BESTIA will enable new regimes of laser plasma accelerators. One for example is shock-wave ion acceleration from gas jets. We review ongoing efforts to achieve stable, monoenergetic proton acceleration by dynamically shaping the plasma density profile from a hydrogen gas target with laser-produced blast waves. At its full power, 100 TW BESTIA promises to achieve proton beams at energy exceeding 200 MeV. In addition to ion acceleration in over-critical plasma, the ultra-intense mid-IR laser BESTIA will open new opportunities in driving wakefields in tenuous plasmas, expanding the landscape of Laser Wake Field Accelerator (LWFA) studies into unexplored long-wavelength spectral domain. Simple wavelength scaling suggests that a 100-TW CO2 laser beam will be capable to efficiently generate plasma “bubbles” thousand times bigger in volume compared to a near-IR solid state laser of an equivalent power. Combined with a femtosecond electron linac available at the ATF, this wavelength scaling will facilitate study of external seeding and staging of LWFA.« less

First Production of C60 Nanoparticle Plasma Jet for Study of Disruption Mitigation for ITER

NASA Astrophysics Data System (ADS)

Bogatu, I. N.; Thompson, J. R.; Galkin, S. A.; Kim, J. S.; Brockington, S.; Case, A.; Messer, S. J.; Witherspoon, F. D.

2012-10-01

Unique fast response and large mass-velocity delivery of nanoparticle plasma jets (NPPJs) provide a novel application for ITER disruption mitigation, runaway electrons diagnostics and deep fueling. NPPJs carry a much larger mass than usual gases. An electromagnetic plasma gun provides a very high injection velocity (many km/s). NPPJ has much higher ram pressure than any standard gas injection method and penetrates the tokamak confining magnetic field. Assimilation is enhanced due to the NP large surface-to-volume ratio. Radially expanding NPPJs help achieving toroidal uniformity of radiation power. FAR-TECH's NPPJ system was successfully tested: a coaxial plasma gun prototype (˜35 cm length, 96 kJ energy) using a solid state TiH2/C60 pulsed power cartridge injector produced a hyper-velocity (>4 km/s), high-density (>10^23 m-3), C60 plasma jet in ˜0.5 ms, with ˜1-2 ms overall response-delivery time. We present the TiH2/C60 cartridge injector output characterization (˜180 mg of sublimated C60 gas) and first production results of a high momentum C60 plasma jet (˜0.6 g.km/s).

Flute Instability of Expanding Plasma Cloud

NASA Astrophysics Data System (ADS)

Dudnikova, Galina; Vshivkov, Vitali

2000-10-01

The expansion of plasma against a magnetized background where collisions play no role is a situation common to many plasma phenomena. The character of interaction between expanding plasma and background plasma is depending of the ratio of the expansion velocity to the ambient Alfven velocity. If the expansion speed is greater than the background Alfven speed (super-Alfvenic flows) a collisionless shock waves are formed in background plasma. It is originally think that if the expansion speed is less than Alfvenic speed (sub-Alfvenic flows) the interaction of plasma flows will be laminar in nature. However, the results of laboratory experiments and chemical releases in magnetosphere have shown the development of flute instability on the boundary of expanding plasma (Rayleigh-Taylor instability). A lot of theoretical and experimental papers have been devoted to study the Large Larmor Flute Instability (LLFI) of plasma expanding into a vacuum magnetic field. In the present paper on the base of computer simulation of plasma cloud expansion in magnetizied background plasma the regimes of development and stabilization LLFI for super- and sub-Alfvenic plasma flows are investigated. 2D hybrid numerical model is based on kinetic Vlasov equation for ions and hydrodynamic approximation for electrons. The similarity parameters characterizing the regimes of laminar flows are founded. The stabilization of LLFI takes place with the transition from sub- to super-Alfvenic plasma cloud expansion. The results of the comparision between computer simulation and laboratory simulation are described.

Paradoxical Effect of Hyperoncotic Albumin in Acutely Burned Children

DTIC Science & Technology

1981-01-01

122-5282, 8I,2I01-l50(ii*$(2AXt/0 IHE .JOURNAL OF TRAUMA VOI, 21. No. I Copyright C 1981 by ’he Williams & Wilkins Co. Printed in V , A ’ Paradoxical...BASIL A. Cqt PRUITT, Jaj, M.D. D 1..... DTIC Hyperoncotic albumin proved ineffective as a plasma volume expander in the E L E C T E- resuscitation of...I).. Jr,, Moncrief . J. A.: Heni odvi resuscitation. The use of large quantities of salt-poor change in the early posthurn patent: The influence t

Spatial structure of ion beams in an expanding plasma

NASA Astrophysics Data System (ADS)

Aguirre, E. M.; Scime, E. E.; Thompson, D. S.; Good, T. N.

2017-12-01

We report spatially resolved perpendicular and parallel, to the magnetic field, ion velocity distribution function (IVDF) measurements in an expanding argon helicon plasma. The parallel IVDFs, obtained through laser induced fluorescence (LIF), show an ion beam with v ≈ 8000 m/s flowing downstream and confined to the center of the discharge. The ion beam is measurable for tens of centimeters along the expansion axis before the LIF signal fades, likely a result of metastable quenching of the beam ions. The parallel ion beam velocity slows in agreement with expectations for the measured parallel electric field. The perpendicular IVDFs show an ion population with a radially outward flow that increases with distance from the plasma axis. Structures aligned to the expanding magnetic field appear in the DC electric field, the electron temperature, and the plasma density in the plasma plume. These measurements demonstrate that at least two-dimensional and perhaps fully three-dimensional models are needed to accurately describe the spontaneous acceleration of ion beams in expanding plasmas.

Ferrokinetic and hematologic studies in cystic fibrosis patients

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wagener, J.S.; McNeill, G.C.; Taussig, L.M.

We investigated 28 cystic fibrosis (CF) patients to determine why hypoxia from their obstructive pulmonary disease does not produce polycythemia. Oxygen saturation was lower and erythropoietin levels were higher in CF patients than in 25 age-comparable reference subjects (90.8% and 47 mimu vs. 94.7% and 29 mimu, p less than 0.01). Hematocrit and red blood cell (RBC) indices were not different between groups. Serum vitamin and iron levels, ferrokinetics, RBC volume, and RBC survival were studied in 10 of the 28 CF patients. Total iron-binding capacity and vitamin E levels were low, and serum iron, ferritin, vitamin B12, and folatemore » levels were normal in these patients. Red blood cell survival was minimally decreased in six patients although there was no other evidence for hemolysis. Ferrokinetics (/sup 59/Fe) indicated a reduction in total erythropoiesis in only two patients. Plasma volume was high-normal in five and above normal in four CF patients; RBC mass was increased appropriately for each patient's degree of hypoxia, when compared to healthy individuals living at different altitudes. These results suggest that CF patients are able to compensate for hypoxia by increasing RBC mass; however, an expanded plasma volume prevents a detectable rise in hematocrit.« less

Insights in the laser induced breakdown spectroscopy signal generation underwater using dual pulse excitation — Part II: Plasma emission intensity as a function of interpulse delay

NASA Astrophysics Data System (ADS)

Lazic, V.; Laserna, J. J.; Jovicevic, S.

2013-04-01

Influence of time delay between two laser pulses on the LIBS (laser induced breakdown spectroscopy) signal inside liquids was investigated and the results are compared with data from literature. Plasma was produced by laser ablation (LA) of aluminum inside water and its emission after the second laser pulse was characterized by spectrally and time resolved detection. Light propagation through the vapor bubble formed by the first laser pulse was studied by measurements of beam scattering and transmission. Optical absorption by the evolving bubble is not significant, but its growth is accompanied by lowering of its refraction index nb with respect to surrounding liquid; this effect increases defocusing both of the incident beam and of the out-coming plasma radiation. Collection efficiency of the secondary plasma emission rapidly degrades with the cavity growth, but close to its full expansion the LIBS signal partially recovers through Snell's reflections at the liquid-vapor interface, which produce a bright spot close to the bubble center. Such a light redistribution allows detecting of the emission from external plasma volume, otherwise deflected out of the collection system. Except for strong line transitions from the main sample constituents, self-absorbed inside the high-pressure cavity, we observed the highest LIBS signal when sending the second pulse well before the bubble is fully expanded. Transitions of the pressure wave through the focal volume, formed by the first laser pulse and reflected from the cell's walls and sample back-plane, enhances the LIBS signal importantly. The measured lifetime of the secondary plasma rapidly decreases with the bubble expansion. Here, we also discuss the optimization of the optical collection system and some analytical aspects of double-pulse (DP) LIBS inside liquids.

Determination of plasma volume by indocyanine green--validation of the method and use in patients after cardiopulmonary bypass.

PubMed

Menth-Meier, S E; Imoberdorf, R; Regli, B; Kipfer, B; Turgay, M; Ballmer, P E

2001-05-01

Validation of plasma volume (PV) determination by indocyanine green (ICG) in comparison to the gold-standard method with radioiodinated albumin, and investigation of the effect of commonly used plasma expanders (albumin, hydroxyethyl starch, and polygelatine) on PV in the early postoperative phase in patients undergoing cardiac surgery. Prospective clinical study. Department of medicine and intensive care unit at a university hospital. Ten healthy volunteers and 21 patients after elective open-heart surgery. PV of subjects was measured by i.v. injecting 5 microCi [125I]albumin (I-ALB). One hour later, PV was determined by a peripheral i. v. injection of 0.25 mg/kg body weight ICG (ICG1). In five subjects PV was measured repeatedly by ICG (ICG2) 1 h after ICG1. Mean PV of I-ALB and ICG1 or ICG2 showed consistent results. Further, we investigated central vs peripheral intravenous injection of ICG in six patients after open-heart surgery compared to [125I]albumin. There was no difference between mean PV measured by [125I]albumin and peripheral ICG (P = 0.40). PV determined by central injection of ICG was significantly higher than by the other methods. In 15 patients PV was determined by [125I]albumin. Thereafter, patients were randomly divided into three groups. Group ALB was infused with 1.75 ml/kg body weight human albumin 20%, group HAES with 5.25 ml/kg body weight hydroxyethyl starch 6%, and group HAEM with 7.0 ml/kg body weight polygelatine 3.5%. PV was measured 1 h and 4 h after infusion by ICG. There were no significant changes in PV between the groups. PV determination by peripheral i. v. injection of ICG produced reliable and consistent results when a reactive hyperaemia was produced by a tourniquet prior to injection. Therefore, central venous injection of ICG may not be prerequisite for precise measurements of PV. The expected acute increase in PV after infusion of commonly used plasma expanders after cardiac surgery was not found.

PREFACE: 12th High-Tech Plasma Processes Conference (HTPP-12)

NASA Astrophysics Data System (ADS)

Gleizes, Alain; Ghedini, Emanuele; Gherardi, Matteo; Sanibondi, Paolo; Dilecce, Giorgio

2012-12-01

The High-Tech Plasma Processes - 12th European Plasma Conference (HTPP-12) was held in Bologna (Italy) on 24-29 June 2012. The conference series started in 1990 as a thermal plasma conference and gradually expanded to include other topic fields as well. Now the High-Tech Plasma Processes - European Plasma Conference (HTPP) is a bi-annual international conference based in Europe with topics encompassing the whole area of plasma processing science. The aim of the conference is to bring different scientific communities together, facilitate the contacts between science, technology and industry and provide a platform for the exploration of both fundamental topics and new applications of plasmas. Thanks to the efforts of the conference chairman, Professor Vittorio Colombo and of the co-chair, Professor Piero Favia, a well balanced participation from both the communities of thermal and nonthermal plasma researchers was achieved; this resulted in just about 196 attendees from 39 countries, with 8 plenary and 15 invited talks, plus 50 oral and 140 poster contributions. This volume of Journal of Physics: Conference Series gathers papers from regular contributions of HTPP-12; each contribution submitted for publication has been peer reviewed and the Editors are very grateful to the referees for their careful support in improving the original manuscripts. In the end, 39 manuscripts were accepted for publication, covering different topics of plasma processing science: from plasma fundamentals and modelling to source design and process diagnostics, from nanomaterial synthesis to surface modification, from waste treatment to plasma applications in a liquid environment. It is an honour to present this volume of Journal of Physics: Conference Series and we deeply thank the authors for their enthusiastic and high-grade contribution. Finally, we would like to thank the conference chairmen, the members of the steering committee, the international scientific committee, the local organizing committee, the organizing secretariat and the financial support from the conference sponsors that allowed the success of HTPP-12. The Editors of the HTPP 12 Proceedings Professor Alain Gleizes (head of the ISC) Dr Emanuele Ghedini Dr Matteo Gherardi Dr Paolo Sanibondi Dr Giorgio Dilecce Bologna, 30 October 2012

Supra-plasma expanders: the future of treating blood loss and anemia without red cell transfusions?

PubMed

Tsai, Amy G; Vázquez, Beatriz Y Salazar; Hofmann, Axel; Acharya, Seetharama A; Intaglietta, Marcos

2015-01-01

Oxygen delivery capacity during profoundly anemic conditions depends on blood's oxygen-carrying capacity and cardiac output. Oxygen-carrying blood substitutes and blood transfusion augment oxygen-carrying capacity, but both have given rise to safety concerns, and their efficacy remains unresolved. Anemia decreases oxygen-carrying capacity and blood viscosity. Present studies show that correcting the decrease of blood viscosity by increasing plasma viscosity with newly developed plasma expanders significantly improves tissue perfusion. These new plasma expanders promote tissue perfusion, increasing oxygen delivery capacity without increasing blood oxygen-carrying capacity, thus treating the effects of anemia while avoiding the transfusion of blood.

Inductive current startup in large tokamaks with expanding minor radius and RF assist

DOE Office of Scientific and Technical Information (OSTI.GOV)

Borowski, S.K.

1983-01-01

Auxiliary RF heating of electrons before and during the current rise phase of a large tokamak, such as the Fusion Engineering Device, is examined as a means of reducing both the initiation loop voltage and resistive flux expenditure during startup. Prior to current initiation, 1 to 2 MW of electron cyclotron resonance heating power at approx.90 GHz is used to create a small volume of high conductivity plasma (T/sub e/ approx. = 100 eV, n/sub e/ approx. = 10/sup 19/m/sup -3/) near the upper hybrid resonance (UHR) region. This plasma conditioning permits a small radius (a/sup 0/ approx.< 0.4 m)more » current channel to be established with a relatively low initial loop voltage (approx.< 25 V as opposed to approx.100 V without RF assist). During the subsequent plasma expansion and current ramp phase, additional RF power is introduced to reduce volt-second consumption due to plasma resistance. To study the preheating phase, a near classical particle and energy transport model is developed to estimate the electron heating efficiency in a currentless toroidal plasma. The model assumes that preferential electron heating at the UHR leads to the formation of an ambipolar sheath potential between the neutral plasma and the conducting vacuum vessel and limiter.« less

Weight Measurement and Volumetric Displacement of Breast Implants and Tissue Expanders: Why Port and Shell Volumes Matter in Breast Reconstruction, Augmentation, and Revision.

PubMed

Wenzel, Chad G; Wacholtz, William F; Janssen, David A; Bengtson, Bradley P

2015-10-01

There are significant differences in weight and volumetric characteristics between silicone and saline breast implants of which most plastic surgeons are unaware. Phase I of this study was a weight measurement focused on recording differences in the weight of saline volumes instilled versus recorded weights of saline implants and expanders. Phase II compared displaced volume differences of tissue expanders with instilled volumes. As a result of this study, surgeons should now be able to precisely calculate the volume created for breast pocket development, allowing for accurate matching of expander and final breast implant. Copyright © 2015 Elsevier Inc. All rights reserved.

Coagulability and Rheology: Hematologic Benefits From Exercise, Fish, and Aspirin. Implications for Athletes and Nonathletes.

PubMed

Eichner, E R

1986-10-01

In brief: Physical activity makes the blood more fluid and less likely to clot. The healthy hematologic adaptations to exercise (enhanced fibrinolysis, expanded plasma volume, decreased hematocrit, increased red cell deformability, and decreased blood viscosity) seem to enhance the delivery of oxygen and decrease the risk of thrombosis. Regular exercise, then, by changing the blood, may offer the elite athlete enhanced performance and the general population reduced risk of heart attack. Increased amounts of fish in the diet and-for selected persons-low-dose aspirin, may be useful antithrombotic adjuncts to exercise.

Canonical angular momentum compression near the Brillouin limit

NASA Astrophysics Data System (ADS)

Jeong, E.; Gilson, E.; Fajans, J.

2000-10-01

Near the Brillouin limit, the angular momentum of a trapped, T=0, pure-electron plasma approaches zero. If the plasma expands axially, its density would appear to drop. However, the plasma's canonical angular momentum is not changed by an axial expansion, so the plasma must stay near the Brillouin limit; thus the plasma's density cannot change when it is expanded. The only way for the plasma density to remain constant as the plasma length increases is for the plasma radius to decrease. Dynamically, this decrease is caused by the polarization drift induced by a small decrease in the density. In this poster we present preliminary experimental evidence demonstrating this radial compression. This work was supported by the ONR.

Methods for recovering a polar solvent from a fluid stream contaminated with at least one polar impurity

DOEpatents

Ginosar, Daniel M.; Wendt, Daniel S.

2012-11-13

A method of removing a polar solvent from a fluid volume contaminated with at least one polar impurity, such as a free fatty acid, is provided. The method comprises providing a fluid volume that includes at least one polar impurity dissolved in at least one solvent. The fluid volume is contacted with an expanding gas to remove the at least one solvent. The expanding gas may be dissolved into the at least one solvent in the fluid volume to form a gas-expanded solvent. The immiscibility of the polar impurities in the gas-expanded solvent enables separation of the polar impurities from the gas-expanded solvent. After separation of the polar impurities, at least one of the temperature and pressure may be reduced to separate the solvent from the expanding gas such that the clean solvent may be reused.

Cold-water acclimation does not modify whole-body fluid regulation during subsequent cold-water immersion.

PubMed

Stocks, J M; Patterson, M J; Hyde, D E; Jenkins, A B; Mittleman, K D; Taylor, N A S

2004-06-01

We investigated the impact of cold-water acclimation on whole-body fluid regulation using tracer-dilution methods to differentiate between the intracellular and extracellular fluid compartments. Seven euhydrated males [age 24.7 (8.7) years, mass 74.4 (6.4) kg, height 176.8 (7.8) cm, sum of eight skinfolds 107.4 (20.4) mm; mean (SD)] participated in a 14-day cold-water acclimation protocol, with 60-min resting cold-water stress tests [CWST; 18.1 (0.1) degrees C] on days 1, 8 and 15, and 90-min resting cold-water immersions [18.4 (0.4) degrees C] on intervening days. Subjects were immersed to the 4th intercostal space. Intracellular and extracellular fluid compartments, and plasma protein, electrolyte and hormone concentrations were investigated. During the first CWST, the intracellular fluid (5.5%) and plasma volumes were reduced (6.1%), while the interstitial fluid volume was simultaneously expanded (5.4%). This pattern was replicated on days 8 and 15, but did not differ significantly among test days. Acclimation did not produce significant changes in the pre-immersion distribution of total body water, or changes in plasma osmolality, total protein, electrolyte, atrial natriuretic peptide or aldosterone concentrations. Furthermore, a 14-day cold-water acclimation regimen did not elicit significant changes in body-fluid distribution, urine production, or the concentrations of plasma protein, electrolytes or the fluid-regulatory hormones. While acclimation trends were not evident, we have confirmed that fluid from extravascular cells is displaced into the interstitium during acute cold-water immersion, both before and after cold acclimation.

Collisionless coupling of a high- β expansion to an ambient, magnetized plasma. I. Rayleigh model and scaling

NASA Astrophysics Data System (ADS)

Bonde, Jeffrey

2018-04-01

The dynamics of a magnetized, expanding plasma with a high ratio of kinetic energy density to ambient magnetic field energy density, or β, are examined by adapting a model of gaseous bubbles expanding in liquids as developed by Lord Rayleigh. New features include scale magnitudes and evolution of the electric fields in the system. The collisionless coupling between the expanding and ambient plasma due to these fields is described as well as the relevant scaling relations. Several different responses of the ambient plasma to the expansion are identified in this model, and for most laboratory experiments, ambient ions should be pulled inward, against the expansion due to the dominance of the electrostatic field.

PREFACE: 13th High-Tech Plasma Processes Conference (HTPP-2014)

NASA Astrophysics Data System (ADS)

2014-11-01

The High-Tech Plasma Processes - 13th European Plasma Conference (HTPP-2014) was held in Toulouse (France) on 22-27 June 2014. The conference series started in 1990 as a thermal plasma conference and has gradually expanded to include other related topics. Now the High-Tech Plasma Processes - European Plasma Conference (HTPP) is an international conference organised in Europe every two years with topics encompassing the whole field of plasma processing science. The aim of the conference is to bring different scientific communities together, to facilitate contacts between science, technology and industry and to provide a platform for the exploration of both the fundamental topics and new applications of plasmas. For this edition of HTPP, as was the case for the last, we have acheived a well balanced participation from the communities of both thermal and non-thermal plasma researchers. 142 people from 17 countries attended the conference with the total number of contributions being 155, consisting of 8 plenary and 8 invited talks plus 51 oral and 88 poster contributions. We have received numerous papers corresponding to the contributions of HTPP-2014 that have been submitted for publication in this volume of Journal of Physics: Conference Series. Each submitted contribution has been peer reviewed (60 referees with at least two reviewing each paper) and the Editors are very grateful to the referees for their careful support in improving the original manuscripts. In total, 52 manuscripts have been accepted for publication covering a range of topics of plasma processing science from plasma fundamentals to process applications through to experiments, diagnostics and modelling. We have grouped the papers into the following 5 topics: - Arc-Materials Interaction and Metallurgy - Plasma Torches and Spraying - Synthesis of Powders and Nanomaterials - Deposition and Surface Treatment - Non-Equilibrium Plasmas We deeply thank the authors for their enthusiastic and high-grade contributions and we are convinced that this volume of Journal of Physics: Conference Series will be interesting for our community. Finally, we would like to thank the conference chairmen, the members of the steering committee, the international scientific committee, the local organizing committee, the organizing secretariat and the financial support from the conference sponsors that allowed the success of HTPP-2014. The Editors of the HTPP-2014 Proceedings Dr Alain Gleizes, chairman of HTPP-2014 Prof. Jochen Schein, head of the ISC Prof. Philippe Teulet Toulouse, 14th October 2014

Atmospheric pressure plasma processing of polymeric materials utilizing close proximity indirect exposure

DOEpatents

Paulauskas, Felix L.; Bonds, Truman

2016-09-20

A plasma treatment method that includes providing treatment chamber including an intermediate heating volume and an interior treatment volume. The interior treatment volume contains an electrode assembly for generating a plasma and the intermediate heating volume heats the interior treatment volume. A work piece is traversed through the treatment chamber. A process gas is introduced to the interior treatment volume of the treatment chamber. A plasma is formed with the electrode assembly from the process gas, wherein a reactive species of the plasma is accelerated towards the fiber tow by flow vortices produced in the interior treatment volume by the electrode assembly.

Method and apparatus for the formation of a spheromak plasma

DOEpatents

Yamada, Masaaki; Furth, Harold P.; Stix, Thomas H.; Todd, Alan M. M.

1982-01-01

A method and apparatus for forming a detached, compact toroidally shaped spheromak plasma by an inductive mechanism. A generally spheroidal vacuum vessel (1) houses a toroidally shaped flux ring or core (2) which contains poloidal and toroidal field generating coils. A plasma discharge occurs with the pulsing of the toroidal field coil, and the plasma is caused to expand away from the core (2) and toward the center of the vacuum vessel (1). When the plasma is in an expanded state, a portion of it is pinched off in order to form a separate, detached spheromak plasma configuration. The detached plasma is supported by a magnetic field generated by externally arranged equilibrium field coils (5).

National Spherical Torus Experiment (NSTX) Facility/Diagnostic Overview

NASA Astrophysics Data System (ADS)

Ono, M.

2005-10-01

The capabilities of the NSTX experimental facility and diagnostics continue to improve. The new TF joints are performing well at 4.5 kG. New in-board shaping coils were installed to produce plasmas with simultaneously high elongation ˜2.5 and high triangularity ˜0.8 needed for advanced operation. The EFC/RWM system with six external coils driven by three switching power amplifiers (1 kHz, 6 kA-turn) is now fully operational. With these new tools, we significantly expanded the NSTX operating parameters, achieving the highest controlled elongation of 2.75, a shape factor q95Ip/aBT of 37 MA/m-T, plasma volume of 14 m^3, stored energy of 430 kJ, normalized beta of 7.4 % MA/m-T, bootstrap current fraction of 60 % at 700 kA, and longest plasma pulse length of 1.5 s or about 4 times the resistive skin time. In the area of the plasma diagnostics, ten additional Thomson scattering channels are providing detailed measurement of the H-mode pedestal and internal barrier regions. The 8 channel MSE diagnostic is providing crucial j(r) measurements including high electron confinement reversed shear plasmas. A tangential microwave scattering system to measure electron-transport- relevant fluctuations is being commissioned.

Dynamics of a pulsed laser generated tin plasma expanding in an oxygen atmosphere

NASA Astrophysics Data System (ADS)

Barreca, F.; Fazio, E.; Neri, F.; Barletta, E.; Trusso, S.; Fazio, B.

2005-10-01

Semiconducting tin oxide can be successfully deposited by means of the laser ablation technique. In particular by ablating metallic tin in a controlled oxygen atmosphere, thin films of SnOx have been deposited. The partial oxygen pressure at which the films are deposited strongly influences both the stoichiometry and the structural properties of the films. In this work, we present a study of the expansion dynamics of the plasma generated by ablating a tin target by means of a pulsed laser using time and space resolved optical emission spectroscopy and fast photography imaging of the expanding plasma. Both Sn I and Sn II optical emission lines have been observed from the time-integrated spectroscopy. Time resolved-measurements revealed the dynamics of the expanding plasma in the ambient oxygen atmosphere. Stoichiometry of the films has been determined by means of X-ray photoelectron spectroscopy and correlated to the expansion dynamics of the plasma.

Low Plasma Volume in Normotensive Formerly Preeclamptic Women Predisposes to Hypertension.

PubMed

Scholten, Ralph R; Lotgering, Fred K; Hopman, Maria T; Van Dijk, Arie; Van de Vlugt, Maureen; Janssen, Mirian C H; Spaanderman, Marc E A

2015-11-01

Formerly preeclamptic women are at risk for cardiovascular disease. Low plasma volume may reflect latent hypertension and potentially links preeclampsia with chronic cardiovascular disease. We hypothesized that low plasma volume in normotensive formerly preeclamptic women predisposes to hypertension. We longitudinally studied n=104 formerly preeclamptic women in whom plasma volume was measured 3 to 30 months after the preeclamptic pregnancy. Cardiovascular variables were assessed at 2 points in time (3-30 months postpartum and 2-5 years thereafter). Study population was divided into low plasma volume (≤1373 mL/m(2)) and normal plasma volume (>1373 mL/m(2)). Primary end point was hypertension at the second visit: defined as ≥140 mm Hg systolic or ≥90 mm Hg diastolic. Secondary outcome of this study was change in traditional cardiovascular risk profile between visits. Variables correlating univariately with change in blood pressure between visits were introduced in regression analysis. Eighteen of 104 (17%) formerly preeclamptic women who were normotensive at first visit had hypertension at second evaluation 2 to 5 years later. Hypertension developed more often in women with low plasma volume (10/35 [29%]) than in women with normal plasma volume (8/69 [12%]; odds ratio, 3.2; 95% confidence interval, 1.4-8.6). After adjustments, relationship between plasma volume status and subsequent hypertension persisted (adjusted odds ratio, 3.0; 95% confidence interval, 1.1-8.5). Mean arterial pressure at second visit correlated inverse linearly with plasma volume (r=-0.49; P<0.01). Initially normotensive formerly preeclamptic women have 17% chance to develop hypertension within 5 years. Women with low plasma volume have higher chance to develop hypertension than women with normal plasma volume. Clinically, follow-up of blood pressure seems warranted in women with history of preeclampsia, even when initially normotensive. © 2015 American Heart Association, Inc.

Evolution of Turbulence in the Expanding Solar Wind, a Numerical Study

NASA Astrophysics Data System (ADS)

Dong, Yue; Verdini, Andrea; Grappin, Roland

2014-10-01

We study the evolution of turbulence in the solar wind by solving numerically the full three-dimensional (3D) magnetohydrodynamic (MHD) equations embedded in a radial mean wind. The corresponding equations (expanding box model or EBM) have been considered earlier but never integrated in 3D simulations. Here, we follow the development of turbulence from 0.2 AU up to about 1.5 AU. Starting with isotropic spectra scaling as k -1, we observe a steepening toward a k -5/3 scaling in the middle of the wave number range and formation of spectral anisotropies. The advection of a plasma volume by the expanding solar wind causes a non-trivial stretching of the volume in directions transverse to radial and the selective decay of the components of velocity and magnetic fluctuations. These two effects combine to yield the following results. (1) Spectral anisotropy: gyrotropy is broken, and the radial wave vectors have most of the power. (2) Coherent structures: radial streams emerge that resemble the observed microjets. (3) Energy spectra per component: they show an ordering in good agreement with the one observed in the solar wind at 1 AU. The latter point includes a global dominance of the magnetic energy over kinetic energy in the inertial and f -1 range and a dominance of the perpendicular-to-the-radial components over the radial components in the inertial range. We conclude that many of the above properties are the result of evolution during transport in the heliosphere, and not just the remnant of the initial turbulence close to the Sun.

Simultaneous time-space resolved reflectivity and interferometric measurements of dielectrics excited with femtosecond laser pulses

NASA Astrophysics Data System (ADS)

Garcia-Lechuga, M.; Haahr-Lillevang, L.; Siegel, J.; Balling, P.; Guizard, S.; Solis, J.

2017-06-01

Simultaneous time-and-space resolved reflectivity and interferometric measurements over a temporal span of 300 ps have been performed in fused silica and sapphire samples excited with 800 nm, 120 fs laser pulses at energies slightly and well above the ablation threshold. The experimental results have been simulated in the frame of a multiple-rate equation model including light propagation. The comparison of the temporal evolution of the reflectivity and the interferometric measurements at 400 nm clearly shows that the two techniques interrogate different material volumes during the course of the process. While the former is sensitive to the evolution of the plasma density in a very thin ablating layer at the surface, the second yields an averaged plasma density over a larger volume. It is shown that self-trapped excitons do not appreciably contribute to carrier relaxation in fused silica at fluences above the ablation threshold, most likely due to Coulomb screening effects at large excited carrier densities. For both materials, at fluences well above the ablation threshold, the maximum measured plasma reflectivity shows a saturation behavior consistent with a scattering rate proportional to the plasma density in this fluence regime. Moreover, for both materials and for pulse energies above the ablation threshold and delays in the few tens of picoseconds range, a simultaneous "low reflectivity" and "low transmission" behavior is observed. Although this behavior has been identified in the past as a signature of femtosecond laser-induced ablation, its origin is alternatively discussed in terms of the optical properties of a material undergoing strong isochoric heating, before having time to substantially expand or exchange energy with the surrounding media.

Particle energization in magnetic reconnection in high-energy-density plasmas

NASA Astrophysics Data System (ADS)

Deng, W.; Fox, W.; Bhattacharjee, A.

2014-10-01

Significant particle energization is inferred to occur in many astrophysical environments and magnetic reconnection has been proposed to be the driver in many cases. Recent observation of magnetic reconnection in high-energy-density (HED) plasmas on the Vulcan, Omega and Shenguang laser facilities has opened up a new regime of reconnection study of great interest to laboratory and plasma astrophysics. In these experiments, plasma bubbles, excited by laser shots on solid targets and carrying magnetic fields, expand into one another, squeezing the opposite magnetic fields together to drive reconnection. 2D particle-in-cell (PIC) simulations have been performed to study the particle energization in such experiments. Two energization mechanisms have been identified. The first is a Fermi acceleration process between the expanding plasma bubbles, wherein the electromagnetic fields of the expanding plasma bounce particles, acting as moving walls. Particles can gain significant energy through multiple bounces between the bubbles. The second mechanism is a subsequent direct acceleration by electric field at the reconnection X-line when the bubbles collide into each other and drive reconnection.

Characteristics of magnetised plasma flow around stationary and expanding magnetic clouds

NASA Astrophysics Data System (ADS)

Dalakishvili, Giorgi

Studies of interplanetary magnetic clouds have shown that the characteristics of the region ahead of these objects, which are moving away from the Sun in the solar wind, play a role in determining their geo-efficiency, i.e. the kind and the degree of their effects on the Earth environment. Therefore, our main goal is to model and study the plasma parameters in the vicinity of interplanetary magnetic clouds. To this end we present a model in which the magnetic clouds are immersed in a magnetised plasma flow with a homogeneous magnetic field. We first calculate the resulting distortion of the external magnetic field and then determine the plasma velocity by employing the frozen-in condition. Subsequently, the plasma density and pressure are expressed as functions of the magnetic field and the velocity field. The plasma flow parameters are determined by solving the time-independent ideal MHD equations for both the stationary regime and for the case of an expand-ing cylindrical magnetic cloud, thus extending previous results that appeared in the literature.

Ringing After a High-Energy Collision: Ambipolar Oscillations During Impact Plasma Expansion

NASA Technical Reports Server (NTRS)

Zimmerman, M. I.; Farrell, W. M.; Stubbs, T. J.

2012-01-01

High-velocity impacts on the Moon and other airless bodies deliver energy and material to the lunar surface and exosphere. The target and i mpactor material may become vaporized and ionized to form a collision al plasma that expands outward and eventually becomes collisionless. In the present work, kinetic simulations of the later collision less stage of impact plasma expansion are performed. Attention is paid to characterizing "ambipolar oscillations" in which thermodynamic distur bances propagate outward to generate "ringing" within the expanding e lectron cloud, which could radiate an electromagnetic signature of lo cal plasma conditions. The process is not unlike a beam-plasma intera ction, with the perturbing electron population in the present case ac ting as a highly thermal "beam" that resonates along the expanding de nsity gradient. Understanding the electromagnetic aspects of impact p lasma expansion could provide insight into the lasting effects of nat ural, impact-generated currents on airless surfaces and charging haza rds to human exploration infrastructure and instrumentation.

Isovolemic hemodilution alters the ratio of whole-body to large-vessel hematocrit (F-cell ratio). A prospective, randomized study comparing the volume effects of hydroxyethyl starch 200,000/0.62 and albumin.

PubMed

Haller, M; Brechtelsbauer, H; Akbulut, C; Fett, W; Briegel, J; Finsterer, U

1995-04-01

To evaluate potential changes in the ratio of whole-body/large-vessel hematocrit (f-cell ratio) during isovolemic hemodilution and to compare the volume effects of 2 different plasma exchange solutions (hydroxyethyl starch 200,000/0.62 6% and human albumin 5%). Prospective, randomized, controlled trial. Operating theater in a university hospital. 24 gynecological patients scheduled for elective surgery. Isovolemic hemodilution was performed using 2 different plasma exchange solutions. Plasma volume was determined using dye dilution technique before and after hemodilution. The volume of withdrawn blood was measured from the change in weight of the blood bags taking into account the specific gravity of blood. The volume of administered plasma exchange solutions exceeded the amount of withdrawn blood by 80 +/- 47 ml (p < 0.001). Plasma volume was 3,067 +/- 327 ml before and 3,517 +/- 458 ml after hemodilution. Using red cell volumes calculated from measured plasma volumes and peripheral hematocrit, a deficit of 249 +/- 133 ml (p < 0.0001) in red cells after hemodilution appeared with the measured withdrawn red cell volumes taken into account. This finding can be explained by a change in the f-cell ratio during isovolemic hemodilution. The volume effect of the exchange solutions was 1.05 for hydroxyethyl starch and 0.95 for albumin. The results demonstrate that a change in the f-cell ratio occurs during isovolemic hemodilution. The estimation of red cell volume or plasma volume changes by using either the hematocrit or plasma or red cell volume determinations together with the hematocrit may lead to erroneous results.

On nonlinear evolution of low-frequency Alfvén waves in weakly-expanding solar wind plasmas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nariyuki, Y.

A multi-dimensional nonlinear evolution equation for Alfvén waves in weakly-expanding solar wind plasmas is derived by using the reductive perturbation method. The expansion of solar wind plasma parcels is modeled by an expanding box model, which includes the accelerating expansion. It is shown that the resultant equation agrees with the Wentzel-Kramers-Brillouin prediction of the low-frequency Alfvén waves in the linear limit. In the cold and one-dimensional limit, a modified derivative nonlinear Schrodinger equation is obtained. Direct numerical simulations are carried out to discuss the effect of the expansion on the modulational instability of monochromatic Alfvén waves and the propagation ofmore » Alfvén solitons. By using the instantaneous frequency, it is quantitatively shown that as far as the expansion rate is much smaller than wave frequencies, effects of the expansion are almost adiabatic. It is also confirmed that while shapes of Alfvén solitons temporally change due to the expansion, some of them can stably propagate after their collision in weakly-expanding plasmas.« less

Effect of leg exercise training on vascular volumes during 30 days of 6 deg head-down bed rest

NASA Technical Reports Server (NTRS)

Greenleaf, J. E.; Vernikos, J.; Wade, C. E.; Barnes, P. R.

1992-01-01

In order to investigate the effects of leg exercise training on vascular volumes during 30 d of 6-deg head-down bed rest, plasma and red cell volumes, body density, and water balance were measured in 19 men confined to bed rest (BR). One group had no exercise training (NOE), another near-maximal variable-intensity isotonic exercise (ITE) for 60 min/d, and the third near-maximal intermittent isokinetic exercise (IKE) for 60 min/d. Mean energy costs for the NOE, IKE, and ITE regimens were determined. Body densities within groups and mean urine volumes between groups were unchanged during BR. Changes in red cell volume followed changes in plasma volume. There was close coupling between resting plasma volume and plasma protein and osmotic content. It is argued that the ITE training protocol is better than the IKE protocol for maintaining plasma volume during prolonged exposure to BR.

Electrolyte and plasma changes after ingestion of pickle juice, water, and a common carbohydrate-electrolyte solution.

PubMed

Miller, Kevin C; Mack, Gary; Knight, Kenneth L

2009-01-01

Health care professionals advocate that athletes who are susceptible to exercise-associated muscle cramps (EAMCs) should moderately increase their fluid and electrolyte intake by drinking sport drinks. Some clinicians have also claimed drinking small volumes of pickle juice effectively relieves acute EAMCs, often alleviating them within 35 seconds. Others fear ingesting pickle juice will enhance dehydration-induced hypertonicity, thereby prolonging dehydration. To determine if ingesting small quantities of pickle juice, a carbohydrate-electrolyte (CHO-e) drink, or water increases plasma electrolytes or other selected plasma variables. Crossover study. Exercise physiology laboratory. Nine euhydrated, healthy men (age = 25 +/- 2 years, height = 179.4 +/- 7.2 cm, mass = 86.3 +/- 15.9 kg) completed the study. Resting blood samples were collected preingestion (-0.5 minutes); immediately postingestion (0 minutes); and at 1, 5, 10, 15, 20, 25, 30, 45, and 60 minutes postingestion of 1 mL/kg body mass of pickle juice, CHO-e drink, or tap water. Plasma sodium concentration, plasma magnesium concentration, plasma calcium concentration, plasma potassium concentration, plasma osmolality, and changes in plasma volume were analyzed. Urine specific gravity, osmolality, and volume were also measured to characterize hydration status. Mean fluid intake was 86.3 +/- 16.7 mL. Plasma sodium concentration, plasma magnesium concentration, plasma calcium concentration, plasma osmolality, and plasma volume did not change during the 60 minutes after ingestion of each fluid (P >or= .05). Water ingestion slightly decreased plasma potassium concentration at 60 minutes (0.21 +/- 0.14 mg/dL [0.21 +/- 0.14 mmol/L]; P

Ambipolar ion acceleration in an expanding magnetic nozzle

NASA Astrophysics Data System (ADS)

Longmier, Benjamin W.; Bering, Edgar A., III; Carter, Mark D.; Cassady, Leonard D.; Chancery, William J.; Díaz, Franklin R. Chang; Glover, Tim W.; Hershkowitz, Noah; Ilin, Andrew V.; McCaskill, Greg E.; Olsen, Chris S.; Squire, Jared P.

2011-02-01

The helicon plasma stage in the Variable Specific Impulse Magnetoplasma Rocket (VASIMR®) VX-200i device was used to characterize an axial plasma potential profile within an expanding magnetic nozzle region of the laboratory based device. The ion acceleration mechanism is identified as an ambipolar electric field produced by an electron pressure gradient, resulting in a local axial ion speed of Mach 4 downstream of the magnetic nozzle. A 20 eV argon ion kinetic energy was measured in the helicon source, which had a peak magnetic field strength of 0.17 T. The helicon plasma source was operated with 25 mg s-1 argon propellant and 30 kW of RF power. The maximum measured values of plasma density and electron temperature within the exhaust plume were 1 × 1020 m-3 and 9 eV, respectively. The measured plasma density is nearly an order of magnitude larger than previously reported steady-state helicon plasma sources. The exhaust plume also exhibits a 95% to 100% ionization fraction. The size scale and spatial location of the plasma potential structure in the expanding magnetic nozzle region appear to follow the size scale and spatial location of the expanding magnetic field. The thickness of the potential structure was found to be 104 to 105 λDe depending on the local electron temperature in the magnetic nozzle, many orders of magnitude larger than typical laboratory double layer structures. The background plasma density and neutral argon pressure were 1015 m-3 and 2 × 10-5 Torr, respectively, in a 150 m3 vacuum chamber during operation of the helicon plasma source. The agreement between the measured plasma potential and plasma potential that was calculated from an ambipolar ion acceleration analysis over the bulk of the axial distance where the potential drop was located is a strong confirmation of the ambipolar acceleration process.

Study of Volumetrically Heated Ultra-High Energy Density Plasmas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rocca, Jorge J.

2016-10-27

Heating dense matter to millions of degrees is important for applications, but requires complex and expensive methods. The major goal of the project was to demonstrate using a compact laser the creation of a new ultra-high energy density plasma regime characterized by simultaneous extremely high temperature and high density, and to study it combining experimental measurements and advanced simulations. We have demonstrated that trapping of intense femtosecond laser pulses deep within ordered nanowire arrays can heat near solid density matter into a new ultra hot plasma regime. Extreme electron densities, and temperatures of several tens of million degrees were achievedmore » using laser pulses of only 0.5 J energy from a compact laser. Our x-ray spectra and simulations showed that extremely highly ionized plasma volumes several micrometers in depth are generated by irradiation of gold and Nickel nanowire arrays with femtosecond laser pulses of relativistic intensities. We obtained extraordinarily high degrees of ionization (e.g. we peeled 52 electrons from gold atoms, and up to 26 electrons from nickel atoms). In the process we generated Gigabar pressures only exceeded in the central hot spot of highly compressed thermonuclear fusion plasmas.. The plasma created after the dissolved wires expand, collide, and thermalize, is computed to have a thermal energy density of 0.3 GJ cm -3 and a pressure of 1-2 Gigabar. These are pressures only exceeded in highly compressed thermonuclear fusion plasmas. Scaling these results to higher laser intensities promises to create plasmas with temperatures and pressures exceeding those in the center of the sun.« less

Human heat adaptation.

PubMed

Taylor, Nigel A S

2014-01-01

In this overview, human morphological and functional adaptations during naturally and artificially induced heat adaptation are explored. Through discussions of adaptation theory and practice, a theoretical basis is constructed for evaluating heat adaptation. It will be argued that some adaptations are specific to the treatment used, while others are generalized. Regarding ethnic differences in heat tolerance, the case is put that reported differences in heat tolerance are not due to natural selection, but can be explained on the basis of variations in adaptation opportunity. These concepts are expanded to illustrate how traditional heat adaptation and acclimatization represent forms of habituation, and thermal clamping (controlled hyperthermia) is proposed as a superior model for mechanistic research. Indeed, this technique has led to questioning the perceived wisdom of body-fluid changes, such as the expansion and subsequent decay of plasma volume, and sudomotor function, including sweat habituation and redistribution. Throughout, this contribution was aimed at taking another step toward understanding the phenomenon of heat adaptation and stimulating future research. In this regard, research questions are posed concerning the influence that variations in morphological configuration may exert upon adaptation, the determinants of postexercise plasma volume recovery, and the physiological mechanisms that modify the cholinergic sensitivity of sweat glands, and changes in basal metabolic rate and body core temperature following adaptation. © 2014 American Physiological Society.

Increased risk of volume overload with plasma compared with four‐factor prothrombin complex concentrate for urgent vitamin K antagonist reversal

PubMed Central

Refaai, Majed A.; Goldstein, Joshua N.; Lee, Martin L.; Durn, Billie L.; Milling, Truman J.; Sarode, Ravi

2015-01-01

BACKGROUND Plasma is commonly used for vitamin K antagonist (VKA) reversal, but observational studies suggest that it is associated with transfusion‐related adverse reactions (e.g., volume overload). However, this issue has not previously been addressed in a randomized controlled trial (RCT). STUDY DESIGN AND METHODS Factors associated with volume overload were examined using data from two Phase IIIb RCTs comparing plasma with four‐factor prothrombin complex concentrate (4F‐PCC, Beriplex/Kcentra, CSL Behring) for urgent VKA reversal. VKA‐treated patients with major bleeding (NCT00708435) or requiring an urgent surgical or invasive procedure (NCT00803101) were randomly assigned (1:1) to receive either plasma or 4F‐PCC, concomitant with vitamin K. Adverse events (AEs) and serious AEs were prospectively captured up to Day 10 and 45, respectively. Volume overload predictors were evaluated on a univariate and multivariate basis. RESULTS A total of 388 patients (4F‐PCC, n = 191; plasma, n = 197) were enrolled. Volume overload occurred in 34 (9%) patients (4F‐PCC, n = 9; plasma, n = 25). In univariate analyses, use of plasma (vs. 4F‐PCC), use of nonstudy plasma and/or platelets, race, history of congestive heart failure (CHF), and history of renal disease were associated with volume overload. In multivariate analyses, use of plasma (vs. 4F‐PCC), history of CHF, and history of renal disease were independent volume overload predictors. In an additional analysis restricted to volume overload events recorded up to Day 7, only use of plasma (vs. 4F‐PCC) was an independent volume overload predictor. CONCLUSIONS After adjusting for other potential risk factors, plasma use was independently associated with a greater risk of volume overload than 4F‐PCC in patients requiring urgent VKA reversal. PMID:26135740

Methods for recovering a solvent from a fluid volume and methods of removing at least one compound from a nonpolar solvent

DOEpatents

Ginosar, Daniel M.; Wendt, Daniel S.; Petkovic, Lucia M.

2014-06-10

A method of removing a nonpolar solvent from a fluid volume that includes at least one nonpolar compound, such as a fat, an oil or a triglyceride, is provided. The method comprises contacting a fluid volume with an expanding gas to expand the nonpolar solvent and form a gas-expanded solvent. The gas-expanded solvent may have a substantially reduced density in comparison to the at least one nonpolar compound and/or a substantially reduced capacity to solubilize the nonpolar compound, causing the nonpolar compounds to separate from the gas-expanded nonpolar solvent into a separate liquid phase. The liquid phase including the at least one nonpolar compound may be separated from the gas-expanded solvent using conventional techniques. After separation of the liquid phase, at least one of the temperature and pressure may be reduced to separate the nonpolar solvent from the expanding gas such that the nonpolar solvent may be recovered and reused.

Lagrangian description of warm plasmas

NASA Technical Reports Server (NTRS)

Kim, H.

1970-01-01

Efforts are described to extend the averaged Lagrangian method of describing small signal wave propagation and nonlinear wave interaction, developed by earlier workers for cold plasmas, to the more general conditions of warm collisionless plasmas, and to demonstrate particularly the effectiveness of the method in analyzing wave-wave interactions. The theory is developed for both the microscopic description and the hydrodynamic approximation to plasma behavior. First, a microscopic Lagrangian is formulated rigorously, and expanded in terms of perturbations about equilibrium. Two methods are then described for deriving a hydrodynamic Lagrangian. In the first of these, the Lagrangian is obtained by velocity integration of the exact microscopic Lagrangian. In the second, the expanded hydrodynamic Lagrangian is obtained directly from the expanded microscopic Lagrangian. As applications of the microscopic Lagrangian, the small-signal dispersion relations and the coupled mode equations are derived for all possible waves in a warm infinite, weakly inhomogeneous magnetoplasma, and their interactions are examined.

Measles virus–specific plasma cells are prominent in subacute sclerosing panencephalitis CSF

PubMed Central

Owens, G.P.; Ritchie, A.M.; Gilden, D.H.; Burgoon, M.P.; Becker, D.; Bennett, J.L.

2012-01-01

Objective To demonstrate the specificity of expanded CD138+ plasma cell clones recovered from the CSF of a patient with subacute sclerosing panencephalitis (SSPE) for measles virus (MV). Methods IgG variable region sequences of single-antibody-secreting CD138+ cells sorted from SSPE CSF were amplified by single-cell PCR and analyzed. Human IgG1 recombinant antibodies (rAbs) were produced from four expanded CD138+ clones and assayed for immunoreactivity against MV proteins. Results Clonal expansion was a prominent feature of the SSPE plasma cell repertoire, and each of the four rAbs assayed was specific for either the MV fusion or the MV nucleocapsid protein. Conclusions Expanded plasma cell clones in the CSF of patients with subacute sclerosing panencephalitis produce disease-relevant antibodies. Recombinant antibodies derived from CSF B cells could provide a tool to identify target antigens in idiopathic inflammatory disorders. PMID:17515543

The effect of chronic erythrocytic polycythemia and high altitude upon plasma and blood volumes.

NASA Technical Reports Server (NTRS)

Burton, R. R.; Smith, A. H.

1972-01-01

Comparison of two kinds of physiological chronic erythrocytic polycythemias in order to differentiate the specific effect of erythrocytic polycythemia from the general effects of high altitude upon the plasma volume. The two kinds were produced hormonally in female chickens, at sea level, or by protracted high-altitude exposures. It appears that the vascular system of the body may account for an increase in red blood cell mass either by reduction in plasma volume, or by no change in plasma volume, resulting in differential changes in total blood volumes.

Correlation of plasma and peritoneal diasylate clomipramine concentration with hemodynamic recovery after intralipid infusion in rabbits.

PubMed

Harvey, Martyn; Cave, Grant; Hoggett, Kerry

2009-02-01

Drug sequestration to an expanded plasma lipid phase has been proposed as a potential mechanism of action for lipid emulsions in lipophilic cardiotoxin overdose. The authors set out to document plasma and peritoneal diasylate clomipramine concentration after resuscitation with lipid emulsion in a rabbit model of clomipramine-induced hypotension. Twenty sedated mechanically ventilated New Zealand White rabbits were allocated to receive either 12 mL/kg 20% Intralipid or 12 mL/kg saline solution, following clomipramine infusion to 50% baseline mean arterial pressure (MAP). Hemodynamic parameters and serum clomipramine concentration were determined to 59 minutes. Peritoneal dialysis with 20% Intralipid or saline solution was evaluated for clomipramine concentration. Mean arterial pressure was greater in lipid-treated animals as assessed by repeated-measures analysis of variance (F[1,14] = 6.84; p = 0.020). Lipid infusion was associated with elevated plasma clomipramine concentration and reduced initial volume of distribution (Vd; 5.7 [+/-1.6] L/kg lipid vs. 15.9 [+/-7.2] L/kg saline; p = 0.0001). Peritoneal diasylate clomipramine concentration was greater in lipid-treated animals (366.2 [+/-186.2] microg/L lipid vs. 37.7 [+/-13.8] microg/L saline; p = 0.002). Amelioration of clomipramine-induced hypotension with lipid infusion is associated with reduced initial Vd and elevated plasma clomipramine concentration consistent with intravascular drug-lipid sequestration. Concomitant peritoneal dialysis with lipid emulsion enhances clomipramine extraction.

Collisionless coupling of a high- β expansion to an ambient, magnetized plasma. II. Experimental fields and measured momentum coupling

NASA Astrophysics Data System (ADS)

Bonde, Jeffrey; Vincena, Stephen; Gekelman, Walter

2018-04-01

The momentum coupled to a magnetized, ambient argon plasma from a high- β, laser-produced carbon plasma is examined in a collisionless, weakly coupled limit. The total electric field was measured by separately examining the induced component associated with the rapidly changing magnetic field of the high- β (kinetic β˜106), expanding plasma and the electrostatic component due to polarization of the expansion. Their temporal and spatial structures are discussed and their effect on the ambient argon plasma (thermal β˜10-2) is confirmed with a laser-induced fluorescence diagnostic, which directly probed the argon ion velocity distribution function. For the given experimental conditions, the electrostatic field is shown to dominate the interaction between the high- β expansion and the ambient plasma. Specifically, the expanding plasma couples energy and momentum into the ambient plasma by pulling ions inward against the flow direction.

Effects of Synthetic Versus Natural Colloid Resuscitation on Inducing Dilutional Coagulopathy and Increasing Hemorrhage in Rabbits

DTIC Science & Technology

2008-05-01

hemostasis, and plasma expanders: a quarter century enigma. Fed Proc. 1975;34:1429–1440. 23. Bergqvist D. Dextran and haemostasis. a review. Acta Chir ...eds. Blood Substitutes and Plasma Expanders. Prog Clin Biol Res. 1978;19:293–298. 57. Kovalik SG, Ledgewood AM, Lucas CE, Higgins RF. The cardiac

Optimal back-extrapolation method for estimating plasma volume in humans using the indocyanine green dilution method.

PubMed

Polidori, David; Rowley, Clarence

2014-07-22

The indocyanine green dilution method is one of the methods available to estimate plasma volume, although some researchers have questioned the accuracy of this method. We developed a new, physiologically based mathematical model of indocyanine green kinetics that more accurately represents indocyanine green kinetics during the first few minutes postinjection than what is assumed when using the traditional mono-exponential back-extrapolation method. The mathematical model is used to develop an optimal back-extrapolation method for estimating plasma volume based on simulated indocyanine green kinetics obtained from the physiological model. Results from a clinical study using the indocyanine green dilution method in 36 subjects with type 2 diabetes indicate that the estimated plasma volumes are considerably lower when using the traditional back-extrapolation method than when using the proposed back-extrapolation method (mean (standard deviation) plasma volume = 26.8 (5.4) mL/kg for the traditional method vs 35.1 (7.0) mL/kg for the proposed method). The results obtained using the proposed method are more consistent with previously reported plasma volume values. Based on the more physiological representation of indocyanine green kinetics and greater consistency with previously reported plasma volume values, the new back-extrapolation method is proposed for use when estimating plasma volume using the indocyanine green dilution method.

Injectable self inflating hydrogel pellet expanders for the treatment of orbital volume deficiency in congenital microphthalmos: preliminary results with a new therapeutic approach

PubMed Central

Schittkowski, M P; Guthoff, R F

2006-01-01

Background/aim Children with congenital microphthalmos are usually able to wear an eye prosthesis but the cosmetic aspect is determined by the size of the orbital volume deficiency. Instead of using a ball shaped standard hydrogel expander or a regular orbital implant, which would necessitate enucleation of the microphthalmic eye, this study investigates the feasibility of volume augmentation with injectable pellet expanders, as formerly suggested for acquired anophthalmos in adults only. Method The pellet expander is made from a self inflating hydrogel that takes up water by osmosis (dry state: length 8 mm, diameter 2 mm, volume 0.025 ml; in vitro hydrated state after around 1 day: length 15 mm, diameter 4 mm, volume 0.24 ml; swelling capacity: 9.6‐fold). This report concerns six patients (two girls and four boys) aged between 4 months and 42 months with unilateral microphthalmos who were treated by injection of 4–14 pellet expanders into the retrobulbar orbital tissue. Volume augmentation was 1–3.5 ml. The pellets were injected using a customised trocar and placed behind the microphthalmos directed into the intraconal space. Results The increasing orbital volume was noticeable within 2 days and was confirmed by ultrasonography and magnetic resonance imaging. The final result can be anticipated by the volume augmentation effect produced by the amount of saline solution injected in the orbital apex region. All patients were fitted with an artificial eye, which was subsequently enlarged every 3–5 months. Anophthalmic enophthalmos was fully compensated with this technique. No complications have been encountered to date. Conclusions Orbital volume augmentation with injectable self inflating hydrogel expander pellets is apparently a safe, quick, and minimally invasive technique for various indications in orbital reconstructive surgery—for example, to treat an enophthalmic appearance in microphthalmos and congenital or acquired anophthalmos. PMID:16707526

Electrolyte and Plasma Changes After Ingestion of Pickle Juice, Water, and a Common Carbohydrate-Electrolyte Solution

PubMed Central

Miller, Kevin C.; Mack, Gary; Knight, Kenneth L.

2009-01-01

Abstract Context: Health care professionals advocate that athletes who are susceptible to exercise-associated muscle cramps (EAMCs) should moderately increase their fluid and electrolyte intake by drinking sport drinks. Some clinicians have also claimed drinking small volumes of pickle juice effectively relieves acute EAMCs, often alleviating them within 35 seconds. Others fear ingesting pickle juice will enhance dehydration-induced hypertonicity, thereby prolonging dehydration. Objective: To determine if ingesting small quantities of pickle juice, a carbohydrate-electrolyte (CHO-e) drink, or water increases plasma electrolytes or other selected plasma variables. Design: Crossover study. Setting: Exercise physiology laboratory. Patients or Other Participants: Nine euhydrated, healthy men (age  =  25 ± 2 years, height  =  179.4 ± 7.2 cm, mass  =  86.3 ± 15.9 kg) completed the study. Intervention(s): Resting blood samples were collected preingestion (−0.5 minutes); immediately postingestion (0 minutes); and at 1, 5, 10, 15, 20, 25, 30, 45, and 60 minutes postingestion of 1 mL/kg body mass of pickle juice, CHO-e drink, or tap water. Main Outcome Measure(s): Plasma sodium concentration, plasma magnesium concentration, plasma calcium concentration, plasma potassium concentration, plasma osmolality, and changes in plasma volume were analyzed. Urine specific gravity, osmolality, and volume were also measured to characterize hydration status. Results: Mean fluid intake was 86.3 ± 16.7 mL. Plasma sodium concentration, plasma magnesium concentration, plasma calcium concentration, plasma osmolality, and plasma volume did not change during the 60 minutes after ingestion of each fluid (P ≥ .05). Water ingestion slightly decreased plasma potassium concentration at 60 minutes (0.21 ± 0.14 mg/dL [0.21 ± 0.14 mmol/L]; P ≤ .05). Conclusions: At these volumes, ingestion of pickle juice and CHO-e drink did not cause substantial changes in plasma electrolyte concentrations, plasma osmolality, or plasma volume in rested, euhydrated men. Concern that ingesting these volumes of pickle juice might exacerbate an athlete's risk of dehydration-induced hypertonicity may be unwarranted. If EAMCs are caused by large electrolyte loss due to sweating, these volumes of pickle juice or CHO-e drink are unlikely to restore any deficit incurred by exercise. PMID:19771282

Ion beams in multi-species plasmas

NASA Astrophysics Data System (ADS)

Aguirre, E. M.; Scime, E. E.; Good, T. N.

2018-04-01

Argon and xenon ion velocity distribution functions are measured in Ar-He, Ar-Xe, and Xe-He expanding helicon plasmas to determine if ion beam velocity is enhanced by the presence of lighter ions. Contrary to observations in mixed gas sheath experiments, we find that adding a lighter ion does not increase the ion beam speed. The predominant effect is a reduction of ion beam velocity consistent with increased drag arising from increased gas pressure under all conditions: constant total gas pressure, equal plasma densities of different ions, and very different plasma densities of different ions. These results suggest that the physics responsible for the acceleration of multiple ion species in simple sheaths is not responsible for the ion acceleration observed in expanding helicon plasmas.

PASylation: a biological alternative to PEGylation for extending the plasma half-life of pharmaceutically active proteins

PubMed Central

Schlapschy, Martin; Binder, Uli; Börger, Claudia; Theobald, Ina; Wachinger, Klaus; Kisling, Sigrid; Haller, Dirk; Skerra, Arne

2013-01-01

A major limitation of biopharmaceutical proteins is their fast clearance from circulation via kidney filtration, which strongly hampers efficacy both in animal studies and in human therapy. We have developed conformationally disordered polypeptide chains with expanded hydrodynamic volume comprising the small residues Pro, Ala and Ser (PAS). PAS sequences are hydrophilic, uncharged biological polymers with biophysical properties very similar to poly-ethylene glycol (PEG), whose chemical conjugation to drugs is an established method for plasma half-life extension. In contrast, PAS polypeptides offer fusion to a therapeutic protein on the genetic level, permitting Escherichia coli production of fully active proteins and obviating in vitro coupling or modification steps. Furthermore, they are biodegradable, thus avoiding organ accumulation, while showing stability in serum and lacking toxicity or immunogenicity in mice. We demonstrate that PASylation bestows typical biologics, such as interferon, growth hormone or Fab fragments, with considerably prolonged circulation and boosts bioactivity in vivo. PMID:23754528

High density plasma gun generates plasmas at 190 kilometers per second

NASA Technical Reports Server (NTRS)

Espy, P. N.

1971-01-01

Gun has thin metal foil disc which positions or localizes gas to be ionized during electrical discharge cycle, overcoming major limiting factor in obtaining such plasmas. Expanding plasma front travels at 190 km/sec, compared to plasmas of 50 to 60 km/sec previously achieved.

Transition from single to multiple axial potential structure in expanding helicon plasma

NASA Astrophysics Data System (ADS)

Ghosh, Soumen; Chattopadhyay, P. K.; Ghosh, J.; Pal, R.; Bora, D.

2017-02-01

Transition from single to multiple axial potential structure (MAPS) formation is reported in expanding helicon plasma. This transition is created by forming a cusp magnetic field at the downstream after the expansion throat. Two distinct potential drops are separated by a uniform axial potential zone. Non-uniform axial density distribution exists in expanding helicon systems. A cusp-like field nourishes both the axial density gradients sufficient enough for the formation of these two distinct potential drops. It is also shown that both single and multiple axial potential structures are observed only when both geometric and magnetic expansions closely coincide with each other. Coexistence of these two expansions at the same location enhances plasma expansion which facilitates deviation from Boltzmann distribution and violates quasi-neutrality locally.

Formation of electron energy spectra during magnetic reconnection in laser-produced plasma

NASA Astrophysics Data System (ADS)

Huang, Kai; Lu, Quanming; Huang, Can; Dong, Quanli; Wang, Huanyu; Fan, Feibin; Sheng, Zhengming; Wang, Shui; Zhang, Jie

2017-10-01

Energetic electron spectra formed during magnetic reconnection between two laser-produced plasma bubbles are investigated by the use of two-dimensional particle-in-cell simulations. It is found that the evolution of such an interaction between the two plasma bubbles can be separated into two distinct stages: squeezing and reconnection stages. In the squeezing stage, when the two plasma bubbles expand quickly and collide with each other, the magnetic field in the inflow region is greatly enhanced. In the second stage, a thin current sheet is formed between the two plasma bubbles, and then, magnetic reconnection occurs therein. During the squeezing stage, electrons are heated in the perpendicular direction by betatron acceleration due to the enhancement of the magnetic field around the plasma bubbles. Meanwhile, non-thermal electrons are generated by the Fermi mechanism when these electrons bounce between the two plasma bubbles approaching quickly and get accelerated mainly by the convective electric field associated with the plasma bubbles. During the reconnection stage, electrons get further accelerated mainly by the reconnection electric field in the vicinity of the X line. When the expanding speed of the plasma bubbles is sufficiently large, the formed electron energy spectra have a kappa distribution, where the lower energy part satisfies a Maxwellian function and the higher energy part is a power-law distribution. Moreover, the increase in the expanding speed will result in the hardening of formed power-law spectra in both the squeezing and reconnection stages.

Optimal back-extrapolation method for estimating plasma volume in humans using the indocyanine green dilution method

PubMed Central

2014-01-01

Background The indocyanine green dilution method is one of the methods available to estimate plasma volume, although some researchers have questioned the accuracy of this method. Methods We developed a new, physiologically based mathematical model of indocyanine green kinetics that more accurately represents indocyanine green kinetics during the first few minutes postinjection than what is assumed when using the traditional mono-exponential back-extrapolation method. The mathematical model is used to develop an optimal back-extrapolation method for estimating plasma volume based on simulated indocyanine green kinetics obtained from the physiological model. Results Results from a clinical study using the indocyanine green dilution method in 36 subjects with type 2 diabetes indicate that the estimated plasma volumes are considerably lower when using the traditional back-extrapolation method than when using the proposed back-extrapolation method (mean (standard deviation) plasma volume = 26.8 (5.4) mL/kg for the traditional method vs 35.1 (7.0) mL/kg for the proposed method). The results obtained using the proposed method are more consistent with previously reported plasma volume values. Conclusions Based on the more physiological representation of indocyanine green kinetics and greater consistency with previously reported plasma volume values, the new back-extrapolation method is proposed for use when estimating plasma volume using the indocyanine green dilution method. PMID:25052018

Laboratory simulation of energetic flows of magnetospheric planetary plasma

NASA Astrophysics Data System (ADS)

Shaikhislamov, I. F.; Posukh, V. G.; Melekhov, A. V.; Boyarintsev, E. L.; Zakharov, Yu P.; Prokopov, P. A.; Ponomarenko, A. G.

2017-01-01

Dynamic interaction of super-sonic counter-streaming plasmas moving in dipole magnetic dipole is studied in laboratory experiment. First, a quasi-stationary flow is produced by plasma gun which forms a magnetosphere around the magnetic dipole. Second, explosive plasma expanding from inner dipole region outward is launch by laser beams focused at the surface of the dipole cover. Laser plasma is energetic enough to disrupt magnetic field and to sweep through the background plasma for large distances. Probe measurements showed that far from the initially formed magnetosphere laser plasma carries within itself a magnetic field of the same direction but order of magnitude larger in value than the vacuum dipole field at considered distances. Because no compression of magnetic field at the front of laser plasma was observed, the realized interaction is different from previous experiments and theoretical models of laser plasma expansion into uniform magnetized background. It was deduced based on the obtained data that laser plasma while expanding through inner magnetosphere picks up a magnetized shell formed by background plasma and carries it for large distances beyond previously existing magnetosphere.

Fibrinogen Reduction During Selective Plasma Exchange due to Membrane Fouling.

PubMed

Ohkubo, Atsushi; Okado, Tomokazu; Miyamoto, Satoko; Hashimoto, Yurie; Komori, Shigeto; Yamamoto, Motoki; Maeda, Takuma; Itagaki, Ayako; Yamamoto, Hiroko; Seshima, Hiroshi; Kurashima, Naoki; Iimori, Soichiro; Naito, Shotaro; Sohara, Eisei; Uchida, Shinichi; Rai, Tatemitsu

2017-06-01

Fibrinogen is substantially reduced by most plasmapheresis modalities but retained in selective plasma exchange using Evacure EC-4A10 (EC-4A). Although EC-4A's fibrinogen sieving coefficient is 0, a session of selective plasma exchange reduced fibrinogen by approximately 19%. Here, we investigated sieving coefficient in five patients. When the mean processed plasma volume was 1.15 × plasma volume, the mean reduction of fibrinogen during selective plasma exchange was approximately 15%. Fibrinogen sieving coefficient was 0 when the processed plasma volume was 1.0 L, increasing to 0.07 when the processed plasma volume was 3.0 L, with a mean of 0.03 during selective plasma exchange. When fibrinogen sieving coefficient was 0, selective plasma exchange reduced fibrinogen by approximately 10%. Scanning electron microscopy images revealed internal fouling of EC-4A's hollow fiber membrane by substances such as fibrinogen fibrils. Thus, fibrinogen reduction by selective plasma exchange may be predominantly caused by membrane fouling rather than filtration. © 2017 International Society for Apheresis, Japanese Society for Apheresis, and Japanese Society for Dialysis Therapy.

A randomized, controlled, double-blind crossover study on the effects of 1-L infusions of 6% hydroxyethyl starch suspended in 0.9% saline (voluven) and a balanced solution (Plasma Volume Redibag) on blood volume, renal blood flow velocity, and renal cortical tissue perfusion in healthy volunteers.

