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Sample records for diaphragm walls

  1. Respiratory kinematics by optoelectronic analysis of chest-wall motion and ultrasonic imaging of the diaphragm

    NASA Astrophysics Data System (ADS)

    Aliverti, Andrea; Pedotti, Antonio; Ferrigno, Giancarlo; Macklem, P. T.

    1998-07-01

    Although from a respiratory point of view, compartmental volume change or lack of it is the most crucial variable, it has not been possible to measure the volume of chest wall compartments directly. Recently we developed a new method based on a optoelectronic motion analyzer that can give the three-dimensional location of many markers with the temporal and spatial accuracy required for respiratory measurements. Marker's configuration has been designed specifically to measure the volume of three chest wall compartments, the pulmonary and abdominal rib cage compartments and the abdomen, directly. However, it can not track the exact border between the two rib cage compartments (pulmonary and abdominal) which is determined by the cephalic extremity of the area of apposition of the diaphragm to the inner surface of the rib cage, and which can change systematically as a result of disease processes. The diaphragm displacement can be detected by ultrasonography. In the present study, we propose an integrated system able to investigate the relationships between external (chest wall) and internal (diaphragm) movements of the different respiratory structures by simultaneous external imaging with the optoelectronic system combined with internal kinematic imaging using ultrasounds. 2D digitized points belonging to the lower lung margin, taken from ultrasonographic views, are mapped into the 3D space, where chest wall markers are acquired. Results are shown in terms of accuracy of 3D probe location, relative movement between the probe and the body landmarks, dynamic relationships between chest wall volume and position of the diaphragm during quiet breathing, slow inspirations, relaxations and exercise.

  2. One-dimensional analysis of thin-walled beams with diaphragms and its application to optimization for stiffness reinforcement

    NASA Astrophysics Data System (ADS)

    Jung, Joon Hee; Jang, Gang-Won; Shin, Dongil; Kim, Yoon Young

    2017-08-01

    This paper presents a method to analyze thin-walled beams with quadrilateral cross sections reinforced with diaphragms using a one-dimensional higher-order beam theory. The effect of a diaphragm is reflected focusing on the increase of static stiffness. The deformations on the beam-interfacing boundary of a thin diaphragm are described by using deformation modes of the beam cross section while the deformations inside the diaphragm are approximated in the form of complete cubic polynomials. By using the principle of minimum potential energy, its stiffness that significantly affects distortional deformation of a thin-walled beam can be considered in the one-dimensional beam analysis. It is shown that the accuracy of the resulting one-dimensional analysis is comparable with that by a shell element based analysis. As a means to demonstrate the usefulness of the present approach for design, position optimization problems of diaphragms for stiffness reinforcement of an automotive side frame are solved.

  3. The DDBD Method In The A-Seismic Design of Anchored Diaphragm Walls

    SciTech Connect

    Manuela, Cecconi; Vincenzo, Pane; Sara, Vecchietti

    2008-07-08

    The development of displacement based approaches for earthquake engineering design appears to be very useful and capable to provide improved reliability by directly comparing computed response and expected structural performance. In particular, the design procedure known as the Direct Displacement Based Design (DDBD) method, which has been developed in structural engineering over the past ten years in the attempt to mitigate some of the deficiencies in current force-based design methods, has been shown to be very effective and promising ([1], [2]). The first attempts of application of the procedure to geotechnical engineering and, in particular, earth retaining structures are discussed in [3], [4] and [5]. However in this field, the outcomes of the research need to be further investigated in many aspects. The paper focuses on the application of the DDBD method to anchored diaphragm walls. The results of the DDBD method are discussed in detail in the paper, and compared to those obtained from conventional pseudo-static analyses.

  4. Wolf Creek Dam - Concrete Diaphragm Walls. Final Completion Reports. Phases 1 and 2

    DTIC Science & Technology

    1988-12-01

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  5. Effect of Groundwater Table Rising and Slurry Reduction during Diaphragm Wall Trenching on Stability of Adjacent Piles

    NASA Astrophysics Data System (ADS)

    Mohamed, A.

    2015-09-01

    The process of diaphragm wall trenching normally affects the surrounding environment. The piles near a diaphragm wall trench are commonly affected by the trenching process as well. During trenching the slurry level and the natural groundwater level are assumed to be constant. However flooding may cause damage to the slurry trenches due to the increase of the groundwater table. Another possible scenario for the trench failure is due to reduction of the slurry level. The reduction of the slurry level could be due to the presence of cavities or a very coarse soil layer. Piles located near a trench could be affected greatly if the trench is subjected to reduction of slurry or increase of the groundwater level. This research focuses on studying numerically the stability of piles adjacent to the diaphragm wall during the trenching process, especially in cause of slurry reduction or increase of groundwater level. The slurry reduction were simulated numerically with the finite different analysis and compared with previous laboratory work. The increase of groundwater level is simulated for a case study in Giza, Egypt. Groundwater level was assumed to increase in the area. Piles are generally affected by the trenching process. The behaviour of the pile is related to its position from the slurry trench. The stability of the pile may not be affected greatly by a normal and successful trenching process. However slurry reduction or increase in the groundwater level may cause a great effect on the stability of the nearby piles. Trenching in general causes an increase in pile settlement, horizontal displacement and bending moment. The pile skin friction and end bearing are affected as well. The percentage of the change in slurry or groundwater levels affects piles deflection and bending moment.

  6. [Gastric wall necrosis owing to its incarceration through a rupture of the diaphragm into the left thoracic cavity].

    PubMed

    Sugar, István; Turcsányi, Gábor; Vajda, Vera; Tulassay, Eszter; Ondrejka, Pál

    2005-02-01

    A 73 year-old female patient was admitted to the 3rd Medical Department of Semmelweis University with a painful haematoma in the left loin and respiratory disorders. Her general condition was getting progressively worse. Chest X-ray demonstrated a left sided hemopneumothorax caused by a fractured rib. Thoracic drainage was planned, but the tube introduced on the usual place into the left thoracic cavity perforated the stomach which was incarcerated in the chest. After this an urgent operation was carried out. We found an incarcerated, twisted stomach prolapsing through a rupture of the diaphragm. It was partially necrotic. Excision of the stomach wall with suturing the diaphragm, lavage and drainage of the thoracic and abdominal cavity was carried out. Despite the operation multi-organ failure developed as a result of sepsis, and the patient'died. We discuss the literature in connection with the presentation of this rare and interesting case. In the past 15 years we could not find similar case in the Hungarian surgical literature.

  7. Effect of chest wall vibration on the canine diaphragm during breathing.

    PubMed

    Leduc, D; De, Troyer A

    2002-03-01

    High-frequency mechanical vibration of the ribcage reduces dyspnoea in patients with chronic obstructive pulmonary disease, and the suggestion has been made that this effect might be related to a decrease in central respiratory drive resulting from an increase in afferent inputs from intercostal muscles. In the present studies, the effects of ribcage vibration on central respiratory drive have been assessed without the confounding influence of conscious reactions. The electromyographic (EMG) activity of the diaphragm and the changes in pleural (Ppl) and abdominal (Pab) pressure were measured in six anaesthetized, spontaneously-breathing dogs while the rostral, the middle, or the caudal portion of the ribcage was vibrated at intervals during inspiration. The EMG activity of the external and parasternal intercostals was also measured. Ribcage vibration consistently elicited a marked increase in the inspiratory EMG activity recorded from the external intercostals, thus indicating that the procedure did activate intercostal muscle spindles. However, no alteration in diaphragmatic or parasternal intercostal EMG activity was seen in any animal. Transdiaphragmatic pressure and the relationship between deltaPab and deltaPpl during inspiration were also unaltered. The authors conclude that ribcage vibration and, with it, stimulation of external intercostal muscle spindles has no significant influence on phrenic motoneurones or on medullary inspiratory neurones. It is unlikely, therefore, that the beneficial effect of the procedure on dyspnoea results from a specific reduction in central respiratory drive.

  8. Dual diaphragm tank with telltale drain

    NASA Technical Reports Server (NTRS)

    Tuthill, Wallace C., Jr. (Inventor)

    1991-01-01

    A fluid storage and expulsion system comprising a tank with an internal flexible diaphragm assembly of dual diaphragms in back-to-back relationship, at least one of which is provided with a patterned surface having fine edges such that the diaphragms are in contact along said edges without mating contact of surface areas to thereby form fluid channels which extend outwardly to the peripheral edges of the diaphragms is described. The interior wall of the tank at the juncture of tank sections is formed with a circumferential annular recess comprising an outer annular recess portion which forms a fluid collection chamber and an inner annular recess portion which accommodates the peripheral edge portions of the diaphragms and a sealing ring in clamped sealing relation therebetween. The sealing ring is perforated with radially extending passages which allow any fluid leaking or diffusing past a diaphragm to flow through the fluid channels between the diaphragms to the fluid collection chamber. Ports connectable to pressure fittings are provided in the tank sections for admission of fluids to opposite sides of the diaphragm assembly. A drain passage through the tank wall to the fluid collection chamber permits detection, analysis and removal of fluids in the collection chamber.

  9. PERFORMANCE OF AN EARTHQUAKE EXCITED ROOF DIAPHRAGM.

    USGS Publications Warehouse

    Celebi, M.; Brady, G.; Safak, E.; Converse, A.; ,

    1986-01-01

    The objective of this paper is to study the earthquake performance of the roof diaphragm of the West Valley College gymnasium in Saratoga, California through a complete set of acceleration records obtained during the 24 April 1984 Morgan Hill Earthquake (M equals 6. 1). The roof diaphragm of the 112 ft. multiplied by 144 ft. rectangular, symmetric gymnasium consists of 3/8 in. plywood over tongue-and-groove sheathing attached to steel trusses supported by reinforced concrete columns and walls. Three sensors placed in the direction of each of the axes of the diaphragm facilitate the evaluation of in-plane deformation of the diaphragm. Other sensors placed at ground level measure vertical and horizontal motion of the building floor, and consequently allow the calculation of the relative motion of the diaphragm with respect to the ground level.

  10. Vibration of micromachined circular piezoelectric diaphragms.

    PubMed

    Hong, Eunki; Trolier-McKinstry, Susan; Smith, Robert; Krishnaswamy, Silai V; Freidhoff, Carl B

    2006-04-01

    Electrically and mechanically excited resonances in micromachined circular piezoelectric diaphragms have been investigated. The diaphragm structures were piezoelectric unimorphs consisting of Pb(Zr0.52,Ti0.48)O3 (PZT) films and thermally grown silicon oxide (SiO2) layers. For electrical excitation, ring-shaped interdigitated (IDT) electrodes formed on the top of the PZT layer were used to induce strain in the diaphragms. The diaphragm structures behaved much like circular membranes in which the membrane tension was approximately 206 N/m, at the fundamental modes. For higher modes, the resonance frequencies deviated from the theoretical values due to the finite stiffness of the diaphragms. Under mechanical drive, both symmetric and asymmetric modes were excited. However, for electrical excitation, the symmetric modes were dominant due to the symmetry of the driving IDT electrodes. At a pressure of 727 Torr, the quality factor was approximately 250, and this rose to 2000 at pressures below 1 Torr. When a forward bias was applied to the diaphragm, the membrane tension decreased, but under reverse biases the tension increased. However, because of repoling under reverse biases greater than the coercive field of the PZT film, the achievable increase in the membrane tension was limited. In the diaphragm structure, the nonlinear vibration was governed by geometric nonlinearity rather than material nonlinearity. In addition, evidence of non-180 degrees domain wall motion of the PZT layer in released diaphragms was observed.

  11. Metallic positive expulsion diaphragms

    NASA Technical Reports Server (NTRS)

    Gleich, D.

    1972-01-01

    High-cycle life ring-reinforced hemispherical type positive expulsion diaphragm performance was demonstrated by room temperature fluid expulsion tests of 13" diameter, 8 mil thick stainless steel configurations. A maximum of eleven (11) leak-free, fluid expulsions were achieved by a 25 deg cone angle diaphragm hoop-reinforced with .110-inch cross-sectional diameter wires. This represents a 70% improvement in diaphragm reversal cycle life compared to results previously obtained. The reversal tests confirmed analytic predictions for diaphragm cycle life increases due to increasing values of diaphragm cone angle, radius to thickness ratio and material strain to necking capacity. Practical fabrication techniques were demonstrated for forming close-tolerance, thin corrugated shells and for obtaining closely controlled reinforcing ring stiffness required to maximize diaphragm cycle life. A non-destructive inspection technique for monitoring large local shell bending strains was developed.

  12. The Diaphragm: Two Muscles

    NASA Astrophysics Data System (ADS)

    de Troyer, Andre; Sampson, Michael; Sigrist, Stephan; Macklem, Peter T.

    1981-07-01

    The costal and crural parts of the diaphragm were separately stimulated in anesthetized dogs. Stimulation of the costal part increased the dimensions of the lower rib cage, whereas stimulation of the crural part decreased the dimensions of the lower rib cage. It is concluded that the diaphragm consists of two muscles that act differently on the rib cage.

  13. Nonmetallic Diaphragms for Instruments

    NASA Technical Reports Server (NTRS)

    Eaton, H N; Buckingham, C T

    1925-01-01

    This report, the second of a series of reports relating to the general subject of instrument diaphragms. The first report of the series was published as Technical Report no. 165, "diaphragms for aeronautic instruments," and comprised an outline of historical developments and theoretical principles. The present report relates entirely to nonmetallic diaphragms, the use of which in certain types of pressure elements has been increasing for some time. Little, if any, information has been available to aid the designer of instruments using this form of pressure element. It was to attempt to meet the need for such information that the investigation reported in this paper was undertaken. The report describes the various materials which have been used as nonmetallic diaphragms, discusses the factors which affect the performance of the diaphragms and gives the results of tests made for the purpose of investigating the effect produced by these factors.

  14. Pressure activated diaphragm bonder

    DOEpatents

    Evans, Leland B.; Malba, Vincent

    1997-01-01

    A device is available for bonding one component to another, particularly for bonding electronic components of integrated circuits, such as chips, to a substrate. The bonder device in one embodiment includes a bottom metal block having a machined opening wherein a substrate is located, a template having machined openings which match solder patterns on the substrate, a thin diaphragm placed over the template after the chips have been positioned in the openings therein, and a top metal block positioned over the diaphragm and secured to the bottom block, with the diaphragm retained therebetween. The top block includes a countersink portion which extends over at least the area of the template and an opening through which a high pressure inert gas is supplied to exert uniform pressure distribution over the diaphragm to keep the chips in place during soldering. A heating means is provided to melt the solder patterns on the substrate and thereby solder the chips thereto.

  15. Pressure activated diaphragm bonder

    DOEpatents

    Evans, L.B.; Malba, V.

    1997-05-27

    A device is available for bonding one component to another, particularly for bonding electronic components of integrated circuits, such as chips, to a substrate. The bonder device in one embodiment includes a bottom metal block having a machined opening wherein a substrate is located, a template having machined openings which match solder patterns on the substrate, a thin diaphragm placed over the template after the chips have been positioned in the openings therein, and a top metal block positioned over the diaphragm and secured to the bottom block, with the diaphragm retained therebetween. The top block includes a countersink portion which extends over at least the area of the template and an opening through which a high pressure inert gas is supplied to exert uniform pressure distribution over the diaphragm to keep the chips in place during soldering. A heating means is provided to melt the solder patterns on the substrate and thereby solder the chips thereto. 4 figs.

  16. Diaphragm pacing: the state of the art

    PubMed Central

    Legras, Antoine; Arame, Alex; Pricopi, Ciprian; Boucherie, Jean-Claude; Badia, Alain; Panzini, Capucine Morelot

    2016-01-01

    Diaphragm pacing (DP) is an orphan surgical procedure that may be proposed in strictly selected ventilator-dependent patients to get an active diaphragm contraction. The goal is to wean from mechanical ventilation (MV) and restore permanent efficient breathing. The two validated indications, despite the lack of randomised control trials, concern patients with high-level spinal cord injuries (SCI) and central hypoventilation syndromes (CHS). To date, two different techniques exist. The first, intrathoracic diaphragm pacing (IT-DP), based on a radiofrequency method, in which the electrodes are directly placed around the phrenic nerve. The second, intraperitoneal diaphragm pacing (IP-DP) uses intradiaphragmatic electrodes implanted through laparoscopy. In both techniques, the phrenic nerves must be intact and diaphragm reconditioning is always required after implantation. No perioperative mortality has been reported and ventilator-weaning rate is about 72% to 96% in both techniques. Improvement of quality of life, by restoring a more physiological breathing, has been almost constant in patients that could be weaned. Failure or delay in recovery of effective diaphragm contractions could be due to irreversible amyotrophy or chest wall damage. Recent works have evaluated the interest of IP-DP in amyotrophic lateral sclerosis (ALS). After some short series were reported in the literature, the only multicentric randomized study including 74 ALS patients was prematurely stopped because of excessive mortality in paced patients. Then, another trial analysed the place of IP-DP in peripheral diaphragm dysfunction but, given the multiple biases, the published results cannot validate that indication. Reviewing all available literature as in our experience, shows that DP is an effective method to wean selected patients dependent on ventilator and improve their daily life. Other potential indications will have to be evaluated by randomised control trials. PMID:27195135

  17. Active Piezoelectric Diaphragms

    NASA Technical Reports Server (NTRS)

    Bryant, Robert G.; Effinger, Robert T., IV; Aranda, Isaiah, Jr.; Copeland, Ben M.; Covington, Ed W., III

    2002-01-01

    Several active piezoelectric diaphragms were fabricated by placing unelectroded piezoelectric disks between copper clad films patterned with Inter-Circulating Electrodes "ICE". When a voltage potential is applied to the electrodes, the result is radially distributed electric field that mechanically strains the piezo-ceramic along the Z-axis (perpendicular to the applied electric field), rather than the expected in-plane (XY-axis) direction. Unlike other out of plane piezoelectric actuators, which are benders, these Radial Field Diaphragms (RFDs) strain concentrically yet afford high displacements while maintaining a constant circumference. This paper covers the fabrication and characterization of these diaphragms as a function of poling field strength, ceramic diameter and line spacing, as well as the surface topography, the resulting strain field and displacement as a function of applied voltage ranging from DC to 10 Hz.

  18. Diaphragms for Aeronautic Instruments

    NASA Technical Reports Server (NTRS)

    Hersey, M D

    1924-01-01

    This investigation was carried out at the request of the National Advisory Committee for Aeronautics and comprises an outline of historical developments and theoretical principles, together with a discussion of expedients for making the most effective use of existing diaphragms actuated by the hydrostatic pressure form an essential element of a great variety instruments for aeronautic and other technical purposes. The various physical data needed as a foundation for rational methods of diaphragm design have not, however, been available hitherto except in the most fragmentary form.

  19. Materials for Slack Diaphragms

    NASA Technical Reports Server (NTRS)

    Puschmann, Traute

    1940-01-01

    This report deals with systematic experiments carried out on five diaphragm materials with different pretreatment, for the purpose of ascertaining the suitability of such materials for slack diaphragms. The relationship of deflection and load, temperature and moisture, was recorded. Of the explored materials, synthetic leather, balloon cloth, goldbeaters skin, Igelit and Buna, synthetic leather treated with castor oil is the most suitable material for the small pressure range required. Balloon cloth is nearly as good, while goldbeaters skin, Igelit and Buna were found to be below the required standards.

  20. A Balanced Diaphragm Type of Maximum Cylinder Pressure Indicator

    NASA Technical Reports Server (NTRS)

    Spanogle, J A; Collins, John H , Jr

    1930-01-01

    A balanced diaphragm type of maximum cylinder pressure indicator was designed to give results consistent with engine operating conditions. The apparatus consists of a pressure element, a source of controlled high pressure and a neon lamp circuit. The pressure element, which is very compact, permits location of the diaphragm within 1/8 inch of the combustion chamber walls without water cooling. The neon lamp circuit used for indicating contact between the diaphragm and support facilitates the use of the apparatus with multicylinder engines.

  1. APU diaphragm testing

    NASA Technical Reports Server (NTRS)

    Shelley, Richard; Ross, William L., Sr.

    1993-01-01

    The Auxiliary Power Unit (APU) fuel (hydrazine) tanks were removed from the Columbia Shuttle during major modification of the vehicle, because of long-term hydrazine compatibility concerns. The three tanks had been in service for 11 years. As part of an effort to determine whether the useful life of the fuel tanks can be extended, examination of the ethylene propylene rubber (EPR) diaphragm and the metal casing from one of the APU tanks was required. NASA Johnson Space Center Propulsion and Power Division requested the NASA Johnson Space Center White Sands Test Facility to examine the EPR diaphragm for signs of degradation that might limit the life of its function in the APU tank and to examine the metal casing for signs of surface corrosion. No appreciable degradation of the EPR diaphragm was noted. A decrease in the tensile properties was found, but tensile failure is considered unlikely because the metal casing constrains the diaphragm, preventing it from elongating more than a few percent. The titanium casing showed no evidence of surface corrosion.

  2. APU diaphragm testing

    NASA Astrophysics Data System (ADS)

    Shelley, Richard; Ross, William L., Sr.

    1993-03-01

    The Auxiliary Power Unit (APU) fuel (hydrazine) tanks were removed from the Columbia Shuttle during major modification of the vehicle, because of long-term hydrazine compatibility concerns. The three tanks had been in service for 11 years. As part of an effort to determine whether the useful life of the fuel tanks can be extended, examination of the ethylene propylene rubber (EPR) diaphragm and the metal casing from one of the APU tanks was required. NASA Johnson Space Center Propulsion and Power Division requested the NASA Johnson Space Center White Sands Test Facility to examine the EPR diaphragm for signs of degradation that might limit the life of its function in the APU tank and to examine the metal casing for signs of surface corrosion. No appreciable degradation of the EPR diaphragm was noted. A decrease in the tensile properties was found, but tensile failure is considered unlikely because the metal casing constrains the diaphragm, preventing it from elongating more than a few percent. The titanium casing showed no evidence of surface corrosion.

  3. Compressor diaphragm assembly

    SciTech Connect

    Scalzo, A.

    1989-12-26

    This patent describes, in a combustion turbine having a casing, one or more slots of a first predetermined cross-section formed circumferentially within the casing at a compressor portion of the turbine, and a compressor diaphragm assembly adapted to be suspended from each of the one or more slots to provide a labyrinth seal with a plurality of compressor discs, a method of forming each compressor diaphragm assembly. It comprises: providing a plurality of vane airfoils each of which have an inner shroud formed integrally with the vane airfoil, and an outer portion attached to the vane airfoil; providing outer ring means for suspending each of the plurality of van airfoils at a stagger angle; suspending the plurality of vane airfoils from the outer ring means, thereby disposing each the vane airfoil and its respective outer portion at the stagger angle; and providing seal carrier means for engagement with each the inner shroud.

  4. Radial Field Piezoelectric Diaphragms

    NASA Technical Reports Server (NTRS)

    Bryant, R. G.; Effinger, R. T., IV; Copeland, B. M., Jr.

    2002-01-01

    A series of active piezoelectric diaphragms were fabricated and patterned with several geometrically defined Inter-Circulating Electrodes "ICE" and Interdigitated Ring Electrodes "ICE". When a voltage potential is applied to the electrodes, the result is a radially distributed electric field that mechanically strains the piezoceramic along the Z-axis (perpendicular to the applied electric field). Unlike other piezoelectric bender actuators, these Radial Field Diaphragms (RFDs) strain concentrically yet afford high displacements (several times that of the equivalent Unimorph) while maintaining a constant circumference. One of the more intriguing aspects is that the radial strain field reverses itself along the radius of the RFD while the tangential strain remains relatively constant. The result is a Z-deflection that has a conical profile. This paper covers the fabrication and characterization of the 5 cm. (2 in.) diaphragms as a function of poling field strength, ceramic thickness, electrode type and line spacing, as well as the surface topography, the resulting strain field and displacement as a function of applied voltage at low frequencies. The unique features of these RFDs include the ability to be clamped about their perimeter with little or no change in displacement, the environmentally insulated packaging, and a highly repeatable fabrication process that uses commodity materials.

  5. Diaphragm Stirling cryocooler developments

    NASA Technical Reports Server (NTRS)

    Stacy, W. D.

    1992-01-01

    This paper reports on the status of several ongoing development programs aimed at the demonstration of diaphragm Stirling cycle cryocooler performance. Key attributes of this technology focus on long reliable operating life and excellent efficiency, making it a candidate for cooling of satellite-borne long wavelength sensors for astrophysics and earth observing missions. Three programs are described, each leading to system or component test hardware: a 2 W 65 K single-stage Standard Spacecraft Cryocooler, a 300 mW 30 K two-stage cooler and a 200 mW 4-20 K single-stage cooler. Design features are described, and breadboard experimental data are presented.

  6. Flexible Sandwich Diaphragms Are Less Permeable

    NASA Technical Reports Server (NTRS)

    Michalovic, John G.; Vassallo, Franklin A.

    1993-01-01

    Diaphragms for use in refrigerator compressors made as laminates of commercially available elastomers and metals. Diaphragms flexible, but less permeable by chlorofluorocarbon refrigerant fluids than diaphragms made of homogeneous mixtures of materials.

  7. [Diaphragm dysfunction : Facts for clinicians].

    PubMed

    Bruells, C S; Marx, G

    2016-10-20

    Diaphragm function is crucial for patient outcome in the ICU setting and during the treatment period. The occurrence of an insufficiency of the respiratory pump, which is predominantly formed by the diaphragm, may result in intubation after failure of noninvasive ventilation. Especially patients suffering from chronic obstructive pulmonary disease are in danger of hypercapnic respiratory failure. Changes in biomechanical properties and fiber texture of the diaphragm are further cofactors directly leading to a need for intubation and mechanical ventilation. After intubation and the following inactivity the diaphragm is subject to profound pathophysiologic changes resulting in atrophy and dysfunction. Besides this inactivity-triggered mechanism (termed as ventilator-induced diaphragmatic dysfunction) multiple factors, comorbidities, pharmaceutical agents and additional hits during the ICU treatment, especially the occurrence of sepsis, influence diaphragm homeostasis and can lead to weaning failure. During the weaning process monitoring of diaphragm function can be done with invasive methods - ultrasound is increasingly established to monitor diaphragm contraction, but further and better powered studies are in need to prove its value as a diagnostic tool.

  8. Novel diaphragm based Stirling cryocooler

    NASA Astrophysics Data System (ADS)

    Caughley, Alan; Tucker, Alan; Gschwendtner, Michael; Sellier, Mathieu

    2012-06-01

    Industrial Research Ltd has developed a unique diaphragm-based pressure wave generator technology for employment in pulse tube and Stirling cryocoolers. The system uses a pair of metal diaphragms to separate the clean cryocooler gas circuit from a conventionally lubricated mechanical driver, thus producing a clean pressure wave with a long-life drive. We have now extended the same diaphragm concept to support and seal the displacer in a free piston Stirling expander. The diaphragms allow displacer movement without rubbing or clearance gap seals, hence allowing for the development of costeffective long-life and efficient Stirling cryocoolers. Initial modeling, operating in conjunction with a 200 cc swept volume pressure wave generator, predicted in excess of 300 W cooling at 77 K with a Carnot efficiency of over 25%. A proof-of-concept prototype has achieved cryogenic temperatures. Details of the concept, modeling, and testing will be presented.

  9. Sponge versus diaphragm for contraception.

    PubMed

    Kuyoh, M A; Toroitich-Ruto, C; Grimes, D A; Schulz, K F; Gallo, M G

    2002-01-01

    The contraceptive vaginal sponge was developed as an alternative to the contraceptive diaphragm. The sponge, made of polyurethane impregnated with nonoxynol-9 (1g), releases 125 mg of the spermicide over 24 h of use. Unlike the diaphragm, the sponge can be used for more than one coital act within 24 h without the insertion of additional spermicide, and the sponge does not require fitting or a prescription from a physician. How the sponge compares with the diaphragm in terms of efficacy and continuation is not clear. To compare the efficacy and continuation rates of the sponge compared with the diaphragm (used with nonoxynol-9 as a spermicide). Our a priori hypothesis was that the sponge would have a higher failure rate and higher discontinuation rates than the diaphragm. We searched the computerized databases MEDLINE, EMBASE, Popline, LILACS, and the Cochrane Controlled Trials Register. In addition, we searched the reference lists of all potentially relevant articles and book chapters. We also contacted investigators involved with both trials identified to seek other published or unpublished trials. We included randomized controlled trials comparing the vaginal contraceptive sponge (Today; Collatex) with any diaphragm used with nonoxynol-9 to prevent pregnancy. We examined the studies identified through the literature searches for possible inclusion and evaluated their methodological quality using the Cochrane guidelines. We contacted an author involved with both published trials for supplementary information about randomization and allocation concealment. We entered data into RevMan 4.1 and calculated Peto odds ratios for overall pregnancy and 12-month discontinuation using numbers of women as the denominator. We also abstracted 12-month cumulative life-table ratios for these same outcomes, but were unable to aggregate these data. The sponge was statistically significantly less effective in both trials in preventing overall pregnancy than was the diaphragm. The 12

  10. Sponge versus diaphragm for contraception.

    PubMed

    Kuyoh, Maureen A; Toroitich-Ruto, Cathy; Grimes, David A; Schulz, Kenneth F; Gallo, Maria F; Lopez, Laureen M

    2002-07-22

    The contraceptive vaginal sponge was developed as an alternative to the contraceptive diaphragm. The sponge, made of polyurethane impregnated with nonoxynol-9 (1g), releases 125 mg of the spermicide over 24 hours of use. Unlike the diaphragm, the sponge can be used for more than one coital act within 24 hours without the insertion of additional spermicide, and the sponge does not require fitting or a prescription from a physician. How the sponge compares with the diaphragm in terms of efficacy and continuation is not clear. To compare the efficacy and continuation rates of the sponge with the diaphragm (used with nonoxynol-9). Our a priori hypothesis was that the sponge would have higher rates for failure and discontinuation than the diaphragm. In April 2013, we searched the computerized databases MEDLINE, POPLINE, LILACS, CENTRAL, ClinicalTrials.gov and ICTRP.Earlier searches also included EMBASE. For the initial review, we searched the reference lists of relevant articles and book chapters.We also contacted investigators involved with the identified trials for other published or unpublished trials. We included randomized controlled trials comparing the vaginal contraceptive sponge (Today; Collatex) with any diaphragm used with nonoxynol-9 to prevent pregnancy. We examined the studies identified through the literature searches for possible inclusion and evaluated their methodological quality using the Cochrane guidelines. We entered data into RevMan and calculated Peto odds ratios for overall pregnancy and 12-month discontinuation using numbers of women as the denominator. We also abstracted 12-month cumulative life-table ratios for these same outcomes but were unable to aggregate these data. Two trials met the inclusion criteria. The sponge was significantly less effective in both trials in preventing overall pregnancy than was the diaphragm. In the larger USA trial, the 12-month cumulative life-table termination rates per 100 women for overall pregnancy were 17

  11. Miniature electrically operated diaphragm valve

    DOEpatents

    Adkins, Douglas R.; Spletzer, Barry L.; Wong, Chungnin C.; Frye-Mason, Gregory C.; Fischer, Gary J.; Hesketh, Peter J.

    2001-01-01

    The present invention provides a miniature electrically operated valve that can stand off significant pressures, that can be inexpensively produced, and that can be made to operate without continuous electrical power. A valve according to the present invention comprises a housing and a beam mounted with the housing. A diaphragm mounted with the housing forms a sealed fluid volume. An electromagnetic energy source, such as an electromagnetic coil, mounts with the housing and when energized urges the beam in one direction. The beam can be urged in the opposing direction by passive means or by reversing the polarity of the electromagnetic energy source or by a second electromagnetic energy source. Two fluid ports mount with the housing. A first fluid port mounts so that, as the beam is urged in one direction or the opposite, the beam urges the diaphragm to move between engaging and substantially sealing the fluid port and disengaging and not substantially sealing the fluid port. A seat can be mounted with the diaphragm to aid in sealing the fluid port. Latching mechanisms such as permanent magnets can be mounted so that the valve remains in the open or closed positions without continuous electrical power input. Fluid can flow through the housing between the two fluid ports when the diaphragm does not seal the first fluid port, but can be prevented from flowing by urging the beam so that the diaphragm seals the first fluid port. Various embodiments accommodate various latching mechanisms, electromagnetic energy sources, number of fluid ports, and diaphragm design considerations.

  12. CFD analysis of a diaphragm free-piston Stirling cryocooler

    NASA Astrophysics Data System (ADS)

    Caughley, Alan; Sellier, Mathieu; Gschwendtner, Michael; Tucker, Alan

    2016-10-01

    This paper presents a Computational Fluid Dynamics (CFD) analysis of a novel free-piston Stirling cryocooler that uses a pair of metal diaphragms to seal and suspend the displacer. The diaphragms allow the displacer to move without rubbing or moving seals. When coupled to a metal diaphragm pressure wave generator, the system produces a complete Stirling cryocooler with no rubbing parts in the working gas space. Initial modelling of this concept using the Sage modelling tool indicated the potential for a useful cryocooler. A proof-of-concept prototype was constructed and achieved cryogenic temperatures. A second prototype was designed and constructed using the experience gained from the first. The prototype produced 29 W of cooling at 77 K and reached a no-load temperature of 56 K. The diaphragm's large diameter and short stroke produces a significant radial component to the oscillating flow fields inside the cryocooler which were not modelled in the one-dimensional analysis tool Sage that was used to design the prototypes. Compared with standard pistons, the diaphragm geometry increases the gas-to-wall heat transfer due to the higher velocities and smaller hydraulic diameters. A Computational Fluid Dynamics (CFD) model of the cryocooler was constructed to understand the underlying fluid-dynamics and heat transfer mechanisms with the aim of further improving performance. The CFD modelling of the heat transfer in the radial flow fields created by the diaphragms shows the possibility of utilizing the flat geometry for heat transfer, reducing the need for, and the size of, expensive heat exchangers. This paper presents details of a CFD analysis used to model the flow and gas-to-wall heat transfer inside the second prototype cryocooler, including experimental validation of the CFD to produce a robust analysis.

  13. APU diaphragm testing. Test plan

    NASA Technical Reports Server (NTRS)

    Shelley, Richard

    1992-01-01

    Auxiliary Power Unit (APU) fuel (hydrazine) tanks have had to be removed from the Columbia Shuttle (OV-102) because they have been in service for 11 years, which is the limit of their useful life. As part of an effort to determine whether the useful life of the fuel tanks can be extended, examination of the ethylene propylene rubber (EPR) diaphragm and the metal from one of the APU tanks is required. The JSC Propulsion and Power Division has requested White Sands Test Facility (WSTF) to examine the EPR diaphragm thoroughly and the metal casing generally from one tank. The objective is to examine the EPR diaphragm for signs of degradation that may limit the life of its function in the APU propellant tank. The metal casing will also be examined for signs of surface corrosion.

  14. Diaphragm defined Stirling cryocooler development

    NASA Astrophysics Data System (ADS)

    Shimko, Martin A.; Stacy, W. D.

    The authors report on progress in developing a long-life cryocooler for spaceborne applications. The work to date is reviewed, focusing on developments over the past year. The basis of the machine design is the use of flat metallic diaphragms to sweep and seal the working volumes of both the expander and compressor in a Stirling cycle cryocooler. Three areas were pursued. An engineering model of a diaphragm compressor using an innovative linear drive was fabricated and tested. The previous year's breadboard expander apparatus was rebuilt. The design of a flightworthy engineering model of a 65 Kelvin standard spacecraft cryocooler (SSC) was completed. Fabrication of two units is ongoing.

  15. Electrolysis-based diaphragm actuators

    NASA Astrophysics Data System (ADS)

    Pang, C.; Tai, Y.-C.; Burdick, J. W.; Andersen, R. A.

    2006-02-01

    This work presents a new electrolysis-based microelectromechanical systems (MEMS) diaphragm actuator. Electrolysis is a technique for converting electrical energy to pneumatic energy. Theoretically electrolysis can achieve a strain of 136 000% and is capable of generating a pressure above 200 MPa. Electrolysis actuators require modest electrical power and produce minimal heat. Due to the large volume expansion obtained via electrolysis, small actuators can create a large force. Up to 100 µm of movement was achieved by a 3 mm diaphragm. The actuator operates at room temperature and has a latching and reversing capability.

  16. The effect of diaphragm contraction on upper airway collapsibility.

    PubMed

    Hillman, David R; Walsh, Jennifer H; Maddison, Kathleen J; Platt, Peter R; Schwartz, Alan R; Eastwood, Peter R

    2013-08-01

    Increasing lung volume increases upper airway patency and decreases airway resistance and collapsibility. The role of diaphragm contraction in producing these changes remains unclear. This study was undertaken to determine the effect of selective diaphragm contraction, induced by phrenic nerve stimulation, on upper airway collapsibility and the extent to which any observed change was attributable to lung volume-related changes in pressure gradients or to diaphragm descent-related mediastinal traction. Continuous bilateral transcutaneous cervical phrenic nerve stimulation (30 Hz) was applied to nine supine, anesthetized human subjects during transient decreases in airway pressure to levels sufficient to produce flow limitation when unstimulated. Stimulation was applied at two intensities (low and high) and its effects on lung volume and airflow quantified relative to unstimulated conditions. Lung volume increased by 386 ± 269 ml (means ± SD) and 761 ± 556 ml during low and high stimulation, respectively (P < 0.05 for the difference between these values), which was associated with peak inspiratory flow increases of 69 ± 57 and 137 ± 108 ml/s, respectively (P < 0.05 for the difference). Stimulation-induced change in lung volume correlated with change in peak flow (r = 0.65, P < 0.01). Diaphragm descent-related outward displacement of the abdominal wall produced no change in airflow unless accompanied by lung volume change. We conclude that phrenic nerve stimulation-induced diaphragm contraction increases lung volume and reduces airway collapsibility in a dose-dependent manner. The effect appears primarily mediated by changes in lung volume rather than mediastinal traction from diaphragm descent. The study provides a rationale for use of continuous phrenic stimulation to treat obstructive sleep apnea.

  17. Computer simulation analysis of normal and abnormal development of the mammalian diaphragm

    PubMed Central

    Fisher, Jason C; Bodenstein, Lawrence

    2006-01-01

    Background Congenital diaphragmatic hernia (CDH) is a birth defect with significant morbidity and mortality. Knowledge of diaphragm morphogenesis and the aberrations leading to CDH is limited. Although classical embryologists described the diaphragm as arising from the septum transversum, pleuroperitoneal folds (PPF), esophageal mesentery and body wall, animal studies suggest that the PPF is the major, if not sole, contributor to the muscular diaphragm. Recently, a posterior defect in the PPF has been identified when the teratogen nitrofen is used to induce CDH in fetal rodents. We describe use of a cell-based computer modeling system (Nudge++™) to study diaphragm morphogenesis. Methods and results Key diaphragmatic structures were digitized from transverse serial sections of paraffin-embedded mouse embryos at embryonic days 11.5 and 13. Structure boundaries and simulated cells were combined in the Nudge++™ software. Model cells were assigned putative behavioral programs, and these programs were progressively modified to produce a diaphragm consistent with the observed anatomy in rodents. Homology between our model and recent anatomical observations occurred under the following simulation conditions: (1) cell mitoses are restricted to the edge of growing tissue; (2) cells near the chest wall remain mitotically active; (3) mitotically active non-edge cells migrate toward the chest wall; and (4) movement direction depends on clonal differentiation between anterior and posterior PPF cells. Conclusion With the PPF as the sole source of mitotic cells, an early defect in the PPF evolves into a posteromedial diaphragm defect, similar to that of the rodent nitrofen CDH model. A posterolateral defect, as occurs in human CDH, would be more readily recreated by invoking other cellular contributions. Our results suggest that recent reports of PPF-dominated diaphragm morphogenesis in the rodent may not be strictly applicable to man. The ability to recreate a CDH defect

  18. Diaphragm Dysfunction in Chronic Obstructive Pulmonary Disease

    PubMed Central

    Ottenheijm, Coen A. C.; Heunks, Leo M. A.; Sieck, Gary C.; Zhan, Wen-Zhi; Jansen, Suzanne M.; Degens, Hans; de Boo, Theo; Dekhuijzen, P. N. Richard

    2005-01-01

    Rationale: Hypercapnic respiratory failure because of inspiratory muscle weakness is the most important cause of death in chronic obstructive pulmonary disease (COPD). However, the pathophysiology of failure of the diaphragm to generate force in COPD is in part unclear. Objectives: The present study investigated contractile function and myosin heavy chain content of diaphragm muscle single fibers from patients with COPD. Methods: Skinned muscle fibers were isolated from muscle biopsies from the diaphragm of eight patients with mild to moderate COPD and five patients without COPD (mean FEV1 % predicted, 70 and 100%, respectively). Contractile function of single fibers was assessed, and afterwards, myosin heavy chain content was determined in these fibers. In diaphragm muscle homogenates, the level of ubiquitin-protein conjugation was determined. Results: Diaphragm muscle fibers from patients with COPD showed reduced force generation per cross-sectional area, and reduced myosin heavy chain content per half sarcomere. In addition, these fibers had decreased Ca2+ sensitivity of force generation, and slower cross-bridge cycling kinetics. Our observations were present in fibers expressing slow and 2A isoforms of myosin heavy chain. Ubiquitin-protein conjugation was increased in diaphragm muscle homogenates of patients with mild to moderate COPD. Conclusions: Early in the development of COPD, diaphragm fiber contractile function is impaired. Our data suggest that enhanced diaphragm protein degradation through the ubiquitin-proteasome pathway plays a role in loss of contractile protein and, consequently, failure of the diaphragm to generate force. PMID:15849324

  19. Diaphragm Dysfunction: Diagnostic Approaches and Management Strategies

    PubMed Central

    Dubé, Bruno-Pierre; Dres, Martin

    2016-01-01

    The diaphragm is the main inspiratory muscle, and its dysfunction can lead to significant adverse clinical consequences. The aim of this review is to provide clinicians with an overview of the main causes of uni- and bi-lateral diaphragm dysfunction, explore the clinical and physiological consequences of the disease on lung function, exercise physiology and sleep and review the available diagnostic tools used in the evaluation of diaphragm function. A particular emphasis is placed on the clinical significance of diaphragm weakness in the intensive care unit setting and the use of ultrasound to evaluate diaphragmatic action. PMID:27929389

  20. Importance of diaphragm thickness in amyotrophic lateral sclerosis patients with diaphragm pacing system implantation.

    PubMed

    Sanli, Aydın; Sengun, Ihsan Sukru; Tertemiz, Kemal Can; Alpaydin, Aylin Ozgen; Karacam, Volkan; Sanli, Bahar Agaoglu; Oz, Didem; Ozalevli, Sevgi; Ozdemir, Nezih

    2016-01-01

    Severe respiratory failure develops as a result of the involvement of the respiratory muscles in patients with amyotrophic lateral sclerosis (ALS). Implantation of diaphragm pacing system (DPS) has been carried out on ALS patients since 2005 to avoid these situations, but the importance of diaphragm thickness has not yet been established clearly. We retrospectively evaluated 34 ALS patients who had previously implanted DPS to detect the importance of diaphragm thickness. We investigated the effect of diaphragm thickness, which was measured by preoperative thorax computerized tomography on preoperative respiratory function tests (RFT), arterial blood gas (ABG) analysis, postoperative 3- and 6-month oxygen saturations and mortality. The right diaphragm thickness was calculated as 4.60 (2.95-6.00) mm, while the left diaphragm thickness was 4.10 (2.77-6.00) mm. Six patients died during the follow-up period. We did not detect a significant relationship between ABG parameters, RFT and diaphragm thickness. However, according to our observations, the diaphragm thickness was significantly related to mortality. The right diaphragm was significantly thinner in cases that required preoperative respiratory support and had percutaneous endoscopic gastrostomy. When the cut-off values for the diaphragm thickness were accepted as 3.50 mm, significantly higher mortality among patients below this was observed. Diaphragm thickness is an important criterion in cases for which DPS implantation is planned. We consider that avoidance of DPS implantation is more suitable for cases with a diaphragm thickness below 3.50 mm because of mortality.

  1. Diaphragm

    MedlinePlus

    ... general, how well each type of birth control method works depends on a lot of things. In the ... ON THIS TOPIC About Birth Control Birth Control Methods: How Well Do They Work? What Can I Expect From the Gynecologist? Cervical ...

  2. Diaphragm

    MedlinePlus

    ... a dome-shaped bowl made of thin, flexible rubber that sits over the cervix. How Does It ... or baby oil. These substances can cause the rubber to become brittle and crack. Other vaginal creams, ...

  3. Passive properties of the diaphragm in COPD.

    PubMed

    Moore, Alastair J; Stubbings, Alison; Swallow, Elisabeth B; Dusmet, Michael; Goldstraw, Peter; Porcher, Raphaël; Moxham, John; Polkey, Michael I; Ferenczi, Michael A

    2006-11-01

    Structural adaptations that occur in the diaphragm muscle of patients with chronic obstructive pulmonary disease (COPD), namely an increase in type I fibers and a decrease in type II fibers, have been explored in terms of the active contractile properties of the diaphragm. The aim of this study was to test the passive properties of the diaphragm by measuring the force response of relaxed diaphragm muscle fibers to stretching to determine the effect of COPD on these properties. Costal diaphragm biopsies were taken from patients with COPD and from controls with normal pulmonary function. From these biopsies, titin expression was assessed in diaphragm homogenates by gel electrophoresis, and the restoring force was measured by incremental stretching of single fibers in the relaxed state and measuring the force response to stretching. A quadratic model was used to illustrate the relationship between restoring force and muscle fiber length, and it revealed that COPD fibers generate significantly lower restoring forces than control fibers as judged by the area under the force-length curve. Furthermore, this finding applies to both type I and type II fibers. Gel electrophoresis revealed different titin isoforms in COPD and controls, consistent with the conclusion that COPD results not only in a change in muscle fiber-type distribution but in a structural change in the titin molecule in all muscle fiber types within the diaphragm. This may assist the muscle with the energetic changes in the length of the diaphragm required during breathing in COPD.

  4. Endotoxemia accelerates diaphragm dysfunction in ventilated rabbits.

    PubMed

    Yang, Yi; Yu, Tao; Pan, Chun; Longhini, Federico; Liu, Ling; Huang, Yingzi; Guo, Fengmei; Qiu, Haibo

    2016-12-01

    Ventilators may induce diaphragm dysfunction, and most of the septic population who are admitted to the intensive care unit require mechanical ventilation. However, there is no evidence that sepsis accelerates the onset of ventilator-induced diaphragm dysfunction or affects the microcirculation. Our study investigated whether lipopolysaccharide (LPS)-induced endotoxemia accelerated diaphragm dysfunction in ventilated rabbits by evaluating microcirculation, lipid accumulation, and diaphragm contractility. After anesthesia and tracheostomy, 25 invasively monitored and mechanically ventilated New Zealand white rabbits were randomized to control (n = 5), controlled mechanical ventilation (CMV) (n = 5), pressure support ventilation (PSV; n = 5), CMV or PSV with LPS-induced endotoxemia (CMV-LPS and PSV-LPS, respectively; n = 5 for each). Rabbits were anesthetized and ventilated for 24 h, except the control rabbits (30 min). Diaphragmatic contractility was evaluated using neuromechanical and neuroventilatory efficiency. We evaluated the following at the end of the protocol: (1) diaphragm microcirculation; (2) lipid accumulation; and (3) diaphragm muscular fibers structure. Diaphragm contractility, microcirculation, lipid accumulation, and fiber structures were severely compromised in endotoxemic animals after 24 h compared to nonendotoxemic rabbits. Moreover, a slight but significant increase in lipid accumulation was observed in CMV and PSV groups compared with controls (P < 0.05). Endotoxemia accelerates the diaphragm dysfunction process in ventilated rabbits, affects the microcirculation, and results in diaphragmatic lipid accumulation and contractility impairment. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Spontaneous diaphragm rupture associated with vaginal delivery.

    PubMed

    Hamaji, Masatsugu; Burt, Bryan M; Ali, Syed Osman; Cohen, Daniel M

    2013-08-01

    Spontaneous rupture of the diaphragm associated with vaginal delivery is a rare occurrence, but has high rates of morbidity and mortality. Herein, we present a first uncomplicated case of spontaneous rupture of the diaphragm associated with vaginal delivery, which was treated successfully with surgery via a thoracotomy.

  6. Benefits of the rotary diaphragm pump.

    PubMed

    Borstell, D

    2005-03-01

    The huge variety of applications in the medical field represents a challenge for the design of miniature pumps. There are well-known designs such as piston pumps, eccenter diaphragm pumps and peristaltic pumps. There are lesser-known types such as the rotary diaphragm pump, the subject of this article. Its design features, variants, and advantages and disadvantages are examined.

  7. Radial-Electric-Field Piezoelectric Diaphragm Pumps

    NASA Technical Reports Server (NTRS)

    Bryant, Robert G.; Working, Dennis C.; Mossi, Karla; Castro, Nicholas D.; Mane, Pooma

    2009-01-01

    In a recently invented class of piezoelectric diaphragm pumps, the electrode patterns on the piezoelectric diaphragms are configured so that the electric fields in the diaphragms have symmetrical radial (along-the-surface) components in addition to through-the-thickness components. Previously, it was accepted in the piezoelectric-transducer art that in order to produce the out-of-plane bending displacement of a diaphragm needed for pumping, one must make the electric field asymmetrical through the thickness, typically by means of electrodes placed on only one side of the piezoelectric material. In the present invention, electrodes are placed on both sides and patterned so as to produce substantial radial as well as through-the-thickness components. Moreover, unlike in the prior art, the electric field can be symmetrical through the thickness. Tests have shown in a given diaphragm that an electrode configuration according to this invention produces more displacement than does a conventional one-sided electrode pattern. The invention admits of numerous variations characterized by various degrees of complexity. Figure 1 is a simplified depiction of a basic version. As in other piezoelectric diaphragm pumps of similar basic design, the prime mover is a piezoelectric diaphragm. Application of a suitable voltage to the electrodes on the diaphragm causes it to undergo out-of-plane bending. The bending displacement pushes a fluid out of, or pulls the fluid into, a chamber bounded partly by the diaphragm. Also as in other diaphragm pumps in general, check valves ensure that the fluid flows only in through one port and only out through another port.

  8. Pressure compensated transducer system with constrained diaphragm

    NASA Astrophysics Data System (ADS)

    Percy, Joseph L.

    1992-08-01

    An acoustic source apparatus has an acoustic transducer that is enclosed in a substantially rigid and watertight enclosure to resist the pressure of water on the transducer and to seal the transducer from the water. The enclosure has an opening through which acoustic signals pass and over which is placed a resilient, expandable and substantially water-impermeable diaphragm. A net stiffens and strengthens the diaphragm as well as constrains the diaphragm from overexpansion or from migrating due to buoyancy forces. Pressurized gas, regulated at slightly above ambient pressure, is supplied to the enclosure and the diaphragm to compensate for underwater ambient pressures. Gas pressure regulated at above ambient pressure is used to selectively tune the pressure levels within the enclosure and diaphragm so that diaphragm resonance can be achieved. Controls are used to selectively fill, as well as vent the enclosure and diaphragm during system descent and ascent, respectively. A signal link is used to activate these controls and to provide the driving force for the acoustic transducer.

  9. Slit Diaphragms Contain Tight Junction Proteins

    PubMed Central

    Fukasawa, Hirotaka; Bornheimer, Scott; Kudlicka, Krystyna; Farquhar, Marilyn G.

    2009-01-01

    Slit diaphragms are essential components of the glomerular filtration apparatus, as changes in these junctions are the hallmark of proteinuric diseases. Slit diaphragms, considered specialized adherens junctions, contain both unique membrane proteins (e.g., nephrin, podocin, and Neph1) and typical adherens junction proteins (e.g., P-cadherin, FAT, and catenins). Whether slit diaphragms also contain tight junction proteins is unknown. Here, immunofluorescence, immunogold labeling, and cell fractionation demonstrated that rat slit diaphragms contain the tight junction proteins JAM-A (junctional adhesion molecule A), occludin, and cingulin. We found these proteins in the same protein complexes as nephrin, podocin, CD2AP, ZO-1, and Neph1 by cosedimentation, coimmunoprecipitation, and pull-down assays. PAN nephrosis increased the protein levels of JAM-A, occludin, cingulin, and ZO-1 several-fold in glomeruli and loosened their attachment to the actin cytoskeleton. These data extend current information about the molecular composition of slit diaphragms by demonstrating the presence of tight junction proteins, although slit diaphragms lack the characteristic morphologic features of tight junctions. The contribution of these proteins to the assembly of slit diaphragms and potential signaling cascades requires further investigation. PMID:19478094

  10. Neuromuscular Ultrasound for Evaluation of the Diaphragm

    PubMed Central

    Sarwal, Aarti; Walker, Francis O.; Cartwright, Michael S.

    2012-01-01

    Neuromuscular clinicians are often asked to evaluate the diaphragm for diagnostic and prognostic purposes. Traditionally, this evaluation is accomplished through history, physical exam, fluoroscopic sniff test, nerve conduction studies, and electromyography (EMG). Nerve conduction studies and EMG in this setting are challenging, uncomfortable, and can cause serious complications such as pneumothorax. Neuromuscular ultrasound has emerged as a non-invasive technique that can be used in the structural and functional assessment of the diaphragm. This article reviews different techniques for assessing the diaphragm using neuromuscular ultrasound and the application of these techniques to enhance diagnosis and prognosis by neuromuscular clinicians. PMID:23382111

  11. Titanium diaphragm makes excellent amplitron cathode support

    NASA Technical Reports Server (NTRS)

    Teich, W. W.

    1965-01-01

    Cathode support structure designed around a titanium diaphragm prevents radial misalignment between the cathode and anode in amplitrons. The titanium exhibits low thermal conductivity, tolerates lateral thermal expansion of the cathode, and is a poor primary and secondary emission medium.

  12. Small bowel diaphragm disease mimicking malignancy

    PubMed Central

    Sarantitis, Ioannis; Gerrard, Adam Daniel; Teasdale, Rebecca; Pettit, Stephen

    2015-01-01

    Non-steroidal anti-inflammatory drugs (NSAIDs) can produce diaphragm disease where multiple strictures develop in the small bowel. This typically presents with anaemia and symptoms of small bowel obstruction. The strictures develop as a result of circumferential mucosal ulceration with subsequent contraction of rings of scar tissue. We report a case of a 47-year-old woman with a 6-month history of NSAIDs abuse who presented with subacute small bowel obstruction 1 year after stopping NSAIDs. CT and MRI showed multiple ileal strictures with florid locoregional lymphadenopathy. A malignant diagnosis such as lymphoma was considered likely as florid mesenteric lymphadenopathy has not been previously reported in diaphragm disease. Laparotomy with small bowel resection was therefore performed. Histology showed diaphragm disease with the enlarged mesenteric nodes having reactive features. Gross locoregional lymphadenopathy should not deter a diagnosis of diaphragm disease in cases of multiple small bowel strictures where there is a strong history of NSAIDs use. PMID:26174729

  13. Flexible diaphragm-extreme temperature usage

    NASA Technical Reports Server (NTRS)

    Lerma, Guillermo (Inventor)

    1991-01-01

    A diaphragm suitable for extreme temperature usage, such as encountered in critical aerospace applications, is fabricated by a unique method, and of a unique combination of materials. The materials include multilayered lay-ups of diaphragm materials sandwiched between layers of bleeder fabrics. After being formed in the desired shape on a mold, they are vacuum sealed and then cured under pressure, in a heated autoclave. A bond capable of withstanding extreme temperatures are produced.

  14. Diaphragm injury in individuals with airflow obstruction.

    PubMed

    Macgowan, N A; Evans, K G; Road, J D; Reid, W D

    2001-06-01

    The purpose of this study was to describe the nature of diaphragm injury, to quantify the injury and number of macrophages at the light microscopic level, and to determine their association with airflow obstruction in humans. Partial-thickness diaphragm biopsies were obtained from 21 subjects going for thoracotomy surgery (FEV(1): 74 +/- 34% predicted; range: 16 to 122% predicted). Cross sections cut from frozen diaphragm were processed with H&E or processed for immunohistochemistry using the monoclonal antibody Ber-MAC3 (DAKO Corp., Carpinteria, CA) to label macrophages. Area fractions (A(A)) or the proportions of the cross- sectional area were determined by point counting all viable fields of H&E-stained diaphragm cross sections. A(A) were 66.2 +/- 9.0% for normal muscle, 17.6 +/- 7.2% for abnormal muscle, and 16.3 +/- 4.2% for connective tissue. Percent predicted FEV(1) was inversely related to the A(A) of abnormal muscle (r = -0.53, p < 0.01) and directly related to the A(A) of normal muscle (r = 0.37, p < 0.05). The number of macrophages was not related to % predicted FEV(1) (mean +/- SD: 0.41 +/- 0.18/fiber; 52 +/- 19/mm(2)). We conclude that increasing severity of airflow obstruction is associated with an increased A(A) of abnormal diaphragm and a decreased A(A) of normal diaphragm.

  15. Is surgical plication necessary in diaphragm eventration?

    PubMed

    Özkan, Serdar; Yazici, Ülkü; Aydin, Ertan; Karaoğlanoğlu, Nurettin

    2016-04-01

    Diaphragm plication surgery is conducted to remove dyspnea, which results from mediastinal shift, atelectasia, and ventilation/perfusion dyssynchrony in lungs that occur because of an eventrated diaphragm. This study aims to determine whether diaphragm plication has any effect on respiration by analyzing the patients' changing values in the respiratory function test (RFT) after plication surgery. Sixteen patients who underwent diaphragm plication surgery in our clinic because of plication eventration or paralysis were examined prospectively. Diaphragm eventration values were assessed using a calculation method that uses posteroanterior pulmonary radiographies taken during patient admission and control; then, these data were recorded. The amount of changes in the eventration levels and in restrictive respiratory failure parameters-forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC) of RFTs-conducted in pre- and postoperative control periods were compared using statistical analysis methods. The compatibility between the amounts of RFT changes was examined through a satisfaction survey-using a questionnaire that consisted of multiple choice questions with answer options such as "better," "the same," and "worse"-to understand preoperative and postoperative symptom levels in the 12(th) month of postoperative control. According to postoperative levels, a decrease between 19% and 23% was observed in eventration amounts within the 1(st) postoperative month, 6(th) postoperative month, and 12(th) postoperative month. In addition, the highest average increase in FEV1 liter (lt) values was 0.2 lt and 0.25 in FVC (lt) values. Researchers of this study believe that more distinctive decisions need to be taken while identifying patients for surgery in unilateral diaphragm eventrations, especially in the adult patient group; surgical option should be used for cases in which the eventrated diaphragm results in mediastinal shift and respiratory failure. Copyright

  16. Airflow limitation is accompanied by diaphragm dysfunction.

    PubMed

    Hellebrandová, L; Chlumský, J; Vostatek, P; Novák, D; Rýznarová, Z; Bunc, V

    2016-07-18

    Chronic airflow limitation, caused by chronic obstructive pulmonary disease (COPD) or by asthma, is believed to change the shape and the position of the diaphragm due to an increase in lung volume. We have made a comparison of magnetic resonance imaging (MRI) of diaphragm in supine position with pulmonary functions, respiratory muscle function and exercise tolerance. We have studied the differences between patients with COPD, patients with asthma, and healthy subjects. Most interestingly we found the lung hyperinflation leads to the changes in diaphragmatic excursions during the breathing cycle, seen in the differences between the maximal expiratory diaphragm position (DPex) in patients with COPD and control group (p=0.0016). The magnitude of the diaphragmatic dysfunction was significantly related to the airflow limitation expressed by the ratio of forced expiratory volume in 1 s to slow vital capacity (FEV(1)/SVC), (%, p=0.0007); to the lung hyperinflation expressed as the ratio of the residual volume to total lung capacity (RV/TLC), (%, p=0.0018) and the extent of tidal volume constrain expressed as maximal tidal volume (V(Tmax)), ([l], p=0.0002); and the ratio of tidal volume to slow vital capacity (V(T)/SVC), (p=0.0038) during submaximal exercise. These results suggest that diaphragmatic movement fails to contribute sufficiently to the change in lung volume in emphysema. Tests of respiratory muscle function were related to the position of the diaphragm in deep expiration, e.g. neuromuscular coupling (P(0.1)/V(T)) (p=0.0232). The results have shown that the lung volumes determine the position of the diaphragm and function of the respiratory muscles. Chronic airflow limitation seems to change the position of the diaphragm, which thereafter influences inspiratory muscle function and exercise tolerance. There is an apparent relationship between the position of the diaphragm and the pulmonary functions and exercise tolerance.

