The Heartmate III: design and in vivo studies of a maglev centrifugal left ventricular assist device.

PubMed

Loree, H M; Bourque, K; Gernes, D B; Richardson, J S; Poirier, V L; Barletta, N; Fleischli, A; Foiera, G; Gempp, T M; Schoeb, R; Litwak, K N; Akimoto, T; Kameneva, M; Watach, M J; Litwak, P

2001-05-01

A compact implantable centrifugal left ventricular assist device (LVAD) (HeartMate III) featuring a magnetically levitated impeller is under development. The goal of our ongoing work is to demonstrate feasibility, low hemolysis, and low thrombogenicity of the titanium pump in chronic bovine in vivo studies. The LVAD is based on so-called bearingless motor technology and combines pump rotor, drive, and magnetic bearing functions in a single unit. The impeller is rotated (theta z) and levitated with both active (X, Y) and passive (Z, theta x, theta y) suspension. Six prototype systems have been built featuring an implantable titanium pump (69 mm diameter, 30 mm height) with textured blood contacting surfaces and extracorporeal electronics. The pumps were implanted in 9 calves (< or = 100 kg at implant) that were anticoagulated with Coumadin (2.5 < or = INR < or = 4.0) throughout the studies. Six studies were electively terminated (at 27-61 days), 1 study was terminated after the development of severe pneumonia and lung atelectasis (at 27 days) another study was terminated after cardiac arrest (at 2 days) while a final study is ongoing (at approximately 100 days). Mean pump flows ranged from 2 to 7 L/min, except for brief periods of exercise at 6 to 9 L/min. Plasma free hemoglobin ranged from 4 to 10 mg/dl. All measured biochemical indicators of end organ function remained within normal range. The pumps have met performance requirements in all 9 implants with acceptable hemolysis and no mechanical failures.

Continuous-wave organic dye lasers and methods

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

Shapira, Ofer; Chua, Song-Liang; Zhen, Bo

2014-09-16

An organic dye laser produces a continuous-wave (cw) output without any moving parts (e.g., without using flowing dye streams or spinning discs of solid-state dye media to prevent photobleaching) and with a pump beam that is stationary with respect to the organic dye medium. The laser's resonant cavity, organic dye medium, and pump beam are configured to excite a lasing transition over a time scale longer than the associated decay lifetimes in the organic dye medium without photobleaching the organic dye medium. Because the organic dye medium does not photobleach when operating in this manner, it may be pumped continuouslymore » so as to emit a cw output beam. In some examples, operation in this manner lowers the lasing threshold (e.g., to only a few Watts per square centimeter), thereby facilitating electrical pumping for cw operation.« less

Pump-probe spectroscopy in organic semiconductors: monitoring fundamental processes of relevance in optoelectronics.

PubMed

Cabanillas-Gonzalez, Juan; Grancini, Giulia; Lanzani, Guglielmo

2011-12-08

In this review we highlight the contribution of pump-probe spectroscopy to understand elementary processes taking place in organic based optoelectronic devices. The techniques described in this article span from conventional pump-probe spectroscopy to electromodulated pump-probe and the state-of-the-art confocal pump-probe microscopy. The article is structured according to three fundamental processes (optical gain, charge photogeneration and charge transport) and the contribution of these techniques on them. The combination of these tools opens up new perspectives for assessing the role of short-lived excited states on processes lying underneath organic device operation. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ocean Biological Pump Sensitivities and Implications for Climate Change Impacts

NASA Technical Reports Server (NTRS)

Romanou, Anastasia

2013-01-01

The ocean is one of the principal reservoirs of CO2, a greenhouse gas, and therefore plays a crucial role in regulating Earth's climate. Currently, the ocean sequesters about a third of anthropogenic CO2 emissions, mitigating the human impact on climate. At the same time, the deeper ocean represents the largest carbon pool in the Earth System and processes that describe the transfer of carbon from the surface of the ocean to depth are intimately linked to the effectiveness of carbon sequestration.The ocean biological pump (OBP), which involves several biogeochemical processes, is a major pathway for transfer of carbon from the surface mixed layer into the ocean interior. About 75 of the carbon vertical gradient is due to the carbon pump with only 25 attributed to the solubility pump. However, the relative importance and role of the two pumps is poorly constrained. OBP is further divided to the organic carbon pump (soft tissue pump) and the carbonate pump, with the former exporting about 10 times more carbon than the latter through processes like remineralization.Major uncertainties about OBP, and hence in the carbon uptake and sequestration, stem from uncertainties in processes involved in OBP such as particulate organicinorganic carbon sinkingsettling, remineralization, microbial degradation of DOC and uptakegrowth rate changes of the ocean biology. The deep ocean is a major sink of atmospheric CO2 in scales of hundreds to thousands of years, but how the export efficiency (i.e. the fraction of total carbon fixation at the surface that is transported at depth) is affected by climate change remains largely undetermined. These processes affect the ocean chemistry (alkalinity, pH, DIC, particulate and dissolved organic carbon) as well as the ecology (biodiversity, functional groups and their interactions) in the ocean. It is important to have a rigorous, quantitative understanding of the uncertainties involved in the observational measurements, the models and the projections of future changes.

[Importance of mechanical assist devices in acute circulatory arrest].

PubMed

Ferrari, Markus Wolfgang

2016-03-01

Mechanical assist devices are indicated for hemodynamic stabilization in acute circulatory arrest if conventional means of cardiopulmonary resuscitation are unable to re-establish adequate organ perfusion. Their temporary use facilitates further diagnostic and therapeutic options in selected patients, e.g. coronary angiography followed by revascularization.External thorax compression devices allow sufficient cardiac massage in case of preclinical or in-hospital circulatory arrest, especially under complex transfer conditions. These devices perform standardized thorax compressions at a rate of 80-100 per minute. Invasive mechanical support devices are used in the catheter laboratory or in the intensive care unit. Axial turbine pumps, e.g. the Impella, continuously pump blood from the left ventricle into the aortic root. The Impella can also provide right ventricle support by pumping blood from the vena cava into the pulmonary artery. So-called emergency systems or ECMO devices consist of a centrifugal pump and a membrane oxygenator allowing complete takeover of cardiac and pulmonary functions. Withdrawing blood from the right atrium and vena cava, oxygenated blood is returned to the abdominal aorta. Isolated centrifugal pumps provide left heart support without an oxygenator after transseptal insertion of a venous cannula into the left atrium.Mechanical assist devices are indicated for acute organ protection and hemodynamic stabilization for diagnostic and therapeutic measures as well as bridge to myocardial recovery. Future technical developments and better insights into the pathophysiology of mechanical circulatory support will broaden the spectrum of indications of such devices in acute circulatory arrest.

Acid stress mediated adaptive divergence in ion channel function during embryogenesis in Rana arvalis

PubMed Central

Shu, Longfei; Laurila, Anssi; Räsänen, Katja

2015-01-01

Ion channels and pumps are responsible for ion flux in cells, and are key mechanisms mediating cellular function. Many environmental stressors, such as salinity and acidification, are known to severely disrupt ionic balance of organisms thereby challenging fitness of natural populations. Although ion channels can have several vital functions during early life-stages (e.g. embryogenesis), it is currently not known i) how developing embryos maintain proper intracellular conditions when exposed to environmental stress and ii) to what extent environmental stress can drive intra-specific divergence in ion channels. Here we studied the moor frog, Rana arvalis, from three divergent populations to investigate the role of different ion channels and pumps for embryonic survival under acid stress (pH 4 vs 7.5) and whether populations adapted to contrasting acidities differ in the relative role of different ion channel/pumps. We found that ion channels that mediate Ca2+ influx are essential for embryonic survival under acidic pH, and, intriguingly, that populations differ in calcium channel function. Our results suggest that adaptive divergence in embryonic acid stress tolerance of amphibians may in part be mediated by Ca2+ balance. We suggest that ion flux may mediate adaptive divergence of natural populations at early life-stages in the face of environmental stress. PMID:26381453

Sand consolidation method

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

Young, B.M.

1965-10-05

This is a new and improved sand consolidation method wherein an in-situ curing of a resinous fluid is undertaken. This method does not require that the resinous fluids be catalyzed at the surface of the well or well bore as is the case in previous methods. This method consists of, first, pumping an acid-curable consolidating fluid into the unconsolidated sand or earth formation and, secondly, pumping an oil overflush solution containing a halogenated organic or other organic acid or delayed acid-producing chemical. A small quantity of diesel oilspacer may be used between the plastic catalyst solution. The overflush functions tomore » remove permeability, and its acid or acid producing component promotes subsequent hardening of the remaining film of consolidating fluid. Trichloroacetic acid and benzotrichloride are satisfactory to add to the overflush solution for curing the resins. (17 claims)« less

The plasma membrane calcium pumps: focus on the role in (neuro)pathology.

PubMed

Brini, Marisa; Carafoli, Ernesto; Calì, Tito

2017-02-19

The plasma membrane Ca 2+ ATPase (PMCA pump) is a member of the superfamily of P-type pumps. It is organized in the plasma membrane with ten transmembrane helices and two main cytosolic loops, one of which contains the catalytic center. It also contains a long C-terminal tail that houses the binding site for calmodulin, the main regulator of the activity of the pump. The pump also contains a number of other regulators, among them acidic phospholipids, kinases, and numerous protein interactors. Separate genes code for 4 basic pump isoforms in mammals, additional isoform complexity being generated by the alternative splicing of primary transcripts. Pumps 1 and 4 are expressed ubiquitously, pumps 2 and 3 are tissue restricted, with preference for the nervous system. In essentially all cells, the pump coexists with much more powerful systems that clear Ca 2+ from the cytosol, e.g. the SERCA pump and the Na + /Ca 2+ exchanger. Its role in the global regulation of cellular Ca 2+ homeostasis is thus quantitatively marginal: its main function is the regulation of Ca 2+ signaling in selected sub-plasma membrane microdomains where Ca 2+ modulated interactors also reside. Malfunctions of the pump linked to genetic mutations are now described with increasing frequency, the disease phenotypes being especially severe in the nervous system where isoforms 2 and 3 predominate. The analysis of the pump defects suggests that the disease phenotypes are likely to be related to the imperfect modulation of Ca 2+ signaling in selected sub-plasma membrane microdomains, leading to the defective control of the activity of important Ca 2+ dependent interactors. Copyright © 2016 Elsevier Inc. All rights reserved.

Zooplankton fecal pellets, marine snow, phytodetritus and the ocean's biological pump

NASA Astrophysics Data System (ADS)

Turner, Jefferson T.

2015-01-01

The 'biological pump' is the process by which photosynthetically-produced organic matter in the ocean descends from the surface layer to depth by a combination of sinking particles, advection or vertical mixing of dissolved organic matter, and transport by animals. Particulate organic matter that is exported downward from the euphotic zone is composed of combinations of fecal pellets from zooplankton and fish, organic aggregates known as 'marine snow' and phytodetritus from sinking phytoplankton. Previous reviews by Turner and Ferrante (1979) and Turner (2002) focused on publications that appeared through late 2001. Since that time, studies of the biological pump have continued, and there have been >300 papers on vertical export flux using sediment traps, large-volume filtration systems and other techniques from throughout the global ocean. This review will focus primarily on recent studies that have appeared since 2001. Major topics covered in this review are (1) an overview of the biological pump, and its efficiency and variability, and the role of dissolved organic carbon in the biological pump; (2) zooplankton fecal pellets, including the contribution of zooplankton fecal pellets to export flux, epipelagic retention of zooplankton fecal pellets due to zooplankton activities, zooplankton vertical migration and fecal pellet repackaging, microbial ecology of fecal pellets, sinking velocities of fecal pellets and aggregates, ballasting of sinking particles by mineral contents, phytoplankton cysts, intact cells and harmful algae toxins in fecal pellets, importance of fecal pellets from various types of zooplankton, and the role of zooplankton fecal pellets in picoplankton export; (3) marine snow, including the origins, abundance, and distributions of marine snow, particles and organisms associated with marine snow, consumption and fragmentation of marine snow by animals, pathogens associated with marine snow; (4) phytodetritus, including pulsed export of phytodetritus, phytodetritus from Phaeocystis spp., picoplankton in phytodetritus, the summer export pulse (SEP) of phytodetritus in the subtropical North Pacific, benthic community responses to phytodetritus; (5) other components of the biological pump, including fish fecal pellets and fish-mediated export, sinking carcasses of animals and macrophytes, feces from marine mammals, transparent exopolymer particles (TEP); (6) the biological pump and climate, including origins of the biological pump, the biological pump and glacial/interglacial cycles, the biological pump and contemporary climate variations, and the biological pump and anthropogenic climate change. The review concludes with potential future modifications in the biological pump due to climate change.

Organic rankine cycle system for use with a reciprocating engine

DOEpatents

Radcliff, Thomas D.; McCormick, Duane; Brasz, Joost J.

2006-01-17

In a waste heat recovery system wherein an organic rankine cycle system uses waste heat from the fluids of a reciprocating engine, provision is made to continue operation of the engine even during periods when the organic rankine cycle system is inoperative, by providing an auxiliary pump and a bypass for the refrigerant flow around the turbine. Provision is also made to divert the engine exhaust gases from the evaporator during such periods of operation. In one embodiment, the auxiliary pump is made to operate simultaneously with the primary pump during normal operations, thereby allowing the primary pump to operate at lower speeds with less likelihood of cavitation.

Parametric presentation of dielectric function of laser pumped wide-zone semiconductor material: Does this function satisfy the Kramers-Kronig relations?

NASA Astrophysics Data System (ADS)

Zimnyakov, D. A.; Yuvchenko, S. A.; Volchkov, S. S.; Samorodina, T. V.

2018-04-01

Dielectric function of wide-zone semiconductor nanoparticles (titanium dioxide) was studied under the condition of laser pumping at various wavelengths. A closed-aperture z-scan method with simultaneous measurements of the right-anglescattered intensity was used to retrieve the real and imaginary parts of dielectric function in the dependence on the pump intensity. It was found that the efficiency of dielectric function modulation by pumping light strongly depends on detuning of the wavelength of pumping light with respect to the fundamental absorption band of nanoparticles. The ColeCole diagrammatic technique was applied for interpretation of the pump-induced changes of the dielectric function in the optical range. Applicability of the Kramers-Kronig relations for description of the observed behavior of the dielectric function is discussed.

Mesoscale eddies drive increased silica export in the subtropical Pacific Ocean.

PubMed

Benitez-Nelson, Claudia R; Bidigare, Robert R; Dickey, Tommy D; Landry, Michael R; Leonard, Carrie L; Brown, Susan L; Nencioli, Francesco; Rii, Yoshimi M; Maiti, Kanchan; Becker, Jamie W; Bibby, Thomas S; Black, Wil; Cai, Wei-Jun; Carlson, Craig A; Chen, Feizhou; Kuwahara, Victor S; Mahaffey, Claire; McAndrew, Patricia M; Quay, Paul D; Rappé, Michael S; Selph, Karen E; Simmons, Melinda P; Yang, Eun Jin

2007-05-18

Mesoscale eddies may play a critical role in ocean biogeochemistry by increasing nutrient supply, primary production, and efficiency of the biological pump, that is, the ratio of carbon export to primary production in otherwise nutrient-deficient waters. We examined a diatom bloom within a cold-core cyclonic eddy off Hawaii. Eddy primary production, community biomass, and size composition were markedly enhanced but had little effect on the carbon export ratio. Instead, the system functioned as a selective silica pump. Strong trophic coupling and inefficient organic export may be general characteristics of community perturbation responses in the warm waters of the Pacific Ocean.

Total heart replacement using dual intracorporeal continuous-flow pumps in a chronic bovine model: a feasibility study.

PubMed

Frazier, O H; Tuzun, Egemen; Cohn, William E; Conger, Jeffrey L; Kadipasaoglu, Kamuran A

2006-01-01

Continuous-flow pumps are small, simple, and respond physiologically to input variations, making them potentially ideal for total heart replacement. However, the physiological effects of complete pulseless flow during long-term circulatory support without a cardiac interface or with complete cardiac exclusion have not been well studied. We evaluated the feasibility of dual continuous-flow pumps as a total artificial heart (TAH) in a chronic bovine model. Both ventricles of a 6-month-old Corriente crossbred calf were excised and sewing rings attached to the reinforced atrioventricular junctions. The inlet portions of 2 Jarvik 2000 pumps were positioned through their respective sewing rings at the mid-atrial level and the pulseless atrial reservoir connected end-to-end to the pulmonary artery and aorta. Pulseless systemic and pulmonary circulations were thereby achieved. Volume status was controlled, and systemic and pulmonary resistance were managed pharmacologically to keep mean arterial pressures at 100+/-10 mmHg (systemic) and 20+/-5 mmHg (pulmonary) and both left and right atrial pressures at 15+/-5 mmHg. The left pump speed was maintained at 14,000 rpm and its output autoregulated in response to variations in right pump flow, systemic and pulmonary pressures, fluid status, and activity level. Hemodynamics, end-organ function, and neurohormonal status remained normal. These results suggest the feasibility of using dual continuous-flow pumps as a TAH.

Description of a flow optimized oxygenator with integrated pulsatile pump.

PubMed

Borchardt, Ralf; Schlanstein, Peter; Arens, Jutta; Graefe, Roland; Schreiber, Fabian; Schmitz-Rode, Thomas; Steinseifer, Ulrich

2010-11-01

Extracorporeal membrane oxygenation (ECMO) is a well-established therapy for several lung and heart diseases in the field of neonatal and pediatric medicine (e.g., acute respiratory distress syndrome, congenital heart failure, cardiomyopathy). Current ECMO systems are typically composed of an oxygenator and a separate nonpulsatile blood pump. An oxygenator with an integrated pulsatile blood pump for small infant ECMO was developed, and this novel concept was tested regarding functionality and gas exchange rate. Pulsating silicone tubes (STs) were driven by air pressure and placed inside the cylindrical fiber bundle of an oxygenator to be used as a pump module. The findings of this study confirm that pumping blood with STs is a viable option for the future. The maximum gas exchange rate for oxygen is 48mL/min/L(blood) at a medium blood flow rate of about 300mL/min. Future design steps were identified to optimize the flow field through the fiber bundle to achieve a higher gas exchange rate. First, the packing density of the hollow-fiber bundle was lower than commercial oxygenators due to the manual manufacturing. By increasing this packing density, the gas exchange rate would increase accordingly. Second, distribution plates for a more uniform blood flow can be placed at the inlet and outlet of the oxygenator. Third, the hollow-fiber membranes can be individually placed to ensure equal distances between the surrounding hollow fibers. © 2010, Copyright the Authors. Artificial Organs © 2010, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

FOREWORD: 6th International Conference on Pumps and Fans with Compressors and Wind Turbines (ICPF2013)

NASA Astrophysics Data System (ADS)

Wu, Yulin; Wang, Zhengwei; Yuan, Shouqi; Shi, Weidong; Liu, Shuhong; Luo, Xingqi; Wang, Fujun

2013-12-01

The 6th International Conference on Pumps and Fans with Compressors and Wind Turbines (ICPF 2013) was held in Beijing, China, 19-22 September 2013, which was jointly organized by Tsinghua University and Jiangsu University. The co-organizers were Zhejiang University, Zhejiang Sci-Tech University, The State Key Laboratory of Hydroscience and Engineering, The State Key Laboratory of Automotive Safety and Energy and Beijing International Science and Technology Cooperation Base for CO2 Utilization and Reduction. The sponsor of the conference was Concepts NREC. The First International Conference on Pumps and Systems (May 1992), the Second International Conference on Pumps and Fans (October 1995), the Third International Conference on Pumps and Fans (October 1998), and the Fourth International Conference on Pumps and Fans (26-29 August 2002) were all held in Beijing and were organized by the late famous Chinese professor on fluid machinery and engineering, Professor Zuyan Mei of Tsinghua University. The conference was interrupted by the death of Professor Mei in 2003. In order to commemorate Professor Mei, the organizing committee of ICPF decided to continue organizing the conference series. The Fifth Conference on Pumps and Systems (2010 ICPF) took place in Hangzhou, Zhejiang Province, China, 18-21 October 2010, and it was jointly organized by Zhejiang University and Tsinghua University. With the development of renewable energy and new energy in China and in the world, some small types of compressor and some types of pump, as well as wind turbines are developing very fast; therefore the ICPF2013 conference included compressors and wind turbines. The theme of the conference was the application of renewable energy of pumps, compressors, fans and blowers. The content of the conference was the basic study, design and experimental study of compressors, fans, blowers and pumps; the CFD application on pumps and fans, their transient behavior, unsteady flows and multi-phase flow; other fluid machinery and devices, such as, wind turbines, turbochargers and reversible pump-turbines, clearance and sealing, jets, filters and mixers; and their engineering application and their system behavior, especially, the application of the renewable energy of pumps, compressors, fans and blowers. The objective of the conference was to provide an opportunity for researchers, engineers and students to report on the latest developments in the fields of pumps, compressors, fans and turbochargers, as well as systems. The participants were encouraged to present their work in progress with a short lead time, and the conference promoted discussion of the problems encountered. The ICPF2013 brought together 191 scientists and researchers from 14 countries, affiliated with universities, technology centers and industrial firms to debate topics related to advanced technologies for pumps and fans, which would enhance the sustainable development of fluid machinery and fluid engineering. The Scientific Committee selected 166 technical papers on the following topics: (i) Principles of Fluid Machinery, (ii) Pumps, (iii) Compressors, Fans and Turbochargers, (iv) Turbines, (v) Cavitation and Multiphase Flow, (vi) Systems and Other Fluid Machinery, and 10 invited plenary and invited session lectures, which were presented at the conference, to be included in the proceedings. All the papers of ICPF2013, which were published in this volume of IOP Conference Series: Materials Science and Engineering, have been peer reviewed through processes administered by the editors of the ICPF2013, those are Yulin Wu, Zhengwei Wang, Shouqi Yuan, Weidong Shi, Shuhong Liu, Xingqi Luo and Fujun Wang. We sincerely hope that the 6th International Conference on Pumps and Fans with Compressors and Wind Turbines is a significant step forward in the worldwide efforts to address the present challenges facing modern fluid machines. Professor Yulin Wu Chairman of the Local Organizing Committee 6th International Conference on Pumps and Fans with Compressors and Wind Turbines (ICPF2013) October 2013 The PDF contains a list of organizers, sponsors and committees.

Structural and Functional Studies of a Newly Grouped Haloquadratum walsbyi Bacteriorhodopsin Reveal the Acid-resistant Light-driven Proton Pumping Activity.

PubMed

Hsu, Min-Feng; Fu, Hsu-Yuan; Cai, Chun-Jie; Yi, Hsiu-Pin; Yang, Chii-Shen; Wang, Andrew H-J

2015-12-04

Retinal bound light-driven proton pumps are widespread in eukaryotic and prokaryotic organisms. Among these pumps, bacteriorhodopsin (BR) proteins cooperate with ATP synthase to convert captured solar energy into a biologically consumable form, ATP. In an acidic environment or when pumped-out protons accumulate in the extracellular region, the maximum absorbance of BR proteins shifts markedly to the longer wavelengths. These conditions affect the light-driven proton pumping functional exertion as well. In this study, wild-type crystal structure of a BR with optical stability under wide pH range from a square halophilic archaeon, Haloquadratum walsbyi (HwBR), was solved in two crystal forms. One crystal form, refined to 1.85 Å resolution, contains a trimer in the asymmetric unit, whereas another contains an antiparallel dimer was refined at 2.58 Å. HwBR could not be classified into any existing subgroup of archaeal BR proteins based on the protein sequence phylogenetic tree, and it showed unique absorption spectral stability when exposed to low pH values. All structures showed a unique hydrogen-bonding network between Arg(82) and Thr(201), linking the BC and FG loops to shield the retinal-binding pocket in the interior from the extracellular environment. This result was supported by R82E mutation that attenuated the optical stability. The negatively charged cytoplasmic side and the Arg(82)-Thr(201) hydrogen bond may play an important role in the proton translocation trend in HwBR under acidic conditions. Our findings have unveiled a strategy adopted by BR proteins to solidify their defenses against unfavorable environments and maintain their optical properties associated with proton pumping. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Structural and Functional Studies of a Newly Grouped Haloquadratum walsbyi Bacteriorhodopsin Reveal the Acid-resistant Light-driven Proton Pumping Activity*

PubMed Central

Hsu, Min-Feng; Fu, Hsu-Yuan; Cai, Chun-Jie; Yi, Hsiu-Pin; Yang, Chii-Shen; Wang, Andrew H.-J.

2015-01-01

Retinal bound light-driven proton pumps are widespread in eukaryotic and prokaryotic organisms. Among these pumps, bacteriorhodopsin (BR) proteins cooperate with ATP synthase to convert captured solar energy into a biologically consumable form, ATP. In an acidic environment or when pumped-out protons accumulate in the extracellular region, the maximum absorbance of BR proteins shifts markedly to the longer wavelengths. These conditions affect the light-driven proton pumping functional exertion as well. In this study, wild-type crystal structure of a BR with optical stability under wide pH range from a square halophilic archaeon, Haloquadratum walsbyi (HwBR), was solved in two crystal forms. One crystal form, refined to 1.85 Å resolution, contains a trimer in the asymmetric unit, whereas another contains an antiparallel dimer was refined at 2.58 Å. HwBR could not be classified into any existing subgroup of archaeal BR proteins based on the protein sequence phylogenetic tree, and it showed unique absorption spectral stability when exposed to low pH values. All structures showed a unique hydrogen-bonding network between Arg82 and Thr201, linking the BC and FG loops to shield the retinal-binding pocket in the interior from the extracellular environment. This result was supported by R82E mutation that attenuated the optical stability. The negatively charged cytoplasmic side and the Arg82–Thr201 hydrogen bond may play an important role in the proton translocation trend in HwBR under acidic conditions. Our findings have unveiled a strategy adopted by BR proteins to solidify their defenses against unfavorable environments and maintain their optical properties associated with proton pumping. PMID:26483542

Slow Organic-to-Inorganic Sub-Lattice Thermalization in Methylammonium Lead Halide Perovskites Observed by Ultrafast Photoluminescence

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

Chang, Angela Y.; Cho, Yi-Ju; Chen, Kuan-Chen

2016-05-31

Carrier dynamics in methylammonium lead halide (CH3NH3PbI3-xClx) perovskite thin films, of differing crystal morphology, are examined as functions of temperature and excitation wavelength. At room temperature, long-lived (> nanosecond) transient absorption signals indicate negligible carrier trapping. However, in measurements of ultrafast photoluminescence excited at 400 nm, a heretofore unexplained, large amplitude (50%-60%), 45 ps decay process is observed. This feature persists for temperatures down to the orthorhombic phase transition. Varying pump photon energy reveals that the fast, band-edge photoluminescence (PL) decay only appears for excitation >= 2.38 eV (520 nm), with larger amplitudes for higher pump energies. Lower photon-energy excitationmore » yields slow dynamics consistent with negligible carrier trapping. Further, sub-bandgap two-photon pumping yields identical PL dynamics as direct absorption, signifying sensitivity to the total deposited energy and insensitivity to interfacial effects. Together with first principles electronic structure and ab initio molecular dynamics calculations, the results suggest the fast PL decay stems from excitation of high energy phonon modes associated with the organic sub-lattice that temporarily enhance wavefunction overlap within the inorganic component owing to atomic displacement, thereby transiently changing the PL radiative rate during thermalization. Hence, the fast PL decay relates a characteristic organic-to-inorganic sub-lattice equilibration timescale at optoelectronic-relevant excitation energies.« less

The pressure is all in your head: A cilia-driven high-pressure pump in the head of a deep-sea animal

NASA Astrophysics Data System (ADS)

Nawroth, Janna; Katija, Kakani; Shelley, Michael; Kanso, Eva

2017-11-01

Motile cilia are microscopic, hair-like structures on the cell surface that can sense and propel the extracellular fluid environment. In many ciliated systems found in nature, such as the mammalian airways and marine sponges, the organization and collective behavior of the cilia favors the pumping of fluids at low pressures and high volumes. We recently discovered an alternate design located in the head of a deep-sea animal called Larvacean. Here, cilia morphology, kinematics and flow indicate a role in maintaining the hydrostatic skeleton of the animal by generating a high-pressure flow. We describe our empirical and computational approaches toward understanding the design principles and dynamic range of this newly discovered pumping mechanism. In ongoing work, we further explore the fluid dynamic constraints on the morphological diversity of cilia and the resulting categories of fluid transport functions.

Immunohistochemical and ultrastructural evidence of functional organization along the Corydoras paleatus intestine.

PubMed

Plaul, Silvia E; Pastor, Raquel; Díaz, Alcira O; Barbeito, Claudio G

2016-03-01

The Neotropical catfish, Corydoras paleatus (Callichthyidae) is a facultative air-breathing teleost that makes use of the caudal portion of the intestine as an accessory air-breathing organ. This portion is highly modified, being well vascularized with capillaries between epithelial cells, which makes it well suited for gas exchange. Instead, the cranial portion is a digestion and absorption site, as it has a typical intestinal epithelium with columnar cells arranged in a single row, villi and less vascularized tunica mucosa. Therefore, the intestine was studied by light and electron microscopy to assess differences between the cranial, middle and caudal portions. To characterize the potential for cell proliferation of this organ, we used anti-proliferating cell nuclear antigen antibody and anti-Na(+) K(+) -ATPase monoclonal antibody to detect the presence of Na(+) /K(+) pump. In C. paleatus it was observed that cell dynamics showed a decreasing gradient of proliferation in cranio-caudal direction. Also, the intestine of this catfish is an important organ in ionoregulation: the basolateral Na(+) /K(+) pump may have an active role, transporting Na(+) out of the cell while helping to maintain the repose potential and to regulate cellular volume. © 2016 Wiley Periodicals, Inc.

Is the Cochlear Amplifier a Fluid Pump?

NASA Astrophysics Data System (ADS)

Karavitaki, K. D.; Mountain, D. C.

2003-02-01

We have visualized and quantified the effects of electrically evoked motility of outer hair cells (OHCs) within the organ of Corti using an excised cochlear preparation. We found that OHC motility induces oscillatory fluid flow in the tunnel of Corti (TC) and this flow is present at physiologically relevant frequencies. We also show, using a simple one-dimensional hydromechanical model of the TC, that a fluid wave within the tunnel can travel without significant attenuation for distances larger than the wavelength of the cochlear traveling wave. These results in combination with a recent hypothesis that fluid flow within the tunnel is necessary for cochlear amplification suggest that the function of the OHCs is to act as a fluid pump.

[Pathophysiology of heat illness].

PubMed

Aruga, Tohru; Miyake, Yasufumi

2012-06-01

Human core temperature is strictly controlled by mechanism of radiation, conduction, convection, and evaporation from skin surface. Serial hot and humid climate induces dehydration which interferes heat pump-out from the body. Heart dysfunction is the third factor to rise body temperature. Hyperthermia and hypo-perfusion caused by dehydration and heart failure deteriorate specific organ functions, i.e. central nervous system, liver and renal functions and coagulation system. Disseminated intravascular coagulopathy is one of the standard indicators of severity and mortality of heat stroke.

[Analogies between heart and respiratory muscle failure. Importance to clinical practice].

PubMed

Köhler, D

2009-01-01

Heart failure is an established diagnosis. Respiratory muscle or ventilatory pump failure, however, is less well known. The latter becomes obvious through hypercapnia, caused by hypoventilation. The respiratory centre tunes into hypercapnea in order to prevent the danger of respiratory muscle overload (hypercapnic ventilatory failure). Hypoventilation will consecutively cause hypoxemia but this will not be responsible for performance limitation. One therefore has to distinguish primary hypoxemia evolving from diseases in the lung parenchyma. Here hypoxemia is the key feature and compensatory hyperventilation usually decreases PaCO2 levels. The cardiac as well as the respiratory pump adapt to an inevitable burden caused by chronic disease. In either case organ muscle mass will increase. If the burden exceeds the range of possible physiological adaptation, compensatory mechanisms will set in that are similar in both instances. During periods of overload either muscle system is mainly fueled by muscular glycogen. In the recovery phase (e. g. during sleep) stores are replenished, which can be recognized by down-regulation of the blood pressure in case of the cardiac pumb or by augmentation of hypercapnia through hypoventilation in case of the respiratory pump. The main function of cardiac and respiratory pump is maintenance of oxygen transport. The human body has developed certain compensatory mechanisms to adapt to insufficient oxygen supply especially during periods of overload. These mechanisms include shift of the oxygen binding curve, expression of respiratory chain isoenzymes capable of producing ATP at lower partial pressures of oxygen and the development of polyglobulia. Medically or pharmacologically the cardiac pump can be unloaded with beta blockers, the respiratory pump by application of inspired oxygen. Newer forms of therapy augment the process of recovery. The heart can be supported through bypass surgery or intravascular pump systems, while respiratory muscles may be supported through elective ventilatory support (mainly non-invasive) in the patient's home. The latter treatment in particular will increase patient endurance and quality of life and decrease mortality. Heart and respiratory pump failure share many common features. Since both take care of oxygen supply to the body, their function and compensatory mechanisms are closely related and linked.

Many-body physics in two-component Bose–Einstein condensates in a cavity: fragmented superradiance and polarization

NASA Astrophysics Data System (ADS)

Lode, Axel U. J.; Diorico, Fritz S.; Wu, RuGway; Molignini, Paolo; Papariello, Luca; Lin, Rui; Lévêque, Camille; Exl, Lukas; Tsatsos, Marios C.; Chitra, R.; Mauser, Norbert J.

2018-05-01

We consider laser-pumped one-dimensional two-component bosons in a parabolic trap embedded in a high-finesse optical cavity. Above a threshold pump power, the photons that populate the cavity modify the effective atom trap and mediate a coupling between the two components of the Bose–Einstein condensate. We calculate the ground state of the laser-pumped system and find different stages of self-organization depending on the power of the laser. The modified potential and the laser-mediated coupling between the atomic components give rise to rich many-body physics: an increase of the pump power triggers a self-organization of the atoms while an even larger pump power causes correlations between the self-organized atoms—the BEC becomes fragmented and the reduced density matrix acquires multiple macroscopic eigenvalues. In this fragmented superradiant state, the atoms can no longer be described as two-level systems and the mapping of the system to the Dicke model breaks down.

Long-term animal experiments with an intraventricular axial flow blood pump.

PubMed

Yamazaki, K; Kormos, R L; Litwak, P; Tagusari, O; Mori, T; Antaki, J F; Kameneva, M; Watach, M; Gordon, L; Mukuo, H; Umezu, M; Tomioka, J; Outa, E; Griffith, B P; Koyanagai, H

1997-01-01

A miniature intraventricular axial flow blood pump (IVAP) is undergoing in vivo evaluation in calves. The IVAP system consists of a miniature (phi 13.9 mm) axial flow pump that resides within the left ventricular (LV) chamber and a brushless DC motor. The pump is fabricated from titanium alloy, and the pump weight is 170 g. It produces a flow rate of over 5 L/min against 100 mmHg pressure at 9,000 rpm with an 8 W total power consumption. The maximum total efficiency exceeds 17%. A purged lip seal system is used in prototype no. 8, and a newly developed "Cool-Seal" (a low temperature mechanical seal) is used in prototype no. 9. In the Cool-Seal system, a large amount of purge flow is introduced behind the seal faces to augment convective heat transfer, keeping the seal face temperature at a low level for prevention of heat denaturation of blood proteins. The Cool-Seal system consumes < 10 cc purge fluid per day and has greatly extended seal life. The pumps were implanted in three calves (26, 30, and 168 days of support). The pump was inserted through a left thoracotomy at the fifth intercostal space. Two pursestring sutures were placed on the LV apex, and the apex was cored with a myocardial punch. The pump was inserted into the LV with the outlet cannula smoothly passing through the aortic valve without any difficulty. Only 5 min elapsed between the time of chest opening and initiation of pumping. Pump function remained stable throughout in all experiments. No cardiac arrhythmias were detected, even at treadmill exercise tests. The plasma free hemoglobin level remained in the acceptable range. Post mortem examination did not reveal any interference between the pump and the mitral apparatus. No major thromboembolism was detected in the vital organs in Cases 1 or 2, but a few small renal infarcts were detected in Case 3.

Work-exposure to PM10 and aromatic volatile organic compounds, excretion of urinary biomarkers and effect on the pulmonary function and heme-metabolism: A study of petrol pump workers and traffic police personnel in Kolkata City, India.

PubMed

Mukherjee, Ashit K; Chattopadhyay, Bhaskar P; Roy, Sanjit K; Das, Surojit; Mazumdar, Dipanjali; Roy, Moumita; Chakraborty, Rajarshi; Yadav, Anupa

2016-01-28

This study focused work-exposure to particulate matter ≤ 10 µm (PM 10 ), volatile organic compounds (VOCs) and biological monitoring of major VOCs (BTEX) to observe the significant effects of traffic related pollutants on respiratory and hematological systems of workers engaged in two occupational settings, petrol pumps and traffic areas of Kolkata metropolitan city, India. PM 10 was assessed by personal sampling and particle size distribution by 8-stage Cascade Impactor. VOCs were analysed by gas chromatography-flame ionization detector (GC-FID) and five urinary metabolites, trans trans- mercapturic acid (tt-MA), S-phenyl mercapturic acid (SPMA), hippuric acid (HA), mandelic acid (MA) and methyl hippuric acid (MHA) of VOCs, benzene, toluene, ethyl benzene and xylenes (BTEX) by reverse phase high performance liquid chromatography (HPLC). Pulmonary functions test (PFT) was measured Spirometrically. ∂-aminoleavulinic acid (ALA) and porphobilinogen (PBG) in lymphocytes were measured spectrophometrically following column chromatographic separation. High exposure to PM 10 , having 50% of particles, ≤ 5.0 µm in both the occupational settings. Exposure to toluene was highest in petrol pumps whereas benzene was highest (104.6 ± 99.0 μg m -3 ) for traffic police personnel. Workplace Benzene is found many fold higher than the National ambient standard. Air-benzene is correlated significantly with pre- and post-shift tt-MA (p < 0.001) and SPMA (p < 0.001) of exposed workers. Blood cell counts indicated benzene induced hematotoxicity. ALA and PBG accumulation in lymphocytes indicated alteration in heme-metabolism, especially among traffic police. Significant reduction of force exploratory volume in one second (FEV 1 ) and forced vital capacity (FVC) of fuel fillers are observed with increased tt-MA and SPMA. Study revealed PFT impairments 11.11% (6.66% restrictive and 2.22% obstructive and combined restrictive and obstructive type, each) among petrol pumps and 8.3% obstructive type among traffic police.

How is a giant sperm ejaculated? Anatomy and function of the sperm pump, or "Zenker organ," in Pseudocandona marchica (Crustacea, Ostracoda, Candonidae)

NASA Astrophysics Data System (ADS)

Yamada, Shinnosuke; Matzke-Karasz, Renate

2012-07-01

`Giant sperm', in terms of exceptionally long spermatozoa, occur in a variety of taxa in the animal kingdom, predominantly in arthropod groups, but also in flatworms, mollusks, and others. In some freshwater ostracods (Cypridoidea), filamentous sperm cells reach up to ten times the animal's body length; nonetheless, during a single copulation several dozen sperm cells can be transferred to the female's seminal receptacle. This highly effective ejaculation has traditionally been credited to a chitinous-muscular structure within the seminal duct, which has been interpreted as a sperm pump. We investigated this organ, also known as the Zenker organ, of a cypridoid ostracod, Pseudocandona marchica, utilizing light and electron microscope techniques and produced a three-dimensional reconstruction based on serial semi-thin histological sections. This paper shows that numerous muscle fibers surround the central tube of the Zenker organ, running in parallel with the central tube and that a thin cellular layer underlies the muscular layer. A cellular inner tube exists inside the central tube. A chitinous-cellular structure at the entrance of the organ has been recognized as an ejaculatory valve. In male specimens during copulation, we confirmed a small hole derived from the passage of a single spermatozoon through the valve. The new data allowed for proposing a detailed course of operation of the Zenker organ during giant sperm ejaculation.

Gravito-inertial sensitivity of the spider - Araneus sericatus

NASA Technical Reports Server (NTRS)

Finck, A.

1982-01-01

The gravito-inertial transfer function of the orb-weaving spider was evaluated by changes in the cardiac reflex. A non-intrusive method, using a laser system recorded the cardiac pulse. Between 1.001 and 1.5 Gz the data are 'best-fit' by a log function (r-squared 0.92). The response of the neurogenic heart is seen to be a good dependent variable for invetebrate research. The arachnid lyriform organ has those qualities which complement the obtained gravity function. It is hypothesized that the cardiac pump maintains the spiders equilibrium in the gravito-inertial field.

A high precision dual feedback pump for unsteady perfusion of small organs.

PubMed

Sutton, D W; Mead, E H; Schmid-Schönbein, G W

1989-01-01

A dynamic pump system is described for perfusion of small organs with whole blood. The pump system was designed with the following aims: Very low flowrates to perfuse single organs in small rodents; high dynamic response for pressure or flow to permit experimenting with a harmonic signal at frequencies up to 20 Hz or by way of sharp step transients in less than 10 msec; high precision to allow detection of fine physiological details, and minimum blood cell trauma or cell activation by use of a piston principle. Representative pressure-flow curves are shown for the rat gracilis muscle after vasodilation. The curves are highly reproducible and serve as a complimentary dataset for microvascular observations in the same organ.

Polyphasic analysis of an Azoarcus-Leptothrix-dominated bacterial biofilm developed on stainless steel surface in a gasoline-contaminated hypoxic groundwater.

PubMed

Benedek, Tibor; Táncsics, András; Szabó, István; Farkas, Milán; Szoboszlay, Sándor; Fábián, Krisztina; Maróti, Gergely; Kriszt, Balázs

2016-05-01

Pump and treat systems are widely used for hydrocarbon-contaminated groundwater remediation. Although biofouling (formation of clogging biofilms on pump surfaces) is a common problem in these systems, scarce information is available regarding the phylogenetic and functional complexity of such biofilms. Extensive information about the taxa and species as well as metabolic potential of a bacterial biofilm developed on the stainless steel surface of a pump submerged in a gasoline-contaminated hypoxic groundwater is presented. Results shed light on a complex network of interconnected hydrocarbon-degrading chemoorganotrophic and chemolitotrophic bacteria. It was found that besides the well-known hydrocarbon-degrading aerobic/facultative anaerobic biofilm-forming organisms (e.g., Azoarcus, Leptothrix, Acidovorax, Thauera, Pseudomonas, etc.), representatives of Fe(2+)-and Mn(2+)-oxidizing (Thiobacillus, Sideroxydans, Gallionella, Rhodopseudomonas, etc.) as well as of Fe(3+)- and Mn(4+)-respiring (Rhodoferax, Geobacter, Magnetospirillum, Sulfurimonas, etc.) bacteria were present in the biofilm. The predominance of β-Proteobacteria within the biofilm bacterial community in phylogenetic and functional point of view was revealed. Investigation of meta-cleavage dioxygenase and benzylsuccinate synthase (bssA) genes indicated that within the biofilm, Azoarcus, Leptothrix, Zoogloea, and Thauera species are most probably involved in intrinsic biodegradation of aromatic hydrocarbons. Polyphasic analysis of the biofilm shed light on the fact that subsurface microbial accretions might be reservoirs of novel putatively hydrocarbon-degrading bacterial species. Moreover, clogging biofilms besides their detrimental effects might supplement the efficiency of pump and treat systems.

Ultrafast frequency-selective optical switching based on thin self-assembled organic chromophoric films with a large second-order nonlinear response

NASA Astrophysics Data System (ADS)

Wang, Gang; Zhu, Peiwang; Marks, Tobin J.; Ketterson, J. B.

2002-09-01

Thin films consisting of self-assembled chromophoric superlattices exhibit very large second-order nonlinear responses [chi](2). Using such films, a "static" diffraction grating is created by the interference of two coherent infrared beams from a pulsed yttritium-aluminum-garnet laser. This grating is used to switch the second-harmonic and third-harmonic "signal" beams (generated from the fundamental "pump" beam or mixed within the chromophoric superlattice) into different channels (directions). Ultrafast switching response as a function of the time overlap of the pumping beams is demonstrated. It is suggested that such devices can be used to spatially and temporally separate signal trains consisting of pulses having different frequencies and arrival times.

Off-pump CABG surgery reduces systemic inflammation compared with on-pump surgery but does not change systemic endothelial responses: a prospective randomized study.

PubMed

Jongman, Rianne M; Zijlstra, Jan G; Kok, Wendelinde F; van Harten, Annemarie E; Mariani, Massimo A; Moser, Jill; Struys, Michel M R F; Absalom, Anthony R; Molema, Grietje; Scheeren, Thomas W L; van Meurs, Matijs

2014-08-01

Coronary artery bypass graft (CABG) surgery can result in severe postoperative organ failure. During CABG surgery, cardiopulmonary bypass (CPB) with cardiac arrest is often used (on-pump CABG), which often results in a systemic inflammatory response. To reduce this inflammatory response, off-pump CABG was reintroduced, thereby avoiding CPB. There is increasing evidence that the endothelium plays an important role in the pathophysiology of organ failure after CABG surgery. In this study, 60 patients who were scheduled for elective CABG surgery were randomized to have surgery for on-pump or off-pump CABG. Blood was collected at four time points: start, end, 6 h, and 24 h postoperatively. Levels of inflammatory cytokines, soluble adhesion molecules, and angiogenic factors and their receptors were measured in the plasma. No differences were found in preoperative characteristics between the patient groups. The levels of tumor necrosis factor-α, interleukin 10, and myeloperoxidase, but not interleukin 6, were increased to a greater extent in the on-pump CABG compared with off-pump CABG after sternum closure. The soluble endothelial adhesion molecules E-selectin, vascular cell adhesion molecule 1, and intracellular adhesion molecule 1 were not elevated in the plasma during and after CABG surgery in both on-pump and off-pump CABG. Angiopoietin 2 was only increased 24 h after surgery in both on-pump and off-pump CABG. Higher levels of sFlt-1 were found after sternum closure in off-pump CABG compared with on-pump CABG. Avoiding CPB and aortic cross clamping in CABG surgery reduces the systemic inflammatory response. On-pump CABG does not lead to an increased release of soluble endothelial adhesion molecules in the circulation compared with off-pump CABG.

Modified host cells with efflux pumps

DOEpatents

Dunlop, Mary J.; Keasling, Jay D.; Mukhopadhyay, Aindrila

2016-08-30

The present invention provides for a modified host cell comprising a heterologous expression of an efflux pump capable of transporting an organic molecule out of the host cell wherein the organic molecule at a sufficiently high concentration reduces the growth rate of or is lethal to the host cell.

The automatic regulation of the basal dose on the insulin pump for the treatment of patients that have diabetes type 1

PubMed Central

Mehanović, Sifet; Mujić, Midhat

2010-01-01

Diabetes mellitus type 1 is a chronic metabolic disorder, and its main characteristic is Hyperglycemia. It usually occurs in the early years because of the absolute or relative absence of the active insulin that is caused by the autoimmune disease of the β cells of the pancreas. Despite the numerous researches and efforts of the scientists, the therapy for Diabetes type 1 is based on the substitution of insulin. Even though the principles of the therapy have not changed so much, still some important changes have occurred in the production and usage of insulin. Lately, the insulin pumps are more frequent in the therapy for Diabetes type 1. The functioning of the pump is based on the continuing delivery of insulin in a small dose (“the basal dose”), that keeps the level of glycemia in the blood constant. The increase of glycemia during the meal is reduced with the additional dose of insulin (“the bolus dose”). The use of the insulin pumps and the continuing glucose sensors has provided an easier and more efficient monitoring of the diabetes, a better metabolic control and a better life quality for the patient and his/her family. This work presents the way of automatic regulation of the basal dose of insulin through the synthesis of the functions of the insulin pump and the continuing glucose sensor. The aim is to give a contribution to the development of the controlling algorithm on the insulin pump for the automatic regulation of the glucose concentration in the blood. This could be a step further which is closer to the delivery of the dose of insulin that is really needed for the basic needs of the organism, and a significant contribution is given to the development of the artificial pancreas. PMID:20507288

The automatic regulation of the basal dose on the insulin pump for the treatment of patients that have Diabetes type 1.

PubMed

Mehanović, Sifet; Mujić, Midhat

2010-05-01

Diabetes mellitus type 1 is a chronic metabolic disorder, and its main characteristic is Hyperglycemia. It usually occurs in the early years because of the absolute or relative absence of the active insulin that is caused by the autoimmune disease of the beta cells of the pancreas. Despite the numerous researches and efforts of the scientists, the therapy for Diabetes type 1 is based on the substitution of insulin. Even though the principles of the therapy have not changed so much, still some important changes have occurred in the production and usage of insulin. Lately, the insulin pumps are more frequent in the therapy for Diabetes type 1. The functioning of the pump is based on the continuing delivery of insulin in a small dose ("the basal dose"), that keeps the level of glycemia in the blood constant. The increase of glycemia during the meal is reduced with the additional dose of insulin ("the bolus dose"). The use of the insulin pumps and the continuing glucose sensors has provided an easier and more efficient monitoring of the diabetes, a better metabolic control and a better life quality for the patient and his/her family. This work presents the way of automatic regulation of the basal dose of insulin through the synthesis of the functions of the insulin pump and the continuing glucose sensor. The aim is to give a contribution to the development of the controlling algorithm on the insulin pump for the automatic regulation of the glucose concentration in the blood. This could be a step further which is closer to the delivery of the dose of insulin that is really needed for the basic needs of the organism, and a significant contribution is given to the development of the artificial pancreas.

Gating of proton and water transfer in the respiratory enzyme cytochrome c oxidase.

PubMed

Wikström, Mårten; Ribacka, Camilla; Molin, Mika; Laakkonen, Liisa; Verkhovsky, Michael; Puustinen, Anne

2005-07-26

The membrane-bound enzyme cytochrome c oxidase is responsible for cell respiration in aerobic organisms and conserves free energy from O2 reduction into an electrochemical proton gradient by coupling the redox reaction to proton-pumping across the membrane. O2 reduction produces water at the bimetallic heme a3/CuB active site next to a hydrophobic cavity deep within the membrane. Water molecules in this cavity have been suggested to play an important role in the proton-pumping mechanism. Here, we show by molecular dynamics simulations that the conserved arginine/heme a3 delta-propionate ion pair provides a gate, which exhibits reversible thermal opening that is governed by the redox state and the water molecules in the cavity. An important role of this gate in the proton-pumping mechanism is supported by site-directed mutagenesis experiments. Transport of the product water out of the enzyme must be rigidly controlled to prevent water-mediated proton leaks that could compromise the proton-pumping function. Exit of product water is observed through the same arginine/propionate gate, which provides an explanation for the observed extraordinary spatial specificity of water expulsion from the enzyme.

PV water pumping: NEOS Corporation recent PV water pumping activities

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

Lane, C.

1995-11-01

NEOS Corporation has been very active in PV-powered water pumping, particularly with respect to electric utilities. Most of the recent activity has been through the Photovoltaic Services Network (PSN). The PSN is an independent, not-for-profit organization comprised of all types of electric utilities: rural electric coops, public power districts, investor-owned utilities, and power marketing agencies. The PSN`s mission is to work pro-actively to promote utility involvement in PV through education and training. PV information is distributed by the PSN in three primary forms: (1) consultation with PSN technical service representatives: (2) literature generated by the PSN; and (3) literature publishedmore » by other organizations. The PSN can also provide assistance to members in developing PV customer service programs. The PSN`s product support activities include consolidation of information on existing packaged PV systems and facilitation of the development of new PV product packages that meet utility-defined specifications for cost performance, and reliability. The PSN`s initial product support efforts will be focused on commercially available packaged PV systems for a variety of off-grid applications. In parallel with this effort, if no products exist that meet the PSN`s functional specifications, the PSN will initiate the second phase of product development support process by encouraging the development of new packaged systems. Through these services and product support activities, the PSN anticipates engaging all segments for the PV industry, thus providing benefits to PV systems suppliers as well as local PV service contractors.This paper describes field testing of pv power systems for water pumping.« less

Peptides at Membrane Surfaces and their Role in the Origin of Life

NASA Technical Reports Server (NTRS)

Pohorille, Andrew; Wilson, Michael A.; DeVincenzi, D. (Technical Monitor)

2002-01-01

All ancestors of contemporary cells (protocells) had to transport ions and organic matter across membranous walls, capture and utilize energy and transduce environmental signals. In modern organisms, all these functions are preformed by membrane proteins. We make the parsimonious assumption that in the protobiological milieu the same functions were carried out by their simple analogs - peptides. This, however, required that simple peptides could self-organize into ordered, functional structures. In a series of detailed, molecular-level computer simulations we demonstrated how this is possible. One example is the peptide (LSLLLSL)3 which forms a trameric bundle capable of transporting protons across membranes. Another example is the transmembrane pore of the influenza M2 protein. This aggregate of four identical alpha-helices, each built of 25 amino acids, forms an efficient and selective voltage-gated proton channel. Our simulations explain the gating mechanism in this channel. The channel can be re-engineered into a simple proton pump.

Multixenobiotic resistance in Mytilus edulis: Molecular and functional characterization of an ABCG2- type transporter in hemocytes and gills.

PubMed

Ben Cheikh, Yosra; Xuereb, Benoit; Boulangé-Lecomte, Céline; Le Foll, Frank

2018-02-01

Among the cellular protection arsenal, ABC transporters play an important role in xenobiotic efflux in marine organisms. Two pumps belonging to B and C subfamily has been identified in Mytilus edulis. In this study, we investigated the presence of the third major subtype ABCG2/BCRP protein in mussel tissues. Transcript was expressed in hemocytes and with higher level in gills. Molecular characterization revealed that mussel ABCG2 transporter shares the sequence and organizational structure with mammalian and molluscan orthologs. Overall identity of the predicted amino acid sequence with corresponding homologs from other organisms was between 49% and 98%. Moreover, protein efflux activity was demonstrated using a combination of fluorescent allocrites and specific inhibitors. The accumulation of bodipy prazosin and pheophorbide A was heterogeneous in gills and hemocytes. Most of the used blockers enhanced probe accumulation at different levels, most significantly for bodipy prazosin. Moreover, Mrp classical blocker MK571 showed a polyspecificity. In conclusion, our data demonstrate that several ABC transporters contribute to MXR phenotype in the blue mussel including ABCG2 that forms an active pump in hemocytes and gills. Efforts are needed to distinguish between the different members and to explore their single function and specificity towards allocrites and chemosensitizers. Copyright © 2017 Elsevier B.V. All rights reserved.

Simulation analysis and experimental verification of spiral-tube-type valveless piezoelectric pump with gyroscopic effect

NASA Astrophysics Data System (ADS)

Leng, Xuefei; Zhang, Jianhui; Jiang, Yan; Wang, Shouyin; Zhao, Chunsheng

2014-07-01

The current research of the valveless piezoelectric pump focuses on increasing the flow rate and pressure differential. Compared with the valve piezoelectric pump, the valveless one has excellent performances in simple structure, low cost, and easy miniaturization. So, their important development trend is the mitigation of their weakness, and the multi-function integration. The flow in a spiral tube element is sensitive to the element attitude caused by the Coriolis force, and that a valveless piezoelectric pump is designed by applying this phenomenon. The pump has gyroscopic effect, and has both the actuator function of fluid transfer and the sensor function, which can obtain the angular velocity when its attitude changes. First, the present paper analyzes the flow characteristics in the tube, obtains the calculation formula for the pump flow, and identifies the relationship between pump attitude and flow, which clarifies the impact of flow and driving voltage, frequency, spiral line type and element attitude, and verifies the gyroscopic effect of the pump. Then, the finite element simulation is used to verify the theory. Finally, a pump is fabricated for experimental testing of the relationship between pump attitude and pressure differential. Experimental results show that when Archimedes spiral θ=4π is selected for the tube design, and the rotation speed of the plate is 70 r/min, the pressure differential is 88.2 Pa, which is 1.5 times that of 0 r/min rotation speed. The spiral-tube-type valveless piezoelectric pump proposed can turn the element attitude into a form of pressure output, which is important for the multi-function integration of the valveless piezoelectric pump and for the development of civil gyroscope in the future.

Lung physiology during ECS resuscitation of DCD donors followed by in situ assessment of lung function.

PubMed

Reoma, Junewai L; Rojas, Alvaro; Krause, Eric M; Obeid, Nabeel R; Lafayette, Nathan G; Pohlmann, Joshua R; Padiyar, Niru P; Punch, Jeffery D; Cook, Keith E; Bartlett, Robert H

2009-01-01

Extracorporeal cardiopulmonary support (ECS) of donors after cardiac death (DCD) has been shown to improve abdominal organs for transplantation. This study assesses whether pulmonary congestion occurs during ECS with the heart arrested and describes an in vivo method to assess if lungs are suitable for transplantation from DCD donors after ECS resuscitation. Cardiac arrest was induced in 30 kg pigs, followed by 10 min of warm ischemia. Cannulae were placed into the right atrium (RA) and iliac artery, and veno-arterial ECS was initiated for 90 min with lungs inflated, group 1 (n = 5) or deflated, group 2 (n = 3). Left atrial pressures were measured as a marker for pulmonary congestion. After 90 min of ECS, lung function was evaluated. Cannulae were placed into the pulmonary artery (PA) and left ventricle (LV). A second pump was included, and ECS was converted to a bi-ventricular (bi-VAD) system. The RVAD drained from the RA and pumped into the PA, and the LVAD drained the LV and pumped into the iliac. This brought the lungs back into circulation for a 1-hr assessment period. The oxygenator was turned off, and ventilation was restarted. Flows, blood gases, PA and left atrial pressures, and compliance were recorded. In both the groups, LA pressure was <15 mm Hg during ECS. During the lung assessment period, PA flows were 1.4-2.2 L/min. PO2 was >300 mm Hg, with normal PCO2. Extracorporeal cardiopulmonary support resuscitation of DCD donors is feasible and allows for assessment of function before procurement. Extracorporeal cardiopulmonary support does not cause pulmonary congestion, and the lungs retain adequate function for transplantation. Compliance correlated with lung function.

LUNG PHYSIOLOGY DURING ECS RESUSCITATION OF DCD DONORS FOLLOWED BY IN-SITU ASSESSMENT OF LUNG FUNCTION

PubMed Central

Reoma, Junewai L.; Rojas, Alvaro; Krause, Eric M.; Obeid, Nabeel R.; Lafayette, Nathan G.; Pohlmann, Joshua R.; Padiyar, Niru P.; Punch, Jeffery D; Cook, Keith E.; Bartlett, Robert H

2009-01-01

Extracorporeal cardiopulmonary support(ECS) of donors following cardiac death(DCD) has been shown to improve abdominal organs for transplantation. This study assesses whether pulmonary congestion occurs during ECS with the heart arrested and describes an in-vivo method to assess if lungs are suitable for transplantation from DCD donors following ECS resuscitation. Cardiac arrest was induced in 30 kg pigs, followed by 10min. of warm ischemia. Cannulas were placed into right atrium (RA) and iliac artery, and veno-arterial ECS was initiated for 90min with lungs inflated, Group 1 (n=5) or deflated Group 2 (n=3). Left atrial pressures were measured as a marker for pulmonary congestion. After 90 min of ECS, lung function was evaluated. Cannulae were placed into the pulmonary artery (PA) and left ventricle (LV). A second pump was included, and ECS was converted to a bi-VAD system. The RVAD drained from the RA and pumped into the PA, and the LVAD drained the LV and pumped into the iliac. This brought the lungs back into circulation for a 1hr assessment period. The oxygenator was turned off, and ventilation restarted. Flows, blood gases, pulmonary artery and left atrial pressures, and compliance were recorded. In both groups: LA pressure was <15mmHg during ECS. During the lung assessment period, PA flows were 1.4−2.2 liter/min. PO2 was >300mmHg, with normal PCO2. ECS resuscitation of DCD donors is feasible and allows for assessment of function prior to procurement. ECS does not cause pulmonary congestion, and lungs retain adequate function for transplantation. Compliance correlated with lung function. PMID:19506464

Organizational, Cultural, and Psychological Determinants of Smart Infusion Pump Work Arounds: A Study of 3 U.S. Health Systems.

PubMed

Dunford, Benjamin B; Perrigino, Matthew; Tucker, Sharon J; Gaston, Cynthia L; Young, Jim; Vermace, Beverly J; Walroth, Todd A; Buening, Natalie R; Skillman, Katherine L; Berndt, Dawn

2017-09-01

We investigated nurse perceptions of smart infusion medication pumps to provide evidence-based insights on how to help reduce work around and improve compliance with patient safety policies. Specifically, we investigated the following 3 research questions: (1) What are nurses' current attitudes about smart infusion pumps? (2) What do nurses think are the causes of smart infusion pump work arounds? and (3) To whom do nurses turn for smart infusion pump training and troubleshooting? We surveyed a large number of nurses (N = 818) in 3 U.S.-based health care systems to address the research questions above. We assessed nurses' opinions about smart infusion pumps, organizational perceptions, and the reasons for work arounds using a voluntary and anonymous Web-based survey. Using qualitative research methods, we coded open-ended responses to questions about the reasons for work arounds to organize responses into useful categories. The nurses reported widespread satisfaction with smart infusion pumps. However, they reported numerous organizational, cultural, and psychological causes of smart pump work arounds. Of 1029 open-ended responses to the question "why do smart pump work arounds occur?" approximately 44% of the causes were technology related, 47% were organization related, and 9% were related to individual factors. Finally, an overwhelming majority of nurses reported seeking solutions to smart pump problems from coworkers and being trained primarily on the job. Hospitals may significantly improve adherence to smart pump safety features by addressing the nontechnical causes of work arounds and by providing more leadership and formalized training for resolving smart pump-related problems.

Kinking and Torsion Can Significantly Improve the Efficiency of Valveless Pumping in Periodically Compressed Tubular Conduits. Implications for Understanding of the Form-Function Relationship of Embryonic Heart Tubes.

PubMed

Hiermeier, Florian; Männer, Jörg

2017-11-19

Valveless pumping phenomena (peristalsis, Liebau-effect) can generate unidirectional fluid flow in periodically compressed tubular conduits. Early embryonic hearts are tubular conduits acting as valveless pumps. It is unclear whether such hearts work as peristaltic or Liebau-effect pumps. During the initial phase of its pumping activity, the originally straight embryonic heart is subjected to deforming forces that produce bending, twisting, kinking, and coiling. This deformation process is called cardiac looping. Its function is traditionally seen as generating a configuration needed for establishment of correct alignments of pulmonary and systemic flow pathways in the mature heart of lung-breathing vertebrates. This idea conflicts with the fact that cardiac looping occurs in all vertebrates, including gill-breathing fishes. We speculate that looping morphogenesis may improve the efficiency of valveless pumping. To test the physical plausibility of this hypothesis, we analyzed the pumping performance of a Liebau-effect pump in straight and looped (kinked) configurations. Compared to the straight configuration, the looped configuration significantly improved the pumping performance of our pump. This shows that looping can improve the efficiency of valveless pumping driven by the Liebau-effect. Further studies are needed to clarify whether this finding may have implications for understanding of the form-function relationship of embryonic hearts.

Kinking and Torsion Can Significantly Improve the Efficiency of Valveless Pumping in Periodically Compressed Tubular Conduits. Implications for Understanding of the Form-Function Relationship of Embryonic Heart Tubes

PubMed Central

Hiermeier, Florian; Männer, Jörg

2017-01-01

Valveless pumping phenomena (peristalsis, Liebau-effect) can generate unidirectional fluid flow in periodically compressed tubular conduits. Early embryonic hearts are tubular conduits acting as valveless pumps. It is unclear whether such hearts work as peristaltic or Liebau-effect pumps. During the initial phase of its pumping activity, the originally straight embryonic heart is subjected to deforming forces that produce bending, twisting, kinking, and coiling. This deformation process is called cardiac looping. Its function is traditionally seen as generating a configuration needed for establishment of correct alignments of pulmonary and systemic flow pathways in the mature heart of lung-breathing vertebrates. This idea conflicts with the fact that cardiac looping occurs in all vertebrates, including gill-breathing fishes. We speculate that looping morphogenesis may improve the efficiency of valveless pumping. To test the physical plausibility of this hypothesis, we analyzed the pumping performance of a Liebau-effect pump in straight and looped (kinked) configurations. Compared to the straight configuration, the looped configuration significantly improved the pumping performance of our pump. This shows that looping can improve the efficiency of valveless pumping driven by the Liebau-effect. Further studies are needed to clarify whether this finding may have implications for understanding of the form-function relationship of embryonic hearts. PMID:29367548

Tunable organic transistors that use microfluidic source and drain electrodes

NASA Astrophysics Data System (ADS)

Maltezos, George; Nortrup, Robert; Jeon, Seokwoo; Zaumseil, Jana; Rogers, John A.

2003-09-01

This letter describes a type of transistor that uses conducting fluidic source and drain electrodes of mercury which flow on top of a thin film of the organic semiconductor pentacene. Pumping the mercury through suitably designed microchannels changes the width of the transistor channel and, therefore, the electrical characteristics of the device. Measurements on transistors with a range of channel lengths reveal low contact resistances between mercury and pentacene. Data collected before, during, and after pumping the mercury through the microchannels demonstrate reversible and systematic tuning of the devices. This unusual type of organic transistor has the potential to be useful in plastic microfluidic devices that require active elements for pumps, sensors, or other components. It also represents a noninvasive way to build transistor test structures that incorporate certain classes of chemically and mechanically fragile organic semiconductors.

Laboratory testing of a supercritical helium pump for a magnetic refrigerator

NASA Technical Reports Server (NTRS)

Wang, Pao-Lien

1988-01-01

A supercritical helium testing system for a magnetic refrigerator has been built. Details of the supercritical helium pump, the test system, and the test instrumentation are given. Actual pump tests were not run during this ASEE term because of delivery problems associated with the required pump flow meter. Consequently, efforts were directed on preliminary design of the magnetic refrigeration system for the pump. The first concern with the magnetic refrigerator design was determining how to effectively make use of the pump. A method to incorporate the supercritical helium pump into a magnetic refrigerator was determined by using a computer model. An illustrated example of this procedure is given to provide a tool for sizing the magnetic refrigerator system as a function of the pump size. The function of the computer model and its operation are also outlined and discussed.

The Plasma Membrane Calcium Pump

NASA Technical Reports Server (NTRS)

Rasmussen, H.

1983-01-01

Three aspect of cellular calcium metabolism in animal cells was discussed including the importance of the plasma membrane in calcium homeostasis, experiments dealing with the actual mechanism of the calcium pump, and the function of the pump in relationship to the mitochondria and to the function of calmodulin in the intact cell.

DISK PUMP FEASIBILITY INVESTIGATION,

DTIC Science & Technology

system as an inducer and/or mainstage pump for liquid rocket applications. This investigation consisted of the analysis, design, and test of a disk...pumping action is a function of the viscous properties of the pumped fluid. (2) The pump does not require the conventional pump lifting forces. ( 3 ...with no apparent head deterioration. The representative maximum suction specific speed at a 3 % head drop was never reached. The pump demonstrated

Heat-Powered Pump for Liquid Metals

NASA Technical Reports Server (NTRS)

Campana, R. J.

1986-01-01

Proposed thermoelectromagnetic pump for liquid metal powered by waste heat; needs no battery, generator, or other external energy source. Pump turns part of heat in liquid metal into pumping energy. In combination with primary pump or on its own, thermoelectric pump circulates coolant between reactor and radiator. As long as there is decay heat to be removed, unit performs function.

Incorporating high-pressure electroosmotic pump and a nano-flow gradient generator into a miniaturized liquid chromatographic system for peptide analysis.

PubMed

Chen, Apeng; Lynch, Kyle B; Wang, Xiaochun; Lu, Joann J; Gu, Congying; Liu, Shaorong

2014-09-24

We integrate a high-pressure electroosmotic pump (EOP), a nanoflow gradient generator, and a capillary column into a miniaturized liquid chromatographic system that can be directly coupled with a mass spectrometer for proteomic analysis. We have recently developed a low-cost high-pressure EOP capable of generating pressure of tens of thousands psi, ideal for uses in miniaturized HPLC. The pump worked smoothly when it was used for isocratic elutions. When it was used for gradient elutions, generating reproducible gradient profiles was challenging; because the pump rate fluctuated when the pump was used to pump high-content organic solvents. This presents an issue for separating proteins/peptides since high-content organic solvents are often utilized. In this work, we solve this problem by incorporating our high-pressure EOP with a nano-flow gradient generator so that the EOP needs only to pump an aqueous solution. With this combination, we develop a capillary-based nano-HPLC system capable of performing nano-flow gradient elution; the pump rate is stable, and the gradient profiles are reproducible and can be conveniently tuned. To demonstrate its utility, we couple it with either a UV absorbance detector or a mass spectrometer for peptide separations. Copyright © 2014. Published by Elsevier B.V.

Experimental Waterflow Determination of the Dynamic Hydraulic Transfer Function for the J-2X Oxidizer Turbopump. Part Two; Results and Interpretation

NASA Technical Reports Server (NTRS)

Zoladz, Tom; Patel, Sandeep; Lee, Erik; Karon, Dave

2011-01-01

Experimental results describing the hydraulic dynamic pump transfer matrix (Yp) for a cavitating J-2X oxidizer turbopump inducer+impeller tested in subscale waterflow are presented. The transfer function is required for integrated vehicle pogo stability analysis as well as optimization of local inducer pumping stability. Dynamic transfer functions across widely varying pump hydrodynamic inlet conditions are extracted from measured data in conjunction with 1D-model based corrections. Derived Dynamic transfer functions are initially interpreted relative to traditional Pogo pump equations. Water-to-liquid oxygen scaling of measured cavitation characteristics are discussed. Comparison of key dynamic transfer matrix terms derived from waterflow testing are made with those implemented in preliminary Ares Upper Stage Pogo stability modeling. Alternate cavitating pump hydraulic dynamic equations are suggested which better reflect frequency dependencies of measured transfer matrices.

Usefulness of Doppler assessment of pulmonary vein and left atrial appendage flow following pulmonary vein isolation of chronic atrial fibrillation in predicting recovery of left atrial function.

PubMed

Donal, Erwan; Grimm, Richard A; Yamada, Hirotsugu; Kim, Yong Jin; Marrouche, Nassir; Natale, Andrea; Thomas, James D

2005-04-15

Atrial fibrillation (AF) is a widespread condition that causes significant morbidity and mortality. Recently, pulmonary venous (PV) isolation using radiofrequency ablation has been used successfully to exclude the pulmonary venous ostia, resulting in correction of AF. Further, miniaturized high-frequency ultrasound phased-array transducers currently provide Doppler and 2-dimensional imaging during the ablation procedure. We examined atrial function and its determinants using intracardiac echocardiography before and after PV isolation in 45 patients who had chronic AF (56 +/- 11 years old). PV, left atrial (LA) appendage, and mitral and tricuspid flows were recorded. Recovery of booster pump function (defined by the presence of mitral inflow A wave, LA appendage a-wave, and PV A-reversal wave velocities >10 cm/s) was observed in 39 of 45 patients (86.6%). PV flow systolic wave before and after ablation correlated with the degree of LA booster pump function after PV isolation. An early systolic PV flow peak velocity >57.47 cm/s predicted "good" LA booster pump function recovery with 96% specificity. Diastolic LA appendage emptying in AF correlated (p <0.001) and predicted good LA booster pump function with 92% specificity for velocities >46.4 cm/s. Thus, monitoring LA function during PV isolation for chronic AF is feasible. Most patients recovered LA booster pump function immediately after PV isolation, and the degree of recovery correlated with LA reservoir function. Preserved reservoir function during AF is predictive of satisfactory recovery of booster pump function after PV isolation.

Substantial energy input to the mesopelagic ecosystem from the seasonal mixed-layer pump

PubMed Central

Dall’Olmo, Giorgio; Dingle, James; Polimene, Luca; Brewin, Robert J.W.; Claustre, Hervé

2016-01-01

The “mesopelagic” is the region of the ocean between about 100 and 1000 m that harbours one of the largest ecosystems and fish stocks on the planet1,2. This vastly unexplored ecosystem is believed to be mostly sustained by chemical energy, in the form of fast-sinking particulate organic carbon, supplied by the biological carbon pump3. Yet, this supply appears insufficient to match mesopelagic metabolic demands4–6. The mixed-layer pump is a physically-driven biogeochemical process7–11 that could further contribute to meet these energetic requirements. However, little is known about the magnitude and spatial distribution of this process at the global scale. Here we show that the mixed-layer pump supplies an important seasonal flux of organic carbon to the mesopelagic. By combining mixed-layer depths from Argo floats with satellite retrievals of particulate organic carbon, we estimate that this pump exports a global flux of about 0.3 Pg C yr−1 (range 0.1 – 0.5 Pg C yr−1). In high-latitude regions where mixed-layers are deep, this flux is on average 23%, but can be greater than 100% of the carbon supplied by fast sinking particles. Our results imply that a relatively large flux of organic carbon is missing from current energy budgets of the mesopelagic. PMID:27857779

Comparison of passive diffusion bag samplers and submersible pump sampling methods for monitoring volatile organic compounds in ground water at Area 6, Naval Air Station, Whidbey Island, Washington

USGS Publications Warehouse

Huffman, Raegan L.

2002-01-01

Ground-water samples were collected in April 1999 at Naval Air Station Whidbey Island, Washington, with passive diffusion samplers and a submersible pump to compare concentrations of volatile organic compounds (VOCs) in water samples collected using the two sampling methods. Single diffusion samplers were installed in wells with 10-foot screened intervals, and multiple diffusion samplers were installed in wells with 20- to 40-foot screened intervals. The diffusion samplers were recovered after 20 days and the wells were then sampled using a submersible pump. VOC concentrations in the 10-foot screened wells in water samples collected with diffusion samplers closely matched concentrations in samples collected with the submersible pump. Analysis of VOC concentrations in samples collected from the 20- to 40-foot screened wells with multiple diffusion samplers indicated vertical concentration variation within the screened interval, whereas the analysis of VOC concentrations in samples collected with the submersible pump indicated mixing during pumping. The results obtained using the two sampling methods indicate that the samples collected with the diffusion samplers were comparable with and can be considerably less expensive than samples collected using a submersible pump.