PubMed

Chowdhury, Abeed H; Cox, Eleanor F; Francis, Susan T; Lobo, Dileep N

2014-05-01

We compared the effects of intravenous administration of 6% hydroxyethyl starch (maize-derived) in 0.9% saline (Voluven; Fresenius Kabi, Runcorn, United Kingdom) and a "balanced" preparation of 6% hydroxyethyl starch (potato-derived) [Plasma Volume Redibag (PVR); Baxter Healthcare, Thetford, United Kingdom] on renal blood flow velocity and renal cortical tissue perfusion in humans using magnetic resonance imaging. Hyperchloremia resulting from 0.9% saline infusion may adversely affect renal hemodynamics when compared with balanced crystalloids. This phenomenon has not been studied with colloids. Twelve healthy adult male subjects received 1-L intravenous infusions of Voluven or PVR over 30 minutes in a randomized, double-blind manner, with crossover studies 7 to 10 days later. Magnetic resonance imaging proceeded for 60 minutes after commencement of infusion to measure renal artery blood flow velocity and renal cortical perfusion. Blood was sampled, and weight was recorded at 0, 30, 60, 120, 180, and 240 minutes. Mean peak serum chloride concentrations were 108 and 106 mmol/L, respectively, after Voluven and PVR infusion (P = 0.032). Changes in blood volume (P = 0.867), strong ion difference (P = 0.219), and mean renal artery flow velocity (P = 0.319) were similar. However, there was a significant increase in mean renal cortical tissue perfusion after PVR when compared with Voluven (P = 0.033). There was no difference in urinary neutrophil gelatinase-associated liopcalin to creatinine ratios after the infusion (P = 0.164). There was no difference in the blood volume-expanding properties of the 2 preparations of 6% hydroxyethyl starch. The balanced starch produced an increase in renal cortical tissue perfusion, a phenomenon not seen with starch in 0.9% saline.

Effect Of Leg Exercise On Vascular Volumes During Bed Rest

NASA Technical Reports Server (NTRS)

Greenleaf, J. E.; Vernikos, J.; Wade, C. E.; Barnes, P. R.

1993-01-01

Report describes experiments on effects of no-exercise regimen and of two leg-exercise regimens on volumes of plasma, volumes of red blood cells, densities of bodies, and water balances of 19 men (32 to 42 years old) confined to minus 6 degrees-head-down bed rest for 30 days. Purpose of study to determine whether either or both exercise regimens maintain plasma volume and to relate levels of hypovolemia to body fluid balances. Results showed during bed rest, plasma volume maintained in isotomic group but not in other two groups, and no significant differences in body densities, body weights, or water balances among three groups. Concludes isotonic-exercise regimen better than isokinetic-exercise regimen for maintaining plasma volume during prolonged exposure to bed rest.

The use of biomarkers to describe plasma-, red cell-, and blood volume from a simple blood test.

PubMed

Lobigs, Louisa Margit; Sottas, Pierre-Edouard; Bourdon, Pitre Collier; Nikolovski, Zoran; El-Gingo, Mohamed; Varamenti, Evdokia; Peeling, Peter; Dawson, Brian; Schumacher, Yorck Olaf

2017-01-01

Plasma volume and red cell mass are key health markers used to monitor numerous disease states, such as heart failure, kidney disease, or sepsis. Nevertheless, there is currently no practically applicable method to easily measure absolute plasma or red cell volumes in a clinical setting. Here, a novel marker for plasma volume and red cell mass was developed through analysis of the observed variability caused by plasma volume shifts in common biochemical measures, selected based on their propensity to present with low variations over time. Once a month for 6 months, serum and whole blood samples were collected from 33 active males. Concurrently, the CO-rebreathing method was applied to determine target levels of hemoglobin mass (HbM) and blood volumes. The variability of 18 common chemistry markers and 27 Full Blood Count variables was investigated and matched to the observed plasma volume variation. After the removal of between-subject variations using a Bayesian model, multivariate analysis identified two sets of 8 and 15 biomarkers explaining 68% and 69% of plasma volume variance, respectively. The final multiparametric model contains a weighting function to allow for isolated abnormalities in single biomarkers. This proof-of-concept investigation describes a novel approach to estimate absolute vascular volumes, with a simple blood test. Despite the physiological instability of critically ill patients, it is hypothesized the model, with its multiparametric approach and weighting function, maintains the capacity to describe vascular volumes. This model has potential to transform volume management in clinical settings. Am. J. Hematol. 92:62-67, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Low current plasmatron fuel converter having enlarged volume discharges

DOEpatents

Rabinovich, Alexander; Alexeev, Nikolai; Bromberg, Leslie; Cohn, Daniel R.; Samokhin, Andrei

2005-04-19

A novel apparatus and method is disclosed for a plasmatron fuel converter (""plasmatron"") that efficiently uses electrical energy to produce hydrogen rich gas. The volume and shape of the plasma discharge is controlled by a fluid flow established in a plasma discharge volume. A plasmatron according to this invention produces a substantially large effective plasma discharge volume allowing for substantially greater volumetric efficiency in the initiation of chemical reactions within a volume of bulk fluid reactant flowing through the plasmatron.

Low current plasmatron fuel converter having enlarged volume discharges

DOEpatents

Rabinovich, Alexander [Swampscott, MA; Alexeev, Nikolai [Moscow, RU; Bromberg, Leslie [Sharon, MA; Cohn, Daniel R [Chestnut Hill, MA; Samokhin, Andrei [Moscow, RU

2009-10-06

A novel apparatus and method is disclosed for a plasmatron fuel converter ("plasmatron") that efficiently uses electrical energy to produce hydrogen rich gas. The volume and shape of the plasma discharge is controlled by a fluid flow established in a plasma discharge volume. A plasmatron according to this invention produces a substantially large effective plasma discharge volume allowing for substantially greater volumetric efficiency in the initiation of chemical reactions within a volume of bulk fluid reactant flowing through the plasmatron.

Exercise training hypotension - Implications for plasma volume, renin, and vasopressin

NASA Technical Reports Server (NTRS)

Greenleaf, J. E.; Sciaraffa, D.; Shvartz, E.; Keil, L. C.; Brock, P. J.

1981-01-01

The relation of changes in plasma volume, plasma renin activity and arginine vasopressin to changes in resting blood pressure during exercise training is investigated. Resting supine, sitting, and standing systolic and fifth-phase diastolic blood pressures were measured in ten men before and after an eight-day training period on a cycle ergometer in either a hot (39.8 C) or cool (23.8 C) environment, and compared with plasma volume, renin and vasopressin levels, heart rates, maximal oxygen uptakes, rectal temperatures and sweat rates. Following acclimatization, resting supine and sitting diastolic pressures are observed to decrease by 6 and 9 mm Hg, respectively, while no significant changes are found in the diastolic pressures of the control group or the systolic pressures of either group. Resting plasma volume is found to increase by 12.2% in the controls and by 17.6% after acclimatization following the exercise training. Results suggest that the resting hypotension produced is not attributable to changes in resting plasma volume, renin or vasopressin, although heat acclimatization, which leads to large decreases in plasma volume and increases in vasopressin and renin activity, may be useful in the treatment of hypertension.

Red cell volume with changes in plasma osmolarity during maximal exercise.

NASA Technical Reports Server (NTRS)

Van Beaumont, W.

1973-01-01

The volume of the red cell in vivo was measured during acute changes in plasma osmolarity evoked through short (6 to 8 min) maximal exercise in six male volunteer subjects. Simultaneous measurements of mean corpuscular red cell volume (MCV), hematocrit, blood hemoglobin, mean corpuscular hemoglobin concentration (MCHC), and plasma osmolarity showed that there was no change in the MCV or MCHC with a concomitant rise of nearly 6% in plasma osmolarity. Apparently, in vivo, the volume of the red cell in exercising healthy human subjects does not change measurably, in spite of significant changes in osmotic pressure of the surrounding medium. Consequently, it is not justified to correct postexercise hematocrit measurements for changes in plasma osmolarity.

The Role of Blood Osmolality and Volume in Regulating Vasopressin Secretion in the Rat

PubMed Central

Dunn, Fredrick L.; Brennan, Thomas J.; Nelson, Averial E.; Robertson, Gary L.

1973-01-01

A sensitive and specific radioimmunoassay for plasma arginine vasopressin (AVP) has been used to study the effects of blood osmolality and volume in regulating AVP secretion in unanesthetized rats. Under basal conditions, plasma AVP and osmolality were relatively constant, averaging 2.3±0.9 (SD) pg/ml and 294±1.4 mosmol/kg, respectively. Fluid restriction, which increased osmolality and decreased volume, resulted in a progressive rise in plasma AVP to about 10 times basal levels after 96 h. A 2-3-fold increase in plasma AVP occurred as early as 12 h, when osmolality and volume had each changed by less than 2%. Intraperitoneal injections of hypertonic saline, which had no effect on blood volume, also produced a rise in plasma AVP that was linearly correlated with the rise in osmolality (r > 0.9) and quantitatively similar to that found during fluid restriction (plasma AVP increased 2-4-fold with each 1% increase in osmolality). Intraperitoneal injection of polyethylene glycol, which decreased blood volume without altering osmolality, also increased plasma AVP but this response followed an exponential pattern and did not become significant until volume had decreased by 8% or more. At these levels of hypovolemia, the osmoregulatory system continued to function but showed a lower threshold and increase sensitivity to osmotic stimulation. We conclude that AVP secretion is regulated principally by blood osmolality but that the responsiveness of this mechanism may be significantly altered by modest changes in blood volume. PMID:4750450

Plasma volume, osmolality, vasopressin, and renin activity during graded exercise in man

NASA Technical Reports Server (NTRS)

Convertino, V. A.; Keil, L. C.; Bernauer, E. M.; Greenleaf, J. E.

1981-01-01

The influence of work intensity on plasma volume, osmolality, vasopressin and renin activity and the interrelationships between these responses are investigated. Plasma volume, renin activity and osmotic, sodium and arginine vasopressin concentrations were measured in venous blood samples taken from 15 healthy male subjects before and after six minutes of bicycle ergometer exercise at 100, 175 and 225 W. Plasma volume is found to decrease significantly with increasing work intensity, while increases in Na(+) concentration, osmolality and vasopressin are only observed to be significant when the work intensity exceeds 40% maximal aerobic capacity and plasma resin activity increased linearly at all work levels. In addition, significant correlations are observed between plasma volume and osmolality and sodium changes, and between vasopressin and osmolality and sodium content changes. Data thus support the hypotheses that (1) vasopressin may be the primary controlling endocrine for fluid and electrolyte levels following exercise; (2) an exercise intensity greater than 40% maximal aerobic capacity is required to stimulate vasopressin release through changes in plasma osmolality; and (3) the stimulation of the renin-angiotensin system is a more general stress response.

Plasma Physics/Fusion Energy Education at the Liberty Science Center

NASA Astrophysics Data System (ADS)

Zwicker, Andrew; Delooper, John; Carpe, Andy; Amara, Joe; Butnick, Nancy; Lynch, Ellen; Osowski, Jeff

2007-11-01

The Liberty Science Center (LSC) is the largest (300,000 sq. ft.) education resource in the New Jersey-New York City region. A major 109 million expansion and renewal was recently completed. Accordingly, PPPL has expanded the science education collaboration with the Center into three innovative, hands-on programs. On the main floor, a new fusion exhibit is one of the focuses of ``Energy Quest.'' This includes a DC glow discharge tube with a permanent external magnet allowing visitors to manipulate the plasma while reading information on plasma creation and fusion energy. In the section of LSC dedicated to intensive science investigations (20,000 sq. ft) we have added ``Live from NSTX'' which will give students an opportunity to connect via video-conferencing to the NSTX control room during plasma operations. A prototype program was completed in May, 2007 with three high school physics classes and will be expanded when NSTX resumes operation. Finally, a plasma physics laboratory in this area will have a fully functioning, research-grade plasma source that will allow long-term visitors an opportunity to perform experiments in plasma processing, plasma spectroscopy, and dusty plasmas.

Effect of Phospholipidosis on the Cellular Pharmacokinetics of ChloroquineS⃞

PubMed Central

Zheng, Nan; Zhang, Xinyuan

2011-01-01

In vivo, the weakly basic, lipophilic drug chloroquine (CQ) accumulates in the kidney to concentrations more than a thousand-fold greater than those in plasma. To study the cellular pharmacokinetics of chloroquine in cells derived from the distal tubule, Madin-Darby canine kidney cells were incubated with CQ under various conditions. CQ progressively accumulated without exhibiting steady-state behavior. Experiments failed to yield evidence that known active transport mechanisms mediated CQ uptake at the plasma membrane. CQ induced a phospholipidosis-like phenotype, characterized by the appearance of numerous multivesicular and multilamellar bodies (MLBs/MVBs) within the lumen of expanded cytoplasmic vesicles. Other induced phenotypic changes including changes in the volume and pH of acidic organelles were measured, and the integrated effects of all these changes were computationally modeled to establish their impact on intracellular CQ mass accumulation. Based on the passive transport behavior of CQ, the measured phenotypic changes fully accounted for the continuous, nonsteady-state CQ accumulation kinetics. Consistent with the simulation results, Raman confocal microscopy of live cells confirmed that CQ became highly concentrated within induced, expanded cytoplasmic vesicles that contained multiple MLBs/MVBs. Progressive CQ accumulation was increased by sucrose, a compound that stimulated the phospholipidosis-like phenotype, and was decreased by bafilomycin A1, a compound that inhibited this phenotype. Thus, phospholipidosis-associated changes in organelle structure and intracellular membrane content can exert a major influence on the local bioaccumulation and biodistribution of drugs. PMID:21156819

Cortisol intermediates and hydrocortisone responsiveness in critical neonatal disease.

PubMed

Khashana, Abdelmoneim; Saarela, Timo; Ramet, Mika; Hallman, Mikko

2017-07-01

Therapy-resistant hypotension complicates diseases in neonates. Our objective was to investigate whether lack of therapeutic response to plasma expanders and inotropes associates with serum levels of cortisol and its precursors. We investigated 96 infants with hypotension and critical neonatal disease for cortisol metabolism and are divided into responders and non-responders to plasma expanders and inotropes. Serum concentrations of steroids were analysed soon after the onset of volume expansion and inotrope treatment for shock. The 48 non-responders were treated with intravenous hydrocortisone (HC) and serum cortisol concentrations were monitored a week later. The mean cortisol concentrations did not differ between the responders and non-responders: 13.6 ± 2.5 and 12.5 ± 4.5 μg/dL, respectively. Dehydroepiandrosterone (37.3 ± 19.5 versus 324.0 ± 106.3; p < 0.0001) and 17-hydroxy-pregnenolone concentrations were lower in responders than in non-responders. Dehydroepiandrosterone levels in non-responders were inversely associated with postnatal age (r = 0.50, p < 0.0001). There were no differences in 17-hydroxy-progesterone, 11-deoxy-cortisol and cortisone between the responders and non-responders. Hydrocortisone administration acutely increased blood pressure. Six non-responders who died despite HC administration had low levels of cortisol. The responders had normal serum cortisol after HC treatment. Precursors of cortisol, proximal to the 3β-hydroxysteroid dehydrogenase activity, accumulated in neonates with hypotension, responding to HC treatment.

Large-volume excitation of air, argon, nitrogen and combustible mixtures by thermal jets produced by nanosecond spark discharges

NASA Astrophysics Data System (ADS)

Stepanyan, Sergey; Hayashi, Jun; Salmon, Arthur; Stancu, Gabi D.; Laux, Christophe O.

2017-04-01

This work presents experimental observations of strong expanding thermal jets following the application of nanosecond spark discharges. These jets propagate in a toroidal shape perpendicular to the interelectrode axis, with high velocities of up to 30 m s-1 and over distances of the order of a cm. Their propagation length is much larger than the thermal expansion region produced by the conventional millisecond sparks used in car engine ignition, thus greatly improving the volumetric excitation of gas mixtures. The shape and velocity of the jets is found to be fairly insensitive to the shape of the electrodes. In addition, their spatial extent is found to increase with the number of nanosecond sparks and with the discharge voltage, and to decrease slightly with the pressure between 1 and 7 atm at constant applied voltage. Finally, this thermal jet phenomenon is observed in experiments conducted with many types of gas mixtures, including air, nitrogen, argon, and combustible CH4/air mixtures. This makes nanosecond repetitively pulsed discharges particularly attractive for aerodynamic flow control or plasma-assisted combustion because of their ability to excite large volumes of gas, typically about 100 times the volume of the discharge.

Effect of leg exercise training on vascular volumes during 30 days of 6 degrees head-down bed rest

NASA Technical Reports Server (NTRS)

Greenleaf, J. E.; Vernikos, J.; Wade, C. E.; Barnes, P. R.

1992-01-01

Plasma and red cell volumes, body density, and water balance were measured in 19 men (32-42 yr) confined to bed rest (BR). One group (n = 5) had no exercise training (NOE), another near-maximal variable-intensity isotonic exercise for 60 min/day (ITE; n = 7), and the third near-maximal intermittent isokinetic exercise for 60 min/day (IKE; n = 7). Caloric intake was 2,678-2,840 kcal/day; mean body weight (n = 19) decreased by 0.58 +/- 0.35 (SE) kg during BR due to a negative fluid balance (diuresis) on day 1. Mean energy costs for the NOE, and IKE, and ITE regimens were 83 (3.6 +/- 0.2 ml O2.min-1.kg-1), 214 (8.9 +/- 0.5 ml.min-1.kg-1), and 446 kcal/h (18.8 +/- 1.6 ml.min-1.kg-1), respectively. Body densities within groups and mean urine volumes (1,752-1,846 ml/day) between groups were unchanged during BR. Resting changes in plasma volume (ml/kg) after BR were -1.5 +/- 2.3% (NS) in ITE, -14.7 +/- 2.8% (P less than 0.05) in NOE, and -16.8 +/- 2.9% (P less than 0.05) in IKE, and mean water balances during BR were +295, -106, and +169 ml/24 h, respectively. Changes in red cell volume followed changes in plasma volume. The significant chronic decreases in plasma volume in the IKE and NOE groups and its maintenance in the ITE group could not be accounted for by water balance or by responses of the plasma osmotic, protein, vasopressin, or aldosterone concentrations or plasma renin activity. There was close coupling between resting plasma volume and plasma protein and osmotic content.(ABSTRACT TRUNCATED AT 250 WORDS).

Collisionless plasma expansion into vacuum: Two new twists on an old problem

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arefiev, Alexey V.; Breizman, Boris N.

The paper deals with a generic problem of collisionless plasma expansion into vacuum in the regimes where the expanding plasma consists of hot electrons and cold ions. The expansion is caused by electron pressure and serves as an energy transfer mechanism from electrons to ions. This process is often described under the assumption of Maxwellian electrons, which easily fails in the absence of collisions. The paper discusses two systems with a naturally occurring non-Maxwellian distribution: an expanding laser-irradiated nanoplasma and a supersonic jet coming out of a magnetic nozzle. The presented rigorous kinetic description demonstrates how the deviation from themore » Maxwellian distribution fundamentally alters the process of ion acceleration during plasma expansion. This result points to the critical importance of a fully kinetic treatment in problems with collisionless plasma expansion.« less

Collisionless plasma expansion into vacuum: Two new twists on an old problema)

NASA Astrophysics Data System (ADS)

Arefiev, Alexey V.; Breizman, Boris N.

2009-05-01

The paper deals with a generic problem of collisionless plasma expansion into vacuum in the regimes where the expanding plasma consists of hot electrons and cold ions. The expansion is caused by electron pressure and serves as an energy transfer mechanism from electrons to ions. This process is often described under the assumption of Maxwellian electrons, which easily fails in the absence of collisions. The paper discusses two systems with a naturally occurring non-Maxwellian distribution: an expanding laser-irradiated nanoplasma and a supersonic jet coming out of a magnetic nozzle. The presented rigorous kinetic description demonstrates how the deviation from the Maxwellian distribution fundamentally alters the process of ion acceleration during plasma expansion. This result points to the critical importance of a fully kinetic treatment in problems with collisionless plasma expansion.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roy, Amitava; Harilal, Sivanandan S.; Hassan, Syed M.

We investigated the expansion dynamics of laser-produced plasmas expanding into an axial magnetic field. Plasmas were generated by focusing 1.064 µm Nd:YAG laser pulses onto a planar tin target in vacuum and allowed to expand into a 0.5 T magnetic-filed where field lines were aligned along the plume expansion direction. Gated images employing intensified CCD showed focusing of the plasma plume, which were also compared with results obtained using particle-in-cell modelling methods. The estimated density and temperature of the plasma plumes employing emission spectroscopy revealed significant changes in the presence and absence of the 0.5T magnetic field. In the presencemore » of the field, the electron temperature is increased with distance from the target, while the density showed opposite effects.« less

Effect of hydration on plasma volume and endocrine responses to water immersion

NASA Technical Reports Server (NTRS)

Harrison, M. H.; Keil, L. C.; Wade, C. A.; Silver, J. E.; Geelen, G.

1986-01-01

The effect of hydration status on early endocrine responses and on osmotic and intravascular volume changes during immersion was determined in humans undergoing successive periods of dehydration, immersion, rehydration, and immersion. Immersion caused an isotonic expansion of plasma volume, as well as suppression of plasma renin activity and aldosterone, which all occurred independently of hydration status. On the other hand, the concentration of plasma vasopressin (PVP) was found to decrease during dehydrated immersion, but not during rehydrated immersion. It is concluded that plasma tonicity is not a factor influencing PVP suppression during water immersion.

Preliminary study of the CRRES magnetospheric barium releases

NASA Technical Reports Server (NTRS)

Huba, J. D.; Bernhardt, P. A.; Lyon, J. G.

1992-01-01

Preliminary theoretical and computational analyses of the Combined Release and Radiation Effects Satellite (CRRES) magnetospheric barium releases are presented. The focus of the studies is on the evolution of the diamagnetic cavity which is formed by the barium ions as they expand outward, and on the structuring of the density and magnetic field during the expansion phase of the releases. Two sets of simulation studies are discussed. The first set is based upon a 2D ideal MHD code and provides estimates of the time and length scales associated with the formation and collapse of the diamagnetic cavity. The second set uses a nonideal MHD code; specifically, the Hall term is included. This additional term is critical to the dynamics of sub-Alfvenic plasma expansions, such as the CRRES barium releases, because it leads to instability of the expanding plasma. Detailed simulations of the G4 and G10 releases were performed. In both cases the expanding plasma rapidly structured: the G4 release structured at time t less than about 3 s and developed scale sizes of about 1-2 km, while the G10 release structured at time t less than about 22 s and developed scale sizes of about 10-15 km. It is also found that the diamagnetic cavity size is reduced from those obtained from the ideal MHD results because of the structure. On the other hand, the structuring allows the formation of plasma blobs which appear to free stream across the magnetic field; thus, the barium plasma can propagate to larger distances traverse to the magnetic field than the case where no structuring occurs. Finally, a new normal mode of the system was discovered which may be excited at the leading edge of the expanding barium plasma.

Measurement of Human Blood and Plasma Volumes

NASA Technical Reports Server (NTRS)

Greenleaf, J. E.; Szalkay, H. G. H.

1987-01-01

Report reviews techniques for measuring blood-plasma volume in humans. Common technique of using radioactive iodine isotope to label plasma albumin involves unwarranted risks from low-level radiation. Report emphasizes techniques using Evans-blue-dye (T-1824) labeling of albumin, hematocrit or hemoglobin/hematocrit measurements, or blood densitometry. In Evans-blue-dye technique, plasma volume determined from decrease in dye concentration occurring after small amount of dye solution injected into circulatory system. Subjection of Evans blue dye to test for carcinogenicity gave negative results.

Pre-exercise ingestion of pickle juice, hypertonic saline, or water and aerobic performance and thermoregulation.

PubMed

Peikert, Jarett; Miller, Kevin C; Albrecht, Jay; Tucker, Jared; Deal, James

2014-01-01

Ingesting high-sodium drinks pre-exercise can improve thermoregulation and performance. Athletic trainers (19%) give athletes pickle juice (PJ) prophylactically for cramping. No data exist on whether this practice affects aerobic performance or thermoregulation. To determine if drinking 2 mL/kg body mass of PJ, hypertonic saline, or deionized water (DIW) pre-exercise affects aerobic performance or thermoregulation. Crossover study. Controlled laboratory study. Nine euhydrated men (age = 22 ± 3 years, height = 184.0 ± 8.2 cm, mass = 82.6 ± 16.0 kg) completed testing. Participants rested for 65 minutes. During this period, they ingested 2 mL/kg of PJ, hypertonic saline, or DIW. Next, they drank 5 mL/kg of DIW. Blood was collected before and after ingestion of all fluids. Participants were weighed and ran in the heat (temperature = 38.3°C ± 1°C, relative humidity = 21.1% ± 4.7%) at increasing increments of maximal heart rate (50%, 60%, 70%, 80%, 90%, 95%) until exhaustion or until rectal temperature exceeded 39.5°C. Participants were weighed postexercise so we could calculate sweat volume. Time to exhaustion, rectal temperature, changes in plasma volume, and sweat volume. Time to exhaustion did not differ among drinks (PJ = 77.4 ± 5.9 minutes, hypertonic saline = 77.4 ± 4.0 minutes, DIW = 75.7 ± 3.2 minutes; F2,16 = 1.1, P = .40). Core temperature of participants was similar among drinks (PJ = 38.7°C ± 0.3°C, hypertonic saline = 38.7°C ± 0.4°C, DIW = 38.8°C ± 0.4°C; P = .74) but increased from pre-exercise (36.7°C ± 0.2°C) to postexercise (38.7°C ± 0.4°C) (P < .05). No differences were observed for changes in plasma volume or sweat volume among drinks (P > .05). Ingesting small amounts of PJ or hypertonic saline with water did not affect performance or select thermoregulatory measures. Drinking larger volumes of PJ and water may be more effective at expanding the extracellular space.

Changes in peak oxygen uptake and plasma volume in fit and unfit subjects following exposure to a simulation of microgravity

NASA Technical Reports Server (NTRS)

Convertino, V. A.

1998-01-01

To test the hypothesis that the magnitude of reduction in plasma volume and work capacity following exposure to simulated microgravity is dependent on the initial level of aerobic fitness, peak oxygen uptake (VO2peak) was measured in a group of physically fit subjects and compared with VO2peak in a group of relatively unfit subjects before and after 10 days of continuous 6 degrees head-down tilt (HDT). Ten fit subjects (40 +/- 2 year) with mean +/- SE VO2peak = 48.9 +/- 1.7 mL kg-1 min-1 were matched for age, height, and lean body weight with 10 unfit subjects (VO2peak = 37.7 +/- 1.6 mL kg-1 min-1). Before and after HDT, plasma, blood, and red cell volumes and body composition were measured and all subjects underwent a graded supine cycle ergometer test to determine VO2peak period needed. Reduced VO2peak in fit subjects (-16.2%) was greater than that of unfit subjects (-6.1%). Similarly, reductions in plasma (-18.3%) and blood volumes (-16.0%) in fit subjects were larger than those of unfit subjects (blood volume = -5.6%; plasma volume = -6.6%). Reduced plasma volume was associated with greater negative body fluid balance during the initial 24 h of HDT in the fit group (912 +/- 154 mL) compared with unfit subjects (453 +/- 200 mL). The percentage change for VO2peak correlated with percentage change in plasma volume (r = +0.79). Following exposure to simulated microgravity, fit subjects demonstrated larger reductions in VO2peak than unfit subjects which was associated with larger reductions in plasma and blood volume. These data suggest that the magnitude of physical deconditioning induced by exposure to microgravity without intervention of countermeasures was influenced by the initial fitness of the subjects.

Estimates of plasma, packed cell and total blood volume in tissues of the rainbow trout (Salmo gairdneri)

USGS Publications Warehouse

Gingerich, W.H.; Pityer, R.A.; Rach, J.J.

1987-01-01

1. Total blood volume and relative blood volumes in selected tissues were determined in non-anesthetized, confined rainbow trout by using 51Cr-labelled trout erythrocytes as a vascular space marker.2. Mean total blood volume was estimated to be 4.09 ± 0.55 ml/100 g, or about 75% of that estimated with the commonly used plasma space marker Evans blue dye.3. Relative tissue blood volumes were greatest in highly perfused tissues such as kidney, gills, brain and liver and least in mosaic muscle.4. Estimates of tissue vascular spaces, made using radiolabelled erythrocytes, were only 25–50% of those based on plasma space markers.5. The consistently smaller vascular volumes obtained with labelled erythrocytes could be explained by assuming that commonly used plasma space markers diffuse from the vascular compartment.

Electron diamagnetic effect in a magnetic nozzle on a helicon plasma thruster performance

NASA Astrophysics Data System (ADS)

Takahashi, Kazunori; Lafleur, Trevor; Charles, Christine; Alexander, Peter; Boswell, Rod

2012-10-01

The axial force, which is called thrust sometimes, imparted from a magnetically expanding helicon plasma thruster is directly measured and the results are compared with a two-dimensional fluid theory. The force component solely transmitted to the expanding field is directly measured and identified as an axial force produced by the azimuthal current due to an electron diamagnetic drift and the radial component of the applied magnetic field. In this type of configuration, plasma diffusion in magnetic field affects a spatial profile of the plasma density and the resultant axial force onto the magnetic field. It is observed that the force component onto the magnetic field increases with an increase in the magnetic field strength, simultaneously with an increase in the plasma density downstream of the source exit, which could be due to suppression of the cross field diffusion in the magnetic nozzle.

Concerning neutral flux shielding in the U-3M torsatron

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dreval, N. B., E-mail: mdreval@kipt.kharkov.ua

2015-03-15

The volume of the torsatron U-3M vacuum chamber is about 70 m{sup 3}, whereas the plasma volume is about 0.3 m{sup 3}. The large buffer volume of the chamber serves as a source of a substantial neutral flux into the U-3M plasma. A fraction of this flux falls onto the torsatron helical coils located in front of the plasma, due to which the dynamics of neutral influx into the plasma modifies. The shielding of the molecular flux from the buffer volume into the plasma is estimated using numerical calculations. Only about 10% of the incident flux reaches the plasma volume.more » Estimates show that about 20% of atoms escape beyond the helical coils without colliding with them. Under these conditions, the helical coils substantially affect the neutral flux. A discharge regime with a hot low-density plasma produced by a frame antenna is considered. The spatial distribution of the molecular density produced in this regime by the molecular flux from the chamber buffer volume after it has passed between the helical coils is calculated. The contributions of the fluxes emerging from the side and inner surfaces of the helical coils are considered. The calculations show that the shape of the spatial distribution of the molecular density differs substantially from the shape of the magnetic surfaces.« less

The use of self-inflating hydrogel expanders in pediatric patients with congenital microphthalmia in China.

PubMed

Hou, Zhijia; Yang, Qiong; Chen, Tao; Hao, Lei; Li, Yang; Li, Dongmei

2012-10-01

To report the results of enlarging orbital volume in consecutive cases of severe congenital microphthalmia by means of solid hydrophilic tissue expanders. The medical records of consecutive patients with congenital microphthalmia who underwent the placement of a hydrogel expander were retrospectively reviewed. Main outcome measures were orbital tissue expansion, prosthetic retention, and patient family satisfaction. A total of 17 patients were included in the study. All patients were able to retain an ocular prosthesis. The horizontal palpebral length increased from 71.3% of the contralateral unaffected eye to 85.4% of the contralateral unaffected eye. The expansion of orbital volume was assessed in seven patients. The volume of the microphthalmic orbits was expanded from 74.7% of the contralateral unaffected orbits to 83.5% of the contralateral unaffected orbits. Aesthetic results were satisfactory to both physicians and patient families. The following complications were noted in two patients: inferior migration of a spherical expander occurred in one case; a hemispheric expander was removed by the patient in another case. Hydrogel implants can successfully expand the dimensions of the conjunctival sac and the orbit in cases of severe congenital microphthalmia. Copyright © 2012 American Association for Pediatric Ophthalmology and Strabismus. Published by Mosby, Inc. All rights reserved.

Insufficient evidence of benefit regarding mortality due to albumin substitution in HCC-free cirrhotic patients undergoing large volume paracentesis.

PubMed

Kütting, Fabian; Schubert, Jens; Franklin, Jeremy; Bowe, Andrea; Hoffmann, Vera; Demir, Muenevver; Pelc, Agnes; Nierhoff, Dirk; Töx, Ulrich; Steffen, Hans-Michael

2017-02-01

Current guidelines for clinical practice recommend the infusion of human albumin after large volume paracentesis. After inspecting the current evidence behind this recommendation, we decided to conduct a systematic review and meta-analysis in order to address the effect of albumin on mortality and morbidity in the context of large volume paracentesis. We performed a comprehensive search of large databases and abstract books of conference proceedings up to March 15th 2016 for randomized controlled trials, testing the infusion of human albumin against alternatives (vs no treatment, vs plasma expanders; vs vasoconstrictors) in HCC-free patients suffering from cirrhosis. We analyzed these trials with regard to mortality, changes in plasma renin activity (PRA), hyponatremia, renal impairment, recurrence of ascites with consequential re-admission into hospital and additional complications. We employed trial sequential analysis in order to calculate the number of patients required in controlled trials to be able to determine a statistically significant advantage of the administration of one agent over another with regard to mortality. We were able to include 21 trials totaling 1277 patients. While the administration of albumin prevents a rise in PRA as well as hyponatremia, no improvement in strong clinical endpoints such as mortality could be demonstrated. Trial sequential analysis showed that at least 1550 additional patients need to be recruited into RCTs and analyzed with regard to this question in order to detect or disprove a 25% mortality effect. There is insufficient evidence that the infusion of albumin after LVP significantly lowers mortality in HCC-free patients with advanced liver disease. © 2016 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.

Inductive current startup in large tokamaks with expanding minor radius and rf assist

DOE Office of Scientific and Technical Information (OSTI.GOV)

Borowski, S.K.

1984-02-01

Auxiliary rf heating of electrons before and during the current-rise phase of a large tokamak, such as the Fusion Engineering Device (R = 4.8 m, a = 1.3 m, sigma = 1.6, B/sub T/ = 3.62 T), is examined as a means of reducing both the initiation loop voltage and resistive flux expenditure during startup. Prior to current initiation, 1 to 2 MW of electron cyclotron resonance heating power at approx. 90 GHz is used to create a small volume of high conductivity plasma (T/sub e/ approx. = 100 eV, n/sub e/ approx. = 10/sup 19/ m/sup -3/) near themore » upper hybrid resonance (UHR) region. This plasma conditioning permits a small radius (a/sub 0/ approx. = 0.2 to 0.4 m) current channel to be established with a relatively low initial loop voltage (less than or equal to 25 V as opposed to approx. 100 V without rf assist). During the subsequent plasma expansion and current ramp phase, a combination of rf heating (up to 5 MW) and current profile control leads to a substantial savings in volt-seconds by: (1) minimizing the resistive flux consumption; and (2) maintaining the internal flux at or near the flat profile limit.« less

Estimation of the quantification uncertainty from flow injection and liquid chromatography transient signals in inductively coupled plasma mass spectrometry

NASA Astrophysics Data System (ADS)

Laborda, Francisco; Medrano, Jesús; Castillo, Juan R.

2004-06-01

The quality of the quantitative results obtained from transient signals in high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICPMS) and flow injection-inductively coupled plasma mass spectrometry (FI-ICPMS) was investigated under multielement conditions. Quantification methods were based on multiple-point calibration by simple and weighted linear regression, and double-point calibration (measurement of the baseline and one standard). An uncertainty model, which includes the main sources of uncertainty from FI-ICPMS and HPLC-ICPMS (signal measurement, sample flow rate and injection volume), was developed to estimate peak area uncertainties and statistical weights used in weighted linear regression. The behaviour of the ICPMS instrument was characterized in order to be considered in the model, concluding that the instrument works as a concentration detector when it is used to monitorize transient signals from flow injection or chromatographic separations. Proper quantification by the three calibration methods was achieved when compared to reference materials, although the double-point calibration allowed to obtain results of the same quality as the multiple-point calibration, shortening the calibration time. Relative expanded uncertainties ranged from 10-20% for concentrations around the LOQ to 5% for concentrations higher than 100 times the LOQ.

Light source employing laser-produced plasma

DOEpatents

Tao, Yezheng; Tillack, Mark S

2013-09-17

A system and a method of generating radiation and/or particle emissions are disclosed. In at least some embodiments, the system includes at least one laser source that generates a first pulse and a second pulse in temporal succession, and a target, where the target (or at least a portion the target) becomes a plasma upon being exposed to the first pulse. The plasma expand after the exposure to the first pulse, the expanded plasma is then exposed to the second pulse, and at least one of a radiation emission and a particle emission occurs after the exposure to the second pulse. In at least some embodiments, the target is a solid piece of material, and/or a time period between the first and second pulses is less than 1 microsecond (e.g., 840 ns).

Hormonal and electrolyte responses to acute isohemic volume expansion in unanesthetized rats

NASA Technical Reports Server (NTRS)

Chenault, V. M.; Morris, M.; Lynch, C. D.; Maultsby, S. J.; Hutchins, P. M.

1993-01-01

This study was undertaken to explore the time course of the metabolic response to isohemic blood volume expansion (30%) in normotensive, unanesthetized Sprague-Dawley rats. Whole blood, drawn from a femoral artery catheter of conscious donor rats, was infused into the jugular vein of recipient rats. Blood samples were drawn from a carotid artery of recipient rats at time points beginning immediately post-volume expansion (IPVE) up through 5 days post-volume expansion (PVE). To characterize the attendant compensatory mechanisms, the plasma concentrations of electrolytes and fluid regulatory hormones were determined. Hematocrit began to raise IPVE and was significantly elevated above control IPVE 20, 30, 40, 60, and 90 min, and 2, 4, 6, 8, 12, and 24 hr PVE. Consistent with our current understanding of the hormonal response to excess volume, atrial natriuretic factor was significantly increased above the prevolume expansion (control) values 0-30 min PVE. Surprisingly, plasma aldosterone levels were significantly increased above control at 20 and 30 min and 6 hr PVE, whereas plasma renin activity was significantly decreased 30-40 min PVE. Plasma sodium was not changed from control values except for a significant increase at 6 hr post-volume expansion. Plasma potassium, osmolality, and arginine vasopressin levels were not altered by the volume expansion. These studies delineate the physiologic time scheme operative in the regulation of fluid volume during acute ischemic volume expansion.

Microscopic analysis of nanostructured plasma coatings

NASA Astrophysics Data System (ADS)

Ageev, E. V.; Altukhov, A. Yu; Ageeva, E. V.; Khardikov, S. V.

2018-03-01

In the course of the study, it was found that plasma nanocomposite coating obtained from a mixture of powders of BRS, VK8 and nichrome with a portable plasma device “ALPES-02M” has high performance properties, which significantly expands the scope of its application.

Treatment of congenital anophthalmos with self-inflating polymer expanders: a new method.

PubMed

Wiese, K G; Vogel, M; Guthoff, R; Gundlach, K K

1999-04-01

Congenital anophthalmos is a rare malformation in which the optic vesicle fails to develop. This leads to a small bony orbit, a constricted mucosal socket, short eyelids, reduced palpebral fissure and malar hypoplasia. The treatment includes both aesthetic and functional aspects. Therefore, a two-step procedure is described using a new self-inflating hydrogel expander. A lens-shaped expander with a diameter of 8 mm expands the lids and the mucosal socket to allow insertion of an eye prosthesis. As a second step, orbital expansion is performed with a spherical device. The expanders absorb lacrimal fluid from the mucosal socket or tissue fluid and start swelling when implanted in the orbital tissue. The insertion of an expander into the orbit as well as into the conjunctival pocket including its fixation by a single suture took only a few minutes and was an easy procedure. The expansion of the small conjunctival sockets was successfully completed in all cases within a period of 2-4 weeks. The weight (= volume in ml) of devices increased from 0.15-1.5 g (lens-shaped expander; weight in grams = volume in ml) respectively, 0.3-3.5 g (spherical device). The expanders inserted in orbital tissue increased from 0.4-4.4 g. This is equivalent to a 10 to 11 fold increase in their water-free volumes. Orbital expansion with spherical devices in combination with the inserted eye prosthesis enlarges the lid and palpebral fissures also. In contrast to conventional silicon balloon expanders, the procedure using self-inflating hydrogel expanders is simple and highly efficient.

Novel 3D-CT evaluation of carotid stent volume: greater chronological expansion of stents in patients with vulnerable plaques.

PubMed

Itami, Hisakazu; Tokunaga, Koji; Okuma, Yu; Hishikawa, Tomohito; Sugiu, Kenji; Ida, Kentaro; Date, Isao

2013-09-01

Although self-expanding carotid stents may dilate gradually, the degrees of residual stenosis have been quantified by the NASCET criteria, which is too simple to reflect the configuration of the stented artery. We measured the volumes of the stent lumens chronologically by 3D-CT in patients after carotid artery stenting (CAS), and analyzed the correlations between the volume change and medical factors. Fourteen patients with carotid artery stenosis were treated using self-expanding, open-cell stents. All patients underwent preoperative plaque MRI (magnetization-prepared rapid acquisition gradient-echo, MPRAGE) and chronological 3D-CT examinations of their stents immediately after their placement and 1 day, 1 week, and 1 month after the procedure. The volume of the stent lumen was measured using a 3D workstation. The correlations between stent volume and various factors including the presence of underlying diseases, plaque characteristics, and the results of the CAS procedure were analyzed. Stent volume gradually increased in each case and had increased by 1.04-1.55 (mean, 1.25)-fold at 1 postoperative month. The presence of underlying medical diseases, plaque length, the degree of residual stenosis immediately after CAS, and plaque calcification did not have an impact on the change in stent volume. On the other hand, the stent volume increase was significantly larger in the patients with vulnerable plaques that demonstrated high MPRAGE signal intensity (P < 0.05). A 3D-CT examination is useful for precisely measuring stent volume. Self-expanding stents in carotid arteries containing vulnerable plaques expand significantly more than those without such plaques in a follow-up period.

Double layers in expanding plasmas and their relevance to the auroral plasma processes

NASA Astrophysics Data System (ADS)

Singh, Nagendra; Khazanov, George

2003-04-01

When a dense plasma consisting of a cold and a sufficiently warm electron population expands, a rarefaction shock forms [, 1978]. In the expansion of the polar wind in the magnetosphere, it has been previously shown that when a sufficiently warm electron population also exists, in addition to the usual cold ionospheric one, a discontinuity forms in the electrostatic potential distribution along the magnetic field lines [, 1984]. Despite the lack of spatial resolution and the assumption of quasi-neutrality in the polar wind models, such discontinuities have been called double layers (DLs). Recently similar discontinuities have been invoked to partly explain the auroral acceleration of electrons and ions in the upward current region [, 2000]. By means of one-dimensional Vlasov simulations of expanding plasmas, for the first time we make here the connection between (1) the rarefaction shocks, (2) the discontinuities in the potential distributions, and (3) DLs. We show that when plasmas expand from opposite directions into a deep density cavity with a potential drop across it and when the plasma on the high-potential side contains hot and cold electron populations, the temporal evolution of the potential and the plasma distribution generates evolving multiple double layers with an extended density cavity between them. One of the DLs is the rarefaction-shock (RFS) and it forms by the reflections of the cold electrons coming from the high-potential side; it supports a part of the potential drop approximately determined by the hot electron temperature. The other DLs evolve from charge separations arising either from reflection of ions coming from the low-potential side or stemming from plasma instabilities; they support the rest of the potential drop. The instabilities forming these additional double layers involve electron-ion (e-i) Buneman or ion-ion (i-i) two-stream interactions. The electron-electron two-stream interactions on the high-potential side of the RFS generate electron-acoustic waves, which evolve into electron phase-space holes. The ion population originating from the low-potential side and trapped by the RFS is energized by the e-i and i-i instabilities and it eventually precipitates into the high-potential plasma along with an electron beam. Applications of these findings to the auroral plasma physics are discussed.

Double Layers in Expanding Plasmas and Their Relevance to the Auroral Plasma Processes

NASA Technical Reports Server (NTRS)

Singh, Nagendra; Khazanov, George

2003-01-01

When a dense plasma consisting of a cold and a sufficiently warm electron population expands, a rarefaction shock forms [Bezzerides et al., 1978]. In the expansion of the polar wind in the magnetosphere, it has been previously shown that when a sufficiently warm electron population also exists, in addition to the usual cold ionospheric one, a discontinuity forms in the electrostatic potential distribution along the magnetic field lines [Barakat and Schunk, 1984]. Despite the lack of spatial resolution and the assumption of quasi-neutrality in the polar wind models, such discontinuities have been called double layers (DLs). Recently similar discontinuities have been invoked to partly explain the auroral acceleration of electrons and ions in the upward current region [Ergun et al., 2000]. By means of one-dimensional Vlasov simulations of expanding plasmas, for the first time we make here the connection between (1) the rarefaction shocks, (2) the discontinuities in the potential distributions, and (3) DLs. We show that when plasmas expand from opposite directions into a deep density cavity with a potential drop across it and when the plasma on the high-potential side contains hot and cold electron populations, the temporal evolution of the potential and the plasma distribution generates evolving multiple double layers with an ,extended density cavity between them. One of the DLs is the rarefaction-shock (RFS) and it forms by the reflections of the cold electrons coming from the high-potential side; it supports a part of the potential drop approximately determined by the hot electron temperature. The other DLs evolve from charge separations arising either from reflection of ions coming from the low-potential side or stemming from plasma instabilities; they support the rest of the potential drop. The instabilities forming these additional double layers involve electron-ion (e-i) Buneman or ion-ion (i-i) two-stream interactions. The electron-electron two-stream interactions on the high-potential side of the RFS generate electron-acoustic waves, which evolve into electron phase-space holes. The ion population originating from the low-potential side and trapped by the RFS is energized by the e-i and i-i instabilities and it eventually precipitates into the high-potential plasma along with an electron beam. Applications of these findings to the auroral plasma physics are discussed.

Post-traumatic changes in, and effect of colloid osmotic pressure on the distribution of body water.

PubMed

Böck, J C; Barker, B C; Clinton, A G; Wilson, M B; Lewis, F R

1989-09-01

The aim of this study was to define the post-traumatic changes in body fluid compartments and to evaluate the effect of plasma colloid osmotic pressure (COP) on the partitioning of body fluid between these compartments. Forty-two measurements of plasma volume (green dye), extracellular volume (bromine), and total body water (deuterium) were done in ten traumatized patients (mean Injury Severity Score, ISS, = 34) and 23 similar control studies were done in eight healthy volunteers who were in stable fluid balance. Interstitial volume, intracellular volume, and blood volume were calculated from measured fluid spaces and hematocrit; COP was directly measured. Studies in volunteers on consecutive days indicated good reproducibility, with coefficients of variation equal to 3.5% for COP, 6.3% for plasma volume, 4.5% for extracellular volume, and 4.9% for total body water. COP values extended over the entire range seen clinically, from 10 to 30 mmHg. Interstitial volume was increased by 55% in patients, but intracellular volume was decreased by 10%. We conclude (1) that posttraumatic peripheral edema resulting from hemodilution is located in the interstitial compartment, with no intracellular space expansion; and (2) that interstitial volume, but not intracellular volume, is closely related to plasma COP.

Preoperative prognostic value of dynamic contrast-enhanced MRI-derived contrast transfer coefficient and plasma volume in patients with cerebral gliomas.

PubMed

Nguyen, T B; Cron, G O; Mercier, J F; Foottit, C; Torres, C H; Chakraborty, S; Woulfe, J; Jansen, G H; Caudrelier, J M; Sinclair, J; Hogan, M J; Thornhill, R E; Cameron, I G

2015-01-01

The prognostic value of dynamic contrast-enhanced MR imaging-derived plasma volume obtained in tumor and the contrast transfer coefficient has not been well-established in patients with gliomas. We determined whether plasma volume and contrast transfer coefficient in tumor correlated with survival in patients with gliomas in addition to other factors such as age, type of surgery, preoperative Karnofsky score, contrast enhancement, and histopathologic grade. This prospective study included 46 patients with a new pathologically confirmed diagnosis of glioma. The contrast transfer coefficient and plasma volume obtained in tumor maps were calculated directly from the signal-intensity curve without T1 measurements, and values were obtained from multiple small ROIs placed within tumors. Survival curve analysis was performed by dichotomizing patients into groups of high and low contrast transfer coefficient and plasma volume. Univariate analysis was performed by using dynamic contrast-enhanced parameters and clinical factors. Factors that were significant on univariate analysis were entered into multivariate analysis. For all patients with gliomas, survival was worse for groups of patients with high contrast transfer coefficient and plasma volume obtained in tumor (P < .05). In subgroups of high- and low-grade gliomas, survival was worse for groups of patients with high contrast transfer coefficient and plasma volume obtained in tumor (P < .05). Univariate analysis showed that factors associated with lower survival were age older than 50 years, low Karnofsky score, biopsy-only versus resection, marked contrast enhancement versus no/mild enhancement, high contrast transfer coefficient, and high plasma volume obtained in tumor (P < .05). In multivariate analysis, a low Karnofsky score, biopsy versus resection in combination with marked contrast enhancement, and a high contrast transfer coefficient were associated with lower survival rates (P < .05). In patients with glioma, those with a high contrast transfer coefficient have lower survival than those with low parameters. © 2015 by American Journal of Neuroradiology.

Atmospheric Gaseous Plasma with Large Dimensions

NASA Astrophysics Data System (ADS)

Korenev, Sergey

2012-10-01

The forming of atmospheric plasma with large dimensions using electrical discharge typically uses the Dielectric Barrier Discharge (DBD). The study of atmospheric DBD was shown some problems related to homogeneous volume plasma. The volume of this plasma determines by cross section and gas gap between electrode and dielectric. The using of electron beam for volume ionization of air molecules by CW relativistic electron beams was shown the high efficiency of this process [1, 2]. The main advantage of this approach consists in the ionization of gas molecules by electrons in longitudinal direction determines by their kinetic energy. A novel method for forming of atmospheric homogeneous plasma with large volume dimensions using ionization of gas molecules by pulsed non-relativistic electron beams is presented in the paper. The results of computer modeling for delivered doses of electron beams in gases and ionization are discussed. The structure of experimental bench with plasma diagnostics is considered. The preliminary results of forming atmospheric plasma with ionization gas molecules by pulsed nanosecond non-relativistic electron beam are given. The analysis of potential applications for atmospheric volume plasma is presented. Reference: [1] S. Korenev. ``The ionization of air by scanning relativistic high power CW electron beam,'' 2002 IEEE International Conference on Plasma Science. May 2002, Alberta, Canada. [2] S. Korenev, I. Korenev. ``The propagation of high power CW scanning electron beam in air.'' BEAMS 2002: 14th International Conference on High-Power Particle Beams, Albuquerque, New Mexico (USA), June 2002, AIP Conference Proceedings Vol. 650(1), pp. 373-376. December 17.

Earthquake lights and the stress-activation of positive hole charge carriers in rocks

USGS Publications Warehouse

St-Laurent, F.; Derr, J.S.; Freund, F.T.

2006-01-01

Earthquake-related luminous phenomena (also known as earthquake lights) may arise from (1) the stress-activation of positive hole (p-hole) charge carriers in igneous rocks and (2) the accumulation of high charge carrier concentrations at asperities in the crust where the stress rates increase very rapidly as an earthquake approaches. It is proposed that, when a critical charge carrier concentration is reached, the p-holes form a degenerated solid state plasma that can break out of the confined rock volume and propagate as a rapidly expanding charge cloud. Upon reaching the surface the charge cloud causes dielectric breakdown at the air-rock interface, i.e. corona discharges, accompanied by the emission of light and high frequency electromagnetic radiation. ?? 2006 Elsevier Ltd. All rights reserved.

Coupling of RF antennas to large volume helicon plasma

NASA Astrophysics Data System (ADS)

Chang, Lei; Hu, Xinyue; Gao, Lei; Chen, Wei; Wu, Xianming; Sun, Xinfeng; Hu, Ning; Huang, Chongxiang

2018-04-01

Large volume helicon plasma sources are of particular interest for large scale semiconductor processing, high power plasma propulsion and recently plasma-material interaction under fusion conditions. This work is devoted to studying the coupling of four typical RF antennas to helicon plasma with infinite length and diameter of 0.5 m, and exploring its frequency dependence in the range of 13.56-70 MHz for coupling optimization. It is found that loop antenna is more efficient than half helix, Boswell and Nagoya III antennas for power absorption; radially parabolic density profile overwhelms Gaussian density profile in terms of antenna coupling for low-density plasma, but the superiority reverses for high-density plasma. Increasing the driving frequency results in power absorption more near plasma edge, but the overall power absorption increases with frequency. Perpendicular stream plots of wave magnetic field, wave electric field and perturbed current are also presented. This work can serve as an important reference for the experimental design of large volume helicon plasma source with high RF power.

Noninvasive in vivo plasma volume and hematocrit in humans: observing long-term baseline behavior to establish homeostasis for intravascular volume and composition

NASA Astrophysics Data System (ADS)

Dent, Paul; Deng, Bin; Goodisman, Jerry; Peterson, Charles M.; Narsipur, Sriram; Chaiken, J.

2016-04-01

A new device incorporating a new algorithm and measurement process allows simultaneous noninvasive in vivo monitoring of intravascular plasma volume and red blood cell volume. The purely optical technique involves probing fingertip skin with near infrared laser light and collecting the wavelength shifted light, that is, the inelastic emission (IE) which includes the unresolved Raman and fluorescence, and the un-shifted emission, that is, the elastic emission (EE) which includes both the Rayleigh and Mie scattered light. Our excitation and detection geometry is designed so that from these two simultaneous measurements we can calculate two parameters within the single scattering regime using radiation transfer theory, the intravascular plasma volume fraction and the red blood cell volume fraction. Previously calibrated against a gold standard FDA approved device, 2 hour monitoring sessions on three separate occasions over a three week span for a specific, motionless, and mostly sleeping individual produced 3 records containing a total of 5706 paired measurements of hematocrit and plasma volume. The average over the three runs, relative to the initial plasma volume taken as 100%, of the plasma volume±1σ was 97.56+/-0.55 or 0.56%.For the same three runs, the average relative hematocrit (Hct), referenced to an assumed initial value of 28.35 was 29.37+/-0.12 or stable to +/-0.4%.We observe local deterministic circulation effects apparently associated with the pressure applied by the finger probe as well as longer timescale behavior due to normal ebb and flow of internal fluids due to posture changes and tilt table induced gravity gradients.

Choice of the replacement fluid during large volume plasma-exchange.

PubMed

Nydegger, U E

1983-01-01

The replacement fluid used during therapeutic large volume plasma-exchange can be seen as an important factor influencing the result of such treatment. The choice includes fluids such as electrolyte solutions, gelatin, hydroxyethyl-starch, albumin and fresh frozen plasma. By evaluating the pathophysiology of the underlying disease, it is possible to choose between merely replacing the removed volume by non-protein fluids or rather to introduce plasma protein components into the patient's circulation by substituting with purified or enriched proteins such as albumin, clotting factors, antithrombin III or fresh frozen plasma. This paper analyzes the rationale for the choice of the appropriate replacement fluid taking into account pathophysiologic, pharmacologic and logistic criteria.

Volume of Plasma Expansion and Functional Outcomes in Stroke.

PubMed

Miller, Joseph B; Lewandowski, Christopher; Wira, Charles R; Taylor, Andrew; Burmeister, Charlotte; Welch, Robert

2017-04-01

Plasma expansion in acute ischemic stroke has potential to improve cerebral perfusion, but the long-term effects on functional outcome are mixed in prior trials. The goal of this study was to evaluate how the magnitude of plasma expansion affects neurological recovery in acute stroke. This was a secondary analysis of data from the Albumin in Acute Stroke Part 2 trial investigating the relationship between the magnitude of overall intravenous volume infusion (crystalloid and colloid) to clinical outcome. The data were inclusive of 841 patients with a mean age of 64 years and a median National Institutes of Health Stroke Scale (NIHSS) of 11. In a multivariable-adjusted logistic regression model, this analysis tested the volume of plasma expansion over the first 48 h of hospitalization as a predictor of favorable outcome, defined as either a modified Rankin Scale score of 0 or 1 or a NIHSS score of 0 or 1 at 90 days. This model included all study patients, irrespective of albumin or isotonic saline treatment. Patients that received higher volumes of plasma expansion more frequently had large vessel ischemic stroke and higher NIHSS scores. The multivariable-adjusted model revealed that there was decreased odds of a favorable outcome for every 250 ml additional volume plasma expansion over the first 48 h (OR 0.91, 95 % CI, 0.88-0.94). The present study demonstrates an association between greater volume of plasma expansion and worse neurological recovery.

A model for plasma volume changes during short duration spaceflight

NASA Technical Reports Server (NTRS)

Davis, John E.

1989-01-01

It is well established that plasma volume decreases during spaceflight and simulated weightlessness (bedrest). The decrement in plasma volume is thought to contribute to the orthostatic intolerance that has been observed in some crew members following spaceflight. To date, no studies have evaluated the effectiveness of fluid countermeasures of varying osmolality in the restoration of plasma volume and orthostatic tolerance in a controlled study. The overall objectives of this project were to: (1) provide a model that would rapidly and safely produce a fluid loss comparable to that which occurs during short duration spaceflight; and (2) design a study that would determine the optimal drink solution to restore orthostatic tolerance and describe the mechanism(s) whereby orthostatic tolerance is restored. In summary, Lasix can be used as a way of simulating the plasma volume changes that occur during short duration spaceflight. The total loss of plasma is comparable to spaceflight. Lasix is fast acting, and has relatively few side effects. The present design for evaluating the optimal fluid countermeasures will have important implications in restoring orthostatic tolerance and function in the latter stages of spaceflight when it is essential for safe operation of the spacecraft.

Prostate-specific antigen lowering effect of metabolic syndrome is influenced by prostate volume.

PubMed

Choi, Woo Suk; Heo, Nam Ju; Paick, Jae-Seung; Son, Hwancheol

2016-04-01

To investigate the influence of metabolic syndrome on prostate-specific antigen levels by considering prostate volume and plasma volume. We retrospectively analyzed 4111 men who underwent routine check-ups including prostate-specific antigen and transrectal ultrasonography. The definition of metabolic syndrome was based on the modified Adult Treatment Panel III criteria. Prostate-specific antigen mass density (prostate-specific antigen × plasma volume / prostate volume) was calculated for adjusting plasma volume and prostate volume. We compared prostate-specific antigen and prostate-specific antigen mass density levels of participants with metabolic syndrome (metabolic syndrome group, n = 1242) and without metabolic syndrome (non-prostate-specific antigen metabolic syndrome group, n = 2869). To evaluate the impact of metabolic syndrome on prostate-specific antigen, linear regression analysis for the natural logarithm of prostate-specific antigen was used. Patients in the metabolic syndrome group had significantly older age (P < 0.001), larger prostate volume (P < 0.001), higher plasma volume (P < 0.001) and lower mean serum prostate-specific antigen (non-metabolic syndrome group vs metabolic syndrome group; 1.22 ± 0.91 vs 1.15 ± 0.76 ng/mL, P = 0.006). Prostate-specific antigen mass density in the metabolic syndrome group was still significantly lower than that in the metabolic syndrome group (0.124 ± 0.084 vs 0.115 ± 0.071 μg/mL, P = 0.001). After adjusting for age, prostate volume and plasma volume using linear regression model, the presence of metabolic syndrome was a significant independent factor for lower prostate-specific antigen (prostate-specific antigen decrease by 4.1%, P = 0.046). Prostate-specific antigen levels in patients with metabolic syndrome seem to be lower, and this finding might be affected by the prostate volume. © 2016 The Japanese Urological Association.

Cold plasma processing to improve food safety

USDA-ARS?s Scientific Manuscript database

Cold plasma is an antimicrobial process being developed for application as a food processing technology. This novel intervention is the subject of an expanding research effort by groups around the world. A variety of devices can be used to generate cold plasma and apply it to the food commodity bein...

A computer simulation of the plasma leakage through a vascular prosthesis made of expanded polytetrafluoroethylene.

PubMed

Tabata, R; Kobayashi, T; Mori, A; Matsuno, S; Watarida, S; Onoe, M; Sugita, T; Shiraisi, S; Nojima, T

1993-04-01

We explored the blood-retaining mechanism of a vascular prosthesis made of expanded polytetrafluoroethylene through analysis of its structure and physicochemical properties. Plasma leakage through this vascular prosthesis was simulated by computer to explore its etiology. These examinations disclosed that leakage is dependent upon the inner pressure and the density of fibers. In other words, the study revealed that the mean distance between fibers constituting the wall of the expanded polytetrafluoroethylene vascular prosthesis is increased by tension (that is, inner pressure), resulting in an increased probability of leakage. It was additionally found that a thin membrane is formed on the polytetrafluoroethylene surface if blood in contact with the surface is dried. This membrane was found to reduce the water-repelling property of polytetrafluoroethylene and to make it impossible to preserve the inter-fiber liquid surface, thus causing leakage through the expanded polytetrafluoroethylene vascular prosthesis.

A simple model for estimating a magnetic field in laser-driven coils

DOE PAGES

Fiksel, Gennady; Fox, William; Gao, Lan; ...

2016-09-26

Magnetic field generation by laser-driven coils is a promising way of magnetizing plasma in laboratory high-energy-density plasma experiments. A typical configuration consists of two electrodes—one electrode is irradiated with a high-intensity laser beam and another electrode collects charged particles from the expanding plasma. The two electrodes are separated by a narrow gap forming a capacitor-like configuration and are connected with a conducting wire-coil. The charge-separation in the expanding plasma builds up a potential difference between the electrodes that drives the electrical current in the coil. A magnetic field of tens to hundreds of Teslas generated inside the coil has beenmore » reported. This paper presents a simple model that estimates the magnetic field using simple assumptions. Lastly, the results are compared with the published experimental data.« less

Whole body and tissue blood volumes of two strains of rainbow trout (Oncorhynchus mykiss)

USGS Publications Warehouse

Gingerich, W.H.; Pityer, R.A.; Rach, J.J.

1990-01-01

1. Estimates of apparent packed cell, plasma and total blood volumes for the whole body and for 13 selected tissues were compared between Kamloops and Wytheville strains of rainbow trout (Oncorhynchus mykiss) by the simultaneous injection of two vascular tracers, radiolabeled trout erythrocytes (51Cr-RBC) and radioiodated bovine serum albumin (125I-BSA).2. Whole body total blood volume, plasma volume and packed cell volume were slightly, but not significantly greater in the Wytheville trout, whereas, the apparent plasma volumes and total blood volumes in 4 of 13 tissues were significantly greater in the Kamloops strain.3. Differences were most pronounced in highly perfused organs, such as the liver and kidney and in organs of digestion such as the stomach and intestines.4. Differences in blood volumes between the two strains may be related to the greater permeability of the vascular membranes in the Kamloops strain fish.

Destruction of newly released red blood cells in space flight

NASA Technical Reports Server (NTRS)

Alfrey, C. P.; Udden, M. M.; Huntoon, C. L.; Driscoll, T.

1996-01-01

Space flight results in a rapid change in total blood volume, plasma volume, and red blood cell mass because the space to contain blood is decreased. The plasma volume and total blood volume decreases during the first hours in space and remain at a decreased level for the remainder of the flight. During the first several hours following return to earth, plasma volume and total blood volume increase to preflight levels. During the first few days in space recently produced red blood cells disappear from the blood resulting in a decrease in red blood cell mass of 10-15%. Red cells 12 d old or older survive normally and production of new cells continues at near preflight levels. After the first few days in space, the red cell mass is stable at the decreased level. Following return to earth the hemoglobin and red blood cell mass concentrations decrease reflecting the increase in plasma volume. The erythropoietin levels increase responding to "postflight anemia"; red cell production increases, and the red cell mass is restored to preflight levels after several weeks.

Plasma volume methodology: Evans blue, hemoglobin-hematocrit, and mass density transformations

NASA Technical Reports Server (NTRS)

Greenleaf, J. E.; Hinghofer-Szalkay, H.

1985-01-01

Methods for measuring absolute levels and changes in plasma volume are presented along with derivations of pertinent equations. Reduction in variability of the Evans blue dye dilution technique using chromatographic column purification suggests that the day-to-day variability in the plasma volume in humans is less than + or - 20 m1. Mass density determination using the mechanical-oscillator technique provides a method for measuring vascular fluid shifts continuously for assessing the density of the filtrate, and for quantifying movements of protein across microvascular walls. Equations for the calculation of volume and density of shifted fluid are presented.

Small intracerebral hemorrhages have a low spot sign prevalence and are less likely to expand.

PubMed

Dowlatshahi, Dar; Yogendrakumar, Vignan; Aviv, Richard I; Rodriguez-Luna, David; Molina, Carlos A; Silva, Yolanda; Dzialowski, Imanuel; Czlonkowska, Anna; Boulanger, Jean-Martin; Lum, Cheemun; Gubitz, Gord; Padma, Vasantha; Roy, Jayanta; Kase, Carlos S; Bhatia, Rohit; Hill, Michael D; Demchuk, Andrew M

2016-02-01

Hematoma expansion is a major predictor of morbidity and mortality after intracerebral hemorrhage (ICH). Both baseline hematoma volume and the CT-angiogram (CTA) spot sign predict hematoma expansion. Because the CTA spot sign may represent foci of active hemorrhage, we hypothesized that patients with smaller baseline hematoma volumes are less likely to be spot sign positive, and therefore less likely to expand. We sought to validate our prior finding that small hematomas are unlikely to expand, and to determine the relationship between baseline hematoma volume, spot sign status, and risk of hematoma expansion. Data were from the prospective PREDICT ICH study. Patients presenting within 6 h of symptom onset with completed baseline CT, CTA, and follow-up CT were included. Baseline hematoma volume was categorized a priori (<3 mL, 3-10 mL, 10-20 mL, >20 mL). The primary outcome was significant hematoma expansion (≥6 mL, ≥12.5 mL or ≥33%) and secondary outcomes were early neurological worsening, good clinical outcome (modified Rankin Scale 0-3), and mortality at 90 days. Among 315 patients meeting the inclusion criteria, baseline hematoma volume category predicted absolute hematoma expansion (p < 0.001), spot sign prevalence (p < 0.001), early neurologic worsening (p = 0.002), clinical outcome (p < 0.001), and mortality (p < 0.001). Very small hematomas (<3 mL) were unlikely to be spot positive (7.7%), unlikely to expand (2.6%), and were associated with a 73% chance of good clinical outcome. Spot sign appeared to be most predictive of expansion in the 3-10 mL baseline hematoma volume category. Very small hematomas are unlikely to expand and have a low spot sign prevalence. Hemostatic therapy trials may be best targeted at hemorrhages >3 mL in volume. © 2016 World Stroke Organization.

Effect of fluid countermeasures of varying osmolarity on cardiovascular responses to orthostatic stress

NASA Technical Reports Server (NTRS)

Davis, John E.

1989-01-01

Current operational procedures for shuttle crewmembers include the ingestion of a fluid countermeasure approximately 2 hours before reentry into the earth's gravitational field. The ingestion of the fluid countermeasure is thought to restore plasma volume and improve orthostatic responses upon reentry. The present countermeasure consists of ingesting salt tablets and water to achieve an isotonic solution. It has yet to be determined whether this is the optimal drink to restore orthostatic tolerance. It is also not known whether the drink solution is effective in increasing plasma volume. The purpose here is to evaluate the effectiveness of drink solutions of different osmolarity on restoring plasma volume and orthostatic responses. A hypertonic drink solution was more effective in restoring plasma volume after dehydration than an isotonic solution. However, there were no differences in their effects on an orthostatic challenge. These data suggest that the plasma volume differences produced in this study were not sufficient to produce differences in the cardiovascular responses to an orthostatic challenge, or there are other changes that occur during space flight that are more important in determining orthostatic intolerance.

Small-volume resuscitation from hemorrhagic shock with polymerized human serum albumin.