  17. Ultrasound Doppler measurements inside a diaphragm valve using novel transducer technologies

    NASA Astrophysics Data System (ADS)

    Kotzé, Reinhardt; Wiklund, Johan

    2014-10-01

    In this project, velocity profiles were measured in a diaphragm valve using an ultrasonic velocity profiling (UVP) technique. A non-Newtonian CMC model fluid was tested in this highly complex geometry and velocity profiles were measured at four different positions at the centre (contraction) of a specially manufactured 50% open diaphragm valve. The coordinates of the complex geometry and velocity magnitudes were analysed and compared to the bulk flow rate measured using an electromagnetic flow meter. Two different ultrasonic transducers (standard and delay line) were used and results were compared in order to assess velocity data close to wall interfaces as well as the accuracy and magnitude of measured velocities. The difference between calculated and measured flow rates was 32% when using the standard ultrasonic transducers. The error difference decreased to 18% when delay line transducers were introduced to the measurements. The velocity data obtained in the diaphragm valve showed a significant improvement close to the wall interfaces when using the delay line transducers. The main limitation when using delay line transducers is that beam refraction can significantly complicate measurements in a highly complex geometry such as a diaphragm valve. A new delay line transducer with no beam refraction could provide a solution. The introduction of delay line transducers showed that UVP can be used as a powerful tool for detailed flow behaviour measurements in complex geometries.

  18. Manual evaluation of the diaphragm muscle

    PubMed Central

    Bordoni, Bruno; Marelli, F; Morabito, B; Sacconi, B

    2016-01-01

    The respiratory diaphragm is the most important muscle for breathing. It contributes to various processes such as expectoration, vomiting, swallowing, urination, and defecation. It facilitates the venous and lymphatic return and helps viscera located above and below the diaphragm to work properly. Its activity is fundamental in the maintenance of posture and body position changes. It can affect the pain perception and emotional state. Many authors reported on diaphragmatic training by using special instruments, whereas only a few studies focused on manual therapy approaches. To the knowledge of the authors, the existing scientific literature does not exhaustively examines the manual evaluation of the diaphragm in its different portions. A complete evaluation of the diaphragm is mandatory for several professional subjects, such as physiotherapists, osteopaths, and chiropractors not only to elaborate a treatment strategy but also to obtain information on the validity of the training performed on the patient. This article aims to describe a strategy of manual evaluation of the diaphragm, with particular attention to anatomical fundamentals, in order to stimulate further research on this less explored field. PMID:27574419

  19. Valveless impedance micropump with integrated magnetic diaphragm.

    PubMed

    Lee, Chia-Yen; Chen, Zgen-Hui

    2010-04-01

    This study presents a planar valveless impedance-based micropump for biomedical applications comprising a lower glass substrate patterned with a copper micro-coil, a microchannel, an upper glass cover plate, and a PDMS diaphragm with an electroplated magnet on its upper surface. When a current is passed through the micro-coil, an electromagnetic force is established between the coil and the magnet. The resulting deflection of the PDMS diaphragm creates an acoustic impedance mismatch within the microchannel, which in turn produces a net flow. The performance of the micropump is characterized experimentally. The experimental results show that a maximum diaphragm deflection of 30 microm is obtained when the micro-coil is supplied with an input current of 0.5 A. The corresponding flow rate is found to be 1.5 microl/sec when the PDMS membrane is driven by an actuating frequency of 240 Hz.

  20. 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.

  1. La chirurgie du diaphragme sous aortique

    PubMed Central

    Moutakiallah, Younes; Maaroufi, Ilham; Aithoussa, Mahdi; Bamous, Mehdi; Abdou, Abdessamad; Atmani, Noureddine; Hatim, Abdedaïm; Amahzoune, Brahim; Bekkali, Youssef El; Boulahya, Abdelatif

    2016-01-01

    Le diaphragme sous aortique se caractérise par une certaine latence clinique et une faible morbi-mortalité. La chirurgie reste le traitement de choix malgré un réel risque de récurrence à long terme. Nous rapportons 18 patients opérés entre Avril 1994 et Mars 2011 pour diaphragme sous aortique d’âge moyen de 18,1±9,7 ans avec 11 patients de sexe masculin. Le diaphragme était de nature fibreuse chez 13 patients et fibro-musculaire chez 5 patients. Tous les patients ont été opérés par résection de diaphragme associée à une myectomie, une plastie aortique, une fermeture de communication interventriculaire et une ligature de canal artériel perméable respectivement chez 3, 3, 2 et 2 patients. La Mortalité opératoire était nulle et sans aucun cas de trouble de conduction postopératoire. Le suivi a duré en moyenne 44,3±36,8 mois sans aucun décès tardif. Deux patients ont présenté une récidive de diaphragme qui a nécessité une réopération avec bonne évolution. La tendance actuelle dans la chirurgie du diaphragme se fait vers des interventions précoces et des résections plus extensives. Cependant, le risque de récidive impose une surveillance échographique systématique et rapprochée. PMID:27516830

  2. Design study of a flexible diaphragm

    SciTech Connect

    Whatley, M E; Morgan, J G

    1982-10-01

    A design study was made to meet the requirements for a diaphragm for a rotary seal at the discharge end of the Consolidated Fuel Reprocessing Program`s prototypic voloxidizer. Using a computer program called NEPSAP, the study examined thickness, outer radius, corrugation wavelength and corrugation amplitude as variables, and established the general effect of each on stiffness and stresses. The result comprises a basis for the selection of diaphragms for similar applications. Limited experimental measurements of stress validate the stress values calculated by NEPSAP.

  3. Optical Detection Of Fractures In Ceramic Diaphragms

    NASA Technical Reports Server (NTRS)

    Laue, Eric G.

    1995-01-01

    Simple optical technique enables quick, nondestructive inspection of surfaces of ceramic diaphragms and disks for fractures and discontinuities. Involves reflecting beam of light from laser at glancing angle of about 20 degrees to 25 degrees off surface inspected and examining pattern of reflected light on suitable viewing surface as beam swept across surface. When fracture present, reflection pattern separates into two or more speckled spots. Technique applied in inspection of ceramic diaphragms bearing electronic circuits. Also useful in detection of fatigue cracks on aircraft.

  4. Early mechanical dysfunction of the diaphragm in the muscular dystrophy with myositis (Ttnmdm) model.

    PubMed

    Lopez, Michael A; Pardo, Patricia S; Cox, Gregory A; Boriek, Aladin M

    2008-11-01

    A complex rearrangement mutation in the mouse titin gene leads to an in-frame 83-amino acid deletion in the N2A region of titin. Autosomal recessive inheritance of the titin muscular dystrophy with myositis (Ttn(mdm/mdm)) mutation leads to a severe early-onset muscular dystrophy and premature death. We hypothesized that the N2A deletion would negatively impact the force-generating capacity and passive mechanical properties of the mdm diaphragm. We measured in vitro active isometric contractile and passive length-tension properties to assess muscle function at 2 and 6 wk of age. Micro-CT, myosin heavy chain Western blotting, and histology were used to assess diaphragm structure. Marked chest wall distortions began at 2 wk and progressively worsened until 5 wk. The percentage of myofibers with centrally located nuclei in mdm mice was significantly (P < 0.01) increased at 2 and 6 wk by 4% and 17%, respectively, compared with controls. At 6 wk, mdm diaphragm twitch stress was significantly (P < 0.01) reduced by 71%, time to peak twitch was significantly (P < 0.05) reduced by 52%, and half-relaxation time was significantly (P < 0.05) reduced by 57%. Isometric tetanic stress was significantly (P < 0.05) depressed in 2- and 6-wk mdm diaphragms by as much as 64%. Length-tension relationships of the 2- and 6-wk mdm diaphragms showed significantly (P < 0.05) decreased extensibility and increased stiffness. Slow myosin heavy chain expression was aberrantly favored in the mdm diaphragm at 6 wk. Our data strongly support early contractile and passive mechanical aberrations of the respiratory pump in mdm mice.

  5. Metabolic Alkalosis resulting from a Congenital Duodenal Diaphragm.

    PubMed

    A, Passariello; Y, Maddalena; M, Malamisura; S, Rojo; N, Aragione; E, Iaccarino; G, Franco; P, Giliberti

    2014-01-01

    Duodenal diaphragm is an unusual cause of upper intestinal obstruction. We present here a neonate with duodenal diaphragm who presented with features of metabolic alkalosis. Further, an algorithm of management of metabolic alkalosis in a newborn is suggested.

  6. Metabolic Alkalosis resulting from a Congenital Duodenal Diaphragm

    PubMed Central

    A, Passariello; Y, Maddalena; M, Malamisura; S, Rojo; N, Aragione; E, Iaccarino; G, Franco; P, Giliberti

    2014-01-01

    Duodenal diaphragm is an unusual cause of upper intestinal obstruction. We present here a neonate with duodenal diaphragm who presented with features of metabolic alkalosis. Further, an algorithm of management of metabolic alkalosis in a newborn is suggested. PMID:26023519

  7. 21 CFR 884.5350 - Contraceptive diaphragm and accessories.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Devices § 884.5350 Contraceptive diaphragm and accessories. (a) Identification. A contraceptive diaphragm is a closely fitting membrane placed between the posterior aspect of the pubic bone and the posterior...

  8. 21 CFR 884.5350 - Contraceptive diaphragm and accessories.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Devices § 884.5350 Contraceptive diaphragm and accessories. (a) Identification. A contraceptive diaphragm is a closely fitting membrane placed between the posterior aspect of the pubic bone and the posterior...

  9. 21 CFR 884.5350 - Contraceptive diaphragm and accessories.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Devices § 884.5350 Contraceptive diaphragm and accessories. (a) Identification. A contraceptive diaphragm is a closely fitting membrane placed between the posterior aspect of the pubic bone and the posterior...

  10. 21 CFR 884.5350 - Contraceptive diaphragm and accessories.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Devices § 884.5350 Contraceptive diaphragm and accessories. (a) Identification. A contraceptive diaphragm is a closely fitting membrane placed between the posterior aspect of the pubic bone and the posterior...

  11. Parametric evaluation of contoured aluminum diaphragm, positive expulsion tanks

    NASA Astrophysics Data System (ADS)

    Marvin, M.; Kammerer, H.; Gidley, J. T.

    1992-07-01

    Development and application of contoured aluminum diaphragm positive expulsion tanks has progressed to the stage where parametric trade studies can be performed confidently. These allow the investigation of the effect of parameters including: size/shape/pressure/wall thickness/overwrap usage, on weight, system volume constraints and other considerations. Both mathematically derived and empirically fit equations relating these parameters have been developed. The resulting graphs show the weight efficiency for graphite wrapped vs all metal tank shells in all but the smallest sizes and low pressures. They also show the penalty for departing from simple oblate spheroid shapes, a need sometimes dictated by system constraints. A comparison between the predicted and actual data from delivered tanks is also shown.

  12. The diaphragm: barrier contraception has a new social role.

    PubMed

    Tagg, P I

    1995-12-01

    Using a diaphragm as a barrier contraceptive has received little attention in recent literature. A discussion of the role of the diaphragm to prevent pregnancy, as well as sexually transmitted diseases, is presented. A procedure for properly fitting the diaphragm is described. To ensure compliance, a review of a plan for education and practice by users is outlined.

  13. 14 CFR 25.1192 - Engine accessory section diaphragm.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Engine accessory section diaphragm. 25.1192....1192 Engine accessory section diaphragm. For reciprocating engines, the engine power section and all portions of the exhaust system must be isolated from the engine accessory compartment by a diaphragm that...

  14. 14 CFR 25.1192 - Engine accessory section diaphragm.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Engine accessory section diaphragm. 25.1192....1192 Engine accessory section diaphragm. For reciprocating engines, the engine power section and all portions of the exhaust system must be isolated from the engine accessory compartment by a diaphragm that...

  15. 14 CFR 125.149 - Engine accessory section diaphragm.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Engine accessory section diaphragm. 125.149... Requirements § 125.149 Engine accessory section diaphragm. Unless equivalent protection can be shown by other means, a diaphragm that complies with § 125.145 must be provided on air-cooled engines to isolate the...

  16. 14 CFR 125.149 - Engine accessory section diaphragm.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Engine accessory section diaphragm. 125.149... Requirements § 125.149 Engine accessory section diaphragm. Unless equivalent protection can be shown by other means, a diaphragm that complies with § 125.145 must be provided on air-cooled engines to isolate the...

  17. 14 CFR 125.149 - Engine accessory section diaphragm.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Engine accessory section diaphragm. 125.149... Requirements § 125.149 Engine accessory section diaphragm. Unless equivalent protection can be shown by other means, a diaphragm that complies with § 125.145 must be provided on air-cooled engines to isolate the...

  18. 14 CFR 25.1192 - Engine accessory section diaphragm.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Engine accessory section diaphragm. 25.1192....1192 Engine accessory section diaphragm. For reciprocating engines, the engine power section and all portions of the exhaust system must be isolated from the engine accessory compartment by a diaphragm that...

  19. 14 CFR 125.149 - Engine accessory section diaphragm.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Engine accessory section diaphragm. 125.149... Requirements § 125.149 Engine accessory section diaphragm. Unless equivalent protection can be shown by other means, a diaphragm that complies with § 125.145 must be provided on air-cooled engines to isolate the...

  20. 21 CFR 884.5350 - Contraceptive diaphragm and accessories.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Contraceptive diaphragm and accessories. 884.5350 Section 884.5350 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Devices § 884.5350 Contraceptive diaphragm and accessories. (a) Identification. A contraceptive diaphragm...

  1. The earliest history of diaphragm physiology.

    PubMed

    Derenne, J P; Debru, A; Grassino, A E; Whitelaw, W A

    1994-12-01

    The diaphragm was recognized as a distinct anatomical structure in the earliest Greek writings. However, the precise description of wounds suffered by warriors during the Trojan war by Homer was not tied to any particular function. The diaphragm was assimilated to the region that harbours thought. The first physiologic explanations of respiration by Empedocles in the 5th century BC and the concepts introduced by Plato and Hippocrates did not include a significant participation of the diaphragm. Aristole was the first to link respiration to a particular organ and a specific movement of the thorax. However, he considered that it was the heart which caused the lungs to expand by heating them, and the lungs in turn forced the thorax to dilate, a concept which was to survive until the 17th century. As in Aristole's theory the diaphragm played no role in respiration and was just a fence separating the thorax from the abdomen. A major break through occurred in Alexandria in the 4th and 3rd century BC: Herophilus was the first to recognize that muscles were the agents of movement and Erasistratus performed animal experiments which showed that the respiratory muscles were the agents of respiratory movements, thus opening the way to the later discoveries of Galen.

  2. Diaphragm remodeling and compensatory respiratory mechanics in a canine model of Duchenne muscular dystrophy.

    PubMed

    Mead, A F; Petrov, M; Malik, A S; Mitchell, M A; Childers, M K; Bogan, J R; Seidner, G; Kornegay, J N; Stedman, H H

    2014-04-01

    Ventilatory insufficiency remains the leading cause of death and late stage morbidity in Duchenne muscular dystrophy (DMD). To address critical gaps in our knowledge of the pathobiology of respiratory functional decline, we used an integrative approach to study respiratory mechanics in a translational model of DMD. In studies of individual dogs with the Golden Retriever muscular dystrophy (GRMD) mutation, we found evidence of rapidly progressive loss of ventilatory capacity in association with dramatic morphometric remodeling of the diaphragm. Within the first year of life, the mechanics of breathing at rest, and especially during pharmacological stimulation of respiratory control pathways in the carotid bodies, shift such that the primary role of the diaphragm becomes the passive elastic storage of energy transferred from abdominal wall muscles, thereby permitting the expiratory musculature to share in the generation of inspiratory pressure and flow. In the diaphragm, this physiological shift is associated with the loss of sarcomeres in series (∼ 60%) and an increase in muscle stiffness (∼ 900%) compared with those of the nondystrophic diaphragm, as studied during perfusion ex vivo. In addition to providing much needed endpoint measures for assessing the efficacy of therapeutics, we expect these findings to be a starting point for a more precise understanding of respiratory failure in DMD.

  3. Diaphragm remodeling and compensatory respiratory mechanics in a canine model of Duchenne muscular dystrophy

    PubMed Central

    Mead, A. F.; Petrov, M.; Malik, A. S.; Mitchell, M. A.; Childers, M. K.; Bogan, J. R.; Seidner, G.; Kornegay, J. N.

    2014-01-01

    Ventilatory insufficiency remains the leading cause of death and late stage morbidity in Duchenne muscular dystrophy (DMD). To address critical gaps in our knowledge of the pathobiology of respiratory functional decline, we used an integrative approach to study respiratory mechanics in a translational model of DMD. In studies of individual dogs with the Golden Retriever muscular dystrophy (GRMD) mutation, we found evidence of rapidly progressive loss of ventilatory capacity in association with dramatic morphometric remodeling of the diaphragm. Within the first year of life, the mechanics of breathing at rest, and especially during pharmacological stimulation of respiratory control pathways in the carotid bodies, shift such that the primary role of the diaphragm becomes the passive elastic storage of energy transferred from abdominal wall muscles, thereby permitting the expiratory musculature to share in the generation of inspiratory pressure and flow. In the diaphragm, this physiological shift is associated with the loss of sarcomeres in series (∼60%) and an increase in muscle stiffness (∼900%) compared with those of the nondystrophic diaphragm, as studied during perfusion ex vivo. In addition to providing much needed endpoint measures for assessing the efficacy of therapeutics, we expect these findings to be a starting point for a more precise understanding of respiratory failure in DMD. PMID:24408990

  4. Toxic shock syndrome associated with diaphragm use.

    PubMed

    Hyde, L

    1983-03-01

    A case report is presented of toxic shock syndrome associated wtih diaphragm use. The patient, an 18-year old white woman, gravida 1, para 1, was in good health prior to the reported episode. She had a low transverse cesarean section for fetal distress 3 months prior to admission and had not yet resumed menstruation. 48 hours prior to admission, after unprotected intercourse, she developed a vaginal discharge requiring the use of a pad. 12 hours later she used a diaphragm, left it in place overnight, and failed to remove it the next morning. During the day pelvic and lumbar pain developed, followed by vomiting and a fever as high as 103 degrees Farenheit. That evening, 12 hours before admission, the diaphragm was removed with drainage of copious purulent discharge. The edges of the diaphragm and the discharge were blood streaked. She also developed a diffuse macular blanching rash, sparing only the circumoral region. At the time of admission the following morning her blood pressure was 60/0mmHg; pulse, 180 beats/minute; and temperature, 102 degrees Farenheit. Significant physical findings included the rash, conjunctivitis, a pharyngeal infection, and a lack of adenopathy. Pelvic examination showed a vaginal discharge, a very tender, slightly enlarged warm uterus, and normal adnexa. Cultures of the vaginal discharge were positive for Staphylococcus aureus, resistant to penicillin and ampicillin, and sensitive to methicillin, cephalothin, erythromycin, colistin, chloramphenicol, tetracycline, sulfisoxazole, and aminoglycoside antibiotics. The white blood count rose from 11,000/mm on admission to a high of 13,000/mm with a left shift the next day. The patient received 1.2 million units of intravenous penicillin every 4 hours, 80 mg of gentamicin every 8 hours, and 300 mg of clindamycin every 6 hours, as well as fluid replacement of 2 g of methylprednisolone followed by 1 g every 6 hours. The shock, fever, and rash resolved in the following 48 hours. 2 days after

  5. Diaphragm paralysis from cervical disc lesions.

    PubMed

    Cloward, R B

    1988-01-01

    An opera singer, who "made her living with her diaphragm", developed a post-traumatic unilateral radiculopathy due to cervical disc lesions, C3 to C6. During one year of severe neck and left arm pain she gradually lost the ability to sing difficult operatic passages which brought an end to her music career. Following a three level anterior cervical decompression and fusion, the neck and arm pain was immediately relieved. One week later her voice and singing ability returned to its full strength and power permitting her to resume her activities as a vocalist. The diagnosis of paresis of the left hemi-diaphragm as part of the cervical disc syndrome was implied by postoperative retrospective inference.

  6. Salutary effect of fall in abdominal pressure during diaphragm paralysis.

    PubMed

    Kelly, S; Zin, W A; Decramer, M; De Troyer, A

    1984-05-01

    To examine the mechanical effects of the fall in abdominal pressure (Pab) that occurs during inspiration in diaphragmatic paralysis, we studied lung inflation and rib cage expansion before and after the abdomen was opened in nine spontaneously breathing dogs with bilateral phrenicotomy . We measured Pab, tidal volume, and parasternal electromyographic (EMG) activity during quiet breathing and CO2-induced hyperpnea. In six dogs, we also measured changes in anteroposterior and transverse rib cage diameters, the resting length of the parasternal intercostal muscles, and the amount of shortening of these muscles during inspiration. Opening the abdomen caused a marked reduction in the fall in Pab during inspiration and invariably resulted in a decrease in tidal volume (mean decrease, 13%), which contrasted with marked increases in inspiratory rib cage expansion and in the amount of parasternal intercostal shortening. The procedure, however, did not affect the resting length or inspiratory EMG activity of the parasternals . These findings indicate that although the fall in Pab, which occurs during inspiration in diaphragmatic paralysis, causes paradoxical inward displacement of the ventral abdominal wall, it has a salutary effect on tidal volume. This phenomenon is probably due to the fact that the diaphragm is part of the abdominal wall.

  7. Diaphragm Pump With Resonant Piezoelectric Drive

    NASA Technical Reports Server (NTRS)

    Izenson, Michael G.; Kline-Schoder, Robert J.; Shimko, Martin A.

    2007-01-01

    A diaphragm pump driven by a piezoelectric actuator is undergoing development. This pump is intended to be a prototype of lightweight, highly reliable pumps for circulating cooling liquids in protective garments and high-power electronic circuits, and perhaps for some medical applications. The pump would be highly reliable because it would contain no sliding seals or bearings that could wear, the only parts subject to wear would be two check valves, and the diaphragm and other flexing parts could be designed, by use of proven methods, for extremely long life. Because the pump would be capable of a large volumetric flow rate and would have only a small dead volume, its operation would not be disrupted by ingestion of gas, and it could be started reliably under all conditions. The prior art includes a number piezoelectrically actuated diaphragm pumps. Because of the smallness of the motions of piezoelectric actuators (typical maximum strains only about 0.001), the volumetric flow rates of those pumps are much too small for typical cooling applications. In the pump now undergoing development, mechanical resonance would be utilized to amplify the motion generated by the piezoelectric actuator and thereby multiply the volumetric flow rate. The prime mover in this pump would be a stack of piezoelectric ceramic actuators, one end of which would be connected to a spring that would be part of a spring-and-mass resonator structure. The mass part of the resonator structure would include the pump diaphragm (see Figure 1). Contraction of the spring would draw the diaphragm to the left, causing the volume of the fluid chamber to increase and thereby causing fluid to flow into the chamber. Subsequent expansion of the spring would push the diaphragm to the right, causing the volume of the fluid chamber to decrease, and thereby expelling fluid from the chamber. The fluid would enter and leave the chamber through check valves. The piezoelectric stack would be driven electrically to

  8. Final analysis of the pilot trial of diaphragm pacing in amyotrophic lateral sclerosis with long-term follow-up: diaphragm pacing positively affects diaphragm respiration.

    PubMed

    Onders, Raymond P; Elmo, MaryJo; Kaplan, Cindy; Katirji, Bashar; Schilz, Robert

    2014-03-01

    Respiratory insufficiency is the major cause of mortality in patients with amyotrophic lateral sclerosis or Lou Gehrig's disease. This is the final report of the diaphragm pacing (DP) pilot trial. Patients underwent laparoscopic diaphragm electrode implantations and subsequent conditioning of diaphragms. Serial respiratory function tests were performed in the initial year and followed until death. Sixteen patients were implanted with no perioperative or unanticipated device-related adverse events. There were 452 implant-months of follow-up. DP allowed greater movement of the diaphragm under fluoroscopy, increased muscle thickness, and decreased the decline in forced vital capacity. Median survival from implant was 19.7 months with the cause of death respiratory in only 31%. Long-term analysis of DP in amyotrophic lateral sclerosis showed no safety issues and can positively influence diaphragm physiology and survival. This formed the initial basis for subsequent US Food and Drug Administration approval. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Inflatable containment diaphragm for sealing and removing stacks

    DOEpatents

    Meskanick, G.R.; Rosso, D.T.

    1993-04-13

    A diaphragm with an inflatable torus-shaped perimeter is used to seal at least one end of a stack so that debris that might be hazardous will not be released during removal of the stack. A diaphragm is inserted and inflated in the lower portion of a stack just above where the stack is to be cut such that the perimeter of the diaphragm expands and forms a seal against the interior surface of the stack.

  10. Contraction of the human diaphragm during rapid postural adjustments.

    PubMed

    Hodges, P W; Butler, J E; McKenzie, D K; Gandevia, S C

    1997-12-01

    1. The response of the diaphragm to the postural perturbation produced by rapid flexion of the shoulder to a visual stimulus was evaluated in standing subjects. Gastric, oesophageal and transdiaphragmatic pressures were measured together with intramuscular and oesophageal recordings of electromyographic activity (EMG) in the diaphragm. To assess the mechanics of contraction of the diaphragm, dynamic changes in the length of the diaphragm were measured with ultrasonography. 2. With rapid flexion of the shoulder in response to a visual stimulus, EMG activity in the costal and crural diaphragm occurred about 20 ms prior to the onset of deltoid EMG. This anticipatory contraction occurred irrespective of the phase of respiration in which arm movement began. The onset of diaphragm EMG coincided with that of transversus abdominis. 3. Gastric and transdiaphragmatic pressures increased in association with the rapid arm flexion by 13.8 +/- 1.9 (mean +/- S.E.M.) and 13.5 +/- 1.8 cmH2O, respectively. The increases occurred 49 +/- 4 ms after the onset of diaphragm EMG, but preceded the onset of movement of the limb by 63 +/- 7 ms. 4. Ultrasonographic measurements revealed that the costal diaphragm shortened and then lengthened progressively during the increase in transdiaphragmatic pressure. 5. This study provides definitive evidence that the human diaphragm is involved in the control of postural stability during sudden voluntary movement of the limbs.

  11. Ultrasonographic Assessment of Diaphragm Function in Critically Ill Subjects.

    PubMed

    Umbrello, Michele; Formenti, Paolo

    2016-04-01

    The majority of patients admitted to the ICU require mechanical ventilation as a part of their process of care. However, mechanical ventilation itself or the underlying disease can lead to dysfunction of the diaphragm, a condition that may contribute to the failure of weaning from mechanical ventilation. However, extended time on the ventilator increases health-care costs and greatly increases patient morbidity and mortality. Nevertheless, symptoms and signs of muscle disease in a bedridden (or bed rest-only) ICU patient are often difficult to assess because of concomitant confounding factors. Conventional assessment of diaphragm function lacks specific, noninvasive, time-saving, and easily performed bedside tools or requires patient cooperation. Recently, the use of ultrasound has raised great interest as a simple, noninvasive method of quantification of diaphragm contractile activity. In this review, we discuss the physiology and the relevant pathophysiology of diaphragm function, and we summarize the recent findings concerning the evaluation of its (dys)function in critically ill patients, with a special focus on the role of ultrasounds. We describe how to assess diaphragm excursion and diaphragm thickening during breathing and the meaning of these measurements under spontaneous or mechanical ventilation as well as the reference values in health and disease. The spread of ultrasonographic assessment of diaphragm function may possibly result in timely identification of patients with diaphragm dysfunction and to a potential improvement in the assessment of recovery from diaphragm weakness. Copyright © 2016 by Daedalus Enterprises.

  12. An Autopsy Case of Amyotrophic Lateral Sclerosis with Diaphragm Pacing

    PubMed Central

    Ito, Hisashi; Kamei, Tetsumasa; Odake, Sanae; Nakano, Masayuki; Okeda, Riki; Kohriki, Shunsaku; Kawachi, Jun; Onders, Raymond P.; Yoshii, Fumihito

    2016-01-01

    Respiratory insufficiency is a critical problem in amyotrophic lateral sclerosis (ALS) patients. We herein present the case of an autopsied patient with sporadic ALS who underwent diaphragm pacing (DP). The pathology showed several localized adhesions with a markedly atrophied diaphragm. A marked loss of motor neurons with Bunina bodies and phosphorylated TDP-43 positive inclusions was found in the spinal cord and primary motor cortex. Mild hyalinization and a few multinucleated giant cells were present around the electrode tracks in the diaphragm. However, no infiltration of inflammatory cells was detected. Our findings suggest that full-time DP might not cause severe damage to adjacent diaphragm tissue. PMID:27904119

  13. An Autopsy Case of Amyotrophic Lateral Sclerosis with Diaphragm Pacing.

    PubMed

    Ito, Hisashi; Kamei, Tetsumasa; Odake, Sanae; Nakano, Masayuki; Okeda, Riki; Kohriki, Shunsaku; Kawachi, Jun; Onders, Raymond P; Yoshii, Fumihito

    Respiratory insufficiency is a critical problem in amyotrophic lateral sclerosis (ALS) patients. We herein present the case of an autopsied patient with sporadic ALS who underwent diaphragm pacing (DP). The pathology showed several localized adhesions with a markedly atrophied diaphragm. A marked loss of motor neurons with Bunina bodies and phosphorylated TDP-43 positive inclusions was found in the spinal cord and primary motor cortex. Mild hyalinization and a few multinucleated giant cells were present around the electrode tracks in the diaphragm. However, no infiltration of inflammatory cells was detected. Our findings suggest that full-time DP might not cause severe damage to adjacent diaphragm tissue.

  14. Heart failure-induced diaphragm myopathy.

    PubMed

    Lima, Aline Regina Ruiz; Martinez, Paula Felippe; Damatto, Ricardo Luiz; Cezar, Marcelo Diarcadia Mariano; Guizoni, Daniele Mendes; Bonomo, Camila; Oliveira, Silvio Assis; Dal-Pai Silva, Maeli; Zornoff, Leonardo Antonio Mamede; Okoshi, Katashi; Okoshi, Marina Politi

    2014-01-01

    Intracellular signaling pathways involved in skeletal myosin heavy chain (MyHC) isoform alterations during heart failure (HF) are not completely understood. We tested the hypothesis that diaphragm expression of mitogen-activated protein kinases (MAPK) and myogenic regulatory factors is changed in rats with myocardial infarction (MI) induced HF. Six months after MI rats were subjected to transthoracic echocardiography. After euthanasia, infarcted rats were subdivided in MI/HF- group (with no HF evidence; n=10), and MI/HF+ (with right ventricular hypertrophy and lung congestion; n=10). Sham-operated rats were used as controls (n=10). MyHC isoforms were analyzed by electrophoresis. ANOVA and Pearson correlation. MI/HF- had left cardiac chambers dilation with systolic and diastolic left ventricular dysfunction. Cardiac injury was more intense in MI/HF+ than MI/HF-. MyHC I isoform percentage was higher in MI/HF+ than MI/HF-, and IIb isoform lower in MI/HF+ than Sham. Left atrial diameter-to-body weight ratio positively correlated with MyHC I (p=0.005) and negatively correlated with MyHC IIb (p=0.02). TNF-α serum concentration positively correlated with MyHC I isoform. Total and phosphorylated ERK was lower in MI/HF- and MI/HF+ than Sham. Phosphorylated JNK was lower in MI/HF- than Sham. JNK and p38 did not differ between groups. Expression of NF-κB and the myogenic regulatory factors MyoD, myogenin, and MRF4 was similar between groups. Diaphragm MyHC fast-to-slow shift is related to cardiac dysfunction severity and TNF-α serum levels in infarcted rats. Reduced ERK expression seems to participate in MyHC isoform changes. Myogenic regulatory factors and NF-κB do not modulate diaphragm MyHC distribution during chronic HF. © 2014 S. Karger AG, Basel.

  15. Production of porous diaphragm for electrolytic cell

    SciTech Connect

    Cairns, J.F.

    1983-02-01

    A process for the production of a porous diaphragm suitable for use in an electrolytic cell, particularly a chlor-alkali cell, characterized in that the process comprises irradiating a porous shaped article of an organic polymeric material, for example, a sheet of a fluoropolymer, with high energy radiation, the irradiation being effected in the presence of, or the irradiated shaped article being subsequently contacted with, a reactant selected from ammonia, carbon monoxide and phosgene, and the sheet preferably being subsequently contacted with an aqueous alkaline solution.

  16. Imaging of the diaphragm: anatomy and function.

    PubMed

    Nason, Laura K; Walker, Christopher M; McNeeley, Michael F; Burivong, Wanaporn; Fligner, Corinne L; Godwin, J David

    2012-01-01

    The diaphragm is the primary muscle of ventilation. Dysfunction of the diaphragm is an underappreciated cause of respiratory difficulties and may be due to a wide variety of entities, including surgery, trauma, tumor, and infection. Diaphragmatic disease usually manifests as elevation at chest radiography. Functional imaging with fluoroscopy (or ultrasonography or magnetic resonance imaging) is a simple and effective method of diagnosing diaphragmatic dysfunction, which can be classified as paralysis, weakness, or eventration. Diaphragmatic paralysis is indicated by absence of orthograde excursion on quiet and deep breathing, with paradoxical motion on sniffing. Diaphragmatic weakness is indicated by reduced or delayed orthograde excursion on deep breathing, with or without paradoxical motion on sniffing. Eventration is congenital thinning of a segment of diaphragmatic muscle and manifests as focal weakness. Treatment of diaphragmatic paralysis depends on the cause of the dysfunction and the severity of the symptoms. Treatment options include plication and phrenic nerve stimulation. Supplemental material available at http://radiographics.rsna.org/lookup/suppl/doi:10.1148/rg.322115127/-/DC1.

  17. Experimental investigation of solar powered diaphragm and helical pumps

    USDA-ARS?s Scientific Manuscript database

    For several years, many types of solar powered water pumping systems were evaluated, and in this paper, diaphragm and helical solar photovoltaic (PV) powered water pumping systems are discussed. Data were collected on diaphragm and helical pumps which were powered by different solar PV arrays at mul...

  18. 14 CFR 23.1192 - Engine accessory compartment diaphragm.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Engine accessory compartment diaphragm. 23... Powerplant Powerplant Fire Protection § 23.1192 Engine accessory compartment diaphragm. For aircooled radial engines, the engine power section and all portions of the exhaust sytem must be isolated from the engine...

  19. 14 CFR 23.1192 - Engine accessory compartment diaphragm.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Engine accessory compartment diaphragm. 23... Powerplant Powerplant Fire Protection § 23.1192 Engine accessory compartment diaphragm. For aircooled radial engines, the engine power section and all portions of the exhaust sytem must be isolated from the engine...

  20. 14 CFR 23.1192 - Engine accessory compartment diaphragm.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Engine accessory compartment diaphragm. 23... Powerplant Powerplant Fire Protection § 23.1192 Engine accessory compartment diaphragm. For aircooled radial engines, the engine power section and all portions of the exhaust sytem must be isolated from the engine...

  1. 14 CFR 23.1192 - Engine accessory compartment diaphragm.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Engine accessory compartment diaphragm. 23... Powerplant Powerplant Fire Protection § 23.1192 Engine accessory compartment diaphragm. For aircooled radial engines, the engine power section and all portions of the exhaust sytem must be isolated from the...

  2. Endurance exercise attenuates ventilator-induced diaphragm dysfunction

    PubMed Central

    Smuder, Ashley J.; Min, Kisuk; Hudson, Matthew B.; Kavazis, Andreas N.; Kwon, Oh-Sung; Nelson, W. Bradley

    2012-01-01

    Controlled mechanical ventilation (MV) is a life-saving measure for patients in respiratory failure. However, MV renders the diaphragm inactive leading to diaphragm weakness due to both atrophy and contractile dysfunction. It is now established that oxidative stress is a requirement for MV-induced diaphragmatic proteolysis, atrophy, and contractile dysfunction to occur. Given that endurance exercise can elevate diaphragmatic antioxidant capacity and the levels of the cellular stress protein heat shock protein 72 (HSP72), we hypothesized that endurance exercise training before MV would protect the diaphragm against MV-induced oxidative stress, atrophy, and contractile dysfunction in female Sprague-Dawley rats. Our results confirm that endurance exercise training before MV increased both HSP72 and the antioxidant capacity in the diaphragm. Importantly, compared with sedentary animals, exercise training before MV protected the diaphragm against MV-induced oxidative damage, protease activation, myofiber atrophy, and contractile dysfunction. Further, exercise protected diaphragm mitochondria against MV-induced oxidative damage and uncoupling of oxidative phosphorylation. These results provide the first evidence that exercise can provide protection against MV-induced diaphragm weakness. These findings are important and establish the need for future experiments to determine the mechanism(s) responsible for exercise-induced diaphragm protection. PMID:22074717

  3. Endurance exercise attenuates ventilator-induced diaphragm dysfunction.

    PubMed

    Smuder, Ashley J; Min, Kisuk; Hudson, Matthew B; Kavazis, Andreas N; Kwon, Oh-Sung; Nelson, W Bradley; Powers, Scott K

    2012-02-01

    Controlled mechanical ventilation (MV) is a life-saving measure for patients in respiratory failure. However, MV renders the diaphragm inactive leading to diaphragm weakness due to both atrophy and contractile dysfunction. It is now established that oxidative stress is a requirement for MV-induced diaphragmatic proteolysis, atrophy, and contractile dysfunction to occur. Given that endurance exercise can elevate diaphragmatic antioxidant capacity and the levels of the cellular stress protein heat shock protein 72 (HSP72), we hypothesized that endurance exercise training before MV would protect the diaphragm against MV-induced oxidative stress, atrophy, and contractile dysfunction in female Sprague-Dawley rats. Our results confirm that endurance exercise training before MV increased both HSP72 and the antioxidant capacity in the diaphragm. Importantly, compared with sedentary animals, exercise training before MV protected the diaphragm against MV-induced oxidative damage, protease activation, myofiber atrophy, and contractile dysfunction. Further, exercise protected diaphragm mitochondria against MV-induced oxidative damage and uncoupling of oxidative phosphorylation. These results provide the first evidence that exercise can provide protection against MV-induced diaphragm weakness. These findings are important and establish the need for future experiments to determine the mechanism(s) responsible for exercise-induced diaphragm protection.

  4. Silicon-micromachined poppet valve with an octagonal diaphragm

    NASA Astrophysics Data System (ADS)

    Siekkinen, James W.; Haltiner, K. J.; Chilcott, Dan W.; Huang, L. X.; Staller, Steve E.

    1996-09-01

    A new pressure-activated silicon micromachined poppet valve design and fabrication process are presented for automotive fuel applications. Although non-electrically activated, micromachining provides a physical structure which is difficult or expensive to achieve with conventional method machined parts. Bulk etching is used to fabricate an octagonal silicon diaphragm which moves in response to the inlet fluid pressure. Silicon direct bonding is used to combine two layers, one with an inlet flow chamber and valve boss, and a second with a movable diaphragm and valve seat. The outlet side of the diaphragm includes a spring locator to position a counter-force mechanical spring. The diaphragm's burst pressure is reduced and varies greatly depending on the alignment of the clamping edges above and below the diaphragm.

  5. A High Deflection Diaphragm concept (HDD) for power transmission shafting

    NASA Astrophysics Data System (ADS)

    Stocco, Joseph A.

    This paper will present a flexible metal diaphragm concept for power transmission shifting or couplings which must not only carry torque, but are also required to accommodate large amounts of axial and angular misalignments. The concept was developed through an analytical research investigation of diaphragm stress and their performance characteristics. This research will be described. The quality, reliability, meantime between failure and expected life characteristics of HDD diaphragms will be presented in this work. As proof of the design concept, diaphragms for a particular hypothetical application were fabricated into a prototype shaft, and tested. The results of this validation study will also be described herein. During the course of the testing program, it was decided to extend the analysis and the test evaluation to examine the effects of inducing damage in a diaphragm, as might occur during hostile encounters or abnormal operation.

  6. Diaphragm degeneration and cardiac structure in mdx mouse: potential clinical implications for Duchenne muscular dystrophy.

    PubMed

    Barbin, Isabel Cristina Chagas; Pereira, Juliano Alves; Bersan Rovere, Matheus; de Oliveira Moreira, Drielen; Marques, Maria Julia; Santo Neto, Humberto

    2016-05-01

    We examined the effects of exercise on diaphragm degeneration and cardiomyopathy in dystrophin-deficient mdx mice. Mdx mice (11 months of age) were exercised (swimming) for 2 months to worsen diaphragm degeneration. Control mdx mice were kept sedentary. Morphological evaluation demonstrated increased fibrosis in the diaphragm of exercised mdx mice (33.3 ± 6.0% area of fibrosis) compared with control mdx mice (20.9 ± 1.7% area of fibrosis). Increased (26%) activity of MMP-2, a marker of fibrosis, was detected in the diaphragms from exercised mdx mice. Morphological evaluation of the heart demonstrated a 45% increase in fibrosis in the right ventricle (8.3 ± 0.6% in sedentary vs. 12.0 ± 0.6% of fibrosis in exercised) and in the left ventricle (35% increase) in the exercised mdx mice. The density of inflammatory cells-degenerating cardiomyocytes increased 95% in the right ventricle (2.3 ± 0.6 in sedentary vs. 4.5 ± 0.8 in exercised) and 71% in the left ventricle (1.4 ± 0.6 sedentary vs. 2.4 ± 0.5 exercised). The levels of both active MMP-2 and the pro-fibrotic factor transforming growth factor beta were elevated in the hearts of exercised compared with sedentary mdx mice. The wall thickness to lumen diameter ratio of the pulmonary trunk was significantly increased in the exercised mdx mice (0.11 ± 0.04 in sedentary vs. 0.28 ± 0.12 in exercised), as was the thickness of the right ventricle wall, which suggests the occurrence of pulmonary hypertension in those animals. It is suggested that diaphragm degeneration is a main contributor to right ventricle dystrophic pathology. These findings may be relevant for future interventional studies for Duchenne muscular dystrophy-associated cardiomyopathy.

  7. Influence of diaphragm configuration on DC diaphragm discharge breakdown in electrolyte solution

    NASA Astrophysics Data System (ADS)

    Hlavatá, L.; Hlochová, L.; Kozáková, Z.; Krčma, F.; Guaitella, O.

    2016-10-01

    This paper deals with generation of diaphragm discharge in water solutions of sodium chloride with fixed conductivity of 275 μS. The photos were recorded by high-speed iCCD camera at defined times synchronized by the current passing through the system. Three different phases in the current-voltage curve were recognized under all conditions. Only electrolysis proceeds during the first phase at the lowest applied voltage (300 - 1200 V depending on the orifice dimensions), while bubbles were created thanks to the intense Joule heating inside the orifice during the second phase. Finally, the discharge was ignited at applied voltages over 1600 V. These facts were confirmed by iCCD images taken during all three phases. We concluded, by comparing current-voltage characteristics of different orifice diameter sizes, that this parameter had an important influence on the bubbles generation phase. On the contrary, the diaphragm thickness played an important role at the discharge breakdown.

  8. Seismic resistance of composite floor diaphragms

    NASA Astrophysics Data System (ADS)

    Porter, M. L.; Greimann, L. F.

    1980-05-01

    The behavioral and strength characteristics of composite steel deck floor slab diaphragms are reported. Principal characteristics investigated include maximum load, ductility, stiffness, and failure mode. The addition of studs increases the flexural load capacity of one-way steel deck reinforced slabs by 10 to 30 percent. Non-studded specimens ultimately fail because of loss of interfacial force in the shear span. Studded specimens ultimately fail due to tearing of the deck near the stud. Two analysis procedures were used, a contributing forces approach and a shear-bond approach. The former was found to be a potential analysis procedure, and results from the shear-bond increase approach demonstrated its feasibility for studded specimens.

  9. Photographic photometry with Iris diaphragm photometers

    NASA Technical Reports Server (NTRS)

    Schaefer, B. E.

    1981-01-01

    A general method is presented for solving problems encountered in the analysis of Iris diaphragm photometer (IDP) data. The method is used to derive the general shape of the calibration curve, allowing both a more accurate fit to the IDP data for comparison stars and extrapolation to magnitude ranges for which no comparison stars are measured. The profile of starlight incident and the characteristic curve of the plate are both assumed and then used to derive the profile of the star image. An IDP reading is then determined for each star image. A procedure for correcting the effects of a nonconstant background fog level on the plate is also demonstrated. Additional applications of the method are made in the appendix to determine the relation between the radius of a photographic star image and the star's magnitude, and to predict the IDP reading of the 'point of optimum density'.

  10. Treatment of Idiopathic Diaphragm Flutter: A Case Study.

    PubMed

    Chiou, Michael; Herrero, María Victoria; Bach, John R; Cole, Jeffrey L; Gonzales, Enrique Luis

    2017-04-01

    Diaphragm flutter is a rare disorder defined by dyspnea and often thoracoabdominal pain associated with rapid rhythmic involuntary contractions of the diaphragm with no effective treatment. A 35-year-old woman's flutter was triggered by increasing the depth of breathing and by (electrical) stimulation of the diaphragm. Medical therapy, phrenic nerve crush, and diaphragm pacer stimulation were ineffective. Since increasing diaphragm activity was a trigger, resting the diaphragm was tried. A manual resuscitator and, subsequently, mouthpiece and nasal noninvasive ventilatory support (NVS) instantaneously halted the flutter for 3 months and almost instantaneously for another 6 months. For 16 months, it has continued to halt flutter with rare episodes when getting out of bed that resolve with up to 40 minutes of NVS. To our knowledge, this is the first case of idiopathic diaphragmatic flutter for which diaphragm rest was used as successful treatment with no adverse effects. This should be tried for future cases. Copyright © 2017 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

  11. Automatic delineation of the diaphragm in computed tomographic images.

    PubMed

    Rangayyan, Rangaraj M; Vu, Randy H; Boag, Graham S

    2008-10-01

    Segmentation of the internal organs in medical images is a difficult task. By incorporating a priori information regarding specific organs of interest, results of segmentation may be improved. Landmarking (i.e., identifying stable structures to aid in gaining more knowledge concerning contiguous structures) is a promising segmentation method. Specifically, segmentation of the diaphragm may help in limiting the scope of segmentation methods to the abdominal cavity; the diaphragm may also serve as a stable landmark for identifying internal organs, such as the liver, the spleen, and the heart. A method to delineate the diaphragm is proposed in the present work. The method is based upon segmentation of the lungs, identification of the lower surface of the lungs as an initial representation of the diaphragm, and the application of least-squares modeling and deformable contour models to obtain the final segmentation of the diaphragm. The proposed procedure was applied to nine X-ray computed tomographic (CT) exams of four pediatric patients with neuroblastoma. The results were evaluated against the boundaries of the diaphragm as identified independently by a radiologist. Good agreement was observed between the results of segmentation and the reference contours drawn by the radiologist, with an average mean distance to the closest point of 5.85 mm over a total of 73 CT slices including the diaphragm.

  12. Heart failure decreases passive tension generation of rat diaphragm fibers.

    PubMed

    van Hees, H W H; Ottenheijm, C A C; Granzier, H L; Dekhuijzen, P N R; Heunks, L M A

    2010-06-11

    Diaphragm dysfunction is well-known to limit quality of life and prognosis of patients with heart failure (HF), but its underlying mechanisms are not well understood. In an animal model for HF we recently showed that impaired diaphragm contractility arises at the single fiber level and is associated with sarcomeric injuries. For optimal muscle function and sarcomeric stability passive elastic structures, like titin, are indispensable. The current study aimed to investigate if impaired passive elasticity contributes to diaphragm dysfunction in rats with heart failure. Skinned muscle fibers were isolated from the diaphragm and soleus of rats with chronic HF, induced by left coronary artery ligation and of sham-operated rats. Passive tension-length relationships were determined by applying segmental extension tests. Immunofluorescence was performed on muscle cryosections using antibodies (T12) against a titin epitope near the Z-line. Titin content was determined by SDS-agarose-gel electrophoresis. Titin's mobility on gel was studied to detect changes in titin size. Passive tension generation upon stretch was significantly reduced (>35%) in HF diaphragm fibers compared to sham. Immunostaining intensities against titin were reduced in diaphragm cryosections of HF rats compared to sham. Soleus fibers from HF and sham rats did not display differences, neither in passive tension nor in immunostaining. No differences in titin's size were detected in HF and sham diaphragm. Titin content, however, was significantly reduced ( approximately 25%) in HF diaphragm. We conclude that in the diaphragm of HF rats, passive elasticity is impaired, mainly resulting from titin loss. Copyright (c) 2008 Elsevier Ireland Ltd. All rights reserved.

  13. Endocytic Trafficking at the Mature Podocyte Slit Diaphragm

    PubMed Central

    Swiatecka-Urban, Agnieszka

    2017-01-01

    Endocytic trafficking couples cell signaling with the cytoskeletal dynamics by organizing a crosstalk between protein networks in different subcellular compartments. Proteins residing in the plasma membrane are internalized and transported as cargo in endocytic vesicles (i.e., endocytosis). Subsequently, cargo proteins can be delivered to lysosomes for degradation or recycled back to the plasma membrane. The slit diaphragm is a modified tight junction connecting foot processes of the glomerular epithelial cells, podocytes. Signaling at the slit diaphragm plays a critical role in the kidney while its dysfunction leads to glomerular protein loss (proteinuria), manifesting as nephrotic syndrome, a rare condition with an estimated incidence of 2–4 new cases per 100,000 each year. Relatively little is known about the role of endocytic trafficking in podocyte signaling and maintenance of the slit diaphragm integrity. This review will focus on the role of endocytic trafficking at the mature podocyte slit diaphragm. PMID:28286744

  14. Seismic response of a large-span roof diaphragm

    USGS Publications Warehouse

    Celebi, Mehmet; Bongiovanni, Giovanni; Safak, Erdal; Brady, A. Gerald

    1989-01-01

    Records obtained from the West Valley College Gymnasium in Saratoga, California during the 1984 Morgan Hill earthquake are used to study the dynamic behavior of the overall gymnasium as well as its flexible disaphragm. The ground-level motions recorded in the two orthogonal axes of the structure differ considerably in peak acceleration and amplify by approximately 1.5 times at the roof edges and by 4-5 times at the center of the diaphragm. The diaphragm responds with a frequency of approximately 4 Hz in both orthogonal axes. A simple finite-element model is used to match the fundamental frequency of the diaphragm with that from the records. Using this model and the ground-level motions as input, the diaphragm center displacements are calculated by varying the structural damping. Best comparisons are obtained for 5% damping. These results are discussed in terms of the code provisions.

  15. Pellagra revealing a congenital duodenal diaphragm in an adult.

    PubMed

    Khouloud, Bouslama; Haykel, Bedioui; Ahmed, Saidani; Houcine, Maghrebi; Yacine, Ben Safta; Farah, Jokho; Zoubeir, Ben Safta

    2013-12-01

    Pellagra is a nutritional disease caused by the deficiency of niacin. It is a clinical syndrome characterized by four "D's": diarrhea, dermatitis, dementia and ultimately death. We describe a case of pellagra as the initial presentation of congenital duodenal diaphragm.

  16. Formation of sodium chlorate in diaphragmed chlorine electrolyzers

    SciTech Connect

    Gorbachev, A.K.; Andryushchenko, F.K.; Maksimchuk, E.F.; Potapov, V.N.

    1985-11-01

    This paper examines the formation of sodium chlorate under conditions of diaphragmed electrolysis with ruthenium-titanium oxide anodes. The authors establish that the sodium chlorate is formed chemically in such an electrolyzer. The data indicate that effective methods of reducing the amounts of sodium chlorate in diaphragm chlorine electrolyzers are to supply an acidified brine and to ensure catalytic decomposition of hypochlorous acid and sodium chlorate directly in the electrolyzer.

  17. Stylus type MEMS texture sensor covered with corrugated diaphragm

    NASA Astrophysics Data System (ADS)

    Tsukamoto, Takashiro; Asao, Hideaki; Tanaka, Shuji

    2017-09-01

    In this paper, a stylus type MEMS texture sensor covered with a corrugated palylene diaphragm, which prevent debris from jamming into the sensor without significant degradation of sensitivity and bandwidth, was reported. A new fabrication process using a lost-foil method to make the corrugated diaphragm on a 3-axis piezoresistive force sensor at wafer level has been developed. The texture sensor could detect the surface microstructure as small as about 10 \

  18. Diaphragm Thickness and Inspiratory Muscle Functions in Chronic Stroke Patients

    PubMed Central

    Kim, Minkyu; Lee, Kyeongbong; Cho, Jieun; Lee, Wanhee

    2017-01-01

    Background The aims of this study are to investigate the difference between the diaphragm thickness at end expiration and the thickness at total lung capacity (TLC), and to examine differences in inspiratory muscle function between stroke patients and healthy individuals. Material/Methods Forty-five stroke patients and 49 healthy volunteers were included in this study. Diaphragm thickness was measured at end expiration and at TLC by ultrasonography. The maximal inspiratory pressure (MIP), peak inspiratory flow (PIF), vital capacity (VC), and inspiratory muscle endurance (IME) were assess to evaluate inspiratory muscle function. Results In stroke patients, the diaphragm was significantly thinner on the affected side than the less affected side at end expiration and at TLC. The change between the thickness at end expiration and at TLC were also significant on both sides. Between groups, the difference in diaphragm thickness at end expiration was not significant, but at TLC, the diaphragms were significantly thicker in healthy individuals than on either side in stroke patients, and the change in diaphragm thickness was significantly greater for healthy individuals. Inspiratory muscle functions were also significantly greater in healthy individuals. MIP, PIF, and VC were positively correlated with the change in thickness in healthy individuals, and MIP was positively correlated with the change in thickness and IME in stroke patients. Conclusions Stroke patients showed decreases in the thickening ability of the diaphragm at TLC and in inspiratory muscle function. The change between the diaphragm thickness at end expiration and at TLC was positively correlated with MIP, PIF, and VC. PMID:28284044

  19. Investigation of the diaphragm-type pressure cell

    NASA Technical Reports Server (NTRS)

    Theodorsen, Theodore

    1932-01-01

    This report relates to various improvements in the process of manufacture of the NACA standard pressure cell. Like most pressure recording devices employing thin diaphragms, they would in general show considerable change in calibration with temperature and also some change of calibration with time or aging effect. The required diaphragm thickness and the desirable rate of mechanical magnification have been determined on the basis of several hundred tests.

  20. Role of the diaphragm in trunk rotation in humans

    PubMed Central

    Hudson, Anna L.; Butler, Jane E.; De Troyer, Andre

    2011-01-01

    The objectives of the present study were to test the hypothesis that the costal diaphragm contracts during ipsilateral rotation of the trunk and that such trunk rotation increases the motor output of the muscle during inspiration. Monopolar electrodes were inserted in the right costal hemidiaphragm in six subjects, and electromyographic (EMG) recordings were made during isometric rotation efforts of the trunk to the right (“ipsilateral rotation”) and to the left (“contralateral rotation”). EMG activity was simultaneously recorded from the parasternal intercostal muscles on the right side. The parasternal intercostals were consistently active during ipsilateral rotation but silent during contralateral rotation. In contrast, the diaphragm was silent in the majority of rotations in either direction, and whenever diaphragm activity was recorded, it involved very few motor units. In addition, whereas parasternal inspiratory activity substantially increased during ipsilateral rotation and decreased during contralateral rotation, inspiratory activity in the diaphragm was essentially unaltered and the discharge frequency of single motor units in the muscle remained at 13–14 Hz in the different postures. It is concluded that 1) the diaphragm makes no significant contribution to trunk rotation and 2) even though the diaphragm and parasternal intercostals contract in a coordinated manner during resting breathing, the inspiratory output of the two muscles is affected differently by voluntary drive during trunk rotation. PMID:21753028

  1. Role of the diaphragm in trunk rotation in humans.

    PubMed

    Hudson, Anna L; Butler, Jane E; Gandevia, Simon C; De Troyer, Andre

    2011-10-01

    The objectives of the present study were to test the hypothesis that the costal diaphragm contracts during ipsilateral rotation of the trunk and that such trunk rotation increases the motor output of the muscle during inspiration. Monopolar electrodes were inserted in the right costal hemidiaphragm in six subjects, and electromyographic (EMG) recordings were made during isometric rotation efforts of the trunk to the right ("ipsilateral rotation") and to the left ("contralateral rotation"). EMG activity was simultaneously recorded from the parasternal intercostal muscles on the right side. The parasternal intercostals were consistently active during ipsilateral rotation but silent during contralateral rotation. In contrast, the diaphragm was silent in the majority of rotations in either direction, and whenever diaphragm activity was recorded, it involved very few motor units. In addition, whereas parasternal inspiratory activity substantially increased during ipsilateral rotation and decreased during contralateral rotation, inspiratory activity in the diaphragm was essentially unaltered and the discharge frequency of single motor units in the muscle remained at 13-14 Hz in the different postures. It is concluded that 1) the diaphragm makes no significant contribution to trunk rotation and 2) even though the diaphragm and parasternal intercostals contract in a coordinated manner during resting breathing, the inspiratory output of the two muscles is affected differently by voluntary drive during trunk rotation.

  2. Fluid Sloshing Characteristics in Spacecraft Propellant Tanks with Diaphragms

    NASA Technical Reports Server (NTRS)

    Green, Steve; Burkey, Russell; Viana, Flavia; Sudermann, James

    2007-01-01

    All spacecraft are launched from the Earth as payloads on a launch vehicle. During portions of the launch profile, the spacecraft could be subjected to nearly purely translational oscillatory lateral motions as the launch vehicle control system guides the rocket along its flight path. All partially-filled liquids tanks, even those with diaphragms, exhibit sloshing behavior under these conditions and some tanks can place large loads on their support structures if the sloshing is in resonance with the control system oscillation frequency. The objectives of this project were to conduct experiments using a full-scale model of a flight tank to 1) determine whether launch vehicle vibrations can cause the diaphragm to achieve a repeatable configuration, regardless of initial condition, and 2) identify the slosh characteristics of the propellant tank under flight-like lateral motions for different diaphragm shapes and vibration levels. The test results show that 1) the diaphragm shape is not affected by launch vibrations, and 2) the resonance-like behavior of the fluid and diaphragm is strongly affected by the nonlinear stiffness and damping provided by the diaphragm.

  3. Diaphragm postural function analysis using magnetic resonance imaging.

    PubMed

    Vostatek, Pavel; Novák, Daniel; Rychnovský, Tomas; Rychnovská, Sarka

    2013-01-01

    We present a postural analysis of diaphragm function using magnetic resonance imaging (MRI). The main aim of the study was to identify changes in diaphragm motion and shape when postural demands on the body were increased (loading applied to a distal part of the extended lower extremities against the flexion of the hips was used). Sixteen healthy subjects were compared with 17 subjects suffering from chronic low back pain and in whom structural spine disorders had been identified. Two sets of features were calculated from MRI recordings: dynamic parameters reflecting diaphragm action, and static parameters reflecting diaphragm anatomic characteristics. A statistical analysis showed that the diaphragm respiratory and postural changes were significantly slower, bigger in size and better balanced in the control group. When a load was applied to the lower limbs, the pathological subjects were mostly not able to maintain the respiratory diaphragm function, which was lowered significantly. Subjects from the control group showed more stable parameters of both respiratory and postural function. Our findings consistently affirmed worse muscle cooperation in the low back pain population subgroup. A clear relation with spinal findings and with low back pain remains undecided, but various findings in the literature were confirmed. The most important finding is the need to further address various mechanisms used by patients to compensate deep muscle insufficiency.

  4. Diaphragm Motor Unit Recruitment in Rats

    PubMed Central

    Mantilla, Carlos B.; Seven, Yasin B.; Zhan, Wen-Zhi; Sieck, Gary C.

    2010-01-01

    We hypothesized that considerable force reserve exists for the diaphragm muscle (DIAm) to generate transdiaphragmatic pressures (Pdi) necessary to sustain ventilation. In rats, we measured Pdi and DIAm EMG activity during different ventilatory (eupnea and hypoxia (10% O2) – hypercapnia (5% CO2)) and non-ventilatory (airway occlusion and sneezing induced by intranasal capsaicin) behaviors. Compared to maximum Pdi (Pdimax - generated by bilateral phrenic nerve stimulation), the Pdi generated during eupnea (21±2%) and hypoxia-hypercapnia (28±4%) were significantly less (P<0.0001) than that generated during airway occlusion (63±4%) and sneezing (94±5%). The Pdi generated during spontaneous sighs was 62±5% of Pdimax. Relative DIAm EMG activity (root mean square [RMS] amplitude) paralleled the changes in Pdi during different ventilatory and non-ventilatory behaviors (r2=0.78; p<0.0001). These results support our hypothesis of a considerable force reserve for the DIAm to accomplish ventilatory behaviors. A model for DIAm motor unit recruitment predicted that ventilatory behaviors would require activation of only fatigue resistant units. PMID:20620243

  5. Diaphragm Dysfunction in Mechanically Ventilated Patients.

    PubMed

    Dot, Irene; Pérez-Teran, Purificación; Samper, Manuel-Andrés; Masclans, Joan-Ramon

    2017-03-01

    Muscle involvement is found in most critical patients admitted to the intensive care unit (ICU). Diaphragmatic muscle alteration, initially included in this category, has been differentiated in recent years, and a specific type of muscular dysfunction has been shown to occur in patients undergoing mechanical ventilation. We found this muscle dysfunction to appear in this subgroup of patients shortly after the start of mechanical ventilation, observing it to be mainly associated with certain control modes, and also with sepsis and/or multi-organ failure. Although the specific etiology of process is unknown, the muscle presents oxidative stress and mitochondrial changes. These cause changes in protein turnover, resulting in atrophy and impaired contractility, and leading to impaired functionality. The term 'ventilator-induced diaphragm dysfunction' was first coined by Vassilakopoulos et al. in 2004, and this phenomenon, along with injury cause by over-distention of the lung and barotrauma, represents a challenge in the daily life of ventilated patients. Diaphragmatic dysfunction affects prognosis by delaying extubation, prolonging hospital stay, and impairing the quality of life of these patients in the years following hospital discharge. Ultrasound, a non-invasive technique that is readily available in most ICUs, could be used to diagnose this condition promptly, thus preventing delays in starting rehabilitation and positively influencing prognosis in these patients. Copyright © 2016 SEPAR. Publicado por Elsevier España, S.L.U. All rights reserved.