Analysis of pressure head-flow loops of pulsatile rotodynamic blood pumps.

PubMed

Jahren, Silje E; Ochsner, Gregor; Shu, Fangjun; Amacher, Raffael; Antaki, James F; Vandenberghe, Stijn

2014-04-01

The clinical importance of pulsatility is a recurring topic of debate in mechanical circulatory support. Lack of pulsatility has been identified as a possible factor responsible for adverse events and has also demonstrated a role in myocardial perfusion and cardiac recovery. A commonly used method for restoring pulsatility with rotodynamic blood pumps (RBPs) is to modulate the speed profile, synchronized to the cardiac cycle. This introduces additional parameters that influence the (un)loading of the heart, including the timing (phase shift) between the native cardiac cycle and the pump pulses, and the amplitude of speed modulation. In this study, the impact of these parameters upon the heart-RBP interaction was examined in terms of the pressure head-flow (HQ) diagram. The measurements were conducted using a rotodynamic Deltastream DP2 pump in a validated hybrid mock circulation with baroreflex function. The pump was operated with a sinusoidal speed profile, synchronized to the native cardiac cycle. The simulated ventriculo-aortic cannulation showed that the level of (un)loading and the shape of the HQ loops strongly depend on the phase shift. The HQ loops displayed characteristic shapes depending on the phase shift. Increased contribution of native contraction (increased ventricular stroke work [WS ]) resulted in a broadening of the loops. It was found that the previously described linear relationship between WS and the area of the HQ loop for constant pump speeds becomes a family of linear relationships, whose slope depends on the phase shift. © 2013 Wiley Periodicals, Inc. and International Center for Artificial Organs and Transplantation.

Self-organization comprehensive real-time state evaluation model for oil pump unit on the basis of operating condition classification and recognition

NASA Astrophysics Data System (ADS)

Liang, Wei; Yu, Xuchao; Zhang, Laibin; Lu, Wenqing

2018-05-01

In oil transmission station, the operating condition (OC) of an oil pump unit sometimes switches accordingly, which will lead to changes in operating parameters. If not taking the switching of OCs into consideration while performing a state evaluation on the pump unit, the accuracy of evaluation would be largely influenced. Hence, in this paper, a self-organization Comprehensive Real-Time State Evaluation Model (self-organization CRTSEM) is proposed based on OC classification and recognition. However, the underlying model CRTSEM is built through incorporating the advantages of Gaussian Mixture Model (GMM) and Fuzzy Comprehensive Evaluation Model (FCEM) first. That is to say, independent state models are established for every state characteristic parameter according to their distribution types (i.e. the Gaussian distribution and logistic regression distribution). Meanwhile, Analytic Hierarchy Process (AHP) is utilized to calculate the weights of state characteristic parameters. Then, the OC classification is determined by the types of oil delivery tasks, and CRTSEMs of different standard OCs are built to constitute the CRTSEM matrix. On the other side, the OC recognition is realized by a self-organization model that is established on the basis of Back Propagation (BP) model. After the self-organization CRTSEM is derived through integration, real-time monitoring data can be inputted for OC recognition. At the end, the current state of the pump unit can be evaluated by using the right CRTSEM. The case study manifests that the proposed self-organization CRTSEM can provide reasonable and accurate state evaluation results for the pump unit. Besides, the assumption that the switching of OCs will influence the results of state evaluation is also verified.

Kidney function after off-pump or on-pump coronary artery bypass graft surgery: a randomized clinical trial.

PubMed

Garg, Amit X; Devereaux, P J; Yusuf, Salim; Cuerden, Meaghan S; Parikh, Chirag R; Coca, Steven G; Walsh, Michael; Novick, Richard; Cook, Richard J; Jain, Anil R; Pan, Xiangbin; Noiseux, Nicolas; Vik, Karel; Stolf, Noedir A; Ritchie, Andrew; Favaloro, Roberto R; Parvathaneni, Sirish; Whitlock, Richard P; Ou, Yongning; Lawrence, Mitzi; Lamy, Andre

2014-06-04

Most acute kidney injury observed in the hospital is defined by sudden mild or moderate increases in the serum creatinine concentration, which may persist for several days. Such acute kidney injury is associated with lower long-term kidney function. However, it has not been demonstrated that an intervention that reduces the risk of such acute kidney injury better preserves long-term kidney function. To characterize the risk of acute kidney injury with an intervention in a randomized clinical trial and to determine if there is a difference between the 2 treatment groups in kidney function 1 year later. The Coronary Artery Bypass Grafting Surgery Off- or On-pump Revascularisation Study (CORONARY) enrolled 4752 patients undergoing first isolated coronary artery bypass graft (CABG) surgery at 79 sites in 19 countries. Patients were randomized to receive CABG surgery either with a beating-heart technique (off-pump) or with cardiopulmonary bypass (on-pump). From January 2010 to November 2011, 2932 patients (from 63 sites in 16 countries) from CORONARY were enrolled into a kidney function substudy to record serum creatinine concentrations during the postoperative period and at 1 year. The last 1-year serum creatinine concentration was recorded on January 18, 2013. Acute kidney injury within 30 days of surgery (≥50% increase in serum creatinine concentration from prerandomization concentration) and loss of kidney function at 1 year (≥20% loss in estimated glomerular filtration rate from prerandomization level). Off-pump (n = 1472) vs on-pump (n = 1460) CABG surgery reduced the risk of acute kidney injury (17.5% vs 20.8%, respectively; relative risk, 0.83 [95% CI, 0.72-0.97], P = .01); however, there was no significant difference between the 2 groups in the loss of kidney function at 1 year (17.1% vs 15.3%, respectively; relative risk, 1.10 [95% CI, 0.95-1.29], P = .23). Results were consistent with multiple alternate continuous and categorical definitions of acute kidney injury or kidney function loss, and in the subgroup with baseline chronic kidney disease. Use of off-pump compared with on-pump CABG surgery reduced the risk of postoperative acute kidney injury, without evidence of better preserved kidney function with off-pump CABG surgery at 1 year. In this setting, an intervention that reduced the risk of mild to moderate acute kidney injury did not alter longer-term kidney function. clinicaltrials.gov Identifier: NCT00463294.

Nuclear Technology. Course 30: Mechanical Inspection. Module 30-2, Pump Functional Testing.

ERIC Educational Resources Information Center

Wasel, Ed; Espy, John

This second in a series of eight modules for a course titled Mechanical Inspection describes typical pump functional tests which are performed after pump installation and prior to release of the plant for unrestricted power operation. The module follows a typical format that includes the following sections: (1) introduction, (2) module…

Experimental Determination of the Dynamic Hydraulic Transfer Function for the J-2X Oxidizer Turbopump. Part One; Methodology

NASA Technical Reports Server (NTRS)

Zoladz, Tom; Patel, Sandeep; Lee, Erik; Karon, Dave

2011-01-01

An advanced methodology for extracting the hydraulic dynamic pump transfer matrix (Yp) for a cavitating liquid rocket engine turbopump inducer+impeller has been developed. The transfer function is required for integrated vehicle pogo stability analysis as well as optimization of local inducer pumping stability. Laboratory pulsed subscale waterflow test of the J-2X oxygen turbo pump is introduced and our new extraction method applied to the data collected. From accurate measures of pump inlet and discharge perturbational mass flows and pressures, and one-dimensional flow models that represents complete waterflow loop physics, we are able to derive Yp and hence extract the characteristic pump parameters: compliance, pump gain, impedance, mass flow gain. Detailed modeling is necessary to accurately translate instrument plane measurements to the pump inlet and discharge and extract Yp. We present the MSFC Dynamic Lump Parameter Fluid Model Framework and describe critical dynamic component details. We report on fit minimization techniques, cost (fitness) function derivation, and resulting model fits to our experimental data are presented. Comparisons are made to alternate techniques for spatially translating measurement stations to actual pump inlet and discharge.

Continuous-wave lasing in an organic-inorganic lead halide perovskite semiconductor

NASA Astrophysics Data System (ADS)

Jia, Yufei; Kerner, Ross A.; Grede, Alex J.; Rand, Barry P.; Giebink, Noel C.

2017-12-01

Hybrid organic-inorganic perovskites have emerged as promising gain media for tunable, solution-processed semiconductor lasers. However, continuous-wave operation has not been achieved so far1-3. Here, we demonstrate that optically pumped continuous-wave lasing can be sustained above threshold excitation intensities of 17 kW cm-2 for over an hour in methylammonium lead iodide (MAPbI3) distributed feedback lasers that are maintained below the MAPbI3 tetragonal-to-orthorhombic phase transition temperature of T ≈ 160 K. In contrast with the lasing death phenomenon that occurs for pure tetragonal-phase MAPbI3 at T > 160 K (ref. 4), we find that continuous-wave gain becomes possible at T ≈ 100 K from tetragonal-phase inclusions that are photogenerated by the pump within the normally existing, larger-bandgap orthorhombic host matrix. In this mixed-phase system, the tetragonal inclusions function as carrier recombination sinks that reduce the transparency threshold, in loose analogy to inorganic semiconductor quantum wells, and may serve as a model for engineering improved perovskite gain media.

Charge generation in organic solar cell materials studied by terahertz spectroscopy

NASA Astrophysics Data System (ADS)

Scarongella, M.; Brauer, J. C.; Douglas, J. D.; Fréchet, J. M. J.; Banerji, N.

2015-09-01

We have investigated the photophysics in neat films of conjugated polymer PBDTTPD and its blend with PCBM using terahertz time-domain spectroscopy. This material has very high efficiency when used in organic solar cells. We were able to identify a THz signature for bound excitons in neat PBDTTPD films, pointing to important delocalization in those excitons. Then, we investigated the nature and local mobility (orders of magnitude higher than bulk mobility) of charges in the PBDTTPPD:PCBM blend as a function of excitation wavelength, fluence and pump-probe time delay. At low pump fluence (no bimolecular recombination phenomena), we were able to observe prompt and delayed charge generation components, the latter originating from excitons created in neat polymer domains which, thanks to delocalization, could reach the PCBM interface and dissociate to charges on a time scale of 1 ps. The nature of the photogenerated charges did not change between 0.5 ps and 800 ps after photo-excitation, which indicated that the excitons split directly into relatively free charges on an ultrafast time scale.

The Plasma Membrane Calcium Pump: New Ways to Look at an Old Enzyme

PubMed Central

Lopreiato, Raffaele; Giacomello, Marta; Carafoli, Ernesto

2014-01-01

The three-dimensional structure of the PMCA pump has not been solved, but its basic mechanistic properties are known to repeat those of the other Ca2+ pumps. However, the pump also has unique properties. They concern essentially its numerous regulatory mechanisms, the most important of which is the autoinhibition by its C-terminal tail. Other regulatory mechanisms involve protein kinases and the phospholipids of the membrane in which the pump is embedded. Permanent activation of the pump, e.g. by calmodulin, is physiologically as harmful to cells as its absence. The concept is now emerging that the global control of cell Ca2+ may not be the main function of the pump; in some cell types, it could even be irrelevant. The main pump role would be the regulation of Ca2+ in cell microdomains in which the pump co-segregates with partners that modulate the Ca2+ message and transduce it to important cell functions. PMID:24570005

Nanoimprinted organic semiconductor laser pumped by a light-emitting diode.

PubMed

Tsiminis, Georgios; Wang, Yue; Kanibolotsky, Alexander L; Inigo, Anto R; Skabara, Peter J; Samuel, Ifor D W; Turnbull, Graham A

2013-05-28

An organic semiconductor laser, simply fabricated by UV-nanoimprint lithography (UV-NIL), that is pumped with a pulsed InGaN LED is demonstrated. Molecular weight optimization of the polymer gain medium on a nanoimprinted polymer distributed feedback resonator enables the lowest reported UV-NIL laser threshold density of 770 W cm(-2) , establishing the potential for scalable organic laser fabrication compatible with mass-produced LEDs. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Micromotor-enabled active drug delivery for in vivo treatment of stomach infection.

PubMed

de Ávila, Berta Esteban-Fernández; Angsantikul, Pavimol; Li, Jinxing; Angel Lopez-Ramirez, Miguel; Ramírez-Herrera, Doris E; Thamphiwatana, Soracha; Chen, Chuanrui; Delezuk, Jorge; Samakapiruk, Richard; Ramez, Valentin; Obonyo, Marygorret; Zhang, Liangfang; Wang, Joseph

2017-08-16

Advances in bioinspired design principles and nanomaterials have led to tremendous progress in autonomously moving synthetic nano/micromotors with diverse functionalities in different environments. However, a significant gap remains in moving nano/micromotors from test tubes to living organisms for treating diseases with high efficacy. Here we present the first, to our knowledge, in vivo therapeutic micromotors application for active drug delivery to treat gastric bacterial infection in a mouse model using clarithromycin as a model antibiotic and Helicobacter pylori infection as a model disease. The propulsion of drug-loaded magnesium micromotors in gastric media enables effective antibiotic delivery, leading to significant bacteria burden reduction in the mouse stomach compared with passive drug carriers, with no apparent toxicity. Moreover, while the drug-loaded micromotors reach similar therapeutic efficacy as the positive control of free drug plus proton pump inhibitor, the micromotors can function without proton pump inhibitors because of their built-in proton depletion function associated with their locomotion.Nano- and micromotors have been demonstrated in vitro for a range of applications. Here the authors demonstrate the in-vivo therapeutic use of micromotors to treat H. pylori infection.

Computational approaches to understand cardiac electrophysiology and arrhythmias

PubMed Central

Roberts, Byron N.; Yang, Pei-Chi; Behrens, Steven B.; Moreno, Jonathan D.

2012-01-01

Cardiac rhythms arise from electrical activity generated by precisely timed opening and closing of ion channels in individual cardiac myocytes. These impulses spread throughout the cardiac muscle to manifest as electrical waves in the whole heart. Regularity of electrical waves is critically important since they signal the heart muscle to contract, driving the primary function of the heart to act as a pump and deliver blood to the brain and vital organs. When electrical activity goes awry during a cardiac arrhythmia, the pump does not function, the brain does not receive oxygenated blood, and death ensues. For more than 50 years, mathematically based models of cardiac electrical activity have been used to improve understanding of basic mechanisms of normal and abnormal cardiac electrical function. Computer-based modeling approaches to understand cardiac activity are uniquely helpful because they allow for distillation of complex emergent behaviors into the key contributing components underlying them. Here we review the latest advances and novel concepts in the field as they relate to understanding the complex interplay between electrical, mechanical, structural, and genetic mechanisms during arrhythmia development at the level of ion channels, cells, and tissues. We also discuss the latest computational approaches to guiding arrhythmia therapy. PMID:22886409

Self-potential response to periodic pumping test: a numerical study

NASA Astrophysics Data System (ADS)

Konosavsky, Pavel; Maineult, Alexis; Narbut, Mikhail; Titov, Konstantin

2017-09-01

We numerically model self-potential responses associated with periodic pumping test experiments by sequential calculation of the hydraulic response and the coupled electrical potential. We assume the pumping test experiments with a fully saturated confined aquifer. Application of different excitation functions leads to quasi-linear trends in electrical records whose direction and intensity depend on the form of the excitation function. The hydraulic response is phase shifted compared to the excitation function; the phase shift increases quasi-linearly with the distance from the pumping well. For the electrical signals, we investigated separately the cases of conducting and insulating casings of the pumping well. For the conducting casing the electrical signals are larger in magnitude than that for the insulating casing; they reproduce the drawdown signals in the pumping well at any distance from the well and exhibit any phase shift with the increased distance. For the insulating casing, the electrical signals are phase shifted and their shape depends on the distance from the pumping well. Three characteristic regimes were found for the phase shift, φ, with the increased distance and for various hydraulic diffusivity values. At small distances φ increases quasi-linearly; at intermediate distances φ attends the value of π/2 and stay about this value (for relatively small diffusivity values); and at large distances φ attends the value of π and, stay about this value at larger distances. This behaviour of the electrical signals can be explained by two electrical sources of reverse polarity. They are (i) linear, time independent, and located at the pumping interval of the well; and (ii) volumetric, time dependent, with maximum value located in the aquifer at the distance corresponding to maximum variation of the hydraulic head magnitude with time. We also model the variation of the amplitude and phase of the hydraulic and electrical signals with increased excitation function period, and we show the characteristic periods corresponding to transition of the periodic pumping test regime to the classical pumping test regime, when the excitation function is considered as the step-function. This transition depends on the distance from the pumping well and the hydraulic diffusivity value of aquifer. Finally, with this modelling of saturated flow we reproduced in sufficient details the field data previously obtained by Maineult et al.

Study of Anti-Vortex Baffle Effect in Suppressing Swirling Flow in LOX Tank

NASA Technical Reports Server (NTRS)

Yang, H. Q.; Peugeot, John

2011-01-01

Experimental results describing the hydraulic dynamic pump transfer matrix (Yp) for a cavitating J-2X oxidizer turbopump inducer+impeller tested in subscale waterflow are presented. The transfer function is required for integrated vehicle pogo stability analysis as well as optimization of local inducer pumping stability. Dynamic transfer functions across widely varying pump hydrodynamic inlet conditions are extracted from measured data in conjunction with 1D-model based corrections. Derived Dynamic transfer functions are initially interpreted relative to traditional Pogo pump equations. Water-to-liquid oxygen scaling of measured cavitation characteristics are discussed. Comparison of key dynamic transfer matrix terms derived from waterflow testing are made with those implemented in preliminary Ares Upper Stage Pogo stability modeling. Alternate cavitating pump hydraulic dynamic equations are suggested which better reflect frequency dependencies of measured transfer matrices.

Artificial heart for humanoid robot

NASA Astrophysics Data System (ADS)

Potnuru, Akshay; Wu, Lianjun; Tadesse, Yonas

2014-03-01

A soft robotic device inspired by the pumping action of a biological heart is presented in this study. Developing artificial heart to a humanoid robot enables us to make a better biomedical device for ultimate use in humans. As technology continues to become more advanced, the methods in which we implement high performance and biomimetic artificial organs is getting nearer each day. In this paper, we present the design and development of a soft artificial heart that can be used in a humanoid robot and simulate the functions of a human heart using shape memory alloy technology. The robotic heart is designed to pump a blood-like fluid to parts of the robot such as the face to simulate someone blushing or when someone is angry by the use of elastomeric substrates and certain features for the transport of fluids.

Functional complementation of anthocyanin sequestration in the vacuole by widely divergent glutathione S-transferases.

PubMed Central

Alfenito, M R; Souer, E; Goodman, C D; Buell, R; Mol, J; Koes, R; Walbot, V

1998-01-01

Glutathione S-transferases (GSTs) traditionally have been studied in plants and other organisms for their ability to detoxify chemically diverse herbicides and other toxic organic compounds. Anthocyanins are among the few endogenous substrates of plant GSTs that have been identified. The Bronze2 (Bz2) gene encodes a type III GST and performs the last genetically defined step of the maize anthocyanin pigment pathway. This step is the conjugation of glutathione to cyanidin 3-glucoside (C3G). Glutathionated C3G is transported to the vacuole via a tonoplast Mg-ATP-requiring glutathione pump (GS-X pump). Genetically, the comparable step in the petunia anthocyanin pathway is controlled by the Anthocyanin9 (An9) gene. An9 was cloned by transposon tagging and found to encode a type I plant GST. Bz2 and An9 have evolved independently from distinct types of GSTs, but each is regulated by the conserved transcriptional activators of the anthocyanin pathway. Here, a phylogenetic analysis is presented, with special consideration given to the origin of these genes and their relaxed substrate requirements. In particle bombardment tests, An9 and Bz2 functionally complement both mutants. Among several other GSTs tested, only soybean GmGST26A (previously called GmHsp26A and GH2/4) and maize GSTIII were found to confer vacuolar sequestration of anthocyanin. Previously, these genes had not been associated with the anthocyanin pathway. Requirements for An9 and Bz2 gene function were investigated by sequencing functional and nonfunctional germinal revertants of an9-T3529, bz2::Ds, and bz2::Mu1. PMID:9668133

[Insulin pump in type 2 diabetes: B-cell focused treatment].

PubMed

Picková, Klára; Rušavý, Zdeněk

Type 2 diabetes is a disorder characterized by insulin resistance and progressive deterioration of B-cell insulin secretion. B-cell protective strategies for lowering glucolipotoxicity by rapid achievement of normoglycemia using exogenous insulin improve their function and prolong diabetes remission. Insulin pump is an effective treatment method in newly diagnosed diabetes, where even short-term pump therapy is B-cell protective. Combination therapy with insulin pump and antidiabetics targeting the incretin system acts in synergy to protect the B-cell. While the positive effect of insulin pump is apparent even a year after stopping the therapy, the effect of incretins lasts only while on the medication. Short-term insulin treatment, especially delivered by insulin pump, is an effective method of B-cell protection in recent type 2 diabetes.Key words: B-cell function - diabetes mellitus - insulin pump - insulin resistance - type 2 diabetes.

Heavy metal pumps in plants. 1998 annual progress report

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

Harper, J.F.

1998-06-01

'The purpose of the proposed DOE research is to determine the function of AMA1, a novel heavy metal pump identified in a model plant system, Arabidopsis. Heavy metal pumps belong to a superfamily of P-type ATPases which include the plasma membrane Na/K-ATPase in animals and the plasma membrane H + ATPase in plants and fungi. Heavy metal pumps have been implicated in heavy metal resistance (e.g., cadmium) and regulation of essential micronutrients (e.g., copper). Although several heavy metal pumps have now been identified in plants, their isoform specific functions have not been investigated. The results suggest that AMA1 is amore » molydenum uptake pump. The authors are exploring the possibility to engineer the ion specificity of these pumps to take up other heavy metals from the soil. This report summarizes work after 2 years of a 3 year project.'« less

[The use experience of enteral nutrition pump (Applix Smart)].

PubMed

Kobayashi, Kaoru; Shirai, Atsushi; Uryu, Shinichi; Kikuchi, Shiro; Momozono, Shinobu; Shimizu, Haruyuki

2006-12-01

Nutritional management by using enteral feeding method of nutrition is required for patients of gastroenterological disease with functional disorder in digestion-absorption, and for cases where the patients have difficulty in taking food orally. There are many cases where enteral nutrition pumps are used for administration of nutritious medicines. Approximately 150 enteral nutrition pumps (including house use and home rental) have currently been utilized at our facility. The department of ME Center takes care of enteral nutrition pumps for maintenance and control. On the other hand, we needed to conduct a study for a new pump in replacing Frenta System IV due to the pump was no longer available. At this presentation, we are introducing a new pump manufactured by Fresenius as a replacement of the Frenta System IV. In the meantime, we would like to report a comparison examination of the pump based on its functionality, performance and user friendliness from the view from a clinical technologist as well.

Off-pump versus on-pump coronary artery revascularization: effects on pulmonary function.

PubMed

e Silva, Ana M R P; Saad, Roberto; Stirbulov, Roberto; Rivetti, Luiz A

2010-07-01

Many studies have shown important changes in lung function tests after coronary artery surgeries. It is controversial if off-pump surgery can give a better and shorter recovery than the on-pump. A prospective study was conducted on 42 patients submitted to coronary artery surgery and divided into two groups: 21 off-pump using intraluminal shunt (G (I)) and 21 on-pump (G (II)), matched by the anatomical location of the coronary arteries lesions. All patients had spirometric evaluation, blood gas measurements and alveolo-arterial oxygen gradient (A-aDO(2)), at the fourth and 10th postoperative days (PO(4) and PO(10)). Preoperatively, G(I) and G(II) had similar results (P>0.372). Spirometry showed decreases at PO(4) and remained decreased until PO(10) for both groups, with significant differences between the groups. The blood gas measurements showed reduction in arterial oxygen pressure (PaO(2)) and carbon dioxide pressure (PaCO(2)), while there was an increase in A-aDO(2) at PO(4) and PO(10) in both groups. The results suggest that different changes occur in pulmonary function when the surgery is performed with or without cardiopulmonary bypass. The off-pump patients showed significantly greater improvement than the on-pump group.

A first-in-man study of the Reitan catheter pump for circulatory support in patients undergoing high-risk percutaneous coronary intervention.

PubMed

Smith, Elliot J; Reitan, Oyvind; Keeble, Thomas; Dixon, Kerry; Rothman, Martin T

2009-06-01

To investigate the safety of a novel percutaneous circulatory support device during high-risk percutaneous coronary intervention (PCI). The Reitan catheter pump (RCP) consists of a catheter-mounted pump-head with a foldable propeller and surrounding cage. Positioned in the descending aorta the pump creates a pressure gradient, reducing afterload and enhancing organ perfusion. Ten consecutive patients requiring circulatory support underwent PCI; mean age 71 +/- 9; LVEF 34% +/- 11%; jeopardy score 8 +/- 2.3. The RCP was inserted via the femoral artery. Hemostasis was achieved using Perclose sutures. PCI was performed via the radial artery. Outcomes included in-hospital death, MI, stroke, and vascular injury. Hemoglobin (Hb), free plasma Hb (fHb), platelets, and creatinine (cre) were measured pre PCI and post RCP removal. The pump was inserted and operated successfully in 9/10 cases (median 79 min). Propeller rotation at 10,444 +/- 1,424 rpm maintained an aortic gradient of 9.8 +/- 2 mm Hg. Although fHb increased, there was no significant hemolysis (4.7 +/- 2.4 mg/dl pre vs. 11.9 +/- 10.5 post, P = 0.04, reference 20 mg/dl). Platelets were unchanged (pre 257 +/- 74 x 10(9) vs. 245 +/- 63, P = NS). Renal function improved (cre pre 110 +/- 27 micromol/l vs. 99 +/- 28, P = 0.004). The RCP was not used in one patient following femoral introducer sheath related aortic dissection. All PCI procedures were successful with no deaths or strokes, one MI, and no vascular complications following pump removal. The RCP can be used safely in high-risk PCI patients. This device may be an alternative to other percutaneous systems when substantial cardiac support is needed. (c) 2009 Wiley-Liss, Inc.

Early in vivo experience with the pediatric continuous-flow total artificial heart.

PubMed

Karimov, Jamshid H; Horvath, David J; Byram, Nicole; Sunagawa, Gengo; Kuban, Barry D; Gao, Shengqiang; Dessoffy, Raymond; Fukamachi, Kiyotaka

2018-03-30

Heart transplantation in infants and children is an accepted therapy for end-stage heart failure, but donor organ availability is low and always uncertain. Mechanical circulatory support is another standard option, but there is a lack of intracorporeal devices due to size and functional range. The purpose of this study was to evaluate the in vivo performance of our initial prototype of a pediatric continuous-flow total artificial heart (P-CFTAH), comprising a dual pump with one motor and one rotating assembly, supported by a hydrodynamic bearing. In acute studies, the P-CFTAH was implanted in 4 lambs (average weight: 28.7 ± 2.3 kg) via a median sternotomy under cardiopulmonary bypass. Pulmonary and systemic pump performance parameters were recorded. The experiments showed good anatomical fit and easy implantation, with an average aortic cross-clamp time of 98 ± 18 minutes. Baseline hemodynamics were stable in all 4 animals (pump speed: 3.4 ± 0.2 krpm; pump flow: 2.1 ± 0.9 liters/min; power: 3.0 ± 0.8 W; arterial pressure: 68 ± 10 mm Hg; left and right atrial pressures: 6 ± 1 mm Hg, for both). Any differences between left and right atrial pressures were maintained within the intended limit of ±5 mm Hg over a wide range of ratios of systemic-to-pulmonary vascular resistance (0.7 to 12), with and without pump-speed modulation. Pump-speed modulation was successfully performed to create arterial pulsation. This initial P-CFTAH prototype met the proposed requirements for self-regulation, performance, and pulse modulation. Copyright © 2018 International Society for the Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

Selectivity of externally facing ion-binding sites in the Na/K pump to alkali metals and organic cations

PubMed Central

Ratheal, Ian M.; Virgin, Gail K.; Yu, Haibo; Roux, Benoît; Gatto, Craig; Artigas, Pablo

2010-01-01

The Na/K pump is a P-type ATPase that exchanges three intracellular Na+ ions for two extracellular K+ ions through the plasmalemma of nearly all animal cells. The mechanisms involved in cation selection by the pump's ion-binding sites (site I and site II bind either Na+ or K+; site III binds only Na+) are poorly understood. We studied cation selectivity by outward-facing sites (high K+ affinity) of Na/K pumps expressed in Xenopus oocytes, under voltage clamp. Guanidinium+, methylguanidinium+, and aminoguanidinium+ produced two phenomena possibly reflecting actions at site III: (i) voltage-dependent inhibition (VDI) of outwardly directed pump current at saturating K+, and (ii) induction of pump-mediated, guanidinium-derivative–carried inward current at negative potentials without Na+ and K+. In contrast, formamidinium+ and acetamidinium+ induced K+-like outward currents. Measurement of ouabain-sensitive ATPase activity and radiolabeled cation uptake confirmed that these cations are external K+ congeners. Molecular dynamics simulations indicate that bound organic cations induce minor distortion of the binding sites. Among tested metals, only Li+ induced Na+-like VDI, whereas all metals tested except Na+ induced K+-like outward currents. Pump-mediated K+-like organic cation transport challenges the concept of rigid structural models in which ion specificity at site I and site II arises from a precise and unique arrangement of coordinating ligands. Furthermore, actions by guanidinium+ derivatives suggest that Na+ binds to site III in a hydrated form and that the inward current observed without external Na+ and K+ represents cation transport when normal occlusion at sites I and II is impaired. These results provide insights on external ion selectivity at the three binding sites. PMID:20937860

Spin Dynamics in Novel Materials Systems

NASA Astrophysics Data System (ADS)

Yu, Howard

Spintronics and organic electronics are fields that have made considerable advances in recent years, both in fundamental research and in applications. Organic materials have a number of attractive properties that enable them to complement applications traditionally fulfilled by inorganic materials, while spintronics seeks to take advantage of the spin degree of freedom to produce new applications. My research is aimed at combining these two fields to develop organic materials for spintronics use. My thesis is divided into three primary projects centered around an organic-based semiconducting ferrimagnet, vanadium tetracyanoethylene. First, we investigated the transport characteristics of a hybrid organic-inorganic heterostructure. Semiconductors form the basis of the electronics industry, and there has been considerable effort put forward to develop organic semiconductors for applications like organic light-emitting diodes and organic thin film transistors. Working with hybrid organic-inorganic semiconductor device structures allows us to potentially take advantage of the infrastructure that has already been developed for silicon and other inorganic semiconductors. This could potentially pave the way for a new class of active hybrid devices with multifunctional behavior. Second, we investigated the magnetic resonance characteristics of V[TCNE]x, in multiple measurement schemes and exploring the effect of temperature, frequency, and chemical tuning. Recently, the spintronics community has shifted focus from static electrical spin injection to various dynamic processes, such as spin pumping and thermal effects. Spin pumping in particular is an intriguing way to generate pure spin currents via magnetic resonance that has attracted a high degree of interest, with the FMR linewidth being an important metric for spin injection. Furthermore, we can potentially use these measurements to probe the magnetic properties as we change the physical properties of the materials by chemically tuning the organic ligand. We are therefore interested in exploring the resonance properties of this materials system to lay the groundwork for future spin pumping applications. Third, we have made preliminary measurements of spin pumping in hybrid and all-organic bilayer structures. As mentioned above, FMR-driven spin pumping is method for generating pure spin currents with no associated charge motion. This can be detected in a number of ways, one of which is monitoring the FMR characteristics of two ferromagnets in close contact, where spins injected from one magnet into the other changes the linewidth. In conjunction with the magnetic resonance measurements, we have started to investigate the FMR properties of these bilayer systems.

Determinants of respiratory pump function in patients with cystic fibrosis.

PubMed

Dassios, Theodore

2015-01-01

Respiratory failure constitutes the major cause of morbidity and mortality in patients with Cystic Fibrosis (CF). Respiratory failure could either be due to lung parenchyma damage or to insufficiency of the respiratory pump which consists of the respiratory muscles, the rib cage and the neuromuscular transmission pathways. Airway obstruction, hyperinflation and malnutrition have been historically recognised as the major determinants of respiratory pump dysfunction in CF. Recent research has identified chronic infection, genetic predisposition, dietary and pharmaceutical interventions as possible additional determinants of this impairment. Furthermore, new methodological approaches in assessing respiratory pump function have led to a better understanding of the pathogenesis of respiratory pump failure in CF. Finally, respiratory muscle function could be partially preserved in CF patients with structured interventions such as aerobic exercise, inspiratory muscle training and non-invasive ventilation and CF patients could consequently be relatively protected from respiratory fatigue and respiratory failure. Copyright © 2014 Elsevier Ltd. All rights reserved.

Electrokinetic pump

DOEpatents

Patel, Kamlesh D.

2007-11-20

A method for altering the surface properties of a particle bed. In application, the method pertains particularly to an electrokinetic pump configuration where nanoparticles are bonded to the surface of the stationary phase to alter the surface properties of the stationary phase including the surface area and/or the zeta potential and thus improve the efficiency and operating range of these pumps. By functionalizing the nanoparticles to change the zeta potential the electrokinetic pump is rendered capable of operating with working fluids having pH values that can range from 2-10 generally and acidic working fluids in particular. For applications in which the pump is intended to handle highly acidic solutions latex nanoparticles that are quaternary amine functionalized can be used.

Physiological control of dual rotary pumps as a biventricular assist device using a master/slave approach.

PubMed

Stevens, Michael C; Wilson, Stephen; Bradley, Andrew; Fraser, John; Timms, Daniel

2014-09-01

Dual rotary left ventricular assist devices (LVADs) can provide biventricular mechanical support during heart failure. Coordination of left and right pump speeds is critical not only to avoid ventricular suction and to match cardiac output with demand, but also to ensure balanced systemic and pulmonary circulatory volumes. Physiological control systems for dual LVADs must meet these objectives across a variety of clinical scenarios by automatically adjusting left and right pump speeds to avoid catastrophic physiological consequences. In this study we evaluate a novel master/slave physiological control system for dual LVADs. The master controller is a Starling-like controller, which sets flow rate as a function of end-diastolic ventricular pressure (EDP). The slave controller then maintains a linear relationship between right and left EDPs. Both left/right and right/left master/slave combinations were evaluated by subjecting them to four clinical scenarios (rest, postural change, Valsalva maneuver, and exercise) simulated in a mock circulation loop. The controller's performance was compared to constant-rotational-speed control and two other dual LVAD control systems: dual constant inlet pressure and dual Frank-Starling control. The results showed that the master/slave physiological control system produced fewer suction events than constant-speed control (6 vs. 62 over a 7-min period). Left/right master/slave control had lower risk of pulmonary congestion than the other control systems, as indicated by lower maximum EDPs (15.1 vs. 25.2-28.4 mm Hg). During exercise, master/slave control increased total flow from 5.2 to 10.1 L/min, primarily due to an increase of left and right pump speed. Use of the left pump as the master resulted in fewer suction events and lower EDPs than when the right pump was master. Based on these results, master/slave control using the left pump as the master automatically adjusts pump speed to avoid suction and increases pump flow during exercise without causing pulmonary venous congestion. Copyright © 2014 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Diode-pumped Tunable 3 Micron Laser Sources

DTIC Science & Technology

2000-02-21

DoD Ballistic Missile Defense Organization U.S. Army Space and Missile Defense Command SBIR Phase I Final Report AC Materials, Inc. 2721 Forsyth...pumped tunable 3 micron laser sources 6. AUTHORISI Arlete Cassanho, Hans Jenssen 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) AC Materials, Inc...impurities in the final crystal, starting materials for the crystal growth were prepared at AC Materials from optical grade barium fluoride and

A blackbody radiation-pumped CO2 laser experiment

NASA Technical Reports Server (NTRS)

Christiansen, W. H.; Insuik, R. J.; Deyoung, R. J.

1982-01-01

Thermal radiation from a high temperature oven was used as an optical pump to achieve lasing from CO2 mixtures. Laser output as a function of blackbody temperature and gas conditions is described. This achievement represents the first blackbody cavity pumped laser and has potential for solar pumping.

Aqueous Polymer Dispersion Coating Used for Osmotic Pump Tablets: Membrane Property Investigation and IVIVC Evaluation.

PubMed

Cheng, Lizhen; Gai, Xiumei; Wen, Haoyang; Liu, Dandan; Tang, Xin; Wang, Yanyan; Wang, Tuanjie; Pan, Weisan; Yang, Xinggang

2018-01-01

The objective of this study was to investigate the fundamental properties of propranolol hydrochloride osmotic pump tablets coated by aqueous polymer dispersion, simultaneously exploring the in vitro and in vivo correlation of the tablet. The physicochemical properties and parameters of aqueous polymer dispersion membranes (SEM, water uptake, and water vapor transmission coefficient) were investigated. In addition, the release behavior and the in vitro release and in vivo absorption profiles of the tablets coated by aqueous polymer dispersion were investigated by comparing with propranolol hydrochloride osmotic pump tablets coated by an organic solvent. Results showed that the similarity factor (f 2 ) between cellulose acetate-coated tablet and Eudragit-coated tablet was 78.1, and f 2 between cellulose acetate-coated tablet and Kollicoat-coated tablet was 77.6. The linear IVIVC of Eudragit-coated and Kollicoat-coated osmotic pump tablets was determined, which confirmed excellent correlation between the absorption in vivo and the drug release in vitro. Consequently, the membrane coated by aqueous polymer dispersion or organic solvent has similar in vitro release rates of controlled release. Also, compared with organic solvent coating, aqueous polymer dispersion has numerous advantages, such as reduced toxicity and no environmental damage. Therefore, the aqueous polymer dispersion technology has enormous potential as a replacement of organic solvent coating.

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

Kisner, Roger A; Melin, Alexander M; Burress, Timothy A

The overall project objective is to demonstrate improved reliability and increased performance made possible by deeply embedding instrumentation and controls (I&C) in nuclear power plant components. The project is employing a highly instrumented canned rotor, magnetic bearing, fluoride salt pump as its I&C technology demonstration vehicle. The project s focus is not primarily on pump design, but instead is on methods to deeply embed I&C within a pump system. However, because the I&C is intimately part of the basic millisecond-by-millisecond functioning of the pump, the I&C design cannot proceed in isolation from the other aspects of the pump. The pumpmore » will not function if the characteristics of the I&C are not embedded within the design because the I&C enables performance of the basic function rather than merely monitoring quasi-stable performance. Traditionally, I&C has been incorporated in nuclear power plant (NPP) components after their design is nearly complete; adequate performance was obtained through over-design. This report describes the progress and status of the project and provides a conceptual design overview for the embedded I&C pump.« less

STEAM CARRYUNDER MEASUREMENT BY MEANS OF TWO-PHASE PUMP PERFORMANCE

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

Niemi, R.O.; Steamer, A.G.

1960-10-01

Pump tests were conducted at the Moss Landing Steam Separation Facility at operating pressures of 600 and 1000 psig to provide a method for determining the rate of steam carryunder. Pump power input and head were measured as functions of water flow and steam flow to the pump suction. The pump tested had a rated flow of 1700 gpm and a rated head of 148 feet. It was found that in this facility, steam carryander can be measured to 0.1% by measuring the recirculating water pump input power and Pump head. (auth)

Modeling our understanding of the His-Purkinje system.

PubMed

Vigmond, Edward J; Stuyvers, Bruno D

2016-01-01

The His-Purkinje System (HPS) is responsible for the rapid electric conduction in the ventricles. It relays electrical impulses from the atrioventricular node to the muscle cells and, thus, coordinates the contraction of ventricles in order to ensure proper cardiac pump function. The HPS has been implicated in the genesis of ventricular tachycardia and fibrillation as a source of ectopic beats, as well as forming distinct portions of reentry circuitry. Despite its importance, it remains much less well characterized, structurally and functionally, than the myocardium. Notably, important differences exist with regard to cell structure and electrophysiology, including ion channels, intracellular calcium handling, and gap junctions. Very few computational models address the HPS, and the majority of organ level modeling studies omit it. This review will provide an overview of our current knowledge of structure and function (including electrophysiology) of the HPS. We will review the most recent advances in modeling of the system from the single cell to the organ level, with considerations for relevant interspecies distinctions. Copyright © 2015 Elsevier Ltd. All rights reserved.

Biomimetics and the case of the remarkable ragworms.

PubMed

Hesselberg, Thomas

2007-08-01

Biomimetics is a rapidly growing field both as an academic and as an applied discipline. This paper gives a short introduction to the current status of the discipline before it describes three approaches to biomimetics: the mechanism-driven, which is based on the study of a specific mechanism; the focused organism-driven, which is based on the study of one function in a model organism; and the integrative organism-driven approach, where multiple functions of a model organism provide inspiration. The first two are established approaches and include many modern studies and the famous biomimetic discoveries of Velcro and the Lotus-Effect, whereas the last approach is not yet well recognized. The advantages of the integrative organism-driven approach are discussed using the ragworms as a case study. A morphological and locomotory study of these marine polychaetes reveals their biomimetic potential, which includes using their ability to move in slippery substrates as inspiration for novel endoscopes, using their compound setae as models for passive friction structures and using their three gaits, slow crawling, fast crawling, and swimming as well as their rapid burrowing technique to provide inspiration for the design of displacement pumps and multifunctional robots.

Biomimetics and the case of the remarkable ragworms

NASA Astrophysics Data System (ADS)

Hesselberg, Thomas

2007-08-01

Biomimetics is a rapidly growing field both as an academic and as an applied discipline. This paper gives a short introduction to the current status of the discipline before it describes three approaches to biomimetics: the mechanism-driven, which is based on the study of a specific mechanism; the focused organism-driven, which is based on the study of one function in a model organism; and the integrative organism-driven approach, where multiple functions of a model organism provide inspiration. The first two are established approaches and include many modern studies and the famous biomimetic discoveries of Velcro and the Lotus-Effect, whereas the last approach is not yet well recognized. The advantages of the integrative organism-driven approach are discussed using the ragworms as a case study. A morphological and locomotory study of these marine polychaetes reveals their biomimetic potential, which includes using their ability to move in slippery substrates as inspiration for novel endoscopes, using their compound setae as models for passive friction structures and using their three gaits, slow crawling, fast crawling, and swimming as well as their rapid burrowing technique to provide inspiration for the design of displacement pumps and multifunctional robots.

[Functional status of musculo-venous pump of shin in various types of of operations for varicose disease].

PubMed

Boítsov, N I; Evtikhov, R M; Potapov, N A

1997-01-01

Functional conditions of the muscular-venous pump of the shin were studied in 280 patients with varicose veins before surgery, in 164 patients in remote terms after various operations and in 54 healthy subjects on the base of guantitative plethysmographic estimation of hemodynamic parameters. At the stage of compensation all volume indices of the bloodflow were close to normal values; in the stage of decompensation the substantial increase of volume effectiveness and volume flow velocity was observed at carrying out the test for direct deep blood flow when walking. It was determined that in natural condition for venous hemodynamics the adaptation mechanisms of musculo-venous pump were not realized. The operation of Linton upsets the function of musculo-venous pump of the shin. The Kocket operation does not eliminate the pathologic overload when working due to insufficient radicalism in liquidation of perforation escape (steal phenomena). The subfascial ligation of perforating veins of the shin through the minor approach, used in clinical practice, proved to be sufficiently radical and does not impair the function of the musculo-venous pump of the shin.

The biological carbon pump in the ocean: Reviewing model representations and its feedbacks on climate perturbations.

NASA Astrophysics Data System (ADS)

Hülse, Dominik; Arndt, Sandra; Ridgwell, Andy; Wilson, Jamie

2016-04-01

The ocean-sediment system, as the biggest carbon reservoir in the Earth's carbon cycle, plays a crucial role in regulating atmospheric carbon dioxide concentrations and climate. Therefore, it is essential to constrain the importance of marine carbon cycle feedbacks on global warming and ocean acidification. Arguably, the most important single component of the ocean's carbon cycle is the so-called "biological carbon pump". It transports carbon that is fixed in the light-flooded surface layer of the ocean to the deep ocean and the surface sediment, where it is degraded/dissolved or finally buried in the deep sediments. Over the past decade, progress has been made in understanding different factors that control the efficiency of the biological carbon pump and their feedbacks on the global carbon cycle and climate (i.e. ballasting = ocean acidification feedback; temperature dependant organic matter degradation = global warming feedback; organic matter sulphurisation = anoxia/euxinia feedback). Nevertheless, many uncertainties concerning the interplay of these processes and/or their relative significance remain. In addition, current Earth System Models tend to employ empirical and static parameterisations of the biological pump. As these parametric representations are derived from a limited set of present-day observations, their ability to represent carbon cycle feedbacks under changing climate conditions is limited. The aim of my research is to combine past carbon cycling information with a spatially resolved global biogeochemical model to constrain the functioning of the biological pump and to base its mathematical representation on a more mechanistic approach. Here, I will discuss important aspects that control the efficiency of the ocean's biological carbon pump, review how these processes of first order importance are mathematically represented in existing Earth system Models of Intermediate Complexity (EMIC) and distinguish different approaches to approximate biogeochemical processes in the sediments. The performance of the respective mathematical representations in constraining the importance of carbon pump feedbacks on marine biogeochemical dynamics is then compared and evaluated under different extreme climate scenarios (e.g. OAE2, Eocene) using the Earth system model 'GENIE' and proxy records. The compiled mathematical descriptions and the model results underline the lack of a complete and mechanistic framework to represent the short-term carbon cycle in most EMICs which seriously limits the ability of these models to constrain the response of the ocean's carbon cycle to past and in particular future climate change. In conclusion, this presentation will critically evaluate the approaches currently used in marine biogeochemical modelling and outline key research directions concerning model development in the future.

Global patterns of organic carbon export and sequestration in the ocean (Arne Richter Award for Outstanding Young Scientists)

NASA Astrophysics Data System (ADS)

Henson, S.; Sanders, R.; Madsen, E.; Le Moigne, F.; Quartly, G.

2012-04-01

A major term in the global carbon cycle is the ocean's biological carbon pump which is dominated by sinking of small organic particles from the surface ocean to its interior. Here we examine global patterns in particle export efficiency (PEeff), the proportion of primary production that is exported from the surface ocean, and transfer efficiency (Teff), the fraction of exported organic matter that reaches the deep ocean. This is achieved through extrapolating from in situ estimates of particulate organic carbon export to the global scale using satellite-derived data. Global scale estimates derived from satellite data show, in keeping with earlier studies, that PEeff is high at high latitudes and low at low latitudes, but that Teff is low at high latitudes and high at low latitudes. However, in contrast to the relationship observed for deep biomineral fluxes in previous studies, we find that Teff is strongly negatively correlated with opal export flux from the upper ocean, but uncorrelated with calcium carbonate export flux. We hypothesise that the underlying factor governing the spatial patterns observed in Teff is ecosystem function, specifically the degree of recycling occurring in the upper ocean, rather than the availability of calcium carbonate for ballasting. Finally, our estimate of global integrated carbon export is only 50% of previous estimates. The lack of consensus amongst different methodologies on the strength of the biological carbon pump emphasises that our knowledge of a major planetary carbon flux remains incomplete.

On-pump versus off-pump coronary artery bypass graft surgery among patients with type 2 diabetes in the Bypass Angioplasty Revascularization Investigation 2 Diabetes trial†

PubMed Central

Singh, Ashima; Schaff, Hartzell V.; Mori Brooks, Maria; Hlatky, Mark A.; Wisniewski, Stephen R.; Frye, Robert L.; Sako, Edward Y.

2016-01-01

OBJECTIVES Conclusive evidence is lacking regarding the benefits and risks of performing off-pump versus on-pump coronary artery bypass graft (CABG) for patients with diabetes. This study aims to compare clinical outcomes after off-pump and on-pump procedures for patients with diabetes. METHODS The Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) trial enrolled patients with type 2 diabetes and documented coronary artery disease, 615 of whom underwent CABG during the trial. The procedural complications, 30-day outcomes, long-term clinical and functional outcomes were compared between the off-pump and on-pump groups overall and within a subset of patients matched on propensity score. RESULTS On-pump CABG was performed in 444 (72%) patients, and off-pump CABG in 171 (28%). The unadjusted 30-day rate of death/myocardial infarction (MI)/stroke was significantly higher after off-pump CABG (7.0 vs 2.9%, P = 0.02) despite fewer complications (10.3 vs 20.7%, P = 0.003). The long-term risk of death [adjusted hazard ratio (aHR): 1.41, P = 0.2197] and major cardiovascular events (death, MI or stroke) (aHR: 1.47, P = 0.1061) did not differ statistically between the off-pump and on-pump patients. Within the propensity-matched sample (153 pairs), patients who underwent off-pump CABG had a higher risk of the composite outcome of death, MI or stroke (aHR: 1.83, P = 0.046); the rates of procedural complications and death did not differ significantly, and there were no significant differences in the functional outcomes. CONCLUSIONS Patients with diabetes had greater risk of major cardiovascular events long-term after off-pump CABG than after on-pump CABG. PMID:25968885

Pump dependence of the dynamics of quantum dot based waveguide absorbers

NASA Astrophysics Data System (ADS)

Viktorov, Evgeny A.; Erneux, Thomas; Piwonski, Tomasz; Pulka, Jaroslaw; Huyet, Guillaume; Houlihan, John

2012-06-01

The nonlinear two stage recovery of quantum dot based reverse-biased waveguide absorbers is investigated experimentally and analytically as a function of the initial ground state occupation probability of the dot. The latter is controlled experimentally by the pump pulse power. The slow stage of the recovery is exponential and its basic timescale is independent of pump power. The fast stage of the recovery is a logistic function which we analyze in detail. The relative strength of slow to fast components is highlighted and the importance of higher order absorption processes at the highest pump level is demonstrated.

[When the heart and/or the lung fails: the ECMO].

PubMed

Giraud, R; Siegenthaler, N; Tassaux, D; Richard, J C M; Reverdin, S; Cikirikcioglu, M; Licker, M J; Bendjelid, K; Brochard, L

2011-12-14

The Extra corporeal membrane oxygenation (ECMO) was initially proposed as a technique of respiratory support using an external membrane oxygenator. With time, it has also become a technique of cardiorespiratory support to ensure both gas exchange and organ perfusion until the restoration of organs function. This technical assistance can be central or peripheral and provides a partial or total circulatory support. The circuit includes a non occlusive centrifugal pump, an oxygenator for an enrichment of O2 and elimination of CO2 and cannulas for drainage and re-injection. Recently, the establishment of such assistance became possible percutaneously, allowing it to be initiated at the intensive care bedside or even before in-hospital admission.

[The Elektronika UVI-01-N portable insulin pump (construction and method of use)].

PubMed

Sharikov, A N; Sklianik, A L

1990-01-01

The design and clinical applications of the first Soviet syringe portable insulin pump Electronica UV1 01 N are described. The technical characteristics and functional possibilities of the pump are discussed. The clinical results demonstrate good compensation for glucose metabolism by the insulin pump Electronica UV1 01 N.

Electrical pumping and tuning of exciton-polaritons in carbon nanotube microcavities

NASA Astrophysics Data System (ADS)

Graf, Arko; Held, Martin; Zakharko, Yuriy; Tropf, Laura; Gather, Malte C.; Zaumseil, Jana

2017-09-01

Exciton-polaritons are hybrid light-matter particles that form upon strong coupling of an excitonic transition to a cavity mode. As bosons, polaritons can form condensates with coherent laser-like emission. For organic materials, optically pumped condensation was achieved at room temperature but electrically pumped condensation remains elusive due to insufficient polariton densities. Here we combine the outstanding optical and electronic properties of purified, solution-processed semiconducting (6,5) single-walled carbon nanotubes (SWCNTs) in a microcavity-integrated light-emitting field-effect transistor to realize efficient electrical pumping of exciton-polaritons at room temperature with high current densities (>10 kA cm-2) and tunability in the near-infrared (1,060 nm to 1,530 nm). We demonstrate thermalization of SWCNT polaritons, exciton-polariton pumping rates ~104 times higher than in current organic polariton devices, direct control over the coupling strength (Rabi splitting) via the applied gate voltage, and a tenfold enhancement of polaritonic over excitonic emission. This powerful material-device combination paves the way to carbon-based polariton emitters and possibly lasers.

Exercise physiology in chronic mechanical circulatory support patients: vascular function and beyond.

PubMed

Hayward, Christopher S; Fresiello, Libera; Meyns, Bart

2016-05-01

The majority of patients currently implanted with left ventricular assist devices have the expectation of support for more than 2 years. As a result, survival alone is no longer a sufficient distinctive for this technology, and there have been many studies within the last few years examining functional capacity and exercise outcomes. Despite strong evidence for functional class improvements and increases in simple measures of walking distance, there remains incomplete normalization of exercise capacity, even in the presence of markedly improved resting hemodynamics. Reasons for this remain unclear. Despite current pumps being run at a fixed speed, it is widely recognized that pump outputs significantly increase with exercise. The mechanism of this increase involves the interaction between preload, afterload, and the intrinsic pump function curves. The role of the residual heart function is also important in determining total cardiac output, as well as whether the aortic valve opens with exercise. Interactions with the vasculature, with skeletal muscle blood flow and the state of the autonomic nervous system are also likely to be important contributors to exercise performance. Further studies examining optimization of pump function with active pump speed modulation and options for optimization of the overall patient condition are likely to be needed to allow left ventricular assist devices to be used with the hope of full functional physiological recovery.

Nanoparticles as Efflux Pump and Biofilm Inhibitor to Rejuvenate Bactericidal Effect of Conventional Antibiotics

NASA Astrophysics Data System (ADS)

Gupta, Divya; Singh, Ajeet; Khan, Asad U.

2017-07-01

The universal problem of bacterial resistance to antibiotic reflects a serious threat for physicians to control infections. Evolution in bacteria results in the development of various complex resistance mechanisms to neutralize the bactericidal effect of antibiotics, like drug amelioration, target modification, membrane permeability reduction, and drug extrusion through efflux pumps. Efflux pumps acquire a wide range of substrate specificity and also the tremendous efficacy for drug molecule extrusion outside bacterial cells. Hindrance in the functioning of efflux pumps may rejuvenate the bactericidal effect of conventional antibiotics. Efflux pumps also play an important role in the exclusion or inclusion of quorum-sensing biomolecules responsible for biofilm formation in bacterial cells. This transit movement of quorum-sensing biomolecules inside or outside the bacterial cells may get interrupted by impeding the functioning of efflux pumps. Metallic nanoparticles represent a potential candidate to block efflux pumps of bacterial cells. The application of nanoparticles as efflux pump inhibitors will not only help to revive the bactericidal effect of conventional antibiotics but will also assist to reduce biofilm-forming capacity of microbes. This review focuses on a novel and fascinating application of metallic nanoparticles in synergy with conventional antibiotics for efflux pump inhibition.

Theory of a peristaltic pump for fermionic quantum fluids

NASA Astrophysics Data System (ADS)

Romeo, F.; Citro, R.

2018-05-01

Motivated by the recent developments in fermionic cold atoms and in nanostructured systems, we propose the model of a peristaltic quantum pump. Differently from the Thouless paradigm, a peristaltic pump is a quantum device that generates a particle flux as the effect of a sliding finite-size microlattice. A one-dimensional tight-binding Hamiltonian model of this quantum machine is formulated and analyzed within a lattice Green's function formalism on the Keldysh contour. The pump observables, as, e.g., the pumped particles per cycle, are studied as a function of the pumping frequency, the width of the pumping potential, the particles mean free path, and system temperature. The proposed analysis applies to arbitrary peristaltic potentials acting on fermionic quantum fluids confined to one dimension. These confinement conditions can be realized in nanostructured systems or, in a more controllable way, in cold atoms experiments. In view of the validation of the theoretical results, we describe the outcomes of the model considering a fermionic cold atoms system as a paradigmatic example.

Tracking metal ions through a Cu/Ag efflux pump assigns the functional roles of the periplasmic proteins

DOE PAGES

Chacon, Kelly N.; Mealman, Tiffany D.; McEvoy, Megan M.; ...

2014-10-13

Copper is an essential nutrient for all aerobic organisms but is toxic in excess. At the host–pathogen interface, macrophages respond to bacterial infection by copper-dependent killing mechanisms, whereas the invading bacteria are thought to counter with an up-regulation of copper transporters and efflux pumps. The tripartite efflux pump CusCBA and its metallochaperone CusF are vital to the detoxification of copper and silver ions in the periplasm of Escherichia coli. However, the mechanism of efflux by this complex, which requires the activation of the inner membrane pump CusA, is poorly understood. In this paper, we use selenomethionine (SeM) active site labelsmore » in a series of biological X-ray absorption studies at the selenium, copper, and silver edges to establish a “switch” role for the membrane fusion protein CusB. We determine that metal-bound CusB is required for activation of cuprous ion transfer from CusF directly to a site in the CusA antiporter, showing for the first time (to our knowledge) the in vitro activation of the Cus efflux pump. This metal-binding site of CusA is unlike that observed in the crystal structures of the CusA protein and is composed of one oxygen and two sulfur ligands. Finally, our results suggest that metal transfer occurs between CusF and apo-CusB, and that, when metal-loaded, CusB plays a role in the regulation of metal ion transfer from CusF to CusA in the periplasm.« less

Tracking metal ions through a Cu/Ag efflux pump assigns the functional roles of the periplasmic proteins.

PubMed

Chacón, Kelly N; Mealman, Tiffany D; McEvoy, Megan M; Blackburn, Ninian J

2014-10-28

Copper is an essential nutrient for all aerobic organisms but is toxic in excess. At the host-pathogen interface, macrophages respond to bacterial infection by copper-dependent killing mechanisms, whereas the invading bacteria are thought to counter with an up-regulation of copper transporters and efflux pumps. The tripartite efflux pump CusCBA and its metallochaperone CusF are vital to the detoxification of copper and silver ions in the periplasm of Escherichia coli. However, the mechanism of efflux by this complex, which requires the activation of the inner membrane pump CusA, is poorly understood. Here, we use selenomethionine (SeM) active site labels in a series of biological X-ray absorption studies at the selenium, copper, and silver edges to establish a "switch" role for the membrane fusion protein CusB. We determine that metal-bound CusB is required for activation of cuprous ion transfer from CusF directly to a site in the CusA antiporter, showing for the first time (to our knowledge) the in vitro activation of the Cus efflux pump. This metal-binding site of CusA is unlike that observed in the crystal structures of the CusA protein and is composed of one oxygen and two sulfur ligands. Our results suggest that metal transfer occurs between CusF and apo-CusB, and that, when metal-loaded, CusB plays a role in the regulation of metal ion transfer from CusF to CusA in the periplasm.

The oceanic biological pump modulates the atmospheric transport of persistent organic pollutants to the Arctic.

PubMed

Galbán-Malagón, Cristóbal; Berrojalbiz, Naiara; Ojeda, María-José; Dachs, Jordi

2012-05-29

Semivolatile persistent organic pollutants have the potential to reach remote environments, such as the Arctic Ocean, through atmospheric transport and deposition. Here we show that this transport of polychlorinated biphenyls to the Arctic Ocean is strongly retarded by the oceanic biological pump. A simultaneous sampling of atmospheric, seawater and plankton samples was performed in July 2007 in the Greenland Current and Atlantic sector of the Arctic Ocean. The atmospheric concentrations declined during atmospheric transport over the Greenland Current with estimated half-lives of 1-4 days. These short half-lives can be explained by the high air-to-water net diffusive flux, which is similar in magnitude to the estimated settling fluxes in the water column. Therefore, the decrease of atmospheric concentrations is due to sequestration of atmospheric polychlorinated biphenyls by enhanced air-water diffusive fluxes driven by phytoplankton uptake and organic carbon settling fluxes (biological pump).

Microfluidic Pumps Containing Teflon [Trademark] AF Diaphragms

NASA Technical Reports Server (NTRS)

Willis, Peter; White, Victor; Grunthaner, Frank; Ikeda, Mike; Mathies, Richard A.

2009-01-01

Microfluidic pumps and valves based on pneumatically actuated diaphragms made of Teflon AF polymers are being developed for incorporation into laboratory-on-a-chip devices that must perform well over temperature ranges wider than those of prior diaphragm-based microfluidic pumps and valves. Other potential applications include implanted biomedical microfluidic devices, wherein the biocompatability of Teflon AF polymers would be highly advantageous. These pumps and valves have been demonstrated to function stably after cycling through temperatures from -125 to 120 C. These pumps and valves are intended to be successors to similar prior pumps and valves containing diaphragms made of polydimethylsiloxane (PDMS) [commonly known as silicone rubber]. The PDMS-containing valves ae designed to function stably only within the temperature range from 5 to 80 C. Undesirably, PDMS membranes are somwehat porous and retain water. PDMS is especially unsuitable for use at temperatures below 0 C because the formation of ice crystals increases porosity and introduces microshear.

The added value of impedance-pH monitoring to Rome III criteria in distinguishing functional heartburn from non-erosive reflux disease.

PubMed

Savarino, Edoardo; Marabotto, Elisa; Zentilin, Patrizia; Frazzoni, Marzio; Sammito, Giorgio; Bonfanti, Daria; Sconfienza, Luca; Assandri, Lorenzo; Gemignani, Lorenzo; Malesci, Alberto; Savarino, Vincenzo

2011-07-01

Functional heartburn is defined by Rome III criteria as an endoscopy-negative condition with normal oesophageal acid exposure time, negative symptom association to acid reflux and unsatisfactory response to proton pump inhibitors. These criteria underestimated the role of non-acid reflux. To assess the contribution of impedance-pH with symptom association probability (SAP) analysis in identifying endoscopy-negative patients with reflux disease and separating them from functional heartburn. Consecutive endoscopy-negative patients treated with proton pump inhibitors (n=219) undergoing impedance-pH monitoring off-therapy were analysed. Distal acid exposure time, reflux episodes, SAP and symptomatic response to proton pump inhibitors were measured. Based on impedance-pH/SAP, 67 (31%) patients were pH+/SAP+, 6 (2%) pH+/SAP-, 83 (38%) hypersensitive oesophagus and 63 (29%) functional heartburn. According to pH-metry alone/response to proton pump inhibitors, 62 (28%) were pH+/SAP+, 11 (5%) pH+/SAP-, 61 (28%) hypersensitive oesophagus and 85 (39%) functional heartburn. In the normal-acid exposure population the contribution of impedance-pH/SAP compared to pH-metry alone/response to proton pump inhibitors in identifying patients with reflux disease and functional heartburn resulted to be 10%. In patients with abnormal-acid exposure, the contribution of impedance-pH/SAP increased by 3%. Comparing impedance-pH testing with pH-metry alone plus the response to proton pump inhibitor therapy demonstrated that the latter ones cause underestimation of reflux disease patients and overestimation of functional heartburn patients. Copyright © 2011 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

Enhancement of survival and electricity production in an engineered bacterium by light-driven proton pumping.

PubMed

Johnson, Ethan T; Baron, Daniel B; Naranjo, Belén; Bond, Daniel R; Schmidt-Dannert, Claudia; Gralnick, Jeffrey A

2010-07-01

Microorganisms can use complex photosystems or light-dependent proton pumps to generate membrane potential and/or reduce electron carriers to support growth. The discovery that proteorhodopsin is a light-dependent proton pump that can be expressed readily in recombinant bacteria enables development of new strategies to probe microbial physiology and to engineer microbes with new light-driven properties. Here, we describe functional expression of proteorhodopsin and light-induced changes in membrane potential in the bacterium Shewanella oneidensis strain MR-1. We report that there were significant increases in electrical current generation during illumination of electrochemical chambers containing S. oneidensis expressing proteorhodopsin. We present evidence that an engineered strain is able to consume lactate at an increased rate when it is illuminated, which is consistent with the hypothesis that proteorhodopsin activity enhances lactate uptake by increasing the proton motive force. Our results demonstrate that there is coupling of a light-driven process to electricity generation in a nonphotosynthetic engineered bacterium. Expression of proteorhodopsin also preserved the viability of the bacterium under nutrient-limited conditions, providing evidence that fulfillment of basic energy needs of organisms may explain the widespread distribution of proteorhodopsin in marine environments.

Electric field-decoupled electroosmotic pump for microfluidic devices.

PubMed

Liu, Shaorong; Pu, Qiaosheng; Lu, Joann J

2003-09-26

An electric field-free electroosmotic pump has been constructed and its pumping rate has been measured under various experimental conditions. The key component of the pump is an ion-exchange membrane grounding joint that serves two major functions: (i) to maintain fluid continuity between pump channels and microfluidic conduit and (ii) to ground the solution in the microfluidic channel at the joint through an external electrode, and hence to decouple the electric field applied to the pump channels from the rest of the microfluidic system. A theoretical model has been developed to calculate the pumping rates and its validity has been demonstrated.

Carbon fluxes in the Arabian Sea: Export versus recycling

NASA Astrophysics Data System (ADS)

Rixen, Tim; Gaye, Birgit; Ramaswamy, Venkitasubramani

2016-04-01

The organic carbon pump strongly influences the exchange of carbon between the ocean and the atmosphere. It is known that it responds to global change but the magnitude and the direction of change are still unpredictable. Sediment trap experiments carried out at various sites in the Arabian Sea between 1986 and 1998 have shown differences in the functioning of the organic carbon pump (OCP). An OCP driven by eukaryotic phytoplankton operated in the upwelling region off Oman and during the spring bloom in the northern Arabian Sea. Cyanobacteria capable of fixing nitrogen seem to dominate the phytoplankton community during all other seasons. The export driven by cyanobacteria was much lower than the export driven by eukaryotic phytoplankton. Productivity and nutrient availability seems to be a main factor controlling fluxes during blooms of eukaryotic phytoplankton. The ballast effect caused by inputs of dust into the ocean and its incorporation into sinking particles seems to be the main factor controlling the export during times when cyanobacteria dominate the phytoplankton community. C/N ratios of organic matter exported from blooms dominated by nitrogen fixing cyanobacteria are enhanced and, furthermore, indicate a more efficient recycling of nutrients at shallower water depth. This implies that the bacterial-driven OCP operates more in a recycling mode that keeps nutrients closer to the euphotic zone whereas the OCP driven by eukaryotic phytoplankton reduces the recycling of nutrients by exporting them into greater water-depth.

Engineering challenges for instrumenting and controlling integrated organ-on-chip systems.

PubMed

Wikswo, John P; Block, Frank E; Cliffel, David E; Goodwin, Cody R; Marasco, Christina C; Markov, Dmitry A; McLean, David L; McLean, John A; McKenzie, Jennifer R; Reiserer, Ronald S; Samson, Philip C; Schaffer, David K; Seale, Kevin T; Sherrod, Stacy D

2013-03-01

The sophistication and success of recently reported microfabricated organs-on-chips and human organ constructs have made it possible to design scaled and interconnected organ systems that may significantly augment the current drug development pipeline and lead to advances in systems biology. Physiologically realistic live microHuman (μHu) and milliHuman (mHu) systems operating for weeks to months present exciting and important engineering challenges such as determining the appropriate size for each organ to ensure appropriate relative organ functional activity, achieving appropriate cell density, providing the requisite universal perfusion media, sensing the breadth of physiological responses, and maintaining stable control of the entire system, while maintaining fluid scaling that consists of ~5 mL for the mHu and ~5 μL for the μHu. We believe that successful mHu and μHu systems for drug development and systems biology will require low-volume microdevices that support chemical signaling, microfabricated pumps, valves and microformulators, automated optical microscopy, electrochemical sensors for rapid metabolic assessment, ion mobility-mass spectrometry for real-time molecular analysis, advanced bioinformatics, and machine learning algorithms for automated model inference and integrated electronic control. Toward this goal, we are building functional prototype components and are working toward top-down system integration.

[Artificial heart--turbo type blood pump for long-term use].

PubMed

Akamatsu, Teruaki

2003-05-01

Shortage of donor heart for transplantation necessitates long-term artificial assist heart. Turbo-pump is smaller, simpler and cheaper than the pulsatile displacement type pump, but the turbo-pump has defect of thrombus formation at the shaft seal. Our centrifugal pump with magnetically suspended impellers overcomes this defect and is ready for clinical trials now. The structures and functions are described and are compared with the other newly-developed pump of the same kinds with us. And also the pumps of centrifugal type and axial-type, of which impellers are supported by pivots, are reviewed briefly from the stand point for long-term use. Other pumps are referred too: pumps with hydrodynamic bearing and a pump with the shaft seal which is washed and cooled by saline solution.

Quantification of Na+,K+ pumps and their transport rate in skeletal muscle: Functional significance

PubMed Central

2013-01-01

During excitation, muscle cells gain Na+ and lose K+, leading to a rise in extracellular K+ ([K+]o), depolarization, and loss of excitability. Recent studies support the idea that these events are important causes of muscle fatigue and that full use of the Na+,K+-ATPase (also known as the Na+,K+ pump) is often essential for adequate clearance of extracellular K+. As a result of their electrogenic action, Na+,K+ pumps also help reverse depolarization arising during excitation, hyperkalemia, and anoxia, or from cell damage resulting from exercise, rhabdomyolysis, or muscle diseases. The ability to evaluate Na+,K+-pump function and the capacity of the Na+,K+ pumps to fill these needs require quantification of the total content of Na+,K+ pumps in skeletal muscle. Inhibition of Na+,K+-pump activity, or a decrease in their content, reduces muscle contractility. Conversely, stimulation of the Na+,K+-pump transport rate or increasing the content of Na+,K+ pumps enhances muscle excitability and contractility. Measurements of [3H]ouabain binding to skeletal muscle in vivo or in vitro have enabled the reproducible quantification of the total content of Na+,K+ pumps in molar units in various animal species, and in both healthy people and individuals with various diseases. In contrast, measurements of 3-O-methylfluorescein phosphatase activity associated with the Na+,K+-ATPase may show inconsistent results. Measurements of Na+ and K+ fluxes in intact isolated muscles show that, after Na+ loading or intense excitation, all the Na+,K+ pumps are functional, allowing calculation of the maximum Na+,K+-pumping capacity, expressed in molar units/g muscle/min. The activity and content of Na+,K+ pumps are regulated by exercise, inactivity, K+ deficiency, fasting, age, and several hormones and pharmaceuticals. Studies on the α-subunit isoforms of the Na+,K+-ATPase have detected a relative increase in their number in response to exercise and the glucocorticoid dexamethasone but have not involved their quantification in molar units. Determination of ATPase activity in homogenates and plasma membranes obtained from muscle has shown ouabain-suppressible stimulatory effects of Na+ and K+. PMID:24081980

Interchangeability of gas detection tubes and hand pumps.

PubMed

Haag, W R

2001-01-01

Users of gas detection tubes occasionally seek the convenience of using a single hand pump with different brands of tubes, to avoid the need to carry more than one pump. Several professional organizations recommend against such interchange. However, these recommendations appear to be based on a single study of pump designs that mostly are no longer in use. The present study was undertaken to determine if current hand pumps are interchangeable. Both piston-type and bellows-type hand pumps were evaluated by comparing pump flow profiles and test gas measurements with a variety of tubes. The results demonstrate that three piston hand pumps in common use (Sensidyne/Gastec GV/100, RAE Systems LP-1200, and Matheson-Kitagawa 8104-400A) are fully interchangeable. Two bellows pumps (Draeger Accuro and MSA Kwik-Draw) also are interchangeable with each other. Mixing of bellows and piston systems is often possible, but there are enough exceptions to conclude that such practice should be discouraged because it can give inaccurate readings. It is recommended that technical standards be adopted, such as total volume and an initial pump vacuum or a pump flow curve, to assess hand pump interchangeability. When two manufacturers' pumps meet the same standard and routine leak tests are conducted, interchangeability is scientifically valid and poses no risk to the end user while offering greater convenience.

The export and fate of organic matter in the ocean: New constraints from combining satellite and oceanographic tracer observations

NASA Astrophysics Data System (ADS)

DeVries, Tim; Weber, Thomas

2017-03-01

The ocean's biological pump transfers carbon from the surface euphotic zone into the deep ocean, reducing the atmospheric CO2 concentration. Despite its climatic importance, there are large uncertainties in basic metrics of the biological pump. Previous estimates of the strength of the biological pump, as measured by the amount of organic carbon exported from the euphotic zone, range from about 4 to 12 Pg C yr-1. The fate of exported carbon, in terms of how efficiently it is transferred into the deep ocean, is even more uncertain. Here we present a new model of the biological pump that assimilates satellite and oceanographic tracer observations to constrain rates and patterns of organic matter production, export, and remineralization in the ocean. The data-assimilated model predicts a global particulate organic carbon (POC) flux out of the euphotic zone of ˜9 Pg C yr-1. The particle export ratio (the ratio of POC export to net primary production) is highest at high latitudes and lowest at low latitudes, but low-latitude export is greater than predicted by previous models, in better agreement with observed patterns of long-term carbon export. Particle transfer efficiency (Teff) through the mesopelagic zone is controlled by temperature and oxygen, with highest Teff for high-latitude regions and oxygen minimum zones. In contrast, Teff in the deep ocean (below 1000 m) is controlled by particle sinking speed, with highest deep ocean Teff below the subtropical gyres. These results emphasize the utility of both remote sensing and oceanographic tracer observations for constraining the operation of the biological pump.

40 CFR 90.424 - Dilute sampling procedures-CVS calibration.

Code of Federal Regulations, 2012 CFR

2012-07-01

.... Air temperature at CVS pump inlet PTI °C ±1.11 °C. Pressure depression at CVS pump inlet PPI kPa ±0... pump inlet depression that will yield a minimum of six data points for the total calibration. Allow the...: PB = barometric pressure, kPa PPI = Pump inlet depression, kPa. (iii) The correlation function at...