PubMed

Messmer, Catalina; Yalcin, Ozlem; Palmer, Andre F; Cabrales, Pedro

2012-10-01

Human serum albumin (HSA) is used as a plasma expander; however, albumin is readily eliminated from the intravascular space. The objective of this study was to establish the effects of various-sized polymerized HSAs (PolyHSAs) during small-volume resuscitation from hemorrhagic shock on systemic parameters, microvascular hemodynamics, and functional capillary density in the hamster window chamber model. Polymerized HSA size was controlled by varying the cross-link density (ie, molar ratio of glutaraldehyde to HSA). Hemorrhage was induced by controlled arterial bleeding of 50% of the animal's blood volume (BV), and hypovolemic shock was maintained for 1 hour. Resuscitation was implemented in 2 phases, first, by infusion of 3.5% of the BV of hypertonic saline (7.5% NaCl) then followed by infusion of 10% of the BV of each PolyHSA. Resuscitation provided rapid recovery of blood pressure, blood gas parameters, and microvascular perfusion. Polymerized HSA at a glutaraldehyde-to-HSA molar ratio of 60:1 (PolyHSA(60:1)) provided superior recovery of blood pressure, microvascular blood flow, and functional capillary density, and acid-base balance, with sustained volume expansion in relation to the volume infused. The high molecular weight of PolyHSA(60:1) increased the hydrodynamic radius and solution viscosity. Pharmacokinetic analysis of PolyHSA(60:1) indicates reduced clearance and increased circulatory half-life compared with monomeric HSA and other PolyHSA formulations. In conclusion, HSA molecular size and solution viscosity affect central hemodynamics, microvascular blood flow, volume expansion, and circulation persistence during small-volume resuscitation from hemorrhagic shock. In addition, PolyHSA can be an alternative to HSA in pathophysiological situations with compromised vascular permeability. Copyright © 2012 Elsevier Inc. All rights reserved.

Flux Compression Magnetic Nozzle

NASA Technical Reports Server (NTRS)

Thio, Y. C. Francis; Schafer, Charles (Technical Monitor)

2001-01-01

In pulsed fusion propulsion schemes in which the fusion energy creates a radially expanding plasma, a magnetic nozzle is required to redirect the radially diverging flow of the expanding fusion plasma into a rearward axial flow, thereby producing a forward axial impulse to the vehicle. In a highly electrically conducting plasma, the presence of a magnetic field B in the plasma creates a pressure B(exp 2)/2(mu) in the plasma, the magnetic pressure. A gradient in the magnetic pressure can be used to decelerate the plasma traveling in the direction of increasing magnetic field, or to accelerate a plasma from rest in the direction of decreasing magnetic pressure. In principle, ignoring dissipative processes, it is possible to design magnetic configurations to produce an 'elastic' deflection of a plasma beam. In particular, it is conceivable that, by an appropriate arrangement of a set of coils, a good approximation to a parabolic 'magnetic mirror' may be formed, such that a beam of charged particles emanating from the focal point of the parabolic mirror would be reflected by the mirror to travel axially away from the mirror. The degree to which this may be accomplished depends on the degree of control one has over the flux surface of the magnetic field, which changes as a result of its interaction with a moving plasma.

NaCl regulation of plasma membrane H(+)-ATPase gene expression in a glycophyte and a halophyte.

PubMed

Niu, X; Narasimhan, M L; Salzman, R A; Bressan, R A; Hasegawa, P M

1993-11-01

NaCl regulation of plasma membrane H(+)-ATPase gene expression in the glycophyte tobacco (Nicotiana tabacum L. var Wisconsin 38) and the halophyte Atriplex nummularia L. was evaluated by comparison of organ-specific mRNA abundance using homologous cDNA probes encoding the ATPases of the respective plants. Accumulation of mRNA was induced by NaCl in fully expanded leaves and in roots but not in expanding leaves or stems. The NaCl responsiveness of the halophyte to accumulate plasma membrane H(+)-ATPase mRNA in roots was substantially greater than that of the glycophyte. Salt-induced transcript accumulation in A. nummularia roots was localized by in situ hybridization predominantly to the elongation zone, but mRNA levels also increased in the zone of differentiation. Increased message accumulation in A. nummularia roots could be detected within 8 h after NaCl (400 mM) treatment, and maximal levels were severalfold greater than in roots of untreated control plants. NaCl-induced plasma membrane H(+)-ATPase gene expression in expanded leaves and roots presumably indicates that these organs require increased H(+)-electrochemical potential gradients for the maintenance of plant ion homeostasis for salt adaptation. The greater capacity of the halophyte to induce plasma membrane H(+)-ATPase gene expression in response to NaCl may be a salt-tolerance determinant.

NaCl regulation of plasma membrane H(+)-ATPase gene expression in a glycophyte and a halophyte.

PubMed Central

Niu, X; Narasimhan, M L; Salzman, R A; Bressan, R A; Hasegawa, P M

1993-01-01

NaCl regulation of plasma membrane H(+)-ATPase gene expression in the glycophyte tobacco (Nicotiana tabacum L. var Wisconsin 38) and the halophyte Atriplex nummularia L. was evaluated by comparison of organ-specific mRNA abundance using homologous cDNA probes encoding the ATPases of the respective plants. Accumulation of mRNA was induced by NaCl in fully expanded leaves and in roots but not in expanding leaves or stems. The NaCl responsiveness of the halophyte to accumulate plasma membrane H(+)-ATPase mRNA in roots was substantially greater than that of the glycophyte. Salt-induced transcript accumulation in A. nummularia roots was localized by in situ hybridization predominantly to the elongation zone, but mRNA levels also increased in the zone of differentiation. Increased message accumulation in A. nummularia roots could be detected within 8 h after NaCl (400 mM) treatment, and maximal levels were severalfold greater than in roots of untreated control plants. NaCl-induced plasma membrane H(+)-ATPase gene expression in expanded leaves and roots presumably indicates that these organs require increased H(+)-electrochemical potential gradients for the maintenance of plant ion homeostasis for salt adaptation. The greater capacity of the halophyte to induce plasma membrane H(+)-ATPase gene expression in response to NaCl may be a salt-tolerance determinant. PMID:8022933

In situ electrostatic characterisation of ion beams in the region of ion acceleration

NASA Astrophysics Data System (ADS)

Bennet, Alexander; Charles, Christine; Boswell, Rod

2018-02-01

In situ and ex situ techniques have been used to measure directional ion beams created by a sharp axial potential drop in low pressure expanding plasmas. Although Retarding Field Energy Analysers (RFEAs) are the most convenient technique to measure the ion velocities and plasma potentials along with the plasma density, they are bulky and are contained in a grounded shield that may perturb the electric potential profile of the expanding plasma. In principle, ex situ techniques produce a more reliable measurement and Laser Induced Fluorescence spectroscopy (LIF) has previously been used to characterise the spatial velocity profile of ion beams in the same region of acceleration for a range of pressures. Here, satisfactory agreement between the ion velocity profiles measured by LIF and RFEA techniques has allowed the RFEA method to be confidently used to probe the ion beam characteristics in the regions of high gradients in plasma density and DC electric fields which have previously proven difficult.

Study of magnetic field expansion using a plasma generator for space radiation active protection

NASA Astrophysics Data System (ADS)

Jia, Xiang-Hong; Jia, Shao-Xia; Xu, Feng; Bai, Yan-Qiang; Wan, Jun; Liu, Hong-Tao; Jiang, Rui; Ma, Hong-Bo; Wang, Shou-Guo

2013-09-01

There are many active protecting methods including Electrostatic Fields, Confined Magnetic Field, Unconfined Magnetic Field and Plasma Shielding etc. for defending the high-energy solar particle events (SPE) and Galactic Cosmic Rays (GCR) in deep space exploration. The concept of using cold plasma to expand a magnetic field is the best one of all possible methods so far. The magnetic field expansion caused by plasma can improve its protective efficiency of space particles. One kind of plasma generator has been developed and installed into the cylindrical permanent magnet in the eccentric. A plasma stream is produced using a helical-shaped antenna driven by a radio-frequency (RF) power supply of 13.56 MHz, which exits from both sides of the magnet and makes the magnetic field expand on one side. The discharging belts phenomenon is similar to the Earth's radiation belt, but the mechanism has yet to be understood. A magnetic probe is used to measure the magnetic field expansion distributions, and the results indicate that the magnetic field intensity increases under higher increments of the discharge power.

Characterization of Flow and Ohm's Law in the Rotating Wall Machine

NASA Astrophysics Data System (ADS)

Hannum, David; Brookhart, M.; Forest, C. B.; Kendrick, R.; Mengin, G.; Paz-Soldan, C.

2010-11-01

The rotating wall machine is a linear screw-pinch built to study the role of different electromagnetic boundary conditions on the Resistive Wall Mode (RWM). Its plasma is created by an array of electrostatic washer guns which can be biased to discharge up to 1 kA of current each. Individual flux ropes from the guns shear, merge, and expand into a 20 cm diameter, ˜1 m long plasma column. Langmuir (singletip) and tri-axial B-dot probes move throughout the column to measure radial and axial profiles of key plasma parameters. As the plasma current increases, more H2 fuel is ionized, raising ne to 5 x10^20 m-3 while Te stays at a constant 3 eV. The electron density expands to the wall while the current density (Jz) stays pinched to the central axis. E xB and diamagnetic drifts create radially and axially sheared plasma rotation. Plasma resistivity follows the Spitzer model in the core while exceeding it at the edge. These measurements improve the model used to predict the RWM growth rate.

Complex astrophysical experiments relating to jets, solar loops, and water ice dusty plasma

NASA Astrophysics Data System (ADS)

Bellan, P. M.; Zhai, X.; Chai, K. B.; Ha, B. N.

2015-10-01

> Recent results of three astrophysically relevant experiments at Caltech are summarized. In the first experiment magnetohydrodynamically driven plasma jets simulate astrophysical jets that undergo a kink instability. Lateral acceleration of the kinking jet spawns a Rayleigh-Taylor instability, which in turn spawns a magnetic reconnection. Particle heating and a burst of waves are observed in association with the reconnection. The second experiment uses a slightly different setup to produce an expanding arched plasma loop which is similar to a solar corona loop. It is shown that the plasma in this loop results from jets originating from the electrodes. The possibility of a transition from slow to fast expansion as a result of the expanding loop breaking free of an externally imposed strapping magnetic field is investigated. The third and completely different experiment creates a weakly ionized plasma with liquid nitrogen cooled electrodes. Water vapour injected into this plasma forms water ice grains that in general are ellipsoidal and not spheroidal. The water ice grains can become quite long (up to several hundred microns) and self-organize so that they are evenly spaced and vertically aligned.

Is there resetting of central venous pressure in microgravity?

NASA Technical Reports Server (NTRS)

Convertino, V. A.; Ludwig, D. A.; Elliott, J. J.; Wade, C. E.

2001-01-01

In the early phase of the Space Shuttle program, NASA flight surgeons implemented a fluid-loading countermeasure in which astronauts were instructed to ingest eight 1-g salt tablets with 960 ml of water approximately 2 hours prior to reentry from space. This fluid loading regimen was intended to enhance orthostatic tolerance by replacing circulating plasma volume reduced during the space mission. Unfortunately, fluid loading failed to replace plasma volume in groundbased experiments and has proven minimally effective as a countermeasure against post-spaceflight orthostatic intolerance. In addition to the reduction of plasma volume, central venous pressure (CVP) is reduced during exposure to actual and groundbased analogs of microgravity. In the present study, we hypothesized that the reduction in CVP due to exposure to microgravity represents a resetting of the CVP operating point to a lower threshold. A lower CVP 'setpoint' might explain the failure of fluid loading to restore plasma volume. In order to test this hypothesis, we conducted an investigation in which we administered an acute volume load (stimulus) and measured responses in CVP, plasma volume and renal functions. If our hypothesis is true, we would expect the elevation in CVP induced by saline infusion to return to its pre-infusion levels in both HDT and upright control conditions despite lower vascular volume during HDT. In contrast to previous experiments, our approach is novel in that it provides information on alterations in CVP and vascular volume during HDT that are necessary for interpretation of the proposed CVP operating point resetting hypothesis.

Increased upstream ionization due to formation of a double layer.

PubMed

Thakur, S Chakraborty; Harvey, Z; Biloiu, I A; Hansen, A; Hardin, R A; Przybysz, W S; Scime, E E

2009-01-23

We report observations that confirm a theoretical prediction that formation of a current-free double layer in a plasma expanding into a chamber of larger diameter is accompanied by an increase in ionization upstream of the double layer. The theoretical model argues that the increased ionization is needed to balance the difference in diffusive losses upstream and downstream of the expansion region. In our expanding helicon source experiments, we find that the upstream plasma density increases sharply at the same antenna frequency at which the double layer appears.

EFFECTS OF LASER RADIATION ON MATTER: Calculation of the gain of a C VI laser plasma expanding as a cylinder and a cylindrical layer

NASA Astrophysics Data System (ADS)

Gulov, A. V.; Derzhiev, V. I.; Zhidkov, A. G.; Pritula, A. G.; Chekmezov, A. N.; Yakovlenko, Sergei I.

1990-08-01

Calculations are reported of the gain due to the 3-2 transition in the C VI ion in an expanding plasma cylinder or a cylindrical layer. Under the conditions in the experiments at the Rutherford Appleton Laboratory (Chilton, England) amplification was observed as a result of evaporation of a fairly thin (~ 0.1 μm) cylindrical layer. A peak of the gain was reached in a relatively short time (~ 0.1 ns).

Visualization of transient phenomena during the interaction of pulsed CO2 laser radiation with matter

NASA Astrophysics Data System (ADS)

Schmitt, R.; Hugenschmidt, Manfred

1996-05-01

Carbon-dioxide-lasers operating in the pulsed mode with energy densities up to several tens of J/cm2 and peak power densities in the multi-MW/cm2-range may cause fast heating and melting. Eventually quasi-explosive ejection, decomposition or vaporization of material can be observed. Surface plasmas are strongly influencing the energy transfer from the laser radiation field to any target. For optically transparent plastics, such as PMMA for example, only slowly expanding plasmas (LSC-waves) are ignited at fluences around 20 J/cm2, with a low level of self-luminosity. High brightness, supersonically expanding plasma jets (LSD-waves) are generated at the same fluences on glasses. Similar conditions were found for metals as well. From recordings with a high speed CCD-camera, interesting features concerning the initial plasma phases and temporal evolution were deduced. Additionally, information was obtained concerning the quasi explosive ejection of material for PMMA.

Moderator's view: High-volume plasma exchange: pro, con and consensus.

PubMed

Kaplan, Andre A

2017-09-01

I have been asked to comment on the pro and con opinions regarding high-volume plasma exchange. The authors of both positions have provided cogent arguments and a reasonable approach to choosing the exchange volume for any given therapeutic plasma exchange. The major issue of relevance in this discussion is the nature of the toxins targeted for removal. These parameters include molecular weight, the apparent volume of distribution, the degree of protein binding, the biologic and chemical half-life, and the severity and rapidity of its toxicity. © The Author 2017. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

The hybrid reactor project based on the straight field line mirror concept

NASA Astrophysics Data System (ADS)

Ågren, O.; Noack, K.; Moiseenko, V. E.; Hagnestâl, A.; Källne, J.; Anglart, H.

2012-06-01

The straight field line mirror (SFLM) concept is aiming towards a steady-state compact fusion neutron source. Besides the possibility for steady state operation for a year or more, the geometry is chosen to avoid high loads on materials and plasma facing components. A comparatively small fusion hybrid device with "semi-poor" plasma confinement (with a low fusion Q factor) may be developed for industrial transmutation and energy production from spent nuclear fuel. This opportunity arises from a large fission to fusion energy multiplication ratio, Qr = Pfis/Pfus>>1. The upper bound on Qr is primarily determined by geometry and reactor safety. For the SFLM, the upper bound is Qr≈150, corresponding to a neutron multiplicity of keff=0.97. Power production in a mirror hybrid is predicted for a substantially lower electron temperature than the requirement Te≈10 keV for a fusion reactor. Power production in the SFLM seems possible with Q≈0.15, which is 10 times lower than typically anticipated for hybrids (and 100 times smaller than required for a fusion reactor). This relaxes plasma confinement demands, and broadens the range for use of plasmas with supra-thermal ions in hybrid reactors. The SFLM concept is based on a mirror machine stabilized by qudrupolar magnetic fields and large expander tanks beyond the confinement region. The purpose of the expander tanks is to distribute axial plasma loss flow over a sufficiently large area so that the receiving plates can withstand the heat. Plasma stability is not relying on a plasma flow into the expander regions. With a suppressed plasma flow into the expander tanks, a possibility arise for higher electron temperature. A brief presentation will be given on basic theory for the SFLM with plasma stability and electron temperature issues, RF heating computations with sloshing ion formation, neutron transport computations with reactor safety margins and material load estimates, magnetic coil designs as well as a discussion on the implications of the geometry for possible diagnostics. Reactor safety issues are addressed and a vertical orientation of the device could assist passive coolant circulation. Specific attention is put to a device with a 25 m long confinement region and 40 cm plasma radius in the mid-plane. In an optimal case (keff = 0.97) with a fusion power of only 10 MW, such a device may be capable of producing a power of 1.5 GWth.

State of the metal core in nanosecond exploding wires and related phenomena

NASA Astrophysics Data System (ADS)

Sarkisov, G. S.; Sasorov, P. V.; Struve, K. W.; McDaniel, D. H.

2004-08-01

Experiments show that an expanding metal wire core that results from a nanosecond electrical explosion in vacuum consists primarily of three different states: solid, microdrop, and gas-plasma. The state of the wire core depends both on the amount of energy deposited before the voltage breakdown and on the heating conditions. For small amounts of deposited energy (on the order of solid-stage enthalpy), the wire core remains in a solid state or is partially disintegrated. For a high level of deposited energy (more than vaporization energy) the wire core is in a gas-plasma state. For an intermediate level of deposited energy (more than melting but less than vaporization), the wire disintegrates into hot liquid microdrops or clusters of submicron size. For a wire core in the cluster state, interferometry demonstrates weak (or even absent) phaseshift. Light emission shows a "firework effect"—the long late-time radiation related to the emission by the expanding cylinder of hot microparticles. For the wire core in a gas-plasma state, interferometry demonstrates a large phaseshift and a fast reduction in light emission due to adiabatic cooling of the expanding wire core. The simulation of this firework effect agrees well with experimental data, assuming submicron size and a temperature approaching boiling for the expanded microparticles cylinder.

High current ion source

DOEpatents

Brown, Ian G.; MacGill, Robert A.; Galvin, James E.

1990-01-01

An ion source utilizing a cathode and anode for producing an electric arc therebetween. The arc is sufficient to vaporize a portion of the cathode to form a plasma. The plasma leaves the generation region and expands through another regon. The density profile of the plasma may be flattened using a magnetic field formed within a vacuum chamber. Ions are extracted from the plasma to produce a high current broad on beam.

Discharge characteristics and hydrodynamics behaviors of atmospheric plasma jets produced in various gas flow patterns

NASA Astrophysics Data System (ADS)

Setsuhara, Yuichi; Uchida, Giichiro; Nakajima, Atsushi; Takenaka, Kosuke; Koga, Kazunori; Shiratani, Masaharu

2015-09-01

Atmospheric nonequilibrium plasma jets have been widely employed in biomedical applications. For biomedical applications, it is an important issue to understand the complicated mechanism of interaction of the plasma jet with liquid. In this study, we present analysis of the discharge characteristics of a plasma jet impinging onto the liquid surface under various gas flow patterns such as laminar and turbulence flows. For this purpose, we analyzed gas flow patters by using a Schlieren gas-flow imaging system in detail The plasma jet impinging into the liquid surface expands along the liquid surface. The diameter of the expanded plasma increases with gas flow rate, which is well explained by an increase in the diameter of the laminar gas-flow channel. When the gas flow rate is further increased, the gas flow mode transits from laminar to turbulence in the gas flow channel, which leads to the shortening of the plasm-jet length. Our experiment demonstrated that the gas flow patterns strongly affect the discharge characteristics in the plasma-jet system. This study was partly supported by a Grant-in-Aid for Scientific Research on Innovative Areas ``Plasma Medical Innovation'' (24108003) from the Ministry of Education, Culture, Sports, Science and Technology, Japan (MEXT).

One-dimensional particle-in-cell simulation on the influence of electron and ion temperature on the sheath expansion process in the post-arc stage of vacuum circuit breaker

NASA Astrophysics Data System (ADS)

Mo, Yongpeng; Shi, Zongqian; Jia, Shenli; Wang, Lijun

2015-02-01

The inter-contact region of vacuum circuit breakers is filled with residual plasma at the moment when the current is zero after the burning of metal vapor arc. The residual plasma forms an ion sheath in front of the post-arc cathode. The sheath then expands towards the post-arc anode under the influence of a transient recovery voltage. In this study, a one-dimensional particle-in-cell model is developed to investigate the post-arc sheath expansion. The influence of ion and electron temperatures on the decrease in local plasma density at the post-arc cathode side and post-arc anode side is discussed. When the decay in the local plasma density develops from the cathode and anode sides into the high-density region and merges, the overall plasma density in the inter-contact region begins to decrease. Meanwhile, the ion sheath begins to expand faster. Furthermore, the theory of ion rarefaction wave only explains quantitatively the decrease in the overall plasma density at relatively low ion temperatures. With the increase of ion temperature to certain extent, another possible reason for the decrease in the overall plasma density is proposed and results from the more active thermal diffusion of plasma.

Pre-Exercise Ingestion of Pickle Juice, Hypertonic Saline, or Water and Aerobic Performance and Thermoregulation

PubMed Central

Peikert, Jarett; Miller, Kevin C.; Albrecht, Jay; Tucker, Jared; Deal, James

2014-01-01

Context: Ingesting high-sodium drinks pre-exercise can improve thermoregulation and performance. Athletic trainers (19%) give athletes pickle juice (PJ) prophylactically for cramping. No data exist on whether this practice affects aerobic performance or thermoregulation. Objective: To determine if drinking 2 mL/kg body mass of PJ, hypertonic saline, or deionized water (DIW) pre-exercise affects aerobic performance or thermoregulation. Design: Crossover study. Setting: Controlled laboratory study. Patients or Other Participants: Nine euhydrated men (age = 22 ± 3 years, height = 184.0 ± 8.2 cm, mass = 82.6 ± 16.0 kg) completed testing. Intervention(s): Participants rested for 65 minutes. During this period, they ingested 2 mL/kg of PJ, hypertonic saline, or DIW. Next, they drank 5 mL/kg of DIW. Blood was collected before and after ingestion of all fluids. Participants were weighed and ran in the heat (temperature = 38.3°C ± 1°C, relative humidity = 21.1% ± 4.7%) at increasing increments of maximal heart rate (50%, 60%, 70%, 80%, 90%, 95%) until exhaustion or until rectal temperature exceeded 39.5°C. Participants were weighed postexercise so we could calculate sweat volume. Main Outcome Measure(s): Time to exhaustion, rectal temperature, changes in plasma volume, and sweat volume. Results: Time to exhaustion did not differ among drinks (PJ = 77.4 ± 5.9 minutes, hypertonic saline = 77.4 ± 4.0 minutes, DIW = 75.7 ± 3.2 minutes; F2,16 = 1.1, P = .40). Core temperature of participants was similar among drinks (PJ = 38.7°C ± 0.3°C, hypertonic saline = 38.7°C ± 0.4°C, DIW = 38.8°C ± 0.4°C; P = .74) but increased from pre-exercise (36.7°C ± 0.2°C) to postexercise (38.7°C ± 0.4°C) (P < .05). No differences were observed for changes in plasma volume or sweat volume among drinks (P > .05). Conclusions: Ingesting small amounts of PJ or hypertonic saline with water did not affect performance or select thermoregulatory measures. Drinking larger volumes of PJ and water may be more effective at expanding the extracellular space. PMID:24568225

A highly stable (SnOx-Sn)@few layered graphene composite anode of sodium-ion batteries synthesized by oxygen plasma assisted milling

NASA Astrophysics Data System (ADS)

Cheng, Deliang; Liu, Jiangwen; Li, Xiang; Hu, Renzong; Zeng, Meiqing; Yang, Lichun; Zhu, Min

2017-05-01

The (SnOx-Sn)@few layered graphene ((SnOx-Sn)@FLG) composite has been synthesized by oxygen plasma-assisted milling. Owing to the synergistic effect of rapid plasma heating and ball mill grinding, SnOx (1 ≤ x ≤ 2) nanoparticles generated from the reaction of Sn with oxygen are tightly wrapped by FLG nanosheets which are simultaneously exfoliated from expanded graphite, forming secondary micro granules. Inside the granules, the small size of the SnOx nanoparticles enables the fast kinetics for Na+ transfer. The in-situ formed FLG and residual Sn nanoparticles improve the electrical conductivity of the composite, meanwhile alleviate the aggregation of SnOx nanoparticles and relieve the volume change during the cycling, which is beneficial for the cyclic stability for the Na+ storage. As an anode material for sodium-ion batteries, the (SnOx-Sn)@FLG composite exhibits a high reversible capacity of 448 mAh g-1 at a current density of 100 mA g-1 in the first cycle, with 82.6% capacity retention after 250 cycles. Even when the current density increases to 1000 mA g-1, this composite retains 316.5 mAh g-1 after 250 cycles. With superior Na+ storage stability, the (SnOx-Sn)@FLG composite can be a promising anode material for high performance sodium-ion batteries.

Electrical method for the measurements of volume averaged electron density and effective coupled power to the plasma bulk

NASA Astrophysics Data System (ADS)

Henault, M.; Wattieaux, G.; Lecas, T.; Renouard, J. P.; Boufendi, L.

2016-02-01

Nanoparticles growing or injected in a low pressure cold plasma generated by a radiofrequency capacitively coupled capacitive discharge induce strong modifications in the electrical parameters of both plasma and discharge. In this paper, a non-intrusive method, based on the measurement of the plasma impedance, is used to determine the volume averaged electron density and effective coupled power to the plasma bulk. Good agreements are found when the results are compared to those given by other well-known and established methods.

Plasma volume during stress in man - Osmolality and red cell volume

NASA Technical Reports Server (NTRS)

Greenleaf, J. E.; Convertino, V. A.; Mangseth, G. R.

1979-01-01

The purpose was (1) to test the hypothesis that in man there is a range of plasma osmolality within which the red cell volume (RCV) and mean corpuscular volume (MCV) remain essentially constant and (2) to determine the upper limit of this range. During a variety of stresses - submaximal and maximal exercise, heat and altitude exposure, +Gz acceleration, and tilting - changes in plasma osmolality between -1 and +13 mosmol/kg resulted in essentially no change in the regression of percent change in plasma volume (PV) calculated from a change in hematocrit (Hct) on that calculated from a change in Hct + hemoglobin (Hb), i.e., the RCV and MCV were constant. Factors that do not influence RCV are the level of metabolism, heat exposure at rest, and short-term orthostasis (heat-to-foot acceleration). Factors that may influence RCV are exposure to high altitude and long-term orthostasis (head-up tilting). Factors that definitely influence RCV are prior dehydration and extended periods of stress. Thus, either the Hct or the Hct + Hb equations can be used to calculate percent changes in PV under short-term periods of stress when the change in plasma osmolality is less than 13 mosmol/kg.

Capillary plasma jet: A low volume plasma source for life science applications

NASA Astrophysics Data System (ADS)

Topala, I.; Nagatsu, M.

2015-02-01

In this letter, we present results from multispectroscopic analysis of protein films, after exposure to a peculiar plasma source, i.e., the capillary plasma jet. This plasma source is able to generate very small pulsed plasma volumes, in kilohertz range, with characteristic dimensions smaller than 1 mm. This leads to specific microscale generation and transport of all plasma species. Plasma diagnosis was realized using general electrical and optical methods. Depending on power level and exposure duration, this miniature plasma jet can induce controllable modifications to soft matter targets. Detailed discussions on protein film oxidation and chemical etching are supported by results from absorption, X-ray photoelectron spectroscopy, and microscopy techniques. Further exploitation of principles presented here may consolidate research interests involving plasmas in biotechnologies and plasma medicine, especially in patterning technologies, modified biomolecule arrays, and local chemical functionalization.

The effect of vitamin C on plasma volume in the early stage of sepsis in the rat.

PubMed

Bark, Björn P; Grände, Per-Olof

2014-12-01

Previous experimental studies have shown that vitamin C has several beneficial effects in sepsis and burns, such as decreased tissue oedema, improved endothelial barrier function and decreased transcapillary leakage of plasma markers. It has still not been investigated, though, if vitamin C has any impact specifically on plasma volume. The present study aims at testing the hypothesis that vitamin C decreases plasma volume loss in sepsis. Anaesthetized male adult Sprague-Dawley rats were used in this prospective randomized study. All experiments were carried out at a university hospital laboratory. Sepsis was induced by caecal ligation and incision. After 3 h, vitamin C was given either as a bolus dose (66 mg/kg) followed by a continuous infusion (33 mg/kg/h) (n = 9), or as a single bolus dose (200 mg/kg) (n = 9). A sham group (n = 9) underwent the same surgical procedure, but no vitamin C was given. Plasma volume was measured ((125)I-dilution technique) at baseline, at 3 h after end of initiation of sepsis and at the end of the experiment 3 h later. Arterial blood samples for analyses of electrolytes, blood gases, haematocrit and lactate were taken at the same time points. There were no significant differences in plasma volumes or the physiological parameters analysed between any of the three groups at any time point. There was a significantly larger urine production in the single bolus dose group (200 mg/kg) compared to the sham group. Vitamin C treatment did not decrease the loss of plasma volume in the septic rat. The diuretic effect of vitamin C was in accordance with previous studies.

Measurement of the permeability, perfusion, and histogram characteristics in relapsing-remitting multiple sclerosis using dynamic contrast-enhanced MRI with extended Tofts linear model.

PubMed

Yin, Ping; Xiong, Hua; Liu, Yi; Sah, Shambhu K; Zeng, Chun; Wang, Jingjie; Li, Yongmei; Hong, Nan

2018-01-01

To investigate the application value of using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) with extended Tofts linear model for relapsing-remitting multiple sclerosis (RRMS) and its correlation with expanded disability status scale (EDSS) scores and disease duration. Thirty patients with multiple sclerosis (MS) underwent conventional magnetic resonance imaging (MRI) and DCE-MRI with a 3.0 Tesla MR scanner. An extended Tofts linear model was used to quantitatively measure MR imaging biomarkers. The histogram parameters and correlation among imaging biomarkers, EDSS scores, and disease duration were also analyzed. The MR imaging biomarkers volume transfer constant (K trans ), volume of the extravascular extracellular space per unit volume of tissue (Ve), fractional plasma volume (V p ), cerebral blood flow (CBF), and cerebral blood volume (CBV) of contrast-enhancing (CE) lesions were significantly higher (P < 0.05) than those of nonenhancing (NE) lesions and normal-appearing white matter (NAWM) regions. The skewness of Ve value in CE lesions was more close to normal distribution. There was no significant correlation among the biomarkers with the EDSS scores and disease duration (P > 0.05). Our study demonstrates that the DCE-MRI with the extended Tofts linear model can measure the permeability and perfusion characteristic in MS lesions and in NAWM regions. The K trans , Ve, Vp, CBF, and CBV of CE lesions were significantly higher than that of NE lesions. The skewness of Ve value in CE lesions was more close to normal distribution, indicating that the histogram can be helpful to distinguish the pathology of MS lesions.

Plasma properties in electron-bombardment ion thrusters

NASA Technical Reports Server (NTRS)

Matossian, J. N.; Beattie, J. R.

1987-01-01

The paper describes a technique for computing volume-averaged plasma properties within electron-bombardment ion thrusters, using spatially varying Langmuir-probe measurements. Average values of the electron densities are defined by integrating the spatially varying Maxwellian and primary electron densities over the ionization volume, and then dividing by the volume. Plasma properties obtained in the 30-cm-diameter J-series and ring-cusp thrusters are analyzed by the volume-averaging technique. The superior performance exhibited by the ring-cusp thruster is correlated with a higher average Maxwellian electron temperature. The ring-cusp thruster maintains the same fraction of primary electrons as does the J-series thruster, but at a much lower ion production cost. The volume-averaged predictions for both thrusters are compared with those of a detailed thruster performance model.

Plasma volume and renal function during and after ultramarathon running.

PubMed

Irving, R A; Noakes, T D; Burger, S C; Myburgh, K H; Querido, D; van Zyl Smit, R

1990-10-01

Plasma volume (PV) and renal function were studied in eight subjects for 3 d prior to and 6 d after a 56 km footrace. Immediately following the race, PV, creatinine clearance, and urine flow were unchanged from pre-race values. Over the subsequent 3 d, PV increased due initially to a 17 g influx of serum albumin and an associated increase in plasma sodium content, which persisted throughout the study period. A reduction in urine sodium secretion occurred during the race day. Creatinine clearance increased after the race and remained elevated for 48 h. Increases serum enzyme activities, C-reactive protein concentration, serum uric acid content, and plasma creatinine concentration and production suggest muscle damage. We suggested the following. First, the persistent post-exercise plasma volume expansion is initiated by an influx of albumin into the intravascular space with an associated increase in plasma sodium content. A decrease in urine sodium excretion during the race day would contribute to the latter. Second, the interpretation of post-race changes in serum constituents must take account of changes in plasma volume. Third, there is an increase in creatinine clearance, indicating an increase in glomerular filtration rate, after both standard and ultramarathon running. This may be caused by the products of muscle cell damage although the physiologic mechanism for this is unclear.

Lack of an association of BDNF Val66Met polymorphism and plasma BDNF with hippocampal volume and memory

PubMed Central

Kim, Ana; Fagan, Anne M; Goate, Alison M; Benzinger, Tammie LS; Morris, John C; Head, Denise

2015-01-01

Brain-derived neurotrophic factor (BDNF) has been shown to be important for neuronal survival and synaptic plasticity in the hippocampus in non-human animals. The Val66Met polymorphism in the BDNF gene, involving a valine (Val) to methionine (Met) substitution at codon 66, has been associated with lower BDNF secretion in vitro. However, there have been mixed results regarding associations between either circulating BDNF or the BDNF Val66Met polymorphism with hippocampal volume and memory in humans. The current study examined the association of BDNF genotype and plasma BDNF with hippocampal volume and memory in two large independent cohorts of middle-aged and older adults (both cognitively normal and early-stage dementia). Sample sizes ranged from 123 to 649. Measures of the BDNF genotype, plasma BDNF, MRI-based hippocampal volume and memory performance were obtained from the Knight Alzheimer Disease Research Center (ADRC) and the Alzheimer’s Disease Neuroimaging Initiative (ADNI). There were no significant differences between BDNF Met+ and Met- groups on either hippocampal volume or memory in either cohort. In addition, plasma BDNF was not significantly associated with either hippocampal volume or memory in either cohort. Neither age, cognitive status nor gender moderated any of the relationships. Overall, current findings suggest that BDNF genotype and plasma BDNF may not be robust predictors for variance in hippocampal volume and memory in middle age and older adult cohorts. PMID:25784293

Evaluation of an integrated orbital tissue expander in congenital anophthalmos: report of preliminary clinical experience.

PubMed

Tse, David T; Abdulhafez, Mohammad; Orozco, Marcia A; Tse, Jeffrey D; Azab, Amr Osama; Pinchuk, Leonard

2011-03-01

To evaluate the effectiveness of an orbital tissue expander designed to stimulate orbital bone growth in an anophthalmic socket. Retrospective, noncomparative, interventional case series. Institutional. Nine consecutive patients with unilateral congenital anophthalmos. The orbital tissue expander is made of an inflatable silicone globe sliding on a titanium T-plate secured to the lateral orbital rim with screws. The globe is inflated by a transconjunctival injection of normal saline through a 30-gauge needle to a final volume of approximately 5 cm(3). Computed tomography scans were used to determine the orbital volume. The data studied were: demographics, prior orbital expansion procedures, secondary interventions, orbital symmetry, and implant-related complications. The primary outcome measure was the orbital volume change, and the secondary outcome measures were changes in forehead, brow, and zygomatic eminence contour and adverse events. The average patient age at implantation was 41.89 ± 39.42 months (range, 9 to 108 months). The initial average volume of inflation was 3.00 ± 0.87 cm(3) (range, 2.0 to 4.0 cm(3)), and the average final volume of 4.33 ± 0.50 cm(3) (range, 4.0 to 5.0 cm(3)) was achieved. The duration of expansion was 18.89 ± 8.80 months (range, 4 to 26 months). All patients demonstrated an average increase in the orbital tissue expander implanted orbital volume of 5.112 ± 2.173 cm(3) (range, 2.81 to 10.38 cm(3)). The average difference between the volume of the implanted and the initial contralateral orbit was 5.68 ± 2.34 cm(3), which decreased to 2.53 ± 1.80 cm(3) at the final measurement (P < .001, paired t test). All implants remained inflated except for 2 iatrogenic punctures at the second inflation and 1 that was the result of implant failure. All were replaced. The integrated orbital tissue expander is safe and effective in stimulating anophthalmic socket bone growth. Copyright © 2011 Elsevier Inc. All rights reserved.

Relation of blood volume and blood pressure in orthostatic intolerance

NASA Technical Reports Server (NTRS)

Jacob, G.; Biaggioni, I.; Mosqueda-Garcia, R.; Robertson, R. M.; Robertson, D.

1998-01-01

A complex but crucial relationship exists between blood volume and blood pressure in human subjects; it has been recognized that in essential hypertension, renovascular hypertension, and pheochromocytoma, the relationship between plasma volume and diastolic blood pressure is an inverse one. This phenomenon has not been studied in individuals with low normal and reduced blood pressures. Orthostatic intolerance is a commonly encountered abnormality in blood pressure regulation often associated with tachycardia in the standing position. Most of these patients have varying degrees of reduced blood volume. We tested the hypothesis that the relationship previously found between plasma volume and diastolic blood pressure in pressor states would also hold in orthostatic intolerance. We studied 16 patients with a history of symptomatic orthostatic intolerance associated with an elevation in plasma norepinephrine in the upright posture and hypovolemia in 9 patients and normovolemia in 7 patients. Our studies demonstrate an inverse relationship between plasma volume and diastolic blood pressure in patients with orthostatic intolerance. This finding also holds for the change in diastolic blood pressure in response to upright posture. In this relationship, patients with orthostatic intolerance with high plasma norepinephrine resemble those with essential hypertension, renovascular hypertension, and pheochromocytoma. We conclude that in a variety of conditions at both ends of the blood pressure spectrum, the seemingly paradoxical association of hypovolemia and diastolic blood pressure is preserved.

Increased renal alpha-epithelial sodium channel (ENAC) protein and increased ENAC activity in normal pregnancy.

PubMed

West, Crystal; Zhang, Zheng; Ecker, Geoffrey; Masilamani, Shyama M E

2010-11-01

Pregnancy-mediated sodium (Na) retention is required to provide an increase in plasma volume for the growing fetus. The mechanisms responsible for this Na retention are not clear. We first used a targeted proteomics approach and found that there were no changes in the protein abundance compared with virgin rats of the β or γ ENaC, type 3 Na(+)/H(+) exchanger (NHE3), bumetanide-sensitive cotransporter (NKCC2), or NaCl cotransporter (NCC) in mid- or late pregnancy. In contrast, we observed marked increases in the abundance of the α-ENaC subunit. The plasma volume increased progressively during pregnancy with the greatest plasma volume being evident in late pregnancy. ENaC inhibition abolished the difference in plasma volume status between virgin and pregnant rats. To determine the in vivo activity of ENaC, we conducted in vivo studies of rats in late pregnancy (days 18-20) and virgin rats to measure the natriuretic response to ENaC blockade (with benzamil). The in vivo activity of ENaC (U(Na)V postbenzamil-U(Na)V postvehicle) was markedly increased in late pregnancy, and this difference was abolished by pretreatment with the mineralocorticoid receptor antagonist, eplerenone. These findings demonstrate that the increased α-ENaC subunit of pregnancy is associated with an mineralocorticoid-dependent increase in ENaC activity. Further, we show that ENaC activity is a major contributor of plasma volume status in late pregnancy. These changes are likely to contribute to the renal sodium retention and plasma volume expansion required for an optimal pregnancy.

Mineral profiling of ostrich (Struthio camelus) seminal plasma and its relationship with semen traits and collection day.

PubMed

Smith, A M J; Bonato, M; Dzama, K; Malecki, I A; Cloete, S W P

2018-06-01

Successful assisted reproduction techniques, with specific focus on in vitro semen storage for artificial insemination, are dependent on certain key elements which includes the biochemical profiling of semen. The objective of this study was to complete an ostrich seminal plasma (SP) evaluation by inductively coupled plasma mass spectrometry (ICP-MS) among seven males at different daily intervals (day 1, 3, 7, 11, 15, 19, 21, 23, 25, 26, 27, 28) for a period of 28 days during spring (August to September) for mineral profiling. The effect of collection day and male on sperm concentration, semen volume and seminal plasma volume, was explored as well as the relationships amongst these specific sperm traits and SP minerals. Variation amongst SP mineral concentrations, accounted for by the fixed effects of sperm concentration, semen volume, seminal plasma volume, collection day and male, ranged from 18% to 77%. Male had the largest effect on variation in SP minerals, namely: phosphorus (P), potassium (K), calcium (Ca), sodium (Na), boron (B), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), molybdenum (Mo), barium (Ba), arsenic (As) and selenium (Se). Sperm concentration instigated fluctuations of P, magnesium (Mg), B, zinc (Zn), Fe, aluminium (Al), Se, manganese (Mn) and lead (Pb). Semen volume had an effect on Na, K, B, Pb and Ba while seminal plasma volume only influenced variation in Na. There were fluctuations among collection days of specific micro minerals, Ni and Mo, with initial Ni concentrations being relatively greater and Mo at lesser concentrations. Semen volume, seminal plasma volume and sperm concentration varied amongst males. Sperm concentrations during the initial collection days, 1 and 3, were less than that for days 7 to 28. Significant variation of SP minerals and sperm characteristics among ejaculates and males suggest an association of these specific elements with sperm function and are, therefore, considered to be of potential importance to success of assisted reproduction technology for the ostrich. The relationship amongst sperm concentration and collection day confirms the need to conduct an initial period of collection to stabilise a greater sperm concentration to optimise sperm numbers for artificial insemination purposes. Copyright © 2018 Elsevier B.V. All rights reserved.

Dietary sodium and plasma volume levels with exercise.

PubMed

Luetkemeier, M J; Coles, M G; Askew, E W

1997-05-01

Sodium is the major cation of the extracellular fluid and has a potent influence on fluid movement. Sodium has been likened to a sponge that draws fluids into the extracellular space, including the plasma volume, to equalize gradients in concentration. Conventional wisdom suggests limiting dietary intake of Na+ to decrease risk of hypertension. However, there are some extreme occupational or exercise-related conditions where sweat losses are great and Na+ losses may exceed normal dietary intake. This can occur acutely such as in an ultra-endurance event or chronically as in hard manual work in the hear. In such cases, additional Na+ in the form of a higher Na+ diet or adding Na+ to beverages used for fluid replacement may be warranted. A higher Na+ diet also appears to accelerate the cardiovascular and thermoregulatory adaptations that accompany heat acclimation or short term exercise training. Saline ingestion before exercise causes an expansion of plasma volume at rest and throughout the subsequent exercise bout. This expansion of plasma volume alters cardiovascular and thermoregulatory responses to exercise in ways that may lead to beneficial changes in endurance exercise performance. Plasma volume expansion also occurs with saline infusion during exercise, but exercise performance advantages have yet to be reported. The purpose of this article is to review the literature concerning dietary sodium and its influence on fluid balance, plasma volume and thermoregulation during exercise. It contains 2 major sections. First, we will discuss manipulations in daily Na+ intake initiated before or throughout an exercise regime. Second, we will examine studies where an acute Na+ load was administered immediately before or during an exercise trial. The dependent variables that we will discuss pertain to: (i) body water compartments, i.e. plasma volume; (ii) thermoregulatory variables, i.e. core temperature and sweat rate; (iii) cardiovascular variables, i.e. heart rate and stroke volume; and (iv) performance, i.e. time trial performance and time to exhaustion. Particular attention will be given to the route by which Na+ was administered, the environmental conditions, the level of acclimation of the participants and specifics relating to Na+ administration such as the osmolality of the Na(+)-containing beverage.

Dynamics of the spatial electron density distribution of EUV-induced plasmas

NASA Astrophysics Data System (ADS)

van der Horst, R. M.; Beckers, J.; Osorio, E. A.; Banine, V. Y.

2015-11-01

We studied the temporal evolution of the electron density distribution in a low pressure pulsed plasma induced by high energy extreme ultraviolet (EUV) photons using microwave cavity resonance spectroscopy (MCRS). In principle, MCRS only provides space averaged information about the electron density. However, we demonstrate here the possibility to obtain spatial information by combining multiple resonant modes. It is shown that EUV-induced plasmas, albeit being a rather exotic plasma, can be explained by known plasma physical laws and processes. Two stages of plasma behaviour are observed: first the electron density distribution contracts, after which it expands. It is shown that the contraction is due to cooling of the electrons. The moment when the density distribution starts to expand is related to the inertia of the ions. After tens of microseconds, the electrons reached the wall of the cavity. The speed of this expansion is dependent on the gas pressure and can be divided into two regimes. It is shown that the acoustic dominated regime the expansion speed is independent of the gas pressure and that in the diffusion dominated regime the expansion depends reciprocal on the gas pressure.

Plasma waves associated with the AMPTE artificial comet

NASA Technical Reports Server (NTRS)

Gurnett, D. A.; Anderson, R. R.; Haeusler, B.; Haerendel, G.; Bauer, O. H.

1985-01-01

Numerous plasma wave effects were detected by the AMPTE/IRM spacecraft during the artificial comet experiment on December 27, 1984. As the barium ion cloud produced by the explosion expanded over the spacecraft, emissions at the electron plasma frequency and ion plasma frequency provided a determination of the local electron density. The electron density in the diamagnetic cavity produced by the ion cloud reached a peak of more than 5 x 10 to the 5th per cu cm, then decayed smoothly as the cloud expanded, varying approximately as t exp-2. As the cloud began to move due to interactions with the solar wind, a region of compressed plasma was encountered on the upstream side of the diamagnetic cavity. The peak electron density in the compression region was about 1.5 x 10 to the 4th per cu cm. Later, a very intense (140 mVolt/m) broadband burst of electrostatic noise was encountered on the sunward side of the compression region. This noise has characteristics very similar to noise observed in the earth's bow shock, and is believed to be a shocklike interaction produced by an ion beam-plasma instability between the nearly stationary barium ions and the streaming solar wind protons.

Effects of 30 day simulated microgravity and recovery on fluid homeostasis and renal function in the rat

NASA Technical Reports Server (NTRS)

Tucker, Bryan J.; Mendonca, Margarida M.

1995-01-01

Transition from a normal gravitational environment to that of microgravity eventually results in decreased plasma and blood volumes, increasing with duration of exposure to microgravity. This loss of vascular fluid is presumably due to negative fluid and electrolyte balance and most likely contributes to the orthostatic intolerance associated with the return to gravity. The decrease in plasma volume is presumed to be a reflection of a concurrent decrease in extracellular fluid volume with maintenance of normal plasma-interstitial fluid balance. In addition, the specific alterations in renal function contributing to these changes in fluid and electrolyte homeostasis are potentially responding to neuro-humoral signals that are not consistent with systemic fluid volume status. We have previously demonstrated an early increase in both glomerular filtration rate and extracellular fluid volume and that this decreases towards control values by 7 days of simulated microgravity. However, longer duration studies relating these changes to plasma volume alterations and the response to return to orthostasis have not been fully addressed. Male Wistar rats were chronically cannulated, submitted to 30 days heat-down tilt (HDT) and followed for 7 days after return to orthostasis from HDT. Measurements of renal function and extracellular and blood volumes were performed in the awake rat.

Body Fluid Regulation and Hemopoiesis in Space Flight

NASA Technical Reports Server (NTRS)

1997-01-01

In this session, Session JA2, the discussion focuses on the following topics: Bodymass and Fluid Distribution During Longterm Spaceflight with and without Countermeasures; Plasma Volume, Extracellular Fluid Volume, and Regulatory Hormones During Long-Term Space Flight; Effect of Microgravity and its Ground-Based Models on Fluid Volumes and Hemocirculatory Volumes; Seventeen Weeks of Horizontal Bed Rest, Lower Body Negative Pressure Testing, and the Associated Plasma Volume Response; Evaporative Waterloss in Space Theoretical and Experimental Studies; Erythropoietin Under Real and Simulated Micro-G Conditions in Humans; and Vertebral Bone Marrow Changes Following Space Flight.

Fludrocortisone does not prevent orthostatic hypotension in astronauts after spaceflight.

PubMed

Shi, Shang-Jin; South, Donna A; Meck, Janice V

2004-03-01

During stand/tilt tests after spaceflight, 20% of astronauts experience orthostatic hypotension and presyncope. Spaceflight-induced hypovolemia is a contributing factor. Fludrocortisone, a synthetic mineralocorticoid, has been shown to increase plasma volume and orthostatic tolerance in Earth-bound patients. The efficacy of fludrocortisone as a treatment for postflight hypovolemia and orthostatic hypotension in astronauts has not been studied. Our purpose was to test the hypothesis that astronauts who ingest fludrocortisone prior to landing would have less loss of plasma volume and greater orthostatic tolerance than astronauts who do not ingest fludrocortisone. There were 25 male astronauts who were randomized into 2 groups: placebo (n = 18) and fludrocortisone (n = 7), and participated in stand tests 10 d before launch and 2-4 h after landing. Subjects took either 0.3 mg fludrocortisone or placebo orally 7 h prior to landing. Supine plasma and red cell volumes, supine and standing HR, arterial pressure, aortic outflow, and plasma norepinephrine and epinephrine were measured. On landing day, 2 of 18 in the placebo group and 1 of 7 in the fludrocortisone group became presyncopal (chi2 = 0.015, p = 0.90). Plasma volumes were significantly decreased after flight in the placebo group, but not in the fludrocortisone group. During postflight stand tests, standing plasma norepinephrine was significantly less in the fludrocortisone group compared with the placebo group. Treatment with a single dose of fludrocortisone results in protection of plasma volume but no protection of orthostatic tolerance. Fludrocortisone is not recommended as a countermeasure for spaceflight-induced orthostatic intolerance.

Intravascular volume in cirrhosis. Reassessment using improved methodology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rector, W.G. Jr.; Ibarra, F.

1988-04-01

Previous studies of blood volume (BV) in cirrhosis have either not adjusted BV properly for body size; determined plasma volume from the dilution of labeled albumin 10-20 min postinjection, when some extravascular redistribution has already occurred; and/or not used the correct whole body-peripheral hematocrit ratio (0.82) in calculating whole BV from plasma volume and the peripheral hematocrit. We measured BV with attention to these considerations in 19 patients with cirrhosis and reexamined the determinants of vascular volume and the relationship between vascular volume and sodium retention. BV was calculated as plasma volume (determined from extrapolated plasma activity of intravenously injectedmore » (/sup 131/I)+albumin at time 0) divided by (peripheral hematocrit X 0.82). The result was expressed per kilogram dry body weight, determined by subtracting the mass of ascites (measured by isotope dilution; 1 liter = 1 kg) from the actual body weight of nonedematous patients. Measured and expressed in this way, BV correlated strongly with esophageal variceal size (r = 0.87, P less than 0.05), although not with net portal, right atrial, inferior vena caval, or arterial pressure, and was significantly greater in patients with sodium retention as compared to patients without sodium retention. The principal modifier of vascular volume in cirrhosis is vascular capacity, which is probably mainly determined by the extent of the portasystemic collateral circulation. Increased vascular volume in patients with sodium retention as compared to patients without sodium retention supports the overflow theory of ascites formation.« less

Stability of stagnation via an expanding accretion shock wave

NASA Astrophysics Data System (ADS)

Velikovich, A. L.; Murakami, M.; Taylor, B. D.; Giuliani, J. L.; Zalesak, S. T.; Iwamoto, Y.

2016-05-01

Stagnation of a cold plasma streaming to the center or axis of symmetry via an expanding accretion shock wave is ubiquitous in inertial confinement fusion (ICF) and high-energy-density plasma physics, the examples ranging from plasma flows in x-ray-generating Z pinches [Maron et al., Phys. Rev. Lett. 111, 035001 (2013)] to the experiments in support of the recently suggested concept of impact ignition in ICF [Azechi et al., Phys. Rev. Lett. 102, 235002 (2009); Murakami et al., Nucl. Fusion 54, 054007 (2014)]. Some experimental evidence indicates that stagnation via an expanding shock wave is stable, but its stability has never been studied theoretically. We present such analysis for the stagnation that does not involve a rarefaction wave behind the expanding shock front and is described by the classic ideal-gas Noh solution in spherical and cylindrical geometry. In either case, the stagnated flow has been demonstrated to be stable, initial perturbations exhibiting a power-law, oscillatory or monotonic, decay with time for all the eigenmodes. This conclusion has been supported by our simulations done both on a Cartesian grid and on a curvilinear grid in spherical coordinates. Dispersion equation determining the eigenvalues of the problem and explicit formulas for the eigenfunction profiles corresponding to these eigenvalues are presented, making it possible to use the theory for hydrocode verification in two and three dimensions.

Stability of stagnation via an expanding accretion shock wave

DOE Office of Scientific and Technical Information (OSTI.GOV)

Velikovich, A. L.; Giuliani, J. L.; Murakami, M.

Stagnation of a cold plasma streaming to the center or axis of symmetry via an expanding accretion shock wave is ubiquitous in inertial confinement fusion (ICF) and high-energy-density plasma physics, the examples ranging from plasma flows in x-ray-generating Z pinches [Maron et al., Phys. Rev. Lett. 111, 035001 (2013)] to the experiments in support of the recently suggested concept of impact ignition in ICF [Azechi et al., Phys. Rev. Lett. 102, 235002 (2009); Murakami et al., Nucl. Fusion 54, 054007 (2014)]. Some experimental evidence indicates that stagnation via an expanding shock wave is stable, but its stability has never beenmore » studied theoretically. We present such analysis for the stagnation that does not involve a rarefaction wave behind the expanding shock front and is described by the classic ideal-gas Noh solution in spherical and cylindrical geometry. In either case, the stagnated flow has been demonstrated to be stable, initial perturbations exhibiting a power-law, oscillatory or monotonic, decay with time for all the eigenmodes. This conclusion has been supported by our simulations done both on a Cartesian grid and on a curvilinear grid in spherical coordinates. Dispersion equation determining the eigenvalues of the problem and explicit formulas for the eigenfunction profiles corresponding to these eigenvalues are presented, making it possible to use the theory for hydrocode verification in two and three dimensions.« less

Orbital volume augmentation using expandable hydrogel implants in acquired anophthalmia and phthisis bulbi.

PubMed

Kim, Esther Lee; Bernardino, Carlo Rob; Levin, Flora

2016-01-01

The purpose of this study is to describe our experience using expandable spherical hydrogel implants and injectable hydrogel pellets for orbital volume augmentation in cases of post-enucleation socket syndrome after acquired anophthalmia or phthisis bulbi. We retrospectively reviewed the clinical records of all adult patients who received an expandable hydrogel implant for orbital volume loss following enucleation or phthisis bulbi at the Emory Eye Center between 2004 and January 2007 and the Yale Eye Center between 2009 and 2011. The study included 9 women and 5 men with a mean age of 51.2 years old (range 35-76 years old). Follow-up spanned 6 to 71 months (median of 18.5 months). Four patients received spherical hydrogel implants and 10 patients received hydrogel pellet injections. On average, nine pellets (range 5-16) were placed in each patient over an average of 1.7 injections (range 1-3). Most commonly, five pellets were injected per session, as was the case for 13 of the 17 treatment sessions. Post-operative complications included 2 cases of pellet migration, one subcutaneously and one anteriorly due to insufficiently posterior implant placement, and 1 hospital admission for pain after injection of 10 pellets in one visit. All patients experienced an overall subjective improvement in cosmesis. Self-expandable hydrogel implants appear to offer several advantages over other existing options for orbital volume augmentation, as they are easy to place, generally well-tolerated, volume-titratable, and to the extent that our follow-up shows, may be a safe and durable means of treating orbital volume loss in patients with acquired anophthalmia and phthisis bulbi.

Compact cell-centered discretization stencils at fine-coarse block structured grid interfaces

NASA Astrophysics Data System (ADS)

Pletzer, Alexander; Jamroz, Ben; Crockett, Robert; Sides, Scott

2014-03-01

Different strategies for coupling fine-coarse grid patches are explored in the context of the adaptive mesh refinement (AMR) method. We show that applying linear interpolation to fill in the fine grid ghost values can produce a finite volume stencil of comparable accuracy to quadratic interpolation provided the cell volumes are adjusted. The volume of fine cells expands whereas the volume of neighboring coarse cells contracts. The amount by which the cells contract/expand depends on whether the interface is a face, an edge, or a corner. It is shown that quadratic or better interpolation is required when the conductivity is spatially varying, anisotropic, the refinement ratio is other than two, or when the fine-coarse interface is concave.

Explosive Emission and Gap Closure from a Relativistic Electron Beam Diode

DTIC Science & Technology

2013-06-01

relationship, impedance and perveance curves, plasma expansion velocity, and the time-resolved light emission on the surface of the cathode. I...indicating a cathode plasma density ~1017 cm-3 that migrates into the gap at ~50 cm/µs and an anode plasma of lower density ~1012 cm-3 that expands axially... plasma to the gap closure velocity. Initial estimates indicate the closure velocity for this relativistic diode is ~ 10 cm/µs. These measurements

One-dimensional particle-in-cell simulation on the influence of electron and ion temperature on the sheath expansion process in the post-arc stage of vacuum circuit breaker

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mo, Yongpeng; Shi, Zongqian; Jia, Shenli

2015-02-15

The inter-contact region of vacuum circuit breakers is filled with residual plasma at the moment when the current is zero after the burning of metal vapor arc. The residual plasma forms an ion sheath in front of the post-arc cathode. The sheath then expands towards the post-arc anode under the influence of a transient recovery voltage. In this study, a one-dimensional particle-in-cell model is developed to investigate the post-arc sheath expansion. The influence of ion and electron temperatures on the decrease in local plasma density at the post-arc cathode side and post-arc anode side is discussed. When the decay inmore » the local plasma density develops from the cathode and anode sides into the high-density region and merges, the overall plasma density in the inter-contact region begins to decrease. Meanwhile, the ion sheath begins to expand faster. Furthermore, the theory of ion rarefaction wave only explains quantitatively the decrease in the overall plasma density at relatively low ion temperatures. With the increase of ion temperature to certain extent, another possible reason for the decrease in the overall plasma density is proposed and results from the more active thermal diffusion of plasma.« less

Evidence of Time-Of-Day Pricing In the United States. Volume 2, Appendices and Case Studies

DOT National Transportation Integrated Search

1984-05-01

This is the companion volume to the research report, Evidence on Time of Transit Pricing in the United States. This volume serves as an expanded appendix to the Volume 1 report, principally providing detailed case-by-case summaries on experiences wit...

Orbit Transfer Vehicle (OTV) advanced expander cycle engine point design study. Volume 1: Executive summary

NASA Technical Reports Server (NTRS)

1981-01-01

The objective of the study was to generate the system design of a performance-optimized, advanced LOX/hydrogen expander cycle space engine. The engine requirements are summarized, and the development and operational experience with the expander cycle RL10 engine were reviewed. The engine development program is outlined.

Solar-Wind Observations of Collisional Thermalization among Multiple Ion-Species

NASA Astrophysics Data System (ADS)

Maruca, B.; Qudzi, R.; Hellinger, P.; Stevens, M. L.; Kasper, J. C.; Korreck, K. E.

2017-12-01

The rate of Coulomb collisions among ions in the solar wind is low enough that significant departures from thermal equilibrium (e.g., different ion species having different temperatures) are frequently observed. Nevertheless, collisions have been found to play an important role in the plasma's large-scale evolution as it expands from the corona and through the heliosphere. Many statistical analyses have found that the temperature ratio of the two most abundant ions, protons (ionized hydrogen) and alpha-particles (fully ionized helium), is heavily influenced by collisional thermalization. This ongoing study expands on this work by including oxygen +6, which, during select periods (of cold, slow, dense plasma), the Wind spacecraft's Faraday Cups can measure at high cadences. Using well-established models of collisional relaxation, the in-situ measurements at 1 AU can be used to estimate ion conditions earlier in the plasma's expansion history. Assessing the physicality of these predictions can indicate to what degree preferential heating and/or heating beyond the corona affected the plasma's evolution.

Optimization of microwave-assisted extraction of analgesic and anti-inflammatory drugs from human plasma and urine using response surface experimental designs.

PubMed

Fernández, Purificación; Fernández, Ana M; Bermejo, Ana M; Lorenzo, Rosa A; Carro, Antonia M

2013-04-01

The performance of microwave-assisted extraction and HPLC with photodiode array detection method for determination of six analgesic and anti-inflammatory drugs from plasma and urine, is described, optimized, and validated. Several parameters affecting the extraction technique were optimized using experimental designs. A four-factor (temperature, phosphate buffer pH 4.0 volume, extraction solvent volume, and time) hybrid experimental design was used for extraction optimization in plasma, and three-factor (temperature, extraction solvent volume, and time) Doehlert design was chosen to extraction optimization in urine. The use of desirability functions revealed the optimal extraction conditions as follows: 67°C, 4 mL phosphate buffer pH 4.0, 12 mL of ethyl acetate and 9 min, for plasma and the same volume of buffer and ethyl acetate, 115°C and 4 min for urine. Limits of detection ranged from 4 to 45 ng/mL in plasma and from 8 to 85 ng/mL in urine. The reproducibility evaluated at two concentration levels was less than 6.5% for both specimens. The recoveries were from 89 to 99% for plasma and from 83 to 99% for urine. The proposed method was successfully applied in plasma and urine samples obtained from analgesic users. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Blood Volume of the Guinea Pig: Effects of Epinephrine and Isoproterenol upon the Red Cell and Plasma Volumes, Heart Rate, and Mean Arterial Pressure,

DTIC Science & Technology

1987-09-01

capillaries (4), blood volumes calculated from plasma volume measures must correct for label that has left the system between the time of the injected dose...Splenic sequestration and contraction are mediated by the autonomic nervous system and blood-borne agents (10). Sympathetic nerve fibers from the truncus...sympathlcus and parasympathetic neurons of the nervus vagus (cranial nerve X) innervate the celiac plexus (8, 11). A subdivision of the celiac plexus

Cytokine signalling in rat pulp interstitial fluid and transcapillary fluid exchange during lipopolysaccharide-induced acute inflammation

PubMed Central

Bletsa, Athanasia; Berggreen, Ellen; Fristad, Inge; Tenstad, Olav; Wiig, Helge

2006-01-01

The dental pulp consists of loose connective tissue encased in rigid dentinal walls. Because of its topography the tissue has low interstitial compliance and limited capacity to expand during fluid volume changes. Due to limitations regarding access to interstitial fluid, basic knowledge on transcapillary fluid transport parameters is lacking for this organ. The scope of this project was dual: first we aimed at establishing a method for isolation of pulp interstitial fluid (IF), and second we applied the method in rats subjected to lipopolysaccharide (LPS)-induced endotoxaemia. The aim was to measure colloid osmotic pressure (COP) and pro-inflammatory cytokines in the pulp IF during acute inflammation. Fluid volumes and pulpal blood flow (PBF) were measured to obtain more information about microcirculatory changes that take place in this pulpitis model. By centrifugation of incisor pulp at 239 g we were able to extract fluid representative for IF. Pulp IF had a relative high control COP (∼83% of plasma COP) and was similar to plasma COP 3 h after LPS challenge. The pulp exhibited a high content of IF (0.60 ± 0.03 ml (g wet weight)−1) and a vascular volume of 0.03 ± 0.01 ml (g w.w.)−1 No differences were observed in the distribution of fluid volumes after 1.5 and 3 h LPS exposure. PBF and systemic blood pressure dropped significantly after LPS administration. PBF remained low whereas systemic blood pressure was re-established during the 3-h period, implying organ dysfunction. There was a differential pattern of cytokine expression in pulp IF and serum with cytokines such as IL-1α, IL-1β and TNF-α locally produced, whereas others such as IFN-γ and IL-6 were produced systemically and probably spilled over to the pulp IF after LPS exposure. Our findings show that pulp IF can be isolated by centrifugation and that this method is useful when studying fluid balance and extracellular signalling mechanisms in the dental pulp in normal and pathological conditions. PMID:16527857

Mucosal Perfusion Preservation by a Novel Shapeable Tissue Expander for Oral Reconstruction

PubMed Central

Barwinska, Daria; Garner, John; Davidson, Darrell D.; Cook, Todd G.; Eckert, George J.; Tholpady, Sunil S.; March, Keith L.; Park, Kinam

2017-01-01

Background: There are few methods for expanding oral mucosa, and these often cause complications such as tissue necrosis and expander eruption. This study examines mucosal blood perfusion following insertion of a novel shapeable hydrogel tissue expander (HTE). The canine model used subgingival insertion of HTE following tooth extraction and alveolar bone reduction. The primary goal of this study was to gain understanding of epithelial perfusion and reparative responses of gingival mucosa during HTE expansion. Methods: Nine Beagle dogs underwent bilateral premolar maxillary and mandibular tooth extraction. Three to four months later, HTE-contoured inserts were implanted submucosally under the buccal surface of the alveolar ridge. After removal and following a 6- to 7-month period of healing, new HTE implants were inserted at the same sites. The area was assessed weekly for tissue perfusion and volume of expansion. Biopsies for histological analysis were performed at the time of expander removal. Results: Within 2 weeks following the second insertion, blood flow returned to baseline (defined as the values of perfusion measurements at the presurgery assessment) and remained normal until hydrogel full expansion and removal. Volume expansion analysis revealed that the hydrogel doubled in volume. Histological assessment showed no macrophage or inflammatory infiltration of the mucosa. No superficial fibrosis, decreased vascularity, or mucosal change was seen. Conclusion: Maintenance of adequate tissue perfusion is a clinically important aspect of tissue expander performance to reduce risk of device loss or injury to the patient, particularly for areas with a history of previous surgeries. PMID:28894668

Influence of Crystal Expansion/Contraction on Zeolite Membrane Permeation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sorenson, Stephanie G; Payzant, E Andrew; Noble, Richard D

X-ray diffraction was used to measure the unit cell parameters of B-ZSM-5, SAPO-34, and NaA zeolite powders as a function of adsorbate loading at 303 K, and in one case, at elevated temperatures. Most adsorbates expanded the zeolite crystals below saturation loading at 303 K: n-hexane and SF6 in B-ZSM-5, methanol and CO2 in SAPO-34, and methanol in NaA zeolite. As the loadings increased, the crystals expanded more. Changes in the unit cell volumes of B-ZSM-5 and SAPO-34 zeolite powders correlated with changes in permeation through zeolite membranes defects. When the zeolite crystals expanded or contracted upon adsorption, the defectmore » sizes decreased or increased. In B-ZSM-5 membranes, the fluxes through defects decreased dramatically when n-hexane or SF6 adsorbed. In contrast, i-butane adsorption at 303 K contracted B-ZSM-5 crystals at low loadings and expanded them at higher loadings. Correspondingly, the flux through B-ZSM-5 membrane defects increased at low i-butane loadings and decreased at high loading because the defects increased in size at low loading and decreased at high loadings. At 398 K and 473 K, n-hexane expanded the B-ZSM-5 unit cell more as the temperature increased from 303 to 473 K. The silicalite-1 and B-ZSM-5 unit cell volumes expanded similarly upon n-hexane adsorption at 303 K; boron substitution had little effect on volume expansion.« less

Renal uptake of radiolabeled octreotide in human subjects is efficiently inhibited by succinylated gelatin.