  6. Extended use of diaphragm pacing in patients with unilateral or bilateral diaphragm dysfunction: a new therapeutic option.

    PubMed

    Onders, Raymond P; Elmo, MaryJo; Kaplan, Cindy; Katirji, Bashar; Schilz, Robert

    2014-10-01

    Diaphragm dysfunction (DD) can cause sleep abnormalities, dyspnea, atelectasis, and respiratory failure. Historical treatments, including positive pressure ventilation or diaphragm plication, may alleviate symptoms but do not restore physiologic diaphragm function. Diaphragm pacing (DP) is approved for spinal cord-injured patients and in amyotrophic lateral sclerosis. We report a series of DD patients undergoing use of DP outside of these initial indications. This report involves a prospective, nonrandomized, interventional trial under institutional review board approval at a single institution. DP involves laparoscopic motor point mapping with implantation of intramuscular electrodes in each hemidiaphragm. Postoperatively, diaphragm conditioning ensues. Twenty-seven patients were evaluated; all patients had symptomatic and objective hypoventilation for an average of 36 months of symptoms. Causes included idiopathic (n = 13), chest surgery (n = 5), shoulder surgery or trauma (n = 6), and others (n = 3); 17 had bilateral involvement, 6 had nonstimulable diaphragms and were not implanted, and 21 were implanted. Thirteen (62%) had substantial clinically relevant respiratory improvements. Four ventilator patients were weaned completely. Four had partial improvement, 3 had no improvement, and 1 patient was lost to follow-up for objective analysis. This is the first report of DP being used to treat diverse causes of DD. Eighty-one percent of implanted patients experienced improvements. This success suggests a potential for a wider use of DP and areas for future research. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Mechanical Ventilation-Induced Oxidative Stress in the Diaphragm

    PubMed Central

    Falk, Darin J.; Kavazis, Andreas N.; Whidden, Melissa A.; Smuder, Ashley J.; McClung, Joseph M.; Hudson, Matthew B.

    2011-01-01

    Background: Prolonged mechanical ventilation (MV) results in a rapid onset of diaphragmatic atrophy that is primarily due to increased proteolysis. Although MV-induced protease activation can involve several factors, it is clear that oxidative stress is a required signal for protease activation in the diaphragm during prolonged MV. However, the oxidant-producing pathways in the diaphragm that contribute to MV-induced oxidative stress remain unknown. We have demonstrated that prolonged MV results in increased diaphragmatic expression of a key stress-sensitive enzyme, heme oxygenase (HO)-1. Paradoxically, HO-1 can function as either a pro-oxidant or an antioxidant, and the role that HO-1 plays in MV-induced diaphragmatic oxidative stress is unknown. We tested the hypothesis that HO-1 acts as a pro-oxidant in the diaphragm during prolonged MV. Methods: To determine whether HO-1 functions as a pro-oxidant or an antioxidant in the diaphragm during MV, we assigned rats into three experimental groups: (1) a control group, (2) a group that received 18 h of MV and saline solution, and (3) a group that received 18 h of MV and was treated with a selective HO-1 inhibitor. Indices of oxidative stress, protease activation, and fiber atrophy were measured in the diaphragm. Results: Inhibition of HO-1 activity did not prevent or exacerbate MV-induced diaphragmatic oxidative stress (as indicated by biomarkers of oxidative damage). Further, inhibition of HO-1 activity did not influence MV-induced protease activation or myofiber atrophy in the diaphragm. Conclusions: Our results indicate that HO-1 is neither a pro-oxidant nor an antioxidant in the diaphragm during MV. Furthermore, our findings reveal that HO-1 does not play an important role in MV-induced protease activation and diaphragmatic atrophy. PMID:21106654

  8. The maximum life expectancy for a micro-fabricated diaphragm

    NASA Astrophysics Data System (ADS)

    Cǎlimǎnescu, Ioan; Stan, Liviu-Constantin; Popa, Viorica

    2015-02-01

    Micro-fabricated diaphragms can be used to provide pumping action in microvalve and microfluidic applications. The functionality of the microdiaphragm in a wirelessly actuated micropump plays a major role in low-powered device actuation. In developing micropumps and their components, it is becoming an increasing trend to predict the performance before the prototype is fabricated. Because performance prediction allows for an accurate estimation of yield and lifetime, in addition to developing better understanding of the device while taking into account the details of the device structure and second order effects. Hence avoid potential pitfalls in the device operation in a practical environment. The goal of this research is to determine via FEA the life expectancy for a corrugated circular diaphragm made out of an aluminum alloy. The geometry of the diaphragm is given below being generated within SolidWorks 2010, all the calculations were made using Ansys 13TM . The sound design of a micropump is heavily depending on the lifetime expectancy of the working part of the device which is the diaphragm. This will be subjected on cyclic loading and the fatigue will limit the life of this part. Once the diaphragm is breaking, the micropump is no more able to fulfill its scope. Any micropump manufacturer will then be very concerned on the life expectancy from the fatigue point of view of the diaphragms. The diaphragm circular and corrugated and made of Al alloy, showed a very good behavior from the fatigue point of view, the maximum life expectancy being 1.9 years of continuous functioning with 100 cycles per second. This work showed an simple and forward application of FEA analysis methods in order to estimate the fatigue behavior of corrugated circular microdiaphragms.

  9. [Clinical relevance of myosin isoforms in the diaphragm].

    PubMed

    Gayan-Ramirez, G; Decramer, M

    2000-06-01

    The diaphragm as a striated muscle is characterized by the repetition of a single element arranged in series: the sarcomere containing two kinds of myofilaments: a thick one constituted by the myosin, and a thin one primarily composed of actin. The myosin molecule consists of two heads where two myosin heavy chains (MHC) are fixed, a flexible hinge with two light (MLC) chains, and long rod-shaped tails. The diaphragm contains 4 MHC isoforms (MHC-slow, MHC-2A, MHC-2B, MHC-2X) and 6 MLC isoforms (MLC-1f, MLC-3f, MLC-1sa, MLC-1sb, MLC-2f, MLC-2s/v). In humans, the diaphragm contains mainly fibers expressing the isoforms MHC-slow, MHC-2A, and MLC-2f, MLC-2s et MLC-1f. For the mechanical properties of the different isoforms, there is a gradient from the MHC-slow to the MHC-2A, MHC-2B and MHC-2X/2B. According to the circumstances, the diaphragm will adapt towards a slow profile (COPD, cardiac failure and in animals: Duchenne muscular dystrophy, denervation-1 week, age-female, corticosteroids, chronic stimulation), or a fast profile (in animals: chronic hypoxia, denervation-2 weeks, age-males) or a more oxidative profile (in animals: cachexia, obesity). The reasons why the diaphragm adapts towards a slower or a faster muscle are not known. In fact, for a given pathological situation, several factors are able to influence the fiber composition of the diaphragm. Therefore, the net result of the influence of these different factors in terms of MHC and MLC diaphragm adaptation is difficult to predict.

  10. Relevant surgical anatomy of the chest wall.

    PubMed

    Naidu, Babu V; Rajesh, Pala B

    2010-11-01

    The chest wall, like other regional anatomy, is a remarkable fusion of form and function. Principal functions are the protection of internal viscera and an expandable cylinder facilitating variable gas flow into the lungs. Knowledge of the anatomy of the whole cylinder (ribs, sternum, vertebra, diaphragm, intercostal spaces, and extrathoracic muscles) is therefore not only important in the local environment of a specific chest wall resection but also in its relation to overall function. An understanding of chest wall kinematics might help define the loss of function after resection and the effects of various chest wall substitutes. Therefore, this article is not an exhaustive anatomic description but a focused summary and discussion.

  11. Synchronization of presynaptic input to motor units of tongue, inspiratory intercostal, and diaphragm muscles.

    PubMed

    Rice, Amber; Fuglevand, Andrew J; Laine, Christopher M; Fregosi, Ralph F

    2011-05-01

    The respiratory central pattern generator distributes rhythmic excitatory input to phrenic, intercostal, and hypoglossal premotor neurons. The degree to which this input shapes motor neuron activity can vary across respiratory muscles and motor neuron pools. We evaluated the extent to which respiratory drive synchronizes the activation of motor unit pairs in tongue (genioglossus, hyoglossus) and chest-wall (diaphragm, external intercostals) muscles using coherence analysis. This is a frequency domain technique, which characterizes the frequency and relative strength of neural inputs that are common to each of the recorded motor units. We also examined coherence across the two tongue muscles, as our previous work shows that, despite being antagonists, they are strongly coactivated during the inspiratory phase, suggesting that excitatory input from the premotor neurons is distributed broadly throughout the hypoglossal motoneuron pool. All motor unit pairs showed highly correlated activity in the low-frequency range (1-8 Hz), reflecting the fundamental respiratory frequency and its harmonics. Coherence of motor unit pairs recorded either within or across the tongue muscles was similar, consistent with broadly distributed premotor input to the hypoglossal motoneuron pool. Interestingly, motor units from diaphragm and external intercostal muscles showed significantly higher coherence across the 10-20-Hz bandwidth than tongue-muscle units. We propose that the lower coherence in tongue-muscle motor units over this range reflects a larger constellation of presynaptic inputs, which collectively lead to a reduction in the coherence between hypoglossal motoneurons in this frequency band. This, in turn, may reflect the relative simplicity of the respiratory drive to the diaphragm and intercostal muscles, compared with the greater diversity of functions fulfilled by muscles of the tongue.

  12. Synchronization of presynaptic input to motor units of tongue, inspiratory intercostal, and diaphragm muscles

    PubMed Central

    Rice, Amber; Fuglevand, Andrew J.; Laine, Christopher M.

    2011-01-01

    The respiratory central pattern generator distributes rhythmic excitatory input to phrenic, intercostal, and hypoglossal premotor neurons. The degree to which this input shapes motor neuron activity can vary across respiratory muscles and motor neuron pools. We evaluated the extent to which respiratory drive synchronizes the activation of motor unit pairs in tongue (genioglossus, hyoglossus) and chest-wall (diaphragm, external intercostals) muscles using coherence analysis. This is a frequency domain technique, which characterizes the frequency and relative strength of neural inputs that are common to each of the recorded motor units. We also examined coherence across the two tongue muscles, as our previous work shows that, despite being antagonists, they are strongly coactivated during the inspiratory phase, suggesting that excitatory input from the premotor neurons is distributed broadly throughout the hypoglossal motoneuron pool. All motor unit pairs showed highly correlated activity in the low-frequency range (1–8 Hz), reflecting the fundamental respiratory frequency and its harmonics. Coherence of motor unit pairs recorded either within or across the tongue muscles was similar, consistent with broadly distributed premotor input to the hypoglossal motoneuron pool. Interestingly, motor units from diaphragm and external intercostal muscles showed significantly higher coherence across the 10–20-Hz bandwidth than tongue-muscle units. We propose that the lower coherence in tongue-muscle motor units over this range reflects a larger constellation of presynaptic inputs, which collectively lead to a reduction in the coherence between hypoglossal motoneurons in this frequency band. This, in turn, may reflect the relative simplicity of the respiratory drive to the diaphragm and intercostal muscles, compared with the greater diversity of functions fulfilled by muscles of the tongue. PMID:21307319

  13. Development of the diaphragm, a skeletal muscle essential for mammalian respiration

    PubMed Central

    Merrell, Allyson J.; Kardon, Gabrielle

    2013-01-01

    The mammalian diaphragm muscle is essential for respiration, and thus it is among the most critical of the skeletal muscles in the human body. Defects in diaphragm development, leading to congenital diaphragmatic hernias (CDH), are common birth defects and result in severe morbidity or mortality. Given its functional importance and the frequency of congenital defects, an understanding of diaphragm development normally and during herniation is important. We review the current knowledge of the embryological origins of the diaphragm, diaphragm development and morphogenesis, and the genetic and developmental etiology of diaphragm birth defects. PMID:23586979

  14. Chondroma of the diaphragm mimicking a giant liver tumor with calcification: report of a case.

    PubMed

    Asahi, Yoh; Kamiyama, Toshiya; Nakanishi, Kazuaki; Yokoo, Hideki; Tahara, Munenori; Usui, Akihiro; Funakoshi, Tohru; Sato, Masanori; Sasaki, Ayami; Matsuno, Yoshihiro; Taketomi, Akinobu; Todo, Satoru

    2014-12-01

    Extraskeletal chondroma is an unusual benign tumor, which rarely arises in the diaphragm. We report a case of chondroma of the diaphragm in a 31-year-old woman. Initially, a benign liver tumor with calcification was suspected, based on pre and intraoperative examination findings. Although parts of the tumor were contiguous with the diaphragm, its connections with the diaphragm were much narrower than its connection with the liver, which suggested a liver tumor. Pathological examination subsequently revealed that the chondroma was contiguous with the diaphragm and that there was a distinct border between the tumor and the liver; thus, the tumor was diagnosed as a chondroma of the diaphragm.

  15. Diaphragm Pressure Wave Generator Developments at Industrial Research Ltd

    NASA Astrophysics Data System (ADS)

    Caughley, A. J.; Emery, N.; Glasson, N. D.

    2010-04-01

    Industrial Research Ltd (IRL) have been developing a unique diaphragm based pressure wave generator technology for pulse tube and Stirling cryocoolers. Our system uses a metal diaphragm to separate the clean cryocooler gas circuit from a conventionally lubricated mechanical driver, thus producing a clean pressure wave with a long life drive that does not require the precision manufacture and associated costs of large linear motors. The first successful diaphragm pressure wave generator produced 3.2 kW of acoustic power at an electro-acoustic efficiency of 72% with a swept volume of 200 ml and a prototype has now accumulated over 2500 hours running. This paper describes recent developments in the technology. To explore scaling, a small diaphragm pressure wave generator with a swept volume of 20 ml has been constructed and has delivered 454 W of acoustic power at an electro-acoustic efficiency of 60%. Improvements have been made to the hydraulic force amplifier mechanism for driving the diaphragms resulting in a cheaper and lighter mechanism than the mechanical linkage originally used. To meet a customer's specific requirements, the 200 ml pressure wave generator's stroke was extended to achieve 240 ml of swept volume thereby increasing its acoustic power delivery to 4.1 kW without compromising efficiency.

  16. Interstitial space and collagen alterations of the developing rat diaphragm

    NASA Technical Reports Server (NTRS)

    Gosselin, L. E.; Martinez, D. A.; Vailas, A. C.; Sieck, G. C.

    1993-01-01

    The effect of growth on the relative interstitial space [%total cross-sectional area (CSA)] and collagen content of the rat diaphragm muscle was examined at postnatal ages of 0, 7, 14, and 21 days as well as in adult males. The proportion of interstitial space relative to total muscle CSA was determined by computerized image analysis of lectin-stained cross sections of diaphragm muscle. To assess collagen content and extent of collagen maturation (i.e., cross-linking), high-pressure liquid chromatography analysis was used to measure hydroxyproline concentration and the nonreducible collagen cross-link hydroxylysylpyridinoline (HP), respectively. At birth, interstitial space accounted for approximately 47% of total diaphragm muscle CSA. During postnatal growth, the relative contribution of interstitial space decreased such that by adulthood the interstitial space accounted for approximately 18% of total muscle CSA. The change in relative interstitial space occurred without a concomitant change in hydroxyproline concentration. However, the concentration of HP markedly increased with age such that the adult diaphragm contained approximately 17 times more HP than at birth. These results indicate that during development the relative CSA occupied by interstitial space decreases as muscle fiber size increases. However, the reduction in relative interstitial space is not associated with a change in collagen concentration. Thus collagen density in the interstitial space may increase with age. It is possible that the observed changes in relative interstitial space and collagen influence the passive length-force properties of the diaphragm.

  17. Idiopathic diaphragmatic paralysis: Bell's palsy of the diaphragm?

    PubMed

    Crausman, Robert S; Summerhill, Eleanor M; McCool, F Dennis

    2009-01-01

    Idiopathic diaphragm paralysis is probably more common and responsible for more morbidity than generally appreciated. Bell's palsy, or idiopathic paralysis of the seventh cranial nerve, may be seen as an analogous condition. The roles of zoster sine herpete and herpes simplex have increasingly been recognized in Bell's palsy, and there are some data to suggest that antiviral therapy is a useful adjunct to steroid therapy. Thus, we postulated that antiviral therapy might have a positive impact on the course of acute idiopathic diaphragm paralysis which is likely related to viral infection. Three consecutive patients with subacute onset of symptomatic idiopathic hemidiaphragm paralysis were empirically treated with valacyclovir, 1,000 mg twice daily for 1 week. Prior to therapy, diaphragmatic function was assessed via pulmonary function testing and two-dimensional B-mode ultrasound, with testing repeated 1 month later. Diaphragmatic function pre- and post-treatment was compared to that of a historical control group of 16 untreated patients. All three subjects demonstrated ultrasound recovery of diaphragm function 4-6 weeks following treatment with valacyclovir. This recovery was accompanied by improvements in maximum inspiratory pressure (PI(max)) and vital capacity (VC). In contrast, in the untreated cohort, diaphragm recovery occurred in only 11 subjects, taking an average of 14.9 +/- 6.1 months (mean +/- SD). The results of this small, preliminary study suggest that antiviral therapy with valacyclovir may be helpful in the treatment of idiopathic diaphragm paralysis induced by a viral infection.

  18. Mechanical ventilation, diaphragm weakness and weaning: A rehabilitation perspective

    PubMed Central

    Martin, A Daniel; Smith, Barbara; Gabrielli, Andrea

    2013-01-01

    Most patients are easily liberated from mechanical ventilation (MV) following resolution of respiratory failure and a successful trial of spontaneous breathing, but about 25% of patients experience difficult weaning. MV use leads to cellular changes and weakness, which has been linked to weaning difficulties and has been labeled ventilator induced diaphragm dysfunction (VIDD). Aggravating factors in human studies with prolonged weaning include malnutrition, chronic electrolyte abnormalities, hyperglycemia, excessive resistive and elastic loads, corticosteroids, muscle relaxant exposure, sepsis and compromised cardiac function. Numerous animal studies have investigated the effects of MV on diaphragm function. Virtually all of these studies have concluded that MV use rapidly leads to VIDD and have identified cellular and molecular mechanisms of VIDD. Molecular and functional studies on the effects of MV on the human diaphragm have largely confirmed the animal results and identified potential treatment strategies. Only recently have potential VIDD treatments been tested in humans, including pharmacologic interventions and diaphragm “training”. A limited number of human studies have found that specific diaphragm training can increase respiratory muscle strength in FTW patients and facilitate weaning, but larger, multicenter trials are needed. PMID:23692928

  19. Mechanical ventilation, diaphragm weakness and weaning: a rehabilitation perspective.

    PubMed

    Daniel Martin, A; Smith, Barbara K; Gabrielli, Andrea

    2013-11-01

    Most patients are easily liberated from mechanical ventilation (MV) following resolution of respiratory failure and a successful trial of spontaneous breathing, but about 25% of patients experience difficult weaning. MV use leads to cellular changes and weakness, which has been linked to weaning difficulties and has been labeled ventilator induced diaphragm dysfunction (VIDD). Aggravating factors in human studies with prolonged weaning include malnutrition, chronic electrolyte abnormalities, hyperglycemia, excessive resistive and elastic loads, corticosteroids, muscle relaxant exposure, sepsis and compromised cardiac function. Numerous animal studies have investigated the effects of MV on diaphragm function. Virtually all these studies have concluded that MV use rapidly leads to VIDD and have identified cellular and molecular mechanisms of VIDD. Molecular and functional studies on the effects of MV on the human diaphragm have largely confirmed the animal results and identified potential treatment strategies. Only recently potential VIDD treatments have been tested in humans, including pharmacologic interventions and diaphragm "training". A limited number of human studies have found that specific diaphragm training can increase respiratory muscle strength in FTW patients and facilitate weaning, but larger, multicenter trials are needed. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Interstitial space and collagen alterations of the developing rat diaphragm

    NASA Technical Reports Server (NTRS)

    Gosselin, L. E.; Martinez, D. A.; Vailas, A. C.; Sieck, G. C.

    1993-01-01

    The effect of growth on the relative interstitial space [%total cross-sectional area (CSA)] and collagen content of the rat diaphragm muscle was examined at postnatal ages of 0, 7, 14, and 21 days as well as in adult males. The proportion of interstitial space relative to total muscle CSA was determined by computerized image analysis of lectin-stained cross sections of diaphragm muscle. To assess collagen content and extent of collagen maturation (i.e., cross-linking), high-pressure liquid chromatography analysis was used to measure hydroxyproline concentration and the nonreducible collagen cross-link hydroxylysylpyridinoline (HP), respectively. At birth, interstitial space accounted for approximately 47% of total diaphragm muscle CSA. During postnatal growth, the relative contribution of interstitial space decreased such that by adulthood the interstitial space accounted for approximately 18% of total muscle CSA. The change in relative interstitial space occurred without a concomitant change in hydroxyproline concentration. However, the concentration of HP markedly increased with age such that the adult diaphragm contained approximately 17 times more HP than at birth. These results indicate that during development the relative CSA occupied by interstitial space decreases as muscle fiber size increases. However, the reduction in relative interstitial space is not associated with a change in collagen concentration. Thus collagen density in the interstitial space may increase with age. It is possible that the observed changes in relative interstitial space and collagen influence the passive length-force properties of the diaphragm.

  1. Diaphragm dysfunction in heart failure is accompanied by increases in neutral sphingomyelinase activity and ceramide content.

    PubMed

    Empinado, Hyacinth M; Deevska, Gergana M; Nikolova-Karakashian, Mariana; Yoo, Jeung-Ki; Christou, Demetra D; Ferreira, Leonardo F

    2014-05-01

    Chronic heart failure (CHF) causes inspiratory (diaphragm) muscle weakness and fatigue that contributes to dyspnoea and limited physical capacity in patients. However, the mechanisms that lead to diaphragm dysfunction in CHF remain poorly understood. Cytokines and angiotensin II are elevated in CHF and stimulate the activity of the enzyme sphingomyelinase (SMase) and accumulation of its reaction product ceramide. In the diaphragm, SMase or ceramide exposure in vitro causes weakness and fatigue. Thus, elevated SMase activity and ceramide content have been proposed as mediators of diaphragm dysfunction in CHF. In the present study, we tested the hypotheses that diaphragm dysfunction was accompanied by increases in diaphragm SMase activity and ceramide content. Myocardial infarction was used to induce CHF in rats. We measured diaphragm isometric force, SMase activity by high-performance liquid chromatography, and ceramide subspecies and total ceramide using mass spectrometry. Diaphragm force was depressed and fatigue accelerated by CHF. Diaphragm neutral SMase activity was increased by 20% in CHF, while acid SMase activity was unchanged. We also found that CHF increased the content of C18 -, C20 -, and C24 -ceramide subspecies and total ceramide. Downstream of ceramide degradation, diaphragm sphingosine was unchanged, and sphingosine-1-phosphate level was increased in CHF. Our major novel finding was that diaphragm dysfunction in CHF rats was accompanied by higher diaphragm neutral SMase activity, which is expected to cause the observed increase in diaphragm ceramide content. © 2014 The Authors. European Journal of Heart Failure © 2014 European Society of Cardiology.

  2. Survey of blood pump diaphragm damage in the NIPRO-ventricular assist device.

    PubMed

    Kashiwa, Koichi; Nishimura, Takashi; Nakahata, Aoi; Momose, Naoki; Umeda, Chinori; Kubo, Hitoshi; Tamai, Hisayoshi; Kinugawa, Koichiro; Adachi, Hideo; Yamaguchi, Atsushi; Yambe, Tomoyuki; Katohgi, Toshiyuki; Kyo, Shunei; Ono, Minoru

    2012-12-01

    We surveyed the incidence of blood pump diaphragm damage (rupture or crack) in the NIPRO-ventricular assist device (VAD). In the cases in which rupture or suspected blood pump crack was detected, we disassembled the pumps to visually check the condition of the diaphragm after replacement or use. Of 366 blood pumps surveyed, diaphragm damage was observed in 2.7 %. The duration of use of the blood pumps with diaphragm damage was significantly longer than that of pumps without damage. The incidence of diaphragm damage increased with longer duration of use. On the basis of these findings, blood pump diaphragm damage in the NIPRO-VAD may be associated with duration of use. However, some blood pumps were used for prolonged periods without diaphragm damage. All blood pumps with damage had a crack in the diaphragm on the air chamber side near the diaphragm-housing (D-H) junction. Cracks were not found in any specific part of the diaphragm. In blood pumps with diaphragm rupture, the crack had a through-hole reaching the blood-contacting surface. Although we were unable to identify the causes of the cracks, it is suggested that when a crack appears in the diaphragm it will gradually expand and eventually lead to rupture. If a crack is detected in a blood pump, we advocate replacing the pump before it grows. When the NIPRO-VAD is used, it is necessary to keep in mind that blood pump diaphragm damage may occur.

  3. Modeling of a dielectric elastomer diaphragm for a prosthetic blood pump

    NASA Astrophysics Data System (ADS)

    Goulbourne, Nakhiah; Frecker, Mary I.; Mockensturm, Eric M.; Snyder, Alan J.

    2003-07-01

    The electromechanical behavior of dielectric elastomers is to be exploited for medical application in artificial blood pumps. It is required that the pump diaphragm achieves a swept volume increase of 70 cc into a systolic pressure of 120 mmHg with the main design objective being volumetric efficiency. As such, a model that accommodates large deformation behavior is used. In order to design prosthetic blood pumps that closely mimic the natural pumping chambers of the heart, a dielectric elastomer diaphragm design is proposed. The elastomer's change in shape in response to the applied electric field will permit it to be the active element of the pump just as the ventricular walls are in the natural heart. A comprehensive analytical model that accounts for the combined elastic and dielectric behavior of the membrane is used to compute the stresses and deformations of the inflated membrane. Dielectric elastomers are often pre-strained in order to obtain optimal electromechanical performance. The resulting model incorporates pre-strain and shows how system parameters such as pre-strain, pressure, electric field, and edge constraints affect membrane deformation. The model predicts more than adequate volume displacement for moderate pre-strain of the elastomer.

  4. A non-diaphragm type small shock tube for application to a molecular beam source.

    PubMed

    Yoshimoto, Yuta; Osuka, Kenichi; Miyoshi, Nobuya; Kinefuchi, Ikuya; Takagi, Shu; Matsumoto, Yoichiro

    2013-07-01

    A non-diaphragm type small shock tube was developed for application to a molecular beam source, which can generate beams in the energy range from 1 to several electron volts and beams containing dissociated species such as atomic oxygen. Since repetitive high-frequency operation is indispensable for rapid signal acquisition in beam scattering experiments, the dimensions of the shock tube were miniaturized to reduce the evacuation time between shots. The designed shock tube is 2-4 mm in diameter and can operate at 0.5 Hz. Moreover, a high shock Mach number at the tube end is required for high-energy molecular beam generation. To reduce the shock attenuation caused by the wall boundary layer, which becomes significant in small-diameter tubes, we developed a high-speed response valve employing the current-loop mechanism. The response time of this mechanism is about 100 μs, which is shorter than the rupture time of conventional diaphragms. We show that the current-loop valve generates shock waves with shorter formation distances (about 200-300 mm) than those of conventional shock tubes. In addition, the converging geometry efficiently accelerates shock wave in the small-diameter tubes. The optimal geometry of the shock tube yields shock Mach number around 7, which indicates that the translation energy of molecular beams can exceed 1 eV even in the presence of the real gas effect.

  5. A non-diaphragm type small shock tube for application to a molecular beam source

    NASA Astrophysics Data System (ADS)

    Yoshimoto, Yuta; Osuka, Kenichi; Miyoshi, Nobuya; Kinefuchi, Ikuya; Takagi, Shu; Matsumoto, Yoichiro

    2013-07-01

    A non-diaphragm type small shock tube was developed for application to a molecular beam source, which can generate beams in the energy range from 1 to several electron volts and beams containing dissociated species such as atomic oxygen. Since repetitive high-frequency operation is indispensable for rapid signal acquisition in beam scattering experiments, the dimensions of the shock tube were miniaturized to reduce the evacuation time between shots. The designed shock tube is 2-4 mm in diameter and can operate at 0.5 Hz. Moreover, a high shock Mach number at the tube end is required for high-energy molecular beam generation. To reduce the shock attenuation caused by the wall boundary layer, which becomes significant in small-diameter tubes, we developed a high-speed response valve employing the current-loop mechanism. The response time of this mechanism is about 100 μs, which is shorter than the rupture time of conventional diaphragms. We show that the current-loop valve generates shock waves with shorter formation distances (about 200-300 mm) than those of conventional shock tubes. In addition, the converging geometry efficiently accelerates shock wave in the small-diameter tubes. The optimal geometry of the shock tube yields shock Mach number around 7, which indicates that the translation energy of molecular beams can exceed 1 eV even in the presence of the real gas effect.

  6. Plasma Discharge Process in a Pulsed Diaphragm Discharge System

    NASA Astrophysics Data System (ADS)

    Duan, Jianjin; Hu, Jue; Zhang, Chao; Wen, Yuanbin; Meng, Yuedong; Zhang, Chengxu

    2014-12-01

    As one of the most important steps in wastewater treatment, limited study on plasma discharge process is a key challenge in the development of plasma applications. In this study, we focus on the plasma discharge process of a pulsed diaphragm discharge system. According to the analysis, the pulsed diaphragm discharge proceeds in seven stages: (1) Joule heating and heat exchange stage; (2) nucleated site formation; (3) plasma generation (initiation of the breakdown stage); (4) avalanche growth and plasma expansion; (5) plasma contraction; (6) termination of the plasma discharge; and (7) heat exchange stage. From this analysis, a critical voltage criterion for breakdown is obtained. We anticipate this finding will provide guidance for a better application of plasma discharges, especially diaphragm plasma discharges.

  7. Interactive Simulation of Diaphragm Motion Through Muscle and Rib Kinematics

    NASA Astrophysics Data System (ADS)

    Villard, Pierre-Frédéric; Bourne, Wesley; Bello, Fernando

    Modeling of diaphragm behaviour is of relevance to a number of clinical procedures such as lung cancer radiotherapy and liver access interventions. The heterogeneity in tissue composition of the diaphragm, as well as the various physiological phenomena influencing its behaviour, requires a complex model in order to accurately capture its motion. In this chapter we present a novel methodology based on a heterogenous model composed of mass-spring and tensegrity elements. The physiological boundary conditions have been carefully taken into account and applied to our model. Thus, it incorporates the influence of the rib kinematics, the muscle natural contraction/relaxation and the motion of the sternum. Initial validation results show that the behaviour of the model closely follows that of a real diaphragm.

  8. The Impact of Midcervical Contusion Injury on Diaphragm Muscle Function

    PubMed Central

    Alvarez-Argote, Santiago; Gransee, Heather M.; Mora, Juan C.; Stowe, Jessica M.; Jorgenson, Amy J.; Sieck, Gary C.

    2016-01-01

    Abstract Midcervical contusion injuries disrupt descending ipsilateral excitatory bulbospinal projections to phrenic motoneurons, compromising ventilation. We hypothesized that a unilateral contusion injury at C3 versus C5 would differentially impact phrenic activity reflecting more prominent disruption of ipsilateral descending excitatory drive to more caudal segments of the phrenic motor pool with more cranial injuries. Phrenic motoneuron counts and evidence of diaphragm muscle denervation at individual neuromuscular junctions (NMJ) were evaluated at 14 days post-injury after unilateral contusion injury (100 kDynes). Whole body plethysmography and chronic diaphragm EMG were measured before the injury and at 3, 7, and 14 days post-injury. Contusion injuries at either level resulted in a similarly sized cavity. C3 contusion resulted in loss of 39 ± 13% of ipsilateral phrenic motoneurons compared with 13 ± 21% after C5 contusion (p = 0.003). Cervical contusion injuries resulted in diaphragm muscle denervation (C3 contusion: 17 ± 4%; C5 contusion: 7 ± 4%; p = 0.047). The pattern of denervation revealed segmental innervation of the diaphragm muscle, with greater denervation ventrally after C3 contusion and dorsally after C5 contusion. Overall, diaphragm root mean square electromyography activity did not change ipsilaterally after C3 or C5 contusion, but increased contralaterally (∼11%) after C3 contusion only on the first day post-injury (p = 0.026). Similarly, there were no significant changes in breathing parameters during eupnea or exposure to hypoxia (10% O2) – hypercapnia (5% CO2) at any time post-injury. Unilateral midcervical contusions minimally impair ventilatory behaviors despite phrenic motoneuron loss and diaphragm muscle denervation. PMID:26413840

  9. Experimental device for measuring the dynamic properties of diaphragm motors

    NASA Astrophysics Data System (ADS)

    Fojtášek, Kamil; Dvořák, Lukáš; Mejzlík, Jan

    The subject of this paper is to design and description of the experimental device for the determination dynamic properties of diaphragm pneumatic motors. These motors are structurally quite different from conventional pneumatic linear cylinders. The working fluid is typically compressed air, the piston of motor is replaced by an elastic part and during the working cycle there is a contact of two elastic environments. In the manufacturers catalogs of these motors are not given any working characteristics. Description of the dynamic behavior of diaphragm motor will be used for verification of mathematical models.

  10. Is Diaphragm Motion a Good Surrogate for Liver Tumor Motion?

    SciTech Connect

    Yang, Juan; Cai, Jing; Wang, Hongjun; Chang, Zheng; Czito, Brian G.; Bashir, Mustafa R.; Palta, Manisha; Yin, Fang-Fang

    2014-11-15

    Purpose: To evaluate the relationship between liver tumor motion and diaphragm motion. Methods and Materials: Fourteen patients with hepatocellular carcinoma (10 of 14) or liver metastases (4 of 14) undergoing radiation therapy were included in this study. All patients underwent single-slice cine–magnetic resonance imaging simulations across the center of the tumor in 3 orthogonal planes. Tumor and diaphragm motion trajectories in the superior–inferior (SI), anterior–posterior (AP), and medial–lateral (ML) directions were obtained using an in-house-developed normalized cross-correlation–based tracking technique. Agreement between the tumor and diaphragm motion was assessed by calculating phase difference percentage, intraclass correlation coefficient, and Bland-Altman analysis (Diff). The distance between the tumor and tracked diaphragm area was analyzed to understand its impact on the correlation between the 2 motions. Results: Of all patients, the mean (±standard deviation) phase difference percentage values were 7.1% ± 1.1%, 4.5% ± 0.5%, and 17.5% ± 4.5% in the SI, AP, and ML directions, respectively. The mean intraclass correlation coefficient values were 0.98 ± 0.02, 0.97 ± 0.02, and 0.08 ± 0.06 in the SI, AP, and ML directions, respectively. The mean Diff values were 2.8 ± 1.4 mm, 2.4 ± 1.1 mm, and 2.2 ± 0.5 mm in the SI, AP, and ML directions, respectively. Tumor and diaphragm motions had high concordance when the distance between the tumor and tracked diaphragm area was small. Conclusions: This study showed that liver tumor motion had good correlation with diaphragm motion in the SI and AP directions, indicating diaphragm motion in the SI and AP directions could potentially be used as a reliable surrogate for liver tumor motion.

  11. Experimental device for measuring the dynamic properties of diaphragm motors

    NASA Astrophysics Data System (ADS)

    Fojtášek, Kamil; Dvořák, Lukáš; Mejzlík, Jan

    2016-11-01

    The subject of this paper is to design and description of the experimental device for the determination dynamic properties of diaphragm pneumatic motors. These motors are structurally quite different from conventional pneumatic linear cylinders. The working fluid is typically compressed air, the piston of motor is replaced by an elastic part and during the working cycle there is a contact of two elastic environments. In the manufacturers catalogs of these motors are not given any working characteristics. Description of the dynamic behavior of diaphragm motor will be used for verification of mathematical models.

  12. Bending-induced electromechanical coupling and large piezoelectric response in a micromachined diaphragm

    PubMed Central

    Wang, Zhihong; Yao, Yingbang; Wang, Xianbin; Yue, Weisheng; Chen, Longqing; Zhang, Xi Xiang

    2013-01-01

    We investigated the dependence of electromechanical coupling and the piezoelectric response of a micromachined Pb(Zr0.52Ti0.48)O3 (PZT) diaphragm on its curvature by observing the impedance spectrum and central deflection responses to a small AC voltage. The curvature of the diaphragm was controlled by applying air pressure to its back. We found that a depolarized flat diaphragm does not initially exhibit electromechanical coupling or the piezoelectric response. However, upon the application of static air pressure to the diaphragm, both electromechanical coupling and the piezoelectric response can be induced in the originally depolarized diaphragm. The piezoelectric response increases as the curvature increases and a giant piezoelectric response can be obtained from a bent diaphragm. The obtained results clearly demonstrate that a high strain gradient in a diaphragm can polarize a PZT film through a flexoelectric effect, and that the induced piezoelectric response of the diaphragm can be controlled by adjusting its curvature. PMID:24185198

  13. Barrier Methods of Birth Control: Spermicide, Condom, Sponge, Diaphragm, and Cervical Cap

    MedlinePlus

    ... Advocacy For Patients About ACOG Barrier Methods of Birth Control: Spermicide, Condom, Sponge, Diaphragm, and Cervical Cap Home ... FAQ022, May 2016 PDF Format Barrier Methods of Birth Control: Spermicide, Condom, Sponge, Diaphragm, and Cervical Cap Contraception ...

  14. Bending-induced electromechanical coupling and large piezoelectric response in a micromachined diaphragm

    NASA Astrophysics Data System (ADS)

    Wang, Zhihong; Yao, Yingbang; Wang, Xianbin; Yue, Weisheng; Chen, Longqing; Zhang, Xi Xiang

    2013-11-01

    We investigated the dependence of electromechanical coupling and the piezoelectric response of a micromachined Pb(Zr0.52Ti0.48)O3 (PZT) diaphragm on its curvature by observing the impedance spectrum and central deflection responses to a small AC voltage. The curvature of the diaphragm was controlled by applying air pressure to its back. We found that a depolarized flat diaphragm does not initially exhibit electromechanical coupling or the piezoelectric response. However, upon the application of static air pressure to the diaphragm, both electromechanical coupling and the piezoelectric response can be induced in the originally depolarized diaphragm. The piezoelectric response increases as the curvature increases and a giant piezoelectric response can be obtained from a bent diaphragm. The obtained results clearly demonstrate that a high strain gradient in a diaphragm can polarize a PZT film through a flexoelectric effect, and that the induced piezoelectric response of the diaphragm can be controlled by adjusting its curvature.

  15. Measured opening characteristics of an electromagnetically opened diaphragm for the Langley expansion tunnel

    NASA Technical Reports Server (NTRS)

    Moore, J. A.

    1976-01-01

    Results from an experimental study of the opening characteristics of an electromagnetically opened, 15.24 cm diameter diaphragm are presented. This diaphragm consists of a polyester film bonded to a preformed wire and is opened by passing a current pulse (capacitor discharge) through the wire. The diaphragm separates the acceleration section of the expansion tunnel from the nozzle so that the nozzle may be at a lower pressure than the acceleration section prior to a test. Opening times and cleanness of the opened area were examined for dependence on diaphragm thickness, on wire diameter, on technique of bonding the wire to the diaphragm, and on voltage and energy level of the energy source. Time histories of the pitot pressure measured at the expansion-tunnel nozzle entrance location are presented for (1) no diaphragm, (2) a flow-opened diaphragm, and (3) an electromagnetically opened diaphragm.

  16. Imaging findings of pulmonary granulomatosis with polyangiitis (Wegener's granulomatosis): lesions invading the pulmonary fissure, pleura or diaphragm mimicking malignancy.

    PubMed

    Guneyli, Serkan; Ceylan, Naim; Bayraktaroglu, Selen; Gucenmez, Sercan; Aksu, Kenan; Kocacelebi, Kenan; Acar, Turker; Savas, Recep; Alper, Hudaver

    2016-11-01

    Granulomatosis with polyangiitis (GPA, formerly Wegener's granulomatosis), in which pulmonary involvement often predominates, is a multisystem granulomatous, necrotizing vasculitis that affects small and medium-sized vessels. In this study we evaluated various radiological findings of pulmonary GPA and focused on spiculated pulmonary lesions invading the pulmonary fissure, pleura or diaphragm mimicking malignancy. This retrospective study included 48 patients, aged 28-73 (mean, 47.3) years, who showed either histopathological diagnosis of GPA (n = 39) or elevated levels of the cytoplasmic anti-neutrophilic cytoplasmic antibody serum marker (n = 9) between January 2003 and December 2013. All patients received a chest computed tomography (CT), and the types of pulmonary lesions were defined and evaluated. Among the 48 patients, 33 had abnormal pulmonary findings on CT. The most commonly detected pulmonary lesion types were nodules and masses (n = 126) observed in 24 patients. Cavitation, necrosis, spiculation and invasion of the fissure, pleura or diaphragm were observed in 14, 9, 10 and 6 patients, respectively. Consolidation was found in 14 patients and thickening of bronchial wall in 8 patients. Pulmonary lesion types of GPA have a wide spectrum, potentially mimicking a high number of diseases including malignancy, infection and noninfectious inflammatory diseases. A spiculated lung lesion invading the fissure, pleura or diaphragm is mostly present in malignancy, but it can be also seen in GPA.

  17. Validation of ultrasonography for non-invasive assessment of diaphragm function in muscular dystrophy.

    PubMed

    Whitehead, Nicholas P; Bible, Kenneth L; Kim, Min Jeong; Odom, Guy L; Adams, Marvin E; Froehner, Stanley C

    2016-12-15

    Duchenne muscular dystrophy (DMD) is a severe, degenerative muscle disease that is commonly studied using the mdx mouse. The mdx diaphragm muscle closely mimics the pathophysiological changes in DMD muscles. mdx diaphragm force is commonly assessed ex vivo, precluding time course studies. Here we used ultrasonography to evaluate time-dependent changes in diaphragm function in vivo, by measuring diaphragm movement amplitude. In mdx mice, diaphragm amplitude decreased with age and values were much lower than for wild-type mice. Importantly, diaphragm amplitude strongly correlated with ex vivo specific force values. Micro-dystrophin administration increased mdx diaphragm amplitude by 26% after 4 weeks. Diaphragm amplitude correlated positively with ex vivo force values and negatively with diaphragm fibrosis, a major cause of DMD muscle weakness. These studies validate diaphragm ultrasonography as a reliable technique for assessing time-dependent changes in mdx diaphragm function in vivo. This technique will be valuable for testing potential therapies for DMD. Duchenne muscular dystrophy (DMD) is a severe, degenerative muscle disease caused by dystrophin mutations. The mdx mouse is a widely used animal model of DMD. The mdx diaphragm muscle most closely recapitulates key features of DMD muscles, including progressive fibrosis and considerable force loss. Diaphragm function in mdx mice is commonly evaluated by specific force measurements ex vivo. While useful, this method only measures force from a small muscle sample at one time point. Therefore, accurate assessment of diaphragm function in vivo would provide an important advance to study the time course of functional decline and treatment benefits. Here, we evaluated an ultrasonography technique for measuring time-dependent changes of diaphragm function in mdx mice. Diaphragm movement amplitude values for mdx mice were considerably lower than those for wild-type, decreased from 8 to 18 months of age, and correlated

  18. Pulmonary complications of abdominal wall defects.

    PubMed

    Panitch, Howard B

    2015-01-01

    The abdominal wall is an integral component of the chest wall. Defects in the ventral abdominal wall alter respiratory mechanics and can impair diaphragm function. Congenital abdominal wall defects also are associated with abnormalities in lung growth and development that lead to pulmonary hypoplasia, pulmonary hypertension, and alterations in thoracic cage formation. Although infants with ventral abdominal wall defects can experience life-threatening pulmonary complications, older children typically experience a more benign respiratory course. Studies of lung and chest wall function in older children and adolescents with congenital abdominal wall defects are few; such investigations could provide strategies for improved respiratory performance, avoidance of respiratory morbidity, and enhanced exercise ability for these children.

  19. Diaphragm plication for eventration or paralysis: a review of the literature.

    PubMed

    Groth, Shawn S; Andrade, Rafael S

    2010-06-01

    Although etiology and pathology of symptomatic diaphragm paralysis and eventration are distinct, their treatments are the same: to reduce dysfunctional caudal excursion of the diaphragm during inspiration by plication. Minimally invasive diaphragm plication techniques have emerged as equally effective and less morbid alternatives to open plication. This review focuses on the etiology, pathophysiology, diagnosis, and treatment of diaphragmatic eventration or paralysis in adults.

  20. Neonatal pericardial effusion associated with central eventration of the diaphragm

    PubMed Central

    Iliff, P J; Eyre, J A; Westaby, S; de Leval, M; de Sousa, C

    1983-01-01

    A normal infant born at term developed tachypnoea. A massive pericardial effusion associated with absent central tendon of the diaphragm and eventration into the pericardium was found. Surgical correction was performed and the baby is now well and developing normally. ImagesFig. 1Fig. 2 PMID:6830293

  1. Diaphragm weakness in Charcot-Marie-Tooth disease.

    PubMed Central

    Laroche, C M; Carroll, N; Moxham, J; Stanley, N N; Evans, R J; Green, M

    1988-01-01

    Two patients are described with Charcot-Marie-Tooth disease and chronic peripheral neuropathy. Both had dyspnoea, orthopnoea, and evidence of severe diaphragm weakness. Expiratory muscle function was well preserved and abnormalities of gas exchange during sleep were only minor. PMID:3420560

  2. Diaphragm Pacing without Tracheostomy in Congenital Central Hypoventilation Syndrome Patients.

    PubMed

    Diep, Bonnie; Wang, Annie; Kun, Sheila; McComb, J Gordon; Shaul, Donald B; Shin, Cathy E; Keens, Thomas G; Perez, Iris A

    2015-01-01

    Congenital central hypoventilation syndrome (CCHS) is a rare disorder affecting central control of breathing. Thus, patients require lifelong assisted ventilation. Diaphragm pacing (DP) may permit decannulation in those who are ventilator dependent only during sleep. The purpose of this study is to determine if patients with CCHS can be successfully ventilated by DP without tracheostomy. We reviewed the records of 18 CCHS patients (mean age 19.5 ± 10.1 years; 44% female) who were ventilated by DP only during sleep. Prior to diaphragm pacer implantation surgery, 14 CCHS patients had been using home portable positive pressure ventilation (PPV) via tracheostomy, 1 had been on PPV via endotracheal tube, and 3 had been using noninvasive PPV (NPPV). Of the patients with tracheostomy prior to DP (n = 15), 11 (73%) were decannulated and ventilated successfully by DP without tracheostomy. Of all the patients reviewed (n = 18), 13 (72%) were successfully ventilated by DP without tracheostomy. Obesity prevented successful DP without tracheostomy in 1 patient, and upper airway obstruction prevented success in another patient. Snoring and/or obstructive apneas were present in some patients, but they were improved by diaphragm pacer changes, adenotonsillectomy, and/or use of nasal steroids. DP without tracheostomy can be successfully achieved in patients with CCHS. Snoring and obstructive apneas, when present, can be managed by diaphragm pacer changes and medical therapies. Obesity can pose a challenge to successful DP. © 2015 S. Karger AG, Basel.

  3. Effect of hyperinflation on inspiratory function of the diaphragm.

    PubMed

    Minh, V D; Dolan, G F; Konopka, R F; Moser, K M

    1976-01-01

    The inspiratory efficiency of the diaphragm during unilateral and bilateral phrenic stimulation (UEPS and BEPS) with constant stimulus was studied in seven dogs from FRC to 120% TLC. Alveolar pressures (PAl) were recorded during relaxation, BEPS and UEPS at each lung volume in the closed respiratory system. From the PAl-lung volume curves, tidal volume (VT), and pressure developed by the diaphragm (Pmus) were derived. Results are summarized below. a) Hyperinflation impaired the inspiratory efficiency of the diaphragm which behaved as an expiratory muscle beyond the lung volume of 103.7% TLC (Vinef). b) The diaphragm during UEPS became expiratory at the same Vinef as during (BEPS. C) The VT-lung volume relationship was linear during BEPS, allowing simple quantitation of VT loss with hyperinflation and prediction of Vinef. d) With only one phrenic nerve stimulated, the functional loss is less pronounced in VT than in Pmus, as compared to BEPS, indicating that the respiratory system was more compliant during UEPS than BEPS. This compliance difference from UEPS to BEPS diminished with severe hyperinflation.

  4. 14 CFR 121.251 - Engine accessory section diaphragm.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Engine accessory section diaphragm. 121.251... REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Special Airworthiness Requirements § 121.251 Engine... complies with § 121.247 must be provided on air-cooled engines to isolate the engine power section and all...

  5. 14 CFR 121.251 - Engine accessory section diaphragm.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Engine accessory section diaphragm. 121.251... REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Special Airworthiness Requirements § 121.251 Engine... complies with § 121.247 must be provided on air-cooled engines to isolate the engine power section and all...

  6. 14 CFR 121.251 - Engine accessory section diaphragm.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Engine accessory section diaphragm. 121.251... REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Special Airworthiness Requirements § 121.251 Engine... complies with § 121.247 must be provided on air-cooled engines to isolate the engine power section and all...

  7. 14 CFR 121.251 - Engine accessory section diaphragm.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Engine accessory section diaphragm. 121.251... REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Special Airworthiness Requirements § 121.251 Engine... complies with § 121.247 must be provided on air-cooled engines to isolate the engine power section and all...

  8. Duplicated right crus of the diaphragm: a cadaveric case report.

    PubMed

    Sirasanagandla, Srinivasa Rao; Nayak, Satheesha B; Bhat, Kumar Mr; Surendran, Sudarshan; Regunathan, Deepthinath; Kumar, Naveen; Shetty, Surekha D; Patil, Jyothsna

    2014-03-01

    The lumbar part of the diaphragm arises from the lumbar vertebrae by right and left crura. The duplication of crura of the diaphragm is rarely reported in the past. During regular dissection classes to the medical students, we came across a case of duplicated right crus of the diaphragm. The right crus of the diaphragm was duplicated completely and presented two separate crura; medial right crus & lateral right crus. The medial right crus was attached to the anterolateral surfaces of the superior three lumbar vertebral bodies and intervertebral discs and merged with the anterior longitudinal ligament. The lateral right crus attached only to the intervertebral disc between the third and fourth lumbar vertebrae. These two crura bordered a retrocrural space in the inferior posterior mediastinum. The greater and lesser splanchnic nerves entered the abdomen by passing through this space. No duplication was observed in the left crus. The muscle fibres of medial right crus contributed to the formation of the esophageal opening. Knowledge of variations in the diaphragmatic crural anatomy is useful in the diagnosis of disease processes in the retrocrural space and also might help while performing the surgical repair of gastroesophageal reflux disease.

  9. Rapid diaphragm atrophy following cervical spinal cord hemisection.

    PubMed

    Gill, L C; Ross, H H; Lee, K Z; Gonzalez-Rothi, E J; Dougherty, B J; Judge, A R; Fuller, D D

    2014-02-01

    A cervical (C2) hemilesion (C2Hx), which disrupts ipsilateral bulbospinal inputs to the phrenic nucleus, was used to study diaphragm plasticity after acute spinal cord injury. We hypothesized that C2Hx would result in rapid atrophy of the ipsilateral hemidiaphragm and increases in mRNA expression of proteolytic biomarkers. Diaphragm tissue was harvested from male Sprague-Dawley rats at 1 or 7 days following C2Hx. Histological analysis demonstrated reduction in cross-sectional area (CSA) of type I and IIa fibers in the ipsilateral hemidiaphragm at 1 but not 7 days. Type IIb/x fibers, however, had reduced CSA at 1 and 7 days. A targeted gene array was used to screen mRNA changes for genes associated with skeletal muscle myopathy and myogenesis; this was followed by qRT-PCR validation. Changes in diaphragm gene expression suggested that profound myoplasticity is initiated immediately following C2Hx including activation of both proteolytic and myogenic pathways. We conclude that an immediate myoplastic response occurs in the diaphragm after C2Hx with atrophy occurring in ipsilateral myofibers within 1 day.

  10. Design of fabric preforms for double diaphragm forming

    NASA Technical Reports Server (NTRS)

    Luby, Steven; Bernardon, Edward

    1992-01-01

    Resin Transfer Molding (RTM) has the potential of becoming one of the most cost effective ways of producing composite structures since the raw materials used, resin and dry fabric, are less costly than prepregs. Unfortunately these low material costs are offset by the high labor costs incurred to layup the dry fabric into 3D shapes. To reduce the layup costs, double diaphragm forming is being investigated as a potential technique for creating a complex 3D preform from a simple flat layup. As part of our effort to develop double diaphragm forming into a production capable process, we have undertaken a series of experiments to investigate the interactions between process parameters, mold geometry, fabric weave, tow size, and the quality of the formed part. The results of these tests will be used to determine the forming geometry limitations of double diaphragm forming and to characterize the formability of fabric configurations. An important part of this work was the development of methods to measure and analyze fiber orientations, deformation angles, tow spreading, and shape conformation of the formed parts. This paper will describe the methods used to mark plies, the double diaphragm forming process, the techniques used to measure the formed parts, and the calculation of the parameters of interest. The results can be displayed as 3D contour plots. These experimental results have also been used to verify and improve a computer model which simulates the draping of fabrics over 3D mold shapes.

  11. Die and telescoping punch form convolutions in thin diaphragm

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Die and punch set forms convolutions in thin dished metal diaphragm without stretching the metal too thin at sharp curvatures. The die corresponds to the metal shape to be formed, and the punch consists of elements that progressively slide against one another under the restraint of a compressed-air cushion to mate with the die.

  12. Cellular adaptations in the diaphragm in chronic obstructive pulmonary disease.

    PubMed

    Levine, S; Kaiser, L; Leferovich, J; Tikunov, B

    1997-12-18

    In patients with severe chronic obstructive pulmonary disease, the diaphragm undergoes physiologic adaptations characterized by an increase in energy expenditure and relative resistance to fatigue. We hypothesized that these physiologic characteristics would be associated with structural adaptations consisting of an increased proportion of less-fatigable slow-twitch muscle fibers and slow isoforms of myofibrillar proteins. We obtained biopsy specimens of the diaphragm from 6 patients with severe chronic obstructive pulmonary disease (mean [+/-SE] forced expiratory volume in one second, 33+/-4 percent of the predicted value; residual volume, 259+/-25 percent of the predicted value) and 10 control subjects. The proportions of the various isoforms of myosin heavy chains, myosin light chains, troponin, and tropomyosin were determined by sodium dodecyl sulfate-polyacrylamide-gel electrophoresis. We also used immunocytochemical techniques to determine the proportions of the various types of muscle fibers. The diaphragm-biopsy specimens from the patients had higher percentages of slow myosin heavy chain I (64+/-3 vs. 45+/-2 percent, P<0.001), and lower percentages of fast myosin heavy chains IIa (29+/-3 vs. 39+/-2 percent, P=0.01) and IIb (8+/-1 vs. 17+/-1 percent, P<0.001) than the diaphragms of the controls. Similar differences were noted when immunohistochemical techniques were used to compare the percentages of these fiber types in the two groups. In addition, the patients had higher percentages of the slow isoforms of myosin light chains, troponins, and tropomyosin, whereas the controls had higher percentages of the fast isoforms of these proteins. Severe chronic obstructive pulmonary disease increases the slow-twitch characteristics of the muscle fibers in the diaphragm, an adaptation that increases resistance to fatigue.

  13. Intraspinal microstimulation and diaphragm activation after cervical spinal cord injury.

    PubMed

    Mercier, L M; Gonzalez-Rothi, E J; Streeter, K A; Posgai, S S; Poirier, A S; Fuller, D D; Reier, P J; Baekey, D M

    2017-02-01

    Intraspinal microstimulation (ISMS) using implanted electrodes can evoke locomotor movements after spinal cord injury (SCI) but has not been explored in the context of respiratory motor output. An advantage over epidural and direct muscle stimulation is the potential of ISMS to selectively stimulate components of the spinal respiratory network. The present study tested the hypothesis that medullary respiratory activity could be used to trigger midcervical ISMS and diaphragm motor unit activation in rats with cervical SCI. Studies were conducted after acute (hours) and subacute (5-21 days) C2 hemisection (C2Hx) injury in adult rats. Inspiratory bursting in the genioglossus (tongue) muscle was used to trigger a 250-ms train stimulus (100 Hz, 100-200 μA) to the ventral C4 spinal cord, targeting the phrenic motor nucleus. After both acute and subacute injury, genioglossus EMG activity effectively triggered ISMS and activated diaphragm motor units during the inspiratory phase. The ISMS paradigm also evoked short-term potentiation of spontaneous inspiratory activity in the previously paralyzed hemidiaphragm (i.e., bursting persisting beyond the stimulus period) in ∼70% of the C2Hx animals. We conclude that medullary inspiratory output can be used to trigger cervical ISMS and diaphragm activity after SCI. Further refinement of this method may enable "closed-loop-like" ISMS approaches to sustain ventilation after severe SCI.NEW & NOTEWORTHY We examined the feasibility of using intraspinal microstimulation (ISMS) of the cervical spinal cord to evoke diaphragm activity ipsilateral to acute and subacute hemisection of the upper cervical spinal cord of the rat. This proof-of-concept study demonstrated the efficacy of diaphragm activation, using an upper airway respiratory EMG signal to trigger ISMS at the level of the ipsilesional phrenic nucleus during acute and advanced postinjury intervals. Copyright © 2017 the American Physiological Society.

  14. Repeated exposure to heat stress results in a diaphragm phenotype that resists ventilator-induced diaphragm dysfunction.

    PubMed

    Yoshihara, Toshinori; Ichinoseki-Sekine, Noriko; Kakigi, Ryo; Tsuzuki, Takamasa; Sugiura, Takao; Powers, Scott K; Naito, Hisashi

    2015-11-01

    Controlled mechanical ventilation (CMV) is a life-saving intervention for patients in respiratory failure. Unfortunately, prolonged mechanical ventilation (MV) results in diaphragmatic atrophy and contractile dysfunction, both of which are predicted to contribute to problems in weaning patients from the ventilator. Therefore, developing a strategy to protect the diaphragm against ventilator-induced weakness is important. We tested the hypothesis that repeated bouts of heat stress result in diaphragm resistance against CMV-induced atrophy and contractile dysfunction. Male Wistar rats were randomly divided into six experimental groups: 1) control; 2) single bout of whole body heat stress; 3) repeated bouts of whole body heat stress; 4) 12 h CMV; 5) single bout of whole body heat stress 24 h before CMV; and 6) repeated bouts of whole body heat stress 1, 3, and 5 days before 12 h of CMV. Our results revealed that repeated bouts of heat stress resulted in increased levels of heat shock protein 72 in the diaphragm and protection against both CMV-induced diaphragmatic atrophy and contractile dysfunction at submaximal stimulation frequencies. The specific mechanisms responsible for this protection remain unclear: this heat stress-induced protection against CMV-induced diaphragmatic atrophy and weakness may be partially due to reduced diaphragmatic oxidative stress, diminished activation of signal transducer/transcriptional activator-3, lower caspase-3 activation, and decreased autophagy in the diaphragm.

  15. The distribution and morphology of lymphatic vessels on the peritoneal surface of the adult human diaphragm, as revealed by an ink-absorption method.

    PubMed

    Shinohara, Harumichi; Kominami, Rieko; Taniguchi, Yutaka; Yasutaka, Satoru

    2003-03-01

    Application of india ink to the peritoneal and pleural surfaces of the adult human diaphragm allowed visualization of the distribution and morphology of the lymphatic vessels by light microscopy and scanning electron microscopy. The diaphragms examined had been fixed and stored in 10% formalin. Numerous lymphatic vessels were stained black with india ink, presenting reticular, radial-meshwork, ladder-like and lacy patterns. They were distributed throughout the entire sternocostal part. Analysis by light and scanning electron microscopy of the areas indicated by india ink revealed the presence of primary lymphatic vessels that formed lymphatic lacunae and stomatal openings to the peritoneal cavity. A layer of secondary collecting lymphatic vessels was located cranially with respect to the layer of primary lymphatic vessels. Thus, the peritoneum had at least two layers of lymphatic vessels. These lymphatic vessels were not tubular vessels but resembled flat cisternae, as has been suggested in the case of the mouse diaphragm. The pleura lacked lymphatic stomata and had no such double-layered lymphatic organization. This is the first report that showed distribution and morphology of the lymphatic vessels in the diaphragmatic peritoneum of the formalin-fixed, adult human diaphragm. The method and results in the present study may contribute to morphological analysis of the lymphatic system in the wall of the human body cavity.