40 CFR 90.424 - Dilute sampling procedures-CVS calibration.

Code of Federal Regulations, 2014 CFR

2014-07-01

.... Air temperature at CVS pump inlet PTI °C ±1.11 °C. Pressure depression at CVS pump inlet PPI kPa ±0... pump inlet depression that will yield a minimum of six data points for the total calibration. Allow the...: PB = barometric pressure, kPa PPI = Pump inlet depression, kPa. (iii) The correlation function at...

40 CFR 90.424 - Dilute sampling procedures-CVS calibration.

Code of Federal Regulations, 2010 CFR

2010-07-01

.... Air temperature at CVS pump inlet PTI °C ±1.11 °C. Pressure depression at CVS pump inlet PPI kPa ±0... pump inlet depression that will yield a minimum of six data points for the total calibration. Allow the...: PB = barometric pressure, kPa PPI = Pump inlet depression, kPa. (iii) The correlation function at...

40 CFR 90.424 - Dilute sampling procedures-CVS calibration.

Code of Federal Regulations, 2013 CFR

2013-07-01

.... Air temperature at CVS pump inlet PTI °C ±1.11 °C. Pressure depression at CVS pump inlet PPI kPa ±0... pump inlet depression that will yield a minimum of six data points for the total calibration. Allow the...: PB = barometric pressure, kPa PPI = Pump inlet depression, kPa. (iii) The correlation function at...

40 CFR 90.424 - Dilute sampling procedures-CVS calibration.

Code of Federal Regulations, 2011 CFR

2011-07-01

.... Air temperature at CVS pump inlet PTI °C ±1.11 °C. Pressure depression at CVS pump inlet PPI kPa ±0... pump inlet depression that will yield a minimum of six data points for the total calibration. Allow the...: PB = barometric pressure, kPa PPI = Pump inlet depression, kPa. (iii) The correlation function at...

Efflux-Mediated Drug Resistance in Bacteria: an Update

PubMed Central

Li, Xian-Zhi; Nikaido, Hiroshi

2010-01-01

Drug efflux pumps play a key role in drug resistance and also serve other functions in bacteria. There has been a growing list of multidrug and drug-specific efflux pumps characterized from bacteria of human, animal, plant and environmental origins. These pumps are mostly encoded on the chromosome although they can also be plasmid-encoded. A previous article (Li X-Z and Nikaido H, Drugs, 2004; 64[2]: 159–204) had provided a comprehensive review regarding efflux-mediated drug resistance in bacteria. In the past five years, significant progress has been achieved in further understanding of drug resistance-related efflux transporters and this review focuses on the latest studies in this field since 2003. This has been demonstrated in multiple aspects that include but are not limited to: further molecular and biochemical characterization of the known drug efflux pumps and identification of novel drug efflux pumps; structural elucidation of the transport mechanisms of drug transporters; regulatory mechanisms of drug efflux pumps; determining the role of the drug efflux pumps in other functions such as stress responses, virulence and cell communication; and development of efflux pump inhibitors. Overall, the multifaceted implications of drug efflux transporters warrant novel strategies to combat multidrug resistance in bacteria. PMID:19678712

Simplified thermodynamic functions for vapor-liquid phase separation and fountain effect pumps

NASA Technical Reports Server (NTRS)

Yuan, S. W. K.; Hepler, W. A.; Frederking, T. H. K.

1984-01-01

He-4 fluid handling devices near 2 K require novel components for non-Newtonian fluid transport in He II. Related sizing of devices has to be based on appropriate thermophysical property functions. The present paper presents simplified equilibrium state functions for porous media components which serve as vapor-liquid phase separators and fountain effect pumps.

Organization of the Topical Meeting on Tunable Solid State Lasers Held in North Falmouth, Massachusetts on 1-3 May 1989

DTIC Science & Technology

1989-08-30

nm to produce blue light at 455 nm (Figure 1). A 20 Hz doubled Nd:YAG pump laser emitting up to 150 mJ at 532 nm 147 WA4-2 was used to resonantly...pumped by a diode laser, then in addition to the processes of Fig. 1, excited state absorption of the pump light from both 4I13,/z and 4I3112 may be...are visible and UV systems pumped at wavelengths that are available from semiconductor diode lasers and infrared emitting systems having high slope

AN EVALUATION OF PERSONAL SAMPLING PUMPS IN SUB-ZERO TEMPERATURES

EPA Science Inventory

Personal sampling pumps suitable for industrial hygiene surveys were evaluated to discover their characteristics as a function of temperature for temperatures between 25 and -50C. The pumps evaluated were significantly influenced by low temperatures. In general, most provided a s...

Terahertz Optical Gain Based on Intersubband Transitions in Optically-Pumped Semiconductor Quantum Wells: Coherent Pumped-Probe Interactions

NASA Technical Reports Server (NTRS)

Liu, Ansheng; Ning, Cun-Zheng

1999-01-01

Terahertz optical gain due to intersubband transitions in optically-pumped semiconductor quantum wells (QW's) is calculated nonperturbatively. We solve the pump- field-induced nonequilibrium distribution function for each subband of the QW system from a set of rate equations that include both intrasubband and intersubband relaxation processes. The gain arising from population inversion and stimulated Raman processes is calculated in a unified manner. We show that the coherent pump and signal wave interactions contribute significantly to the THz gain. Because of the optical Stark effect and pump-induced population redistribution, optical gain saturation at larger pump intensities is predicted.

Environmental DNA sampling protocol - filtering water to capture DNA from aquatic organisms

USGS Publications Warehouse

Laramie, Matthew B.; Pilliod, David S.; Goldberg, Caren S.; Strickler, Katherine M.

2015-09-29

Environmental DNA (eDNA) analysis is an effective method of determining the presence of aquatic organisms such as fish, amphibians, and other taxa. This publication is meant to guide researchers and managers in the collection, concentration, and preservation of eDNA samples from lentic and lotic systems. A sampling workflow diagram and three sampling protocols are included as well as a list of suggested supplies. Protocols include filter and pump assembly using: (1) a hand-driven vacuum pump, ideal for sample collection in remote sampling locations where no electricity is available and when equipment weight is a primary concern; (2) a peristaltic pump powered by a rechargeable battery-operated driver/drill, suitable for remote sampling locations when weight consideration is less of a concern; (3) a 120-volt alternating current (AC) powered peristaltic pump suitable for any location where 120-volt AC power is accessible, or for roadside sampling locations. Images and detailed descriptions are provided for each step in the sampling and preservation process.

A microfluidic two-pump system inspired by liquid feeding in mosquitoes

NASA Astrophysics Data System (ADS)

Marino, Andrew; Goad, Angela; Stremler, Mark; Socha, John; Jung, Sunghwan

Mosquitoes feed on nectar and blood using a two-pump system in the head-a smaller cibarial pump in line with a larger a pharyngeal pump, with a valve in between. To suck, mosquitoes transport the liquid (which may be a multi-component viscous fluid, blood) through a long micro-channel, the proboscis. In the engineering realm, microfluidic devices in biomedical applications, such as lab-on-a-chip technology, necessitate implementing a robust pump design to handle clogging and increase flow control compared to a single-pump system. In this talk, we introduce a microfluidic pump design inspired by the mosquito's two-pump system. The pumping performance (flow rate) in presence of impurities (air bubbles, soft clogs) is quantified as a function of phase difference and volume expansion of the pumps, and the elasticity of the valve.

Functional Relationships between the AcrA Hairpin Tip Region and the TolC Aperture Tip Region for the Formation of the Bacterial Tripartite Efflux Pump AcrAB-TolC ▿ † ‡

PubMed Central

Kim, Hong-Man; Xu, Yongbin; Lee, Minho; Piao, Shunfu; Sim, Se-Hoon; Ha, Nam-Chul; Lee, Kangseok

2010-01-01

Tripartite efflux pumps found in Gram-negative bacteria are involved in antibiotic resistance and toxic-protein secretion. In this study, we show, using site-directed mutational analyses, that the conserved residues located in the tip region of the α-hairpin of the membrane fusion protein (MFP) AcrA play an essential role in the action of the tripartite efflux pump AcrAB-TolC. In addition, we provide in vivo functional data showing that both the length and the amino acid sequence of the α-hairpin of AcrA can be flexible for the formation of a functional AcrAB-TolC pump. Genetic-complementation experiments further indicated functional interrelationships between the AcrA hairpin tip region and the TolC aperture tip region. Our findings may offer a molecular basis for understanding the multidrug resistance of pathogenic bacteria. PMID:20581201

Tubular Heart Pumping Mechanisms in Ciona Intestinalis

NASA Astrophysics Data System (ADS)

Battista, Nicholas; Miller, Laura

2015-11-01

In vertebrate embryogenesis, the first organ to form is the heart, beginning as a primitive heart tube. However, many invertebrates have tubular hearts from infancy through adulthood. Heart tubes have been described as peristaltic and impedance pumps. Impedance pumping assumes a single actuation point of contraction, while traditional peristalsis assumes a traveling wave of actuation. In addition to differences in flow, this inherently implies differences in the conduction system. It is possible to transition from pumping mechanism to the other with a change in the diffusivity of the action potential. In this work we consider the coupling between the fluid dynamics and electrophysiology of both mechanisms, within a basal chordate, the tunicate. Using CFD with a neuro-mechanical model of tubular pumping, we discuss implications of the both mechanisms. Furthermore, we discuss the implications of the pumping mechanism on evolution and development.

Semianalytical model predicting transfer of volatile pollutants from groundwater to the soil surface.

PubMed

Atteia, Olivier; Höhener, Patrick

2010-08-15

Volatilization of toxic organic contaminants from groundwater to the soil surface is often considered an important pathway in risk analysis. Most of the risk models use simplified linear solutions that may overpredict the volatile flux. Although complex numerical models have been developed, their use is restricted to experienced users and for sites where field data are known in great detail. We present here a novel semianalytical model running on a spreadsheet that simulates the volatilization flux and vertical concentration profile in a soil based on the Van Genuchten functions. These widely used functions describe precisely the gas and water saturations and movement in the capillary fringe. The analytical model shows a good accuracy over several orders of magnitude when compared to a numerical model and laboratory data. The effect of barometric pumping is also included in the semianalytical formulation, although the model predicts that barometric pumping is often negligible. A sensitivity study predicts significant fluxes in sandy vadose zones and much smaller fluxes in other soils. Fluxes are linked to the dimensionless Henry's law constant H for H < 0.2 and increase by approximately 20% when temperature increases from 5 to 25 degrees C.

Conjugated polymer-titania nanoparticle hybrid films: random lasing action and ultrasensitive detection of explosive vapors.

PubMed

Deng, Changmin; He, Qingguo; He, Chao; Shi, Liqi; Cheng, Jiangong; Lin, Tong

2010-04-08

We have first demonstrated that a random laser action generated by a hybrid film composed of a semiconducting organic polymer (SOP) and TiO(2) nanoparticles can be used to detect 2,4,6-trinitrotoluene (TNT) vapors. The hybrid film was fabricated by spin-casting SOP solution dispersed with nanosized TiO(2) particles on quartz glass. The SOP in the hybrid film functioned as both the gain medium and the sensory transducer. A random lasing action was observed with a certain pump power when the size (diameter of 50 nm) and concentration (8.9 x 10(12)/cm(3)) of TiO(2) nanoparticles were optimized. Measurements of fluorescence quenching behavior of the hybrid film in TNT vapor atmosphere (10 ppb) showed that attenuated lasing in optically pumped hybrid film displayed a sensitivity to vapors of explosives more than 20 times higher than was observed from spontaneous emission. This phenomenon has been explained with the four-level laser model. Since the sensory transducer used in the hybrid polymer/nanoparticles system could be replaced by other functional materials, the concept developed could be extended to more general domains of chemical or environment detection.

Pipeline Optimization Program (PLOP)

DTIC Science & Technology

2006-08-01

the framework of the Dredging Operations Decision Support System (DODSS, https://dodss.wes.army.mil/wiki/0). PLOP compiles industry standards and...efficiency point ( BEP ). In the interest of acceptable wear rate on the pump, industrial standards dictate that the flow Figure 2. Pump class as a function of...percentage of the flow rate corresponding to the BEP . Pump Acceptability Rules. The facts for pump performance, industrial standards and pipeline and

Replumbing of the Biological Pump caused by Millennial Climate Variability

NASA Astrophysics Data System (ADS)

Galbraith, E.; Sarmiento, J.

2008-12-01

It has been hypothesized that millennial-timescale variability in the biological pump was a critical instigator of glacial-interglacial cycles. However, even in the absence of changes in ecosystem function (e.g. due to iron fertilization), determining the mechanisms by which physical climate variability alters the biological pump is not simple. Changes in upper ocean circulation and deep water formation have previously been shown to alter both the downward flux of organic matter and the mass of respired carbon in the ocean interior, often in non- intuitive ways. For example, a reduced upward flux of nutrients at the global scale will decrease the global rate of export production, but it could either increase or decrease the respired carbon content of the ocean interior, depending on where the reduced upward flux of nutrients occurs. Furthermore, viable candidates for physical climate forcing are numerous, including changes in the westerly winds, changes in the depth of the thermocline, and changes in the formation rate of North Atlantic Deep Water, among others. We use a simple, prognostic, light-and temperature-dependent model of biogeochemical cycling within a state-of-the- art global coupled ocean-atmosphere model to examine the response of the biological pump to changes in the coupled Earth system over multiple centuries. The biogeochemical model explicitly distinguishes respired carbon from preformed and saturation carbon, allowing the activity of the biological pump to be clearly quantified. Changes are forced in the model by altering the background climate state, and by manipulating the flux of freshwater to the North Atlantic region. We show how these changes in the physical state of the coupled ocean-atmosphere system impact the distribution and mass of respired carbon in the ocean interior, and the relationship these changes bear to global patterns of export production via the redistribution of nutrients.

MdMYB1 Regulates Anthocyanin and Malate Accumulation by Directly Facilitating Their Transport into Vacuoles in Apples1[OPEN

PubMed Central

Hu, Da-Gang; Sun, Cui-Hui; Ma, Qi-Jun; You, Chun-Xiang; Hao, Yu-Jin

2016-01-01

Tonoplast transporters, including proton pumps and secondary transporters, are essential for plant cell function and for quality formation of fleshy fruits and ornamentals. Vacuolar transport of anthocyanins, malate, and other metabolites is directly or indirectly dependent on the H+-pumping activities of vacuolar H+-ATPase (VHA) and/or vacuolar H+-pyrophosphatase, but how these proton pumps are regulated in modulating vacuolar transport is largely unknown. Here, we report a transcription factor, MdMYB1, in apples that binds to the promoters of two genes encoding the B subunits of VHA, MdVHA-B1 and MdVHA-B2, to transcriptionally activate its expression, thereby enhancing VHA activity. A series of transgenic analyses in apples demonstrates that MdMYB1/10 controls cell pH and anthocyanin accumulation partially by regulating MdVHA-B1 and MdVHA-B2. Furthermore, several other direct target genes of MdMYB10 are identified, including MdVHA-E2, MdVHP1, MdMATE-LIKE1, and MdtDT, which are involved in H+-pumping or in the transport of anthocyanins and malates into vacuoles. Finally, we show that the mechanism by which MYB controls malate and anthocyanin accumulation in apples also operates in Arabidopsis (Arabidopsis thaliana). These findings provide novel insights into how MYB transcription factors directly modulate the vacuolar transport system in addition to anthocyanin biosynthesis, consequently controlling organ coloration and cell pH in plants. PMID:26637549

Origin and Evolution of the Sodium -Pumping NADH: Ubiquinone Oxidoreductase

PubMed Central

Reyes-Prieto, Adrian; Barquera, Blanca; Juárez, Oscar

2014-01-01

The sodium -pumping NADH: ubiquinone oxidoreductase (Na+-NQR) is the main ion pump and the primary entry site for electrons into the respiratory chain of many different types of pathogenic bacteria. This enzymatic complex creates a transmembrane gradient of sodium that is used by the cell to sustain ionic homeostasis, nutrient transport, ATP synthesis, flagellum rotation and other essential processes. Comparative genomics data demonstrate that the nqr operon, which encodes all Na+-NQR subunits, is found in a large variety of bacterial lineages with different habitats and metabolic strategies. Here we studied the distribution, origin and evolution of this enzymatic complex. The molecular phylogenetic analyses and the organizations of the nqr operon indicate that Na+-NQR evolved within the Chlorobi/Bacteroidetes group, after the duplication and subsequent neofunctionalization of the operon that encodes the homolog RNF complex. Subsequently, the nqr operon dispersed through multiple horizontal transfer events to other bacterial lineages such as Chlamydiae, Planctomyces and α, β, γ and δ -proteobacteria. Considering the biochemical properties of the Na+-NQR complex and its physiological role in different bacteria, we propose a detailed scenario to explain the molecular mechanisms that gave rise to its novel redox- dependent sodium -pumping activity. Our model postulates that the evolution of the Na+-NQR complex involved a functional divergence from its RNF homolog, following the duplication of the rnf operon, the loss of the rnfB gene and the recruitment of the reductase subunit of an aromatic monooxygenase. PMID:24809444

MdMYB1 Regulates Anthocyanin and Malate Accumulation by Directly Facilitating Their Transport into Vacuoles in Apples.

PubMed

Hu, Da-Gang; Sun, Cui-Hui; Ma, Qi-Jun; You, Chun-Xiang; Cheng, Lailiang; Hao, Yu-Jin

2016-03-01

Tonoplast transporters, including proton pumps and secondary transporters, are essential for plant cell function and for quality formation of fleshy fruits and ornamentals. Vacuolar transport of anthocyanins, malate, and other metabolites is directly or indirectly dependent on the H(+)-pumping activities of vacuolar H(+)-ATPase (VHA) and/or vacuolar H(+)-pyrophosphatase, but how these proton pumps are regulated in modulating vacuolar transport is largely unknown. Here, we report a transcription factor, MdMYB1, in apples that binds to the promoters of two genes encoding the B subunits of VHA, MdVHA-B1 and MdVHA-B2, to transcriptionally activate its expression, thereby enhancing VHA activity. A series of transgenic analyses in apples demonstrates that MdMYB1/10 controls cell pH and anthocyanin accumulation partially by regulating MdVHA-B1 and MdVHA-B2. Furthermore, several other direct target genes of MdMYB10 are identified, including MdVHA-E2, MdVHP1, MdMATE-LIKE1, and MdtDT, which are involved in H(+)-pumping or in the transport of anthocyanins and malates into vacuoles. Finally, we show that the mechanism by which MYB controls malate and anthocyanin accumulation in apples also operates in Arabidopsis (Arabidopsis thaliana). These findings provide novel insights into how MYB transcription factors directly modulate the vacuolar transport system in addition to anthocyanin biosynthesis, consequently controlling organ coloration and cell pH in plants. © 2016 American Society of Plant Biologists. All Rights Reserved.

Cyclodextrin Enhanced In-situ Removal of Organic Contaminants from Groundwater at Department of Defense Sites

DTIC Science & Technology

2003-12-16

mass recovery results achieved by applying CDEF technology are shown in comparison with those of a (theoretical) pump-and-treat system without CD...results achieved by applying CDEF technology are shown in comparison with those of a (theoretical) pump-and-treat system without CD present. ESTCP...The TCE mass recovery results achieved by applying CDEF technology are shown in comparison with those of a (theoretical) pump-and-treat system

A new model of centrifugal blood pump for cardiopulmonary bypass: design improvement, performance, and hemolysis tests.

PubMed

Leme, Juliana; Fonseca, Jeison; Bock, Eduardo; da Silva, Cibele; da Silva, Bruno Utiyama; Dos Santos, Alex Eugênio; Dinkhuysen, Jarbas; Andrade, Aron; Biscegli, José F

2011-05-01

A new model of blood pump for cardiopulmonary bypass (CPB) application has been developed and evaluated in our laboratories. Inside the pump housing is a spiral impeller that is conically shaped and has threads on its surface. Worm gears provide an axial motion of the blood column. Rotational motion of the conical shape generates a centrifugal pumping effect and improves pumping performance. One annular magnet with six poles is inside the impeller, providing magnetic coupling to a brushless direct current motor. In order to study the pumping performance, a mock loop system was assembled. Mock loop was composed of Tygon tubes (Saint-Gobain Corporation, Courbevoie, France), oxygenator, digital flowmeter, pressure monitor, electronic driver, and adjustable clamp for flow control. Experiments were performed on six prototypes with small differences in their design. Each prototype was tested and flow and pressure data were obtained for rotational speed of 1000, 1500, 2000, 2500, and 3000 rpm. Hemolysis was studied using pumps with different internal gap sizes (1.35, 1.45, 1.55, and 1.7 mm). Hemolysis tests simulated CPB application with flow rate of 5 L/min against total pressure head of 350 mm Hg. The results from six prototypes were satisfactory, compared to the results from the literature. However, prototype #6 showed the best results. Best hemolysis results were observed with a gap of 1.45 mm, and showed a normalized index of hemolysis of 0.013 g/100 L. When combined, axial and centrifugal pumping principles produce better hydrodynamic performance without increasing hemolysis. © 2011, Copyright the Authors. Artificial Organs © 2011, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Simulation model of a variable-speed pumped-storage power plant in unstable operating conditions in pumping mode

NASA Astrophysics Data System (ADS)

Martínez-Lucas, G.; Pérez-Díaz, J. I.; Sarasúa, J. I.; Cavazzini, G.; Pavesi, G.; Ardizzon, G.

2017-04-01

This paper presents a dynamic simulation model of a laboratory-scale pumped-storage power plant (PSPP) operating in pumping mode with variable speed. The model considers the dynamic behavior of the conduits by means of an elastic water column approach, and synthetically generates both pressure and torque pulsations that reproduce the operation of the hydraulic machine in its instability region. The pressure and torque pulsations are generated each from a different set of sinusoidal functions. These functions were calibrated from the results of a CFD model, which was in turn validated from experimental data. Simulation model results match the numerical results of the CFD model with reasonable accuracy. The pump-turbine model (the functions used to generate pressure and torque pulsations inclusive) was up-scaled by hydraulic similarity according to the design parameters of a real PSPP and included in a dynamic simulation model of the said PSPP. Preliminary conclusions on the impact of unstable operation conditions on the penstock fatigue were obtained by means of a Monte Carlo simulation-based fatigue analysis.

Gain dynamics of clad-pumped Yb-fiber amplifier and intensity noise control.

PubMed

Zhao, Jian; Guiraud, Germain; Floissat, Florian; Gouhier, Benoit; Rota-Rodrigo, Sergio; Traynor, Nicholas; Santarelli, Giorgio

2017-01-09

Gain dynamics study provides an attractive method to understand the intensity noise behavior in fiber amplifiers. Here, the gain dynamics of a medium power (5 W) clad-pumped Yb-fiber amplifier is experimentally evaluated by measuring the frequency domain transfer functions for the input seed and pump lasers from 10 Hz to 1 MHz. We study gain dynamic behavior of the fiber amplifier in the presence of significant residual pump power (compared to the seed power), showing that the seed transfer function is strongly saturated at low Fourier frequencies while the pump power modulation transfer function is nearly unaffected. The characterization of relative intensity noise (RIN) of the fiber amplifier is well explained by the gain dynamics analysis. Finally, a 600 kHz bandwidth feedback loop using an acoustic-optical modulator (AOM) controlling the seed intensity is successfully demonstrated to suppress the broadband laser intensity noise. A maximum noise reduction of about 30 dB is achieved leading to a RIN of -152 dBc/Hz (~1 kHz-10 MHz) at 2.5 W output power.

Artificial Organs 2016: A Year in Review.

PubMed

Hadsell, Angela T; Malchesky, Paul S

2017-03-01

In this Editor's Review, articles published in 2016 are organized by category and briefly summarized. We aim to provide a brief reflection of the currently available worldwide knowledge that is intended to advance and better human life while providing insight for continued application of technologies and methods of organ Replacement, Recovery, and Regeneration. As the official journal of The International Federation for Artificial Organs, The International Faculty for Artificial Organs, the International Society for Mechanical Circulatory Support, the International Society for Pediatric Mechanical Cardiopulmonary Support, and the Vienna International Workshop on Functional Electrical Stimulation, Artificial Organs continues in the original mission of its founders "to foster communications in the field of artificial organs on an international level." Artificial Organs continues to publish developments and clinical applications of artificial organ technologies in this broad and expanding field of organ Replacement, Recovery, and Regeneration from all over the world. We were pleased to publish our second Virtual Issue in April 2016 on "Tissue Engineering in Bone" by Professor Tsuyoshi Takato. Our first was published in 2011 titled "Intra-Aortic Balloon Pumping" by Dr. Ashraf Khir. Other peer-reviewed Special Issues this year included contributions from the 11th International Conference on Pediatric Mechanical Circulatory Support Systems and Pediatric Cardiopulmonary Perfusion edited by Dr. Akif Ündar and selections from the 23rd Congress of the International Society for Rotary Blood Pumps edited by Dr. Bojan Biocina. We take this time also to express our gratitude to our authors for offering their work to this journal. We offer our very special thanks to our reviewers who give so generously of time and expertise to review, critique, and especially provide meaningful suggestions to the author's work whether eventually accepted or rejected. Without these excellent and dedicated reviewers the quality expected from such a journal could not be possible. We also express our special thanks to our Publisher, John Wiley & Sons for their expert attention and support in the production and marketing of Artificial Organs. We look forward to reporting further advances in the coming years. © 2017 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Indirectly pumped 3.7 THz InGaAs/InAlAs quantum-cascade lasers grown by metal-organic vapor-phase epitaxy.

PubMed

Fujita, Kazuue; Yamanishi, Masamichi; Furuta, Shinichi; Tanaka, Kazunori; Edamura, Tadataka; Kubis, Tillmann; Klimeck, Gerhard

2012-08-27

Device-performances of 3.7 THz indirect-pumping quantum-cascade lasers are demonstrated in an InGaAs/InAlAs material system grown by metal-organic vapor-phase epitaxy. The lasers show a low threshold-current-density of ~420 A/cm2 and a peak output power of ~8 mW at 7 K, no sign of parasitic currents with recourse to well-designed coupled-well injectors in the indirect pump scheme, and a maximum operating temperature of Tmax ~100 K. The observed roll-over of output intensities in current ranges below maximum currents and limitation of Tmax are discussed with a model for electron-gas heating in injectors. Possible ways toward elevation of Tmax are suggested.

Development of the NEDO implantable ventricular assist device with Gyro centrifugal pump.

PubMed

Yoshikawa, M; Nonaka, K; Linneweber, J; Kawahito, S; Ohtsuka, G; Nakata, K; Takano, T; Schulte-Eistrup, S; Glueck, J; Schima, H; Wolner, E; Nosé, Y

2000-06-01

The Gyro centrifugal pump, PI (permanently implantable) series, is being developed as a totally implantable artificial heart. Our final goal is to establish a "functional TAH," a totally implantable biventricular assist system (BiVAS) with centrifugal pumps. A plastic prototype pump, Gyro PI 601, was evaluated through in vitro and in vivo studies as a single ventricular assist device (VAD). Based upon these results, the pump head material was converted to a titanium alloy, and the actuator was modified. These titanium Gyro pumps, PI 700 series, also were subjected to in vitro and in vivo studies. The Gyro PI 601 and PI 700 series have the same inner dimensions and characteristics, such as the eccentric inlet port, double pivot bearing system, secondary vane, and magnet coupling system; however, the material of the PI 700 is different from the PI 601. The Gyro PI series is driven by the Vienna DC brushless motor actuator. The inlet cannula of the right ventricular assist system (RVAS) specially made for this system consists of 2 parts: a hat-shaped silicone tip biolized with gelatin and an angled wire reinforced tube made of polyvinylchloride. The pump-actuator package was implanted into 8 calves in the preperitoneal space, bypassing from the left ventricle apex to the descending aorta for the left ventricular assist system (LVAS) and bypassing the right ventricle to the main pulmonary artery for the RVAS. According to the PI 601 feasibility protocol, 2 LVAS cases were terminated after 2 weeks, and 1 LVAS case and 1 RVAS were terminated after 1 month. The PI 700 series was implanted into 4 cases: 3 LVAS cases survived for a long term, 2 of them over 200 days (72-283 days), and 1 RVAS case survived for 1 month and was terminated according to the protocol for a short-term antithrombogenic screening and system feasibility study. Regarding power consumption, the plastic pump cases demonstrated from 6.2 to 12.1 W as LVAS and 7.3 W as RVAS, the titanium pump cases showed from 10.4 to 14.2 W as LVAS and 15.8 W as RVAS. All cases exhibited low hemolysis. The renal function and the liver function were maintained normally in all cases throughout these experimental periods. In the 2 RVAS cases, pulmonary function was normally maintained. No calves demonstrated thromboembolic signs or symptoms throughout the experiments except Case 1 with the plastic pump. However, in the plastic pump cases, bilateral renal infarction was suspected in 2 cases during necropsy whereas no abnormal findings were revealed in the titanium pump cases. There were also no blood clots inside the PI 700 series. As for the 601, the explanted pumps demonstrated slight thrombus formations at the top and bottom pivots except in 1 case. The Gyro PI series, especially the PI 700 series, demonstrated superior performance, biocompatibility, antithrombogenicity and low hemolysis. Also, the durability of the actuator was demonstrated. Based on these results, this titanium centrifugal pump is suitable as an implantable LVAS and RVAS. It is likely that the Gyro PI series is a feasible component of the BiVAS functional TAH.

The correlation between ouabain binding and potassium pump inhibition in human and sheep erythrocytes.

PubMed Central

Joiner, C H; Lauf, P K

1978-01-01

1. [3H]Ouabain binding to human and sheep red blood cells was shown to be specific for receptors associated with Na/K transport. Virtually all tritium binding was abolished by dilution with unlabelled drug. Saturation levels of binding were independent of glycoside concentration and were identical to those associated with 100% inhibition of K pumping. 2. [3H]Ouabain binding and 42K influx were measured simultaneously in order to correlate the degree of K pump inhibition with the amount of glycoside bound. Results by this method agreed exactly with those obtained by pre-exposing cells to drug, followed by washing and then measuring K influx. 3. Plots of [3H]oubain binding vs. K pump inhibition were rectilinear for human and low K (LK) sheep red cells, indicating one glycoside receptor per K pump site and functional homogeneity of pump sites. High K (HK) sheep red cells exhibited curved plots of binding versus inhibition, which were best explained in terms of one receptor per pump, but a heterogeneous population of pump sites. 4. External K reduced the rate of glycoside binding, but did not alter the relationship between binding and inhibition. 5. The number of K pump sites was estimated as 450--500 per human cell and 30--50 per LK sheep cell. HK sheep cells had 90--130 sites per cell, of which eighty to ninety were functionally dominant. The number of K pump sites on LK sheep cells was not changed by anti-L, although the maximum velocity of pump turnover was increased. PMID:722573

A Teaspoon Pump for Pumping Blood with High Hydraulic Efficiency and Low Hemolysis Potential.

PubMed

Dame, Don

1996-05-01

Virtually all blood pumps contain some kind of rubbing, sliding, closely moving machinery surfaces that are exposed to the blood being pumped. These valves, internal bearings, magnetic bearing position sensors, and shaft seals cause most of the problems with blood pumps. The original teaspoon pump design prevented the rubbing, sliding machinery surfaces from contacting the blood. However, the hydraulic efficiency was low because the blood was able to "slip around" the rotating impeller so that the blood itself never rotated fast enough to develop adequate pressure. An improved teaspoon blood pump has been designed and tested and has shown acceptable hydraulic performance and low hemolysis potential. The new pump uses a nonrotating "swinging" hose as the pump impeller. The fluid enters the pump through the center of the swinging hose; therefore, there can be no fluid slip between the revolving blood and the revolving impeller. The new pump uses an impeller that is comparable to a flexible garden hose. If the free end of the hose were swung around in a circle like half of a jump rope, the fluid inside the hose would rotate and develop pressure even though the hose impeller itself did not "rotate"; therefore, no rotating shaft seal or internal bearings are required. © 1996 International Society for Artificial Organs.

40 CFR 60.562-2 - Standards: Equipment leaks of VOC.

Code of Federal Regulations, 2010 CFR

2010-07-01

... PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Volatile Organic Compound (VOC) Emissions from the Polymer Manufacturing Industry § 60.562-2 Standards... feature of the pump whereby polymer fluid used to provide lubrication and/or cooling of the pump shaft...

Preserved function of the plasma membrane calcium pump of red blood cells from diabetic subjects with high levels of glycated haemoglobin.

PubMed

Bookchin, Robert M; Etzion, Zipora; Lew, Virgilio L; Tiffert, Teresa

2009-03-01

The activity of the plasma membrane Ca(2+)-pump decreases steeply throughout the 120 days lifespan of normal human red blood cells. Experiments with isolated membrane preparations showed that glycation of a lysine residue near the catalytic site of the pump ATPase had a powerful inhibitory effect. This prompted the question of whether glycation is the mechanism of age-related decline in pump activity in vivo. It is important to investigate this mechanism because the Ca(2+) pump is a major regulator of Ca(2+) homeostasis in all cells. Its impaired activity in diabetic patients, continuously exposed to high glycation rates, may thus contribute to varied tissue pathology in this disease. We measured Ca(2+)-pump activity as a function of red cell age in red cells from diabetics continuously exposed to high glucose concentrations, as documented by their high mean levels of glycated haemoglobin. The distribution of Ca(2+)-pump activities was indistinguishable from that in non-diabetics, and the pattern of activity decline with cell age in the diabetics' red cells was identical to that observed in red cells from non-diabetics. These results indicate that in intact cells the Ca(2+) pump is protected from glycation-induced inactivation.

SUSTAINABLE WATER EXTRACTION AND DISTRIBUTION SYSTEM FOR AGRICULTURAL APPLICATIONS IN NAMAWANGA, KENYA

EPA Science Inventory

In order to ensure that the pumps are successful when installed for the community, working prototypes were tested, analyzed, and modified. The chief concerns of our functional analysis were the flow rate of the pump, the stability/durability of the system, total pumping head, ...

Study of application rates of aerosol and pump hair sprays. Final report, July 1986-November 1987

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

Boggs, R.R.; Belmont, B.

Application rates of three hair spray dispensing systems, aerosol, pump, and Exxel packaging were determined through a six-week user panel of approximately 300 people. In addition, photochemically reactive organic compounds (PROC) application rates were determined through chemical analysis of the products. The user panel was stratified on the basis of sex, dispenser (pump/aerosol), and age (adult/teen). Weighted-application rates and weighted PROC application rates are included. A Mann-Whitney evaluation was made to evaluate differences between data sets. Product-usage data for both male and female adult groups support the conclusion that increased use of either pumps or Exxel packaging for hair spraymore » would reduce PROC emissions in California. Data from adult groups also indicate that use of Exxel packaging in place of pumps would not reduce PROC. Consumer preference was also sampled. Adult pump users were not very willing to switch to aerosols, but on the order of half of aerosol users were willing to switch to pumps.« less

Estimating Mechanical Blood Trauma in a Centrifugal Blood Pump: Laser Doppler Anemometer Measurements of the Mean Velocity Field.

PubMed

Pinotti, Marcos; Paone, Nicola

1996-05-01

A laser Doppler anemometer (LDA) was used to obtain the mean velocity and the Reynolds stress fields in the inner channels of a well-known centrifugal vaneless pump (Bio-pump). Effects of the excessive flow resistance against which an occlusive pump operates in some surgical situations, such as cardiopulmonary bypass, are illustrated. The velocity vector field obtained from LDA measurements reveals that the constraint-forced vortex provides pumping action in a restricted area in the core of the pump. In such situations, recirculating zones dominate the flow and consequently increase the damage to blood cells and raise the risk of thrombus formation in the device. Reynolds normal and shear stress fields were obtained in the entry flow for the channel formed by two rotating cones to illustrate the effects of flow disturbances on the potential for blood cell damage. © 1996 International Society for Artificial Organs.

Dielectric elastomer peristaltic pump module with finite deformation

NASA Astrophysics Data System (ADS)

Mao, Guoyong; Huang, Xiaoqiang; Liu, Junjie; Li, Tiefeng; Qu, Shaoxing; Yang, Wei

2015-07-01

Inspired by various peristaltic structures existing in nature, several bionic peristaltic actuators have been developed. In this study, we propose a novel dielectric elastomer peristaltic pump consisting of short tubular modules, with the saline solution as the electrodes. We investigate the performance of this soft pump module under hydraulic pressure and voltage via experiments and an analytical model based on nonlinear field theory. It is observed that the individual pump module undergoes finite deformation and may experience electromechanical instability during operations. The driving pressure and displaced volume of the peristaltic pump module can be modulated by applied voltage. The efficiency of the pump module is enhanced by alternating current voltage, which can suppress the electromechanical pull-in instability. An analytical model is developed within the framework of the nonlinear field theory, and its predictive capacity is checked by experimental observations. The effects of the prestretch, aspect ratio, and voltage on the performance of the pump modules are characterized by the analytical model. This work can guide the designs of soft active peristaltic pumps in the field of artificial organs and industrial conveying systems.

Tank farms pump critical characteristic and specification guide

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

Titzler, P.A.

The Design Authority group for Tank Farms, in conjunction with the Construction Projects organization, have recognized that there is a need to provide consistency in the procurement and testing of pumps and to assure that known critical attributes and features are included with each pump order as well as to reduce potential confusion by pump suppliers. As a result, a panel of pump experts representing Lockheed Martin Hanford Company (LMHC), Fluor Daniel Northwest (FDNW), Numatec Hanford Corporation (NHC), SGN Eurisys Services Corporation (SESC), and ARES Corporation has been assembled to prepare a guide for pump specifications. This document contains themore » consensus listing of critical characteristics and procurement recommendations of the panel. It is intended to be used as a guide for future pump procurement activities. If followed, it will help reduce cleanup costs at the Hanford Site and promote prompt approval of pumping system designs and procurement specifications. Alternate criteria may be specified on a case by case basis if deviation from the requirements contained herein is merited due to special circumstances.« less

A Primer on Insulin Pump Therapy for Health Care Providers.

PubMed

McCrea, Deborah L

2017-12-01

An estimated 1 million people use an insulin pump to manage their diabetes. Few medical professionals understand or feel comfortable caring for people who use an insulin pump. This article will help the medical professional understand the reasons why the insulin pump helps the user to achieve better glycemic control, have more flexibility, and enjoy a better quality of life. Additionally, this article discusses the advantages, disadvantages, candidate selection, contraindications, basic functions, and troubleshooting of the insulin pump. Copyright © 2017 Elsevier Inc. All rights reserved.

Seawater Hydraulics: A Multi-Function Tool System for U.S. Navy Construction Divers.

DTIC Science & Technology

1991-05-01

0.80. Each tool was designed so that it can be repaired in a minimum time. Tool maintenance at the end of the day is satisfied by a fresh- water rinse...oil hydraulic system is used to regulate the speed of the centrifugal pump. The centrifugal pump supplies 200 psi water to a jet eductor pump suspended...in the ocean. The jet eductor pump returns a larger volume of water to fill the 50-gallon reservoir. The seawater output from the jet eductor pump is

Stimulated Brillouin scattering in the field of a two-dimensionally localized pumping wave

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

Solikhov, D. K., E-mail: davlat56@mail.ru; Dvinin, S. A., E-mail: dvinin@phys.msu.ru

2016-06-15

Stimulated Brillouin scattering of electromagnetic waves in the field of a two-dimensionally localized pump wave at arbitrary scattering angles in the regime of forward scattering is analyzed. Spatial variations in the amplitudes of interacting waves are studied for different values of the pump field and different dimensions of the pump wave localization region. The intensity of scattered radiation is determined as a function of the scattering angle and the dimensions of the pump wave localization region. It is shown that the intensity increases with increasing scattering angle.

Serotonin Activates Overall Feeding by Activating Two Separate Neural Pathways in Caenorhabditis elegans

PubMed Central

Song, Bo-mi; Avery, Leon

2012-01-01

Food intake in the nematode Caenorhabditis elegans requires two distinct feeding motions, pharyngeal pumping and isthmus peristalsis. Bacteria, the natural food of C. elegans, activate both feeding motions (Croll, 1978; Horvitz et al., 1982; Chiang et al., 2006). The mechanisms by which bacteria activate the feeding motions are largely unknown. To understand the process, we studied how serotonin, an endogenous pharyngeal pumping activator whose action is triggered by bacteria, activates feeding motions. Here, we show that serotonin, like bacteria, activates overall feeding by activating isthmus peristalsis as well as pharyngeal pumping. During active feeding, the frequencies and the timing of onset of the two motions were distinct, but each isthmus peristalsis was coupled to the preceding pump. We found that serotonin activates the two feeding motions mainly by activating two separate neural pathways in response to bacteria. For activating pumping, the SER-7 serotonin receptor in the MC motor neurons in the feeding organ activated cholinergic transmission from MC to the pharyngeal muscles by activating the Gsα signaling pathway. For activating isthmus peristalsis, SER-7 in the M4 (and possibly M2) motor neuron in the feeding organ activated the G12α signaling pathway in a cell-autonomous manner, which presumably activates neurotransmission from M4 to the pharyngeal muscles. Based on our results and previous calcium imaging of pharyngeal muscles (Shimozono et al., 2004), we propose a model that explains how the two feeding motions are separately regulated yet coupled. The feeding organ may have evolved this way to support efficient feeding. PMID:22323705

Thermal and Spectroscopic Characterization of a Proton Pumping Rhodopsin from an Extreme Thermophile*

PubMed Central

Tsukamoto, Takashi; Inoue, Keiichi; Kandori, Hideki; Sudo, Yuki

2013-01-01

So far retinylidene proteins (∼rhodopsin) have not been discovered in thermophilic organisms. In this study we investigated and characterized a microbial rhodopsin derived from the extreme thermophilic bacterium Thermus thermophilus, which lives in a hot spring at around 75 °C. The gene for the retinylidene protein, named thermophilic rhodopsin (TR), was chemically synthesized with codon optimization. The codon optimized TR protein was functionally expressed in the cell membranes of Escherichia coli cells and showed active proton transport upon photoillumination. Spectroscopic measurements revealed that the purified TR bound only all-trans-retinal as a chromophore and showed an absorption maximum at 530 nm. In addition, TR exhibited both photocycle kinetics and pH-dependent absorption changes, which are characteristic of rhodopsins. Of note, time-dependent thermal denaturation experiments revealed that TR maintained its absorption even at 75 °C, and the denaturation rate constant of TR was much lower than those of other proton pumping rhodopsins such as archaerhodopsin-3 (200 ×), Haloquadratum walsbyi bacteriorhodopsin (by 10-times), and Gloeobacter rhodopsin (100 ×). Thus, these results suggest that microbial rhodopsins are also distributed among thermophilic organisms and have high stability. TR should allow the investigation of the molecular mechanisms of ion transport and protein folding. PMID:23740255

Thermal and spectroscopic characterization of a proton pumping rhodopsin from an extreme thermophile.

PubMed

Tsukamoto, Takashi; Inoue, Keiichi; Kandori, Hideki; Sudo, Yuki

2013-07-26

So far retinylidene proteins (∼rhodopsin) have not been discovered in thermophilic organisms. In this study we investigated and characterized a microbial rhodopsin derived from the extreme thermophilic bacterium Thermus thermophilus, which lives in a hot spring at around 75 °C. The gene for the retinylidene protein, named thermophilic rhodopsin (TR), was chemically synthesized with codon optimization. The codon optimized TR protein was functionally expressed in the cell membranes of Escherichia coli cells and showed active proton transport upon photoillumination. Spectroscopic measurements revealed that the purified TR bound only all-trans-retinal as a chromophore and showed an absorption maximum at 530 nm. In addition, TR exhibited both photocycle kinetics and pH-dependent absorption changes, which are characteristic of rhodopsins. Of note, time-dependent thermal denaturation experiments revealed that TR maintained its absorption even at 75 °C, and the denaturation rate constant of TR was much lower than those of other proton pumping rhodopsins such as archaerhodopsin-3 (200 ×), Haloquadratum walsbyi bacteriorhodopsin (by 10-times), and Gloeobacter rhodopsin (100 ×). Thus, these results suggest that microbial rhodopsins are also distributed among thermophilic organisms and have high stability. TR should allow the investigation of the molecular mechanisms of ion transport and protein folding.

Muscle Contraction.

PubMed

Sweeney, H Lee; Hammers, David W

2018-02-01

SUMMARYMuscle cells are designed to generate force and movement. There are three types of mammalian muscles-skeletal, cardiac, and smooth. Skeletal muscles are attached to bones and move them relative to each other. Cardiac muscle comprises the heart, which pumps blood through the vasculature. Skeletal and cardiac muscles are known as striated muscles, because the filaments of actin and myosin that power their contraction are organized into repeating arrays, called sarcomeres, that have a striated microscopic appearance. Smooth muscle does not contain sarcomeres but uses the contraction of filaments of actin and myosin to constrict blood vessels and move the contents of hollow organs in the body. Here, we review the principal molecular organization of the three types of muscle and their contractile regulation through signaling mechanisms and discuss their major structural and functional similarities that hint at the possible evolutionary relationships between the cell types. Copyright © 2018 Cold Spring Harbor Laboratory Press; all rights reserved.

Polylactic acid promotes healing of photodegraded disperse orange 11 molecules

NASA Astrophysics Data System (ADS)

Stubbs, Najee; Bridgewater, Mauricio; Stubbs, Micheala; Kabir, Amin; Crescimanno, Michael; Kuzyk, Mark G.; Dawson, Nathan J.

2018-02-01

We report on the recovery of a photodegraded organic molecule mediated by a biopolymer. Amplified spontaneous emission (ASE) from disperse orange 11 (DO11) dye-doped polylactic acid (PLA) was used to monitor photodegradation while the material was being damaged by a strong pump laser. The ASE signal fully recovers over two hours time when the pump beam is blocked. The fluorescence spectra was also observed to recover after partial photobleaching the dye-doped polymer. PLA is the first biopolymer known to mediate the recovery of a photodegraded organic dye molecule.

Ex-vivo porcine organs with a circulation pump are effective for teaching hemostatic skills

PubMed Central

2012-01-01

Surgical residents have insufficient opportunites to learn basic hemostatic skills from clinical experience alone. We designed an ex-vivo training system using porcine organs and a circulation pump to teach hemostatic skills. Residents were surveyed before and after the training and showed significant improvement in their self-confidence (1.83 ± 1.05 vs 3.33 ± 0.87, P < 0.01) on a 5 point Likert scale. This training may be effective to educate residents in basic hemostatic skills. PMID:22404974

Engineering approach for cost effective operation of industrial pump systems

NASA Astrophysics Data System (ADS)

Krickis, O.; Oleksijs, R.

2017-10-01

Power plants operators are persuaded to operate the main equipment such as centrifugal pumps in economically effective way. The operation of pump sets of district heating network at power plants should be done according to prescriptions of the original equipment manufacturer with further implementation of these requirements to distributed control system of the plant. In order to operate industrial pump sets with a small number of malfunctions is necessary to control the duty point of pump sets in H-Q coordinates, which could be complex task in some installations. Alternatively, pump operation control could be organized in H-n (head vs rpm) coordinates, utilizing pressure transmitters in pressure pipeline and value of rpm from variable speed driver. Safe operation range of the pump has to be limited with system parabolas, which prevents the duty point location outside of the predefined operation area. The particular study demonstrates the engineering approach for pump’s safe operation control development in MATLAB/Simulink environment, which allows to simulate the operation of the pump at different capacities in hydraulic system with variable characteristic and to predefine the conditions for efficient simultaneous pump operation in parallel connection.

Bayesian estimation of the transmissivity spatial structure from pumping test data

NASA Astrophysics Data System (ADS)

Demir, Mehmet Taner; Copty, Nadim K.; Trinchero, Paolo; Sanchez-Vila, Xavier

2017-06-01

Estimating the statistical parameters (mean, variance, and integral scale) that define the spatial structure of the transmissivity or hydraulic conductivity fields is a fundamental step for the accurate prediction of subsurface flow and contaminant transport. In practice, the determination of the spatial structure is a challenge because of spatial heterogeneity and data scarcity. In this paper, we describe a novel approach that uses time drawdown data from multiple pumping tests to determine the transmissivity statistical spatial structure. The method builds on the pumping test interpretation procedure of Copty et al. (2011) (Continuous Derivation method, CD), which uses the time-drawdown data and its time derivative to estimate apparent transmissivity values as a function of radial distance from the pumping well. A Bayesian approach is then used to infer the statistical parameters of the transmissivity field by combining prior information about the parameters and the likelihood function expressed in terms of radially-dependent apparent transmissivities determined from pumping tests. A major advantage of the proposed Bayesian approach is that the likelihood function is readily determined from randomly generated multiple realizations of the transmissivity field, without the need to solve the groundwater flow equation. Applying the method to synthetically-generated pumping test data, we demonstrate that, through a relatively simple procedure, information on the spatial structure of the transmissivity may be inferred from pumping tests data. It is also shown that the prior parameter distribution has a significant influence on the estimation procedure, given the non-uniqueness of the estimation procedure. Results also indicate that the reliability of the estimated transmissivity statistical parameters increases with the number of available pumping tests.

Computational Fluid Dynamics and Experimental Characterization of the Pediatric Pump-Lung.

PubMed

Wu, Zhongjun J; Gellman, Barry; Zhang, Tao; Taskin, M Ertan; Dasse, Kurt A; Griffith, Bartley P

2011-12-01

The pediatric pump-lung (PediPL) is a miniaturized integrated pediatric pump-oxygenator specifically designed for cardiac or cardiopulmonary support for patients weighing 5-20 kg to allow mobility and extended use for 30 days. The PediPL incorporates a magnetically levitated impeller with uniquely configured hollow fiber membranes into a single unit capable of performing both pumping and gas exchange. A combined computational and experimental study was conducted to characterize the functional and hemocompatibility performances of this newly developed device. The three-dimensional flow features of the PediPL and its hemolytic characteristics were analyzed using computational fluid dynamics based modeling. The oxygen exchange was modeled based on a convection-diffusion-reaction process. The hollow fiber membranes were modeled as a porous medium which incorporates the flow resistance in the bundle by an added momentum sink term. The pumping function was evaluated for the required range of operating conditions (0.5-2.5 L/min and 1000-3000 rpm). The blood damage potentials were further analyzed in terms of flow and shear stress fields, and the calculations of hemolysis index. In parallel, the hydraulic pump performance, oxygen transfer and hemolysis level were quantified experimentally. Based on the computational and experimental results, the PediPL device is found to be functional to provide necessary oxygen transfer and blood pumping requirements for the pediatric patients. Smooth blood flow characteristics and low blood damage potential were observed in the entire device. The in-vitro tests further confirmed that the PediPL can provide adequate blood pumping and oxygen transfer over the range of intended operating conditions with acceptable hemolytic performance. The rated flow rate for oxygenation is 2.5 L/min. The normalized index of hemolysis is 0.065 g/100L at 1.0 L/min and 3000 rpm.

A single center's conversion from roller pump to centrifugal pump technology in extracorporeal membrane oxygenation.

PubMed

Shade, Brandon C; Schiavo, Kellie; Rosenthal, Tami; Connelly, James T; Melchior, Richard W

2016-06-05

Recent advances in blood pump technology have led to an increased use of centrifugal pumps for prolonged extracorporeal membrane oxygenation (ECMO). Data from the Extracorporeal Life Support Organization confirms that many institutions have converted to centrifugal pumps after prior experience with roller pump technology. Centrifugal pump technology is more compact and may generate less heat and hemolysis than a conventional roller pump. Based on the potential advantages of centrifugal pumps, a decision was made institution-wide to convert to centrifugal pump technology in pediatric implementation of ECMO. Based on limited prior experience with centrifugal pumps, a multidisciplinary approach was used to implement this new technology. The new centrifugal pump (Sorin Revolution, Arvada, CO) was intended for ECMO support in the cardiac intensive care unit (CICU), the pediatric intensive care unit (PICU) and the neonatal intensive care unit (NICU). The perfusion team used their knowledge and expertise with centrifugal pumps to create the necessary teaching tools and interactive training sessions for the technical specialists who consisted primarily of registered nurses and respiratory therapists. The first phase consisted of educating all personnel involved in the care of the ECMO patient, followed by patient implementation in the CICU, followed by the PICU and NICU. The institution-wide conversion took several months to complete and was well received among all disciplines in the CICU and PICU. The NICU personnel did use the centrifugal pump circuit, but decided to revert back to using the roller pump technology. A systematic transition from roller pump to centrifugal pump technology with a multidisciplinary team can ensure a safe and successful implementation. © The Author(s) 2016.

Characterization of the intramolecular transfer state of marine carotenoid fucoxanthin by femtosecond pump-probe spectroscopy.

PubMed

Kosumi, Daisuke; Fujii, Ritsuko; Sugisaki, Mitsuru; Oka, Naohiro; Iha, Masahiko; Hashimoto, Hideki

2014-07-01

Fucoxanthin, containing a carbonyl group in conjugation with its polyene backbone, is a naturally occurring pigment in marine organisms and is essential to the photosynthetic light-harvesting function in brown alga and diatom. Fucoxanthin exhibits optical characteristics attributed to an intramolecular charge transfer (ICT) state that arises in polar environments due to the presence of the carbonyl group. In this study, we report the spectroscopic properties of fucoxanthin in methanol (polar and protic solvent) observed by femtosecond pump-probe measurements in the near-infrared region, where transient absorption associated with the optically allowed S2 (1(1)B u (+) ) state and stimulated emission from the strongly coupled S1/ICT state were observed following one-photon excitation to the S2 state. The results showed that the amplitude of the stimulated emission of the S1/ICT state increased with decreasing excitation energy, demonstrating that the fucoxanthin form associated with the lower energy of the steady-state absorption exhibits stronger ICT character.

Proton-coupled electron transfer and the role of water molecules in proton pumping by cytochrome c oxidase

PubMed Central

Sharma, Vivek; Enkavi, Giray; Vattulainen, Ilpo; Róg, Tomasz; Wikström, Mårten

2015-01-01

Molecular oxygen acts as the terminal electron sink in the respiratory chains of aerobic organisms. Cytochrome c oxidase in the inner membrane of mitochondria and the plasma membrane of bacteria catalyzes the reduction of oxygen to water, and couples the free energy of the reaction to proton pumping across the membrane. The proton-pumping activity contributes to the proton electrochemical gradient, which drives the synthesis of ATP. Based on kinetic experiments on the O–O bond splitting transition of the catalytic cycle (A → PR), it has been proposed that the electron transfer to the binuclear iron–copper center of O2 reduction initiates the proton pump mechanism. This key electron transfer event is coupled to an internal proton transfer from a conserved glutamic acid to the proton-loading site of the pump. However, the proton may instead be transferred to the binuclear center to complete the oxygen reduction chemistry, which would constitute a short-circuit. Based on atomistic molecular dynamics simulations of cytochrome c oxidase in an explicit membrane–solvent environment, complemented by related free-energy calculations, we propose that this short-circuit is effectively prevented by a redox-state–dependent organization of water molecules within the protein structure that gates the proton transfer pathway. PMID:25646428

Exchangers man the pumps: Functional interplay between proton pumps and proton-coupled Ca(2+) exchangers

USDA-ARS?s Scientific Manuscript database

Tonoplast-localised proton-coupled Ca(2+) transporters encoded by cation/H(+) exchanger (CAX) genes play a critical role in sequestering Ca(2+) into the vacuole. These transporters may function in coordination with Ca(2+) release channels, to shape stimulus-induced cytosolic Ca(2+) elevations. Recen...

Steady-state, cavityless, multimode superradiance in a cold vapor

NASA Astrophysics Data System (ADS)

Greenberg, Joel A.; Gauthier, Daniel J.

2012-07-01

We demonstrate steady-state, mirrorless superradiance in a cold vapor pumped by weak optical fields. Beyond a critical pump intensity of 1 mW/cm2, the vapor spontaneously transforms into a spatially self-organized state: a density grating forms. Scattering of the pump beams off this grating generates a pair of new, intense optical fields that act back on the vapor to enhance the atomic organization. We map out experimentally the superradiant phase transition boundary and show that it is well described by our theoretical model. The resulting superradiant emission is nearly coherent, persists for several seconds, displays strong temporal correlations between the various modes, and has a coherence time of several hundred μs. This system therefore has applications in fundamental studies of many-body physics with long-range interactions as well as all-optical and quantum information processing.

Coherence specific signal detection via chiral pump-probe spectroscopy.

PubMed

Holdaway, David I H; Collini, Elisabetta; Olaya-Castro, Alexandra

2016-05-21

We examine transient circular dichroism (TRCD) spectroscopy as a technique to investigate signatures of exciton coherence dynamics under the influence of structured vibrational environments. We consider a pump-probe configuration with a linearly polarized pump and a circularly polarized probe, with a variable angle θ between the two directions of propagation. In our theoretical formalism the signal is decomposed in chiral and achiral doorway and window functions. Using this formalism, we show that the chiral doorway component, which beats during the population time, can be isolated by comparing signals with different values of θ. As in the majority of time-resolved pump-probe spectroscopy, the overall TRCD response shows signatures of both excited and ground state dynamics. However, we demonstrate that the chiral doorway function has only a weak ground state contribution, which can generally be neglected if an impulsive pump pulse is used. These findings suggest that the pump-probe configuration of optical TRCD in the impulsive limit has the potential to unambiguously probe quantum coherence beating in the excited state. We present numerical results for theoretical signals in an example dimer system.

Posterior papillary muscle anchoring affects remote myofiber stress and pump function: finite element analysis.

PubMed

Pantoja, Joe Luis; Ge, Liang; Zhang, Zhihong; Morrel, William G; Guccione, Julius M; Grossi, Eugene A; Ratcliffe, Mark B

2014-10-01

The role of posterior papillary muscle anchoring (PPMA) in the management of chronic ischemic mitral regurgitation (CIMR) is controversial. We studied the effect of anchoring point direction and relocation displacement on left ventricular (LV) regional myofiber stress and pump function. Previously described finite element models of sheep 16 weeks after posterolateral myocardial infarction (MI) were used. True-sized mitral annuloplasty (MA) ring insertion plus different PPM anchoring techniques were simulated. Anchoring points tested included both commissures and the central anterior mitral annulus; relocation displacement varied from 10% to 40% of baseline diastolic distance from the PPM to the anchor points on the annulus. For each reconstruction scenario, myofiber stress in the MI, border zone, and remote myocardium as well as pump function were calculated. PPMA caused reductions in myofiber stress at end-diastole and end-systole in all regions of the left ventricle that were proportional to the relocation displacement. Although stress reduction was greatest in the MI region, it also occurred in the remote region. The maximum 40% displacement caused a slight reduction in LV pump function. However, with the correction of regurgitation by MA plus PPMA, there was an overall increase in forward stroke volume. Finally, anchoring point direction had no effect on myofiber stress or pump function. PPMA reduces remote myofiber stress, which is proportional to the absolute distance of relocation and independent of anchoring point. Aggressive use of PPMA techniques to reduce remote myofiber stress may accelerate reverse LV remodeling without impairing LV function. Copyright © 2014 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Preoperative optimization of multi-organ failure following acute myocardial infarction and ischemic mitral regurgitation by placement of a transthoracic intra-aortic balloon pump.

PubMed

Umakanthan, Ramanan; Dubose, Robert; Byrne, John G; Ahmad, Rashid M

2010-10-01

The management of acute myocardial infarction with resultant acute ischemic mitral regurgitation and acute multi-organ failure can prove to be a very challenging scenario. The presence of concomitant vascular disease can only serve to further compromise the complexity of the situation. We demonstrate a new indication for the transthoracic intra-aortic balloon pump as a preoperative means of unloading the heart and improving clinical outcome in such high-risk patients with severe vascular disease. We present the case of a 75-year-old man with a history of severe vascular disease who was transferred emergently to Vanderbilt University Medical Center with an acute inferolateral wall myocardial infarction resulting in severe acute ischemic mitral regurgitation and acute multi-organ failure. He presented with shock liver (serum glutamic-oxaloacetic transaminase [SGOT] of 958), renal failure (creatinine of 3.0), and respiratory failure with a pH of 7.18. Emergent cardiac catheterization revealed 100% occlusion of the left circumflex artery as well as severe ileofemoral disease. The advanced nature of his ileofemoral disease was such that the arterial access catheter occluded the right femoral artery. The duration of time that the catheter was in the artery led to transient limb ischemia with an elevation of his creatine phosphokinase (CPK) to 10,809. Balloon angioplasty followed by stent placement was successfully performed, which restored flow to the coronary vessel. Given the grave nature of the patient's condition, we were very concerned that immediate operative intervention for his condition would entail prohibitively high risk. In fact, the Society of Thoracic Surgeons predicted risk adjusted mortality was calculated to be 56%. In order to minimize patient mortality and morbidity, it was critical to help restore perfusion and organ recovery. Therefore, we decided that the chances for this patient's survival would improve if his condition could be optimized by placement of an intra-aortic balloon pump before undergoing surgery. Given the limb ischemia following arterial sheath insertion, femoral placement of an intra-aortic balloon pump was not an option. Placement of the intra-aortic balloon pump was attempted via a left subclavian artery cutdown, but was not successful. Therefore, a sternotomy was performed, and we placed a transthoracic intra-aortic balloon pump in order to stabilize the patient's hemodynamics and allow for organ recovery. The patient showed immediate improvement, and 4 days later, the multi-organ failure resolved and he successfully underwent mitral valve replacement. The patient was ultimately discharged to a local rehabilitation facility in satisfactory condition. This case demonstrates the utility of a transthoracic intra-aortic balloon pump as a preoperative means of stabilization in very high risk patients with severe peripheral vascular disease in whom the conventional approaches are not possible.

Generation of high-field terahertz pulses in an HMQ-TMS organic crystal pumped by an ytterbium laser at 1030 nm.

PubMed

Rovere, Andrea; Jeong, Young-Gyun; Piccoli, Riccardo; Lee, Seung-Heon; Lee, Seung-Chul; Kwon, O-Pil; Jazbinsek, Mojca; Morandotti, Roberto; Razzari, Luca

2018-02-05

We present the generation of high-peak-electric-field terahertz pulses via collinear optical rectification in a 2-(4-hydroxy-3-methoxystyryl)-1-methilquinolinium-2,4,6-trimethylbenzenesulfonate (HMQ-TMS) organic crystal. The crystal is pumped by an amplified ytterbium laser system, emitting 170-fs-long pulses centered at 1030 nm. A terahertz peak electric field greater than 200 kV/cm is obtained for 420 µJ of optical pump energy, with an energy conversion efficiency of 0.26% - about two orders of magnitude higher than in common inorganic crystals collinearly pumped by amplified femtosecond lasers. An open-aperture Z-scan measurement performed on an n-doped InGaAs thin film using such terahertz source shows a nonlinear increase in the terahertz transmission of about 2.2 times. Our findings demonstrate the potential of this terahertz generation scheme, based on ytterbium laser technology, as a simple and efficient alternative to the existing intense table-top terahertz sources. In particular, we show that it can be readily used to explore nonlinear effects at terahertz frequencies.

Clinical Evaluation of the Use of a Multifunctional Remotely Controlled Insulin Pump

PubMed Central

Pinget, Michel; Lachgar, Karim; Parkin, Christopher G.; Grulet, Hervé; Guillon-Metz, Françoise; Weissmann, Joerg

2014-01-01

Current insulin pumps now feature advanced functions for calculating insulin dosages, delivering insulin and analyzing data, however, the perceived usefulness of these functions in clinical settings has not been well studied. We assessed the use and patient perceptions of an insulin delivery system (Accu-Chek® Combo, Roche Diagnostics, Mannheim, Germany) that combines an insulin pump and a handheld multifunctional blood glucose meter with integrated remote control functions. This prospective, observational, multicenter study enrolled 74 type 1 diabetes patients within 13 weeks after starting use of the pump system. At 4 to 24 weeks, investigators collected usage data from the latest 14-day period. Seventy-two patients completed the evaluation, aged 39 ± 15 years, diabetes duration 16 ± 13 years, HbA1c 8.3 ± 1.6%. At follow-up, 62 (86.1%) patients used the remote control for ≥50% of all boluses, 20 (27.8%) used the bolus advisor for ≥50% of all boluses, and 42 (58.3%) viewed at least 1 of the e-logbook reports. More than 95% of users appraised the functions as easy-to-use and useful; median scores from VAS (0 = useless to 100 = indispensable) ranged from 72 to 85. A high percentage of study patients used the system’s advanced features, especially the remote control feature for bolusing. Overall, patients assessed the functions as useful and easy to use. Results support the implementation of these smart capabilities in further insulin pump developments. PMID:25107708

In vivo study of transepithelial potential difference (TEPD) in proximal convoluted tubules of rat kidney by synchronization modulation electric field.

PubMed

Clausell, Mathis; Fang, Zhihui; Chen, Wei

2014-07-01

Synchronization modulation (SM) electric field has been shown to effectively activate function of Na(+)/K(+) pumps in various cells and tissues, including skeletal muscle cells, cardiomyocyte, monolayer of cultured cell line, and peripheral blood vessels. We are now reporting the in vivo studies in application of the SM electric field to kidney of living rats. The field-induced changes in the transepithelial potential difference (TEPD) or the lumen potential from the proximal convoluted tubules were monitored. The results showed that a short time (20 s) application of the SM electric field can significantly increase the magnitude of TEPD from 1-2 mV to about 20 mV. The TEPD is an active potential representing the transport current of the Na/K pumps in epithelial wall of renal tubules. This study showed that SM electric field can increase TEPD by activation of the pump molecules. Considering renal tubules, many active transporters are driven by the Na(+) concentration gradient built by the Na(+)/K(+) pumps, activation of the pump functions and increase in the magnitude of TEPD imply that the SM electric field may improve reabsorption functions of the renal tubules.

Fluid driven reciprocating apparatus

DOEpatents

Whitehead, J.C.

1997-04-01

An apparatus is described comprising a pair of fluid driven pump assemblies in a back-to-back configuration to yield a bi-directional pump. Each of the pump assemblies includes a piston or diaphragm which divides a chamber therein to define a power section and a pumping section. An intake-exhaust valve is connected to each of the power sections of the pump chambers, and function to direct fluid, such as compressed air, into the power section and exhaust fluid therefrom. At least one of the pistons or diaphragms is connected by a rod assembly which is constructed to define a signal valve, whereby the intake-exhaust valve of one pump assembly is controlled by the position or location of the piston or diaphragm in the other pump assembly through the operation of the rod assembly signal valve. Each of the pumping sections of the pump assemblies are provided with intake and exhaust valves to enable filling of the pumping section with fluid and discharging fluid therefrom when a desired pressure has been reached. 13 figs.

Fluid driven recipricating apparatus

DOEpatents

Whitehead, John C.

1997-01-01

An apparatus comprising a pair of fluid driven pump assemblies in a back-to-back configuration to yield a bi-directional pump. Each of the pump assemblies includes a piston or diaphragm which divides a chamber therein to define a power section and a pumping section. An intake-exhaust valve is connected to each of the power sections of the pump chambers, and function to direct fluid, such as compressed air, into the power section and exhaust fluid therefrom. At least one of the pistons or diaphragms is connected by a rod assembly which is constructed to define a signal valve, whereby the intake-exhaust valve of one pump assembly is controlled by the position or location of the piston or diaphragm in the other pump assembly through the operation of the rod assembly signal valve. Each of the pumping sections of the pump assemblies are provided with intake and exhaust valves to enable filling of the pumping section with fluid and discharging fluid therefrom when a desired pressure has been reached.

Use of a combined effect model approach for discriminating between ABCB1- and ABCC1-type efflux activities in native bivalve gill tissue

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

Faria, Melissa; CESAM & Departamento de Biologia, Universidade de Aveiro, 3810-193 Aveiro; Pavlichenko, Vasiliy

Aquatic organisms, such as bivalves, employ ATP binding cassette (ABC) transporters for efflux of potentially toxic chemicals. Anthropogenic water contaminants can, as chemosensitizers, disrupt efflux transporter function enabling other, putatively toxic compounds to enter the organism. Applying rapid amplification of cDNA ends (RACE) PCR we identified complete cDNAs encoding ABCB1- and ABCC1-type transporter homologs from zebra mussel providing the molecular basis for expression of both transporter types in zebra mussel gills. Further, efflux activities of both transporter types in gills were indicated with dye accumulation assays where efflux of the dye calcein-am was sensitive to both ABCB1- (reversin 205, verapamil)more » and ABCC1- (MK571) type specific inhibitors. The assumption that different inhibitors targeted different efflux pump types was confirmed when comparing measured effects of binary inhibitor compound mixtures in dye accumulation assays with predictions from mixture effect models. Effects by the MK571/reversin 205 mixture corresponded better with independent action, whereas reversin 205/verapamil joint effects were better predicted by the concentration addition model indicating different and equal targets, respectively. The binary mixture approach was further applied to identify the efflux pump type targeted by environmentally relevant chemosensitizing compounds. Pentachlorophenol and musk ketone, which were selected after a pre-screen of twelve compounds that previously had been identified as chemosensitizers, showed mixture effects that corresponded better with concentration addition when combined with reversine 205 but with independent action predictions when combined with MK571 indicating targeting of an ABCB1-type efflux pump by these compounds. - Highlights: • Sequences and function of ABC efflux transporters in bivalve gills were explored. • Full length Dreissena polymorpha abcb1 and abcc1 cDNA sequences were identified. • A mixture effect design with inhibitors was applied in transporter activity assays. • ABCB1- and ABCC-type efflux activities were distinguished in native gill tissue. • Inhibitory action of environmental chemicals targeted ABCB1-type efflux activity.« less

Growth and characterization of organic material 4-dimethylaminobenzaldehyde single crystal.

PubMed

Jebin, R P; Suthan, T; Rajesh, N P; Vinitha, G; Madhusoodhanan, U

2015-01-25

The organic material 4-dimethylaminobenzaldehyde single crystals were grown by slow evaporation technique. The grown crystal was confirmed by the single crystal and powder X-ray diffraction analyses. The functional groups of the crystal have been identified from the Fourier Transform Infrared (FTIR) and FT-Raman studies. The optical property of the grown crystal was analyzed by UV-Vis-NIR and photoluminescence (PL) spectral measurements. The thermal behavior of the grown crystal was analyzed by thermogravimetric (TG) and differential thermal analyses (DTA). Dielectric measurements were carried out with different frequencies by using parallel plate capacitor method. The third order nonlinear optical properties of 4-dimethylaminobenzaldehyde was measured by the Z-scan technique using 532 nm diode pumped continuous wave (CW) Nd:YAG laser. Copyright © 2014 Elsevier B.V. All rights reserved.

Selecting statistical model and optimum maintenance policy: a case study of hydraulic pump.

PubMed

Ruhi, S; Karim, M R

2016-01-01

Proper maintenance policy can play a vital role for effective investigation of product reliability. Every engineered object such as product, plant or infrastructure needs preventive and corrective maintenance. In this paper we look at a real case study. It deals with the maintenance of hydraulic pumps used in excavators by a mining company. We obtain the data that the owner had collected and carry out an analysis and building models for pump failures. The data consist of both failure and censored lifetimes of the hydraulic pump. Different competitive mixture models are applied to analyze a set of maintenance data of a hydraulic pump. Various characteristics of the mixture models, such as the cumulative distribution function, reliability function, mean time to failure, etc. are estimated to assess the reliability of the pump. Akaike Information Criterion, adjusted Anderson-Darling test statistic, Kolmogrov-Smirnov test statistic and root mean square error are considered to select the suitable models among a set of competitive models. The maximum likelihood estimation method via the EM algorithm is applied mainly for estimating the parameters of the models and reliability related quantities. In this study, it is found that a threefold mixture model (Weibull-Normal-Exponential) fits well for the hydraulic pump failures data set. This paper also illustrates how a suitable statistical model can be applied to estimate the optimum maintenance period at a minimum cost of a hydraulic pump.

Geophysical Assessment of Groundwater Potential: A Case Study from Mian Channu Area, Pakistan.

PubMed

Hasan, Muhammad; Shang, Yanjun; Akhter, Gulraiz; Jin, Weijun

2017-11-17

An integrated study using geophysical method in combination with pumping tests and geochemical method was carried out to delineate groundwater potential zones in Mian Channu area of Pakistan. Vertical electrical soundings (VES) using Schlumberger configuration with maximum current electrode spacing (AB/2 = 200 m) were conducted at 50 stations and 10 pumping tests at borehole sites were performed in close proximity to 10 of the VES stations. The aim of this study is to establish a correlation between the hydraulic parameters obtained from geophysical method and pumping tests so that the aquifer potential can be estimated from the geoelectrical surface measurements where no pumping tests exist. The aquifer parameters, namely, transmissivity and hydraulic conductivity were estimated from Dar Zarrouyk parameters by interpreting the layer parameters such as true resistivities and thicknesses. Geoelectrical succession of five-layer strata (i.e., topsoil, clay, clay sand, sand, and sand gravel) with sand as a dominant lithology was found in the study area. Physicochemical parameters interpreted by World Health Organization and Food and Agriculture Organization were well correlated with the aquifer parameters obtained by geoelectrical method and pumping tests. The aquifer potential zones identified by modeled resistivity, Dar Zarrouk parameters, pumped aquifer parameters, and physicochemical parameters reveal that sand and gravel sand with high values of transmissivity and hydraulic conductivity are highly promising water bearing layers in northwest of the study area. Strong correlation between estimated and pumped aquifer parameters suggest that, in case of sparse well data, geophysical technique is useful to estimate the hydraulic potential of the aquifer with varying lithology. © 2017, National Ground Water Association.

Functional reconstitution of Arabidopsis thaliana plant uncoupling mitochondrial protein (AtPUMP1) expressed in Escherichia coli.

PubMed

Borecký, J; Maia, I G; Costa, A D; Jezek, P; Chaimovich, H; de Andrade, P B; Vercesi, A E; Arruda, P

2001-09-14

The Arabidopsis thaliana uncoupling protein (UCP) gene was expressed in Escherichia coli and isolated protein reconstituted into liposomes. Linoleic acid-induced H+ fluxes were sensitive to purine nucleotide inhibition with an apparent K(i) (in mM) of 0.8 (GDP), 0.85 (ATP), 0.98 (GTP), and 1.41 (ADP); the inhibition was pH-dependent. Kinetics of AtPUMP1-mediated H+ fluxes were determined for lauric, myristic, palmitic, oleic, linoleic, and linolenic acids. Properties of recombinant AtPUMP1 indicate that it represents a plant counterpart of animal UCP2 or UCP3. This work brings the functional and genetic approaches together for the first time, providing strong support that AtPUMP1 is truly an UCP.