PubMed

Vegt, Erik; Wetzels, Jack F M; Russel, Frans G M; Masereeuw, Rosalinde; Boerman, Otto C; van Eerd, Juliette E; Corstens, Frans H M; Oyen, Wim J G

2006-03-01

Peptide receptor-mediated radiotherapy of neuroendocrine and other somatostatin receptor-positive tumors with radiolabeled somatostatin analogs has been applied in several experimental settings. The kidneys are the organs responsible for dose-limiting toxicity attributable to the retention of radiolabeled octreotide in the renal cortex, leading to a relatively high radiation dose that may result in irreversible loss of kidney function. The administration of basic amino acids reduces renal uptake but does have significant side effects. We observed that gelatin-based plasma expanders induced tubular low-molecular-weight proteinuria in healthy volunteers, suggesting that components in these solutions can interfere with the tubular reabsorption of proteins and peptides. Here, we studied the effects of infusion of low doses of the plasma expander succinylated gelatin (GELO) on the renal uptake of 111In-labeled octreotide (111In-OCT). Five healthy volunteers were given 111In-OCT, first in combination with normal saline and 2 wk later in combination with GELO. Scintigraphic images of the kidneys as well as blood and urine samples were analyzed. To exclude a nonspecific hemodynamic effect of the plasma expander, the procedure was repeated with 5 other volunteers who received the carbohydrate-based plasma expander hydroxyethyl starch (HES). Low doses of GELO were able to effectively reduce the kidney retention of 111In-OCT. The renal radiation dose was significantly reduced by 45% +/- 10% (mean +/- SD) (P = 0.006), whereas HES showed no significant effect (0% +/- 12%). The infusion of GELO did not cause any side effects. GELO effectively reduces the renal uptake of 111In-OCT. In contrast to currently used mixtures of amino acids, GELO does not cause any side effects.

Endocrine considerations in the red-cell-mass and plasma volume changes of the Skylab 2 and 3 crews

NASA Technical Reports Server (NTRS)

Johnson, P. C.; Leach, C. S.; Driscoll, T.

1975-01-01

The effect of unknown endocrine changes on blood volume of crewmembers was investigated. The results are presented in tabular form. The fact that some of the changes were in the wrong direction suggests that changes in endocrine function were not the primary cause of the decreases in the plasma volume and red cell mass.

Tissue regeneration during tissue expansion and choosing an expander

PubMed Central

Agrawal, K.; Agrawal, S.

2012-01-01

This paper reviews the various aspects of tissue regeneration during the process of tissue expansion. “Creep” and mechanical and biological “stretch” are responsible for expansion. During expansion, the epidermis thickens, the dermis thins out, vascularity improves, significant angiogenesis occurs, hair telogen phase becomes shorter and the peripheral nerves, vessels and muscle fibres lengthen. Expansion is associated with molecular changes in the tissue. Almost all these biological changes are reversible after the removal of the expander.This study is also aimed at reviewing the difficulty in deciding the volume and dimension of the expander for a defect. Basic mathematical formulae and the computer programmes for calculating the dimension of tissue expanders, although available in the literature, are not popular. A user-friendly computer programme based on the easily available Microsoft Excel spread sheet has been introduced. When we feed the area of defect and base dimension of the donor area or tissue expander, this programme calculates the volume and height of the expander. The shape of the expander is decided clinically based on the availability of the donor area and the designing of the future tissue movement. Today, tissue expansion is better understood biologically and mechanically. Clinical judgement remains indispensable in choosing the size and shape of the tissue expander. PMID:22754146

Highly intensified emission of laser-accelerated electrons from a foil target through an additional rear laser plasma

NASA Astrophysics Data System (ADS)

Inoue, Shunsuke; Nakamiya, Yoshihide; Teramoto, Kensuke; Hashida, Masaki; Sakabe, Shuji

2018-04-01

Intensification of electrons escaping from an intense laser-produced plasma is demonstrated by using double femtosecond laser pulses. The electron density distribution at the rear surface of a laser-irradiated foil target is controlled by preirradiation to suppress sheath field growth and to expand the plasma into which the fast electrons are released. Consequently, the number of electrons escaping from the plasma that have an energy of 380 keV increases by a factor of 7. The experimental results are well explained by numerical simulations of a foil plasma with a preformed plasma and analytical evaluations considering the plasma expansion.

Numerical Analysis of Plasma Transport in Tandem Volume Magnetic Multicusp Ion Sources

DTIC Science & Technology

1992-03-01

the results of the model are qualitatively correct. Boltzmann Equation, Ion Sources, Plasma Simulation, Electron Temperature, Plasma Density, Ion Temperature, Hydrogen Ions, Magnetic Filters, Hydrogen Plasma Chemistry .

Maternal nutritional status in early pregnancy is associated with body water and plasma volume changes in a pregnancy cohort in rural Bangladesh.

PubMed

Gernand, Alison D; Christian, Parul; Schulze, Kerry J; Shaikh, Saijuddin; Labrique, Alain B; Shamim, Abu Ahmed; West, Keith P

2012-06-01

Plasma volume expansion has been associated with fetal growth. Our objective was to examine the associations between maternal nutritional status in early pregnancy and extracellular water (ECW), total body water (TBW), and percentage plasma volume change across pregnancy. In a subsample of 377 pregnant women participating in a cluster-randomized trial of micronutrient supplementation, hemoglobin, hematocrit, and multi-frequency bioelectrical impedance were measured at ~10, 20, and 32 wk of gestation. In early pregnancy, women were short (mean ± SD, 148.9 ± 5.3 cm) and thin (19.5 ± 2.5 kg/m(2)). In mixed-effects multiple regression models, a 1-unit higher BMI at ~10 wk was associated with higher ECW and TBW (0.27 and 0.66 kg per kg/m(2), respectively; P < 0.01) at ~10, ~20, and ~32 wk. Height was also positively associated with ECW and TBW at each time point. Early pregnancy BMI was negatively associated with gains in ECW and TBW (-0.06 and -0.14 kg per kg/m(2), respectively; P < 0.01) from 10 to 20 wk, but not with 20- to 32-wk gains after accounting for weight gain. BMI was positively associated with percentage changes in plasma volume from 20 to 32 wk (0.57% per kg/m(2); P < 0.05). Height was not associated with changes in body water or plasma volume. Women with low BMI and height in early pregnancy have lower ECW and TBW in early, mid, and late pregnancy and lower late pregnancy plasma volume expansion, potentially increasing risk of fetal growth restriction.

Regional Hippocampal Atrophy and Higher Levels of Plasma Amyloid-Beta Are Associated With Subjective Memory Complaints in Nondemented Elderly Subjects.

PubMed

Cantero, Jose L; Iglesias, Juan E; Van Leemput, Koen; Atienza, Mercedes

2016-09-01

Evidence suggests a link between the presence of subjective memory complaints (SMC) and lower volume of the hippocampus, one of the first regions to show neuropathological lesions in Alzheimer's disease. However, it remains unknown whether this pattern of hippocampal atrophy is regionally specific and whether SMC are also paralleled by changes in peripheral levels of amyloid-beta (Aβ). The volume of hippocampal subregions and plasma Aβ levels were cross-sectionally compared between elderly individuals with (SMC(+); N = 47) and without SMC (SMC(-); N = 48). Significant volume differences in hippocampal subregions were further correlated with plasma Aβ levels and with objective memory performance. Individuals with SMC exhibited significantly higher Aβ1-42 concentrations and lower volumes of CA1, CA4, dentate gyrus, and molecular layer compared with SMC(-) participants. Regression analyses further showed significant associations between lower volume of the dentate gyrus and both poorer memory performance and higher plasma Aβ1-42 levels in SMC(+) participants. The presence of SMC, lower volumes of specific hippocampal regions, and higher plasma Aβ1-42 levels could be conditions associated with aging vulnerability. If such associations are confirmed in longitudinal studies, the combination may be markers recommending clinical follow-up in nondemented older adults. © The Author 2016. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Evolution of turbulence in the expanding solar wind, a numerical study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dong, Yue; Grappin, Roland; Verdini, Andrea, E-mail: Yue.Dong@lpp.polytechnique.fr, E-mail: verdini@arcetri.astro.it, E-mail: grappin@lpp.polytechnique.fr

2014-10-01

We study the evolution of turbulence in the solar wind by solving numerically the full three-dimensional (3D) magnetohydrodynamic (MHD) equations embedded in a radial mean wind. The corresponding equations (expanding box model or EBM) have been considered earlier but never integrated in 3D simulations. Here, we follow the development of turbulence from 0.2 AU up to about 1.5 AU. Starting with isotropic spectra scaling as k {sup –1}, we observe a steepening toward a k {sup –5/3} scaling in the middle of the wave number range and formation of spectral anisotropies. The advection of a plasma volume by the expandingmore » solar wind causes a non-trivial stretching of the volume in directions transverse to radial and the selective decay of the components of velocity and magnetic fluctuations. These two effects combine to yield the following results. (1) Spectral anisotropy: gyrotropy is broken, and the radial wave vectors have most of the power. (2) Coherent structures: radial streams emerge that resemble the observed microjets. (3) Energy spectra per component: they show an ordering in good agreement with the one observed in the solar wind at 1 AU. The latter point includes a global dominance of the magnetic energy over kinetic energy in the inertial and f {sup –1} range and a dominance of the perpendicular-to-the-radial components over the radial components in the inertial range. We conclude that many of the above properties are the result of evolution during transport in the heliosphere, and not just the remnant of the initial turbulence close to the Sun.« less

Changes in renal function and fluid and electrolyte regulation in space flight

NASA Technical Reports Server (NTRS)

Leach, C. S.

1992-01-01

The cephalad fluid redistribution resulting from weightlessness has a number of physiologic consequences. Plasma volume is reduced soon after weightlessness is reached, and red blood cell mass reduction follows. Plasma atrial natriuretic peptide, which inhibits aldosterone secretion, was elevated during space flight while plasma aldosterone was below preflight levels. Serum sodium was also reduced and potassium was elevated. Antidiuretic hormone (ADH) was markedly elevated at almost all measurement times in the first eight days of flight, but plasma volume did not return to preflight levels.

Hypervolemia and plasma vasopressin response during water immersion in men

NASA Technical Reports Server (NTRS)

Greenleaf, J. E.; Morse, J. T.; Barnes, P. R.; Silver, J.; Keil, L. C.

1983-01-01

Immersion studies were performed on seven mildly dehydrated male subjects to examine the effect of suppression of plasma vasopressin (PVP) on diuresis in water immersion. The water was kept at close to 34.5 C and the subjects remained in the water for 4 hr after sitting for 2 hr. Na and K levels in the serum and urine were analyzed, as were osmolality, red blood cell count, renin activity, total protein, albumin amounts, hematocrit, and hemoglobin. Plasma volume was monitored from samples drawn at specified intervals during immersion. The plasma volume increased significantly 30 min after immersion, but no PVP was observed. The dehydration induced elevated serum osmotic concentrations. It is concluded that the hydration condition before immersion and the volume of fluid intake during immersion affects the hemodilution during immersion.

A High-Efficiency Superhydrophobic Plasma Separator

PubMed Central

Liu, Changchun; Liao, Shih-Chuan; Song, Jinzhao; Mauk, Michael G.; Li, Xuanwen; Wu, Gaoxiang; Ge, Dengteng; Greenberg, Robert M.; Yang, Shu; Bau, Haim H.

2016-01-01

To meet stringent limit-of-detection specifications for low abundance target molecules, a relatively large volume of plasma is needed for many blood-based clinical diagnostics. Conventional centrifugation methods for plasma separation are not suitable for on-site testing or bedside diagnostics. Here, we report a simple, yet high-efficiency, clamshell-style, superhydrophobic plasma separator that is capable of separating a relatively large volume of plasma from several hundred microliters of whole blood (finger-prick blood volume). The plasma separator consists of a superhydrophobic top cover with a separation membrane and a superhydrophobic bottom substrate. Unlike previously reported membrane-based plasma separators, the separation membrane in our device is positioned at the top of the sandwiched whole blood film to increase the membrane separation capacity and plasma yield. In addition, the device’s superhydrophobic characteristics (i) facilitates the formation of well-defined, contracted, thin blood film with a high contact angle; (ii) minimizes biomolecular adhesion to surfaces; (iii) increases blood clotting time; and (iv) reduces blood cell hemolysis. The device demonstrated a “blood in-plasma out” capability, consistently extracting 65±21.5 μL of plasma from 200 μL of whole blood in less than 10 min without electrical power. The device was used to separate plasma from Schistosoma mansoni genomic DNA-spiked whole blood with a recovery efficiency of > 84.5 ± 25.8 %. The S. mansoni genomic DNA in the separated plasma was successfully tested on our custom-made microfluidic chip by using loop mediated isothermal amplification (LAMP) method. PMID:26732765

Method of processing materials using an inductively coupled plasma

DOEpatents

Hull, D.E.; Bieniewski, T.M.

1987-04-13

A method of processing materials. The invention enables ultrafine, ultrapure powders to be formed from solid ingots in a gas free environment. A plasma is formed directly from an ingot which insures purity. The vaporized material is expanded through a nozzle and the resultant powder settles on a cold surface. An inductively coupled plasma may also be used to process waste chemicals. Noxious chemicals are directed through a series of plasma tubes, breaking molecular bonds and resulting in relatively harmless atomic constituents. 3 figs.

EFFECTS OF LASER RADIATION ON MATTER. LASER PLASMA: Formation of amplified spontaneous radiation in an expanding laser plasma allowing for refraction

NASA Astrophysics Data System (ADS)

Gulov, A. V.; Derzhiev, V. I.; Zhidkov, A. G.; Terskikh, A. O.; Yakovlenko, Sergei I.

1990-06-01

Calculations are made of the divergence of amplified spontaneous radiation in a laser plasma allowing for refraction by free electrons. An analysis is made of the divergence of the radiation generated due to a 3p→3s' transition in neon-like ions. Calculations are made of the divergence of the radiation due to the 4→3 transition in the O VIII ion allowing for refraction during expansion of a Formvar plasma.

Elevated central venous pressure: A consequence of exercise training-induced hypervolemia

NASA Technical Reports Server (NTRS)

Convertino, Victor A.; Mack, Gary W.; Nadel, Ethan R.

1990-01-01

Resting plasma volumes, and arterial and central venous pressures (CVP) were measured in 16 men before and after exercise training to determine if training-induced hypervolemia could be explained by a change in total vascular capacitance. In addition, resting levels of plasma vasopressin (AVP), atrial natriuretic peptide (ANP), aldosterone (ALD), and norepinephrine (NE) were measured before and after training. The same measurements of vacular volume, pressures, and plasma hormones were measured in 8 subjects who did not undergo exercise and acted as controls. The exercise training program consisted of 10 weeks of controlled cycle exercise for 30 min/d, 4 d/wk at 75 to 80 percent of maximal oxygen uptake (VO2max). A training effect was verified by a 20 percent increase in VO2max, a resting bradycardia, and a 370 ml (9 percent) increase in blood volume. Mean arterial blood pressure was unaltered by exercise training, but resting CVP increased. The percent change in blood volume from before to after training was linearly related to the percent change in CVP. As a consequence of elevations in both blood volume and CVP, the volume-to-pressure ratio was essentially unchanged following exercise training. Plasma AVP, ANP, ALD, and NE were unaltered. Results indicate that elevated CVP is a consequence of training-induced hypervolemia without alteration in total effective venous capacitance. This may represent a resetting of the pressure-volume stimulus-response relation for regulation of blood volume.

Right heart overload contributes to cardiac natriuretic hormone elevation in patients with heart failure.

PubMed

Passino, Claudio; Maria Sironi, Anna; Favilli, Brunella; Poletti, Roberta; Prontera, Concetta; Ripoli, Andrea; Lombardi, Massimo; Emdin, Michele

2005-09-15

Atrial and brain natriuretic peptides (ANP and BNP) plasma concentration increases and holds a prognostic significance in patients with left ventricular dysfunction. We assessed the hypothesis that right ventricular (RV) overload might significantly contribute to plasma elevation of cardiac natriuretic hormones in patients with heart failure. Forty-one patients with cardiomyopathy and depressed left ventricular (LV) function (ejection fraction, EF, <40%), underwent cardiac magnetic resonance imaging (MRI) and resting plasma determination of ANP and BNP. Nineteen healthy subjects were also studied as control group. Ventricular volumes and function were assessed by MRI. In the group of patients, LVEF was 22.6+/-1.2% (controls: 61.2+/-1.3%, P<0.001, mean+/-S.E.M.), while RVEF was 48.2+/-2.5% (controls: 66.7+/-1.6%, P<0.001); LV and RV end diastolic/systolic volumes, corrected by body surface area, were 143+/-7/114+/-7 ml/m2 (controls 70+/-3/27+/-2 ml/m2, both P<0.001) and 66+/-3/37+/-4 ml/m2 (controls: 63+/-4/21+/-2 ml/m2, P<0.01 only for end-systolic volume). BNP plasma value was on average 324+/-39 pg/ml (range: 23-1280, controls 10+/-2 pg/ml), ANP value was 144+/-17 pg/ml (range: 26-534, controls 15+/-1 pg/ml). BNP positively correlated with either end-diastolic or end-systolic RV volume in patients, less with LV systolic, and not with LV diastolic volume. Moreover, a significant negative correlation was observed between BNP and either LVEF or RVEF. Conversely, ANP showed a significant correlation only with end-systolic RV volume and with both RVEF and LVEF. When multivariate stepwise linear regression analysis was applied LVEF resulted the only independent predictor for ANP plasma values (R=0.591, P<0.001), while LVEF and RV end-diastolic volume for BNP (R=0.881, P<0.001, and R=0.881, P=0.035, respectively). Right heart overload contributes independently to plasma elevation of natriuretic peptides. RV involvement, which is known to independently worsen prognosis in patients with cardiomyopathy, might contribute to their established prognostic power, inducing compensatory secretion of plasma cardiac natriuretic hormones.

Adiabatic Expansion of Electron Gas in a Magnetic Nozzle.

PubMed

Takahashi, Kazunori; Charles, Christine; Boswell, Rod; Ando, Akira

2018-01-26

A specially constructed experiment shows the near perfect adiabatic expansion of an ideal electron gas resulting in a polytropic index greater than 1.4, approaching the adiabatic value of 5/3, when removing electric fields from the system, while the polytropic index close to unity is observed when the electrons are trapped by the electric fields. The measurements were made on collisionless electrons in an argon plasma expanding in a magnetic nozzle. The collision lengths of all electron collision processes are greater than the scale length of the expansion, meaning the system cannot be in thermodynamic equilibrium, yet thermodynamic concepts can be used, with caution, in explaining the results. In particular, a Lorentz force, created by inhomogeneities in the radial plasma density, does work on the expanding magnetic field, reducing the internal energy of the electron gas that behaves as an adiabatically expanding ideal gas.

Adiabatic Expansion of Electron Gas in a Magnetic Nozzle

NASA Astrophysics Data System (ADS)

Takahashi, Kazunori; Charles, Christine; Boswell, Rod; Ando, Akira

2018-01-01

A specially constructed experiment shows the near perfect adiabatic expansion of an ideal electron gas resulting in a polytropic index greater than 1.4, approaching the adiabatic value of 5 /3 , when removing electric fields from the system, while the polytropic index close to unity is observed when the electrons are trapped by the electric fields. The measurements were made on collisionless electrons in an argon plasma expanding in a magnetic nozzle. The collision lengths of all electron collision processes are greater than the scale length of the expansion, meaning the system cannot be in thermodynamic equilibrium, yet thermodynamic concepts can be used, with caution, in explaining the results. In particular, a Lorentz force, created by inhomogeneities in the radial plasma density, does work on the expanding magnetic field, reducing the internal energy of the electron gas that behaves as an adiabatically expanding ideal gas.

Structural Evaluation of Radially Expandable Cardiovascular Stents Encased in a Polyurethane Film

NASA Technical Reports Server (NTRS)

Trigwell, Steve; De, Samiran; Sharma, Rajesh; Mazumder, Malay K.; Mehta, Jawahar L.

2004-01-01

A method of encasing cardiovascular stents with an expandable polyurethane coating has been developed to provide a smooth homogeneous inner wall allowing for a confluent growth of endothelial cells. In this design, the metal wire stent structure is completely covered by the polyurethane film minimizing biocorrosion of the metal (stainless steel or nitinol), and providing a homogeneous surface for surface treatment and incorporation of various eluting drugs to prevent platelet aggregation while supporting endothelialization. The polyurethane surface was treated with a helium plasma for sterilization and promotes growth of cells. The paper details the performance of the coated film to expand with the metal stent up to 225 % during deployment. We present stress/strain behavior of polyurethane films, and subsequent plasma treatment of the surface and the adhesion of the coating to the stent structure upon expansion. A film of less than 25 tm was found to be sufficient for corrosion resistance and flexibility without producing any excess stress on the stent structure. Straining the film to 225 % and plasma modification did not affect the mechanical and surface properties while allowing for improved biocompatibility as determined by the critical surface tension, surface chemistry, and roughness.

PLASMA TURBULENCE AND KINETIC INSTABILITIES AT ION SCALES IN THE EXPANDING SOLAR WIND

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hellinger, Petr; Trávnícek, Pavel M.; Matteini, Lorenzo

The relationship between a decaying strong turbulence and kinetic instabilities in a slowly expanding plasma is investigated using two-dimensional (2D) hybrid expanding box simulations. We impose an initial ambient magnetic field perpendicular to the simulation box, and we start with a spectrum of large-scale, linearly polarized, random-phase Alfvénic fluctuations that have energy equipartition between kinetic and magnetic fluctuations and vanishing correlation between the two fields. A turbulent cascade rapidly develops; magnetic field fluctuations exhibit a power-law spectrum at large scales and a steeper spectrum at ion scales. The turbulent cascade leads to an overall anisotropic proton heating, protons are heatedmore » in the perpendicular direction, and, initially, also in the parallel direction. The imposed expansion leads to generation of a large parallel proton temperature anisotropy which is at later stages partly reduced by turbulence. The turbulent heating is not sufficient to overcome the expansion-driven perpendicular cooling and the system eventually drives the oblique firehose instability in a form of localized nonlinear wave packets which efficiently reduce the parallel temperature anisotropy. This work demonstrates that kinetic instabilities may coexist with strong plasma turbulence even in a constrained 2D regime.« less

COMPARATIVE DETERMINATION OF BLOOD VOLUME WITH EVANS BLUE AND Cr$sup 51$ IN HEALTHY SUBJECTS AND POLYCYTHEMIA PATIENTS TREATED WITH P$sup 3$$sup 2$ (in German)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schneider, K.W.; Becker, G.

1962-09-12

Blood volume was determined by the Evans blue and the Cr/sup 51/ methods in 40 normals and 17 cases of polycythemia. In normals there was good agreement of the results of both methods, however, in polycythemia differences were observed. With the Crsl-method the erythrocyte volume was found to be lower than with the Evans blue technique although the difference was not significant. When the active circulating blood volume is determined, the introduction of a correction factor for the so-called body hematocrit is not necessary. lt is possible that the difference between venous hematocrit and the quotient Evans blueplasma volume/Cr/sup 51/more » erythrocyte volume is caused by an increase of the error due to the trapped plasma. In case with increased hematocrit values the plasma volume should be determined by Evans blue and the erythrocyte volume by Cr/ sup 51/. In polycythemia the mean values were lower the those previously estimated by Seyderheim and Lampe. In the untreated state of polycythemia the mean plasma volume is reduced; in 80% of the cases a reduction was found initially. With successful treatment the plasma volume increased. Treatment consisted of injection of 0.08-0.09 mC P/sup 32/ per kg body wt, which was repeated three months later if necessary. Half the patients required only one such dose for remission; only one required three doses. Improvement in plasma volume showed no correlation with the size of the spleen or the presence of hypertension. The venous pressure was normal in all cases. Circulation time was variable but showed a tendency to become shorter following treatment with P/sup 32/. Renal function studies are discussed. Creatinine-clearance and phenolsulfonphthalein (PSP) excretion were often reduced, and albuminuria, hematuria, and azotemia were present. With clinical improvement after P/sup 32/ treatment these symptoms are reversible except for the reduced PSP excretion. (BBB)« less

Production of large resonant plasma volumes in microwave electron cyclotron resonance ion sources

DOEpatents

Alton, Gerald D.

1998-01-01

Microwave injection methods for enhancing the performance of existing electron cyclotron resonance (ECR) ion sources. The methods are based on the use of high-power diverse frequency microwaves, including variable-frequency, multiple-discrete-frequency, and broadband microwaves. The methods effect large resonant "volume" ECR regions in the ion sources. The creation of these large ECR plasma volumes permits coupling of more microwave power into the plasma, resulting in the heating of a much larger electron population to higher energies, the effect of which is to produce higher charge state distributions and much higher intensities within a particular charge state than possible in present ECR ion sources.

The Plasma-Based Instruction in Ethiopia: Utopia or Dystopia?

ERIC Educational Resources Information Center

Abera, Berhanu

2013-01-01

This article highlights the utopian and dystopian viewpoints held on the plasma-based instruction in Ethiopian by looking into the existing literature works and by analyzing attitudes of implementing bodies and implementers towards the program. The article identified that though implementing bodies were enthusiastic in developing and expanding the…

Viscous plasma evolution from gravity using anti-de sitter/conformal-field-theory correspondence.

PubMed

Janik, Romuald A

2007-01-12

We analyze the anti-de Sitter/conformal-field-theory dual geometry of an expanding boost-invariant plasma. We show that the requirement of nonsingularity of the dual geometry for leading and subasymptotic times predicts, without any further assumptions about gauge theory dynamics, hydrodynamic expansion of the plasma with viscosity coefficient exactly matching the one obtained earlier in the static case by Policastro, Son, and Starinets.

Ion Acceleration by Double Layers with Multi-Component Ion Species

NASA Astrophysics Data System (ADS)

Good, Timothy; Aguirre, Evan; Scime, Earl; West Virginia University Team

2017-10-01

Current-free double layers (CFDL) models have been proposed to explain observations of magnetic field-aligned ion acceleration in plasmas expanding into divergent magnetic field regions. More recently, experimental studies of the Bohm sheath criterion in multiple ion species plasma reveal an equilibration of Bohm speeds at the sheath-presheath boundary for a grounded plate in a multipole-confined filament discharge. We aim to test this ion velocity effect for CFDL acceleration. We report high resolution ion velocity distribution function (IVDF) measurements using laser induced fluorescence downstream of a CFDL in a helicon plasma. Combinations of argon-helium, argon-krypton, and argon-xenon gases are ionized and measurements of argon or xenon IVDFs are investigated to determine whether ion acceleration is enhanced (or diminished) by the presence of lighter (or heavier) ions in the mix. We find that the predominant effect is a reduction of ion acceleration consistent with increased drag arising from increased gas pressure under all conditions, including constant total gas pressure, equal plasma densities of different ions, and very different plasma densities of different ions. These results suggest that the physics responsible for acceleration of multiple ion species in simple sheaths is not responsible for the ion acceleration observed in these expanding plasmas. Department of Physics, Gettysburg College.

Modeling of breakdown during the post-arc phase of a vacuum circuit breaker

NASA Astrophysics Data System (ADS)

Sarrailh, P.; Garrigues, L.; Boeuf, J. P.; Hagelaar, G. J. M.

2010-12-01

After a high-current interruption in a vacuum circuit breaker (VCB), the electrode gap is filled with a high density copper vapor plasma in a large copper vapor density (~1022 m-3). The copper vapor density is sustained by electrode evaporation. During the post-arc phase, a rapidly increasing voltage is applied to the gap, and a sheath forms and expands, expelling the plasma from the gap when circuit breaking is successful. There is, however, a risk of breakdown during that phase, leading to the failure of the VCB. Preventing breakdown during the post-arc phase is an important issue for the improvement of VCB reliability. In this paper, we analyze the risk of Townsend breakdown in the high copper vapor density during the post-arc phase using a numerical model that takes into account secondary electron emission, volume ionization, and plasma and neutral transport, for given electrode temperatures. The simulations show that fast neutrals created in the cathode sheath by charge exchange collisions with ions generate a very large secondary electron emission current that can lead to Townsend breakdown. The results also show that the risk of failure of the VCB due to Townsend breakdown strongly depends on the electrode temperatures (which govern the copper vapor density) and becomes important for temperatures greater than 2100 K, which can be reached in vacuum arcs. The simulations also predict that a hotter anode tends to increase the risk of Townsend breakdown.

A linear helicon plasma device with controllable magnetic field gradient.

PubMed

Barada, Kshitish K; Chattopadhyay, P K; Ghosh, J; Kumar, Sunil; Saxena, Y C

2012-06-01

Current free double layers (CFDLs) are localized potential structures having spatial dimensions - Debye lengths and potential drops of more than local electron temperature across them. CFDLs do not need a current for them to be sustained and hence they differ from the current driven double layers. Helicon antenna produced plasmas in an expanded chamber along with an expanding magnetic field have shown the existence of CFDL near the expansion region. A helicon plasma device has been designed, fabricated, and installed in the Institute for Plasma Research, India to study the role of maximum magnetic field gradient as well as its location with respect to the geometrical expansion region of the chamber in CFDL formation. The special feature of this machine consisting of two chambers of different radii is its capability of producing different magnetic field gradients near the physical boundary between the two chambers either by changing current in one particular coil in the direction opposite to that in other coils and/or by varying the position of this particular coil. Although, the machine is primarily designed for CFDL experiments, it is also capable of carrying out many basic plasma physics experiments such as wave propagation, wave coupling, and plasma instabilities in a varying magnetic field topology. In this paper, we will present the details of the machine construction, its specialties, and some preliminary results about the production and characterization of helicon plasma in this machine.

A simple high-performance liquid chromatography for the determination of linezolid in human plasma and saliva.

PubMed

Hara, Shuuji; Uchiyama, Masanobu; Yoshinari, Masami; Matsumoto, Taichi; Jimi, Shiro; Togawa, Atsushi; Takata, Tohru; Takamatsu, Yasushi

2015-09-01

Linezolid is an antimicrobial agent for the treatment of multiresistant Gram-positive infections. A practical high-performance liquid chromatography method was developed for the determination of linezolid in human plasma and saliva. Linezolid and an internal standard (o-ethoxybenzamide) were extracted from plasma and saliva with ethyl acetate and analyzed on a Capcell Pak C18 MG column with UV detection at 254 nm. The calibration curve was linear through the range 0.5-50 µg/mL using a 200 μL sample volume. The intra- and interday precisions were all <6.44% for plasma and 5.60% for saliva. The accuracies ranged from 98.8 to 110% for both matrices. The mean recoveries of linezolid were 80.8% for plasma and 79.0% for saliva. This method was used to determine the plasma and saliva concentrations of linezolid in healthy volunteers who were orally administered a 600 mg dose of linezolid. Our liquid-liquid extraction procedure is easy and requires a small volume of plasma or saliva (200 μL). This small volume can be advantageous in clinical pharmacokinetic studies, especially if children participate. Copyright © 2015 John Wiley & Sons, Ltd.

Sustained and generalized extracellular fluid expansion following heat acclimation

PubMed Central

Patterson, Mark J; Stocks, Jodie M; Taylor, Nigel A S

2004-01-01

We measured intra- and extravascular body-fluid compartments in 12 resting males before (day 1; control), during (day 8) and after (day 22) a 3-week, exercise–heat acclimation protocol to investigate plasma volume (PV) changes. Our specific focus was upon the selective nature of the acclimation-induced PV expansion, and the possibility that this expansion could be sustained during prolonged acclimation. Acclimation was induced by cycling in the heat, and involved 16 treatment days (controlled hyperthermia (90 min); core temperature = 38.5°C) and three experimental exposures (40 min rest, 96.9 min (s.d. 9.5 min) cycling), each preceded by a rest day. The environmental conditions were a temperature of 39.8°C (s.d. 0.5°C) and relative humidity of 59.2% (s.d. 0.8%). On days 8 and 22, PV was expanded and maintained relative to control values (day 1: 44.0 ± 1.8; day 8: 48.8 ± 1.7; day 22: 48.8 ± 2.0 ml kg−1; P < 0.05). The extracellular fluid compartment (ECF) was equivalently expanded from control values on days 8 (279.6 ± 14.2versus 318.6 ± 14.3 ml kg−1; n = 8; P < 0.05) and 22 (287.5 ± 10.6 versus 308.4 ± 14.8 ml kg−1; n = 12; P < 0.05). Plasma electrolyte, total protein and albumin concentrations were unaltered following heat acclimation (P > 0.05), although the total plasma content of these constituents was elevated (P < 0.05). The PV and interstitial fluid (ISF) compartments exhibited similar relative expansions on days 8 (15.0 ± 2.2% versus 14.7 ± 4.1%; P > 0.05) and 22 (14.4 ± 3.6%versus 6.4 ± 2.2%; P = 0.10). It is concluded that the acclimation-induced PV expansion can be maintained following prolonged heat acclimation. In addition, this PV expansion was not selective, but represented a ubiquitous expansion of the extracellular compartment. PMID:15218070

The Hematocrit Affects the Volume of Plasma Treated With Coupled Plasma Filtration and Adsorption With Predilution.

PubMed

Finazzi, Stefano; Garbero, Elena; Trussardi, Giampietro; Bertolini, Guido

2017-05-01

Coupled plasma filtration and adsorption (CPFA) is an extracorporeal blood purification technique proposed for the treatment of septic-shock. By removing pro- and anti-inflammatory mediators from plasma, CPFA is supposed to have a therapeutic effect on the abnormal inflammatory response seen in this condition. Recently, blood predilution with citrate solution has been adopted to prevent clotting in the CPFA circuit-one of the main problems of the technique. Taking into account the patient's hematocrit, we worked out a formula for the volume of plasma effectively treated by CPFA after predilution. Neglecting this effect, as is commonly done, introduces significant distortions in the estimation of the volume, possibly causing under-treatment. The distortion is stronger when the hematocrit and the predilution fraction are large and weaker when both values shrink. By correctly indicating the daily dose of plasma adsorption received by patients, this formula is essential for assessing the therapeutic efficacy of CPFA and, subsequently, establishing its optimal doses. © 2017 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Generator of chemically active low-temperature plasma

NASA Astrophysics Data System (ADS)

Tyuftyaev, A. S.; Gadzhiev, M. Kh; Sargsyan, M. A.; Demirov, N. A.; Spector, N. O.

2016-11-01

A new generator of high enthalpy (H 0 > 40 kJ/g), chemically active nitrogen and air plasmas was designed and constructed. Main feature of the generator is an expanding channel of an output electrode; the generator belongs to the class of DC plasma torches with thermionic cathode with an efficiency of 80%. The generator ensures the formation of a slightly divergent plasma jet (2α = 12°) with a diameter of D = 10-12 mm, an electric arc maximum power of 20-50 kW, plasma forming gas flow rate 1.0-2.0 g/s, and the average plasma temperature at an outlet of 8000-11000 K.

Application of low-temperature plasma for the synthesis of hydrogenated graphene (graphane)

NASA Astrophysics Data System (ADS)

Shavelkina, M. B.; Amirov, R. H.; Katarzhis, V. A.; Kiselev, V. I.

2017-12-01

The possibility of a direct synthesis of hydrogenated graphene in decomposition of methane by means of low-temperature plasma was investigated. A DC plasma torch with an expanding channel-anode, a vortex gas supply and a self-setting arc length was used as a generator of low-temperature plasma. Argon was used as the plasma-forming gas. The temperatures of argon plasma and with methane addition to it were determined on the basis of spectral measurements. The synthesis products were characterized by electron microscopy and thermogravimetry. The effect of hydrogenated graphene as a nanomodifier on the properties of the cubic boron nitride based functional ceramics was investigated.

Fields in laser-ablated plasmas generalized to degenerate electrons and to Fermi energy in nuclei with change to quark-gluon plasma

NASA Astrophysics Data System (ADS)

Hora, Heinrich; Miley, George H.; Osman, Frederick; Hammerling, Peter X.

2004-09-01

The studies of laser ablation have lead to a new theory of nuclei, endothermic nuclei generation and quark-gluon plasmas. The surface of ablated plasma expanding into vacuum after high power laser irradiation of targets, contains an electric double layer having the thickness of the Debye length. This led to the discovery of surface tension of plasmas and to the internal dynamic electric fields in all inhomogeneous plasmas. The surface causes stabilization by short length surface waves smoothing the expanding plasma plume. Generalizing this to the degenerate electrons in a metal with the Fermi energy instead of the temperature, resulted in the surface tension of metals in agreement with measurements. Taking then the Fermi energy in the Debye length for nucleons results in a theory of nuclei with stable confinement of protons and neutrons just at the well known nuclear density, and in the Debye length equal to Hofstadter's decay of the nuclear surface. Increasing the nuclear density by a factor of 6 leads to the change of the Fermi energy into its relativistic branch where no surface energy is possible and the particle mass is not defined, permitting the quark-gluon plasma. Expansion of this higher density at the big band or in a supernova results in nucleation and element generation. The Boltzmann equilibrium permits the synthesis of nuclei even in the endothermic range limited to about uranium.

Alfvén Waves Generated by Expanding Plasmas in the Laboratory and in Space

NASA Astrophysics Data System (ADS)

Gekelman, W.; Vanzeeland, M.; Vincena, S.; Pribyl, P.

2002-12-01

There are many situations, which occur in space (coronal mass ejections, supernovas), or are man-made (upper atmospheric detonations) in which a dense plasma expands into a background magnetized plasma, that can support Alfvén waves. The LArge Plasma Device (LAPD) is a machine, at UCLA, in which Alfvén waves propagation in homogeneous and inhomogeneous plasmas has been studied. These will be briefly reviewed. Then a new class of experiments which involve the expansion of a dense (initially, n/no>>1) laser-produced plasma into an ambient highly magnetized background plasma capable of supporting Alfvén waves will be presented. The 150 MW laser is pulsed at the same 1 Hz repetition rate as the plasma in a highly reproducible experiment. The laser beam impacts a solid target such that the initial plasma burst is directed either along or across the magnetic field. The interaction results in the production of intense shear and compressional Alfvén waves, as well as large density perturbations. The waves propagate away from the target and are observed to become plasma column resonances. The magnetic fields of the waves are obtained with a 3-axis inductive probe. Spatial patterns of the magnetic fields associated with the waves and density perturbations are measured at over {10}4 locations and will be shown in dramatic movies. These are used to estimate the coupling efficiency of the laser energy and kinetic energy of the dense plasma into wave energy. The wave generation mechanism is due to field aligned return currents, which replace fast electrons escaping the initial blast. Work supported by ONR, DOE, and NSF

Pressure dependence of an ion beam accelerating structure in an expanding helicon plasma

NASA Astrophysics Data System (ADS)

Zhang, Xiao; Aguirre, Evan; Thompson, Derek S.; McKee, John; Henriquez, Miguel; Scime, Earl E.

2018-02-01

We present measurements of the parallel ion velocity distribution function and electric field in an expanding helicon source plasma plume as a function of downstream gas pressure and radial and axial positions. The ion beam that appears spontaneously in the plume persists for all downstream pressures investigated, with the largest parallel ion beam velocities obtained for the lowest downstream pressures. However, the change in ion beam velocity exceeds what would be expected simply for a change in the collisionality of the system. Electric field measurements confirm that it is the magnitude of the potential structure responsible for accelerating the ion beam that changes with downstream pressure. Interestingly, the ion density radial profile is hollow close to the end of the plasma source for all pressures, but it is hollow at downstream distances far from the source only at the highest downstream neutral pressures.

Expansion of Titan atmosphere

NASA Astrophysics Data System (ADS)

Salem, S.; Moslem, W. M.; Radi, A.

2017-05-01

Self-similar plasma expansion approach is used to solve a plasma model based on the losing phenomenon of Titan atmospheric composition. To this purpose, a set of hydrodynamic fluid equations describing a plasma consisting of two positive ions with different masses and isothermal electrons is used. With the aid of self-similar transformation, numerical solution of the fluid equations has been performed to examine the density, velocity, and potential profiles. The effects of different plasma parameters, i.e., density and temperature ratios, are studied on the expanding plasma profiles. The present investigation could be useful to recognize the ionized particles escaping from Titan atmosphere.

Pulsatile plasma filtration and cell-free DNA amplification using a water-head-driven point-of-care testing chip.

PubMed

Lee, Yonghun; Kim, Dong-Min; Li, Zhenglin; Kim, Dong-Eun; Kim, Sung-Jin

2018-03-13

We demonstrate a microfiltration chip that separates blood plasma by using water-head-driven pulsatile pressures rather than any external equipment and use it for on-chip amplification of nucleic acids. The chip generates pulsatile pressures to significantly reduce filter clogging without hemolysis, and consists of an oscillator, a plasma-extraction pump, and filter units. The oscillator autonomously converts constant water-head pressure to pulsatile pressure, and the pump uses the pulsatile pressure to extract plasma through the filter. Because the pulsatile pressure can periodically clear blood cells from the filter surface, filter clogging can be effectively reduced. In this way, we achieve plasma extraction with 100% purity and 90% plasma recovery at 15% hematocrit. During a 10 min period, the volume of plasma extracted was 43 μL out of a 243 μL extraction volume at 15% hematocrit. We also studied the influence of the pore size and diameter of the filter, blood loading volume, oscillation period, and hematocrit level on the filtration performance. To demonstrate the utility of our chip for point-of-care testing (POCT) applications, we successfully implemented on-chip amplification of a nucleic acid (miDNA21) in plasma filtered from blood. We expect our chip to be useful not only for POCT applications but also for other bench-top analysis tools using blood plasma.

Interaction of nanosecond ultraviolet laser pulses with reactive dusty plasma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wetering, F. M. J. H. van de; Oosterbeek, W.; Beckers, J.

2016-05-23

Even though UV laser pulses that irradiate a gas discharge are small compared to the plasma volume (≲3%) and plasma-on time (≲6 × 10{sup −6}%), they are found to dramatically change the discharge characteristics on a global scale. The reactive argon–acetylene plasma allows the growth of nanoparticles with diameters up to 1 μm, which are formed inside the discharge volume due to spontaneous polymerization reactions. It is found that the laser pulses predominantly accelerate and enhance the coagulation phase and are able to suppress the formation of a dust void.

Elevated Plasma Marinobufagenin, An Endogenous Cardiotonic Steroid, Is Associated With Right Ventricular Dysfunction and Nitrative Stress in Heart Failure.

PubMed

Kennedy, David J; Shrestha, Kevin; Sheehey, Brendan; Li, Xinmin S; Guggilam, Anuradha; Wu, Yuping; Finucan, Michael; Gabi, Alaa; Medert, Charles M; Westfall, Kristen; Borowski, Allen; Fedorova, Olga; Bagrov, Alexei Y; Tang, W H Wilson

2015-11-01

Plasma levels of cardiotonic steroids are elevated in volume-expanded states, such as chronic kidney disease, but the role of these natriuretic hormones in subjects with heart failure (HF) is unclear. We sought to determine the prognostic role of the cardiotonic steroids marinobufagenin (MBG) in HF, particularly in relation to long-term outcomes. We first measured plasma MBG levels and performed comprehensive clinical, laboratory, and echocardiographic assessment in 245 patients with HF. All-cause mortality, cardiac transplantation, and HF hospitalization were tracked for 5 years. In our study cohort, median (interquartile range) MBG was 583 (383-812) pM. Higher MBG was associated with higher myeloperoxidase (r=0.42, P<0.0001), B-type natriuretic peptide (r=0.25, P=0.001), and asymmetrical dimethylarginine (r=0.32, P<0.001). Elevated levels of MBG were associated with measures of worse right ventricular function (RV s', r=-0.39, P<0.0001) and predicted increased risk of adverse clinical outcomes (MBG≥574 pmol/L: hazard ratio 1.58 [1.10-2.31], P=0.014) even after adjustment for age, sex, diabetes mellitus, and ischemic pathogenesis. In mice, a left anterior descending coronary artery ligation model of HF lead to increases in MBG, whereas infusion of MBG into mice for 4 weeks lead to significant increases in myeloperoxidase, asymmetrical dimethylarginine, and cardiac fibrosis. In the setting of HF, elevated plasma levels of MBG are associated with right ventricular dysfunction and predict worse long-term clinical outcomes in multivariable models adjusting for established clinical and biochemical risk factors. Infusion of MBG seems to directly contribute to increased nitrative stress and cardiac fibrosis. © 2015 American Heart Association, Inc.

EFFECTS OF LASER RADIATION ON MATTER. LASER PLASMA: Formation of a plasma jet of multiply charged ions in the interaction of a laser plasma with an external pulsed magnetic field

NASA Astrophysics Data System (ADS)

Dyakin, V. M.; Pikuz, T. A.; Skobelev, I. Yu; Faenov, A. Ya; Wolowski, J.; Karpinski, L.; Kasperczuk, A.; Pisarczyk, T.

1994-12-01

A dense jet of a plasma consisting of multiply charged ions was generated in the interaction of a laser plasma with a strong external axial magnetic field. Images were formed by spectral lines and the soft x-ray spectrum range of the plasma jet was obtained with a large-aperture spectrograph containing a mica crystal bent to form a spherical surface with a radius of R = 10 cm. A tenfold increase in the density of the He-like Mg XI plasma, compared with a freely expanding plasma, was observed at a distance of 5 mm from the target.

Interaction of laser radiation with plasma under the MG external magnetic field

NASA Astrophysics Data System (ADS)

Ivanov, V. V.; Maximov, A. V.; Betti, R.; Sawada, H.; Sentoku, Y.

2016-10-01

Strong magnetic fields play an important role in many physical processes relevant to astrophysical events and fusion research. Laser produced plasma in the MG external magnetic field was studied at the 1 MA pulsed power generator coupled with the laser operated in ns and ps regimes. Rod loads and coils under 1 MA current were used to produce a magnetic field of 2-3 MG. In one type of experiments, a 0.8 ns laser pulse was focused on the load surface with intensity of 3x1015 W/cm2. Laser diagnostics showed that the laser produced plasma expands in the transversal magnetic field and forms a thin plasma disc with a typical diameter of 3-7 mm and thickness of 0.2-0.4 mm. A magnetosonic-type wave was observed in the plasma disc and on the surface of the rod load. The plasma disc expands radially across the magnetic field with a velocity of the order of the magnetosonic velocity. Physical mechanisms involved in the formation of the plasma disc may be relevant to the generation of plasma loops in sun flares. Other experiments, with a 0.4 ps laser pulse were carried for investigation of the isochoric heating of plasma with fast electrons confined by the strong magnetic field. The laser beam was focused by the parabola mirror on a solid target in the magnetic field of the coil. Work was supported by the DOE Grant DE-SC0008824 and DOE/NNSA UNR Grant DE-FC52-06NA27616.

Tissue Expander Overfilling: Achieving New Dimensions of Customization in Breast Reconstruction.

PubMed

Treiser, Matthew D; Lahair, Tracy; Carty, Matthew J

2016-02-01

Overfill of tissue expanders is a commonly used modality to achieve customized dimensions in breast reconstruction. Little formal study of the dynamics of hyperexpansion of these devices has been performed to date, however. Overfill trials were performed using both Natrelle 133 MV and Mentor 8200 tissue expanders of indicated capacities ranging from 250 to 800 mL. Each expander was initially filled to its indicated capacity with normal water and then injected in regular increments to 400% overfill. Measurements of each expander's width, height, and projection were made at indicated capacity and with each successive incremental overfill injection, and these results were then recorded, collated, and analyzed. Over the first 50% overfill, all expanders demonstrated a logarithmic increase in projection (mean increase, 143 ± 9%) while maintaining essentially stable base dimensions. Overfill levels in excess of 50% were accompanied by linear increases in height, width, and projection, during which projection approached, but never equaled, base dimensions. Stress versus strain analyses demonstrated nonlinear biomechanical dynamics during the first 50% overfill, followed by standard elastic dynamics up to 400% overfill. At no point during the study, did expander tensions outstrip elastic properties, thereby explaining the lack of device rupture. Through overfilling, tunable geometries of tissue expanders can be accessed that may provide for increasing customization of reconstructions, particularly at overfill volumes up to 50% over indicated capacity. This study should serve to guide tissue expander selection and fill volumes that surgeons may implement in obtaining ideal reconstructed breast shapes.

Therapeutic potential of ixmyelocel-T, an expanded autologous multicellular therapy for treatment of ischemic cardiovascular diseases.

PubMed

Ledford, Kelly J; Murphy, Nikki; Zeigler, Frank; Bartel, Ronnda L; Tubo, Ross

2015-03-13

Bone marrow derived cellular therapies are an emerging approach to promoting therapeutic angiogenesis in ischemic cardiovascular disease. However, the percentage of regenerative cells in bone marrow mononuclear cells (BMMNCs) is small, and large amounts of BMMNCs are required. Ixmyelocel-T, an expanded autologous multicellular therapy, is manufactured from a small sample of bone marrow aspirate. Ixmyelocel-T contains expanded populations of mesenchymal stromal cells (MSCs) and M2-like macrophages, as well as many of the CD45+ cells found in the bone marrow. It is hypothesized that this expanded multi-cellular therapy would induce angiogenesis and endothelial repair. A rat model of hind limb ischemia was used to determine the effects of ixmyelocel-T on blood flow recovery. To further determine the effects on endothelial cells, ixmyelocel-T was co-cultured with human umbilical vein endothelial cells (HUVEC) in non-contacting Transwell® inserts. Co-culture of HUVECs with ixmyelocel-T resulted secretion of a variety of pro-angiogenic factors. HUVECs stimulated by ixmyelocel-T exhibited enhanced migration, proliferation, and branch formation. Ixmyelocel-T co-culture also resulted in increased endothelial nitric oxide synthase (eNOS) expression and nitric oxide (NO) production. In tumor necrosis factor alpha (TNFα)-stimulated HUVECs, ixmyelocel-T co-culture decreased apoptosis and reactive oxygen species generation, increased super oxide dismutase activity, and decreased nuclear factor kappa B (NFκB) activation. Treatment with ixmyelocel-T in a rat model of hind limb ischemia resulted in significantly increased blood flow perfusion and capillary density, gene expression and plasma levels of the anti-inflammatory cytokine interleukin (IL)-10, plasma nitrates, plasma platelet-derived growth factor (PDGF)-BB, vascular endothelial growth factor (VEGF) expression, and significantly decreased plasma thiobarbituric acid reactive substances (TBARS). This work demonstrates that ixmyelocel-T interacts with endothelial cells in a paracrine manner, resulting in angiogenesis and endothelial protection. This data suggests that ixmyelocel-T could be useful for promoting of angiogenesis and tissue repair in ischemic cardiovascular diseases. In conclusion, ixmyelocel-T therapy may provide a new aspect of therapeutic angiogenesis in this patient population where expanded populations of regenerative cells might be required.

Effects of hypertonic saline (7.5%) on extracellular fluid volumes compared with normal saline (0.9%) and 6% hydroxyethyl starch after aortocoronary bypass graft surgery.

PubMed

Järvelä, K; Koskinen, M; Kaukinen, S; Kööbi, T

2001-04-01

To compare the effects of hypertonic (7.5%) saline (HS), normal (0.9%) saline (NS), and 6% hydroxyethyl starch (HES) on extracellular fluid volumes in the early postoperative period after cardiopulmonary bypass. A prospective, randomized, double-blind study. University teaching hospital. Forty-eight patients scheduled for elective coronary artery bypass graft surgery. Patients were randomly allocated to receive 4 mL/kg of HS, NS, or HES during 30 minutes when volume loading was needed during the postoperative rewarming period in the intensive care unit. Plasma volume was measured using a dilution of iodine-125-labeled human serum albumin. Extracellular water and cardiac output were measured by whole-body impedance cardiography. Plasma volume had increased by 19 +/- 7% in the HS group and by 10 +/- 3% in the NS group (p = 0.001) at the end of the study fluid infusion. After 1-hour follow-up time, the plasma volume increase was greatest (23 +/- 8%) in the group receiving HES (p < 0.001). The increase of extracellular water was greater than the infused volume in the HS and HES groups at the end of the infusion. One-hour diuresis after the study infusion was greater in the HS group (536 +/- 280 mL) than in the NS (267 +/- 154 mL, p = 0.006) and HES groups (311 +/- 238 mL, p = 0.025). The effect of HS on plasma volume was short-lasting, but it stimulated excretion of excess body fluid accumulated during cardiopulmonary bypass and cardiac surgery. HS may be used in situations in which excess free water administration is to be avoided but the intravascular volume needs correction. Copyright 2001 by W.B. Saunders Company

Production of large resonant plasma volumes in microwave electron cyclotron resonance ion sources

DOEpatents

Alton, G.D.

1998-11-24

Microwave injection methods are disclosed for enhancing the performance of existing electron cyclotron resonance (ECR) ion sources. The methods are based on the use of high-power diverse frequency microwaves, including variable-frequency, multiple-discrete-frequency, and broadband microwaves. The methods effect large resonant ``volume`` ECR regions in the ion sources. The creation of these large ECR plasma volumes permits coupling of more microwave power into the plasma, resulting in the heating of a much larger electron population to higher energies, the effect of which is to produce higher charge state distributions and much higher intensities within a particular charge state than possible in present ECR ion sources. 5 figs.

Hemodynamic and ADH responses to central blood volume shifts in cardiac-denervated humans

NASA Technical Reports Server (NTRS)

Convertino, V. A.; Thompson, C. A.; Benjamin, B. A.; Keil, L. C.; Savin, W. M.; Gordon, E. P.; Haskell, W. L.; Schroeder, J. S.; Sandler, H.

1990-01-01

Hemodynamic responses and antidiuretic hormone (ADH) were measured during body position changes designed to induce blood volume shifts in ten cardiac transplant recipients to assess the contribution of cardiac and vascular volume receptors in the control of ADH secretion. Each subject underwent 15 min of a control period in the seated posture, then assumed a lying posture for 30 min at 6 deg head down tilt (HDT) followed by 20 min of seated recovery. Venous blood samples and cardiac dimensions (echocardiography) were taken at 0 and 15 min before HDT, 5, 15, and 30 min of HDT, and 5, 15, and 30 min of seated recovery. Blood samples were analyzed for hematocrit, plasma osmolality, plasma renin activity (PRA), and ADH. Resting plasma volume (PV) was measured by Evans blue dye and percent changes in PV during posture changes were calculated from changes in hematocrit. Heart rate (HR) and blood pressure (BP) were recorded every 2 min. Results indicate that cardiac volume receptors are not the only mechanism for the control of ADH release during acute blood volume shifts in man.

Measurement of breast volume using body scan technology(computer-aided anthropometry).

PubMed

Veitch, Daisy; Burford, Karen; Dench, Phil; Dean, Nicola; Griffin, Philip

2012-01-01

Assessment of breast volume is an important tool for preoperative planning in various breast surgeries and other applications, such as bra development. Accurate assessment can improve the consistency and quality of surgery outcomes. This study outlines a non-invasive method to measure breast volume using a whole body 3D laser surface anatomy scanner, the Cyberware WBX. It expands on a previous publication where this method was validated against patients undergoing mastectomy. It specifically outlines and expands the computer-aided anthropometric (CAA) method for extracting breast volumes in a non-invasive way from patients enrolled in a breast reduction study at Flinders Medical Centre, South Australia. This step-by-step description allows others to replicate this work and provides an additional tool to assist them in their own clinical practice and development of designs.

Increased volume of distribution for recombinant activated factor VII and longer plasma-derived factor VII half-life may explain their long lasting prophylactic effect.

PubMed

Mathijssen, Natascha C J; Masereeuw, Rosalinde; Holme, Pal Andre; van Kraaij, Marian G J; Laros-van Gorkom, Britta A P; Peyvandi, Flora; van Heerde, Waander L

2013-08-01

Prophylaxis with plasma-derived or recombinant activated factor VII is beneficial in severe factor VII deficiency. To understand why prophylactic treatment with both products is efficacious, we conducted a pharmacokinetic study. Ten factor VII deficient patients were treated with either recombinant activated (20 μg/kg) or plasma-derived (25 IU/kg) factor VII in a cross-over design. Pharmacokinetic parameters were analyzed through activated factor VII activity, factor VII clotting activity, and factor VII antigen levels on depicted time points. Factor VII activity half-lifes, determined by non-compartmental and one-compartmental analysis (results in brackets), were shorter for recombinant activated (1.4h; 0.7h) than for plasma-derived factor VII (6.8h; 3.2h); both recombinant activated (5.1h; 2.1h and plasma-derived factor VII (5.8h; 3.2h) resulted in longer half-lives of factor VII antigen. Activated factor VII half-lives (based on activated factor VII activity levels) were significantly higher compared to factor VII clotting activity (1.6h; 0.9h). Volumes of distribution were significantly higher for activated factor VII (236 ml/kg; 175 ml/kg, measured by activated factor VII) as compared to plasma-derived factor VII (206 ml/kg; 64 ml/kg, measured by factor FVII activity), suggesting a plasma- and extracellular fluid distribution for recombinant activated factor VII. Recombinant activated factor VII showed significantly shorter half-lifes than plasma-derived factor VII. Volumes of distribution were significantly higher for treatment with recombinant activated factor VII. The longer half-life for plasma-derived factor VII, compared to recombinant activated factor VII, and the increased volume of distribution for recombinant activated factor VII, compared to plasma-derived factor VII may further elucidate the beneficial effect of prophylactic treatment of both products. Copyright © 2013 Elsevier Ltd. All rights reserved.

NaCl-Induced Alterations in Both Cell Structure and Tissue-Specific Plasma Membrane H+ -ATPase Gene Expression.

PubMed Central

Niu, X.; Damsz, B.; Kononowicz, A. K.; Bressan, R. A.; Hasegawa, P. M.

1996-01-01

NaCl-induced plasma membrane H+-ATPase gene expression, which occurs in roots and fully expanded leaves of the halophyte Atriplex nummularia L. (X. Niu, M.L. Narasimhan, R.A. Salzman, R.A. Bressan, P.M. Hasegawa [1993] Plant Physiol 103: 713-718), has been differentially localized to specific tissues using in situ RNA hybridization techniques. Twenty-four-hour exposure of plants to 400 mM NaCl resulted in substantial accumulation of H+ pump message in the epidermis of the root tip and the endodermis of the root elongation/differentiation zone. In expanded leaves, NaCl induction of plasma membrane H+-ATPase message accumulation was localized to bundle-sheath cells. Ultrastructural analyses indicated that significant cytological adaptations in root cells included plasmolysis that is accompanied by plasma membrane invaginations, formation of Hechtian strands and vesiculation, and vacuolation. These results identify specific tissues that are involved in the regulation of Na+ and Cl- uptake into different organs of the halophyte A. nummularia and provide evidence of the intercellular and interorgan coordination that occurs in the mediation of NaCl adaptation. PMID:12226321

NaCl-Induced Alterations in Both Cell Structure and Tissue-Specific Plasma Membrane H+ -ATPase Gene Expression.

PubMed

Niu, X.; Damsz, B.; Kononowicz, A. K.; Bressan, R. A.; Hasegawa, P. M.

1996-07-01

NaCl-induced plasma membrane H+-ATPase gene expression, which occurs in roots and fully expanded leaves of the halophyte Atriplex nummularia L. (X. Niu, M.L. Narasimhan, R.A. Salzman, R.A. Bressan, P.M. Hasegawa [1993] Plant Physiol 103: 713-718), has been differentially localized to specific tissues using in situ RNA hybridization techniques. Twenty-four-hour exposure of plants to 400 mM NaCl resulted in substantial accumulation of H+ pump message in the epidermis of the root tip and the endodermis of the root elongation/differentiation zone. In expanded leaves, NaCl induction of plasma membrane H+-ATPase message accumulation was localized to bundle-sheath cells. Ultrastructural analyses indicated that significant cytological adaptations in root cells included plasmolysis that is accompanied by plasma membrane invaginations, formation of Hechtian strands and vesiculation, and vacuolation. These results identify specific tissues that are involved in the regulation of Na+ and Cl- uptake into different organs of the halophyte A. nummularia and provide evidence of the intercellular and interorgan coordination that occurs in the mediation of NaCl adaptation.

Spatial Studies of Ion Beams in an Expanding Plasma

NASA Astrophysics Data System (ADS)

Aguirre, Evan; Good, Timothy; Scime, Earl; Thompson, Derek

2017-10-01

We report spatially resolved perpendicular and parallel ion velocity distribution function (IVDF) measurements in an expanding argon helicon plasma. The parallel IVDFs, obtained through laser induced fluorescence (LIF), show an ion beam with v 8 km/s flowing downstream that is confined to the center of the discharge. The ion beam is confined to within a few centimeters radially and is measurable for tens of centimeters axially before the LIF signal fades, likely a result of metastable quenching of the beam ions. The axial ion beam velocity slows in agreement with collisional processes. The perpendicular IVDFs show an ion population with a radially outward flow that increases with radial location. The DC electric field, electron temperature, and the plasma density in the double layer plume are all consistent with magnetic field aligned structures. The upstream and downstream electric field measurements show clear evidence of an ion hole that maps along the magnetic field at the edge of the plasma. Current theories and simulations of double layers, which are one-dimensional, completely miss these critically important two-dimensional features.

Membrane-based, sedimentation-assisted plasma separator for point-of-care applications.

PubMed

Liu, Changchun; Mauk, Michael; Gross, Robert; Bushman, Frederic D; Edelstein, Paul H; Collman, Ronald G; Bau, Haim H

2013-11-05

Often, high-sensitivity, point-of-care (POC) clinical tests, such as HIV viral load, require large volumes of plasma. Although centrifuges are ubiquitously used in clinical laboratories to separate plasma from whole blood, centrifugation is generally inappropriate for on-site testing. Suitable alternatives are not readily available to separate the relatively large volumes of plasma from milliliters of blood that may be needed to meet stringent limit-of-detection specifications for low-abundance target molecules. We report on a simple-to-use, low-cost, pump-free, membrane-based, sedimentation-assisted plasma separator capable of separating a relatively large volume of plasma from undiluted whole blood within minutes. This plasma separator consists of an asymmetric, porous, polysulfone membrane housed in a disposable chamber. The separation process takes advantage of both gravitational sedimentation of blood cells and size exclusion-based filtration. The plasma separator demonstrated a "blood in-plasma out" capability, consistently extracting 275 ± 33.5 μL of plasma from 1.8 mL of undiluted whole blood within less than 7 min. The device was used to separate plasma laden with HIV viruses from HIV virus-spiked whole blood with recovery efficiencies of 95.5% ± 3.5%, 88.0% ± 9.5%, and 81.5% ± 12.1% for viral loads of 35,000, 3500, and 350 copies/mL, respectively. The separation process is self-terminating to prevent excessive hemolysis. The HIV-laden plasma was then injected into our custom-made microfluidic chip for nucleic acid testing and was successfully subjected to reverse-transcriptase loop-mediated isothermal amplification (RT-LAMP), demonstrating that the plasma is sufficiently pure to support high-efficiency nucleic acid amplification.

Membrane-based, sedimentation-assisted plasma separator for point-of-care applications

PubMed Central

Liu, Changchun; Mauk, Michael; Gross, Robert; Bushman, Frederic D.; Edelstein, Paul H.; Collman, Ronald G.; Bau, Haim H.

2014-01-01

Often, high sensitivity, point of care, clinical tests, such as HIV viral load, require large volumes of plasma. Although centrifuges are ubiquitously used in clinical laboratories to separate plasma from whole blood, centrifugation is generally inappropriate for on-site testing. Suitable alternatives are not readily available to separate the relatively large volumes of plasma from milliliters of blood that may be needed to meet stringent limit-of-detection specifications for low abundance target molecules. We report on a simple to use, low-cost, pump-free, membrane-based, sedimentation-assisted plasma separator capable of separating a relatively large volume of plasma from undiluted whole blood within minutes. This plasma separator consists of an asymmetric, porous, polysulfone membrane housed in a disposable chamber. The separation process takes advantage of both gravitational sedimentation of blood cells and size exclusion-based filtration. The plasma separator demonstrated a “blood in-plasma out” capability, consistently extracting 275 ±33.5 μL of plasma from 1.8 mL of undiluted whole blood in less than 7 min. The device was used to separate plasma laden with HIV viruses from HIV virus-spiked whole blood with recovery efficiencies of 95.5% ± 3.5%, 88.0% ± 9.5%, and 81.5% ± 12.1% for viral loads of 35,000, 3,500 and 350 copies/mL, respectively. The separation process is self-terminating to prevent excessive hemolysis. The HIV-laden plasma was then injected into our custom-made microfluidic chip for nucleic acid Testing And Was Successfully Subjected To Reverse Transcriptase Loop mediated isothermal amplification (RT-LAMP), demonstrating that the plasma is sufficiently pure to support high efficiency nucleic acid amplification. PMID:24099566

Role of cardiac volume receptors in the control of ADH release during acute simulated weightlessness in man

NASA Technical Reports Server (NTRS)

Convertino, V. A.; Benjamin, B. A.; Keil, L. C.; Sandler, H.

1984-01-01

Hemodynamic responses and antidiuretic hormone (ADH) were measured during body position changes, designed to induce central blood volume shifts in ten cardiac and one heart-lung transplant recipients, to assess the contribution of cardiac volume receptors in the control of ADH release during the initial acute phase of exposure to weightlessness. Each subject underwent 15 min of a sitting-control period (C) followed by 30 min of 6 deg headdown tilt (T) and 30 min of resumed sitting (S). Venous blood samples and cardiac dimensions were taken at 0 and 15 min of C; 5, 15, and 30 min of T; and 5, 15, and 30 min of S. Blood samples were analyzed for hematocrit, plasma osmolality, plasma renin activity (PRA), and ADH. Heart rate and blood pressure were recorded every two min. Plasma osmolality was not altered by posture changes. Mean left ventricular end-diastolic volume increased (P less than 0.05) from 90 ml in C to 106 ml in T and returned to 87 ml in S. Plasma ADH was reduced by 20 percent (P less than 0.05) with T, and returned to control levels with S. These responses were similar in six normal cardiac-innervated control subjects. These data may suggest that cardiac volume receptors are not the primary mechanism for the control of ADH release during acute central volume shifts in man.

TRAVELING WAVE PYROTRON

DOEpatents

Post, R.F.

1963-06-11

The invention relates to a pyrotron, i.e., magnetic mirror device, designed for continuous operation in producing a high-temperature fusion reaction plasma and for directly converting the plasma energy into electrical power. The device utilizes a system in which an axially symmetric magnetic field is produced and transports plasma through a first zone of progressively rising field intensity, a second reaction zone of slowly increasing intensity, and thenceforth through a third zone of progressively decreasing intensity wherein the plasma expands against the magnetic field thereby producing electrical current in magnetic field generating solenoids associated with said third zone. (AEC)

Prenatal Testosterone Exposure Decreases Aldosterone Production but Maintains Normal Plasma Volume and Increases Blood Pressure in Adult Female Rats.

PubMed

More, Amar S; Mishra, Jay S; Hankins, Gary D; Kumar, Sathish

2016-08-01

Plasma testosterone levels are elevated in pregnant women with preeclampsia and polycystic ovaries; their offspring are at increased risk for hypertension during adult life. We tested the hypothesis that prenatal testosterone exposure induces dysregulation of the renin-angiotensin-aldosterone system, which is known to play an important role in water and electrolyte balance and blood pressure regulation. Female rats (6 mo old) prenatally exposed to testosterone were examined for adrenal expression of steroidogenic genes, telemetric blood pressure, blood volume and Na(+) and K(+) levels, plasma aldosterone, angiotensin II and vasopressin levels, and vascular responses to angiotensin II and arg(8)-vasopressin. The levels of Cyp11b2 (aldosterone synthase), but not the other adrenal steroidogenic genes, were decreased in testosterone females. Accordingly, plasma aldosterone levels were lower in testosterone females. Plasma volume and serum and urine Na(+) and K(+) levels were not significantly different between control and testosterone females; however, prenatal testosterone exposure significantly increased plasma vasopressin and angiotensin II levels and arterial pressure in adult females. In testosterone females, mesenteric artery contractile responses to angiotensin II were significantly greater, while contractile responses to vasopressin were unaffected. Angiotensin II type-1 receptor expression was increased, while angiotensin II type-2 receptor was decreased in testosterone arteries. These results suggest that prenatal testosterone exposure downregulates adrenal Cyp11b2 expression, leading to decreased plasma aldosterone levels. Elevated angiotensin II and vasopressin levels along with enhanced vascular responsiveness to angiotensin II may serve as an underlying mechanism to maintain plasma volume and Na(+) and K(+) levels and mediate hypertension in adult testosterone females. © 2016 by the Society for the Study of Reproduction, Inc.

Report on Federal Productivity. Volume 2, Productivity Case Studies.

ERIC Educational Resources Information Center

Joint Financial Management Improvement Program, Washington, DC.