  16. Levosimendan improves calcium sensitivity of diaphragm muscle fibres from a rat model of heart failure.

    PubMed

    van Hees, H W H; Andrade Acuña, Gl; Linkels, M; Dekhuijzen, P N R; Heunks, L M A

    2011-02-01

    Diaphragm muscle weakness occurs in patients with heart failure (HF) and is associated with exercise intolerance and increased mortality. Reduced sensitivity of diaphragm fibres to calcium contributes to diaphragm weakness in HF. Here we have investigated the ability of the calcium sensitizer levosimendan to restore the reduced calcium sensitivity of diaphragm fibres from rats with HF. Coronary artery ligation in rats was used as an animal model for HF. Sham-operated rats served as controls. Fifteen weeks after induction of HF or sham operations animals were killed and muscle fibres were isolated from the diaphragm. Diaphragm fibres were skinned and activated with solutions containing incremental calcium concentrations and 10 µM levosimendan or vehicle (0.02% DMSO). Developed force was measured at each calcium concentration, and force-calcium concentration relationships were plotted. Calcium sensitivity of force generation was reduced in diaphragm muscle fibres from HF rats, compared with fibres from control rats (P < 0.01). Maximal force generation was ∼25% lower in HF diaphragm fibres than in control fibres (P < 0.05). Levosimendan significantly increased calcium sensitivity of force generation in diaphragm fibres from HF and control rats, without affecting maximal force generation. Levosimendan enhanced the force generating capacity of diaphragm fibres from HF rats by increasing the sensitivity of force generation to calcium concentration. These results provide strong support for testing the effect of calcium sensitizers on diaphragm muscle weakness in patients with HF. © 2011 The Authors. British Journal of Pharmacology © 2011 The British Pharmacological Society.

  17. Sulphonated polyether ether ketone diaphragms used in commercial scale alkaline water electrolysis

    NASA Astrophysics Data System (ADS)

    Otero, Jesus; Sese, Javier; Michaus, Igor; Santa Maria, Maria; Guelbenzu, Eugenio; Irusta, Silvia; Carrilero, Isabel; Arruebo, Manuel

    2014-02-01

    Sulphonated poly-ether-ether-ketone porous diaphragms were prepared by immersion precipitation using chemically induced phase separation to obtain a tight diaphragm skin layer and underneath finger-like bulk morphology. Different variables including sulphonation degree, diaphragm thickness, precipitation temperature and the presence of an inorganic filler were analyzed in order to evaluate the performance of the resulting diaphragms in water alkaline electrolysis using a bipolar electrolyzer and a commercial scale (50 kW) electrolyzer stack. Their performance was compared with a commercially available diaphragm in terms of cell voltage and oxygen purity (HTO) under normal operation conditions (10 bar, 80 °C) and under transient operation with up to 80 shutdown cycles (a total of 20 days in operation). Long term stability and operation reliability were assured for the SPEEK diaphragms showing lower cell voltage and HTO than the ones obtained with the commercial Zirfon® HTP 500 diaphragm.

  18. Audiovisual biofeedback improves diaphragm motion reproducibility in MRI

    PubMed Central

    Kim, Taeho; Pollock, Sean; Lee, Danny; O’Brien, Ricky; Keall, Paul

    2012-01-01

    Purpose: In lung radiotherapy, variations in cycle-to-cycle breathing results in four-dimensional computed tomography imaging artifacts, leading to inaccurate beam coverage and tumor targeting. In previous studies, the effect of audiovisual (AV) biofeedback on the external respiratory signal reproducibility has been investigated but the internal anatomy motion has not been fully studied. The aim of this study is to test the hypothesis that AV biofeedback improves diaphragm motion reproducibility of internal anatomy using magnetic resonance imaging (MRI). Methods: To test the hypothesis 15 healthy human subjects were enrolled in an ethics-approved AV biofeedback study consisting of two imaging sessions spaced ∼1 week apart. Within each session MR images were acquired under free breathing and AV biofeedback conditions. The respiratory signal to the AV biofeedback system utilized optical monitoring of an external marker placed on the abdomen. Synchronously, serial thoracic 2D MR images were obtained to measure the diaphragm motion using a fast gradient-recalled-echo MR pulse sequence in both coronal and sagittal planes. The improvement in the diaphragm motion reproducibility using the AV biofeedback system was quantified by comparing cycle-to-cycle variability in displacement, respiratory period, and baseline drift. Additionally, the variation in improvement between the two sessions was also quantified. Results: The average root mean square error (RMSE) of diaphragm cycle-to-cycle displacement was reduced from 2.6 mm with free breathing to 1.6 mm (38% reduction) with the implementation of AV biofeedback (p-value < 0.0001). The average RMSE of the respiratory period was reduced from 1.7 s with free breathing to 0.3 s (82% reduction) with AV biofeedback (p-value < 0.0001). Additionally, the average baseline drift obtained using a linear fit was reduced from 1.6 mm/min with free breathing to 0.9 mm/min (44% reduction) with AV biofeedback (p-value = 0.012). The

  19. Microlens fabrication using an excimer laser and the diaphragm method.

    PubMed

    Chen, Tao; Wang, Tong; Wang, Zhen; Zuo, Tiechuan; Wu, Jian; Liu, Shibing

    2009-06-08

    A new microlens fabrication method using an excimer laser is described in this paper. This method is based on the light vignetting effect. An excimer laser beam was propagated through two groups of fly's-eye lens arrays and separated by the groups, after which divergent beams were formed. When the beams were sectioned by a mask and passed through a circular diaphragm, a vignetting effect was produced relative to an excimer laser mask projection image lens. Then the irradiating intensity at the processing plane varied from the beam center to its margin. This intensity difference in the transverse distribution would result in microlens curvature forming. This diaphragm method has the extinct advantage of short production time, few steps and easy setup construction.

  20. Miniature fiber-optic pressure sensor with a polymer diaphragm.

    PubMed

    Cibula, Edvard; Donlagić, Denis

    2005-05-10

    The fabrication and experimental investigation of a miniature optical fiber pressure sensor for biomedical and industrial applications are described. The sensor measures only 125 microm in diameter. The essential element is a thin polymer diaphragm that is positioned inside the hollow end of an optical fiber. The cavity at the fiber end is made by a simple and effective micromachining process based on wet etching in diluted HF acid. Thus a Fabry-Perot interferometer is formed between the inner fiber-cavity interface and the diaphragm. The fabrication technique is described in detail. Different sensor prototypes were fabricated upon 125 microm-diameter optical fiber that demonstrated pressure ranges from 0 to 40 and from 0 to 1200 kPa. A resolution of less than 10 Pa was demonstrated in practice. The fabrication technique presented facilitates production of simple and low-cost disposable pressure sensors by use of materials with that ensure the required biocompatibility.

  1. Coupling impedance of a periodic array of diaphragms

    SciTech Connect

    Stupakov, G.V.

    1995-06-01

    A method is presented for calculating the high-frequency longitudinal and transverse coupling impedances in a periodic array of diaphragms in a circular perfectly conducting pipe. The method is based on Weinstein`s theory of diffraction of a plane electromagnetic wave on a stack of halfplanes. Using Weinstein`s solution, it is shown that the problem of finding the beam field in the pipe reduces to an effective boundary condition at the radius of the diaphragms that couples the longitudinal electric field with the azimuthal magnetic one. Solving Maxwell`s equations with this boundary condition leads to simple formulae for Z{sub long} and Z{sub tr}. A good agreement with a numerical solution of the problem found by other authors is demonstrated.

  2. Effects of diaphragm discharge in water solutions containing humic substances

    NASA Astrophysics Data System (ADS)

    Halamova, Ivana; Stara, Zdenka; Krcma, Frantisek

    2010-01-01

    Preliminary results of research focused on the applications of DC diaphragm discharge in water solutions containing humic substances are presented in this paper. Diaphragm discharge investigated by this work was created in the reactor using constant DC high voltage up to 2 kV that gave the total input power from 100 to 200 W. Presented work investigated decomposition of humic substances by the electric discharge in the dependence of discharge conditions (electrode polarity) as well as solution properties (electrolyte kind, pH). Especially substantial effect of pH on humic acid decomposition has been observed when acidic conditions stimulated the degradation process. Absorption spectroscopy in UV-VIS region together with fluorescence spectroscopy has been used for the detection of changes in humic solutions. Index of humification was calculated from obtained fluorescence spectra and a significant decrease of aromatic components in the humic mixture was determined during the discharge treatment.

  3. Integrated optical interferometer with micromechanical diaphragm for pressure sensing

    NASA Astrophysics Data System (ADS)

    De Brabander, Gregory N.; Boyd, Joseph T.; Beheim, Glenn

    1994-10-01

    An electrically passive optical pressure sensor has been fabricated which uses a integrated-optical Y-junction ring resonator to measure the strain induced in a micromachined silicon diaphragm. A silicon substrate is etched from the side opposite the silicon oxynitride optical waveguides to produce a rectangular diaphragm whose long edge lies underneath a straight section in the ring. Pressure-induced changes in the resonant frequency of the ring are measured using a frequency swept laser diode. A linear response to pressure is observed for the TM mode with a sensitivity of 0.0094 rad/kPa. The transmissivity function of the resonator is derived and compared with measured response. This pressure sensor is rugged, amenable to batch fabrication, and it provides a link insensitive readout.

  4. Coupling Impedance of a Periodic Array of Diaphragms (Erratum)

    SciTech Connect

    Stupakov, G.V.; /SLAC

    2012-05-24

    A method is presented for calculating the high-frequency longitudinal and transverse coupling impedances in a periodic array of diaphragms in a circular perfectly conducting pipe. The method is based on Weinstein's theory of diffraction of a plane electromagnetic wave on a stack of halfplanes. Using Weinstein's solution, it is shown that the problem of finding the beam field in the pipe reduces to an effective boundary condition at the radius of the diaphragms that couples the longitudinal electric field with the azimuthal magnetic one. Solving Maxwell's equations with this boundary condition leads to simple formulae for Z{sub long} and Z{sub tr}. A good agreement with a numerical solution of the problem found by other authors is demonstrated.

  5. In utero LPS exposure impairs preterm diaphragm contractility.

    PubMed

    Song, Yong; Karisnan, Kanakeswary; Noble, Peter B; Berry, Clare A; Lavin, Tina; Moss, Timothy J M; Bakker, Anthony J; Pinniger, Gavin J; Pillow, J Jane

    2013-11-01

    Preterm birth is associated with inflammation of the fetal membranes (chorioamnionitis). We aimed to establish how chorioamnionitis affects the contractile function and phenotype of the preterm diaphragm. Pregnant ewes received intra-amniotic injections of saline or 10 mg LPS, 2 days or 7 days before delivery at 121 days of gestation (term = 150 d). Diaphragm strips were dissected for the assessment of contractile function after terminal anesthesia. The inflammatory cytokine response, myosin heavy chain (MHC) fibers, proteolytic pathways, and intracellular molecular signaling were analyzed using quantitative PCR, ELISA, immunofluorescence staining, biochemical assays, and Western blotting. Diaphragm peak twitch force and maximal tetanic force were approximately 30% lower than control values in the 2-day and 7-day LPS groups. Activation of the NF-κB pathway, an inflammatory response, and increased proteasome activity were observed in the 2-day LPS group relative to the control or 7-day LPS group. No inflammatory response was evident after a 7-day LPS exposure. Seven-day LPS exposure markedly decreased p70S6K phosphorylation, but no effect on other signaling pathways was evident. The proportion of MHC IIa fibers was lower than that for control samples in the 7-day LPS group. MHC I fiber proportions did not differ between groups. These results demonstrate that intrauterine LPS impairs preterm diaphragmatic contractility after 2-day and 7-day exposures. Diaphragm dysfunction, resulting from 2-day LPS exposure, was associated with a transient activation of proinflammatory signaling, with subsequent increased atrophic gene expression and enhanced proteasome activity. Persistently impaired contractility for the 7-day LPS exposure was associated with the down-regulation of a key component of the protein synthetic signaling pathway and a reduction in the proportions of MHC IIa fibers.

  6. Mechanical ventilation-induced diaphragm disuse in humans triggers autophagy.

    PubMed

    Hussain, Sabah N A; Mofarrahi, Mahroo; Sigala, Ioanna; Kim, Ho Cheol; Vassilakopoulos, Theodoros; Maltais, Francois; Bellenis, Ion; Chaturvedi, Rakesh; Gottfried, Stewart B; Metrakos, Peter; Danialou, Gawiyou; Matecki, Stefan; Jaber, Samir; Petrof, Basil J; Goldberg, Peter

    2010-12-01

    Controlled mechanical ventilation (CMV) results in atrophy of the human diaphragm. The autophagy-lysosome pathway (ALP) contributes to skeletal muscle proteolysis, but its contribution to diaphragmatic protein degradation in mechanically ventilated patients is unknown. To evaluate the autophagy pathway responses to CMV in the diaphragm and limb muscles of humans and to identify the roles of FOXO transcription factors in these responses. Muscle biopsies were obtained from nine control subjects and nine brain-dead organ donors. Subjects were mechanically ventilated for 2 to 4 hours and 15 to 276 hours, respectively. Activation of the ubiquitin-proteasome system was detected by measuring mRNA expressions of Atrogin-1, MURF1, and protein expressions of UBC2, UBC4, and the α subunits of the 20S proteasome (MCP231). Activation of the ALP was detected by electron microscopy and by measuring the expressions of several autophagy-related genes. Total carbonyl content and HNE-protein adduct formation were measured to assess oxidative stress. Total AKT, phosphorylated and total FOXO1, and FOXO3A protein levels were also measured. Prolonged CMV triggered activation of the ALP as measured by the appearance of autophagosomes in the diaphragm and increased expressions of autophagy-related genes, as compared with controls. Induction of autophagy was associated with increased protein oxidation and enhanced expression of the FOXO1 gene, but not the FOXO3A gene. CMV also triggered the inhibition of both AKT expression and FOXO1 phosphorylation. We propose that prolonged CMV causes diaphragm disuse, which, in turn, leads to activation of the ALP through oxidative stress and the induction of the FOXO1 transcription factor.

  7. Several designs of iris diaphragms for multichannel mirror and lens-mirror objectives

    NASA Astrophysics Data System (ADS)

    Denisov, Nikolay A.; Koroleva, Tatyana V.

    1996-08-01

    Five original designs of iris diaphragms to overlap coaxes round and annular apertures of the multichannel mirror or lens-mirror objectives are considered. Authors have proposed three novel configurations of the iris diaphragm lobes and also several diaphragm designs where referred lobes have been combined with ordinary ones. Horse-shoe shape lobe has been basic for all types of proposed iris diaphragm designs. Firstly this lobe is a main part of fan-diaphragm to intercept mirror objective annular aperture. Secondary that had been a prototype for both moon shape lobe and flat ring shape one. Thirdly usual iris diaphragm should be formed annular zone diaphragm in combination with fan-diaphragm. Proposed iris diaphragms has been designed to intercept both annular and round apertures of mirror and lens-mirror objectives simultaneously as well alternately. Formulas for calculation geometrical parameters of different kinds of the lobes and their disposition on the stationary mountings have been adduced. One attends that total light losses through screening should not be more than 18 - 20%. Technical realization most of proposed iris diaphragm designs have to be of interest for purposes of electro-optical test facility.

  8. Diaphragm pacers as a treatment for congenital central hypoventilation syndrome.

    PubMed

    Chen, Maida Lynn; Tablizo, Mary Anne; Kun, Sheila; Keens, Thomas G

    2005-09-01

    Congenital central hypoventilation syndrome is a rare syndrome present from birth, and is defined as the failure of automatic control of breathing. All patients with congenital central hypoventilation syndrome require life-long ventilatory support during sleep, although approximately a third of patients require ventilatory support 24 h per day. Diaphragm pacers offer a modality of ventilatory support that affords congenital central hypoventilation syndrome patients with maximal mobility for full-time ventilatory patients, and they may allow for a more normal lifestyle in the appropriate patient. They may permit tracheostomy decannulation in those requiring only support during sleep. Diaphragm pacing entails surgical placement of an electrode onto the phrenic nerve, connected to a subcutaneous receiver. There is an external battery-operated transmitter and antenna placed on the skin over the receiver. The transmitter emits energy, similar to radio transmission, which is converted into an electrical current by the receiver. This stimulates the phrenic nerve resulting in a diaphragmatic contraction. Settings on the transmitter include respiratory rate and electrical voltage, and are adjusted to give enough tidal volume to allow for adequate oxygenation and ventilation. Therefore, diaphragm pacing is an attractive alternative mode of mechanically assisted ventilation for many patients with congenital central hypoventilation syndrome.

  9. Bottom diaphragm for transporter for a seismic energy source

    SciTech Connect

    Martin, P.N.

    1983-12-06

    An improved portable seismic energy source is disclosed including a base member having cylindrical sidewalls and an open lower end for resting on the earth's surface. A horizontal baseplate is secured to the base member upper end, the baseplate having a central opening therein, a gun mounted on the horizontal baseplate for firing a projectile through the opening therein to impact the earth's surface and generate a seismic signal, a spatter plate mounted to the base member such as by means of a vertical cylinder secured to the lower surface of the baseplate with the lower end of the cylinder being affixed to the spatter plate. The spatter plate has an opening therein in register with the cylinder so that a projectile fired passes through the opening, the spatter plate being positioned above the earth's surface, and a flexible diaphragm secured at its periphery to the lower circumferential surface of the base member and having a central opening therein. The diaphragm is stretched over the top of the spatter plate, the spatter plate and diaphragm serving to intercept gas, liquids, and solid objects which are ejected when a projectile is fired to generate a seismic signal.

  10. PO2 cycling reduces diaphragm fatigue by attenuating ROS formation.

    PubMed

    Zuo, Li; Diaz, Philip T; Chien, Michael T; Roberts, William J; Kishek, Juliana; Best, Thomas M; Wagner, Peter D

    2014-01-01

    Prolonged muscle exposure to low PO2 conditions may cause oxidative stress resulting in severe muscular injuries. We hypothesize that PO2 cycling preconditioning, which involves brief cycles of diaphragmatic muscle exposure to a low oxygen level (40 Torr) followed by a high oxygen level (550 Torr), can reduce intracellular reactive oxygen species (ROS) as well as attenuate muscle fatigue in mouse diaphragm under low PO2. Accordingly, dihydrofluorescein (a fluorescent probe) was used to monitor muscular ROS production in real time with confocal microscopy during a lower PO2 condition. In the control group with no PO2 cycling, intracellular ROS formation did not appear during the first 15 min of the low PO2 period. However, after 20 min of low PO2, ROS levels increased significantly by ∼30% compared to baseline, and this increase continued until the end of the 30 min low PO2 condition. Conversely, muscles treated with PO2 cycling showed a complete absence of enhanced fluorescence emission throughout the entire low PO2 period. Furthermore, PO2 cycling-treated diaphragm exhibited increased fatigue resistance during prolonged low PO2 period compared to control. Thus, our data suggest that PO2 cycling mitigates diaphragm fatigue during prolonged low PO2. Although the exact mechanism for this protection remains to be elucidated, it is likely that through limiting excessive ROS levels, PO2 cycling initiates ROS-related antioxidant defenses.

  11. A free-piston Stirling cryocooler using metal diaphragms

    NASA Astrophysics Data System (ADS)

    Caughley, Alan; Sellier, Mathieu; Gschwendtner, Michael; Tucker, Alan

    2016-12-01

    A novel concept for a free-piston Stirling cryocooler has been proposed. The concept uses a pair of metal diaphragms to seal and suspend the displacer of a free-piston Stirling cryocooler. The diaphragms allow the displacer to move without rubbing or moving seals, potentially resulting in a long-life mechanism. When coupled to a metal diaphragm pressure wave generator, the system produces a complete Stirling cryocooler with no rubbing parts in the working gas space. Initial modelling of this concept using the Sage modelling tool indicates the potential for a useful cryocooler. A proof-of-concept prototype was constructed and achieved cryogenic temperatures. A second prototype was designed and constructed using the experience gained from the first. The prototype produced 29 W of cooling at 77 K and reached a no-load temperature of 56 K. Sage predicted the macroscopic behaviour of the prototype well but did not provide sufficient insights to improve performance significantly. This paper presents details of the development, modelling and testing of the proof-of-concept prototype and a second, improved prototype.

  12. Integrated Optical Interferometers with Micromachined Diaphragms for Pressure Sensing

    NASA Technical Reports Server (NTRS)

    DeBrabander, Gregory N.; Boyd, Joseph T.

    1996-01-01

    Optical pressure sensors have been fabricated which use an integrated optical channel waveguide that is part of an interferometer to measure the pressure-induced strain in a micromachined silicon diaphragm. A silicon substrate is etched from the back of the wafer leaving a rectangular diaphragm. On the opposite side of the wafer, ring resonator and Mach-Zehnder interferometers are formed with optical channel waveguides made from a low pressure chemical vapor deposited film of silicon oxynitride. The interferometer's phase is altered by pressure-induced stress in a channel segment positioned over the long edge of the diaphragm. The phase change in the ring resonator is monitored using a link-insensitive swept frequency laser diode, while in the Mach-Zehnder it is determined using a broad band super luminescent diode with subsequent wavelength separation. The ring resonator was found to be highly temperature sensitive, while the Mach-Zehnder, which had a smaller optical path length difference, was proportionally less so. The quasi-TM mode was more sensitive to pressure, in accord with calculations. Waveguide and sensor theory, sensitivity calculations, a fabrication sequence, and experimental results are presented.

  13. Ventilator-induced diaphragm dysfunction: cause and effect.

    PubMed

    Powers, Scott K; Wiggs, Michael P; Sollanek, Kurt J; Smuder, Ashley J

    2013-09-01

    Mechanical ventilation (MV) is used clinically to maintain gas exchange in patients that require assistance in maintaining adequate alveolar ventilation. Common indications for MV include respiratory failure, heart failure, drug overdose, and surgery. Although MV can be a life-saving intervention for patients suffering from respiratory failure, prolonged MV can promote diaphragmatic atrophy and contractile dysfunction, which is referred to as ventilator-induced diaphragm dysfunction (VIDD). This is significant because VIDD is thought to contribute to problems in weaning patients from the ventilator. Extended time on the ventilator increases health care costs and greatly increases patient morbidity and mortality. Research reveals that only 18-24 h of MV is sufficient to develop VIDD in both laboratory animals and humans. Studies using animal models reveal that MV-induced diaphragmatic atrophy occurs due to increased diaphragmatic protein breakdown and decreased protein synthesis. Recent investigations have identified calpain, caspase-3, autophagy, and the ubiquitin-proteasome system as key proteases that participate in MV-induced diaphragmatic proteolysis. The challenge for the future is to define the MV-induced signaling pathways that promote the loss of diaphragm protein and depress diaphragm contractility. Indeed, forthcoming studies that delineate the signaling mechanisms responsible for VIDD will provide the knowledge necessary for the development of a pharmacological approach that can prevent VIDD and reduce the incidence of weaning problems.

  14. SU8 diaphragm micropump with monolithically integrated cantilever check valves.

    PubMed

    Ezkerra, Aitor; Fernández, Luis José; Mayora, Kepa; Ruano-López, Jesús Miguel

    2011-10-07

    This paper presents a SU8 unidirectional diaphragm micropump with embedded out-of-plane cantilever check valves. The device represents a reliable and low-cost solution for integration of microfluidic control in lab-on-a-chip devices. Its planar architecture allows monolithic definition of its components in a single step and potential integration with previously reported PCR, electrophoresis and flow-sensing SU8 microdevices. Pneumatic actuation is applied on a PDMS diaphragm, which is bonded to the SU8 body at wafer level, further enhancing its integration and mass production capabilities. The cantilever check valves move synchronously with the diaphragm, feature fast response (10ms), low dead volume (86nl) and a 94% flow blockage up to 300kPa. The micropump achieves a maximum flow rate of 177 μl min(-1) at 6 Hz and 200 kPa with an effective area of 10 mm(2). The device is reliable, self-priming and tolerant to particles and big bubbles. To the knowledge of the authors, this is the first micropump in SU8 with monolithically integrated cantilever check valves.

  15. Muscle connective tissue controls development of the diaphragm and is a source of congenital diaphragmatic hernias

    PubMed Central

    Merrell, Allyson J.; Ellis, Benjamin J.; Fox, Zachary D.; Lawson, Jennifer A.; Weiss, Jeffrey A.; Kardon, Gabrielle

    2015-01-01

    The diaphragm is an essential mammalian skeletal muscle, and defects in diaphragm development are the cause of congenital diaphragmatic hernias (CDH), a common and often lethal birth defect. The diaphragm is derived from multiple embryonic sources, but how these give rise to the diaphragm is unknown and, despite the identification of many CDH-associated genes, the etiology of CDH is incompletely understood. Using mouse genetics, we show that the pleuroperitoneal folds (PPFs), transient embryonic structures, are the source of the diaphragm’s muscle connective tissue, regulate muscle development, and their striking migration controls diaphragm morphogenesis. Furthermore, Gata4 mosaic mutations in PPF-derived muscle connective tissue fibroblasts result in the development of localized amuscular regions that are biomechanically weaker and more compliant and lead to CDH. Thus the PPFs and muscle connective tissue are critical for diaphragm development and mutations in PPF-derived fibroblasts are a source of CDH. PMID:25807280

  16. The Manual Diaphragm Release Technique improves diaphragmatic mobility, inspiratory capacity and exercise capacity in people with chronic obstructive pulmonary disease: a randomised trial.

    PubMed

    Rocha, Taciano; Souza, Helga; Brandão, Daniela Cunha; Rattes, Catarina; Ribeiro, Luana; Campos, Shirley Lima; Aliverti, Andrea; de Andrade, Armèle Dornelas

    2015-10-01

    In people with chronic obstructive pulmonary disease, does the Manual Diaphragm Release Technique improve diaphragmatic mobility after a single treatment, or cumulatively? Does the technique also improve exercise capacity, maximal respiratory pressures, and kinematics of the chest wall and abdomen? Randomised, controlled trial with concealed allocation, intention-to-treat analysis, and blinding of participants and assessors. Twenty adults aged over 60 years with clinically stable chronic obstructive pulmonary disease. The experimental group received six treatments with the Manual Diaphragm Release Technique on non-consecutive days within a 2-week period. The control group received sham treatments following the same regimen. The primary outcome was diaphragmatic mobility, which was analysed using ultrasonography. The secondary outcomes were: the 6-minute walk test; maximal respiratory pressures; and abdominal and chest wall kinematics measured by optoelectronic plethysmography. Outcomes were measured before and after the first and sixth treatments. The Manual Diaphragm Release Technique significantly improved diaphragmatic mobility over the course of treatments, with a between-group difference in cumulative improvement of 18mm (95% CI 8 to 28). The technique also significantly improved the 6-minute walk distance over the treatment course, with a between-group difference in improvement of 22 m (95% CI 11 to 32). Maximal expiratory pressure and sniff nasal inspiratory pressure both showed significant acute benefits from the technique during the first and sixth treatments, but no cumulative benefit. Inspiratory capacity estimated by optoelectronic plethysmography showed significant cumulative benefit of 330ml (95% CI 100 to 560). The effects on other outcomes were non-significant or small. The Manual Diaphragm Release Technique improves diaphragmatic mobility, exercise capacity and inspiratory capacity in people with chronic obstructive pulmonary disease. This

  17. Lateral Abdominal Wall Reconstruction

    PubMed Central

    Baumann, Donald P.; Butler, Charles E.

    2012-01-01

    Lateral abdominal wall (LAW) defects can manifest as a flank hernias, myofascial laxity/bulges, or full-thickness defects. These defects are quite different from those in the anterior abdominal wall defects and the complexity and limited surgical options make repairing the LAW a challenge for the reconstructive surgeon. LAW reconstruction requires an understanding of the anatomy, physiologic forces, and the impact of deinnervation injury to design and perform successful reconstructions of hernia, bulge, and full-thickness defects. Reconstructive strategies must be tailored to address the inguinal ligament, retroperitoneum, chest wall, and diaphragm. Operative technique must focus on stabilization of the LAW to nonyielding points of fixation at the anatomic borders of the LAW far beyond the musculofascial borders of the defect itself. Thus, hernias, bulges, and full-thickness defects are approached in a similar fashion. Mesh reinforcement is uniformly required in lateral abdominal wall reconstruction. Inlay mesh placement with overlying myofascial coverage is preferred as a first-line option as is the case in anterior abdominal wall reconstruction. However, interposition bridging repairs are often performed as the surrounding myofascial tissue precludes a dual layered closure. The decision to place bioprosthetic or prosthetic mesh depends on surgeon preference, patient comorbidities, and clinical factors of the repair. Regardless of mesh type, the overlying soft tissue must provide stable cutaneous coverage and obliteration of dead space. In cases where the fasciocutaneous flaps surrounding the defect are inadequate for closure, regional pedicled flaps or free flaps are recruited to achieve stable soft tissue coverage. PMID:23372458

  18. Optical MEMS pressure sensor based on a mesa-diaphragm structure.

    PubMed

    Ge, Yixian; Wang, Ming; Yan, Haitao

    2008-12-22

    An optical MEMS pressure sensor based on a mesa-diaphragm is presented. The operating principle of the sensor is expatiated by Fabry-Perot (F-P) interference. Both the mechanical model and the signal averaging effect of the mesa diaphragm is validated by simulation, which declares that the mesa diaphragm is superior to the planar one on the parallelism and can reduce the signal averaging effect. Experimental results demonstrate that the mesa structure sensor has a reasonable linearity and sensitivity.

  19. Blockage of the Ryanodine Receptor via Azumolene Does Not Prevent Mechanical Ventilation-Induced Diaphragm Atrophy.

    PubMed

    Talbert, Erin E; Smuder, Ashley J; Kwon, Oh Sung; Sollanek, Kurt J; Wiggs, Michael P; Powers, Scott K

    2016-01-01

    Mechanical ventilation (MV) is a life-saving intervention for patients in respiratory failure. However, prolonged MV causes the rapid development of diaphragm muscle atrophy, and diaphragmatic weakness may contribute to difficult weaning from MV. Therefore, developing a therapeutic countermeasure to protect against MV-induced diaphragmatic atrophy is important. MV-induced diaphragm atrophy is due, at least in part, to increased production of reactive oxygen species (ROS) from diaphragm mitochondria and the activation of key muscle proteases (i.e., calpain and caspase-3). In this regard, leakage of calcium through the ryanodine receptor (RyR1) in diaphragm muscle fibers during MV could result in increased mitochondrial ROS emission, protease activation, and diaphragm atrophy. Therefore, these experiments tested the hypothesis that a pharmacological blockade of the RyR1 in diaphragm fibers with azumolene (AZ) would prevent MV-induced increases in mitochondrial ROS production, protease activation, and diaphragmatic atrophy. Adult female Sprague-Dawley rats underwent 12 hours of full-support MV while receiving either AZ or vehicle. At the end of the experiment, mitochondrial ROS emission, protease activation, and fiber cross-sectional area were determined in diaphragm muscle fibers. Decreases in muscle force production following MV indicate that the diaphragm took up a sufficient quantity of AZ to block calcium release through the RyR1. However, our findings reveal that AZ treatment did not prevent the MV-induced increase in mitochondrial ROS emission or protease activation in the diaphragm. Importantly, AZ treatment did not prevent MV-induced diaphragm fiber atrophy. Thus, pharmacological inhibition of the RyR1 in diaphragm muscle fibers is not sufficient to prevent MV-induced diaphragm atrophy.

  20. Inhibition of forkhead boxO-specific transcription prevents mechanical ventilation-induced diaphragm dysfunction.

    PubMed

    Smuder, Ashley J; Sollanek, Kurt J; Min, Kisuk; Nelson, W Bradley; Powers, Scott K

    2015-05-01

    Mechanical ventilation is a lifesaving measure for patients with respiratory failure. However, prolonged mechanical ventilation results in diaphragm weakness, which contributes to problems in weaning from the ventilator. Therefore, identifying the signaling pathways responsible for mechanical ventilation-induced diaphragm weakness is essential to developing effective countermeasures to combat this important problem. In this regard, the forkhead boxO family of transcription factors is activated in the diaphragm during mechanical ventilation, and forkhead boxO-specific transcription can lead to enhanced proteolysis and muscle protein breakdown. Currently, the role that forkhead boxO activation plays in the development of mechanical ventilation-induced diaphragm weakness remains unknown. This study tested the hypothesis that mechanical ventilation-induced increases in forkhead boxO signaling contribute to ventilator-induced diaphragm weakness. University research laboratory. Young adult female Sprague-Dawley rats. Cause and effect was determined by inhibiting the activation of forkhead boxO in the rat diaphragm through the use of a dominant-negative forkhead boxO adeno-associated virus vector delivered directly to the diaphragm. Our results demonstrate that prolonged (12 hr) mechanical ventilation results in a significant decrease in both diaphragm muscle fiber size and diaphragm-specific force production. However, mechanically ventilated animals treated with dominant-negative forkhead boxO showed a significant attenuation of both diaphragm atrophy and contractile dysfunction. In addition, inhibiting forkhead boxO transcription attenuated the mechanical ventilation-induced activation of the ubiquitin-proteasome system, the autophagy/lysosomal system, and caspase-3. Forkhead boxO is necessary for the activation of key proteolytic systems essential for mechanical ventilation-induced diaphragm atrophy and contractile dysfunction. Collectively, these results suggest that

  1. Impaired isotonic contractility and structural abnormalities in the diaphragm of congestive heart failure rats.

    PubMed

    van Hees, Hieronymus W H; van der Heijden, Henricus F M; Hafmans, Theo; Ennen, Leo; Heunks, Leo M A; Verheugt, Freek W A; Dekhuijzen, P N Richard

    2008-08-29

    Metabolic alterations and decreased isometric force generation have been demonstrated in different animal models for congestive heart failure (CHF). However, as few morphological examinations have been performed on the CHF diaphragm, it is unknown if structural abnormalities comprise a substrate for diaphragm dysfunction in CHF. Therefore, we investigated CHF diaphragm isometric and isotonic contractility together with the presence of structural abnormalities. Isometric twitch (P(t)) and maximal (P(o)) force, shortening velocity and power generation were determined in diaphragm bundles from rats with CHF, induced by myocardial infarction, and sham-operated rats. Immunofluorescence staining of myosin and sarcolemmal components fibronectin, laminin and dystrophin was performed on diaphragm cryosections. Electron microscopy was used to study the ultrastructure of diaphragm fibres. P(t) and P(o) were respectively approximately 30% and approximately 20% lower in CHF diaphragm bundles than sham. Maximal shortening velocity was reduced by approximately 20% and maximal power generation by approximately 35%. Structural abnormalities were frequently observed in CHF diaphragm fibres and were mainly marked by focal degradation of sarcomeric constituents and expansion of intermyofibrillar spaces with swollen and degenerated mitochondria. Immunofluorescence microscopy showed reduced staining intensities of myosin in CHF diaphragm fibres compared to sham. No differences were found regarding the distribution of fibronectin, laminin and dystrophin, indicating an intact sarcolemma in both groups. This study demonstrates impaired isometric and isotonic contractility together with structural abnormalities in the CHF diaphragm. The sarcolemma of CHF diaphragm fibres appeared to be intact, excluding a role for sarcolemmal injuries in the development of CHF diaphragm dysfunction.

  2. Blockage of the Ryanodine Receptor via Azumolene Does Not Prevent Mechanical Ventilation-Induced Diaphragm Atrophy

    PubMed Central

    Talbert, Erin E.; Smuder, Ashley J.; Kwon, Oh Sung; Sollanek, Kurt J.; Wiggs, Michael P.; Powers, Scott K.

    2016-01-01

    Mechanical ventilation (MV) is a life-saving intervention for patients in respiratory failure. However, prolonged MV causes the rapid development of diaphragm muscle atrophy, and diaphragmatic weakness may contribute to difficult weaning from MV. Therefore, developing a therapeutic countermeasure to protect against MV-induced diaphragmatic atrophy is important. MV-induced diaphragm atrophy is due, at least in part, to increased production of reactive oxygen species (ROS) from diaphragm mitochondria and the activation of key muscle proteases (i.e., calpain and caspase-3). In this regard, leakage of calcium through the ryanodine receptor (RyR1) in diaphragm muscle fibers during MV could result in increased mitochondrial ROS emission, protease activation, and diaphragm atrophy. Therefore, these experiments tested the hypothesis that a pharmacological blockade of the RyR1 in diaphragm fibers with azumolene (AZ) would prevent MV-induced increases in mitochondrial ROS production, protease activation, and diaphragmatic atrophy. Adult female Sprague-Dawley rats underwent 12 hours of full-support MV while receiving either AZ or vehicle. At the end of the experiment, mitochondrial ROS emission, protease activation, and fiber cross-sectional area were determined in diaphragm muscle fibers. Decreases in muscle force production following MV indicate that the diaphragm took up a sufficient quantity of AZ to block calcium release through the RyR1. However, our findings reveal that AZ treatment did not prevent the MV-induced increase in mitochondrial ROS emission or protease activation in the diaphragm. Importantly, AZ treatment did not prevent MV-induced diaphragm fiber atrophy. Thus, pharmacological inhibition of the RyR1 in diaphragm muscle fibers is not sufficient to prevent MV-induced diaphragm atrophy. PMID:26849371

  3. Diaphragm curvature modulates the relationship between muscle shortening and volume displacement.

    PubMed

    Greybeck, Brad J; Wettergreen, Matthew; Hubmayr, Rolf D; Boriek, Aladin M

    2011-07-01

    During physiological spontaneous breathing maneuvers, the diaphragm displaces volume while maintaining curvature. However, with maximal diaphragm activation, curvature decreases sharply. We tested the hypotheses that the relationship between diaphragm muscle shortening and volume displacement (VD) is nonlinear and that curvature is a determinant of such a relationship. Radiopaque markers were surgically placed on three neighboring muscle fibers in the midcostal region of the diaphragm in six dogs. The three-dimensional locations were determined using biplanar fluoroscopy and diaphragm VD, curvature, and muscle shortening were computed in the prone and supine postures during spontaneous breathing (SB), spontaneous inspiration efforts after airway occlusion at lung volumes ranging from functional residual capacity (FRC) to total lung capacity, and during bilateral maximal phrenic nerve stimulation at those same lung volumes. In supine dogs, diaphragm VD was approximately two- to three-fold greater during maximal phrenic nerve stimulation than during SB. The contribution of muscle shortening to VD nonlinearly increases with level of diaphragm activation independent of posture. During submaximal diaphragm activation, the contribution is essentially linear due to constancy of diaphragm curvature in both the prone and supine posture. However, the sudden loss of curvature during maximal bilateral phrenic nerve stimulation at muscle shortening values greater than 40% (ΔL/L(FRC)) causes a nonlinear increase in the contribution of muscle shortening to diaphragm VD, which is concomitant with a nonlinear change in diaphragm curvature. We conclude that the nonlinear relationship between diaphragm muscle shortening and its VD is, in part, due to a loss of its curvature at extreme muscle shortening.

  4. Diameter and position effect determination of diaphragm on hybrid rocket motor

    NASA Astrophysics Data System (ADS)

    Sun, Xingliang; Tian, Hui; Cai, Guobiao

    2016-09-01

    This study is aimed to determine and better reveal the mixture enhancement and regression rate distribution of hybrid rocket motor with diaphragm by numerical approach. A numerical model based on the computational fluid dynamics software is built to simulate the flow and combustion inside the motor. Four firing tests of the motor, including one without diaphragm and three with diaphragm, are conducted on a standard experimental system and also used as a reference for numerical simulation, the consistency between the simulation and experiment demonstrates that the numerical approach is an effective method to study the diaphragm effect on the motor performance. The flow field characteristic and regression rate distribution inside the hybrid rocket motor are then calculated to analyze the effect of position and diameter of the diaphragm. The results indicate that the diaphragm almost have no effect on the regression rate before it. However, the regression rate after the diaphragm has a strong dependence on the position and diameter of the diaphragm. As the diameter decreases and the position moves backward, the regression rate increases larger and larger, this is mainly due to the augmentation of the eddy generated by the diaphragm, which enhances the heat feedback transferred to the grain surface. When the diameter of diaphragm located at middle of grain decreases from 50 mm to 20 mm, regression rate is increased from 0.30 mm/s to 0.57 mm/s. The use of the diaphragm does cause a combustion efficiency improvement; the maximum combustion efficiency is enhanced to 98.9% from lower than 90% of the motor with no diaphragm. The increasing amplitude displays a square relation with the diameter decrease, since the entrainment of the eddy make the reactants mix sufficiently to release more energy inside the motor.

  5. Investigation on the effect of diaphragm on the combustion characteristics of solid-fuel ramjet

    NASA Astrophysics Data System (ADS)

    Gong, Lunkun; Chen, Xiong; Yang, Haitao; Li, Weixuan; Zhou, Changsheng

    2017-10-01

    The flow field characteristics and the regression rate distribution of solid-fuel ramjet with three-hole diaphragm were investigated by numerical and experimental methods. The experimental data were obtained by burning high-density polyethylene using a connected-pipe facility to validate the numerical model and analyze the combustion efficiency of the solid-fuel ramjet. The three-dimensional code developed in the present study adopted three-order MUSCL and central difference schemes, AUSMPW + flux vector splitting method, and second-order moment turbulence-chemistry model, together with k-ω shear stress transport (SST) turbulence model. The solid fuel surface temperature was calculated with fluid-solid heat coupling method. The numerical results show that strong circumferential flow exists in the region upstream of the diaphragm. The diaphragm can enhance the regression rate of the solid fuel in the region downstream of the diaphragm significantly, which mainly results from the increase of turbulent viscosity. As the diaphragm port area decreases, the regression rate of the solid fuel downstream of the diaphragm increases. The diaphragm can result in more sufficient mixing between the incoming air and fuel pyrolysis gases, while inevitably producing some pressure loss. The experimental results indicate that the effect of the diaphragm on the combustion efficiency of hydrocarbon fuels is slightly negative. It is conjectured that the diaphragm may have some positive effects on the combustion efficiency of the solid fuel with metal particles.

  6. A Study of Free-Piston Double-Diaphragm Drivers for Expansion Tubes. Report 1

    NASA Technical Reports Server (NTRS)

    Kendall, M. A.

    1997-01-01

    In recent years the free-piston double-diaphragm driver has been used to increase the performance of the XI pilot expansion tube to super-orbital test conditions. However, the actual performance of the double-diaphragm driver was found to be considerably less than ideal. An experimental study of the double-diaphragm driver was carried out on the XI facility over a range of conditions with the objective of determining the effect of. heat losses; and the non-ideal rupture of the 'light' secondary diaphragm on the driver performance. The disparity between the theoretical and measured performance envelope are highlighted. A viscous limit for the experiments vas established. Heat transfer behind the primary shock is shown to be the mechanism behind this limit Incident, reflected and transmitted shock trajectories for the secondary diaphragm were experimentally determined and compared with computed trajectories from a one-dimensional diaphragm inertia model. It was found that the diaphragm did influence the unsteady expansion. A good agreement between experimental and computed shock trajectories was obtained using a diaphragm inertia model assuming that the diaphragm mass became negligible 3 microns after shock impact.

  7. Application of Microsecond Voltage Pulses for Water Disinfection by Diaphragm Electric Discharge

    NASA Astrophysics Data System (ADS)

    Kakaurov, S. V.; Suvorov, I. F.; Yudin, A. S.; Solovyova, T. L.; Kuznetsova, N. S.

    2015-11-01

    The paper presents the dependence of copper and silver ions formation on the duration of voltage pulses of diaphragm electric discharge and on the pH of treated liquid medium. Knowing it allows one to create an automatic control system to control bactericidal agent's parameters obtained in diaphragm electric discharge reactor. The current-voltage characteristic of the reactor with a horizontal to the diaphragm membrane water flow powered from the author's custom pulse voltage source is also presented. The results of studies of the power consumption of diaphragm electric discharge depending on temperature of the treated liquid medium are given.

  8. Exercise Training Prevents Diaphragm Contractile Dysfunction in Heart Failure.

    PubMed

    Mangner, Norman; Bowen, T Scott; Werner, Sarah; Fischer, Tina; Kullnick, Yvonne; Oberbach, Andreas; Linke, Axel; Steil, Leif; Schuler, Gerhard; Adams, Volker

    2016-11-01

    Patient studies have demonstrated the efficacy of exercise training in attenuating respiratory muscle weakness in chronic heart failure (HF), yet direct assessment of muscle fiber contractile function together with data on the underlying intracellular mechanisms remains elusive. The present study, therefore, used a mouse model of HF to assess whether exercise training could prevent diaphragm contractile fiber dysfunction by potentially mediating the complex interplay between intracellular oxidative stress and proteolysis. Mice underwent sham operation (n = 10) or a ligation of the left coronary artery and were randomized to sedentary HF (n = 10) or HF with aerobic exercise training (HF + AET; n = 10). Ten weeks later, echocardiography and histological analyses confirmed HF. In vitro diaphragm fiber bundles demonstrated contractile dysfunction in sedentary HF compared with sham mice that was prevented by AET, with maximal force 21.0 ± 0.7 versus 26.7 ± 1.4 and 25.4 ± 1.4 N·cm, respectively (P < 0.05). Xanthine oxidase enzyme activity and MuRF1 protein expression, markers of oxidative stress and protein degradation, were ~20% and ~70% higher in sedentary HF compared with sham mice (P < 0.05) but were not different when compared with the HF + AET group. Oxidative modifications to numerous contractile proteins (i.e., actin and creatine kinase) and markers of proteolysis (i.e., proteasome and calpain activity) were elevated in sedentary HF compared with HF + AET mice (P < 0.05); however, these indices were not significantly different between sedentary HF and sham mice. Antioxidative enzyme activities were also not different between groups. Our findings demonstrate that AET can protect against diaphragm contractile fiber dysfunction induced by HF, but it remains unclear whether alterations in oxidative stress and/or protein degradation are primarily responsible.

  9. [Surgery of the diaphragm in the planned thoracic surgery].

    PubMed

    Parshin, V D; Parshin, V V; Mirzoian, O S; Stepanian, A

    2013-01-01

    122 patients with different diseases of the diaphragm were operated on during 1963-2011 yy. The majority of patients - 76 (62.3%) - had hernias of the weak phrenic zones. 14 (11.5%) and 17 (14.0%) patients had posttraumatic hernia and phrenic relaxation, respectively. The majority of patients had no complaints and the disease was diagnosed on the X-ray examination. Rarely, the compression syndrome, caused by the translocation of the bowel into the thoracic cavity, was registered. That clinically emerged as short breath, heaviness sensation and cardiac rhythm disorders. The worked out reconstructive operations allow to cure such patients with minimal risk.

  10. Titanium acoustic diaphragm coated with polycrystal diamond film

    SciTech Connect

    Zhiwei Zhang; Zhen Yan; Hesun Zhu

    1995-12-31

    The spherical titanium diaphragm, which is widely used in high frequency loudspeaker, coat with polycrystal diamond film (DF) was prepared for the first time in China by the method of DC arc plasma jet. Its acoustic performance was remarkably upgraded, as confirmed by Raman Shift Spectrum and frequency response curve. Its sensibility was improved by 3-6 dB and frequency widened by 5x10{sup 3}Hz. The frequency range extended from 2.2x10{sup 3}Hz to 25x10{sup 3}Hz. The preparation and process of DF is discussed.

  11. Gene Expression Profiling in the Type 1 Diabetes Rat Diaphragm

    PubMed Central

    van Lunteren, Erik; Moyer, Michelle

    2009-01-01

    Background Respiratory muscle contractile performance is impaired by diabetes, mechanisms of which included altered carbohydrate and lipid metabolism, oxidative stress and changes in membrane electrophysiology. The present study examined to what extent these cellular perturbations involve changes in gene expression. Methodology/Principal Findings Diaphragm muscle from streptozotocin-diabetic rats was analyzed with Affymetrix gene expression arrays. Diaphragm from diabetic rats had 105 genes with at least ±2-fold significantly changed expression (55 increased, 50 decreased), and these were assigned to gene ontology groups based on over-representation analysis using DAVID software. There was increased expression of genes involved in palmitoyl-CoA hydrolase activity (a component of lipid metabolism) (P = 0.037, n = 2 genes, fold change 4.2 to 27.5) and reduced expression of genes related to carbohydrate metabolism (P = 0.000061, n = 8 genes, fold change −2.0 to −8.5). Other gene ontology groups among upregulated genes were protein ubiquitination (P = 0.0053, n = 4, fold change 2.2 to 3.4), oxidoreductase activity (P = 0.024, n = 8, fold change 2.1 to 6.0), and morphogenesis (P = 0.012, n = 10, fold change 2.1 to 4.3). Other downregulated gene groups were extracellular region (including extracellular matrix and collagen) (P = 0.00032, n = 13, fold change −2.2 to −3.7) and organogenesis (P = 0.032, n = 7, fold change −2.1 to −3.7). Real-time PCR confirmed the directionality of changes in gene expression for 30 of 31 genes tested. Conclusions/Significance These data indicate that in diaphragm muscle type 1 diabetes increases expression of genes involved in lipid energetics, oxidative stress and protein ubiquitination, decreases expression of genes involved in carbohydrate metabolism, and has little effect on expression of ion channel genes. Reciprocal changes in expression of genes involved in

  12. Diaphragm muscle fiber weakness and ubiquitin-proteasome activation in critically ill patients.

    PubMed

    Hooijman, Pleuni E; Beishuizen, Albertus; Witt, Christian C; de Waard, Monique C; Girbes, Armand R J; Spoelstra-de Man, Angelique M E; Niessen, Hans W M; Manders, Emmy; van Hees, Hieronymus W H; van den Brom, Charissa E; Silderhuis, Vera; Lawlor, Michael W; Labeit, Siegfried; Stienen, Ger J M; Hartemink, Koen J; Paul, Marinus A; Heunks, Leo M A; Ottenheijm, Coen A C

    2015-05-15

    The clinical significance of diaphragm weakness in critically ill patients is evident: it prolongs ventilator dependency, and increases morbidity and duration of hospital stay. To date, the nature of diaphragm weakness and its underlying pathophysiologic mechanisms are poorly understood. We hypothesized that diaphragm muscle fibers of mechanically ventilated critically ill patients display atrophy and contractile weakness, and that the ubiquitin-proteasome pathway is activated in the diaphragm. We obtained diaphragm muscle biopsies from 22 critically ill patients who received mechanical ventilation before surgery and compared these with biopsies obtained from patients during thoracic surgery for resection of a suspected early lung malignancy (control subjects). In a proof-of-concept study in a muscle-specific ring finger protein-1 (MuRF-1) knockout mouse model, we evaluated the role of the ubiquitin-proteasome pathway in the development of contractile weakness during mechanical ventilation. Both slow- and fast-twitch diaphragm muscle fibers of critically ill patients had approximately 25% smaller cross-sectional area, and had contractile force reduced by half or more. Markers of the ubiquitin-proteasome pathway were significantly up-regulated in the diaphragm of critically ill patients. Finally, MuRF-1 knockout mice were protected against the development of diaphragm contractile weakness during mechanical ventilation. These findings show that diaphragm muscle fibers of critically ill patients display atrophy and severe contractile weakness, and in the diaphragm of critically ill patients the ubiquitin-proteasome pathway is activated. This study provides rationale for the development of treatment strategies that target the contractility of diaphragm fibers to facilitate weaning.

  13. Diaphragm Muscle Fiber Weakness and Ubiquitin–Proteasome Activation in Critically Ill Patients

    PubMed Central

    Hooijman, Pleuni E.; Beishuizen, Albertus; Witt, Christian C.; de Waard, Monique C.; Girbes, Armand R. J.; Spoelstra-de Man, Angelique M. E.; Niessen, Hans W. M.; Manders, Emmy; van Hees, Hieronymus W. H.; van den Brom, Charissa E.; Silderhuis, Vera; Lawlor, Michael W.; Labeit, Siegfried; Stienen, Ger J. M.; Hartemink, Koen J.; Paul, Marinus A.; Heunks, Leo M. A.

    2015-01-01

    Rationale: The clinical significance of diaphragm weakness in critically ill patients is evident: it prolongs ventilator dependency, and increases morbidity and duration of hospital stay. To date, the nature of diaphragm weakness and its underlying pathophysiologic mechanisms are poorly understood. Objectives: We hypothesized that diaphragm muscle fibers of mechanically ventilated critically ill patients display atrophy and contractile weakness, and that the ubiquitin–proteasome pathway is activated in the diaphragm. Methods: We obtained diaphragm muscle biopsies from 22 critically ill patients who received mechanical ventilation before surgery and compared these with biopsies obtained from patients during thoracic surgery for resection of a suspected early lung malignancy (control subjects). In a proof-of-concept study in a muscle-specific ring finger protein-1 (MuRF-1) knockout mouse model, we evaluated the role of the ubiquitin–proteasome pathway in the development of contractile weakness during mechanical ventilation. Measurements and Main Results: Both slow- and fast-twitch diaphragm muscle fibers of critically ill patients had approximately 25% smaller cross-sectional area, and had contractile force reduced by half or more. Markers of the ubiquitin–proteasome pathway were significantly up-regulated in the diaphragm of critically ill patients. Finally, MuRF-1 knockout mice were protected against the development of diaphragm contractile weakness during mechanical ventilation. Conclusions: These findings show that diaphragm muscle fibers of critically ill patients display atrophy and severe contractile weakness, and in the diaphragm of critically ill patients the ubiquitin–proteasome pathway is activated. This study provides rationale for the development of treatment strategies that target the contractility of diaphragm fibers to facilitate weaning. PMID:25760684

  14. The movement of the diaphragm monitored by ultrasound imaging: preliminary findings of diaphragm movements in classical singing.

    PubMed

    Pettersen, Viggo; Eggebø, Torbjørn M

    2010-10-01

    This study will by ultrasound imaging (USI) investigate the movement of the diaphragm (DPH) during classical singing. Due to the complex structures of the DPH both the anterior and dorsal sections of the DPH will be investigated. The movement of the anterior section is surveyed by performing a transabdominal scan from the right hypochondrium. The movement of the dorsal section is surveyed by examining the movement of the left kidney. We conclude that USI is a promising tool for surveying the movement of the DPH. Especially the anterior section is easily assessed; however, also the dorsal section may indirectly be surveyed by USI of the movement of the left kidney.

  15. 30 kW metal diaphragm pressure wave generator

    NASA Astrophysics Data System (ADS)

    Caughley, A.; Branje, P.; Klok, T.

    2014-01-01

    Callaghan Innovation has been developing a metal-diaphragm pressure wave generator technology for pulse tube or Stirling cryocoolers since 2005. A series of successful pressure wave generators have been designed, fabricated and demonstrated ranging in swept volume from 20 to 240 cc driven by commercially available induction motors of powers from 0.5 kW to 7.5 kW respectively. A number of pulse tubes have also been design and successfully trialed with these pressure wave generators. Cooling powers up to 600 W at 120 K have been achieved. We have now scaled the pressure wave generator technology to 1000cc swept volume, powered by a 30 kW induction motor with the intention of providing over 20 kW of acoustic power to either pulse tube or Stirling expanders. The aim is to develop a cryocooler with more than 1000 W of refrigeration at 77 K. Target applications include liquefaction and High Temperature Superconducting devices. Initial results from testing the 1000 cc pressure wave generator are presented and we will discuss the challenges and advantages involved in scaling the metal diaphragm technology to higher acoustic powers.

  16. A highly sensitive fiber Bragg grating diaphragm pressure transducer

    NASA Astrophysics Data System (ADS)

    Allwood, Gary; Wild, Graham; Lubansky, Alex; Hinckley, Steven

    2015-10-01

    In this work, a novel diaphragm based pressure transducer with high sensitivity is described, including the physical design structure, in-depth analysis of optical response to changes in pressure, and a discussion of practical implementation and limitations. A flat circular rubber membrane bonded to a cylinder forms the body of the transducer. A fiber Bragg grating bonded to the center of the diaphragm structure enables the fractional change in pressure to be determined by analyzing the change in Bragg wavelength of the reflected spectra. Extensive evaluation of the physical properties and optical characteristics of the transducer has been performed through experimentation, and modeling using small deformation theory. The results show the transducer has a sensitivity of 0.116 nm/kPa, across a range of 15 kPa. Ultra-low cost interrogation of the optical signal was achieved through the use of an optically mismatched Bragg grating acting as an edge filter to convert the spectral change into an intensity change. A numerical model of the intensity based interrogation was implemented in order to validate the experimental results. Utilizing this interrogation technique and housing both the sensing and reference Bragg gratings within the main body of the transducer means it is effectively temperature insensitive and easily connected to electronic systems.

  17. Passive mechanics of muscle tendinous junction of canine diaphragm.

    PubMed

    Hwang, Willy; Kelly, Neil G; Boriek, Aladin M

    2005-04-01

    The diaphragmatic muscle tendon is a biaxially loaded junction in vivo. Stress-strain relations along and transverse to the fiber directions are important in understanding its mechanical properties. We hypothesized that 1) the central tendon possesses greater passive stiffness than adjacent muscle, 2) the diaphragm muscle is anisotropic, whereas the central tendon near the junction is essentially isotropic, and 3) a gradient in passive stiffness exists as one approaches the muscle-tendinous junction (MTJ). To investigate these hypotheses, we conducted uniaxial and biaxial mechanical loading on samples of the MTJ excised from the midcostal region of dog diaphragm. We measured passive length-tension relationships of the muscle, tendon, and MTJ in the direction along the muscle fibers as well as transverse to the fibers. The MTJ was slack in the unloaded state, resulting in a J-shaped passive tension-strain curve. Generally, muscle strain was greater than that of MTJ, which was greater than tendon strain. In the muscular region, stiffness in the direction transverse to the fibers is much greater than that along the fibers. The central tendon is essentially inextensible in the direction transverse to the fibers as well as along the fibers. Our data demonstrate the existence of more pronounced anisotropy in the muscle than in the tendon near the junction. Furthermore, a gradient in muscle stiffness exists as one approaches the MTJ, consistent with the hypothesis of continuous passive stiffness across the MTJ.

  18. Experimental Characterization of Piezoelectric Radial Field Diaphragms for Fluidic Control

    NASA Technical Reports Server (NTRS)

    Bryant, R. G.; Kavli, S. E.; Thomas, R. A., Jr.; Darji, K. J.; Mossi, K. M.

    2004-01-01

    NASA has recently developed a new piezoelectric actuator, the Radial Field Diaphragm or RFD. This actuator uses a radially-directed electric field to generate concentric out-of-plane (Z-axis) motion that allows this packaged device to be used as a pump or valve diaphragm. In order to efficiently use this new active device, experimental determination of pressure, flow rate, mechanical work, power consumption and overall efficiency needs to be determined by actually building a pump. However, without an optimized pump design, it is difficult to assess the quality of the data, as these results are inherent to the actual pump. Hence, separate experiments must be conducted in order to generate independent results to help guide the design criteria and pump quality. This paper focuses on the experiments used to generate the RFD's operational parameters and then compares these results to the experimentally determined results of several types of ball pumps. Also discussed are how errors are inherently introduced into the experiments, the pump design, experimental hardware and their effects on the overall system efficiency.

  19. Podocin localizes in the kidney to the slit diaphragm area.

    PubMed

    Roselli, Séverine; Gribouval, Olivier; Boute, Nicolas; Sich, Mireille; Benessy, France; Attié, Tania; Gubler, Marie-Claire; Antignac, Corinne

    2002-01-01

    We recently cloned a novel gene, NPHS2, involved in autosomal recessive steroid-resistant nephrotic syndrome. This gene encodes a novel podocyte protein, podocin. Given its similarity with the stomatin family proteins, podocin is predicted to be an integral membrane protein with a single membrane domain forming a hairpin-like structure placing both N- and C-termini in the cytosol. Here, we show by in situ hybridization, that during development, the NPHS2 transcript is first expressed in mesonephric podocytes from the S-shaped body and, later, in the metanephric kidney, in the future podocytes at the late S-shaped body stage. In the mature kidney, NPHS2 is exclusively expressed in the podocytes of mature glomeruli. We generated rabbit polyclonal antibodies against fusion proteins derived from the N- and the C-terminal regions of podocin which detected a single band of 49-kd in transfected HEK293 cell lysates by immunoprecipitation and Western blotting. By immunohistology, podocin was detected in podocytes from the early capillary loop stage in the developing nephrons, and at the basal pole, along the GBM, in mature glomeruli. By electron microscopy, we demonstrate that podocin is facing the slit diaphragm with its two ends in the cytoplasm of the foot processes, in agreement with its predicted structure. Our results suggest that podocin could serve to anchor directly or indirectly components of the slit diaphragm to the cytoskeleton.