Determining Mass and Persistence of a Reactive Brominated-Solvent DNAPL Source Using Mass Depletion-Mass Flux Reduction Relationships During Pumping

NASA Astrophysics Data System (ADS)

Johnston, C. D.; Davis, G. B.; Bastow, T.; Annable, M. D.; Trefry, M. G.; Furness, A.; Geste, Y.; Woodbury, R.; Rhodes, S.

2011-12-01

Measures of the source mass and depletion characteristics of recalcitrant dense non-aqueous phase liquid (DNAPL) contaminants are critical elements for assessing performance of remediation efforts. This is in addition to understanding the relationships between source mass depletion and changes to dissolved contaminant concentration and mass flux in groundwater. Here we present results of applying analytical source-depletion concepts to pumping from within the DNAPL source zone of a 10-m thick heterogeneous layered aquifer to estimate the original source mass and characterise the time trajectory of source depletion and mass flux in groundwater. The multi-component, reactive DNAPL source consisted of the brominated solvent tetrabromoethane (TBA) and its transformation products (mostly tribromoethene - TriBE). Coring and multi-level groundwater sampling indicated the DNAPL to be mainly in lower-permeability layers, suggesting the source had already undergone appreciable depletion. Four simplified source dissolution models (exponential, power function, error function and rational mass) were able to describe the concentration history of the total molar concentration of brominated organics in extracted groundwater during 285 days of pumping. Approximately 152 kg of brominated compounds were extracted. The lack of significant kinetic mass transfer limitations in pumped concentrations was notable. This was despite the heterogeneous layering in the aquifer and distribution of DNAPL. There was little to choose between the model fits to pumped concentration time series. The variance of groundwater velocities in the aquifer determined during a partitioning inter-well tracer test (PITT) were used to parameterise the models. However, the models were found to be relatively insensitive to this parameter. All models indicated an initial source mass around 250 kg which compared favourably to an estimate of 220 kg derived from the PITT. The extrapolated concentrations from the dissolution models diverged, showing disparate approaches to possible remediation objectives. However, it also showed that an appreciable proportion of the source would need to be removed to discriminate between the models. This may limit the utility of such modelling early in the history of a DNAPL source. A further limitation is the simplified approach of analysing the combined parent/daughter compounds with different solubilities as a total molar concentration. Although the fitted results gave confidence to this approach, there were appreciable changes in relative abundance. The dissolution and partitioning processes are discussed in relation to the lower-solubility TBA becoming dominant in pumped groundwater over time, despite its known rapid transformation to TriBE. These processes are also related to the architecture of the depleting source as revealed by multi-level groundwater sampling under reversed pumping/injection conditions.

Flow tube used to cool solar-pumped laser

NASA Technical Reports Server (NTRS)

1968-01-01

A flow tube has been designed and constructed to provide two major functions in the application of a laser beam for transmission of both sound and video. It maintains the YAG laser at the proper operating temperature of 300 degrees K under solar pumping conditions, and it serves as a pump cavity for the laser crystal.

Mathematical Modeling of Rotary Blood Pumps in a Pulsatile In Vitro Flow Environment.

PubMed

Pirbodaghi, Tohid

2017-08-01

Nowadays, sacrificing animals to develop medical devices and receive regulatory approval has become more common, which increases ethical concerns. Although in vivo tests are necessary for development and evaluation of new devices, nonetheless, with appropriate in vitro setups and mathematical models, a part of the validation process can be performed using these models to reduce the number of sacrificed animals. The main aim of this study is to present a mathematical model simulating the hydrodynamic function of a rotary blood pump (RBP) in a pulsatile in vitro flow environment. This model relates the pressure head of the RBP to the flow rate, rotational speed, and time derivatives of flow rate and rotational speed. To identify the model parameters, an in vitro setup was constructed consisting of a piston pump, a compliance chamber, a throttle, a buffer reservoir, and the CentriMag RBP. A 40% glycerin-water mixture as a blood analog fluid and deionized water were used in the hydraulic circuit to investigate the effect of viscosity and density of the working fluid on the model parameters. First, model variables were physically measured and digitally acquired. Second, an identification algorithm based on regression analysis was used to derive the model parameters. Third, the completed model was validated with a totally different set of in vitro data. The model is usable for both mathematical simulations of the interaction between the pump and heart and indirect pressure measurement in a clinical context. © 2017 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

The plant energy-dissipating mitochondrial systems: depicting the genomic structure and the expression profiles of the gene families of uncoupling protein and alternative oxidase in monocots and dicots.

PubMed

Borecky, Jirí; Nogueira, Fábio T S; de Oliveira, Kívia A P; Maia, Ivan G; Vercesi, Aníbal E; Arruda, Paulo

2006-01-01

The simultaneous existence of alternative oxidases and uncoupling proteins in plants has raised the question as to why plants need two energy-dissipating systems with apparently similar physiological functions. A probably complete plant uncoupling protein gene family is described and the expression profiles of this family compared with the multigene family of alternative oxidases in Arabidopsis thaliana and sugarcane (Saccharum sp.) employed as dicot and monocot models, respectively. In total, six uncoupling protein genes, AtPUMP1-6, were recognized within the Arabidopsis genome and five (SsPUMP1-5) in a sugarcane EST database. The recombinant AtPUMP5 protein displayed similar biochemical properties as AtPUMP1. Sugarcane possessed four Arabidopsis AOx1-type orthologues (SsAOx1a-1d); no sugarcane orthologue corresponding to Arabidopsis AOx2-type genes was identified. Phylogenetic and expression analyses suggested that AtAOx1d does not belong to the AOx1-type family but forms a new (AOx3-type) family. Tissue-enriched expression profiling revealed that uncoupling protein genes were expressed more ubiquitously than the alternative oxidase genes. Distinct expression patterns among gene family members were observed between monocots and dicots and during chilling stress. These findings suggest that the members of each energy-dissipating system are subject to different cell or tissue/organ transcriptional regulation. As a result, plants may respond more flexibly to adverse biotic and abiotic conditions, in which oxidative stress is involved.

Rapid Speed Modulation of a Rotary Total Artificial Heart Impeller.

PubMed

Kleinheyer, Matthias; Timms, Daniel L; Tansley, Geoffrey D; Nestler, Frank; Greatrex, Nicholas A; Frazier, O Howard; Cohn, William E

2016-09-01

Unlike the earlier reciprocating volume displacement-type pumps, rotary blood pumps (RBPs) typically operate at a constant rotational speed and produce continuous outflow. When RBP technology is used in constructing a total artificial heart (TAH), the pressure waveform that the TAH produces is flat, without the rise and fall associated with a normal arterial pulse. Several studies have suggested that pulseless circulation may impair microcirculatory perfusion and the autoregulatory response and may contribute to adverse events such as gastrointestinal bleeding, arteriovenous malformations, and pump thrombosis. It may therefore be beneficial to attempt to reproduce pulsatile output, similar to that generated by the native heart, by rapidly modulating the speed of an RBP impeller. The choice of an appropriate speed profile and control strategy to generate physiologic waveforms while minimizing power consumption and blood trauma becomes a challenge. In this study, pump operation modes with six different speed profiles using the BiVACOR TAH were evaluated in vitro. These modes were compared with respect to: hemodynamic pulsatility, which was quantified as surplus hemodynamic energy (SHE); maximum rate of change of pressure (dP/dt); pulse power index; and motor power consumption as a function of pulse pressure. The results showed that the evaluated variables underwent different trends in response to changes in the speed profile shape. The findings indicated a possible trade-off between SHE levels and flow rate pulsatility related to the relative systolic duration in the speed profile. Furthermore, none of the evaluated measures was sufficient to fully characterize hemodynamic pulsatility. © 2016 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Evaluation of Ti-Zr-V (NEG) Thin Films for their pumping speed and pumping Capacity

NASA Astrophysics Data System (ADS)

Bansod, Tripti; Sindal, B. K.; Kumar, K. V. A. N. P. S.; Shukla, S. K.

2012-11-01

Deposition of NEG thin films onto the interior walls of the vacuum chambers is an advanced technique to convert a vacuum chamber from a gas source to an effective pump. These films offer considerably large pumping speed for reactive gases like CO, H2 etc. A UHV compatible pumping speed measurement system was developed in-house to measure the pumping speed of NEG coated chambers. To inject the fixed quantity of CO and H2 gas in pumping speed measurement set-up a calibrated leak was also developed. Stainless steel chambers were sputter coated with thin film of Ti-Zr-V getter material using varied parameters for different compositions and thickness. Pumping capacity which is a function of sorbed gas quantities was also studied at various activation temperatures. In order to optimize the activation temperature for maximum pumping speed for CO and H2, pumping speeds were measured at room temperature after activation at different temperatures. The experimental system detail, pumping performance of the NEG film at various activation temperatures and RGA analysis are presented.

A displacement pump procedure to load extracts for automated gel permeation chromatography.

PubMed

Daft, J; Hopper, M; Hensley, D; Sisk, R

1990-01-01

Automated gel permeation chromatography (GPC) effectively separates lipids from pesticides in sample extracts that contain fat. Using a large syringe to load sample extracts manually onto GPC models having 5 mL holding loops is awkward, slow, and potentially hazardous. Loading with a small-volume displacement pump, however, is convenient and fast (ca 1 loop every 20 s). And more importantly, the analyst is not exposed to toxic organic vapors because the loading pump and its connecting lines do not leak in the way that a syringe does.

Vibrations Detection in Industrial Pumps Based on Spectral Analysis to Increase Their Efficiency

NASA Astrophysics Data System (ADS)

Rachid, Belhadef; Hafaifa, Ahmed; Boumehraz, Mohamed

2016-03-01

Spectral analysis is the key tool for the study of vibration signals in rotating machinery. In this work, the vibration analysis applied for conditional preventive maintenance of such machines is proposed, as part of resolved problems related to vibration detection on the organs of these machines. The vibration signal of a centrifugal pump was treated to mount the benefits of the approach proposed. The obtained results present the signal estimation of a pump vibration using Fourier transform technique compared by the spectral analysis methods based on Prony approach.

Protonation-state-Coupled Conformational Dynamics in Reaction Mechanisms of Channel and Pump Rhodopsins

DOE PAGES

Bondar, Ana-Nicoleta; Smith, Jeremy C.

2017-07-25

Channel and pump rhodopsins use energy from light absorbed by a covalently bound retinal chromophore to transport ions across membranes of microbial cells. Ion transfer steps, including proton transfer, can couple to changes in protein conformational dynamics and water positions. Although general principles of how microbial rhodopsins function are largely understood, key issues pertaining to reaction mechanisms remain unclear. Here, we compare the protonation-coupled dynamics of pump and channelrhodopsins, highlighting the roles that water dynamics, protein electrostatics and protein flexibility can have in ion transport mechanisms. We discuss observations supporting important functional roles of inter- and intra-helical carboxylate/hydroxyl hydrogen-bonding motifs.more » Specifically, we use the proton pump bacteriorhodopsin, the sodium pump KR2, channelrhodopsins and Anabaena sensory rhodopsin. We outline the usefulness of theoretic biophysics approaches to the study of retinal proteins, challenges in studying the hydrogen-bond dynamics of rhodopsin active sites, and implications for conformational coupling in membrane transporters.« less

Protonation-state-Coupled Conformational Dynamics in Reaction Mechanisms of Channel and Pump Rhodopsins

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

Bondar, Ana-Nicoleta; Smith, Jeremy C.

Channel and pump rhodopsins use energy from light absorbed by a covalently bound retinal chromophore to transport ions across membranes of microbial cells. Ion transfer steps, including proton transfer, can couple to changes in protein conformational dynamics and water positions. Although general principles of how microbial rhodopsins function are largely understood, key issues pertaining to reaction mechanisms remain unclear. Here, we compare the protonation-coupled dynamics of pump and channelrhodopsins, highlighting the roles that water dynamics, protein electrostatics and protein flexibility can have in ion transport mechanisms. We discuss observations supporting important functional roles of inter- and intra-helical carboxylate/hydroxyl hydrogen-bonding motifs.more » Specifically, we use the proton pump bacteriorhodopsin, the sodium pump KR2, channelrhodopsins and Anabaena sensory rhodopsin. We outline the usefulness of theoretic biophysics approaches to the study of retinal proteins, challenges in studying the hydrogen-bond dynamics of rhodopsin active sites, and implications for conformational coupling in membrane transporters.« less

The complete genome, comparative and functional analysis of Stenotrophomonas maltophilia reveals an organism heavily shielded by drug resistance determinants

PubMed Central

Crossman, Lisa C; Gould, Virginia C; Dow, J Maxwell; Vernikos, Georgios S; Okazaki, Aki; Sebaihia, Mohammed; Saunders, David; Arrowsmith, Claire; Carver, Tim; Peters, Nicholas; Adlem, Ellen; Kerhornou, Arnaud; Lord, Angela; Murphy, Lee; Seeger, Katharine; Squares, Robert; Rutter, Simon; Quail, Michael A; Rajandream, Mari-Adele; Harris, David; Churcher, Carol; Bentley, Stephen D; Parkhill, Julian; Thomson, Nicholas R; Avison, Matthew B

2008-01-01

Background Stenotrophomonas maltophilia is a nosocomial opportunistic pathogen of the Xanthomonadaceae. The organism has been isolated from both clinical and soil environments in addition to the sputum of cystic fibrosis patients and the immunocompromised. Whilst relatively distant phylogenetically, the closest sequenced relatives of S. maltophilia are the plant pathogenic xanthomonads. Results The genome of the bacteremia-associated isolate S. maltophilia K279a is 4,851,126 bp and of high G+C content. The sequence reveals an organism with a remarkable capacity for drug and heavy metal resistance. In addition to a number of genes conferring resistance to antimicrobial drugs of different classes via alternative mechanisms, nine resistance-nodulation-division (RND)-type putative antimicrobial efflux systems are present. Functional genomic analysis confirms a role in drug resistance for several of the novel RND efflux pumps. S. maltophilia possesses potentially mobile regions of DNA and encodes a number of pili and fimbriae likely to be involved in adhesion and biofilm formation that may also contribute to increased antimicrobial drug resistance. Conclusion The panoply of antimicrobial drug resistance genes and mobile genetic elements found suggests that the organism can act as a reservoir of antimicrobial drug resistance determinants in a clinical environment, which is an issue of considerable concern. PMID:18419807

Control of Brillouin short-pulse seed amplification by chirping the pump pulse

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

Lehmann, G.; Spatschek, K. H.

Seed amplification via Brillouin backscattering of a long pump pulse is considered. Similar to Raman amplification, several obstructive effects may occur during short-pulse Brillouin amplification. One is the spontaneous Raman backscattering of the pump before interacting with the seed. Preforming the plasma and/or chirping the pump will reduce unwanted pump backscattering. Optimized regions for low-loss pump propagation were proposed already in conjunction with Raman seed amplification. Hence, the influence of the chirp of the pump during Brillouin interaction with the seed becomes important and will be considered here. Both, the linear as well as the nonlinear evolution phases of themore » seed caused by Brillouin amplification under the action of a chirped pump are investigated. The amplification rate as well as the seed profiles are presented as function of the chirping rate. Also the dependence of superradiant scaling rates on the chirp parameter is discussed.« less

Pump spot size dependent lasing threshold in organic semiconductor DFB lasers fabricated via nanograting transfer.

PubMed

Liu, Xin; Klinkhammer, Sönke; Wang, Ziyao; Wienhold, Tobias; Vannahme, Christoph; Jakobs, Peter-Jürgen; Bacher, Andreas; Muslija, Alban; Mappes, Timo; Lemmer, Uli

2013-11-18

Optically excited organic semiconductor distributed feedback (DFB) lasers enable efficient lasing in the visible spectrum. Here, we report on the rapid and parallel fabrication of DFB lasers via transferring a nanograting structure from a flexible mold onto an unstructured film of the organic gain material. This geometrically well-defined structure allows for a systematic investigation of the laser threshold behavior. The laser thresholds for these devices show a strong dependence on the pump spot diameter. This experimental finding is in good qualitative agreement with calculations based on coupled-wave theory. With further investigations on various DFB laser geometries prepared by different routes and based on different organic gain materials, we found that these findings are quite general. This is important for the comparison of threshold values of various devices characterized under different excitation areas.

NHEXAS PHASE I ARIZONA STUDY--STANDARD OPERATING PROCEDURE FOR PREPARATION OF MULTISORBENT TUBES FOR ACTIVELY-PUMPED VOC SAMPLERS (BCO-L-18.1)

EPA Science Inventory

The purpose of this SOP is to describe the procedures followed in the preparation of carbon-based multisorbent tubes for the collection of volatile organic compounds (VOCs) in air using actively-pumped samplers. This procedure was followed to ensure consistent data retrieval duri...

Characteristics of dissolved organic matter in the Upper Klamath River, Lost River, and Klamath Straits Drain, Oregon and California

USGS Publications Warehouse

Goldman, Jami H.; Sullivan, Annett B.

2017-12-11

Concentrations of particulate organic carbon (POC) and dissolved organic carbon (DOC), which together comprise total organic carbon, were measured in this reconnaissance study at sampling sites in the Upper Klamath River, Lost River, and Klamath Straits Drain in 2013–16. Optical absorbance and fluorescence properties of dissolved organic matter (DOM), which contains DOC, also were analyzed. Parallel factor analysis was used to decompose the optical fluorescence data into five key components for all samples. Principal component analysis (PCA) was used to investigate differences in DOM source and processing among sites.At all sites in this study, average DOC concentrations were higher than average POC concentrations. The highest DOC concentrations were at sites in the Klamath Straits Drain and at Pump Plant D. Evaluation of optical properties indicated that Klamath Straits Drain DOM had a refractory, terrestrial source, likely extracted from the interaction of this water with wetland peats and irrigated soils. Pump Plant D DOM exhibited more labile characteristics, which could, for instance, indicate contributions from algal or microbial exudates. The samples from Klamath River also had more microbial or algal derived material, as indicated by PCA analysis of the optical properties. Most sites, except Pump Plant D, showed a linear relation between fluorescent dissolved organic matter (fDOM) and DOC concentration, indicating these measurements are highly correlated (R2=0.84), and thus a continuous fDOM probe could be used to estimate DOC loads from these sites.

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

Robb, Kevin R.; Jain, Prashant K.; Hazelwood, Thomas J.

Fluoride salt cooled high-temperature reactor (FHR) concepts include pumps for forced circulation of the primary and secondary coolants. As part of a cooperative research and development agreement between the Shanghai Institute of Applied Physics and the Oak Ridge National Laboratory (ORNL), a research project was initiated to aid in the development of pumps for high-temperature salts. The objectives of the task included characterization of the behavior of an existing ORNL LSTL pump; design and test a modified impeller and volute for improved pump characteristics; and finally, provide lessons learned, recommendations, and guidelines for salt pump development and design. The pumpmore » included on the liquid salt test loop (LSTL) at ORNL served as a case study. This report summarizes the progress to date. The report is organized as follows. First, there is a review, focused on pumps, of the significant amount of work on salts at ORNL during the 1950s 1970s. The existing pump on the LSTL is then described. Plans for hot and cold testing of the pump are then discussed, including the design for a cold shakedown test stand and the required LSTL modifications for hot testing. Initial hydraulic and vibration modeling of the LSTL pump is documented. Later, test data from the LSTL will be used to validate the modeling approaches, which could then be used for future pump design efforts. Some initial insights and test data from the pump are then provided. Finally, some preliminary design goals and requirements for a future LSTL pump are provided as examples of salt pump design considerations.« less

Nuclear magnetic resonance of laser-polarized noble gases in molecules, materials and organisms

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

Goodson, Boyd McLean

1999-12-01

Conventional nuclear magnetic resonance (NMR) spectroscopy and magnetic resonance imaging (MRI) are fundamentally challenged by the insensitivity that stems from the ordinarily low spin polarization achievable in even the strongest NMR magnets. However, by transferring angular momentum from laser light to electronic and nuclear spins, optical pumping methods can increase the nuclear spin polarization of noble gases by several orders of magnitude, thereby greatly enhancing their NMR sensitivity. This dissertation is primarily concerned with the principles and practice of optically pumped nuclear magnetic resonance (OPNMR). The enormous sensitivity enhancement afforded by optical pumping noble gases can be exploited to permitmore » a variety of novel NMR experiments across many disciplines. Many such experiments are reviewed, including the void-space imaging of organisms and materials, NMR and MRI of living tissues, probing structure and dynamics of molecules in solution and on surfaces, and zero-field NMR and MRI.« less

Single-dose volume regulation algorithm for a gas-compensated intrathecal infusion pump.

PubMed

Nam, Kyoung Won; Kim, Kwang Gi; Sung, Mun Hyun; Choi, Seong Wook; Kim, Dae Hyun; Jo, Yung Ho

2011-01-01

The internal pressures of medication reservoirs of gas-compensated intrathecal medication infusion pumps decrease when medication is discharged, and these discharge-induced pressure drops can decrease the volume of medication discharged. To prevent these reductions, the volumes discharged must be adjusted to maintain the required dosage levels. In this study, the authors developed an automatic control algorithm for an intrathecal infusion pump developed by the Korean National Cancer Center that regulates single-dose volumes. The proposed algorithm estimates the amount of medication remaining and adjusts control parameters automatically to maintain single-dose volumes at predetermined levels. Experimental results demonstrated that the proposed algorithm can regulate mean single-dose volumes with a variation of <3% and estimate the remaining medication volume with an accuracy of >98%. © 2010, Copyright the Authors. Artificial Organs © 2010, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Organic flash cycles for efficient power production

DOEpatents

Ho, Tony; Mao, Samuel S.; Greif, Ralph

2016-03-15

This disclosure provides systems, methods, and apparatus related to an Organic Flash Cycle (OFC). In one aspect, a modified OFC system includes a pump, a heat exchanger, a flash evaporator, a high pressure turbine, a throttling valve, a mixer, a low pressure turbine, and a condenser. The heat exchanger is coupled to an outlet of the pump. The flash evaporator is coupled to an outlet of the heat exchanger. The high pressure turbine is coupled to a vapor outlet of the flash evaporator. The throttling valve is coupled to a liquid outlet of the flash evaporator. The mixer is coupled to an outlet of the throttling valve and to an outlet of the high pressure turbine. The low pressure turbine is coupled to an outlet of the mixer. The condenser is coupled to an outlet of the low pressure turbine and to an inlet of the pump.

Organo-erbium systems for optical amplification at telecommunications wavelengths.

PubMed

Ye, H Q; Li, Z; Peng, Y; Wang, C C; Li, T Y; Zheng, Y X; Sapelkin, A; Adamopoulos, G; Hernández, I; Wyatt, P B; Gillin, W P

2014-04-01

Modern telecommunications rely on the transmission and manipulation of optical signals. Optical amplification plays a vital part in this technology, as all components in a real telecommunications system produce some loss. The two main issues with present amplifiers, which rely on erbium ions in a glass matrix, are the difficulty in integration onto a single substrate and the need of high pump power densities to produce gain. Here we show a potential organic optical amplifier material that demonstrates population inversion when pumped from above using low-power visible light. This system is integrated into an organic light-emitting diode demonstrating that electrical pumping can be achieved. This opens the possibility of direct electrically driven optical amplifiers and optical circuits. Our results provide an alternative approach to producing low-cost integrated optics that is compatible with existing silicon photonics and a different route to an effective integrated optics technology.

Estimation of Distributed Groundwater Pumping Rates in Yolo County,CA—Intercomparison of Two Modeling Frameworks

NASA Astrophysics Data System (ADS)

Maples, S.; Fogg, G. E.; Harter, T.

2015-12-01

Accurate estimation of groundwater (GW) budgets and effective management of agricultural GW pumping remains a challenge in much of California's Central Valley (CV) due to a lack of irrigation well metering. CVHM and C2VSim are two regional-scale integrated hydrologic models that provide estimates of historical and current CV distributed pumping rates. However, both models estimate GW pumping using conceptually different agricultural water models with uncertainties that have not been adequately investigated. Here, we evaluate differences in distributed agricultural GW pumping and recharge estimates related to important differences in the conceptual framework and model assumptions used to simulate surface water (SW) and GW interaction across the root zone. Differences in the magnitude and timing of GW pumping and recharge were evaluated for a subregion (~1000 mi2) coincident with Yolo County, CA, to provide similar initial and boundary conditions for both models. Synthetic, multi-year datasets of land-use, precipitation, evapotranspiration (ET), and SW deliveries were prescribed for each model to provide realistic end-member scenarios for GW-pumping demand and recharge. Results show differences in the magnitude and timing of GW-pumping demand, deep percolation, and recharge. Discrepancies are related, in large part, to model differences in the estimation of ET requirements and representation of soil-moisture conditions. CVHM partitions ET demand, while C2VSim uses a bulk ET rate, resulting in differences in both crop-water and GW-pumping demand. Additionally, CVHM assumes steady-state soil-moisture conditions, and simulates deep percolation as a function of irrigation inefficiencies, while C2VSim simulates deep percolation as a function of transient soil-moisture storage conditions. These findings show that estimates of GW-pumping demand are sensitive to these important conceptual differences, which can impact conjunctive-use water management decisions in the CV.

Power consumption of rotary blood pumps: pulsatile versus constant-speed mode.

PubMed

Pirbodaghi, Tohid; Cotter, Chris; Bourque, Kevin

2014-12-01

We investigated the power consumption of a HeartMate III rotary blood pump based on in vitro experiments performed in a cardiovascular simulator. To create artificial-pulse mode, we modulated the pump speed by decreasing the mean speed by 2000 rpm for 200 ms and then increasing speed by 4000 rpm (mean speeds plus 2000 rpm) for another 200 ms, creating a square waveform shape. The HeartMate III was connected to a cardiovascular simulator consisting of a hydraulic pump system to simulate left ventricle pumping action, arterial and venous compliance chambers, and an adjustable valve for peripheral resistance to facilitate the desired aortic pressure. The simulator operated based on Suga's elastance model to mimic the Starling response of the heart, thereby reproducing physiological blood flow and pressure conditions. We measured the instantaneous total electrical current and voltage of the pump to evaluate its power consumption. The aim was to answer these fundamental questions: (i) How does pump speed modulation affect pump power consumption? (ii) How does the power consumption vary in relation to external pulsatile flow? The results indicate that speed modulation and external pulsatile flow both moderately increase the power consumption. Increasing the pump speed reduces the impact of external pulsatile flow. Copyright © 2014 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Hemodynamics of a functional centrifugal-flow total artificial heart with functional atrial contraction in goats.

PubMed

Shiga, Takuya; Shiraishi, Yasuyuki; Sano, Kyosuke; Taira, Yasunori; Tsuboko, Yusuke; Yamada, Akihiro; Miura, Hidekazu; Katahira, Shintaro; Akiyama, Masatoshi; Saiki, Yoshikatsu; Yambe, Tomoyuki

2016-03-01

Implantation of a total artificial heart (TAH) is one of the therapeutic options for the treatment of patients with end-stage biventricular heart failure. There is no report on the hemodynamics of the functional centrifugal-flow TAH with functional atrial contraction (fCFTAH). We evaluated the effects of pulsatile flow by atrial contraction in acute animal models. The goats received fCFTAH that we created from two centrifugal-flow ventricular assist devices. Some hemodynamic parameters maintained acceptable levels: heart rate 115.5 ± 26.3 bpm, aortic pressure 83.5 ± 10.1 mmHg, left atrial pressure 18.0 ± 5.9 mmHg, pulmonary pressure 28.5 ± 9.7 mmHg, right atrial pressure 13.6 ± 5.2 mmHg, pump flow 4.0 ± 1.1 L/min (left) 3.9 ± 1.1 L/min (right), and cardiac index 2.13 ± 0.14 L/min/m(2). fCFTAH with atrial contraction was able to maintain the TAH circulation by forming a pulsatile flow in acute animal experiments. Taking the left and right flow rate balance using the low internal pressure loss of the VAD pumps may be easier than by other pumps having considerable internal pressure loss. We showed that the remnant atrial contraction effected the flow rate change of the centrifugal pump, and the atrial contraction waves reflected the heart rate. These results indicate that remnant atria had the possibility to preserve autonomic function in fCFTAH. We may control fCFTAH by reflecting the autonomic function, which is estimated with the flow rate change of the centrifugal pump.

Correlation between the Serum Pepsinogen I Level and the Symptom Degree in Proton Pump Inhibitor-Users Administered with a Probiotic

PubMed Central

Igarashi, Muneki; Nagano, Jun; Tsuda, Ayumi; Suzuki, Takayoshi; Koike, Jun; Uchida, Tetsufumi; Matsushima, Masashi; Mine, Tetsuya; Koga, Yasuhiro

2014-01-01

In patients with functional upper gastrointestinal disorders such as gastroesophageal reflux disease and functional dyspepsia, the presence of symptoms is thought to occur in the absence of any organic diseases and the mechanisms behind this remain unclear. We therefore examined the relationship between stomach-related biomarker levels and symptoms. Twenty-four outpatients who had taken proton-pump inhibitors every day were enrolled in this study. The subjects consumed yogurt containing 109 colony-forming units of Lactobacillus gasseri OLL2716 (LG21) every day for three months. They underwent four clinical examinations in total. Each examination consisted of answering a questionnaire with a frequency scale for the symptoms of GERD (FSSG), and included measurements of the serum gastrin, ghrelin, and pepsinogens I and II levels. As a result, the FSSG score and the PGI value showed a decrease and an increase, respectively, after LG21 treatment when analyzed without age adjustment. A multiple regression analysis with additional adjustments for gender and age revealed a strong association between the PGI value and the FSSG symptom scores. Therefore either the PGI level itself or the factors regulating the PGI level might be involved in the etiology of these symptoms. PMID:24967535

[Obesity as pathology of adipocytes: number of cells, volume of arterial bloodstream,local pools of circulation in vivo, natriuretic peptides and arterial hypertension].

PubMed

Titov, V N; Dmitriev, V A

2015-03-01

The non-specific systemic biological reaction of arterial pressure from the level of organism. vasomotor center and proximal section of arterial bloodstream is appealed to compensate disorders of metabolism and microcirculation in distal section of arteries. This phenomenon occurs in several cases. The primarily local disorders of metabolism at autocrine level, physiological (aphysiological) death of cells, "littering" of intercellular medium become the cause of disorder of microcirculation in paracrin cenosises and deteriorate realization of biological functions of homeostasis, trophology, endoecology and adaptation. The local compensation of affected perfusion in paracrin cenosises at the expense of function of peripheral peristaltic pumps, redistribution of local bloodflow in biological reaction of endothelium-depended vaso-dilation has no possibility to eliminate disorders in realization of biological functions. The systemic increase of arterial pressure under absence of specific symptoms of symptomatic arterial hypertension is a test to detect disorder of biological functions of homeostasis, trophology, biological function of endoecology and adaptation. Allforms of arterial hypertension develop by common algorithm independently from causes of disorders of blood flow, microcirculation in distal section of arteries. The non-specific systemic compensation ofdisorders of metabolism from level of organism, in proximal section of arterial bloodstream always is the same one and results in aphysiological alterations in organs-targets. To comprehend etiological characteristics of common pathogenesis of arterial hypertension is possible in case of application of such technically complicated and still unclear in differential diagnostic of deranged functions modes of metabolomics.

Fine structures of the ejaculatory sac and sperm pump of the scorpionfly Panorpa liui Hua (Mecoptera: Panorpidae).

PubMed

Shen, Jian; Hua, Baozhen

2013-08-01

Male adults of Panorpidae possess a special sperm pump, through which the males transfer liquid sperm to the females. However, the structures of the sperm pump and the transfer mechanism have not been satisfactorily elucidated hitherto. In this paper the structures of the ejaculatory sac and sperm pump of the scorpionfly Panorpa liui Hua were investigated using light microscopy and scanning electron microscopy. The ejaculatory sac is located between the basal end of the paired vasa deferentia and the aedeagus, comprising a small anterior part and a large posterior part. The anterior part is simple and functions only as a channel for sperm transfer. The epithelial cells of the large posterior part likely have secretory functions. The sperm pump is formed by the posterior region of the ejaculatory sac and derivates of the genital field, which enclose the pumping chamber, a piston and the associated muscles. The orifice of the ejaculatory duct lies ventrad of the piston. The piston of the sperm pump is heavily sclerotized and controlled by two antagonistic muscle pairs. A pair of simple tubular accessory glands opens to the pumping chamber. Two well-developed sex pheromone glands are located on the ventral side of the ejaculatory sac, and are composed of two fan-shaped lamellae. The epithelium of the sex pheromone glands is single-layered, and forms densely filamentous processes. The ejaculation mechanism is briefly discussed based on the morphology of ejaculatory sac and sperm pump. Copyright © 2013 Elsevier Ltd. All rights reserved.

Hippo pathway deficiency reverses systolic heart failure after infarction.

PubMed

Leach, John P; Heallen, Todd; Zhang, Min; Rahmani, Mahdis; Morikawa, Yuka; Hill, Matthew C; Segura, Ana; Willerson, James T; Martin, James F

2017-10-12

Mammalian organs vary widely in regenerative capacity. Poorly regenerative organs, such as the heart are particularly vulnerable to organ failure. Once established, heart failure commonly results in mortality. The Hippo pathway, a kinase cascade that prevents adult cardiomyocyte proliferation and regeneration, is upregulated in human heart failure. Here we show that deletion of the Hippo pathway component Salvador (Salv) in mouse hearts with established ischaemic heart failure after myocardial infarction induces a reparative genetic program with increased scar border vascularity, reduced fibrosis, and recovery of pumping function compared with controls. Using translating ribosomal affinity purification, we isolate cardiomyocyte-specific translating messenger RNA. Hippo-deficient cardiomyocytes have increased expression of proliferative genes and stress response genes, such as the mitochondrial quality control gene, Park2. Genetic studies indicate that Park2 is essential for heart repair, suggesting a requirement for mitochondrial quality control in regenerating myocardium. Gene therapy with a virus encoding Salv short hairpin RNA improves heart function when delivered at the time of infarct or after ischaemic heart failure following myocardial infarction was established. Our findings indicate that the failing heart has a previously unrecognized reparative capacity involving more than cardiomyocyte renewal.

Optical silencing of body wall muscles induces pumping inhibition in Caenorhabditis elegans

PubMed Central

Takahashi, Megumi

2017-01-01

Feeding, a vital behavior in animals, is modulated depending on internal and external factors. In the nematode Caenorhabditis elegans, the feeding organ called the pharynx ingests food by pumping driven by the pharyngeal muscles. Here we report that optical silencing of the body wall muscles, which drive the locomotory movement of worms, affects pumping. In worms expressing the Arch proton pump or the ACR2 anion channel in the body wall muscle cells, the pumping rate decreases after activation of Arch or ACR2 with light illumination, and recovers gradually after terminating illumination. Pumping was similarly inhibited by illumination in locomotion-defective mutants carrying Arch, suggesting that perturbation of locomotory movement is not critical for pumping inhibition. Analysis of mutants and cell ablation experiments showed that the signals mediating the pumping inhibition response triggered by activation of Arch with weak light are transferred mainly through two pathways: one involving gap junction-dependent mechanisms through pharyngeal I1 neurons, which mediate fast signals, and the other involving dense-core vesicle-dependent mechanisms, which mediate slow signals. Activation of Arch with strong light inhibited pumping strongly in a manner that does not rely on either gap junction-dependent or dense-core vesicle-dependent mechanisms. Our study revealed a new aspect of the neural and neuroendocrine controls of pumping initiated from the body wall muscles. PMID:29281635

Engine lubrication circuit including two pumps

DOEpatents

Lane, William H.

2006-10-03

A lubrication pump coupled to the engine is sized such that the it can supply the engine with a predetermined flow volume as soon as the engine reaches a peak torque engine speed. In engines that operate predominately at speeds above the peak torque engine speed, the lubrication pump is often producing lubrication fluid in excess of the predetermined flow volume that is bypassed back to a lubrication fluid source. This arguably results in wasted power. In order to more efficiently lubricate an engine, a lubrication circuit includes a lubrication pump and a variable delivery pump. The lubrication pump is operably coupled to the engine, and the variable delivery pump is in communication with a pump output controller that is operable to vary a lubrication fluid output from the variable delivery pump as a function of at least one of engine speed and lubrication flow volume or system pressure. Thus, the lubrication pump can be sized to produce the predetermined flow volume at a speed range at which the engine predominately operates while the variable delivery pump can supplement lubrication fluid delivery from the lubrication pump at engine speeds below the predominant engine speed range.

Left atrial booster function in valvular heart disease.

PubMed

Heidenreich, F P; Shaver, J A; Thompson, M E; Leonard, J J

1970-09-01

This study was designed to assess atrial booster pump action in valvular heart disease and to dissect booster pump from reservoir-conduit functions. In five patients with aortic stenosis and six with mitral stenosis, sequential atrioventricular (A-V) pacing was instituted during the course of diagnostic cardiac catheterization. Continuous recording of valvular gradient allowed estimation of flow for each cardiac cycle by transposition of the Gorlin formula. Left ventricular ejection time and left ventricular stroke work in aortic stenosis or left ventricular mean systolic pressure in mitral stenosis were also determined. Control observations were recorded during sequential A-V pacing with well-timed atrial systole. Cardiac cycles were then produced with no atrial contraction but undisturbed atrial reservoir function by intermittently interrupting the atrial pacing stimulus during sequential A-V pacing. This intervention significantly reduced valvular gradient, flow, left ventricular ejection time, and left ventricular mean systolic pressure or stroke work. Cardiac cycles were then produced with atrial booster action eliminated by instituting synchronous A-V pacing. The resultant simultaneous contraction of the atrium and ventricle not only eliminated effective atrial systole but also placed atrial systole during the normal period of atrial reservoir function. This also significantly reduced all the hemodynamic measurements. However, comparison of the magnitude of change from these two different pacing interventions showed no greater impairment of hemodynamic state when both booster pump action and reservoir function were impaired than when booster pump action alone was impaired. The study confirms the potential benefit of well placed atrial booster pump action in valvular heart disease in man.

40 CFR 89.422 - Dilute sampling procedures-CVS calibration.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Pressure depression at CVS pump inlet PPI kPa ±.055 kPa Pressure head at CVS pump outlet PPO kPa ±.055 kPa... restricted condition in an increment of pump inlet depression that will yield a minimum of six data points... depression, (kPa). (iii) The correlation function at each test point is then calculated from the calibration...

40 CFR 89.422 - Dilute sampling procedures-CVS calibration.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Pressure depression at CVS pump inlet PPI kPa ±.055 kPa Pressure head at CVS pump outlet PPO kPa ±.055 kPa... restricted condition in an increment of pump inlet depression that will yield a minimum of six data points... depression, (kPa). (iii) The correlation function at each test point is then calculated from the calibration...

40 CFR 89.422 - Dilute sampling procedures-CVS calibration.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Pressure depression at CVS pump inlet PPI kPa ±.055 kPa Pressure head at CVS pump outlet PPO kPa ±.055 kPa... restricted condition in an increment of pump inlet depression that will yield a minimum of six data points... depression, (kPa). (iii) The correlation function at each test point is then calculated from the calibration...

40 CFR 89.422 - Dilute sampling procedures-CVS calibration.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Pressure depression at CVS pump inlet PPI kPa ±.055 kPa Pressure head at CVS pump outlet PPO kPa ±.055 kPa... restricted condition in an increment of pump inlet depression that will yield a minimum of six data points... depression, (kPa). (iii) The correlation function at each test point is then calculated from the calibration...

40 CFR 89.422 - Dilute sampling procedures-CVS calibration.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Pressure depression at CVS pump inlet PPI kPa ±.055 kPa Pressure head at CVS pump outlet PPO kPa ±.055 kPa... restricted condition in an increment of pump inlet depression that will yield a minimum of six data points... depression, (kPa). (iii) The correlation function at each test point is then calculated from the calibration...

Smiths Medical Medfusion 3010a syringe pump may overinfuse if software is outdated.

PubMed

2010-04-01

Smiths Medical Medfusion 3010a syringe pumps that aren't equipped with the latest software version (2.0.6) could overinfuse if the "recall last settings" function is used following an infusion in volume/time mode. If your facility has pumps equipped with software versions older than 2.0.6, contact Smiths Medical to obtain an upgrade.

Multiphysics Modeling of an Annular Linear Induction Pump With Applications to Space Nuclear Power Systems

NASA Technical Reports Server (NTRS)

Kilbane, J.; Polzin, K. A.

2014-01-01

An annular linear induction pump (ALIP) that could be used for circulating liquid-metal coolant in a fission surface power reactor system is modeled in the present work using the computational COMSOL Multiphysics package. The pump is modeled using a two-dimensional, axisymmetric geometry and solved under conditions similar to those used during experimental pump testing. Real, nonlinear, temperature-dependent material properties can be incorporated into the model for both the electrically-conducting working fluid in the pump (NaK-78) and structural components of the pump. The intricate three-phase coil configuration of the pump is implemented in the model to produce an axially-traveling magnetic wave that is qualitatively similar to the measured magnetic wave. The model qualitatively captures the expected feature of a peak in efficiency as a function of flow rate.

Microgravity heat pump for space station thermal management.

PubMed

Domitrovic, R E; Chen, F C; Mei, V C; Spezia, A L

2003-01-01

A highly efficient recuperative vapor compression heat pump was developed and tested for its ability to operate independent of orientation with respect to gravity while maximizing temperature lift. The objective of such a heat pump is to increase the temperature of, and thus reduce the size of, the radiative heat rejection panels on spacecrafts such as the International Space Station. Heat pump operation under microgravity was approximated by gravitational-independent experiments. Test evaluations include functionality, efficiency, and temperature lift. Commercially available components were used to minimize costs of new hardware development. Testing was completed on two heat pump design iterations--LBU-I and LBU--II, for a variety of operating conditions under the variation of several system parameters, including: orientation, evaporator water inlet temperature (EWIT), condenser water inlet temperature (CWIT), and compressor speed. The LBU-I system employed an ac motor, belt-driven scroll compressor, and tube-in-tube heat exchangers. The LBU-II system used a direct-drive AC motor compressor assembly and plate heat exchangers. The LBU-II system in general outperformed the LBU-I system on all accounts. Results are presented for all systems, showing particular attention to those states that perform with a COP of 4.5 +/- 10% and can maintain a temperature lift of 55 degrees F (30.6 degrees C) +/- 10%. A calculation of potential radiator area reduction shows that points with maximum temperature lift give the greatest potential for reduction, and that area reduction is a function of heat pump efficiency and a stronger function of temperature lift.

High V-PPase activity is beneficial under high salt loads, but detrimental without salinity.

PubMed

Graus, Dorothea; Konrad, Kai R; Bemm, Felix; Patir Nebioglu, Meliha Görkem; Lorey, Christian; Duscha, Kerstin; Güthoff, Tilman; Herrmann, Johannes; Ferjani, Ali; Cuin, Tracey Ann; Roelfsema, M Rob G; Schumacher, Karin; Neuhaus, H Ekkehard; Marten, Irene; Hedrich, Rainer

2018-06-25

The membrane-bound proton-pumping pyrophosphatase (V-PPase), together with the V-type H + -ATPase, generates the proton motive force that drives vacuolar membrane solute transport. Transgenic plants constitutively overexpressing V-PPases were shown to have improved salinity tolerance, but the relative impact of increasing PP i hydrolysis and proton-pumping functions has yet to be dissected. For a better understanding of the molecular processes underlying V-PPase-dependent salt tolerance, we transiently overexpressed the pyrophosphate-driven proton pump (NbVHP) in Nicotiana benthamiana leaves and studied its functional properties in relation to salt treatment by primarily using patch-clamp, impalement electrodes and pH imaging. NbVHP overexpression led to higher vacuolar proton currents and vacuolar acidification. After 3 d in salt-untreated conditions, V-PPase-overexpressing leaves showed a drop in photosynthetic capacity, plasma membrane depolarization and eventual leaf necrosis. Salt, however, rescued NbVHP-hyperactive cells from cell death. Furthermore, a salt-induced rise in V-PPase but not of V-ATPase pump currents was detected in nontransformed plants. The results indicate that under normal growth conditions, plants need to regulate the V-PPase pump activity to avoid hyperactivity and its negative feedback on cell viability. Nonetheless, V-PPase proton pump function becomes increasingly important under salt stress for generating the pH gradient necessary for vacuolar proton-coupled Na + sequestration. © 2018 The Authors. New Phytologist © 2018 New Phytologist Trust.

The dynamic ocean biological pump: Insights from a global compilation of particulate organic carbon, CaCO3, and opal concentration profiles from the mesopelagic

NASA Astrophysics Data System (ADS)

Lam, Phoebe J.; Doney, Scott C.; Bishop, James K. B.

2011-09-01

We have compiled a global data set of 62 open ocean profiles of particulate organic carbon (POC), CaCO3, and opal concentrations collected by large volume in situ filtration in the upper 1000 m over the last 30 years. We define concentration-based metrics for the strength (POC concentration at depth) and efficiency (attenuation of POC with depth in the mesopelagic) of the biological pump. We show that the strength and efficiency of the biological pump are dynamic and are characterized by a regime of constant and high transfer efficiency at low to moderate surface POC and a bloom regime where the height of the bloom is characterized by a weak deep biological pump and low transfer efficiency. The variability in POC attenuation length scale manifests in a clear decoupling between the strength of the shallow biological pump (e.g., POC at the export depth) and the strength of the deep biological pump (POC at 500 m). We suggest that the paradigm of diatom-driven export production is driven by a too restrictive perspective on upper mesopelagic dynamics. Indeed, our full mesopelagic analysis suggests that large, blooming diatoms have low transfer efficiency and thus may not export substantially to depth; rather, our analysis suggests that ecosystems characterized by smaller cells and moderately high %CaCO3 have a high mesopelagic transfer efficiency and can have higher POC concentrations in the deep mesopelagic even with relatively low surface or near-surface POC. This has negative implications for the carbon sequestration prospects of deliberate iron fertilization.

Active urea transport in lower vertebrates and mammals.

PubMed

Bankir, Lise

2014-01-01

Some unicellular organisms can take up urea from the surrounding fluids by an uphill pumping mechanism. Several active (energy-dependent) urea transporters (AUTs) have been cloned in these organisms. Functional studies show that active urea transport also occurs in elasmobranchs, amphibians, and mammals. In the two former groups, active urea transport may serve to conserve urea in body fluids in order to balance external high ambient osmolarity or prevent desiccation. In mammals, active urea transport may be associated with the need to either store and/or reuse nitrogen in the case of low nitrogen supply, or to excrete nitrogen efficiently in the case of excess nitrogen intake. There are probably two different families of AUTs, one with a high capacity able to establish only a relatively modest transepithelial concentration difference (renal tubule of some frogs, pars recta of the mammalian kidney, early inner medullary collecting duct in some mammals eating protein-poor diets) and others with a low capacity but able to maintain a high transepithelial concentration difference that has been created by another mechanism or in another organ (elasmobranch gills, ventral skin of some toads, and maybe mammalian urinary bladder). Functional characterization of these transporters shows that some are coupled to sodium (symports or antiports) while others are sodium-independent. In humans, only one genetic anomaly, with a mild phenotype (familial azotemia), is suspected to concern one of these transporters. In spite of abundant functional evidence for such transporters in higher organisms, none have been molecularly identified yet.

New generation extracorporeal membrane oxygenation with MedTech Mag-Lev, a single-use, magnetically levitated, centrifugal blood pump: preclinical evaluation in calves.

PubMed

Fujiwara, Tatsuki; Nagaoka, Eiki; Watanabe, Taiju; Miyagi, Naoto; Kitao, Takashi; Sakota, Daisuke; Mamiya, Taichi; Shinshi, Tadahiko; Arai, Hirokuni; Takatani, Setsuo

2013-05-01

We have evaluated the feasibility of a newly developed single-use, magnetically levitated centrifugal blood pump, MedTech Mag-Lev, in a 3-week extracorporeal membrane oxygenation (ECMO) study in calves against a Medtronic Bio-Pump BPX-80. A heparin- and silicone-coated polypropylene membrane oxygenator MERA NHP Excelung NSH-R was employed as an oxygenator. Six healthy male Holstein calves with body weights of about 100 kg were divided into two groups, four in the MedTech group and two in the Bio-Pump group. Under general anesthesia, the blood pump and oxygenator were inserted extracorporeally between the main pulmonary artery and the descending aorta via a fifth left thoracotomy. Postoperatively, both the pump and oxygen flow rates were controlled at 3 L/min. Heparin was continuously infused to maintain the activated clotting time at 200-240 s. All the MedTech ECMO calves completed the study duration. However, the Bio-Pump ECMO calves were terminated on postoperative days 7 and 10 because of severe hemolysis and thrombus formation. At the start of the MedTech ECMO, the pressure drop across the oxygenator was about 25 mm Hg with the pump operated at 2800 rpm and delivering 3 L/min flow. The PO2 of the oxygenator outlet was higher than 400 mm Hg with the PCO2 below 45 mm Hg. Hemolysis and thrombus were not seen in the MedTech ECMO circuits (plasma-free hemoglobin [PFH] < 5 mg/dL), while severe hemolysis (PFH > 20 mg/dL) and large thrombus were observed in the Bio-Pump ECMO circuits. Plasma leakage from the oxygenator did not occur in any ECMO circuits. Three-week cardiopulmonary support was performed successfully with the MedTech ECMO without circuit exchanges. The MedTech Mag-Lev could help extend the durability of ECMO circuits by the improved biocompatible performances. © 2013, Copyright the Authors. Artificial Organs © 2013, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Advanced methods for modeling water-levels and estimating drawdowns with SeriesSEE, an Excel add-in

USGS Publications Warehouse

Halford, Keith; Garcia, C. Amanda; Fenelon, Joe; Mirus, Benjamin B.

2012-12-21

Water-level modeling is used for multiple-well aquifer tests to reliably differentiate pumping responses from natural water-level changes in wells, or “environmental fluctuations.” Synthetic water levels are created during water-level modeling and represent the summation of multiple component fluctuations, including those caused by environmental forcing and pumping. Pumping signals are modeled by transforming step-wise pumping records into water-level changes by using superimposed Theis functions. Water-levels can be modeled robustly with this Theis-transform approach because environmental fluctuations and pumping signals are simulated simultaneously. Water-level modeling with Theis transforms has been implemented in the program SeriesSEE, which is a Microsoft® Excel add-in. Moving average, Theis, pneumatic-lag, and gamma functions transform time series of measured values into water-level model components in SeriesSEE. Earth tides and step transforms are additional computed water-level model components. Water-level models are calibrated by minimizing a sum-of-squares objective function where singular value decomposition and Tikhonov regularization stabilize results. Drawdown estimates from a water-level model are the summation of all Theis transforms minus residual differences between synthetic and measured water levels. The accuracy of drawdown estimates is limited primarily by noise in the data sets, not the Theis-transform approach. Drawdowns much smaller than environmental fluctuations have been detected across major fault structures, at distances of more than 1 mile from the pumping well, and with limited pre-pumping and recovery data at sites across the United States. In addition to water-level modeling, utilities exist in SeriesSEE for viewing, cleaning, manipulating, and analyzing time-series data.

Pump-probe optical microscopy for imaging nonfluorescent chromophores.

PubMed

Wei, Lu; Min, Wei

2012-06-01

Many chromophores absorb light intensely but have undetectable fluorescence. Hence microscopy techniques other than fluorescence are highly desirable for imaging these chromophores inside live cells, tissues, and organisms. The recently developed pump-probe optical microscopy techniques provide fluorescence-free contrast mechanisms by employing several fundamental light-molecule interactions including excited state absorption, stimulated emission, ground state depletion, and the photothermal effect. By using the pump pulse to excite molecules and the subsequent probe pulse to interrogate the created transient states on a laser scanning microscope, pump-probe microscopy offers imaging capability with high sensitivity and specificity toward nonfluorescent chromophores. Single-molecule sensitivity has even been demonstrated. Here we review and summarize the underlying principles of this emerging class of molecular imaging techniques.

Biomechanics of Cardiac Function

PubMed Central

Voorhees, Andrew P.; Han, Hai-Chao

2015-01-01

The heart pumps blood to maintain circulation and ensure the delivery of oxygenated blood to all the organs of the body. Mechanics play a critical role in governing and regulating heart function under both normal and pathological conditions. Biological processes and mechanical stress are coupled together in regulating myocyte function and extracellular matrix structure thus controlling heart function. Here we offer a brief introduction to the biomechanics of left ventricular function and then summarize recent progress in the study of the effects of mechanical stress on ventricular wall remodeling and cardiac function as well as the effects of wall mechanical properties on cardiac function in normal and dysfunctional hearts. Various mechanical models to determine wall stress and cardiac function in normal and diseased hearts with both systolic and diastolic dysfunction are discussed. The results of these studies have enhanced our understanding of the biomechanical mechanism in the development and remodeling of normal and dysfunctional hearts. Biomechanics provide a tool to understand the mechanism of left ventricular remodeling in diastolic and systolic dysfunction and guidance in designing and developing new treatments. PMID:26426462

Novel technique for airless connection of artificial heart to vascular conduits.

PubMed

Karimov, Jamshid H; Gao, Shengqiang; Dessoffy, Raymond; Sunagawa, Gengo; Sinkewich, Martin; Grady, Patrick; Sale, Shiva; Moazami, Nader; Fukamachi, Kiyotaka

2017-12-01

Successful implantation of a total artificial heart relies on multiple standardized procedures, primarily the resection of the native heart, and exacting preparation of the atrial and vascular conduits for pump implant and activation. Achieving secure pump connections to inflow/outflow conduits is critical to a successful outcome. During the connection process, however, air may be introduced into the circulation, traveling to the brain and multiple organs. Such air emboli block blood flow to these areas and are detrimental to long-term survival. A correctly managed pump-to-conduit connection prevents air from collecting in the pump and conduits. To further optimize pump-connection techniques, we have developed a novel connecting sleeve that enables airless connection of the Cleveland Clinic continuous-flow total artificial heart (CFTAH) to the conduits. In this brief report, we describe the connecting sleeve design and our initial results from two acute in vivo implantations using a scaled-down version of the CFTAH.

Evolution of the α-Subunit of Na/K-ATPase from Paramecium to Homo sapiens: Invariance of Transmembrane Helix Topology.

PubMed

Morrill, Gene A; Kostellow, Adele B; Liu, Lijun; Gupta, Raj K; Askari, Amir

2016-05-01

Na/K-ATPase is a key plasma membrane enzyme involved in cell signaling, volume regulation, and maintenance of electrochemical gradients. The α-subunit, central to these functions, belongs to a large family of P-type ATPases. Differences in transmembrane (TM) helix topology, sequence homology, helix-helix contacts, cell signaling, and protein domains of Na/K-ATPase α-subunit were compared in fungi (Beauveria), unicellular organisms (Paramecia), primitive multicellular organisms (Hydra), and vertebrates (Xenopus, Homo sapiens), and correlated with evolution of physiological functions in the α-subunit. All α-subunits are of similar length, with groupings of four and six helices in the N- and C-terminal regions, respectively. Minimal homology was seen for protein domain patterns in Paramecium and Hydra, with high correlation between Hydra and vertebrates. Paramecium α-subunits display extensive disorder, with minimal helix contacts. Increases in helix contacts in Hydra approached vertebrates. Protein motifs known to be associated with membrane lipid rafts and cell signaling reveal significant positional shifts between Paramecium and Hydra vulgaris, indicating that regional membrane fluidity changes occur during evolution. Putative steroid binding sites overlapping TM-3 occurred in all species. Sites associated with G-protein-receptor stimulation occur both in vertebrates and amphibia but not in Hydra or Paramecia. The C-terminus moiety "KETYY," necessary for the Na(+) activation of pump phosphorylation, is not present in unicellular species indicating the absence of classical Na(+)/K(+)-pumps. The basic protein topology evolved earliest, followed by increases in protein domains and ordered helical arrays, correlated with appearance of α-subunit regions known to involve cell signaling, membrane recycling, and ion channel formation.

77 FR 25084 - Revisions to the Hawaii State Implementation Plan

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-27

... ), and particulate matter (PM) emissions from motor vehicles, water separation, pumps, compressors, waste... organic 11/14/03 12/14/11 compound water separation. HDOH 11-60.1-41 Pump and compressor 11/14/03 12/14/11 requirements. HDOH 11-60.1-42 Waste gas disposal...... 11/14/03 12/14/11 HDOH 11-60.1-51 Definitions 11/14/03...

High-Pressure Open-Channel On-Chip Electroosmotic Pump for Nanoflow High Performance Liquid Chromatography

PubMed Central

2015-01-01

Here, we construct an open-channel on-chip electroosmotic pump capable of generating pressures up to ∼170 bar and flow rates up to ∼500 nL/min, adequate for high performance liquid chromatographic (HPLC) separations. A great feature of this pump is that a number of its basic pump units can be connected in series to enhance its pumping power; the output pressure is directly proportional to the number of pump units connected. This additive nature is excellent and useful, and no other pumps can work in this fashion. We demonstrate the feasibility of using this pump to perform nanoflow HPLC separations; tryptic digests of bovine serum albumin (BSA), transferrin factor (TF), and human immunoglobulins (IgG) are utilized as exemplary samples. We also compare the performance of our electroosmotic (EO)-driven HPLC with Agilent 1200 HPLC; comparable efficiencies, resolutions, and peak capacities are obtained. Since the pump is based on electroosmosis, it has no moving parts. The common material and process also allow this pump to be integrated with other microfabricated functional components. Development of this high-pressure on-chip pump will have a profound impact on the advancement of lab-on-a-chip devices. PMID:24495233

Analysis of baroreflex sensitivity during undulation pump ventricular assist device support.

PubMed

Liu, Hongjian; Shiraishi, Yasuyuki; Zhang, Xiumin; Song, Hojin; Saijo, Yoshifumi; Baba, Atsushi; Yambe, Tomoyuki; Abe, Yusuke; Imachi, Kou

2009-07-01

The aim of this study was to examine the baroreflex sensitivity (BRS), which involves the autonomic nervous system, in a goat with a chronically implanted undulation pump ventricular assist device (UPVAD). The UPVAD involved transforming the rotation of a brushless DC motor into an undulating motion by a disc attached via a special linking mechanism, and a jellyfish valve in the outflow cannula to prevent diastolic backflow. The pump was implanted into the thoracic cavity of a goat by a left thoracotomy, and the inflow and outflow cannulae were sutured to the apex of the left ventricle and to the descending aorta, respectively. The driving cable was wired percutaneously to an external controller. Electrocardiogram and hemodynamic waveforms were recorded at a sampling frequency of 1 kHz. BRS was determined when awake by the slope of the linear regression of R-R interval against mean arterial pressure changes, which were induced by the administration of methoxamine hydrochloride, both with continuous driving of the UPVAD as well as without assistance. BRS values during the UPVAD support and without assistance were 1.60 +/- 0.30 msec/mm Hg and 0.98 +/- 0.22 msec/mm Hg (n = 5, P < 0.05), respectively. BRS was significantly improved during left ventricular assistance. Therefore, UPVAD support might decrease sympathetic nerve activity and increase parasympathetic nerve activity to improve both microcirculation and organ function.

Novel electronic ferroelectricity in an organic charge-order insulator investigated with terahertz-pump optical-probe spectroscopy

PubMed Central

Yamakawa, H.; Miyamoto, T.; Morimoto, T.; Yada, H.; Kinoshita, Y.; Sotome, M.; Kida, N.; Yamamoto, K.; Iwano, K.; Matsumoto, Y.; Watanabe, S.; Shimoi, Y.; Suda, M.; Yamamoto, H. M.; Mori, H.; Okamoto, H.

2016-01-01

In electronic-type ferroelectrics, where dipole moments produced by the variations of electron configurations are aligned, the polarization is expected to be rapidly controlled by electric fields. Such a feature can be used for high-speed electric-switching and memory devices. Electronic-type ferroelectrics include charge degrees of freedom, so that they are sometimes conductive, complicating dielectric measurements. This makes difficult the exploration of electronic-type ferroelectrics and the understanding of their ferroelectric nature. Here, we show unambiguous evidence for electronic ferroelectricity in the charge-order (CO) phase of a prototypical ET-based molecular compound, α-(ET)2I3 (ET:bis(ethylenedithio)tetrathiafulvalene), using a terahertz pulse as an external electric field. Terahertz-pump second-harmonic-generation(SHG)-probe and optical-reflectivity-probe spectroscopy reveal that the ferroelectric polarization originates from intermolecular charge transfers and is inclined 27° from the horizontal CO stripe. These features are qualitatively reproduced by the density-functional-theory calculation. After sub-picosecond polarization modulation by terahertz fields, prominent oscillations appear in the reflectivity but not in the SHG-probe results, suggesting that the CO is coupled with molecular displacements, while the ferroelectricity is electronic in nature. The results presented here demonstrate that terahertz-pump optical-probe spectroscopy is a powerful tool not only for rapidly controlling polarizations, but also for clarifying the mechanisms of ferroelectricity. PMID:26864779

Thermoresponsive Supramolecular Chemotherapy by "V"-Shaped Armed β-Cyclodextrin Star Polymer to Overcome Drug Resistance.

PubMed

Fan, Xiaoshan; Cheng, Hongwei; Wang, Xiaoyuan; Ye, Enyi; Loh, Xian Jun; Wu, Yun-Long; Li, Zibiao

2018-04-01

Pump mediated drug efflux is the key reason to result in the failure of chemotherapy. Herein, a novel star polymer β-CD-v-(PEG-β-PNIPAAm) 7 consisting of a β-CD core, grafted with thermo-responsive poly(N-isopropylacrylamide) (PNIPAAm) and biocompatible poly(ethylene glycol) (PEG) in the multiple "V"-shaped arms is designed and further fabricated into supramolecular nanocarriers for drug resistant cancer therapy. The star polymer could encapsulate chemotherapeutics between β-cyclodextrin and anti-cancer drug via inclusion complex (IC). Furthermore, the temperature induced chain association of PNIPAAm segments facilitated the IC to form supramolecular nanoparticles at 37 °C, whereas the presence of PEG impart great stability to the self-assemblies. When incubated with MDR-1 membrane pump regulated drug resistant tumor cells, much higher and faster cellular uptake of the supramolecular nanoparticles were detected, and the enhanced intracellular retention of drugs could lead to significant inhibition of cell growth. Further in vivo evaluation showed high therapeutic efficacy in suppressing drug resistant tumor growth without a significant impact on the normal functions of main organs. This work signifies thermo-responsive supramolecular chemotherapy is promising in combating pump mediated drug resistance in both in vitro and in vivo models, which may be encouraging for the advanced drug delivery platform design to overcome drug resistant cancer. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Novel electronic ferroelectricity in an organic charge-order insulator investigated with terahertz-pump optical-probe spectroscopy.

PubMed

Yamakawa, H; Miyamoto, T; Morimoto, T; Yada, H; Kinoshita, Y; Sotome, M; Kida, N; Yamamoto, K; Iwano, K; Matsumoto, Y; Watanabe, S; Shimoi, Y; Suda, M; Yamamoto, H M; Mori, H; Okamoto, H

2016-02-11

In electronic-type ferroelectrics, where dipole moments produced by the variations of electron configurations are aligned, the polarization is expected to be rapidly controlled by electric fields. Such a feature can be used for high-speed electric-switching and memory devices. Electronic-type ferroelectrics include charge degrees of freedom, so that they are sometimes conductive, complicating dielectric measurements. This makes difficult the exploration of electronic-type ferroelectrics and the understanding of their ferroelectric nature. Here, we show unambiguous evidence for electronic ferroelectricity in the charge-order (CO) phase of a prototypical ET-based molecular compound, α-(ET)2I3 (ET:bis(ethylenedithio)tetrathiafulvalene), using a terahertz pulse as an external electric field. Terahertz-pump second-harmonic-generation(SHG)-probe and optical-reflectivity-probe spectroscopy reveal that the ferroelectric polarization originates from intermolecular charge transfers and is inclined 27° from the horizontal CO stripe. These features are qualitatively reproduced by the density-functional-theory calculation. After sub-picosecond polarization modulation by terahertz fields, prominent oscillations appear in the reflectivity but not in the SHG-probe results, suggesting that the CO is coupled with molecular displacements, while the ferroelectricity is electronic in nature. The results presented here demonstrate that terahertz-pump optical-probe spectroscopy is a powerful tool not only for rapidly controlling polarizations, but also for clarifying the mechanisms of ferroelectricity.

Functioning of the Ocean Biological Pump in the Oxygen Minimum Zones

NASA Astrophysics Data System (ADS)

Moore, J. K.

2015-12-01

Oxygen minimum zones occur at mid-depths in the water column in regions with weak ventilation and relatively high export of organic matter from surface waters. They are important ocean for ocean biogeochemistry, and potentially for climate, as sites of water column denitrification and nitrous oxide production. Denitrification is the dominant loss process for fixed nitrogen in the oceans, and can thus affect the ocean inventory of this key nutrient. Denitrification is less energetically efficient than oxic remineralization. Larger zooplankton, which feed on sinking particles, are not present in the lowest oxygen waters. Both of these factors suggest that the remineralization of sinking particles may be slower within the OMZs than in more oxygenated waters. There is limited field evidence and from some modeling studies that remineralization is slower (remineralization length scales are longer) within OMZ waters. In this talk, I will present results from the Community Earth System Model (CESM) ocean component attempting to test this hypothesis. Comparing model results with observed ocean biogeochemical tracer distributions (i.e., phosphate, oxygen), I will examine whether slower remineralization within low oxygen waters provides a better match between simulated and observed tracer distributions. Longer remineralization length scales under low oxygen conditions would provide a negative feedback under global warming scenarios. The biological pump would transfer organic materials to depth more efficiently as ocean oxygen concentrations decline and the OMZs expand.

Gain statistics of a fiber optical parametric amplifier with a temporally incoherent pump.

PubMed

Xu, Y Q; Murdoch, S G

2010-03-15

We present an investigation of the statistics of the gain fluctuations of a fiber optical parametric amplifier pumped with a temporally incoherent pump. We derive a simple expression for the probability distribution of the gain of the amplified optical signal. The gain statistics are shown to be a strong function of the signal detuning and allow the possibility of generating optical gain distributions with controllable long-tails. Very good agreement is found between this theory and the experimentally measured gain distributions of an incoherently pumped amplifier.

Thermally induced optical deformation of a Nd:YVO4 active disk under the action of multi-beam spatially periodic diode pumping

NASA Astrophysics Data System (ADS)

Guryev, D. A.; Nikolaev, D. A.; Tsvetkov, V. B.; Shcherbakov, I. A.

2018-05-01

A study of how the transverse distribution of an optical path changes in a Nd:YVO4 active disk was carried out in a ten-beam spatially periodic diode pumping in the one-dimensional case. The pumping beams’ transverse dimensions were comparable with the distances between them. The investigations were carried out using laser interferometry methods. It was found that the optical thickness changing in the active disk along the line of pumping spots was well described by a Gaussian function.

Dynamics and acoustics of a cavitating Venturi flow using a homogeneous air-propylene glycol mixture

NASA Astrophysics Data System (ADS)

Navarrete, M.; Naude, J.; Mendez, F.; Godínez, F. A.

2015-12-01

Dynamics and acoustics generated in a cavitating Venturi tube are followed up as a function of the input power of a centrifugal pump. The pump of 5 hp with a modified impeller to produce uniform bubbly flow, pumps 70 liters of propylene glycol in a closed loop (with a water cooling system), in which the Venturi is arranged. The goal was to obtain correlations among acoustical emission, dynamics of the shock waves and the light emission from cavitation bubbles. The instrumentation includes: two piezoelectric transducers, a digital camera, a high-speed video camera, and photomultipliers. As results, we show the cavitation patterns as function of the pump power, and a graphical template of the distribution of the Venturi conditions as a function of the cavitation parameter. Our observations show for the first time the sudden formation of bubble clouds in the straight portion of the pipe after the diverging section of the Venturi. We assume that this is due to pre-existing of nuclei-cloud structures which suddenly grow up by the tensile tails of propagating shock waves (producing a sudden drop in pressure).

Fibre-coupled red diode-pumped Alexandrite TEM00 laser with single and double-pass end-pumping

NASA Astrophysics Data System (ADS)

Arbabzadah, E. A.; Damzen, M. J.

2016-06-01

We report the investigation of an Alexandrite laser end-pumped by a fibre-coupled red diode laser module. Power, efficiency, spatial, spectral, and wavelength tuning performance are studied as a function of pump and laser cavity parameters. It is the first demonstration, to our knowledge, of greater than 1 W power and also highest laser slope efficiency (44.2%) in a diode-pumped Alexandrite laser with diffraction-limited TEM00 mode operation. Spatial quality was excellent with beam propagation parameter M 2 ~ 1.05. Wavelength tuning from 737-796 nm was demonstrated using an intracavity birefringent tuning filter. Using a novel double pass end-pumping scheme to get efficient absorption of both polarisation states of the scrambled fibre-delivered diode pump, a total output coupled power of 1.66 W is produced in TEM00 mode with 40% slope efficiency.

Inward H+ pump xenorhodopsin: Mechanism and alternative optogenetic approach.

PubMed

Shevchenko, Vitaly; Mager, Thomas; Kovalev, Kirill; Polovinkin, Vitaly; Alekseev, Alexey; Juettner, Josephine; Chizhov, Igor; Bamann, Christian; Vavourakis, Charlotte; Ghai, Rohit; Gushchin, Ivan; Borshchevskiy, Valentin; Rogachev, Andrey; Melnikov, Igor; Popov, Alexander; Balandin, Taras; Rodriguez-Valera, Francisco; Manstein, Dietmar J; Bueldt, Georg; Bamberg, Ernst; Gordeliy, Valentin

2017-09-01

Generation of an electrochemical proton gradient is the first step of cell bioenergetics. In prokaryotes, the gradient is created by outward membrane protein proton pumps. Inward plasma membrane native proton pumps are yet unknown. We describe comprehensive functional studies of the representatives of the yet noncharacterized xenorhodopsins from Nanohaloarchaea family of microbial rhodopsins. They are inward proton pumps as we demonstrate in model membrane systems, Escherichia coli cells, human embryonic kidney cells, neuroblastoma cells, and rat hippocampal neuronal cells. We also solved the structure of a xenorhodopsin from the nanohalosarchaeon Nanosalina ( Ns XeR) and suggest a mechanism of inward proton pumping. We demonstrate that the Ns XeR is a powerful pump, which is able to elicit action potentials in rat hippocampal neuronal cells up to their maximal intrinsic firing frequency. Hence, inwardly directed proton pumps are suitable for light-induced remote control of neurons, and they are an alternative to the well-known cation-selective channelrhodopsins.

Sump bay fever: inhalational fever associated with a biologically contaminated water aerosol.

PubMed Central

Anderson, K; McSharry, C P; Clark, C; Clark, C J; Barclay, G R; Morris, G P

1996-01-01

OBJECTIVE: To investigate the clinical, serological, and environmental features of a work related inhalational fever associated with exposure to an aerosol generated from a biologically contaminated 130,000 gallon water pool in a building used for testing scientific equipment. METHOD: Cross sectional survey of all exposed subjects (n = 83) by symptom questionnaire, clinical examination, spirometry, and serology for antibody to Pseudomonads, pool water extract, and endotoxin. In symptomatic patients diffusion capacity was measured, and chest radiology was performed if this was abnormal. Serial peak flow was recorded in those subjects with wheeze. Bacterial and fungal air sampling was performed before and during operation of the water pool pump mechanism. Endotoxin was measured in the trapped waters and in the pumps. Serum cotinine was measured as an objective indicator of smoking. RESULTS: Of the 20 symptomatic subjects, fever was most common in those with the highest exposure (chi 2 42.7, P < 0.001) in the sump bay when the water was (torrentially) recirculated by the water pumps. Symptoms occurred late in the working day only on days when the water pumps were used, and were independent of the serum cotinine. Pulmonary function was normal in most subjects (spirometry was normal in 79/83, diffusion capacity was low in five subjects, chest radiology was normal). Peak flow recording did not suggest a work relation. The bacterial content of the aerosol rose from 6 to > 10,000 colony forming units per cubic metre (cfu/m3) (predominantly environmental Pseudomonads) when the pumps were operating. High endotoxin concentrations were measured in the waters and oil sumps in the pumps. Low concentrations of antibody to the organisms isolated were detected (apart from two subjects with high antibody) but there was no relation to exposure or the presence of symptoms and similar antibody was found in the serum samples from a non-exposed population. The fever symptoms settled completely with the simple expedient of changing the water and cleaning the pumps. CONCLUSION: Given the results of our study, the development of inhalational fever in this unique environment and clearly restricted cohort was closely related to the degree of exposure to contaminated aerosol and mainly occurred in the absence of distinct serological abnormality and independent of cigarette smoking. PMID:8777446

Advances in Valveless Piezoelectric Pump with Cone-shaped Tubes

NASA Astrophysics Data System (ADS)

Zhang, Jian-Hui; Wang, Ying; Huang, Jun

2017-07-01

This paper reviews the development of valveless piezoelectric pump with cone-shaped tube chronologically, which have widely potential application in biomedicine and micro-electro-mechanical systems because of its novel principles and deduces the research direction in the future. Firstly, the history of valveless piezoelectric pumps with cone-shaped tubes is reviewed and these pumps are classified into the following types: single pump with solid structure or plane structure, and combined pump with parallel structure or series structure. Furthermore, the function of each type of cone-shaped tubes and pump structures are analyzed, and new directions of potential expansion of valveless piezoelectric pumps with cone-shaped tubes are summarized and deduced. The historical argument, which is provided by the literatures, that for a valveless piezoelectric pump with cone-shaped tubes, cone angle determines the flow resistance and the flow resistance determines the flow direction. The argument is discussed in the reviewed pumps one by one, and proved to be convincing. Finally, it is deduced that bionics is pivotal in the development of valveless piezoelectric pump with cone-shaped tubes from the perspective of evolution of biological structure. This paper summarizes the current valveless piezoelectric pumps with cone-shaped tubes and points out the future development, which may provide guidance for the research of piezoelectric actuators.