Volume 2 contains 15 productivity case studies which illustrate and expand on the causal factors mentioned in volume 1. The cases illustrate many different approaches to productivity measurement improvement. The case studies are: Development of an Output-Productivity Measure for the Air Force Medical Service; Measuring Effectiveness and Efficiency…

Studies of Magnetic Reconnection in Colliding Laser-Produced Plasmas

NASA Astrophysics Data System (ADS)

Rosenberg, Michael

2013-10-01

Novel images of magnetic fields and measurements of electron and ion temperatures have been obtained in the magnetic reconnection region of high- β, laser-produced plasmas. Experiments using laser-irradiated foils produce expanding, hemispherical plasma plumes carrying MG Biermann-battery magnetic fields, which can be driven to interact and reconnect. Thomson-scattering measurements of electron and ion temperatures in the interaction region of two colliding, magnetized plasmas show no thermal enhancement due to reconnection, as expected for β ~ 8 plasmas. Two different proton radiography techniques used to image the magnetic field structures show deformation, pileup, and annihilation of magnetic flux. High-resolution images reveal unambiguously reconnection-induced jets emerging from the interaction region and show instabilities in the expanding plasma plumes and supersonic, hydrodynamic jets due to the plasma collision. Quantitative magnetic flux data show that reconnection in experiments with asymmetry in the scale size, density, temperature, and plasma flow across the reconnection region occurs less efficiently than in similar, symmetric experiments. This result is attributed to disruption of the Hall mechanism mediating collisionless reconnection. The collision of plasmas carrying parallel magnetic fields has also been probed, illustrating the deformation of magnetic field structures in high-energy-density plasmas in the absence of reconnection. These experiments are particularly relevant to high- β reconnection environments, such as the magnetopause. This work was performed in collaboration with C. Li, F. Séguin, A. Zylstra, H. Rinderknecht, H. Sio, J. Frenje, and R. Petrasso (MIT), I. Igumenshchev, V. Glebov, C. Stoeckl, and D. Froula (LLE), J. Ross and R. Town (LLNL), W. Fox (UNH), and A. Nikroo (GA), and was supported in part by the NLUF, FSC/UR, U.S. DOE, LLNL, and LLE.

The effect of a period of intense exercise on the marker approach to detect growth hormone doping in sports.

PubMed

Voss, Sven Christian; Robinson, Neil; Alsayrafi, Mohammed; Bourdon, Pitre C; Schumacher, Yorck Olaf; Saugy, Martial; Giraud, Sylvain

2014-06-01

The major objective of this study was to investigate the effects of several days of intense exercise on the growth hormone marker approach to detect doping with human growth hormone (hGH). In addition we investigated the effect of changes in plasma volume on the test. Fifteen male athletes performed a simulated nine-day cycling stage race. Blood samples were collected twice daily over a period of 15 days (stage race + three days before and after). Plasma volumes were estimated by the optimized CO Rebreathing method. IGF-1 and P-III-NP were analyzed by Siemens Immulite and Cisbio Assays, respectively. All measured GH 2000 scores were far below the published decision limits for an adverse analytical finding. The period of exercise did not increase the GH-scores; however the accompanying effect of the increase in Plasma Volume yielded in essentially lower GH-scores. We could demonstrate that a period of heavy, long-term exercise with changes in plasma volume does not interfere with the decision limits for an adverse analytical finding. Copyright © 2014 John Wiley & Sons, Ltd.

Solutions of conformal Israel-Stewart relativistic viscous fluid dynamics

NASA Astrophysics Data System (ADS)

Marrochio, Hugo; Noronha, Jorge; Denicol, Gabriel S.; Luzum, Matthew; Jeon, Sangyong; Gale, Charles

2015-01-01

We use symmetry arguments developed by Gubser to construct the first radially expanding explicit solutions of the Israel-Stewart formulation of hydrodynamics. Along with a general semi-analytical solution, an exact analytical solution is given which is valid in the cold plasma limit where viscous effects from shear viscosity and the relaxation time coefficient are important. The radially expanding solutions presented in this paper can be used as nontrivial checks of numerical algorithms employed in hydrodynamic simulations of the quark-gluon plasma formed in ultrarelativistic heavy ion collisions. We show this explicitly by comparing such analytic and semi-analytic solutions with the corresponding numerical solutions obtained using the music viscous hydrodynamics simulation code.

Initial signatures of magnetic field and energetic particle fluxes at tail reconfiguration - Explosive growth phase

NASA Technical Reports Server (NTRS)

Ohtani, S.; Takahashi, K.; Zanetti, L. J.; Potemra, T. A.; Mcentire, R. W.; Iijima, T.

1992-01-01

The initial signatures of tail field reconfiguration observed in the near-earth magnetotail are examined using data obtained by the AMPTE/CCE magnetometer and the Medium Energy Particle Analyzer. It is found that the tail reconfiguration events could be classified as belonging to two types, Type I and Type II. In Type I events, a current disruption is immersed in a hot plasma region expanding from inward (earthward/equatorward) of the spacecraft; consequently, the spacecraft is immersed in a hot plasma region expanding from inward. The Type II reconfiguration event is characterized by a distinctive interval (explosive growth phase) just prior to the local commencement of tail phase.

Gravitational force and the cardiovascular system

NASA Technical Reports Server (NTRS)

Pendergast, D. R.; Olszowka, A. J.; Rokitka, M. A.; Farhi, L. E.

1991-01-01

Ground-based simulation studies have been conducted to clarify the problems of the cardiovascular adaptation to alterations in gravitational force. Simulated microgravity experiments resulted in increases in cardiac stretch, urine flow, and sodium excretion, which were accompanied by lower plasma renin, aldosterone, and ADH. There appears to be a decrease in plasma volume as well as in sympathetic tone after 2-3 days of 0 Gz. Complete adjustment to 0 Gz is found within 8 h without a decrease in plasma volume, when subjects are allowed to dehydrate mildly.

Evaluation of the Massachusetts Expanded Learning Time (ELT) Initiative. Year Five Final Report: 2010-2011. Volume I

ERIC Educational Resources Information Center

Checkoway, Amy; Gamse, Beth; Velez, Melissa; Caven, Meghan; de la Cruz, Rodolfo; Donoghue, Nathaniel; Kliorys, Kristina; Linkow, Tamara; Luck, Rachel; Sahni, Sarah; Woodford, Michelle

2012-01-01

The Massachusetts Expanded Learning Time (ELT) initiative was established in 2005 with planning grants that allowed a limited number of schools to explore a redesign of their respective schedules and add time to their day or year. Participating schools are required to expand learning time by at least 300 hours per academic year to improve student…

Inter-conversion of Work and Heat With Plasma Electric Fields

NASA Astrophysics Data System (ADS)

Avinash, K.

2010-11-01

Thermodynamics of a model system where a group of cold charged particles locally confined in a volume VP within a warm plasma of temperature T and fixed volume V (VP<

Experiments on the Expansion of a Dense Plasma into a Background Magnetoplasma

NASA Astrophysics Data System (ADS)

Gekelman, Walter; Vanzeeland, Mike; Vincena, Steve; Pribyl, Pat

2003-10-01

There are many situations, which occur in space (coronal mass ejections, or are man-made (upper atmospheric detonations) as well as the initial stages of a supernovae, in which a dense plasma expands into a background magnetized plasma, that can support Alfvèn waves. The upgraded LArge Plasma Device (LAPD) is a machine, at UCLA, in which Alfvèn wave propagation in homogeneous and inhomogeneous plasmas has been studied. We describe a series of experiments,which involve the expansion of a dense (initially, n_laser-plasma/n_0≫1) laser-produced plasma into an ambient highly magnetized background plasma capable of supporting Alfvèn waves will be presented. The 150 MW laser is pulsed at the same 1 Hz repetition rate as the plasma in a highly reproducible experiment. The interaction results in the production of intense shear Alfvèn waves, as well as large density perturbations. The waves propagate away from the target and are observed to become plasma column resonances. In the initial phase the background magnetic field is expelled from a plasma bubble. Currents in the main body of the plasma are generated to neutralize the positively charged bubble. The current system which results, becomes that of a spectrum of shear Alfvèn waves. Spatial patterns of the wave magnetic fields waves are measured at over 10^4 locations. As the dense plasma expands across the magnetic field it seeds the column with shear waves. Most of the Alfvèn wave energy is in shear waves, which become field line resonances after a machine transit time. The interplay between waves, currents, inductive electric fields and space charge is analyzed in great detail. Dramatic movies of the measured wave fields and their associated currents will be presented. Work supported by ONR, and DOE /NSF.

Generator of the low-temperature heterogeneous plasma flow

NASA Astrophysics Data System (ADS)

Yusupov, D. I.; Gadzhiev, M. Kh; Tyuftyaev, A. S.; Chinnov, V. F.; Sargsyan, M. A.

2018-01-01

A generator of low-temperature dc plasma with an expanding channel of an output electrode for gas-thermal spraying was designed and constructed. The delivery of the sprayed powder into the cathode and anode arc-binding zones or into the plasma jet below the anode binding was realized. The electrophysical characteristics of both the plasma torch and the heterogeneous plasma flow with Al2O3 powder are studied. It is shown that the current-voltage characteristic (CVC) of a plasma torch depends on the gas flow rate. If the flow rate varies from 1 to 3 g/s, the falling CVC becomes gradually increasing. The speed and temperature of the sprayed powder are determined.

Plasma 8-iso-Prostaglandin F2α concentrations and outcomes after acute intracerebral hemorrhage.

PubMed

Du, Quan; Yu, Wen-Hua; Dong, Xiao-Qiao; Yang, Ding-Bo; Shen, Yong-Feng; Wang, Hao; Jiang, Li; Du, Yuan-Feng; Zhang, Zu-Yong; Zhu, Qiang; Che, Zhi-Hao; Liu, Qun-Jie

2014-11-01

Higher plasma 8-iso-Prostaglandin F2α concentrations have been associated with poor outcome of severe traumatic brain injury. We further investigated the relationships between plasma 8-iso-Prostaglandin F2α concentrations and clinical outcomes in patients with acute intracerebral hemorrhage. Plasma 8-iso-Prostaglandin F2α concentrations of 128 consecutive patients and 128 sex- and gender-matched healthy subjects were measured by enzyme-linked immunosorbent assay. We assessed their relationships with disease severity and clinical outcomes including 1-week mortality, 6-month mortality and unfavorable outcome (modified Rankin Scale score>2). Plasma 8-iso-Prostaglandin F2α concentrations were substantially higher in patients than in healthy controls. Plasma 8-iso-Prostaglandin F2α concentrations were positively associated with National Institutes of Health Stroke Scale (NIHSS) scores and hematoma volume using a multivariate linear regression. It emerged as an independent predictor for clinical outcomes of patients using a forward stepwise logistic regression. ROC curves identified the predictive values of plasma 8-iso-Prostaglandin F2α concentrations, and found its predictive value was similar to NIHSS scores and hematoma volumes. However, it just numerically added the predictive values of NIHSS score and hematoma volume. Increased plasma 8-iso-Prostaglandin F2α concentrations are associated with disease severity and clinical outcome after acute intracerebral hemorrhage. Copyright © 2014 Elsevier B.V. All rights reserved.

Current Status of the Polyamine Research Field

PubMed Central

Pegg, Anthony E.; Casero, Robert A.

2013-01-01

This chapter provides an overview of the polyamine field and introduces the 32 other chapters that make up this volume. These chapters provide a wide range of methods, advice, and background relevant to studies of the function of polyamines, the regulation of their content, their role in disease, and the therapeutic potential of drugs targeting polyamine content and function. The methodology provided in this new volume will enable laboratories already working in this area to expand their experimental techniques and facilitate the entry of additional workers into this rapidly expanding field. PMID:21318864

[Transfusion supply optimization in multiple-discipline surgical hospital].

PubMed

Solov'eva, I N; Trekova, N A; Krapivkin, I A

2016-01-01

To define optimal variant of transfusion supply of hospital by blood components and to decrease donor blood expense via application of blood preserving technologies. Donor blood components expense, volume of hemotransfusions and their proportion for the period 2012-2014 were analyzed. Number of recipients of packed red cells, fresh-frozen plasma and packed platelets reduced 18.5%, 25% and 80% respectively. Need for donor plasma decreased 35%. Expense of autologous plasma in cardiac surgery was 76% of overall volume. Preoperative plasma sampling is introduced in patients with aortic aneurysm. Number of cardiac interventions performed without donor blood is increased 7-31% depending on its complexity.

Adhesive blood microsampling systems for steroid measurement via LC-MS/MS in the rat.

PubMed

Heussner, Kirsten; Rauh, Manfred; Cordasic, Nada; Menendez-Castro, Carlos; Huebner, Hanna; Ruebner, Matthias; Schmidt, Marius; Hartner, Andrea; Rascher, Wolfgang; Fahlbusch, Fabian B

2017-04-01

Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS) allows for the direct analysis of multiple hormones in a single probe with minimal sample volume. Rodent-based animal studies strongly rely on microsampling, such as the dry blood spot (DBS) method. However, DBS suffers the drawback of hematocrit-dependence (non-volumetric). Hence, novel volumetric microsampling techniques were introduced recently, allowing sampling of fixed accurate volumes. We compared these methods for steroid analysis in the rat to improve inter-system comparability. We analyzed steroid levels in blood using the absorptive microsampling devices Whatman® 903 Protein Saver Cards, Noviplex™ Plasma Prep Cards and the Mitra™ Microsampling device and compared the obtained results to the respective EDTA plasma levels. Quantitative steroid analysis was performed via LC-MS/MS. For the determination of the plasma volume factor for each steroid, their levels in pooled blood samples from each human adults and rats (18weeks) were compared and the transferability of these factors was evaluated in a new set of juvenile (21days) and adult (18weeks) rats. Hematocrit was determined concomitantly. Using these approaches, we were unable to apply one single volume factor for each steroid. Instead, plasma volume factors had to be adjusted for the recovery rate of each steroid and device individually. The tested microsampling systems did not allow the use of one single volume factor for adult and juvenile rats based on an unexpectedly strong hematocrit-dependency and other steroid specific (pre-analytic) factors. Our study provides correction factors for LC-MS/MS steroid analysis of volumetric and non-volumetric microsampling systems in comparison to plasma. It argues for thorough analysis of chromatographic effects before the use of novel volumetric systems for steroid analysis. Copyright © 2017 Elsevier Inc. All rights reserved.

A linear helicon plasma device with controllable magnetic field gradient

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barada, Kshitish K.; Chattopadhyay, P. K.; Ghosh, J.

2012-06-15

Current free double layers (CFDLs) are localized potential structures having spatial dimensions - Debye lengths and potential drops of more than local electron temperature across them. CFDLs do not need a current for them to be sustained and hence they differ from the current driven double layers. Helicon antenna produced plasmas in an expanded chamber along with an expanding magnetic field have shown the existence of CFDL near the expansion region. A helicon plasma device has been designed, fabricated, and installed in the Institute for Plasma Research, India to study the role of maximum magnetic field gradient as well asmore » its location with respect to the geometrical expansion region of the chamber in CFDL formation. The special feature of this machine consisting of two chambers of different radii is its capability of producing different magnetic field gradients near the physical boundary between the two chambers either by changing current in one particular coil in the direction opposite to that in other coils and/or by varying the position of this particular coil. Although, the machine is primarily designed for CFDL experiments, it is also capable of carrying out many basic plasma physics experiments such as wave propagation, wave coupling, and plasma instabilities in a varying magnetic field topology. In this paper, we will present the details of the machine construction, its specialties, and some preliminary results about the production and characterization of helicon plasma in this machine.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Niemann, Christoph; Gekelman, W.; Winske, D.

We have performed several thousand high-energy laser shots in the LAPD to investigate the dynamics of an exploding laser-produced plasma in a large ambient magneto-plasma. Debris-ions expanding at super-Alfvenic velocity (up to MA=1.5) expel the ambient magnetic field, creating a large (> 20 cm) diamagnetic cavity. We observed field compressions of up to B/B{sub 0} = 1.5 at the edge of the bubble, consistent with the MHD jump conditions, as well as localized electron heating at the edge of the bubble. Two-dimensional hybrid simulations reproduce these measurements well and show that the majority of the ambient ions are energized bymore » the magnetic piston to super-Alfvenic speeds and swept outside the bubble volume. Nonlinear shear-Alfven waves ({delta}B/B{sub 0} > 25%) are radiated from the cavity with a coupling efficiency of 70% from magnetic energy in the bubble to the wave. While the data is consistent with a weak magneto-sonic shock, the experiments were severely limited by the low ambient plasma densities (10{sup 12} cm{sup -3}). 2D hybrid simulations indicate that future experiments with the new LAPD plasma source and densities in excess of 10{sup 13} cm{sup -3} will drive full-blown collisionless shocks with MA>10 over several c/wpi and shocked Larmor radii. In a separate experiment at the LANL Trident laser facility we have performed a proof-of-principle experiment at higher densities to demonstrate key elements of collisionless shocks in laser-produced magnetized plasmas with important implications to NIF. Simultaneously we have upgraded the UCLA glass-laser system by adding two large amplitude disk amplifiers from the NOVA laser and boost the on-target energy from 30 J to up to 1 kJ, making this one of the world’s largest university-scale laser systems. We now have the infrastructure in place to perform novel and unique high-impact experiments on collision-less shocks at the LAPD.« less

On-line atomic data access

NASA Astrophysics Data System (ADS)

Schultz, David R.; Nash, Jeffrey K.

1996-07-01

The need for atomic data is one which continues to expand in a wide variety of applications including fusion energy, astrophysics, laser-produced plasma research, and plasma processing. Modern computer database and communications technology enables this data to be placed on-line and obtained by users over the INTERNET. Presented here is a summary of the observations and conclusions regarding such on-line atomic data access derived from a forum held at the Tenth APS Topical Conference on Atomic Processes in Plasmas.

The natural history of Becker expandable breast implants: a single-center 10-year experience.

PubMed

Sindali, Katia; Davis, Marcus; Mughal, Maleeha; Orkar, Kusu S

2013-09-01

Use of Becker expandable breast implants in single-stage breast surgery is a well-established technique; however, replacement with fixed-volume implants is common. The authors sought to analyze the long-term natural history of these implants over a wide range of surgical indications. A retrospective review of 330 consecutive patients who underwent 384 Becker expander breast reconstructions over a 10-year period in a dedicated plastic surgery unit was undertaken. Implant indication, Becker type, volume and site, complications, expander lifespan, and explant reasons were assessed. Two hundred twenty-eight patients (267 implants) and 102 patients (117 implants) underwent implantation for congenital deformities and breast cancer reconstruction, respectively. One hundred eighty-seven (48 percent) were explanted at a median period of 13.0 months (range, 9.0 to 26.0 months), 149 (39 percent) for aesthetic reasons and 38 (10 percent) for complications. Complication rates were higher in breast cancer reconstruction compared with congenital patients (19.6 percent versus 7.9 percent; p = 0.002), driven by an increased rate of wound complications (13.7 percent versus 4.4 percent; p = 0.003). Cancer-related surgery and advancing age were the only predictors of complication risk. The overall Becker expander retention rate was 24.9 percent and 46.8 percent at 150 months in the cancer reconstruction and congenital groups, respectively. Forty-seven percent of Becker implants were retained long term after congenital corrective surgery; only 25 percent were retained after postmastectomy reconstruction. Poor aesthetics was driving the exchange for fixed-volume implants, indicating that after breast cancer reconstruction, Becker expanders were being used as part of a two-stage reconstructive strategy.

Wiggler magnetic field assisted third harmonic generation in expanding clusters

NASA Astrophysics Data System (ADS)

Vij, Shivani

2018-04-01

A simple theoretical model is constructed to study the wiggler magnetic field assisted third harmonic generation of intense short pulse laser in a cluster in its expanding phase. The ponderomotive force of laser causes density perturbations in cluster electron density which couples with wiggler magnetic field to produce a nonlinear current that generates transverse third harmonic. An intense short pulse laser propagating through a gas embedded with atomic clusters, converts it into hot plasma balls via tunnel ionization. Initially, the electron plasma frequency inside the clusters ω pe > \\sqrt{3}{ω }1 (with ω 1 being the frequency of the laser). As the cluster expands under Coulomb force and hydrodynamic pressure, ω pe decreases to \\sqrt{3}{ω }1. At this time, there is resonant enhancement in the efficiency of the third harmonic generation. The efficiency of third harmonic generation is enhanced due to cluster plasmon resonance and by phase matching due to wiggler magnetic field. The effect of cluster size on the expansion rate is studied to observe that the clusters of different radii would expand differently. The impact of laser intensity and wiggler magnetic field on the efficiency of third harmonic generation is also explored.

GIANT LOBES OF CENTAURUS A RADIO GALAXY OBSERVED WITH THE SUZAKU X-RAY SATELLITE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stawarz, L.; Gandhi, P.; Takahashi, T.

2013-03-20

We report on Suzaku observations of selected regions within the southern giant lobe of the radio galaxy Centaurus A. In our analysis we focus on distinct X-ray features detected with the X-ray Imaging Spectrometer within the range 0.5-10 keV, some of which are likely associated with fine structure of the lobe revealed by recent high-quality radio intensity and polarization maps. With the available photon statistics, we find that the spectral properties of the detected X-ray features are equally consistent with thermal emission from hot gas with temperatures kT > 1 keV, or with a power-law radiation continuum characterized by photonmore » indices {Gamma} {approx} 2.0 {+-} 0.5. However, the plasma parameters implied by these different models favor a synchrotron origin for the analyzed X-ray spots, indicating that a very efficient acceleration of electrons up to {approx}> 10 TeV energies is taking place within the giant structure of Centaurus A, albeit only in isolated and compact regions associated with extended and highly polarized radio filaments. We also present a detailed analysis of the diffuse X-ray emission filling the whole field of view of the instrument, resulting in a tentative detection of a soft excess component best fitted by a thermal model with a temperature of kT {approx} 0.5 keV. The exact origin of the observed excess remains uncertain, although energetic considerations point to thermal gas filling the bulk of the volume of the lobe and mixed with the non-thermal plasma, rather than to the alternative scenario involving a condensation of the hot intergalactic medium around the edges of the expanding radio structure. If correct, this would be the first detection of the thermal content of the extended lobes of a radio galaxy in X-rays. The corresponding number density of the thermal gas in such a case is n{sub g} {approx} 10{sup -4} cm{sup -3}, while its pressure appears to be in almost exact equipartition with the volume-averaged non-thermal pressure provided by the radio-emitting electrons and the lobes' magnetic field. A prominent large-scale fluctuation of the Galactic foreground emission, resulting in excess foreground X-ray emission aligned with the lobe, cannot be ruled out. Although tentative, our findings potentially imply that the structure of the extended lobes in active galaxies is likely to be highly inhomogeneous and non-uniform, with magnetic reconnection and turbulent acceleration processes continuously converting magnetic energy to internal energy of the plasma particles, leading to possibly significant spatial and temporal variations in the plasma {beta} parameter around the volume-averaged equilibrium condition {beta} {approx} 1.« less

Tokamak experimental power reactor conceptual design. Volume II

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1976-08-01

Volume II contains the following appendices: (1) summary of EPR design parameters, (2) impurity control, (3) plasma computational models, (4) structural support system, (5) materials considerations for the primary energy conversion system, (6) magnetics, (7) neutronics penetration analysis, (8) first wall stress analysis, (9) enrichment of isotopes of hydrogen by cryogenic distillation, and (10) noncircular plasma considerations. (MOW)

A Physiologically Based Pharmacokinetic Model to Predict the Pharmacokinetics of Highly Protein-Bound Drugs and Impact of Errors in Plasma Protein Binding

PubMed Central

Ye, Min; Nagar, Swati; Korzekwa, Ken

2015-01-01

Predicting the pharmacokinetics of highly protein-bound drugs is difficult. Also, since historical plasma protein binding data was often collected using unbuffered plasma, the resulting inaccurate binding data could contribute to incorrect predictions. This study uses a generic physiologically based pharmacokinetic (PBPK) model to predict human plasma concentration-time profiles for 22 highly protein-bound drugs. Tissue distribution was estimated from in vitro drug lipophilicity data, plasma protein binding, and blood: plasma ratio. Clearance was predicted with a well-stirred liver model. Underestimated hepatic clearance for acidic and neutral compounds was corrected by an empirical scaling factor. Predicted values (pharmacokinetic parameters, plasma concentration-time profile) were compared with observed data to evaluate model accuracy. Of the 22 drugs, less than a 2-fold error was obtained for terminal elimination half-life (t1/2, 100% of drugs), peak plasma concentration (Cmax, 100%), area under the plasma concentration-time curve (AUC0–t, 95.4%), clearance (CLh, 95.4%), mean retention time (MRT, 95.4%), and steady state volume (Vss, 90.9%). The impact of fup errors on CLh and Vss prediction was evaluated. Errors in fup resulted in proportional errors in clearance prediction for low-clearance compounds, and in Vss prediction for high-volume neutral drugs. For high-volume basic drugs, errors in fup did not propagate to errors in Vss prediction. This is due to the cancellation of errors in the calculations for tissue partitioning of basic drugs. Overall, plasma profiles were well simulated with the present PBPK model. PMID:26531057

Millimeter wave generation by relativistic electron beams and microwave-plasma interaction

NASA Astrophysics Data System (ADS)

Kuo, Spencer

1990-12-01

The design and operation of a compact, high power, millimeter wave source (cusptron) has been completed and proven successful. Extensive theoretical analysis of cusptron beam and rf dynamics has been carried out and published. Theory agrees beautifully with experiment. Microwave Bragg scattering due to been achieved by using expanding plasmas to upshift rf signal frequencies.

Experimental Characterization of Plasma Detachment from Magnetic Nozzles

NASA Astrophysics Data System (ADS)

Olsen, Christopher Scott

Magnetic nozzles, like Laval nozzles, are observed in several natural systems and have application in areas such as electric propulsion and plasma processing. Plasma flowing through these nozzles is inherently tied to the field lines and must separate for momentum redirection or particle transport to occur. Plasma detachment and associated mechanisms from a magnetic nozzle are investigated. Experimental results are presented from the plume of the VASIMRRTM VX-200 device flowing along an axisymmetric magnetic nozzle and operated at two ion energies to explore momentum dependent detachment. The argon plume expanded into a 150m3 vacuum chamber where the background pressure was low enough that charge-exchange mean-free-paths were longer than experiment scale lengths. This magnetic nozzle system is demonstrated to hydrodynamically scale up to astrophysical plasmas, particularly the solar chromosphere, implying general relevance to many systems. Plasma parameters were mapped over a large spatial range using measurements from multiple plasma diagnostics. The data show that the plume does not follow the magnetic field lines. A mapped integration of the ion flux shows the plume may be divided into three regions where 1) the plume briefly follows the magnetic flux, 2) diverges quadratically before 3) expanding with linear trajectories. Transitioning from region 1→2, the ion flux departs from the magnetic flux suggesting ion detachment. An instability forms in region 2 driving an oscillating electric field that causes ions to expand before enhancing electron cross-field transport through anomalous resistivity. Transitioning from region 2→3 the electric field dissipates, the trajectories linearize, and the plume effectively detaches. A delineation of sub-to-super Alfvenic flow aligns well with the inflection points of the linearization without a change in magnetic topology. The detachment process is best described as a two part process: First, ions detach by a breakdown of the magnetic moment when the quantity |v/fcLB| becomes of order unity. Second, the turbulent electric field enhances electron transport up to a factor of 4+/-1 above collisional diffusion; electron cross-field velocities approximate that of the ions and depart on more centralized field lines. Electrons are believed to detach by breakdown of magnetic moment further downstream in the weaker magnetic field.

Overview of HIT-SI Results and Plans

NASA Astrophysics Data System (ADS)

Ennis, D. A.; Akcay, C.; Hansen, C. J.; Hicks, N. K.; Hossack, A. C.; Jarboe, T. R.; Marklin, G. J.; Nelson, B. A.; Victor, B. S.

2011-10-01

Experiments in the Helicity Injected Torus-Steady Inductive (HIT-SI) device have achieved record spheromak current amplification during operations in deuterium plasmas. HIT-SI investigates steady inductive helicity injection with the aim of forming and sustaining a high-beta equilibrium in a spheromak geometry using two semi-toroidal injectors. Recent operations in deuterium plasmas have produced toroidal plasma currents greater than 50 kA, with current amplifications (Itor / Iinj) > 3 , and poloidal flux amplifications (ψpol /ψinj) > 10 . High performance deuterium discharges are achieved by initially conditioning the plasma-facing alumina surface of the HIT-SI confinement volume with helium plasmas. During subsequent deuterium operation the alumina surface strongly pumps deuterium, thereby limiting the density in the confinement volume. Additional measurements during high current deuterium discharges demonstrate reduced current and electron density fluctuations, impurity O III ion temperatures up to 50 eV and a toroidal current persistence for 0.6 ms after the injectors are shut off. Progress and plans for the HIT-SI3 configuration, with three injectors mounted on the same side of the confinement volume, will also be presented. Work supported by USDoE and ARRA.

Automated processing of whole blood samples into microliter aliquots of plasma.

PubMed

Burtis, C A; Johnson, W W; Walker, W A

1988-01-01

A rotor that accepts and automatically processes a bulk aliquot of a single blood sample into multiple aliquots of plasma has been designed and built. The rotor consists of a central processing unit, which includes a disk containing eight precision-bore capillaries. By varying the internal diameters of the capillaries, aliquot volumes ranging 1 to 10 mul can be prepared. In practice, an unmeasured volume of blood is placed in a centre well, and, as the rotor begins to spin, is moved radially into a central annular ring where it is distributed into a series of processing chambers. The rotor is then spun at 3000 rpm for 10 min. When the centrifugal field is removed by slowly decreasing the rotor speed, an aliquot of plasma is withdrawn by capillary action into each of the capillary tubes. The disk containing the eight measured aliquots of plasma is subsequently removed and placed in a modifed rotor for conventional centrifugal analysis. Initial evaluation of the new rotor indicates that it is capable of producing discrete, microliter volumes of plasma with a degree of accuracy and precision approaching that of mechanical pipettes.

Role of atrial natriuretic peptide in systemic responses to acute isotonic volume expansion

NASA Technical Reports Server (NTRS)

Watenpaugh, Donald E.; Yancy, Clyde W.; Buckey, Jay C.; Lane, Lynda D.; Hargens, Alan R.; Blomqvist, C. G.

1992-01-01

A hypothesis is proposed that a temporal relationship exists between increases in cardiac filling pressure and plasma artrial natriuretic peptide (ANP) concentration and also between ANP elevation and vasodilation, fluid movement from plasma to interstitium, and increased urine volume (UV). To test the hypothesis, 30 ml/kg isotonic saline were infused in supine male subjects over 24 min and responses were monitored for 3 h postinfusion. Results show that at end infusion, mean arterial pressure (RAP), heart rate and plasma volume exhibited peak increases of 146, 23, and 27 percent, respectively. Mean plasma ANP and UV peaked (45 and 390 percent, respectively) at 30 min postinfusion. Most cardiovascular variables had returned toward control levels by 1 h postinfusion, and net reabsorption of extravascular fluid ensued. It is concluded that since ANP was not significantly increased until 30 min postinfusion, factors other than ANP initiate responses to intravascular fluid loading. These factors include increased vascular pressures, baroreceptor-mediated vasolidation, and hemodilution of plasma proteins. ANP is suggested to mediate, in part, the renal response to saline infusion.

PREFACE Preface

NASA Astrophysics Data System (ADS)

Degrez, Gérard; van der Mullen, Joost

2011-01-01

It is with pleasure and pride that we present the selected contributions from participants of the 11th High-Tech Plasma Processes conference. This conference, which took place in Brussels from June 28 to July 2 2010, is based on a European forum with a history of more than twenty years. The conference series started as a thermal plasma conference and gradually expanded to include other topics and fields as well. HTPP 11 was organized in collaboration with the Belgian Interuniversity Attraction Pole (IAP): Physical chemistry of Plasma-surface Interactions (PSI-ψ). The program was devised by the plasma group of the Technische Universiteit Eindhoven in collaboration with the IAP, the Association Arc Electrique and the International Scientific Committee. The organization was guided by the Steering Committee and supervised by the two founding members, Jacques Amouroux and Pierre Fauchais. HTPP aims to bring together different scientific communities to facilitate contacts between science, technology and industry, providing a platform for the exploration of elementary processes in and by plasmas. This implies that, apart from fundamental topics, considerable attention is paid to new plasma applications; plasma engineering in Europe is one of the main driving forces behind HTPP. The conference supports the dissemination of methods for plasma diagnostics and monitoring and the exchange of models for plasmas sources and plasma applications. A novelty of HTPP 11 was the model market; a special type of poster session where running models were demonstrated and spectators were challenged to assemble their own plasma models using one of the available construction platforms. For the first time in this series of conferences, the proceedings are published in two companion issues: Journal of Physics D: Applied Physics, which presents a selection of papers including invited and keynote papers, and the Journal of Physics: Conference Series. The present volume of the Journal of Physics: Conference Series includes 21 papers devoted to various branches of plasma physics. In line with the objectives of the HTPP conference, you will find papers on plasma sources, diagnostics and theory, covering the fields of thermal and non-thermal (even cold) plasmas, plasma-electrode interactions, surface treatment, synthesis, light generation and transport, and on applications in the fields of environmental technologies, biochemistry, and aeronautical and space sciences. We would like to thank the members of the various committees, the participants who sent their contributions and the referees who did an excellent job giving support to improve the manuscripts. We greatly appreciate the financial support from the conference sponsors: Association Arc Electrique, Belspo (Belgian Science Policy), Fonds National de la Recherche Scientifique, Ocean Optics Inc., Technifutur - Pôle Génie Mécanique & Solvay S.A.. Gérard DegrezChairman of the Local Organizing Committee Joost van der MullenChairman of the Steering Committee

Laser Ablation Molecular Isotopic Spectrometry for Molecules Formation Chemistry in Femtosecond-Laser Ablated Plasmas.

PubMed

Hou, Huaming; Mao, Xianglei; Zorba, Vassilia; Russo, Richard E

2017-07-18

Recently, laser ablated molecular isotopic spectrometry (LAMIS) has expanded its capability to explore molecules formation mechanism in laser-induced plasma in addition to isotope analysis. LAMIS is a powerful tool for tracking the origination of atoms that is involved in formation of investigated molecules by labeling atoms with their isotopic substitution. The evolutionary formation pathways of organic molecules, especially of C 2 dimers and CN radicals, were frequently reported. However, very little is known about the formation pathways for metallic radicals and heterodimers in laser ablated plasma. This research focuses on elucidating the formation pathways of AlO radicals in femtosecond laser ablated plasma from 18 O-labeled Al 2 O 3 pellet. Plasmas expanding with strong forward bias in the direction normal to the sample surface were generated in the wake of a weakly ionized channel created by a femtosecond laser. The formation mechanism of AlO and influence of air were investigated with multiple plasma diagnostic methods such as monochromatic fast gating imaging, spatiotemporal resolved optical emission spectroscopy, and LAMIS. An advanced LAMIS fitting procedure was used to deduce the spatiotemporal distributions of Al 18 O and Al 16 O number densities and also their ratios. We found that the Al 16 O/Al 18 O number density ratio is higher for plasma portion closer to the sample surface, which suggests that chemical reactions between the plasma plume and ambient air are more intense at the tail of the plasma. The results also reveals that direct association of free Al and O atoms is the main mechanism for the formation of AlO at the early stage of the plasma. To the contrast, chemical reactions between plasma materials and ambient oxygen molecules and the isotope exchange effect are the dominant mechanisms of the formation of AlO and evolution of Al 16 O/Al 18 O number density ratio at the late stage of the plasma.

Laboratory study of collisionless coupling between explosive debris plasma and magnetized ambient plasma

NASA Astrophysics Data System (ADS)

Bondarenko, A. S.; Schaeffer, D. B.; Everson, E. T.; Clark, S. E.; Lee, B. R.; Constantin, C. G.; Vincena, S.; Van Compernolle, B.; Tripathi, S. K. P.; Winske, D.; Niemann, C.

2017-08-01

The explosive expansion of a localized plasma cloud into a relatively tenuous, magnetized, ambient plasma characterizes a variety of astrophysical and space phenomena. In these rarified environments, collisionless electromagnetic processes rather than Coulomb collisions typically mediate the transfer of momentum and energy from the expanding "debris" plasma to the surrounding ambient plasma. In an effort to better understand the detailed physics of collisionless coupling mechanisms, compliment in situ measurements of space phenomena, and provide validation of previous computational and theoretical work, the present research jointly utilizes the Large Plasma Device and the Raptor laser facility at the University of California, Los Angeles to study the super-Alfvénic, quasi-perpendicular expansion of laser-produced carbon (C) and hydrogen (H) debris plasma through preformed, magnetized helium (He) ambient plasma via a variety of diagnostics, including emission spectroscopy, wavelength-filtered imaging, and a magnetic flux probe. Doppler shifts detected in a He1+ ion spectral line indicate that the ambient ions initially accelerate transverse to both the debris plasma flow and the background magnetic field. A qualitative analysis in the framework of a "hybrid" plasma model (kinetic ions and inertia-less fluid electrons) demonstrates that the ambient ion trajectories are consistent with the large-scale laminar electric field expected to develop due to the expanding debris. In particular, the transverse ambient ion motion provides direct evidence of Larmor coupling, a collisionless momentum exchange mechanism that has received extensive theoretical and numerical investigation. In order to quantitatively evaluate the observed Doppler shifts, a custom simulation utilizing a detailed model of the laser-produced debris plasma evolution calculates the laminar electric field and computes the initial response of a distribution of ambient test ions. A synthetic Doppler-shifted spectrum constructed from the simulated test ion velocities excellently reproduces the experimental measurements, verifying that the observed ambient ion motion corresponds to collisionless coupling through the laminar electric field.

Factors Affecting Canagliflozin-Induced Transient Urine Volume Increase in Patients with Type 2 Diabetes Mellitus.

PubMed

Tanaka, Hiroyuki; Takano, Kazuhiko; Iijima, Hiroaki; Kubo, Hajime; Maruyama, Nobuko; Hashimoto, Toshio; Arakawa, Kenji; Togo, Masanori; Inagaki, Nobuya; Kaku, Kohei

2017-02-01

Sodium glucose co-transporter 2 (SGLT2) inhibitors exhibit diuretic activity, which is a possible mechanism underlying the cardiovascular benefit of these inhibitors. However, the osmotic diuresis-induced increase in urine volume, and the risk of dehydration have been of concern with SGLT2 inhibitor treatment. This study aimed to investigate the mechanism underlying SGLT2 inhibitor canagliflozin-induced diuresis in Japanese type 2 diabetes mellitus (T2DM) patients. Thirteen T2DM patients received a daily oral dose of 100 mg canagliflozin before breakfast for 6 days. Blood and urine samples were collected at predetermined time points. The primary endpoint was evaluation of correlations between changes from baseline in urine volume and factors that are known to affect urine volume and between actual urine volume and these factors. Canagliflozin transiently increased urine volume and urinary sodium excretion on Day 1 with a return to baseline levels thereafter. Canagliflozin administration increased urinary glucose excretion, which was sustained during repeated-dose administration. Plasma atrial natriuretic peptide (ANP) and N-terminal pro-b-type natriuretic peptide (NT-proBNP) levels decreased, while plasma renin activity increased. On Day 1 of treatment, changes in sodium and potassium excretion were closely correlated with changes in urine output. A post hoc multiple regression analysis showed changes in sodium excretion and water intake as factors that affected urine volume change at Day 1. Furthermore, relative to that at baseline, canagliflozin decreased blood glucose throughout the day and increased plasma total GLP-1 after breakfast. Canagliflozin induced transient sodium excretion and did not induce water intake at Day 1; hence, natriuresis rather than glucose-induced osmotic diuresis may be a major factor involved in the canagliflozin-induced transient increase in urine output. In addition, canagliflozin decreased plasma ANP and NT-proBNP levels and increased plasma renin activity, which may be a compensatory mechanism for sodium retention, leading to subsequent urine output recovery. UMIN000019462. Mitsubishi Tanabe Pharma Corporation.

( sup 99m Tc)diphosphonate uptake and hemodynamics in arthritis of the immature dog knee

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hansen, E.S.; Soballe, K.; Henriksen, T.B.

1991-03-01

The relationship between (99mTc)diphosphonate uptake and bone hemodynamics was studied in canine carrageenan-induced juvenile chronic arthritis. Blood flow was determined with microspheres, plasma and red cell volumes were measured by labeled fibrinogen and red cells, and the microvascular volume and mean transit time of blood were calculated. Normal femoral epiphyses had lower central and higher subchondral blood flow and diphosphonate uptake values. Epiphyseal vascular volume was uniform, resulting in a greater transit time of blood centrally. In arthritis, blood flow and diphosphonate uptake were increased subchondrally and unaffected centrally, while epiphyseal vascular volume was increased throughout, leading to prolonged transitmore » time centrally. The normal metaphyses had low blood flow and diphosphonate uptake values in cancellous bone and very high values in growth plates, but a large vascular volume throughout. The mean transit time therefore was low in growth plates and high in adjacent cancellous bone. Arthritis caused decreased blood flow and diphosphonate uptake in growth plates but increased vascular volume and transit time of blood. Diphosphonate uptake correlated positively with blood flow and plasma volume and negatively with red cell volume in a nonlinear fashion. Thus, changes in diphosphonate uptake and microvascular hemodynamics occur in both epiphyseal and metaphyseal bone in chronic synovitis of the immature knee. The (99mTc)diphosphonate bone scan seems to reflect blood flow, plasma volume, and red cell volume of bone.« less

New Concept Study for Repair of Bomb-Damaged Runways. Volume I. Concept Identification.

DTIC Science & Technology

1979-09-01

Expanded polystyrene beads would be pneumatically mixed with the cement to form a low density material. Initially, the ratio of foam to cement would...the combinations are presented with this concept. PRIMARY MATERIALS 0 Expanded polystyrene foam beads * Graded aggregate * Quick setting cement 61 E-4...probability of success - high ALTERNATE MATERIALS * Expanded polystyrene foam beads * Organic binders Furan Methyl Methacrylate Epoxy Aminos * Graded

Difference in target definition using three different methods to include respiratory motion in radiotherapy of lung cancer.

PubMed

Sloth Møller, Ditte; Knap, Marianne Marquard; Nyeng, Tine Bisballe; Khalil, Azza Ahmed; Holt, Marianne Ingerslev; Kandi, Maria; Hoffmann, Lone

2017-11-01

Minimizing the planning target volume (PTV) while ensuring sufficient target coverage during the entire respiratory cycle is essential for free-breathing radiotherapy of lung cancer. Different methods are used to incorporate the respiratory motion into the PTV. Fifteen patients were analyzed. Respiration can be included in the target delineation process creating a respiratory GTV, denoted iGTV. Alternatively, the respiratory amplitude (A) can be measured based on the 4D-CT and A can be incorporated in the margin expansion. The GTV expanded by A yielded GTV + resp, which was compared to iGTV in terms of overlap. Three methods for PTV generation were compared. PTV del (delineated iGTV expanded to CTV plus PTV margin), PTV σ (GTV expanded to CTV and A was included as a random uncertainty in the CTV to PTV margin) and PTV ∑ (GTV expanded to CTV, succeeded by CTV linear expansion by A to CTV + resp, which was finally expanded to PTV ∑ ). Deformation of tumor and lymph nodes during respiration resulted in volume changes between the respiratory phases. The overlap between iGTV and GTV + resp showed that on average 7% of iGTV was outside the GTV + resp implying that GTV + resp did not capture the tumor during the full deformable respiration cycle. A comparison of the PTV volumes showed that PTV σ was smallest and PTV Σ largest for all patients. PTV σ was in mean 14% (31 cm 3 ) smaller than PTV del , while PTV del was 7% (20 cm 3 ) smaller than PTV Σ . PTV σ yields the smallest volumes but does not ensure coverage of tumor during the full respiratory motion due to tumor deformation. Incorporating the respiratory motion in the delineation (PTV del ) takes into account the entire respiratory cycle including deformation, but at the cost, however, of larger treatment volumes. PTV Σ should not be used, since it incorporates the disadvantages of both PTV del and PTV σ .

In the Age of Breast Augmentation, Breast Reconstruction Provides an Opportunity to Augment the Breast.

PubMed

Zimmerman, Amanda L; Tugertimur, Bugra; Smith, Paul D; Kumar, Ambuj; Dayicioglu, Deniz

2017-01-01

Augmentation mammoplasty remains the most common cosmetic surgery procedure performed. The objective of this article is to evaluate the impact of augmented volume of the reconstructed breast in patients that undergo nipple-sparing mastectomy and patients previously augmented who undergo mastectomy with tissue expander/implant-based reconstruction. Patients undergoing skin-sparing mastectomy, nipple-sparing mastectomy, and mastectomy after previous augmentation followed by tissue expander/implant-based reconstruction between June 2011 and April 2015 by 2 surgeons at the same institution were included. Retrospective chart review of the patients identified using these criteria was performed to record patient characteristics, complications, breast volume, implant volume, and percentage change in volume at the time of reconstruction. Percentage change of breast volume was calculated using the formula (implant breast weight)/(breast weight) for skin-sparing and nipple-sparing mastectomy patients and (final breast implant weight - [breast weight + augmentation breast implant weight])/([breast weight + augmentation breast implant]) for patients undergoing mastectomy following previous augmentation. A total of 293 patients were included in the study with 63 patients who underwent nipple-sparing mastectomy, 166 patients who underwent skin-sparing mastectomy, and 64 patients who underwent previous augmentation with subsequent mastectomy. Mean percentage change in breast volume was 66% in the nipple-sparing mastectomy group, 15% for the right breast and 18% for the left breast in the skin-sparing mastectomy group, and 81% for the right breast and 72% for the left breast in the mastectomy following previous augmentation group. Complication rate for nipple-sparing mastectomy was 27%, mastectomy following previous augmentation was 20.3%, and skin-sparing mastectomy group was 18.7%. Patients who undergo nipple-sparing mastectomy or mastectomy following previous augmentation have the ability to achieve greater volume in their reconstructed breast via tissue expander/implant-based reconstruction.

Tailoring nanocrystalline diamond film properties

DOEpatents

Gruen, Dieter M [Downers Grove, IL; McCauley, Thomas G [Somerville, MA; Zhou, Dan [Orlando, FL; Krauss, Alan R [Naperville, IL

2003-07-15

A method for controlling the crystallite size and growth rate of plasma-deposited diamond films. A plasma is established at a pressure in excess of about 55 Torr with controlled concentrations of hydrogen up to about 98% by volume, of unsubstituted hydrocarbons up to about 3% by volume and an inert gas of one or more of the noble gases and nitrogen up to about 98% by volume. The volume ratio of inert gas to hydrogen is preferably maintained at greater than about 4, to deposit a diamond film on a suitable substrate. The diamond film is deposited with a predetermined crystallite size and at a predetermined growth rate.

Process scale-up considerations for non-thermal atmospheric-pressure plasma synthesis of nanoparticles by homogenous nucleation

NASA Astrophysics Data System (ADS)

Cole, Jonathan; Zhang, Yao; Liu, Tianqi; Liu, Chang-jun; Mohan Sankaran, R.

2017-08-01

Scale-up of non-thermal atmospheric-pressure plasma reactors for the synthesis of nanoparticles by homogeneous nucleation is challenging because the active volume is typically reduced to facilitate gas breakdown, enhance discharge stability, and limit particle size and agglomeration, but thus limits throughput. Here, we introduce a dielectric barrier discharge reactor consisting of a coaxial electrode geometry for nanoparticle production that enables a simple scale-up strategy whereby increasing the outer and inner electrode diameters, the plasma volume is increased approximately linearly, while maintaining a sufficiently small electrode gap to maintain the electric field strength. We show with two test reactors that for a given residence time, the nanoparticle production rate increases linearly with volume over a range of precursor concentrations, while having minimal effect on the shape of the particle size distribution. However, our study also reveals that increasing the total gas flow rate in a smaller volume reactor leads to an enhancement of precursor conversion and a comparable production rate to a larger volume reactor. These results suggest that scale-up requires better understanding of the influence of reactor geometry on particle growth dynamics and may not always be a simple function of reactor volume.

Observation of a Relaxed Plasma State in a Quasi-Infinite Cylinder

NASA Astrophysics Data System (ADS)

Gray, T.; Brown, M. R.; Dandurand, D.

2013-02-01

A helical relaxed plasma state is observed in a long cylindrical volume. The cylinder is long enough so that the predicted minimum energy state is a close approximation to the infinite cylinder solution. The plasma is injected at v≥50km/s by a coaxial magnetized plasma gun located at one end of the cylindrical volume. The relaxed state is rapidly attained in 1-2 axial Alfvén times after initiation of the plasma. Magnetic data are favorably compared with an analytical model. Magnetic data exhibit broadband fluctuations of the measured axial modes during the formation period. The broadband activity rapidly decays as the energy condenses into the lowest energy mode, which is in agreement with the minimum energy eigenstate of ∇×B=λB.

Observation of a relaxed plasma state in a quasi-infinite cylinder.

PubMed

Gray, T; Brown, M R; Dandurand, D

2013-02-22

A helical relaxed plasma state is observed in a long cylindrical volume. The cylinder is long enough so that the predicted minimum energy state is a close approximation to the infinite cylinder solution. The plasma is injected at v ≥ 50 km/s by a coaxial magnetized plasma gun located at one end of the cylindrical volume. The relaxed state is rapidly attained in 1-2 axial Alfvén times after initiation of the plasma. Magnetic data are favorably compared with an analytical model. Magnetic data exhibit broadband fluctuations of the measured axial modes during the formation period. The broadband activity rapidly decays as the energy condenses into the lowest energy mode, which is in agreement with the minimum energy eigenstate of [Symbol: see text] × B = λB.

Blood Volume: Its Adaptation to Endurance Training

NASA Technical Reports Server (NTRS)

Convertino, Victor A.

1991-01-01

Expansion of blood volume (hypervolemia) has been well documented in both cross-sectional and longitudinal studies as a consequence of endurance exercise training. Plasma volume expansion can account for nearly all of the exercise-induced hypervolemia up to 2-4 wk; after this time expansion may be distributed equally between plasma and red cell volumes. The exercise stimulus for hypervolemia has both thermal and nonthermal components that increase total circulating plasma levels of electrolytes and proteins. Although protein and fluid shifts from the extravascular to intravascular space may provide a mechanism for rapid hypervolemia immediately after exercise, evidence supports the notion that chronic hypervolemia associated with exercise training represents a net expansion of total body water and solutes. This net increase of body fluids with exercise training is associated with increased water intake and decreased urine volume output. The mechanism of reduced urine output appears to be increased renal tubular reabsorption of sodium through a more sensitive aldosterone action in man. Exercise training-induced hypervolemia appears to be universal among most animal species, although the mechanisms may be quite different. The hypervolemia may provide advantages of greater body fluid for heat dissipation and thermoregulatory stability as well as larger vascular volume and filling pressure for greater cardiac stroke volume and lower heart rates during exercise.

A new multi-line cusp magnetic field plasma device (MPD) with variable magnetic field

NASA Astrophysics Data System (ADS)

Patel, A. D.; Sharma, M.; Ramasubramanian, N.; Ganesh, R.; Chattopadhyay, P. K.

2018-04-01

A new multi-line cusp magnetic field plasma device consisting of electromagnets with core material has been constructed with a capability to experimentally control the relative volume fractions of magnetized to unmagnetized plasma volume as well as accurate control on the gradient length scales of mean density and temperature profiles. Argon plasma has been produced using a hot tungsten cathode over a wide range of pressures 5 × 10-5 -1 × 10-3 mbar, achieving plasma densities ranging from 109 to 1011 cm-3 and the electron temperature in the range 1-8 eV. The radial profiles of plasma parameters measured along the non-cusp region (in between two consecutive magnets) show a finite region with uniform and quiescent plasma, where the magnetic field is very low such that the ions are unmagnetized. Beyond that region, both plasma species are magnetized and the profiles show gradients both in temperature and density. The electrostatic fluctuation measured using a Langmuir probe radially along the non-cusp region shows less than 1% (δIisat/Iisat < 1%). The plasma thus produced will be used to study new and hitherto unexplored physics parameter space relevant to both laboratory multi-scale plasmas and astrophysical plasmas.

Plasma Sodium-Osmotic Dissociation and Hormonal Interaction with Drinking-Induced Hypervolemia at 2800 m Altitude

NASA Technical Reports Server (NTRS)

Greenleaf, J. E.; Hinghofer-Szalkay, H.; Roessler, A.; Farrell, P. A.; Loomis, J. L.; Fedele, M. J.; West, J.; Cowell, S. A.; Bowley, Susan M. (Technical Monitor)

2000-01-01

Dissociation between beverage sodium [Na(+)] and osmotic [Osm] concentrations for increasing plasma volume (PV, hypervolemia) appears to refute the high theoretical correlation between plasma [pNa(+)] and [pOsm].

Fluid shifts and endocrine responses during chair rest and water immersion in man

NASA Technical Reports Server (NTRS)

Greenleaf, J. E.; Shvartz, E.; Kravik, S.; Keil, L. C.

1980-01-01

The effects of external water pressure on intercompartmental fluid volume shifts and endocrine responses in man are investigated. Extracellular fluid volumes and plasma and urine electrolyte and endocrine responses of four male subjects were measured during eight hours of head-out water immersion and 16 hours of recovery bed rest and compared to responses obtained during eight hours of chair rest and 16 hours of bed rest without external hydrostatic pressure obtained in the same subjects five months later. Immersion is found to result in a substantial diuresis with respect to chair rest, accounted for by decreases in extracellular volume. A negative water balance during immersion and a positive water balance during chair rest were observed to be accompanied by a shift of extracellular volume to the intracellular compartment, as well as the suppression of plasma arginine vasopressin and renin activities in both regimes. The vasopressin and renin activity decreases are attributed to the increased central blood volume, and half of the plasma loss in immersed subjects is attributed to the effects of external water pressure.

Indocyanine green: A test of hepatic function and a measure of plasma volume in the duck

USGS Publications Warehouse

Patton, J.F.

1978-01-01

1. The exponential removal of ICG from the plasma by the mallard duck liver made possible the measurement of fractional dye clearance (K), plasma volume (PV) and plasma clearance (PC).2. Values obtained for K (14.9%/min), PV (39.2 ml/kg) and PC (5.8 ml/min per kg) agreed with those obtained by other techniques used in a number of species.3. Sex did not affect the removal of ICG by the liver. However, increases in K, PV and PC were noted in hen mallards in laying condition.4. The data should prove useful as baseline values for physiological and pathological studies on the avian liver

Cosmological Implications of the Electron-Positron Aether

NASA Astrophysics Data System (ADS)

Rothwarf, Allen

1997-04-01

An aether is not prohibited on theoretical nor experimental grounds; only a credible physical model for it is lacking.By assuming that the particles and anti-particles created during the "big-bang" origin of the universe have not annihilated one another, but instead, form a bound state plasma, we have a model for a real aether.This aether is dominated by electron-positron pairs at very high density(10**30/cm3),in close analogy with electron-hole droplets formed in laser irradiated semiconductors. The Fermi velocity of this plasma is the speed of light, and the plasma expands at this speed. This gives results for the expanding universe in agreement with the Einstein-deSitter result for a universe dominated by radiation.The speed of light varies with time as do the other fundamental constants.This leads to an alternate explanation for cosmological redshifts. Independent,mini big bangs can occur and account for observed anomalous redshifts. The model can be tested using LIGO apparatus.

21 CFR 864.5950 - Blood volume measuring device.

Code of Federal Regulations, 2011 CFR

2011-04-01

... § 864.5950 Blood volume measuring device. (a) Identification. A blood volume measuring device is a manual, semiautomated, or automated system that is used to calculate the red cell mass, plasma volume... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Blood volume measuring device. 864.5950 Section...

21 CFR 864.5950 - Blood volume measuring device.

Code of Federal Regulations, 2010 CFR

2010-04-01

... § 864.5950 Blood volume measuring device. (a) Identification. A blood volume measuring device is a manual, semiautomated, or automated system that is used to calculate the red cell mass, plasma volume... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Blood volume measuring device. 864.5950 Section...

21 CFR 864.5950 - Blood volume measuring device.

Code of Federal Regulations, 2014 CFR

2014-04-01

... § 864.5950 Blood volume measuring device. (a) Identification. A blood volume measuring device is a manual, semiautomated, or automated system that is used to calculate the red cell mass, plasma volume... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Blood volume measuring device. 864.5950 Section...

21 CFR 864.5950 - Blood volume measuring device.

Code of Federal Regulations, 2013 CFR

2013-04-01

... § 864.5950 Blood volume measuring device. (a) Identification. A blood volume measuring device is a manual, semiautomated, or automated system that is used to calculate the red cell mass, plasma volume... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Blood volume measuring device. 864.5950 Section...

21 CFR 864.5950 - Blood volume measuring device.

Code of Federal Regulations, 2012 CFR

2012-04-01

... § 864.5950 Blood volume measuring device. (a) Identification. A blood volume measuring device is a manual, semiautomated, or automated system that is used to calculate the red cell mass, plasma volume... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Blood volume measuring device. 864.5950 Section...

Ad libitum fluid intake and plasma responses after pickle juice, hypertonic saline, or deionized water ingestion.

PubMed

Allen, Scott; Miller, Kevin C; Albrecht, Jay; Garden-Robinson, Julie; Blodgett-Salafia, Elizabeth

2013-01-01

Adding sodium (Na(+)) to drinks improves rehydration and ad libitum fluid consumption. Clinicians (∼25%) use pickle juice (PJ) to treat cramping. Scientists warn against PJ ingestion, fearing it will cause rapid plasma volume restoration and thereby decrease thirst and delay rehydration. Advice about drinking PJ has been developed but never tested. To determine if drinking small volumes of PJ, hypertonic saline (HS), or deionized water (DIW) affects ad libitum DIW ingestion, plasma variables, or perceptual indicators. Crossover study. Laboratory. Fifteen, euhydrated (urine specific gravity ≤ 1.01) men (age = 22 ± 2 years, height = 178 ± 6 cm, mass = 82.9 ± 8.4 kg). Participants completed 3 testing days (≥ 72 hours between days). After a 30-minute rest, a blood sample was collected. Participants completed 60 minutes of hard exercise (temperature = 36 ± 2°C, relative humidity = 16 ± 1%). Postexercise, they rested for 30 minutes; had a blood sample collected; rated thirst, fullness, and nausea; and ingested 83 ± 8 mL of PJ, HS, or DIW. They rated drink palatability (100-mm visual analog scale) and were allowed to drink DIW ad libitum for 60 minutes. Blood samples and thirst, fullness, and nausea ratings (100-mm visual analog scales) were collected at 15, 30, 45, and 60 minutes posttreatment drink ingestion. Ad libitum DIW volume, percentage change in plasma volume, plasma osmolality (OSMp,) plasma sodium concentration ([Na(+)]p), and thirst, fullness, nausea, and palatability ratings. Participants consumed more DIW ad libitum after HS (708.03 ± 371.03 mL) than after DIW (532.99 ± 337.14 mL, P < .05). Ad libitum DIW ingested after PJ (700.35 ± 366.15 mL) was similar to that after HS and DIW (P > .05). Plasma sodium concentration, OSMp, percentage change in plasma volume, thirst, fullness, and nausea did not differ among treatment drinks over time (P > .05). Deionized water (73 ± 14 mm) was more palatable than HS (17 ± 13 mm) or PJ (26 ± 16 mm, P < .05). The rationale behind advice about drinking PJ is questionable. Participants drank more, not less, after PJ ingestion, and plasma variables and perceptual indicators were similar after PJ and DIW ingestion. Pickle juice did not inhibit short-term rehydration.

Magnetic field in expanding quark-gluon plasma

NASA Astrophysics Data System (ADS)

Stewart, Evan; Tuchin, Kirill

2018-04-01

Intense electromagnetic fields are created in the quark-gluon plasma by the external ultrarelativistic valence charges. The time evolution and the strength of this field are strongly affected by the electrical conductivity of the plasma. Yet, it has recently been observed that the effect of the magnetic field on the plasma flow is small. We compute the effect of plasma flow on magnetic field and demonstrate that it is less than 10%. These observations indicate that the plasma hydrodynamics and the dynamics of electromagnetic field decouple. Thus, it is a very good approximation, on the one hand, to study QGP in the background electromagnetic field generated by external sources and, on the other hand, to investigate the dynamics of magnetic field in the background plasma. We also argue that the wake induced by the magnetic field in plasma is negligible.

Plasma expansion into a waveguide created by a linearly polarized femtosecond laser pulse

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lemos, N.; Grismayer, T.; Cardoso, L.

2013-06-15

We demonstrate the efficient generation of 4 mm and 8 mm long plasma waveguides in hydrogen and helium. These waveguides have matching spots sizes for 13 to 34 μm laser beams. The plasma waveguides are created by ultra-short laser pulses (sub-picosecond) of moderate intensities, ∼10{sup 15}–10{sup 16} W cm{sup −2}, that heat the plasma to initial temperatures of tens of eV in order to create a hot plasma column that will expand into a plasma waveguide. We have determined that the main heating mechanism when using fs laser pulses and plasma densities ∼10{sup 18–19} cm{sup −3} is Above Threshold Ionization.more » Detailed time and space electron density measurements are presented for the laser produced plasma waveguides.« less

Regulation of body fluid volume and electrolyte concentrations in spaceflight.

PubMed

Smith, S M; Krauhs, J M; Leach, C S

1997-01-01

Despite a number of difficulties in performing experiments during weightlessness, a great deal of information has been obtained concerning the effects of spaceflight on the regulation of body fluid and electrolytes. Many paradoxes and questions remain, however. Although body mass, extracellular fluid volume, and plasma volume are reduced during spaceflight and remain so at landing, the changes in total body water are comparatively small. Serum or plasma sodium and osmolality have generally been unchanged or reduced during the spaceflight, and fluid intake is substantially reduced, especially during the first of flight. The diuresis that was predicted to be caused by weightlessness, has only rarely been observed as an increased urine volume. What has been well established by now, is the occurrence of a relative diuresis, where fluid intake decreases more than urine volume does. Urinary excretion of electrolytes has been variable during spaceflight, but retention of fluid and electrolytes at landing has been consistently observed. The glomerular filtration rate was significantly elevated during the SLS missions, and water and electrolyte loading tests have indicated that renal function is altered during readaptation to Earth's gravity. Endocrine control of fluid volumes and electrolyte concentrations may be altered during weightlessness, but levels of hormones in body fluids do not conform to predictions based on early hypotheses. Antidiuretic hormone is not suppressed, though its level is highly variable and its secretion may be affected by space motion sickness and environmental factors. Plasma renin activity and aldosterone are generally elevated at landing, consistent with sodium retention, but inflight levels have been variable. Salt intake may be an important factor influencing the levels of these hormones. The circadian rhythm of cortisol has undoubtedly contributed to its variability, and little is known yet about the influence of spaceflight on circadian rhythms. Atrial natriuretic peptide does not seem to play an important role in the control of natriuresis during spaceflight. Inflight activity of the sympathetic nervous system, assessed by measuring catecholamines and their metabolites and precursors in body fluids, generally seems to be no greater than on Earth, but this system is usually activated at landing. Collaborative experiments on the Mir and the International Space Station should provide more of the data needed from long-term flights, and perhaps help to resolve some of the discrepancies between U.S. and Russian data. The use of alternative methods that are easier to execute during spaceflight, such as collection of saliva instead of blood and urine, should permit more thorough study of circadian rhythms and rapid hormone changes in weightlessness. More investigations of dietary intake of fluid and electrolytes must be performed to understand regulatory processes. Additional hormones that may participate in these processes, such as other natriuretic hormones, should be determined during and after spaceflight. Alterations in body fluid volume and blood electrolyte concentrations during spaceflight have important consequences for readaptation to the 1-G environment. The current assessment of fluid and electrolyte status during weightlessness and at landing and our still incomplete understanding of the processes of adaptation to weightlessness and readaptation to Earth's gravity have resulted in the development of countermeasures that are only partly successful in reducing the postflight orthostatic intolerance experienced by astronauts and cosmonauts. More complete knowledge of these processes can be expected to produce countermeasures that are even more successful, as well as expand our comprehension of the range of adaptability of human physiologic processes.

Regulation of body fluid volume and electrolyte concentrations in spaceflight

NASA Technical Reports Server (NTRS)

Smith, S. M.; Krauhs, J. M.; Leach, C. S.

1997-01-01

Despite a number of difficulties in performing experiments during weightlessness, a great deal of information has been obtained concerning the effects of spaceflight on the regulation of body fluid and electrolytes. Many paradoxes and questions remain, however. Although body mass, extracellular fluid volume, and plasma volume are reduced during spaceflight and remain so at landing, the changes in total body water are comparatively small. Serum or plasma sodium and osmolality have generally been unchanged or reduced during the spaceflight, and fluid intake is substantially reduced, especially during the first of flight. The diuresis that was predicted to be caused by weightlessness, has only rarely been observed as an increased urine volume. What has been well established by now, is the occurrence of a relative diuresis, where fluid intake decreases more than urine volume does. Urinary excretion of electrolytes has been variable during spaceflight, but retention of fluid and electrolytes at landing has been consistently observed. The glomerular filtration rate was significantly elevated during the SLS missions, and water and electrolyte loading tests have indicated that renal function is altered during readaptation to Earth's gravity. Endocrine control of fluid volumes and electrolyte concentrations may be altered during weightlessness, but levels of hormones in body fluids do not conform to predictions based on early hypotheses. Antidiuretic hormone is not suppressed, though its level is highly variable and its secretion may be affected by space motion sickness and environmental factors. Plasma renin activity and aldosterone are generally elevated at landing, consistent with sodium retention, but inflight levels have been variable. Salt intake may be an important factor influencing the levels of these hormones. The circadian rhythm of cortisol has undoubtedly contributed to its variability, and little is known yet about the influence of spaceflight on circadian rhythms. Atrial natriuretic peptide does not seem to play an important role in the control of natriuresis during spaceflight. Inflight activity of the sympathetic nervous system, assessed by measuring catecholamines and their metabolites and precursors in body fluids, generally seems to be no greater than on Earth, but this system is usually activated at landing. Collaborative experiments on the Mir and the International Space Station should provide more of the data needed from long-term flights, and perhaps help to resolve some of the discrepancies between U.S. and Russian data. The use of alternative methods that are easier to execute during spaceflight, such as collection of saliva instead of blood and urine, should permit more thorough study of circadian rhythms and rapid hormone changes in weightlessness. More investigations of dietary intake of fluid and electrolytes must be performed to understand regulatory processes. Additional hormones that may participate in these processes, such as other natriuretic hormones, should be determined during and after spaceflight. Alterations in body fluid volume and blood electrolyte concentrations during spaceflight have important consequences for readaptation to the 1-G environment. The current assessment of fluid and electrolyte status during weightlessness and at landing and our still incomplete understanding of the processes of adaptation to weightlessness and readaptation to Earth's gravity have resulted in the development of countermeasures that are only partly successful in reducing the postflight orthostatic intolerance experienced by astronauts and cosmonauts. More complete knowledge of these processes can be expected to produce countermeasures that are even more successful, as well as expand our comprehension of the range of adaptability of human physiologic processes.

Ex-vivo expansion of CFU-GM and BFU-E in unselected PBMC cultures with Flt3L is enhanced by autologous plasma.

PubMed

Guo, M; Miller, W M; Papoutsakis, E T; Patel, S; James, C; Goolsby, C; Winter, J N

1999-01-01

Previous ex-vivo expansion studies in our laboratory, comparing unselected and CD34(+)-selected PBMC, have shown no advantage for CD34(+) cell selection, in terms of the expansion achieved. Our goal was to develop procedures for consistent generation of large numbers of hematopoietic progenitor and post-progenitor cells from unselected PBMC. Unselected PBMC, collected from cancer patients undergoing apheresis prior to high-dose chemotherapy and autologous stem cell rescue, were expanded ex vivo in static cultures, without a stromal layer, in the presence of Flt3 ligand (Flt3L), a recombinant GM-CSF/IL-3 fusion protein (PIXY321), G-CSF and GM-CSF for 10 days. The addition of 2% autologous plasma to this cytokine combination enhanced expansion of total cell numbers (3.2 fold versus 1.9 fold; p < 0.01), colony-forming units granulocyte-macrophage (CFU-GM) (22.0 fold versus 8.1 fold, p < 0.01) and burst-forming units erythroid (BFU-E) (17.6 fold versus 7.0 fold, 0.01 < p < 0.02). The optimal seeding density for a given specimen was inversely related to the frequency of CD34(+) cells in the sample. CFU-GM expansion with the Flt3L-containing cytokine cocktail was equivalent to that obtained with IL-3, IL-6, G-CSF and SCF, whether or not the cultures were supplemented with autologous plasma. In plasma-free cultures, BFU-E expansion was significantly higher with IL-3, IL-6, G-CSF and SCF than with Flt3L, PIXY321, G-CSF and GM-CSF. In the presence of autologous plasma, however BFU-E expansion was higher in the Flt3L-containing media. In comparison studies, autologous plasma suppressed BFU-E expansion in SCF-containing cultures. Consistent with our colony assay results, dual-parameter flow cytometric analysis of the expanded cell population revealed that supplementation with autologous plasma yielded a significant increase in the numbers of myeloid progenitors in Flt3L-containing cultures. Unselected PBMC from cancer patients can be effectively expanded ex vivo in Flt3L, PIXY321, G-CSF and GM-CSF, supplemented with autologous plasma, yielding high numbers of myeloid and erythroid progenitors.