  20. A comparison of rates of protein turnover in rat diaphragm in vivo and in vitro.

    PubMed Central

    Preedy, V R; Smith, D M; Sugden, P H

    1986-01-01

    Protein synthesis and degradation rates in diaphragms from fed or starved rats were compared in vivo and in vitro. For fed rats, synthesis rates in vivo were approximately twice those in vitro, but for starved rats rates were similar. Degradation rates were less in vivo than in vitro in diaphragms from either fed or starved rats. PMID:2420323

  1. Effects of perinatal undernutrition on elimination of immature myosin isoforms in the rat diaphragm.

    PubMed

    Brozanski, B S; Daood, M J; LaFramboise, W A; Watchko, J F; Foley, T P; Butler-Browne, G S; Whalen, R G; Guthrie, R D; Ontell, M

    1991-08-01

    The effect of perinatal undernutrition on the postnatal elimination of immature myosin isoforms in rat diaphragm muscle was examined using electrophoretic and immunocytochemical techniques. Electrophoresis of native myosin showed that neonatal bands were present in diaphragm muscles of both control and undernourished rats on day 4. By day 21, the neonatal bands were diminished in the control diaphragm compared with the diaphragm of the undernourished rats. Neonatal bands persisted on postnatal day 30 in the diaphragm of the undernourished rats but not in the diaphragm of control rats. No significant difference in the time course of elimination of embryonic myosin light chain (LCemb) was observed between the diaphragm muscles of control and undernourished rats with two-dimensional gel electrophoresis. Immunocytochemical analysis demonstrated embryonic myosin heavy chain (MHCemb) in all myofibers of the diaphragm muscle of both groups at day 4, but this isoform was not detected in either group by day 14. Reactivity with anti-neonatal myosin heavy chain (MHCneo) indicated that rate of elimination of the MHCneo was delayed in the undernourished state as compared with the normal rats (P less than 0.001). Serum triiodothyronine levels were measured at 14, 21, and 30 days and were significantly lower in the undernourished rats compared with age-matched controls. These data demonstrate that the normal postnatal decrease in MHCneo, but not MHCemb or LCemb, is affected by the nutritional state of the animal. We speculate that these alterations in myosin isoform transitions are induced by hypothyroidism associated with undernutrition.

  2. Functional assessment of the diaphragm by speckle tracking ultrasound during inspiratory loading.

    PubMed

    Oppersma, Eline; Hatam, Nima; Doorduin, Jonne; van der Hoeven, Johannes G; Marx, Gernot; Goetzenich, Andreas; Fritsch, Sebastian; Heunks, Leo M A; Bruells, Christian S

    2017-05-18

    Assessment of diaphragmatic effort is challenging especially in critically ill patients in the phase of weaning. Fractional thickening during inspiration assessed by ultrasound has been used to estimate diaphragm effort. It is unknown whether more sophisticated ultrasound techniques such as speckle tracking are superior in the quantification of inspiratory effort. This study evaluates the validity of speckle tracking ultrasound to quantify diaphragm contractility. Thirteen healthy volunteers underwent a randomized stepwise threshold loading protocol of 0 to 50% of the maximal inspiratory pressure. Electric activity of the diaphragm and transdiaphragmatic pressures were recorded. Speckle tracking ultrasound was used to assess strain and strain rate as measures of diaphragm tissue deformation and deformation velocity, respectively. Fractional thickening was assessed by measurement of diaphragm thickness at end-inspiration and end-expiration. Strain and strain rate increased with progressive loading of the diaphragm. Both strain and strain rate were highly correlated to transdiaphragmatic pressure (strain R(2)=0.72; strain rate R(2)=0.80) and diaphragm electric activity (strain R(2)=0.60; strain rate R(2)=0.66). No correlation between fractional thickening and strain and strain rate was found. Speckle tracking ultrasound is superior to conventional ultrasound techniques to estimate diaphragm contractility under inspiratory threshold loading. Copyright © 2017, Journal of Applied Physiology.

  3. Effect of diaphragm breathing exercise applied on the basis of overload principle.

    PubMed

    Lee, Hae-Yong; Cheon, Song-Hee; Yong, Min-Sik

    2017-06-01

    [Purpose] The purpose of this study was to examine effects of diaphragm breathing exercise applied on the basis overload principle on respiratory function. [Subjects and Methods] The subjects of this study were 35 normal adults. They were randomly assigned to two group; the maneuver-diaphragm exercise group and self-diaphragm exercise group. The respiratory function was evaluated using the CardioTouch 3000S (BIONET, Korea) as a pulmometry device. [Results] The maneuver-diaphragm exercise was more effective on functional vital capacity and forced expiratory volume at one second when compared to the self-diaphragm exercise. [Conclusion] According to the results of this study, although the self-diaphragm exercise did not show effects as much as the maneuver one, but the self-diaphragm exercise had a similar effects as the maneuver-diaphragm exercise. The self-diaphragmatic respiration applied on the basis of overload principle may be used as an effective respiratory exercise as a part of home respiration program.

  4. Computed tomography to diagnose blunt diaphragm injuries: not ready for prime time.

    PubMed

    Sprunt, Julie M; Brown, Carlos V R; Reifsnyder, Andrew C; Shestopalov, Alex V; Ali, Sadia; Fielder, W Drew

    2014-11-01

    Diaphragm injuries after blunt trauma are uncommon but require early diagnosis to expedite repair. The advancing technology of computed tomography (CT) scanners has improved the detection of almost all traumatic injuries; however, the literature regarding the diagnostic accuracy of CT scan for blunt diaphragm injuries is lacking. The purpose of this study was to determine the CT scan findings in the setting of known blunt diaphragm injury. We performed a retrospective review of all blunt trauma patients with a known diaphragm injury confirmed at laparotomy who also had a preoperative CT scan of the torso. Every CT scan was retrospectively reviewed by a board-certified radiologist for evidence of diaphragm injury as well as associated abdominal and thoracic injuries. Forty-two patients sustaining blunt trauma had preoperative CT scans of the torso and a diaphragm injury confirmed at laparotomy. Only 57 per cent of CT scans showed evidence of diaphragmatic injury. The most common thoracic injury identified was a pulmonary contusion (79%). Although the advancement of imaging technology has markedly improved the diagnosis and management of blunt traumatic injuries, the detection of diaphragm injuries using CT continues to be low and reconstructions do not help in finding diaphragm injuries.

  5. Mitochondrial-targeted antioxidants protect against mechanical ventilation-induced diaphragm weakness

    PubMed Central

    Powers, Scott K.; Hudson, Matthew B.; Nelson, W. Bradley; Talbert, Erin E.; Min, Kisuk; Szeto, Hazel H.; Kavazis, Andreas N.; Smuder, Ashley J.

    2015-01-01

    BACKGROUND Mechanical ventilation (MV) is a life-saving intervention used to provide adequate pulmonary ventilation in patients suffering from respiratory failure. However, prolonged MV is associated with significant diaphragmatic weakness resulting from both myofiber atrophy and contractile dysfunction. Although several signaling pathways contribute to diaphragm weakness during MV, it is established that oxidative stress is required for diaphragmatic weakness to occur. Therefore, identifying the site(s) of MV-induced reactive oxygen species (ROS) production in the diaphragm is important. OBJECTIVE These experiments tested the hypothesis that elevated mitochondrial ROS emission is required for MV-induced oxidative stress, atrophy, and contractile dysfunction in the diaphragm. DESIGN Cause and effect was determined by preventing MV-induced mitochondrial ROS emission in the diaphragm of rats using a novel mitochondrial-targeted antioxidant (SS-31). MEASUREMENTS AND MAIN RESULTS Compared to mechanically ventilated animals treated with saline, animals treated with SS-31 were protected against MV-induced mitochondrial dysfunction, oxidative stress, and protease activation in the diaphragm. Importantly, treatment of animals with the mitochondrial antioxidant also protected the diaphragm against MV-induced myofiber atrophy and contractile dysfunction. CONCLUSIONS These results reveal that prevention of MV-induced increases in diaphragmatic mitochondrial ROS emission protects the diaphragm MV-induced diaphragmatic weakness. This important new finding indicates that mitochondria are a primary source of ROS production in the diaphragm during prolonged MV. These results could lead to the development of a therapeutic intervention to impede MV-induced diaphragmatic weakness. PMID:21460706

  6. Improved tolerance of acute severe hypoxic stress in chronic hypoxic diaphragm is nitric oxide-dependent.

    PubMed

    Lewis, Philip; McMorrow, Clodagh; Bradford, Aidan; O'Halloran, Ken D

    2015-09-01

    The effects of chronic hypoxia (CH) on respiratory muscle performance have hardly been investigated, despite clinical relevance. Results from recent studies are indicative of unique adaptive strategies in hypoxic diaphragm. Respiratory muscle tolerance of acute severe hypoxic stress was examined in normoxic and CH diaphragm in the presence and absence of a nitric oxide (NO) synthase inhibitor. We tested the hypothesis that improved tolerance of severe hypoxic stress in CH diaphragm is NO-dependent. Wistar rats were exposed to normoxia (sea-level, n = 6) or CH (ambient pressure = 380 mmHg, n = 6) for 6 weeks. Diaphragm muscle functional properties were determined ex vivo under severe hypoxic conditions (gassed with 95%N2/5% CO2) with and without 1 mM L-N(G)-nitroarginine (L-NNA, nNOS inhibitor). Fatigue tolerance, but not force, was significantly improved in CH diaphragm (p = 0.008). CH exposure did not affect diaphragm muscle fibre oxidative capacity determined from cluster analysis of area-density plots of muscle fibre succinate dehydrogenase activity. Acute NOS inhibition reduced diaphragm peak tetanic force (p = 0.018), irrespective of gas treatment, and completely reversed improved fatigue tolerance of the CH diaphragm. We conclude that CH exposure improves fatigue tolerance during acute severe hypoxic stress in an NO-dependent manner, independent of muscle fibre oxidative capacity.

  7. Hydraulic Resistance and Liberation of Air in Aviation Kerosene Flow Through Diaphragms at Low Pressure

    NASA Astrophysics Data System (ADS)

    Kitanin, É. L.; Kitanina, E. É.; Zherebtsov, V. A.; Peganova, M. M.; Stepanov, S. G.; Bondarenko, D. A.; Morisson, D.

    2016-09-01

    This paper presents the results of experimental investigations of the liberation of air in gravity flow of aviation fuel through a pipeline with diaphragms. Experiments were carried out in the pressure range 0.2-1.0 bar and temperature range -20 to +20°C. The TC-1 kerosene was preliminarily saturated with air at atmospheric pressure. The liberation of air after the diaphragms with three ratios of the flow area to the cross-sectional area of the pipeline has been investigated. The results of investigations of the two-phase flow in several experimental pipelines containing one or two diaphragms and other local hydraulic resistances have been generalized. The obtained approximation equations permit calculating the hydraulic resistance of the diaphragm in the two-phase flow and the mass gas content of air after the diaphragm in pipelines of complex geometry.

  8. Effects of diaphragm breathing exercise and feedback breathing exercise on pulmonary function in healthy adults.

    PubMed

    Yong, Min-Sik; Lee, Hae-Yong; Lee, Yun-Seob

    2017-01-01

    [Purpose] The present study investigated effects of diaphragm breathing exercise and feedback breathing exercise on respiratory function. [Subjects and Methods] Thirty-one subjects were randomly assigned to two groups; the feedback breathing exercise group and the maneuver-diaphragm exercise group. The feedback breathing exercise group was asked to breathe with feedback breathing device, and the maneuver-diaphragm exercise group was asked to perform diaphragm respiration. Respiratory function was evaluated when a subject sat on a chair comfortably. [Results] There was a significant difference in the functional vital capacity and slow vital capacity before and after all breathing exercises. There was a significant between-group difference in functional vital capacity. However, no between-group difference was found in slow vital capacity. [Conclusion] Diaphragm breathing exercise and feedback breathing exercise can affect respiratory function.

  9. Introducing diaphragms into the mix: what happens to male condom use patterns?

    PubMed

    Posner, Samuel F; van der Straten, Ariane; Kang, Mi-Suk; Padian, Nancy; Chipato, Tsungai

    2005-12-01

    The objective of this analysis was to assess the effect of introducing the diaphragm on condom use patterns. Participants included one hundred eighty-nine women attending family planning clinics in Harare, Zimbabwe who reported less than 100% condom use. The proportion of acts where at least one method was used significantly increased over using follow-up; male condom use remained stable. A diaphragm was used with 50% to 54% of acts; male condoms were also used about 50% of the time. The proportion of acts where a female condom was used decreased. Women who used both male and female condoms were more likely to use diaphragms than those who reported not using female condoms. Introducing the diaphragm increased the overall proportion of protected acts. The proportion of acts where a male condom was used did not change. Female condoms use declined because concurrent use with the diaphragm is not possible.

  10. Effects of diaphragm breathing exercise and feedback breathing exercise on pulmonary function in healthy adults

    PubMed Central

    Yong, Min-Sik; Lee, Hae-Yong; Lee, Yun-Seob

    2017-01-01

    [Purpose] The present study investigated effects of diaphragm breathing exercise and feedback breathing exercise on respiratory function. [Subjects and Methods] Thirty-one subjects were randomly assigned to two groups; the feedback breathing exercise group and the maneuver-diaphragm exercise group. The feedback breathing exercise group was asked to breathe with feedback breathing device, and the maneuver-diaphragm exercise group was asked to perform diaphragm respiration. Respiratory function was evaluated when a subject sat on a chair comfortably. [Results] There was a significant difference in the functional vital capacity and slow vital capacity before and after all breathing exercises. There was a significant between-group difference in functional vital capacity. However, no between-group difference was found in slow vital capacity. [Conclusion] Diaphragm breathing exercise and feedback breathing exercise can affect respiratory function. PMID:28210046

  11. Electro-Active Device Using Radial Electric Field Piezo-Diaphragm for Control of Fluid Movement

    NASA Technical Reports Server (NTRS)

    Bryant, Robert G. (Inventor); Working, Dennis C. (Inventor)

    2005-01-01

    A fluid-control electro-active device includes a piezo-diaphragm made from a ferroelectric material sandwiched by first and second electrode patterns configured to introduce an electric field into the ferroelectric material when voltage is applied thereto. The electric field originates at a region of the ferroelectric material between the first and second electrode patterns, and extends radially outward from this region of the ferroelectric material and substantially parallel to the plane of the ferroelectric material. The piezo-diaphragm deflects symmetrically about this region in a direction substantially perpendicular to the electric field. An annular region coupled to and extending radially outward from the piezo-diaphragm perimetrically borders the piezo-diaphragm, A housing is connected to the region and at least one fluid flow path with piezo-diaphragm disposed therein.

  12. Use of diaphragm transducers in the measurement of pressures on soft materials.

    PubMed

    Jhoun, J H; Childress, D S

    1998-11-01

    Diaphragm pressure transducers are designed to measure pressures in fluids, but have also been applied to measuring pressures on soft materials, such as at the interface between the residual limb of a lower-limb amputee and the supporting surface defined by the prosthetic socket. The reliability and accuracy of Kulite XTM-190 transducer as a pressure monitor on soft materials, such as silicone and Pelite was evaluated in three physical model set-ups. The evaluations included the uniform loading of solid disks of silicone and Pelite, the application of air pressure to the core of a contained thick-walled cylinder made of silicone, and the dynamic indentation of a contained solid silicone cylinder. Sensor measurements in all situations were similar to analytical, iterative or finite element solutions when certain conditions were met. These conditions include: (i) lubricating the interface between the soft material and the supporting structure; (ii) calibrating the transducers under surface and material conditions used during measurements; and (iii) using compatible soft materials (e.g. silicone but not Pelite).

  13. Fully automatic algorithm for segmenting full human diaphragm in non-contrast CT Images

    NASA Astrophysics Data System (ADS)

    Karami, Elham; Gaede, Stewart; Lee, Ting-Yim; Samani, Abbas

    2015-03-01

    The diaphragm is a sheet of muscle which separates the thorax from the abdomen and it acts as the most important muscle of the respiratory system. As such, an accurate segmentation of the diaphragm, not only provides key information for functional analysis of the respiratory system, but also can be used for locating other abdominal organs such as the liver. However, diaphragm segmentation is extremely challenging in non-contrast CT images due to the diaphragm's similar appearance to other abdominal organs. In this paper, we present a fully automatic algorithm for diaphragm segmentation in non-contrast CT images. The method is mainly based on a priori knowledge about the human diaphragm anatomy. The diaphragm domes are in contact with the lungs and the heart while its circumference runs along the lumbar vertebrae of the spine as well as the inferior border of the ribs and sternum. As such, the diaphragm can be delineated by segmentation of these organs followed by connecting relevant parts of their outline properly. More specifically, the bottom surface of the lungs and heart, the spine borders and the ribs are delineated, leading to a set of scattered points which represent the diaphragm's geometry. Next, a B-spline filter is used to find the smoothest surface which pass through these points. This algorithm was tested on a noncontrast CT image of a lung cancer patient. The results indicate that there is an average Hausdorff distance of 2.96 mm between the automatic and manually segmented diaphragms which implies a favourable accuracy.

  14. Evaluation of concrete masonry unit walls for lateral natural phenomena hazards loads

    SciTech Connect

    Faires, W.E. Jr.

    1996-03-08

    Older single-story facilities (Pre-1985 vintage) are commonly constructed of structural steel framing with concrete masonry unit (CMU) walls connected to columns and roof girders of the steel framing system. The CMU walls are designed for lateral wind and seismic loads (perpendicular to the wall) and transmit shear loads from the roof diaphragm to the foundation footings. The lateral loads normally govern their design. The structural framing system and the roof diaphragm system are straight forward when analyzing or upgrading the structure for NPH loads. Because of a buildings design vintage, probable use of empirical methodology, and poor design basis documentation (and record retention); it is difficult to qualify or upgrade CMU walls for lateral Natural Phenomena Hazards (NPH) loads in accordance with References 1, 2 and 3. This paper discusses three analytical approaches and/or techniques (empirical, working stress and yield line) to determine the collapse capacity of a laterally loaded CMU wall, and compares their results

  15. SEISMIC EVALUATION OF ATYPICAL SPECIAL PLATE SHEAR WALLS

    SciTech Connect

    Mark J. Russell; Robert E. Spears; Ryan G. Kobbe

    2007-07-01

    The structure of a building undergoing a seismic reevaluation at the Idaho National Laboratory includes a number of steel plate walls and a roof liner which will act as shear diaphragms during an earthquake. Since the facility was designed and built long before such criteria were formulated, it is not surprising that these walls are not configured to meet all of the recently formulated requirements for such structures. To take advantage of this unusual structural feature, nonlinear analysis was used to ensure accurate modeling of the plate walls in a linear elastic seismic analysis of the full superstructure. The modeling was also used to establish the capacity of the plate.

  16. Diaphragm compound muscle action potential measured with magnetic stimulation and chest wall surface electrodes.

    PubMed

    Luo, Y M; Mustfa, N; Lyall, R A; Man, W D C; Glérant, J C; Polkey, M I; Moxham, J

    2002-06-01

    To seek a method to reliably measure phrenic nerve conduction time (PNCT) with magnetic stimulation we investigated two stimulus sites, placing the magnetic coil at the cricoid cartilage (high position) or close to the clavicle (low position). We also compared compound muscle action potential (CMAP) recorded from three different sites: in the sixth to eighth intercostal spaces in the anterior axillary line (Ant-a); in the 8th intercostal space close to the midclavicular line; and with one electrode at the lower sternum and the other at the costal margin. Fourteen normal subjects were studied. The PNCT measured by magnetic stimulation in the high position recorded from (Ant-a) was 7.6+/-0.6 on the left side and 8.4+/-0.7 on the right. The PNCT recorded from all three sites become much shorter when the magnetic coil was moved from the high to the low position. Our results show that PNCT can be accurately measured with magnetic stimulation when care is taken to avoid coactivation of the brachial plexus.

  17. Diaphragm Stirling engine heat-actuated heat pump development

    NASA Astrophysics Data System (ADS)

    Ackermann, R. A.; Swenson, P.

    A power module, consisting of a free displacer, resonant Stirling engine, hydraulic transmission, and resonant Rankine refrigerant (F-22) compressor, embodies several innovative concepts in free-piston Stirling engine heat pump design that will advance the state of the art of this technology. Progress is reported in three areas of the program. A compressor/engine matching analysis and a stability analysis show that the power module, which is representative of a two-degree-of-freedom resonant system, can operate stably over the full range of heat pump conditions. A compressor design evolved that has met criteria for performance and cost. Tests employing a hydraulic simulator test rig show that the transmission losses are less than had been predicted, and that properly designed and fabricated diaphragms can attain long life.

  18. Piconewton force measurement using a nanometric photonic crystal diaphragm.

    PubMed

    Jo, Wonuk; Digonnet, Michel J F

    2014-08-01

    A compact force fiber sensor capable of measuring forces at the piconewton level is reported. It consists of a miniature Fabry-Perot cavity fabricated at the tip a single-mode fiber, in which the external reflector is a compliant photonic-crystal diaphragm that deflects when subjected to a force. In the laboratory environment, this sensor was able to detect a force of only ∼4  pN generated by the radiation pressure of a laser beam. Its measured minimum detectable force (MDF) at 3 kHz was as weak as 1.3  pN/√Hz. In a quiet environment, the measured noise was ∼16 times lower, and the MDF predicted to be ∼76  fN/√Hz.

  19. Modulation of glucose transporters in rat diaphragm by sodium tungstate.

    PubMed

    Girón, M D; Caballero, J J; Vargas, A M; Suárez, M D; Guinovart, J J; Salto, R

    2003-05-08

    Oral administration of sodium tungstate is an effective treatment for diabetes in animal models. We examined the effects of 6 weeks of oral administration of tungstate on glucose transporters (GLUT) in streptozotocin-induced diabetic rat diaphragm. Diabetes decreased GLUT4 expression while tungstate treatment normalized not only GLUT4 protein but also GLUT4 mRNA in the diabetic rats. Furthermore, treatment increased GLUT4 protein in plasma and internal membranes, suggesting a stimulation of its translocation to the plasma membrane. Tungstate had no effect on healthy animals. There were no differences in the total amount of GLUT1 transporter in any group. We conclude that the normoglycemic effect of tungstate may be partly due to a normalization of the levels and subcellular localization of GLUT4, which should result in an increase in muscle glucose uptake.

  20. DC diaphragm discharge in water solutions of selected organic acids

    NASA Astrophysics Data System (ADS)

    Vyhnankova, Edita J.; Hammer, Malte U.; Reuter, Stephan; Krcma, Frantisek

    2015-07-01

    Effect of four simple organic acids water solution on a DC diaphragm discharge was studied. Efficiency of the discharge was quantified by the hydrogen peroxide production determined by UV-VIS spectrometry of a H2O2 complex formed with specific titanium reagent. Automatic titration was used to study the pH behaviour after the plasma treatment. Optical emission spectroscopy overview spectra were recorded and detailed spectra of OH band and Hβ line were used to calculate the rotational temperature and comparison of the line profile (reflecting electron concentration) in the acid solutions. Contribution to the topical issue "The 14th International Symposium on High Pressure Low Temperature Plasma Chemistry (HAKONE XIV)", edited by Nicolas Gherardi, Ronny Brandenburg and Lars Stollenwark

  1. Progress in Karl Fischer coulometry using diaphragm-free cells.

    PubMed

    Cedergren, A; Jonsson, S

    2001-11-15

    Different designs of a semiopen, drainable cathode compartment of a medium-sized coulometric Karl Fischer (KF) cell for the determination of water in the range 0.1-500 microg were evaluated. The main criterion for the design was to keep the resistance between the anolyte and catholyte low enough to permit the generation of currents larger than 20 mA (for an output voltage of 28 V). It was found that a good compromise between the size of this current and a minimal influence from diffusing/migrating oxidizable reduction products from the catholyte was achieved by means of an interface having a channel length and diameter of 8 and 2.1 mm, respectively (catholyte volume, approximately 1 mL). To show the general applicability of the concept, the following different types of coulometric reagents suitable for nonpolar and polar samples, as well as for samples containing active carbonyl compounds, were investigated: Hydranal Coulomat A, AD, AK, AG-H (modified with chloroform, Merck), and two homemade methanolic reagents modified with 40% (v/v) chloroform and 50% (v/v) formamide, respectively. Except for Hydranal Coulomat A, the mean value of five consecutive titrations of 50 microg water did not deviate by more than 0.2% from the expected value for all reagents. Draining after every titration was sufficient to obtain accurate results, even for Coulomat A which, when used in the commercial diaphragm-free system of Metrohm, gave values which were about 10% too high. As compared to earlier reported results for diaphragm-free coulometry, the descibed modified cell represents a significant improvement, mainly because of the high accuracy achieved for all types of reagents.

  2. Cerium oxide nanoparticle treatment ameliorates peritonitis-induced diaphragm dysfunction.

    PubMed

    Asano, Shinichi; Arvapalli, Ravikumar; Manne, Nandini D P K; Maheshwari, Mani; Ma, Bing; Rice, Kevin M; Selvaraj, Vellaisamy; Blough, Eric R

    2015-01-01

    The severe inflammation observed during sepsis is thought to cause diaphragm dysfunction, which is associated with poor patient prognosis. Cerium oxide (CeO2) nanoparticles have been posited to exhibit anti-inflammatory and antioxidative activities suggesting that these particles may be of potential use for the treatment of inflammatory disorders. To investigate this possibility, Sprague Dawley rats were randomly assigned to the following groups: sham control, CeO2 nanoparticle treatment only (0.5 mg/kg iv), sepsis, and sepsis+CeO2 nanoparticles. Sepsis was induced by the introduction of cecal material (600 mg/kg) directly into the peritoneal cavity. Nanoparticle treatment decreased sepsis-associated impairments in diaphragmatic contractile (P(o)) function (sham: 25.6±1.6 N/cm(2) vs CeO2: 23.4±0.8 N/cm(2) vs Sep: 15.9±1.0 N/cm(2) vs Sep+CeO2: 20.0±1.0 N/cm(2), P<0.05). These improvements in diaphragm contractile function were accompanied by a normalization of protein translation signaling (Akt, FOXO-1, and 4EBP1), diminished proteolysis (caspase 8 and ubiquitin levels), and decreased inflammatory signaling (Stat3 and iNOS). Histological analysis suggested that nanoparticle treatment was associated with diminished sarcolemma damage and diminished inflammatory cell infiltration. These data indicate CeO2 nanoparticles may improve diaphragmatic function in the septic laboratory rat.

  3. Convergence of pattern generator outputs on a common mechanism of diaphragm motor unit recruitment

    PubMed Central

    Mantilla, Carlos B.; Seven, Yasin B.; Sieck, Gary C.

    2014-01-01

    Motor units are the final element of neuromotor control. In manner analogous to the organization of neuromotor control in other skeletal muscles, diaphragm motor units comprise phrenic motoneurons located in the cervical spinal cord that innervate the diaphragm muscle, the main inspiratory muscle in mammals. Diaphragm motor units play a primary role in sustaining ventilation, but are also active in other non-ventilatory behaviors, including coughing, sneezing, vomiting, defecation and parturition. Diaphragm muscle fibers comprise all fiber types. Thus, diaphragm motor units display substantial differences in contractile and fatigue properties, but importantly properties of the motoneuron and muscle fibers within a motor unit are matched. As in other skeletal muscles, diaphragm motor units are recruited in order such that motor units that display greater fatigue resistance are recruited earlier and more often than more fatigable motor units. The properties of the motor unit population are critical determinants of the function of a skeletal muscle across the range of possible motor tasks. Accordingly, fatigue-resistant motor units are sufficient to generate the forces necessary for ventilatory behaviors whereas more fatigable units are only activated during expulsive behaviors important for airway clearance. Neuromotor control of diaphragm motor units may reflect selective inputs from distinct pattern generators distributed according to the motor unit properties necessary to accomplish these different motor tasks. In contrast, widely-distributed inputs to phrenic motoneurons from various pattern generators (e.g., for breathing, coughing or vocalization) would dictate recruitment order based on intrinsic electrophysiological properties. PMID:24746055

  4. Finite element analysis of AlGaN/GaN micro-diaphragms with diamond coating

    NASA Astrophysics Data System (ADS)

    Dzuba, J.; Vanko, G.; Vojs, M.; Rýger, I.; Ižák, T.; Jirásek, V.; Kutiš, V.; Lalinský, T.

    2015-05-01

    In this work, we present a pressure sensor based on diamond coated AlGaN/GaN diaphragm with integrated high electron mobility transistor (HEMT). The influence of the diamond film thickness (in the range of 1 μm to 50 μm) on the properties of the AlGaN/GaN diaphragm is studied by finite element simulation method (FEM). The effect of thermal buckling as well as the induced piezoelectric charge of HEMTs as a function of pressure and temperature is investigated. It was found out that diamond coated sensor better prevents the effect known as thermal buckling of the diaphragm at elevated temperature. Thermal buckling of diaphragms with 1, 5, 10 μm diamond coating occurs at temperature 40, 73 and 142 °C, respectively. Compared with original GaN diaphragm, diamond expanded the operational temperature range of the pressure sensor. Moreover, compared with the operational range of pressure sensor based on pure GaN diaphragm (up to 30 kPa), diamond coated modified MEMS sensors withstand relatively higher pressures (2.2 MPa). The maximum load on the diaphragm increased two times by adding only 1 μm of diamond coating.

  5. Investigating the functionality of diamond-like carbon films on an artificial heart diaphragm.

    PubMed

    Ohgoe, Yasuharu; Takada, Satoshi; Hirakuri, Kenji K; Tsuchimoto, Katsuya; Homma, Akihiko; Miyamatsu, Toshinobu; Saitou, Tomoyuki; Friedbacher, Gernot; Tatsumi, Eisuke; Taenaka, Yoshiyuki; Fukui, Yasuhiro

    2003-01-01

    In this study, the authors used diamond-like carbon film to coat the ellipsoidal diaphragm (polyurethane elastomer) of artificial hearts. The purpose of such coatings is to prevent the penetration of hydraulic silicone oil and blood through the diaphragm. To attach diamond-like carbon film uniformly on the diaphragm, the authors developed a special electrode. In estimating the uniformity of the diamond-like carbon film, the thickness was measured using a scanning electron microscope, and the characteristics of the diamond-like carbon film was investigated using infrared spectroscopy, Ar-laser Raman spectrophotometer, and x-ray photoelectron spectrometer. Also, to estimate the penetration of silicone oil through the diaphragm, in vitro testing was operated by alternating the pressure of silicone oil for 20 days. The authors were able to successfully attach uniform deposition of diamond-like carbon film on the ellipsoidal diaphragm. In this in vitro test, diamond-like carbon film was proven to have good stability. The amount of silicone oil penetration was improved by one-third using the diamond-like carbon film coating compared with an uncoated diaphragm. It is expected that through the use of the diamond-like carbon film, the dynamic compatibility of an artificial heart diaphragm will increase.

  6. Monitoring of Diaphragm Position in Pulsatile Pnumatic Ventricular Assisted Device by Ultrasound Sensor

    NASA Astrophysics Data System (ADS)

    Kamimura, Tadayuki; Homma, Akihiko; Tsukiya, Tomonori; Kakuta, Yukihide; Lee, Hwansung; Tatsumi, Eisuke; Taenaka, Yoshiyuki; Kitamura, Soichiro

    A new method using ultrasound sensors to detect the diaphragm position of a ventricular assist device (VAD) was proposed. Two small ultrasound sensors of 2.4mm diameter were attached to the outside surface of blood chamber of a pneumatic VAD. The receiving crystal received the ultrasound from the transmitting crystal reflected by the diaphragm. The diaphragm position was calculated by using geometric relation among two sensors and ultrasound propagation time. Validity of this method was evaluated in a mock circulation test under various driving conditions of VAD by comparing the ultrasound signals with driving pressure waveforms. The ultrasound signals could detect full-fill (FF) and full-eject (FE) status shortly before the spikes appeared on pressure waves, which are currently available to detect FE and FF but accompanies excessive extension of the diaphragm. This method would be helpful to avoid overloading of diaphragm. Linear correlation was observed between the output from VAD and blood volume calculated from the change of diaphragm position multiplied by the heart rate. This monitoring method of diaphragm of a VAD was proven to have advantages over the current method toward better control of a pneumatic VAD.

  7. Investigation of the Durability of a Diaphragm for a Total Artificial Heart.

    PubMed

    Gräf, Felix; Rossbroich, Ralf; Finocchiaro, Thomas; Steinseifer, Ulrich

    2016-10-01

    One of the most critical components regarding the durability of the ReinHeart total artificial heart (TAH) is its biocompatible diaphragm, which separates the drive unit from the ventricles. Hence, a durability tester was designed to investigate its required 5-year lifetime. The aim of this study was to prove the validity of accelerated testing of the polyurethane diaphragm. The durability tester allows simultaneous testing of 12 diaphragms and mimics physiological conditions. To accelerate the time of testing, it operates with an increased speed at a frequency of 8 Hz. To prove the correctness of this acceleration, a servo-hydraulic testing machine was used to study the effect of different frequencies and their corresponding loads. Thereby the viscoelastic behavior of the polyurethane was investigated. Additionally, high-speed video measurements were performed. The force against frequency and the high-speed video measurements showed constant behavior. In the range of 1-10 Hz, the maximum resulting forces varied by 3%, and the diaphragm movement was identical. Frequencies below 10 Hz allow a valid statement of the diaphragm's mechanical durability. Viscoelasticity of the polyurethane in the considered frequency-range is negligible. The accelerated durability test is applicable to polyurethane diaphragms, and the results are applicable to TAH use. The reliability of the diaphragm for a lifetime of 5 years was found to be 80% with a confidence of 62%. Copyright © 2015 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  8. Wt1 and β-catenin cooperatively regulate diaphragm development in the mouse

    PubMed Central

    Paris, Nicole D.; Coles, Garry L.; Ackerman, Kate G.

    2015-01-01

    The developing diaphragm consists of various differentiating cell types, many of which are not well characterized during organogenesis. One important but incompletely understood tissue, the diaphragmatic mesothelium, is distinctively present from early stages of development. Congenital Diaphragmatic Hernia (CDH) occurs in humans when diaphragm tissue is lost during development, resulting in high morbidity and mortality postnatally. We utilized a Wilms Tumor 1 (Wt1) mutant mouse model to investigate the involvement of the mesothelium in normal diaphragm signaling and development. Additionally, we developed and characterized a Wt1CreERT2 -driven β-catenin loss-of-function model of CDH after finding that canonical Wnt signaling and β-catenin are reduced in Wt1 mutant mesothelium. Mice with β-catenin loss or constitutive activation induced in the Wt1 lineage are only affected when tamoxifen injection occurs between E10.5 and E11.5, revealing a critical time-frame for Wt1/β-catenin activity. Conditional β-catenin loss phenocopies the Wt1 mutant diaphragm defect, while constitutive activation of β-catenin on the Wt1 mutant background is sufficient to close the diaphragm defect. Proliferation and apoptosis are affected, but primarily these genetic manipulations appear to lead to a change in normal diaphragm differentiation. Our data suggest a fundamental role for mesothelial signaling in proper formation of the diaphragm. PMID:26278035

  9. Effects of undernutrition on diaphragm fiber size, SDH activity, and fatigue resistance.

    PubMed

    Sieck, G C; Lewis, M I; Blanco, C E

    1989-05-01

    The influence of prolonged nutritional deprivation on the succinate dehydrogenase (SDH) activity and cross-sectional areas of individual fibers in the rat diaphragm and deep portion of the medial gastrocnemius (MGr) muscles was determined. Fatigue resistance of the diaphragm was measured by means of an in vitro nerve-muscle strip preparation. Fiber SDH activity and cross-sectional area were quantified by means of an image processing system. Diaphragm fatigue resistance was significantly improved in the nutritionally deprived (ND) group. In both muscles, nutritional deprivation resulted in a significant decrease in fiber cross-sectional area (both type I and II), type II fibers showing greater atrophy. The SDH activities of type I and II fibers in the diaphragm were not affected by nutritional deprivation. This contrasted with a significant decrease in the SDH activity of both type I and II fibers in the MGr of ND animals. An assessment of the interrelationships between fiber atrophy and fiber SDH activity revealed a greater effect of malnutrition on those diaphragm type II fibers that had the lowest relative SDH activities and the largest cross-sectional areas. By comparison, the effect of malnutrition on type I and II fibers in the MGr was nonselective with regard to fiber SDH activity. We conclude that the enhanced diaphragm fatigue resistance in the ND animals does not result from an increase in the oxidative capacity of muscle fibers and is best explained by the pattern of diaphragm muscle fiber atrophy.

  10. Quantification of Diaphragm Mechanics in Pompe Disease Using Dynamic 3D MRI

    PubMed Central

    Mogalle, Katja; Perez-Rovira, Adria; Ciet, Pierluigi; Wens, Stephan C. A.; van Doorn, Pieter A.; Tiddens, Harm A. W. M.; van der Ploeg, Ans T.; de Bruijne, Marleen

    2016-01-01

    Background Diaphragm weakness is the main reason for respiratory dysfunction in patients with Pompe disease, a progressive metabolic myopathy affecting respiratory and limb-girdle muscles. Since respiratory failure is the major cause of death among adult patients, early identification of respiratory muscle involvement is necessary to initiate treatment in time and possibly prevent irreversible damage. In this paper we investigate the suitability of dynamic MR imaging in combination with state-of-the-art image analysis methods to assess respiratory muscle weakness. Methods The proposed methodology relies on image registration and lung surface extraction to quantify lung kinematics during breathing. This allows for the extraction of geometry and motion features of the lung that characterize the independent contribution of the diaphragm and the thoracic muscles to the respiratory cycle. Results Results in 16 3D+t MRI scans (10 Pompe patients and 6 controls) of a slow expiratory maneuver show that kinematic analysis from dynamic 3D images reveals important additional information about diaphragm mechanics and respiratory muscle involvement when compared to conventional pulmonary function tests. Pompe patients with severely reduced pulmonary function showed severe diaphragm weakness presented by minimal motion of the diaphragm. In patients with moderately reduced pulmonary function, cranial displacement of posterior diaphragm parts was reduced and the diaphragm dome was oriented more horizontally at full inspiration compared to healthy controls. Conclusion Dynamic 3D MRI provides data for analyzing the contribution of both diaphragm and thoracic muscles independently. The proposed image analysis method has the potential to detect less severe diaphragm weakness and could thus be used to determine the optimal start of treatment in adult patients with Pompe disease in prospect of increased treatment response. PMID:27391236

  11. Quantification of Diaphragm Mechanics in Pompe Disease Using Dynamic 3D MRI.

    PubMed

    Mogalle, Katja; Perez-Rovira, Adria; Ciet, Pierluigi; Wens, Stephan C A; van Doorn, Pieter A; Tiddens, Harm A W M; van der Ploeg, Ans T; de Bruijne, Marleen

    2016-01-01

    Diaphragm weakness is the main reason for respiratory dysfunction in patients with Pompe disease, a progressive metabolic myopathy affecting respiratory and limb-girdle muscles. Since respiratory failure is the major cause of death among adult patients, early identification of respiratory muscle involvement is necessary to initiate treatment in time and possibly prevent irreversible damage. In this paper we investigate the suitability of dynamic MR imaging in combination with state-of-the-art image analysis methods to assess respiratory muscle weakness. The proposed methodology relies on image registration and lung surface extraction to quantify lung kinematics during breathing. This allows for the extraction of geometry and motion features of the lung that characterize the independent contribution of the diaphragm and the thoracic muscles to the respiratory cycle. Results in 16 3D+t MRI scans (10 Pompe patients and 6 controls) of a slow expiratory maneuver show that kinematic analysis from dynamic 3D images reveals important additional information about diaphragm mechanics and respiratory muscle involvement when compared to conventional pulmonary function tests. Pompe patients with severely reduced pulmonary function showed severe diaphragm weakness presented by minimal motion of the diaphragm. In patients with moderately reduced pulmonary function, cranial displacement of posterior diaphragm parts was reduced and the diaphragm dome was oriented more horizontally at full inspiration compared to healthy controls. Dynamic 3D MRI provides data for analyzing the contribution of both diaphragm and thoracic muscles independently. The proposed image analysis method has the potential to detect less severe diaphragm weakness and could thus be used to determine the optimal start of treatment in adult patients with Pompe disease in prospect of increased treatment response.

  12. Mechanical ventilation reduces rat diaphragm blood flow and impairs oxygen delivery and uptake.

    PubMed

    Davis, Robert T; Bruells, Christian S; Stabley, John N; McCullough, Danielle J; Powers, Scott K; Behnke, Bradley J

    2012-10-01

    Although mechanical ventilation is a life-saving intervention in patients suffering from respiratory failure, prolonged mechanical ventilation is often associated with numerous complications including problematic weaning. In contracting skeletal muscle, inadequate oxygen supply can limit oxidative phosphorylation resulting in muscular fatigue. However, whether prolonged mechanical ventilation results in decreased diaphragmatic blood flow and induces an oxygen supply-demand imbalance in the diaphragm remains unknown. We tested the hypothesis that prolonged controlled mechanical ventilation results in a time-dependent reduction in rat diaphragmatic blood flow and microvascular PO2 and that prolonged mechanical ventilation would diminish the diaphragm's ability to increase blood flow in response to muscular contractions. Compared to 30 mins of mechanical ventilation, 6 hrs of mechanical ventilation resulted in a 75% reduction in diaphragm blood flow (via radiolabeled microspheres), which did not occur in the intercostal muscle or high-oxidative hindlimb muscle (e.g., soleus). There was also a time-dependent decline in diaphragm microvascular PO2 (via phosphorescence quenching). Further, contrary to 30 mins of mechanical ventilation, 6 hrs of mechanical ventilation significantly compromised the diaphragm's ability to increase blood flow during electrically-induced contractions, which resulted in a ~80% reduction in diaphragm oxygen uptake. In contrast, 6 hrs of spontaneous breathing in anesthetized animals did not alter diaphragm blood flow or the ability to augment flow during electrically-induced contractions. These new and important findings reveal that prolonged mechanical ventilation results in a time-dependent decrease in the ability of the diaphragm to augment blood flow to match oxygen demand in response to contractile activity and could be a key contributing factor to difficult weaning. Although additional experiments are required to confirm, it is tempting to

  13. Pharmacological targeting of mitochondrial reactive oxygen species counteracts diaphragm weakness in chronic heart failure.

    PubMed

    Laitano, Orlando; Ahn, Bumsoo; Patel, Nikhil; Coblentz, Philip D; Smuder, Ashley J; Yoo, Jeung-Ki; Christou, Demetra D; Adhihetty, Peter J; Ferreira, Leonardo F

    2016-04-01

    Diaphragm muscle weakness in chronic heart failure (CHF) is caused by elevated oxidants and exacerbates breathing abnormalities, exercise intolerance, and dyspnea. However, the specific source of oxidants that cause diaphragm weakness is unknown. We examined whether mitochondrial reactive oxygen species (ROS) cause diaphragm weakness in CHF by testing the hypothesis that CHF animals treated with a mitochondria-targeted antioxidant have normal diaphragm function. Rats underwent CHF or sham surgery. Eight weeks after surgeries, we administered a mitochondrial-targeted antioxidant (MitoTEMPO; 1 mg·kg(-1)·day(-1)) or sterile saline (Vehicle). Left ventricular dysfunction (echocardiography) pre- and posttreatment and morphological abnormalities were consistent with the presence of CHF. CHF elicited a threefold (P < 0.05) increase in diaphragm mitochondrial H2O2 emission, decreased diaphragm glutathione content by 23%, and also depressed twitch and maximal tetanic force by ∼20% in Vehicle-treated animals compared with Sham (P < 0.05 for all comparisons). Diaphragm mitochondrial H2O2 emission, glutathione content, and twitch and maximal tetanic force were normal in CHF animals receiving MitoTEMPO. Neither CHF nor MitoTEMPO altered the diaphragm protein levels of antioxidant enzymes: superoxide dismutases (CuZn-SOD or MnSOD), glutathione peroxidase, and catalase. In both Vehicle and MitoTEMPO groups, CHF elicited a ∼30% increase in cytochrome c oxidase activity, whereas there were no changes in citrate synthase activity. Our data suggest that elevated mitochondrial H2O2 emission causes diaphragm weakness in CHF. Moreover, changes in protein levels of antioxidant enzymes or mitochondrial content do not seem to mediate the increase in mitochondria H2O2 emission in CHF and protective effects of MitoTEMPO. Copyright © 2016 the American Physiological Society.

  14. Diaphragm Abnormalities in Patients with End-Stage Heart Failure: NADPH Oxidase Upregulation and Protein Oxidation.

    PubMed

    Ahn, Bumsoo; Coblentz, Philip D; Beharry, Adam W; Patel, Nikhil; Judge, Andrew R; Moylan, Jennifer S; Hoopes, Charles W; Bonnell, Mark R; Ferreira, Leonardo F

    2016-01-01

    Patients with heart failure (HF) have diaphragm abnormalities that contribute to disease morbidity and mortality. Studies in animals suggest that reactive oxygen species (ROS) cause diaphragm abnormalities in HF. However, the effects of HF on ROS sources, antioxidant enzymes, and protein oxidation in the diaphragm of humans is unknown. NAD(P)H oxidase, especially the Nox2 isoform, is an important source of ROS in the diaphragm. Our main hypothesis was that diaphragm from patients with HF have heightened Nox2 expression and p47(phox) phosphorylation (marker of enzyme activation) that is associated with elevated protein oxidation. We collected diaphragm biopsies from patients with HF and brain-dead organ donors (controls). Diaphragm mRNA levels of Nox2 subunits were increased 2.5-4.6-fold over controls (p < 0.05). Patients also had increased protein levels of Nox2 subunits (p47(phox), p22(phox), and p67(phox)) and total p47(phox) phosphorylation, while phospho-to-total p47(phox) levels were unchanged. The antioxidant enzyme catalase was increased in patients, whereas glutathione peroxidase and superoxide dismutases were unchanged. Among markers of protein oxidation, carbonyls were increased by ~40% (p < 0.05) and 4-hydroxynonenal and 3-nitrotyrosines were unchanged in patients with HF. Overall, our findings suggest that Nox2 is an important source of ROS in the diaphragm of patients with HF and increases in levels of antioxidant enzymes are not sufficient to maintain normal redox homeostasis. The net outcome is elevated diaphragm protein oxidation that has been shown to cause weakness in animals.

  15. Diaphragm Abnormalities in Patients with End-Stage Heart Failure: NADPH Oxidase Upregulation and Protein Oxidation

    PubMed Central

    Ahn, Bumsoo; Coblentz, Philip D.; Beharry, Adam W.; Patel, Nikhil; Judge, Andrew R.; Moylan, Jennifer. S.; Hoopes, Charles W.; Bonnell, Mark R.; Ferreira, Leonardo F.

    2017-01-01

    Patients with heart failure (HF) have diaphragm abnormalities that contribute to disease morbidity and mortality. Studies in animals suggest that reactive oxygen species (ROS) cause diaphragm abnormalities in HF. However, the effects of HF on ROS sources, antioxidant enzymes, and protein oxidation in the diaphragm of humans is unknown. NAD(P)H oxidase, especially the Nox2 isoform, is an important source of ROS in the diaphragm. Our main hypothesis was that diaphragm from patients with HF have heightened Nox2 expression and p47phox phosphorylation (marker of enzyme activation) that is associated with elevated protein oxidation. We collected diaphragm biopsies from patients with HF and brain-dead organ donors (controls). Diaphragm mRNA levels of Nox2 subunits were increased 2.5–4.6-fold over controls (p < 0.05). Patients also had increased protein levels of Nox2 subunits (p47phox, p22phox, and p67phox) and total p47phox phosphorylation, while phospho-to-total p47phox levels were unchanged. The antioxidant enzyme catalase was increased in patients, whereas glutathione peroxidase and superoxide dismutases were unchanged. Among markers of protein oxidation, carbonyls were increased by ~40% (p < 0.05) and 4-hydroxynonenal and 3-nitrotyrosines were unchanged in patients with HF. Overall, our findings suggest that Nox2 is an important source of ROS in the diaphragm of patients with HF and increases in levels of antioxidant enzymes are not sufficient to maintain normal redox homeostasis. The net outcome is elevated diaphragm protein oxidation that has been shown to cause weakness in animals. PMID:28119629

  16. Redox Remodeling Is Pivotal in Murine Diaphragm Muscle Adaptation to Chronic Sustained Hypoxia.

    PubMed

    Lewis, Philip; Sheehan, David; Soares, Renata; Coelho, Ana Varela; O'Halloran, Ken D

    2016-07-01

    Mechanisms underpinning chronic sustained hypoxia (CH)-induced structural and functional adaptations in respiratory muscles are unclear despite the clinical relevance to respiratory diseases. The objectives of the present study were to thoroughly assess the putative role of CH-induced redox remodeling in murine diaphragm muscle over time and the subsequent effects on metabolic enzyme activities, catabolic signaling and catabolic processes, and diaphragm muscle contractile function. C57Bl6/J mice were exposed to normoxia or normobaric CH (fraction of inspired oxygen = 0.1) for 1, 3, or 6 weeks. A second cohort was exposed to CH for 6 weeks with and without antioxidant supplementation (tempol or N-acetyl cysteine). After CH exposure, we performed two-dimensional redox proteomics with mass spectrometry, enzyme activity assays, and cell-signaling assays on diaphragm homogenates. We also assessed diaphragm isotonic contractile and endurance properties ex vivo. Global protein redox changes in the diaphragm after CH are indicative of oxidation. Remodeling of proteins key to contractile, metabolic, and homeostatic functions was observed. Several oxidative and glycolytic enzyme activities were decreased by CH. Redox-sensitive chymotrypsin-like proteasome activity of the diaphragm was increased. CH decreased phospho-forkhead box O3a (FOXO3a) and phospho-mammalian target of rapamycin content. Hypoxia-inducible factor-1α and phospho-p38 mitogen-activated protein kinase content was increased in CH diaphragm, and this was attenuated by antioxidant treatment. CH exposure decreased force- and power-generating capacity of the diaphragm, and this was prevented by antioxidant supplementation with N-acetyl cysteine but not tempol. Redox remodeling is pivotal for diaphragm adaptation to CH, affecting metabolic activity, atrophy signaling, and functional performance. Antioxidant supplementation may be useful as an adjunctive therapy in respiratory-related diseases characterized by

  17. The action of the canine diaphragm on the lower ribs depends on activation.

    PubMed

    De Troyer, André

    2011-11-01

    Conventional wisdom maintains that the diaphragm lifts the lower ribs during isolated contraction. Recent studies in dogs have shown, however, that supramaximal, tetanic stimulation of the phrenic nerves displaces the lower ribs caudally and inward. In the present study, the hypothesis was tested that the action of the canine diaphragm on these ribs depends on the magnitude of muscle activation. Two experiments were performed. In the first, the C5 and C6 phrenic nerve roots were selectively stimulated in 6 animals with the airway occluded, and the level of diaphragm activation was altered by adjusting the stimulation frequency. In the second experiment, all the inspiratory intercostal muscles were severed in 7 spontaneously breathing animals, so that the diaphragm was the only muscle active during inspiration, and neural drive was increased by a succession of occluded breaths. The changes in airway opening pressure and the craniocaudal displacements of ribs 5 and 10 were measured in each animal. The data showed that 1) contraction of the diaphragm causes the upper ribs to move caudally; 2) during phrenic nerve stimulation, the lower ribs move cranially when the level of diaphragm activation is low, but they move caudally when the level of muscle activation is high and the entire rib cage is exposed to pleural pressure; and 3) during spontaneous diaphragm contraction, however, the lower ribs always move cranially, even when neural drive is elevated and the change in pleural pressure is large. It is concluded that the action of the diaphragm on the lower ribs depends on both the magnitude and the mode of muscle activation. These findings can reasonably explain the apparent discrepancies between previous studies. They also imply that observations made during phrenic nerve stimulation do not necessarily reflect the physiological action of the diaphragm.

  18. Effect of Elastase-induced Emphysema on the Force-generating Ability of the Diaphragm

    PubMed Central

    Supinski, Gerald S.; Kelsen, Steven G.

    1982-01-01

    The effect of emphysema on the ability of the diaphragm to generate force was examined in costal diaphragm muscle strips from 10 Golden hamsters killed 18 mo after intratracheal injection of pancreatic elastase in a dose producing hyperinflation (mean total lung capacity [TLC] = 163% of control) and generalized panacinar emphysema. 13 saline-injected normal animals served as controls. The time course of isometric tension and the effect of alterations in muscle fiber and sarcomere length on the isometric tension (T) generated in response to tetanizing electrical stimuli (length-tension [L-T] relationship) were examined. Elastase administration caused an increase in diaphragm muscle thickness and reduction in the length of costal diaphragm muscle fibers measured in situ. Emphysema significantly increased the maximum tetanic tension as a result of hypertrophy. Maximal tension corrected for increases in muscle cross-sectional area (T/cm2), however, was the same in emphysematous (E) and control (C) animals. Emphysema also shifted the muscle fiber L-T curve of the diaphragm but not of a control muscle, the soleus, toward shorter lengths. In contrast to the effects of E on the diaphragm muscle fiber L-T curve, the sarcomere L-T curve was the same in E and C. Since the length at which tension was maximal correlated closely with sarcomere number (r = 0.94; P < 0.001) reduction in the number of sarcomeres in series in muscles from emphysematous animals appeared to explain the shift in the muscle fiber L-T curve. We conclude that in elastase-induced emphysema adaptive changes both in diaphragm cross-sectional area and sarcomere number augment the force-generating ability of the diaphragm. We speculate that changes in sarcomere number compensate for alterations in muscle fiber length resulting from chronic hyperinflation of the thorax, while diaphragmatic muscle hypertrophy represents a response to changes in respiratory load and/or diaphragm configuration (La

  19. High-sensitivity Fabry-Perot interferometric pressure sensor based on a nanothick silver diaphragm.

    PubMed

    Xu, Feng; Ren, Dongxu; Shi, Xiaolong; Li, Can; Lu, Weiwei; Lu, Lu; Lu, Liang; Yu, Benli

    2012-01-15

    We present a fiber-optic extrinsic Fabry-Perot interferometer pressure sensor based on a nanothick silver diaphragm. The sensing diaphragm, with a thickness measured in a few hundreds of nanometers, is fabricated by the electroless plating method, which provides a simple fabrication process involving a high-quality diaphragm at a low cost. The sensor exhibits a relatively linear response within the pressure variation range of 0-50 kPa, with a high pressure sensitivity of 70.5 nm/kPa. This sensor is expected to have potential applications in the field of highly sensitive pressure sensors.

  20. Internally-cooled centrifugal compressor with cooling jacket formed in the diaphragm

    DOEpatents

    Moore, James J.; Lerche, Andrew H.; Moreland, Brian S.

    2014-08-26

    An internally-cooled centrifugal compressor having a shaped casing and a diaphragm disposed within the shaped casing having a gas side and a coolant side so that heat from a gas flowing though the gas side is extracted via the coolant side. An impeller disposed within the diaphragm has a stage inlet on one side and a stage outlet for delivering a pressurized gas to a downstream connection. The coolant side of the diaphragm includes at least one passageway for directing a coolant in a substantially counter-flow direction from the flow of gas through the gas side.

  1. Understanding the physiology of the asymptomatic diaphragm of the M1592V hyperkalemic periodic paralysis mouse

    PubMed Central

    Ammar, Tarek; Lin, Wei; Higgins, Amanda; Hayward, Lawrence J.

    2015-01-01

    The diaphragm muscle of hyperkalemic periodic paralysis (HyperKPP) patients and of the M1592V HyperKPP mouse model rarely suffers from the myotonic and paralytic symptoms that occur in limb muscles. Enigmatically, HyperKPP diaphragm expresses the mutant NaV1.4 channel and, more importantly, has an abnormally high Na+ influx similar to that in extensor digitorum longus (EDL) and soleus, two hindlimb muscles suffering from the robust HyperKPP abnormalities. The objective was to uncover the physiological mechanisms that render HyperKPP diaphragm asymptomatic. A first mechanism involves efficient maintenance of resting membrane polarization in HyperKPP diaphragm at various extracellular K+ concentrations compared with larger membrane depolarizations in HyperKPP EDL and soleus. The improved resting membrane potential (EM) results from significantly increased Na+ K+ pump electrogenic activity, and not from an increased protein content. Action potential amplitude was greater in HyperKPP diaphragm than in HyperKPP soleus and EDL, providing a second mechanism for the asymptomatic behavior of the HyperKPP diaphragm. One suggested mechanism for the greater action potential amplitude is lower intracellular Na+ concentration because of greater Na+ K+ pump activity, allowing better Na+ current during the action potential depolarization phase. Finally, HyperKPP diaphragm had a greater capacity to generate force at depolarized EM compared with wild-type diaphragm. Action potential amplitude was not different between wild-type and HyperKPP diaphragm. There was also no evidence for an increased activity of the Na+–Ca2+ exchanger working in the reverse mode in the HyperKPP diaphragm compared with the wild-type diaphragm. So, a third mechanism remains to be elucidated to fully understand how HyperKPP diaphragm generates more force compared with wild type. Although the mechanism for the greater force at depolarized resting EM remains to be determined, this study provides support for

  2. High-sensitivity fiber-tip pressure sensor with graphene diaphragm.

    PubMed

    Ma, Jun; Jin, Wei; Ho, Hoi Lut; Dai, Ji Yan

    2012-07-01

    A miniature fiber-tip pressure sensor was built by using an extremely thin graphene film as the diaphragm. The graphene also acts as a light reflector, which, in conjunction with the reflection at the fiber end-air interface, forms a low finesse Fabry-Perot interferometer. The graphene based sensor demonstrated pressure sensitivity over 39.4 nm/kPa with a diaphragm diameter of 25 μm. The use of graphene as diaphragm material would allow highly sensitive and compact fiber-tip sensors.

  3. Development, Fabrication, and Characterization of Hydrogel Based Piezoresistive Pressure Sensors with Perforated Diaphragms

    PubMed Central

    Orthner, M.P.; Buetefisch, Sebastian; Magda, J.; Rieth, L.W.; Solzbacher, F.

    2010-01-01

    Hydrogels have been demonstrated to swell in response to a number of external stimuli including pH, CO2, glucose, and ionic strength making them useful for detection of metabolic analytes. To measure hydrogel swelling pressure, we have fabricated and tested novel perforated diaphragm piezoresistive pressure sensor arrays that couple the pressure sensing diaphragm with a perforated semi-permeable membrane. The 2×2 arrays measure approximately 3 × 5 mm2 and consist of four square sensing diaphragms with widths of 1.0, 1.25, and 1.5 mm used to measure full scale pressures of 50, 25, and 5 kPa, respectively. An optimized geometry of micro pores was etched in silicon diaphragm to allow analyte diffusion into the sensor cavity where the hydrogel material is located. The 14-step front side wafer process was carried out by a commercial foundry service (MSF, Frankfurt (Oder), Germany) and diaphragm pores were created using combination of potassium hydroxide (KOH) etching and deep reactive ion etching (DRIE). Sensor characterization was performed (without the use of hydrogels) using a custom bulge testing apparatus that simultaneously measured deflection, pressure, and electrical output. Test results are used to quantify the sensor sensitivity and demonstrate proof-of-concept. Simulations showed that the sensitivity was slightly improved for the perforated diaphragm designs while empirical electrical characterization showed that the perforated diaphragm sensors were slightly less sensitive than solid diaphragm sensors. This discrepancy is believed to be due to the influence of compressive stress found within passivation layers and poor etching uniformity. The new perforated diaphragm sensors were fully functional with sensitivities ranging from 23 to 252 μV/V-kPa (FSO= 5 to 80mV), and show a higher nonlinearity at elevated pressures than identical sensors with solid diaphragms. Sensors (1.5×1.5 mm2) with perforated diaphragms (pores=40 μm) have a nonlinearity of

  4. Understanding the physiology of the asymptomatic diaphragm of the M1592V hyperkalemic periodic paralysis mouse.

    PubMed

    Ammar, Tarek; Lin, Wei; Higgins, Amanda; Hayward, Lawrence J; Renaud, Jean-Marc

    2015-12-01

    The diaphragm muscle of hyperkalemic periodic paralysis (HyperKPP) patients and of the M1592V HyperKPP mouse model rarely suffers from the myotonic and paralytic symptoms that occur in limb muscles. Enigmatically, HyperKPP diaphragm expresses the mutant NaV1.4 channel and, more importantly, has an abnormally high Na(+) influx similar to that in extensor digitorum longus (EDL) and soleus, two hindlimb muscles suffering from the robust HyperKPP abnormalities. The objective was to uncover the physiological mechanisms that render HyperKPP diaphragm asymptomatic. A first mechanism involves efficient maintenance of resting membrane polarization in HyperKPP diaphragm at various extracellular K(+) concentrations compared with larger membrane depolarizations in HyperKPP EDL and soleus. The improved resting membrane potential (EM) results from significantly increased Na(+) K(+) pump electrogenic activity, and not from an increased protein content. Action potential amplitude was greater in HyperKPP diaphragm than in HyperKPP soleus and EDL, providing a second mechanism for the asymptomatic behavior of the HyperKPP diaphragm. One suggested mechanism for the greater action potential amplitude is lower intracellular Na(+) concentration because of greater Na(+) K(+) pump activity, allowing better Na(+) current during the action potential depolarization phase. Finally, HyperKPP diaphragm had a greater capacity to generate force at depolarized EM compared with wild-type diaphragm. Action potential amplitude was not different between wild-type and HyperKPP diaphragm. There was also no evidence for an increased activity of the Na(+)-Ca(2+) exchanger working in the reverse mode in the HyperKPP diaphragm compared with the wild-type diaphragm. So, a third mechanism remains to be elucidated to fully understand how HyperKPP diaphragm generates more force compared with wild type. Although the mechanism for the greater force at depolarized resting EM remains to be determined, this study

  5. [Routes of resorption of peritoneal fluid in the diaphragm in liver cirrhosis (morphologic study)].