Preparation and In Vitro/In Vivo Evaluation of Vinpocetine Elementary Osmotic Pump System

PubMed Central

Ning, Meiying; Zhou, Yue; Chen, Guojun; Mei, Xingguo

2011-01-01

Preparation and in vitro and in vivo evaluation of vinpocetine (VIN) elementary osmotic pump (EOP) formulations were investigated. A method for the preparation of VIN elementary osmotic pump tablet was obtained by adding organic acid additives to increase VIN solubility. VIN was used as the active pharmaceutical ingredient, lactose and mannitol as osmotic agent. Citric acid was used as increasing API solubility and without resulting in the API degradation. It is found that the VIN release rate was increasing with the citric acid amount at a constant range. Cellulose acetate 398-3 was employed as semipermeable membrane containing polyethylene glycol 6000 and diethyl-o-phthalate as pore-forming agent and plasticizer for controlling membrane permeability. In addition, a clear difference between the pharmacokinetic patterns of VIN immediate release and VIN elementary osmotic pump formulations was revealed. The area under the plasma concentration-time curve after oral administration of elementary osmotic pump formulations was equivalent to VIN immediate release formulation. Furthermore, significant differences found for mean residence time, elimination half-life, and elimination rate constant values corroborated prolonged release of VIN from elementary osmotic pump formulations. These results suggest that the VIN osmotic pump controlled release tablets have marked controlled release characters and the VIN osmotic pump controlled release tablets and the normal tablets were bioequivalent. PMID:21577257

Dielectric elastomer pump for artificial organisms

NASA Astrophysics Data System (ADS)

Bowers, Amy E.; Rossiter, Jonathan M.; Walters, Peter J.; Ieropoulos, Ioannis A.

2011-04-01

This paper presents a bio-inspired, dielectric elastomer (DE) based tubular pumping unit, developed for eventual use as a component of an artificial digestive tract onboard a microbial fuel cell powered robot (EcoBot). The pump effects fluid displacement by direct actuation of the tube wall as opposed to excitation by an external body. The actuator consists of a DE tube moulded from silicone, held in a negative pressure chamber, which is used for prestraining the tube. The pump is coupled with custom designed polymeric check valves in order to rectify the fluid flow and assess the performance of the unit. The valves exhibited the necessary low opening pressures required for use with the actuator. The tube's actuation characteristics were measured both with and without liquid in the system. Based on these data the optimal operating conditions for the pump are discussed. The pump and valve system has achieved flowrates in excess of 40μl/s. This radially contracting/expanding actuator element is the fundamental component of a peristaltic pump. This 'soft pump' concept is suitable for biomimetic robotic systems, or for the medical or food industries where hard contact with the delivered substrate may be undesirable. Future work will look at connecting multiple tubes in series in order to achieve peristalsis.

The Control of Welding Deformation of the Three-Section Arm of Placing Boom of HB48B Pump Truck

NASA Astrophysics Data System (ADS)

Wang, Zhi-ling

2018-02-01

The concrete pump truck is the construction equipment of conveying concrete with self contained base plate and distributing boom. It integrates the pump transport mechanism of the concrete pump, and the hydraulic roll-folding type distributing boom used to distribute materials, and the supporting mechanism into the automobile chassis, and it is the concrete conveying equipment with high efficient and the functions of driving, pumping, and distributing materials. The placing boom of the concrete pump truck is the main force member in the pump parts with bearing great pressure, and its stress condition is complex. Taking the HB48B placing boom as an example, this paper analyzes and studies the deformation produced by placing boom of pump truck, and then obtains some main factors affecting the welding deformation. Through the riveter “joint” size, we controlled the process parameters, post-welding processing, and other aspects. These measures had some practical significance to prevent, control, and reduce the deformation of welding.

Heat Radiators for Electromagnetic Pumps

NASA Technical Reports Server (NTRS)

Campana, R. J.

1986-01-01

Report proposes use of carbon/carbon composite radiators in electromagnetic coolant pumps of nuclear reactors on spacecraft. Carbon/carbon composite materials function well at temperatures in excess of 2,200 K. Aluminum has melting temperature of only 880 K.

Self-powered enzyme micropumps

NASA Astrophysics Data System (ADS)

Sengupta, Samudra; Patra, Debabrata; Ortiz-Rivera, Isamar; Agrawal, Arjun; Shklyaev, Sergey; Dey, Krishna K.; Córdova-Figueroa, Ubaldo; Mallouk, Thomas E.; Sen, Ayusman

2014-05-01

Non-mechanical nano- and microscale pumps that function without the aid of an external power source and provide precise control over the flow rate in response to specific signals are needed for the development of new autonomous nano- and microscale systems. Here we show that surface-immobilized enzymes that are independent of adenosine triphosphate function as self-powered micropumps in the presence of their respective substrates. In the four cases studied (catalase, lipase, urease and glucose oxidase), the flow is driven by a gradient in fluid density generated by the enzymatic reaction. The pumping velocity increases with increasing substrate concentration and reaction rate. These rechargeable pumps can be triggered by the presence of specific analytes, which enables the design of enzyme-based devices that act both as sensor and pump. Finally, we show proof-of-concept enzyme-powered devices that autonomously deliver small molecules and proteins in response to specific chemical stimuli, including the release of insulin in response to glucose.

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

Holdaway, David I. H., E-mail: d.holdaway@ucl.ac.uk; Olaya-Castro, Alexandra, E-mail: a.olaya@ucl.ac.uk; Collini, Elisabetta, E-mail: elisabetta.collini@unipd.it

We examine transient circular dichroism (TRCD) spectroscopy as a technique to investigate signatures of exciton coherence dynamics under the influence of structured vibrational environments. We consider a pump-probe configuration with a linearly polarized pump and a circularly polarized probe, with a variable angle θ between the two directions of propagation. In our theoretical formalism the signal is decomposed in chiral and achiral doorway and window functions. Using this formalism, we show that the chiral doorway component, which beats during the population time, can be isolated by comparing signals with different values of θ. As in the majority of time-resolved pump-probemore » spectroscopy, the overall TRCD response shows signatures of both excited and ground state dynamics. However, we demonstrate that the chiral doorway function has only a weak ground state contribution, which can generally be neglected if an impulsive pump pulse is used. These findings suggest that the pump-probe configuration of optical TRCD in the impulsive limit has the potential to unambiguously probe quantum coherence beating in the excited state. We present numerical results for theoretical signals in an example dimer system.« less

A seal-less centrifugal pump (Baylor Gyro Pump) for application to long-term circulatory support.

PubMed

Minato, N; Sakuma, I; Sasaki, T; Shiono, M; Ohara, Y; Takatani, S; Noon, G P; Nosé, Y

1993-01-01

We are developing a new centrifugal pump, the Baylor Gyro Centrifugal Pump (Gyro Pump), which can function for more than 2 weeks. The concept of the Gyro Pump is that a one-piece rotor-impeller with embedded permanent magnets, driven directly by a brushless direct current motor stator placed outside, rotates like a "gyroscope," and the rotor-impeller is supported by one pivot bearing at the bottom in accordance with the gyroscopic principle. This concept enables us to eliminate a driving shaft and a seal between the driving shaft and the blood chamber, which results in extending the life of the centrifugal pump. The blood passes through the space between the motor stator and the rotor to the impeller portion. In this preliminary phase, two pivot bearings were applied to support the rotor-impeller at the top and the bottom inside the blood chamber. Both pivot bearings showed less blood trauma and less thrombogenicity in in vitro and in vivo studies. The Gyro Pump is a promising second-generation centrifugal pump for long-term circulatory support in the near future.

Current randomized control trials, observational studies and meta analysis in off-pump coronary surgery.

PubMed

Parissis, Haralabos; Lau, Man Chi; Parissis, Mondrian; Lampridis, Savvas; Graham, Victoria; Al-Saudi, Reza; Mhandu, Peter

2015-12-17

The off-pump literature is divided into three eras: the "early phase" with results favouring off-pump surgery supported with randomized control trials (RCTs) mainly from Bristol, UK; an "intermediate phase" dominated by the results of the ROOBY trial and finally a more "contemporary phase" whereby the off/on-pump argument is unsettled. Although the literature has failed to project an overall superiority of off-pump versus on-pump surgery, nevertheless, small randomized control trials and large meta-analysis studies are concluding that the incidence of a stroke is less than 1 % when an aortic off-pump techniques (especially the non-touch technique) are advocated in patients with diseased ascending aorta. Furthermore, off-pump combined with hybrid procedures may lead to a reduction of adverse outcome in the aged high-risk population with concomitant poor left ventricular function and co-morbidities.The current review attempts to bring an insight onto the last ten years knowledge on the on/off-pump debate, with an aim to draw some clear conclusions in order to allow practitioners to reflect on the subject.

Electromagnetic Pumps for Conductive-Propellant Feed Systems

NASA Technical Reports Server (NTRS)

Markusic, Thomas E.; Polzin, Kurt A.; Dehoyos, Amado

2005-01-01

Prototype electromagnetic pumps for use with lithium and bismuth propellants were constructed and tested. Such pumps may be used to pressurize future electric propulsion liquid metal feed systems, with the primary advantages being the compactness and simplicity versus alternative pressurization technologies. Design details for two different pumps are described: the first was designed to withstand (highly corrosive) lithium propellant, and t he second was designed to tolerate the high temperature required to pump liquid bismuth. Both qualitative and quantitative test results are presented. Open-loop tests demonstrated the capability of each device to electromagnetically pump its design propellant (lithium or bismuth). A second set of tests accurately quantified the pump pressure developed as a function of current. These experiments, which utilized a more easily handled material (gallium), demonstrated continuously-adjustable pump pressure levels ranging from 0-100 Torr for corresponding input current levels of 0-75 A. While the analysis and testing in this study specifically targeted lithium and bismuth propellants, the underlying design principles should be useful in implementing liquid metal pumps in any conductive-propellant feed system.

Electrical controllable spin pump based on a zigzag silicene nanoribbon junction.

PubMed

Zhang, Lin; Tong, Peiqing

2017-12-13

We propose a possible electrical controllable spin pump based on a zigzag silicene nanoribbon ferromagnetic junction by applying two time-dependent perpendicular electric fields. By using the Keldysh Green's function method, we derive the analytic expression of the spin-resolved current at the adiabatic approximation and demonstrate that two asymmetric spin up and spin down currents can be pumped out in the device without an external bias. The pumped currents mainly come from the interplay between the photon-assisted spin pump effect and the electrically-modulated energy band structure of the tunneling junction. The spin valve phenomena are not only related to the energy gap opened by two perpendicular staggered potentials, but also dependent on the system parameters such as the pumping frequency, the pumping phase difference, the spin-orbit coupling and the Fermi level, which can be tuned by the electrical methods. The proposed device can also be used to produce a pure spin current and a 100% polarized spin current through the photon-assisted pumping process. Our investigations may provide an electrical manipulation of spin-polarized electrons in graphene-like pumping devices.

New methods for the development of pneumatic displacement pumps for cardiac assist.

PubMed

Knierbein, B; Rosarius, N; Reul, H; Rau, G

1990-11-01

The primary goal of the presented project was to develop a pump family with stroke volumes of 20, 50, 70 and 90 ml, which could be produced at low cost but with sufficient quality. The housing parts of the pump were thermoformed from technical semifinished materials. All blood contacting surfaces of the pump were coated with biomaterials in a controlled dipping process. During the design and fabrication process a professional CAD-system was used. This facilitated spatial presentations of pump components for first evaluations at the initial draft stages. The CAD-design data were then transformed to CNC-controlled lathes and mill's for the fabrication of pump tools. The stresses and strains of the moving blood pump components, such as membranes and valves, were precalculated by means of Finite-Element-Analysis (FEM). After completion of the pump, the internal flow fields were investigated by flow-visualization techniques using non-Newtonian test fluids, and the pump characteristics (function curves) were investigated in appropriate circulatory mock loops. The paper covers all above aspects from first draft to final fabrication and testing.

Interacting Genes Required for Pharyngeal Excitation by Motor Neuron Mc in Caenorhabditis Elegans

PubMed Central

Raizen, D. M.; Lee, RYN.; Avery, L.

1995-01-01

We studied the control of pharyngeal excitation in Caenorhabditis elegans. By laser ablating subsets of the pharyngeal nervous system, we found that the MC neuron type is necessary and probably sufficient for rapid pharyngeal pumping. Electropharyngeograms showed that MC transmits excitatory postsynaptic potentials, suggesting that MC acts as a neurogenic pacemaker for pharyngeal pumping. Mutations in genes required for acetylcholine (ACh) release and an antagonist of the nicotinic ACh receptor (nAChR) reduced pumping rates, suggesting that a nAChR is required for MC transmission. To identify genes required for MC neurotransmission, we screened for mutations that cause slow pumping but no other defects. Mutations in two genes, eat-2 and eat-18, eliminated MC neurotransmission. A gain-of-function eat-18 mutation, ad820sd, and a putative loss-of-function eat-18 mutation, ad1110, both reduced the excitation of pharyngeal muscle in response to the nAChR agonists nicotine and carbachol, suggesting that eat-18 is required for the function of a pharyngeal nAChR. Fourteen recessive mutations in eat-2 fell into five complementation classes. We found allele-specific genetic interactions between eat-2 and eat-18 that correlated with complementation classes of eat-2. We propose that eat-18 and eat-2 function in a multisubunit protein complex involved in the function of a pharyngeal nAChR. PMID:8601480

Suppression of the endoplasmic reticulum calcium pump during zebrafish gastrulation affects left-right asymmetry of the heart and brain.

PubMed

Kreiling, Jill A; Balantac, Zaneta L; Crawford, Andrew R; Ren, Yuexin; Toure, Jamal; Zchut, Sigalit; Kochilas, Lazaros; Creton, Robbert

2008-01-01

Vertebrate embryos generate striking Ca(2+) patterns, which are unique regulators of dynamic developmental events. In the present study, we used zebrafish embryos as a model system to examine the developmental roles of Ca(2+) during gastrulation. We found that gastrula stage embryos maintain a distinct pattern of cytosolic Ca(2+) along the dorsal-ventral axis, with higher Ca(2+) concentrations in the ventral margin and lower Ca(2+) concentrations in the dorsal margin and dorsal forerunner cells. Suppression of the endoplasmic reticulum Ca(2+) pump with 0.5 microM thapsigargin elevates cytosolic Ca(2+) in all embryonic regions and induces a randomization of laterality in the heart and brain. Affected hearts, visualized in living embryos by a subtractive imaging technique, displayed either a reversal or loss of left-right asymmetry. Brain defects include a left-right reversal of pitx2 expression in the dorsal diencephalon and a left-right reversal of the prominent habenular nucleus in the brain. Embryos are sensitive to inhibition of the endoplasmic reticulum Ca(2+) pump during early and mid gastrulation and lose their sensitivity during late gastrulation and early segmentation. Suppression of the endoplasmic reticulum Ca(2+) pump during gastrulation inhibits expression of no tail (ntl) and left-right dynein related (lrdr) in the dorsal forerunner cells and affects development of Kupffer's vesicle, a ciliated organ that generates a counter-clockwise flow of fluid. Previous studies have shown that Ca(2+) plays a role in Kupffer's vesicle function, influencing ciliary motility and translating the vesicle's counter-clockwise flow into asymmetric patterns of gene expression. The present results suggest that Ca(2+) plays an additional role in the formation of Kupffer's vesicle.

Analysis of the cochlear amplifier fluid pump hypothesis.

PubMed

Zagadou, Brissi Franck; Mountain, David C

2012-04-01

We use analysis of a realistic three-dimensional finite-element model of the tunnel of Corti (ToC) in the middle turn of the gerbil cochlea tuned to the characteristic frequency (CF) of 4 kHz to show that the anatomical structure of the organ of Corti (OC) is consistent with the hypothesis that the cochlear amplifier functions as a fluid pump. The experimental evidence for the fluid pump is that outer hair cell (OHC) contraction and expansion induce oscillatory flow in the ToC. We show that this oscillatory flow can produce a fluid wave traveling in the ToC and that the outer pillar cells (OPC) do not present a significant barrier to fluid flow into the ToC. The wavelength of the resulting fluid wave launched into the tunnel at the CF is 1.5 mm, which is somewhat longer than the wavelength estimated for the classical traveling wave. This fluid wave propagates at least one wavelength before being significantly attenuated. We also investigated the effect of OPC spacing on fluid flow into the ToC and found that, for physiologically relevant spacing between the OPCs, the impedance estimate is similar to that of the underlying basilar membrane. We conclude that the row of OPCs does not significantly impede fluid exchange between ToC and the space between the row of OPC and the first row of OHC-Dieter's cells complex, and hence does not lead to excessive power loss. The BM displacement resulting from the fluid pumped into the ToC is significant for motion amplification. Our results support the hypothesis that there is an additional source of longitudinal coupling, provided by the ToC, as required in many non-classical models of the cochlear amplifier.

The V-ATPase accessory protein Atp6ap1b mediates dorsal forerunner cell proliferation and left-right asymmetry in zebrafish.

PubMed

Gokey, Jason J; Dasgupta, Agnik; Amack, Jeffrey D

2015-11-01

Asymmetric fluid flows generated by motile cilia in a transient 'organ of asymmetry' are involved in establishing the left-right (LR) body axis during embryonic development. The vacuolar-type H(+)-ATPase (V-ATPase) proton pump has been identified as an early factor in the LR pathway that functions prior to cilia, but the role(s) for V-ATPase activity are not fully understood. In the zebrafish embryo, the V-ATPase accessory protein Atp6ap1b is maternally supplied and expressed in dorsal forerunner cells (DFCs) that give rise to the ciliated organ of asymmetry called Kupffer's vesicle (KV). V-ATPase accessory proteins modulate V-ATPase activity, but little is known about their functions in development. We investigated Atp6ap1b and V-ATPase in KV development using morpholinos, mutants and pharmacological inhibitors. Depletion of both maternal and zygotic atp6ap1b expression reduced KV organ size, altered cilia length and disrupted LR patterning of the embryo. Defects in other ciliated structures-neuromasts and olfactory placodes-suggested a broad role for Atp6ap1b during development of ciliated organs. V-ATPase inhibitor treatments reduced KV size and identified a window of development in which V-ATPase activity is required for proper LR asymmetry. Interfering with Atp6ap1b or V-ATPase function reduced the rate of DFC proliferation, which resulted in fewer ciliated cells incorporating into the KV organ. Analyses of pH and subcellular V-ATPase localizations suggested Atp6ap1b functions to localize the V-ATPase to the plasma membrane where it regulates proton flux and cytoplasmic pH. These results uncover a new role for the V-ATPase accessory protein Atp6ap1b in early development to maintain the proliferation rate of precursor cells needed to construct a ciliated KV organ capable of generating LR asymmetry. Copyright © 2015 Elsevier Inc. All rights reserved.

The V-ATPase accessory protein Atp6ap1b mediates dorsal forerunner cell proliferation and left-right asymmetry in zebrafish

PubMed Central

Gokey, Jason J.; Dasgupta, Agnik; Amack, Jeffrey D.

2015-01-01

Asymmetric fluid flows generated by motile cilia in a transient ‘organ of asymmetry’ are involved in establishing the left-right (LR) body axis during embryonic development. The vacuolar-type H+-ATPase (V-ATPase) proton pump has been identified as an early factor in the LR pathway that functions prior to cilia, but the role(s) for V-ATPase activity are not fully understood. In the zebrafish embryo, the V-ATPase accessory protein Atp6ap1b is maternally supplied and expressed in dorsal forerunner cells (DFCs) that give rise to the ciliated organ of asymmetry called Kupffer’s vesicle (KV). V-ATPase accessory proteins modulate V-ATPase activity, but little is known about their functions in development. We investigated Atp6ap1b and V-ATPase in KV development using morpholinos, mutants and pharmacological inhibitors. Depletion of both maternal and zygotic atp6ap1b expression reduced KV organ size, altered cilia length and disrupted LR patterning of the embryo. Defects in other ciliated structures—neuromasts and olfactory placodes—suggested a broad role for Atp6ap1b during development of ciliated organs. V-ATPase inhibitor treatments reduced KV size and identified a window of development in which V-ATPase activity is required for proper LR asymmetry. Interfering with Atp6ap1b or V-ATPase function reduced the rate of DFC proliferation, which resulted in fewer ciliated cells incorporating into the KV organ. Analyses of pH and subcellular V-ATPase localizations suggested Atp6ap1b functions to localize the V-ATPase to the plasma membrane where it regulates proton flux and cytoplasmic pH. These results uncover a new role for the V-ATPase accessory protein Atp6ap1b in early development to maintain the proliferation rate of precursor cells needed to construct a ciliated KV organ capable of generating LR asymmetry. PMID:26254189

Low-dose or standard-dose proton pump inhibitors for maintenance therapy of gastro-oesophageal reflux disease: a cost-effectiveness analysis.

PubMed

You, J H S; Lee, A C M; Wong, S C Y; Chan, F K L

2003-03-15

Studies on the use of low-dose proton pump inhibitor for the maintenance therapy of gastro-oesophageal reflux disease have shown that it might be comparable with standard-dose proton pump inhibitor treatment and superior to standard-dose histamine-2 receptor antagonist therapy. To compare the impact of standard-dose histamine-2 receptor antagonist, low-dose proton pump inhibitor and standard-dose proton pump inhibitor treatment for the maintenance therapy of gastro-oesophageal reflux disease on symptom control and health care resource utilization from the perspective of a public health organization in Hong Kong. A Markov model was designed to simulate, over 12 months, the economic and clinical outcomes of gastro-oesophageal reflux disease patients treated with standard-dose histamine-2 receptor antagonist, low-dose proton pump inhibitor and standard-dose proton pump inhibitor. The transition probabilities were derived from the literature. Resource utilization was retrieved from a group of gastro-oesophageal reflux disease patients in Hong Kong. Sensitivity analysis was conducted to examine the robustness of the model. The standard-dose proton pump inhibitor strategy was associated with the highest numbers of symptom-free patient-years (0.954 years) and quality-adjusted life-years gained (0.999 years), followed by low-dose proton pump inhibitor and standard-dose histamine-2 receptor antagonist. The direct medical cost per patient in the standard-dose proton pump inhibitor group (904 US dollars) was lower than those of the low-dose proton pump inhibitor and standard-dose histamine-2 receptor antagonist groups. The standard-dose proton pump inhibitor strategy appears to be the most effective and least costly for the maintenance management of patients with gastro-oesophageal reflux disease in Hong Kong.

Scalable diode array pumped Nd rod laser

NASA Technical Reports Server (NTRS)

Zenzie, H. H.; Knights, M. G.; Mosto, J. R.; Chicklis, E. P.; Perkins, P. E.

1991-01-01

Experiments were carried out on a five-array pump head which utilizes gold-coated reflective cones to couple the pump energy to Nd:YAG and Nd:YLF rod lasers, demonstrating high efficiency and uniform energy deposition. Because the cones function as optical diodes to light outside their acceptance angle (typically 10-15 deg), much of the diode energy not absorbed on the first pass can be returned to the rod.

Crystal structure of the plasma membrane proton pump.

PubMed

Pedersen, Bjørn P; Buch-Pedersen, Morten J; Morth, J Preben; Palmgren, Michael G; Nissen, Poul

2007-12-13

A prerequisite for life is the ability to maintain electrochemical imbalances across biomembranes. In all eukaryotes the plasma membrane potential and secondary transport systems are energized by the activity of P-type ATPase membrane proteins: H+-ATPase (the proton pump) in plants and fungi, and Na+,K+-ATPase (the sodium-potassium pump) in animals. The name P-type derives from the fact that these proteins exploit a phosphorylated reaction cycle intermediate of ATP hydrolysis. The plasma membrane proton pumps belong to the type III P-type ATPase subfamily, whereas Na+,K+-ATPase and Ca2+-ATPase are type II. Electron microscopy has revealed the overall shape of proton pumps, however, an atomic structure has been lacking. Here we present the first structure of a P-type proton pump determined by X-ray crystallography. Ten transmembrane helices and three cytoplasmic domains define the functional unit of ATP-coupled proton transport across the plasma membrane, and the structure is locked in a functional state not previously observed in P-type ATPases. The transmembrane domain reveals a large cavity, which is likely to be filled with water, located near the middle of the membrane plane where it is lined by conserved hydrophilic and charged residues. Proton transport against a high membrane potential is readily explained by this structural arrangement.

Dynamics of a single-atom electron pump.

PubMed

van der Heijden, J; Tettamanzi, G C; Rogge, S

2017-03-15

Single-electron pumps based on isolated impurity atoms have recently been experimentally demonstrated. In these devices the Coulomb potential of an atom creates a localised electron state with a large charging energy and considerable orbital level spacings, enabling robust charge capturing processes. In contrast to the frequently used gate-defined quantum dot pumps, which experience a strongly time-dependent potential, the confinement potential in these single-atom pumps is hardly affected by the periodic driving of the system. Here we describe the behaviour and performance of an atomic, single parameter, electron pump. This is done by considering the loading, isolating and unloading of one electron at the time, on a phosphorous atom embedded in a silicon double gate transistor. The most important feature of the atom pump is its very isolated ground state, which is populated through the fast loading of much higher lying excited states and a subsequent fast relaxation process. This leads to a substantial increase in pumping accuracy, and is opposed to the adverse role of excited states observed for quantum dot pumps due to non-adiabatic excitations. The pumping performance is investigated as a function of dopant position, revealing a pumping behaviour robust against the expected variability in atomic position.

Dynamics of a single-atom electron pump

PubMed Central

van der Heijden, J.; Tettamanzi, G. C.; Rogge, S.

2017-01-01

Single-electron pumps based on isolated impurity atoms have recently been experimentally demonstrated. In these devices the Coulomb potential of an atom creates a localised electron state with a large charging energy and considerable orbital level spacings, enabling robust charge capturing processes. In contrast to the frequently used gate-defined quantum dot pumps, which experience a strongly time-dependent potential, the confinement potential in these single-atom pumps is hardly affected by the periodic driving of the system. Here we describe the behaviour and performance of an atomic, single parameter, electron pump. This is done by considering the loading, isolating and unloading of one electron at the time, on a phosphorous atom embedded in a silicon double gate transistor. The most important feature of the atom pump is its very isolated ground state, which is populated through the fast loading of much higher lying excited states and a subsequent fast relaxation process. This leads to a substantial increase in pumping accuracy, and is opposed to the adverse role of excited states observed for quantum dot pumps due to non-adiabatic excitations. The pumping performance is investigated as a function of dopant position, revealing a pumping behaviour robust against the expected variability in atomic position. PMID:28295055

Recent progress in reversible photodegradation of Disperse Orange 11 when doped in PMMA

NASA Astrophysics Data System (ADS)

Ramini, Shiva K.; Anderson, Benjamin; Kuzyk, Mark G.

2011-12-01

We report observations that dye-doped PMMA polymer with the organic dye Disperse Orange 11 exhibits self healing after photodegradation by continuous optical pumping whereas in liquid solution, degradation is permanent. This observation illustrates the important role of the polymer matrix in facilitating recovery of the dye molecules. In this work, we report on linear optical absorbance studies that confirm the existence of a quasi-stable state that is not formed in liquid solution. Studies as a function of dye concentration and temperature support our hypothesis of the role of molecular interactions in the decay and healing process that is mediated by the polymer host.

[Changes in the peritoneum of the small intestine and diaphragm in experimental portal hypertension].

PubMed

Khoroshaev, V A; Vorozheĭkin, V M; Baĭbekov, I M

1991-04-01

Diaphragm and small intestine peritoneum morphology was studied in experimental portal hypertension in rats with the help of luminescent, transmission and scanning electron microscopy techniques. Structural organizations of these peritoneum portions and performance function were different: fluid transudation realized through the small intestine peritoneum and resorption occurred via diaphragm peritoneum. Morphological signs allowed to judge about the increasing of fluid transudation in abdominal cavity and diaphragmatic resorption in early period of portal hypertension. Morphological alterations appeared in peritoneum resorption sites (pumping diaphragmatic hatchs) according to progress of portal hypertension that indicated decompensation process of peritoneal fluid absorption and led to ascites.

Can Outer Hair Cells Actively Pump Fluid into the Tunnel of Corti?

NASA Astrophysics Data System (ADS)

Zagadou, Brissi Franck; Mountain, David C.

2011-11-01

Non-classical models of the cochlear traveling wave have been introduced in attempt to capture the unique features of the cochlear amplifier (CA). These models include multiple modes of longitudinal coupling. In one approach, it is hypothesized that two wave modes can add their energies to create amplification such as that desired in the CA. The tunnel of Corti (ToC) was later used to represent the second wave mode for the proposed traveling wave amplifier model, and was incorporated in a multi-compartment cochlea model. The results led to the hypothesis that the CA functions as a fluid pump. However, this hypothesis must be consistent with the anatomical structure of the organ of Corti (OC). The fluid must pass between the outer pillar cells before reaching the ToC, and the ToC fluid and the underlying basilar membrane must constitute an appropriate waveguide. We have analyzed an anatomically based 3D finite element model of the ToC of the gerbil. Our results demonstrate that the OC structure is consistent with the hypothesis.

Evaluation of the impeller shroud performance of an axial flow ventricular assist device using computational fluid dynamics.

PubMed

Su, Boyang; Chua, Leok P; Lim, Tau M; Zhou, Tongming

2010-09-01

Generally, there are two types of impeller design used in the axial flow blood pumps. For the first type, which can be found in most of the axial flow blood pumps, the magnet is embedded inside the impeller hub or blades. For the second type, the magnet is embedded inside the cylindrical impeller shroud, and this design has not only increased the rotating stability of the impeller but has also avoided the flow interaction between the impeller blade tip and the pump casing. Although the axial flow blood pumps with either impeller design have been studied individually, the comparisons between these two designs have not been conducted in the literature. Therefore, in this study, two axial flow blood pumps with and without impeller shrouds were numerically simulated with computational fluid dynamics and compared with each other in terms of hydraulic and hematologic performances. For the ease of comparison, these two models have the same inner components, which include a three-blade straightener, a two-blade impeller, and a three-blade diffuser. The simulation results showed that the model with impeller shroud had a lower static pressure head with a lower hydraulic efficiency than its counterpart. It was also found that the blood had a high possibility to deposit on the impeller shroud inner surface, which greatly enhanced the possibility of thrombus formation. The blood damage indices in both models were around 1%, which was much lower than the 13.1% of the axial flow blood pump of Yano et al. with the corresponding experimental hemolysis of 0.033 g/100 L. © 2010, Copyright the Authors. Artificial Organs © 2010, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Evaluating Cellular Instrumentation on Rural Handpumps to Improve Service Delivery-A Longitudinal Study in Rural Rwanda.

PubMed

Nagel, Corey; Beach, Jack; Iribagiza, Chantal; Thomas, Evan A

2015-12-15

In rural sub-Saharan Africa, where handpumps are common, 10-67% are nonfunctional at any one time, and many never get repaired. Increased reliability requires improved monitoring and responsiveness of maintenance providers. In 2014, 181 cellular enabled water pump use sensors were installed in three provinces of Rwanda. In three arms, the nominal maintenance model was compared against a "best practice" circuit rider model, and an "ambulance" service model. In only the ambulance model was the sensor data available to the implementer, and used to dispatch technicians. The study ran for seven months in 2014-2015. In the study period, the nominal maintenance group had a median time to successful repair of approximately 152 days, with a mean per-pump functionality of about 68%. In the circuit rider group, the median time to successful repair was nearly 57 days, with a per-pump functionality mean of nearly 73%. In the ambulance service group, the successful repair interval was nearly 21 days with a functionality mean of nearly 91%. An indicative cost analysis suggests that the cost per functional pump per year is approximately similar between the three models. However, the benefits of reliable water service may justify greater focus on servicing models over installation models.

Does off-pump coronary surgery reduce morbidity and mortality?

PubMed

Sabik, Joseph F; Gillinov, A Marc; Blackstone, Eugene H; Vacha, Catherine; Houghtaling, Penny L; Navia, Jose; Smedira, Nicholas G; McCarthy, Patrick M; Cosgrove, Delos M; Lytle, Bruce W

2002-10-01

To compare hospital outcomes of on-pump and off-pump coronary artery bypass surgery. From 1997 to 2000, primary coronary artery bypass grafting was performed in 481 patients off pump and in 3231 patients on pump. Hospital outcomes were compared between propensity-matched pairs of 406 on-pump and 406 off-pump patients. The 2 groups were similar in age (P =.9), left ventricular function (P =.7), extent of coronary artery disease (P =.5), carotid artery disease (P =.4), and chronic obstructive pulmonary disease (P =.5). However, off-pump patients had more previous strokes (P =.05) and peripheral vascular disease (P =.02); on-pump patients had a higher preoperative New York Heart Association class (P =.01). In the matched pairs the mean number of bypass grafts was 2.8 +/- 1.0 in off-pump patients and 3.5 +/- 1.1 in on-pump patients (P <.001). Fewer grafts were performed to the circumflex (P <.001) and right coronary (P =.006) artery systems in the off-pump patients. Postoperative mortality, stroke, myocardial infarction, and reoperation for bleeding were similar in the 2 groups. There was more encephalopathy (P =.02), sternal wound infection (P =.04), red blood cell use (P =.002), and renal failure requiring dialysis (P =.03) in the on-pump patients. Both off- and on-pump procedures produced excellent early clinical results with low mortality. An advantage of an off-pump operation was less postoperative morbidity; however, less complete revascularization introduced uncertainty about late results. A disadvantage of on-pump bypass was higher morbidity that seemed attributable to cardiopulmonary bypass.

Advanced heat pump for the recovery of volatile organic compounds

NASA Astrophysics Data System (ADS)

1992-03-01

Emissions of Volatile Organic Compounds (VOC) from stationary industrial and commercial sources represent a substantial portion of the total U.S. VOC emissions. The 'Toxic-Release Inventory' of the U.S. Environmental Protection Agency estimates this to be at about 3 billion pounds per year (1987 estimates). The majority of these VOC emissions are from coating processes, cleaning processes, polymer production, fuel production and distribution, foam blowing, refrigerant production, and wood products production. The U.S. Department of Energy's (DOE) interest in the recovery of VOC stems from the energy embodied in the recovered solvents and the energy required to dispose of them in an environmentally acceptable manner. This Phase 1 report documents 3M's work in close working relationship with its subcontractor Nuclear Consulting Services (Nucon) for the preliminary conceptual design of an advanced Brayton cycle heat pump for the recovery of VOC. The Nucon designed Brayton cycle heat pump for the recovery of methyl ethyl ketone and toluene from coating operations at 3M Weatherford, OK, was used as a base line for the work under cooperative agreement between 3M and ODE. See appendix A and reference (4) by Kovach of Nucon. This cooperative agreement report evaluates and compares an advanced Brayton cycle heat pump for solvent recovery with other competing technologies for solvent recovery and reuse. This advanced Brayton cycle heat pump is simple (very few components), highly reliable (off the shelf components), energy efficient, and economically priced.

Some exact properties of the nonequilibrium response function for transient photoabsorption

NASA Astrophysics Data System (ADS)

Perfetto, E.; Stefanucci, G.

2015-03-01

The physical interpretation of time-resolved photoabsorption experiments is not as straightforward as for the more conventional photoabsorption experiments conducted on equilibrium systems. In fact, the relation between the transient photoabsorption spectrum and the properties of the examined sample can be rather intricate since the former is a complicated functional of both the driving pump and the feeble probe fields. In this work, we critically review the derivation of the time-resolved photoabsorption spectrum in terms of the nonequilibrium dipole response function χ and assess its domain of validity. We then analyze χ in detail and discuss a few exact properties useful to interpret the transient spectrum during (overlapping regime) and after (nonoverlapping regime) the action of the pump. The nonoverlapping regime is the simplest to address. The absorption energies are indeed independent of the delay between the pump and probe pulses and hence the transient spectrum can change only by a rearrangement of the spectral weights. We give a close expression of these spectral weights in two limiting cases (ultrashort and everlasting monochromatic probes) and highlight their strong dependence on coherence and probe envelope. In the overlapping regime, we obtain a Lehmann-type representation of χ in terms of light-dressed states and provide a unifying framework of various well-known effects in pump-driven systems. We also show the emergence of spectral substructures due to the finite duration of the pump pulse.

Experimental study of operation performance for hydrocarbon fuel pump with low specific speed

NASA Astrophysics Data System (ADS)

Wu, Xianyu; Yang, Jun; Jin, Xuan

2017-10-01

In this paper, a small flow rate hydrocarbon turbine pump was used to pressurize the fuel supply system of scramjet engine. Some experiments were carried out to investigate the characteristics of turbine pump driven by nitrogen or combustion gas under different operating conditions. A experimental database with regard to the curves of the rotational speed, mass flow rate and net head with regard to centrifugal pump were plotted. These curves were represented as functions of the pressure and temperature at turbine inlet/outlet and the throttle diameter at downstream of centrifugal pump. A sensitivity study has been carried out based on design of experiments. The experimental was employed to analyze net head of centrifugal and throttle characteristics. The research results can accumulate foundations for the close loop control system of turbine pump.

RGB and white-emitting organic lasers on flexible glass.

PubMed

Foucher, C; Guilhabert, B; Kanibolotsky, A L; Skabara, P J; Laurand, N; Dawson, M D

2016-02-08

Two formats of multiwavelength red, green and blue (RGB) laser on mechanically-flexible glass are demonstrated. In both cases, three all-organic, vertically-emitting distributed feedback (DFB) lasers are assembled onto a common ultra-thin glass membrane substrate and fully encapsulated by a thin polymer overlayer and an additional 50 µm-thick glass membrane in order to improve the performance. The first device format has the three DFB lasers sitting next to each other on the glass substrate. The DFB lasers are simultaneously excited by a single overlapping optical pump, emitting spatially separated red, green and blue laser output with individual thresholds of, respectively, 28 µJ/cm(2), 11 µJ/cm(2) and 32 µJ/cm(2) (for 5 ns pump pulses). The second device format has the three DFB lasers, respectively the red, green and blue laser, vertically stacked onto the flexible glass. This device format emits a white laser output for an optical pump fluence above 42 µJ/cm(2).

Low threshold Amplified Spontaneous Emission properties in deep blue of poly[(9,9-dioctylfluorene-2,7-dyil)-alt-p-phenylene] thin films

NASA Astrophysics Data System (ADS)

Lattante, Sandro; De Giorgi, Maria Luisa; Pasini, Mariacecilia; Anni, Marco

2017-10-01

Amongst the different optoelectronic applications of conjugated polymers, the development of new active materials for optically pumped organic lasers is still an open question particularly in the blue-near UV spectral range. We investigate the emission properties of poly[(9,9-dioctylfluorene-2,7-dyil)- alt-p-phenylene] (PFP) neat films under nanosecond pump. We demonstrate that thanks to the introduction of a phenylene moiety between two fluorene units it is possible to obtain Amplified Spontaneous Emission (ASE) with a lower threshold and a blue shifted wavelength with respect to poly(9,9-dioctylfluorene) (PFO). We demonstrate efficient ASE with a minimum threshold as low as 23 μJcm-2 and a minimum ASE wavelength of 436 nm. A maximum net optical gain of about 26 cm-1 is measured at an excitation density of 0.23 mJcm-2. These results make the PFP a good active material for optically pumped deep blue organic lasers.

Advanced solar energy conversion. [solar pumped gas lasers

NASA Technical Reports Server (NTRS)

Lee, J. H.

1981-01-01

An atomic iodine laser, a candidate for the direct solar pumped lasers, was successfully excited with a 4 kW beam from a xenon arc solar simulator, thus proving the feasibility of the concept. The experimental set up and the laser output as functions of operating conditions are presented. The preliminary results of the iodine laser amplifier pumped with the HCP array to which a Q switch for giant pulse production was coupled are included. Two invention disclosures - a laser driven magnetohydrodynamic generator for conversion of laser energy to electricity and solar pumped gas lasers - are also included.

Rotary drum separator system

NASA Technical Reports Server (NTRS)

Barone, Michael R. (Inventor); Murdoch, Karen (Inventor); Scull, Timothy D. (Inventor); Fort, James H. (Inventor)

2009-01-01

A rotary phase separator system generally includes a step-shaped rotary drum separator (RDS) and a motor assembly. The aspect ratio of the stepped drum minimizes power for both the accumulating and pumping functions. The accumulator section of the RDS has a relatively small diameter to minimize power losses within an axial length to define significant volume for accumulation. The pumping section of the RDS has a larger diameter to increase pumping head but has a shorter axial length to minimize power losses. The motor assembly drives the RDS at a low speed for separating and accumulating and a higher speed for pumping.

The putative drug efflux systems of the Bacillus cereus group

PubMed Central

Elbourne, Liam D. H.; Vörös, Aniko; Kroeger, Jasmin K.; Simm, Roger; Tourasse, Nicolas J.; Finke, Sarah; Henderson, Peter J. F.; Økstad, Ole Andreas; Paulsen, Ian T.; Kolstø, Anne-Brit

2017-01-01

The Bacillus cereus group of bacteria includes seven closely related species, three of which, B. anthracis, B. cereus and B. thuringiensis, are pathogens of humans, animals and/or insects. Preliminary investigations into the transport capabilities of different bacterial lineages suggested that genes encoding putative efflux systems were unusually abundant in the B. cereus group compared to other bacteria. To explore the drug efflux potential of the B. cereus group all putative efflux systems were identified in the genomes of prototypical strains of B. cereus, B. anthracis and B. thuringiensis using our Transporter Automated Annotation Pipeline. More than 90 putative drug efflux systems were found within each of these strains, accounting for up to 2.7% of their protein coding potential. Comparative analyses demonstrated that the efflux systems are highly conserved between these species; 70–80% of the putative efflux pumps were shared between all three strains studied. Furthermore, 82% of the putative efflux system proteins encoded by the prototypical B. cereus strain ATCC 14579 (type strain) were found to be conserved in at least 80% of 169 B. cereus group strains that have high quality genome sequences available. However, only a handful of these efflux pumps have been functionally characterized. Deletion of individual efflux pump genes from B. cereus typically had little impact to drug resistance phenotypes or the general fitness of the strains, possibly because of the large numbers of alternative efflux systems that may have overlapping substrate specificities. Therefore, to gain insight into the possible transport functions of efflux systems in B. cereus, we undertook large-scale qRT-PCR analyses of efflux pump gene expression following drug shocks and other stress treatments. Clustering of gene expression changes identified several groups of similarly regulated systems that may have overlapping drug resistance functions. In this article we review current knowledge of the small molecule efflux pumps encoded by the B. cereus group and suggest the likely functions of numerous uncharacterised pumps. PMID:28472044

Biological proton pumping in an oscillating electric field.

PubMed

Kim, Young C; Furchtgott, Leon A; Hummer, Gerhard

2009-12-31

Time-dependent external perturbations provide powerful probes of the function of molecular machines. Here we study biological proton pumping in an oscillating electric field. The protein cytochrome c oxidase is the main energy transducer in aerobic life, converting chemical energy into an electric potential by pumping protons across a membrane. With the help of master-equation descriptions that recover the key thermodynamic and kinetic properties of this biological "fuel cell," we show that the proton pumping efficiency and the electronic currents in steady state depend significantly on the frequency and amplitude of the applied field, allowing us to distinguish between different microscopic mechanisms of the machine. A spectral analysis reveals dominant reaction steps consistent with an electron-gated pumping mechanism.

Analytical solution of the transient temperature profile in gain medium of passively Q-switched microchip laser.

PubMed

Han, Xiahui; Li, Jianlang

2014-11-01

The transient temperature evolution in the gain medium of a continuous wave (CW) end-pumped passively Q-switched microchip (PQSM) laser is analyzed. By approximating the time-dependent population inversion density as a sawtooth function of time and treating the time-dependent pump absorption of a CW end-pumped PQSM laser as the superposition of an infinite series of short pumping pulses, the analytical expressions of transient temperature evolution and distribution in the gain medium for four- and three-level laser systems, respectively, are given. These analytical solutions are applied to evaluate the transient temperature evolution and distribution in the gain medium of CW end-pumped PQSM Nd:YAG and Yb:YAG lasers.

Diode-Pumped Organo-Lead Halide Perovskite Lasing in a Metal-Clad Distributed Feedback Resonator.

PubMed

Jia, Yufei; Kerner, Ross A; Grede, Alex J; Brigeman, Alyssa N; Rand, Barry P; Giebink, Noel C

2016-07-13

Organic-inorganic lead halide perovskite semiconductors have recently reignited the prospect of a tunable, solution-processed diode laser, which has the potential to impact a wide range of optoelectronic applications. Here, we demonstrate a metal-clad, second-order distributed feedback methylammonium lead iodide perovskite laser that marks a significant step toward this goal. Optically pumping this device with an InGaN diode laser at low temperature, we achieve lasing above a threshold pump intensity of 5 kW/cm(2) for durations up to ∼25 ns at repetition rates exceeding 2 MHz. We show that the lasing duration is not limited by thermal runaway and propose instead that lasing ceases under continuous pumping due to a photoinduced structural change in the perovskite that reduces the gain on a submicrosecond time scale. Our results indicate that the architecture demonstrated here could provide the foundation for electrically pumped lasing with a threshold current density Jth < 5 kA/cm(2) under sub-20 ns pulsed drive.

Pharyngeal pumping inhibition and avoidance by acute exposure to high CO2 levels are both regulated by the BAG neurons via different molecular pathways

PubMed Central

Sharabi, Kfir; Charar, Chayki; Gruenbaum, Yosef

2015-01-01

Carbon dioxide (CO2) is a key molecule in many biological processes. Studies in humans, mice, D. melanogaster, C. elegans, unicellular organisms and plants have shed light on the molecular pathways activated by elevated levels of CO2. However, the mechanisms that organisms use to sense and respond to high CO2 levels remain largely unknown. Previous work has shown that C. elegans quickly avoid elevated CO2 levels using mechanisms that involve the BAG, ASE and AFD neurons via cGMP- and calcium- signaling pathways. Here, we discuss our recent finding that exposure of C. elegans to high CO2 levels leads to a very rapid cessation in the contraction of the pharynx muscles. Surprisingly, none of the tested CO2 avoidance mutants affected the rapid pumping inhibition response to elevated CO2 levels. A forward genetic screen identified that the hid-1-mediated pathway of dense core vesicle maturation regulates the pumping inhibition, probably through affecting neuropeptide secretion. Genetic studies and laser ablation experiments showed that the CO2 response of the pharyngeal muscle pumping is regulated by the BAG neurons, the same neurons that mediate CO2 avoidance. PMID:26430557

Future directions in 980-nm pump lasers: submarine deployment to low-cost watt-class terrestrial pumps

NASA Astrophysics Data System (ADS)

Gulgazov, Vadim N.; Jackson, Gordon S.; Lascola, Kevin M.; Major, Jo S.; Parke, Ross; Richard, Tim; Rossin, Victor V.; Zhang, Kai

1999-09-01

The demands of global bandwidth and distribution are rising rapidly as Internet usage grows. This fundamentally means that more photons are flowing within optical cables. While transmitting sources launches some optical power, the majority of the optical power that is present within modern telecommunication systems originates from optical amplifiers. In addition, modern optical amplifiers offer flat optical gain over broad wavelength bands, thus making possible dense wavelength de-multiplexing (DWDM) systems. Optical amplifier performance, and by extension the performance of the laser pumps that drive them, is central to the future growth of both optical transmission and distribution systems. Erbium-doped amplifiers currently dominate optical amplifier usage. These amplifiers absorb pump light at 980 nm and/or 1480 nm, and achieve gain at wavelengths around 1550 nm. 980 nm pumps achieve better noise figures and are therefore used for the amplification of small signals. Due to the quantum defect, 1480 nm lasers deliver more signal photon per incident photon. In addition, 1480 nm lasers are less expensive than 980 nm lasers. Thus, 1480 nm pump lasers are used for amplification in situations where noise is not critical. The combination of these traits leads to the situation where many amplifiers contain 980 nm lasers to pump the input section of the Er- doped fiber with 1480 nm lasers being used to pump the latter section of Er fiber. This can be thought of as using 980 nm lasers to power an optical pre-amplifier with the power amplification function being pump with 1480 nm radiation. This paper will focus on 980 nm pump lasers and the impact that advances in 980 nm pump technology will have on optical amplification systems. Currently, 980 nm technology is rapidly advancing in two areas, power and reliability. Improving reliability is becoming increasingly important as amplifiers move towards employing more pump lasers and using these pump lasers without redundancy. Since the failure rate allowable for an amplifier is not a function of the number of pumps employed in the amplifier, the allowable failure rate of an individual pump laser is decreasing for next-generation amplifiers. This will lead to specifications for terrestrial pumps well below 1000 FIT, and may lead to the case where high power amplifiers need laser pump reliability to approach 100 FIT. In addition, 980 nm laser diodes are now being deployed in submarine systems where failure rates lower than 100 FIT are commonly specified. It is obvious that both terrestrial and submarine markets are pushing allowable failure rates for pumps for optical amplifiers to continually decrease. A second push for improvement is in the output power of 980 nm pump modules. There exist a number of motivations for increasing the output power of pump lasers. First, each additional channel in a DWDM system requires additional power. To first order, a doubling in channel count implies a doubling in pump power. Second, larger amplifiers require multiple pumps. Higher output power from pump modules allows for fewer pumps, less complicated control systems and smaller size amplifiers. The discussion of this paper will focus on how current development progress of 980 nm laser diodes addresses these issues: better reliability and higher output powers.

Microbial control of the dark end of the biological pump

PubMed Central

2014-01-01

A fraction of the carbon captured by phytoplankton in the sunlit surface ocean sinks to depth as dead organic matter and faecal material. The microbial breakdown of this material in the subsurface ocean generates carbon dioxide. Collectively, this microbially mediated flux of carbon from the atmosphere to the ocean interior is termed the biological pump. In recent decades it has become clear that the composition of the phytoplankton community in the surface ocean largely determines the quantity and quality of organic matter that sinks to depth. This settling organic matter, however, is not sufficient to meet the energy demands of microbes in the dark ocean. Two additional sources of organic matter have been identified: non-sinking organic particles of debated origin that escape capture by sediment traps and exhibit stable concentrations throughout the dark ocean, and microbes that convert inorganic carbon into organic matter. Whether these two sources can together account for the significant mismatch between organic matter consumption and supply in the dark ocean remains to be seen. It is clear, however, that the microbial community of the deep ocean works in a fundamentally different way from surface water communities. PMID:24707320

A Ferrofluidic Seal Specially Designed for Rotary Blood Pumps.

PubMed

Mitamura, Yoshinori; Fujiyoshi, Masayoshi; Yoshida, Toshiobu; Yozu, Ryohei; Okamoto, Eiji; Tanaka, Takashi; Kawada, Shiaki

1996-05-01

One of the key technologies required for rotary blood pumps is sealing of the motor shaft. A ferrofluidic seal was developed for an axial flow pump. The seal body was composed of a plastic magnet and two pole pieces. This seal was formed by injecting ferrofluid into the gap between the pole pieces and the motor shaft. To contain the ferrofluid in the seal and to minimize the possibility of ferrofluid making contact with blood, a shield with a small cavity was provided on the pole piece. Sealing pressure of the seal was measured. The sealing pressure was maintained at more than 23.3 kPa (175 mm Hg) for a motor speed up to 11,000 rpm. The specially designed ferrofluidic seal for sealing out liquids is useful for axial flow blood pumps. © 1996 International Society for Artificial Organs.

The numerical simulation based on CFD of hydraulic turbine pump

NASA Astrophysics Data System (ADS)

Duan, X. H.; Kong, F. Y.; Liu, Y. Y.; Zhao, R. J.; Hu, Q. L.

2016-05-01

As the functions of hydraulic turbine pump including self-adjusting and compensation with each other, it is far-reaching to analyze its internal flow by the numerical simulation based on CFD, mainly including the pressure field and the velocity field in hydraulic turbine and pump.The three-dimensional models of hydraulic turbine pump are made by Pro/Engineer software;the internal flow fields in hydraulic turbine and pump are simulated numerically by CFX ANSYS software. According to the results of the numerical simulation in design condition, the pressure field and the velocity field in hydraulic turbine and pump are analyzed respectively .The findings show that the static pressure decreases systematically and the pressure gradient is obvious in flow area of hydraulic turbine; the static pressure increases gradually in pump. The flow trace is regular in suction chamber and flume without spiral trace. However, there are irregular traces in the turbine runner channels which contrary to that in flow area of impeller. Most of traces in the flow area of draft tube are spiral.

Hypothesized diprotomeric enzyme complex supported by stochastic modelling of palytoxin-induced Na/K pump channels

PubMed Central

Vilallonga, Gabriel D.; de Almeida, Antônio-Carlos G.; Ribeiro, Kelison T.; Campos, Sergio V. A.

2018-01-01

The sodium–potassium pump (Na+/K+ pump) is crucial for cell physiology. Despite great advances in the understanding of this ionic pumping system, its mechanism is not completely understood. We propose the use of a statistical model checker to investigate palytoxin (PTX)-induced Na+/K+ pump channels. We modelled a system of reactions representing transitions between the conformational substates of the channel with parameters, concentrations of the substates and reaction rates extracted from simulations reported in the literature, based on electrophysiological recordings in a whole-cell configuration. The model was implemented using the UPPAAL-SMC platform. Comparing simulations and probabilistic queries from stochastic system semantics with experimental data, it was possible to propose additional reactions to reproduce the single-channel dynamic. The probabilistic analyses and simulations suggest that the PTX-induced Na+/K+ pump channel functions as a diprotomeric complex in which protein–protein interactions increase the affinity of the Na+/K+ pump for PTX. PMID:29657808

Effect of wetting-layer density of states on the gain and phase recovery dynamics of quantum-dot semiconductor optical amplifiers

NASA Astrophysics Data System (ADS)

Kim, Jungho; Yu, Bong-Ahn

2015-03-01

We numerically investigate the effect of the wetting-layer (WL) density of states on the gain and phase recovery dynamics of quantum-dot semiconductor optical amplifiers in both electrical and optical pumping schemes by solving 1088 coupled rate equations. The temporal variations of the ultrafast gain and phase recovery responses at the ground state (GS) are calculated as a function of the WL density of states. The ultrafast gain recovery responses do not significantly depend on the WL density of states in the electrical pumping scheme and the three optical pumping schemes such as the optical pumping to the WL, the optical pumping to the excited state ensemble, and the optical pumping to the GS ensemble. The ultrafast phase recovery responses are also not significantly affected by the WL density of states except the optical pumping to the WL, where the phase recovery component caused by the WL becomes slowed down as the WL density of states increases.

Dual-channel current valve in a three terminal zigzag graphene nanoribbon junction

NASA Astrophysics Data System (ADS)

Zhang, L.

2017-02-01

We theoretically propose a dual-channel current valve based on a three terminal zigzag graphene nanoribbon (ZGNR) junction driven by three asymmetric time-dependent pumping potentials. By means of the Keldysh Green’s function method, we show that two asymmetric charge currents can be pumped in the different left-right terminals of the device at a zero bias, which mainly stems from the single photon-assisted pumping approximation and the valley valve effect in a ZGNR p-n junction. The ON and OFF states of pumped charge currents are crucially dependent on the even-odd chain widths of the three electrodes, the pumping frequency, the lattice potential and the Fermi level. Two-tunneling spin valves are also considered to spatially separate and detect 100% polarized spin currents owing to the combined spin pump effect and the valley selective transport in a three terminal ZGNR ferromagnetic junction. Our investigations might be helpful to control the spatial and spin degrees of freedom of electrons in graphene pumping devices.

Well hydraulics in pumping tests with exponentially decayed rates of abstraction in confined aquifers

NASA Astrophysics Data System (ADS)

Wen, Zhang; Zhan, Hongbin; Wang, Quanrong; Liang, Xing; Ma, Teng; Chen, Chen

2017-05-01

Actual field pumping tests often involve variable pumping rates which cannot be handled by the classical constant-rate or constant-head test models, and often require a convolution process to interpret the test data. In this study, we proposed a semi-analytical model considering an exponentially decreasing pumping rate started at a certain (higher) rate and eventually stabilized at a certain (lower) rate for cases with or without wellbore storage. A striking new feature of the pumping test with an exponentially decayed rate is that the drawdowns will decrease over a certain period of time during intermediate pumping stage, which has never been seen before in constant-rate or constant-head pumping tests. It was found that the drawdown-time curve associated with an exponentially decayed pumping rate function was bounded by two asymptotic curves of the constant-rate tests with rates equaling to the starting and stabilizing rates, respectively. The wellbore storage must be considered for a pumping test without an observation well (single-well test). Based on such characteristics of the time-drawdown curve, we developed a new method to estimate the aquifer parameters by using the genetic algorithm.

Surface plasmon-mediated energy transfer of electrically-pumped excitons

DOEpatents

An, Kwang Hyup; Shtein, Max; Pipe, Kevin P.

2015-08-25

An electrically pumped light emitting device emits a light when powered by a power source. The light emitting device includes a first electrode, a second electrode including an outer surface, and at least one active organic semiconductor disposed between the first and second electrodes. The device also includes a dye adjacent the outer surface of the second electrode such that the second electrode is disposed between the dye and the active organic semiconductor. A voltage applied by the power source across the first and second electrodes causes energy to couple from decaying dipoles into surface plasmon polariton modes, which then evanescently couple to the dye to cause the light to be emitted.

Reduced levels of skeletal muscle Na+K+ -ATPase in McArdle disease

NASA Technical Reports Server (NTRS)

Haller, R. G.; Clausen, T.; Vissing, J.; Blomqvist, C. G. (Principal Investigator)

1998-01-01

We evaluated the hypothesis that impaired sarcolemmal function associated with exaggerated potassium release, impaired potassium uptake, or both may contribute to exertional fatigue and abnormal circulatory responses to exercise in McArdle disease (MD). The cellular mechanism of exertional fatigue and muscle injury in MD is unknown but likely involves impaired function of the ATPases that couple ATP hydrolysis to cellular work, including the muscle sodium potassium pump (Na+K+-ATPase). However, the concentration of muscle Na+K+ pumps in MD is not known, and no studies have related exercise increases in blood potassium concentrations to muscle Na+K+ pump levels. We measured muscle Na+K+ pumps (3H-ouabain binding) and plasma K+ in response to 20 minutes of cycle exercise in six patients with MD and in six sex-, age-, and weight-matched sedentary individuals. MD patients had lower levels of 3H-ouabain binding (231 +/- 18 pmol/g w.w., mean +/- SD, range, 210 to 251) than control subjects (317 +/- 37, range, 266 to 371, p < 0.0004), higher peak increases in plasma potassium in response to 45 +/- 7 W cycle exercise (MD, 1.00 +/- 0.15 mmol/L; control subjects, 0.48 +/- 0.09; p < 0.0001), and mean exercise heart rate responses to exercise that were 45 +/- 12 bpm greater than control subjects. Our results indicate that Na+K+ pump levels are low in MD patients compared with healthy subjects and identify a limitation of potassium reuptake that could result in sarcolemmal failure during peak rates of membrane activation and may promote exaggerated potassium-activated circulatory responses to submaximal exercise. The mechanism of the low Na+K+ pump concentrations in MD is unknown but may relate to deconditioning or to disruption of a close functional relationship between membrane ion transport and glycolysis.

Development of a Centrifugal Pump with Improved Antithrombogenicity and Hemolytic Property for Chronic Circulatory Support.

PubMed

Taenaka, Yoshiyuki; Wakisaka, Yoshinari; Masuzawa, Toru; Tatsumi, Eisuke; Toda, Koichi; Miyazaki, Koji; Eya, Kazuhiro; Baba, Yuzo; Nakatani, Takeshi; Ohno, Takashi; Nishimura, Takashi; Takano, Hisateru

1996-05-01

A centrifugal pump with a unique structure has been developed for chronic support. The pump is driven by a magnetic coupling and has no rotating shaft, no seal around the rotating part, and a balancing hole at the center of the impeller and the thrust bearing. The pump was improved in stepwise fashion to realize good antithrombogenicity and low hemolysis. The first pump, the National Cardiovascular Center (NCVC)-O, had an impeller with 4 rectangular and curved vanes; 6 triangularly shaped curved vanes were employed in the second model, the NCVC-1, to reduce trauma to the blood. In the third design, the NCVC-2, the central hole was enlarged, and the thrust bearing shoulder was rounded so that blood washing was enhanced around the impeller; stream lines also were smoothed for improved antithrombogenicity. The hemolytic property of the device was evaluated in vitro with heparinized fresh goat blood; hemolysis indexes of the NCVC-0, -1, and -2 were 0.05, 0.01, and 0.006 g per 100 L, respectively. Antithrombogenicity of the pumps was examined in animal experiments as a left heart bypass device in goats weighing 52-75 kg. Six NCVC-0 pumps were driven for 14 to 33 (22.0 ± 7.6) days in goats receiving the antiplatelet drug cilostazol orally. Four NCVC-I pumps ran for 1 to 80 (28.5 ± 30.6) days with the same drug regimen in 2 cases and with no anticoagulation therapy in 2 cases. After 3 preliminary 1-week tests of NCVC-2 pumps in animals, the pump was installed in 3 goats; 2 pumps were still running on the 182nd and 58th pumping day. Intracorporeal implantation also was attempted successfully. The results indicate that this pump has promising features for chronic support although longer term and additional evaluations are necessary. © 1996 International Society for Artificial Organs.

Using Mortar Mixing Pump for Magnesia Mortars Preparing and Transporting

NASA Astrophysics Data System (ADS)

Kiyanets, A. V.

2017-11-01

The article is devoted to the problem of preparation and transportation of magnesia mortars with the help of screw mortar mixing pumps. The urgency of the wide use of mortars on magnesia binders (Sorel’s cement) in construction is substantiated due to their high characteristics: strength, hardening speed, wear resistance, possibility of using organic and mineral aggregates, ecological purity and economic efficiency. The necessity for the development of a technique for calculating the main parameters of a mortar mixing pump for its application in the technology of preparation and transportation of magnesia mortars is demonstrated. The analysis of various types of modern mortar mixing pumps is given. The conclusions are drawn about the advantages and disadvantages of standard schemes. The description of the experiment for determination of the productivity of a mortar mixing pump is described depending on the plasticity (mobility) of the used magnesia mortar. The graph and description of the mathematical dependency of the productivity of the mortar mixing pump on the magnesia mortar plasticity are given. On the basis of the obtained dependency, as well as the already known formulas given in the article, a new method is proposed for calculating the main parameters of the screw mortar mixing pump in preparation and transportation of magnesia mortar: productivity, feed range, supply pressure, drive power.

A Relevance Vector Machine-Based Approach with Application to Oil Sand Pump Prognostics

PubMed Central

Hu, Jinfei; Tse, Peter W.

2013-01-01

Oil sand pumps are widely used in the mining industry for the delivery of mixtures of abrasive solids and liquids. Because they operate under highly adverse conditions, these pumps usually experience significant wear. Consequently, equipment owners are quite often forced to invest substantially in system maintenance to avoid unscheduled downtime. In this study, an approach combining relevance vector machines (RVMs) with a sum of two exponential functions was developed to predict the remaining useful life (RUL) of field pump impellers. To handle field vibration data, a novel feature extracting process was proposed to arrive at a feature varying with the development of damage in the pump impellers. A case study involving two field datasets demonstrated the effectiveness of the developed method. Compared with standalone exponential fitting, the proposed RVM-based model was much better able to predict the remaining useful life of pump impellers. PMID:24051527

2011 IEEE Visualization Contest winner: Visualizing unsteady vortical behavior of a centrifugal pump.

PubMed

Otto, Mathias; Kuhn, Alexander; Engelke, Wito; Theisel, Holger

2012-01-01

In the 2011 IEEE Visualization Contest, the dataset represented a high-resolution simulation of a centrifugal pump operating below optimal speed. The goal was to find suitable visualization techniques to identify regions of rotating stall that impede the pump's effectiveness. The winning entry split analysis of the pump into three parts based on the pump's functional behavior. It then applied local and integration-based methods to communicate the unsteady flow behavior in different regions of the dataset. This research formed the basis for a comparison of common vortex extractors and more recent methods. In particular, integration-based methods (separation measures, accumulated scalar fields, particle path lines, and advection textures) are well suited to capture the complex time-dependent flow behavior. This video (http://youtu.be/oD7QuabY0oU) shows simulations of unsteady flow in a centrifugal pump.

A relevance vector machine-based approach with application to oil sand pump prognostics.

PubMed

Hu, Jinfei; Tse, Peter W

2013-09-18

Oil sand pumps are widely used in the mining industry for the delivery of mixtures of abrasive solids and liquids. Because they operate under highly adverse conditions, these pumps usually experience significant wear. Consequently, equipment owners are quite often forced to invest substantially in system maintenance to avoid unscheduled downtime. In this study, an approach combining relevance vector machines (RVMs) with a sum of two exponential functions was developed to predict the remaining useful life (RUL) of field pump impellers. To handle field vibration data, a novel feature extracting process was proposed to arrive at a feature varying with the development of damage in the pump impellers. A case study involving two field datasets demonstrated the effectiveness of the developed method. Compared with standalone exponential fitting, the proposed RVM-based model was much better able to predict the remaining useful life of pump impellers.

A global design of high power Nd 3+-Yb 3+ co-doped fiber lasers

NASA Astrophysics Data System (ADS)

Fan, Zhang; Chuncan, Wang; Tigang, Ning

2008-09-01

A global optimization method - niche hybrid genetic algorithm (NHGA) based on fitness sharing and elite replacement is applied to optimize Nd3+-Yb3+ co-doped fiber lasers (NYDFLs) for obtaining maximum signal output power. With a objective function and different pumping powers, five critical parameters (the fiber length, L; the proportion of pump power for pumping Nd3+, η; Nd3+ and Yb3+ concentrations, NNd and NYb and output mirror reflectivity, Rout) of the given NYDFLs are optimized by solving the rate and power propagation equations. Results show that dividing equally the input pump power among 808 nm (Nd3+) and 940 nm (Yb3+) is not an optimal choice and the pump power of Nd3+ ions should be kept around 10-13.78% of the total pump power. Three optimal schemes are obtained by NHGA and the highest slope efficiency of the laser is able to reach 80.1%.

Nonlinear model for offline correction of pulmonary waveform generators.

PubMed

Reynolds, Jeffrey S; Stemple, Kimberly J; Petsko, Raymond A; Ebeling, Thomas R; Frazer, David G

2002-12-01

Pulmonary waveform generators consisting of motor-driven piston pumps are frequently used to test respiratory-function equipment such as spirometers and peak expiratory flow (PEF) meters. Gas compression within these generators can produce significant distortion of the output flow-time profile. A nonlinear model of the generator was developed along with a method to compensate for gas compression when testing pulmonary function equipment. The model and correction procedure were tested on an Assess Full Range PEF meter and a Micro DiaryCard PEF meter. The tests were performed using the 26 American Thoracic Society standard flow-time waveforms as the target flow profiles. Without correction, the pump loaded with the higher resistance Assess meter resulted in ten waveforms having a mean square error (MSE) higher than 0.001 L2/s2. Correction of the pump for these ten waveforms resulted in a mean decrease in MSE of 87.0%. When loaded with the Micro DiaryCard meter, the uncorrected pump outputs included six waveforms with MSE higher than 0.001 L2/s2. Pump corrections for these six waveforms resulted in a mean decrease in MSE of 58.4%.

Fluid Dynamics in Rotary Piston Blood Pumps.

PubMed

Wappenschmidt, Johannes; Sonntag, Simon J; Buesen, Martin; Gross-Hardt, Sascha; Kaufmann, Tim; Schmitz-Rode, Thomas; Autschbach, Ruediger; Goetzenich, Andreas

2017-03-01

Mechanical circulatory support can maintain a sufficient blood circulation if the native heart is failing. The first implantable devices were displacement pumps with membranes. They were able to provide a sufficient blood flow, yet, were limited because of size and low durability. Rotary pumps have resolved these technical drawbacks, enabled a growing number of mechanical circulatory support therapy and a safer application. However, clinical complications like gastrointestinal bleeding, aortic insufficiency, thromboembolic complications, and impaired renal function are observed with their application. This is traced back to their working principle with attenuated or non-pulsatile flow and high shear stress. Rotary piston pumps potentially merge the benefits of available pump types and seem to avoid their complications. However, a profound assessment and their development requires the knowledge of the flow characteristics. This study aimed at their investigation. A functional model was manufactured and investigated with particle image velocimetry. Furthermore, a fluid-structure interaction computational simulation was established to extend the laboratory capabilities. The numerical results precisely converged with the laboratory measurements. Thus, the in silico model enabled the investigation of relevant areas like gap flows that were hardly feasible with laboratory means. Moreover, an economic method for the investigation of design variations was established.

Robust technology and system for management of sucker rod pumping units in oil wells

NASA Astrophysics Data System (ADS)

Aliev, T. A.; Rzayev, A. H.; Guluyev, G. A.; Alizada, T. A.; Rzayeva, N. E.

2018-01-01

We propose a technology for calculating the robust, normalized correlation functions of the signal from the force sensor on the rod string attached to the hanger of the sucker rod pumping unit. The robust normalized correlation functions are used to form sets of informative attribute combinations, each of which corresponds to a technical condition of the sucker rod pumping unit. We demonstrate how these sets can be used to solve identification and management problems in the oil production process in real time using inexpensive controllers. The results obtained from using the system on real objects are also presented in this paper. It was determined that the energy saved and prolonged overhaul period substantially increased the cost-effectiveness.

Coherence and dimensionality of intense spatiospectral twin beams

NASA Astrophysics Data System (ADS)

Peřina, Jan

2015-07-01

Spatiospectral properties of twin beams at their transition from low to high intensities are analyzed in parametric and paraxial approximations using decomposition into paired spatial and spectral modes. Intensity auto- and cross-correlation functions are determined and compared in the spectral and temporal domains as well as the transverse wave-vector and crystal output planes. Whereas the spectral, temporal, and transverse wave-vector coherence increases with the increasing pump intensity, coherence in the crystal output plane is almost independent of the pump intensity owing to the mode structure in this plane. The corresponding auto- and cross-correlation functions approach each other for larger pump intensities. The entanglement dimensionality of a twin beam is determined with a comparison of several approaches.

Brain function monitoring during off-pump cardiac surgery: a case report

PubMed Central

Zanatta, Paolo; Bosco, Enrico; Di Pasquale, Piero; Nivedita, Agarwal; Valfrè, Carlo; Sorbara, Carlo

2008-01-01

Background Early postoperative stroke is an adverse syndrome after coronary bypass surgery. This report focuses on overcoming of cerebral ischemia as a result of haemodynamic instability during heart enucleation in off-pump procedure. Case presentation A 67 year old male patient, Caucasian race, with a body mass index of 28, had a recent non-Q posterolateral myocardial infarction one month before and recurrent instable angina. His past history includes an uncontrolled hypertension, dyslipidemia, insulin dependent diabetes mellitus, epiaortic vessel stenosis. The patient was scheduled for an off-pump procedure and monitored with bilateral somatosensory evoked potentials, whose alteration signalled the decrement of the cardiac index during operation. The somatosensory evoked potentials appeared when the blood pressure was increased with a pharmacological treatment. Conclusion During the off-pump coronary bypass surgery, a lower cardiac index, predisposes patients, with multiple stroke risk factors, to a reduction of the cerebral blood flow. Intraoperative somatosensory evoked potentials monitoring provides informations about the functional status of somatosensory cortex to reverse effects of brain ischemia. PMID:18706094

Method and system for homogenizing diode laser pump arrays

DOEpatents

Bayramian, Andrew James

2016-05-03

An optical amplifier system includes a diode pump array including a plurality of semiconductor diode laser bars disposed in an array configuration and characterized by a periodic distance between adjacent semiconductor diode laser bars. The periodic distance is measured in a first direction perpendicular to each of the plurality of semiconductor diode laser bars. The diode pump array provides a pump output propagating along an optical path and characterized by a first intensity profile measured as a function of the first direction and having a variation greater than 10%. The optical amplifier system also includes a diffractive optic disposed along the optical path. The diffractive optic includes a photo-thermo-refractive glass member. The optical amplifier system further includes an amplifier slab having an input face and position along the optical path and separated from the diffractive optic by a predetermined distance. A second intensity profile measured at the input face of the amplifier slab as a function of the first direction has a variation less than 10%.

Method and system for homogenizing diode laser pump arrays

DOEpatents

Bayramian, Andy J

2013-10-01

An optical amplifier system includes a diode pump array including a plurality of semiconductor diode laser bars disposed in an array configuration and characterized by a periodic distance between adjacent semiconductor diode laser bars. The periodic distance is measured in a first direction perpendicular to each of the plurality of semiconductor diode laser bars. The diode pump array provides a pump output propagating along an optical path and characterized by a first intensity profile measured as a function of the first direction and having a variation greater than 10%. The optical amplifier system also includes a diffractive optic disposed along the optical path. The diffractive optic includes a photo-thermo-refractive glass member. The optical amplifier system further includes an amplifier slab having an input face and position along the optical path and separated from the diffractive optic by a predetermined distance. A second intensity profile measured at the input face of the amplifier slab as a function of the first direction has a variation less than 10%.