The effect of radio-frequency self bias on ion acceleration in expanding argon plasmas in helicon sources

NASA Astrophysics Data System (ADS)

Wiebold, Matthew D.

Time-averaged plasma potential differences up to ˜ 165 V over several hundred Debye lengths are observed in low pressure (pn < 1 mTorr) expanding argon plasmas in the Madison Helicon Experiment. The potential gradient leads to ion acceleration exceeding Ei ≈ 7 kTe in some cases. Up to 1 kW of 13.56 MHz RF power is supplied to a half-turn, double-helix antenna in the presence of a nozzle magnetic field up to 1 kG. An RPA measures the IEDF and an emissive probe measures the plasma potential. Single and double probes measure the electron density and temperature. Two distinct mode hops, the capacitive-inductive (E-H) and inductive-helicon (H-W) transitions, are identified by jumps in electron density as RF power is increased. In the capacitive mode, large fluctuations of the plasma potential (Vp--p ≳ 140 V, Vp--p/Vp ≈ 150%) exist at the RF frequency, leading to formation of a self-bias voltage. The mobile electrons can flow from the upstream region during an RF cycle whereas ions cannot, leading to an initial imbalance of flux, and the self-bias voltage builds as a result. The plasma potential in the expansion chamber is held near the floating potential for argon (Vp ≈ 5kTe/e). In the capacitive mode, the ion acceleration is not well described by an ambipolar relation. The accelerated population decay is consistent with that predicted by charge-exchange collisions. Grounding the upstream endplate increases the self-bias voltage compared to a floating endplate. In the inductive and helicon modes, the ion acceleration more closely follows an ambipolar relation, a result of decreased capacitive coupling due to the decreased RF skin depth. The scaling of the potential gradient with the argon flow rate, magnetic field and RF power are investigated, with the highest potential gradients observed for the lowest flow rates in the capacitive mode. The magnitude of the self-bias voltage agrees well with that predicted for RF sheaths. Use of the self-bias effect in a plasma thruster is explored, possibly for a low thrust, high specific impulse mode in a multi-mode helicon thruster. This work could also explain similar potential gradients in expanding helicon plasmas that are ascribed to double layer formation in the literature.

Current-free double layers: A review

NASA Astrophysics Data System (ADS)

Singh, Nagendra

2011-12-01

During the last decade, there has been an upsurge in the research on current-free DLs (CFDLs). Research includes theory, laboratory measurements, and various applications of CFDLs ranging from plasma thrusters to acceleration of charged particles in space and astrophysical plasmas. The purpose of this review is to present a unified understanding of the basic plasma processes, which lead to the formation of CFDLs. The review starts with the discussion on early research on electric fields and double layers (DLs) and ion acceleration in planar plasma expansion. The review continues with the formation of DLs and rarefaction shocks (RFS) in expanding plasma with two electron populations with different temperatures. The basic theory mitigating the formation of a CFDL by two-electron temperature population is reviewed; we refer to such CFDLs as double layers structures formation by two-temperature electron populations (TET-CFDLs). Application of TET-CFDLS to ion acceleration in laboratory and space plasmas was discussed including the formation of stationary steady-state DLs. A quite different type of CFDLs forms in a helicon plasma device (HPD), in which plasma abruptly expands from a narrow plasma source tube into a wide diffusion tube with abruptly diverging magnetic fields. The formation mechanism of the CFDL in HPD, referred here as current free double layer structure in helicon plasma device (HPD-CFDL), and its applications are reviewed. The formation of a TET-CFDL is due to the self-consistent separation of the two electron populations parallel to the ambient magnetic field. In contrast, a HPD-CFDL forms due to self-consistent separation of electrons and ion perpendicular to the abruptly diverging magnetic field in conjunction with the conducting wall of the expansion chamber in the HPD. One-dimensional theoretical models of CFDLs based on steady-state solution of Vlasov-Poisson system of equations are briefly discussed. Applications of CFDLs ranging from helicon double-layer thrusters (HDLTs) to the accelerations of ions in space and astrophysical plasmas are summarized.

Job Counseling and Placement for the Use of Basic Skills. Volume 2: Jobs.

ERIC Educational Resources Information Center

Munger, Sara J.; And Others

Primary intended users of this second volume of a two-volume handbook are professional counselors and placement officers involved in expanding the range of jobs available to persons having only basic cognitive skills (e.g., mentally retarded, slow learners, learning disabled). Summary job requirements information is presented for more than 8,000…

A faster running speed is associated with a greater body weight loss in 100-km ultra-marathoners.

PubMed

Knechtle, Beat; Knechtle, Patrizia; Wirth, Andrea; Alexander Rüst, Christoph; Rosemann, Thomas

2012-01-01

In 219 recreational male runners, we investigated changes in body mass, total body water, haematocrit, plasma sodium concentration ([Na(+)]), and urine specific gravity as well as fluid intake during a 100-km ultra-marathon. The athletes lost 1.9 kg (s = 1.4) of body mass, equal to 2.5% (s = 1.8) of body mass (P < 0.001), 0.7 kg (s = 1.0) of predicted skeletal muscle mass (P < 0.001), 0.2 kg (s = 1.3) of predicted fat mass (P < 0.05), and 0.9 L (s = 1.6) of predicted total body water (P < 0.001). Haematocrit decreased (P < 0.001), urine specific gravity (P < 0.001), plasma volume (P < 0.05), and plasma [Na(+)] (P < 0.05) all increased. Change in body mass was related to running speed (r = -0.16, P < 0.05), change in plasma volume was associated with change in plasma [Na(+)] (r = -0.28, P < 0.0001), and change in body mass was related to both change in plasma [Na(+)] (r = -0.36) and change in plasma volume (r = 0.31) (P < 0.0001). The athletes consumed 0.65 L (s = 0.27) fluid per hour. Fluid intake was related to both running speed (r = 0.42, P < 0.0001) and change in body mass (r = 0.23, P = 0.0006), but not post-race plasma [Na(+)] or change in plasma [Na(+)] (P > 0.05). In conclusion, faster runners lost more body mass, runners lost more body mass when they drank less fluid, and faster runners drank more fluid than slower runners.

Plasma flame for mass purification of contaminated air with chemical and biological warfare agents

NASA Astrophysics Data System (ADS)

Uhm, Han S.; Shin, Dong H.; Hong, Yong C.

2006-09-01

An elimination of airborne simulated chemical and biological warfare agents was carried out by making use of a plasma flame made of atmospheric plasma and a fuel-burning flame, which can purify the interior air of a large volume in isolated spaces such as buildings, public transportation systems, and military vehicles. The plasma flame generator consists of a microwave plasma torch connected in series to a fuel injector and a reaction chamber. For example, a reaction chamber, with the dimensions of a 22cm diameter and 30cm length, purifies an airflow rate of 5000lpm contaminated with toluene (the simulated chemical agent) and soot from a diesel engine (the simulated aerosol for biological agents). Large volumes of purification by the plasma flame will free mankind from the threat of airborne warfare agents. The plasma flame may also effectively purify air that is contaminated with volatile organic compounds, in addition to eliminating soot from diesel engines as an environmental application.

Sheath and bulk expansion induced by RF bias in atmospheric pressure microwave plasma

NASA Astrophysics Data System (ADS)

Lee, Jimo; Nam, Woojin; Lee, Jae Koo; Yun, Gunsu

2017-10-01

A large axial volume expansion of microwave-driven plasma at atmospheric pressure is achieved by applying a low power radio frequency (RF) bias at an axial location well isolated from the original plasma bulk. The evolution of the plasma plume visualized by high speed ICCD imaging suggest that the free electrons drifting toward the bias electrode cause the prodigious expansion of the sheath, creating a stable plasma stream channel between the microwave and the RF electrodes. For argon plasma in ambient air, enhanced emissions of OH and N2 spectral lines are measured in the extended plume region, supporting the acceleration of electrons and subsequent generation of radical species. The coupling of RF bias with microwave provides an efficient way of enlarging the plasma volume and enhancing the production of radicals. Work supported by the National Research Foundation of Korea under BK21+ program and Grant No. 2015R1D1A1A01061556 (Ministry of Education).

Cell volume and plasma membrane osmotic water permeability in epithelial cell layers measured by interferometry.

PubMed

Farinas, J; Verkman, A S

1996-12-01

The development of strategies to measure plasma membrane osmotic water permeability (Pf) in epithelial cells has been motivated by the identification of a family of molecular water channels. A general approach utilizing interferometry to measure cell shape and volume was developed and applied to measure Pf in cell layers. The method is based on the cell volume dependence of optical path length (OPL) for a light beam passing through the cell. The small changes in OPL were measured by interferometry. A mathematical model was developed to relate the interference signal to cell volume changes for cells of arbitrary shape and size. To validate the model, a Mach-Zehnder interference microscope was used to image OPL in an Madin Darby Canine Kidney (MDCK) cell layer and to reconstruct the three-dimensional cell shape (OPL resolution < lambda/25). As predicted by the model, a doubling of cell volume resulted in a change in OPL that was proportional to the difference in refractive indices between water and the extracellular medium. The time course of relative cell volume in response to an osmotic gradient was computed from serial interference images. To measure cell volume without microscopy and image analysis, a Mach-Zehnder interferometer was constructed in which one of two interfering laser beams passed through a flow chamber containing the cell layer. The interference signal in response to an osmotic gradient was analyzed to quantify the time course of relative cell volume. The calculated MDCK cell plasma membrane Pf of 6.1 x 10(-4) cm/s at 24 degrees C agreed with that obtained by interference microscopy and by a total internal reflection fluorescence method. Interferometry was also applied to measure the apical plasma membrane water permeability of intact toad urinary bladder; Pf increased fivefold after forskolin stimulation to 0.04 cm/s at 23 degrees C. These results establish and validate the application of interferometry to quantify cell volume and osmotic water permeability in cell layers.

Restoration of plasma volume after 16 days of head-down tilt induced by a single bout of maximal exercise

NASA Technical Reports Server (NTRS)

Convertino, V. A.; Engelke, K. A.; Ludwig, D. A.; Doerr, D. F.

1996-01-01

Seven healthy men performed maximal exercise 24 h before the end of 16 days exposure to 6 degrees head-down tilt (HDT) to test the hypothesis that such an exercise technique could restore plasma volume (PV) at the end of a simulated space mission. Exercise consisted of supine cycling with graded work rates increasing by 16 W/min to volitional fatigue and required an average of 16 min. The experimental protocol was a standard cross-over design in which the order of treatment (exercise or control) was counterbalanced across all seven subjects. PV, fluid intake (ad libitum), urine output, renal function, and hormones associated with fluid homeostasis were measured before HDT, 24 h before the end of HDT just prior to exercise, and at the end of HDT 24 h after exercise. HDT reduced PV by 16% in both control and exercise conditions. Maximal exercise completely restored plasma volume within 24 h to 3.9 +/- 3.2% of pre-HDT levels despite continued HDT. Compared with control, exercise induced a 660-ml larger positive fluid balance because of greater fluid intake and reduced urine volume during the 24 h after exercise. These results suggest that one bout of maximal leg exercise before return from 16 days of spaceflight may be completely effective in stimulating thirst and restoring plasma volume to preflight levels.

A power-balance model for local helicity injection startup in a spherical tokamak

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barr, Jayson L.; Bongard, Michael W.; Burke, Marcus G.

A 0D circuit model for predicting I p( t) in Local Helicity Injection (LHI) discharges is developed. Analytic formulas for estimating the surface flux of finite-A plasmas developed are modified and expanded to treat highly shaped, ultralow-A tokamak geometry using a database of representative equilibria. Model predictions are compared to sample LHI discharges in the A ~ 1 Pegasus spherical tokamak, and are found to agree within 15% of experimental I p( t). High performance LHI discharges are found to follow the Taylor relaxation current limit for approximately the first half of the current ramp, or I p ≲ 75more » kA. The second half of the current ramp follows a limit imposed by power-balance as plasmas expand from high- A to ultralow- A. Here, this shape evolution generates a significant drop in external plasma inductance, effectively using the plasma’s initially high inductance to drive the current ramp and provide > 70% of the current drive V-s. Projections using this model indicate the relative influences of higher helicity input rate and injector current on the attainable total plasma current.« less

A power-balance model for local helicity injection startup in a spherical tokamak

DOE PAGES

Barr, Jayson L.; Bongard, Michael W.; Burke, Marcus G.; ...

2018-05-15

A 0D circuit model for predicting I p( t) in Local Helicity Injection (LHI) discharges is developed. Analytic formulas for estimating the surface flux of finite-A plasmas developed are modified and expanded to treat highly shaped, ultralow-A tokamak geometry using a database of representative equilibria. Model predictions are compared to sample LHI discharges in the A ~ 1 Pegasus spherical tokamak, and are found to agree within 15% of experimental I p( t). High performance LHI discharges are found to follow the Taylor relaxation current limit for approximately the first half of the current ramp, or I p ≲ 75more » kA. The second half of the current ramp follows a limit imposed by power-balance as plasmas expand from high- A to ultralow- A. Here, this shape evolution generates a significant drop in external plasma inductance, effectively using the plasma’s initially high inductance to drive the current ramp and provide > 70% of the current drive V-s. Projections using this model indicate the relative influences of higher helicity input rate and injector current on the attainable total plasma current.« less

Analysis of Expandability and Modifiability of Computer Configuration Concepts for ATC : Volume I, Distributed Concept

DOT National Transportation Integrated Search

1979-11-01

The questions of expandability and modifiability of a 1990-era Air Traffic Control (ATC) system are addressed. Two strawman systems are described at the functional level: a Baseline System, which represents the ATC system as it might be just after th...

SRB Environment Evaluation and Analysis. Volume 3: ASRB Plume Induced Environments

NASA Technical Reports Server (NTRS)

Bender, R. L.; Brown, J. R.; Reardon, J. E.; Everson, J.; Coons, L. W.; Stuckey, C. I.; Fulton, M. S.

1991-01-01

Contract NAS8-37891 was expanded in late 1989 to initiate analysis of Shuttle plume induced environments as a result of the substitution of the Advanced Solid Rocket Booster (ASRB) for the Redesigned Solid Rocket Booster (RSRB). To support this analysis, REMTECH became involved in subscale and full-scale solid rocket motor test programs which further expanded the scope of work. Later contract modifications included additional tasks to produce initial design cycle environments and to specify development flight instrumentation. Volume 3 of the final report describes these analyses and contains a summary of reports resulting from various studies.

Development of large volume double ring penning plasma discharge source for efficient light emissions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prakash, Ram; Vyas, Gheesa Lal; Jain, Jalaj

In this paper, the development of large volume double ring Penning plasma discharge source for efficient light emissions is reported. The developed Penning discharge source consists of two cylindrical end cathodes of stainless steel having radius 6 cm and a gap 5.5 cm between them, which are fitted in the top and bottom flanges of the vacuum chamber. Two stainless steel anode rings with thickness 0.4 cm and inner diameters 6.45 cm having separation 2 cm are kept at the discharge centre. Neodymium (Nd{sub 2}Fe{sub 14}B) permanent magnets are physically inserted behind the cathodes for producing nearly uniform magnetic fieldmore » of {approx}0.1 T at the center. Experiments and simulations have been performed for single and double anode ring configurations using helium gas discharge, which infer that double ring configuration gives better light emissions in the large volume Penning plasma discharge arrangement. The optical emission spectroscopy measurements are used to complement the observations. The spectral line-ratio technique is utilized to determine the electron plasma density. The estimated electron plasma density in double ring plasma configuration is {approx}2 Multiplication-Sign 10{sup 11} cm{sup -3}, which is around one order of magnitude larger than that of single ring arrangement.« less

Development of large volume double ring penning plasma discharge source for efficient light emissions.

PubMed

Prakash, Ram; Vyas, Gheesa Lal; Jain, Jalaj; Prajapati, Jitendra; Pal, Udit Narayan; Chowdhuri, Malay Bikas; Manchanda, Ranjana

2012-12-01

In this paper, the development of large volume double ring Penning plasma discharge source for efficient light emissions is reported. The developed Penning discharge source consists of two cylindrical end cathodes of stainless steel having radius 6 cm and a gap 5.5 cm between them, which are fitted in the top and bottom flanges of the vacuum chamber. Two stainless steel anode rings with thickness 0.4 cm and inner diameters 6.45 cm having separation 2 cm are kept at the discharge centre. Neodymium (Nd(2)Fe(14)B) permanent magnets are physically inserted behind the cathodes for producing nearly uniform magnetic field of ~0.1 T at the center. Experiments and simulations have been performed for single and double anode ring configurations using helium gas discharge, which infer that double ring configuration gives better light emissions in the large volume Penning plasma discharge arrangement. The optical emission spectroscopy measurements are used to complement the observations. The spectral line-ratio technique is utilized to determine the electron plasma density. The estimated electron plasma density in double ring plasma configuration is ~2 × 10(11) cm(-3), which is around one order of magnitude larger than that of single ring arrangement.

The Role of an Electric Field in the Formation of a Detached Regime in Tokamak Plasma

NASA Astrophysics Data System (ADS)

Senichenkov, I.; Kaveeva, E.; Rozhansky, V.; Sytova, E.; Veselova, I.; Voskoboynikov, S.; Coster, D.

2018-03-01

Modeling of the transition to the detachment of ASDEX Upgrade tokamak plasma with increasing density is performed using the SOLPS-ITER numerical code with a self-consistent account of drifts and currents. Their role in plasma redistribution both in the confinement region and in the scrape-off layer (SOL) is investigated. The mechanism of high field side high-density formation in the SOL in the course of detachment is suggested. In the full detachment regime, when the cold plasma region expands above the X-point and reaches closed magnetic-flux surfaces, plasma perturbation in a confined region may lead to a change in the confinement regime.

Hematological variations at rest and during maximal and submaximal exercise in a cold (0°C) environment

NASA Astrophysics Data System (ADS)

Vogelaere, P.; Brasseur, M.; Quirion, A.; Leclercq, R.; Laurencelle, L.; Bekaert, S.

1990-03-01

The affect of negative thermal stress on hematological variables at rest, and during submaximal (sub ex) and maximal exercise (max ex) were observed for young males who volunteered in two experimental sessions, performed in cold (0°C) and in normal room temperature (20°C). At rest, hematological variables such as RBC and derivates Hb and Hct were significantly increased ( P<0.05) during cold stress exposure, while plasma volume decreased. The findings of this study suggest that the major factor inducing hypovolemia during low thermal stress can be imputed to local plasma water-shift mechanisms and especially to a transient shift of plasma water from intrato extravascular compartments. Rest values for WBC and platelets (Pla) were also slightly increased during cold stress exposure. However this increase can partly be related to hemoconcentration but also to the cold induced hyperventilation activating the lung circulation. Maximal exhaustive exercise induced, in both experimental temperatures, significant ( P<0.05) increments of RBC, Hb, Hct, and WBC while plasma volume decreased. However, Pla increase was less marked. On the other hand, cold stress raised slightly the observed variations of the different hematological variables. Submaximal exercise induced a similar, though non-significant, pattern for the different hematological variables in both experimental conditions. Observed plasma volume (Δ PV%) reduction appears during exercise. However cold stress induced resting plasma volume variations that are transferred at every exercise level. Neither exercise nor cold inducement significantly modified the hematological indices (MCH, MCV, MCHC). In conclusion hematological variables are affected by cold stress exposure, even when subjects perform a physical activity.

Analytical Comparison of In Vitro-Spiked Human Serum and Plasma for PCR-Based Detection of Aspergillus fumigatus DNA: a Study by the European Aspergillus PCR Initiative

PubMed Central

Mengoli, Carlo; Springer, Jan; Bretagne, Stéphane; Cuenca-Estrella, Manuel; Klingspor, Lena; Lagrou, Katrien; Melchers, Willem J. G.; Morton, C. Oliver; Barnes, Rosemary A.; Donnelly, J. Peter; White, P. Lewis

2015-01-01

The use of serum or plasma for Aspergillus PCR testing facilitates automated and standardized technology. Recommendations for serum testing are available, and while serum and plasma are regularly considered interchangeable for use in fungal diagnostics, differences in galactomannan enzyme immunoassay (GM-EIA) performance have been reported and are attributed to clot formation. Therefore, it is important to assess plasma PCR testing to determine if previous recommendations for serum are applicable and also to compare analytical performance with that of serum PCR. Molecular methods testing serum and plasma were compared through multicenter distribution of quality control panels, with additional studies to investigate the effect of clot formation and blood fractionation on DNA availability. Analytical sensitivity and time to positivity (TTP) were compared, and a regression analysis was performed to identify variables that enhanced plasma PCR performance. When testing plasma, sample volume, preextraction-to-postextraction volume ratio, PCR volume, duplicate testing, and the use of an internal control for PCR were positively associated with performance. When whole-blood samples were spiked and then fractionated, the analytical sensitivity and TTP were superior when testing plasma. Centrifugation had no effect on DNA availability, whereas the presence of clot material significantly lowered the concentration (P = 0.028). Technically, there are no major differences in the molecular processing of serum and plasma, but the formation of clot material potentially reduces available DNA in serum. During disease, Aspergillus DNA burdens in blood are often at the limits of PCR performance. Using plasma might improve performance while maintaining the methodological simplicity of serum testing. PMID:26085614

A physiologically based pharmacokinetic model to predict the pharmacokinetics of highly protein-bound drugs and the impact of errors in plasma protein binding.

PubMed

Ye, Min; Nagar, Swati; Korzekwa, Ken

2016-04-01

Predicting the pharmacokinetics of highly protein-bound drugs is difficult. Also, since historical plasma protein binding data were often collected using unbuffered plasma, the resulting inaccurate binding data could contribute to incorrect predictions. This study uses a generic physiologically based pharmacokinetic (PBPK) model to predict human plasma concentration-time profiles for 22 highly protein-bound drugs. Tissue distribution was estimated from in vitro drug lipophilicity data, plasma protein binding and the blood: plasma ratio. Clearance was predicted with a well-stirred liver model. Underestimated hepatic clearance for acidic and neutral compounds was corrected by an empirical scaling factor. Predicted values (pharmacokinetic parameters, plasma concentration-time profile) were compared with observed data to evaluate the model accuracy. Of the 22 drugs, less than a 2-fold error was obtained for the terminal elimination half-life (t1/2 , 100% of drugs), peak plasma concentration (Cmax , 100%), area under the plasma concentration-time curve (AUC0-t , 95.4%), clearance (CLh , 95.4%), mean residence time (MRT, 95.4%) and steady state volume (Vss , 90.9%). The impact of fup errors on CLh and Vss prediction was evaluated. Errors in fup resulted in proportional errors in clearance prediction for low-clearance compounds, and in Vss prediction for high-volume neutral drugs. For high-volume basic drugs, errors in fup did not propagate to errors in Vss prediction. This is due to the cancellation of errors in the calculations for tissue partitioning of basic drugs. Overall, plasma profiles were well simulated with the present PBPK model. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Analytical Comparison of In Vitro-Spiked Human Serum and Plasma for PCR-Based Detection of Aspergillus fumigatus DNA: a Study by the European Aspergillus PCR Initiative.

PubMed

Loeffler, Juergen; Mengoli, Carlo; Springer, Jan; Bretagne, Stéphane; Cuenca-Estrella, Manuel; Klingspor, Lena; Lagrou, Katrien; Melchers, Willem J G; Morton, C Oliver; Barnes, Rosemary A; Donnelly, J Peter; White, P Lewis

2015-09-01

The use of serum or plasma for Aspergillus PCR testing facilitates automated and standardized technology. Recommendations for serum testing are available, and while serum and plasma are regularly considered interchangeable for use in fungal diagnostics, differences in galactomannan enzyme immunoassay (GM-EIA) performance have been reported and are attributed to clot formation. Therefore, it is important to assess plasma PCR testing to determine if previous recommendations for serum are applicable and also to compare analytical performance with that of serum PCR. Molecular methods testing serum and plasma were compared through multicenter distribution of quality control panels, with additional studies to investigate the effect of clot formation and blood fractionation on DNA availability. Analytical sensitivity and time to positivity (TTP) were compared, and a regression analysis was performed to identify variables that enhanced plasma PCR performance. When testing plasma, sample volume, preextraction-to-postextraction volume ratio, PCR volume, duplicate testing, and the use of an internal control for PCR were positively associated with performance. When whole-blood samples were spiked and then fractionated, the analytical sensitivity and TTP were superior when testing plasma. Centrifugation had no effect on DNA availability, whereas the presence of clot material significantly lowered the concentration (P = 0.028). Technically, there are no major differences in the molecular processing of serum and plasma, but the formation of clot material potentially reduces available DNA in serum. During disease, Aspergillus DNA burdens in blood are often at the limits of PCR performance. Using plasma might improve performance while maintaining the methodological simplicity of serum testing. Copyright © 2015 Loeffler et al.

Debye sheath mechanism at laser plasma interaction and generalization to nuclear forces and quark-gluon plasma

NASA Astrophysics Data System (ADS)

Osman, Frederick; Ghahramani, Nader; Hora, Heinrich

2005-10-01

The studies of laser ablation have lead to a new theory of nuclei, endothermic nuclei generation, and quark-gluon plasmas. The surface of ablated plasma expanding into vacuum after high power laser irradiation of targets contains an electric double layer having the thickness of the Debye length. This led to the discovery of surface tension in plasmas, and led to the internal dynamic electric fields in all inhomogeneous plasmas. The surface tension causes stabilization by short length surface wave smoothing the expanding plasma plume and to stabilization against the Rayleigh Taylor instability. Generalizing this to the degenerate electrons in a metal with the Fermi energy instead of the temperature resulted in the first quantum theory of surface tension of metals in agreement with measurements. Taking the Fermi energy in the Debye length for nucleons results in a theory of nuclei with stable confinement of protons and neutrons just at the well-known nuclear density, and the Debye lengths equal to the Hofstadter decay of the nuclear surface. Increasing the nuclear density by a factor of 10 leads to a change of the Fermi energy into its relativistic branch where no surface energy is possible and the particle mass is not defined, permitting the quark gluon plasma. Expansion of this higher density at the big bang or in super-nova results in nucleation and element generation. The Boltzmann equilibrium permits the synthesis of nuclei even in the endothermic range, however with the limit to about uranium. A relation for the magic numbers leads to a quark structure of nuclear shells that can be understood as a duality property of nuclei with respect to nucleons and quarks

Tissue Expander Overfilling: Achieving New Dimensions of Customization in Breast Reconstruction

PubMed Central

Treiser, Matthew D.; Lahair, Tracy

2016-01-01

Introduction: Overfill of tissue expanders is a commonly used modality to achieve customized dimensions in breast reconstruction. Little formal study of the dynamics of hyperexpansion of these devices has been performed to date, however. Methods: Overfill trials were performed using both Natrelle 133 MV and Mentor 8200 tissue expanders of indicated capacities ranging from 250 to 800 mL. Each expander was initially filled to its indicated capacity with normal water and then injected in regular increments to 400% overfill. Measurements of each expander’s width, height, and projection were made at indicated capacity and with each successive incremental overfill injection, and these results were then recorded, collated, and analyzed. Results: Over the first 50% overfill, all expanders demonstrated a logarithmic increase in projection (mean increase, 143 ± 9%) while maintaining essentially stable base dimensions. Overfill levels in excess of 50% were accompanied by linear increases in height, width, and projection, during which projection approached, but never equaled, base dimensions. Stress versus strain analyses demonstrated nonlinear biomechanical dynamics during the first 50% overfill, followed by standard elastic dynamics up to 400% overfill. At no point during the study, did expander tensions outstrip elastic properties, thereby explaining the lack of device rupture. Conclusions: Through overfilling, tunable geometries of tissue expanders can be accessed that may provide for increasing customization of reconstructions, particularly at overfill volumes up to 50% over indicated capacity. This study should serve to guide tissue expander selection and fill volumes that surgeons may implement in obtaining ideal reconstructed breast shapes. PMID:27014541

Comparison of saline and fludrocortisone as fluid-loading countermeasures following exposure to simulated microgravity

NASA Technical Reports Server (NTRS)

Vernikos, J.; Ludwig, D. A.; Convertino, V. A.

1992-01-01

Saline loading (SL) within hours of reentry is currently used as a countermeasure against postflight orthostatic hypotension in astronauts. However, its effects on blood volume expansion is not quantified and its effectiveness has proved marginal at best. The purposes of the present study were: (1) to quantify the effects of SL on plasma volume and orthostatic tolerance following exposure to simulated microgravity and (2) to compare these effects with the use of a pharacological fluid expander, fludrcortisone (F). Method: Eleven men (30-45 yr.) underwent a 15-minute stand test before and immediately after 7 days of head-down bedrest (BR). Five subjects ingested SL (8 g salt tablets with 1 liter of water) 2 hours before standing at the end of BR while the other 6 subjects received 0.2 mg oral doses of F at 0800 and 2200 hours the day before and 0800 hours the day the subjects got out of bed (i.e., 2 hours before standing). Plasma volume (PV) was measured before BR on day 7 of BR and after the final SL and F treatments just before the post-BR stand test. Blood pressure and heart rate were measured continuously during the stand tests. Results: BR decreased PV from 40.7 plus or minus 1.9 mml/kg to 35.9 plus or minus 1.1 ml/kg (minus 11.8 percent P less than 0.05). Following SL, PV remained at 36.4 plus or minus 1.5 ml/kg while F returned PV to 39.1 plus or minus 1.8 ml/kg. The post BR stand test was completed without syncopal symptoms by 5 of 6 F subjects but only 2 of 5 SL subjects. Conclusions: SL may be ineffective in restoring PV to preflight levels and may provide inadequate protection against postflight orthostatic hypotension. In contrast, F may provide a promising countermeasure since it restored PV and reduced the incidence of syncope following exposure to simulated microgravity in the present study.

Inappropriate Vasopressin Secretion (SIADH) in Burned Patients

DTIC Science & Technology

1983-03-01

cular route, can promote the secretion of AVP in animals effective arterial volume relative to increased metabolic (24, 28, 29). Plasma renin activity...caloric intake (estimated resting metabolic (ileus or obtundation) were considered separately (Figs. rate, +25%) was begun in the first week. Morphine...further suggest adequate effective volume. for AVP secretion is set at a lower than normal plasma Whether the hypermetabolic state and increased O de

Physiological Responses to Acute Exercise-Heat Stress

DTIC Science & Technology

1988-01-01

muscle contraction and to dissipate the associated heat release. In hot environments, the core to skin temperature gradient is reduced to skin blood flow needs to be relatively high (compared to cooler environments) to achieve heat transfer sufficient for thermal balance. In addition, sweat secretion can result in a reduced plasma (by dehydration) and thus blood volume. Both high skin blood flow and reduced plasma volume can reduce

Rapid Weight Loss and the Body Fluid Balance and Hemoglobin Mass of Elite Amateur Boxers

PubMed Central

Reljic, Dejan; Hässler, Eike; Jost, Joachim; Friedmann-Bette, Birgit

2013-01-01

Context Dehydration is assumed to be a major adverse effect associated with rapid loss of body mass for competing in a lower weight class in combat sports. However, the effects of such weight cutting on body fluid balance in a real-life setting are unknown. Objective To examine the effects of 5% or greater loss of body mass within a few days before competition on body water, blood volume, and plasma volume in elite amateur boxers. Design Case-control study. Setting Sports medicine laboratory. Patients or Other Participants Seventeen male boxers (age = 19.2 ± 2.9 years, height = 175.1 ± 7.0 cm, mass = 65.6 ± 9.2 kg) were assigned to the weight-loss group (WLG; n = 10) or the control group (CON; n = 7). Intervention(s) The WLG reduced body mass by restricting fluid and food and inducing excessive sweat loss by adhering to individual methods. The CON participated in their usual precompetition training. Main Outcome Measure(s) During an ordinary training period (t-1), 2 days before competition (t-2), and 1 week after competition (t-3), we performed bioelectrical impedance measurements; calculated total body water, intracellular water, and extracellular water; and estimated total hemoglobin mass (tHbmass), blood volume, and plasma volume by the CO-rebreathing method. Results In the WLG, the loss of body mass (5.6% ± 1.7%) led to decreases in total body water (6.0% ± 0.9%), extracellular water (12.4% ± 7.6%), tHbmass (5.3% ± 3.8%), blood volume (7.6% ± 2.1%; P < .001), and plasma volume (8.6% ± 3.9%). The intracellular water did not change (P > .05). At t-3, total body water, extracellular water, and plasma volume had returned to near baseline values, but tHbmass and blood volume still were less than baseline values (P < .05). In CON, we found no changes (P > .05). Conclusions In a real-life setting, the loss of approximately 6% body mass within 5 days induced hypohydration, which became evident by the decreases in body water and plasma volume. The reduction in tHbmass was a surprising observation that needs further investigation. PMID:23672332

Atmospheric and Space Sciences: Ionospheres and Plasma Environments

NASA Astrophysics Data System (ADS)

Yiǧit, Erdal

2018-01-01

The SpringerBriefs on Atmospheric and Space Sciences in two volumes presents a concise and interdisciplinary introduction to the basic theory, observation & modeling of atmospheric and ionospheric coupling processes on Earth. The goal is to contribute toward bridging the gap between meteorology, aeronomy, and planetary science. In addition recent progress in several related research topics, such atmospheric wave coupling and variability, is discussed. Volume 1 will focus on the atmosphere, while Volume 2 will present the ionospheres and the plasma environments. Volume 2 is aimed primarily at (research) students and young researchers that would like to gain quick insight into the basics of space sciences and current research. In combination with the first volume, it also is a useful tool for professors who would like to develop a course in atmospheric and space physics.

Pentagastrin-induced hemoconcentration in healthy volunteers and patients with panic disorder: effect of pretreatment with ethinyl estradiol.

PubMed

Le Melledo, Jean Michel; Perez-Parada, Jorge; Morrow, Jarret; Bellavance, Francois; Lara, Nathalie; Jahandar, Farideh; Granger, Robert; Tait, Glendon; McManus, Karen

2011-01-01

Panic disorder has been associated with both an increased risk of coronary events as well as an increased risk of stroke. Hemoconcentration, with both a decrease in plasma volume and an increase in plasma viscosity, is a possible contributor to the risk of acute ischemic events. Our objectives were to demonstrate the process of hemoconcentration in response to induced panic symptoms and to assess the effect of pretreatment with ethinyl estradiol on panic-induced hemoconcentration. Fifteen male patients with panic disorder and 10 male healthy volunteers were included in a double-blind cross-over placebo-controlled design consisting of two injections of pentagastrin following randomized pretreatment with placebo and ethinyl estradiol. Plasma levels of hematocrit and hemoglobin were assessed at baseline and post-injections, and used to calculate an indirect estimation of the change in plasma volume. Pentagastrin-induced panic symptoms were associated with a mean decrease in plasma volume of 4.8% in the placebo pretreatment condition. Pretreatment with ethinyl estradiol attenuated this effect. The acute hemoconcentration observed in relation to pentagastrin-induced panic symptoms may be relevant to the increased risk of stroke and acute coronary events found in patients with panic disorder.

Numerical analysis of the static performance of an annular aerostatic gas thrust bearing applied in the cryogenic turbo-expander of the EAST subsystem

NASA Astrophysics Data System (ADS)

Lai, Tianwei; Fu, Bao; Chen, Shuangtao; Zhang, Qiyong; Hou, Yu

2017-02-01

The EAST superconducting tokamak, an advanced steady-state plasma physics experimental device, has been built at the Institute of Plasma Physics, Chinese Academy of Sciences. All the toroidal field magnets and poloidal field magnets, made of NbTi/Cu cable-in-conduit conductor, are cooled with forced flow supercritical helium at 3.8 K. The cryogenic system of EAST consists of a 2 kW/4 K helium refrigerator and a helium distribution system for the cooling of coils, structures, thermal shields, bus-lines, etc. The high-speed turbo-expander is an important refrigerating component of the EAST cryogenic system. In the turbo-expander, the axial supporting technology is critical for the smooth operation of the rotor bearing system. In this paper, hydrostatic thrust bearings are designed based on the axial load of the turbo-expander. Thereafter, a computational fluid dynamics-based numerical model of the aerostatic thrust bearing is set up to evaluate the bearing performance. Tilting effect on the pressure distribution and bearing load is analyzed for the thrust bearing. Bearing load and stiffness are compared with different static supply pressures. The net force from the thrust bearings can be calculated for different combinations of bearing clearance and supply pressure.

Severe leptospirosis with multiple organ failure successfully treated by plasma exchange and high-volume hemofiltration.

PubMed

Bourquin, Vincent; Ponte, Belén; Hirschel, Bernard; Pugin, Jérôme; Martin, Pierre-Yves; Saudan, Patrick

2011-01-01

Background. Leptospirosis is a spirochetal zoonosis with complex clinical features including renal and liver failure. Case report. We report the case of a Swiss fisherman presenting with leptospirosis. After initial improvement, refractory septic shock and severe liver and kidney failure developed. The expected mortality was estimated at 90% with clinical scores. The patient underwent plasma exchanges and high-volume hemofiltration (HVHF) with complete recovery of hepatic and kidney functions. Discussion. Plasma exchanges and HVHF may confer survival benefit on patients with severe leptospirosis, refractory septic shock, and multiple-organ failure.

Thermophysical Properties of Matter - the TPRC Data Series. Volume 14. Master Index - To Materials and Properties

DTIC Science & Technology

1979-01-01

Chloropentalfluoroothane - - - - - - - 11 140 1 - Chloropropane - 69 22 -- - - - Chlorosi lane - 6s 22 - - - - - - a-Chlorotoluens - 6s 22 - - - - - - -Chlorotofuene - 6s...Properties,’ Touloukian, 1 .S. and Ho, C. Y., 197 pp., 1979. To further expand this Data Series and to facilitate current research studies, this Master...Editor Volume 1 . Thermal Conductivity-Metallic Elements and Alloys Volume 2. Thermal Conductivity-Nonmetallic Solids Volume 3. Thermal Conductivity

Physiologic volume of phosphorus during hemodialysis: predictions from a pseudo one-compartment model.

PubMed

Leypoldt, John K; Akonur, Alp; Agar, Baris U; Culleton, Bruce F

2012-10-01

The kinetics of plasma phosphorus concentrations during hemodialysis (HD) are complex and cannot be described by conventional one- or two-compartment kinetic models. It has recently been shown by others that the physiologic (or apparent distribution) volume for phosphorus (Vr-P) increases with increasing treatment time and shows a large variation among patients treated by thrice weekly and daily HD. Here, we describe the dependence of Vr-P on treatment time and predialysis plasma phosphorus concentration as predicted by a novel pseudo one-compartment model. The kinetics of plasma phosphorus during conventional and six times per week daily HD were simulated as a function of treatment time per session for various dialyzer phosphate clearances and patient-specific phosphorus mobilization clearances (K(M)). Vr-P normalized to extracellular volume from these simulations were reported and compared with previously published empirical findings. Simulated results were relatively independent of dialyzer phosphate clearance and treatment frequency. In contrast, Vr-P was strongly dependent on treatment time per session; the increase in Vr-P with treatment time was larger for higher values of K(M). Vr-P was inversely dependent on predialysis plasma phosphorus concentration. There was significant variation among predicted Vr-P values, depending largely on the value of K(M). We conclude that a pseudo one-compartment model can describe the empirical dependence of the physiologic volume of phosphorus on treatment time and predialysis plasma phosphorus concentration. Further, the variation in physiologic volume of phosphorus among HD patients is largely due to differences in patient-specific phosphorus mobilization clearance. © 2012 The Authors. Hemodialysis International © 2012 International Society for Hemodialysis.

Mechanism of Thirst Attenuation During Head-Out Water Immersion in Men

NASA Technical Reports Server (NTRS)

Wada, F.; Sagawa, S.; Miki, K.; Nagaya, K.; Nakamitsu, S.; Shiraki, K.; Greenleaf, J. E.

1994-01-01

The purpose was to determine whether extracellular volume or osmolality was the major contributing factor for reduction of thirst in air and head-out water immersion in hypohydrated subjects. Eight males (19 - 25 yr) were subjected to thermoneutral immersion and thermoneutral air under two hydration conditions without further drinking: euhydration in water (Eu-H2O) and euhydration in air, and hypohydration in water (Hypo-H2O) and hypohydration in air (3.7% wt loss after exercise in heat). The increased thirst sensation with Hypo-H2O decreased (P less than 0.05) within 10 min of immersion and continued thereafter. Mean plasma osmolality (288 +/- 1 mosmol/kg H2O) and sodium (140 +/- 1 meq/1) remained elevated, and plasma volume increased by 4.2 +/- 1.0% (P less than 0.05) throughout Hypo-H2O. A sustained increase (P less than 0.05) in stroke volume accompanied the prompt and sustained decrease in plasma renin activity and sustained increase (P less than 0.05) in plasma atrial natriuretic peptide during Eu-H2O and Hypo-H2O. Plasma vasopressin decreased from 5.3 +/- 0.7 to 2.9 +/- 0.5 pg/ml (P less than 0.05) during Hypo-H2O but was unchanged in Eu-H2O. These findings suggest a sustained stimulation of the atrial baroreceptors and reduction of a dipsogenic stimulus without major alterations of extracellular osmolality in Hypo-H2O. Thus it appears that vascular volume induced stimuli of cardiopulmonary baroreceptors play a more important role than extracellular osmolality in reducing thirst sensations during immersion in hypohydrated subjects. Thus the purpose for this study was to determine the relative importance of volume and osmotic stimuli, and associated hormonal interaction, for attenuation of thirst during immersion.

Pressure-dependent changes in haematocrit and plasma volume during anaesthesia, a randomised clinical trial.

PubMed

Damén, T; Reinsfelt, B; Redfors, B; Nygren, A

2016-05-01

Induction of general anaesthesia has been shown to cause haemodilution and an increase in plasma volume. The aim of this study was to evaluate whether prevention of hypotension during anaesthesia induction could avoid haemodilution. Twenty-four cardiac surgery patients, 66 ± 10 years, were randomised to receive either norepinephrine in a dose needed to maintain mean arterial blood pressure (MAP) at pre-anaesthesia levels after induction or to a control group that received vasopressor if MAP decreased below 60 mmHg. No fluids were infused. Changes in plasma volume were calculated with standard formula: 100 × (Hct(pre)/Hct(post) - 1)/(1 - Hct(pre)). Arterial blood gas was analysed every 10 minutes and non-invasive continuous haemoglobin (SpHb) was continuously measured. Pre-anaesthesia MAP was 98 ± 7 mmHg. Ten minutes after anaesthesia induction, the haematocrit decreased by 5.0 ± 2.5% in the control group compared with 1.2 ± 1.4% in the intervention group, which corresponds to increases in plasma volume by 310 ml and 85 ml respectively. MAP decreased to 69 ± 15 mmHg compared to 92 ± 10 mmHg in the intervention group. The difference maintained throughout the 70 min intervention period. The change in haemoglobin level measured by blood gas analysis could not be detected by SpHb measurement. The mean bias between the SpHb and blood gas haemoglobin was 15 g/l. During anaesthesia induction, haematocrit decreases and plasma volume increases early and parallel to a decrease in blood pressure. This autotransfusion is blunted when blood pressure is maintained at pre-induction levels with norepinephrine. © 2016 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Disassembly time of deuterium-cluster-fusion plasma irradiated by an intense laser pulse.

PubMed

Bang, W

2015-07-01

Energetic deuterium ions from large deuterium clusters (>10nm diameter) irradiated by an intense laser pulse (>10(16)W/cm(2)) produce DD fusion neutrons for a time interval determined by the geometry of the resulting fusion plasma. We present an analytical solution of this time interval, the plasma disassembly time, for deuterium plasmas that are cylindrical in shape. Assuming a symmetrically expanding deuterium plasma, we calculate the expected fusion neutron yield and compare with an independent calculation of the yield using the concept of a finite confinement time at a fixed plasma density. The calculated neutron yields agree quantitatively with the available experimental data. Our one-dimensional simulations indicate that one could expect a tenfold increase in total neutron yield by magnetically confining a 10-keV deuterium fusion plasma for 10ns.

Very Large Area/Volume Microwave ECR Plasma and Ion Source

NASA Technical Reports Server (NTRS)

Foster, John E. (Inventor); Patterson, Michael J. (Inventor)

2009-01-01

The present invention is an apparatus and method for producing very large area and large volume plasmas. The invention utilizes electron cyclotron resonances in conjunction with permanent magnets to produce dense, uniform plasmas for long life ion thruster applications or for plasma processing applications such as etching, deposition, ion milling and ion implantation. The large area source is at least five times larger than the 12-inch wafers being processed to date. Its rectangular shape makes it easier to accommodate to materials processing than sources that are circular in shape. The source itself represents the largest ECR ion source built to date. It is electrodeless and does not utilize electromagnets to generate the ECR magnetic circuit, nor does it make use of windows.

A new multi-line cusp magnetic field plasma device (MPD) with variable magnetic field.

PubMed

Patel, A D; Sharma, M; Ramasubramanian, N; Ganesh, R; Chattopadhyay, P K

2018-04-01

A new multi-line cusp magnetic field plasma device consisting of electromagnets with core material has been constructed with a capability to experimentally control the relative volume fractions of magnetized to unmagnetized plasma volume as well as accurate control on the gradient length scales of mean density and temperature profiles. Argon plasma has been produced using a hot tungsten cathode over a wide range of pressures 5 × 10 -5 -1 × 10 -3 mbar, achieving plasma densities ranging from 10 9 to 10 11 cm -3 and the electron temperature in the range 1-8 eV. The radial profiles of plasma parameters measured along the non-cusp region (in between two consecutive magnets) show a finite region with uniform and quiescent plasma, where the magnetic field is very low such that the ions are unmagnetized. Beyond that region, both plasma species are magnetized and the profiles show gradients both in temperature and density. The electrostatic fluctuation measured using a Langmuir probe radially along the non-cusp region shows less than 1% (δI isat /I isat < 1%). The plasma thus produced will be used to study new and hitherto unexplored physics parameter space relevant to both laboratory multi-scale plasmas and astrophysical plasmas.

Universal attractor in a highly occupied non-Abelian plasma

NASA Astrophysics Data System (ADS)

Berges, J.; Boguslavski, K.; Schlichting, S.; Venugopalan, R.

2014-06-01

We study the thermalization process in highly occupied non-Abelian plasmas at weak coupling. The nonequilibrium dynamics of such systems is classical in nature and can be simulated with real-time lattice gauge theory techniques. We provide a detailed discussion of this framework and elaborate on the results reported in J. Berges, K. Boguslavski, S. Schlichting, and R. Venugopalan, Phys. Rev. D 89, 074011 (2014), 10.1103/PhysRevD.89.074011 along with novel findings. We demonstrate the emergence of universal attractor solutions, which govern the nonequilibrium evolution on large time scales both for nonexpanding and expanding non-Abelian plasmas. The turbulent attractor for a nonexpanding plasma drives the system close to thermal equilibrium on a time scale t ˜Q-1αs-7/4. The attractor solution for an expanding non-Abelian plasma leads to a strongly interacting albeit highly anisotropic system at the transition to the low-occupancy or quantum regime. This evolution in the classical regime is, within the uncertainties of our simulations, consistent with the "bottom up" thermalization scenario [R. Baier, A. H. Mueller, D. Schiff, and D. T. Son, Phys. Lett. B 502, 51 (2001), 10.1016/S0370-2693(01)00191-5]. While the focus of this paper is to understand the nonequilibrium dynamics in weak coupling asymptotics, we also discuss the relevance of our results for larger couplings in the early time dynamics of heavy ion collision experiments.

Laser sustained discharge nozzle apparatus for the production of an intense beam of high kinetic energy atomic species

DOEpatents

Cross, Jon B.; Cremers, David A.

1988-01-01

Laser sustained discharge apparatus for the production of intense beams of high kinetic energy atomic species. A portion of the plasma resulting from a laser sustained continuous optical discharge which generates energetic atomic species from a gaseous source thereof is expanded through a nozzle into a region of low pressure. The expanded plasma contains a significant concentration of the high kinetic energy atomic species which may be used to investigate the interaction of surfaces therewith. In particular, O-atoms having velocities in excess of 3.5 km/s can be generated for the purpose of studying their interaction with materials in order to develop protective materials for spacecraft which are exposed to such energetic O-atoms during operation in low earth orbit.

Laser sustained discharge nozzle apparatus for the production of an intense beam of high kinetic energy atomic species

DOEpatents

Cross, J.B.; Cremers, D.A.

1986-01-10

Laser sustained discharge apparatus for the production of intense beams of high kinetic energy atomic species is described. A portion of the plasma resulting from a laser sustained continuous optical discharge which generates energetic atomic species from a gaseous source thereof is expanded through a nozzle into a region of low pressure. The expanded plasma contains a significant concentration of the high kinetic energy atomic species which may be used to investigate the interaction of surfaces therewith. In particular, O-atoms having velocities in excess of 3.5 km/s can be generated for the purpose of studying their interaction with materials in order to develop protective materials for spacecraft which are exposed to such energetic O-atoms during operation in low earth orbit.

A simple spectral model of the dynamics of the Venus ionosphere

NASA Technical Reports Server (NTRS)

Singhal, R. P.; Whitten, R. C.

1987-01-01

A two-dimensional model of the ionosphere of Venus has been constructed by expanding pertinent quantities in Legendre polynomials. The model is simplified by including only a single ion species, O(+). Horizontal plasma flow velocity and plasma density have been calculated as a coupled system. The calculated plasma flow velocity is found to be in good agreement with observations and the results of earlier studies. Solar zenith angle dependence of plasma density, particularly on the nightside, shows some features which differ from results of earlier studies and observed values. Effects of raising or lowering the ionopause height and changing the nightside neutral atmosphere have been discussed.

Study of X-ray photoionized Fe plasma and comparisons with astrophysical modeling codes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Foord, M E; Heeter, R F; Chung, H

The charge state distributions of Fe, Na and F are determined in a photoionized laboratory plasma using high resolution x-ray spectroscopy. Independent measurements of the density and radiation flux indicate the ionization parameter {zeta} in the plasma reaches values {zeta} = 20-25 erg cm s{sup -1} under near steady-state conditions. A curve-of-growth analysis, which includes the effects of velocity gradients in a one-dimensional expanding plasma, fits the observed line opacities. Absorption lines are tabulated in the wavelength region 8-17 {angstrom}. Initial comparisons with a number of astrophysical x-ray photoionization models show reasonable agreement.

Vascular Uptake of Six Rehydration Drinks at Rest and Exercise

NASA Technical Reports Server (NTRS)

Greenleaf, J. E.; Geelen, G.; Jackson, C. G. R.; Saumet, J.-L.; Juhos, L. T.; Keil, L. C.; Fegan-Meyer, D.; Dearborn, A.; Hinghofer-Szalkay, H.; Whittam, J. H.

1996-01-01

A report presents data on the effectiveness of each of six rehydration fluids in restoring total body water and plasma volume in human subjects during rest and exercise. One of the six fluids was water sweetened with aspartame: the others were water containing various amounts of sodium chloride and/or sodium citrate, plus various amounts of aspartame and/or other carbohydrates. In one experiment, five men who had previously dehydrated themselves for 24 hours drank one of the rehydration fluids, then sat for 70 minutes. Pretest plasma volumes were measured and changes in plasma volumes were calculated. This procedure was repeated at weekly intervals until all six rehydration fluids had been tested. Another similar experiment involved four men who exercised on a cycle ergometer for 70 minutes in the supine position after drinking the fluids.

Good Governance Connects Science and Society

ERIC Educational Resources Information Center

Hurlbut, J. Benjamin; Robert, Jason Scott

2012-01-01

Owen-Smith et al. (this issue) answer the question about expanding funding for human pluripotent stem cell (hPSC) research decisively and emphatically. They conclude that the U.S. federal government should expand funding in volume and scope, and stabilize it through regularity. According to Hurlbut and Robert, If the clear goal of policy should…

Building Technology Forecast and Evaluation (BTFE). Volume 2. Evaluation of Two Structural Systems

DTIC Science & Technology

1990-11-01

insulative foam ( expanded polystyrene ) strips between each truss. The assembly is held together with 14-gauge wires welded to the trusses on 2-in. centers...structural load bearing qualities expanded polystyrene . No taping and mudding. Ar. ~J~ .wplrtpd( at each irllnfrnPllo Tile I hin- set or float over

Matching Students to Opportunity: Expanding College Choice, Access, and Quality

ERIC Educational Resources Information Center

Kelly, Andrew P., Ed.; Howell, Jessica S., Ed.; Sattin-Bajaj, Carolyn, Ed.

2016-01-01

"Matching Students to Opportunity" expands on the discussion of a critical issue in college access and success: the match between prospective students and the colleges in which they enroll. Research indicates that ensuring a good match significantly increases a student's chance of graduating. The contributors to this volume argue that…

The component content of active particles in a plasma-chemical reactor based on volume barrier discharge

NASA Astrophysics Data System (ADS)

Soloshenko, I. A.; Tsiolko, V. V.; Pogulay, S. S.; Terent'yeva, A. G.; Bazhenov, V. Yu; Shchedrin, A. I.; Ryabtsev, A. V.; Kuzmichev, A. I.

2007-02-01

In this paper the results of theoretical and experimental studies of the component content of active particles formed in a plasma-chemical reactor composed of a multiple-cell generator of active particles, based on volume barrier discharge, and a working chamber are presented. For calculation of the content of uncharged plasma components an approach is proposed which is based on averaging of the power introduced over the entire volume. Advantages of such an approach lie in an absence of fitting parameters, such as the dimensions of microdischarges, their surface density and rate of breakdown. The calculation and the experiment were accomplished with the use of dry air (20% relative humidity) as the plasma generating medium. Concentrations of O3, HNO3, HNO2, N2 O5 and NO3 were measured experimentally in the discharge volume and working chamber for the residence time of particles on a discharge of 0.3 s and more and discharge specific power of 1.5 W cm-3. It has been determined that the best agreement between the calculation and the experiment occurs at calculated gas medium temperatures in the discharge plasma of about 400-425 K, which correspond to the experimentally measured rotational temperature of nitrogen. In most cases the calculated concentrations of O3, HNO3, HNO2, N2O5 and NO3 for the barrier discharge and the working chamber are in fairly good agreement with the respective measured values.

Kinetic electron model for plasma thruster plumes

NASA Astrophysics Data System (ADS)

Merino, Mario; Mauriño, Javier; Ahedo, Eduardo

2018-03-01

A paraxial model of an unmagnetized, collisionless plasma plume expanding into vacuum is presented. Electrons are treated kinetically, relying on the adiabatic invariance of their radial action integral for the integration of Vlasov's equation, whereas ions are treated as a cold species. The quasi-2D plasma density, self-consistent electric potential, and electron pressure, temperature, and heat fluxes are analyzed. In particular, the model yields the collisionless cooling of electrons, which differs from the Boltzmann relation and the simple polytropic laws usually employed in fluid and hybrid PIC/fluid plume codes.

Lagrangian methods in nonlinear plasma wave interaction

NASA Technical Reports Server (NTRS)

Crawford, F. W.

1980-01-01

Analysis of nonlinear plasma wave interactions is usually very complicated, and simplifying mathematical approaches are highly desirable. The application of averaged-Lagrangian methods offers a considerable reduction in effort, with improved insight into synchronism and conservation (Manley-Rowe) relations. This chapter indicates how suitable Lagrangian densities have been defined, expanded, and manipulated to describe nonlinear wave-wave and wave-particle interactions in the microscopic, macroscopic and cold plasma models. Recently, further simplifications have been introduced by the use of techniques derived from Lie algebra. These and likely future developments are reviewed briefly.

Macroscopic Lagrangian description of warm plasmas. II Nonlinear wave interactions

NASA Technical Reports Server (NTRS)

Kim, H.; Crawford, F. W.

1983-01-01

A macroscopic Lagrangian is simplified to the adiabatic limit and expanded about equilibrium, to third order in perturbation, for three illustrative cases: one-dimensional compression parallel to the static magnetic field, two-dimensional compression perpendicular to the static magnetic field, and three-dimensional compression. As examples of the averaged-Lagrangian method applied to nonlinear wave interactions, coupling coefficients are derived for interactions between two electron plasma waves and an ion acoustic wave, and between an ordinary wave, an electron plasma wave, and an ion acoustic wave.

Physiological adaptation of maternal plasma volume during pregnancy: a systematic review and meta-analysis.

PubMed

de Haas, S; Ghossein-Doha, C; van Kuijk, S M J; van Drongelen, J; Spaanderman, M E A

2017-02-01

To describe the physiological pattern of gestational plasma volume adjustments in normal singleton pregnancy and compare this with the pattern in pregnancies complicated by pregnancy-induced hypertension, pre-eclampsia or fetal growth restriction. We performed a meta-analysis of the current literature on plasma volume adjustments during physiological and complicated pregnancies. Literature was retrieved from PubMed (NCBI) and EMBASE (Ovid) databases. Included studies reported both reference plasma volume measurements (non-pregnant, prepregnancy or postpartum) and measurements obtained during predetermined gestational ages. Mean differences bet ween the reference and pregnancy plasma volume measurements were calculated for predefined intervals of gestational age using a random-effects model described by DerSimonian and Laird. Thirty studies were included in the meta-analysis with publication dates ranging from 1934 to 2007. Plasma volume increased in the first weeks of pregnancy, with the steepest increase occurring during the second trimester. Plasma volume continued to increase in the third trimester with a pooled maximum increase of 1.13 L (95% CI, 1.07-1.19 L), an increase of 45.6% (95% CI, 43.0-48.1%) in physiological pregnancies compared with the reference value. The plasma volume expansion in gestational hypertensive and growth-restricted pregnancies was 0.80 L (95% CI, 0.59-1.02 L), an increase of 32.3% (95% CI, 23.6-41.1%) in the third trimester, a smaller increase than in physiological pregnancies (P < 0.0001). During physiological pregnancy, plasma volume increases by, on average, more than 1 L as compared with non-pregnant conditions. In pregnancies complicated by pregnancy-induced hypertension, pre-eclampsia or fetal growth restriction, plasma volume increase in the third trimester is 13.3% lower than in normal pregnancy. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd. Adaptación fisiológica del volumen del plasma materno durante el embarazo: una revisi\\xF3n sistemática y metaanálisis RESUMEN OBJETIVO: Describir el patrón fisiológico de los cambios en el volumen del plasma gestacional en embarazos normales con feto único y compararlo con el patrón en los embarazos complicados por hipertensión gestacional, preeclampsia o restricción del crecimiento fetal. MÉTODOS: Se realizó un metaanálisis de la literatura actual sobre los cambios en el volumen de plasma durante embarazos complicados y fisiológicos. La literatura se obtuvo de las bases de datos PubMed (NCBI) y EMBASE (Ovid). Los estudios incluidos mencionaban tanto mediciones de referencia del volumen plasmático (no embarazada, antes del embarazo o después del parto) como mediciones tomadas a edades gestacionales predeterminadas. Se calcularon las medias de las diferencias entre las mediciones de referencia y las del embarazo para el volumen plasmático a intervalos predefinidos de la edad gestacional, utilizando un modelo de efectos aleatorios descrito por DerSimonian y Laird. En el metaanálisis se incluyeron treinta estudios con fechas de publicación entre 1934 y 2007. El volumen plasmático aumentó en las primeras semanas de embarazo y el mayor incremento se produjo durante el segundo trimestre. El volumen de plasma continuó aumentando en el tercer trimestre con un aumento combinado máximo de 1,13L (IC 95%, 1,7-1,19 L), lo que supone un aumento del 45,6% (IC 95%, 43,0-48,1%) en embarazos fisiológicas en comparación con el valor de referencia. El aumento del volumen plasmático en los embarazos con hipertensión y con crecimiento intrauterino restringido fue de 0,80L (IC 95%, 0,59-1,02 L), lo que supone un aumento del 32,3% (IC 95%, 23,6-41,1%) en el tercer trimestre, y un incremento menor que en los embarazos fisiológicos (P <0,0001). Durante el embarazo fisiológico el volumen de plasma aumenta, en promedio, más de 1L, en comparación con el de las no embarazadas. En los embarazos complicados por hipertensión gestacional, preeclampsia o restricción del crecimiento fetal, el aumento del volumen plasmático en el tercer trimestre es un 13,3% menor que en el embarazo normal. :meta : ,、。 : meta。PubMed(NCBI)EMBASE(Ovid)。(、)。DerSimonianLaird,。 : Meta30,19342007。,。,1.13 L(95% CI,1.07~1.19 L),,45.6%(95% CI,43.0%~48.1%)。0.80 L(95%CI,0.59~1.02 L),32.3%(95% CI,23.6%~41.1%),(P<0.0001)。 : ,,1 L。、,13.3%。. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Continuous monitoring of blood volume changes in humans

NASA Technical Reports Server (NTRS)

Hinghofer-Szalkay, H.; Greenleaf, J. E.

1987-01-01

Use of on-line high-precision mass densitometry for the continuous monitoring of blood volume changes in humans was demonstrated by recording short-term blood volume alterations produced by changes in body position. The mass density of antecubital venous blood was measured continuously for 80 min per session with 0.1 g/l precision at a flow rate of 1.5 ml/min. Additional discrete plasma density and hematocrit measurements gave linear relations between all possible combinations of blood density, plasma density, and hematocrit. Transient filtration phenomena were revealed that are not amenable to discontinuous measurements.

Modification of the Steel Surface Treated by a Volume Discharge Plasma in Nitrogen at Atmospheric Pressure

NASA Astrophysics Data System (ADS)

Erofeev, M. V.; Shulepov, M. A.; Ivanov, Yu. F.; Oskomov, K. V.; Tarasenko, V. F.

2016-03-01

Effect of volume discharge plasma initiated by an avalanche electron beam on the composition, structure, and properties of the surface steel layer is investigated. Voltage pulses with incident wave amplitude up to 30 kV, full width at half maximum of about 4 ns, and wave front of about 2.5 ns were applied to the gap with an inhomogeneous electric field. Changes indicating the hardening effect of the volume discharge initiated by an avalanche electron beam are revealed in St3-grade steel specimens treated by the discharge of this type.

Mechanisms of Decreased Plasma Volume During Acute Psychological Stress and Postural Change in Humans

DTIC Science & Technology

1993-09-14

follicular phase of their menstrual cycle as defined as 1 to 11 days post menses . Experimental Protocol Each subject was screened by telephone to...studies exist regarding possible gender differences in plasma volume changes during acute psychological stress. Menstrual cycle effects on physiologic...the different phases of the menstrual cycle (Strauss, Schultheiss, & Cohen, 1983; Carroll , ’I\\lrner I Lee I & Stephenson, 1984). Conflicting

Physical-chemical characterization of the textile dye Azo Ab52 degradation by corona plasma

NASA Astrophysics Data System (ADS)

Gómez, A.; Torres-Arenas, A. J.; Vergara-Sánchez, J.; Torres, C.; Reyes, P. G.; Martínez, H.; Saldarriaga-Noreña, Hugo

2017-10-01

This work characterizes the degradation of the textile dye azo Acid Black 52 by measuring several physical and chemical parameters. A corona plasma was created at atmospheric pressure and applied on the liquid-air interface of water samples containing the dye. 1.0 mM of ferrous sulfate (FeSO4) was added to 1.0 mM dye solution, for a total volume of 250 mL. For each treatment, a number of parameters were quantified. These were voltage, current, temperature, loss of volume, pH, electrical conductivity, concentration, optical mission spectra, chemical oxygen demand (COD), total organic carbon (TOC), and the removal ratio. Because of the increase in the sample temperature, the volume lost by evaporation was explored. The results show that the efficiency of the dye degradation by plasma is a function of treatment time. Moreover, the reactive concentration of FeSO4 and the exposition time of the plasma were varied at a constant volume, leading to the determination of the concentrations and optimal times. Considering the degradation and removal parameters, at the maximum treated time of 80 min, it found that COD was of 96.36%, TOC of 93.93%, and the removal ratio of 97.47%.

Study of electromagnetic wave scattering from an inhomogeneous plasma layer using Green's function volume integral equation method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Soltanmoradi, Elmira; Shokri, Babak, E-mail: b-shokri@sbu.ac.ir; Laser and Plasma Research Institute, Shahid Beheshti University, G. C., Evin, Tehran 19839-63113

Gigahertz electromagnetic wave scattering from an inhomogeneous collisional plasma layer with bell-like and Epstein electron density distributions is studied by the Green's function volume integral equation method to find the reflectance, transmittance, and absorbance coefficients of this inhomogeneous plasma. Also, the effects of the frequency of the electromagnetic wave, plasma parameters, such as collision frequency, electron density, and plasma thickness, and the effects of the profile of the electron density on the electromagnetic wave scattering from this plasma slab are investigated. According to the results, when the electron density, collision frequency, and plasma thickness are increased, collisional absorbance is enhanced,more » and as a result, the absorbance bandwidth of plasma is broadened. Moreover, this broadening is more evident for plasma with bell-like electron density profile. Also, the bandwidth of the frequency and the range of pressure in which plasma behaves as a good reflector are determined in this article. According to the results, the bandwidth of the frequency is decreased for thicker plasma with bell-like profile, while it does not vary for a different plasma thickness with Epstein profile. Moreover, the range of the pressure is decreased for bell-like profile in comparison with Epstein profile. Furthermore, due to the sharp inhomogeneity of the Epstein profile, the coefficients of plasma that are uniform for plasma with bell-like profile are changed for plasma with Epstein profile, and some perturbations are seen.« less

Expansion of extracellular volume and suppression of atrial natriuretic peptide after growth hormone administration in normal man.

PubMed

Møller, J; Jørgensen, J O; Møller, N; Hansen, K W; Pedersen, E B; Christiansen, J S

1991-04-01

Sodium retention and symptoms and signs of fluid retention are commonly recorded during GH administration in both GH-deficient patients and normal subjects. Most reports have however, been casuistic or uncontrolled. In a randomized double blind placebo-controlled cross-over study we therefore examined the effect of 14-day GH administration (12 IU sc at 2000 h) on plasma volume, extracellular volume (ECV), atrial natriuretic peptide (ANP), arginine vasopressin, and the renin angiotensin system in eight healthy adult men. A significant GH induced increase in serum insulin growth factor I was observed. GH caused a significant increase in ECV (L): 20.45 +/- 0.45 (GH), 19.53 +/- 0.48 (placebo) (P less than 0.01), whereas plasma volume (L) remained unchanged 3.92 +/- 0.16 (GH), 4.02 +/- 0.13 (placebo). A significant decrease in plasma ANP (pmol/L) after GH administration was observed: 2.28 +/- 0.54 (GH), 3.16 +/- 0.53 (placebo) P less than 0.01. Plasma aldosterone (pmol/L): 129 +/- 14 (GH), 89 +/- 17 (placebo), P = 0.08, and plasma angiotensin II (pmol/L) levels: 18 +/- 12 (GH), 14 +/- 7 (placebo), P = 0.21, were not significantly elevated. No changes in plasma arginine vasopressin occurred (1.86 +/- 0.05 pmol/L vs. 1.90 +/- 0.05, P = 0.33). Serum sodium and blood pressure remained unaffected. Moderate complaints, which could be ascribed to water retention, were recorded in four subjects [periorbital edema (n = 3), acral paraesthesia (n = 2) and light articular pain (n = 1)]. The symptoms were most pronounced after 2-3 days of treatment and diminished at the end of the period. In summary, 14 days of high dose GH administration caused a significant increase in ECV and a significant suppression of ANP.