    PubMed

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

    1991-01-01

    The diaphragm peritoneum from 12 operated patients and 34 patients who died from liver cirrhosis with or without ascites was studied by means of light microscopy and electron transmission and scanning microscopy. Considerable lesions are found in the peritoneum: cuboidization of mesothelial cells, basal membrane thickening, dilation of stomata, lymphatic lacunae and collectors lumina. Liver cirrhosis with ascites is frequently followed by lymphatic vessels thrombosis and firm attachment of the diaphragm to the liver resulting in the inhibition of the ascitic liquid elimination. Thus both the enhancement of liquid transudation into the abdominal cavity and the disturbance of the drainage function of the diaphragm peritoneum take place.

  6. Delayed Traumatic Diaphragm Hernia after Thoracolumbar Fracture in a Patient with Ankylosing Spondylitis

    PubMed Central

    Lee, Hyoun-Ho; Kim, Sang Woo; Jung, Young Jin

    2015-01-01

    Traumatic diaphragm hernia can occur in rare cases and generally accompanies thoracic or abdominal injuries. When suffering from ankylosing spondylitis, a small force can develop into vertebral fracture and an adjacent structural injury, and lead to diaphragm hernia without accompanying concomitant thoracoabdominal injury. A high level of suspicion may be a most reliable diagnostic tool in the detection of a diaphragm injury, and we need to keep in mind a possibility in a patient with ankylosing spondylitis and a thoracolumbar fracture, even in the case of minor trauma. PMID:25733996

  7. Diaphragm flange and method for lowering particle beam impedance at connected beam tubes of a particle accelerator

    DOEpatents

    Biallas, George Herman

    2017-07-04

    A diaphragm flange for connecting the tubes in a particle accelerator while minimizing beamline impedance. The diaphragm flange includes an outer flange and a thin diaphragm integral with the outer flange. Bolt holes in the outer flange provide a means for bolting the diaphragm flange to an adjacent flange or beam tube having a mating bolt-hole pattern. The diaphragm flange includes a first surface for connection to the tube of a particle accelerator beamline and a second surface for connection to a CF flange. The second surface includes a recessed surface therein and a knife-edge on the recessed surface. The diaphragm includes a thickness that enables flexing of the integral diaphragm during assembly of beamline components. The knife-edge enables compression of a soft metal gasket to provide a leak-tight seal.

  8. An experimental evaluation of metallic diaphragms for positive fuel expulsion in the atmosphere explorer hydrazine propulsion subsystem

    NASA Technical Reports Server (NTRS)

    Woodruff, W. L.

    1973-01-01

    Four Arde conospheroid metallic diaphragms were tested to evaluate their capability for use in the orbit adjust propulsion subsystem (OAPS) of the Explorer spacecraft. The diaphragms will be used for positive propellant expulsion and spacecraft center of mass control. A leak-free cycle life capability of nine reversals was demonstrated. The diaphragms rolled smoothly from ring to ring in a predictable manner on the first reversal. Varying amounts of diaphragm cocking and ring skipping were observed on subsequent reversals. The diaphragm pressure differential did not exceed 7 N/sq cm during any reversal. Cycle life capability, reversal mode, and pressure differential were not affected by sudden reversals, environmental tests, or 18,000 partial reversals. An expulsion efficiency of approximately 97 percent was demonstrated. The results of these tests show that metallic diaphragms can be used as an effective means of positive fuel expulsion; however, to achieve spacecraft center of mass control, the diaphragm must not be reversed prior to flight.

  9. Full-scale shear wall tests for force transfer around openings

    Treesearch

    Tom Skaggs; Borjen Yeh; Frank Lam; Douglas Rammer; James Wacker

    2010-01-01

    Wood structural panel sheathed shear walls and diaphragms are the primary lateral-load resisting elements in wood-frame construction. The historical performance of light-frame structures in North America are very good due, in part, to model building codes that are designed to preserve life safety, as well as the inherent redundancy of wood-frame construction using wood...

  10. Modelling Force Transfer Around Openings of Full-Scale Shear Walls

    Treesearch

    Tom Skaggs; Borjen Yeh; Frank Lam; Minghao Li; Doug Rammer; James Wacker

    2011-01-01

    Wood structural panel (WSP) sheathed shear walls and diaphragms are the primary lateralload-resisting elements in wood-frame construction. The historical performance of lightframe structures in North America has been very good due, in part, to model building codes that are designed to preserve life safety. These model building codes have spawned continual improvement...

  11. Wall turbulence without walls

    NASA Astrophysics Data System (ADS)

    Mizuno, Yoshinori; Jimenez, Javier

    2008-11-01

    Direct numerical simulations are presented of isolated logarithmic layers without an underlying buffer zone. They are implemented by enforcing artificial boundary conditions within the logarithmic layer which are synthesized from values from the interior of the flow. As an example, simulations of a half-channel employing this technique are discussed. The results exhibit logarithmic mean velocity profiles, and velocity fluctuation intensities that are similar to those obtained by the full DNS of half or full channels. Those results strongly suggest that the formation of a logarithmic layer is not overly dependent on the presence of a near-wall region, and that such a flow can exist by itself. The technique enables us to perform conceptual experiments to clarify what is essential to the logarithmic layer. For example, preliminary results show that the logarithmic layer cannot be created only by a non-uniform shear, and requires a spatial gradient of the scales of the fluctuations. Somewhat surprisingly, some simulations result in Kármán constants fairly different from κ=0.4, providing clues to what determines κ in real wall turbulence.

  12. Anatomic connections of the diaphragm: influence of respiration on the body system

    PubMed Central

    Bordoni, Bruno; Zanier, Emiliano

    2013-01-01

    The article explains the scientific reasons for the diaphragm muscle being an important crossroads for information involving the entire body. The diaphragm muscle extends from the trigeminal system to the pelvic floor, passing from the thoracic diaphragm to the floor of the mouth. Like many structures in the human body, the diaphragm muscle has more than one function, and has links throughout the body, and provides the network necessary for breathing. To assess and treat this muscle effectively, it is necessary to be aware of its anatomic, fascial, and neurologic complexity in the control of breathing. The patient is never a symptom localized, but a system that adapts to a corporeal dysfunction. PMID:23940419

  13. Design of Diaphragm and Coil for Stable Performance of an Eddy Current Type Pressure Sensor

    PubMed Central

    Lee, Hyo Ryeol; Lee, Gil Seung; Kim, Hwa Young; Ahn, Jung Hwan

    2016-01-01

    The aim of this work was to develop an eddy current type pressure sensor and investigate its fundamental characteristics affected by the mechanical and electrical design parameters of sensor. The sensor has two key components, i.e., diaphragm and coil. On the condition that the outer diameter of sensor is 10 mm, two key parts should be designed so as to keep a good linearity and sensitivity. Experiments showed that aluminum is the best target material for eddy current detection. A round-grooved diaphragm is suggested in order to measure more precisely its deflection caused by applied pressures. The design parameters of a round-grooved diaphragm can be selected depending on the measuring requirements. A developed pressure sensor with diaphragm of t = 0.2 mm and w = 1.05 mm was verified to measure pressure up to 10 MPa with very good linearity and errors of less than 0.16%. PMID:27376306

  14. Diaphragm weakness as a cause of breathlessness after anatomically distant surgery

    PubMed Central

    Moore, A; Moxham, J; Polkey, M

    2005-01-01

    The case histories are presented of two patients in whom breathlessness developed following surgery to an anatomically distant site. Respiratory muscle testing demonstrated diaphragm weakness in both patients. PMID:16135683

  15. Lead-Free Piezoelectric Diaphragm Biosensors Based on Micro-Machining Technology and Chemical Solution Deposition

    PubMed Central

    Li, Xiaomeng; Wu, Xiaoqing; Shi, Peng; Ye, Zuo-Guang

    2016-01-01

    In this paper, we present a new approach to the fabrication of integrated silicon-based piezoelectric diaphragm-type biosensors by using sodium potassium niobate-silver niobate (0.82KNN-0.18AN) composite lead-free thin film as the piezoelectric layer. The piezoelectric diaphragms were designed and fabricated by micro-machining technology and chemical solution deposition. The fabricated device was very sensitive to the mass changes caused by various targets attached on the surface of diaphragm. The measured mass sensitivity value was about 931 Hz/μg. Its good performance shows that the piezoelectric diaphragm biosensor can be used as a cost-effective platform for nucleic acid testing. PMID:26771617

  16. Lead-Free Piezoelectric Diaphragm Biosensors Based on Micro-Machining Technology and Chemical Solution Deposition.

    PubMed

    Li, Xiaomeng; Wu, Xiaoqing; Shi, Peng; Ye, Zuo-Guang

    2016-01-12

    In this paper, we present a new approach to the fabrication of integrated silicon-based piezoelectric diaphragm-type biosensors by using sodium potassium niobate-silver niobate (0.82KNN-0.18AN) composite lead-free thin film as the piezoelectric layer. The piezoelectric diaphragms were designed and fabricated by micro-machining technology and chemical solution deposition. The fabricated device was very sensitive to the mass changes caused by various targets attached on the surface of diaphragm. The measured mass sensitivity value was about 931 Hz/μg. Its good performance shows that the piezoelectric diaphragm biosensor can be used as a cost-effective platform for nucleic acid testing.

  17. Seismic design repair and retrofit strategies for steel roof deck diaphragms

    NASA Astrophysics Data System (ADS)

    Franquet, John-Edward

    Structural engineers will often rely on the roof diaphragm to transfer lateral seismic loads to the bracing system of single-storey structures. The implementation of capacity-based design in the NBCC 2005 has caused an increase in the diaphragm design load due to the need to use the probable capacity of the bracing system, thus resulting in thicker decks, closer connector patterns and higher construction costs. Previous studies have shown that accounting for the in-plane flexibility of the diaphragm when calculating the overall building period can result in lower seismic forces and a more cost-efficient design. However, recent studies estimating the fundamental period of single storey structures using ambient vibration testing showed that the in-situ approximation was much shorter than that obtained using analytical means. The difference lies partially in the diaphragm stiffness characteristics which have been shown to decrease under increasing excitation amplitude. Using the diaphragm as the energy-dissipating element in the seismic force resisting system has also been investigated as this would take advantage of the diaphragm's ductility and limited overstrength; thus, lower capacity based seismic forces would result. An experimental program on 21.0m by 7.31m diaphragm test specimens was carried out so as to investigate the dynamic properties of diaphragms including the stiffness, ductility and capacity. The specimens consisted of 20 and 22 gauge panels with nailed frame fasteners and screwed sidelap connections as well a welded and button-punch specimen. Repair strategies for diaphragms that have previously undergone inelastic deformations were devised in an attempt to restitute the original stiffness and strength and were then experimentally evaluated. Strength and stiffness experimental estimations are compared with those predicted with the Steel Deck Institute (SDI) method. A building design comparative study was also completed. This study looks at the

  18. Embossed Teflon AF Laminate Membrane Microfluidic Diaphragm Valves

    NASA Technical Reports Server (NTRS)

    Willis, Peter; Hunt, Brian; White,Victor; Grunthaner, Frank

    2008-01-01

    A microfluidic system has been designed to survive spaceflight and to function autonomously on the Martian surface. It manipulates microscopic quantities of liquid water and performs chemical analyses on these samples to assay for the presence of molecules associated with past or present living processes. This technology lies at the core of the Urey Instrument, which is scheduled for inclusion on the Pasteur Payload of the ESA ExoMars rover mission in 2013. Fabrication processes have been developed to make the microfabricated Teflon-AF microfluidic diaphragm pumps capable of surviving extreme temperature excursions before and after exposure to liquid water. Two glass wafers are etched with features and a continuous Teflon membrane is sandwiched between them (see figure). Single valves are constructed using this geometry. The microfabricated devices are then post processed by heating the assembled device while applying pneumatic pressure to force the Teflon diaphragm against the valve seat while it is softened. After cooling the device, the embossed membrane retains this new shape. This solves previous problems with bubble introduction into the fluid flow where deformations of the membrane at the valve seat occurred during device bonding at elevated temperatures (100-150 C). The use of laminated membranes containing commercial Teflon AF 2400 sheet sandwiched between spun Teflon AF 1600 layers performed best, and were less gas permeable than Teflon AF 1600 membranes on their own. Spinning Teflon AF 1600 solution (6 percent in FLOURINERT(Registered TradeMark) FC40 solvent, 3M Company) at 500 rpm for 1.5 seconds, followed by 1,000 rpm for 3 seconds onto Borofloat glass wafers, results in a 10-micron-thick film of extremely smooth Teflon AF. This spinning process is repeated several times on flat, blank, glass wafers in order to gradually build a thick, smooth membrane. After running this process at least five times, the wafer and Teflon coating are heated under vacuum

  19. A new scenario of the evolutionary derivation of the mammalian diaphragm from shoulder muscles.

    PubMed

    Hirasawa, Tatsuya; Kuratani, Shigeru

    2013-05-01

    The evolutionary origin of the diaphragm remains unclear, due to the lack of a comparable structure in other extant taxa. However, recent researches into the developmental mechanism of this structure have yielded new insights into its origin. Here we summarize current understanding regarding the development of the diaphragm, and present a possible scenario for the evolutionary acquisition of this uniquely mammalian structure. Recent developmental analyses indicate that the diaphragm and forelimb muscles are derived from a shared cell population during embryonic development. Therefore, the embryonic positions of forelimb muscle progenitors, which correspond to the position of the brachial plexus, likely played an important role in the evolution of the diaphragm. We surveyed the literature to reexamine the position of the brachial plexus among living amniotes and confirmed that the cervico-thoracic transition in ribs reflects the brachial plexus position. Using this osteological correlate, we concluded that the anterior borders of the brachial plexuses in the stem synapsids were positioned at the level of the fourth spinal nerve, suggesting that the forelimb buds were laid in close proximity of the infrahyoid muscles. The topology of the phrenic and suprascapular nerves of mammals is similar to that of subscapular and supracoracoid nerves, respectively, of the other amniotes, suggesting that the diaphragm evolved from a muscle positioned medial to the pectoral girdle (cf. subscapular muscle). We hypothesize that the diaphragm was acquired in two steps: first, forelimb muscle cells were incorporated into tissues to form a primitive diaphragm in the stem synapsid grade, and second, the diaphragm in cynodonts became entrapped in the region controlled by pulmonary development. © 2013 Anatomical Society.

  20. Mitochondria-targeted antioxidants protect against mechanical ventilation-induced diaphragm weakness.

    PubMed

    Powers, Scott K; Hudson, Matthew B; Nelson, W Bradley; Talbert, Erin E; Min, Kisuk; Szeto, Hazel H; Kavazis, Andreas N; Smuder, Ashley J

    2011-07-01

    Mechanical ventilation is a life-saving intervention used to provide adequate pulmonary ventilation in patients suffering from respiratory failure. However, prolonged mechanical ventilation is associated with significant diaphragmatic weakness resulting from both myofiber atrophy and contractile dysfunction. Although several signaling pathways contribute to diaphragm weakness during mechanical ventilation, it is established that oxidative stress is required for diaphragmatic weakness to occur. Therefore, identifying the site(s) of mechanical ventilation- induced reactive oxygen species production in the diaphragm is important. These experiments tested the hypothesis that elevated mitochondrial reactive oxygen species emission is required for mechanical ventilation-induced oxidative stress, atrophy, and contractile dysfunction in the diaphragm. Cause and effect was determined by preventing mechanical ventilation-induced mitochondrial reactive oxygen species emission in the diaphragm of rats using a novel mitochondria-targeted antioxidant (SS-31). None. Compared to mechanically ventilated animals treated with saline, animals treated with SS-31 were protected against mechanical ventilation-induced mitochondrial dysfunction, oxidative stress, and protease activation in the diaphragm. Importantly, treatment of animals with the mitochondrial antioxidant also protected the diaphragm against mechanical ventilation-induced myofiber atrophy and contractile dysfunction. These results reveal that prevention of mechanical ventilation-induced increases in diaphragmatic mitochondrial reactive oxygen species emission protects the diaphragm from mechanical ventilation-induced diaphragmatic weakness. This important new finding indicates that mitochondria are a primary source of reactive oxygen species production in the diaphragm during prolonged mechanical ventilation. These results could lead to the development of a therapeutic intervention to impede mechanical ventilation

  1. A new scenario of the evolutionary derivation of the mammalian diaphragm from shoulder muscles

    PubMed Central

    Hirasawa, Tatsuya; Kuratani, Shigeru

    2013-01-01

    The evolutionary origin of the diaphragm remains unclear, due to the lack of a comparable structure in other extant taxa. However, recent researches into the developmental mechanism of this structure have yielded new insights into its origin. Here we summarize current understanding regarding the development of the diaphragm, and present a possible scenario for the evolutionary acquisition of this uniquely mammalian structure. Recent developmental analyses indicate that the diaphragm and forelimb muscles are derived from a shared cell population during embryonic development. Therefore, the embryonic positions of forelimb muscle progenitors, which correspond to the position of the brachial plexus, likely played an important role in the evolution of the diaphragm. We surveyed the literature to reexamine the position of the brachial plexus among living amniotes and confirmed that the cervico-thoracic transition in ribs reflects the brachial plexus position. Using this osteological correlate, we concluded that the anterior borders of the brachial plexuses in the stem synapsids were positioned at the level of the fourth spinal nerve, suggesting that the forelimb buds were laid in close proximity of the infrahyoid muscles. The topology of the phrenic and suprascapular nerves of mammals is similar to that of subscapular and supracoracoid nerves, respectively, of the other amniotes, suggesting that the diaphragm evolved from a muscle positioned medial to the pectoral girdle (cf. subscapular muscle). We hypothesize that the diaphragm was acquired in two steps: first, forelimb muscle cells were incorporated into tissues to form a primitive diaphragm in the stem synapsid grade, and second, the diaphragm in cynodonts became entrapped in the region controlled by pulmonary development. PMID:23448284

  2. Diaphragm and intercostal muscle activity following mid-cervical spinal cord contusion in the rat.

    PubMed

    Wen, Ming-Han; Lee, Kun-Ze

    2017-08-26

    The present study was designed to investigate the diaphragm and intercostal muscle activity following unilateral mid-cervical spinal cord contusion in rats. Electromyogram (EMG) activity of the bilateral diaphragm and T2 intercostal muscle was measured in anesthetized and spontaneously breathing rats. Unilateral mid-cervical contusion caused an immediate reduction in inspiratory bursting in the bilateral diaphragm and intercostal muscles. From 3 days to 8 weeks post-contusion, the contused animals displayed significantly lower tidal volume than uninjured animals, regardless of the time point after injury. The burst amplitude of the contralateral diaphragm EMG was augmented in contused animals at 3 days post-injury. When the data were normalized by the maximal response during hypoxic-hypercapnic challenge (12-13 % O2, 3-4 % CO2), the ipsilateral diaphragm EMG of contused animals was greater than that of uninjured animals at 3 days and 2 weeks post-injury. Moreover, hypoxia-hypercapnia induced increases in ipsilateral diaphragm EMG activity were blunted in contused animals at 2 weeks post-injury but recovered at 8 weeks post-injury. Bilateral diaphragm EMG activity in contused animals was comparable to uninjured animals at 8 weeks post-injury. Notably, intercostal muscle activity was not substantially changed by mid-cervical spinal cord contusion from 3 days to 8 weeks post-contusion. These results suggest that mid-cervical spinal contusion induces a compensatory increase in contralateral diaphragmatic activity and greater utilization of a percentage of maximal inspiratory activity in the ipsilateral diaphragm. The maintenance of intercostal muscle activity may enable the animal to sustain essential breathing capacity following cervical spinal cord injury.

  3. Measurement of thermal expansion coefficient of graphene diaphragm using optical fiber Fabry-Perot interference

    NASA Astrophysics Data System (ADS)

    Li, Cheng; Liu, Qianwen; Peng, Xiaobin; Fan, Shangchun

    2016-07-01

    Application of the Fabry-Perot (FP) interference method for determining the coefficient of thermal expansion (CTE) of a graphene diaphragm is investigated in this paper. A miniature extrinsic FP interferometric (EFPI) sensor was fabricated by using an approximate 8-layer graphene diaphragm. The extremely thin diaphragm was transferred onto the endface of a ferrule with an inner diameter of 125 μm, and van der Waals interactions between the graphene diaphragm and its substrate created a low finesse FP interferometer with a cavity length of 36.13 μm. Double reference FP cavities using two cleaved optical fibers as reflectors were also constructed to differentially cancel the thermal expansion effects of the trapped gas and adhesive material. A temperature test demonstrated an approximate cavity length change of 166.1 nm °C-1 caused by film thermal expansion in the range of 20-60 °C. Then along with the established thermal deformation model of the suspended circular diaphragm, the calculated CTE ranging from  -9.98  ×  10-6 K-1 to  -2.09  ×  10-6 K-1 conformed well to the previously measured results. The proposed method would be applicable in other types of elastic materials as the sensitive diaphragm of an EFPI sensor over a wide temperature range.

  4. Estimation of vibration frequency of loudspeaker diaphragm by parallel phase-shifting digital holography

    NASA Astrophysics Data System (ADS)

    Kakue, T.; Endo, Y.; Shimobaba, T.; Ito, T.

    2014-11-01

    We report frequency estimation of loudspeaker diaphragm vibrating at high speed by parallel phase-shifting digital holography which is a technique of single-shot phase-shifting interferometry. This technique records multiple phaseshifted holograms required for phase-shifting interferometry by using space-division multiplexing. We constructed a parallel phase-shifting digital holography system consisting of a high-speed polarization-imaging camera. This camera has a micro-polarizer array which selects four linear polarization axes for 2 × 2 pixels. We set a loudspeaker as an object, and recorded vibration of diaphragm of the loudspeaker by the constructed system. By the constructed system, we demonstrated observation of vibration displacement of loudspeaker diaphragm. In this paper, we aim to estimate vibration frequency of the loudspeaker diaphragm by applying the experimental results to frequency analysis. Holograms consisting of 128 × 128 pixels were recorded at a frame rate of 262,500 frames per second by the camera. A sinusoidal wave was input to the loudspeaker via a phone connector. We observed displacement of the loudspeaker diaphragm vibrating by the system. We also succeeded in estimating vibration frequency of the loudspeaker diaphragm by applying frequency analysis to the experimental results.

  5. Action of the isolated canine diaphragm on the lower ribs at high lung volumes

    PubMed Central

    De Troyer, André; Wilson, Theodore A

    2014-01-01

    The normal diaphragm has an inspiratory action on the lower ribs, but subjects with chronic obstructive pulmonary disease commonly have an inward displacement of the lateral portions of the lower rib cage during inspiration. This paradoxical displacement, conventionally called ‘Hoover's sign’, has traditionally been attributed to the direct action of radially oriented diaphragmatic muscle fibres. In the present study, the inspiratory intercostal muscles in all interspaces in anaesthetized dogs were severed so that the diaphragm was the only muscle active during inspiration. The displacements of the lower ribs along the craniocaudal and laterolateral axes and the changes in pleural pressure (ΔPpl) and transdiaphragmatic pressure were measured during occluded breaths and mechanical ventilation at different lung volumes between functional residual capacity (FRC) and total lung capacity. From these data, the separate effects on rib displacement of ΔPpl and of the force exerted by the diaphragm on the ribs were determined. Isolated spontaneous diaphragm contraction at FRC displaced the lower ribs cranially and outward, but this motion was progressively reversed into a caudal and inward motion as lung volume increased. However, although the force exerted by the diaphragm on the ribs decreased with increasing volume, it continued to displace the ribs cranially and outward. These observations suggest that Hoover's sign is usually caused by the decrease in the zone of apposition and, thus, by the dominant effect of ΔPpl on the lower ribs, rather than an inward pull from the diaphragm. PMID:25063819

  6. An analytical solution for curved piezoelectric micromachined ultrasonic transducers with spherically shaped diaphragms.

    PubMed

    Sammoura, Firas; Akhbari, Sina; Lin, Liwei

    2014-09-01

    An analytical solution for piezoelectrically actuated spherically shaped diaphragms has been developed to study their dynamic behavior with targeted applications in piezoelectric micromachined ultrasonic transducers (pMUT). The analytical model starts with a curved pMUT composed of a piezoelectric diaphragm with a nominal radius in size, a radius of curvature in shape, and under both possible actuation sources of radial pressure and electric potential. The diaphragm has the piezoelectric material polarized in the direction perpendicular to its surface and sandwiched between two metal electrodes. When an electric field is applied between the two electrodes, the in-plane piezoelectric strain can cause larger out-of-plane deflections than a flat unimorph piezoelectric diaphragm because of the diaphragm's spherical curvature with a clamped periphery for high electromechanical coupling factor. Key performance parameters, including mechanical mode shapes, resonant frequencies, dynamic responses, and displacements, with respect to the curvature and size of the diaphragm have been investigated. Both analytical derivations and numerical simulations using finite element analysis have been performed for the optimal design of the electromechanical coupling factor, with varying factors such as mechanical resonant frequency, radius of curvature, nominal radius, and thickness. As such, this work provides theoretical foundations for the design of curved pMUTs with high electromechanical coupling factor compared with planar-shape pMUTs.

  7. Microwave ablation of hepatic tumors abutting the diaphragm is safe and effective.

    PubMed

    Smolock, Amanda R; Lubner, Meghan G; Ziemlewicz, Timothy J; Hinshaw, J Louis; Kitchin, Douglas R; Brace, Christopher L; Lee, Fred T

    2015-01-01

    The purpose of this study was to evaluate the incidence of clinically significant diaphragmatic injuries and local tumor progression after microwave ablation of hepatic tumors abutting the diaphragm. This retrospective study included 55 peripheral hepatic tumors abutting the diaphragm treated by microwave ablation versus a control group of 15 centrally located tumors. Treated tumors were further subdivided according to the use of artificial ascites (fluid vs no fluid) and whether instilled fluid achieved displacement of the liver surface away from the diaphragm (displaced vs nondisplaced). Measurements of tumor size, distance to the diaphragm, ablation zone size, displacement distance, length of the ablation zone along the liver capsule, diaphragm thickness, diaphragmatic hernia, and local tumor progression were made on pre- and postablation CT and MRI. The electronic medical record was reviewed for patient self-reported pain scores and other symptoms. Data were analyzed by use of the Kruskal-Wallis and Fisher exact tests. There were no cases of diaphragmatic hernia in peripheral or central tumors. Postablation diaphragm thickness was higher in peripheral hepatic tumors than in control tumors. Peripheral tumors had an overall higher incidence of postprocedure shoulder pain (18% vs 0%) and local tumor progression (5.5% vs 0%) compared with control tumors, but these differences did not achieve statistical significance (p = 0.2 and p = 1, respectively). Our study shows that microwave ablation of peridiaphragmatic hepatic tumors is safe, without incidence of diaphragmatic hernia, and can be performed with a low rate of local tumor progression.

  8. Vascular-specific growth factor mRNA levels in the human diaphragm.

    PubMed

    Alexopoulou, Christina; Mitrouska, Ioanna; Arvanitis, Dimitrios; Tzanakis, Nikolaos; Chalkiadakis, George; Melissas, John; Zervou, Maria; Siafakas, Nikolaos

    2005-01-01

    Angiogenesis is an adaptation mechanism of skeletal muscles to increased load. Animal data have shown increased vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and transforming growth factor-beta(1) (TGF-beta(1)) mRNA levels in the diaphragm as a result of increased minute ventilation, but there are no data concerning the human diaphragm. The purpose of this study was to investigate the VEGF, bFGF, TGF-beta(1) mRNA levels in the human diaphragm of normal subjects and patients with altered respiratory mechanics. We studied 9 patients with chronic obstructive pulmonary disease (COPD), 4 obese patients and 12 controls. We performed multiplex semiquantitative reverse transcription polymerase chain reaction to determine the VEGF, bFGF and TGF-beta(1) mRNA levels in specimens taken from their diaphragm. VEGF mRNA levels were 18% higher in COPD patients compared with controls (p = 0.04), while for the obese patients, these levels were not statistically significantly different. bFGF and TGF-beta(1) mRNA levels in COPD patients or obese individuals compared with controls did not differ significantly either. The results of our study showed that TGF-beta(1), VEGF and bFGF mRNA was detected in the human diaphragm. The VEGF levels were higher in COPD patients than in normal subjects. This upregulation of VEGF may suggest an enhancement of angiogenesis in the diaphragm in COPD patients.

  9. Biomechanical strength of two laparoscopic herniorrhaphy techniques in a cadaveric diaphragm and in a neoprene model.

    PubMed

    Fugazzi, R W; Fransson, B A; Davis, H M; Gay, J P

    2013-01-01

    Our objectives were to 1) Biomechanically compare two laparoscopic repair techniques; an automated suturing device and a stapling device to conventional open suturing, and 2) Evaluate a model for canine diaphragmatic tissue by comparisons to similar constructs in fresh diaphragms. We hypothesized that automated suturing is biomechanically superior to laparoscopic stapling in dogs, and that neoprene defect repair is an acceptable model for experimental cadaveric diaphragm herniorrhaphy. Samples of diaphragm pars costalis were prepared with defects mimicking radial muscular tears. Defects were repaired using conventional open suturing, laparoscopic automated suturing, and laparoscopic stapling techniques. Similar defects were created in 6.35 mm thick single-sided neoprene. Samples were biomechanically tested across a biaxial loading machine. Site and mode of failure were noted for all samples. In both the diaphragm muscle and neoprene, the laparoscopic stapling technique was significantly weaker. The neoprene model showed a similar failure load as the diaphragm in both laparoscopic techniques, and a similar stiffness in an open-sutured and stapled diaphragm compared to the neoprene samples. Site and mode of failure in neoprene were similar to cadaveric diaphragmatic tissue, but the overall median load-to-failure was higher for the neoprene. The strength of laparoscopically repaired simulated diaphragmatic hernias was higher with an automated suture technique than with a stapling technique. Neoprene defect repair is an acceptable model of canine diaphragmatic herniorrhaphy for biomechanical testing.

  10. Action of the isolated canine diaphragm on the lower ribs at high lung volumes.

    PubMed

    De Troyer, André; Wilson, Theodore A

    2014-10-15

    The normal diaphragm has an inspiratory action on the lower ribs, but subjects with chronic obstructive pulmonary disease commonly have an inward displacement of the lateral portions of the lower rib cage during inspiration. This paradoxical displacement, conventionally called 'Hoover's sign', has traditionally been attributed to the direct action of radially oriented diaphragmatic muscle fibres. In the present study, the inspiratory intercostal muscles in all interspaces in anaesthetized dogs were severed so that the diaphragm was the only muscle active during inspiration. The displacements of the lower ribs along the craniocaudal and laterolateral axes and the changes in pleural pressure (∆Ppl) and transdiaphragmatic pressure were measured during occluded breaths and mechanical ventilation at different lung volumes between functional residual capacity (FRC) and total lung capacity. From these data, the separate effects on rib displacement of ∆Ppl and of the force exerted by the diaphragm on the ribs were determined. Isolated spontaneous diaphragm contraction at FRC displaced the lower ribs cranially and outward, but this motion was progressively reversed into a caudal and inward motion as lung volume increased. However, although the force exerted by the diaphragm on the ribs decreased with increasing volume, it continued to displace the ribs cranially and outward. These observations suggest that Hoover's sign is usually caused by the decrease in the zone of apposition and, thus, by the dominant effect of ∆Ppl on the lower ribs, rather than an inward pull from the diaphragm.

  11. 31P-NMR study of resting in vitro rat diaphragm exposed to hypercapnia.

    PubMed

    Fitzgerald, R S; Howell, S; Jacobus, W E

    1988-11-01

    We have reported previously that, when exposed to hypercapnia of various intensities, the diaphragm reduces its force of twitch and tetanic contractions in the in vitro rat preparation as well as in the in vivo dog preparation. The experiments reported here with 31P nuclear magnetic resonance (31P-NMR) spectroscopy attempt to examine cellular mechanisms that might be responsible for this deterioration in mechanical performance. Specifically they describe certain characteristics of this preparation and cautions needed to study the resting in vitro rat diaphragm with such techniques. Second, they report the response of intracellular pH (pHi), phosphocreatine (PCr), ATP, and inorganic phosphate (Pi) in the resting in vitro rat diaphragm exposed to long-term normocapnia or to long-term hypercapnia. The results show that 1) to maintain a viable preparation, it was necessary to keep the diaphragm extended to an area approximating that at functional residual capacity, 2) the diaphragm seemed quite capable of maintaining a constant pHi and constant contents of ATP and Pi during normocapnia, but there was a gradual decline in PCr, and 3) during hypercapnia there was a significant decrease in pHi, but the behavior of the phosphate metabolites was exactly as during normocapnia. The results suggest that the decrease in mechanical performance of the diaphragm is probably not due to a decrease in the availability of the high-energy phosphates, although they do not completely exclude this possibility or possibilities related to regional compartmentation.

  12. The chaperone co-inducer BGP-15 alleviates ventilation-induced diaphragm dysfunction.

    PubMed

    Salah, Heba; Li, Meishan; Cacciani, Nicola; Gastaldello, Stefano; Ogilvie, Hannah; Akkad, Hazem; Namuduri, Arvind Venkat; Morbidoni, Valeria; Artemenko, Konstantin A; Balogh, Gabor; Martinez-Redondo, Vicente; Jannig, Paulo; Hedström, Yvette; Dworkin, Barry; Bergquist, Jonas; Ruas, Jorge; Vigh, Laszlo; Salviati, Leonardo; Larsson, Lars

    2016-08-03

    Ventilation-induced diaphragm dysfunction (VIDD) is a marked decline in diaphragm function in response to mechanical ventilation, which has negative consequences for individual patients' quality of life and for the health care system, but specific treatment strategies are still lacking. We used an experimental intensive care unit (ICU) model, allowing time-resolved studies of diaphragm structure and function in response to long-term mechanical ventilation and the effects of a pharmacological intervention (the chaperone co-inducer BGP-15). The marked loss of diaphragm muscle fiber function in response to mechanical ventilation was caused by posttranslational modifications (PTMs) of myosin. In a rat model, 10 days of BGP-15 treatment greatly improved diaphragm muscle fiber function (by about 100%), although it did not reverse diaphragm atrophy. The treatment also provided protection from myosin PTMs associated with HSP72 induction and PARP-1 inhibition, resulting in improvement of mitochondrial function and content. Thus, BGP-15 may offer an intervention strategy for reducing VIDD in mechanically ventilated ICU patients. Copyright © 2016, American Association for the Advancement of Science.

  13. Improvement of low-frequency characteristics of piezoelectric speakers based on acoustic diaphragms.

    PubMed

    Kim, Hye Jin; Yang, Woo Seok; No, Kwangsoo

    2012-09-01

    The vibrational characteristics of 3 types of the acoustic diaphragms are investigated to enhance the output acoustic performance of the piezoelectric ceramic speaker in a low-frequency range. In other to achieve both a higher output sound pressure level and wider frequency range of the piezoelectric speaker, we have proposed a rubber/resin bi-layer acoustic diaphragm. The theoretical square-root dependence of the fundamental resonant frequency on the thickness and Young's modulus of the acoustic diaphragm was verified by finite-element analysis simulation and laser scanning vibrometer measurement. The simulated resonant frequencies for each diaphragm correspond well to the measured results. From the simulated and measured resonant frequency results, it is found that the fundamental resonant frequency of the piezoelectric ceramic speaker can be designed by adjusting the thickness ratio of the rubber/resin bi-layer acoustic diaphragm. Compared with a commercial piezoelectric speaker, the fabricated piezoelectric ceramic speaker with the rubber/resin bi-layer diaphragm has at least 10 dB higher sound pressures in the low-frequency range of less than 1 kHz.

  14. Impact of diaphragm muscle fiber atrophy on neuromotor control.

    PubMed

    Mantilla, Carlos B; Sieck, Gary C

    2013-11-01

    In skeletal muscles, motor units comprise a motoneuron and the group of muscle fibers innervated by it, which are usually classified based on myosin heavy chain isoform expression. Motor units displaying diverse contractile and fatigue properties are important in determining the range of motor behaviors that can be accomplished by a muscle. Muscle fiber atrophy and weakness may disproportionately affect specific fiber types across a variety of diseases or clinical conditions, thus impacting neuromotor control. In this regard, fiber atrophy that affects a specific fiber type will alter the relative contribution of different motor units to overall muscle structure and function. For example, in various diseases there is fairly selective atrophy of type IIx and/or IIb fibers comprising the strongest yet most fatigable motor units. As a result, there is muscle weakness (i.e., reductions in force per cross-sectional area) associated with an apparent improvement in resistance to fatiguing contractions. This review will examine neuromotor control of respiratory muscles such as the diaphragm muscle and the impact of muscle fiber atrophy on motor performance. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Rat diaphragm muscle contraction with and without oxygen enrichment.

    PubMed

    Gölgeli, A; Coşkun, A; Ozesmi, C

    1995-10-01

    We investigated the effect of deprivation of oxygen circulation in the organ bath on the tension generation of the diaphragm in vitro. Adult male Swiss Albino rats were quickly killed and the left hemidiaphragms removed. Isolated phrenic nerve-diaphragmatic strip preparations were placed in an individual organ chamber containing Krebs solution and were connected to a force displacement transducer. The solution was maintained at 32 degrees C and bubbled with 95% O2-5% CO2. For the measurement of isometric twitch characteristics, supramaximal voltage was delivered via phrenic nerve electrodes. After turning off the gas circulation, isometric twitch characteristics were determined at 5, 10, 15, and 20 minutes. Then the muscle was allowed to recover under aerobic conditions (i.e., while bathed in a fresh solution, gassed with 95% O2-5% CO2). The isometric contractile properties were determined at the same intervals. In spite of no change in contraction time (CT) and relaxation time (1/2 RT), twitch amplitude (Pt) decreased following the termination of oxygen circulation (p < 0.05). The twitch tension improved in the recovery period but the decrease of tension developed more rapidly than the increase of tension development. We suggest that the decrease in the twitch tension was possibly due to a direct effect of intracellular acidosis. This study shows that no important change occurred in Ca+2 release and/or in the uptake in the sarcoplasmic reticulum, because of the finding of the CT and 1/2 RT values.

  16. Diaphragm Based Fiber Bragg Grating Acceleration Sensor with Temperature Compensation

    PubMed Central

    Li, Tianliang; Tan, Yuegang; Han, Xue; Zheng, Kai; Zhou, Zude

    2017-01-01

    A novel fiber Bragg grating (FBG) sensing-based acceleration sensor has been proposed to simultaneously decouple and measure temperature and acceleration in real-time. This design applied a diaphragm structure and utilized the axial property of a tightly suspended optical fiber, enabling improvement in its sensitivity and resonant frequency and achieve a low cross-sensitivity. The theoretical vibrational model of the sensor has been built, and its design parameters and sensing properties have been analyzed through the numerical analysis. A decoupling method has been presented with consideration of the thermal expansion of the sensor structure to realize temperature compensation. Experimental results show that the temperature sensitivity is 8.66 pm/°C within the range of 30–90 °C. The acceleration sensitivity is 20.189 pm/g with a linearity of 0.764% within the range of 5~65 m/s2. The corresponding working bandwidth is 10~200 Hz and its resonant frequency is 600 Hz. This sensor possesses an excellent impact resistance for the cross direction, and the cross-axis sensitivity is below 3.31%. This implementation can avoid the FBG-pasting procedure and overcome its associated shortcomings. The performance of the proposed acceleration sensor can be easily adjusted by modifying their corresponding physical parameters to satisfy requirements from different vibration measurements. PMID:28124998

  17. Energy harvester array using piezoelectric circular diaphragm for rail vibration

    NASA Astrophysics Data System (ADS)

    Wang, Wei; Huang, Rong-Jin; Huang, Chuan-Jun; Li, Lai-Feng

    2014-12-01

    Generating electric energy from mechanical vibration using a piezoelectric circular membrane array is presented in this paper. The electrical characteristics of the functional array consisted of three plates with varies tip masses are examined under dynamic conditions. With an optimal load resistor of 11 kΩ, an output power of 21.4 mW was generated from the array in parallel connection at 150 Hz under a pre-stress of 0.8 N and a vibration acceleration of 9.8 m/s2. Moreover, the broadband energy harvesting using this array still can be realized with different tip masses. Three obvious output power peaks can be obtained in a frequency spectra of 110 Hz to 260 Hz. The results show that using a piezoelectric circular diaphragm array can increase significantly the output of energy compared with the use of a single plate. And by optimizing combination of tip masses with piezoelectric elements in array, the frequency range can be tuned to meet the broadband vibration. This array may possibly be exploited to design the energy harvesting for practical applications such as future high speed rail.

  18. Embryonic development of rat diaphragm. An electron-microscopic study.

    PubMed

    Angelov, D N; Manolov, S A

    1989-01-01

    Ultrastructural aspects of white Wistar rats diaphragm during part of its embryonic development (from the 13th embryonic day till birth) have been studied. The dominating structures observed in the period of the thirteenth embryonic day (ED 13) are undifferentiated cells, their cytoplasm being poor in organelles but rich in ribosomes. The close examination of these cells reveals that some of them possess a kind of thin filaments near their Golgi zones. At ED 14-15 clusters of myoblasts are readily detected (their cytoplasm containing a lot of glycogen granules and myofibrils, some of them even with Z-line material); contact sites between their cell membranes appear, somewhere forming specialized junctions; in this period the myoblasts start to fuse giving rise to the primary generation of myotubes. At ED 16-17 the quantity of myofilaments and glycogen granules increases alongside with the initiation of a basal-lamina formation; occasionally some oval, undifferentiated cells very similar to those viewed at ED 13 are found. At ED 18-19 the cytoplasm of the myotubes contains a lot of myofibrils and a well-developed endoplasmic reticulum; at some places the adjacent membranes still form deep interdigitations. At the end of the prenatal myogenesis (ED 20-21) most of the muscle cells are close to their mature morphological appearance--the sarcomers are well-organized and some nuclei present a peripheral localization; nevertheless, in this period new generations of myotubes can be also distinguished.

  19. Differential adenosine sensitivity of diaphragm and skeletal muscle arterioles.

    PubMed

    Aaker, Aaron; Laughlin, M H

    2002-09-01

    The hyperemic response in exercising skeletal muscle is dependent on muscle fiber-type composition and fiber recruitment patterns, but the vascular control mechanisms producing exercise hyperemia in skeletal muscle remain poorly understood. The purpose of this study was to test the hypothesis that arterioles from white, low-oxidative skeletal muscle are less responsive to adenosine-induced dilation than are arterioles from diaphragm (Dia) and red, high-oxidative skeletal muscle. Second-order arterioles (2As) were isolated from the white portion of gastrocnemius muscle (WG; low-oxidative, fast-twitch muscle tissue) and two types of high-oxidative skeletal muscle [Dia and red portion of gastrocnemius muscle (RG)] of rats. Results reveal that 2As from all three types of muscle dilated in response to the endothelium-dependent dilator acetylcholine (WG: 48 +/- 3%, Dia: 51 +/- 3%, RG: 74 +/- 3%). In contrast, adenosine dilated only 2As from WG (48 +/- 4%) and Dia (46 +/- 5%) but not those from RG (5 +/- 5%). Thus adenosine-induced dilator responses differed among 2As of these different types of muscle tissue. However, the results do not support our hypothesis because 2As from Dia and WG dilated in response to adenosine, whereas 2As from RG did not. We conclude that the adenosine responsiveness of 2As from rat skeletal muscle cannot be predicted only by the fiber-type composition or oxidative capacity of the skeletal muscle tissue wherein the arteriole lies.

  20. Inhibition of Janus kinase signaling during controlled mechanical ventilation prevents ventilation-induced diaphragm dysfunction.

    PubMed

    Smith, Ira J; Godinez, Guillermo L; Singh, Baljit K; McCaughey, Kelly M; Alcantara, Raniel R; Gururaja, Tarikere; Ho, Melissa S; Nguyen, Henry N; Friera, Annabelle M; White, Kathy A; McLaughlin, John R; Hansen, Derek; Romero, Jason M; Baltgalvis, Kristen A; Claypool, Mark D; Li, Wei; Lang, Wayne; Yam, George C; Gelman, Marina S; Ding, Rongxian; Yung, Stephanie L; Creger, Daniel P; Chen, Yan; Singh, Rajinder; Smuder, Ashley J; Wiggs, Michael P; Kwon, Oh-Sung; Sollanek, Kurt J; Powers, Scott K; Masuda, Esteban S; Taylor, Vanessa C; Payan, Donald G; Kinoshita, Taisei; Kinsella, Todd M

    2014-07-01

    Controlled mechanical ventilation (CMV) is associated with the development of diaphragm atrophy and contractile dysfunction, and respiratory muscle weakness is thought to contribute significantly to delayed weaning of patients. Therefore, therapeutic strategies for preventing these processes may have clinical benefit. The aim of the current study was to investigate the role of the Janus kinase (JAK)/signal transducer and activator of transcription 3 (STAT3) signaling pathway in CMV-mediated diaphragm wasting and weakness in rats. CMV-induced diaphragm atrophy and contractile dysfunction coincided with marked increases in STAT3 phosphorylation on both tyrosine 705 (Tyr705) and serine 727 (Ser727). STAT3 activation was accompanied by its translocation into mitochondria within diaphragm muscle and mitochondrial dysfunction. Inhibition of JAK signaling during CMV prevented phosphorylation of both target sites on STAT3, eliminated the accumulation of phosphorylated STAT3 within the mitochondria, and reversed the pathologic alterations in mitochondrial function, reduced oxidative stress in the diaphragm, and maintained normal diaphragm contractility. In addition, JAK inhibition during CMV blunted the activation of key proteolytic pathways in the diaphragm, as well as diaphragm atrophy. These findings implicate JAK/STAT3 signaling in the development of diaphragm muscle atrophy and dysfunction during CMV and suggest that the delayed extubation times associated with CMV can be prevented by inhibition of Janus kinase signaling.-Smith, I. J., Godinez, G. L., Singh, B. K., McCaughey, K. M., Alcantara, R. R., Gururaja, T., Ho, M. S., Nguyen, H. N., Friera, A. M., White, K. A., McLaughlin, J. R., Hansen, D., Romero, J. M., Baltgalvis, K. A., Claypool, M. D., Li, W., Lang, W., Yam, G. C., Gelman, M. S., Ding, R., Yung, S. L., Creger, D. P., Chen, Y., Singh, R., Smuder, A. J., Wiggs, M. P., Kwon, O.-S., Sollanek, K. J., Powers, S. K., Masuda, E. S., Taylor, V. C., Payan, D. G

  1. Inhibition of Janus kinase signaling during controlled mechanical ventilation prevents ventilation-induced diaphragm dysfunction

    PubMed Central

    Smith, Ira J.; Godinez, Guillermo L.; Singh, Baljit K.; McCaughey, Kelly M.; Alcantara, Raniel R.; Gururaja, Tarikere; Ho, Melissa S.; Nguyen, Henry N.; Friera, Annabelle M.; White, Kathy A.; McLaughlin, John R.; Hansen, Derek; Romero, Jason M.; Baltgalvis, Kristen A.; Claypool, Mark D.; Li, Wei; Lang, Wayne; Yam, George C.; Gelman, Marina S.; Ding, Rongxian; Yung, Stephanie L.; Creger, Daniel P.; Chen, Yan; Singh, Rajinder; Smuder, Ashley J.; Wiggs, Michael P.; Kwon, Oh-Sung; Sollanek, Kurt J.; Powers, Scott K.; Masuda, Esteban S.; Taylor, Vanessa C.; Payan, Donald G.; Kinoshita, Taisei; Kinsella, Todd M.

    2014-01-01

    Controlled mechanical ventilation (CMV) is associated with the development of diaphragm atrophy and contractile dysfunction, and respiratory muscle weakness is thought to contribute significantly to delayed weaning of patients. Therefore, therapeutic strategies for preventing these processes may have clinical benefit. The aim of the current study was to investigate the role of the Janus kinase (JAK)/signal transducer and activator of transcription 3 (STAT3) signaling pathway in CMV-mediated diaphragm wasting and weakness in rats. CMV-induced diaphragm atrophy and contractile dysfunction coincided with marked increases in STAT3 phosphorylation on both tyrosine 705 (Tyr705) and serine 727 (Ser727). STAT3 activation was accompanied by its translocation into mitochondria within diaphragm muscle and mitochondrial dysfunction. Inhibition of JAK signaling during CMV prevented phosphorylation of both target sites on STAT3, eliminated the accumulation of phosphorylated STAT3 within the mitochondria, and reversed the pathologic alterations in mitochondrial function, reduced oxidative stress in the diaphragm, and maintained normal diaphragm contractility. In addition, JAK inhibition during CMV blunted the activation of key proteolytic pathways in the diaphragm, as well as diaphragm atrophy. These findings implicate JAK/STAT3 signaling in the development of diaphragm muscle atrophy and dysfunction during CMV and suggest that the delayed extubation times associated with CMV can be prevented by inhibition of Janus kinase signaling.—Smith, I. J., Godinez, G. L., Singh, B. K., McCaughey, K. M., Alcantara, R. R., Gururaja, T., Ho, M. S., Nguyen, H. N., Friera, A. M., White, K. A., McLaughlin, J. R., Hansen, D., Romero, J. M., Baltgalvis, K. A., Claypool, M. D., Li, W., Lang, W., Yam, G. C., Gelman, M. S., Ding, R., Yung, S. L., Creger, D. P., Chen, Y., Singh, R., Smuder, A. J., Wiggs, M. P., Kwon, O.-S., Sollanek, K. J., Powers, S. K., Masuda, E. S., Taylor, V. C., Payan, D. G

  2. A novel anti-shock silicon etching apparatus for solving diaphragm release problems

    NASA Astrophysics Data System (ADS)

    Shi, Sha-Li; Chen, Da-Peng; Ou, Yi; Jing, Yu-Peng; Xu, Qiu-Xia; Ye, Tian-Chun

    2010-06-01

    This paper presents a novel anti-shock bulk silicon etching apparatus for solving a universal problem which occurs when releasing the diaphragm (e.g. SiNx), that the diaphragm tends to be probably cracked by the impact of heating-induced bubbles, the swirling of heating-induced etchant, dithering of the hand and imbalanced etchant pressure during the wafer being taken out. Through finite element methods, the causes of the diaphragm cracking are analysed. The impact of heating-induced bubbles could be the main factor which results in the failure stress of the SiNx diaphragm and the rupture of it. In order to reduce the four potential effects on the cracking of the released diaphragm, an anti-shock bulk silicon etching apparatus is proposed for using during the last etching process of the diaphragm release. That is, the silicon wafer is first put into the regular constant temperature etching apparatus or ultrasonic plus, and when the residual bulk silicon to be etched reaches near the interface of the silicon and SiNx diaphragm, within a distance of 50-80 μm (the exact value is determined by the thickness, surface area and intensity of the released diaphragm), the wafer is taken out carefully and put into the said anti-shock silicon etching apparatus. The wafer's position is at the geometrical centre, also the centre of gravity of the etching vessel. An etchant outlet is built at the bottom. The wafer is etched continuously, and at the same time the etchant flows out of the vessel. Optionally, two symmetrically placed low-power heating resistors are put in the anti-shock silicon etching apparatus to quicken the etching process. The heating resistors' power should be low enough to avoid the swirling of the heating-induced etchant and the impact of the heating-induced bubbles on the released diaphragm. According to the experimental results, the released SiNx diaphragm thus treated is unbroken, which proves the practicality of the said anti-shock bulk silicon etching

  3. Time course of diaphragm function recovery after controlled mechanical ventilation in rats

    PubMed Central

    Thomas, Debby; Maes, Karen; Agten, Anouk; Heunks, Leo; Dekhuijzen, Richard; Decramer, Marc; Van Hees, Hieronymus

    2013-01-01

    Controlled mechanical ventilation (CMV) is known to result in rapid and severe diaphragmatic dysfunction, but the recovery response of the diaphragm to normal function after CMV is unknown. Therefore, we examined the time course of diaphragm function recovery in an animal model of CMV. Healthy rats were submitted to CMV for 24–27 h (n = 16), or to 24-h CMV followed by either 1 h (CMV + 1 h SB, n = 9), 2 h (CMV + 2 h SB, n = 9), 3 h (CMV + 3 h SB, n = 9), or 4–7 h (CMV + 4–7 h SB, n = 9) of spontaneous breathing (SB). At the end of the experiment, the diaphragm muscle was excised for functional and biochemical analysis. The in vitro diaphragm force was significantly improved in the CMV + 3 h SB and CMV + 4–7 h SB groups compared with CMV (maximal tetanic force: +27%, P < 0.05, and +59%, P < 0.001, respectively). This was associated with an increase in the type IIx/b fiber dimensions (P < 0.05). Neutrophil influx was increased in the CMV + 4–7 h SB group (P < 0.05), while macrophage numbers remained unchanged. Markers of protein synthesis (phosphorylated Akt and eukaryotic initiation factor 4E binding protein 1) were significantly increased (±40%, P < 0.001, and ±52%, P < 0.01, respectively) in the CMV + 3 h SB and CMV + 4–7 h SB groups and were positively correlated with diaphragm force (P < 0.05). Finally, also the maximal specific force generation of skinned single diaphragm fibers was increased in the CMV + 4–7 h SB group compared with CMV (+45%, P < 0.05). In rats, reloading the diaphragm for 3 h after CMV is sufficient to improve diaphragm function, while complete recovery occurs after longer periods of reloading. Enhanced muscle fiber dimensions, increased protein synthesis, and improved intrinsic contractile properties of diaphragm muscle fibers may have contributed to diaphragm function recovery. PMID:23845980

  4. Decreased diaphragm excursion in stroke patients with dysphagia as assessed by M-mode sonography.

    PubMed

    Park, Geun-Young; Kim, Seong-Rim; Kim, Young Woo; Jo, Kwang Wook; Lee, Eu Jeen; Kim, Young Moon; Im, Sun

    2015-01-01

    To record diaphragm excursion via M-mode ultrasonography in stroke patients with dysphagia and determine whether they present reduced diaphragm excursion during voluntary cough compared with stroke patients without dysphagia and healthy subjects. Prospective cross-sectional study. University rehabilitation hospital. Acute stroke patients with dysphagia (n=23), acute stroke patients without dysphagia (n=24), and healthy control participants (n=27) (N=74). Not applicable. Diaphragm motions during quiet breathing, deep breathing, and voluntary coughing were recorded via ultrasonography using M-mode tracing (mm). Maximum inspiratory and expiratory pressures (cmH2O) and peak cough flow (L/min) during voluntary coughing were measured. The mean diaphragm movement (mm) of the hemiplegic side for all groups during quiet breathing, deep breathing, and voluntary coughing was 14.8±4.3, 17.6±4.8, and 20.9±3.7 (P<.001); 23.8±7.1, 32.7±10.6, and 44.7±10.3 (P<.001); and 16.8±4.8, 28.5±4.9, and 36.0±8.2 (P<.001), respectively. The differences were statistically significant. Differences were observed in the maximum inspiratory (P<.001) and expiratory (P<.001) pressures and peak cough flow (P=.027) among the 3 groups. Forward selection stepwise regression analysis, which was performed to determine variables that help predict diaphragm excursion during voluntary coughing, showed that the presence of dysphagia explained up to 60% (P<.001) of the hemiplegic diaphragm movement during voluntary coughing in patients with stroke. M-mode ultrasonography showed that stroke patients with dysphagia have decreased diaphragm excursion and compromised respiratory function during voluntary coughing. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  5. High-intensity interval training prevents oxidant-mediated diaphragm muscle weakness in hypertensive mice.

    PubMed

    Bowen, T Scott; Eisenkolb, Sophia; Drobner, Juliane; Fischer, Tina; Werner, Sarah; Linke, Axel; Mangner, Norman; Schuler, Gerhard; Adams, Volker

    2017-01-01

    Hypertension is a key risk factor for heart failure, with the latter characterized by diaphragm muscle weakness that is mediated in part by increased oxidative stress. In the present study, we used a deoxycorticosterone acetate (DOCA)-salt mouse model to determine whether hypertension could independently induce diaphragm dysfunction and further investigated the effects of high-intensity interval training (HIIT). Sham-treated (n = 11), DOCA-salt-treated (n = 11), and DOCA-salt+HIIT-treated (n = 15) mice were studied over 4 wk. Diaphragm contractile function, protein expression, enzyme activity, and fiber cross-sectional area and type were subsequently determined. Elevated blood pressure confirmed hypertension in DOCA-salt mice independent of HIIT (P < 0.05). Diaphragm forces were impaired by ∼15-20% in DOCA-salt vs. sham-treated mice (P < 0.05), but this effect was prevented after HIIT. Myosin heavy chain (MyHC) protein expression tended to decrease (∼30%; P = 0.06) in DOCA-salt vs. sham- and DOCA-salt+HIIT mice, whereas oxidative stress increased (P < 0.05). Enzyme activity of NADPH oxidase was higher, but superoxide dismutase was lower, with MyHC oxidation elevated by ∼50%. HIIT further prevented direct oxidant-mediated diaphragm contractile dysfunction (P < 0.05) after a 30 min exposure to H2O-2 (1 mM). Our data suggest that hypertension induces diaphragm contractile dysfunction via an oxidant-mediated mechanism that is prevented by HIIT.-Bowen, T. S., Eisenkolb, S., Drobner, J., Fischer, T., Werner, S., Linke, A., Mangner, N., Schuler, G., Adams, V. High-intensity interval training prevents oxidant-mediated diaphragm muscle weakness in hypertensive mice.

  6. Force transmission, compliance, and viscoelasticity are altered in the alpha7-integrin-null mouse diaphragm.

    PubMed

    Lopez, M A; Mayer, U; Hwang, W; Taylor, T; Hashmi, M A; Jannapureddy, S R; Boriek, Aladin M

    2005-02-01

    Alpha7beta1 integrin is a transmembrane structural and receptor protein of skeletal muscles, and the absence of alpha7-integrin causes muscular dystrophy. We hypothesized that the absence of alpha7-integrin alters compliance and viscoelasticity and disrupts the mechanical coupling between passive transverse and axial contractile elements in the diaphragm. In vivo the diaphragm is loaded with pressure, and therefore axial and transverse length-tension relationships are important in assessing its function. We determined diaphragm passive length-tension relationships and the viscoelastic properties of its muscle in 1-month-old alpha7-integrin-null mice and age-matched controls. Furthermore, we measured the isometric contractile properties of the diaphragm from mutant and normal mice in the absence and presence of passive force applied in the transverse direction to fibers in 1-month-old and 5-month-old mutant mice. We found that compared with controls, the diaphragm direction of alpha7-integrin-null mutants showed 1) a significant decrease in muscle extensibility in 1-year-old mice, whereas muscle extensibility increased in the 1-month-old mice; 2) altered muscle viscoelasticity in the transverse direction of the muscle fibers of 1-month-old mice; 3) a significant increase in force-generating capacity in the diaphragms of 1-month-old mice, whereas in 5-month-old mice muscle contractility was depressed; and 4) significant reductions in mechanical coupling between longitudinal and transverse properties of the muscle fibers of 1-month-old mice. These findings suggest that alpha7-integrin serves an important mechanical function in the diaphragm by contributing to passive compliance, viscoelasticity, and modulation of its muscle contractile properties.

  7. Diaphragm efficiency estimated as power output relative to activation in chronic obstructive pulmonary disease.

    PubMed

    Finucane, Kevin E; Singh, Bhajan

    2012-11-01

    Muscle efficiency increases with fiber length and decreases with load. Diaphragm efficiency (Eff(di)) in healthy humans, measured as power output (Wdi) relative to the root mean square of diaphragm electromyogram (RMS(di)), increases with hyperpnea due to phasic activity of abdominal muscles acting to increase diaphragm length at end expiration (L(di ee)) and decrease inspiratory load. In chronic obstructive pulmonary disease (COPD), hyperpnea may decrease Eff(di) if L(di ee) decreases and load increases due to airflow obstruction and dynamic hyperinflation. To examine this hypothesis, we measured Eff(di) in six COPD subjects (mean forced expiratory volume in 1 s: 54% predicted) when breathing air and at intervals during progressive hypercapnic hyperpnea. Wdi was measured as the product of mean inspiratory transdiaphragmatic pressure (ΔPdi(mean)), diaphragm tidal volume measured fluoroscopically, and 1/inspiratory duration. Results were compared with those of six healthy subjects reported previously. In COPD, L(di ee) was normal when breathing air. ΔPdi(mean) and Wdi increased normally, and RMS(di) increased disproportionately (P = 0.01) with hyperpnea, and, unlike health, inspiratory capacity (IC), L(di ee), and Eff(di) did not increase. IC and L(di ee) were constant with hyperpnea because mean expiratory flow increased as expiratory duration decreased (r(2) = 0.65), and because expiratory flow was terminated actively by the balance between expiratory and inspiratory muscle forces near end expiration, and these forces increased proportionately with hyperpnea (r(2) = 0.49). At maximum ventilation, diaphragm radius of curvature at end inspiration increased in COPD (P = 0.04) but not controls; diaphragm radius of curvature at end inspiration and ln(Eff(di)) were negatively correlated (P = 0.01). Thus in COPD with modest airflow obstruction, Eff(di) did not increase normally with hyperpnea due to a constant L(di ee) and inspiratory flattening of the diaphragm.