Structures and transport dynamics of a Campylobacter jejuni multidrug efflux pump

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

Su, Chih-Chia; Yin, Linxiang; Kumar, Nitin

2017-08-01

Resistance-nodulation-cell division efflux pumps are integral membrane proteins that catalyze the export of substrates across cell membranes. Within the hydrophobe-amphiphile efflux subfamily, these resistance-nodulation-cell division proteins largely form trimeric efflux pumps. The drug efflux process has been proposed to entail a synchronized motion between subunits of the trimer to advance the transport cycle, leading to the extrusion of drug molecules. Here we use X-ray crystallography and single-molecule fluorescence resonance energy transfer imaging to elucidate the structures and functional dynamics of the Campylobacter jejuni CmeB multidrug efflux pump. We find that the CmeB trimer displays a very unique conformation. A directmore » observation of transport dynamics in individual CmeB trimers embedded in membrane vesicles indicates that each CmeB subunit undergoes conformational transitions uncoordinated and independent of each other. On the basis of our findings and analyses, we propose a model for transport mechanism where CmeB protomers function independently within the trimer.« less

Centaur boost pump turbine icing investigation

NASA Technical Reports Server (NTRS)

Rollbuhler, R. J.

1976-01-01

An investigation was conducted to determine if ice formation in the Centaur vehicle liquid oxygen boost pump turbine could prevent rotation of the pump and whether or not this phenomenon could have been the failure mechanism for the Titan/Centaur vehicle TC-1. The investigation consisted of a series of tests done in the LeRC Space Power Chamber Facility to evaluate evaporative cooling behavior patterns in a turbine as a function of the quantity of water trapped in the turbine and as a function of the vehicle ascent pressure profile. It was found that evaporative freezing of water in the turbine housing, due to rapid depressurization within the turbine during vehicle ascent, could result in the formation of ice that would block the turbine and prevent rotation of the boost pump. But for such icing conditions to exist it would be necessary to have significant quantities of water in the turbine and/or its components, and the turbine housing temperature would have to be colder than 40 F at vehicle liftoff.

Anisotropic Reinforcement of Acute Anteroapical Infarcts Improves Pump Function

PubMed Central

Fomovsky, Gregory M.; Clark, Samantha A.; Parker, Katherine M.; Ailawadi, Gorav; Holmes, Jeffrey W.

2012-01-01

Background We hypothesize that a therapy that improves LV pump function early after infarction should decrease the need for compensation through sympathetic activation and dilation, thereby reducing the risk of developing heart failure. The mechanical properties of healing myocardial infarcts are an important determinant of left ventricular (LV) function, yet improving function by altering infarct properties has proven unexpectedly difficult. Using a computational model, we recently predicted that stiffening a large anterior infarct anisotropically (in only one direction) would improve LV function, while isotropic stiffening, the focus of previous studies and therapies, would not. The goal of this study was to test the novel strategy of anisotropic infarct reinforcement. Methods and Results We tested the effects of anisotropic infarct reinforcement in 10 open-chest dogs with large anteroapical infarcts that depressed LV pump function. We measured regional mechanics, LV volumes, and cardiac output at a range of preloads at Baseline, 45 minutes after coronary ligation (Ischemia), and 30 minutes later, following surgical reinforcement in the longitudinal direction (Anisotropic). Ischemia shifted the end-systolic pressure-volume relationship (ESPVR) and cardiac output curves rightward, decreasing cardiac output at matched end-diastolic pressure (EDP) by 44%. Anisotropic reinforcement significantly improved systolic function without impairing diastolic function, recovering half the deficit in overall LV function. Conclusions We conclude that anisotropic reinforcement is a promising new approach to improving LV function following a large myocardial infarction. PMID:22665716

30-Day In-vivo Performance of a Wearable Artificial Pump-Lung for Ambulatory Respiratory Support

PubMed Central

Wu, Zhongjun J; Zhang, Tao; Bianchi, Giacomo; Wei, Xufeng; Son, Ho-Sung; Zhou, Kang; Sanchez, Pablo; Garcia, Jose; Griffith, Bartley P

2011-01-01

Background The purpose of this study was to evaluate the long-term in-vivo hemodynamics, gas transfer and biocompatibility of an integrated artificial pump-lung (APL) developed for ambulatory respiratory support. Methods The study was conducted in an ovine model by surgically placing the APL between the right atrium and pulmonary artery. Nine sheep were implanted. Heparin was infused as an anticoagulant. The device flow, gas transfer and plasma free hemoglobin (PFH) were measured daily. Hematological data, platelet activation and blood biochemistry were assessed twice a week. After 30 days, the sheep were euthanized for necropsy. The explanted devices were examined for gross thrombosis. Results Five sheep survived for 29 to 31 days and were electively terminated. Four sheep expired or were terminated early due to mechanical failure of IV lines or device. The APL devices in the five long-term animals were capable of delivering an oxygen transfer rate of 148±18 ml/min at a flow rate of 2.99±0.46 l/min with blood oxygen saturation of 96.7±1.3%. The device flow and oxygen transfer were stable over 30 days. The animals had normal end-organ functions except for surgery-related transient alteration in kidney function, liver function, and cell and tissue injury. There was no hemolysis. The device flow path and membrane surface were free of gross thrombus. Conclusions The APL exhibited the capability of providing respiratory support with excellent biocompatibility, long-term reliability and the potential for bridging to lung transplant. PMID:22115337

Full counting statistics of a charge pump in the Coulomb blockade regime

NASA Astrophysics Data System (ADS)

Andreev, A. V.; Mishchenko, E. G.

2001-12-01

We study full charge counting statistics (FCCS) of a charge pump based on a nearly open single electron transistor. The problem is mapped onto an exactly soluble problem of a nonequilibrium g=1/2 Luttinger liquid with an impurity. We obtain an analytic expression for the generating function of the transmitted charge for an arbitrary pumping strength. Although this model contains fractionally charged excitations only integer transmitted charges can be observed. In the weak pumping limit FCCS correspond to a Poissonian transmission of particles with charge e*=e/2 from which all events with odd numbers of transferred particles are excluded.

Integrating Patient-Controlled Analgesia Using Implanted Intrathecal Pumps for Postoperative Pain Management: A Case Report.

PubMed

Peniche, Alec; Poree, Lawrence; Schumacher, Mark; Yu, Xiaobing

2018-06-01

Intrathecal patient-controlled analgesia (IT-PCA) through implanted intrathecal infusion pumps has been increasingly utilized for severe cancer and chronic noncancer pain management. However, its application for acute postoperative pain management has not been reported to date. We present a case of a patient with an implanted intrathecal pump for chronic nonmalignant back pain who underwent an extensive spinal fusion surgery. The IT-PCA functionality of her intrathecal pump was successfully integrated into her postoperative multimodal pain regimen. Hence, IT-PCA can be safely incorporated into acute postoperative pain management with vigilant monitoring and close multidisciplinary collaboration.

Experimental Simulation of Turbine-Exhaust Oxygen Recovery

NASA Technical Reports Server (NTRS)

Clark, Jim A.; Branch, Ryan W.

2004-01-01

In some liquid-propellant rocket engines, the liquid-oxygen boost pump is driven by a turbine that is powered by high-pressure gaseous oxygen. Once it exits the turbine, this gaseous oxygen can be salvaged by injecting it into the subcooled liquid oxygen exiting the boost pump. If the main LOX pump is to function correctly under these circumstances, complete condensation of the gaseous oxygen must quickly follow its injection into the boost-pump discharge. The current investigation uses steam and water in a simple rig that allows the condensation process to be visualized and quantified. This paper offers dimensionless-parameter correlations of the data and trends observed.

Field testing of two prototype air-source integrated heat pumps for net zero energy home (nZEH) application

DOE PAGES

Baxter, Van D.; Munk, Jeffrey D.

2017-11-08

By integrating multiple functions into a single system it offers potential efficiency and cost reduction benefits. Oak Ridge National Laboratory (ORNL) and its partners have designed, developed, and tested two air-source heat pump designs that not only provide space heating and cooling, but also water heating, dehumidification, and ventilation functions. Some details on the design, simulated performance, prototype field test, measured performance, and lessons learned are provided.

Field testing of two prototype air-source integrated heat pumps for net zero energy home (nZEH) application

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

Baxter, Van D.; Munk, Jeffrey D.

By integrating multiple functions into a single system it offers potential efficiency and cost reduction benefits. Oak Ridge National Laboratory (ORNL) and its partners have designed, developed, and tested two air-source heat pump designs that not only provide space heating and cooling, but also water heating, dehumidification, and ventilation functions. Some details on the design, simulated performance, prototype field test, measured performance, and lessons learned are provided.

Magnetic Pumping as a Source of Particle Heating and Power-law Distributions in the Solar Wind

NASA Astrophysics Data System (ADS)

Lichko, E.; Egedal, J.; Daughton, W.; Kasper, J.

2017-12-01

Based on the rate of expansion of the solar wind, the plasma should cool rapidly as a function of distance to the Sun. Observations show this is not the case. In this work, a magnetic pumping model is developed as a possible explanation for the heating and the generation of power-law distribution functions observed in the solar wind plasma. Most previous studies in this area focus on the role that the dissipation of turbulent energy on microscopic kinetic scales plays in the overall heating of the plasma. However, with magnetic pumping, particles are energized by the largest-scale turbulent fluctuations, thus bypassing the energy cascade. In contrast to other models, we include the pressure anisotropy term, providing a channel for the large-scale fluctuations to heat the plasma directly. A complete set of coupled differential equations describing the evolution, and energization, of the distribution function are derived, as well as an approximate closed-form solution. Numerical simulations using the VPIC kinetic code are applied to verify the model’s analytical predictions. The results of the model for realistic solar wind scenario are computed, where thermal streaming of particles are important for generating a phase shift between the magnetic perturbations and the pressure anisotropy. In turn, averaged over a pump cycle, the phase shift permits mechanical work to be converted directly to heat in the plasma. The results of this scenario show that magnetic pumping may account for a significant portion of the solar wind energization.

Integration of a Micro-Chip Amino Acid Chirality Detector into the MOD Instrument Concept

NASA Technical Reports Server (NTRS)

Bada, Jeffrey L.; Grunthaner, Frank; Mathies, Richard

2004-01-01

The MOD (Mars Organic Detector) instrument concept consists of a sublimation apparatus for organic compound isolation connected to a microfabricated microfluidic analyzer containing a sipper, pumps and a separation channel for organic compound characterization. The target organic compounds are amino acids and polycyclic aromatic hydrocarbons (PAHs). Solid samples are placed within the sublimation apparatus and heated to release organic compounds which sublime onto a cold finger. Half of the cold finger is coated with fluorescamine. which reacts with amino acids and other primary amines to generate an intense fluorescent derivative while the other half is uncoated and is used to directly detect PAH fluorescence, A capillary sipper is then used to dissolve and sample the labeled amino acids and integrated microfabricated pumps transport the labeled amino acids to the chip for analysis. The sample is separated using capillary zone electrophoresis (CZE) together with chiral dextrins to determine amino acid composition and chirality. During the grant period, the following steps have been completed toward the development of a robust instrument and chemistry.

Ring-Down Spectroscopy for Characterizing a CW Raman Laser

NASA Technical Reports Server (NTRS)

Matsko, Andrey; Savchenkov, Anatoliy; Maleki, Lute

2007-01-01

.A relatively simple technique for characterizing an all-resonant intracavity continuous-wave (CW) solid-state Raman laser involves the use of ring-down spectroscopy. As used here, characterizing signifies determining such parameters as threshold pump power, Raman gain, conversion efficiency, and quality factors (Q values) of the pump and Stokes cavity modes. Heretofore, in order to characterize resonant-cavity-based Raman lasers, it has usually been necessary to manipulate the frequencies and power levels of pump lasers and, in each case, to take several sets of measurements. In cases involving ultra-high-Q resonators, it also has been desirable to lock pump lasers to resonator modes to ensure the quality of measurement data. Simpler techniques could be useful. In the present ring-down spectroscopic technique, one infers the parameters of interest from the decay of the laser out of its steady state. This technique does not require changing the power or frequency of the pump laser or locking the pump laser to the resonator mode. The technique is based on a theoretical analysis of what happens when the pump laser is abruptly switched off after the Raman generation reaches the steady state. The analysis starts with differential equations for the evolution of the amplitudes of the pump and Stokes electric fields, leading to solutions for the power levels of the pump and Stokes fields as functions of time and of the aforementioned parameters. Among other things, these solutions show how the ring-down time depends, to some extent, on the electromagnetic energy accumulated in the cavity. The solutions are readily converted to relatively simple equations for the parameters as functions of quantities that can be determined from measurements of the time-dependent power levels. For example, the steady-state intracavity conversion efficiency is given by G1/G2 1 and the threshold power is given by Pin(G2/G1)2, where Pin is the steady-state input pump power immediately prior to abrupt switch-off, G1 is the initial rate of decay of the pump field, and G2 is the final rate of decay of the pump field. Hence, it is possible to determine all the parameters from a single ring-down scan, provided that the measurements taken in that scan are sufficiently accurate and complete.

Research on networked manufacturing system for reciprocating pump industry

NASA Astrophysics Data System (ADS)

Wu, Yangdong; Qi, Guoning; Xie, Qingsheng; Lu, Yujun

2005-12-01

Networked manufacturing is a trend of reciprocating pump industry. According to the enterprises' requirement, the architecture of networked manufacturing system for reciprocating pump industry was proposed, which composed of infrastructure layer, system management layer, application service layer and user layer. Its main functions included product data management, ASP service, business management, and customer relationship management, its physics framework was a multi-tier internet-based model; the concept of ASP service integration was put forward and its process model was also established. As a result, a networked manufacturing system aimed at the characteristics of reciprocating pump industry was built. By implementing this system, reciprocating pump industry can obtain a new way to fully utilize their own resources and enhance the capabilities to respond to the global market quickly.

Biological proton pumping in an oscillating electric field

PubMed Central

Kim, Young C.; Furchtgott, Leon A.; Hummer, Gerhard

2010-01-01

Time-dependent external perturbations provide powerful probes of the function of molecular machines. Here we study biological proton pumping in an oscillating electric field. The protein cytochrome c oxidase is the main energy transducer in aerobic life, converting chemical energy into an electric potential by pumping protons across a membrane. With the help of master-equation descriptions that recover the key thermodynamic and kinetic properties of this biological “fuel cell,” we show that the proton pumping efficiency and the electronic currents in steady state both depend significantly and distinctly on the frequency and amplitude of the applied field, allowing us to distinguish between different microscopic mechanisms of the machine. A spectral analysis reveals dominant kinetic modes that show reaction steps consistent with an electron-gated pumping mechanism. PMID:20366348

Low power integrated pumping and valving arrays for microfluidic systems

DOEpatents

Krulevitch, Peter A [Pleasanton, CA; Benett, William J [Livermore, CA; Rose, Klint A [Livermore, CA; Hamilton, Julie [Tracy, CA; Maghribi, Mariam [Davis, CA

2006-04-11

Low power integrated pumping and valving arrays which provide a revolutionary approach for performing pumping and valving approach for performing pumping and valving operations in microfabricated fluidic systems for applications such as medical diagnostic microchips. Traditional methods rely on external, large pressure sources that defeat the advantages of miniaturization. Previously demonstrated microfabrication devices are power and voltage intensive, only function at sufficient pressure to be broadly applicable. This approach integrates a lower power, high-pressure source with a polymer, ceramic, or metal plug enclosed within a microchannel, analogous to a microsyringe. When the pressure source is activated, the polymer plug slides within the microchannel, pumping the fluid on the opposite side of the plug without allowing fluid to leak around the plug. The plugs also can serve as microvalves.

Analytical thermal model for end-pumped solid-state lasers

NASA Astrophysics Data System (ADS)

Cini, L.; Mackenzie, J. I.

2017-12-01

Fundamentally power-limited by thermal effects, the design challenge for end-pumped "bulk" solid-state lasers depends upon knowledge of the temperature gradients within the gain medium. We have developed analytical expressions that can be used to model the temperature distribution and thermal-lens power in end-pumped solid-state lasers. Enabled by the inclusion of a temperature-dependent thermal conductivity, applicable from cryogenic to elevated temperatures, typical pumping distributions are explored and the results compared with accepted models. Key insights are gained through these analytical expressions, such as the dependence of the peak temperature rise in function of the boundary thermal conductance to the heat sink. Our generalized expressions provide simple and time-efficient tools for parametric optimization of the heat distribution in the gain medium based upon the material and pumping constraints.

Pumping Performance and Turbidity Generation of Model 600/100 PNEUMA Pump. Main Text and Appendixes A and B.

DTIC Science & Technology

1982-04-01

E. Hite, Jr. Richard A. Shafer James D. Ethridge, Jr. 9 . PERFORMING ORGANIZATION NAME AND ADDRESS i0. PROGRAM ELEMENT. PROJECT. TASK AREA A WORK UNIT...Appendix C (bound separately) contains tables of measured dat a and cal-LnIuated parameters interpolated at 9 -sec intervals for each test run. Unc lassi...Test Program . . . . . . . . . . . . . . . . . . . . . . . . 9 PART III: TEST RESULTS....................... Data Reduction and Presentation

Human endomembrane H+ pump strongly resembles the ATP-synthetase of Archaebacteria.

PubMed Central

Südhof, T C; Fried, V A; Stone, D K; Johnston, P A; Xie, X S

1989-01-01

Preparations of mammalian H+ pumps that acidify intracellular vesicles contain eight or nine polypeptides, ranging in size from 116 to 17 kDa. Biochemical analysis indicates that the 70- and 58-kDa polypeptides are subunits critical for ATP hydrolysis. The amino acid sequences of the major catalytic subunits (58 and 70 kDa) of the endomembrane H+ pump are unknown from animal cells. We report here the complete sequence of the 58-kDa subunit derived from a human kidney cDNA clone and partial sequences of the 70- and 58-kDa subunits purified from clathrin-coated vesicles of bovine brain. The amino acid sequences of both proteins strongly resemble the sequences of the corresponding subunits of the vacuolar H+ pumps of Archaebacteria, plants, and fungi. The archaebacterial enzyme is believed to use a H+ gradient to synthesize ATP. Thus, a common ancestral protein has given rise to a H+ pump that synthesizes ATP in one organism and hydrolyzes it in another and is highly conserved from prokaryotes to humans. The same pump appears to mediate the acidification of intracellular organelles, including coated vesicles, lysosomes, and secretory granules, as well as extracellular fluids such as urine. PMID:2527371

Lifelike Vascular Reperfusion of a Thiel-Embalmed Pig Model and Evaluation as a Surgical Training Tool.

PubMed

Willaert, Wouter; Tozzi, Francesca; Van Hoof, Tom; Ceelen, Wim; Pattyn, Piet; D''Herde, Katharina

2016-01-01

Vascular reperfusion of Thiel cadavers can aid surgical and anatomical instruction. This study investigated whether ideal embalming circumstances provide lifelike vascular flow, enabling surgical practice and enhancing anatomical reality. Pressure-controlled pump-driven administration of blue embalming solution was assessed directly postmortem in a pig model (n = 4). Investigation of subsequent pump-driven vascular injection of red paraffinum perliquidum (PP) included assessment of flow parameters, intracorporeal distribution, anatomical alterations, and feasibility for surgical training. The microscopic distribution of PP was analyzed in pump-embalmed pig and gravity-embalmed human small intestines. Embalming lasted 50-105 min, and maximum arterial pressure was 65 mm Hg. During embalming, the following consecutive alterations were observed: arterial filling, organ coloration, venous perfusion, and further tissue coloration during the next weeks. Most organs were adequately preserved. PP generated low arterial pressures (<30 mm Hg) and drained through the venous cannula. Generally, realistic reperfusion and preservation of original anatomy were observed, but leakage in the pleural, abdominal, and retroperitoneal cavities occurred, and computed tomography showed edematous spleen and liver. Reduction of arterial flow rates after venous drainage is a prerequisite to prevent anatomical deformation, allowing simulation of various surgeries. In pump-embalmed pig small intestines, PP flowed from artery to vein through the capillaries without extravasation. In contrast, arterioles were blocked in gravity-embalmed human tissues. In a pig model, immediate postmortem pressure-controlled pump embalming generates ideal circumstances for (micro)vascular reperfusion with PP, permitting lifelike anatomy instruction and surgical training. © 2016 S. Karger AG, Basel.

Organic Separation Test Results

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

Russell, Renee L.; Rinehart, Donald E.; Peterson, Reid A.

2014-09-22

Separable organics have been defined as “those organic compounds of very limited solubility in the bulk waste and that can form a separate liquid phase or layer” (Smalley and Nguyen 2013), and result from three main solvent extraction processes: U Plant Uranium Recovery Process, B Plant Waste Fractionation Process, and Plutonium Uranium Extraction (PUREX) Process. The primary organic solvents associated with tank solids are TBP, D2EHPA, and NPH. There is concern that, while this organic material is bound to the sludge particles as it is stored in the tanks, waste feed delivery activities, specifically transfer pump and mixer pump operations,more » could cause the organics to form a separated layer in the tank farms feed tank. Therefore, Washington River Protection Solutions (WRPS) is experimentally evaluating the potential of organic solvents separating from the tank solids (sludge) during waste feed delivery activities, specifically the waste mixing and transfer processes. Given the Hanford Tank Waste Treatment and Immobilization Plant (WTP) waste acceptance criteria per the Waste Feed Acceptance Criteria document (24590-WTP-RPT-MGT-11-014) that there is to be “no visible layer” of separable organics in the waste feed, this would result in the batch being unacceptable to transfer to WTP. This study is of particular importance to WRPS because of these WTP requirements.« less

A Simplified Method for Sampling and Analysis of High Volume Surface Water for Organic Contaminants Using XAD-2

USGS Publications Warehouse

Datta, S.; Do, L.V.; Young, T.M.

2004-01-01

A simple compressed-gas driven system for field processing and extracting water for subsequent analyses of hydrophobic organic compounds is presented. The pumping device is a pneumatically driven pump and filtration system that can easily clarify at 4L/min. The extraction device uses compressed gas to drive filtered water through two parallel XAD-2 resin columns, at about 200 mL/min. No batteries or inverters are required for water collection or processing. Solvent extractions were performed directly in the XAD-2 glass columns. Final extracts are cleaned-up on Florisil cartridges without fractionation and contaminants analyzed by GC-MS. Method detection limits (MDLs) and recoveries for dissolved organic contaminants, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and pesticides are reported along with results of surface water analysis for the San Francisco Bay, CA.

Spectrally narrowed laserlike emission in a novel organic salt, DEST: cooperative emission

NASA Astrophysics Data System (ADS)

Tan, Shida; Mishra, Alpana; Ahyi, Ayayi; Bhowmik, Achintya; Dharmadhikari, Aditya; Thakur, Mrinal

2001-03-01

We have synthesized a novel organic salt, 4'-diethylamino-N-methyl-4-stilbazolium p-toluenesulfonate (DEST). Frequency-doubled pulses (55 ps) from a Nd:YAG laser at 10 Hz repetition rate were used to pump DEST solution in methanol and a 20% conversion efficiency in laserlike emission was observed without external mirrors. The low energy PL quantum efficiency of DEST is very low. The peak of the emission spectrum was at 617 nm and the threshold pump energy for spectral-narrowing was less than 1 μJ. Beyond the threshold, the FWHM of the spectrum was found to have reduced from 70 nm to 14 nm The characteristics are similar to that of another organic salt, SPCD^1, which has been recently reported. Cooperative emission appears to play a dominant role in this emission process. 1. A. K. Bhowmik, A. Dharmadhikari, and M. Thakur, OSA Technical Digest, 467, CLEO (1999).

Effects of Cardiopulmonary Support With a Novel Pediatric Pump-Lung in a 30-Day Ovine Animal Model.

PubMed

Liu, Yang; Sanchez, Pablo G; Wei, Xufeng; Watkins, Amelia C; Niu, Shuqiong; Wu, Zhongjun J; Griffith, Bartley P

2015-12-01

The scarcity of donor organs has led to the development of devices that provide optimal long-term respiratory or cardiopulmonary support to bridge recipients as they wait for lung and/or heart transplantation. This study was designed to evaluate the 30-day in vivo performance of the newly developed pediatric pump-lung (PediPL) for cardiopulmonary support using a juvenile sheep model. The PediPL device was placed surgically between the right atrium and descending aorta in eight sheep (25.4-31.2 kg) and evaluated for 30 days. Anticoagulation was maintained with continuous heparin infusion (activated clotting time 150-200 s). The flow rate was measured continually, and gas transfer was measured daily. Plasma free hemoglobin, platelet activation, hematologic data, and blood biochemistry were assessed twice a week. Sheep were euthanized after 30 days. The explanted devices were examined for gross thrombosis. Six sheep survived for 30-32 days. During the study, the oxygen transfer rate of the devices was 54.9 ± 13.2 mL/min at a mean flow rate of 1.14 ± 0.46 L/min with blood oxygen saturation of 95.4% ± 1.7%. Plasma free hemoglobin was 8.2 ± 3.7 mg/dL. Platelet activation was 5.35 ± 2.65%. The animals had normal organ chemistries except for surgery-related transient alterations in kidney and liver function. Although we found some scattered thrombi on the membrane surfaces of some explanted devices during the necropsy, the device function and performance did not degrade. The PediPL device was capable of providing cardiopulmonary support with long-term reliability and good biocompatibility over the 30-day duration and offers the potential option for bridging pediatric patients with end-stage heart or lung disease to heart and/or lung transplantation. Copyright © 2015 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Hierarchical approaches for systems modeling in cardiac development.

PubMed

Gould, Russell A; Aboulmouna, Lina M; Varner, Jeffrey D; Butcher, Jonathan T

2013-01-01

Ordered cardiac morphogenesis and function are essential for all vertebrate life. The heart begins as a simple contractile tube, but quickly grows and morphs into a multichambered pumping organ complete with valves, while maintaining regulation of blood flow and nutrient distribution. Though not identical, cardiac morphogenesis shares many molecular and morphological processes across vertebrate species. Quantitative data across multiple time and length scales have been gathered through decades of reductionist single variable analyses. These range from detailed molecular signaling pathways at the cellular levels to cardiac function at the tissue/organ levels. However, none of these components act in true isolation from others, and each, in turn, exhibits short- and long-range effects in both time and space. With the absence of a gene, entire signaling cascades and genetic profiles may be shifted, resulting in complex feedback mechanisms. Also taking into account local microenvironmental changes throughout development, it is apparent that a systems level approach is an essential resource to accelerate information generation concerning the functional relationships across multiple length scales (molecular data vs physiological function) and structural development. In this review, we discuss relevant in vivo and in vitro experimental approaches, compare different computational frameworks for systems modeling, and the latest information about systems modeling of cardiac development. Finally, we conclude with some important future directions for cardiac systems modeling. Copyright © 2013 Wiley Periodicals, Inc.

Control of lysosomal biogenesis and Notch-dependent tissue patterning by components of the TFEB-V-ATPase axis in Drosophila melanogaster.

PubMed

Tognon, Emiliana; Kobia, Francis; Busi, Ilaria; Fumagalli, Arianna; De Masi, Federico; Vaccari, Thomas

2016-01-01

In vertebrates, TFEB (transcription factor EB) and MITF (microphthalmia-associated transcription factor) family of basic Helix-Loop-Helix (bHLH) transcription factors regulates both lysosomal function and organ development. However, it is not clear whether these 2 processes are interconnected. Here, we show that Mitf, the single TFEB and MITF ortholog in Drosophila, controls expression of vacuolar-type H(+)-ATPase pump (V-ATPase) subunits. Remarkably, we also find that expression of Vha16-1 and Vha13, encoding 2 key components of V-ATPase, is patterned in the wing imaginal disc. In particular, Vha16-1 expression follows differentiation of proneural regions of the disc. These regions, which will form sensory organs in the adult, appear to possess a distinctive endolysosomal compartment and Notch (N) localization. Modulation of Mitf activity in the disc in vivo alters endolysosomal function and disrupts proneural patterning. Similar to our findings in Drosophila, in human breast epithelial cells we observe that impairment of the Vha16-1 human ortholog ATP6V0C changes the size and function of the endolysosomal compartment and that depletion of TFEB reduces ligand-independent N signaling activity. Our data suggest that lysosomal-associated functions regulated by the TFEB-V-ATPase axis might play a conserved role in shaping cell fate.

The pump, the exchanger, and the holy spirit: origins and 40-year evolution of ideas about the ouabain-Na+ pump endocrine system.

PubMed

Blaustein, Mordecai P

2018-01-01

Two prescient 1953 publications set the stage for the elucidation of a novel endocrine system: Schatzmann's report that cardiotonic steroids (CTSs) are all Na + pump inhibitors, and Szent-Gyorgi's suggestion that there is an endogenous "missing screw" in heart failure that CTSs like digoxin may replace. In 1977 I postulated that an endogenous Na + pump inhibitor acts as a natriuretic hormone and simultaneously elevates blood pressure (BP) in salt-dependent hypertension. This hypothesis was based on the idea that excess renal salt retention promoted the secretion of a CTS-like hormone that inhibits renal Na + pumps and salt reabsorption. The hormone also inhibits arterial Na + pumps, elevates myocyte Na + and promotes Na/Ca exchanger-mediated Ca 2+ gain. This enhances vasoconstriction and arterial tone-the hallmark of hypertension. Here I describe how those ideas led to the discovery that the CTS-like hormone is endogenous ouabain (EO), a key factor in the pathogenesis of hypertension and heart failure. Seminal observations that underlie the still-emerging picture of the EO-Na + pump endocrine system in the physiology and pathophysiology of multiple organ systems are summarized. Milestones include: 1) cloning the Na + pump isoforms and physiological studies of mutated pumps in mice; 2) discovery that Na + pumps are also EO-triggered signaling molecules; 3) demonstration that ouabain, but not digoxin, is hypertensinogenic; 4) elucidation of EO's roles in kidney development and cardiovascular and renal physiology and pathophysiology; 5) discovery of "brain ouabain", a component of a novel hypothalamic neuromodulatory pathway; and 6) finding that EO and its brain receptors modulate behavior and learning.

[The use of continuous subcutaneous insulin infusion (CSII) with personal insulin pumps in the treatment of children and adolescents with diabetes type 1].

PubMed

Jarosz-Chobot, Przemysława

2004-01-01

This paper sums up recently published researches on the continuous subcutaneous insulin infusion (CSII) with the use of insulin pump in children and adolescents with diabetes type 1. Obtaining a balance in the organism metabolism in childhood and adolescence diabetology is nowadays one of the most important rules of the diabetes management in children. One of the modern ways to achieve that goal is the intensive insulin therapy model with use of the insulin pump. In this paper the advantages and disadvantages as well as the indications and contraindications for the CSII in children and adolescents with diabetes are widely discussed.

Continuously tunable solution-processed organic semiconductor DFB lasers pumped by laser diode.

PubMed

Klinkhammer, Sönke; Liu, Xin; Huska, Klaus; Shen, Yuxin; Vanderheiden, Sylvia; Valouch, Sebastian; Vannahme, Christoph; Bräse, Stefan; Mappes, Timo; Lemmer, Uli

2012-03-12

The fabrication and characterization of continuously tunable, solution-processed distributed feedback (DFB) lasers in the visible regime is reported. Continuous thin film thickness gradients were achieved by means of horizontal dipping of several conjugated polymer and blended small molecule solutions on cm-scale surface gratings of different periods. We report optically pumped continuously tunable laser emission of 13 nm in the blue, 16 nm in the green and 19 nm in the red spectral region on a single chip respectively. Tuning behavior can be described with the Bragg-equation and the measured thickness profile. The laser threshold is low enough that inexpensive laser diodes can be used as pump sources.

Challenges in realizing a self-contained hydraulically-driven contractile fiber actuator.

PubMed

Smela, Elisabeth

2017-07-01

The field of soft robots would benefit from electrically controlled contractile actuators in the form of fibers that achieve a strain of 20% in less than a second while exerting high force. This work explores possible designs for achieving this goal using self-contained electroosmotic fluid pumping within a tube-shaped structure. The most promising configuration is a combination of a bellows and a McKibben-type muscle, since pumping fluid from the former to the latter results in contraction of both portions. Realizing such a device entails challenges in fabrication and electrokinetic fluid pumping in closed systems. Further studies of electroosmotic flow in salt-free organic solvents are needed.

Evaluation of a series of 2-napthamide derivatives as inhibitors of the drug efflux pump AcrB for the reversal of antimicrobial resistance.

PubMed

Wang, Yinhu; Mowla, Rumana; Guo, Liwei; Ogunniyi, Abiodun D; Rahman, Taufiq; De Barros Lopes, Miguel A; Ma, Shutao; Venter, Henrietta

2017-02-15

Drug efflux pumps confer multidrug resistance to dangerous pathogens which makes these pumps important drug targets. We have synthesised a novel series of compounds based on a 2-naphthamide pharmacore aimed at inhibiting the efflux pumps from Gram-negative bacteria. The archeatypical transporter AcrB from Escherichia coli was used as model efflux pump as AcrB is widely conserved throughout Gram-negative organisms. The compounds were tested for their antibacterial action, ability to potentiate the action of antibiotics and for their ability to inhibit Nile Red efflux by AcrB. None of the compounds were antimicrobial against E. coli wild type cells. Most of the compounds were able to inhibit Nile Red efflux indicating that they are substrates of the AcrB efflux pump. Three compounds were able to synergise with antibiotics and reverse resistance in the resistant phenotype. Compound A3, 4-(isopentyloxy)-2-naphthamide, reduced the MICs of erythromycin and chloramphenicol to the MIC levels of the drug sensitive strain that lacks an efflux pump. A3 had no effect on the MIC of the non-substrate rifampicin indicating that this compound acts specifically through the AcrB efflux pump. A3 also does not act through non-specific mechanisms such as outer membrane or inner membrane permeabilisation and is not cytotoxic against mammalian cell lines. Therefore, we have designed and synthesised a novel chemical compound with great potential to further optimisation as inhibitor of drug efflux pumps. Copyright © 2017 Elsevier Ltd. All rights reserved.

Development of a standardized, citywide process for managing smart-pump drug libraries.

PubMed

Walroth, Todd A; Smallwood, Shannon; Arthur, Karen; Vance, Betsy; Washington, Alana; Staublin, Therese; Haslar, Tammy; Reddan, Jennifer G; Fuller, James

2018-06-15

Development and implementation of an interprofessional consensus-driven process for review and optimization of smart-pump drug libraries and dosing limits are described. The Indianapolis Coalition for Patient Safety (ICPS), which represents 6 Indianapolis-area health systems, identified an opportunity to reduce clinically insignificant alerts that smart infusion pumps present to end users. Through a consensus-driven process, ICPS aimed to identify best practices to implement at individual hospitals in order to establish specific action items for smart-pump drug library optimization. A work group of pharmacists, nurses, and industrial engineers met to evaluate variability within and lack of scrutiny of smart-pump drug libraries. The work group used Lean Six Sigma methodologies to generate a list of key needs and barriers to be addressed in process standardization. The group reviewed targets for smart-pump drug library optimization, including dosing limits, types of alerts reviewed, policies, and safety best practices. The work group also analyzed existing processes at each site to develop a final consensus statement outlining a model process for reviewing alerts and managing smart-pump data. Analysis of the total number of alerts per device across ICPS-affiliated health systems over a 4-year period indicated a 50% decrease (from 7.2 to 3.6 alerts per device per month) after implementation of the model by ICPS member organizations. Through implementation of a standardized, consensus-driven process for smart-pump drug library optimization, ICPS member health systems reduced clinically insignificant smart-pump alerts. Copyright © 2018 by the American Society of Health-System Pharmacists, Inc. All rights reserved.

Control Optimization for a Dual-Mode Single-State Nuclear Shuttle,

DTIC Science & Technology

1980-01-01

Variables at a •.2 as Functions of the Pump ! Power# ..... ............ ......... 36 ’’i I ’I [ I I OIAPTER I INTRODUCTION Since the end of the Apollo...If this is not the case, the assIumption is slightly optimistic. 4. The effective pump power and the reactor-exit stagnation tempar- ature are...independent of the reactor-exit stagnation pressure. I ("Effective puImp power" is the power required to pump the propellants, assumed to be incompressible

EVAHEART: an implantable centrifugal blood pump for long-term circulatory support.

PubMed

Yamazaki, Kenji; Kihara, Shinichiro; Akimoto, Takehide; Tagusari, Osamu; Kawai, Akihiko; Umezu, Mitsuo; Tomioka, Jun; Kormos, Robert L; Griffith, Bartley P; Kurosawa, Hiromi

2002-11-01

We developed "EVAHEART": a compact centrifugal blood pump system as an implantable left ventricular assist device for long-term circulatory support. The 55 x 64 mm pump is made from pure titanium, and weighs 370 g. The entire blood-contacting surface is covered with an anti-thrombogenic coating of diamond like carbon (DLC) or 2-methacryloyloxyethyl phosphorylcholine (MPC) to improve blood compatibility. Flows exceeding 12 L/min against 100 mmHg pressure at 2600 rpm was measured. A low-temperature mechanical seal with recirculating cooling system is used to seal the shaft. EVAHEART demonstrated an acceptably low hemolysis rate with normalized index of hemolysis of 0.005 +/- 0.002 g/100L. We evaluated the pump in long-term in-vivo experiments with seven calves. Via left thoracotomy, we conducted left ventricular apex-descending aorta bypass, placing the pump in the left thoracic cavity. Pump flow rates was maintained at 5-9 L/min, pump power consumption remained stable at 9-10 W in all cases, plasma free Hb levels were less than 15 mg/dl, and the seal system showed good seal capability throughout the experiments. The calves were sacrificed on schedule on postoperative day 200, 222, 142, 90, 151, 155, and 133. No thrombi formed on the blood contacting surface with either the DLC or MPC coating, and no major organ thromboembolisms occurred except for a few small renal infarcts. EVAHEART centrifugal blood pump demonstrated excellent performance in long-term in-vivo experiments.

Preliminary validation of a new magnetic wireless blood pump.

PubMed

Kim, Sung Hoon; Ishiyama, Kazushi; Hashi, Shuichiro; Shiraishi, Yasuyuki; Hayatsu, Yukihiro; Akiyama, Masatoshi; Saiki, Yoshikatsu; Yambe, Tomoyuki

2013-10-01

In general, a blood pump must be small, have a simple configuration, and have sufficient hydrodynamic performance. Herein, we introduce new mechanisms for a wireless blood pump that is small and simple and provides wireless and battery-free operation. To achieve wireless and battery-free operation, we implement magnetic torque and force control methods that use two external drivers: an external coil and a permanent magnet with a DC-motor, respectively. Power harvesting can be used to drive an electronic circuit for wireless monitoring (the observation of the pump conditions and temperature) without the use of an internal battery. The power harvesting will be used as a power source to drive other electronic devices, such as various biosensors with their driving circuits. To have both a compact size and sufficient pumping capability, the fully magnetic impeller has five stages and each stage includes four backward-curved blades. The pump has total and inner volumes of 20 and 9.8 cc, respectively, and weighs 52 g. The pump produces a flow rate of approximately 8 L/min at 80 mm Hg and the power generator produces 0.3 W of electrical power at 120 Ω. The pump also produces a minimum flow rate of 1.5 L/min and a pressure of 30 mm Hg for circulation at a maximum distance of 7.5 cm. © 2013 Wiley Periodicals, Inc. and International Center for Artificial Organs and Transplantation.

RECCAS - REmoval of Cytokines during CArdiac Surgery: study protocol for a randomised controlled trial.

PubMed

Baumann, Andreas; Buchwald, Dirk; Annecke, Thorsten; Hellmich, Martin; Zahn, Peter K; Hohn, Andreas

2016-03-12

On-pump cardiac surgery triggers a significant postoperative systemic inflammatory response, sometimes resulting in multiple-organ dysfunction associated with poor clinical outcome. Extracorporeal cytokine elimination with a novel haemoadsorption (HA) device (CytoSorb®) promises to attenuate inflammatory response. This study primarily assesses the efficacy of intraoperative HA during cardiopulmonary bypass (CPB) to reduce the proinflammatory cytokine burden during and after on-pump cardiac surgery, and secondarily, we aim to evaluate effects on postoperative organ dysfunction and outcomes in patients at high risk. This will be a single-centre randomised, two-arm, patient-blinded trial of intraoperative HA in patients undergoing on-pump cardiac surgery. Subjects will be allocated to receive either CPB with intraoperative HA or standard CPB without HA. The primary outcome is the difference in mean interleukin 6 (IL-6) serum levels between the two study groups on admission to the intensive care unit. A total number of 40 subjects was calculated as necessary to detect a clinically relevant 30 % reduction in postoperative IL-6 levels. Secondary objectives evaluate effects of HA on markers of inflammation up to 48 hours postoperatively, damage to the endothelial glycocalyx and effects on clinical scores and parameters of postoperative organ dysfunction and outcomes. In this pilot trial we try to assess whether intraoperative HA with CytoSorb® can relevantly reduce postoperative IL-6 levels in patients undergoing on-pump cardiac surgery. Differences in secondary outcome variables between the study groups may give rise to further studies and may lead to a better understanding of the mechanisms of haemoadsorption. German Clinical Trials Register number DRKS00007928 (Date of registration 3 Aug 2015).

Domain of validity of the perturbative approach to femtosecond optical spectroscopy

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

Gelin, Maxim F.; Rao, B. Jayachander; Nest, Mathias

2013-12-14

We have performed numerical nonperturbative simulations of transient absorption pump-probe responses for a series of molecular model systems. The resulting signals as a function of the laser field strength and the pump-probe delay time are compared with those obtained in the perturbative response function formalism. The simulations and their theoretical analysis indicate that the perturbative description remains valid up to moderately strong laser pulses, corresponding to a rather substantial depopulation (population) of the initial (final) electronic states.

A non-equilibrium thermodynamics model of reconstituted Ca(2+)-ATPase.

PubMed

Waldeck, A R; van Dam, K; Berden, J; Kuchel, P W

1998-01-01

A non-equilibrium thermodynamics (NET) model describing the action of completely coupled or 'slipping' reconstituted Ca(2+)-ATPase is presented. Variation of the coupling stoichiometries with the magnitude of the electrochemical gradients, as the ATPase hydrolyzes ATP, is an indication of molecular slip. However, the Ca2+ and H+ membrane-leak conductances may also be a function of their respective gradients. Such non-ohmic leak typically yields 'flow-force' relationships that are similar to those that are obtained when the pump slips; hence, caution needs to be exercised when interpreting data of Ca(2+)-ATPase-mediated fluxes that display a non-linear dependence on the electrochemical proton (delta mu H) and/or calcium gradients (delta mu Ca). To address this issue, three experimentally verifiable relationships differentiating between membrane leak and enzymic slip were derived. First, by measuring delta mu H as a function of the rate of ATP hydrolysis by the enzyme. Second, by measuring the overall 'efficiency' of the pump as a function of delta mu H. Third, by measuring the proton ejection rate by the pump as a function of its ATP hydrolysis rate.

Optimized Reduction of Unsteady Radial Forces in a Singlechannel Pump for Wastewater Treatment

NASA Astrophysics Data System (ADS)

Kim, Jin-Hyuk; Cho, Bo-Min; Choi, Young-Seok; Lee, Kyoung-Yong; Peck, Jong-Hyeon; Kim, Seon-Chang

2016-11-01

A single-channel pump for wastewater treatment was optimized to reduce unsteady radial force sources caused by impeller-volute interactions. The steady and unsteady Reynolds- averaged Navier-Stokes equations using the shear-stress transport turbulence model were discretized by finite volume approximations and solved on tetrahedral grids to analyze the flow in the single-channel pump. The sweep area of radial force during one revolution and the distance of the sweep-area center of mass from the origin were selected as the objective functions; the two design variables were related to the internal flow cross-sectional area of the volute. These objective functions were integrated into one objective function by applying the weighting factor for optimization. Latin hypercube sampling was employed to generate twelve design points within the design space. A response-surface approximation model was constructed as a surrogate model for the objectives, based on the objective function values at the generated design points. The optimized results showed considerable reduction in the unsteady radial force sources in the optimum design, relative to those of the reference design.

Carrier envelope offset frequency detection and stabilization of a diode-pumped mode-locked Ti:sapphire laser.

PubMed

Gürel, Kutan; Wittwer, Valentin J; Hakobyan, Sargis; Schilt, Stéphane; Südmeyer, Thomas

2017-03-15

We demonstrate the first diode-pumped Ti:sapphire laser frequency comb. It is pumped by two green laser diodes with a total pump power of 3 W. The Ti:sapphire laser generates 250 mW of average output power in 61-fs pulses at a repetition rate of 216 MHz. We generated an octave-spanning supercontinuum spectrum in a photonic-crystal fiber and detected the carrier envelope offset (CEO) frequency in a standard f-to-2f interferometer setup. We stabilized the CEO-frequency through direct current modulation of one of the green pump diodes with a feedback bandwidth of 55 kHz limited by the pump diode driver used in this experiment. We achieved a reduction of the CEO phase noise power spectral density by 140 dB at 1 Hz offset frequency. An advantage of diode pumping is the ability for high-bandwidth modulation of the pump power via direct current modulation. After this experiment, we studied the modulation capabilities and noise properties of green pump laser diodes with improved driver electronics. The current-to-output-power modulation transfer function shows a bandwidth larger than 1 MHz, which should be sufficient to fully exploit the modulation bandwidth of the Ti:sapphire gain for CEO stabilization in future experiments.

Performance of high-recovery recycling reverse osmosis with wash water

NASA Technical Reports Server (NTRS)

Herrmann, Cal C.

1993-01-01

Inclusion of a recycling loop for partially-desalted water from second-stage reverse-osmosis permeate has been shown useful for achieving high-recovery at moderate applied pressures. This approach has now been applied to simulated wash waters, to obtain data on retention by the membranes of solutes in a mixture comparable to anticipated spacecraft hygiene wastewaters, and to generate an estimate of the maximum concentration that can be expected without causing membrane fouling. A first experiment set provides selectivity information from a single membrane and an Igepon detergent, as a function of final concentration. A reject concentration of 3.1% Total Organic Carbon has been reached, at a pressure of 1.4 Mega Pascals, without membrane fouling. Further experiments have generated selectivity values for the recycle configuration from two washwater simulations, as a function of applied pump pressure. Reverse osmosis removal has also been tested for washwater containing detergent formulated for plant growth compatibility (containing nitrogen, phosphorous and potassium functional groups.)

Experimental investigation on charcoal adsorption for cryogenic pump application

NASA Astrophysics Data System (ADS)

Scannapiego, Matthieu; Day, Christian

2017-12-01

Fusion reactors are generating energy by nuclear fusion between deuterium and tritium. In order to evacuate the high gas throughputs from the plasma exhaust, large pumping speed systems are required. Within the European Fusion Programme, the Karlsruhe Institute of Technology (KIT) has taken the lead to design a three-stage cryogenic pump that can provide a separation function of hydrogen isotopes from the remaining gases; hence limiting the tritium inventory in the machine. A primary input parameter for the detailed design of a cryopump is the sticking coefficient between the gas and the pumping surface. For this purpose, the so-called TIMO open panel pump experiment was conducted in the TIMO-2 test facility at KIT in order to measure pumping speeds on an activated carbon surface cooled at temperatures between 6 K and 22 K, for various pure gases and gas mixtures, under fusion relevant gas flow conditions, and for two different geometrical pump configurations. The influences of the panel temperature, the gas throughput and the intake gas temperature on the pumping speed have been characterized, providing valuable qualitative results for the design of the three-stage cryopump. In a future work, supporting Monte Carlo simulations should allow for derivation of the sticking coefficients.

Development of a pump-turbine runner based on multiobjective optimization

NASA Astrophysics Data System (ADS)

Xuhe, W.; Baoshan, Z.; Lei, T.; Jie, Z.; Shuliang, C.

2014-03-01

As a key component of reversible pump-turbine unit, pump-turbine runner rotates at pump or turbine direction according to the demand of power grid, so higher efficiencies under both operating modes have great importance for energy saving. In the present paper, a multiobjective optimization design strategy, which includes 3D inverse design method, CFD calculations, response surface method (RSM) and multiobjective genetic algorithm (MOGA), is introduced to develop a model pump-turbine runner for middle-high head pumped storage plant. Parameters that controlling blade shape, such as blade loading and blade lean angle at high pressure side are chosen as input parameters, while runner efficiencies under both pump and turbine modes are selected as objective functions. In order to validate the availability of the optimization design system, one runner configuration from Pareto front is manufactured for experimental research. Test results show that the highest unit efficiency is 91.0% under turbine mode and 90.8% under pump mode for the designed runner, of which prototype efficiencies are 93.88% and 93.27% respectively. Viscous CFD calculations for full passage model are also conducted, which aim at finding out the hydraulic improvement from internal flow analyses.

Functional design criteria for interim stabilization safety class 1 trip circuit

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

Larson, R.E., Westinghouse Hanford

1996-06-10

This Functional Design Criteria document outlines the basic requirements for the Safety Class 1 Trip Circuit. The objective of the Safety Class 1 Trip Circuit is to isolate the power circuitry to the Class 1 Division 2, Group B or lesser grade electrically fed loads located in the pump pit. The electrically fed load circuits need to have power isolated to them upon receipt of the following conditions, loss of flammable gases being released (above a predetermined threshold), and seismic(greater than 0.12g acceleration) activity. The two circuits requiring power isolation are the pump and heat trace power circuits. The Safetymore » Class 1 Trip Circuit will be used to support salt well pumping in SST`s containing potentially flammable gas-bearing / gas-producing radioactive waste.« less

The noncavitating performance and life of a small vane-type positive displacement pump in liquid hydrogen

NASA Technical Reports Server (NTRS)

Ulbricht, T. E.; Hemminger, J. A.

1986-01-01

The low flow rate and high head rise requirements of hydrogen/oxygen auxiliary propulsion systems make the application of centrifugal pumps difficult. Positive displacement pumps are well-suited for these flow conditions, but little is known about their performance and life characteristics in liquid hydrogen. An experimental and analytical investigation was conducted to determine the performance and life characteristics of a vane-type, positive displacement pump. In the experimental part of this effort, mass flow rate and shaft torque were determined as functions of shaft speed and pump pressure rise. Since liquid hydrogen offers little lubrication in a rubbing situation, pump life is an issue. During the life test, the pump was operated intermittently for 10 hr at the steady-state point of 0.074 lbm/sec (0.03 kg/sec) flow rate, 3000 psid (2.07 MPa) pressure rise, and 8000 rpm (838 rad/sec) shaft speed. Pump performance was monitored during the life test series and the results indicated no loss in performance. Material loss from the vanes was recorded and wear of the other components was documented. In the analytical part of this effort, a comprehensive pump performance analysis computer code, developed in-house, was used to predict pump performance. The results of the experimental investigation are presented and compared with the results of the analysis. Results of the life test are also presented.

Quantification of atrial dynamics using cardiovascular magnetic resonance: inter-study reproducibility.

PubMed

Kowallick, Johannes T; Morton, Geraint; Lamata, Pablo; Jogiya, Roy; Kutty, Shelby; Hasenfuß, Gerd; Lotz, Joachim; Nagel, Eike; Chiribiri, Amedeo; Schuster, Andreas

2015-05-17

Cardiovascular magnetic resonance (CMR) offers quantification of phasic atrial functions based on volumetric assessment and more recently, on CMR feature tracking (CMR-FT) quantitative strain and strain rate (SR) deformation imaging. Inter-study reproducibility is a key requirement for longitudinal studies but has not been defined for CMR-based quantification of left atrial (LA) and right atrial (RA) dynamics. Long-axis 2- and 4-chamber cine images were acquired at 9:00 (Exam A), 9:30 (Exam B) and 14:00 (Exam C) in 16 healthy volunteers. LA and RA reservoir, conduit and contractile booster pump functions were quantified by volumetric indexes as derived from fractional volume changes and by strain and SR as derived from CMR-FT. Exam A and B were compared to assess the inter-study reproducibility. Morning and afternoon scans were compared to address possible diurnal variation of atrial function. Inter-study reproducibility was within acceptable limits for all LA and RA volumetric, strain and SR parameters. Inter-study reproducibility was better for volumetric indexes and strain than for SR parameters and better for LA than for RA dynamics. For the LA, reservoir function showed the best reproducibility (intraclass correlation coefficient (ICC) 0.94-0.97, coefficient of variation (CoV) 4.5-8.2%), followed by conduit (ICC 0.78-0.97, CoV 8.2-18.5%) and booster pump function (ICC 0.71-0.95, CoV 18.3-22.7). Similarly, for the RA, reproducibility was best for reservoir function (ICC 0.76-0.96, CoV 7.5-24.0%) followed by conduit (ICC 0.67-0.91, CoV 13.9-35.9) and booster pump function (ICC 0.73-0.90, CoV 19.4-32.3). Atrial dynamics were not measurably affected by diurnal variation between morning and afternoon scans. Inter-study reproducibility for CMR-based derivation of LA and RA functions is acceptable using either volumetric, strain or SR parameters with LA function showing higher reproducibility than RA function assessment. Amongst the different functional components, reservoir function is most reproducibly assessed by either technique followed by conduit and booster pump function, which needs to be considered in future longitudinal research studies.

Deep Aquifer Remediation Tools (DARTs): A new technology for ground-water remediation

USGS Publications Warehouse

Naftz, David L.; Davis, James A.

1999-01-01

Potable ground-water supplies throughout the world are contaminated or threatened by advancing plumes containing radionuclides, metals, and organic compounds. Currently (1999), the most widely used method of ground-water remediation is a combination of extraction, ex-situ treatment, and discharge of the treated water, commonly known as pump and treat. Pump-and-treat methods are costly and often ineffective in meeting long-term protection standards (Travis and Doty, 1990; Gillham and Burris, 1992; National Research Council, 1994). This fact sheet describes a new and potentially cost-effective technology for removal of organic and inorganic contaminants from ground water. The U.S. Geological Survey (USGS) is currently exploring the possibilities of obtaining a U.S. Patent for this technology.

Adding the 'heart' to hanging drop networks for microphysiological multi-tissue experiments.

PubMed

Rismani Yazdi, Saeed; Shadmani, Amir; Bürgel, Sebastian C; Misun, Patrick M; Hierlemann, Andreas; Frey, Olivier

2015-11-07

Microfluidic hanging-drop networks enable culturing and analysis of 3D microtissue spheroids derived from different cell types under controlled perfusion and investigating inter-tissue communication in multi-tissue formats. In this paper we introduce a compact on-chip pumping approach for flow control in hanging-drop networks. The pump includes one pneumatic chamber located directly above one of the hanging drops and uses the surface tension at the liquid-air-interface for flow actuation. Control of the pneumatic protocol provides a wide range of unidirectional pulsatile and continuous flow profiles. With the proposed concept several independent hanging-drop networks can be operated in parallel with only one single pneumatic actuation line at high fidelity. Closed-loop medium circulation between different organ models for multi-tissue formats and multiple simultaneous assays in parallel are possible. Finally, we implemented a real-time feedback control-loop of the pump actuation based on the beating of a human iPS-derived cardiac microtissue cultured in the same system. This configuration allows for simulating physiological effects on the heart and their impact on flow circulation between the organ models on chip.

A near infrared luminescent metal-organic framework for temperature sensing in the physiological range.

PubMed

Lian, Xiusheng; Zhao, Dian; Cui, Yuanjing; Yang, Yu; Qian, Guodong

2015-12-28

A near infrared pumped luminescent metal-organic framework thermometer Nd(0.577)Yb(0.423)BDC-F4, with near infrared fluorescence and excellent sensitivity in the physiological temperature range (293-313 K), has been first realized, and might be potentially applied for biomedical systems.

Multimorbidities and Overprescription of Proton Pump Inhibitors in Older Patients.

PubMed

Delcher, Anne; Hily, Sylvie; Boureau, Anne Sophie; Chapelet, Guillaume; Berrut, Gilles; de Decker, Laure

2015-01-01

To determine whether there is an association between overprescription of proton pump inhibitors (PPIs) and multimorbidities in older patients. Multicenter prospective study. Acute geriatric medicine at the University Hospital of Nantes and the Hospital of Saint-Nazaire. Older patients aged 75 and over hospitalized in acute geriatric medicine. Older patients in acute geriatric medicine who received proton pump inhibitors. Variables studied were individual multimorbidities, the burden of multimorbidity evaluated by the Cumulative Illness Rating Scale, age, sex, type of residence (living in nursing home or not), functional abilities (Lawton and Katz scales), nutritional status (Body Mass Index), and the type of concomitant medications (antiaggregant, corticosteroids', or anticoagulants). Overprescription of proton pump inhibitors was found in 73.9% older patients. In the full model, cardiac diseases (odds ratio [OR] = 4.17, p = 0.010), metabolic diseases (OR = 2.14, p = 0.042) and corticosteroids (OR = 5.39, p = 0.028) were significantly associated with overprescription of proton pump inhibitors. Esogastric diseases (OR = 0.49, p = 0.033) were negatively associated with overprescription of proton pump inhibitors. Cardiac diseases and metabolic diseases were significantly associated with overprescription of proton pump inhibitors.

Design and Characterization of Optically Pumped Vertical Cavity Surface Emitting Lasers

DTIC Science & Technology

1992-12-01

technology to make VCSELs (e.g. Molecular Beam Epitaxy (MBE) and Metal-Organic Chemical Vapor Deposition (MOCVD)) motivated the research in this area over the...Resistances for Current Injected VCSELs 3-14 4.1. Equipment Configuration used for Output Beam Characterization . . . 4-1 4.2. Optical Pump Beam and Focusing...pursued over the past few years because VCSELs have ad- ditional inherent advantages. The VCSEL design exhibits better exit beam quality, is of smaller

Developments in control systems for rotary left ventricular assist devices for heart failure patients: a review.

PubMed

AlOmari, Abdul-Hakeem H; Savkin, Andrey V; Stevens, Michael; Mason, David G; Timms, Daniel L; Salamonsen, Robert F; Lovell, Nigel H

2013-01-01

From the moment of creation to the moment of death, the heart works tirelessly to circulate blood, being a critical organ to sustain life. As a non-stopping pumping machine, it operates continuously to pump blood through our bodies to supply all cells with oxygen and necessary nutrients. When the heart fails, the supplement of blood to the body's organs to meet metabolic demands will deteriorate. The treatment of the participating causes is the ideal approach to treat heart failure (HF). As this often cannot be done effectively, the medical management of HF is a difficult challenge. Implantable rotary blood pumps (IRBPs) have the potential to become a viable long-term treatment option for bridging to heart transplantation or destination therapy. This increases the potential for the patients to leave the hospital and resume normal lives. Control of IRBPs is one of the most important design goals in providing long-term alternative treatment for HF patients. Over the years, many control algorithms including invasive and non-invasive techniques have been developed in the hope of physiologically and adaptively controlling left ventricular assist devices and thus avoiding such undesired pumping states as left ventricular collapse caused by suction. In this paper, we aim to provide a comprehensive review of the developments of control systems and techniques that have been applied to control IRBPs.

Root bacterial endophytes confer drought resistance and enhance expression and activity of a vacuolar H+ -pumping pyrophosphatase in pepper plants.

PubMed

Vigani, Gianpiero; Rolli, Eleonora; Marasco, Ramona; Dell'Orto, Marta; Michoud, Grégoire; Soussi, Asma; Raddadi, Noura; Borin, Sara; Sorlini, Claudia; Zocchi, Graziano; Daffonchio, Daniele

2018-05-22

It has been previously shown that the transgenic overexpression of the plant root vacuolar proton pumps H + -ATPase (V-ATPase) and H + -PPase (V-PPase) confer tolerance to drought. Since plant-root endophytic bacteria can also promote drought tolerance, we hypothesize that such promotion can be associated to the enhancement of the host vacuolar proton pumps expression and activity. To test this hypothesis, we selected two endophytic bacteria endowed with an array of in vitro plant growth promoting traits. Their genome sequences confirmed the presence of traits previously shown to confer drought resistance to plants, such as the synthesis of nitric oxide and of organic volatile organic compounds. We used the two strains on pepper (Capsicuum annuum L.) because of its high sensitivity to drought. Under drought conditions, both strains stimulated a larger root system and enhanced the leaves' photosynthetic activity. By testing the expression and activity of the vacuolar proton pumps, H + -ATPase (V-ATPase) and H + -PPase (V-PPase), we found that bacterial colonization enhanced V-PPase only. We conclude that the enhanced expression and activity of V-PPase can be favoured by the colonization of drought-tolerance-inducing bacterial endophytes. This article is protected by copyright. All rights reserved. © 2018 Society for Applied Microbiology and John Wiley & Sons Ltd.

Potential for advection of volatile organic compounds in ground water to the Cochato River, Baird & McGuire Superfund Site, Holbrook, Massachusetts, March and April 1998

USGS Publications Warehouse

Savoie, Jennifer G.; Lyford, Forest P.; Clifford, Scott

1999-01-01

In March and April 1998, a network of water-to-vapor diffusion samplers was installed along the Cochato River at the Baird & McGuire Superfund Site in Holbrook, Massachusetts, where a plume of volatile organic compounds (VOCs) is present in ground water. The purpose of installing the sampler network was to determine if VOCs were present in river-bottom sediments while a ground-water extraction system was operating and after the system had been shut down for two weeks. Water-to-water diffusion samplers placed at selected locations provided supplemental information about concentrations of VOCs in pore water in the river-bottom sediments. Water levels in piezometers and river stage were measured concurrently to determine if ground water was discharging to the river. Benzene, toluene, ethylbenzene and xylenes (BTEX compounds) were detected in water-tovapor and water-to-water diffusion samplers located in the area where the plume is known to pass beneath the river for both pumping and nonpumping conditions. Concentrations of total BTEX compounds in water-to-vapor diffusion samplers ranged from non-detect upriver and downriver from the plume area to greater than 200 parts per million by volume in the plume area. Concentrations of total BTEX compounds were not significantly different for pumping than for non-pumping conditions. Concentrations of total BTEX compounds in water-to-water diffusion samplers ranged from non-detect to 680 micrograms per liter. The limited number of water-to-water diffusion samplers did not indicate that concentrations were higher for pumping or non-pumping conditions. Trichloroethylene and tetrachloroethylene also were detected in water-to-vapor diffusion samplers downriver from the area where the BTEX compounds were detected. Water levels in four piezometers were consistently higher than the river stage, indicating an upward hydraulic gradient and ground-water discharge to the river. The concentrations of VOCs in riverbottom sediments and the upward hydraulic gradients observed indicate that contaminants from the Baird & McGuire ground-water plume were discharging to the Cochato River during the study period for both pumping and non-pumping conditions. 

Comparison of diffusion- and pumped-sampling methods to monitor volatile organic compounds in ground water, Massachusetts Military Reservation, Cape Cod, Massachusetts, July 1999-December 2002

USGS Publications Warehouse

Archfield, Stacey A.; LeBlanc, Denis R.

2005-01-01

To evaluate diffusion sampling as an alternative method to monitor volatile organic compound (VOC) concentrations in ground water, concentrations in samples collected by traditional pumped-sampling methods were compared to concentrations in samples collected by diffusion-sampling methods for 89 monitoring wells at or near the Massachusetts Military Reservation, Cape Cod. Samples were analyzed for 36 VOCs. There was no substantial difference between the utility of diffusion and pumped samples to detect the presence or absence of a VOC. In wells where VOCs were detected, diffusion-sample concentrations of tetrachloroethene (PCE) and trichloroethene (TCE) were significantly lower than pumped-sample concentrations. Because PCE and TCE concentrations detected in the wells dominated the calculation of many of the total VOC concentrations, when VOC concentrations were summed and compared by sampling method, visual inspection also showed a downward concentration bias in the diffusion-sample concentration. The degree to which pumped- and diffusion-sample concentrations agreed was not a result of variability inherent within the sampling methods or the diffusion process itself. A comparison of the degree of agreement in the results from the two methods to 13 quantifiable characteristics external to the sampling methods offered only well-screen length as being related to the degree of agreement between the methods; however, there is also evidence to indicate that the flushing rate of water through the well screen affected the agreement between the sampling methods. Despite poor agreement between the concentrations obtained by the two methods at some wells, the degree to which the concentrations agree at a given well is repeatable. A one-time, well-bywell comparison between diffusion- and pumped-sampling methods could determine which wells are good candidates for the use of diffusion samplers. For wells with good method agreement, the diffusion-sampling method is a time-saving and cost-effective alternative to pumped-sampling methods in a long-term monitoring program, such as at the Massachusetts Military Reservation.

Factors associated with postoperative requirement of renal replacement therapy following off-pump coronary bypass surgery.

PubMed

Kato, Tomoko S; Machida, Yoichiro; Kuwaki, Kenji; Yamamoto, Taira; Amano, Atsushi

2017-02-01

Cardiopulmonary bypass usage provokes a systemic inflammatory response resulting in deterioration of renal function. However, risk factors for requiring renal replacement therapy (RRT) following off-pump coronary artery bypass graft surgery (CABG) have not yet been fully elucidated. We reviewed 718 consecutive patients undergoing elective off-pump CABG at our institution, excluding patients on chronic hemodialysis preoperatively. Sub-analysis of patients with preserved renal function, defined as a creatinine level below a cut-off value of 1.12 mg/dL (obtained by receiver operating characteristic curve), was also performed. Of the 718 patients, 41 (5.7 %) required RRT. There were 556 patients (77.4 %) with preserved renal function preoperatively, and 13 (2.4 %) of these required postoperative RRT. Multivariate analysis revealed that age (years) and preoperative serum creatinine (mg/dL) and brain natriuretic peptide (BNP) levels (pg/dL) were associated with RRT [odds ratios (OR) 1.052, 95 % confidence interval (CI) 9.064 and 1.001, respectively, all p < 0.05] in the total population, whereas low albumin concentration was the only independent predictor for RRT in patients with preserved renal function (OR 0.062, p < 0.0001). When creatinine levels were below 1.5 mg/dL, the predictive power of hypoalbuminemia for RRT requirement overwhelmed that of creatinine or BNP levels. Older age, preoperative elevated creatinine and BNP levels were associated with a requirement for RRT following off-pump CABG. In patients with preserved renal function, hypoalbuminemia was most significantly related to the RRT requirement.

Mechanism and energetics by which glutamic acid 242 prevents leaks in cytochrome c oxidase.

PubMed

Kaila, Ville R I; Verkhovsky, Michael I; Hummer, Gerhard; Wikström, Mårten

2009-10-01

Cytochrome c oxidase (CcO) is the terminal enzyme of aerobic respiration. The energy released from the reduction of molecular oxygen to water is used to pump protons across the mitochondrial or bacterial membrane. The pump function introduces a mechanistic requirement of a valve that prevents protons from flowing backwards during the process. It was recently found that Glu-242, a key amino acid in transferring protons to be pumped across the membrane and to the site of oxygen reduction, fulfils the function of such a valve by preventing simultaneous contact to the pump site and to the proton-conducting D-channel (Kaila V.R.I. et al. Proc. Natl. Acad. Sci. USA 105, 2008). Here we have incorporated the valve model into the framework of the reaction mechanism. The function of the Glu valve is studied by exploring how the redox state of the surrounding metal centers, dielectric effects, and membrane potential, affects the energetics and leaks of this valve. Parallels are drawn between the dynamics of Glu-242 and the long-standing obscure difference between the metastable O(H) and stable O states of the binuclear center. Our model provides a suggestion for why reduction of the former state is coupled to proton translocation while reduction of the latter is not.

Venturi vacuum systems for hypobaric chamber operations.

PubMed

Robinson, R; Swaby, G; Sutton, T; Fife, C; Powell, M; Butler, B D

1997-11-01

Physiological studies of the effects of high altitude on man often require the use of a hypobaric chamber to simulate the reduced ambient pressures. Typical "altitude" chambers in use today require complex mechanical vacuum systems to evacuate the chamber air, either directly or via reservoir system. Use of these pumps adds to the cost of both chamber procurement and maintenance, and service of these pumps requires trained support personnel and regular upkeep. In this report we describe use of venturi vacuum pumps to perform the function of mechanical vacuum pumps for human and experimental altitude chamber operations. Advantages of the venturi pumps include their relatively low procurement cost, small size and light weight, ease of installation and plumbing, lack of moving parts, and independence from electrical power sources, fossil fuels and lubricants. Conversion of three hyperbaric chambers to combined hyper/hypobaric use is described.

Keeping Hearts Pumping

NASA Technical Reports Server (NTRS)

2002-01-01

A collaboration between NASA, Dr. Michael DeBakey, Dr. George Noon, and MicroMed Technology, Inc., resulted in a life-saving heart pump for patients awaiting heart transplants. The MicroMed DeBakey VAD functions as a "bridge to heart transplant" by pumping blood throughout the body to keep critically ill patients alive until a donor heart is available. Weighing less than 4 ounces and measuring 1 inch by 3 inches, the pump is approximately one-tenth the size of other currently marketed pulsatile VADs. This makes it less invasive and ideal for smaller adults and children. Because of the pump's small size, less than 5 percent of the patients implanted developed device-related infections. It can operate up to 8 hours on batteries, giving patients the mobility to do normal, everyday activities.The MicroMed DeBakey VAD is a registered trademark of MicroMed Technology, Inc.

Conjecture Regarding Posttranslational Modifications to the Arabidopsis Type I Proton-Pumping Pyrophosphatase (AVP1)

PubMed Central

Pizzio, Gaston A.; Hirschi, Kendal D.; Gaxiola, Roberto A.

2017-01-01

Agbiotechnology uses genetic engineering to improve the output and value of crops. Altering the expression of the plant Type I Proton-pumping Pyrophosphatase (H+-PPase) has already proven to be a useful tool to enhance crop productivity. Despite the effective use of this gene in translational research, information regarding the intracellular localization and functional plasticity of the pump remain largely enigmatic. Using computer modeling several putative phosphorylation, ubiquitination and sumoylation target sites were identified that may regulate Arabidopsis H+-PPase (AVP1- Arabidopsis Vacuolar Proton-pump 1) subcellular trafficking and activity. These putative regulatory sites will direct future research that specifically addresses the partitioning and transport characteristics of this pump. We posit that fine-tuning H+-PPases activity and cellular distribution will facilitate rationale strategies for further genetic improvements in crop productivity. PMID:28955362

Influence of optical pumping wavelength on the ultrafast gain and phase recovery acceleration of quantum-dot semiconductor optical amplifiers

NASA Astrophysics Data System (ADS)

Kim, Jungho

2013-10-01

We numerically investigate the influence of the optical pumping wavelength on the ultrafast gain and phase recovery acceleration of quantum-dot (QD) semiconductor optical amplifiers (SOAs) by solving 1088 coupled rate equations. The temporal variations of the gain and phase recovery response at the ground state (GS) of QDs are calculated at various signal wavelengths when the optical pumping wavelengths at the excited state (ES) of QDs are varied. The phase recovery response is fastest when the wavelength of the signal and pumping beams corresponds to the respective emission wavelength of the GS and the ES in the same size of QDs. The absorption efficiency of the optical pumping beam at the ES is determined by the Lorentzian line shape function of the homogeneous broadening.

Integrated Analysis of Flow, Temperature, and Specific-Conductance Logs and Depth-Dependent Water-Quality Samples from Three Deep Wells in a Fractured-Sandstone Aquifer, Ventura County, California

USGS Publications Warehouse

Williams, John H.; Knutson, Kevin D.

2009-01-01

Analysis of flow, temperature, and specific-conductance logs and depth-dependent water-quality samples collected under ambient and pumped conditions provided a preliminary delineation of flow zones and water quality in three deep abandoned water-supply wells. The integrated analysis was completed as part of the characterization of a fractured-sandstone aquifer in the mountainous setting of the Santa Susana Field Laboratory in southern Ventura County, California. In the deepest well, which was 1,768 feet deep and had the highest specific capacity (120 gallons per minute per foot), flow zones were detected at 380 feet (base of casing) and at 440, 595, and 770 feet in the open hole. Under ambient conditions, measured flow was downward from the 380- and 440-foot zones to the 595- and 770-foot zones. Under pumped conditions, most of flow was contributed by the 595-foot zone. Flow from the 380- and 440-foot zones appeared to have lower specific conductance and higher trichloroethylene concentrations than that from the 595-foot zone. In the shallowest well, which was reportedly 940 feet deep but only logged to 915 feet due to blockage, flow zones were detected behind the perforated casing and at 867 feet in the open hole. Under ambient conditions, downward and upward flows appeared to exit at a zone behind the perforated casing at 708 feet. Most of the pumped flow was contributed from zones behind the perforated casing between 565 and 708 feet. Pumped flow also was contributed by zones at 867 feet and below the logged depth. Volatile organic compounds were not detected in the ambient and pumped flows. In the third well, which was 1,272 feet deep and had the lowest specific capacity (3.6 gallons per minute per foot), flow zones were detected in the open hole above and just below the water level near 337 feet and at 615, 785, 995, and 1,070 feet. Under ambient conditions, measured flow in well was downward from the shallowmost zones to the 995-foot zone. Fracture zones at 615, 785, and 995 feet each contributed about one-third of the pumped flow measured below the pump. Volatile organic compounds were not detected in the ambient and pumped flows.

Determination of pump flow rate during cardiopulmonary bypass in obese patients avoiding hemodilution.

PubMed

Santambrogio, Luisa; Leva, Cristian; Musazzi, Giorgio; Bruno, Piergiorgio; Vailati, Andrea; Zecchillo, Franco; Di Credico, Germano

2009-01-01

During cardiopulmonary bypass the pump flow is usually set on 2.4 L/min/m(2) of body surface area (BSA) to guarantee adequate tissue perfusion without differences for patient constitutional type. The present study attempts to evaluate the adequacy of pump flow rate in obese patients, considering the ideal weight instead of the real one, avoiding the overflow side effects and hemodilution. Obese patients with body mass index (BMI) > 30 presented for cardiac surgery were randomized in two groups: in one the cardiopulmonary bypass was led traditionally, in the other, pump flow rate was calculated on ideal BMI of 25. Demographics, preoperative tests, and monitoring data were registered. Mortality at hospital discharge and 30 days after were analyzed. The pump flow rate between the groups was different (4.46 vs. 4.87; p = 0.004); there were no differences in organ perfusion (SvO(2); diuresis) and mortality, but the study group presented fewer complications and blood transfusions. The BSA is widely used as the biometric unit to normalize physiologic parameters included pump flow rate, but it is disputable if this practice is correct also in obese patients. The study group, in which pump flow rate was set on ideal BSA, presented no difference in diuresis and mixed venous saturation but fewer complications and fewer perioperative blood transfusions.