Analyzing near infrared scattering from human skin to monitor changes in hematocrit

NASA Astrophysics Data System (ADS)

Chaiken, Joseph; Deng, Bin; Goodisman, Jerry; Shaheen, George; Bussjager, R. J.

2012-01-01

The leading preventable cause of death, world-wide, civilian or military, for all people between the ages of 18-45 is undetected internal hemorrhage. Autonomic compensation mechanisms mask changes such as e.g. hematocrit fluctuations that could give early warning if only they could be monitored continuously with reasonable degrees of precision and relative accuracy. Probing tissue with near infrared radiation (NIR) simultaneously produces remitted fluorescence and Raman scattering (IE) plus Rayleigh/Mie light scattering (EE) that noninvasively give chemical and physical information about the materials and objects within. We model tissue as a three-phase system: plasma and red blood cell (RBC) phases that are mobile and a static tissue phase. In vivo, any volume of tissue naturally experiences spatial and temporal fluctuations of blood plasma and RBC content. Plasma and RBC fractions may be discriminated from each other on the basis of their physical, chemical and optical properties. Thus IE and EE from NIR probing yield information about these fractions. Assuming there is no void volume in viable tissue, or that void volume is constant, changes in plasma and RBC volume fractions may be calculated from simultaneous measurements of the two observables, EE and IE. In a previously published analysis we showed the underlying phenomenology but did not provide an algorithm for calculating volume fractions from experimental data. Here we present a simple analysis that allows continuous monitoring of fluid fraction and hematocrit (Hct) changes by measuring IE and EE, and apply it to some experimental in vivo measurements.

Electromagnetic Effices from Impacts on Spacecraft

NASA Astrophysics Data System (ADS)

Close, Sigrid

2018-04-01

Hypervelocity micro particles, including meteoroids and space debris with masses < 1 ng, routinely impact spacecraft and create dense plasma that expands at the isothermal sound speed. This plasma, with a charge separation commensurate with different species mobilities, can produce a strong electromagnetic pulse (EMP) with a broad frequency spectrum. Subsequent plasma oscillations resulting from instabilities can also emit significant power and may be responsible for many reported satellite anomalies. We present theory and recent results from ground-based impact tests aimed at characterizing hypervelocity impact plasma and show that impact-produced radio frequency (RF) emissions occurred in frequencies ranging from VHF through L-band and that these emissions were highly correlated with fast (> 20 km/s) impacts that produced a fully ionized plasma.

Guiding of laser pulses in plasma waveguides created by linearly-polarized femtosecond laser pulses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lemos, N.; Cardoso, L.; Geada, J.

We experimentally demonstrate that plasma waveguides produced with ultra-short laser pulses (sub-picosecond) in gas jets are capable of guiding high intensity laser pulses. This scheme has the unique ability of guiding a high-intensity laser pulse in a plasma waveguide created by the same laser system in the very simple and stable experimental setup. A hot plasma column was created by a femtosecond class laser that expands into an on-axis parabolic low density profile suitable to act as a waveguide for high intensity laser beams. We have successfully guided ~10 15 W cm -2 laser pulses in a 8 mm longmore » hydrogen plasma waveguide with a 35% guiding efficiency.« less

Guiding of laser pulses in plasma waveguides created by linearly-polarized femtosecond laser pulses

DOE PAGES

Lemos, N.; Cardoso, L.; Geada, J.; ...

2018-02-16

We experimentally demonstrate that plasma waveguides produced with ultra-short laser pulses (sub-picosecond) in gas jets are capable of guiding high intensity laser pulses. This scheme has the unique ability of guiding a high-intensity laser pulse in a plasma waveguide created by the same laser system in the very simple and stable experimental setup. A hot plasma column was created by a femtosecond class laser that expands into an on-axis parabolic low density profile suitable to act as a waveguide for high intensity laser beams. We have successfully guided ~10 15 W cm -2 laser pulses in a 8 mm longmore » hydrogen plasma waveguide with a 35% guiding efficiency.« less

Investigating Tribological Characteristics of HVOF Sprayed AISI 316 Stainless Steel Coating by Pulsed Plasma Nitriding

NASA Astrophysics Data System (ADS)

Mindivan, H.

2018-01-01

In this study, surface modification of aluminum alloy using High-Velocity Oxygen Fuel (HVOF) thermal spray and pulsed plasma nitriding processes was investigated. AISI 316 stainless steel coating on 1050 aluminum alloy substrate by HVOF process was pulsed plasma nitrided at 793 K under 0.00025 MPa pressure for 43200 s in a gas mixture of 75 % N2 and 25 % H2. The results showed that the pulse plasma nitriding process produced a surface layer with CrN, iron nitrides (Fe3N, Fe4N) and expanded austenite (γN). The pulsed plasma nitrided HVOF-sprayed coating showed higher surface hardness, lower wear rate and coefficient of friction than the untreated HVOF-sprayed one.

Comparison of Reconstructive Outcomes in Breast Cancer Patients With Preexisting Subpectoral Implants: Implant-Sparing Mastectomy With Delayed Implant Exchange Versus Immediate Tissue Expander Reconstruction.

PubMed

Parabkaharan, Sangeetha; Melody, Megan; Trotta, Rose; Lleshi, Amina; Sun, Weihong; Smith, Paul D; Khakpour, Nazanin; Dayicioglu, Deniz

2016-06-01

Women who have undergone prior augmentation mammoplasty represent a unique subset of breast cancer patients with several options available for breast reconstruction. We performed a single institution review of surgical outcomes of breast reconstruction performed in patients with breast cancer with prior history of subpectoral breast augmentation. Institutional review board-approved retrospective review was conducted among patients with previously mentioned criteria treated at our institution between 2000 and 2014. Reconstructions were grouped into 2 categories as follows: (1) removal of preexisting subpectoral implant during mastectomy with immediate tissue expander placement and (2) implant-sparing mastectomy followed by delayed exchange to a larger implant. We reviewed demographics, tumor features, and reconstruction outcomes of these groups. Fifty-three patients had preexisting subpectoral implants. Of the 63 breast reconstructions performed, 18 (28.6%) had immediate tissue expander placed and 45 (71.4%) had implant-sparing mastectomy followed by delayed implant exchange. The groups were comparable based on age, body mass index, cancer type, tumor grade, TNM stage at presentation, and hormonal receptor status. No significant difference was noted between tumor margins or subsequent recurrence, mastectomy specimen weight, removed implant volume, volume of implant placed during reconstruction, or time from mastectomy to final implant placement. Rates of complications were significantly higher in the tissue expander group compared to the implant-sparing mastectomy group 7 (38.9%) versus 4 (8.9%) (P = 0.005). Implant-sparing mastectomy with delayed implant exchange in patients with preexisting subpectoral implants is safe and has fewer complications compared to tissue expander placement. There was no difference noted in the final volume of implant placed, time interval for final implant placement, or tumor margins.

Hemodynamics, renal function, plasma renin, and aldosterone in man after 5 to 14 days of bedrest

NASA Technical Reports Server (NTRS)

Melada, G. A.; Goldman, R. H.; Luetscher, J. A.; Zager, P. G.

1975-01-01

Continuous bedrest for 5 to 14 days had no significant effect on resting heart rate, blood pressure, or cardiac output in six normal men. Head-up tilt induced greater tachycardia in 5 of 6 patients after bed rest than in the control period. Propranolol diminished both tachycardia and the incidence of hypotension and faintness in upright posture. Plasma volume fell, extracellular fluid volume increased, and plasma renin activity was significantly elevated following bedrest. Unusually large increases in plasma renin followed head-up tilt or administration of isoproterenol during bedrest and after resuming normal activity. During bedrest, plasma aldosterone was often increased in the early morning. It is concluded that after bedrest, upright posture evokes strong beta-adrenergic activity as well as exaggerated metabolic and circulatory responses which can be reduced or abolished by the beta-adrenergic blocker, propranolol.

Two dimensional radial gas flows in atmospheric pressure plasma-enhanced chemical vapor deposition

NASA Astrophysics Data System (ADS)

Kim, Gwihyun; Park, Seran; Shin, Hyunsu; Song, Seungho; Oh, Hoon-Jung; Ko, Dae Hong; Choi, Jung-Il; Baik, Seung Jae

2017-12-01

Atmospheric pressure (AP) operation of plasma-enhanced chemical vapor deposition (PECVD) is one of promising concepts for high quality and low cost processing. Atmospheric plasma discharge requires narrow gap configuration, which causes an inherent feature of AP PECVD. Two dimensional radial gas flows in AP PECVD induces radial variation of mass-transport and that of substrate temperature. The opposite trend of these variations would be the key consideration in the development of uniform deposition process. Another inherent feature of AP PECVD is confined plasma discharge, from which volume power density concept is derived as a key parameter for the control of deposition rate. We investigated deposition rate as a function of volume power density, gas flux, source gas partial pressure, hydrogen partial pressure, plasma source frequency, and substrate temperature; and derived a design guideline of deposition tool and process development in terms of deposition rate and uniformity.

Inflow Ducting in High-Volume-Flow Subsonic Anechoic Chambers.

DTIC Science & Technology

1983-10-12

resin with 1/4" (6.4mm) thick walls and its inner diameter is 9 1/2" (21.4cm). A bellmouth was fabricated from expanded polystyrene and fitted to the...is modeled with steel-angle-reinforced 1/4" (6.4mm) plywood walls that are lined with expanded polystyrene wedges. Great care was taken during the...t, mounted, the wedges are made of expanded polystyrene , and were cut to shape by the supplier with a hot wire system. The wedges are p

Study of scattering cross section of a plasma column using Green's function volume integral equation method

NASA Astrophysics Data System (ADS)

Soltanmoradi, Elmira; Shokri, Babak

2017-05-01

In this article, the electromagnetic wave scattering from plasma columns with inhomogeneous electron density distribution is studied by the Green's function volume integral equation method. Due to the ready production of such plasmas in the laboratories and their practical application in various technological fields, this study tries to find the effects of plasma parameters such as the electron density, radius, and pressure on the scattering cross-section of a plasma column. Moreover, the incident wave frequency influence of the scattering pattern is demonstrated. Furthermore, the scattering cross-section of a plasma column with an inhomogeneous collision frequency profile is calculated and the effect of this inhomogeneity is discussed first in this article. These results are especially used to determine the appropriate conditions for radar cross-section reduction purposes. It is shown that the radar cross-section of a plasma column reduces more for a larger collision frequency, for a relatively lower plasma frequency, and also for a smaller radius. Furthermore, it is found that the effect of the electron density on the scattering cross-section is more obvious in comparison with the effect of other plasma parameters. Also, the plasma column with homogenous collision frequency can be used as a better shielding in contrast to its inhomogeneous counterpart.

Nanoparticle formation in a low pressure argon/aniline RF plasma

NASA Astrophysics Data System (ADS)

Pattyn, C.; Kovacevic, E.; Hussain, S.; Dias, A.; Lecas, T.; Berndt, J.

2018-01-01

The formation of nanoparticles in low temperature plasmas is of high importance for different fields: from astrophysics to microelectronics. The plasma based synthesis of nanoparticles is a complex multi-scale process that involves a great variety of different species and comprises timescales ranging from milliseconds to several minutes. This contribution focuses on the synthesis of nanoparticles in a low temperature, low pressure capacitively coupled plasma containing mixtures of argon and aniline. Aniline is commonly used for the production of polyaniline, a material that belongs to the family of conductive polymers, which has attracted increasing interest in the last few years due to the large number of potential applications. The nanoparticles which are formed in the plasma volume and levitate there due to the collection of negative charges are investigated in this contribution by means of in-situ FTIR spectroscopy. In addition, the plasma is analyzed by means of plasma (ion) mass spectroscopy. The experiments reveal the possibility to synthesize nanoparticles both in continuous wave and in pulsed discharges. The formation of particles in the plasma volume can be suppressed by pulsing the plasma in a specific frequency range. The in-situ FTIR analysis also reveals the influence of the argon plasma on the characteristics of the nanoparticles.

Observations of field-aligned currents, waves, and electric fields at substorm onset

NASA Technical Reports Server (NTRS)

Smits, D. P.; Hughes, W. J.; Cattell, C. A.; Russell, C. T.

1986-01-01

Substorm onsets, identified Pi 2 pulsations observed on the Air Force Geophysics Laboratory Magnetometer Network, are studied using magnetometer and electric field data from ISEE 1 as well as magnetometer data from the geosynchronous satellites GOES 2 and 3. The mid-latitude magnetometer data provides the means of both timing and locating the substorm onset so that the spacecraft locations with respect to the substorm current systems are known. During two intervals, each containing several onsets or intensifications, ISEE 1 observed field-aligned current signatures beginning simultaneously with the mid-latitude Pi 2 pulsation. Close to the earth broadband bursts of wave noise were observed in the electric field data whenever field-aligned currents were detected. One onset occurred when ISEE 1 and GOES 2 were on the same field line but in opposite hemispheres. During this onset ISEE 1 and GOES 2 saw magnetic signatures which appear to be due to conjugate field-aligned currents flowing out of the western end of the westward auroral electrojets. The ISEE 1 signature is of a line current moving westward past the spacecraft. During the other interval, ISEE 1 was in the near-tail region near the midnight meridian. Plasma data confirms that the plasma sheet thinned and subsequently expanded at onset. Electric field data shows that the plasma moved in the opposite direction to the plasma sheet boundary as the boundary expanded which implies that there must have been an abundant source of hot plasma present. The plasma motion was towards the center of the plasma sheet and earthwards and consisted of a series of pulses rather than a steady flow.

Highway Safety Information System guidebook for the Utah state data files. Volume 1 : SAS file formats

DOT National Transportation Integrated Search

1996-06-01

This volume expands on the presentations in the main manual by presenting further discussions and examples. Contents: Appendix A: The Costs of Travel Surveys; Appendix B: Census Data for Travel Surveys; Appendix C: An Example of the Systems Capabilit...

Effects of oral powder electrolyte administration on packed cell volume, plasma chemistry parameters, and incidence of colic in horses participating in a 6-day 162-km trail ride

PubMed Central

Walker, Wade T.; Callan, Robert J.; Hill, Ashley E.; Tisher, Kelly B.

2014-01-01

This study evaluated the effects of administering oral powder electrolytes on packed cell volume (PCV), plasma chemistry parameters, and incidence of colic in horses participating on a 6-day 162-km trail ride in which water was not offered ad libitum. Twenty-three horses received grain with powder electrolytes daily while 19 control horses received grain only. Horses were ridden approximately 32 km a day at a walk or trot. Packed cell volume and plasma chemistry parameters were analyzed daily. Episodes of colic were diagnosed and treated by a veterinarian unaware of treatment group allocation. Blood parameters and incidence of colic were compared between treatment groups. Electrolyte administration did not alter PCV or plasma chemistry parameters compared to controls. The incidence of colic was significantly higher in treated horses (P = 0.05). Oral powder electrolytes did not enhance hydration status or electrolyte homeostasis and may be associated with colic in horses participating on long distance trail rides similar to this model. PMID:25082992

Effects of oral powder electrolyte administration on packed cell volume, plasma chemistry parameters, and incidence of colic in horses participating in a 6-day 162-km trail ride.

PubMed

Walker, Wade T; Callan, Robert J; Hill, Ashley E; Tisher, Kelly B

2014-08-01

This study evaluated the effects of administering oral powder electrolytes on packed cell volume (PCV), plasma chemistry parameters, and incidence of colic in horses participating on a 6-day 162-km trail ride in which water was not offered ad libitum. Twenty-three horses received grain with powder electrolytes daily while 19 control horses received grain only. Horses were ridden approximately 32 km a day at a walk or trot. Packed cell volume and plasma chemistry parameters were analyzed daily. Episodes of colic were diagnosed and treated by a veterinarian unaware of treatment group allocation. Blood parameters and incidence of colic were compared between treatment groups. Electrolyte administration did not alter PCV or plasma chemistry parameters compared to controls. The incidence of colic was significantly higher in treated horses (P = 0.05). Oral powder electrolytes did not enhance hydration status or electrolyte homeostasis and may be associated with colic in horses participating on long distance trail rides similar to this model.

Computational studies for a multiple-frequency electron cyclotron resonance ion source (abstract)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alton, G.D.

1996-03-01

The number density of electrons, the energy (electron temperature), and energy distribution are three of the fundamental properties which govern the performance of electron cyclotron resonance (ECR) ion sources in terms of their capability to produce high charge state ions. The maximum electron energy is affected by several processes including the ability of the plasma to absorb power. In principle, the performances of an ECR ion source can be realized by increasing the physical size of the ECR zone in relation to the total plasma volume. The ECR zones can be increased either in the spatial or frequency domains inmore » any ECR ion source based on B-minimum plasma confinement principles. The former technique requires the design of a carefully tailored magnetic field geometry so that the central region of the plasma volume is a large, uniformly distributed plasma volume which surrounds the axis of symmetry, as proposed in Ref. . Present art forms of the ECR source utilize single frequency microwave power supplies to maintain the plasma discharge; because the magnetic field distribution continually changes in this source design, the ECR zones are relegated to thin {open_quote}{open_quote}surfaces{close_quote}{close_quote} which surround the axis of symmetry. As a consequence of the small ECR zone in relation to the total plasma volume, the probability for stochastic heating of the electrons is quite low, thereby compromising the source performance. This handicap can be overcome by use of broadband, multiple frequency microwave power as evidenced by the enhanced performances of the CAPRICE and AECR ion sources when two frequency microwave power was utilized. We have used particle-in-cell codes to simulate the magnetic field distributions in these sources and to demonstrate the advantages of using multiple, discrete frequencies over single frequencies to power conventional ECR ion sources. (Abstract Truncated)« less

Disassembly time of deuterium-cluster-fusion plasma irradiated by an intense laser pulse

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bang, W.

Energetic deuterium ions from large deuterium clusters (>10 nm diameter) irradiated by an intense laser pulse (>10¹⁶ W/cm²) produce DD fusion neutrons for a time interval determined by the geometry of the resulting fusion plasma. We show an analytical solution of this time interval, the plasma disassembly time, for deuterium plasmas that are cylindrical in shape. Assuming a symmetrically expanding deuterium plasma, we calculate the expected fusion neutron yield and compare with an independent calculation of the yield using the concept of a finite confinement time at a fixed plasma density. The calculated neutron yields agree quantitatively with the availablemore » experimental data. Our one-dimensional simulations indicate that one could expect a tenfold increase in total neutron yield by magnetically confining a 10 - keV deuterium fusion plasma for 10 ns.« less

Disassembly time of deuterium-cluster-fusion plasma irradiated by an intense laser pulse

DOE PAGES

Bang, W.

2015-07-02

Energetic deuterium ions from large deuterium clusters (>10 nm diameter) irradiated by an intense laser pulse (>10¹⁶ W/cm²) produce DD fusion neutrons for a time interval determined by the geometry of the resulting fusion plasma. We show an analytical solution of this time interval, the plasma disassembly time, for deuterium plasmas that are cylindrical in shape. Assuming a symmetrically expanding deuterium plasma, we calculate the expected fusion neutron yield and compare with an independent calculation of the yield using the concept of a finite confinement time at a fixed plasma density. The calculated neutron yields agree quantitatively with the availablemore » experimental data. Our one-dimensional simulations indicate that one could expect a tenfold increase in total neutron yield by magnetically confining a 10 - keV deuterium fusion plasma for 10 ns.« less

Efficacy of different bone volume expanders for augmenting lumbar fusions.

PubMed

Epstein, Nancy E

2008-01-01

A wide variety of bone volume expanders are being used in performing posterolateral lumbar noninstrumented and instrumented lumbar fusions. This article presents a review of their efficacy based on fusion rates, complications, and outcomes. Lumbar noninstrumented and instrumented fusions frequently use laminar autografts and different bone graft expanders. This review presents the utility of multiple forms/ratios of DBMs containing allografts. It also discusses the efficacy of artificial bone graft substitutes, including HA and B-TCP. Dynamic x-ray and/or CT examinations were used to document fusion in most series. Outcomes were variously assessed using Odom's criteria or different outcome questionnaires (Oswestry Questionnaire, SF-36, Dallas Pain Questionnaire, and/or Low Back Pain Rating Scale). Performing noninstrumented and instrumented lumbar posterolateral fusions resulted in comparable fusion rates in many series. Similar outcomes were also documented based on Odom's criteria or the multiple patient-based questionnaires. However, in some studies, the addition of spinal instrumentation increased the reoperation rate, operative time, blood loss, and cost. Various forms of DBMs, applied in different ratios to autografts, effectively supplemented spinal fusions in animal models and patient series. beta-Tricalcium phosphate, which is used to augment autograft fusions addressing idiopathic scoliosis or lumbar disease, also proved to be effective. Different types of bone volume expanders, including various forms of allograft-based DBMs, and artificial bone graft substitutes (HA and B-TCP) effectively promote posterolateral lumbar noninstrumented and instrumented fusions when added to autografts.

Simultaneous Determination of Fluid Shifts during Thermal Stress in a Small Animal Model,

DTIC Science & Technology

1985-09-01

extracellular fluid voitmie (BCF) was measured using a single injection c- inulin , technique, and plasma voilme (PV) was determined by ca.rdio--yreen dye...using tritiated water, extracell1ular fluid volume (ECF) was measured using a single injection C- inulin technique, and plasma volume (PV) was...space. However, inulin (10) has several advantages over the aforementioned because it Is not metabolized, stored, or incorporated by cells or

Plasma Volume during Heat Stress and Exercise in Women,

DTIC Science & Technology

1986-11-01

in the osmoregulation of vasopressin during the luteal phase may not be adequate to explain the lower plasma volume that was observed in this study...P.H., B.A. Spruce, 3. Burd (1985) Osmoregulation of vasopressin secretion during the menstrual cycle. -In: Schrier, R.W. (ed) Vasopressin, Raven... osmoregulation of arginine vasopressin during the human menstrual cycle. Clin Endocrinol 22: 37-42 23. Stephenson LA, Kolka MA, Gonzalez RR (1984) Circadian and

Effect of Increased Plasma Osmolality on Cold-Induced Thirst Attenuation

DTIC Science & Technology

2008-08-01

Xuid intake. Oropharyngeal and gastric stim- uli, as well as blood volume and plasma osmolality (Posm) are important factors modifying thirst (Greenleaf...reported to result in an increase in the osmotic thresh- old for the stimulation of thirst due to an increase in central blood volume (Sobocinska and...model 5877, Abbott Hospital, Inc., Chicago, IL, USA) was inserted into the catheter port for acquisition of subsequent blood samples. The catheter

Kinetic interpretation of resonance phenomena in low pressure capacitively coupled radio frequency plasmas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilczek, Sebastian; Trieschmann, Jan; Eremin, Denis

Low pressure capacitive radio frequency (RF) plasmas are often described by equivalent circuit models based on fluid approaches that predict the self-excitation of resonances, e.g., high frequency oscillations of the total current in asymmetric discharges, but do not provide a kinetic interpretation of these effects. In fact, they leave important questions open: How is current continuity ensured in the presence of energetic electron beams generated by the expanding sheaths that lead to a local enhancement of the conduction current propagating through the bulk? How do the beam electrons interact with cold bulk electrons? What is the kinetic origin of resonancemore » phenomena? Based on kinetic simulations, we find that the energetic beam electrons interact with cold bulk electrons (modulated on a timescale of the inverse local electron plasma frequency) via a time dependent electric field outside the sheaths. This electric field is caused by the electron beam itself, which leaves behind a positive space charge, that attracts cold bulk electrons towards the expanding sheath. The resulting displacement current ensures current continuity by locally compensating the enhancement of the conduction current. The backflow of cold electrons and their interaction with the nonlinear plasma sheath cause the generation of multiple electron beams during one phase of sheath expansion and contribute to a strongly non-sinusoidal RF current. These kinetic mechanisms are the basis for a fundamental understanding of the electron power absorption dynamics and resonance phenomena in such plasmas, which are found to occur in discharges of different symmetries including perfectly symmetric plasmas.« less

Air plasma effect on dental disinfection

NASA Astrophysics Data System (ADS)

Duarte, S.; Kuo, S. P.; Murata, R. M.; Chen, C. Y.; Saxena, D.; Huang, K. J.; Popovic, S.

2011-07-01

A nonthermal low temperature air plasma jet is characterized and applied to study the plasma effects on oral pathogens and biofilms. Experiments were performed on samples of six defined microorganisms' cultures, including those of gram-positive bacteria and fungi, and on a cultivating biofilm sample of Streptococcus mutans UA159. The results show that the plasma jet creates a zone of microbial growth inhibition in each treated sample; the zone increases with the plasma treatment time and expands beyond the entire region directly exposed to the plasma jet. With 30s plasma treatment twice daily during 5 days of biofilm cultivation, its formation was inhibited. The viability of S. mutans cells in the treated biofilms dropped to below the measurable level and the killed bacterial cells concentrated to local regions as manifested by the fluorescence microscopy via the environmental scanning electron microscope. The emission spectroscopy of the jet indicates that its plasma effluent carries an abundance of reactive atomic oxygen, providing catalyst for the observed plasma effect.

Air plasma effect on dental disinfection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Duarte, S.; Murata, R. M.; Saxena, D.

2011-07-15

A nonthermal low temperature air plasma jet is characterized and applied to study the plasma effects on oral pathogens and biofilms. Experiments were performed on samples of six defined microorganisms' cultures, including those of gram-positive bacteria and fungi, and on a cultivating biofilm sample of Streptococcus mutans UA159. The results show that the plasma jet creates a zone of microbial growth inhibition in each treated sample; the zone increases with the plasma treatment time and expands beyond the entire region directly exposed to the plasma jet. With 30s plasma treatment twice daily during 5 days of biofilm cultivation, its formationmore » was inhibited. The viability of S. mutans cells in the treated biofilms dropped to below the measurable level and the killed bacterial cells concentrated to local regions as manifested by the fluorescence microscopy via the environmental scanning electron microscope. The emission spectroscopy of the jet indicates that its plasma effluent carries an abundance of reactive atomic oxygen, providing catalyst for the observed plasma effect.« less

NUCLEAR REACTORS

DOEpatents

Koch, L.J.; Rice, R.E. Jr.; Denst, A.A.; Rogers, A.J.; Novick, M.

1961-12-01

An active portion assembly for a fast neutron reactor is described wherein physical distortions resulting in adverse changes in the volume-to-mass ratio are minimized. A radially expandable locking device is disposed within a cylindrical tube within each fuel subassembly within the active portion assembly, and clamping devices expandable toward the center of the active portion assembly are disposed around the periphery thereof. (AEC)

Rethinking Our Classrooms: Teaching for Equity and Justice. Volume 1. New Edition--Revised and Expanded

ERIC Educational Resources Information Center

Au, Wayne, Ed.; Bigelow, Bill, Ed.; Karp, Stan, Ed.

2007-01-01

Since the first edition was published in 1994, Rethinking Our Classrooms has sold over 180,000 copies. This revised and expanded edition includes new essays on: (1) science and environmental education; (2) immigration and language; (3) military recruitment; (4) teaching about the world through mathematics; and (5) gay and lesbian issues. Creative…

Numerical solution for linear cyclotron and diocotron modes in a nonneutral plasma column

NASA Astrophysics Data System (ADS)

Walsh, Daniel; Dubin, Daniel H. E.

2014-10-01

This poster presents numerical methods for solution of the linearized Vlasov-Poisson (LVP) equation applied to a cylindrical single-species plasma in a uniform magnetic field. The code is used to study z-independent cyclotron and diocotron modes of these plasmas, including kinetic effects. We transform to polar coordinates in both position and velocity space and Fourier expand in both polar angles (i.e. the cyclotron gyro angle and θ). In one approach, we then discretize in the remaining variables r and v (where v is the magnitude of the perpendicular velocity). However, using centered differences the method is unstable to unphysical eigenmodes with rapid variation on the scale of the grid. We remedy this problem by averaging particular terms in the discretized LVP operator over neighboring gridpoints. We also present a stable Galerkin method that expands the r and v dependence in basis functions. We compare the numerical results from both methods to exact analytic results for various modes. Supported by NSF/DOE Partnership Grants PHY-0903877 and DE-SC0002451.

Cell volume and plasma membrane osmotic water permeability in epithelial cell layers measured by interferometry.

PubMed Central

Farinas, J; Verkman, A S

1996-01-01

The development of strategies to measure plasma membrane osmotic water permeability (Pf) in epithelial cells has been motivated by the identification of a family of molecular water channels. A general approach utilizing interferometry to measure cell shape and volume was developed and applied to measure Pf in cell layers. The method is based on the cell volume dependence of optical path length (OPL) for a light beam passing through the cell. The small changes in OPL were measured by interferometry. A mathematical model was developed to relate the interference signal to cell volume changes for cells of arbitrary shape and size. To validate the model, a Mach-Zehnder interference microscope was used to image OPL in an Madin Darby Canine Kidney (MDCK) cell layer and to reconstruct the three-dimensional cell shape (OPL resolution < lambda/25). As predicted by the model, a doubling of cell volume resulted in a change in OPL that was proportional to the difference in refractive indices between water and the extracellular medium. The time course of relative cell volume in response to an osmotic gradient was computed from serial interference images. To measure cell volume without microscopy and image analysis, a Mach-Zehnder interferometer was constructed in which one of two interfering laser beams passed through a flow chamber containing the cell layer. The interference signal in response to an osmotic gradient was analyzed to quantify the time course of relative cell volume. The calculated MDCK cell plasma membrane Pf of 6.1 x 10(-4) cm/s at 24 degrees C agreed with that obtained by interference microscopy and by a total internal reflection fluorescence method. Interferometry was also applied to measure the apical plasma membrane water permeability of intact toad urinary bladder; Pf increased fivefold after forskolin stimulation to 0.04 cm/s at 23 degrees C. These results establish and validate the application of interferometry to quantify cell volume and osmotic water permeability in cell layers. Images FIGURE 1 FIGURE 2 FIGURE 3 FIGURE 4 FIGURE 6 PMID:8968620

Comparative analyses of industrial-scale human platelet lysate preparations.

PubMed

Pierce, Jan; Benedetti, Eric; Preslar, Amber; Jacobson, Pam; Jin, Ping; Stroncek, David F; Reems, Jo-Anna

2017-12-01

Efforts are underway to eliminate fetal bovine serum from mammalian cell cultures for clinical use. An emerging, viable replacement option for fetal bovine serum is human platelet lysate (PL) as either a plasma-based or serum-based product. Nine industrial-scale, serum-based PL manufacturing runs (i.e., lots) were performed, consisting of an average ± standard deviation volume of 24.6 ± 2.2 liters of pooled, platelet-rich plasma units that were obtained from apheresis donors. Manufactured lots were compared by evaluating various biochemical and functional test results. Comprehensive cytokine profiles of PL lots and product stability tests were performed. Global gene expression profiles of mesenchymal stromal cells (MSCs) cultured with plasma-based or serum-based PL were compared to MSCs cultured with fetal bovine serum. Electrolyte and protein levels were relatively consistent among all serum-based PL lots, with only slight variations in glucose and calcium levels. All nine lots were as good as or better than fetal bovine serum in expanding MSCs. Serum-based PL stored at -80°C remained stable over 2 years. Quantitative cytokine arrays showed similarities as well as dissimilarities in the proteins present in serum-based PL. Greater differences in MSC gene expression profiles were attributable to the starting cell source rather than with the use of either PL or fetal bovine serum as a culture supplement. Using a large-scale, standardized method, lot-to-lot variations were noted for industrial-scale preparations of serum-based PL products. However, all lots performed as well as or better than fetal bovine serum in supporting MSC growth. Together, these data indicate that off-the-shelf PL is a feasible substitute for fetal bovine serum in MSC cultures. © 2017 AABB.

Large-Volume Resonant Microwave Discharge for Plasma Cleaning of a CEBAF 5-Cell SRF Cavity

DOE Office of Scientific and Technical Information (OSTI.GOV)

J. Mammosser, S. Ahmed, K. Macha, J. Upadhyay, M. Nikoli, S. Popovi, L. Vuakovi

2012-07-01

We report the preliminary results on plasma generation in a 5-cell CEBAF superconducting radio-frequency (SRF) cavity for the application of cavity interior surface cleaning. CEBAF currently has {approx}300 of these five cell cavities installed in the Jefferson Lab accelerator which are mostly limited by cavity surface contamination. The development of an in-situ cavity surface cleaning method utilizing a resonant microwave discharge could lead to significant CEBAF accelerator performance improvement. This microwave discharge is currently being used for the development of a set of plasma cleaning procedures targeted to the removal of various organic, metal and metal oxide impurities. These contaminantsmore » are responsible for the increase of surface resistance and the reduction of RF performance in installed cavities. The CEBAF five cell cavity volume is {approx} 0.5 m2, which places the discharge in the category of large-volume plasmas. CEBAF cavity has a cylindrical symmetry, but its elliptical shape and transversal power coupling makes it an unusual plasma application, which requires special consideration of microwave breakdown. Our preliminary study includes microwave breakdown and optical spectroscopy, which was used to define the operating pressure range and the rate of removal of organic impurities.« less

21 CFR 640.72 - Records.

Code of Federal Regulations, 2010 CFR

2010-04-01

... STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Source Plasma § 640.72 Records. (a) In addition to the... § 640.74(b)(2) are being met for Source Plasma intended for manufacture into injectable products. (2... volume or weight of plasma withdrawn from a donor need not be kept on the individual donor record...

21 CFR 640.72 - Records.

Code of Federal Regulations, 2012 CFR

2012-04-01

... STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Source Plasma § 640.72 Records. (a) In addition to the... § 640.74(b)(2) are being met for Source Plasma intended for manufacture into injectable products. (2... volume or weight of plasma withdrawn from a donor need not be kept on the individual donor record...

21 CFR 640.72 - Records.

Code of Federal Regulations, 2011 CFR

2011-04-01

... STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Source Plasma § 640.72 Records. (a) In addition to the... § 640.74(b)(2) are being met for Source Plasma intended for manufacture into injectable products. (2... volume or weight of plasma withdrawn from a donor need not be kept on the individual donor record...

21 CFR 640.72 - Records.

Code of Federal Regulations, 2013 CFR

2013-04-01

... STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Source Plasma § 640.72 Records. (a) In addition to the... § 640.74(b)(2) are being met for Source Plasma intended for manufacture into injectable products. (2... volume or weight of plasma withdrawn from a donor need not be kept on the individual donor record...

21 CFR 640.72 - Records.

Code of Federal Regulations, 2014 CFR

2014-04-01

... STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Source Plasma § 640.72 Records. (a) In addition to the... § 640.74(b)(2) are being met for Source Plasma intended for manufacture into injectable products. (2... volume or weight of plasma withdrawn from a donor need not be kept on the individual donor record...

Therapeutic plasma exchange: a paired comparison of Fresenius AS104 vs. COBE Spectra.

PubMed

Burgstaler, E A; Pineda, A A

2001-01-01

For therapeutic plasma exchange (TPE), continuous flow separators are known to be efficient as exemplified by Fresenius AS104 and COBE Spectra. The AS104 uses an interface monitoring system in the centrifuge during TPE, whereas Spectra uses computer algorithms to establish the plasma-cell interface. To determine the plasma collection efficiency (PLCE), anticoagulant (AC) volumes used, and platelets (PLT) lost of the AS104 and the Spectra, we performed a prospective paired comparison of 20 TPE (each machine). The study included 17 patients, 1.3 plasma volume exchanges (without AC), equal inlet rates, and AC ratio of 13:1. Processing times did not include reinfuse mode. Platelet loss was determined by sampling the collection bags. Inlet rates were between 60-110 ml/min. Diagnosis included peripheral neuropathies, TTP and cryoglobulinemia. The AS104 had significantly (P<0.0001) lower average whole blood processed (F:6,601 vs. S:8,584 ml), AC volume (F:532 vs. S:719 ml), and processing time (F:80 vs. S:102 minutes) than Spectra. The AS104 had significantly (P<0.0001) higher average plasma flow rates (F:53 vs. S:44 ml/minute), plasma collection efficiency (F:90 vs. S:69%), and platelet loss (F:2.0 vs. S:0.14 x 10(11) plt) than Spectra. Platelet loss correlated with inlet flow rate with the AS104 but not with the Spectra. The AS104 has a significantly higher collection efficiency than Spectra allowing it to remove the same amount of plasma in significantly less time, by processing significantly less blood, using significantly less AC, but removing significantly more platelets than Spectra. Copyright 2001 Wiley-Liss, Inc.

APA Handbook of Industrial and Organizational Psychology. Three-Volume Set--Volume 1: Building and Developing the Organization. Volume 2: Selecting and Developing Members for the Organization. Volume 3: Maintaining, Expanding, and Contracting the Organization. APA Handbooks in Psychology Series. APA Reference Books Collection

ERIC Educational Resources Information Center

Zedeck, Sheldon, Ed.

2011-01-01

APA Books® announces the "APA Handbook of Industrial and Organizational Psychology"--the first offering in an new reference series covering core and emerging subdisciplines, the "APA Handbooks in Psychology." I/O Psychology is both a science/practice and an applied/basic research discipline. Appropriately, the "APA…

COASTING ARC ION SOURCE

DOEpatents

Foster, J.S. Jr.

1957-09-10

An improved ion source is described and in particular a source in which the ions are efficiently removed. The plasma is generated in a tubular amode structure by the oscillation of electrons in an axial magnetic field, as in the Phillips Ion Gage. The novel aspect of the source is the expansion of the plasma as it leaves the anode structure, so as to reduce the ion density at the axis of the anode and present a uniform area of plasma to an extraction grid. The structure utilized in the present patent to expand the plasma comprises flange members of high permeability at the exitgrid end of the amode to diverge the magnetic field adjacent the exit.

Absorption of laser plasma in competition with oscillation currents for a terahertz spectrum.

PubMed

Li, Xiaolu; Bai, Ya; Li, Na; Liu, Peng

2018-01-01

We generate terahertz radiation in a supersonic jet of nitrogen molecules pumped by intense two-color laser pulses. The tuning of terahertz spectra from blue shift to red shift is observed by increasing laser power and stagnation pressure, and the red shift range is enlarged with the increased stagnation pressure. Our simulation reveals that the plasma absorption of the oscillation currents and expanded plasma column owing to increased laser intensity and gas number density are crucial factors in the recurrence of the red shift of terahertz spectra. The findings disclose the microscopic mechanism of terahertz radiation and present a controlling knob for the manipulation of a broadband terahertz spectrum from laser plasma.

Mechanism of thirst attenuation during head-out water immersion in men

NASA Technical Reports Server (NTRS)

Wada, F.; Sagawa, S.; Miki, K.; Nagaya, K.; Nakamitsu, S.; Shiraki, K.; Greenleaf, J. E.

1995-01-01

The purpose was to determine whether extracellular volume or osmolality was the major contributing factor for reduction of thirst in air and head-out water immersion in hypohydrated subjects. Eight males (19-25 yr) were subjected to thermoneutral immersion and thermoneutral air under two hydration conditions without further drinking: euhydration in water (Eu-H2O) and euhydration in air, and hypohydration in water (Hypo-H2O) and hypohydration in air (3.7% wt loss after exercise in heat). The increased thirst sensation with Hypo-H2O decreased (P < 0.05) within 10 min of immersion and continued thereafter. Mean plasma osmolality (288 +/- 1 mosmol/kgH2O) and sodium (140 +/- 1 meq/l) remained elevated, and plasma volume increased by 4.2 +/- 1.0% (P < 0.05) throughout Hypo-H2O. A sustained increase (P < 0.05) in stroke volume accompanied the prompt and sustained decrease in plasma renin activity and sustained increase (P < 0.05) in plasma atrial natriuretic peptide during Eu-H2O and Hypo-H2O. Plasma vasopressin decreased from 5.3 +/- 0.7 to 2.9 +/- 0.5 pg/ml (P < 0.05) during Hypo-H2O but was unchanged in Eu-H2O. These findings suggest a sustained stimulation of the atrial baroreceptors and reduction of a dipsogenic stimulus without major alterations of extracellular osmolality in Hypo-H2O. Thus it appears that vascular volume-induced stimuli of cardiopulmonary baroreceptors play a more important role than extracellular osmolality in reducing thirst sensations during immersion in hypohydrated subjects.

Influence of intracervical and intravaginal seminal plasma on the endometrium in assisted reproduction: a double-blind, placebo-controlled, randomized study.

PubMed

Mayer, R B; Ebner, T; Yaman, C; Hartl, J; Sir, A; Krain, V; Oppelt, P; Shebl, O

2015-02-01

To investigate the effect of intracervical and intravaginal application of seminal plasma on the endometrium, as assessed by endometrial/subendometrial vascularization and endometrial volume between the day of oocyte retrieval and the day of embryo transfer in an in-vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) cycle. This was a double-blind, placebo-controlled, randomized study including patients undergoing a first or second IVF/ICSI cycle. Homologous seminal plasma or placebo (sodium chloride) was injected into the cervix and posterior vaginal fornix just after follicle aspiration. Three-dimensional power Doppler examination was performed 30 min before oocyte retrieval and 30 min before embryo transfer. Main outcome measures were changes in vascularization flow index (VFI), flow index (FI) and vascularization index (VI) of the endometrium/subendometrium using VOCAL™ (Virtual Organ Computer-aided AnaLysis) and endometrial volume. One hundred patients agreed to participate in the study. Twenty-three patients were excluded, mainly as a result of canceled embryo transfer. Data were analyzed from 40 patients receiving seminal plasma and 37 receiving placebo. No significant differences between the two groups were seen in VFI, FI or VI of the endometrium or subendometrium or in endometrial volume on the day of oocyte pick-up and on the day of embryo transfer. Neither endometrial/subendometrial vascularization parameters nor endometrial volume seem to be affected by the application of seminal plasma in patients undergoing their first or second IVF/ICSI cycle. Copyright © 2014 ISUOG. Published by John Wiley & Sons Ltd.

The pathogenesis of hypertension: black-white differences.

PubMed

Blaustein, M P; Grim, C E

1991-01-01

In summary, for reasons that are not clear, some persons seem to be extremely good at retaining sodium on a high-sodium diet or poor at excreting sodium on a high-sodium intake. This is more frequent in Western hemisphere blacks than in whites in the West or in blacks in Africa. These geographic/ethnic differences in sodium handling ability may be related to environmental factors or, more likely, to inherited differences in the ability to conserve sodium based on the evolutionary principle of survival fo the fittest for the ability to conserve sodium. The frequency of this salt-conserving (thrifty) genotype in Western hemisphere blacks may have been further increased as a consequence of severe selection pressures for survival based on the ability to conserve sodium during the slavery period of history in the West. One characteristic of the blood pressure control systems of Western hemisphere blacks is suppression of plasma renin activity without suppression of aldosterone production. In addition there is greater nephrosclerosis in blacks than whites and a more rapid decline in creatinine clearance with age. When more sodium is ingested than the kidneys are able to handle (excrete), there is a (transient) slight positive sodium balance; as a result sodium, chloride, and water are retained, resulting in an expansion of plasma volume (Fig. 7-3). The initial physiologic responses include (increased) secretion of atrial natriuretic peptides and the digitalis-like substance (natriuretic hormone), and inhibition of vasopressin and aldosterone secretion. The net effect is directly enhanced natriuresis and diuresis, and a reduction in plasma volume, with no significant effect on blood pressure. However, if there is a continuing tendency to sodium retention and volume expansion, the capacity of the aforementioned mechanisms to control plasma volume will be exceeded; then, the chronically elevated level of the digitalis-like substance will inhibit the sodium pumps in the arterial and venous smooth muscle cells and in the sympathetic neurons. The increased venous tone will help to reduce plasma volume directly by reducing central venous volume. Arterial tone will be increased by direct action of the digitalis-like substance on the arterial smooth muscle and, indirectly, via the hormone's action on the sympathetic neurons. Initially, of course, blood pressure will be maintained in the normal range (but will be labile) because of the compensating cardiovascular reflexes. Once the capacity of these reflexes to control blood pressure is exceeded, however, the blood pressure will begin to rise; this will induce a pressure natriuresis to help restore plasma volume to normal.(ABSTRACT TRUNCATED AT 400 WORDS)

Balancing risk and benefit: maintenance of a thawed Group A plasma inventory for trauma patients requiring massive transfusion.

PubMed

Mehr, Chelsea R; Gupta, Rajan; von Recklinghausen, Friedrich M; Szczepiorkowski, Zbigniew M; Dunbar, Nancy M

2013-06-01

Transfusion of plasma and red blood cell (RBC) units in a balanced ratio approximating 1:1 has been shown in retrospective studies to be associated with improved outcomes for trauma patients. Our low-volume rural trauma center uses a trauma-activated transfusion algorithm. Plasma is thawed upon activation to avoid wastage. However, the time required for plasma thawing has made achievement of a 1:1 ratio early in resuscitation challenging. In this study, the time required for plasma thawing is characterized, and a potential solution is proposed. A retrospective chart study of 38 moderately and massively transfused (≥6 U in the first 24 hours) trauma patients admitted from January 2008 to March 2012 was performed. We evaluated the time required to dispense plasma and the number of RBCs dispensed before plasma in these patients. The average time between the dispense of RBCs and plasma was 26 minutes (median, 28; range, 0-48 minutes). The average number of RBCs dispensed before plasma was 8 U (median, 7 U; range, 0-24 U). Nearly one third of massively transfused patients had 10 RBCs or greater dispensed before plasma was available. There exists the potential for delayed plasma availability owing to time required for thawing, which may compromise the ability to provide balanced plasma to RBC transfusion to trauma patients. Maintenance of a thawed Group AB plasma inventory may not be operationally feasible for rural centers with low trauma volumes. Use of a thawed Group A plasma inventory is a potential alternative to ensure rapid plasma availability. Therapeutic study, level V.

Native State Volume Fluctuations in Proteins as a Mechanism for Dynamic Allostery.

PubMed

Law, Anthony B; Sapienza, Paul J; Zhang, Jun; Zuo, Xiaobing; Petit, Chad M

2017-03-15

Allostery enables tight regulation of protein function in the cellular environment. Although existing models of allostery are firmly rooted in the current structure-function paradigm, the mechanistic basis for allostery in the absence of structural change remains unclear. In this study, we show that a typical globular protein is able to undergo significant changes in volume under native conditions while exhibiting no additional changes in protein structure. These native state volume fluctuations were found to correlate with changes in internal motions that were previously recognized as a source of allosteric entropy. This finding offers a novel mechanistic basis for allostery in the absence of canonical structural change. The unexpected observation that function can be derived from expanded, low density protein states has broad implications for our understanding of allostery and suggests that the general concept of the native state be expanded to allow for more variable physical dimensions with looser packing.

Disposable photonic integrated circuits for evanescent wave sensors by ultra-high volume roll-to-roll method.

PubMed

Aikio, Sanna; Hiltunen, Jussi; Hiitola-Keinänen, Johanna; Hiltunen, Marianne; Kontturi, Ville; Siitonen, Samuli; Puustinen, Jarkko; Karioja, Pentti

2016-02-08

Flexible photonic integrated circuit technology is an emerging field expanding the usage possibilities of photonics, particularly in sensor applications, by enabling the realization of conformable devices and introduction of new alternative production methods. Here, we demonstrate that disposable polymeric photonic integrated circuit devices can be produced in lengths of hundreds of meters by ultra-high volume roll-to-roll methods on a flexible carrier. Attenuation properties of hundreds of individual devices were measured confirming that waveguides with good and repeatable performance were fabricated. We also demonstrate the applicability of the devices for the evanescent wave sensing of ambient refractive index. The production of integrated photonic devices using ultra-high volume fabrication, in a similar manner as paper is produced, may inherently expand methods of manufacturing low-cost disposable photonic integrated circuits for a wide range of sensor applications.

Three-dimensional evaluation of upper airway following rapid maxillary expansion: a CBCT study.

PubMed

El, Hakan; Palomo, Juan Martin

2014-03-01

To evaluate, by using cone beam computed tomography, the skeletal, dental, oropharyngeal (OP) airway volume, and nasal passage (NP) volume changes that occur after rapid maxillary expansion (RME). Two groups were selected, each with 35 patients (15 males, 20 females), an RME group (mean age, 14.02 ± 1.46 years) and a control group (mean age, 14.10 ± 1.44 years). The RME group consisted of patients with maxillary constriction who were treated with Hyrax palatal expanders, and the control group comprised age- and sex-matched patients who underwent comprehensive orthodontic treatment without the use of a rapid maxillary expander. All of the transverse skeletal (medial orbital width, lateral nasal width, maxillary width, and mandibular width) and interdental (intermolar, interpremolar, and intercanine) parameters were significantly enlarged in the RME group. A statistically significant increase in airway variables was seen in both groups between pretreatment (T0) and final records (T1). The mean increase of NP airway volume for the RME group (1719.9 ± 1510.7 mm(3)) was twofold compared with the control group (813.6 ± 1006.7 mm(3)), and no intergroup significant difference was found for the OP volume. Rapid maxillary expansion creates a significant increase in nasal passage airway volume but no significant change in the oropharyngeal airway volume.

Stimulated Brillouin scattering reduction induced by self-focusing for a single laser speckle interacting with an expanding plasma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Masson-Laborde, P. E.; Depierreux, S.; Loiseau, P.

2014-03-15

The origin of the low level of stimulated Brillouin scattering (SBS) observed in laser-plasma experiments carried out with a single laser speckle is investigated by means of three-dimensional simulations and modeling in the limit when the laser beam power P is well above the critical power for ponderomotive self-focusing We find that the order of magnitude of the time averaged reflectivities, together with the temporal and spatial SBS localization observed in our simulations, are correctly reproduced by our modeling. It is observed that, after a short transient stage, SBS reaches a significant level only (i) as long as the incidentmore » laser pulse is increasing in amplitude and (ii) in a single self-focused speckle located in the low-density front part of the plasma. In order to describe self-focusing in an inhomogeneous expanding plasma, we have derived a new Lagrangian density describing this process. Using then a variational approach, our model reproduces the position and the peak intensity of the self-focusing hot spot in the front part of the plasma density profile as well as the local density depletion in this hot spot. The knowledge of these parameters then makes it possible to estimate the spatial amplification of SBS as a function of the laser beam power and consequently to explain the experimentally observed SBS reflectivity, considerably reduced with respect to standard theory in the regime of large laser beam power.« less

Theory of Dust Voids in Plasmas

NASA Technical Reports Server (NTRS)

Goree, J.; Morfill, G. E.; Tsytovich, V. N.; Vladimirov, S. V.

1999-01-01

Dusty plasmas in a gas discharge often feature a stable void, i.e., a dust-free region inside the dust cloud. This occurs under conditions relevant to both plasma processing discharges and plasma crystal experiments. The void results from a balance of the electrostatic and ion drag forces on a dust particle. The ion drag force is driven by a flow of ions outward from an ionization source and toward the surrounding dust cloud, which has a negative space charge. In equilibrium the force balance for dust particles requires that the boundary with the dust cloud be sharp, provided that the particles are cold and monodispersive. Numerical solutions of the one-dimensional nonlinear fluid equations are carried out including dust charging and dust-neutral collisions, but not ion-neutral collisions. The regions of parameter space that allow stable void equilibria are identified. There is a minimum ionization rate that can sustain a void. Spatial profiles of plasma parameters in the void are reported. In the absence of ion-neutral collisions, the ion flow enters the dust cloud's edge at Mach number M = 1. Phase diagrams for expanding or contracting voids reveal a stationary point corresponding to a single stable equilibrium void size, provided the ionization rate is constant. Large voids contract and small voids expand until they attain this stationary void size. On the other hand, if the ionization rate is not constant, the void size can oscillate. Results are compared to recent laboratory and microgravity experiments.

The use of human albumin for the treatment of ascites in patients with liver cirrhosis: item of safety, facts, controversies and perspectives.

PubMed

Facciorusso, Antonio; Nacchiero, Maurizio Cosimo; Rosania, Rosa; Laonigro, Giulio; Longo, Nunzio; Panella, Carmine; Ierardi, Enzo

2011-09-01

Albumin constitutes approximately one half of the proteins in the plasma and plays a pivotal role in modulating the distribution of fluid between body compartments. Hence it is commonly employed in cirrhotic patients in association with diuretics for the treatment of ascites. Nevertheless, its usefulness is controversial in this condition and well-stated only in some circumstances. The item of safety of the drug appears to be convincing due to the accurate cautions in the course of its preparation. Side effects are described in literature only as sporadic events. Indeed, albumin administration is effective to prevent the circulatory dysfunctions after large-volume paracentesis and renal failure and after Spontaneous Bacterial Peritonitis (SBP). Finally albumin represents, associated with vasoconstrictors, the therapeutic gold standard for the hepatorenal-syndrome (HRS). Physiopathological bases of the therapeutic use of albumin in hepatic cirrhosis consist in both hypoalbuminemia and portal hypertension consequences. In fact, cirrhotic patient with ascites, in spite of hydrosaline retention, shows an effective hypovolemia with peripheral arterial vasodilatation and increase in heart rate. Therefore the effectiveness of albumin administration in the treatment of ascites is due to its plasma volume expander property as well as its efficacy in restoring plasmatic oncotic pressure. Trials are in progress in order to define the effectiveness of the prolonged home-administration of human albumin in the treatment and prevention of ascites. Finally, it has been recently demonstrated that the binding, transport and detoxification capacities of human albumin are severely reduced in cirrhotics and this impairment correlates with the degree of liver failure. Therefore, the next challenge will be to determine whether the alterations of non-oncotic properties of albumin are able to forecast mortality in cirrhotics with ascites and exogenous albumin chronic administration will be effective in predicting and preventing such alterations.

Earthquake-origin expansion of the Earth inferred from a spherical-Earth elastic dislocation theory

NASA Astrophysics Data System (ADS)

Xu, Changyi; Sun, Wenke

2014-12-01

In this paper, we propose an approach to compute the coseismic Earth's volume change based on a spherical-Earth elastic dislocation theory. We present a general expression of the Earth's volume change for three typical dislocations: the shear, tensile and explosion sources. We conduct a case study for the 2004 Sumatra earthquake (Mw9.3), the 2010 Chile earthquake (Mw8.8), the 2011 Tohoku-Oki earthquake (Mw9.0) and the 2013 Okhotsk Sea earthquake (Mw8.3). The results show that mega-thrust earthquakes make the Earth expand and earthquakes along a normal fault make the Earth contract. We compare the volume changes computed for finite fault models and a point source of the 2011 Tohoku-Oki earthquake (Mw9.0). The big difference of the results indicates that the coseismic changes in the Earth's volume (or the mean radius) are strongly dependent on the earthquakes' focal mechanism, especially the depth and the dip angle. Then we estimate the cumulative volume changes by historical earthquakes (Mw ≥ 7.0) since 1960, and obtain an Earth mean radius expanding rate about 0.011 mm yr-1.

United States Air Force Summer Research Program -- 1993. Volume 7. Armstrong Laboratory

DTIC Science & Technology

1993-12-01

formulation, absorption, plasma binding affinity, biomembrane barriers, and relative extraction by the specific organ of the body concerned with...simultaneously administered or a drug may "interact" with itself. The concomitant administration of phenobarbital and warfarin results in lower plasma ... plasma protein which binds to basic lipophilic drugs including propranolol, meperidine, quinidine, and chlorpromazine. If a variation in the plasma

Bed-rest studies: Fluid and electrolyte responses

NASA Technical Reports Server (NTRS)

Greenleaf, J. E.

1983-01-01

Confinement in the horizontal position for 2 to 3 weeks results in a chronic decrease in plasma volume, increased interstitial fluid volume, and unchanged or slightly increased extracellular fluid volume. Concentrations of blood electrolytes, glucose, and nitrogenous constituents remain within normal limits of variability when maintenance levels of isometric or isotonic exercise are performed for 1 hr/day. Hematocrit and plasma osmolality can be elevated significantly throughout bed rest (BR). Significant diuresis occurs on the first day, and increases in urine Na and Ca continue throughout BR, although voluntary fluid intake is unchanged. Urine Na and K are evaluated during the second week of BR in spite of stabilization of PV and extracellular volume. The initial diuresis probably arises from the extracellular fluid while subsequent urine loss above control levels must come from the intracellular fluid. Preservation of the extracellular volume takes precedance over maintenance of the intracellular fluid volume. The functioning of a natriuretic factor (hormone) to account for the continued increased loss of Na in the urine is suggested.

Red Blood Cell Volume, Plasma Volume and Total Blood Volume in Healthy Elderly Men and Women Aged 64 to 100

DTIC Science & Technology

1992-05-06

Robert Valeri, Linda E. Pivacek, Hiliary Siebens, and Mark D. Altschule ». PERFORMING ORGANIZATION NAME AND AOORESS Naval Blood Research Laboratory...Gibson JG, Peacock WC, Seligman AM, Sack T: Circulating red cell volume measured simultaneously by the radioactive iron and dye methods. J Clin

21 CFR 640.20 - Platelets.

Code of Federal Regulations, 2010 CFR

2010-04-01

... one unit of blood and resuspended in an appropriate volume of original plasma, as prescribed in § 640.24(d). (b) Source. The source material for Platelets is plasma which may be obtained by whole blood...

21 CFR 640.20 - Platelets.

Code of Federal Regulations, 2012 CFR

2012-04-01

... one unit of blood and resuspended in an appropriate volume of original plasma, as prescribed in § 640.24(d). (b) Source. The source material for Platelets is plasma which may be obtained by whole blood...

21 CFR 640.20 - Platelets.

Code of Federal Regulations, 2011 CFR

2011-04-01

... one unit of blood and resuspended in an appropriate volume of original plasma, as prescribed in § 640.24(d). (b) Source. The source material for Platelets is plasma which may be obtained by whole blood...

21 CFR 640.20 - Platelets.

Code of Federal Regulations, 2013 CFR

2013-04-01

... one unit of blood and resuspended in an appropriate volume of original plasma, as prescribed in § 640.24(d). (b) Source. The source material for Platelets is plasma which may be obtained by whole blood...

21 CFR 640.20 - Platelets.

Code of Federal Regulations, 2014 CFR

2014-04-01

... one unit of blood and resuspended in an appropriate volume of original plasma, as prescribed in § 640.24(d). (b) Source. The source material for Platelets is plasma which may be obtained by whole blood...

A simple high-performance liquid chromatography (HPLC) method for the measurement of pyridoxal-5-phosphate and 4-pyridoxic acid in human plasma.

PubMed

Cabo, Rona; Kozik, Karolina; Milanowski, Maciej; Hernes, Sigrunn; Slettan, Audun; Haugen, Margaretha; Ye, Shu; Blomhoff, Rune; Mansoor, M Azam

2014-06-10

Low concentration of plasma pyridoxal-5-phosphate (PLP) is associated with hyperhomocysteinemia and inflammation. Most methods for the measurement of plasma PLP require large specimen volume and involve the use of toxic reagents. We have developed a HPLC method for the measurement of PLP and 4-pyridoxic acid (4-PA) in plasma, which requires small specimen volume. The samples are prepared without adding any toxic reagents. Furthermore, we have examined whether intake of vitamin B6 affects the concentration of plasma PLP and 4-PA. The coefficient of variation of the method was 6% and the recovery of the added vitamin in plasma was about 100%. The concentrations of plasma PLP and 4-PA in 168 healthy subjects were 40.6 (8.4-165.0) nmol/L, median and (range) and 17.5 (3.7-114.79) nmol/L, median and (range) respectively. In the multiple regression analyses, the concentration of plasma PLP was associated with the concentration of plasma 4-PA (p<0.0001), BMI, (p=0.02) and sex, (p=0.0008). The concentration of plasma 4-PA was associated with plasma PLP (p<0.0001), serum folate (p=0.004), smoking (p=0.03) and vitamin B6 intake (p=0.01). The present method is suitable for large clinical studies for the measurement of plasma PLP and 4-PA. Our findings demonstrate that plasma 4-PA, BMI and sex are the major determinants of plasma PLP in healthy individuals. Copyright © 2014 Elsevier B.V. All rights reserved.

Large Volume Non-Equilibrium Air Plasma at Atmospheric Pressure: A Novel Method with Low Power Requirements

DTIC Science & Technology

2007-02-28

of magnitude in size. Also unlike corona -like devices such as the plasma needle , which generates 2-3 mm long plasma at the tip of a sharp wire...Distribution Unlimited Table of Contents Abstract AC System with Water Electrode Current voltage characteristics Plasma diagnostics results Experimental setup...Laroussi, PI. 4 AC SYSTEM WITH WATER ELECTRODE Recently, non-equilibrium atmospheric pressure plasmas have been used in a variety of material processing

Immunoglobulin G levels during collection of large volume plasma for fractionation.

PubMed

Burkhardt, Thomas; Rothe, Remo; Moog, Rainer

2017-06-01

There is a need of comprehensive work dealing with the quality of plasma for fractionation with respect to the IgG content as today most plasma derivates are used to treat patients with immunodeficiencies and autoimmune disorders. Therefore, a prospective study was carried out to analyse IgG levels before plasmapheresis and every 200ml collected plasma. Fifty-four experienced plasmapheresis donors were recruited for subsequent 850ml plasmapheresis using the Aurora Plasmapheresis System. Donorś peripheral blood counts were analysed before and after plasmapheresis using an electronic counter. Total protein, IgG and citrate were measured turbidometrically before, during and after apheresis as well as in the plasma product. Furthermore, platelets, red and white blood cells were analysed as parameters of product quality. An average of 2751±247ml blood was processed in 47±6min. The collected plasma volume was 850±1mL and citrate consumption was 177±15mL. A continuous drop of donors' IgG level was observed during plasmapheresis. The drop was 13% of the IgG baseline value at 800mL collected plasma. Total protein, IgG and cell counts of the plasma product met current guidelines of plasma for fractionation. Donors' IgG levels during apheresis showed a steady decrease without compromising the quality of plasma product. Copyright © 2017 Elsevier Ltd. All rights reserved.

Inertial stratification of an expanding highly ionized multicomponent plasma bunch

NASA Astrophysics Data System (ADS)

Kozhenkova, O. A.; Motorin, A. A.; Stupitskii, E. L.

2013-09-01

The initial composition of a four-component plasma bunch of a high specific energy has been determined, as well as its characteristics during the process of expansion. It is shown that the interaction of particles under a high energy is of the Coulomb character and this interaction is unable to ensure the same velocity of components with different atomic masses right from the very beginning of bunch expansion, leading to their radical stratification.

Small Surf

NASA Image and Video Library

2016-11-04

A minor solar eruption triggered a crackling, white flash that sent an expanding wave of plasma below it over about six hours (Nov. 4, 2016). Some of the plasma also appeared to surge along a narrow path above the active region as well. Such occurrences are fairly common, but still interesting to watch up close. The images were taken in a wavelength of extreme ultraviolet light. Movies are available at http://photojournal.jpl.nasa.gov/catalog/PIA21202

"Chartering" Maryland's Future: Is There an Expanded Role for National Charter Management Organizations in Our Schools? The Abell Report. Volume 28, No. 1

ERIC Educational Resources Information Center

Abell Foundation, 2015

2015-01-01

Over the past decade, a handful of high performing public charter schools have developed in Baltimore, but the need for high quality educational offerings, particularly for low-income students, remains high. "'Chartering' Maryland's Future: Is There an Expanded Role for National Charter Management Organizations in Our Schools?" considers…

Orbit transfer vehicle advanced expander cycle engine point design study. Volume 2: Study results

NASA Technical Reports Server (NTRS)

Diem, H. G.

1980-01-01

The design characteristics of the baseline engine configuration of the advanced expander cycle engine are described. Several aspects of engine optimization are considered which directly impact the design of the baseline thrust chamber. Four major areas of the power cycle optimization are emphasized: main turbine arrangement; cycle engine source; high pressure pump design; and boost pump drive.

Purge water management system

DOEpatents

Cardoso-Neto, J.E.; Williams, D.W.

1995-01-01

A purge water management system is described for effectively eliminating the production of purge water when obtaining a groundwater sample from a monitoring well. In its preferred embodiment, the purge water management system comprises an expandable container, a transportation system, and a return system. The purge water management system is connected to a wellhead sampling configuration, typically permanently installed at the well site. A pump, positioned with the monitoring well, pumps groundwater through the transportation system into the expandable container, which expands in direct proportion with volume of groundwater introduced, usually three or four well volumes, yet prevents the groundwater from coming into contact with the oxygen in the air. After this quantity of groundwater has been removed from the well, a sample is taken from a sampling port, after which the groundwater in the expandable container can be returned to the monitoring well through the return system. The purge water management system prevents the purge water from coming in contact with the outside environment, especially oxygen, which might cause the constituents of the groundwater to oxidize. Therefore, by introducing the purge water back into the monitoring well, the necessity of dealing with the purge water as a hazardous waste under the Resource Conservation and Recovery Act is eliminated.

Purge water management system

DOEpatents

Cardoso-Neto, Joao E.; Williams, Daniel W.

1996-01-01

A purge water management system for effectively eliminating the production of purge water when obtaining a groundwater sample from a monitoring well. In its preferred embodiment, the purge water management system comprises an expandable container, a transportation system, and a return system. The purge water management system is connected to a wellhead sampling configuration, typically permanently installed at the well site. A pump, positioned with the monitoring well, pumps groundwater through the transportation system into the expandable container, which expands in direct proportion with volume of groundwater introduced, usually three or four well volumes, yet prevents the groundwater from coming into contact with the oxygen in the air. After this quantity of groundwater has been removed from the well, a sample is taken from a sampling port, after which the groundwater in the expandable container can be returned to the monitoring well through the return system. The purge water management system prevents the purge water from coming in contact with the outside environment, especially oxygen, which might cause the constituents of the groundwater to oxidize. Therefore, by introducing the purge water back into the monitoring well, the necessity of dealing with the purge water as a hazardous waste under the Resource Conservation and Recovery Act is eliminated.

Decreased contralateral breast volume after mastectomy, adjuvant chemotherapy, and anti-estrogen therapy, in particular in breasts with high density.

PubMed

Ishii, Naohiro; Ando, Jiro; Harao, Michiko; Takemae, Masaru; Kishi, Kazuo

2017-10-01

Adjuvant chemotherapy and anti-estrogenic therapy can result in decreased volume of the contralateral breast, following mastectomy for the treatment of breast cancer. However, no data on the effect of adjuvant therapy on contralateral breast volume have previously been reported. We aimed to evaluate the extent to which adjuvant therapy and differences in breast density contribute to decreased breast volume. We conducted a prospective cohort study, selecting 40 nonconsecutive patients who underwent immediate breast reconstruction with mastectomy and expander insertion followed by expander replacement. We measured the contralateral breast volume before each procedure. The extent of the change was analyzed with respect to adjuvant therapy and breast density measured by preoperative mammography. The greatest decrease in breast volume was 135.1 cm 3 . The decrease in breast volume was significantly larger in the adjuvant therapy (+) group, particularly in patients with high breast density, than in the adjuvant therapy (-) group. Significant differences between the chemotherapy (+), tamoxifen (+) group and the chemotherapy (-), tamoxifen (+) group were not found. Breast density scores had a range of 2.0-3.3 (mean: 2.8). In breast reconstruction, particularly when performed in one stage, preoperative mammography findings are valuable to plastic surgeons, and possible decreases in the contralateral breast volume due to adjuvant therapy, particularly in patients with high breast density, should be considered carefully. Copyright © 2017 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Investigation of the boundary layer during the transition from volume to surface dominated H- production at the BATMAN test facility

NASA Astrophysics Data System (ADS)

Wimmer, C.; Schiesko, L.; Fantz, U.

2016-02-01

BATMAN (Bavarian Test Machine for Negative ions) is a test facility equipped with a 1/8 scale H- source for the ITER heating neutral beam injection. Several diagnostics in the boundary layer close to the plasma grid (first grid of the accelerator system) followed the transition from volume to surface dominated H- production starting with a Cs-free, cleaned source and subsequent evaporation of caesium, while the source has been operated at ITER relevant pressure of 0.3 Pa: Langmuir probes are used to determine the plasma potential, optical emission spectroscopy is used to follow the caesiation process, and cavity ring-down spectroscopy allows for the measurement of the H- density. The influence on the plasma during the transition from an electron-ion plasma towards an ion-ion plasma, in which negative hydrogen ions become the dominant negatively charged particle species, is seen in a strong increase of the H- density combined with a reduction of the plasma potential. A clear correlation of the extracted current densities (jH-, je) exists with the Cs emission.