  8. Mechanical ventilation reduces rat diaphragm blood flow and impairs O2 delivery and uptake

    PubMed Central

    Davis, Robert T.; Bruells, Christian S.; Stabley, John N.; McCullough, Danielle J.; Powers, Scott K.; Behnke, Bradley J.

    2012-01-01

    Objectives Although mechanical ventilation (MV) is a life-saving intervention in patients suffering from respiratory failure, prolonged MV is often associated with numerous complications including problematic weaning. In contracting skeletal muscle, inadequate O2 supply can limit oxidative phosphorylation resulting in muscular fatigue. However, whether prolonged MV results in decreased diaphragmatic blood and induces an O2 supply-demand imbalance in the diaphragm remains unknown. Design We tested the hypothesis that prolonged controlled MV results in a time-dependent reduction in rat diaphragmatic blood flow and microvascular PO2 and that prolonged MV would diminish the diaphragm’s ability to increase blood flow in response to muscular contractions. Measurements and Main Results Compared to 30 min of MV, 6 hrs of MV resulted in a 75% reduction in diaphragm blood flow (via radiolabeled microspheres), which did not occur in the intercostal muscle or high-oxidative hindlimb muscle (e.g., soleus). There was also a time-dependent decline in diaphragm microvascular PO2 (via phosphorescence quenching). Further, when contrasted to 30 min of MV, 6 hrs of MV significantly compromised the diaphragm’s ability to increase blood flow during electrically-induced contractions which resulted in a ~80% reduction in diaphragm O2 uptake. In contrast, 6 hrs of spontaneous breathing in anesthetized animals did not alter diaphragm blood flow or the ability to augment flow during electrically-induced contractions. Conclusions These new and important findings reveal that prolonged MV results in a time-dependent decrease in the ability of the diaphragm to augment blood flow to match O2 demand in response to contractile activity and could be a key contributing factor to difficult weaning. Although additional experiments are required to confirm, it is tempting to speculate that this ventilator-induced decline in diaphragmatic oxygenation could promote a hypoxia-induced generation of

  9. Muscle reorganisation through local injection of stem cells in the diaphragm of mdx mice.

    PubMed

    Lessa, Thais Borges; Carvalho, Rafael Cardoso; Franciolli, André Luis Rezende; de Oliveira, Lilian Jesus; Barreto, Rodrigo Silva da Nunes; Feder, David; Bressan, Fabiana Fernandes; Miglino, Maria Angélica; Ambrósio, Carlos Eduardo

    2012-12-12

    The diaphragm is the major respiratory muscle affected by Duchenne muscular dystrophy (DMD) and is responsible for causing 80% of deaths. The use of mechanical forces that act on the body or intermittent pressure on the airways improves the quality of life of patients but does not prevent the progression of respiratory failure. Thus, diseases that require tissue repair, such as DMD, represent a group of pathologies that have great potential for cell therapy. The application of stem cells directly into the diaphragm instead of systemic application can reduce cell migration to other affected areas and increase the chances of muscle reorganisation. The mdx mouse is a suitable animal model for this research because its diaphragmatic phenotype is similar to human DMD. Therefore, the aim of this study was to assess the potential cell implantation in the diaphragm muscle after the xenotransplantation of stem cells. A total of 9 mice, including 3 control BALB/Cmice, 3 5-month-old mdx mice without stem cell injections and 3 mdx mice injected with stem cells, were used. The animals injected with stem cells underwent laparoscopy so that stem cells from GFP-labelled rabbit olfactory epithelium could be locally injected into the diaphragm muscle. After 8 days, all animals were euthanised, and the diaphragm muscle was dissected and subjected to histological and immunohistochemical analyses. Both the fresh diaphragm tissue and immunohistochemical analyses showed immunopositive GFP labelling of some of the cells and immunonegativity of myoblast bundles. In the histological analysis, we observed a reduction in the inflammatory infiltrate as well as the presence of a few peripheral nuclei and myoblast bundles. We were able to implant stem cells into the diaphragm via local injection, which promoted moderate muscle reorganisation. The presence of myoblast bundles cannot be attributed to stem cell incorporation because there was no immunopositive labelling in this structure. It is

  10. REDOX MODULATION OF DIAPHRAGM CONTRACTILITY: INTERACTION BETWEEN DHPR and RyR CHANNELS

    PubMed Central

    Lawler, John M.; Kim, Jong-hee; Kwak, Hyo-Bum; Barnes, William S.

    2010-01-01

    Previous reports indicate that reactive oxygen species (ROS) may modulate contractility in skeletal muscle. Although Ca2+-sensitivity of the contractile apparatus appears to be a primary site of regulation, dihydropyridine receptor (DHPR or L-type Ca2+ channels) and calcium efflux in isolated sarcoplasmic reticulum (SR) vesicles appear to be redox sensitive as well. However, DHPR as a target is poorly understood in intact muscles at body temperature, particularly in the diaphragm, a muscle more dependent on external Ca2+ than locomotor muscles. Previously, we reported that oxidant challenge via xanthine oxidase (XO) alters the K+ contractures in diaphragm fiber bundles, suggestive of a role of L-type Ca2+ channels. Contractility of isolated rat diaphragm fiber bundles revealed a biphasic response to ROS challenge that was dose and time dependent. Potentiation of twitch and low-frequency diaphragm fiber bundle contractility with 0.02 U•ml−1 XO was reversible or partially preventable with washout, dithiothreitol, and the SOD/catalase mimetic EUK-134. The RyR antagonist ruthenium red inhibited xanthine oxidase-induced potentiation, while the RyR agonist caffeine elevated diaphragm twitch and low-frequency tension in a non-additive manner by 55% when introduced simultaneously with ROS challenge. The DHPR antagonist nitrendipine (15 μM) inhibited elevation in low-frequency diaphragm tension produced by ROS challenge. Caffeine threshold tension curves were shifted to the left with 0.02 U•ml−1 XO, but this effect was partially reversed with 15 μM nitrendipine. These results are consistent with the hypothesis that DHPR redox state and RyR function are modulated in an interactive manner, affecting contractility in intact diaphragm fiber bundles. PMID:20920578

  11. Janus kinase inhibition prevents cancer- and myocardial infarction-mediated diaphragm muscle weakness in mice.

    PubMed

    Smith, Ira J; Roberts, Brandon; Beharry, Adam; Godinez, Guillermo L; Payan, Donald G; Kinsella, Todd M; Judge, Andrew R; Ferreira, Leonardo F

    2016-04-15

    Respiratory dysfunction is prevalent in critically ill patients and can lead to adverse clinical outcomes, including respiratory failure and increased mortality. Respiratory muscles, which normally sustain respiration through inspiratory muscle contractions, become weakened during critical illness, and recent studies suggest that respiratory muscle weakness is related to systemic inflammation. Here, we investigate the pathophysiological role of the inflammatory JAK1/3 signaling pathway in diaphragm weakness in two distinct experimental models of critical illness. In the first experiment, mice received subcutaneous injections of PBS or C26 cancer cells and were fed chow formulated with or without the JAK1/3 inhibitor R548 for 26 days. Diaphragm specific force was significantly reduced in tumor-bearing mice receiving standard chow; however, treatment with the JAK1/3 inhibitor completely prevented diaphragm weakness. Diaphragm cross-sectional area was diminished by ∼25% in tumor-bearing mice but was similar to healthy mice in tumor-bearing animals treated with R548. In the second study, mice received sham surgery or coronary artery ligation, leading to myocardial infarction (MI), and were treated with R548 or vehicle 1 h postsurgery, and once daily for 3 days. Diaphragm specific force was comparable between sham surgery/vehicle, sham surgery/R548 and MI/R548 groups, but significantly decreased in the MI/vehicle group. Markers of oxidative damage and activated caspase-3, mechanisms previously identified to reduce muscle contractility, were not elevated in diaphragm extracts. These experiments implicate JAK1/3 signaling in cancer- and MI-mediated diaphragm weakness in mice, and provide a compelling case for further investigation. Copyright © 2016 the American Physiological Society.

  12. Janus kinase inhibition prevents cancer- and myocardial infarction-mediated diaphragm muscle weakness in mice

    PubMed Central

    Smith, Ira J.; Roberts, Brandon; Beharry, Adam; Godinez, Guillermo L.; Payan, Donald G.; Judge, Andrew R.; Ferreira, Leonardo F.

    2016-01-01

    Respiratory dysfunction is prevalent in critically ill patients and can lead to adverse clinical outcomes, including respiratory failure and increased mortality. Respiratory muscles, which normally sustain respiration through inspiratory muscle contractions, become weakened during critical illness, and recent studies suggest that respiratory muscle weakness is related to systemic inflammation. Here, we investigate the pathophysiological role of the inflammatory JAK1/3 signaling pathway in diaphragm weakness in two distinct experimental models of critical illness. In the first experiment, mice received subcutaneous injections of PBS or C26 cancer cells and were fed chow formulated with or without the JAK1/3 inhibitor R548 for 26 days. Diaphragm specific force was significantly reduced in tumor-bearing mice receiving standard chow; however, treatment with the JAK1/3 inhibitor completely prevented diaphragm weakness. Diaphragm cross-sectional area was diminished by ∼25% in tumor-bearing mice but was similar to healthy mice in tumor-bearing animals treated with R548. In the second study, mice received sham surgery or coronary artery ligation, leading to myocardial infarction (MI), and were treated with R548 or vehicle 1 h postsurgery, and once daily for 3 days. Diaphragm specific force was comparable between sham surgery/vehicle, sham surgery/R548 and MI/R548 groups, but significantly decreased in the MI/vehicle group. Markers of oxidative damage and activated caspase-3, mechanisms previously identified to reduce muscle contractility, were not elevated in diaphragm extracts. These experiments implicate JAK1/3 signaling in cancer- and MI-mediated diaphragm weakness in mice, and provide a compelling case for further investigation. PMID:26864813

  13. Surplus acetylcholine and acetylcholine release in the rat diaphragm.

    PubMed Central

    Molenaar, P C; Oen, B S; Polak, R L; van der Laaken, A L

    1987-01-01

    1. Skeletal muscles from rat, mouse and frog were incubated under different conditions and the amounts of acetylcholine (ACh) extractable from the tissue and released into the medium were determined by mass fragmentography. In some experiments measurements were made of the amounts of ACh ('bound' ACh) surviving in a muscle homogenate to which an excess of acetylcholinesterase had been added. In other experiments the membrane potentials, end-plate potentials (e.p.p.s), and miniature end-plate potentials (m.e.p.p.s) were studied. 2. During incubation in Ringer medium the ACh content of the rat hemidiaphragm usually did not change, but after inhibition of cholinesterase by soman the ACh content rose gradually from about 100 to 150 pmol to a plateau of about 400 pmol after 4 h. A similar formation of 'surplus ACh' after cholinesterase inhibition was found in the mouse diaphragm, but not in the frog sartorius muscle. 3. Surplus ACh accumulated predominantly in the end-plate region of the rat diaphragm. In muscles, 16-18 h after in vivo denervation, the capacity to form surplus ACh was decreased by more than 80%. 4. The amount of ACh diffusing from the resting hemidiaphragm into the incubation medium ('resting release') varied between 0.5 and 0.9 pmol min-1 in different experiments; it remained at the same level during accumulation of surplus ACh. It was reduced by more than 80% 16-18 h after denervation. 5. The amplitude of m.e.p.p.s and e.p.p.s did not increase while surplus ACh was accumulating. 6. Incubation of hemidiaphragms in Ringer solution containing [3H]choline caused the formation of [3H]ACh. Additional amounts of [3H]choline were incorporated into ACh when the nerve was stimulated for 60 min. However, incubation in the presence of soman (3,3-dimethyl-2-butylmethylphosphonofluoridate), in the absence of stimulation, did not cause an increase of the [3H]ACh content of the muscles. 7. From hemidiaphragms with active cholinesterase about 120 pmol ACh was lost

  14. Diaphragm Muscle Sarcopenia in Fischer 344 and Brown Norway Rats

    PubMed Central

    Elliott, Jonathan E.; Omar, Tanya S.; Mantilla, Carlos B.; Sieck, Gary C.

    2016-01-01

    The risk for respiratory diseases increases in adults >65 years of age, which may be partially due to ageing-related weakening and atrophy (i.e., sarcopenia) of the diaphragm muscle (DIAm). However, mechanisms underlying DIAm sarcopenia remain unknown. Based on existing evidence, we hypothesized that sarcopenia is most evident in type IIx and/or IIb DIAm fibres comprising more fatigable motor units. Currently, the USA National Institute on Aging supports Fischer 344 (F344) and Brown Norway (BN) rat strains for ageing related research, yet DIAm sarcopenia has not been comprehensively evaluated in either strain. Thus, the current study examined DIAm sarcopenia in older adult (24 month, 50% survival) F344 and (32 month, 50% survival) BN rats, compared to young adult (6 month) F344 and BN rats. Measurements of contractility, contractile protein concentration, fibre type distribution and fibre cross-sectional area were obtained from midcostal DIAm strips. Maximal specific force was reduced by ∼24% and ∼13% in older F344 and BN rats, respectively. Additionally, although cross-sectional area of type I and IIa DIAm fibres was unchanged in both F344 and BN rats, cross-sectional area of type IIx and/or IIb DIAm fibres was reduced by ∼20% and ∼15% in F344 and BN rats, respectively. Thus, although there was ageing-related DIAm weakness and atrophy, selective to type IIx and/or IIb DIAm fibres in both F344 and BN rats, the sarcopenic phenotype was more pronounced in F344 rats. PMID:27126607

  15. Human diaphragm efficiency estimated as power output relative to activation increases with hypercapnic hyperpnea.

    PubMed

    Finucane, Kevin E; Singh, Bhajan

    2009-11-01

    Hyperpnea with exercise or hypercapnia causes phasic contraction of abdominal muscles, potentially lengthening the diaphragm at end expiration and unloading it during inspiration. Muscle efficiency in vitro varies with load, fiber length, and precontraction stretch. To examine whether these properties of muscle contractility determine diaphragm efficiency (Eff(di)) in vivo, we measured Eff(di) in six healthy adults breathing air and during progressive hypercapnia at three levels of end-tidal Pco(2) with mean values of 48 (SD 2), 55 (SD 2), and 61 (SD 1) Torr. Eff(di) was estimated as the ratio of diaphragm power (Wdi) [the product of mean inspiratory transdiaphragmatic pressure, diaphragm volume change (DeltaVdi) measured fluoroscopically, and 1/inspiratory duration (Ti(-1))] to activation [root mean square values of inspiratory diaphragm electromyogram (RMS(di)) measured from esophageal electrodes]. At maximum hypercapnea relative to breathing air, 1) gastric pressure and diaphragm length at end expiration (Pg(ee) and Ldi(ee), respectively) increased 1.4 (SD 0.2) and 1.13 (SD 0.08) times, (P < 0.01 for both); 2) inspiratory change (Delta) in Pg decreased from 4.5 (SD 2.2) to -7.7 (SD 3.8) cmH(2)O (P < 0.001); 3) DeltaVdi.Ti(-1), Wdi, RMS(di), and Eff(di) increased 2.7 (SD 0.6), 4.9 (SD 1.8), 2.6 (SD 0.9), and 1.8 (SD 0.3) times, respectively (P < 0.01 for all); and 4) net and inspiratory Wdi were not different (P = 0.4). Eff(di) was predicted from Ldi(ee) (P < 0.001), Pg(ee) (P < 0.001), DeltaPg.Ti(-1) (P = 0.03), and DeltaPg (P = 0.04) (r(2) = 0.52) (multivariate regression analysis). We conclude that, with hypercapnic hyperpnea, 1) approximately 47% of the maximum increase of Wdi was attributable to increased Eff(di); 2) Eff(di) increased due to preinspiratory lengthening and inspiratory unloading of the diaphragm, consistent with muscle behavior in vitro; 3) passive recoil of the diaphragm did not contribute to inspiratory Wdi or Eff(di); and 4) phasic

  16. Time course analysis of mechanical ventilation-induced diaphragm contractile muscle dysfunction in the rat

    PubMed Central

    Corpeno, R; Dworkin, B; Cacciani, N; Salah, H; Bergman, H-M; Ravara, B; Vitadello, M; Gorza, L; Gustafson, A-M; Hedström, Y; Petersson, J; Feng, H-Z; Jin, J-P; Iwamoto, H; Yagi, N; Artemenko, K; Bergquist, J; Larsson, L

    2014-01-01

    Controlled mechanical ventilation (CMV) plays a key role in triggering the impaired diaphragm muscle function and the concomitant delayed weaning from the respirator in critically ill intensive care unit (ICU) patients. To date, experimental and clinical studies have primarily focused on early effects on the diaphragm by CMV, or at specific time points. To improve our understanding of the mechanisms underlying the impaired diaphragm muscle function in response to mechanical ventilation, we have performed time-resolved analyses between 6 h and 14 days using an experimental rat ICU model allowing detailed studies of the diaphragm in response to long-term CMV. A rapid and early decline in maximum muscle fibre force and preceding muscle fibre atrophy was observed in the diaphragm in response to CMV, resulting in an 85% reduction in residual diaphragm fibre function after 9–14 days of CMV. A modest loss of contractile proteins was observed and linked to an early activation of the ubiquitin proteasome pathway, myosin:actin ratios were not affected and the transcriptional regulation of myosin isoforms did not show any dramatic changes during the observation period. Furthermore, small angle X-ray diffraction analyses demonstrate that myosin can bind to actin in an ATP-dependent manner even after 9–14 days of exposure to CMV. Thus, quantitative changes in muscle fibre size and contractile proteins are not the dominating factors underlying the dramatic decline in diaphragm muscle function in response to CMV, in contrast to earlier observations in limb muscles. The observed early loss of subsarcolemmal neuronal nitric oxide synthase activity, onset of oxidative stress, intracellular lipid accumulation and post-translational protein modifications strongly argue for significant qualitative changes in contractile proteins causing the severely impaired residual function in diaphragm fibres after long-term mechanical ventilation. For the first time, the present study

  17. Diaphragm assessment by two dimensional speckle tracking imaging in normal subjects.

    PubMed

    Orde, Sam R; Boon, Andrea J; Firth, Daniel G; Villarraga, Hector R; Sekiguchi, Hiroshi

    2016-07-25

    Conventionally, ultrasonographic assessment of diaphragm contractility has involved measuring respiratory changes in diaphragm thickness (thickening fraction) using B-mode or caudal displacement with M-mode. Two-dimensional speckle-tracking has been increasingly used to assess muscle deformation ('strain') in echocardiography. We sought to determine in a pilot study if this technology could be utilized to analyze diaphragmatic contraction. Fifty healthy adult volunteers with normal exercise capacity underwent ultrasound imaging. A linear array transducer was used for the assessment of diaphragm thickness, thickening fraction (TF), and strain in the right anterior axillary line at approximately the ninth intercostal space. A phased array transducer was applied subcostally for the assessment of diaphragm displacement on the right mid-clavicular line. Diaphragmatic images were recorded from the end of expiration through the end of inspiration at 60 % maximal inspiratory capacity. Diaphragm strain was analyzed off-line by speckle tracking imaging. Blinded inter- and intra-rater variability was tested in 10 cases. Mean right diaphragm thickness at end-expiration (±SD: standard deviation) was 0.24 cm (±0.1), with TF of 45.1 % (±12) at 60 % peak inspiratory effort. Mean right diaphragm caudal displacement was 4.9 cm (±1). Mean right diaphragm strain was -40.3 % (±9). A moderate correlation was seen between longitudinal strain and TF (R(2) 0.44, p < 0.0001). A weak correlation was seen between strain and caudal displacement (R(2) 0.14, p < 0.01), and an even weaker correlation was seen between caudal displacement and TF (R(2) 0.1, p = 0.04). Age, gender, and body mass index were not significantly associated with right diaphragm strain or TF. Although inter- and intra-rater variability was overall good for TF, caudal displacement, and strain (inter-rater R(2); 0.8, 0.9, and 0.7, respectively [p < 0.01], intra-rater R(2); 0.9, 0.7, and 0

  18. Skeletal muscle alterations in chronic heart failure: differential effects on quadriceps and diaphragm

    PubMed Central

    Mangner, Norman; Weikert, Bettina; Bowen, T Scott; Sandri, Marcus; Höllriegel, Robert; Erbs, Sandra; Hambrecht, Rainer; Schuler, Gerhard; Linke, Axel; Gielen, Stephan; Adams, Volker

    2015-01-01

    Background Chronic heart failure (CHF) results in limb and respiratory muscle weakness, which contributes to exercise intolerance and increased morbidity and mortality, yet the molecular mechanisms remain poorly understood. Therefore, we aimed to compare parameters of antioxidative capacity, energy metabolism, and catabolic/anabolic balance in diaphragm and quadriceps muscle in an animal model of CHF. Methods Ligation of the left anterior descending coronary artery (n = 13) or sham operation (n = 11) was performed on Wistar Kyoto rats. After 12 weeks, echocardiography and invasive determination of maximal rates of left ventricular (LV) pressure change were performed. Antioxidative and metabolic enzyme activities and expression of catabolic/anabolic markers were assessed in quadriceps and diaphragm muscle. Results Ligated rats developed CHF (i.e. severe LV dilatation, reduced LV ejection fraction, and impaired maximal rates of LV pressure change; P < 0.001). There was a divergent response for antioxidant enzymes between the diaphragm and quadriceps in CHF rats, with glutathione peroxidase and manganese superoxide dismutase activity increased in the diaphragm but reduced in the quadriceps relative to shams (P < 0.01). Metabolic enzymes were unaltered in the diaphragm, but cytochrome c oxidase activity (P < 0.01) decreased and lactate dehydrogenase activity (P < 0.05) increased in the quadriceps of CHF animals. Protein expression of the E3 ligase muscle ring finger 1 and proteasome activity were increased (P < 0.05) in both the diaphragm and quadriceps in CHF rats compared with shams. Conclusion Chronic heart failure induced divergent antioxidative and metabolic but similar catabolic responses between the diaphragm and quadriceps. Despite the quadriceps demonstrating significant impairments in CHF, apparent beneficial adaptations of an increased antioxidative capacity were induced in the diaphragm. Nevertheless, muscle ring finger 1 and

  19. Skeletal muscle alterations in chronic heart failure: differential effects on quadriceps and diaphragm.

    PubMed

    Mangner, Norman; Weikert, Bettina; Bowen, T Scott; Sandri, Marcus; Höllriegel, Robert; Erbs, Sandra; Hambrecht, Rainer; Schuler, Gerhard; Linke, Axel; Gielen, Stephan; Adams, Volker

    2015-12-01

    Chronic heart failure (CHF) results in limb and respiratory muscle weakness, which contributes to exercise intolerance and increased morbidity and mortality, yet the molecular mechanisms remain poorly understood. Therefore, we aimed to compare parameters of antioxidative capacity, energy metabolism, and catabolic/anabolic balance in diaphragm and quadriceps muscle in an animal model of CHF. Ligation of the left anterior descending coronary artery (n = 13) or sham operation (n = 11) was performed on Wistar Kyoto rats. After 12 weeks, echocardiography and invasive determination of maximal rates of left ventricular (LV) pressure change were performed. Antioxidative and metabolic enzyme activities and expression of catabolic/anabolic markers were assessed in quadriceps and diaphragm muscle. Ligated rats developed CHF (i.e. severe LV dilatation, reduced LV ejection fraction, and impaired maximal rates of LV pressure change; P < 0.001). There was a divergent response for antioxidant enzymes between the diaphragm and quadriceps in CHF rats, with glutathione peroxidase and manganese superoxide dismutase activity increased in the diaphragm but reduced in the quadriceps relative to shams (P < 0.01). Metabolic enzymes were unaltered in the diaphragm, but cytochrome c oxidase activity (P < 0.01) decreased and lactate dehydrogenase activity (P < 0.05) increased in the quadriceps of CHF animals. Protein expression of the E3 ligase muscle ring finger 1 and proteasome activity were increased (P < 0.05) in both the diaphragm and quadriceps in CHF rats compared with shams. Chronic heart failure induced divergent antioxidative and metabolic but similar catabolic responses between the diaphragm and quadriceps. Despite the quadriceps demonstrating significant impairments in CHF, apparent beneficial adaptations of an increased antioxidative capacity were induced in the diaphragm. Nevertheless, muscle ring finger 1 and proteasome activity (markers of protein

  20. Time course analysis of mechanical ventilation-induced diaphragm contractile muscle dysfunction in the rat.

    PubMed

    Corpeno, R; Dworkin, B; Cacciani, N; Salah, H; Bergman, H-M; Ravara, B; Vitadello, M; Gorza, L; Gustafson, A-M; Hedström, Y; Petersson, J; Feng, H-Z; Jin, J-P; Iwamoto, H; Yagi, N; Artemenko, K; Bergquist, J; Larsson, L

    2014-09-01

    Controlled mechanical ventilation (CMV) plays a key role in triggering the impaired diaphragm muscle function and the concomitant delayed weaning from the respirator in critically ill intensive care unit (ICU) patients. To date, experimental and clinical studies have primarily focused on early effects on the diaphragm by CMV, or at specific time points. To improve our understanding of the mechanisms underlying the impaired diaphragm muscle function in response to mechanical ventilation, we have performed time-resolved analyses between 6 h and 14 days using an experimental rat ICU model allowing detailed studies of the diaphragm in response to long-term CMV. A rapid and early decline in maximum muscle fibre force and preceding muscle fibre atrophy was observed in the diaphragm in response to CMV, resulting in an 85% reduction in residual diaphragm fibre function after 9-14 days of CMV. A modest loss of contractile proteins was observed and linked to an early activation of the ubiquitin proteasome pathway, myosin:actin ratios were not affected and the transcriptional regulation of myosin isoforms did not show any dramatic changes during the observation period. Furthermore, small angle X-ray diffraction analyses demonstrate that myosin can bind to actin in an ATP-dependent manner even after 9-14 days of exposure to CMV. Thus, quantitative changes in muscle fibre size and contractile proteins are not the dominating factors underlying the dramatic decline in diaphragm muscle function in response to CMV, in contrast to earlier observations in limb muscles. The observed early loss of subsarcolemmal neuronal nitric oxide synthase activity, onset of oxidative stress, intracellular lipid accumulation and post-translational protein modifications strongly argue for significant qualitative changes in contractile proteins causing the severely impaired residual function in diaphragm fibres after long-term mechanical ventilation. For the first time, the present study demonstrates

  1. A pressure-deformation analytical model for rectangular diaphragm of MEMS pressure sensors

    NASA Astrophysics Data System (ADS)

    Zhou, Wu; Wang, Dong; Yu, Huijun; Peng, Bei

    2017-02-01

    Rectangular diaphragm is commonly used as a pressure sensitive component in MEMS pressure sensors. Its deformation under applied pressure directly determines the performance of micro-devices, accurately acquiring the pressure-deflection relationship, therefore, plays a significant role in pressure sensor design. This paper analyzes the deflection of an isotropic rectangular diaphragm under combined effects of loads. The model is regarded as a clamped plate with full surface uniform load and partially uniform load applied on its opposite sides. The full surface uniform load stands for the external measured pressure. The partial load is used to approximate the opposite reaction of the silicon island which is planted on the diaphragm to amplify the deformation displacement, thus to improve the sensitivity of the pressure sensor. Superposition method is proposed to calculate the diaphragm deflections. This method considers separately the actions of loads applied on the simple supported plate and moments distributed on edges. Considering the boundary condition of all edges clamped, the moments are constructed to eliminate the boundary rotations caused by lateral load. The diaphragm’s deflection is computed by superposing deflections which produced by loads applied on the simple supported plate and moments distributed on edges. This method provides higher calculation accuracy than Galerkin variational method, and it is used to analyze the influence factors of the diaphragm’s deflection, includes aspect ratio, thickness and the applied force area of the diaphragm.

  2. Diaphragm motion characterization using chest motion data for biomechanics-based lung tumor tracking during EBRT

    NASA Astrophysics Data System (ADS)

    Karami, Elham; Gaede, Stewart; Lee, Ting-Yim; Samani, Abbas

    2016-03-01

    Despite recent advances in image-guided interventions, lung cancer External Beam Radiation Therapy (EBRT) is still very challenging due to respiration induced tumor motion. Among various proposed methods of tumor motion compensation, real-time tumor tracking is known to be one of the most effective solutions as it allows for maximum normal tissue sparing, less overall radiation exposure and a shorter treatment session. As such, we propose a biomechanics-based real-time tumor tracking method for effective lung cancer radiotherapy. In the proposed algorithm, the required boundary conditions for the lung Finite Element model, including diaphragm motion, are obtained using the chest surface motion as a surrogate signal. The primary objective of this paper is to demonstrate the feasibility of developing a function which is capable of inputting the chest surface motion data and outputting the diaphragm motion in real-time. For this purpose, after quantifying the diaphragm motion with a Principal Component Analysis (PCA) model, correlation coefficient between the model parameters of diaphragm motion and chest motion data was obtained through Partial Least Squares Regression (PLSR). Preliminary results obtained in this study indicate that the PCA coefficients representing the diaphragm motion can be obtained through chest surface motion tracking with high accuracy.

  3. Age-related changes in satellite cell proliferation by compensatory activation in rat diaphragm muscles.

    PubMed

    Kawai, Minako; Saitsu, Kiyokazu; Yamashita, Hiroki; Miyata, Hirofumi

    2012-06-01

    To investigate the age-related changes in satellite cell (SC) proliferation in vivo, we used a compensatory activation (CAC) model of the hemi-diaphragm muscle. Young (2-month), adult (14-month) and old (24-month) rats were randomly divided into control and CAC groups. In the CAC group, denervation surgery in the left hemi-diaphragm was performed to induce CAC of the right hemi-diaphragm. Six days after the surgery, the CAC diaphragm muscle was removed and separated into two blocks for immunohistochemical staining and real time RT-PCR procedures. The number of SCs in type I and IIa fibers were not affected significantly by the CAC in any age groups, but that in type IIx/b fibers was significantly increased in the young and adult groups. As compared to the age-matched control group, the Pax7 mRNA expression level was significantly higher in the young and adult CAC groups, but not in the old CAC group. These results may suggest that the mechanism of SC proliferation in type IIx/b fibers is impaired in aged diaphragm muscles.

  4. Assessing breathing motion by shape matching of lung and diaphragm surfaces

    NASA Astrophysics Data System (ADS)

    Urschler, Martin; Bischof, Horst

    2005-04-01

    Studying complex thorax breating motion is an important research topic for accurate fusion of functional and anatomical data, radiotherapy planning or reduction of breathing motion artifacts. We investigate segmented CT lung, airway and diaphragm surfaces at several different breathing states between Functional Residual and Total Lung Capacity. In general, it is hard to robustly derive corresponding shape features like curvature maxima from lung and diaphragm surfaces since diaphragm and rib cage muscles tend to deform the elastic lung tissue such that e.g. ridges might disappear. A novel registration method based on the shape context approach for shape matching is presented where we extend shape context to 3D surfaces. The shape context approach was reported as a promising method for matching 2D shapes without relying on extracted shape features. We use the point correspondences for a non-rigid thin-plate-spline registration to get deformation fields that describe the movement of lung and diaphragm. Our validation consists of experiments on phantom and real sheep thorax data sets. Phantom experiments make use of shapes that are manipulated with known transformations that simulate breathing behaviour. Real thorax data experiments use a data set showing lungs and diaphragm at 5 distinct breathing states, where we compare subsets of the data sets and qualitatively and quantitatively asses the registration performance by using manually identified corresponding landmarks.

  5. Effect of undernutrition on contractile and fatigue properties of rat diaphragm during development.

    PubMed

    Brozanski, B S; Watchko, J F; O'Day, T L; Guthrie, R D

    1993-05-01

    The present study was designed to assess the effects of combined pre- and postnatal undernutrition on the in vitro contractile and fatigue properties of the rat diaphragm during development. In vitro direct stimulation of costal diaphragm from control (CTL) and undernourished (UN) rats was done on postnatal days 1, 4, 14, 21, 30, 40, 50, and 60. Combined pre- and postnatal undernutrition resulted in stunted animal growth but did not alter the diaphragm-to-total body weight ratio. Twitch contraction time, half-relaxation time, and force-frequency relationships were not consistently affected by undernutrition. Specific twitch force and specific tetanic force were also unchanged in the UN group. Fatigue resistance was high and comparable in UN and CTL groups at days 1 and 4. At day 14 and thereafter, fatigue resistance declined but was consistently higher in the UN than in the CTL group. We conclude that combined pre- and postnatal undernutrition results in a significant increase in fatigue resistance of the diaphragm compared with CTL, whereas diaphragm muscle contractile properties are not appreciably affected by prolonged undernutrition.

  6. Effects of continuous low-frequency pacing on immature canine diaphragm.

    PubMed

    Marzocchi, M; Brouillette, R T; Klemka-Walden, L M; Heller, S L; Weese-Mayer, D E; Brozanski, B S; Caliendo, J; Daood, M; Ilbawi, M N; Hunt, C E

    1990-09-01

    Although diaphragm pacing has been shown to be a practical method of supporting ventilation in children, its usefulness has been limited because of concern that continuous (24 h/day) diaphragm pacing would fatigue and damage the diaphragm. We examined the functional and structural effects of continuous low-frequency diaphragm pacing on the left hemidiaphragm of five immature dogs aged 65 +/- 2 (SD) days at onset of pacing. Stimulus parameters approximated those required to pace infants: frequency 11.1 Hz, inspiratory time 810 ms, and respiratory rate 20 breaths/min. Animals were paced 24 h/day for 24-28 days. Paced tidal volumes and airway occlusion pressures were unchanged at low (less than 15 Hz) stimulus frequencies but were reduced at high (greater than 20 Hz) stimulus frequencies. Although histologically the paced hemidiaphragms appeared normal, histochemical studies showed a conversion from a mixture of type I (54%) and type II (46%) fibers to a uniform population of type I fibers with high oxidative enzyme activity. Transformation of muscle type was also demonstrated by pyrophosphate gel electrophoresis; fast and slow isomyosin bands were noted in control specimens, whereas only slow isomyosin was identified in paced specimens. Thus, in immature dogs, continuous low-frequency pacing affects both function and structure of the diaphragm.

  7. Theoretical Evaluation of Electroactive Polymer Based Micropump Diaphragm for Air Flow Control

    NASA Technical Reports Server (NTRS)

    Xu, Tian-Bing; Su, Ji; Zhang, Qiming

    2004-01-01

    An electroactive polymer (EAP), high energy electron irradiated poly(vinylidene fluoride-trifluoroethylene) [P(VDFTrFE)] copolymer, based actuation micropump diaphragm (PAMPD) have been developed for air flow control. The displacement strokes and profiles as a function of amplifier and frequency of electric field have been characterized. The volume stroke rates (volume rate) as function of electric field, driving frequency have been theoretically evaluated, too. The PAMPD exhibits high volume rate. It is easily tuned with varying of either amplitude or frequency of the applied electric field. In addition, the performance of the diaphragms were modeled and the agreement between the modeling results and experimental data confirms that the response of the diaphragms follow the design parameters. The results demonstrated that the diaphragm can fit some future aerospace applications to replace the traditional complex mechanical systems, increase the control capability and reduce the weight of the future air dynamic control systems. KEYWORDS: Electroactive polymer (EAP), micropump, diaphragm, actuation, displacement, volume rate, pumping speed, clamping ratio.

  8. Mechanical ventilation triggers abnormal mitochondrial dynamics and morphology in the diaphragm.

    PubMed

    Picard, Martin; Azuelos, Ilan; Jung, Boris; Giordano, Christian; Matecki, Stefan; Hussain, Sabah; White, Kathryn; Li, Tong; Liang, Feng; Benedetti, Andrea; Gentil, Benoit J; Burelle, Yan; Petrof, Basil J

    2015-05-01

    The diaphragm is a unique skeletal muscle designed to be rhythmically active throughout life, such that its sustained inactivation by the medical intervention of mechanical ventilation (MV) represents an unanticipated physiological state in evolutionary terms. Within a short period after initiating MV, the diaphragm develops muscle atrophy, damage, and diminished strength, and many of these features appear to arise from mitochondrial dysfunction. Notably, in response to metabolic perturbations, mitochondria fuse, divide, and interact with neighboring organelles to remodel their shape and functional properties-a process collectively known as mitochondrial dynamics. Using a quantitative electron microscopy approach, here we show that diaphragm contractile inactivity induced by 6 h of MV in mice leads to fragmentation of intermyofibrillar (IMF) but not subsarcolemmal (SS) mitochondria. Furthermore, physical interactions between adjacent organellar membranes were less abundant in IMF mitochondria during MV. The profusion proteins Mfn2 and OPA1 were unchanged, whereas abundance and activation status of the profission protein Drp1 were increased in the diaphragm following MV. Overall, our results suggest that mitochondrial morphological abnormalities characterized by excessive fission-fragmentation represent early events during MV, which could potentially contribute to the rapid onset of mitochondrial dysfunction, maladaptive signaling, and associated contractile dysfunction of the diaphragm.

  9. Transneuronal tracing of neural pathways influencing both diaphragm and genioglossal muscle activity in the ferret.

    PubMed

    Shintani, T; Anker, A R; Billig, I; Card, J P; Yates, B J

    2003-10-01

    In prior experiments that employed the transneuronal transport of isogenic recombinants of pseudorabies virus (PRV), we demonstrated that neurons located ventrally in the medial medullary reticular formation (MRF) of the ferret provide collateralized projections to both diaphragm and abdominal muscle motoneurons as well as to multiple abdominal muscle motoneuron pools. The goal of the present study was to determine whether single MRF neurons also furnish inputs to diaphragm motoneurons and those innervating an airway muscle with inspiratory-related activity: the tongue protruder genioglossus. For this purpose, PRV recombinants expressing unique reporters (beta-galactosidase or enhanced green fluorescent protein) were injected into either the diaphragm or the genioglossal muscle. The virus injections produced transneuronal infection of overlapping populations of MRF neurons. A small proportion of these neurons (<15%) was infected by both PRV recombinants, which indicated that they provide collateralized inputs to genioglossal and diaphragm motoneurons. These findings show that, whereas some MRF neurons simultaneously influence the activity of upper airway and respiratory pump muscles, other cells in this brain stem region independently contribute to diaphragm and genioglossal muscle contraction regulation.

  10. The role of Sema3–Npn-1 signaling during diaphragm innervation and muscle development

    PubMed Central

    Huettl, Rosa-Eva; Hanuschick, Philipp; Amend, Anna-Lena; Alberton, Paolo; Aszodi, Attila; Huber, Andrea B.

    2016-01-01

    ABSTRACT Correct innervation of the main respiratory muscle in mammals, namely the thoracic diaphragm, is a crucial pre-requisite for the functionality of this muscle and the viability of the entire organism. Systemic impairment of Sema3A–Npn-1 (Npn-1 is also known as NRP1) signaling causes excessive branching of phrenic nerves in the diaphragm and into the central tendon region, where the majority of misguided axons innervate ectopic musculature. To elucidate whether these ectopic muscles are a result of misguidance of myoblast precursors due to the loss of Sema3A–Npn-1 signaling, we conditionally ablated Npn-1 in somatic motor neurons, which led to a similar phenotype of phrenic nerve defasciculation and, intriguingly, also formation of innervated ectopic muscles. We therefore hypothesize that ectopic myocyte fusion is caused by additional factors released by misprojecting growth cones. Slit2 and its Robo receptors are expressed by phrenic motor axons and migrating myoblasts, respectively, during innervation of the diaphragm. In vitro analyses revealed a chemoattractant effect of Slit2 on primary diaphragm myoblasts. Thus, we postulate that factors released by motor neuron growth cones have an influence on the migration properties of myoblasts during establishment of the diaphragm. PMID:27466379

  11. Methodology for mitigation of seismic hazards in existing unreinforced masonry buildings: Diaphragm testing

    NASA Astrophysics Data System (ADS)

    1981-12-01

    An experimental program conducted on horizontal diaphragms subjected to quasi-static, cyclic, in-plane displacement and dynamic, in-plane earthquake shaking is described. The experimental program is one of several tasks in an overall research program, sponsored by the National Science Foundation, whose objective is to develop a methodology for mitigation of seismic hazards in existing unreinforced masonary buildings. Full-scale component tests on horizontal diaphragms subjected to quasi-static, cyclic, in-plane displacement and dynamic, in-plane earthquake shaking were designed and conducted on 14 diaphragm specimens subjected to 139 test sequences that were comprised of intermingled static and dynamic loadings. The quasi-static tests produced deformations in the diaphragms that ranged from elastic excursions to excursions that produced ductilities of 2, 3, 4, and 6; however, only one diaphragm was driven to the ductility of 6. The dynamic earthquake loadings covered the full range of seismicity in the United States from an Effective Peak Acceleration of 0.1 g to 0.4 g.

  12. Diaphragm opening effects on shock wave formation and acceleration in a rectangular cross section channel

    NASA Astrophysics Data System (ADS)

    Pakdaman, S. A.; Garcia, M.; Teh, E.; Lincoln, D.; Trivedi, M.; Alves, M.; Johansen, C.

    2016-11-01

    Shock wave formation and acceleration in a high-aspect ratio cross section shock tube were studied experimentally and numerically. The relative importance of geometric effects and diaphragm opening time on shock formation are assessed. The diaphragm opening time was controlled through the use of slit-type (fast opening time) and petal-type (slow opening time) diaphragms. A novel method of fabricating the petal-type diaphragms, which results in a consistent burst pressure and symmetric opening without fragmentation, is presented. High-speed schlieren photography was used to visualize the unsteady propagation of the lead shock wave and trailing gas dynamic structures. Surface-mounted pressure sensors were used to capture the spatial and temporal development of the pressure field. Unsteady Reynolds-Averaged Navier-Stokes simulation predictions using the shear-stress-transport turbulence model are compared to the experimental data. Simulation results are used to explain the presence of high-frequency pressure oscillations observed experimentally in the driver section as well as the cause of the initial acceleration and subsequent rapid decay of shock velocity measured along the top and bottom channel surfaces. A one-dimensional theoretical model predicting the effect of the finite opening time of the diaphragm on the rate of driver depressurization and shock acceleration is proposed. The model removes the large amount of empiricism that accompanies existing models published in the literature. Model accuracy is assessed through comparisons with experiments and simulations. Limitations of and potential improvements in the model are discussed.

  13. Oxidative stress is required for mechanical ventilation-induced protease activation in the diaphragm

    PubMed Central

    Smuder, Ashley J.; Wu, Min; Hudson, Matthew B.; Nelson, W. Bradley; Powers, Scott K.

    2010-01-01

    Prolonged mechanical ventilation (MV) results in diaphragmatic weakness due to fiber atrophy and contractile dysfunction. Recent work reveals that activation of the proteases calpain and caspase-3 is required for MV-induced diaphragmatic atrophy and contractile dysfunction. However, the mechanism(s) responsible for activation of these proteases remains unknown. To address this issue, we tested the hypothesis that oxidative stress is essential for the activation of calpain and caspase-3 in the diaphragm during MV. Cause-and-effect was established by prevention of MV-induced diaphragmatic oxidative stress using the antioxidant Trolox. Treatment of animals with Trolox prevented MV-induced protein oxidation and lipid peroxidation in the diaphragm. Importantly, the Trolox-mediated protection from MV-induced oxidative stress prevented the activation of calpain and caspase-3 in the diaphragm during MV. Furthermore, the avoidance of MV-induced oxidative stress not only averted the activation of these proteases but also rescued the diaphragm from MV-induced diaphragmatic myofiber atrophy and contractile dysfunction. Collectively, these findings support the prediction that oxidative stress is required for MV-induced activation of calpain and caspase-3 in the diaphragm and are consistent with the concept that antioxidant therapy can retard MV-induced diaphragmatic weakness. PMID:20203072

  14. Recovery of Diaphragm Function following Mechanical Ventilation in a Rodent Model

    PubMed Central

    Bruells, Christian S.; Bergs, Ingmar; Rossaint, Rolf; Du, Jun; Bleilevens, Christian; Goetzenich, Andreas; Weis, Joachim; Wiggs, Michael P.; Powers, Scott K.; Hein, Marc

    2014-01-01

    Background Mechanical ventilation (MV) induces diaphragmatic muscle fiber atrophy and contractile dysfunction (ventilator induced diaphragmatic dysfunction, VIDD). It is unknown how rapidly diaphragm muscle recovers from VIDD once spontaneous breathing is restored. We hypothesized that following extubation, the return to voluntary breathing would restore diaphragm muscle fiber size and contractile function using an established rodent model. Methods Following 12 hours of MV, animals were either euthanized or, after full wake up, extubated and returned to voluntary breathing for 12 hours or 24 hours. Acutely euthanized animals served as controls (each n = 8/group). Diaphragmatic contractility, fiber size, protease activation, and biomarkers of oxidative damage in the diaphragm were assessed. Results 12 hours of MV induced VIDD. Compared to controls diaphragm contractility remained significantly depressed at 12 h after extubation but rebounded at 24 h to near control levels. Diaphragmatic levels of oxidized proteins were significantly elevated after MV (p = 0.002) and normalized at 24 hours after extubation. Conclusions These findings indicate that diaphragm recovery from VIDD, as indexed by fiber size and contractile properties, returns to near control levels within 24 hours after returning to spontaneous breathing. Besides the down-regulation of proteolytic pathways and oxidative stress at 24 hours after extubation further repairing mechanisms have to be determined. PMID:24475293

  15. Plastic Deformation of Micromachined Silicon Diaphragms with a Sealed Cavity at High Temperatures

    PubMed Central

    Ren, Juan; Ward, Michael; Kinnell, Peter; Craddock, Russell; Wei, Xueyong

    2016-01-01

    Single crystal silicon (SCS) diaphragms are widely used as pressure sensitive elements in micromachined pressure sensors. However, for harsh environments applications, pure silicon diaphragms are hardly used because of the deterioration of SCS in both electrical and mechanical properties. To survive at the elevated temperature, the silicon structures must work in combination with other advanced materials, such as silicon carbide (SiC) or silicon on insulator (SOI), for improved performance and reduced cost. Hence, in order to extend the operating temperatures of existing SCS microstructures, this work investigates the mechanical behavior of pressurized SCS diaphragms at high temperatures. A model was developed to predict the plastic deformation of SCS diaphragms and was verified by the experiments. The evolution of the deformation was obtained by studying the surface profiles at different anneal stages. The slow continuous deformation was considered as creep for the diaphragms with a radius of 2.5 mm at 600 °C. The occurrence of plastic deformation was successfully predicted by the model and was observed at the operating temperature of 800 °C and 900 °C, respectively. PMID:26861332

  16. A biomechanical approach for in vivo diaphragm muscle motion prediction during normal respiration

    NASA Astrophysics Data System (ADS)

    Coelho, Brett; Karami, Elham; Haddad, Seyyed M. H.; Seify, Behzad; Samani, Abbas

    2017-03-01

    Lung cancer is one of the leading causes of cancer death in men and women. External Beam Radiation Therapy (EBRT) is a commonly used primary treatment for the condition. A major challenge with such treatments is the delivery of sufficient radiation dose to the lung tumor while ensuring that surrounding healthy lung parenchyma receives only minimal dose. This can be achieved by coupling EBRT with respiratory computer models which can predict the tumour location as a function of phase during the breathing cycle1. The diaphragm muscle contraction is mainly responsible for a large portion of the lung tumor motion during normal breathing, especially when tumours are in the lower lobes, therefore the importance of accurately modelling the diaphragm is paramount in lung tumour motion prediction. The goal of this research is to develop a biomechanical model of the diaphragm, including its active and passive response, using detailed geometric, biomechanical and anatomical information that mimics the diaphragmatic behaviour in a patient specific manner. For this purpose, a Finite Element Model (FEM) of the diaphragm was developed in order to predict the in vivo motion of the diaphragm, paving the way for computer assisted lung cancer tumor tracking in EBRT. Preliminary results obtained from the proposed model are promising and they indicate that it can be used as a plausible tool for effective lung cancer EBRT to improve patient care.

  17. Mechanostimulation, electrostimulation and force measurement in an in vitro model of the isolated rat diaphragm.

    PubMed

    Armbruster, Caroline; Dassow, Constanze; Gamerdinger, Katharina; Schneider, Matthias; Sumkauskaite, Migle; Guttmann, Josef; Schumann, Stefan

    2011-12-01

    In an in vitro model of the entire rat diaphragm, diaphragmatic contraction forces at defined preload levels were investigated. A total of 24 excised rat diaphragms were electrically stimulated inside a two-chamber strain-applicator. The resulting contraction forces were determined on eight adjusted preload levels via measuring the elicited pressure in the chamber below the diaphragm. Subsequently, diaphragms were exposed for 6 h to one of four treatments: (1) control, (2) cyclic mechanical stretch, (3) intermittent electrical stimulation or (4) combination of cyclic mechanical stretch and electrical stimulation. Diaphragmatic contraction force increased from 116 ± 21 mN at the lowest preload level to 775 ± 85 mN at the maximal preload level. After 6 h maximal muscle contraction forces were smallest after non-electrostimulated treatment (control: 81 ± 15 mN, mechanical deflection: 94 ± 12 mN) and largest after electrostimulation treatment (mere electrostimulation: 165 ± 20 mN, combined mechano- and electro-stimulation: 164 ± 14 mN). We conclude that our model allows force measurements on isolated rat diaphragms. Furthermore, we conclude that by intermediate electrical stimulation diaphragmatic force generation was better preserved than by mechanical stimulation.

  18. Characteristic analysis of diaphragm-type transducer that is thick relative to its size

    NASA Astrophysics Data System (ADS)

    Ishiguro, Yuya; Zhu, Jing; Tagawa, Norio; Okubo, Tsuyoshi; Okubo, Kan

    2017-07-01

    In recent years, high-performance piezoelectric micromachined ultrasonic transducers (PMUTs) have been fabricated by micro electro mechanical systems (MEMS) technology. For high-resolution imaging, it is important to broaden the frequency bandwidth. By reducing the diaphragm size to increase the resonance frequency, the film thickness becomes relatively larger and hence the transmitting and receiving characteristics may different from those of a usual thin diaphragm. In this study, we examine the performance of a square-diaphragm-type lead zirconate titanate (PZT) transducer through simulations. To realize the desired resonance frequency of 20 MHz, firstly, the diaphragm size and the thickness of the layers of PZT and Si constituting a PMUT are examined, and then, three PZT/Si models with different thicknesses are selected. Subsequently, using the models, we analyze the transmitting efficiency, transmitting bandwidth, receiving sensitivity (piezoelectric voltage/electric charge), and receiving bandwidth using an FEM simulator. It is found that the proposed models can transmit ultrasound independently of the diaphragm vibration and have wide bandwidth of the receiving frequency as compared with that of a typical PMUT.

  19. Dynamics modeling and vibration analysis of a piezoelectric diaphragm applied in valveless micropump

    NASA Astrophysics Data System (ADS)

    He, Xiuhua; Xu, Wei; Lin, Nan; Uzoejinwa, B. B.; Deng, Zhidan

    2017-09-01

    This paper presents the dynamical model involved with load of fluid pressure, electric-solid coupling simulation and experimental performance of the piezoelectric diaphragm fabricated and applied in valveless micropump. The model is based on the theory of plate-shell with small deflection, considering the two-layer structure of piezoelectric ceramic and elastic substrate. The high-order non-homogeneous vibration equation of the piezoelectric diaphragm, derived in the course of the study, was solved by being divided into a homogeneous Bessel equation and a non-homogeneous static equation according to the superposition principle. The amplitude of the piezoelectric diaphragm driven by sinusoidal voltage against the load of fluid pressure was obtained from the solution of the vibration equation. Also, finite element simulation of electric-solid coupling between displacement of piezoelectric diaphragm due to an applied voltage and resulting deformation of membrane was considered. The simulation result showed that the maximum deflection of diaphragm is 9.51 μm at a quarter cycle time when applied a peak-to-peak voltage of 150VP-P with a frequency of 90 Hz, and the displacement distribution according to the direction of the radius was demonstrated. Experiments were performed to verify the prediction of the dynamic modeling and the coupling simulation, the experimental data showed a good agreement with the dynamical model and simulation.

  20. Diaphragm correction factors for free-air chamber standards for air kerma in x-rays.

    PubMed

    Burns, D T; Kessler, C

    2009-05-07

    At present, only a correction factor for photon transmission, k(l), is systematically applied for the entrance diaphragm of free-air chamber standards for air kerma. In the present work, the Monte Carlo code PENELOPE is used to re-evaluate k(l) for the BIPM standards and new correction factors are calculated for photon scatter and for fluorescence production in the diaphragm. An additional effect arising from electrons emitted from the diaphragm is shown to be significant at the highest photon energies. The results for the radiation qualities used for international comparisons give a combined diaphragm correction factor k(dia) = 0.9980(3) for the BIPM medium-energy standard at 250 kV. This is significantly different from the factor k(l) = 0.9996(1) in use at present and it might be concluded that differences are likely to exist for all free-air chamber standards. The effect of using a conical taper at the downstream edge of the diaphragm is shown to be negligible for these radiation qualities.

  1. Wonderful Walls

    ERIC Educational Resources Information Center

    Greenman, Jim

    2006-01-01

    In this article, the author emphasizes the importance of "working" walls in children's programs. Children's programs need "working" walls (and ceilings and floors) which can be put to use for communication, display, storage, and activity space. The furnishings also work, or don't work, for the program in another sense: in aggregate, they serve as…

  2. NAD(P)H oxidase subunit p47phox is elevated, and p47phox knockout prevents diaphragm contractile dysfunction in heart failure.

    PubMed

    Ahn, Bumsoo; Beharry, Adam W; Frye, Gregory S; Judge, Andrew R; Ferreira, Leonardo F

    2015-09-01

    Patients with chronic heart failure (CHF) have dyspnea and exercise intolerance, which are caused in part by diaphragm abnormalities. Oxidants impair diaphragm contractile function, and CHF increases diaphragm oxidants. However, the specific source of oxidants and its relevance to diaphragm abnormalities in CHF is unclear. The p47(phox)-dependent Nox2 isoform of NAD(P)H oxidase is a putative source of diaphragm oxidants. Thus, we conducted our study with the goal of determining the effects of CHF on the diaphragm levels of Nox2 complex subunits and test the hypothesis that p47(phox) knockout prevents diaphragm contractile dysfunction elicited by CHF. CHF caused a two- to sixfold increase (P < 0.05) in diaphragm mRNA and protein levels of several Nox2 subunits, with p47(phox) being upregulated and hyperphosphorylated. CHF increased diaphragm extracellular oxidant emission in wild-type but not p47(phox) knockout mice. Diaphragm isometric force, shortening velocity, and peak power were decreased by 20-50% in CHF wild-type mice (P < 0.05), whereas p47(phox) knockout mice were protected from impairments in diaphragm contractile function elicited by CHF. Our experiments show that p47(phox) is upregulated and involved in the increased oxidants and contractile dysfunction in CHF diaphragm. These findings suggest that a p47(phox)-dependent NAD(P)H oxidase mediates the increase in diaphragm oxidants and contractile dysfunction in CHF. Copyright © 2015 the American Physiological Society.

  3. Discharge ignition in the diaphragm configuration supplied by DC non-pulsing voltage

    NASA Astrophysics Data System (ADS)

    Hlochová, L.; Hlavatá, L.; Kozáková, Z.; Krčma, F.

    2016-05-01

    This work deals with the ignition of the discharge in the diaphragm configuration generated in water solutions containing supporting NaCl electrolyte. The reactor has volume of 110 ml and it is made of polycarbonate. HV electrodes made of stainless steel are placed in this reactor. Ceramic (Shapal-MTM) diaphragm is placed in the barrier separating the cathode and the anode space. An electric power source supplies the reactor by constant DC voltage up to 4 kV and electric current up to 300 mA. The discharge ignition is compared in the reactor with different sizes of diaphragms. Measurements are carried out in electrolyte solutions with the same conductivity. Images of plasma streamers and bubble formation are taken by an ICCD camera iStar 734. Electrical characteristics are measured by an oscilloscope LeCroy LT 374 L in order to determine breakdown moments at different experimental conditions.

  4. Eventration of diaphragm with dextrocardia and type 2 respiratory failure: A rare entity.

    PubMed

    Mir, Mohmad Hussain; Arshad, Faheem; Bagdadi, Farhana Siraj; Nasir, Syed Aejaz; Hajni, Mubashir Rashid

    2014-09-01

    Eventration of the diaphragm is a rare condition where the muscle is permanently elevated, but retains its continuity and attachments to costal margin. In this condition, all or part of the diaphragm is largely composed of fibrous tissue with a few or no interspersed muscle fibers. It can be complete or partial. It is seldom symptomatic and often requires no treatment. We present a 70-year-old male who came with progressive breathlessness and was admitted with type 2 respiratory failure, and on evaluation was found to have complete eventration of the left diaphragm with herniation of colon and stomach in the left chest with dextrocardia. Aim of reporting this rare case is to highlight the importance of history taking, good physical examination, and imaging in the diagnosis of diaphragmatic eventration.

  5. Nano silica diaphragm in-fiber cavity for gas pressure measurement.

    PubMed

    Liu, Shen; Wang, Yiping; Liao, Changrui; Wang, Ying; He, Jun; Fu, Cailing; Yang, Kaiming; Bai, Zhiyong; Zhang, Feng

    2017-04-11

    We demonstrate an ultrahigh-sensitivity gas pressure sensor based on the Fabry-Perot interferometer employing a fiber-tip diaphragm-sealed cavity. The cavity is comprised of a silica capillary and ultrathin silica diaphragm with a thickness of 170 nm, with represents the thinnest silica diaphragm fabricated thus far by an electrical arc discharge technique. The resulting Fabry-Perot interferometer-based gas pressure sensor demonstrates a gas pressure sensitivity of about 12.22 nm/kPa, which is more than two orders of magnitude greater than that of a similarly configured fiber-tip air bubble sensor. Moreover, our gas pressure sensor has a low temperature cross-sensitivity of about 106 Pa/°C, and the sensor functions well up to a temperature of about 1000 °C. As such, the sensor can potentially be employed in high-temperature environments.

  6. Miniature all-silica optical fiber pressure sensor with an ultrathin uniform diaphragm.

    PubMed

    Wang, Wenhui; Wu, Nan; Tian, Ye; Niezrecki, Christopher; Wang, Xingwei

    2010-04-26

    This paper presents an all-silica miniature optical fiber pressure/acoustic sensor based on the Fabry-Perot (FP) interferometric principle. The endface of the etched optical fiber tip and silica thin diaphragm on it form the FP structure. The uniform and thin silica diaphragm was fabricated by etching away the silicon substrate from a commercial silicon wafer that has a thermal oxide layer. The thin film was directly thermally bonded to the endface of the optical fiber thus creating the Fabry-Perot cavity. Thin films with a thickness from 1microm to 3microm have been bonded successfully. The sensor shows good linearity and hysteresis during measurement. A sensor with 0.75 microm-thick diaphragm thinned by post silica etching was demonstrated to have a sensitivity of 11 nm/kPa. The new sensor has great potential to be used as a non-intrusive pressure sensor in a variety of sensing applications.

  7. TRPC6 is a glomerular slit diaphragm-associated channel required for normal renal function

    PubMed Central

    Reiser, Jochen; Polu, Krishna R.; Möller, Clemens C.; Kenlan, Peter; Altintas, Mehmet M.; Wei, Changli; Faul, Christian; Herbert, Stephanie; Villegas, Ivan; Avila-Casado, Carmen; McGee, Mary; Sugimoto, Hikaru; Brown, Dennis; Kalluri, Raghu; Mundel, Peter; Smith, Paula L.; Clapham, David E.; Pollak, Martin R.

    2006-01-01

    Progressive kidney failure is a genetically and clinically heterogeneous group of disorders. Podocyte foot processes and the interposed glomerular slit diaphragm are critical components of the permeability barrier in the kidney. Mutations in genes encoding for structural proteins of the podocyte lead to the development of proteinuria resulting in progressive kidney failure and focal segmental glomerulosclerosis (FSGS). Here, we show that the canonical transient receptor potential 6 (TRPC6) ion channel is expressed in podocytes and represents a component of the glomerular slit diaphragm. We identified five families with autosomal dominant FSGS in which disease segregated with mutations in the TRPC6 gene on chromosome 11q. Two of the TRPC6 mutants displayed increased current amplitudes. Together, this data demonstrates that TRPC6 channel activity at the slit diaphragm is essential for proper regulation of podocyte structure and function. PMID:15924139

  8. Myosin heavy chain composition in the rat diaphragm - Effect of age and exercise training

    NASA Technical Reports Server (NTRS)

    Gosselin, Luc E.; Betlach, Michael; Vailas, Arthur C.; Greaser, Marion L.; Thomas, D. P.