Synaptic Activity and Bioenergy Homeostasis: Implications in Brain Trauma and Neurodegenerative Diseases

PubMed Central

Khatri, Natasha; Man, Heng-Ye

2013-01-01

Powered by glucose metabolism, the brain is the most energy-demanding organ in our body. Adequate ATP production and regulation of the metabolic processes are essential for the maintenance of synaptic transmission and neuronal function. Glutamatergic synaptic activity utilizes the largest portion of bioenergy for synaptic events including neurotransmitter synthesis, vesicle recycling, and most importantly, the postsynaptic activities leading to channel activation and rebalancing of ionic gradients. Bioenergy homeostasis is coupled with synaptic function via activities of the sodium pumps, glutamate transporters, glucose transport, and mitochondria translocation. Energy insufficiency is sensed by the AMP-activated protein kinase (AMPK), a master metabolic regulator that stimulates the catalytic process to enhance energy production. A decline in energy supply and a disruption in bioenergy homeostasis play a critical role in multiple neuropathological conditions including ischemia, stroke, and neurodegenerative diseases including Alzheimer’s disease and traumatic brain injuries. PMID:24376435

Regulation of Na+ and K+ homeostasis in plants: towards improved salt stress tolerance in crop plants

PubMed Central

Almeida, Diego M.; Oliveira, M. Margarida; Saibo, Nelson J. M.

2017-01-01

Abstract Soil salinity is a major abiotic stress that results in considerable crop yield losses worldwide. However, some plant genotypes show a high tolerance to soil salinity, as they manage to maintain a high K+/Na+ ratio in the cytosol, in contrast to salt stress susceptible genotypes. Although, different plant genotypes show different salt tolerance mechanisms, they all rely on the regulation and function of K+ and Na+ transporters and H+ pumps, which generate the driving force for K+ and Na+ transport. In this review we will introduce salt stress responses in plants and summarize the current knowledge about the most important ion transporters that facilitate intra- and intercellular K+ and Na+ homeostasis in these organisms. We will describe and discuss the regulation and function of the H+-ATPases, H+-PPases, SOS1, HKTs, and NHXs, including the specific tissues where they work and their response to salt stress. PMID:28350038

Two simple models of classical heat pumps.

PubMed

Marathe, Rahul; Jayannavar, A M; Dhar, Abhishek

2007-03-01

Motivated by recent studies of models of particle and heat quantum pumps, we study similar simple classical models and examine the possibility of heat pumping. Unlike many of the usual ratchet models of molecular engines, the models we study do not have particle transport. We consider a two-spin system and a coupled oscillator system which exchange heat with multiple heat reservoirs and which are acted upon by periodic forces. The simplicity of our models allows accurate numerical and exact solutions and unambiguous interpretation of results. We demonstrate that while both our models seem to be built on similar principles, one is able to function as a heat pump (or engine) while the other is not.

Distribution and Characterization of Antigens Found in Subcellular Fractions of African Trypanosomes.

DTIC Science & Technology

1982-08-01

CLASSIFICATION AUTHORITY 3. DISTRIBUTION /AVAILABILITY OF REPORT 2b. DECLASSIFICATION / DOWNGRADING SCHEDULE 4. PERFORMING ORGANIZATION REPORT NUMBER(S...S. MONITORING ORGANIZATION REPORT NUMBER(S) 6a. NAME OF PERFORMING ORGANIZATION 6b OFFICE SYMBOL 7a. NAME OF MONITORING ORGANIZATION University of...was passed through the column using a peristaltic pump adjusted to flow rate of 8.0 ml/h. To allow full binding of sugar residues to lectin the eluent

A microfluidic circulatory system integrated with capillary-assisted pressure sensors.

PubMed

Chen, Yangfan; Chan, Ho Nam; Michael, Sean A; Shen, Yusheng; Chen, Yin; Tian, Qian; Huang, Lu; Wu, Hongkai

2017-02-14

The human circulatory system comprises a complex network of blood vessels interconnecting biologically relevant organs and a heart driving blood recirculation throughout this system. Recreating this system in vitro would act as a bridge between organ-on-a-chip and "body-on-a-chip" and advance the development of in vitro models. Here, we present a microfluidic circulatory system integrated with an on-chip pressure sensor to closely mimic human systemic circulation in vitro. A cardiac-like on-chip pumping system is incorporated in the device. It consists of four pumping units and passive check valves, which mimic the four heart chambers and heart valves, respectively. Each pumping unit is independently controlled with adjustable pressure and pump rate, enabling users to control the mimicked blood pressure and heartbeat rate within the device. A check valve is located downstream of each pumping unit to prevent backward leakage. Pulsatile and unidirectional flow can be generated to recirculate within the device by programming the four pumping units. We also report an on-chip capillary-assisted pressure sensor to monitor the pressure inside the device. One end of the capillary was placed in the measurement region, while the other end was sealed. Time-dependent pressure changes were measured by recording the movement of the liquid-gas interface in the capillary and calculating the pressure using the ideal gas law. The sensor covered the physiologically relevant blood pressure range found in humans (0-142.5 mmHg) and could respond to 0.2 s actuation time. With the aid of the sensor, the pressure inside the device could be adjusted to the desired range. As a proof of concept, human normal left ventricular and arterial pressure profiles were mimicked inside this device. Human umbilical vein endothelial cells (HUVECs) were cultured on chip and cells can respond to mechanical forces generated by arterial-like flow patterns.

Generic picture of the emission properties of III-nitride polariton laser diodes: Steady state and current modulation response

NASA Astrophysics Data System (ADS)

Iorsh, Ivan; Glauser, Marlene; Rossbach, Georg; Levrat, Jacques; Cobet, Munise; Butté, Raphaël; Grandjean, Nicolas; Kaliteevski, Mikhail A.; Abram, Richard A.; Kavokin, Alexey V.

2012-09-01

The main emission characteristics of electrically driven polariton lasers based on planar GaN microcavities with embedded InGaN quantum wells are studied theoretically. The polariton emission dependence on pump current density is first modeled using a set of semiclassical Boltzmann equations for the exciton polaritons that are coupled to the rate equation describing the electron-hole plasma population. Two experimentally relevant pumping geometries are considered, namely the direct injection of electrons and holes into the strongly coupled microcavity region and intracavity optical pumping via an embedded light-emitting diode. The theoretical framework allows the determination of the minimum threshold current density Jthr,min as a function of lattice temperature and exciton-cavity photon detuning for the two pumping schemes. A Jthr,min value of 5 and 6 A cm-2 is derived for the direct injection scheme and for the intracavity optical pumping one, respectively, at room temperature at the optimum detuning. Then an approximate quasianalytical model is introduced to derive solutions for both the steady-state and high-speed current modulation. This analysis makes it possible to show that the exciton population, which acts as a reservoir for the stimulated relaxation process, gets clamped once the condensation threshold is crossed, a behavior analogous to what happens in conventional laser diodes with the carrier density above threshold. Finally, the modulation transfer function is calculated for both pumping geometries and the corresponding cutoff frequency is determined.

Interaction of Aquifer and River-Canal Network near Well Field.

PubMed

Ghosh, Narayan C; Mishra, Govinda C; Sandhu, Cornelius S S; Grischek, Thomas; Singh, Vikrant V

2015-01-01

The article presents semi-analytical mathematical models to asses (1) enhancements of seepage from a canal and (2) induced flow from a partially penetrating river in an unconfined aquifer consequent to groundwater withdrawal in a well field in the vicinity of the river and canal. The nonlinear exponential relation between seepage from a canal reach and hydraulic head in the aquifer beneath the canal reach is used for quantifying seepage from the canal reach. Hantush's (1967) basic solution for water table rise due to recharge from a rectangular spreading basin in absence of pumping well is used for generating unit pulse response function coefficients for water table rise in the aquifer. Duhamel's convolution theory and method of superposition are applied to obtain water table position due to pumping and recharge from different canal reaches. Hunt's (1999) basic solution for river depletion due to constant pumping from a well in the vicinity of a partially penetrating river is used to generate unit pulse response function coefficients. Applying convolution technique and superposition, treating the recharge from canal reaches as recharge through conceptual injection wells, river depletion consequent to variable pumping and recharge is quantified. The integrated model is applied to a case study in Haridwar (India). The well field consists of 22 pumping wells located in the vicinity of a perennial river and a canal network. The river bank filtrate portion consequent to pumping is quantified. © 2014, National GroundWater Association.

Long-term in vivo left ventricular assist device study with a titanium centrifugal pump.

PubMed

Ohtsuka, G; Nakata, K; Yoshikawa, M; Mueller, J; Takano, T; Yamane, S; Gronau, N; Glueck, J; Takami, Y; Sueoka, A; Letsou, G; Schima, H; Schmallegger, H; Wolner, E; Koyanagi, H; Fujisawa, A; Baldwin, J C; Nosé, Y

1998-01-01

A totally implantable centrifugal artificial heart has been developed. The plastic prototype, Gyro PI 601, passed 2 day hemodynamic tests as a functional total artificial heart, 2 week screening tests for antithrombogenicity, and 1 month system feasibility. Based on these results, a metallic prototype, Gyro PI 702, was subjected to in vivo left ventricular assist device (LVAD) studies. The pump system employed the Gyro PI 702, which has the same inner dimensions and the same characteristics as the Gyro PI 601, including an eccentric inlet port, a double pivot bearing system, and a magnet coupling system. The PI 702 is driven with the Vienna DC brushless motor actuator. For the in vivo LVAD study, the pump actuator package was implanted in the preperitoneal space in two calves, from the left ventricular apex to the descending aorta. Case 1 achieved greater than 9 month survival without any complications, at an average flow rate of 6.6 L/min with 10.2 W input power. Case 2 was killed early due to the excessive growth of the calf, which caused functional obstruction of the inlet port. There was no blood clot inside the pump. During these periods, neither case exhibited any physiologic abnormalities. The PI 702 pump gives excellent results as a long-term implantable LVAD.

Diversity and regulation of plant Ca2+ pumps: insights from expression in yeast

NASA Technical Reports Server (NTRS)

Sze, H.; Liang, F.; Hwang, I.; Curran, A. C.; Harper, J. F.; Evans, M. L. (Principal Investigator)

2000-01-01

The spatial and temporal regulation of calcium concentration in plant cells depends on the coordinate activities of channels and active transporters located on different organelles and membranes. Several Ca2+ pumps have been identified and characterized by functional expression of plant genes in a yeast mutant (K616). This expression system has opened the way to a genetic and biochemical characterization of the regulatory and catalytic features of diverse Ca2+ pumps. Plant Ca(2+)-ATPases fall into two major types: AtECA1 represents one of four or more members of the type IIA (ER-type) Ca(2+)-ATPases in Arabidopsis, and AtACA2 is one of seven or more members of the type IIB (PM-type) Ca(2+)-ATPases that are regulated by a novel amino terminal domain. Type IIB pumps are widely distributed on membranes, including the PM (plasma membrane), vacuole, and ER (endoplasmic reticulum). The regulatory domain serves multiple functions, including autoinhibition, calmodulin binding, and sites for modification by phosphorylation. This domain, however, is considerably diverse among several type IIB ATPases, suggesting that the pumps are differentially regulated. Understanding of Ca2+ transporters at the molecular level is providing insights into their roles in signaling networks and in regulating fundamental processes of cell biology.

Ca2+ Induces Spontaneous Dephosphorylation of a Novel P5A-type ATPase

PubMed Central

Sørensen, Danny Mollerup; Møller, Annette B.; Jakobsen, Mia K.; Jensen, Michael K.; Vangheluwe, Peter; Buch-Pedersen, Morten J.; Palmgren, Michael G.

2012-01-01

P5 ATPases constitute the least studied group of P-type ATPases, an essential family of ion pumps in all kingdoms of life. Although P5 ATPases are present in every eukaryotic genome analyzed so far, they have remained orphan pumps, and their biochemical function is obscure. We show that a P5A ATPase from barley, HvP5A1, locates to the endoplasmic reticulum and is able to rescue knock-out mutants of P5A genes in both Arabidopsis thaliana and Saccharomyces cerevisiae. HvP5A1 spontaneously forms a phosphorylated reaction cycle intermediate at the catalytic residue Asp-488, whereas, among all plant nutrients tested, only Ca2+ triggers dephosphorylation. Remarkably, Ca2+-induced dephosphorylation occurs at high apparent [Ca2+] (Ki = 0.25 mm) and is independent of the phosphatase motif of the pump and the putative binding site for transported ligands located in M4. Taken together, our results rule out that Ca2+ is a transported substrate but indicate the presence of a cytosolic low affinity Ca2+-binding site, which is conserved among P-type pumps and could be involved in pump regulation. Our work constitutes the first characterization of a P5 ATPase phosphoenzyme and points to Ca2+ as a modifier of its function. PMID:22730321

Functional analysis of the musculo-skeletal system of the gill apparatus in Heptranchias perlo (Chondrichthyes: Hexanchidae).

PubMed

Kryukova, Nadezhda V

2017-08-01

Musculo-skeletal morphology is an indispensable source for understanding functional adaptations. Analysis of morphology of the branchial apparatus of Hexanchiform sharks can provide insight into aspects of their respiration that are difficult to observe directly. In this study, I compare the structure of the musculo-skeletal system of the gill apparatus of Heptranchias perlo and Squalus acanthias in respect to their adaptation for one of two respiratory mechanisms known in sharks, namely, the active two-pump (oropharyngeal and parabranchial) ventilation and the ram-jet ventilation. In both species, the oropharyngeal pump possesses two sets of muscles, one for compression and the other for expansion. The parabranchial pump only has constrictors. Expansion of this pump occurs only due to passive elastic recoil of the extrabranchial cartilages. In Squalus acanthias the parabranchial chambers are large and equipped by powerful superficial constrictors. These muscles and the outer walls of the parabranchial chambers are much reduced in Heptranchias perlo, and thus it likely cannot use this pump. However, this reduction allows for vertical elongation of outer gill slits which, along with greater number of gill pouches, likely decreases branchial resistance and, at the same time, increases the gill surface area, and can be regarded as an adaptation for ram ventilation at lower speeds. © 2017 Wiley Periodicals, Inc.

Adaptation of Mesenteric Collecting Lymphatic Pump Function Following Acute Alcohol Intoxication

PubMed Central

Souza-Smith, Flavia M.; Kurtz, Kristine M.; Molina, Patricia E.; Breslin, Jerome W.

2010-01-01

Objective Acute alcohol intoxication increases intestinal lymph flow by unknown mechanisms, potentially impacting mucosal immunity. We tested the hypothesis that enhanced intrinsic pump function of mesenteric lymphatics contributes to increased intestinal lymph flow during alcohol intoxication. Methods Acute alcohol intoxication was produced by intragastric administration of 30% alcohol to concious, unrestrained rats through surgically-implanted catheters. Time-matched controls received either no bolus, vehicle, or isocaloric dextrose. Thirty minutes after alcohol administration, rats were anesthetized and mesenteric collecting lymphatics were isolated and cannulated to study intrinsic pumping parameters. In separate experiments, mesenteric lymphatics were isolated to examine direct effects of alcohol on intrinsic pump activity. Results Lymphatics isolated from alcohol-intoxicated animals displayed slgnificantly decreased contraction frequency (CF) than the dextrose group, elevated stroke volume index (SVI) versus all other groups, and decreased myogenic responsiveness compared to sham. Elevating pressure from 2 to 4 cm H2O increased the volume flow index 2.4-fold in the alcohol group versus 1.4-fold for shams. Isolated lymphatics exposed to 20 mM alcohol had reduced myogenic tone, without changes in CF or SVI. Conclusions Alcohol intoxication enhances intrinsic pumping by mesenteric collecting lymphatics. Alcohol directly decreases lymphatic myogenic tone, but effects on phasic contractions occur by an unidentified mechanism. PMID:21040117

Cyanobacterial Light-Driven Proton Pump, Gloeobacter Rhodopsin: Complementarity between Rhodopsin-Based Energy Production and Photosynthesis

PubMed Central

Choi, Ah Reum; Shi, Lichi; Brown, Leonid S.; Jung, Kwang-Hwan

2014-01-01

A homologue of type I rhodopsin was found in the unicellular Gloeobacter violaceus PCC7421, which is believed to be primitive because of the lack of thylakoids and peculiar morphology of phycobilisomes. The Gloeobacter rhodopsin (GR) gene encodes a polypeptide of 298 amino acids. This gene is localized alone in the genome unlike cyanobacterium Anabaena opsin, which is clustered together with 14 kDa transducer gene. Amino acid sequence comparison of GR with other type I rhodopsin shows several conserved residues important for retinal binding and H+ pumping. In this study, the gene was expressed in Escherichia coli and bound all-trans retinal to form a pigment (λmax  = 544 nm at pH 7). The pKa of proton acceptor (Asp121) for the Schiff base, is approximately 5.9, so GR can translocate H+ under physiological conditions (pH 7.4). In order to prove the functional activity in the cell, pumping activity was measured in the sphaeroplast membranes of E. coli and one of Gloeobacter whole cell. The efficient proton pumping and rapid photocycle of GR strongly suggests that Gloeobacter rhodopsin functions as a proton pumping in its natural environment, probably compensating the shortage of energy generated by chlorophyll-based photosynthesis without thylakoids. PMID:25347537

Comparison of the Gyro C1E3 and BioMedicus centrifugal pump performances during cardiopulmonary bypass.

PubMed

Nakazawa, T; Takami, Y; Makinouchi, K; Gay, J; Taylor, D; Ueyama, K; Ohashi, Y; Kawahito, K; Tayama, E; Glueck, J; Nosé, Y

1997-07-01

The compact eccentric inlet port (C1E3) centrifugal blood pump was developed as a cardiopulmonary bypass (CPB) pump. The C1E3 pump incorporated a sealless design with a blood stagnation free structure. The pump impeller was magnetically coupled to the driver magnet in a sealless manner. To develop an atraumatic and antithrombogenic centrifugal pump without a shaft seal junction, a double pivot bearing system was introduced. Recently, a mass production model of the C1E3 was fabricated and evaluated. The ratio of the normalized index of hemolysis (NIH) of the C1E3 was 0.007 g/ 100 L, in comparison to the NIH of the BP-80, 0.018 g/ 100 L, each in a CPB condition of 5 L/min against 325 mm Hg. Both pumps were compared in identical in vitro circuits. To further evaluate the pumps during cardiopulmonary bypass for reliability and function, 6 h of CPB was performed on each of 8 bovines using either the C1E3 or BP-80 centrifugal pump. The BP-80 and C1E3 provided pump flows of 50-60 ml/kg/min without incident. The hemodynamics were stable, and the hematology and biochemistry data were within normal ranges. There were no statistically significant differences between the 2 groups. Concerning the plasma free hemoglobin values, a mass production model of the C1E3 pump had the same hemolysis levels as the BP-80. Our preliminary studies reveal that the C1E3 pump is reliable. Also, the C1E3 will satisfy clinical requirements as a cardiopulmonary bypass pump.

Theory of Excitation Transfer between Two-Dimensional Semiconductor and Molecular Layers

NASA Astrophysics Data System (ADS)

Specht, Judith F.; Verdenhalven, Eike; Bieniek, Björn; Rinke, Patrick; Knorr, Andreas; Richter, Marten

2018-04-01

The geometry-dependent energy transfer rate from an electrically pumped inorganic semiconductor quantum well into an organic molecular layer is studied theoretically. We focus on Förster-type nonradiative excitation transfer between the organic and inorganic layers and include quasimomentum conservation and intermolecular coupling between the molecules in the organic film. (Transition) partial charges calculated from density-functional theory are used to calculate the coupling elements. The partial charges describe the spatial charge distribution and go beyond the common dipole-dipole interaction. We find that the transfer rates are highly sensitive to variations in the geometry of the hybrid inorganic-organic system. For instance, the transfer efficiency is improved by up to 2 orders of magnitude by tuning the spatial arrangement of the molecules on the surface: Parameters of importance are the molecular packing density along the effective molecular dipole axis and the distance between the molecules and the surface. We also observe that the device performance strongly depends on the orientation of the molecular dipole moments relative to the substrate dipole moments determined by the inorganic crystal structure. Moreover, the operating regime is identified where inscattering dominates over unwanted backscattering from the molecular layer into the substrate.

Peptide-based ambidextrous bifunctional gelator: applications in oil spill recovery and removal of toxic organic dyes for waste water management.

PubMed

Basu, Kingshuk; Nandi, Nibedita; Mondal, Biplab; Dehsorkhi, Ashkan; Hamley, Ian W; Banerjee, Arindam

2017-12-06

A low molecular weight peptide-based ambidextrous gelator molecule has been discovered for efficient control of water pollution. The gelator molecules can gel various organic solvents with diverse polarity, e.g. n -hexane, n -octane, petroleum ether, petrol, diesel, aromatic solvents like chlorobenzene, toluene, benzene, o -xylene and even aqueous phosphate buffer of pH 7.5. These gels have been thoroughly characterized using various techniques including field emission scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray powder diffraction analysis, small angle X-ray scattering and rheological experiments. Interestingly, hydrogel obtained from the gelator molecule has been found to absorb toxic organic dyes (both cationic and anionic dyes) from dye-contaminated water. The gelator molecule can be reused for several cycles, indicating its possible future use in waste water management. Moreover, this gelator can selectively gel petrol, diesel, pump oil from an oil-water mixture in the presence of a carrier solvent, ethyl acetate, suggesting its efficient application for oil spill recovery. These results indicate that the peptide-based ambidextrous gelator produces soft materials (gels) with dual function: (i) removal of toxic organic dyes in waste water treatment and (ii) oil spill recovery.

Heat driven pulse pump

NASA Technical Reports Server (NTRS)

Benner, Steve M (Inventor); Martins, Mario S. (Inventor)

2000-01-01

A heat driven pulse pump includes a chamber having an inlet port, an outlet port, two check valves, a wick, and a heater. The chamber may include a plurality of grooves inside wall of the chamber. When heated within the chamber, a liquid to be pumped vaporizes and creates pressure head that expels the liquid through the outlet port. As liquid separating means, the wick, disposed within the chamber, is to allow, when saturated with the liquid, the passage of only liquid being forced by the pressure head in the chamber, preventing the vapor from exiting from the chamber through the outlet port. A plurality of grooves along the inside surface wall of the chamber can sustain the liquid, which is amount enough to produce vapor for the pressure head in the chamber. With only two simple moving parts, two check valves, the heat driven pulse pump can effectively function over the long lifetimes without maintenance or replacement. For continuous flow of the liquid to be pumped a plurality of pumps may be connected in parallel.

Mosquitoes drink with a burst in reserve: explaining pumping behavior with a fluid mechanics model

NASA Astrophysics Data System (ADS)

Chatterjee, Souvick; Socha, Jake; Stremler, Mark

2014-11-01

Mosquitoes drink using a pair of in-line pumps in the head that draw liquid food through the proboscis. Experimental observations with synchrotron x-ray imaging indicate two modes of drinking: a predominantly occurring continuous mode, in which the cibarial and pharyngeal pumps expand cyclically at a constant phase difference, and an occasional, isolated burst mode, in which the pharyngeal pump expansion is 10 to 30 times larger than in the continuous mode. We have used a reduced order model of the fluid mechanics to hypothesize an explanation of this variation in drinking behavior. Our model results show that the continuous mode is more energetically efficient, whereas the burst mode creates a large pressure drop across the proboscis, which could potentially be used to clear blockages. Comparisons with pump knock-out configurations demonstrate different functional roles of the pumps in mosquito feeding. This material is based upon work supported by the NSF under Grant No. #0938047.

Role of the precursor in a triple-pulse pumping scheme of a nickel-like silver soft-x-ray laser in the grazing-incidence-pumping geometry.

PubMed

Janulewicz, K A; Kim, C M

2010-11-01

Soft x-ray lasers pumped in the grazing incidence geometry show strongly reduced energetic needs but hardly changed conversion efficiency between the pump energy and the output short-wavelength radiation. Numerical analysis presented in the paper concerns with performance of a Ni-like Ag soft-x-ray laser pumped by a triple-pulse structure in the grazing incidence geometry as a function of the puming conditions. It was found that a weak precursor preceding the main preforming and heating pulses by a few nanoseconds is crucial for the energy deposition. Its presence enables in different arrangements a reasonable reduction in the pump energy and relaxation of the steep density gradients as well as a control over partition of the deposited energy. As a consequence, it was concluded that a well energetically balanced three- or multipulse composition seems to be a reasonable way to achieve performance improvement.

Development of the pump protection system against cavitation on the basis of the stator current signature analysis of drive electric motor

NASA Astrophysics Data System (ADS)

Kipervasser, M. V.; Gerasimuk, A. V.; Simakov, V. P.

2018-05-01

In the present paper a new registration method of such inadmissible phenomenon as cavitation in the operating mode of centrifugal pump is offered. Influence of cavitation and extent of its development on the value of mechanical power consumed by the pump from the electric motor is studied. On the basis of design formulas the joint mathematical model of centrifugal pumping unit with the synchronous motor is created. In the model the phenomena accompanying the work of a pumping installation in the cavitation mode are considered. Mathematical modeling of the pump operation in the considered emergency operation is carried out. The chart of stator current of the electric motor, depending on the degree of cavitation development of is received. On the basis of the analysis of the obtained data the conclusion on the possibility of registration of cavitation by the current of drive electric motor is made and the functional diagram of the developed protection system is offered, its operation principle is described.

Evaluation of Pump Pulsation in Respirable Size-Selective Sampling: Part II. Changes in Sampling Efficiency

PubMed Central

Lee, Eun Gyung; Lee, Taekhee; Kim, Seung Won; Lee, Larry; Flemmer, Michael M.; Harper, Martin

2015-01-01

This second, and concluding, part of this study evaluated changes in sampling efficiency of respirable size-selective samplers due to air pulsations generated by the selected personal sampling pumps characterized in Part I (Lee E, Lee L, Möhlmann C et al. Evaluation of pump pulsation in respirable size-selective sampling: Part I. Pulsation measurements. Ann Occup Hyg 2013). Nine particle sizes of monodisperse ammonium fluorescein (from 1 to 9 μm mass median aerodynamic diameter) were generated individually by a vibrating orifice aerosol generator from dilute solutions of fluorescein in aqueous ammonia and then injected into an environmental chamber. To collect these particles, 10-mm nylon cyclones, also known as Dorr-Oliver (DO) cyclones, were used with five medium volumetric flow rate pumps. Those were the Apex IS, HFS513, GilAir5, Elite5, and Basic5 pumps, which were found in Part I to generate pulsations of 5% (the lowest), 25%, 30%, 56%, and 70% (the highest), respectively. GK2.69 cyclones were used with the Legacy [pump pulsation (PP) = 15%] and Elite12 (PP = 41%) pumps for collection at high flows. The DO cyclone was also used to evaluate changes in sampling efficiency due to pulse shape. The HFS513 pump, which generates a more complex pulse shape, was compared to a single sine wave fluctuation generated by a piston. The luminescent intensity of the fluorescein extracted from each sample was measured with a luminescence spectrometer. Sampling efficiencies were obtained by dividing the intensity of the fluorescein extracted from the filter placed in a cyclone with the intensity obtained from the filter used with a sharp-edged reference sampler. Then, sampling efficiency curves were generated using a sigmoid function with three parameters and each sampling efficiency curve was compared to that of the reference cyclone by constructing bias maps. In general, no change in sampling efficiency (bias under ±10%) was observed until pulsations exceeded 25% for the DO cyclone. However, for three models of pumps producing 30%, 56%, and 70% pulsations, substantial changes were confirmed. The GK2.69 cyclone showed a similar pattern to that of the DO cyclone, i.e. no change in sampling efficiency for the Legacy producing 15% pulsation and a substantial change for the Elite12 producing 41% pulsation. Pulse shape did not cause any change in sampling efficiency when compared to the single sine wave. The findings suggest that 25% pulsation at the inlet of the cyclone as measured by this test can be acceptable for the respirable particle collection. If this test is used in place of that currently in European standards (EN 1232–1997 and EN 12919-1999) or is used in any International Organization for Standardization standard, then a 25% pulsation criterion could be adopted. This work suggests that a 10% criterion as currently specified in the European standards for testing may be overly restrictive and not able to be met by many pumps on the market. Further work is recommended to determine which criterion would be applicable to this test if it is to be retained in its current form. PMID:24064963

Evaluation of pump pulsation in respirable size-selective sampling: part II. Changes in sampling efficiency.

PubMed

Lee, Eun Gyung; Lee, Taekhee; Kim, Seung Won; Lee, Larry; Flemmer, Michael M; Harper, Martin

2014-01-01

This second, and concluding, part of this study evaluated changes in sampling efficiency of respirable size-selective samplers due to air pulsations generated by the selected personal sampling pumps characterized in Part I (Lee E, Lee L, Möhlmann C et al. Evaluation of pump pulsation in respirable size-selective sampling: Part I. Pulsation measurements. Ann Occup Hyg 2013). Nine particle sizes of monodisperse ammonium fluorescein (from 1 to 9 μm mass median aerodynamic diameter) were generated individually by a vibrating orifice aerosol generator from dilute solutions of fluorescein in aqueous ammonia and then injected into an environmental chamber. To collect these particles, 10-mm nylon cyclones, also known as Dorr-Oliver (DO) cyclones, were used with five medium volumetric flow rate pumps. Those were the Apex IS, HFS513, GilAir5, Elite5, and Basic5 pumps, which were found in Part I to generate pulsations of 5% (the lowest), 25%, 30%, 56%, and 70% (the highest), respectively. GK2.69 cyclones were used with the Legacy [pump pulsation (PP) = 15%] and Elite12 (PP = 41%) pumps for collection at high flows. The DO cyclone was also used to evaluate changes in sampling efficiency due to pulse shape. The HFS513 pump, which generates a more complex pulse shape, was compared to a single sine wave fluctuation generated by a piston. The luminescent intensity of the fluorescein extracted from each sample was measured with a luminescence spectrometer. Sampling efficiencies were obtained by dividing the intensity of the fluorescein extracted from the filter placed in a cyclone with the intensity obtained from the filter used with a sharp-edged reference sampler. Then, sampling efficiency curves were generated using a sigmoid function with three parameters and each sampling efficiency curve was compared to that of the reference cyclone by constructing bias maps. In general, no change in sampling efficiency (bias under ±10%) was observed until pulsations exceeded 25% for the DO cyclone. However, for three models of pumps producing 30%, 56%, and 70% pulsations, substantial changes were confirmed. The GK2.69 cyclone showed a similar pattern to that of the DO cyclone, i.e. no change in sampling efficiency for the Legacy producing 15% pulsation and a substantial change for the Elite12 producing 41% pulsation. Pulse shape did not cause any change in sampling efficiency when compared to the single sine wave. The findings suggest that 25% pulsation at the inlet of the cyclone as measured by this test can be acceptable for the respirable particle collection. If this test is used in place of that currently in European standards (EN 1232-1997 and EN 12919-1999) or is used in any International Organization for Standardization standard, then a 25% pulsation criterion could be adopted. This work suggests that a 10% criterion as currently specified in the European standards for testing may be overly restrictive and not able to be met by many pumps on the market. Further work is recommended to determine which criterion would be applicable to this test if it is to be retained in its current form.

Functional and biocompatibility performances of an integrated Maglev pump-oxygenator.

PubMed

Zhang, Tao; Cheng, Guangming; Koert, Andrew; Zhang, Juntao; Gellman, Barry; Yankey, G Kwame; Satpute, Aditee; Dasse, Kurt A; Gilbert, Richard J; Griffith, Bartley P; Wu, Zhongjun J

2009-01-01

To provide respiratory support for patients with lung failure, a novel compact integrated pump-oxygenator is being developed. The functional and biocompatibility performances of this device are presented. The pump-oxygenator is designed by combining a magnetically levitated pump/rotor with a uniquely configured hollow fiber membrane bundle to create an assembly free, ultracompact, all-in-one system. The hemodynamics, gas transfer and biocompatibility performances of this novel device were investigated both in vitro in a circulatory flow loop and in vivo in an ovine animal model. The in vitro results showed that the device was able to pump blood flow from 2 to 8 L/min against a wide range of pressures and to deliver an oxygen transfer rate more than 300 mL/min at a blood flow of 6 L/min. Blood damage tests demonstrated low hemolysis (normalized index of hemolysis [NIH] approximately 0.04) at a flow rate of 5 L/min against a 100-mm Hg afterload. The data from five animal experiments (4 h to 7 days) demonstrated that the device could bring the venous blood to near fully oxygen-saturated condition (98.6% +/- 1.3%). The highest oxygen transfer rate reached 386 mL/min. The gas transfer performance was stable over the study duration for three 7-day animals. There was no indication of blood damage. The plasma free hemoglobin and platelet count were within the normal ranges. No gross thrombus is found on the explanted pump components and fiber surfaces. Both in vitro and in vivo results demonstrated that the newly developed pump-oxygenator can achieve sufficient blood flow and oxygen transfer with excellent biocompatibility.

Investigation of pump and pump switch failures in rainwater harvesting systems

NASA Astrophysics Data System (ADS)

Moglia, Magnus; Gan, Kein; Delbridge, Nathan; Sharma, Ashok K.; Tjandraatmadja, Grace

2016-07-01

Rainwater harvesting is an important technology in cities that can contribute to a number of functions, such as sustainable water management in the face of demand growth and drought as well as the detention of rainwater to increase flood protection and reduce damage to waterways. The objective of this article is to investigate the integrity of residential rainwater harvesting systems, drawing on the results of the field inspection of 417 rainwater systems across Melbourne that was combined with a survey of householders' situation, maintenance behaviour and attitudes. Specifically, the study moves beyond the assumption that rainwater systems are always operational and functional and draws on the collected data to explore the various reasons and rates of failure associated with pumps and pump switches, leaving for later further exploration of the failure in other components such as the collection area, gutters, tank, and overflows. To the best of the authors' knowledge, there is no data like this in academic literature or in the water sector. Straightforward Bayesian Network models were constructed in order to analyse the factors contributing to various types of failures, including system age, type of use, the reason for installation, installer, and maintenance behaviour. Results show that a number of issues commonly exist, such as failure of pumps (5% of systems), automatic pump switches that mediate between the tank and reticulated water (9% of systems), and systems with inadequate setups (i.e. no pump) limiting their use. In conclusion, there appears to be a lack of enforcement or quality controls in both installation practices by sometimes unskilled contractors and lack of ongoing maintenance checks. Mechanisms for quality control and asset management are required, but difficult to promote or enforce. Further work is needed into how privately owned assets that have public benefits could be better managed.

Oceanic biogeochemical controls on global dynamics of persistent organic pollutants.

PubMed

Dachs, Jordi; Lohmann, Rainer; Ockenden, Wendy A; Méjanelle, Laurence; Eisenreich, Steven J; Jones, Kevin C

2002-10-15

Understanding and quantifying the global dynamics and sinks of persistent organic pollutants (POPs) is important to assess their environmental impact and fate. Air-surface exchange processes, where temperature plays a central role in controlling volatilization and deposition, are of key importance in controlling global POP dynamics. The present study is an assessment of the role of oceanic biogeochemical processes, notably phytoplankton uptake and vertical fluxes of particles, on the global dynamics of POPs. Field measurements of atmospheric polychlorinated biphenyls (PCBs), polychlorinated dibenzodioxins (PCDDs), and furans (PCDFs) are combined with remote sensing estimations of oceanic temperature, wind speed, and chlorophyll, to model the interactions between air-water exchange, phytoplankton uptake, and export of organic matter and POPs out of the mixed surface ocean layer. Deposition is enhanced in the mid-high latitudes and is driven by sinking marine particulate matter, rather than by a cold condensation effect. However, the relative contribution of the biological pump is a function of the physical-chemical properties of POPs. It is concluded that oceanic biogeochemical processes play a critical role in controlling the global dynamics and the ultimate sink of POPs.

Time-domain ab initio modeling of photoinduced dynamics at nanoscale interfaces.

PubMed

Wang, Linjun; Long, Run; Prezhdo, Oleg V

2015-04-01

Nonequilibrium processes involving electronic and vibrational degrees of freedom in nanoscale materials are under active experimental investigation. Corresponding theoretical studies are much scarcer. The review starts with the basics of time-dependent density functional theory, recent developments in nonadiabatic molecular dynamics, and the fusion of the two techniques. Ab initio simulations of this kind allow us to directly mimic a great variety of time-resolved experiments performed with pump-probe laser spectroscopies. The focus is on the ultrafast photoinduced charge and exciton dynamics at interfaces formed by two complementary materials. We consider purely inorganic materials, inorganic-organic hybrids, and all organic interfaces, involving bulk semiconductors, metallic and semiconducting nanoclusters, graphene, carbon nanotubes, fullerenes, polymers, molecular crystals, molecules, and solvent. The detailed atomistic insights available from time-domain ab initio studies provide a unique description and a comprehensive understanding of the competition between electron transfer, thermal relaxation, energy transfer, and charge recombination processes. These advances now make it possible to directly guide the development of organic and hybrid solar cells, as well as photocatalytic, electronic, spintronic, and other devices relying on complex interfacial dynamics.

Glymes as Versatile Solvents for Chemical Reactions and Processes: from the Laboratory to Industry

PubMed Central

Tang, Shaokun; Zhao, Hua

2014-01-01

Glymes, also known as glycol diethers, are saturated non-cyclic polyethers containing no other functional groups. Most glymes are usually less volatile and less toxic than common laboratory organic solvents; in this context, they are more environmentally benign solvents. However, it is also important to point out that some glymes could cause long-term reproductive and developmental damages despite their low acute toxicities. Glymes have both hydrophilic and hydrophobic characters that common organic solvents are lack of. In addition, they are usually thermally and chemically stable, and can even form complexes with ions. Therefore, glymes are found in a broad range of laboratory applications including organic synthesis, electrochemistry, biocatalysis, materials, and Chemical Vapor Deposition (CVD), etc. In addition, glyme are used in numerous industrial applications, such as cleaning products, inks, adhesives and coatings, batteries and electronics, absorption refrigeration and heat pumps, as well as pharmaceutical formulations, etc. However, there is a lack of comprehensive and critical review on this attractive subject. This review aims to accomplish this task by providing an in-depth understanding of glymes’ physicochemical properties, toxicity and major applications. PMID:24729866

Magnetic Pumping as a Source of Particle Heating and Power-Law Distributions in the Solar Wind

DOE PAGES

Lichko, Emily Rose; Egedal, Jan; Daughton, William Scott; ...

2017-11-27

Based on the rate of expansion of the solar wind, the plasma should cool rapidly as a function of distance to the Sun. Observations show this is not the case. In this work, a magnetic pumping model is developed as a possible explanation for the heating and the generation of power-law distribution functions observed in the solar wind plasma. Most previous studies in this area focus on the role that the dissipation of turbulent energy on microscopic kinetic scales plays in the overall heating of the plasma. However, with magnetic pumping, particles are energized by the largest-scale turbulent fluctuations, thusmore » bypassing the energy cascade. In contrast to other models, we include the pressure anisotropy term, providing a channel for the large-scale fluctuations to heat the plasma directly. A complete set of coupled differential equations describing the evolution, and energization, of the distribution function are derived, as well as an approximate closed-form solution. Numerical simulations using the VPIC kinetic code are applied to verify the model's analytical predictions. The results of the model for realistic solar wind scenario are computed, where thermal streaming of particles are important for generating a phase shift between the magnetic perturbations and the pressure anisotropy. In turn, averaged over a pump cycle, the phase shift permits mechanical work to be converted directly to heat in the plasma. Here, the results of this scenario show that magnetic pumping may account for a significant portion of the solar wind energization.« less

Magnetic Pumping as a Source of Particle Heating and Power-Law Distributions in the Solar Wind

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

Lichko, Emily Rose; Egedal, Jan; Daughton, William Scott

Based on the rate of expansion of the solar wind, the plasma should cool rapidly as a function of distance to the Sun. Observations show this is not the case. In this work, a magnetic pumping model is developed as a possible explanation for the heating and the generation of power-law distribution functions observed in the solar wind plasma. Most previous studies in this area focus on the role that the dissipation of turbulent energy on microscopic kinetic scales plays in the overall heating of the plasma. However, with magnetic pumping, particles are energized by the largest-scale turbulent fluctuations, thusmore » bypassing the energy cascade. In contrast to other models, we include the pressure anisotropy term, providing a channel for the large-scale fluctuations to heat the plasma directly. A complete set of coupled differential equations describing the evolution, and energization, of the distribution function are derived, as well as an approximate closed-form solution. Numerical simulations using the VPIC kinetic code are applied to verify the model's analytical predictions. The results of the model for realistic solar wind scenario are computed, where thermal streaming of particles are important for generating a phase shift between the magnetic perturbations and the pressure anisotropy. In turn, averaged over a pump cycle, the phase shift permits mechanical work to be converted directly to heat in the plasma. Here, the results of this scenario show that magnetic pumping may account for a significant portion of the solar wind energization.« less

Enhancement of Survival and Electricity Production in an Engineered Bacterium by Light-Driven Proton Pumping▿ †

PubMed Central

Johnson, Ethan T.; Baron, Daniel B.; Naranjo, Belén; Bond, Daniel R.; Schmidt-Dannert, Claudia; Gralnick, Jeffrey A.

2010-01-01

Microorganisms can use complex photosystems or light-dependent proton pumps to generate membrane potential and/or reduce electron carriers to support growth. The discovery that proteorhodopsin is a light-dependent proton pump that can be expressed readily in recombinant bacteria enables development of new strategies to probe microbial physiology and to engineer microbes with new light-driven properties. Here, we describe functional expression of proteorhodopsin and light-induced changes in membrane potential in the bacterium Shewanella oneidensis strain MR-1. We report that there were significant increases in electrical current generation during illumination of electrochemical chambers containing S. oneidensis expressing proteorhodopsin. We present evidence that an engineered strain is able to consume lactate at an increased rate when it is illuminated, which is consistent with the hypothesis that proteorhodopsin activity enhances lactate uptake by increasing the proton motive force. Our results demonstrate that there is coupling of a light-driven process to electricity generation in a nonphotosynthetic engineered bacterium. Expression of proteorhodopsin also preserved the viability of the bacterium under nutrient-limited conditions, providing evidence that fulfillment of basic energy needs of organisms may explain the widespread distribution of proteorhodopsin in marine environments. PMID:20453141

A Benzimidazole Proton Pump Inhibitor Increases Growth and Tolerance to Salt Stress in Tomato.

PubMed

Van Oosten, Michael J; Silletti, Silvia; Guida, Gianpiero; Cirillo, Valerio; Di Stasio, Emilio; Carillo, Petronia; Woodrow, Pasqualina; Maggio, Albino; Raimondi, Giampaolo

2017-01-01

Pre-treatment of tomato plants with micromolar concentrations of omeprazole (OP), a benzimidazole proton pump inhibitor in mammalian systems, improves plant growth in terms of fresh weight of shoot and roots by 49 and 55% and dry weight by 54 and 105% under salt stress conditions (200 mM NaCl), respectively. Assessment of gas exchange, ion distribution, and gene expression profile in different organs strongly indicates that OP interferes with key components of the stress adaptation machinery, including hormonal control of root development (improving length and branching), protection of the photosynthetic system (improving quantum yield of photosystem II) and regulation of ion homeostasis (improving the K + :Na + ratio in leaves and roots). To our knowledge OP is one of the few known molecules that at micromolar concentrations manifests a dual function as growth enhancer and salt stress protectant. Therefore, OP can be used as new inducer of stress tolerance to better understand molecular and physiological stress adaptation paths in plants and to design new products to improve crop performance under suboptimal growth conditions. Highlight: Omeprazole enhances growth of tomato and increases tolerance to salinity stress through alterations of gene expression and ion uptake and transport.

Renin-angiotensin-aldosterone (RAAS): The ubiquitous system for homeostasis and pathologies.

PubMed

Patel, Seema; Rauf, Abdur; Khan, Haroon; Abu-Izneid, Tareq

2017-10-01

Renin-angiotensin-aldosterone system (RAAS) is a vital system of human body, as it maintains plasma sodium concentration, arterial blood pressure and extracellular volume. Kidney-secreted renin enzyme acts on its substrate to form angiotensin II, a versatile effector peptide hormone. Every organ is affected by RAAS activation and the resultant hypertension, cell proliferation, inflammation, and fibrosis. The imbalance of renin and angiotensin II can result in an overwhelming number of chronic and acute diseases. RAAS is influenced by other enzymes, hormones, pumps and signaling pathways, hence, this review discusses important facets of this system, its crosstalk with other crucial factors like estrogen, thyroid, cortisol, kallikrein-kinin system, Wnt/β-catenin signaling, and sodium-potassium pump. The nexus of RAAS with the above-discussed systems was scantily explored before. So, this review furnishes a new perspective in comprehension of inflammation diseases. It is followed by the formulation of hypotheses, which can contribute to better management of an array of pathologies plaguing mankind. Manipulation of RAAS, by bending it towards ACE2 expression can regulate endocrine functions, which can be critical for a number of pathological management. Dietary intervention can restore RAAS to normalcy. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

A Benzimidazole Proton Pump Inhibitor Increases Growth and Tolerance to Salt Stress in Tomato

PubMed Central

Van Oosten, Michael J.; Silletti, Silvia; Guida, Gianpiero; Cirillo, Valerio; Di Stasio, Emilio; Carillo, Petronia; Woodrow, Pasqualina; Maggio, Albino; Raimondi, Giampaolo

2017-01-01

Pre-treatment of tomato plants with micromolar concentrations of omeprazole (OP), a benzimidazole proton pump inhibitor in mammalian systems, improves plant growth in terms of fresh weight of shoot and roots by 49 and 55% and dry weight by 54 and 105% under salt stress conditions (200 mM NaCl), respectively. Assessment of gas exchange, ion distribution, and gene expression profile in different organs strongly indicates that OP interferes with key components of the stress adaptation machinery, including hormonal control of root development (improving length and branching), protection of the photosynthetic system (improving quantum yield of photosystem II) and regulation of ion homeostasis (improving the K+:Na+ ratio in leaves and roots). To our knowledge OP is one of the few known molecules that at micromolar concentrations manifests a dual function as growth enhancer and salt stress protectant. Therefore, OP can be used as new inducer of stress tolerance to better understand molecular and physiological stress adaptation paths in plants and to design new products to improve crop performance under suboptimal growth conditions. Highlight: Omeprazole enhances growth of tomato and increases tolerance to salinity stress through alterations of gene expression and ion uptake and transport. PMID:28769943

Lead (Pb) contamination of self-supply groundwater systems in coastal Madagascar and predictions of blood lead levels in exposed children.

PubMed

Akers, D Brad; MacCarthy, Michael F; Cunningham, Jeffrey A; Annis, Jonathan; Mihelcic, James R

2015-03-03

Thousands of households in coastal Madagascar rely on locally manufactured pitcher-pump systems to provide water for drinking, cooking, and household use. These pumps typically include components made from lead (Pb). In this study, concentrations of Pb in water were monitored at 18 household pitcher pumps in the city of Tamatave over three sampling campaigns. Concentrations of Pb frequently exceeded the World Health Organization's provisional guideline for drinking water of 10 μg/L. Under first-draw conditions (i.e., after a pump had been inactive for 1 h), 67% of samples analyzed were in excess of 10 μg/L Pb, with a median concentration of 13 μg/L. However, flushing the pump systems before collecting water resulted in a statistically significant (p < 0.0001) decrease in Pb concentrations: 35% of samples collected after flushing exceeded 10 μg/L, with a median concentration of 9 μg/L. Based on measured Pb concentrations, a biokinetic model estimates that anywhere from 15% to 70% of children living in households with pitcher pumps may be at risk for elevated blood lead levels (>5 μg/dL). Measured Pb concentrations in water were not correlated at statistically significant levels with pump-system age, well depth, system manufacturer, or season of sample collection; only the contact time (i.e., flushed or first-draw condition) was observed to correlate significantly with Pb concentrations. In two of the 18 systems, Pb valve weights were replaced with iron, which decreased the observed Pb concentrations in the water by 57-89% in one pump and by 89-96% in the other. Both systems produced samples exclusively below 10 μg/L after substitution. Therefore, relatively straightforward operational changes on the part of the pump-system manufacturers and pump users might reduce Pb exposure, thereby helping to ensure the continued sustainability of pitcher pumps in Madagascar.

Leonardo da Vinci's studies of the heart.

PubMed

Shoja, Mohammadali M; Agutter, Paul S; Loukas, Marios; Benninger, Brion; Shokouhi, Ghaffar; Namdar, Husain; Ghabili, Kamyar; Khalili, Majid; Tubbs, R Shane

2013-08-20

Leonardo da Vinci's detailed drawings are justly celebrated; however, less well known are his accounts of the structures and functions of the organs. In this paper, we focus on his illustrations of the heart, his conjectures about heart and blood vessel function, his experiments on model systems to test those conjectures, and his unprecedented conclusions about the way in which the cardiovascular system operates. In particular, da Vinci seems to have been the first to recognize that the heart is a muscle and that systole is the active phase of the pump. He also seems to have understood the functions of the auricles and pulmonary veins, identified the relationship between the cardiac cycle and the pulse, and explained the hemodynamic mechanism of valve opening and closure. He also described anatomical variations and changes in structure and function that occurred with age. We outline da Vinci's varied career and suggest ways in which his personality, experience, skills and intellectual heritage contributed to these advances in understanding. We also consider his influence on later studies in anatomy and physiology. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Computational physiology and the Physiome Project.

PubMed

Crampin, Edmund J; Halstead, Matthew; Hunter, Peter; Nielsen, Poul; Noble, Denis; Smith, Nicolas; Tawhai, Merryn

2004-01-01

Bioengineering analyses of physiological systems use the computational solution of physical conservation laws on anatomically detailed geometric models to understand the physiological function of intact organs in terms of the properties and behaviour of the cells and tissues within the organ. By linking behaviour in a quantitative, mathematically defined sense across multiple scales of biological organization--from proteins to cells, tissues, organs and organ systems--these methods have the potential to link patient-specific knowledge at the two ends of these spatial scales. A genetic profile linked to cardiac ion channel mutations, for example, can be interpreted in relation to body surface ECG measurements via a mathematical model of the heart and torso, which includes the spatial distribution of cardiac ion channels throughout the myocardium and the individual kinetics for each of the approximately 50 types of ion channel, exchanger or pump known to be present in the heart. Similarly, linking molecular defects such as mutations of chloride ion channels in lung epithelial cells to the integrated function of the intact lung requires models that include the detailed anatomy of the lungs, the physics of air flow, blood flow and gas exchange, together with the large deformation mechanics of breathing. Organizing this large body of knowledge into a coherent framework for modelling requires the development of ontologies, markup languages for encoding models, and web-accessible distributed databases. In this article we review the state of the field at all the relevant levels, and the tools that are being developed to tackle such complexity. Integrative physiology is central to the interpretation of genomic and proteomic data, and is becoming a highly quantitative, computer-intensive discipline.

Design of three-well indirect pumping terahertz quantum cascade lasers for high optical gain based on nonequilibrium Green's function analysis

NASA Astrophysics Data System (ADS)

Liu, Tao; Kubis, Tillmann; Jie Wang, Qi; Klimeck, Gerhard

2012-03-01

The nonequilibrium Green's function approach is applied to the design of three-well indirect pumping terahertz (THz) quantum cascade lasers (QCLs) based on a resonant phonon depopulation scheme. The effects of the anticrossing of the injector states and the dipole matrix element of the laser levels on the optical gain of THz QCLs are studied. The results show that a design that results in a more pronounced anticrossing of the injector states will achieve a higher optical gain in the indirect pumping scheme compared to the traditional resonant-tunneling injection scheme. This offers in general a more efficient coherent resonant-tunneling transport of electrons in the indirect pumping scheme. It is also shown that, for operating temperatures below 200 K and low lasing frequencies, larger dipole matrix elements, i.e., vertical optical transitions, offer a higher optical gain. In contrast, in the case of high lasing frequencies, smaller dipole matrix elements, i.e., diagonal optical transitions are better for achieving a higher optical gain.

Effects of Cardiopulmonary Support with a Novel Pediatric Pump-Lung (PediPL) in a Thirty-Day Ovine Animal Model

PubMed Central

Liu, Yang; Sanchez, Pablo G; Wei, Xufeng; Watkins, Amelia C; Niu, Shuqiong; Wu, Zhongjun J; Griffith, Bartley P

2016-01-01

The scarcity of donor organs has led to the development of devices that provide optimal long-term respiratory or cardiopulmonary support to bridge recipients as they wait for lung and/or heart transplantation. This study was designed to evaluate the 30-day in-vivo performance of the newly developed pediatric pump-lung (PediPL) for cardiopulmonary support using a juvenile sheep model. The PediPL device was placed surgically between the right atrium and descending aorta in eight sheep (25.4 to 31.2kg) and evaluated for 30 days. Anticoagulation was maintained with continuous heparin infusion (ACT 150–200 sec). The flow rate was measured continually and gas transfer was measured daily. Plasma free hemoglobin, platelet activation, hematologic data, and blood biochemistry were assessed twice a week. Sheep were euthanized after 30 days. The explanted devices were examined for gross thrombosis. Six sheep survived for 30 to 32 days. During the study, the oxygen transfer rate of the devices was 54.9 ± 13.2mL/min at a mean flow rate of 1.14 ± 0.46 L/min with blood oxygen saturation of 95.4% ± 1.7%. Plasma free hemoglobin was 8.2 ± 3.7 mg/dL. Platelet activation was 5.35 ± 2.65%. The animals had normal organ chemistries except for surgery-related transient alterations in kidney and liver function. Although we found some scattered thrombi on the membrane surfaces of some explanted devices during the necropsy, the device function and performance did not degrade. The PediPL device was capable of providing cardiopulmonary with long-term reliability and good biocompatibility over the 30 day duration and offering the potential option for bridging to heart and/or lung transplant pediatric patients with end-stage heart or lung disease. PMID:25921361

Associations between Deceased-Donor Urine MCP-1 and Kidney Transplant Outcomes.

PubMed

Mansour, S G; Puthumana, J; Reese, P P; Hall, I E; Doshi, M D; Weng, F L; Schröppel, B; Thiessen-Philbrook, H; Bimali, M; Parikh, C R

2017-07-01

Existing methods to predict recipient allograft function during deceased-donor kidney procurement are imprecise. Understanding the potential renal reparative role for monocyte chemoattractant protein-1 (MCP-1), a cytokine involved in macrophage recruitment after injury, might help predict allograft outcomes. We conducted a sub-study of the multicenter prospective Deceased Donor Study cohort, which evaluated deceased kidney donors from five organ procurement organizations from May 2010 to December 2013. We measured urine MCP-1 (uMCP-1) concentrations from donor samples collected at nephrectomy to determine associations with donor acute kidney injury (AKI), recipient delayed graft function (DGF), 6-month estimated GFR (eGFR), and graft failure. We also assessed perfusate MCP-1 concentrations from pumped kidneys for associations with DGF and 6-month eGFR. AKI occurred in 111 (9%) donors. Median (interquartile range) uMCP-1 concentration was higher in donors with AKI compared to donors without AKI (1.35 [0.41-3.93] ng/ml vs. 0.32 [0.11-0.80] ng/ml, p<0.001). DGF occurred in 756 (31%) recipients, but uMCP-1 was not independently associated with DGF. Higher donor uMCP-1 concentrations were independently associated with higher 6-month eGFR in those without DGF [0.77 (0.10, 1.45) ml/min/1.73m 2 per doubling of uMCP1]. However, there were no independent associations between uMCP-1 and graft failure over a median follow-up of about 2 years. Lastly, perfusate MCP-1 concentrations significantly increased during pump perfusion but were not associated with DGF or 6-month eGFR. Donor uMCP-1 concentrations were modestly associated with higher recipient 6-month eGFR in those without DGF. However, the results suggest that donor uMCP-1 has minimal clinical utility given no associations with graft failure.

Real-Time Observation of Thrombus Growth Process in an Impeller of a Hydrodynamically Levitated Centrifugal Blood Pump by Near-Infrared Hyperspectral Imaging.

PubMed

Sakota, Daisuke; Murashige, Tomotaka; Kosaka, Ryo; Fujiwara, Tatsuki; Nishida, Masahiro; Maruyama, Osamu

2015-08-01

Understanding the thrombus formation in cardiovascular devices such as rotary blood pumps is the most important issue in developing more hemocompatible devices. The objective of this study was to develop a hyperspectral imaging (HSI) method to visualize the thrombus growth process within a rotary blood pump and investigate the optical properties of the thrombus. An in vitro thrombogenic test was conducted using fresh porcine blood and a specially designed hydrodynamically levitated centrifugal blood pump with a transparent bottom. The pump rotating at 3000 rpm circulated the blood at 1.0 L/min. The bottom surface of the pump was illuminated with white light pulsed at the same frequency as the pump rotation, and the backward-scattered light was imaged using the HSI system. Using stroboscopic HSI and an image construction algorithm, dynamic spectral imaging at wavelengths ranging from 608 to 752 nm within the rotating pump was achieved. After completing the experiment, we collected the red thrombus formed in the pump impeller and quantified the thrombus hemoglobin concentration (Hbthrombus ). The spectrum changed around the center of the impeller, and the area of change expanded toward the impeller flow path. The shape corresponded approximately to the shape of the thrombus. The spectrum change indicated that the light scattering derived from red blood cells decreased. The Hbthrombus was 4.7 ± 1.3 g/dL versus a total hemoglobin of 13 ± 0.87 g/dL. The study revealed that Hbthrombus was reduced by the surrounding blood flow. Copyright © 2015 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Mechanical circulatory support of a univentricular Fontan circulation with a continuous axial-flow pump in a piglet model.

PubMed

Wei, Xufeng; Sanchez, Pablo G; Liu, Yang; Li, Tieluo; Watkins, A Claire; Wu, Zhongjun J; Griffith, Bartley P

2015-01-01

Despite the significant contribution of the Fontan procedure to the therapy of complex congenital heart diseases, many patients progress to failure of their Fontan circulation. The use of ventricular assist devices to provide circulatory support to these patients remains challenging. In the current study, a continuous axial-flow pump was used to support a univentricular Fontan circulation. A modified Fontan circulation (atrio-pulmonary connection) was constructed in six Yorkshire piglets (8-14 kg). A Dacron conduit (12 mm) with two branches was constructed to serve as a complete atrio-pulmonary connection without the use of cardiopulmonary bypass. The Impella pump was inserted into the conduit through an additional Polytetrafluoroethylene (PTFE) graft in five animals. Hemodynamic data were collected for 6 hours under the supported Fontan circulation. The control animal died after initiating the Fontan circulation independent of resuscitation. Four pump supported animals remained hemodynamically stable for 6 hours with pump speeds between 18,000 rpm and 22,000 rpm (P1-P3). Oxygen saturation was maintained between 95% and 100%. Normal organ perfusion was illustrated by blood gas analysis and biochemical assays. A continuous axial-flow pump can be used for temporal circulatory support to the failing Fontan circulation as "bridge" to heart transplantation or recovery.

Computer controlled titration with piston burette or peristaltic pump - a comparison.

PubMed

Hoffmann, W

1996-09-01

The advantages and problems of the use of piston burettes and peristaltic pumps for dosage of titrant solutions in automatic titrations are shown. For comparison, only the dosing devices were exchanged and all other components and conditions remained unchanged. The results of continuous acid base titration show good agreement and comparable reproducibility. Potentiometric sensors (glass electrodes) with different equilibration behaviour influence the results. The capability of such electrodes was tested. Conductometric measurements allow a much faster detection because there is no equilibration of electrodes. Piston burettes should be used for titration with very high precision, titration with organic solvents and slow titrations. Peristaltic pumps seem to be more suitable for continuous titrations and long time operation without service.

An Integrated Microfabricated Chip with Double Functions as an Ion Source and Air Pump Based on LIGA Technology

PubMed Central

Li, Hua; Jiang, Linxiu; Guo, Chaoqun; Zhu, Jianmin; Jiang, Yongrong; Chen, Zhencheng

2017-01-01

The injection and ionization of volatile organic compounds (VOA) by an integrated chip is experimentally analyzed in this paper. The integrated chip consists of a needle-to-cylinder electrode mounting on the Polymethyl Methacrylate (PMMA) substrate. The needle-to-cylinder electrode is designed and fabricated by Lithographie, Galvanoformung and Abformung (LIGA) technology. In this paper, the needle is connected to a negative power supply of −5 kV and used as the cathode; the cylinder electrodes are composed of two arrays of cylinders and serve as the anode. The ionic wind is produced based on corona and glow discharges of needle-to-cylinder electrodes. The experimental setup is designed to observe the properties of the needle-to-cylinder discharge and prove its functions as an ion source and air pump. In summary, the main results are as follows: (1) the ionic wind velocity produced by the chip is about 0.79 m/s at an applied voltage of −3300 V; (2) acetic acid and ammonia water can be injected through the chip, which is proved by pH test paper; and (3) the current measured by a Faraday cup is about 10 pA for acetic acid and ammonia with an applied voltage of −3185 V. The integrated chip is promising for portable analytical instruments, such as ion mobility spectrometry (IMS), field asymmetric ion mobility spectrometry (FAIMS), and mass spectrometry (MS). PMID:28054980

An Integrated Microfabricated Chip with Double Functions as an Ion Source and Air Pump Based on LIGA Technology.

PubMed

Li, Hua; Jiang, Linxiu; Guo, Chaoqun; Zhu, Jianmin; Jiang, Yongrong; Chen, Zhencheng

2017-01-04

The injection and ionization of volatile organic compounds (VOA) by an integrated chip is experimentally analyzed in this paper. The integrated chip consists of a needle-to-cylinder electrode mounting on the Polymethyl Methacrylate (PMMA) substrate. The needle-to-cylinder electrode is designed and fabricated by Lithographie, Galvanoformung and Abformung (LIGA) technology. In this paper, the needle is connected to a negative power supply of -5 kV and used as the cathode; the cylinder electrodes are composed of two arrays of cylinders and serve as the anode. The ionic wind is produced based on corona and glow discharges of needle-to-cylinder electrodes. The experimental setup is designed to observe the properties of the needle-to-cylinder discharge and prove its functions as an ion source and air pump. In summary, the main results are as follows: (1) the ionic wind velocity produced by the chip is about 0.79 m/s at an applied voltage of -3300 V; (2) acetic acid and ammonia water can be injected through the chip, which is proved by pH test paper; and (3) the current measured by a Faraday cup is about 10 pA for acetic acid and ammonia with an applied voltage of -3185 V. The integrated chip is promising for portable analytical instruments, such as ion mobility spectrometry (IMS), field asymmetric ion mobility spectrometry (FAIMS), and mass spectrometry (MS).

Optical Silencing of C. elegans Cells with Arch Proton Pump

PubMed Central

Okazaki, Ayako; Sudo, Yuki; Takagi, Shin

2012-01-01

Background Optogenetic techniques using light-driven ion channels or ion pumps for controlling excitable cells have greatly facilitated the investigation of nervous systems in vivo. A model organism, C. elegans, with its small transparent body and well-characterized neural circuits, is especially suitable for optogenetic analyses. Methodology/Principal Findings We describe the application of archaerhodopsin-3 (Arch), a recently reported optical neuronal silencer, to C. elegans. Arch::GFP expressed either in all neurons or body wall muscles of the entire body by means of transgenes were localized, at least partially, to the cell membrane without adverse effects, and caused locomotory paralysis of worms when illuminated by green light (550 nm). Pan-neuronal expression of Arch endowed worms with quick and sustained responsiveness to such light. Worms reliably responded to repeated periods of illumination and non-illumination, and remained paralyzed under continuous illumination for 30 seconds. Worms expressing Arch in different subsets of motor neurons exhibited distinct defects in the locomotory behavior under green light: selective silencing of A-type motor neurons affected backward movement while silencing of B-type motor neurons affected forward movement more severely. Our experiments using a heat-shock-mediated induction system also indicate that Arch becomes fully functional only 12 hours after induction and remains functional for more than 24 hour. Conclusions/Sgnificance Arch can be used for silencing neurons and muscles, and may be a useful alternative to currently widely used halorhodopsin (NpHR) in optogenetic studies of C. elegans. PMID:22629299

Simulation and evaluation of latent heat thermal energy storage

NASA Technical Reports Server (NTRS)

Sigmon, T. W.

1980-01-01

The relative value of thermal energy storage (TES) for heat pump storage (heating and cooling) as a function of storage temperature, mode of storage (hotside or coldside), geographic locations, and utility time of use rate structures were derived. Computer models used to simulate the performance of a number of TES/heat pump configurations are described. The models are based on existing performance data of heat pump components, available building thermal load computational procedures, and generalized TES subsystem design. Life cycle costs computed for each site, configuration, and rate structure are discussed.

Well pump

DOEpatents

Ames, Kenneth R.; Doesburg, James M.

1987-01-01

A well pump includes a piston and an inlet and/or outlet valve assembly of special structure. Each is formed of a body of organic polymer, preferably PTFE. Each includes a cavity in its upper portion and at least one passage leading from the cavity to the bottom of the block. A screen covers each cavity and a valve disk covers each screen. Flexible sealing flanges extend upwardly and downwardly from the periphery of the piston block. The outlet valve block has a sliding block and sealing fit with the piston rod.

Sub-wavelength plasmon laser

DOEpatents

Bora, Mihail; Bond, Tiziana C.

2016-04-19

A plasmonic laser device has resonant nanocavities filled with a gain medium containing an organic dye. The resonant plasmon frequencies of the nanocavities are tuned to align with both the absorption and emission spectra of the dye. Variables in the system include the nature of the dye and the wavelength of its absorption and emission, the wavelength of the pumping radiation, and the resonance frequencies of the nanocavities. In addition the pumping frequency of the dye is selected to be close to the absorption maximum.

Design of a high-pressure circulating pump for viscous liquids.

PubMed

Seifried, Bernhard; Temelli, Feral

2009-07-01

The design of a reciprocating dual action piston pump capable of circulating viscous fluids at pressures of up to 34 MPa (5000 psi) and temperatures up to 80 degrees C is described. The piston of this pump is driven by a pair of solenoids energized alternatively by a 12 V direct current power supply controlled by an electronic controller facilitating continuously adjustable flow rates. The body of this seal-less pump is constructed using off-the-shelf parts eliminating the need for custom made parts. Both the electronic controller and the pump can be assembled relatively easily. Pump performance has been evaluated at room temperature (22 degrees C) and atmospheric pressure using liquids with low and moderately high viscosities, such as ethanol and corn oil, respectively. At ambient conditions, the pump delivered continuous flow of ethanol and corn oil at a flow rate of up to 170 and 17 cm3/min, respectively. For pumping viscous fluids comparable to corn oil, an optimum reciprocation frequency was ascertained to maximize flow rate. For low viscosity liquids such as ethanol, a linear relationship between the flow rate and reciprocation frequency was determined up to the maximum reciprocation frequency of the pump. Since its fabrication, the pump has been used in our laboratory for circulating triglycerides in contact with supercritical carbon dioxide at pressures of up to 25 MPa (3600 psi) and temperatures up to 70 degrees C on a daily basis for a total of more than 1500 h of operation functioning trouble free.

Impact of left ventricular assist device speed adjustment on exercise tolerance and markers of wall stress.

PubMed

Hayward, Christopher S; Salamonsen, Robert; Keogh, Anne M; Woodard, John; Ayre, Peter; Prichard, Roslyn; Kotlyar, Eugene; Macdonald, Peter S; Jansz, Paul; Spratt, Phillip

2015-09-01

Left ventricular assist devices are crucial in rehabilitation of patients with end-stage heart failure. Whether cardiopulmonary function is enhanced with higher pump output is unknown. 10 patients (aged 39±16 years, mean±SD) underwent monitored adjustment of pump speed to determine minimum safe low speed and maximum safe high speed at rest. Patients were then randomized to these speed settings and underwent three 6-minute walk tests (6MWT) and symptom-limited cardiopulmonary stress tests (CPX) on separate days. Pump speed settings (low, normal and high) resulted in significantly different resting pump flows of 4.43±0.6, 5.03±0.94, and 5.72±1.2 l/min (P<.001). There was a significant enhancement of pump flows (greater at higher speed settings) with exercise (P<0.05). Increased pump speed was associated with a trend to increased 6MWT distance (P=.10); and CPX exercise time (p=.27). Maximum workload achieved and peak oxygen consumption were significantly different comparing low to high pump speed settings only (P<.05). N-terminal-pro-B-type natriuretic peptide release was significantly reduced at higher pump speed with exercise (P<.01). We have found that alteration of pump speed setting resulted in significant variation in estimated pump flow. The high-speed setting was associated with lower natriuretic hormone release consistent with lower myocardial wall stress. This did not, however, improve exercise tolerance.

Diffusion sampler testing at Naval Air Station North Island, San Diego County, California, November 1999 to January 2000

USGS Publications Warehouse

Vroblesky, Don A.; Peters, Brian C.

2000-01-01

Volatile organic compound concentrations in water from diffusion samplers were compared to concentrations in water obtained by low-flow purging at 15 observation wells at the Naval Air Station North Island, San Diego, California. Multiple diffusion samplers were installed in the wells. In general, comparisons using bladder pumps and diffusion samplers showed similar volatile organic carbon concentrations. In some wells, sharp concentration gradients were observed, such as an increase in cis-1,2-dichloroethene concentration from 100 to 2,600 micrograms per liter over a vertical distance of only 3.4 feet. In areas where such sharp gradients were observed, concentrations in water obtained by low-flow sampling at times reflected an average concentration over the area of influence; however, concentrations obtained by using the diffusion sampler seemed to represent the immediate vicinity of the sampler. When peristaltic pumps were used to collect ground-water samples by low-flow purging, the volatile organic compound concentrations commonly were lower than concentrations obtained by using diffusion samplers. This difference may be due to loss of volatiles by degassing under negative pressures in the sampling lines induced while using the peristaltic pump, mixing in the well screen, or possible short-circuiting of water from an adjacent depth. Diffusion samplers placed in buckets of freephase jet fuel (JP-5) and Stoddard solvent from observation wells did not show evidence of structural integrity loss during the 2 months of equilibration, and volatile organic compounds detected in the free-phase fuel also were detected in the water from the diffusion samplers.

Vibrational dynamics of adsorbed molecules under conditions of photodesorption: pump-probe SFG spectra of CO/Pt(111).

PubMed

Fournier, Frédéric; Zheng, Wanquan; Carrez, Serge; Dubost, Henri; Bourguignon, Bernard

2004-09-08

Interaction of CO adsorbed on Pt(111) with electrons and phonons is studied experimentally by means of a pump-probe experiment where CO is probed by IR + visible sum frequency generation under a pump laser intensity that allows photodesorption. Vibrational spectra of CO internal stretch are obtained as a function of pump-probe delay. A two-temperature and anharmonic coupling model is used to extract from the spectra the real time variations of CO peak frequency and dephasing time. The main conclusions are the following: (i) The CO stretch is perturbed by two low-frequency modes, assigned to frustrated rotation and frustrated translation. (ii) The frustrated rotation is directly coupled to electrons photoexcited in Pt(111) by the pump laser. (iii) There is no evidence of Pt-CO stretch excitation in the spectra. The implications for the photodesorption dynamics are discussed. Copyright 2004 American Institute of Physics

Vibrational dynamics of adsorbed molecules under conditions of photodesorption: Pump-probe SFG spectra of CO/Pt(111)

NASA Astrophysics Data System (ADS)

Fournier, Frédéric; Zheng, Wanquan; Carrez, Serge; Dubost, Henri; Bourguignon, Bernard

2004-09-01

Interaction of CO adsorbed on Pt(111) with electrons and phonons is studied experimentally by means of a pump-probe experiment where CO is probed by IR+visible sum frequency generation under a pump laser intensity that allows photodesorption. Vibrational spectra of CO internal stretch are obtained as a function of pump-probe delay. A two-temperature and anharmonic coupling model is used to extract from the spectra the real time variations of CO peak frequency and dephasing time. The main conclusions are the following: (i) The CO stretch is perturbed by two low-frequency modes, assigned to frustrated rotation and frustrated translation. (ii) The frustrated rotation is directly coupled to electrons photoexcited in Pt(111) by the pump laser. (iii) There is no evidence of Pt-CO stretch excitation in the spectra. The implications for the photodesorption dynamics are discussed.

Amplified emission and lasing in a plasmonic nanolaser with many three-level molecules

NASA Astrophysics Data System (ADS)

Zhang, Yuan; Mølmer, Klaus

2018-01-01

Steady-state plasmonic lasing is studied theoretically for a system consisting of many dye molecules arranged regularly around a gold nanosphere. A three-level model with realistic molecular dissipation is employed to analyze the performance as a function of the pump field amplitude and number of molecules. Few molecules and moderate pumping produce a single narrow emission peak because the excited molecules transfer energy to a single dipole plasmon mode by amplified spontaneous emission. Under strong pumping, the single peak splits into broader and weaker emission peaks because two molecular excited levels interfere with each other through coherent coupling with the pump field and with the dipole plasmon field. A large number of molecules gives rise to a Poisson-like distribution of plasmon number states with a large mean number characteristic of lasing action. These characteristics of lasing, however, deteriorate under strong pumping because of the molecular interference effect.

Optimal groundwater remediation design of pump and treat systems via a simulation-optimization approach and firefly algorithm

NASA Astrophysics Data System (ADS)

Javad Kazemzadeh-Parsi, Mohammad; Daneshmand, Farhang; Ahmadfard, Mohammad Amin; Adamowski, Jan; Martel, Richard

2015-01-01

In the present study, an optimization approach based on the firefly algorithm (FA) is combined with a finite element simulation method (FEM) to determine the optimum design of pump and treat remediation systems. Three multi-objective functions in which pumping rate and clean-up time are design variables are considered and the proposed FA-FEM model is used to minimize operating costs, total pumping volumes and total pumping rates in three scenarios while meeting water quality requirements. The groundwater lift and contaminant concentration are also minimized through the optimization process. The obtained results show the applicability of the FA in conjunction with the FEM for the optimal design of groundwater remediation systems. The performance of the FA is also compared with the genetic algorithm (GA) and the FA is found to have a better convergence rate than the GA.