Investigation of the boundary layer during the transition from volume to surface dominated H⁻ production at the BATMAN test facility.

PubMed

Wimmer, C; Schiesko, L; Fantz, U

2016-02-01

BATMAN (Bavarian Test Machine for Negative ions) is a test facility equipped with a 18 scale H(-) source for the ITER heating neutral beam injection. Several diagnostics in the boundary layer close to the plasma grid (first grid of the accelerator system) followed the transition from volume to surface dominated H(-) production starting with a Cs-free, cleaned source and subsequent evaporation of caesium, while the source has been operated at ITER relevant pressure of 0.3 Pa: Langmuir probes are used to determine the plasma potential, optical emission spectroscopy is used to follow the caesiation process, and cavity ring-down spectroscopy allows for the measurement of the H(-) density. The influence on the plasma during the transition from an electron-ion plasma towards an ion-ion plasma, in which negative hydrogen ions become the dominant negatively charged particle species, is seen in a strong increase of the H(-) density combined with a reduction of the plasma potential. A clear correlation of the extracted current densities (j(H(-)), j(e)) exists with the Cs emission.

The relationship between uric acid and potassium in normal subjects.

PubMed Central

Kennedy, A C; Boddy, K; King, P C; Brennan, J; Anderson, J A; Buchanan, W W

1978-01-01

The serum uric acid concentration in normal healthy subjects has been studied in relation to sex, height, weight, lean body mass measured from total body potassium and predicted from the Hume-Weyers formula (1971), total body potassium, plasma potassium and urea, and packed cell volume. The strongest correlation was found with sex, but height, weight, total body potassium, lean body mass (measured and predicted) also correlated significantly with serum uric acid concentration. However, when the sex variable was removed, the other factors lost their significant correlation. Finally, total red blood cell and plasma volumes were predicted (Hume and Goldberg, 1964) and from these an estimate of total plasma uric acid, total plasma potassium, and total red blood cell potassium obtained. Measured total body potassium was found to correlate well with total plasma potassium and total red blood cell potassium independent of sex. Total plasma uric acid correlated well with measured total body potassium when both sexes were considered and when separated into male and female groups the males retained a significant correlation as did the female group. PMID:686865

Orbit transfer vehicle engine study, phase A, extension 1: Volume 2: Study results

NASA Technical Reports Server (NTRS)

Mellish, J. A.

1981-01-01

Because of the advantage of the Advanced Expander Cycle Engine brought out in initial studies, further design optimization and comparative analyses were undertaken. The major results and conclusion derived are summarized. The primary areas covered are (1) thrust chamber geometry optimization, (2) expander cycle optimization, (3) alternate low thrust capability, (4) safety and reliability, (5) development risk comparison, and (6) cost comparisons. All of the results obtained were used to baseline the initial design concept for the OTV Advanced Expander Cycle Engine Point Design Study.

Sports anaemia and anthropometric evaluation of footballers at Kwame Nkrumah University of Science and Technology (KNUST)

PubMed Central

Opoku-Okrah, Clement; Sam, Daniel Kwasi; Nkum, Bernard; Dogbe, Elliot Eli; Antwi-Boateng, Lilian; Sackey, Benedict; Gyamfi, Daniel; Danquah, Kwabena Owusu

2016-01-01

Introduction Sports anaemia is a physiological activity that occurs amongst footballers and may be due to poor diet, over-training, as well as an increase in plasma volume in endurance training activities. High plasma volume leads to changes in haematological parameters that may impact on endurance of footballers. The objective of the study was to determine the correlation between haematological and an-thropometric indices and their role in sports anaemia in a tropical setting. Methods Venous blood was taken into EDTA for 12 soccer players of KNUST soccer team before training and after training for the first (W1) and fifth (W5) weeks of training sessions. Complete blood count analysis was done for each blood sample and anthropometric parameters such as height, weight, body mass index, body fat percent and lean body mass were also measured. Cross-tabulations with mean and standard deviation or median and range were computed. Paired t-test & and Mann-Whitney test for parametric and non-parametric data computations were carried out and a p-value ≤ 0.05 was taken to rep-resent significant difference between data groups. Results There was significant reduction in haemoglobin (p = 0.003), haematocrit (p = 0.002), mean cell volume (MCV) (p = 0.034) and red blood cell (RBC) count (p = 0.011) as a result of a significant expansion of plasma volume (p= 0.006). Neutrophil, lymphocyte and eosinophil counts were reduced significantly (p= 0.043, 0.001 and 0.007, respectively) after the training at W5. Lean body mass (LBM) inversely correlated with haemoglobin (r = -0.787, p = 0.002) and haematocrit (r = -0.588, p = 0.044). Body fat percentage (BFP) also negatively correlated with lymphocyte count (r = -0.700, p = 0.011). Furthermore, there was a positive correlation between body mass index (BMI) and plasma volume change after the training programme (r = 0.689, p = 0.013). Conclusion The results suggest that sports anaemia was induced by an increase in plasma volume that resulted in changes in haematological parameters. PMID:27583089

Sports anaemia and anthropometric evaluation of footballers at Kwame Nkrumah University of Science and Technology (KNUST).

PubMed

Opoku-Okrah, Clement; Sam, Daniel Kwasi; Nkum, Bernard; Dogbe, Elliot Eli; Antwi-Boateng, Lilian; Sackey, Benedict; Gyamfi, Daniel; Danquah, Kwabena Owusu

2016-01-01

Sports anaemia is a physiological activity that occurs amongst footballers and may be due to poor diet, over-training, as well as an increase in plasma volume in endurance training activities. High plasma volume leads to changes in haematological parameters that may impact on endurance of footballers. The objective of the study was to determine the correlation between haematological and an-thropometric indices and their role in sports anaemia in a tropical setting. Venous blood was taken into EDTA for 12 soccer players of KNUST soccer team before training and after training for the first (W1) and fifth (W5) weeks of training sessions. Complete blood count analysis was done for each blood sample and anthropometric parameters such as height, weight, body mass index, body fat percent and lean body mass were also measured. Cross-tabulations with mean and standard deviation or median and range were computed. Paired t-test & and Mann-Whitney test for parametric and non-parametric data computations were carried out and a p-value ≤ 0.05 was taken to rep-resent significant difference between data groups. There was significant reduction in haemoglobin (p = 0.003), haematocrit (p = 0.002), mean cell volume (MCV) (p = 0.034) and red blood cell (RBC) count (p = 0.011) as a result of a significant expansion of plasma volume (p= 0.006). Neutrophil, lymphocyte and eosinophil counts were reduced significantly (p= 0.043, 0.001 and 0.007, respectively) after the training at W5. Lean body mass (LBM) inversely correlated with haemoglobin (r = -0.787, p = 0.002) and haematocrit (r = -0.588, p = 0.044). Body fat percentage (BFP) also negatively correlated with lymphocyte count (r = -0.700, p = 0.011). Furthermore, there was a positive correlation between body mass index (BMI) and plasma volume change after the training programme (r = 0.689, p = 0.013). The results suggest that sports anaemia was induced by an increase in plasma volume that resulted in changes in haematological parameters.

Waves generated in the plasma plume of helicon magnetic nozzle

DOE Office of Scientific and Technical Information (OSTI.GOV)

Singh, Nagendra; Rao, Sathyanarayan; Ranganath, Praveen

2013-03-15

Experimental measurements have shown that the plasma plume created in a helicon plasma device contains a conical structure in the plasma density and a U-shaped double layer (US-DL) tightly confined near the throat where plasma begins to expand from the source. Recently reported two-dimensional particle-in-cell simulations verified these density and US-DL features of the plasma plume. Simulations also showed that the plasma in the plume develops non-thermal feature consisting of radial ion beams with large densities near the conical surface of the density structure. The plasma waves that are generated by the radial ion beams affecting the structure of themore » plasma plume are studied here. We find that most intense waves persist in the high-density regions of the conical density structure, where the transversely accelerated ions in the radial electric fields in the plume are reflected setting up counter-streaming. The waves generated are primarily ion Bernstein modes. The nonlinear evolution of the waves leads to magnetic field-aligned striations in the fields and the plasma near the conical surface of the density structure.« less

Demonstration of current drive by a rotating magnetic dipole field

NASA Astrophysics Data System (ADS)

Giersch, L.; Slough, J. T.; Winglee, R.

2007-04-01

Abstract.A dipole-like rotating magnetic field was produced by a pair of circular, orthogonal coils inside a metal vacuum chamber. When these coils were immersed in plasma, large currents were driven outside the coils: the currents in the plasma were generated and sustained by the rotating magnetic dipole (RMD) field. The peak RMD-driven current was at roughly two RMD coil radii, and this current (60 kA m-) was sufficient to reverse the ambient magnetic field (33 G). Plasma density, electron temperature, magnetic field and current probes indicated that plasma formed inside the coils, then expanded outward until the plasma reached equilibrium. This equilibrium configuration was adequately described by single-fluid magnetohydrodynamic equilibrium, wherein the cross product of the driven current and magnetic filed was approximately equal to the pressure gradient. The ratio of plasma pressure to magnetic field pressure, β, was locally greater than unity.

Simulation of magnetic holes formation in the magnetosheath

NASA Astrophysics Data System (ADS)

Ahmadi, Narges; Germaschewski, Kai; Raeder, Joachim

2017-12-01

Magnetic holes have been frequently observed in the Earth's magnetosheath and are believed to be the consequence of the nonlinear evolution of the mirror instability. Mirror mode perturbations mainly form as magnetic holes in regions where the plasma is marginally mirror stable with respect to the linear instability criterion. We present an expanding box particle-in-cell simulation to mimic the changing conditions in the magnetosheath as the plasma is convected through it that produces mirror mode magnetic holes. We show that in the initial nonlinear evolution, where the plasma conditions are mirror unstable, the magnetic peaks are dominant, while later, as the plasma relaxes toward marginal stability, the fluctuations evolve into deep magnetic holes. While the averaged plasma parameters in the simulation remain close to the mirror instability threshold, the local plasma in the magnetic holes is highly unstable to mirror instability and locally mirror stable in the magnetic peaks.

A spectral Poisson solver for kinetic plasma simulation

NASA Astrophysics Data System (ADS)

Szeremley, Daniel; Obberath, Jens; Brinkmann, Ralf

2011-10-01

Plasma resonance spectroscopy is a well established plasma diagnostic method, realized in several designs. One of these designs is the multipole resonance probe (MRP). In its idealized - geometrically simplified - version it consists of two dielectrically shielded, hemispherical electrodes to which an RF signal is applied. A numerical tool is under development which is capable of simulating the dynamics of the plasma surrounding the MRP in electrostatic approximation. In this contribution we concentrate on the specialized Poisson solver for that tool. The plasma is represented by an ensemble of point charges. By expanding both the charge density and the potential into spherical harmonics, a largely analytical solution of the Poisson problem can be employed. For a practical implementation, the expansion must be appropriately truncated. With this spectral solver we are able to efficiently solve the Poisson equation in a kinetic plasma simulation without the need of introducing a spatial discretization.

Characterizing Hypervelocity Impact Plasma Through Experiments and Simulations

NASA Astrophysics Data System (ADS)

Close, Sigrid; Lee, Nicolas; Fletcher, Alex; Nuttall, Andrew; Hew, Monica; Tarantino, Paul

2017-10-01

Hypervelocity micro particles, including meteoroids and space debris with masses <1 ng, routinely impact spacecraft and create dense plasma that expands at the isothermal sound speed. This plasma, with a charge separation commensurate with different species mobilities, can produce a strong electromagnetic pulse (EMP) with a broad frequency spectrum. Subsequent plasma oscillations resulting from instabilities can also emit significant power and may be responsible for many reported satellite anomalies. We present theory and recent results from ground-based impact tests aimed at characterizing hypervelocity impact plasma. We also show results from particle-in-cell (PIC) and computational fluid dynamics (CFD) simulations that allow us to extend to regimes not currently possible with ground-based technology. We show that significant impact-produced radio frequency (RF) emissions occurred in frequencies ranging from VHF through L-band and that these emissions were highly correlated with fast (>20 km/s) impacts that produced a fully ionized plasma.

Characteristics of an under-expanded supersonic flow in arcjet plasmas

NASA Astrophysics Data System (ADS)

Namba, Shinichi; Shikama, Taiichi; Sasano, Wataru; Tamura, Naoki; Endo, Takuma

2018-06-01

A compact apparatus to produce arcjet plasma was fabricated to investigate supersonic flow dynamics. Periodic bright–dark emission structures were formed in the arcjets, depending on the plasma source and ambient gas pressures in the vacuum chamber. A directional Langmuir probe (DLP) and emission spectroscopy were employed to characterize plasma parameters such as the Mach number of plasma flows and clarify the mechanism for the generation of the emission pattern. In particular, in order to investigate the influence of the Mach number on probe size, we used two DLPs of different probe size. The results indicated that the arcjets could be classified into shock-free expansion and under-expansion, and the behavior of plasma flow could be described by compressible fluid dynamics. Comparison of the Langmuir probe results with emission and laser absorption spectroscopy showed that the small diameter probe was reliable to determine the Mach number, even for the supersonic jet.

Operation of Wastewater Treatment Plants: A Field Study Training Program. Volume II. Second Edition.

ERIC Educational Resources Information Center

California State Univ., Sacramento. Dept. of Civil Engineering.

This manual was prepared by experienced wastewater collection system workers to provide a home study course to develop new qualified workers and expand the abilities of existing workers. This volume emphasizes material needed by intermediate-level operators and stresses the operation and maintenance of conventional treatment plants. This volume…

Agricultural Structures. Volume I. Instructor's Guide. Volume 13, Number 1.

ERIC Educational Resources Information Center

Linhardt, Richard E.; Burhoe, Steve

This document is a curriculum unit in agricultural structures designed to expand the curriculum materials available in vocational agriculture in Missouri. The guide consists of three units on constructing farm buildings, planning farm water systems, and building fences. Each unit contains 10-15 lessons on various aspects of the unit's topic. Each…

Science, Philosophy & Religion. Working Papers Series Volume 1.

ERIC Educational Resources Information Center

Schenck, David, Ed.

Lehigh University Technology Studies Resource Center has coordinated and produced a series of publications that focus on expanding an understanding of the social context of technology in contemporary society. This volume is the first in a series of working papers that aim to stimulate new research, facilitate dissemination, encourage peer review,…

A review of direct experimental measurements of detachment

DOE PAGES

Boedo, J.; McLean, A. G.; Rudakov, D. L.; ...

2018-02-22

Detached divertor plasmas feature strong radial and parallel gradients of density, temperature, electric fields and flow over the divertor volume and therefore, sampling the divertor plasma directly provides crucial knowledge to the interpretation and modeling efforts. Here, we review the contribution of diagnostics that directly sample the plasma to the advancement of knowledge of the physics of detachment and detached divertors, such as the characteristics of the various regimes, discovery and quantification of drifts and identification of convection of heat and particles. We focus on wall probes, scanning probes, retarding field analyzers and Thomson Scattering (TS) in the divertor regionmore » and also include the contribution of measurements away from the divertor that provide insight on how divertor detachment affects core, edge or pedestal conditions. Wall probes are critical as they can be installed in closed volumes of difficult access to other diagnostics and measure plasma parameters at the divertor structures, which define the plasma boundary conditions and where detachment effects are more likely to be strongest.« less

A review of direct experimental measurements of detachment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boedo, J.; McLean, A. G.; Rudakov, D. L.

Detached divertor plasmas feature strong radial and parallel gradients of density, temperature, electric fields and flow over the divertor volume and therefore, sampling the divertor plasma directly provides crucial knowledge to the interpretation and modeling efforts. Here, we review the contribution of diagnostics that directly sample the plasma to the advancement of knowledge of the physics of detachment and detached divertors, such as the characteristics of the various regimes, discovery and quantification of drifts and identification of convection of heat and particles. We focus on wall probes, scanning probes, retarding field analyzers and Thomson Scattering (TS) in the divertor regionmore » and also include the contribution of measurements away from the divertor that provide insight on how divertor detachment affects core, edge or pedestal conditions. Wall probes are critical as they can be installed in closed volumes of difficult access to other diagnostics and measure plasma parameters at the divertor structures, which define the plasma boundary conditions and where detachment effects are more likely to be strongest.« less

Incorporation of an Energy Equation into a Pulsed Inductive Thruster Performance Model

NASA Technical Reports Server (NTRS)

Polzin, Kurt A.; Reneau, Jarred P.; Sankaran, Kameshwaran

2011-01-01

A model for pulsed inductive plasma acceleration containing an energy equation to account for the various sources and sinks in such devices is presented. The model consists of a set of circuit equations coupled to an equation of motion and energy equation for the plasma. The latter two equations are obtained for the plasma current sheet by treating it as a one-element finite volume, integrating the equations over that volume, and then matching known terms or quantities already calculated in the model to the resulting current sheet-averaged terms in the equations. Calculations showing the time-evolution of the various sources and sinks in the system are presented to demonstrate the efficacy of the model, with two separate resistivity models employed to show an example of how the plasma transport properties can affect the calculation. While neither resistivity model is fully accurate, the demonstration shows that it is possible within this modeling framework to time-accurately update various plasma parameters.

Plasma /Na+/, /Ca++/, and volume shifts and thermoregulation during exercise in man

NASA Technical Reports Server (NTRS)

Greenleaf, J. E.; Convertino, V. A.; Stremel, R. W.; Bernauer, E. M.; Adams, W. C.; Vignau, S. R.; Brock, P. J.

1977-01-01

Graded-exercise experiments are conducted on six trained male runners (19-23 yr) subjected to ergometer exercise in a program consisting of 30-min resting control period, 60 min of rest or exercise at work loads that resulted in a maximal oxygen uptake equivalent to 6% (resting), 23%, 43%, and 62% of maximal oxygen uptake, followed by 30 min of recovery. The parameters measured and discussed are rectal temperature (T-re), skin temperatures at different spots, maximal oxygen uptake, plasma volume (PV), and various plasma electrolyte and protein concentrations. The objectives are to determine whether the increased T-re during progressively greater work loads are related to plasma sodium ion and calcium ion concentrations, as well as to evaluate the influence of PV shifts on the electrolyte and osmotic concentrations. The results suggest that the shift (loss) in PV accounts for the increases in the plasma constituent concentrations that result in significant correlations with T-re.

A review of direct experimental measurements of detachment

NASA Astrophysics Data System (ADS)

Boedo, J.; McLean, A. G.; Rudakov, D. L.; Watkins, J. G.

2018-04-01

Detached divertor plasmas feature strong radial and parallel gradients of density, temperature, electric fields and flow over the divertor volume and therefore, sampling the divertor plasma directly provides crucial knowledge to the interpretation and modeling efforts. We review the contribution of diagnostics that directly sample the plasma to the advancement of knowledge of the physics of detachment and detached divertors, such as the characteristics of the various regimes, discovery and quantification of drifts and identification of convection of heat and particles. We focus on wall probes, scanning probes, retarding field analyzers and Thomson scattering in the divertor region and also include the contribution of measurements away from the divertor that provide insight on how divertor detachment affects core, edge or pedestal conditions. Wall probes are critical as they can be installed in closed volumes of difficult access to other diagnostics and measure plasma parameters at the divertor structures, which define the plasma boundary conditions and where detachment effects are more likely to be strongest.

Effects of Electric Discharge Plasma Treatment on the Thermal Conductivity of Polymer-Metal Nitride/Carbide Composites

NASA Astrophysics Data System (ADS)

Parali, Levent; Kurbanov, Mirza A.; Bayramov, Azad A.; Tatardar, Farida N.; Sultanakhmedova, Ramazanova I.; Xanlar, Huseynova Gulnara

2015-11-01

High-density polymer composites with semiconductor or dielectric fillers such as aluminum nitride (AIN), aluminum oxide (Al2O3), titanium carbide (TiC), titanium nitride (TiN), boron nitride (BN), silicon nitride (Si3N4), and titanium carbonitride (TiCN) were prepared by the hot pressing method. Each powder phase of the composites was exposed to an electric discharge plasma process before composite formation. The effects of the electric discharge plasma process and the filler content (volume fraction) on the thermal conductivity, volt-ampere characteristics, thermally stimulated depolarization current, as well as electrical and mechanical strength were investigated. The results of the study indicate that, with increasing filler volume fraction, the thermal conductivity of the samples also increased. Furthermore, the thermal conductivity, and electrophysical and mechanical properties of the high-density polyethylene + 70% BN composite modified using the electric discharge plasma showed improvement when compared with that without electric discharge plasma treatment.

Low-volume high-intensity swim training is superior to high-volume low-intensity training in relation to insulin sensitivity and glucose control in inactive middle-aged women.

PubMed

Connolly, Luke J; Nordsborg, Nikolai B; Nyberg, Michael; Weihe, Pál; Krustrup, Peter; Mohr, Magni

2016-10-01

We tested the hypothesis that low-volume high-intensity swimming has a larger impact on insulin sensitivity and glucose control than high-volume low-intensity swimming in inactive premenopausal women with mild hypertension. Sixty-two untrained premenopausal women were randomised to an inactive control (n = 20; CON), a high-intensity low-volume (n = 21; HIT) or a low-intensity high-volume (n = 21; LIT) training group. During the 15-week intervention period, HIT performed 3 weekly 6-10 × 30-s all-out swimming intervals (average heart rate (HR) = 86 ± 3 % HRmax) interspersed by 2-min recovery periods and LIT swam continuously for 1 h at low intensity (average HR = 73 ± 3 % HRmax). Fasting blood samples were taken and an oral glucose tolerance test (OGTT) was conducted pre- and post-intervention. After HIT, resting plasma [insulin] was lowered (17 ± 34 %; P < 0.05) but remained similar after LIT and CON. Following HIT, 60-min OGTT plasma [insulin] and [glucose] was lowered (24 ± 30 % and 10 ± 16 %; P < 0.05) but remained similar after LIT and CON. Total area under the curve for plasma [glucose] was lower (P < 0.05) after HIT than LIT (660 ± 141 vs. 860 ± 325 mmol min L(-1)). Insulin sensitivity (HOMA-IR) had increased (P < 0.05) by 22 ± 34 % after HIT, with no significant change after LIT or CON, respectively. Plasma soluble intracellular cell adhesion molecule 1 was lowered (P < 0.05) by 4 ± 8 and 3 ± 9 % after HIT and CON, respectively, while plasma soluble vascular cell adhesion molecule 1 had decreased (P < 0.05) by 8 ± 23 % after HIT only. These findings suggest that low-volume high-intensity intermittent swimming is an effective and time-efficient training strategy for improving insulin sensitivity, glucose control and biomarkers of vascular function in inactive, middle-aged mildly hypertensive women.

Noninductively Driven Tokamak Plasmas at Near-Unity Toroidal Beta

DOE PAGES

Schlossberg, David J.; Bodner, Grant M.; Bongard, Michael W.; ...

2017-07-01

Access to and characterization of sustained, toroidally confined plasmas with a very high plasma-to-magnetic pressure ratio (β t), low internal inductance, high elongation, and nonsolenoidal current drive is a central goal of present tokamak plasma research. Stable access to this desirable parameter space is demonstrated in plasmas with ultralow aspect ratio and high elongation. Local helicity injection provides nonsolenoidal sustainment, low internal inductance, and ion heating. Equilibrium analyses indicate β t up to ~100% with a minimum |B| well spanning up to ~50% of the plasma volume.

Noninductively Driven Tokamak Plasmas at Near-Unity Toroidal Beta.

PubMed

Schlossberg, D J; Bodner, G M; Bongard, M W; Burke, M G; Fonck, R J; Perry, J M; Reusch, J A

2017-07-21

Access to and characterization of sustained, toroidally confined plasmas with a very high plasma-to-magnetic pressure ratio (β_{t}), low internal inductance, high elongation, and nonsolenoidal current drive is a central goal of present tokamak plasma research. Stable access to this desirable parameter space is demonstrated in plasmas with ultralow aspect ratio and high elongation. Local helicity injection provides nonsolenoidal sustainment, low internal inductance, and ion heating. Equilibrium analyses indicate β_{t} up to ∼100% with a minimum |B| well spanning up to ∼50% of the plasma volume.

Impact of ABO-Identical vs ABO-Compatible Nonidentical Plasma Transfusion in Trauma Patients

DTIC Science & Technology

2010-09-01

and B patients in turn could receive AB donor plasma. Few studies have examined the im- pact of compatible nonidentical plasma transfusion . In platelet ... transfusion ,19 the administration of compatible nonidenti- cal platelets to patients undergoing coro- nary artery bypass grafting or valve re...significantly different (in boldface) and for the volume of packed red blood cells, plasma, platelets , cryoprecipitate, and factor VIIa transfused . cBecause

Bigelow Expandable Activity Module (BEAM) - ISS Inflatable Module Technology Demonstration

NASA Technical Reports Server (NTRS)

Dasgupta, Rajib; Munday, Steve; Valle, Gerard D.

2014-01-01

INNOVATION: BEAM is a pathway project demonstrating the design, fabrication, test, certification, integration, operation, on-orbit performance, and disposal of the first ever man-rated space inflatable structure. The groundwork laid through the BEAM project will support developing and launching a larger inflatable space structure with even greater mass per volume (M/V) advantages need for longer space missions. OVERVIEW: Inflatable structures have been shown to have much lower mass per volume ratios (M/V) when compared with conventional space structures. BEAM is an expandable structure, launched in a packed state, and then expanded once on orbit. It is a temporary experimental module to be used for gathering structural, thermal, and radiation data while on orbit. BEAM will be launched on Space X-8, be extracted from the dragon trunk, and will attach to ISS at Node 3- Aft. BEAM performance will be monitored over a two-year period and then BEAM will be jettison using the SSRMS.

APPARATUS FOR MINIMIZING ENERGY LOSSES FROM MAGNETICALLY CONFINED VOLUMES OF HOT PLASMA

DOEpatents

Post, R.F.

1961-10-01

An apparatus is described for controlling electron temperature in plasma confined in a Pyrotron magnetic containment field. Basically the device comprises means for directing low temperature electrons to the plasma in controlled quantities to maintain a predetermined optimum equilibrium electron temperature whereat minimum losses of plasma ions due to ambipolar effects and energy damping of the ions due to dynamical friction with the electrons occur. (AEC)

Annular vortex merging processes in non-neutral electron plasmas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaga, Chikato, E-mail: d146073@hiroshima-u.ac.jp; Ito, Kiyokazu; Higaki, Hiroyuki

2015-06-29

Non-neutral electron plasmas in a uniform magnetic field are investigated experimentally as a two dimensional (2D) fluid. Previously, it was reported that 2D phase space volume increases during a vortex merging process with viscosity. However, the measurement was restricted to a plasma with a high density. Here, an alternative method is introduced to evaluate a similar process for a plasma with a low density.

Characterization of argon direct-current glow discharge with a longitudinal electric field applied at ambient air

NASA Astrophysics Data System (ADS)

Jiang, Weiman; Tang, Jie; Wang, Yishan; Zhao, Wei; Duan, Yixiang

2014-09-01

A direct-current-driven plasma jet is developed by applying a longitudinal electric field on the flowing argon at ambient air. This plasma shows a torch shape with its cross-section increased from the anode to the cathode. Comparison with its counterparts indicates that the gas flow plays a key role in variation of the plasma structure and contributes much to enlarging the plasma volume. It is also found that the circular hollow metal base promotes generation of plasma with a high-power volume density in a limited space. The optical emission spectroscopy (OES) diagnosis indicates that the plasma comprises many reactive species, such as OH, O, excited N2, and Ar metastables. Examination of the rotational and vibrational temperature indicates that the plasma is under nonequilibrium condition and the excited species OH(A 2Σ+), O(5P), and N2(C 3Πu) are partly generated by energy transfer from argon metastables. The spatially resolved OES of plasma reveals that the negative glow, Faraday dark space, and positive column are distributed across the gas gap. The absence of the anode glow is attributed to the fact that many electrons in the vicinity of the anode follow ions into the positive column due to the ambipolar diffusion in the flowing gas.

Molecular Diagnostics of Fusion and Laboratory Plasmas

NASA Astrophysics Data System (ADS)

Fantz, U.

2005-05-01

The presence of molecules in the cold scrape-off layer of fusion experiments and industrial plasmas requires an understanding of the molecular dynamics in these low temperature plasmas. Suitable diagnostic methods can provide an insight in molecular processes in the plasma volume as well as for plasma surface interactions. A very simple but powerful technique is the molecular emission spectroscopy. Spectra are obtained easily, whereas interpretation might be very complex and relies on the availability of atomic and molecular data. Examples are given for hydrogen plasmas and plasmas with hydrocarbons which both are of importance in industrial applications as well as in fusion experiments.

Dynamic polarizability of tungsten atoms reconstructed from fast electrical explosion of fine wires in vacuum

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sarkisov, G. S.; Rosenthal, S. E.; Struve, K. W.

For nanosecond electrical explosion of fine metal wires in vacuum generates calibrated, radially expanded gas cylinders of metal atoms are surrounded by low-density fast expanding plasma corona. Here, a novel integrated-phase technique, based on laser interferometry, provides the dynamic dipole polarizability of metal atoms. This data was previously unavailable for tungsten atoms. Furthermore, an extremely high melting temperature and significant pre-melt electronic emission make these measurements particularly complicated for this refractory metal.

Dynamic polarizability of tungsten atoms reconstructed from fast electrical explosion of fine wires in vacuum

DOE PAGES

Sarkisov, G. S.; Rosenthal, S. E.; Struve, K. W.

2016-10-12

For nanosecond electrical explosion of fine metal wires in vacuum generates calibrated, radially expanded gas cylinders of metal atoms are surrounded by low-density fast expanding plasma corona. Here, a novel integrated-phase technique, based on laser interferometry, provides the dynamic dipole polarizability of metal atoms. This data was previously unavailable for tungsten atoms. Furthermore, an extremely high melting temperature and significant pre-melt electronic emission make these measurements particularly complicated for this refractory metal.

Significant increase in salivary substance p level after a single oral dose of cevimeline in humans.

PubMed

Suzuki, Yosuke; Itoh, Hiroki; Amada, Kohei; Yamamura, Ryota; Sato, Yuhki; Takeyama, Masaharu

2013-01-01

Cevimeline is a novel muscarinic acetylcholine receptor agonist currently being developed as a therapeutic agent for xerostomia. We examined the effects of cevimeline on salivary and plasma levels of substance-P- (SP-), calcitonin-gene-related-peptide- (CGRP-), and vasoactive-intestinal-polypeptide- (VIP-) like immunoreactive substances (ISs) in humans. An open-labeled crossover study was conducted on seven healthy volunteers. Saliva volume was measured, and saliva and venous blood samples were collected before and 30-240 min after a single oral dose of cevimeline or placebo. Salivary and plasma levels of SP-, CGRP-, and VIP-IS were measured using a highly sensitive enzyme immunoassay. A single oral dose of cevimeline resulted in significant increases in salivary but not plasma SP-IS level compared to placebo. Cevimeline administration did not alter the salivary or plasma levels of CGRP-IS or VIP-IS compared to placebo. Significant increases in salivary volume were observed after cevimeline administration compared to placebo. A significant correlation was observed between the total release of SP-IS and that of salivary volume. These findings suggest an association of SP with the enhancement of salivary secretion by cevimeline.

Significant Increase in Salivary Substance P Level after a Single Oral Dose of Cevimeline in Humans

PubMed Central

Suzuki, Yosuke; Itoh, Hiroki; Amada, Kohei; Yamamura, Ryota; Sato, Yuhki; Takeyama, Masaharu

2013-01-01

Cevimeline is a novel muscarinic acetylcholine receptor agonist currently being developed as a therapeutic agent for xerostomia. We examined the effects of cevimeline on salivary and plasma levels of substance-P- (SP-), calcitonin-gene-related-peptide- (CGRP-), and vasoactive-intestinal-polypeptide- (VIP-) like immunoreactive substances (ISs) in humans. An open-labeled crossover study was conducted on seven healthy volunteers. Saliva volume was measured, and saliva and venous blood samples were collected before and 30–240 min after a single oral dose of cevimeline or placebo. Salivary and plasma levels of SP-, CGRP-, and VIP-IS were measured using a highly sensitive enzyme immunoassay. A single oral dose of cevimeline resulted in significant increases in salivary but not plasma SP-IS level compared to placebo. Cevimeline administration did not alter the salivary or plasma levels of CGRP-IS or VIP-IS compared to placebo. Significant increases in salivary volume were observed after cevimeline administration compared to placebo. A significant correlation was observed between the total release of SP-IS and that of salivary volume. These findings suggest an association of SP with the enhancement of salivary secretion by cevimeline. PMID:23589717

Application of a novel large-volume injection method using a stomach-shaped inlet liner in capillary gas chromatographic trace analysis of dioxins in human milk and plasma.

PubMed

Saito, Koichi; Ohmura, Atsuko; Takekuma, Mikiko; Sasano, Ryoichi; Matsuki, Yasuhiko; Nakazawa, Hiroyuki

2007-06-01

A newly developed large-volume injection (LVI) technique that employs a unique stomach-shaped inlet liner (SSIL) inside of a programmable temperature vaporizer was used for the determination of trace amounts of dioxins in human milk and plasma. The initial temperature and the initial dwelling time of the inlet and the kind of solvent used were found to be critical in determining the analytical sensitivity of dioxins due to the loss of these relatively volatile compounds during solvent vaporization. Human milk and plasma were purified and fractionated by pre-packed multi-layered silica-gel chromatography and activated carbon silica-gel column chromatography. A 20-microL aliquot of the fraction collected from the chromatography with toluene was directly applied to the LVI system in high-resolution gas chromatography/high-resolution mass spectrometry. Excellent correlation (r > 0.97) between the values obtained by the LVI method using the SSIL device and those by the conventional regular-volume splitless injection method was obtained for PCDDs, PCDFs and non-ortho PCBs in human milk and plasma samples.

The mechanism of the increase in glomerular filtration rate in the twelve-day pregnant rat.

PubMed Central

Baylis, C

1980-01-01

1. Whole kidney and micropuncture techniques were employed to investigate the determinants of glomerular ultrafiltration in virgin and 12-day pregnant rats. 2. A significant increase in whole kidney glomerular filtration rate (g.f.r.) and superficial cortical single nephron g.f.r. was noted in pregnant rats compared to virgins. 3. Increases in whole kidney and glomerular plasma flow rate also occurred in pregnancy which were in proportion to the increase in rate of filtration. No differences were noted in the hydrostatic and oncotic pressures which influence formation of glomerular ultrafiltrate in the superficial nephron population. 4. Reduction in arterial haematocrit and no change in mean red cell volume indicate that a plasma volume expansion has occurred by day 12 of pregnancy in the rat. 5. It is concluded that the increased g.f.r. seen in 12-day pregnant rats is exclusively the result of an increase in renal plasma flow rate (r.p.f.) since the other determinants of glomerular ultrafiltration are unaffected by pregnancy. The plasma volume expansion which also occurs must be, at least in part, responsible for the increase in r.p.f. PMID:7441561

Investigations of microwave plasmas - Applications in electrothermal thruster systems

NASA Technical Reports Server (NTRS)

Haraburda, Scott S.; Hawley, Martin C.

1989-01-01

Experimental studies which have been conducted to develop understanding of plasma processes used for spacecraft propulsion are reviewed. The techniques discussed are calorimetry and volume measurements using the TM 011 and TM 012 modes in the microwave cavity system. The use of plasmas in electrical propulsion and microwave induction is reviewed. Plasma containment, microwave power production, energy distribution, and the pressure and flow dependence of the energy distribution are addressed. The plasma dimensions and their dependence on pressure, flow, and power are considered.

Investigations of microwave plasmas - Applications in electrothermal thruster systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haraburda, S.S.; Hawley, M.C.

1989-01-01

Experimental studies which have been conducted to develop understanding of plasma processes used for spacecraft propulsion are reviewed. The techniques discussed are calorimetry and volume measurements using the TM 011 and TM 012 modes in the microwave cavity system. The use of plasmas in electrical propulsion and microwave induction is reviewed. Plasma containment, microwave power production, energy distribution, and the pressure and flow dependence of the energy distribution are addressed. The plasma dimensions and their dependence on pressure, flow, and power are considered. 10 refs.

Characteristics of soft x-ray and extreme ultraviolet (XUV) emission from laser-produced highly charged rhodium ions

NASA Astrophysics Data System (ADS)

Barte, Ellie Floyd; Hara, Hiroyuki; Tamura, Toshiki; Gisuji, Takuya; Chen, When-Bo; Lokasani, Ragava; Hatano, Tadashi; Ejima, Takeo; Jiang, Weihua; Suzuki, Chihiro; Li, Bowen; Dunne, Padraig; O'Sullivan, Gerry; Sasaki, Akira; Higashiguchi, Takeshi; Limpouch, Jiří

2018-05-01

We have characterized the soft x-ray and extreme ultraviolet (XUV) emission of rhodium (Rh) plasmas produced using dual pulse irradiation by 150-ps or 6-ns pre-pulses, followed by a 150-ps main pulse. We have studied the emission enhancement dependence on the inter-pulse time separation and found it to be very significant for time separations less than 10 ns between the two laser pulses when using 6-ns pre-pulses. The behavior using a 150-ps pre-pulse was consistent with such plasmas displaying only weak self-absorption effects in the expanding plasma. The results demonstrate the advantage of using dual pulse irradiation to produce the brighter plasmas required for XUV applications.

Studying the Generation Stage of a Plasma Jet in a Plasma Focus Discharge

NASA Astrophysics Data System (ADS)

Polukhin, S. N.; Gurei, A. E.; Nikulin, V. Ya.; Peregudova, E. N.; Silin, P. V.; Kharrasov, A. M.

2017-12-01

A dense compact plasmoid generated at the pinch collapse stage is revealed in a plasma focus discharge by laser optical methods. The initial size of the plasmoid is 1 mm, its electron density is more than 2 × 1019 cm-3, and the plasmoid propagates along the axis from the anode at an average velocity of more than 107 cm/s. A shock wave is generated in the residual argon plasma during the motion of the bunch, its density decreases to 1018 cm-3 at a distance of 3 cm from its place of generation, and the plasmoid expands by 3-5 times and almost merges together with the leading edge of the shock wave.

Reduction in central venous pressure enhances erythropoietin synthesis: role of volume-regulating hormones.

PubMed

Montero, D; Rauber, S; Goetze, J P; Lundby, C

2016-10-01

Erythropoiesis is a tightly controlled biological event, but its regulation under non-hypoxic conditions, however, remains unresolved. We examined whether acute changes in central venous blood pressure (CVP) elicited by whole-body tilting affect erythropoietin (EPO) concentration according to volume-regulating hormones. Plasma EPO, angiotensin II (ANGII), aldosterone, pro-atrial natriuretic peptide (proANP) and copeptin concentrations were measured at supine rest and up to 3 h during 30° head-up (HUT) and head-down tilt (HDT) in ten healthy male volunteers. Plasma albumin concentration was used to correct for changes in plasma volume and CVP was estimated through the internal jugular vein (IJV) aspect ratio with ultrasonography. From supine rest, the IJV aspect ratio was decreased and increased throughout HUT and HDT respectively. Plasma EPO concentration increased during HUT (13%; P = 0.001, P for linear component = 0.017), independent of changes in albumin concentration. Moreover, ANGII and copeptin concentrations increased during HUT, while proANP decreased. The increase in EPO concentration during HUT disappeared when adjusted for changes in copeptin. During HDT, EPO, ANGII and copeptin concentrations remained unaffected while proANP increased. In regression analyses, EPO was positively associated with copeptin (β = 0.55; 95% CI = 0.18, 0.93; P = 0.004) irrespective of changes in other hormones and albumin concentration. Reduction in CVP prompts an increase in plasma EPO concentration independent of hemoconcentration and hence suggests CVP per se as an acute regulator of EPO synthesis. This effect may be explained by changes in volume-regulating hormones. © 2016 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

Vasoactive neuroendocrine responses associated with tolerance to lower body negative pressure in humans

NASA Technical Reports Server (NTRS)

Convertino, V. A.; Sather, T. M.

2000-01-01

The purpose of this investigation was to test the hypothesis that peripheral vasoconstriction and orthostatic tolerance are associated with increased circulating plasma concentrations of noradrenaline, vasopressin and renin-angiotensin. Sixteen men were categorized as having high (HT, n=9) or low (LT, n=7) tolerance to lower body negative pressure (LBNP) based on whether the endpoint of their pre-syncopal-limited LBNP (peak LBNP) exposure exceeded -60 mmHg. The two groups were matched for age, height, weight, leg volume, blood volume and maximal oxygen uptake, as well as baseline blood volume and plasma concentrations of vasoactive hormones. Peak LBNP induced similar reductions in mean arterial pressure in both groups. The reduction in leg arterial pulse volume (measured by impedance rheography), an index of peripheral vascular constriction, from baseline to peak LBNP was greater (P<0.05) in the HT group (-0.041 +/- 0.005 ml 100 ml-1) compared to the reduction in the LT group (-0. 025 +/- 0.003 ml 100 ml-1). Greater peak LBNP in the HT group was associated with higher (P<0.05) average elevations in plasma concentrations of vasopressin (pVP, Delta=+7.2 +/- 2.0 pg ml-1) and plasma renin-angiotensin (PRA, Delta=+2.9 +/- 1.3 ng Ang II ml-1 h-1) compared to average elevations of pVP (+2.2 +/- 1.0 pg ml-1) and PRA (+0.1 +/- 0.1 ng Ang II ml-1 h-1) in the LT group. Plasma noradrenaline concentrations were increased (P<0.05) from baseline to peak LBNP in both HT and LT groups, with no statistically distinguishable difference between groups. These data suggest that the renin-angiotensin and vasopressin systems may contribute to sustaining arterial pressure and orthostatic tolerance by their vasoconstrictive actions.

Paracetamol plasma and cerebrospinal fluid pharmacokinetics in children

PubMed Central

Anderson, B J; Holford, N H G; Woollard, G A; Chan, P L S

1998-01-01

Aims Paracetamol has a central action for both antipyresis and analgesia. Maximum temperature decrease and peak analgesia are reported at 1–2 h after peak plasma paracetamol concentration. We wished to determine the relationship between plasma and cerebrospinal fluid (CSF) pharmacokinetics in children. Methods Concentration-time profiles in plasma and CSF after nasogastric paracetamol 40 mg kg−1 were measured in nine children who had indwelling ventricular drains. Estimation of population pharmacokinetic parameters was made using both a standard two-stage population approach (MKMODEL) and a nonlinear mixed effect model (NONMEM). Results were standardized to a 70 kg person using an allometric power model. Results Both approaches gave similar estimates. NONMEM parameter estimates were clearance 10.2 l h−1 (CV 47%), volume of distribution 67.1 l (CV 58%) and absorption rate constant 0.77 h−1 (CV 49%). Cerebrospinal fluid concentrations lagged behind those of plasma. The equilibration half time was 0.72 h (CV 117%). The CSF/plasma partition coefficient was 1.18 (CV 8%). Conclusions Higher concentrations in the CSF probably reflect the lower free water volume of plasma. The CSF equilibration half time suggests that CSF kinetics approximate more closely to the effect compartment than plasma, but further time is required for paracetamol to exert its effects. Effect site concentrations equilibrate slowly with plasma. Paracetamol should be given 1–2 h before anticipated pain or fever in children. PMID:9764964

Determination of plasma volume in anaesthetized piglets using the carbon monoxide (CO) method.

PubMed

Heltne, J K; Farstad, M; Lund, T; Koller, M E; Matre, K; Rynning, S E; Husby, P

2002-07-01

Based on measurements of the circulating red blood cell volume (V(RBC)) in seven anaesthetized piglets using carbon monoxide (CO) as a label, plasma volume (PV) was calculated for each animal. The increase in carboxyhaemoglobin (COHb) concentration following administration of a known amount of CO into a closed circuit re-breathing system was determined by diode-array spectrophotometry. Simultaneously measured haematocrit (HCT) and haemoglobin (Hb) values were used for PV calculation. The PV values were compared with simultaneously measured PVs determined using the Evans blue technique. Mean values (SD) for PV were 1708.6 (287.3)ml and 1738.7 (412.4)ml with the CO method and the Evans blue technique, respectively. Comparison of PVs determined with the two techniques demonstrated good correlation (r = 0.995). The mean difference between PV measurements was -29.9 ml and the limits of agreement (mean difference +/-2SD) were -289.1 ml and 229.3 ml. In conclusion, the CO method can be applied easily under general anaesthesia and controlled ventilation with a simple administration system. The agreement between the compared methods was satisfactory. Plasma volume determined with the CO method is safe, accurate and has no signs of major side effects.

Low Energy X-Ray and Electron Physics and Technology for High-Temperature Plasma Diagnostics

DTIC Science & Technology

1987-10-01

This program in low-energy x-ray physics and technology has expanded into a major program with the principal objective of supporting research and application programs at the new large x-ray source facilities, particularly the high temperature plasma and synchrotron radiation sources. This program addresses the development of absolute x-ray diagnostics for the fusion energy and x-ray laser research and development. The new laboratory includes five specially designed

Free-piston reciprocating cryogenic expander utilizing phase controller

NASA Astrophysics Data System (ADS)

Cha, Jeongmin; Park, Jiho; Kim, Kyungjoong; Jeong, Sangkwon

2017-02-01

In a free-piston expander which eliminates mechanical linkages, a prescribed behaviour of the free-piston movement is the key to an expander performance. In this paper, we have proposed an idea of reducing complexity of the free-piston expander. It is to replace both multiple solenoid valves and reservoirs that are indispensable in a previous machine with a combination of a single orifice-reservoir assembly. It functions as a phase controller like that of a pulse tube refrigerator so that it generates time-delay of pressure variation between the warm-end and the reservoir resulting in the intended expansion of the cold-end volume down to the pre-set reservoir pressure. The modeling of this unique free-piston reciprocating expander utilizing phase controller is developed to understand and predict the performance of the new-type expander. Additionally, the operating parameters are analysed at the specified conditions to enable one to develop a more efficient free-piston type cryogenic expander.

Heating and Acceleration of Solar Wind Ions by Turbulent Wave Spectrum in Inhomogeneous Expanding Plasma

NASA Technical Reports Server (NTRS)

Ofman, Leon; Ozak, Nataly; Vinas, Adolfo F.

2016-01-01

Near the Sun (< 10Rs) the acceleration, heating, and propagation of the solar wind are likely affected by the background inhomogeneities of the magnetized plasma. The heating and the acceleration of the solar wind ions by turbulent wave spectrum in inhomogeneous plasma is studied using a 2.5D hybrid model. The hybrid model describes the kinetics of the ions, while the electrons are modeled as massless neutralizing fluid in an expanding box approach. Turbulent magnetic fluctuations dominated by power-law frequency spectra, which are evident from in-situ as well as remote sensing measurements, are used in our models. The effects of background density inhomogeneity across the magnetic field on the resonant ion heating are studied. The effect of super- Alfvenic ion drift on the ion heating is investigated. It is found that the turbulent wave spectrum of initially parallel propagating waves cascades to oblique modes, and leads to enhanced resonant ion heating due to the inhomogeneity. The acceleration of the solar wind ions is achieved by the parametric instability of large amplitude waves in the spectrum, and is also affected by the inhomogeneity. The results of the study provide the ion temperature anisotropy and drift velocity temporal evolution due to relaxation of the instability. The non-Maxwellian velocity distribution functions (VDFs) of the ions are modeled in the inhomogeneous solar wind plasma in the acceleration region close to the Sun.

Inductively coupled Cl2/Ar plasma: Experimental investigation and modeling

NASA Astrophysics Data System (ADS)

Efremov, A. M.; Kim, Dong-Pyo; Kim, Chang-Il

2003-07-01

Electrophysical and kinetic characteristics of Cl2/Ar plasma were investigated to understand the influence of the addition of Ar on the volume densities and fluxes of active particles, both neutral and charged. Our analysis combined both experimental methods and plasma modeling. It was found that addition of Ar to Cl2 leads to deformation of the electron energy distribution function and an increase of the electron mean energy due to the ``transparency'' effect. Direct electron impact dissociation of Cl2 molecules represents the main source of chlorine atoms in the plasma volume. The contributions of stepwise dissociation and ionization involving Ar metastable atoms were found to be negligible. Addition of Ar to Cl2 causes the decrease of both electron and ion densities due to a decrease in the total ionization rate and the acceleration of heterogeneous decay of charged particles.

Deep anisotropic ICP plasma etching designed for high-volume MEMS manufacturing

NASA Astrophysics Data System (ADS)

Yu, Keven; Feldbaum, Michael; Pandhumsoporn, Tam; Gadgil, Prashant

1999-08-01

ICP plasma etching is gaining widespread acceptance as an enabling micromachining technology for advanced MEMS fabrication. Whereas this technology has shown a capability of delivering multiple novel applications for R and D, its acceptance by industry for high volume production has been limited. This acceptance into production will only occur when the plasma etching equipment with this technology offers the device performance, throughput, reliability, and uptime criteria required by a production facility. The design of the plasma etcher using this technology and the process capability it consequently delivers, has significant implications in making this a reality. Alcatel has been supplying such a technology to this MEMS industry for over 5 years and in the interim has evolved its product and process to make this technology production worthy. Alcatel's next generation etcher, the Alcatel 601E, offers multiple advantages to MEMS manufacturers in realizing their production goals.

Direct current dielectric barrier assistant discharge to get homogeneous plasma in capacitive coupled discharge

DOE Office of Scientific and Technical Information (OSTI.GOV)

Du, Yinchang, E-mail: ycdu@mail.ustc.edu.cn; Max-Planck Institute for Extraterrestrial Physics, D-85748 Garching; Li, Yangfang

In this paper, we propose a method to get more homogeneous plasma in the geometrically asymmetric capacitive coupled plasma (CCP) discharge. The dielectric barrier discharge (DBD) is used for the auxiliary discharge system to improve the homogeneity of the geometrically asymmetric CCP discharge. The single Langmuir probe measurement shows that the DBD can increase the electron density in the low density volume, where the DBD electrodes are mounted, when the pressure is higher than 5 Pa. By this manner, we are able to improve the homogeneity of the plasma production and increase the overall density in the target volume. At last,more » the finite element simulation results show that the DC bias, applied to the DBD electrodes, can increase the homogeneity of the electron density in the CCP discharge. The simulation results show a good agreement with the experiment results.« less

Fuel Retention Improvement at High Temperatures in Tungsten-Uranium Dioxide Dispersion Fuel Elements by Plasma-Spray Cladding

NASA Technical Reports Server (NTRS)

Grisaffe, Salvatore J.; Caves, Robert M.

1964-01-01

An investigation was undertaken to determine the feasibility of depositing integrally bonded plasma-sprayed tungsten coatings onto 80-volume-percent tungsten - 20-volume-percent uranium dioxide composites. These composites were face clad with thin tungsten foil to inhibit uranium dioxide loss at elevated temperatures, but loss at the unclad edges was still significant. By preheating the composite substrates to approximately 3700 degrees F in a nitrogen environment, metallurgically bonded tungsten coatings could be obtained directly by plasma spraying. Furthermore, even though these coatings were thin and somewhat porous, they greatly inhibited the loss of uranium dioxide. For example, a specimen that was face clad but had no edge cladding lost 5.8 percent uranium dioxide after 2 hours at 4750 dgrees F in flowing hydrogen. A similar specimen with plasma-spray-coated edges, however, lost only 0.75 percent uranium dioxide under the same testing conditions.

Atmospheric-pressure glow plasma synthesis of plasmonic and photoluminescent zinc oxide nanocrystals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bilik, N., E-mail: bilik006@umn.edu, E-mail: kortshagen@umn.edu; Greenberg, B. L.; Yang, J.

In this paper, we present a large-volume (non-micro) atmospheric pressure glow plasma capable of rapid, large-scale zinc oxide nanocrystal synthesis and deposition (up to 400 μg/min), whereas in the majority of the literature, nanoparticles are synthesized using micro-scale or filamentary plasmas. The reactor is an RF dielectric barrier discharge with a non-uniform gap spacing. This design encourages pre-ionization during the plasma breakdown, making the discharge uniform over a large volume. The produced zinc oxide nanocrystals typically have diameters ranging from 4 to 15 nm and exhibit photoluminescence at ≈550 nm and localized surface plasmon resonance at ≈1900 cm{sup −1} due to oxygen vacancies. Themore » particle size can be tuned to a degree by varying the gas temperature and the precursor mixing ratio.« less

Novel Technology for Enrichment of Biomolecules from Cell-Free Body Fluids and Subsequent DNA Sizing.

PubMed

Patel, Vipulkumar; Celec, Peter; Grunt, Magdalena; Schwarzenbach, Heidi; Jenneckens, Ingo; Hillebrand, Timo

2016-01-01

Circulating cell-free DNA (ccfDNA) is a promising diagnostic tool and its size fractionation is of interest. However, kits for isolation of ccfDNA available on the market are designed for small volumes hence processing large sample volumes is laborious. We have tested a new method that enables enrichment of ccfDNA from large volumes of plasma and subsequently allows size-fractionation of isolated ccfDNA into two fractions with individually established cut-off levels of ccfDNA length. This method allows isolation of low-abundant DNA as well as separation of long and short DNA molecules. This procedure may be important e.g., in prenatal diagnostics and cancer research that have been already confirmed by our primary experiments. Here, we report the results of selective separation of 200- and 500-bp long synthetic DNA fragments spiked in plasma samples. Furthermore, we size-fractionated ccfDNA from the plasma of pregnant women and verified the prevalence of fetal ccfDNA in all fractions.

[Measurement of maternal plasma volume during pregnancy].

PubMed

Uzan, S; Beaufils, M; Uzan, M; Donsimoni, R; Mareck, A; Salat-Baroux, J; Sureau, C

1988-02-01

An increased maternal plasma volume (PV) is a characteristic phenomenon of normal pregnancy, which may be related to a physiological decrease of peripheral resistances. The authors have studied the plasma volume of 1,105 patients distributed as follows: normal (387), permanently hypertensive patients (84), hypertensive patients during pregnancy (390), patients with apparently isolated RCIU (154) or with a pathological past-history during previous pregnancies (90). It appears that the PV is a sign of a severe HBP, and presents a rather early and good predictive value regarding the weight of the fetus and some complications such as severe UCIU and fetal death in utero. In case of pathological past events or pre-existing hypertension, the PV enables to differentiate rather well patients who will be prone to a complicated pregnancy. In view of these results, utilization and interpretation criteria of this parameter during pregnancies with hypertension or pregnancies in which there is a suspicion or a risk of intra-uterine growth delay, are defined.

Collective phenomena in volume and surface barrier discharges

NASA Astrophysics Data System (ADS)

Kogelschatz, U.

2010-11-01

Barrier discharges are increasingly used as a cost-effective configuration to produce non-equilibrium plasmas at atmospheric pressure. This way, copious amounts of electrons, ions, free radicals and excited species can be generated without significant heating of the background gas. In most applications the barrier is made of dielectric material. Major applications utilizing mainly dielectric barriers include ozone generation, surface cleaning and modification, polymer and textile treatment, sterilization, pollution control, CO2 lasers, excimer lamps, plasma display panels (flat TV screens). More recent research efforts are devoted to biomedical applications and to plasma actuators for flow control. Sinusoidal feeding voltages at various frequencies as well as pulsed excitation schemes are used. Volume as well as surface barrier discharges can exist in the form of filamentary, regularly patterned or diffuse, laterally homogeneous discharges. The physical effects leading to collective phenomena in volume and surface barrier discharges are discussed in detail. Special attention is paid to self-organization of current filaments and pattern formation. Major similarities of the two types of barrier discharges are elaborated.

Three-Dimensional Analysis of Syncytial-Type Cell Plates during Endosperm Cellularization Visualized by High Resolution Electron Tomography W⃞

PubMed Central

Otegui, Marisa S.; Mastronarde, David N.; Kang, Byung-Ho; Bednarek, Sebastian Y.; Staehelin, L. Andrew

2001-01-01

The three-dimensional architecture of syncytial-type cell plates in the endosperm of Arabidopsis has been analyzed at ∼6-nm resolution by means of dual-axis high-voltage electron tomography of high-pressure frozen/freeze-substituted samples. Mini-phragmoplasts consisting of microtubule clusters assemble between sister and nonsister nuclei. Most Golgi-derived vesicles appear connected to these microtubules by two molecules that resemble kinesin-like motor proteins. These vesicles fuse with each other to form hourglass-shaped intermediates, which become wide (∼45 nm in diameter) tubules, the building blocks of wide tubular networks. New mini-phragmoplasts also are generated de novo around the margins of expanding wide tubular networks, giving rise to new foci of cell plate growth, which later become integrated into the main cell plate. Spiral-shaped rings of the dynamin-like protein ADL1A constrict but do not fission the wide tubules at irregular intervals. These rings appear to maintain the tubular geometry of the network. The wide tubular network matures into a convoluted fenestrated sheet in a process that involves increases of 45 and 130% in relative membrane surface area and volume, respectively. The proportionally larger increase in volume appears to reflect callose synthesis. Upon fusion with the parental plasma membrane, the convoluted fenestrated sheet is transformed into a planar fenestrated sheet. This transformation involves clathrin-coated vesicles that reduce the relative membrane surface area and volume by ∼70%. A ribosome-excluding matrix encompasses the cell plate membranes from the fusion of the first vesicles until the onset of the planar fenestrated sheet formation. We postulate that this matrix contains the molecules that mediate cell plate assembly. PMID:11549762

Lung ventilation injures areas with discrete alveolar flooding, in a surface tension-dependent fashion.

PubMed

Wu, You; Kharge, Angana Banerjee; Perlman, Carrie E

2014-10-01

With proteinaceous-liquid flooding of discrete alveoli, a model of the edema pattern in the acute respiratory distress syndrome, lung inflation over expands aerated alveoli adjacent to flooded alveoli. Theoretical considerations suggest that the overexpansion may be proportional to surface tension, T. Yet recent evidence indicates proteinaceous edema liquid may not elevate T. Thus whether the overexpansion is injurious is not known. Here, working in the isolated, perfused rat lung, we quantify fluorescence movement from the vasculature to the alveolar liquid phase as a measure of overdistension injury to the alveolar-capillary barrier. We label the perfusate with fluorescence; micropuncture a surface alveolus and instill a controlled volume of nonfluorescent liquid to obtain a micropunctured-but-aerated region (control group) or a region with discrete alveolar flooding; image the region at a constant transpulmonary pressure of 5 cmH2O; apply five ventilation cycles with a positive end-expiratory pressure of 0-20 cmH2O and tidal volume of 6 or 12 ml/kg; return the lung to a constant transpulmonary pressure of 5 cmH2O; and image for an additional 10 min. In aerated areas, ventilation is not injurious. With discrete alveolar flooding, all ventilation protocols cause sustained injury. Greater positive end-expiratory pressure or tidal volume increases injury. Furthermore, we determine T and find injury increases with T. Inclusion of either plasma proteins or Survanta in the flooding liquid does not alter T or injury. Inclusion of 2.7-10% albumin and 1% Survanta together, however, lowers T and injury. Contrary to expectation, albumin inclusion in our model facilitates exogenous surfactant activity. Copyright © 2014 the American Physiological Society.

Lung ventilation injures areas with discrete alveolar flooding, in a surface tension-dependent fashion

PubMed Central

Wu (吴右), You; Kharge, Angana Banerjee

2014-01-01

With proteinaceous-liquid flooding of discrete alveoli, a model of the edema pattern in the acute respiratory distress syndrome, lung inflation over expands aerated alveoli adjacent to flooded alveoli. Theoretical considerations suggest that the overexpansion may be proportional to surface tension, T. Yet recent evidence indicates proteinaceous edema liquid may not elevate T. Thus whether the overexpansion is injurious is not known. Here, working in the isolated, perfused rat lung, we quantify fluorescence movement from the vasculature to the alveolar liquid phase as a measure of overdistension injury to the alveolar-capillary barrier. We label the perfusate with fluorescence; micropuncture a surface alveolus and instill a controlled volume of nonfluorescent liquid to obtain a micropunctured-but-aerated region (control group) or a region with discrete alveolar flooding; image the region at a constant transpulmonary pressure of 5 cmH2O; apply five ventilation cycles with a positive end-expiratory pressure of 0–20 cmH2O and tidal volume of 6 or 12 ml/kg; return the lung to a constant transpulmonary pressure of 5 cmH2O; and image for an additional 10 min. In aerated areas, ventilation is not injurious. With discrete alveolar flooding, all ventilation protocols cause sustained injury. Greater positive end-expiratory pressure or tidal volume increases injury. Furthermore, we determine T and find injury increases with T. Inclusion of either plasma proteins or Survanta in the flooding liquid does not alter T or injury. Inclusion of 2.7–10% albumin and 1% Survanta together, however, lowers T and injury. Contrary to expectation, albumin inclusion in our model facilitates exogenous surfactant activity. PMID:25080924

Brillouin Scattering of Picosecond Laser Pulses in Preformed, Short-Scale-Length Plasmas

NASA Astrophysics Data System (ADS)

Gaeris, A. C.; Fisher, Y.; Delettrez, J. A.; Meyerhofer, D. D.

1996-11-01

Brillouin scattering (BS) has been studied in short-scale-length, preformed plasmas. The backscattered and specularly reflected light resulting from the interaction of high-power picosecond pulses with preformed silicon plasmas has been measured. A first laser pulse forms a short-scale-length plasma -- without significant BS -- while a second delayed pulse interacts with an expanded, drifting underdense region of the plasma with density scale length (0 <= Ln <= 600 λ _L). The pulses are generated at λ L = 1054 nm, with intensities up to 10^16 W/cm^2. The backscattered light spectra, threshold intensities, and enhanced reflectivities have been determined for different plasma-density scale lengths and are compared to Liu, Rosenbluth, and White's(C. S. Liu, M. N. Rosenbluth, and R. B. White, Phys. Fluids 17, 1211 (1974).) WKB treatment of stimulated Brillouin scattering in inhomogeneous drifting plasmas. This work was supported by the U.S. Department of Energy Office of Inertial Confinement Fusion under Cooperative Agreement No. DE-FC03-92SF19460.

Electron Temperature and Plasma Flow Measurements of NIF Hohlraum Plasmas

NASA Astrophysics Data System (ADS)

Barrios, M. A.; Liedahl, D. A.; Schneider, M. B.; Jones, O.; Brow, G. V.; Regan, S. P.; Fournier, K. B.; Moore, A. S.; Ross, J. S.; Eder, D.; Landen, O.; Kauffman, R. L.; Nikroo, A.; Kroll, J.; Jaquez, J.; Huang, H.; Hansen, S. B.; Callahan, D. A.; Hinkel, D. E.; Bradley, D.; Moody, J. D.; LLNL Collaboration; LLE Collaboration; GA Collaboration; SNL Collaboration

2016-10-01

Characterizing the plasma conditions inside NIF hohlraums, in particular mapping the plasma Te, is critical to gaining insight into mechanisms that affect energy coupling and transport in the hohlraum. The dot spectroscopy platform provides a temporal history of the localized Te and plasma flow inside a NIF hohlraum, by introducing a Mn-Co tracer dot, at strategic locations inside the hohlraum, that comes to equilibrium with the local plasma. K-shell X-ray spectroscopy of the tracer dot is recorded onto an absolutely calibrated X-ray streak spectrometer. Isoelectronic and interstage line ratios are used to infer localized Te through comparison with atomic physics calculations using SCRAM. Time resolved X-ray images are simultaneously taken of the expanding dot, providing plasma (ion) flow information. We present recent results provided by this platform and compare with simulations using HYDRA. This work was performed under the auspices of the U.S. Department of Energy by LLNL under Contract DE-AC52-07NA27344.

Detection of IDH1 mutation in the plasma of patients with glioma.

PubMed

Boisselier, Blandine; Gállego Pérez-Larraya, Jaime; Rossetto, Marta; Labussière, Marianne; Ciccarino, Pietro; Marie, Yannick; Delattre, Jean-Yves; Sanson, Marc

2012-10-16

The IDH1(R132H) mutation is both a strong prognostic predictor and a diagnostic hallmark of gliomas and therefore has major clinical relevance. Here, we developed a new technique to detect the IDH1(R132H) mutation in the plasma of patients with glioma. Small-size DNA (150-250 base pairs) was extracted from the plasma of 31 controls and 80 patients with glioma with known IDH1(R132H) status and correlated with MRI data. The IDH1(R132H) mutation was detected by a combination of coamplification at lower denaturation temperature and digital PCR. The small size DNA concentration was 1.2 ng/mL (range 0.1-6.6) in controls vs 1.2 ng/mL (range 0.1-50.3) in patients with glioma (p = not significant) and 0.9 ng/mL (0.0-3.0) in low-grade gliomas vs 1.5 ng/mL in high-grade gliomas (p < 0.01). The small size DNA concentration correlated with enhancing tumor volume (1.6 ng/mL [0.4-24.9] when <10 cm(3) and 14.0 ng/mL [0.6-50.3] when ≥10 cm(3)). The IDH1(R132H) mutation was detected in 15 out of 25 plasma DNA mixtures (60%) from patients with mutated tumors and in none of the 14 patients with a nonmutated tumor. The sensitivity increased with enhancing tumor volume (3/9 in nonenhancing tumors, 6/10 for enhancing volume <10 cm(3), and 6/6 for enhancing volume ≥10 cm(3)). With a specificity of 100% and a sensitivity related to the tumor volume and contrast enhancement, IDH1(R132H) identification has a valuable diagnostic accuracy in patients not amenable to biopsy.

Nuclear light bulb

NASA Technical Reports Server (NTRS)

Latham, Tom

1991-01-01

The nuclear light bulb engine is a closed cycle concept. The nuclear light bulb concept provides containment by keeping the nuclear fuel fluid mechanically suspended in a cylindrical geometry. Thermal heat passes through an internally cooled, fused-silica, transparent wall and heats hydrogen propellant. The seeded hydrogen propellant absorbs radiant energy and is expanded through a nozzle. Internal moderation was used in the configuration which resulted in a reduced critical density requirement. This result was supported by criticality experiments. A reference engine was designed that had seven cells and was sized to fit in what was then predicted to be the shuttle bay mass and volume limitations. There were studies done of nozzle throat cooling schemes to remove the radiant heat. Elements of the nuclear light bulb program included closed loop critical assembly tests done at Los Alamos with UF6 confined by argon buffer gas. It was shown that the fuel region could be seeded with constituents that would block UV radiation from the uranium plasma. A combination of calculations and experiments showed that internal moderation produced a critical mass reduction. Other aspects of the research are presented.

Influence of Factors of Cryopreservation and Hypothermic Storage on Survival and Functional Parameters of Multipotent Stromal Cells of Placental Origin

PubMed Central

Pogozhykh, Olena; Mueller, Thomas; Prokopyuk, Olga

2015-01-01

Human placenta is a highly perspective source of multipotent stromal cells (MSCs) both for the purposes of patient specific auto-banking and allogeneic application in regenerative medicine. Implementation of new GMP standards into clinical practice enforces the search for relevant methods of cryopreservation and short-term hypothermic storage of placental MSCs. In this paper we analyze the effect of different temperature regimes and individual components of cryoprotective media on viability, metabolic and culture properties of placental MSCs. We demonstrate (I) the possibility of short-term hypothermic storage of these cells; (II) determine DMSO and propanediol as the most appropriate cryoprotective agents; (III) show the possibility of application of volume expanders (plasma substituting solutions based on dextran or polyvinylpyrrolidone); (IV) reveal the priority of ionic composition over the serum content in cryopreservation media; (V) determine a cooling rate of 1°C/min down to -40°C followed by immersion into liquid nitrogen as the optimal cryopreservation regime for this type of cells. This study demonstrates perspectives for creation of new defined cryopreservation methods towards GMP standards. PMID:26431528

Plasma Reforming of Liquid Hydrocarbon Fuels in Non-Thermal Plasma-Liquid Systems

DTIC Science & Technology

2010-04-30

microporous liquid which has a very large ratio of the plasma-liquid contact surface to the plasma volume. As is known the ultrasonic (US) cavitation is a very...effective method for creating micropores in liquid [17]. Therefore, the DGCLW with additional US pumping is also very interesting for research and...electrodes. Another PLS reactor was prepared with the DGCLW working with the air flow in the liquid under the induced microporous