A simple bedside approach to therapeutic goals achievement during the management of deceased organ donors--An adapted version of the "VIP" approach.

PubMed

Westphal, Glauco Adrieno

2016-02-01

The disproportion between the supply and demand of transplant organs could be alleviated by improving the quality of clinical management of deceased potential donors. As a large number of donor losses by cardiac arrest occur due to hemodynamic instability, without instituting all essential maintenance measures, it is likely that the application of simplified potential donor maintenance protocols will help to decrease potential donor losses and increase the supply of organs for transplantation. The Ventilation, Infusion and Pumping (VIP) strategy is a mnemonic method that brings together key aspects of the restoration of oxygen delivery to tissues during hemodynamic instability: adequate mechanical Ventilation, volume Infusion and evaluation of heart Pump effectiveness. The inclusion of the additional initials, "P" and "S," refers to Pharmacological treatment and Specificities involved in the etiology of shock. The use of simplified care standards can assist in adhering to essential potential donor management measures. Therefore, using a simplified method as the adapted VIP approach can contribute to improving management standards of potential organ donors and increasing the supply of organs for transplantation. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Dissolved Organic Carbon Mobilisation in a Groundwater System Stressed by Pumping

PubMed Central

Graham, P. W.; Baker, A.; Andersen, M. S.

2015-01-01

The concentration and flux of organic carbon in aquifers is influenced by recharge and abstraction, and surface and subsurface processing. In this study groundwater was abstracted from a shallow fractured rock aquifer and dissolved organic carbon (DOC) was measured in observation bores at different distances from the abstraction bore. Groundwater abstraction at rates exceeding the aquifers yield resulted in increased DOC concentration up to 3,500 percent of initial concentrations. Potential sources of this increased DOC were determined using optical fluorescence and absorbance analysis. Groundwater fluorescent dissolved organic material (FDOM) were found to be a combination of terrestrial-derived humic material and microbial or protein sourced material. Relative molecular weight of FDOM within four metres of the abstraction well increased during the experiment, while the relative molecular weight of FDOM between four and ten metres from the abstraction well decreased. When the aquifer is not being pumped, DOC mobilisation in the aquifer is low. We hypothesise that the physical shear stress on aquifer materials caused by intense abstraction significantly increases the temporary release of DOC from sloughing of biofilms and release of otherwise bound colloidal and sedimentary organic carbon (SOC). PMID:26691238

Development of an Advanced Respirometer for Experimental Studies of Benthic Rate Processes

NASA Astrophysics Data System (ADS)

Barry, J. P.; Buck, K. R.; Okuda, C.; Risi, M.; Parker, M.; Levesque, C.

2005-05-01

Rates of carbon remineralization and nutrient cycling by seafloor biotic assemblages are influenced by the availability of organic material, temperature, and oxygen availability, among other factors. The relative importance of various factors in controlling carbon cycling by the sediment community is poorly constrained, in part by technological limits on experiments that evaluate independently the effects of these factors. We have developed an advanced respiration chamber system capable of repeated rate measurements during a single deployment, with added capabilities for manipulating conditions within replicate chambers to test hypotheses concerning biogeochemical cycling by the benthos. The ROV-deployed respiration system has 12 syringes for tracer injection or sample withdrawal from 3 respiration chambers, pH, oxygen, and temperature sensors, stirring paddles, and a recirculation pump. The pump system is used to flush each chamber at preprogrammed intervals or oxygen tensions. Areas of investigation that are enabled by the system include the effects various factors on benthic oxygen consumptions (e.g. hypercapnia (elevated CO2), acidosis, ambient oxygen availability, temperature, organic carbon availability), rates of nutrient regeneration by the benthos in response to organic enrichments (labile and refractory organic carbon), time lags in carbon uptake and trophic pathways in responses to organic enrichment.

Feasibility of the optical imaging of thrombus formation in a rotary blood pump by near-infrared light.

PubMed

Sakota, Daisuke; Murashige, Tomotaka; Kosaka, Ryo; Nishida, Masahiro; Maruyama, Osamu

2014-09-01

Blood coagulation is one of the primary concerns when using mechanical circulatory support devices such as blood pumps. Noninvasive detection and imaging of thrombus formation is useful not only for the development of more hemocompatible devices but also for the management of blood coagulation to avoid risk of infarction. The objective of this study is to investigate the use of near-infrared light for imaging of thrombus formation in a rotary blood pump. The optical properties of a thrombus at wavelengths ranging from 600 to 750 nm were analyzed using a hyperspectral imaging (HSI) system. A specially designed hydrodynamically levitated centrifugal blood pump with a visible bottom area was used. In vitro antithrombogenic testing was conducted five times with the pump using bovine whole blood in which the activated blood clotting time was adjusted to 200 s prior to the experiment. Two halogen lights were used for the light sources. The forward scattering through the pump and backward scattering on the pump bottom area were imaged using the HSI system. HSI showed an increase in forward scattering at wavelengths ranging from 670 to 750 nm in the location of thrombus formation. The time at which the thrombus began to form in the impeller rotating at 2780 rpm could be detected. The spectral difference between the whole blood and the thrombus was utilized to image thrombus formation. The results indicate the feasibility of dynamically detecting and imaging thrombus formation in a rotary blood pump. Copyright © 2014 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Pseudo-malfunction of the Coloplast Titan Inflatable Penile Prosthesis One-Touch Release Pump.

PubMed

Garber, Bruce B; Khurgin, Jacob L; Stember, Doron S; Perito, Paul E

2014-10-01

To define and describe a type of pseudo-malfunction of the Coloplast Titan Inflatable Penile Prosthesis (IPP) One-Touch Release (OTR) pump (Coloplast Corp, Minneapolis, MN). We retrospectively reviewed a consecutive series of 550 patients with refractory organic erectile dysfunction who were implanted with a Coloplast Titan IPP with the OTR pump during a period of approximately 4 years. All patients were implanted using standard techniques through an infrapubic or penoscrotal approach. Twenty-nine patients (5.3%) complained that their IPP would not inflate and that the pump bulb felt "hard." Examination revealed that their IPP was working normally; however, the inflate/deflate valve disc had become stuck in the deflate position. Very firm pressure had to be applied to the pump bulb to move the valve disc into the inflate position. Once this was accomplished, the device inflated and deflated normally. Another 14 patients (2.5%) reported this phenomenon to us but were able to apply enough pressure on the pump bulb to rectify it. The inflate/deflate valve disc in the Coloplast Titan OTR pump can occasionally become stuck in the deflate position (7.8% of patients in our experience). Patients may be unable to inflate the device and return for evaluation. In all cases we have encountered, firm pressure on the pump bulb caused the valve to shift into the inflate position, and the device worked properly thereafter. Patients and implanting urologists should be aware of this issue and of the way in which it can be rectified. Copyright © 2014 Elsevier Inc. All rights reserved.

Evaluating an approach to improving the adoption rate of wireless drug library updates for smart pumps.

PubMed

Poppe, Lindsey B; Eckel, Stephen F

2011-01-15

An academic medical center's approach to improving the adoption rate of wireless drug library updates for smart pumps was evaluated. A multidisciplinary team composed of pharmacy, nursing, medical engineering, materials management, and patient equipment personnel at an academic medical center collaborated to update the drug libraries of more than 1800 smart pumps via a wireless control system. Two pilot tests were completed to identify and resolve issues before the live wireless update was attempted. The second pilot test, a passive approach, produced an adoption rate of 42% of 1804 pumps at the end of one week and a rate of 56% on day 10. The goal of 80% was not achieved until day 22. The change to an active multidisciplinary process three months later produced an adoption rate of 80% for 1869 pumps on day 10, resulting in a 45.4% increase in the adoption rate between the two trials on day 10 (p < 0.001). Communication regarding the updates was disseminated via e-mail to the entire organization, with fliers posted on all patient care units, and verbally during staff meetings. Patient equipment personnel manually tagged each pump with a blue zip tie after verifying the update to easily identify which pumps had been updated. Areas for improvement include increasing communication to the staff detailing when the update will occur and changing the day of the week the update is performed. A multidisciplinary team actively engaged in the updating of wireless i.v. smart pump drug libraries reduced the amount of time required to reach a goal adoption rate of 80%.

In vivo experimental testing of a microaxial blood pump for right ventricular support.

PubMed

Christiansen, Stefan; Perez-Bouza, Alberto; Reul, Helmut; Autschbach, Rüdiger

2006-02-01

The incidence of isolated right ventricular (RV) failure is rare in postcardiotomy patients, but high in patients undergoing implantation of a left ventricular assist device or cardiac transplantation. Therefore, we have developed a new microaxial flow device and report on our first in vivo animal trials. Six healthy adult female sheep weighing 80-90 kg underwent implantation of the microaxial blood pump for partial unloading of the right ventricle. This pump is a miniaturized rotary blood pump with a diameter of only 6.4 mm and a weight of 11 g. The inner volume of the pump is limited to 12 mL, and the inner artificial blood contacting surface is 65 cm(2). The pump consists of a rotor driven by an incorporated brushless direct current motor, the housing of the rotor, the inflow cage, the outflow cannula, and the driveline. At the maximum speed of 32,500 rotations/min, a flow of 6 L/min can be delivered. The inflow and outflow conduit were anastomosed to the right atrium and the main pulmonary artery, respectively. Hemodynamic and echocardiographic data as well as blood samples were measured over the whole test period of 7 days. The hearts and lungs as well as the pump were explanted for a thorough examination at the end of the trial. Systemic arterial blood pressures remained unchanged during the entire test period. RV cardiac output was diminished significantly as demonstrated by the echocardiographic studies. The number of platelets decreased perioperatively, but recovered within the test period. The free hemoglobin was not enhanced postoperatively indicating no significant hemolysis. Liver function was only slightly impaired due to operative reasons (increase in bilirubin on the first postoperative day but normalization within the test period). The pathologic examination revealed some clots at the inflow cage and fibrin depositions on the impeller as well as on the inner surface of the outflow graft without an impairment of pump function. Our results demonstrate that this newly developed microaxial blood pump is a promising device for RV support, but it cannot be driven without any anticoagulation.

Generic Safety Requirements for Developing Safe Insulin Pump Software

PubMed Central

Zhang, Yi; Jetley, Raoul; Jones, Paul L; Ray, Arnab

2011-01-01

Background The authors previously introduced a highly abstract generic insulin infusion pump (GIIP) model that identified common features and hazards shared by most insulin pumps on the market. The aim of this article is to extend our previous work on the GIIP model by articulating safety requirements that address the identified GIIP hazards. These safety requirements can be validated by manufacturers, and may ultimately serve as a safety reference for insulin pump software. Together, these two publications can serve as a basis for discussing insulin pump safety in the diabetes community. Methods In our previous work, we established a generic insulin pump architecture that abstracts functions common to many insulin pumps currently on the market and near-future pump designs. We then carried out a preliminary hazard analysis based on this architecture that included consultations with many domain experts. Further consultation with domain experts resulted in the safety requirements used in the modeling work presented in this article. Results Generic safety requirements for the GIIP model are presented, as appropriate, in parameterized format to accommodate clinical practices or specific insulin pump criteria important to safe device performance. Conclusions We believe that there is considerable value in having the diabetes, academic, and manufacturing communities consider and discuss these generic safety requirements. We hope that the communities will extend and revise them, make them more representative and comprehensive, experiment with them, and use them as a means for assessing the safety of insulin pump software designs. One potential use of these requirements is to integrate them into model-based engineering (MBE) software development methods. We believe, based on our experiences, that implementing safety requirements using MBE methods holds promise in reducing design/implementation flaws in insulin pump development and evolutionary processes, therefore improving overall safety of insulin pump software. PMID:22226258

Quantum charge pumping through resonant crossed Andreev reflection in a superconducting hybrid junction of silicene

NASA Astrophysics Data System (ADS)

Paul, Ganesh C.; Saha, Arijit

2017-01-01

We theoretically investigate the phenomena of adiabatic quantum charge pumping through a normal-insulator-superconductor-insulator-normal (NISIN) setup of silicene within the scattering matrix formalism. Assuming a thin barrier limit, we consider the strength of the two barriers (χ1 and χ2) as the two pumping parameters in the adiabatic regime. Within this geometry, we obtain crossed Andreev reflection (CAR) with probability unity in the χ1-χ2 plane without concomitant transmission or elastic co-tunneling. Tunability of the band gap at the Dirac point by applying an external electric field perpendicular to the silicene sheet and variation of the chemical potential at the normal silicene region, open up the possibility of achieving either a perfect CAR or transmission process through our setup. This resonant behavior is periodic with the barrier strengths. We analyze the behavior of the pumped charge through the NISIN structure as a function of the pumping strength and angles of the incident electrons. We show that large (Q ˜2 e ) pumped charge can be obtained through our geometry when the pumping contour encloses either the CAR or transmission resonance in the pumping parameter space. We discuss possible experimental feasibility of our theoretical predictions.

Hydro pumped storage, international experience: An overview of ASCE task committee report

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

Makarechian, A.H.; Rummel, G.

1995-12-31

This paper presents an overview of a report that is being prepared by ASCE Task Committee on Pumped Storage, International Experience. The reader is referred to the committee report that will be available in 1996. Many pumped storage projects in Europe, but particularly in Japan are becoming an indispensable resource in management of loads and resources on the electrical system. They serve to enhance reliability of the system and to provide for efficient utilization of thermal resources. Pumped storage is increasingly being used as a system management tool. To serve such purposes and to function in this key role, pumpedmore » storage projects are designed for very fast loading and unloading, for very fast mode reversals from pumping to generating and visa versa, for synchronous generation, and more importantly for load ramping during the pumping mode. This is achieved by use of variable-speed pump turbine units. The use of variable-speed units has proven so successful in Japan that many older projects are retrofitted with this new feature. Other interesting equipment applications are discussed including utilization of multi-stage unregulated pump turbines for very high heads (up to 1,250 m), and continued extension of the experience for high head reversible Francis unit, currently in excess of 750 m.« less

Embryogenic competence acquisition in sugarcane callus is associated with differential H+ pump abundance and activity.

PubMed

Passamani, Lucas Z; Bertolazi, Amanda A; Ramos, Alessandro C; Santa-Catarina, Claudete; Thelen, Jay J; Silveira, Vanildo

2018-06-22

Somatic embryogenesis is an important biological process in several plant species, including sugarcane. Proteomics approaches have shown that H + pumps are differentially regulated during somatic embryogenesis; however, the relationship between H + flux and embryogenic competence is still unclear. This work aimed to elucidate the association between extracellular H + flux and somatic embryo maturation in sugarcane. We performed a microsomal proteomics analysis and analyzed changes in extracellular H + flux and H + pump (P-H + -ATPase, V-H + -ATPase and H + -PPase) activity in embryogenic and non-embryogenic callus. A total of 657 proteins were identified, 16 of which were H + pumps. We observed that P-H + -ATPase and H + -PPase were more abundant in embryogenic callus. Compared with non-embryogenic callus, embryogenic callus showed higher H + influx, especially on maturation day 14, as well as higher H+ pump activity (mainly P-H+-ATPase and H+-PPase activity). H+-PPase appears to be the major H + pump in embryogenic callus during somatic embryo formation, functioning in both vacuole acidification and PPi homeostasis. These results provide evidence for an association between higher H + pump protein abundance and, consequently, higher H + flux and embryogenic competence acquisition in the callus of sugarcane, allowing for optimization of the somatic embryo conversion process by modulating the activities of these H + pumps.

Metal-Organic Frameworks in Adsorption-Driven Heat Pumps: The Potential of Alcohols as Working Fluids.

PubMed

de Lange, Martijn F; van Velzen, Benjamin L; Ottevanger, Coen P; Verouden, Karlijn J F M; Lin, Li-Chiang; Vlugt, Thijs J H; Gascon, Jorge; Kapteijn, Freek

2015-11-24

A large fraction of global energy is consumed for heating and cooling. Adsorption-driven heat pumps and chillers could be employed to reduce this consumption. MOFs are often considered to be ideal adsorbents for heat pumps and chillers. While most published works to date on this topic have focused on the use of water as a working fluid, the instability of many MOFs to water and the fact that water cannot be used at subzero temperatures pose certain drawbacks. The potential of using alcohol-MOF pairs in adsorption-driven heat pumps and chillers is investigated. To this end, 18 different selected MOF structures in combination with either methanol or ethanol as a working fluid are considered, and their potential is assessed on the basis of adsorption measurements and thermodynamic efficiencies. If alcohols are used instead of water, then (1) adsorption occurs at lower relative pressures for methanol and even lower pressure for ethanol, (2) larger pores can be utilized efficiently, as hysteresis is absent for pores smaller than 3.4 nm (2 nm for water), (3) larger pore sizes need to be employed to ensure the desired stepwise adsorption, (4) the effect of (polar/apolar) functional groups in the MOF is far less pronounced, (5) the energy released or taken up per cycle is lower, but heat and mass transfer may be enhanced, (6) stability of MOFs seems to be less of an issue, and (7) cryogenic applications (e.g., ice making) become feasible. From a thermodynamic perspective, UiO-67, CAU-3, and ZIF-8 seem to be the most promising MOFs for both methanol and ethanol as working fluids. Although UiO-67 might not be completely stable, both CAU-3 and ZIF-8 have the potential to be applied, especially in subzero-temperature adsorption chillers (AC).

Tunable light source for use in photoacoustic spectrometers

DOEpatents

Bisson, Scott E.; Kulp, Thomas J.; Armstrong, Karla M.

2005-12-13

The present invention provides a photoacoustic spectrometer that is field portable and capable of speciating complex organic molecules in the gas phase. The spectrometer has a tunable light source that has the ability to resolve the fine structure of these molecules over a large wavelength range. The inventive light source includes an optical parametric oscillator (OPO) having combined fine and coarse tuning. By pumping the OPO with the output from a doped-fiber optical amplifier pumped by a diode seed laser, the inventive spectrometer is able to speciate mixtures having parts per billion of organic compounds, with a light source that has a high efficiency and small size, allowing for portability. In an alternative embodiment, the spectrometer is scanned by controlling the laser wavelength, thus resulting in an even more compact and efficient design.

Highly nonlinear organic crystal OHQ-T for efficient ultra-broadband terahertz wave generation beyond 10 THz.

PubMed

Kang, Bong Joo; Baek, In Hyung; Lee, Seung-Heon; Kim, Won Tae; Lee, Seung-Jun; Jeong, Young Uk; Kwon, O-Pil; Rotermund, Fabian

2016-05-16

We report on efficient generation of ultra-broadband terahertz (THz) waves via optical rectification in a novel nonlinear organic crystal with acentric core structure, i.e. 2-(4-hydroxystyryl)-1-methylquinolinium 4-methylbenzenesulfonate (OHQ-T), which possesses an ideal molecular structure leading to a maximized nonlinear optical response for near-infrared-pumped THz wave generation. By systematic studies on wavelength-dependent phase-matching conditions in OHQ-T crystals of different thicknesses we are able to generate coherent THz waves with a high peak-to-peak electric field amplitude of up to 650 kV/cm and an upper cut-off frequency beyond 10 THz. High optical-to-THz conversion efficiency of 0.31% is achieved by efficient index matching with a selective pumping at 1300 nm.

Artificial Organs 2015: A Year in Review.

PubMed

Malchesky, Paul S

2016-03-01

In this Editor's Review, articles published in 2015 are organized by category and briefly summarized. We aim to provide a brief reflection of the currently available worldwide knowledge that is intended to advance and better human life while providing insight for continued application of technologies and methods of organ Replacement, Recovery, and Regeneration. As the official journal of The International Federation for Artificial Organs, The International Faculty for Artificial Organs, the International Society for Rotary Blood Pumps, the International Society for Pediatric Mechanical Cardiopulmonary Support, and the Vienna International Workshop on Functional Electrical Stimulation, Artificial Organs continues in the original mission of its founders "to foster communications in the field of artificial organs on an international level." Artificial Organs continues to publish developments and clinical applications of artificial organ technologies in this broad and expanding field of organ Replacement, Recovery, and Regeneration from all over the world. We take this time also to express our gratitude to our authors for providing their work to this journal. We offer our very special thanks to our reviewers who give so generously of their time and expertise to review, critique, and especially provide meaningful suggestions to the author's work whether eventually accepted or rejected. Without these excellent and dedicated reviewers, the quality expected from such a journal could not be possible. We also express our special thanks to our Publisher, John Wiley & Sons for their expert attention and support in the production and marketing of Artificial Organs. We look forward to reporting further advances in the coming years. Copyright © 2016 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Artificial organs 2014: a year in review.

PubMed

Malchesky, Paul S

2015-03-01

In this Editor's Review, articles published in 2014 are organized by category and briefly summarized. We aim to provide a brief reflection of the currently available worldwide knowledge that is intended to advance and better human life while providing insight for continued application of technologies and methods of organ Replacement, Recovery, and Regeneration. As the official journal of the International Federation for Artificial Organs, the International Faculty for Artificial Organs, the International Society for Rotary Blood Pumps, the International Society for Pediatric Mechanical Cardiopulmonary Support, and the Vienna International Workshop on Functional Electrical Stimulation, Artificial Organs continues in the original mission of its founders "to foster communications in the field of artificial organs on an international level." Artificial Organs continues to publish developments and clinical applications of artificial organ technologies in this broad and expanding field of organ Replacement, Recovery, and Regeneration from all over the world. We take this time also to express our gratitude to our authors for offering their work to this journal. We offer our very special thanks to our reviewers who give so generously of time and expertise to review, critique, and especially provide meaningful suggestions to the author's work whether eventually accepted or rejected. Without these excellent and dedicated reviewers, the quality expected from such a journal could not be possible. We also express our special thanks to our Publisher, John Wiley & Sons, for their expert attention and support in the production and marketing of Artificial Organs. We look forward to reporting further advances in the coming years. Copyright © 2015 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

H+/K+-ATPase-Inhibition Causes Left-Right Aortic Arch Inversion in Mouse Development.

PubMed

Miyachi, Yukihisa

2017-09-01

An organ known as a "node" forms during embryogenesis and plays a vital role in determining laterality in vertebrates. However, according to some reports in vertebrates, left-right patterning may be determined long before the node has developed. In this study, we analyzed left-right asymmetry formation in mammals based on ion-signaling factors, which has never been attempted before. First, a proton pump inhibitor was injected into pregnant mice to investigate whether H + /K + -ATPase is involved in the differentiation of pharyngeal arch arteries during embryonic development. Injection of 30 mg/kg of lansoprazole early in the organogenesis period increased the penetrance of right aortic arch formation by 34% compared to a saline injection. Furthermore, administration of a proton pump inhibitor resulted in strong expression of PI3K/phosphor-AKT, which led to potent inhibition of apoptosis induction factors such as BAD. This could relate to why the right pharyngeal arch arteries, which should have disappeared during differentiation, remained intact. The other important point is that proton pump inhibitors suppressed calcineurin signaling, and Wnt5a expression was significantly higher than in the controls. This research is particularly notable for demonstrating that administration of an H + /K + -ATPase inhibitor could cause dextroposition of the fetal vasculature. Moreover, since previous publications have reported that H + /K + -ATPase plays a role in asymmetry in other species, this article adds important information for developmental biology in that the role of H + /K + -ATPase in asymmetry is conserved in the mouse model, suggesting that rodents are not unique and that a common mechanism may function across vertebrates.

Properties of excited states in organic light emitting diodes and lasers

NASA Astrophysics Data System (ADS)

Giebink, Noel C.

The field of organic semiconductors has grown rapidly over the past decade with the development of light emitting diodes, solar cells, and lasers that promise a new generation of low-cost, flexible optoelectronic devices. In each case, the behavior of molecular excited states, or excitons, is of fundamental importance. The present study explores the nature and interactions of such excited states in the attempt to develop an electrically pumped organic semiconductor laser, and to improve the performance and operational stability of organic light emitting diodes. We begin by investigating intrinsic loss processes in optically pumped organic semiconductor lasers and demonstrate that exciton annihilation implies a fundamental limit that will prevent lasing by electrical injection in currently known materials. Searching for an alternative approach to reach threshold leads us to study metastable geminate charge pairs, where we find that optically generated excitons can be accumulated over time in an external electric field via these intermediate states. Upon field turn-off, the excitons are immediately restored, leading to a sudden burst of excitation density over 30 times higher than that generated by the pump alone. Unfortunately, we identify limitations that have thus far prevented reaching laser threshold with this technique. In a parallel push toward high power density, we investigate the origins of quantum efficiency roll-off in organic light emitting diodes (OLEDs) and find that it is dominated by loss of charge balance in the majority of fluorescent and phosphorescent devices. The second major theme of this work involves understanding the intrinsic modes of OLED operational degradation. Based on extensive modeling and supported directly by experimental evidence, we identify exciton-charge carrier annihilation reactions as a principle degradation pathway. Exploiting the diffusion of triplet excitons, we show that fluorescence and phosphorescence can be combined to increase the operational lifetime of white OLEDs and still retain the potential for unity internal quantum efficiency.

Multimorbidities and Overprescription of Proton Pump Inhibitors in Older Patients

PubMed Central

Delcher, Anne; Hily, Sylvie; Boureau, Anne Sophie; Chapelet, Guillaume; Berrut, Gilles; de Decker, Laure

2015-01-01

Objectives To determine whether there is an association between overprescription of proton pump inhibitors (PPIs) and multimorbidities in older patients. Design Multicenter prospective study. Setting Acute geriatric medicine at the University Hospital of Nantes and the Hospital of Saint-Nazaire. Participants Older patients aged 75 and over hospitalized in acute geriatric medicine. Measurements Older patients in acute geriatric medicine who received proton pump inhibitors. Variables studied were individual multimorbidities, the burden of multimorbidity evaluated by the Cumulative Illness Rating Scale, age, sex, type of residence (living in nursing home or not), functional abilities (Lawton and Katz scales), nutritional status (Body Mass Index), and the type of concomitant medications (antiaggregant, corticosteroids’, or anticoagulants). Results Overprescription of proton pump inhibitors was found in 73.9% older patients. In the full model, cardiac diseases (odds ratio [OR] = 4.17, p = 0.010), metabolic diseases (OR = 2.14, p = 0.042) and corticosteroids (OR = 5.39, p = 0.028) were significantly associated with overprescription of proton pump inhibitors. Esogastric diseases (OR = 0.49, p = 0.033) were negatively associated with overprescription of proton pump inhibitors. Conclusion Cardiac diseases and metabolic diseases were significantly associated with overprescription of proton pump inhibitors. PMID:26535585

Adiabatic quantum pump in a zigzag graphene nanoribbon junction

NASA Astrophysics Data System (ADS)

Zhang, Lin

2015-11-01

The adiabatic electron transport is theoretically studied in a zigzag graphene nanoribbon (ZGNR) junction with two time-dependent pumping electric fields. By modeling a ZGNR p-n junction and applying the Keldysh Green’s function method, we find that a pumped charge current is flowing in the device at a zero external bias, which mainly comes from the photon-assisted tunneling process and the valley selection rule in an even-chain ZGNR junction. The pumped charge current and its ON and OFF states can be efficiently modulated by changing the system parameters such as the pumping frequency, the pumping phase difference, and the Fermi level. A ferromagnetic ZGNR device is also studied to generate a pure spin current and a fully polarized spin current due to the combined spin pump effect and the valley valve effect. Our finding might pave the way to manipulate the degree of freedom of electrons in a graphene-based electronic device. Project supported by the National Natural Science Foundation of China (Grant No. 110704033), the Natural Science Foundation of Jiangsu Province, China (Grant No. BK2010416), and the Natural Science Foundation for Colleges and Universities in Jiangsu Province, China (Grant No. 13KJB140005).

Postprandial lymphatic pump function after a high-fat meal: a characterization of contractility, flow, and viscosity

PubMed Central

Kassis, Timothy; Yarlagadda, Sri Charan; Kohan, Alison B.; Tso, Patrick; Breedveld, Victor

2016-01-01

Dietary lipids are transported from the intestine through contractile lymphatics. Chronic lipid loads can adversely affect lymphatic function. However, the acute lymphatic pump response in the mesentery to a postprandial lipid meal has gone unexplored. In this study, we used the rat mesenteric collecting vessel as an in vivo model to quantify the effect of lipoproteins on vessel function. Lipid load was continuously monitored by using the intensity of a fluorescent fatty-acid analog, which we infused along with a fat emulsion through a duodenal cannula. The vessel contractility was simultaneously quantified. We demonstrated for the first time that collecting lymphatic vessels respond to an acute lipid load by reducing pump function. High lipid levels decreased contraction frequency and amplitude. We also showed a strong tonic response through a reduction in the end-diastolic and systolic diameters. We further characterized the changes in flow rate and viscosity and showed that both increase postprandially. In addition, shear-mediated Ca2+ signaling in lymphatic endothelial cells differed when cultured with lipoproteins. Together these results show that the in vivo response could be both shear and lipid mediated and provide the first evidence that high postprandial lipid has an immediate negative effect on lymphatic function even in the acute setting. PMID:26968208

Combining computer modelling and cardiac imaging to understand right ventricular pump function.

PubMed

Walmsley, John; van Everdingen, Wouter; Cramer, Maarten J; Prinzen, Frits W; Delhaas, Tammo; Lumens, Joost

2017-10-01

Right ventricular (RV) dysfunction is a strong predictor of outcome in heart failure and is a key determinant of exercise capacity. Despite these crucial findings, the RV remains understudied in the clinical, experimental, and computer modelling literature. This review outlines how recent advances in using computer modelling and cardiac imaging synergistically help to understand RV function in health and disease. We begin by highlighting the complexity of interactions that make modelling the RV both challenging and necessary, and then summarize the multiscale modelling approaches used to date to simulate RV pump function in the context of these interactions. We go on to demonstrate how these modelling approaches in combination with cardiac imaging have improved understanding of RV pump function in pulmonary arterial hypertension, arrhythmogenic right ventricular cardiomyopathy, dyssynchronous heart failure and cardiac resynchronization therapy, hypoplastic left heart syndrome, and repaired tetralogy of Fallot. We conclude with a perspective on key issues to be addressed by computational models of the RV in the near future. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions, please email: journals.permissions@oup.com.

Extracorporeal gas exchange with the DeltaStream rotary blood pump in experimental lung injury.

PubMed

Dembinski, Rolf; Kopp, Rüdger; Henzler, Dietrich; Hochhausen, Nadine; Oslender, Nicole; Max, Martin; Rossaint, Rolf; Kuhlen, Ralf

2003-06-01

In most severe cases of the acute respiratory distress syndrome, veno-venous extracorporeal membrane oxygenation (ECMO) can be used to facilitate gas exchange. However, the clinical use is limited due to the size and the concomitant risk of severe adverse events of conventionally-used centrifugal blood pumps with high extracorporeal blood volumes. The DeltaStream blood pump is a small-sized rotary blood pump that may reduce extracorporeal blood volume, foreign surfaces, contact activation of the coagulation system, and blood trauma. The aim of the present study was to test the safety and efficacy of the DeltaStream pump for ECMO in animals with normal lung function and experimental acute lung injury (ALI). Therefore, veno-venous ECMO was performed for 6 hours in mechanically ventilated pigs with normal lung function (n=6) and with ALI induced by repeated lung lavage (n=6) with a blood flow of 30% of the cardiac output. Gas flow with a FiO2 of 1.0 was set to equal blood flow. With a mean activated clotting time of 121 +/- 22 s, no circulatory impairment or thrombus formation was revealed during ECMO. Furthermore, free plasma Hb did not increase. In controls, hemodynamics and gas exchange remained unchanged. In animals with ALI, hemodynamics remained stable and gas transfer across the extracorporeal oxygenators was optimal, but only in 2 animals was a marked increase in PaO2 observed. CO2 removal was efficacious in all animals. We concluded that the DeltaStream blood pump may be used for veno-venous ECMO without major blood damage or hemodynamic impairment.

Solid State Mobile Lidar for Ozone Atmospheric Profiling

NASA Technical Reports Server (NTRS)

De Young, Russell; Carrion, William; Pliutau, Denis; Ganoe, Rene

2014-01-01

A tunable Ce:LiCAF laser is pumped by a CLBO crystal pumped by a doubled Nd:YLF laser running at 1 kilohertz. The UV tunable Ce:LiCAF laser produces two UV pulses between 280 to 295 nanometers. These pulses are transmitted into the atmosphere to profile the concentration of ozone as a function of altitude.

Radiolabeled Microsphere Technique in Conscious Subjects during Acceleration Exposures on the USAFSAM Centrifuge.

DTIC Science & Technology

1980-03-01

function even though the pump is pumping air into the blood manifold. R-2 is secured to the plate with two thumb screws, and when the syringes are...the scapula . The animals were allowed 2-4 weeks of surgical recovery before the acceleration studies were performed. Experimental Protocol--On the day

Activity-Dependent Excitability Changes Suggest Na[superscript +]/K[superscript +] Pump Dysfunction in Diabetic Neuropathy

ERIC Educational Resources Information Center

Krishnan, Arun V.; Lin, Cindy S.-Y.; Kiernan, Matthew C.

2008-01-01

The present study was undertaken to evaluate the role of Na[superscript +]/K[superscript +] pump dysfunction in the development of diabetic neuropathy (DN). Nerve excitability techniques, which provide information about membrane potential and axonal ion channel function, were undertaken in 15 patients with established DN and in 10 patients with…

Phase 0 and phase III transport in various organs: combined concept of phases in xenobiotic transport and metabolism.

PubMed

Döring, Barbara; Petzinger, Ernst

2014-08-01

The historical phasing concept of drug metabolism and elimination was introduced to comprise the two phases of metabolism: phase I metabolism for oxidations, reductions and hydrolyses, and phase II metabolism for synthesis. With this concept, biological membrane barriers obstructing the accessibility of metabolism sites in the cells for drugs were not considered. The concept of two phases was extended to a concept of four phases when drug transporters were detected that guided drugs and drug metabolites in and out of the cells. In particular, water soluble or charged drugs are virtually not able to overcome the phospholipid membrane barrier. Drug transporters belong to two main clusters of transporter families: the solute carrier (SLC) families and the ATP binding cassette (ABC) carriers. The ABC transporters comprise seven families with about 20 carriers involved in drug transport. All of them operate as pumps at the expense of ATP splitting. Embedded in the former phase concept, the term "phase III" was introduced by Ishikawa in 1992 for drug export by ABC efflux pumps. SLC comprise 52 families, from which many carriers are drug uptake transporters. Later on, this uptake process was referred to as the "phase 0 transport" of drugs. Transporters for xenobiotics in man and animal are most expressed in liver, but they are also present in extra-hepatic tissues such as in the kidney, the adrenal gland and lung. This review deals with the function of drug carriers in various organs and their impact on drug metabolism and elimination.

Potential Danger of Pre-Pump Clamping on Negative Pressure-Associated Gaseous Microemboli Generation During Extracorporeal Life Support--An In Vitro Study.

PubMed

Wang, Shigang; Chin, Brian J; Gentile, Frank; Kunselman, Allen R; Palanzo, David; Ündar, Akif

2016-01-01

The objectives of this study were to investigate the relationship between revolution speed of a conventional centrifugal pump and negative pressure at the inlet of the pump by clamping the tubing upstream of the pump, and to verify whether negative pressure leads to gaseous microemboli (GME) production in a simulated adult extracorporeal life support (ECLS) system. The experimental circuit, including a Maquet Rotaflow centrifugal pump and a Medos Hilite 7000 LT polymethyl-pentene membrane oxygenator, was primed with packed red blood cells (hematocrit 35%). Negative pressure was created in the circuit by clamping the tubing upstream of the pump for 10 s, and then releasing the clamp. An emboli detection and classification quantifier was used to record GME volume and count at pre-oxygenator and post-oxygenator sites, and pressure and flow rate data were collected using a custom-based data acquisition system. All trials were conducted at 36°C at revolution speeds of 2000-4000 rpm (500 rpm increment). The flow rates were 1092.5-4708.4 mL/min at the revolution speeds of 2000-4000 rpm. Higher revolution speed generated higher negative pressure at the pre-pump site when clamping the tubing upstream of the pump (-108.3 ± 0.1 to -462.0 ± 0.5 mm Hg at 2000-4000 rpm). Moreover, higher negative pressure was associated with a larger number and volume of GME at pre-oxygenator site after de-clamp (GME count 10,573 ± 271 at pre-oxygenator site at 4000 rpm). The results showed that there was a potential danger of delivering GME to the patient when clamping pre-pump tubing during ECLS using a centrifugal pump. Our results warrant further clinical studies to investigate this phenomenon. Copyright © 2015 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Sport socks do not enhance calf muscle pump function but inelastic wraps do.

PubMed

Partsch, H; Mosti, G

2014-12-01

Aim of the study was to measure the effect of elastic and inelastic compression on calf muscle pump function in healthy male athletes. This was an experimental study which included 21 healthy male athletes. The ejection fraction (EF) of the venous calf pump was measured comparing the effects of a variety of compression materials: 1) sport compression stockings; 2) light zinc paste bandages; 3) sport compression stockings with additional Velcro® wraps over the calf. The influence of sport stocking and wraps on the venous calibre at the largest calf circumference in the lying and standing position was investigated using MRI. Inelastic compression exerting a median pressure in the standing position of 37.5 mmHg (zinc paste) and 48 mmHg (loosely applied straps over a sport stocking) achieved a significant increase of EF up to 100%. Sport stockings alone with a standing pressure of 19-24 mmHg did not show a significant change of EF. MRI demonstrated some venous narrowing in the lying but not in the standing position. By wrapping inelastic straps over the stocking an emptying of the veins in the lying and a considerable narrowing in the standing position could be observed. Venous calf pump function in athletes is not influenced by elastic sport stockings, but inelastic wraps either alone or applied over sport stockings lead to a significant enhancement.

Wave Intensity Analysis of Right Ventricular Function during Pulsed Operation of Rotary Left Ventricular Assist Devices.

PubMed

Bouwmeester, J Christopher; Park, Jiheum; Valdovinos, John; Bonde, Pramod

2018-05-29

Changing the speed of left ventricular assist devices (LVADs) cyclically may be useful to restore aortic pulsatility; however, the effects of this pulsation on right ventricular (RV) function are unknown. This study investigates the effects of direct ventricular interaction by quantifying the amount of wave energy created by RV contraction when axial and centrifugal LVADs are used to assist the left ventricle. In 4 anesthetized pigs, pressure and flow were measured in the main pulmonary artery and wave intensity analysis was used to identify and quantify the energy of waves created by the RV. The axial pump depressed the intensity of waves created by RV contraction compared with the centrifugal pump. In both pump designs, there were only minor and variable differences between the continuous and pulsed operation on RV function. The axial pump causes the RV to contract with less energy compared with a centrifugal design. Diminishing the ability of the RV to produce less energy translates to less pressure and flow produced, which may lead to LVAD-induced RV failure. The effects of pulsed LVAD operation on the RV appear to be minimal during acute observation of healthy hearts. Further study is necessary to uncover the effects of other modes of speed modulation with healthy and unhealthy hearts to determine if pulsed operation will benefit patients by reducing LVAD complications.

Short-term memory of motor network performance via activity-dependent potentiation of Na+/K+ pump function.

PubMed

Zhang, Hong-Yan; Sillar, Keith T

2012-03-20

Brain networks memorize previous performance to adjust their output in light of past experience. These activity-dependent modifications generally result from changes in synaptic strengths or ionic conductances, and ion pumps have only rarely been demonstrated to play a dynamic role. Locomotor behavior is produced by central pattern generator (CPG) networks and modified by sensory and descending signals to allow for changes in movement frequency, intensity, and duration, but whether or how the CPG networks recall recent activity is largely unknown. In Xenopus frog tadpoles, swim bout duration correlates linearly with interswim interval, suggesting that the locomotor network retains a short-term memory of previous output. We discovered an ultraslow, minute-long afterhyperpolarization (usAHP) in network neurons following locomotor episodes. The usAHP is mediated by an activity- and sodium spike-dependent enhancement of electrogenic Na(+)/K(+) pump function. By integrating spike frequency over time and linking the membrane potential of spinal neurons to network performance, the usAHP plays a dynamic role in short-term motor memory. Because Na(+)/K(+) pumps are ubiquitously expressed in neurons of all animals and because sodium spikes inevitably accompany network activity, the usAHP may represent a phylogenetically conserved but largely overlooked mechanism for short-term memory of neural network function. Copyright © 2012 Elsevier Ltd. All rights reserved.

Ground-source heat pump case studies and utility programs

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

Lienau, P.J.; Boyd, T.L.; Rogers, R.L.

1995-04-01

Ground-source heat pump systems are one of the promising new energy technologies that has shown rapid increase in usage over the past ten years in the United States. These systems offer substantial benefits to consumers and utilities in energy (kWh) and demand (kW) savings. The purpose of this study was to determine what existing monitored data was available mainly from electric utilities on heat pump performance, energy savings and demand reduction for residential, school and commercial building applications. In order to verify the performance, information was collected for 253 case studies from mainly utilities throughout the United States. The casemore » studies were compiled into a database. The database was organized into general information, system information, ground system information, system performance, and additional information. Information was developed on the status of demand-side management of ground-source heat pump programs for about 60 electric utility and rural electric cooperatives on marketing, incentive programs, barriers to market penetration, number units installed in service area, and benefits.« less

Ideas and perspectives: hydrothermally driven redistribution and sequestration of early Archaean biomass - the "hydrothermal pump hypothesis"

NASA Astrophysics Data System (ADS)

Duda, Jan-Peter; Thiel, Volker; Bauersachs, Thorsten; Mißbach, Helge; Reinhardt, Manuel; Schäfer, Nadine; Van Kranendonk, Martin J.; Reitner, Joachim

2018-03-01

Archaean hydrothermal chert veins commonly contain abundant organic carbon of uncertain origin (abiotic vs. biotic). In this study, we analysed kerogen contained in a hydrothermal chert vein from the ca. 3.5 Ga Dresser Formation (Pilbara Craton, Western Australia). Catalytic hydropyrolysis (HyPy) of this kerogen yielded n-alkanes up to n-C22, with a sharp decrease in abundance beyond n-C18. This distribution ( ≤ n-C18) is very similar to that observed in HyPy products of recent bacterial biomass, which was used as reference material, whereas it differs markedly from the unimodal distribution of abiotic compounds experimentally formed via Fischer-Tropsch-type synthesis. We therefore propose that the organic matter in the Archaean chert veins has a primarily microbial origin. The microbially derived organic matter accumulated in anoxic aquatic (surface and/or subsurface) environments and was then assimilated, redistributed and sequestered by the hydrothermal fluids (hydrothermal pump hypothesis).

A Biomimetic Approach to Discrimination Between Sequential and Concerted Models for the Oxidation of Ubiquinol at the Qo­ site of the Cyt bc1 Complex

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

Cape, Jonathan L.; Forquer, Isaac P.; Bowman, Michael K.

2005-09-26

The cytochrome bc complexes function as quinol:cytochrome c oxidoreductases in the energy conserving membranes of nearly all organisms, where they couple the oxidation of a quinol substrate (QH2) to the pumping of protons across the bioenergetic membrane, resulting in the establishment of a proton motive force, which is used to drive the (C)F0/(C)F1 ATP synthase (Trumpower and Gennis 1994). Among the variety of biological quinols characterized, ubiquinol is the substrate used by most bc-type complexes, and its reactions are of great interest concerning diseases related to oxidative stress and the fundamentals of biological energy transduction.

Assembly processes comparison for a miniaturized laser used for the Exomars European Space Agency mission

NASA Astrophysics Data System (ADS)

Ribes-Pleguezuelo, Pol; Inza, Andoni Moral; Basset, Marta Gilaberte; Rodríguez, Pablo; Rodríguez, Gemma; Laudisio, Marco; Galan, Miguel; Hornaff, Marcel; Beckert, Erik; Eberhardt, Ramona; Tünnermann, Andreas

2016-11-01

A miniaturized diode-pumped solid-state laser (DPSSL) designed as part of the Raman laser spectrometer (RLS) instrument for the European Space Agency (ESA) Exomars mission 2020 is assembled and tested for the mission purpose and requirements. Two different processes were tried for the laser assembling: one based on adhesives, following traditional laser manufacturing processes; another based on a low-stress and organic-free soldering technique called solderjet bumping technology. The manufactured devices were tested for the processes validation by passing mechanical, thermal cycles, radiation, and optical functional tests. The comparison analysis showed a device improvement in terms of reliability of the optical performances from the soldered to the assembled by adhesive-based means.

Off-pump grafting does not reduce postoperative pulmonary dysfunction.

PubMed

Izzat, Mohammad Bashar; Almohammad, Farouk; Raslan, Ahmad Fahed

2017-02-01

Objectives Pulmonary dysfunction is a recognized postoperative complication that may be linked to use of cardiopulmonary bypass. The off-pump technique of coronary artery bypass aims to avoid some of the complications that may be related to cardiopulmonary bypass. In this study, we compared the influence of on-pump or off-pump coronary artery bypass on pulmonary gas exchange following routine surgery. Methods Fifty patients (mean age 60.4 ± 8.4 years) with no preexisting lung disease and good left ventricular function undergoing primary coronary artery bypass grafting were prospectively randomized to undergo surgery with or without cardiopulmonary bypass. Alveolar/arterial oxygen pressure gradients were calculated prior to induction of anesthesia while the patients were breathing room air, and repeated postoperatively during mechanical ventilation and after extubation while inspiring 3 specific fractions of oxygen. Results Baseline preoperative arterial blood gases and alveolar/arterial oxygen pressure gradients were similar in both groups. At both postoperative stages, the partial pressure of arterial oxygen and alveolar/arterial oxygen pressure gradients increased with increasing fraction of inspired oxygen, but there were no statistically significant differences between patients who underwent surgery with or without cardiopulmonary bypass, either during ventilation or after extubation. Conclusions Off-pump surgery is not associated with superior pulmonary gas exchange in the early postoperative period following routine coronary artery bypass grafting in patients with good left ventricular function and no preexisting lung disease.

Long-term in vivo left ventricular assist device study for 284 days with Gyro PI pump.

PubMed

Ohtsuka, G; Nakata, K; Yoshikawa, M; Takano, T; Glueck, J; Sankai, Y; Takami, Y; Mueller, J; Sueoka, A; Letsou, G; Schima, H; Schmallegger, H; Wolner, E; Koyanagi, H; Fujisawa, A; Baldwin, J C; Nosé, Y

1999-06-01

A totally implantable centrifugal artificial heart has been developed. The plastic prototype, the Gyro PI 601, passed 2 day hemodynamic tests as a functional total artificial heart (TAH), 2 week screening tests for anti-thrombogenecity, and a 1 month system feasibility study. Based upon these results, a metallic prototype, the Gyro PI 700 series, was subjected to long-term in vivo left ventricular assist device (LVAD) studies of over 1 month. The Gyro PI 700 series has the same inner dimension and same characteristics of the Gyro PI 601 such as an eccentric inlet port, a double pivot bearing system, and a magnet coupling system. The PI metallic pump is also driven with the Vienna DC brushless motor actuator like the PI 601. The pump-actuator package was implanted in 3 calves in the preperitoneal space, bypassing from the left ventricular (LV) apex to the descending aorta. Case 1 achieved a 284 day survival. Case 2 was euthanized early at 72 postoperative days as a result of the functional obstruction of the inlet port due to the excessive growth of the calf. There was no blood clot inside the pumps of either case. Case 3 is on-going (22 days on July 24, 1998). During these periods, all cases showed no physiological abnormalities. In conclusion, the PI 700 series pump has excellent results as a long-term implantable LVAD.

Alcohols are inhibitors of Saccharomyces cerevisiae multidrug-resistance pumps Pdr5p and Snq2p.

PubMed

Gášková, Dana; Plášek, Jaromír; Zahumenský, Jakub; Benešová, Ivana; Buriánková, Luboslava; Sigler, Karel

2013-12-01

The effect of alcohols on cell membrane proteins has originally been assumed to be mediated by their primary action on membrane lipid matrix. Many studies carried out later on both animal and yeast cells have revealed that ethanol and other alcohols inhibit the functions of various membrane channels, receptors and solute transport proteins, and a direct interaction of alcohols with these membrane proteins has been proposed. Using our fluorescence diS-C3 (3) diagnostic assay for multidrug-resistance pump inhibitors in a set of isogenic yeast Pdr5p and Snq2p mutants, we found that n-alcohols (from ethanol to hexanol) variously affect the activity of both pumps. Beginning with propanol, these alcohols have an inhibitory effect that increases with increasing length of the alcohol acyl chain. While ethanol does not exert any inhibitory effect at any of the concentration used (up to 3%), hexanol exerts a strong inhibition at 0.1%. The alcohol-induced inhibition of MDR pumps was detected even in cells whose membrane functional and structural integrity were not compromised. This supports a notion that the inhibitory action does not necessarily involve only changes in the lipid matrix of the membrane but may entail a direct interaction of the alcohols with the pump proteins. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Persistent gastro-oesophageal reflux symptoms despite proton pump inhibitor therapy

PubMed Central

Ang, Daphne; How, Choon How; Ang, Tiing Leong

2016-01-01

About one-third of patients with suspected gastro-oesophageal reflux disease (GERD) do not respond symptomatically to proton pump inhibitors (PPIs). Many of these patients do not suffer from GERD, but may have underlying functional heartburn or atypical chest pain. Other causes of failure to respond to PPIs include inadequate acid suppression, non-acid reflux, oesophageal hypersensitivity, oesophageal dysmotility and psychological comorbidities. Functional oesophageal tests can exclude cardiac and structural causes, as well as help to confi rm or exclude GERD. The use of PPIs should only be continued in the presence of acid reflux or oesophageal hypersensitivity for acid reflux-related events that is proven on functional oesophageal tests. PMID:27779277

Optimization of two-photon wave function in parametric down conversion by adaptive optics control of the pump radiation.

PubMed

Minozzi, M; Bonora, S; Sergienko, A V; Vallone, G; Villoresi, P

2013-02-15

We present an efficient method for optimizing the spatial profile of entangled-photon wave function produced in a spontaneous parametric down conversion process. A deformable mirror that modifies a wavefront of a 404 nm CW diode laser pump interacting with a nonlinear β-barium borate type-I crystal effectively controls the profile of the joint biphoton function. The use of a feedback signal extracted from the biphoton coincidence rate is used to achieve the optimal wavefront shape. The optimization of the two-photon coupling into two, single spatial modes for correlated detection is used for a practical demonstration of this physical principle.

Persistent gastro-oesophageal reflux symptoms despite proton pump inhibitor therapy.

PubMed

Ang, Daphne; How, Choon How; Ang, Tiing Leong

2016-10-01

About one-third of patients with suspected gastro-oesophageal reflux disease (GERD) do not respond symptomatically to proton pump inhibitors (PPIs). Many of these patients do not suffer from GERD, but may have underlying functional heartburn or atypical chest pain. Other causes of failure to respond to PPIs include inadequate acid suppression, non-acid reflux, oesophageal hypersensitivity, oesophageal dysmotility and psychological comorbidities. Functional oesophageal tests can exclude cardiac and structural causes, as well as help to confi rm or exclude GERD. The use of PPIs should only be continued in the presence of acid reflux or oesophageal hypersensitivity for acid reflux-related events that is proven on functional oesophageal tests. Copyright: © Singapore Medical Association.

Prototype Continuous Flow Ventricular Assist Device Supported on Magnetic Bearings.

PubMed

Allaire, P E; Kim, H C; Maslen, E H; Olsen, D B; Bearnson, G B

1996-05-01

This article describes a prototype continuous flow pump (CFVAD2) fully supported in magnetic bearings. The pump performance was measured in a simulated adult human circulation system. The pump delivered 6 L/min of flow at 100 mm Hg of differential pressure head operating at 2,400 rpm in water. The pump is totally supported in 4 magnetic bearings: 2 radial and 2 thrust. Magnetic bearings offer the advantages of no required lubrication and large operating clearances. The geometry and other properties of the bearings are described. Bearing parameters such as load capacity and current gains are discussed. Bearing coil currents were measured during operation in air and water. The rotor was operated in various orientations to determine the actuator current gains. These values were then used to estimate the radial and thrust forces acting on the rotor in both air and water. Much lower levels of force were found than were expected, allowing for a very significant reduction in the size of the next prototype. Hemolysis levels were measured in the prototype pump and found not to indicate damage to the blood cells. © 1996 International Society for Artificial Organs.

Reviving Antibiotics: Efflux Pump Inhibitors That Interact with AcrA, a Membrane Fusion Protein of the AcrAB-TolC Multidrug Efflux Pump

DOE PAGES

Abdali, Narges; Parks, Jerry M.; Haynes, Keith M.; ...

2016-10-21

Antibiotic resistance is a major threat to human welfare. Inhibitors of multidrug efflux pumps (EPIs) are promising alternative therapeutics that could revive activities of antibiotics and reduce bacterial virulence. Identification of new druggable sites for inhibition is critical for developing effective EPIs, especially in light of constantly emerging resistance. We describe new EPIs that interact with and possibly inhibit the function of periplasmic membrane fusion proteins, critical components of efflux pumps that are responsible for the activation of the transporter and the recruitment of the outer-membrane channel. The discovered EPIs bind to AcrA, a component of the prototypical AcrAB-TolC pump,more » change its structure in vivo, inhibit efflux of fluorescent probes and potentiate the activities of antibiotics in Escherichia coli cells. These findings expand the chemical and mechanistic diversity of EPIs, suggest the mechanism for regulation of the efflux pump assembly and activity, and provide a promising path for reviving the activities of antibiotics in resistant bacteria.« less

Fixed-speed and Variable-speed Pumped Storage Dispatch Model in Power Systems with High Renewable Penetration

NASA Astrophysics Data System (ADS)

Yuan, Bo; Zong, Jin; Xu, Zhicheng

2018-06-01

According to different operating characteristics of pumped storage fixed speed unit and variable speed unit, a joint dispatching model of pumped storage unit and other types of units based on mixed integer linear optimization is constructed. The model takes into account the operating conditions, reservoir capacity, cycle type and other pumped storage unit constraints, but also consider the frequent start and stop and the stability of the operation of the unit caused by the loss. Using the Cplex solver to solve the model, the empirical example of the provincial power grid shows that the model can effectively arrange the pumping storage speed and the dispatching operation of the variable speed unit under the precondition of economic life of the unit, and give full play to the function of peak shaving and accommodating new energy. Because of its more flexible regulation characteristics of power generation and pumping conditions, the variable speed unit can better improve the operating conditions of other units in the system and promote the new energy dissipation.

Development of electric drive for centrifugal mine pumps in Solikamsk Potassium Mine Group Based on Industrial OMRON Controller

NASA Astrophysics Data System (ADS)

Kostarev, S. N.; Sereda, T. G.; Tatarnikova, N. A.; Kochetova, O. V.

2018-03-01

The electric drive for automation pumping out of filtration waters in the Second Solikamsk Potasssium Mine Group is developed. The emergency situation of flooding of the Mine has been considered in the course of development of the Upper Kama deposits of potash-magnesium salts. The functional scheme of automation of a drive of the pump is developed. The scheme is stipulated with manual and automatic control. To decrease the risk of flooding of mine, it is recommended to establish gauges of both bottom and top level control of a brine and other equipment in the collector of a brine: the gauge of measurementof a level, the gauge of the signal system of a level, the gauge of the pump control, the gauge of the signal system of a level with remote data transmission. For regulation of the charge of sewage, the P-regulator with the executive mechanism is stipulated. The ladder diagram of a pump control is developed to improve the work of centrifugal pumps and to prevent the cases of mines flooding.

Vapor compression heat pump system field tests at the TECH complex

NASA Astrophysics Data System (ADS)

Baxter, V. D.

1985-07-01

The Tennessee Energy Conservation In Housing (TECH) complex has been utilized since 1977 as a field test site for several novel and conventional heat pump systems for space conditioning and water heating. Systems tested include the Annual Cycle Energy System (ACES), solar assisted heat pumps (SAHP) both parallel and series, two conventional air-to-air heat pumps, an air-to-air heat pump with desuperheater water heater, and horizontal coil and multiple shallow vertical coil ground-coupled heat pumps (GCHP). A direct comparison of the measured annual performance of the test systems was not possible. However, a cursory examination revealed that the ACES had the best performance. However, its high cost makes it unlikely that it will achieve widespread use. Costs for the SAHP systems are similar to those of the ACES but their performance is not as good. Integration of water heating and space conditioning functions with a desuperheater yielded significant efficiency improvement at modest cost. The GCHP systems performed much better for heating than for cooling and may well be the most efficient alternative for residences in cold climates.

Vapor compression heat pump system field tests at the tech complex

NASA Astrophysics Data System (ADS)

Baxter, Van D.

1985-11-01

The Tennessee Energy Conservation In Housing (TECH) complex has been utilized since 1977 as a field test site for several novel and conventional heat pump systems for space conditioning and water heating. Systems tested include the Annual Cycle Energy System (ACES), solar assisted heat pumps (SAHP) both parallel and series, two conventional air-to-air heat pumps, an air-to-air heat pump with desuperheater water heater, and horizontal coil and multiple shallow vertical coil ground-coupled heat pumps (GCHP). A direct comparison of the measured annual performance of the test systems was not possible. However, a cursory examination revealed that the ACES had the best performance, however, its high cost makes it unlikely that it will achieve wide-spread use. Costs for the SAHP systems are similar to those of the ACES but their performance is not as good. Integration of water heating and space conditioning functions with a desuperheater yielded significant efficiency improvement at modest cost. The GCHP systems performed much better for heating than for cooling and may well be the most efficient alternative for residences in cold climates.

Effect of the self-pumped limiter concept on the tritium fuel cycle

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

Finn, P.A.; Sze, D.K.; Hassanein, A.

1988-09-01

The self-pumped limiter concept was the impurity control system for the reactor in the Tokamak Power Systems Study (TPSS). The use of a self-pumped limiter had a major impact on the design of the tritium systems of the TPSS fusion reactor. The self-pumped limiter functions by depositing the helium ash under a layer of metal (vanadium). The majority of the hydrogen species are recycled at the plasma edge; a small fraction permeates to the blanket/coolant which was lithium in TPSS. Use of the self-pumped limiter results in the elimination of the plasma processing system. Thus, the blanket tritium processing systemmore » becomes the major tritium system. The main advantages achieved for the tritium systems with a self-pumped limiter are a reduction in the capital cost of tritium processing equipment as well as a reduction in building space, a reduced tritium inventory for processing and for reserve storage, an increase in the inherent safety of the fusion plant and an improvement in economics for a fusion world economy.« less

Hotfire testing of a SSME HPOTP with an annular hydrostatic bearing

NASA Technical Reports Server (NTRS)

Nolan, Steven A.; Hibbs, Robert I.; Genge, Gary G.

1993-01-01

A new fluid film bearing package has been tested in the SSME High Pressure Oxygen Turbopump (HPOTP). This fluid film element functions as both the pump end bearing and the preburner pump rear wear ring seal. Most important, it replaces a duplex ball bearing package which has been the primary life limiting component in the turbopump. The design and predicted performance of the turbopump are reviewed. Results are presented for measured pump and bearing performance. The most significant results were obtained from proximity probes located in the bearing bore which revealed large subsynchronous precession at 10 percent of shaft speed during engine start which subsided prior to mainstage power levels and reappeared during engine shutdown at equivalent power levels below 65 percent of nominal. This phenomenon has been attributed to rotating stall in the diffuser. The proximity probes also revealed the location of the bearing in the bore for different operating speeds. Pump vibration characteristics were improved as compared to pumps tested with ball bearings. After seven starts and more than 700 seconds of testing, the pump showed no signs of performance degradation.

Reviving Antibiotics: Efflux Pump Inhibitors That Interact with AcrA, a Membrane Fusion Protein of the AcrAB-TolC Multidrug Efflux Pump

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

Abdali, Narges; Parks, Jerry M.; Haynes, Keith M.

Antibiotic resistance is a major threat to human welfare. Inhibitors of multidrug efflux pumps (EPIs) are promising alternative therapeutics that could revive activities of antibiotics and reduce bacterial virulence. Identification of new druggable sites for inhibition is critical for developing effective EPIs, especially in light of constantly emerging resistance. We describe new EPIs that interact with and possibly inhibit the function of periplasmic membrane fusion proteins, critical components of efflux pumps that are responsible for the activation of the transporter and the recruitment of the outer-membrane channel. The discovered EPIs bind to AcrA, a component of the prototypical AcrAB-TolC pump,more » change its structure in vivo, inhibit efflux of fluorescent probes and potentiate the activities of antibiotics in Escherichia coli cells. These findings expand the chemical and mechanistic diversity of EPIs, suggest the mechanism for regulation of the efflux pump assembly and activity, and provide a promising path for reviving the activities of antibiotics in resistant bacteria.« less

Marine biodiversity, ecosystem functioning, and carbon cycles.

PubMed

Beaugrand, Grégory; Edwards, Martin; Legendre, Louis

2010-06-01

Although recent studies suggest that climate change may substantially accelerate the rate of species loss in the biosphere, only a few studies have focused on the potential consequences of a spatial reorganization of biodiversity with global warming. Here, we show a pronounced latitudinal increase in phytoplanktonic and zooplanktonic biodiversity in the extratropical North Atlantic Ocean in recent decades. We also show that this rise in biodiversity paralleled a decrease in the mean size of zooplanktonic copepods and that the reorganization of the planktonic ecosystem toward dominance by smaller organisms may influence the networks in which carbon flows, with negative effects on the downward biological carbon pump and demersal Atlantic cod (Gadus morhua). Our study suggests that, contrary to the usual interpretation of increasing biodiversity being a positive emergent property promoting the stability/resilience of ecosystems, the parallel decrease in sizes of planktonic organisms could be viewed in the North Atlantic as reducing some of the services provided by marine ecosystems to humans.

Implantable centrifugal blood pump with dual impeller and double pivot bearing system: electromechanical actuator, prototyping, and anatomical studies.

PubMed

Bock, Eduardo; Antunes, Pedro; Leao, Tarcisio; Uebelhart, Beatriz; Fonseca, Jeison; Leme, Juliana; Utiyama, Bruno; da Silva, Cibele; Cavalheiro, Andre; Filho, Diolino Santos; Dinkhuysen, Jarbas; Biscegli, Jose; Andrade, Aron; Arruda, Celso

2011-05-01

An implantable centrifugal blood pump has been developed with original features for a left ventricular assist device. This pump is part of a multicenter and international study with the objective to offer simple, affordable, and reliable devices to developing countries. Previous computational fluid dynamics investigations and wear evaluation in bearing system were performed followed by prototyping and in vitro tests. In addition, previous blood tests for assessment of normalized index of hemolysis show results of 0.0054±2.46 × 10⁻³ mg/100 L. An electromechanical actuator was tested in order to define the best motor topology and controller configuration. Three different topologies of brushless direct current motor (BLDCM) were analyzed. An electronic driver was tested in different situations, and the BLDCM had its mechanical properties tested in a dynamometer. Prior to evaluation of performance during in vivo animal studies, anatomical studies were necessary to achieve the best configuration and cannulation for left ventricular assistance. The results were considered satisfactory, and the next step is to test the performance of the device in vivo. © 2011, Copyright the Authors. Artificial Organs © 2011, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Adding the ‘heart’ to hanging drop networks for microphysiological multi-tissue experiments†

PubMed Central

Yazdi, Saeed Rismani; Shadmani, Amir; Bürgel, Sebastian C.; Misun, Patrick M.; Hierlemann, Andreas; Frey, Olivier

2017-01-01

Microfluidic hanging-drop networks enable culturing and analysis of 3D microtissue spheroids derived from different cell types under controlled perfusion and investigating inter-tissue communication in multi-tissue formats. In this paper we introduce a compact on-chip pumping approach for flow control in hanging-drop networks. The pump includes one pneumatic chamber located directly above one of the hanging drops and uses the surface tension at the liquid–air-interface for flow actuation. Control of the pneumatic protocol provides a wide range of unidirectional pulsatile and continuous flow profiles. With the proposed concept several independent hanging-drop networks can be operated in parallel with only one single pneumatic actuation line at high fidelity. Closed-loop medium circulation between different organ models for multi-tissue formats and multiple simultaneous assays in parallel are possible. Finally, we implemented a real-time feedback control-loop of the pump actuation based on the beating of a human iPS-derived cardiac microtissue cultured in the same system. This configuration allows for simulating physiological effects on the heart and their impact on flow circulation between the organ models on chip. PMID:26401602

Right ventricular systolic pressure measurements in combination with harvest of lung and immune tissue samples in mice.

PubMed

Chen, Wen-Chi; Park, Sung-Hyun; Hoffman, Carol; Philip, Cecil; Robinson, Linda; West, James; Grunig, Gabriele

2013-01-16

The function of the right heart is to pump blood through the lungs, thus linking right heart physiology and pulmonary vascular physiology. Inflammation is a common modifier of heart and lung function, by elaborating cellular infiltration, production of cytokines and growth factors, and by initiating remodeling processes. Compared to the left ventricle, the right ventricle is a low-pressure pump that operates in a relatively narrow zone of pressure changes. Increased pulmonary artery pressures are associated with increased pressure in the lung vascular bed and pulmonary hypertension. Pulmonary hypertension is often associated with inflammatory lung diseases, for example chronic obstructive pulmonary disease, or autoimmune diseases. Because pulmonary hypertension confers a bad prognosis for quality of life and life expectancy, much research is directed towards understanding the mechanisms that might be targets for pharmaceutical intervention. The main challenge for the development of effective management tools for pulmonary hypertension remains the complexity of the simultaneous understanding of molecular and cellular changes in the right heart, the lungs and the immune system. Here, we present a procedural workflow for the rapid and precise measurement of pressure changes in the right heart of mice and the simultaneous harvest of samples from heart, lungs and immune tissues. The method is based on the direct catheterization of the right ventricle via the jugular vein in close-chested mice, first developed in the late 1990s as surrogate measure of pressures in the pulmonary artery. The organized team-approach facilitates a very rapid right heart catheterization technique. This makes it possible to perform the measurements in mice that spontaneously breathe room air. The organization of the work-flow in distinct work-areas reduces time delay and opens the possibility to simultaneously perform physiology experiments and harvest immune, heart and lung tissues. The procedural workflow outlined here can be adapted for a wide variety of laboratory settings and study designs, from small, targeted experiments, to large drug screening assays. The simultaneous acquisition of cardiac physiology data that can be expanded to include echocardiography and harvest of heart, lung and immune tissues reduces the number of animals needed to obtain data that move the scientific knowledge basis forward. The procedural workflow presented here also provides an ideal basis for gaining knowledge of the networks that link immune, lung and heart function. The same principles outlined here can be adapted to study other or additional organs as needed.

Comparative study of DPAL and XPAL systems and selection principal of parameters

NASA Astrophysics Data System (ADS)

Huang, Wei; Tan, Rongqing; Li, Zhiyong; Han, Gaoce; Li, Hui

2016-10-01

A theoretical model based on common pump structure is proposed to analyze the laser output characteristics of DPAL (Diode pumped alkali vapor laser) and XPAL (Exciplex pumped alkali laser) in this paper. The model predicts that an optical-to-optical efficiency approaching 80% can be achieved for continuous-wave four- and five-XPAL systems with broadband pumping which is several times of pumped linewidth for DPAL. Operation parameters including pumped intensity, temperature, cell' s length, mixed gas concentration, pumped linewidth and output mirror reflectivity are analyzed for DPAL and XPAL systems basing on the kinetic model. The result shows a better performance in Cs-Ar XPAL laser with requirements of relatively high Ar concentration, high pumped intensity and high temperature. Comparatively, for Cs-DPAL laser, lower temperature and lower pumped intensity should be acquired. In addition, the predictions of selection principal of temperature and cell's length are also presented. The conception of the equivalent "alkali areal density" is proposed in this paper. It is defined as the product of the alkali density and cell's length. The result shows that the output characteristics of DPAL (or XPAL) system with the same alkali areal density but different temperatures turn out to be equal. It is the areal density that reflects the potential of DPAL or XPAL systems directly. A more detailed analysis of similar influences of cavity parameters with the same areal density is also presented. The detailed results of continuous-wave DPAL and XPAL performances as a function of pumped laser linewidth and mixed gas pressure are presented along with an analysis of influences of output coupler.

Theoretical model and simulations for a cw exciplex pumped alkali laser.

PubMed

Huang, Wei; Tan, Rongqing; Li, Zhiyong; Lu, Xiaochuan

2015-12-14

The Exciplex Pumped Alkali Laser (XPAL) system, which is similar to DPAL (Diode Pumped Alkali vapor Laser), has been demonstrated in mixtures of Cs vapor, Ar, with and without ethane. Unlike DPAL, it uses the broadband absorption blue satellite of the alkali D₂ line, created by naturally occuring collision pairs. For example, Cs-Ar collision pairs have an absorption width which is as wide as the one of commercial semiconductor diode lasers. A continuous wave XPAL four-level theoretical model is presented in this paper. More factors are considered, such as the spectral dependence of pumped laser absorption for broadband pumping and the longitudinal population variation. Some intra-cavity details, such as longitudinal distributions of pumped laser and alkali laser, can also be solved well. The predictions of optical-to-optical efficiency as a function of temperature and pumped laser intensity are presented. The model predicts that there is an optimum value of temperature or pumped laser intensity. The analysis of the influence of cell length on optical-to-optical efficiency shows that a better performance can be achieved when using longer cell. The prediction of influence of Ar concentration and reflectivity of output coupler shows that higher optical-to-optical efficiency could be achieved if lower reflectivity of output coupler and higher Ar concentration are used. The optical-to-optical efficiency as high as 84% achieved by optimizing configuration with the pumped intensity of 5 × 10⁷ W/cm² presented shows that broadband pumped four-level XPAL system has a potential of high optical-to-optical efficiency.

Numerical investigation of the effect of number of blades on centrifugal pump performance

NASA Astrophysics Data System (ADS)

Kocaaslan, O.; Ozgoren, M.; Babayigit, O.; Aksoy, M. H.

2017-07-01

In this study, the flow structure in a centrifugal pump was numerically investigated for the different blade numbers in the impeller between 5 and 9. The pump used in the study is a single-stage horizontal shafted centrifugal pump. The original pump impeller was designed as 7 blades for the parameters of flow rate Q=100 mł/h, head Hm=180 kPa and revolution n=1480 rpm. First, models of impellers with the different blade numbers between 5 and 9 and the volute section of the centrifugal pump were separately drawn using Solidworks software. Later, grid structures were generated on the flow volume of the pump. Last, the flow analyses were performed and the flow characteristics under different operational conditions were determined numerically. In the numerical analyses, k-ɛ turbulence model and standard wall functions were used to solve turbulent flow. Balance holes and surface roughness, which adversely affect the hydraulic efficiency of pumps, were also considered. The obtained results of the analyses show that the hydraulic torque and head values have increased with the application of higher number of the impeller blades. For the impellers with 5 and 9 blades on the design flow rate of 100 mł/h (Q/Qd=1), the hydraulic torque and head were found 49/59.1 Nm and 153.1/184.4 kPa, respectively. Subsequently the hydraulic efficiencies of each pump were calculated. As a result, the highest hydraulic efficiency on the design flow rate was calculated as 54.16% for the pump impeller having 8 blades.

Optically induced metal-to-dielectric transition in Epsilon-Near-Zero metamaterials

PubMed Central

Kaipurath, R. M.; Pietrzyk, M.; Caspani, L.; Roger, T.; Clerici, M.; Rizza, C.; Ciattoni, A.; Di Falco, A.; Faccio, D.

2016-01-01

Epsilon-Near-Zero materials exhibit a transition in the real part of the dielectric permittivity from positive to negative value as a function of wavelength. Here we study metal-dielectric layered metamaterials in the homogenised regime (each layer has strongly subwavelength thickness) with zero real part of the permittivity in the near-infrared region. By optically pumping the metamaterial we experimentally show that close to the Epsilon-Near-Zero (ENZ) wavelength the permittivity exhibits a marked transition from metallic (negative permittivity) to dielectric (positive permittivity) as a function of the optical power. Remarkably, this transition is linear as a function of pump power and occurs on time scales of the order of the 100 fs pump pulse that need not be tuned to a specific wavelength. The linearity of the permittivity increase allows us to express the response of the metamaterial in terms of a standard third order optical nonlinearity: this shows a clear inversion of the roles of the real and imaginary parts in crossing the ENZ wavelength, further supporting an optically induced change in the physical behaviour of the metamaterial. PMID:27292270

125-mJ diode-pumped injection-seeded Ho:Tm:YLF laser.

PubMed

Yu, J; Singh, U N; Barnes, N P; Petros, M

1998-05-15

We describe a diode-pumped, room-temperature Ho:Tm:YLF power oscillator with an optical-to-optical efficiency of 0.03. A Q -switched output energy of as much as 125 mJ at 6 Hz with a pulse width of 170 ns was obtained. Single-frequency, nearly transform-limited operation of the laser was achieved by injection seeding. Laser performance as a function of laser rod temperature and pump intensity was also investigated. The high power and high beam quality of this laser make it well suited for use as a coherent wind lidar transmitter on a space platform.

Theoretcial studies of solar-pumped lasers

NASA Technical Reports Server (NTRS)

Harries, W. L.; Fong, Z. S.

1984-01-01

A method of pumping a COhZ laser by a hot cavity was demonstrated. The cavity, heated by solar radiation, should increase the efficiency of solar pumped lasers used for energy conversion. Kinetic modeling is used to examine the behavior of such a COhZ laser. The kinetic equations are solved numerically vs. time and, in addition, steady state solutions are obtained analytically. The effect of gas heating filling the lower laser level is included. The output power and laser efficiency are obtained as functions of black body temperature and gas ratios (COhZ-He-Ar) and pressures. The values are compared with experimental results.