    1992-01-01

    The effects of aging and exercise training on the myosin heavy chain (MHC) composition were determined in both the costal and crural diaphragm regions of female Fischer 344 rats. Treadmill running at 75 percent maximal oxygen consumption resulted in similar increases in plantaris muscle citrate synthase activity in both young (5 mo) and old (23mo) trained animals (P less than 0.05). It was found that the ratio of fast to slow MHC was significantly higher (P less than 0.005) in the crural compared with costal diaphragm region in both age groups. A significant age-related increase in persentage of slow MHC was observed in both diaphragm regions. The relative proportion of slow MHC in either costal or crural region was not changed by exercise training.

  9. Ectopic hepatic parenchyma attached to the diaphragm: simulating a pulmonary mass in a cat.

    PubMed

    Dhaliwal, Ravinder S; Lacey, Janice K

    2009-01-01

    A case of an ectopic lobe of the liver connected to a normal diaphragm is described. A 9-year-old, castrated male cat underwent thoracotomy for a pulmonary mass. The removed mass was attached to the diaphragm that histologically was ectopic liver. The ectopic liver had no connection with the main liver. Because the occurrence of ectopic supradiaphragmatic hepatic tissue is a possibility, this should be considered as a differential diagnosis for caudal pulmonary or caudal mediastinal masses in a cat. This report describes, to the authors' knowledge, the first case of ectopic hepatic tissue attached to the diaphragm of a cat. The authors also characterize the asymptomatic clinical presentation and radiographic findings of this cat and suggest further imaging with computed tomography in unusual case presentations.

  10. Sepsis increases contraction-related generation of reactive oxygen species in the diaphragm.

    PubMed

    Nethery, D; DiMarco, A; Stofan, D; Supinski, G

    1999-10-01

    Recent work indicates that free radicals mediate sepsis-induced diaphragmatic dysfunction. These previous experiments have not, however, established the source of the responsible free radical species. In theory, this phenomenon could be explained if one postulates that sepsis elicits an upregulation of contraction-related free radical formation in muscle. The purpose of the present study was to test this hypothesis by examination of the effect of sepsis on contraction-related free radical generation [i.e. , formation of reactive oxygen species (ROS)] by the diaphragm. Rats were killed 18 h after injection with either saline or endotoxin. In vitro hemidiaphragms were then prepared, and ROS generation during electrically induced contractions (20-Hz trains delivered for 10 min) was assessed by measurement of the conversion of hydroethidine to ethidium. ROS generation was negligible in noncontracting diaphragms from both saline- and endotoxin-treated groups (2.0 +/- 0. 6 and 2.8 +/- 1.0 ng ethidium/mg tissue, respectively), but it was marked in contracting diaphragms from saline-treated animals (19.0 +/- 2.8 ng/mg tissue) and even more pronounced (30.0 +/- 2.8 ng/mg tissue) in diaphragms from septic animals (P < 0.01). This enhanced free radical generation occurred despite the fact that the force-time integral (i.e., the area under the curve of force vs. time) for control diaphragms was higher than that for the septic group. In additional studies, in which we altered the stimulation paradigm in control muscles to achieve a force-time integral similar to that achieved in septic muscles, an even greater difference between control and septic muscle ROS formation was observed. These data indicate that ROS formation during contraction is markedly enhanced in diaphragms from endotoxin-treated septic animals. We speculate that ROS generated in this fashion plays a central role in producing sepsis-related skeletal muscle dysfunction.

  11. Short-term influences of lung volume reduction surgery on the diaphragm in emphysematous hamsters.

    PubMed

    Lewis, Michael I; Fournier, Mario; Da, Xiaoyu; Li, Hongmei; Mosenifar, Zab; McKenna, Robert J; Cohen, Arthur H

    2004-10-01

    With emphysema, diaphragm length adaptation results in shortened fibers. We hypothesize that passive diaphragm stretch occurring acutely after lung volume reduction surgery (LVRS) results in fiber injury. Bilateral LVRS was performed in emphysematous hamsters. Studies were performed 1 (D1) and 4 (D4) days after LVRS, and compared with sham-treated groups. Sarcolemmal rupture was evident in 10.9% of fibers in LVRS-D1 and reduced to 1.6% in LVRS-D4. Ultrastructural analysis revealed focal abnormalities in both LVRS-D1 and LVRS-D4 animals in over one-third of fibers. Myofibrillar disruption was not observed in sham-treated animals. Diaphragm insulin-like growth factor-I (IGF-I) was increased in LVRS-D4 compared with other emphysematous groups. Increased IGF-I immunoreactivity was localized to types IIA and I fibers. The abundance of the splice variant of IGF-I mRNA sensitive to muscle stretch (IGF-IEb) increased 3.2-fold in LVRS D-4 diaphragms, compared with emphysema-sham animals. The main form of IGF-I mRNA was unchanged. Marked force deficit was observed in the LVRS-D1 diaphragm, compared with emphysema-sham and emphysema (no surgery) animals. These data highlight a markedly compromised ventilatory pump acutely after LVRS. Acute fiber stretch predisposes to muscle fiber injury and may also be a necessary mechanotransductive stimulus for fiber remodeling as the diaphragm adapts to reduced lung volume.

  12. Identifying decreased diaphragmatic mobility and diaphragm thickening in interstitial lung disease: the utility of ultrasound imaging

    PubMed Central

    Santana, Pauliane Vieira; Prina, Elena; Albuquerque, André Luis Pereira; Carvalho, Carlos Roberto Ribeiro; Caruso, Pedro

    2016-01-01

    Objective: To investigate the applicability of ultrasound imaging of the diaphragm in interstitial lung disease (ILD). Methods: Using ultrasound, we compared ILD patients and healthy volunteers (controls) in terms of diaphragmatic mobility during quiet and deep breathing; diaphragm thickness at functional residual capacity (FRC) and at total lung capacity (TLC); and the thickening fraction (TF, proportional diaphragm thickening from FRC to TLC). We also evaluated correlations between diaphragmatic dysfunction and lung function variables. Results: Between the ILD patients (n = 40) and the controls (n = 16), mean diaphragmatic mobility was comparable during quiet breathing, although it was significantly lower in the patients during deep breathing (4.5 ± 1.7 cm vs. 7.6 ± 1.4 cm; p < 0.01). The patients showed greater diaphragm thickness at FRC (p = 0.05), although, due to lower diaphragm thickness at TLC, they also showed a lower TF (p < 0.01). The FVC as a percentage of the predicted value (FVC%) correlated with diaphragmatic mobility (r = 0.73; p < 0.01), and an FVC% cut-off value of < 60% presented high sensitivity (92%) and specificity (81%) for indentifying decreased diaphragmatic mobility. Conclusions: Using ultrasound, we were able to show that diaphragmatic mobility and the TF were lower in ILD patients than in healthy controls, despite the greater diaphragm thickness at FRC in the former. Diaphragmatic mobility correlated with ILD functional severity, and an FVC% cut-off value of < 60% was found to be highly accurate for indentifying diaphragmatic dysfunction on ultrasound. PMID:27167428

  13. Recruitment and plasticity in diaphragm, intercostal, and abdominal muscles in unanesthetized rats.

    PubMed

    Navarrete-Opazo, A; Mitchell, G S

    2014-07-15

    Although rats are a frequent model for studies of plasticity in respiratory motor control, the relative capacity of rat accessory respiratory muscles to express plasticity is not well known, particularly in unanesthetized animals. Here, we characterized external intercostal (T2, T4, T5, T6, T7, T8, T9 EIC) and abdominal muscle (external oblique and rectus abdominis) electromyogram (EMG) activity in unanesthetized rats via radiotelemetry during normoxia (Nx: 21% O2) and following acute intermittent hypoxia (AIH: 10 × 5-min, 10.5% O2; 5-min intervals). Diaphragm and T2-T5 EIC EMG activity, and ventilation were also assessed during maximal chemoreceptor stimulation ( 7% CO2, 10.5% O2) and sustained hypoxia (SH: 10.5% O2). In Nx, T2 EIC exhibits prominent inspiratory activity, whereas T4, T5, T6, and T7 EIC inspiratory activity decreases in a caudal direction. T8 and T9 EIC and abdominal muscles show only tonic or sporadic activity, without consistent respiratory activity. MCS increases diaphragm and T2 EIC EMG amplitude and tidal volume more than SH (0.94 ± 0.10 vs. 0.68 ± 0.05 ml/100 g; P < 0.001). Following AIH, T2 EIC EMG amplitude remained above baseline for more than 60 min post-AIH (i.e., EIC long-term facilitation, LTF), and was greater than diaphragm LTF (41.5 ± 1.3% vs. 19.1 ± 2.0% baseline; P < 0.001). We conclude that 1) diaphragm and rostral T2-T5 EIC muscles exhibit inspiratory activity during Nx; 2) MCS elicits greater ventilatory, diaphragm, and rostral T2-T5 EIC muscle activity vs. SH; and 3) AIH induces greater rostral EIC LTF than diaphragm LTF. Copyright © 2014 the American Physiological Society.

  14. Recruitment and plasticity in diaphragm, intercostal, and abdominal muscles in unanesthetized rats

    PubMed Central

    Navarrete-Opazo, A.

    2014-01-01

    Although rats are a frequent model for studies of plasticity in respiratory motor control, the relative capacity of rat accessory respiratory muscles to express plasticity is not well known, particularly in unanesthetized animals. Here, we characterized external intercostal (T2, T4, T5, T6, T7, T8, T9 EIC) and abdominal muscle (external oblique and rectus abdominis) electromyogram (EMG) activity in unanesthetized rats via radiotelemetry during normoxia (Nx: 21% O2) and following acute intermittent hypoxia (AIH: 10 × 5-min, 10.5% O2; 5-min intervals). Diaphragm and T2–T5 EIC EMG activity, and ventilation were also assessed during maximal chemoreceptor stimulation (MCS: 7% CO2, 10.5% O2) and sustained hypoxia (SH: 10.5% O2). In Nx, T2 EIC exhibits prominent inspiratory activity, whereas T4, T5, T6, and T7 EIC inspiratory activity decreases in a caudal direction. T8 and T9 EIC and abdominal muscles show only tonic or sporadic activity, without consistent respiratory activity. MCS increases diaphragm and T2 EIC EMG amplitude and tidal volume more than SH (0.94 ± 0.10 vs. 0.68 ± 0.05 ml/100 g; P < 0.001). Following AIH, T2 EIC EMG amplitude remained above baseline for more than 60 min post-AIH (i.e., EIC long-term facilitation, LTF), and was greater than diaphragm LTF (41.5 ± 1.3% vs. 19.1 ± 2.0% baseline; P < 0.001). We conclude that 1) diaphragm and rostral T2–T5 EIC muscles exhibit inspiratory activity during Nx; 2) MCS elicits greater ventilatory, diaphragm, and rostral T2–T5 EIC muscle activity vs. SH; and 3) AIH induces greater rostral EIC LTF than diaphragm LTF. PMID:24833779

  15. A diaphragm tampon applied to an ovulation method in a birth control system.

    PubMed

    Cattanach, J F

    1991-12-01

    Gynaeseal is a re-usable diaphragm tampon made from latex which forms a unique cervico-vaginal seal and isolates menstrual loss. In a prospective study involving 80 women, Gynaeseal was offered in combination with the Billings Ovulation Method in an advised birth control system. This system included: use of the diaphragm tampon during the menstruation-fertile phase interphase; periodic abstinence during the overtly fertile phase of the cycle; and if extreme reliability was required, for a further 2 days after the Billings method 'rules' allow resumption of intercourse. The diaphragm tampon successfully complemented the Billings Ovulation Method with 44 women (60.4%) assessing the GOM System as being as good, or better than, currently available reversible methods. It functioned effectively as a tampon with 50% (31 women) stating that they used the product as a contraceptive. One woman claimed an unplanned pregnancy. No significant medical complications were recorded. The product has major advantages as a tampon: it is easily and accurately inserted because of the efficient applicator; it isolated menstrual loss within a collection chamber; it protects the cervix; and it facilitates sexual activity. Based on a minimum effective diameter (62mm), the diaphragm tampon does not interfere with the normal physiology of the vagina. There appeared to be no significant distortion of normal adult pelvic anatomy, and properly placed, no sensation of the diaphragm tampon's presence. Regarding insertion of the diaphragm tampon using the spiral-curved applicator: 31 women (42.5%) had little or no difficulty; 29 (39.7%) moderate difficulty; 13 (17.8%) experienced serious difficulty; and 7 (8.7%) were unable to use the product.

  16. Process engineering and economic evaluations of diaphragm and membrane chlorine cell technologies. Final report

    SciTech Connect

    Not Available

    1980-12-01

    The chlor-alkali manufacturing technologies of (1), diaphragm cells (2), current technology membrane cells (3), catalytic cathode membrane cells (4), oxygen-cathode membrane cells and to a lesser extent several other related emerging processes are studied. Comparisons have been made on the two bases of (1) conventional industrial economics, and (2) energy consumption. The current diaphragm cell may have a small economic advantage over the other technologies at the plant size of 544 metric T/D (600 T/D). The three membrane cells all consume less energy, with the oxygen-cathode cell being the lowest. The oxygen-cathode cell appears promising as a low energy chlor-alkali cell where there is no chemical market for hydrogen. Federal funding of the oxygen-cathode cell has been beneficial to the development of the technology, to electrochemical cell research, and may help maintain the US's position in the international chlor-alkali technology marketplace. Tax law changes inducing the installation of additional cells in existing plants would produce the quickest reduction in power consumption by the chlor-alkali industry. Alternative technologies such as the solid polymer electrolyte cell, the coupling of diaphragm cells with fuel cells and the dynamic gel diaphragm have a strong potential for reducing chloralkali industry power consumption. Adding up all the recent and expected improvements that have become cost-effective, the electrical energy required to produce a unit of chlorine by 1990 should be only 50% to 60% of that used in 1970. In the United States the majority of the market does not demand salt-free caustic. About 75% of the electrolytic caustic is produced in diaphragm cells and only a small part of that is purified. This study indicates that unless membrane cell costs are greatly reduced or a stronger demand develops for salt-free caustic, the diaphragm cells will remain competitive. (WHK)

  17. Diaphragm-based fiber optic Fabry-Perot hydrophone with hydrostatic pressure compensation

    NASA Astrophysics Data System (ADS)

    Wang, Zhaogang; Zhang, Wentao; Li, Fang

    2013-09-01

    A fiber optic Fabry-Perot (FP) hydrophone with hydrostatic pressure compensation was demonstrated. A polyimide (PI) diaphragm attached on the end of an Acrylonitrile Butadiene Styrene (ABS) tube was used as the sensing element. A pair of grooves was designed in an inner ABS tube to connect the Fabry-Perot cavity with the outside environment, which made the hydrophone hydrostatic pressure compensated. The operation principle, design and testing of polyimide diaphragm-based sensor were described. Experiment results show that it has not only high stability in different hydrostatic pressures, but also flat frequency response of about 158 ±3 dB within 300-3000 Hz.

  18. Effects of cartap on isolated mouse phrenic nerve diaphragm and its related mechanism.

    PubMed

    Liao, J W; Kang, J J; Liu, S H; Jeng, C R; Cheng, Y W; Hu, C M; Tsai, S F; Wang, S C; Pang, V F

    2000-06-01

    Cartap, a nereistoxin analogue pesticide, is reported to have no irritation to eyes in rabbits. However, we have demonstrated recently that cartap could actually cause acute death in rabbits via ocular exposure. Our preliminary study with isolated mouse phrenic nerve diaphragms has shown that instead of neuromuscular blockade, cartap caused muscular contracture. The objective of the study was to examine the effect of cartap on the neuromuscular junction in more detail and to investigate its possible underlying mechanism with isolated mouse phrenic nerve diaphragms and sarcoplasmic reticulum (SR) vesicles. Cartap or nereistoxin at various concentrations was added in the organ bath with isolated mouse phrenic nerve diaphragm and both nerve- and muscle-evoked twitches were recorded. Instead of blocking the neuromuscular transmission as nereistoxin did, cartap caused contracture in stimulated or quiescent isolated mouse phrenic nerve diaphragm. Both the cartap-induced muscular contracture force and the time interval to initiate the contracture were dose-dependent. The contracture induced by cartap was not affected by the pretreatment of the diaphragm with the acetylcholine receptor blocker alpha-bungarotoxin; the Na(+) channel blocker tetrodotoxin; or various Ca(2+) channel blockers, NiCl(2), verapamil, and nifedipine. On the contrary, the contracture was significantly inhibited when the diaphragm was pretreated with ryanodine or EGTA containing Ca(2+)-free Krebs solution or in combination. This suggested that both internal and extracellular Ca(2+) might participate in cartap-induced skeletal muscle contracture. Moreover, cartap inhibited the [(3)H]-ryanodine binding to the Ca(2+) release channel of SR in a dose-dependent manner. Additionally, cartap could induce a significant reduction in Ca(2+)-ATPase activity of SR vesicles at a relatively high dose. The results suggested that cartap might cause the influx of extracellular Ca(2+) and the release of internal Ca(2

  19. WE-G-18C-06: Is Diaphragm Motion a Good Surrogate for Liver Tumor Motion?

    SciTech Connect

    Yang, J; Cai, J; Zheng, C; Czito, B; Palta, M; Yin, F; Wang, H; Bashir, M

    2014-06-15

    Purpose: To investigate whether diaphragm motion is a good surrogate for liver tumor motion by comparing their motion trajectories obtained from cine-MRI. Methods: Fourteen patients with hepatocellular carcinoma (10/14) or liver metastases (4/14) undergoing radiation therapy were included in this study. All patients underwent single-slice 2D cine-MRI simulations across the center of the tumor in three orthogonal planes. Tumor and diaphragm motion trajectories in the superior-inferior (SI), anteriorposterior (AP), and medial-lateral (ML) directions were obtained using the normalized cross-correlation based tracking technique. Agreement between tumor and diaphragm motions was assessed by calculating the phase difference percentage (PDP), intra-class correlation coefficient (ICC), Bland-Altman analysis (Diffs) and paired t-test. The distance (D) between tumor and tracked diaphragm area was analyzed to understand its impact on the correlation between tumor and diaphragm motions. Results: Of all patients, the means (±standard deviations) of PDP were 7.1 (±1.1)%, 4.5 (±0.5)% and 17.5 (±4.5)% in the SI, AP and ML directions, respectively. The means of ICC were 0.98 (±0.02), 0.97 (±0.02), and 0.08 (±0.06) in the SI, AP and ML directions, respectively. The Diffs were 2.8 (±1.4) mm, 2.4 (±1.1) mm, and 2.2 (±0.5) mm in the SI, AP and ML directions, respectively. The p-values derived from the paired t-test were < 0.02 in SI and AP directions, whereas were > 0.58 in ML direction primarily due to the small motion in ML direction. Tumor and diaphragmatic motion had high concordance when the distance between the tumor and tracked diaphragm areas was small. Conclusion: Preliminary results showed that liver tumor motion had good correlations with diaphragm motion in the SI and AP directions, indicating diaphragm motion in the SI and AP directions could potentially be a reliable surrogate for liver tumor motion. NIH (1R21CA165384-01A1), Golfers Against Cancer (GAC

  20. Respiratory muscle activity during REM sleep in patients with diaphragm paralysis.

    PubMed

    Bennett, J R; Dunroy, H M A; Corfield, D R; Hart, N; Simonds, A K; Polkey, M I; Morrell, M J

    2004-01-13

    The diaphragm is the main inspiratory muscle during REM sleep. It was hypothesized that patients with isolated bilateral diaphragm paralysis (BDP) might not be able to sustain REM sleep. Polysomnography with EMG recordings was undertaken from accessory respiratory muscles in patients with BDP and normal subjects. Patients with BDP had a normal quantity of REM sleep (mean +/- SD, 18.6 +/- 7.5% of total sleep time) achieved by inspiratory recruitment of extradiaphragmatic muscles in both tonic and phasic REM, suggesting brainstem reorganization.

  1. Diaphragm-based extrinsic Fabry-Perot interferometric optical fiber sensor for acoustic wave detection under high background pressure

    NASA Astrophysics Data System (ADS)

    Han, Ming; Wang, Xingwei; Xu, Jucheng; Cooper, Kristie L.; Wang, Anbo

    2005-06-01

    A new structure for diaphragm-based extrinsic Fabry-Perot interferometric (EFPI) optical fiber sensors is presented. This structure introduces a through hole in a conventional diaphragm-based EFPI sensor and significantly reduces the effect of operating point drift due to the background pressure and fluctuations. This structure also potentially has high temperature stability.

  2. Improving the Performance of Two-Stage Gas Guns By Adding a Diaphragm in the Pump Tube

    NASA Technical Reports Server (NTRS)

    Bogdanoff, D. W.; Miller, Robert J.

    1995-01-01

    Herein, we study the technique of improving the gun performance by installing a diaphragm in the pump tube of the gun. A CFD study is carried out for the 0.28 in. gun in the Hypervelocity Free Flight Radiation (HFF RAD) range at the NASA Ames Research Center. The normal, full-length pump tube is studied as well as two pump tubes of reduced length (approximately 75% and approximately 33% of the normal length). Significant improvements in performance are calculated to be gained for the reduced length pump tubes upon the addition of the diaphragm. These improvements are identified as reductions in maximum pressures in the pump tube and at the projectile base of approximately 20%, while maintaining the projectile muzzle velocity or as increases in muzzle velocity of approximately 0.5 km/sec while not increasing the maximum pressures in the gun. Also, it is found that both guns with reduced pump tube length (with diaphragms) could maintain the performance of gun with the full length pump tube without diaphragms, whereas the guns with reduced pump tube lengths without diaphragms could not. A five-shot experimental investigation of the pump tube diaphragm technique is carried out for the gun with a pump tube length of 75% normal. The CFD predictions of increased muzzle velocity are borne out by the experimental data. Modest, but useful muzzle velocity increases (2.5 - 6%) are obtained upon the installation of a diaphragm, compared to a benchmark shot without a diaphragm.

  3. Pickering NGS 1990 vacuum building outage: Inspection of pressure-relief -valve diaphragms. Report No. 90-203-K

    SciTech Connect

    Lewak, R.J.

    1990-01-01

    This report details the Pickering Nuclear Generating Station inspection of the replacement of both upper and lower neoprene rolling diaphragms with EPDM (Ethylene-Propylene-Diene Monomer) rolling diaphragms in the pressure relief valves which isolate the atmosphere of the pressure relief duct from that of the vacuum building.

  4. Wall Turbulence.

    ERIC Educational Resources Information Center

    Hanratty, Thomas J.

    1980-01-01

    This paper gives an account of research on the structure of turbulence close to a solid boundary. Included is a method to study the flow close to the wall of a pipe without interferring with it. (Author/JN)

  5. Effects of prosthetic reconstruction of the abdominal wall on respiratory mechanics in rats.

    PubMed

    Rocco, P R; Fonseca, S M; Pinto, A P; Medeiros, A S; Contador, R S; Zin, W A

    1999-01-01

    Respiratory mechanics and thoracoabdominal morphometry were determined in four sets of animal experiments before and after surgery. In group RRA the rectus abdominus muscles were removed; in RRAH rats the muscle resection was followed by lung hyperinflation; in PPM animals the defect was repaired by suturing a polypropylene mesh (Marlex); and in PPMH lung hyperinflation was performed after abdominal wall reconstruction. Lung and chest wall elastances, and chest wall viscoelastic/inhomogeneous pressures increased in RRA, RRAH and PPM groups. Static lung elastance was progressively smaller in the following order: RRA, PPM, and PPMH. In conclusion, removal of the rectus abdominus muscles and abdominal wall reconstruction could account for higher energy losses against viscoelastic and elastic forces acting on the chest wall, and these are related to a cephalad deviation of the diaphragm. Furthermore, hyperinflation reverses lung elastic modification after abdominal wall reconstruction with PPM, without beneficial effects in the presence of abdominal wall defect.

  6. Acceptability and use of the female condom and diaphragm among sex workers in Dominican Republic: results from a prospective study.

    PubMed

    Lara, Diana K; Grossman, Daniel A; Muñoz, Jhoanne E; Rosario, Santo R; Gómez, Bayardo J; García, Sandra G

    2009-12-01

    To assess the acceptability and use of the female condom and diaphragm among female sex workers in the Dominican Republic, 243 participants were followed for 5 months. Participants received female and male condoms and a diaphragm along with proper counseling at monthly visits. Seventy-six percent reported used of female condom at least once during the final month of the study, compared with 50% that used the diaphragm with male condoms and 9% that used the diaphragm alone. The proportion of women reporting every sex act protected with some barrier method increased from 66% at first month to 77% at final month (p < 0.05). Participants reported higher acceptability and use of the female condom than the diaphragm. The introduction of female-controlled barrier methods resulted in the use of a wide range of prevention methods and a significant reduction in unprotected sex.

  7. Hydrogen sulfide prevents diaphragm weakness in cecal ligation puncture-induced sepsis by preservation of mitochondrial function

    PubMed Central

    Zhang, Hai-Xia; Du, Jun-Ming; Ding, Zhong-Nuo; Zhu, Xiao-Yan; Jiang, Lai; Liu, Yu-Jian

    2017-01-01

    Mitochondrial dysfunction plays an important role in the pathogenesis of diaphragm weakness during sepsis. Recently, hydrogen sulfide (H2S), a gaseous transmitter endogenously generated by cystathionine-β-synthase (CBS), cystathionine-γ-lyase (CSE) and 3-mercaptopyruvate sulfurtransferase (3-MST), is found to improve mitochondrial function. The present study aimed to examine whether H2S synthases are expressed in the diaphragm, and investigated the effect of H2S donor in sepsis-induced diaphragm weakness and its relationship with mitochondrial function. Immunohistochemical staining of the rat diaphragm revealed that positive immunoreactivity for CBS, CSE as well as 3-MST was predominately localized to muscle cells. Using a cecal ligation and puncture (CLP)-induced sepsis model, it was found that CBS and CSE, but not 3-MST, was significantly down-regulated in the diaphragm at 24 h post-CLP compared with sham group. To determine the effect of H2S on sepsis-induced diaphragm weakness, H2S donor NaHS was intraperitoneally administered 30 min after CLP operation. NaHS at a dose of 50 μmol/kg significantly decreased the mortality in septic rats. CLP markedly reduced diaphragm-specific force generation (force/cross-sectional area and maximal titanic force), which was improved by NaHS treatment. In addition, CLP caused mitochondrial damage in the diaphragm tissues as evidenced by increased mitochondrial superoxide production, decreased mitochondrial membrane potential and ATP production, as well as mitochondrial ultrastructural abnormalities, which was also attenuated by NaHS treatment. These findings indicate that H2S donor may prevent sepsis-induced diaphragm weakness by preservation of mitochondrial function, suggesting that modulation of H2S levels may be considered as a potential therapeutic approach for diaphragm dysfunction during sepsis. PMID:28804545

  8. Hydrogen sulfide prevents diaphragm weakness in cecal ligation puncture-induced sepsis by preservation of mitochondrial function.

    PubMed

    Zhang, Hai-Xia; Du, Jun-Ming; Ding, Zhong-Nuo; Zhu, Xiao-Yan; Jiang, Lai; Liu, Yu-Jian

    2017-01-01

    Mitochondrial dysfunction plays an important role in the pathogenesis of diaphragm weakness during sepsis. Recently, hydrogen sulfide (H2S), a gaseous transmitter endogenously generated by cystathionine-β-synthase (CBS), cystathionine-γ-lyase (CSE) and 3-mercaptopyruvate sulfurtransferase (3-MST), is found to improve mitochondrial function. The present study aimed to examine whether H2S synthases are expressed in the diaphragm, and investigated the effect of H2S donor in sepsis-induced diaphragm weakness and its relationship with mitochondrial function. Immunohistochemical staining of the rat diaphragm revealed that positive immunoreactivity for CBS, CSE as well as 3-MST was predominately localized to muscle cells. Using a cecal ligation and puncture (CLP)-induced sepsis model, it was found that CBS and CSE, but not 3-MST, was significantly down-regulated in the diaphragm at 24 h post-CLP compared with sham group. To determine the effect of H2S on sepsis-induced diaphragm weakness, H2S donor NaHS was intraperitoneally administered 30 min after CLP operation. NaHS at a dose of 50 μmol/kg significantly decreased the mortality in septic rats. CLP markedly reduced diaphragm-specific force generation (force/cross-sectional area and maximal titanic force), which was improved by NaHS treatment. In addition, CLP caused mitochondrial damage in the diaphragm tissues as evidenced by increased mitochondrial superoxide production, decreased mitochondrial membrane potential and ATP production, as well as mitochondrial ultrastructural abnormalities, which was also attenuated by NaHS treatment. These findings indicate that H2S donor may prevent sepsis-induced diaphragm weakness by preservation of mitochondrial function, suggesting that modulation of H2S levels may be considered as a potential therapeutic approach for diaphragm dysfunction during sepsis.

  9. Thoracic meningocele in lumbo-costo-vertebral syndrome in a child: possible enlargement with repeated motion by anchoring to the diaphragm.

    PubMed

    Wataya, Takafumi; Horikawa, Kyohei; Kitagawa, Masashi; Tashiro, Yuzuru

    2016-08-01

    Lumbo-costo-vertebral syndrome (LCVS) is a rare disorder in children that is characterized by hemivertebrae, congenital absence of ribs, meningocele, and hypoplasia of the truncal and abdominal wall presenting as a congenital lumbar hernia. An otherwise healthy 12-month-old girl was referred to the authors' hospital with soft swelling on her left middle back; scoliosis had been present since birth. Imaging revealed a thoracic meningocele, ectopia of the spleen suggesting lumbar hernia, multiple anomalies of the thoracic vertebral columns, and defects of the ribs; thus, LCVS was diagnosed. Surgical observation revealed that the meningocele was firmly anchored to part of the diaphragm, which created stretching tension in the meningocele continuously with exhalation. Once detached, the meningocele shrank spontaneously and never developed again after cauterization. In this case, continuous or pulsatile pressure in the presence of a vertebral defect was thus considered to be an important factor for formation of the thoracic meningocele.

  10. The effect of hypodynamia on the structure of the intraorganic blood vessels and the capacity of the blood stream in the diaphragm of white rats

    NASA Technical Reports Server (NTRS)

    Gerus, A. I.

    1980-01-01

    The effect of hypodynamia on the vascular system of white rats with diaphragm deprivation was investigated. Morphological changes in the intraorganic blood stream of the diaphragm were determined. The capacity of the intraorganic vascular flow within the diaphragm muscles was established.

  11. Age and Chest-wall Physiology

    NASA Astrophysics Data System (ADS)

    Ferenc, Kovats

    1986-07-01

    The mechanisme of the breathing pump-system changes with age. Morphometrical informations are presented by means of Photogrammetry.The effectiveness of the diaphragm contraction in relation to the ribcage was observed with trunc-surface deforrnations.The thorax-wall of new-borns and sucklings are pliable:the diaphragm action sipps the ribcage. Growing childrens thorax can resist against this sipping effect, but practically they have no thoracal, only abdominal breathing.Later in childhood the thoracal breathing type developps individually. Introduction Since 1974 I have the honour to participate with my papers on several Biostereometrics Session. At that time I had 15 years of Photogrammetry study of the breathing movements behind me. Based on Photogrammetrical documentations I worked with manual geometry, constructing my designes,hoping, that I can elaborate a model-method and to grope around the photogrammetrical possibilities in the study of the mechanism of the human breathing pump-system. Using a ruler and a pair of compasses, with steady obstinacy I arrived to realise three abstractions:Spatial; spatiotemporal analysis informations and the velocity or the acceleration factors, this last one being the most sensitive. Recently I made the-first steps to study four dimensional information, with two time factors.

  12. Where Did the Water Go?: Boyle's Law and Pressurized Diaphragm Water Tanks

    ERIC Educational Resources Information Center

    Brimhall, James; Naga, Sundar

    2007-01-01

    Many homes use pressurized diaphragm tanks for storage of water pumped from an underground well. These tanks are very carefully constructed to have separate internal chambers for the storage of water and for the air that provides the pressure. One might expect that the amount of water available for use from, for example, a 50-gallon tank would be…

  13. Electrophysiological and Ultrastructural Characterization of Neuromuscular Junctions in Diaphragm Muscle of Acetylcholinesterase Knockout Mice

    DTIC Science & Technology

    2008-04-01

    Electrophysiological and Ultrastructural Characterization of Neuromuscular Junctions in 5a. CONTRACT NUMBER Diaphragm Muscle of Acetylcholinesterase Knockout Mice...AChE +/+) and acetylcholinesterase knockout (AChE -/-) mice to determine the compensatory mechanism manifested by the neuromuscular junction to...had smaller nerve terminals and diminished pre- and postsynaptic surface contacts relative to neuromuscular junctions of AChE +/+ mice. The

  14. Studies on neuromuscular blockade by boldine in the mouse phrenic nerve-diaphragm.

    PubMed

    Kang, J J; Cheng, Y W; Fu, W M

    1998-02-01

    The effects of boldine [(S)-2,9-dihydroxyl-1,10-dimethoxy-aporphine], a major alkaloid in the leaves and bark of Boldo (Peumus boldus Mol.), on neuromuscular transmission were studied using a muscle phrenic-nerve diaphragm preparation. Boldine at concentrations lower than 200 microM preferentially inhibited, after an initial period of twitch augmentation, the nerve-evoked twitches of the mouse diaphragm and left the muscle-evoked twitches unaffected. The twitch inhibition could be restored by neostigmine or washout with Krebs solution. The twitches evoked indirectly and directly were both augmented initially, suggesting that the twitch augmentation induced by boldine was myogenic. Boldine inhibited the acetylcholine-induced contraction of denervated diaphragm dose-dependently with an IC50 value of 13.5 microM. At 50 microM, boldine specifically inhibited the amplitude of the miniature end plate potential. In addition, boldine was similar to d-tubocurarine in its action to reverse the neuromuscular blocking action of alpha-bungarotoxin. These results showed that the neuromuscular blockade by boldine on isolated mouse phrenic-nerve diaphragm might be due to its direct interaction with the postsynaptic nicotinic acetylcholine receptor.

  15. Novel diaphragm microfabrication techniques for high-sensitivity biomedical fiber optic Fabry-Perot interferometric sensors

    NASA Astrophysics Data System (ADS)

    Poeggel, Sven; Tosi, Daniele; Duraibabu, Dineshbabu; Kelly, James; Munroe, Maria; Leen, Gabriel; Lewis, Elfed

    2014-06-01

    In this paper new algorithms and procedures are reported which enable miniaturization and optimization of the thickness of a diaphragm for an all-glass extrinsic Fabry-Perot interferometer (EFPI)-based pressure sensor. Diaphragm etching improves the EFPI sensors ability to detect relatively small changes in pressure (0.1mmHg) and the resulting sensor exhibits excellent stability over time (drift < 1 mmHg / hour) for measurement in air and liquid. The diaphragm etching procedure involves fiber polishing followed by etching in hydrofluoric (HF) acid. An additional Ion-beam etching technique was investigated separately to compare with the HF-etching technique. A sensitivity better than 10 10 nm/kPa, which provides a pressure resolution of 0.05mmHg, is achieved by reducing the EFPI diaphragm thickness down to less than 2μm for the miniature pressure sensor used in this investigation (overall diameter of 200μm). The techniques reported is also applicable for the fabrication of high sensitivity sensors using a smaller fiber diameter e.g. 80μm.

  16. Comparison of solar powered water pumping systems which use diaphragm pumps

    USDA-ARS?s Scientific Manuscript database

    Four solar photovoltaic (PV) powered diaphragm pumps were tested at different simulated pumping depths at the USDA-ARS Conservation and Production Research Laboratory near Bushland, Texas. Two of the pumps were designed for intermediate pumping depths (30 to 70 meters), and the other two pumps were...

  17. Surgical anatomy of the diaphragm in the anterolateral approach to the spine: a cadaveric study.

    PubMed

    Baaj, Ali A; Papadimitriou, Kyriakos; Amin, Anubhav G; Kretzer, Ryan M; Wolinsky, Jean-Paul; Gokaslan, Ziya L

    2014-06-01

    Laboratory cadaveric study. To delineate the pertinent surgical anatomy of the diaphragm during access to the anterolateral thoracolumbar junction. The general anatomy of the thoracic diaphragm is well described. The specific surgical anatomy as it pertains to the lateral and thoracoabdominal approaches to the thoracolumbar junction is not well described. Dissections were performed on adult fresh cadaveric specimens. Special attention was paid to the diaphragmatic attachments to the lower rib cage and to the spinal thoracolumbar junction. The pertinent diaphragmatic attachments to the rib cage are at the 11th and 12th ribs. Whether the diaphragm is incised or mobilized ventrally, the pertinent spinal attachments are the lateral and medial arcuate ligaments. Identifying and sectioning these structures allows for direct access to the thoracolumbar junction, particularly the L1 vertebral body. An understanding of the diaphragmatic-costal and diaphragmatic-spinal attachments is key for the safe and effective implementation of diaphragm mobilization during the lateral and thoracoabdominal approaches to the spine.

  18. Effects of diaphragm respiration exercise on pulmonary function of male smokers in their twenties.

    PubMed

    Seo, KyoChul; Park, Seung Hwan; Park, KwangYong

    2015-07-01

    [Purpose] We investigated how diaphragm respiration exercises can affect pulmonary function in long-term male smokers in their twenties. [Subjects and Methods] Twenty-eight healthy males between 20 and 29 years of age were randomly divided into an experimental and a control group (14 members each). The experiment was conducted during 30 min sessions, 3 times a week for 4 weeks. The experimental group performed diaphragm respiration exercises and the control group performed exercises using MOTOmed. Pulmonary function (tidal volume, breathing capacity, inspiratory reserve volume, inspiratory capacity, and expiratory reserve volume) was evaluated and analyzed before and after the experiment. [Results] Our results revealed significant increases in tidal volume, inspiratory reserve volume, inspiratory capacity, and breathing capacity in the experimental group. These increases were greater in the experimental group than in the control group. [Conclusion] In our study, the experimental group which performed diaphragm respiration exercises showed a greater improvement in pulmonary function compared with the control group. It is hypothesized that greater improvement in pulmonary function is expected if diaphragm respiration exercises are implemented taking into account the age of the smokers.

  19. Diaphragm structure and function in the Florida manatee (Trichechus manatus latirostris).

    PubMed

    Rommel, S; Reynolds, J E

    2000-05-01

    Relative to many other mammals, little is known about the functional morphology of the four extant species of the order Sirenia. In this study, 166 Florida manatee (Trichechus manatus latirostris) carcasses fresh enough to collect detailed anatomical information were examined to describe the gross anatomy of the diaphragm. Our results show that the Florida manatee's diaphragm differs from those of other mammals in that it: lies in a dorsal plane, rather than in the more typical transverse plane; is located dorsal to the heart and does not attach to the sternum; and attaches medially at the "I"-shaped central tendon to bony projections extending ventrally from the vertebral bodies, forming two distinct hemidiaphragms. The manatee's transverse septum is a separate structure that lies at a right angle to the diaphragm and separates the heart from the liver and other viscera. The extreme muscularity of the diaphragm and the ability of manatees to adjust their position in the water column with minimal external movement suggest that diaphragmatic contractions may change the volume of each pleural cavity to affect buoyancy, roll, and pitch. We also hypothesize that such contractions, in concert with contractions of powerful abdominal muscles, may compress gas in the massive large intestine, and thereby also contribute to buoyancy control. Copyright 2000 Wiley-Liss, Inc.

  20. Tissue damage in kidney, adrenal glands and diaphragm following extracorporeal shock wave lithotripsy.

    PubMed

    Gecit, Ilhan; Kavak, Servet; Oguz, Elif Kaval; Pirincci, Necip; Günes, Mustafa; Kara, Mikail; Ceylan, Kadir; Kaba, Mehmet; Tanık, Serhat

    2014-10-01

    This study was designed to investigate whether exposure to short-term extracorporeal shock wave lithotripsy (ESWL) produces histologic changes or induces apoptosis in the kidney, adrenal glands or diaphragm muscle in rats. The effect of shock waves on the kidney of male Wistar rats (n = 12) was investigated in an experimental setting using a special ESWL device. Animals were killed at 72 h after the last ESWL, and the tissues were stained with an in situ Cell Death Detection Kit, Fluorescein. Microscopic examination was performed by fluorescent microscopy. Apoptotic cell deaths in the renal tissue were not observed in the control group under fluorescent microscopy. In the ESWL group, local apoptotic changes were observed in the kidney in the area where the shock wave was focused. The apoptotic cell deaths observed in the adrenal gland of the control group were similar to those observed in the ESWL groups, and apoptosis was occasionally observed around the capsular structure. Apoptotic cell deaths in the diaphragm muscle were infrequently observed in the control group. Apoptosis in the ESWL group was limited to the mesothelial cells. This study demonstrated that serious kidney, adrenal gland and diaphragm muscles damage occurred following ESWL, which necessitated the removal of the organ in the rat model. It is recognized that the ESWL complications related to the kidney, adrenal gland and diaphragm muscles are rare and may be managed conservatively. © The Author(s) 2012.

  1. Mitochondrial function in diaphragm of emphysematous hamsters after treatment with nandrolone

    PubMed Central

    Wijnhoven, Hanneke JH; Ennen, Leo; Rodenburg, Richard JT; Dekhuijzen, PN Richard

    2006-01-01

    Respiratory failure in patients with COPD may be caused by insufficient force production or insufficient endurance capacity of the respiratory muscles. Anabolic steroids may improve respiratory muscle function in COPD. The effect of anabolic steroids on mitochondrial function in the diaphragm in emphysema is unknown. In an emphysematous male hamster model, we investigated whether administration of the anabolic steroid nandrolone decanoate (ND) altered the activity of mitochondrial respiratory chain complexes in the diaphragm. The bodyweight of hamsters treated with ND was decreased after treatment compared with initial values, and serum testosterone levels were significantly lower in hamsters treated with ND than in control hamsters. No difference in the activity of mitochondrial respiratory chain complexes in the diaphragm between normal and emphysematous hamsters was observed. Treatment with ND did not change the activity of mitochondrial respiratory chain complexes in the diaphragm of both normal and emphysematous hamsters. In emphysematous hamsters, administration of ND decreased the activity of succinate:cytochrome c oxidoreductase compared with ND treatment in normal hamsters. We conclude that anabolic steroids have negative effects on the activity of succinate:cytochrome c oxidoreductase and anabolic status in this emphysematous hamster model. PMID:18046906

  2. Wheel-running exercise alters rat diaphragm action potentials and their regulation by K+ channels.

    PubMed

    Van Lunteren, Erik; Moyer, Michelle

    2003-08-01

    Endurance exercise modifies regulatory systems that control skeletal muscle Na+ and K+ fluxes, in particular Na+-K+-ATPase-mediated transport of these ions. Na+ and K+ ion channels also play important roles in the regulation of ionic movements, specifically mediating Na+ influx and K+ efflux that occur during contractions resulting from action potential depolarization and repolarization. Whether exercise alters skeletal muscle electrophysiological properties controlled by these ion channels is unclear. The present study tested the hypothesis that endurance exercise modifies diaphragm action potential properties. Exercised rats spent 8 wk with free access to running wheels, and they were compared with sedentary rats living in conventional rodent housing. Diaphragm muscle was subsequently removed under anesthesia and studied in vitro. Resting membrane potential was not affected by endurance exercise. Muscle from exercised rats had a slower rate of action potential repolarization than that of sedentary animals (P = 0.0098), whereas rate of depolarization was similar in the two groups. The K+ channel blocker 3,4-diaminopyridine slowed action potential repolarization and increased action potential area of both exercised and sedentary muscle. However, these effects were significantly smaller in diaphragm from exercised than sedentary rats. These data indicate that voluntary running slows diaphragm action potential repolarization, most likely by modulating K+ channel number or function.

  3. Morphological and ultrastructural evaluation of the golden retriever muscular dystrophy trachea, lungs, and diaphragm muscle.

    PubMed

    Lessa, Thais Borges; de Abreu, Dilayla Kelly; Rodrigues, Márcio Nogueira; Brólio, Marina Pandolphi; Miglino, Maria Angélica; Ambrósio, Carlos Eduardo

    2014-11-01

    Duchenne muscular dystrophy (DMD) is a genetic disease, characterized by atrophy and muscle weakness. The respiratory failure is a common cause of early death in patients with DMD. Golden retriever muscular dystrophy (GRMD) is a canine model which has been extensively used for many advances in therapeutics applications. As the patients with DMD, the GRMD frequently died from cardiac and respiratory failure. Observing the respiratory failure in DMD is one of the major causes of mortality we aimed to describe the morphological and ultrastructural data of trachea, lungs (conductive and respiratory portion of the system), and diaphragm muscle using histological and ultrastructural analysis. The diaphragm muscle showed discontinuous fibers architecture, with different diameter; a robust perimysium inflammatory infiltrate and some muscle cells displayed central nuclei. GRMD trachea and lungs presented collagen fibers and in addition, the GRMD lungs showed higher of levels collagen fibers that could limit the alveolar ducts and alveoli distension. Therefore, the most features observed were the collagen areas and fibrosis. We suggested in this study that the collagen remodeling in the trachea, lungs, and diaphragm muscle may increase fibrosis and affect the trachea, lungs, and diaphragm muscle function that can be a major cause of respiratory failure that occur in patients with DMD. © 2014 Wiley Periodicals, Inc.

  4. Vertical Diaphragm Electrostatic Actuator for a High Density Ink Jet Printer Head

    NASA Astrophysics Data System (ADS)

    Norimatsu, Takayuki; Tanaka, Shuji; Esashi, Masayoshi

    This paper describes the design, fabrication process and preliminary evaluation of an electrostatic ink jet printer head with vertical diaphragms in deep trenches. By adopting the novel structure where an ink cavity is surrounded by the vertical diaphragm, the footprint of each unit (40 μm × 500 μm) becomes approximately one fifth as small as that of a conventional one. Such small footprint is advantageous in cost, resolution and printing speed. To make the vertical diaphragms, a 0.5 μm thick sacrificial thermally-oxidized layer and a 4.5 μm thick poly-silicon layer are sequentially formed in deep-reactive-ion-etched trenches, and then the sacrificial layer is etched away by fluoric acid. The nozzles are fabricated on a Pyrex glass substrate by femtosecond laser ablation, and the nozzle outside is covered with a water repellant Au/Pt/Ti layer. Impedance measurement found that the electrostatic gaps were in contact or closely approaching. This could be because the diaphragms buckled by compressive stress induced in low pressure chemical vapor deposition (LPCVD). Ink ejection was tried using commercially-available blue ink, but failed. The nozzles were covered with the ink, because the water repellant finish of the nozzle outside was not good.

  5. Experimental research of the synthetic jet generator designs based on actuation of diaphragm with piezoelectric actuator

    NASA Astrophysics Data System (ADS)

    Rimasauskiene, R.; Matejka, M.; Ostachowicz, W.; Kurowski, M.; Malinowski, P.; Wandowski, T.; Rimasauskas, M.

    2015-01-01

    Experimental analyses of four own developed synthetic jet generator designs were presented in this paper. The main task of this work was to find the most appropriate design of the synthetic jet generator. Dynamic characteristics of the synthetic jet generator's diaphragm with piezoelectric material were measured using non-contact measuring equipment laser vibrometer Polytec®PSV 400. Temperatures of the piezoelectric diaphragms working in resonance frequency were measured with Fiber Bragg Grating (FBG) sensor. Experimental analysis of the synthetic jet generator amplitude-frequency characteristics were performed using CTA (hot wire anemometer) measuring techniques. Piezoelectric diaphragm in diameter of 27 mm was excited by sinusoidal voltage signal and it was fixed tightly inside the chamber of the synthetic jet generator. The number of the synthetic jet generator orifices (1 or 3) and volume of cavity (height of cavity vary from 0.5 mm to 1.5 mm) were changed. The highest value of the synthetic jet velocity 25 m/s was obtained with synthetic jet generator which has cavity 0.5 mm and 1 orifice (resonance frequency of the piezoelectric diaphragm 2.8 kHz). It can be concluded that this type of the design is preferred in order to get the peak velocity of the synthetic jet.

  6. Vanadium diaphragm electrode serves as hydrogen diffuser in lithium hydride cell

    NASA Technical Reports Server (NTRS)

    Crouthamel, C. E.; Heinrich, R. R.; Johnson, C. E.

    1967-01-01

    Lithium hydride cell uses vanadium diaphragm electrode as a hydrogen diffuser. Vanadium is high in hydrogen gas solubility and permeability, is least sensitive to adverse surface effects, maintains good mechanical strength in hydrogen atmospheres, and appears to be compatible with all alkali-halide electrolytes and lithium metals.

  7. The JAK–STAT Pathway Is Critical in Ventilator-Induced Diaphragm Dysfunction

    PubMed Central

    Tang, Huibin; Smith, Ira J; Hussain, Sabah NA; Goldberg, Peter; Lee, Myung; Sugiarto, Sista; Godinez, Guillermo L; Singh, Baljit K; Payan, Donald G; Rando, Thomas A; Kinsella, Todd M; Shrager, Joseph B

    2014-01-01

    Mechanical ventilation (MV) is one of the lynchpins of modern intensive-care medicine and is life saving in many critically ill patients. Continuous ventilator support, however, results in ventilation-induced diaphragm dysfunction (VIDD) that likely prolongs patients’ need for MV and thereby leads to major associated complications and avoidable intensive care unit (ICU) deaths. Oxidative stress is a key pathogenic event in the development of VIDD, but its regulation remains largely undefined. We report here that the JAK–STAT pathway is activated in MV in the human diaphragm, as evidenced by significantly increased phosphorylation of JAK and STAT. Blockage of the JAK–STAT pathway by a JAK inhibitor in a rat MV model prevents diaphragm muscle contractile dysfunction (by ~85%, p < 0.01). We further demonstrate that activated STAT3 compromises mitochondrial function and induces oxidative stress in vivo, and, interestingly, that oxidative stress also activates JAK–STAT. Inhibition of JAK–STAT prevents oxidative stress-induced protein oxidation and polyubiquitination and recovers mitochondrial function in cultured muscle cells. Therefore, in ventilated diaphragm muscle, activation of JAK–STAT is critical in regulating oxidative stress and is thereby central to the downstream pathogenesis of clinical VIDD. These findings establish the molecular basis for the therapeutic promise of JAK–STAT inhibitors in ventilated ICU patients. PMID:25286450

  8. The JAK-STAT pathway is critical in ventilator-induced diaphragm dysfunction.

    PubMed

    Tang, Huibin; Smith, Ira J; Hussain, Sabah N A; Goldberg, Peter; Lee, Myung; Sugiarto, Sista; Godinez, Guillermo L; Singh, Baljit K; Payan, Donald G; Rando, Thomas A; Kinsella, Todd M; Shrager, Joseph B

    2015-02-19

    Mechanical ventilation (MV) is one of the lynchpins of modern intensive-care medicine and is life saving in many critically ill patients. Continuous ventilator support, however, results in ventilation-induced diaphragm dysfunction (VIDD) that likely prolongs patients' need for MV and thereby leads to major associated complications and avoidable intensive care unit (ICU) deaths. Oxidative stress is a key pathogenic event in the development of VIDD, but its regulation remains largely undefined. We report here that the JAK-STAT pathway is activated in MV in the human diaphragm, as evidenced by significantly increased phosphorylation of JAK and STAT. Blockage of the JAK-STAT pathway by a JAK inhibitor in a rat MV model prevents diaphragm muscle contractile dysfunction (by ~85%, p < 0.01). We further demonstrate that activated STAT3 compromises mitochondrial function and induces oxidative stress in vivo, and, interestingly, that oxidative stress also activates JAK-STAT. Inhibition of JAK-STAT prevents oxidative stress-induced protein oxidation and polyubiquitination and recovers mitochondrial function in cultured muscle cells. Therefore, in ventilated diaphragm muscle, activation of JAK-STAT is critical in regulating oxidative stress and is thereby central to the downstream pathogenesis of clinical VIDD. These findings establish the molecular basis for the therapeutic promise of JAK-STAT inhibitors in ventilated ICU patients.

  9. Influence of space flight factors on the ultrastructure of rat diaphragm muscle.

    PubMed

    Babakova, L L; Baranov, V M; Pozdnyakov, O M

    2013-05-01

    Analysis of ultrastructural changes in diaphragm muscle and synaptic apparatus after 7- and 14-day biosatellite spaceflight showed destructive and atrophic changes that developed starting from in the early terms of exposure. Structural alterations of different severity were revealed in all elements of the muscle (muscle fibers, neuromuscular junctions, intramuscular nerves, and blood vessels) and were paralleled by activation of regeneration processes.

  10. CFD Fuel Slosh Modeling of Fluid-Structure Interaction in Spacecraft Propellant Tanks with Diaphragms

    NASA Technical Reports Server (NTRS)

    Sances, Dillon J.; Gangadharan, Sathya N.; Sudermann, James E.; Marsell, Brandon

    2010-01-01

    Liquid sloshing within spacecraft propellant tanks causes rapid energy dissipation at resonant modes, which can result in attitude destabilization of the vehicle. Identifying resonant slosh modes currently requires experimental testing and mechanical pendulum analogs to characterize the slosh dynamics. Computational Fluid Dynamics (CFD) techniques have recently been validated as an effective tool for simulating fuel slosh within free-surface propellant tanks. Propellant tanks often incorporate an internal flexible diaphragm to separate ullage and propellant which increases modeling complexity. A coupled fluid-structure CFD model is required to capture the damping effects of a flexible diaphragm on the propellant. ANSYS multidisciplinary engineering software employs a coupled solver for analyzing two-way Fluid Structure Interaction (FSI) cases such as the diaphragm propellant tank system. Slosh models generated by ANSYS software are validated by experimental lateral slosh test results. Accurate data correlation would produce an innovative technique for modeling fuel slosh within diaphragm tanks and provide an accurate and efficient tool for identifying resonant modes and the slosh dynamic response.

  11. Where Did the Water Go?: Boyle's Law and Pressurized Diaphragm Water Tanks

    ERIC Educational Resources Information Center

    Brimhall, James; Naga, Sundar

    2007-01-01

    Many homes use pressurized diaphragm tanks for storage of water pumped from an underground well. These tanks are very carefully constructed to have separate internal chambers for the storage of water and for the air that provides the pressure. One might expect that the amount of water available for use from, for example, a 50-gallon tank would be…

  12. Central and peripheral defects in motor units of the diaphragm of spinal muscular atrophy mice.

    PubMed

    Neve, Anuja; Trüb, Judith; Saxena, Smita; Schümperli, Daniel

    2016-01-01

    Spinal muscular atrophy (SMA) is characterized by motoneuron loss and muscle weakness. However, the structural and functional deficits that lead to the impairment of the neuromuscular system remain poorly defined. By electron microscopy, we previously found that neuromuscular junctions (NMJs) and muscle fibres of the diaphragm are among the earliest affected structures in the severe mouse SMA model. Because of certain anatomical features, i.e. its thinness and its innervation from the cervical segments of the spinal cord, the diaphragm is particularly suitable to characterize both central and peripheral events. Here we show by immunohistochemistry that, at postnatal day 3, the cervical motoneurons of SMA mice receive less stimulatory synaptic inputs. Moreover, their mitochondria become less elongated which might represent an early stage of degeneration. The NMJs of the diaphragm of SMA mice show a loss of synaptic vesicles and active zones. Moreover, the partly innervated endplates lack S100 positive perisynaptic Schwann cells (PSCs). We also demonstrate the feasibility of comparing the proteomic composition between diaphragm regions enriched and poor in NMJs. By this approach we have identified two proteins that are significantly upregulated only in the NMJ-specific regions of SMA mice. These are apoptosis inducing factor 1 (AIFM1), a mitochondrial flavoprotein that initiates apoptosis in a caspase-independent pathway, and four and a half Lim domain protein 1 (FHL1), a regulator of skeletal muscle mass that has been implicated in several myopathies. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  13. Phrenic nerve pacing in a tetraplegic patient via intramuscular diaphragm electrodes.

    PubMed

    DiMarco, Anthony F; Onders, Raymond P; Kowalski, Krzysztof E; Miller, Michael E; Ferek, Sandra; Mortimer, J Thomas

    2002-12-15

    In patients with ventilator-dependent tetraplegia, phrenic nerve pacing (PNP) provides significant clinical advantages compared with mechanical ventilation. This technique however generally requires a thoracotomy with its associated risks and in-patient hospital stay and carries some risk of phrenic nerve injury. We have developed a method by which the phrenic nerves can be activated via intramuscular diaphragm electrodes. In one patient with ventilator-dependent tetraplegia, two intramuscular diaphragm electrodes were implanted into each hemidiaphragm near the phrenic nerve motor points via laparoscopic surgery. The motor points were identified employing a previously devised mapping technique. Because inspired volumes were suboptimal on the right, a second laparoscopic procedure was necessary to position electrodes near the anterior and posterior branches of the right phrenic nerve. During bilateral stimulation, inspired volume was 580 ml. After a reconditioning program of progressively increasing diaphragm pacing, maximum inspired volumes on the left and right hemidiaphragms increased significantly. Maximum combined bilateral stimulation was 1120 ml. Importantly, the patient has been able to comfortably tolerate full-time pacing. If confirmed in additional patients, PNP with intramuscular diaphragm electrodes via laparoscopic surgery may provide a less invasive and less costly alternative to conventional PNP.

  14. Protection by pyridostigmine bromide of marmoset hemi-diaphragm acetylcholinesterase activity after soman exposure.

    PubMed

    Haigh, Julian R; Adler, Michael; Apland, James P; Deshpande, Sharad S; Barham, Charles B; Desmond, Patrick; Koplovitz, Irwin; Lenz, David E; Gordon, Richard K

    2010-09-06

    Pyridostigmine bromide (PB) was approved by the U.S. Food and Drug Administration (FDA) in 2003 as a pretreatment in humans against the lethal effects of the irreversible nerve agent soman (GD). Organophosphate (OP) chemical warfare agents such as GD exert their toxic effects by inhibiting acetylcholinesterase (AChE) from terminating the action of acetylcholine at postsynaptic sites in cholinergic nerve terminals (including crucial peripheral muscle such as diaphragm). As part of the post-marketing approval of PB, the FDA required (under 21CFR314, the "two animal rule") the study of a non-human primate model (the common marmoset Callithrix jacchus jacchus) to demonstrate increased survival against lethal GD poisoning, and protection of physiological hemi-diaphragm function after PB pretreatment and subsequent GD exposure. Marmosets (male and female) were placed in the following experimental groups: (i) control (saline pretreatment only), (ii) low dose PB (12.5 microg/kg), or (iii) high dose (39.5 microg/kg) PB. Thirty minutes after the PB dose, animals were challenged with either saline (control) or soman (GD, 45 microg/kg), followed 1 min later by atropine (2mg/kg) and 2-PAM (25mg/kg). After a further 16 min, animals were euthanized and the complete diaphragm removed; the right hemi-diaphragm was frozen immediately at -80 degrees C, and the left hemi-diaphragm was placed in a tissue bath for 4h (to allow for decarbamylation to occur), then frozen. AChE activities were determined using the automated WRAIR cholinesterase assay. Blood samples were collected for AChE activities prior to PB, before GD challenge, and after sacrifice. RBC-AChE was inhibited by approximately 18% and 50% at the low and high doses of PB, respectively, compared to control (baseline) activity. In the absence of PB pretreatment, the inhibition of RBC-AChE by GD was 98%. The recovery of hemi-diaphragm AChE activity after the 4h wash period (decarbamylation) was approximately 8% and 17%, at the

  15. Muscle reorganisation through local injection of stem cells in the diaphragm of mdx mice

    PubMed Central

    2012-01-01

    Background The diaphragm is the major respiratory muscle affected by Duchenne muscular dystrophy (DMD) and is responsible for causing 80% of deaths. The use of mechanical forces that act on the body or intermittent pressure on the airways improves the quality of life of patients but does not prevent the progression of respiratory failure. Thus, diseases that require tissue repair, such as DMD, represent a group of pathologies that have great potential for cell therapy. The application of stem cells directly into the diaphragm instead of systemic application can reduce cell migration to other affected areas and increase the chances of muscle reorganisation. The mdx mouse is a suitable animal model for this research because its diaphragmatic phenotype is similar to human DMD. Therefore, the aim of this study was to assess the potential cell implantation in the diaphragm muscle after the xenotransplantation of stem cells. Methods A total of 9 mice, including 3 control BALB/Cmice, 3 5-month-old mdx mice without stem cell injections and 3 mdx mice injected with stem cells, were used. The animals injected with stem cells underwent laparoscopy so that stem cells from GFP-labelled rabbit olfactory epithelium could be locally injected into the diaphragm muscle. After 8 days, all animals were euthanised, and the diaphragm muscle was dissected and subjected to histological and immunohistochemical analyses. Results Both the fresh diaphragm tissue and immunohistochemical analyses showed immunopositive GFP labelling of some of the cells and immunonegativity of myoblast bundles. In the histological analysis, we observed a reduction in the inflammatory infiltrate as well as the presence of a few peripheral nuclei and myoblast bundles. Conclusion We were able to implant stem cells into the diaphragm via local injection, which promoted moderate muscle reorganisation. The presence of myoblast bundles cannot be attributed to stem cell incorporation because there was no immunopositive

  16. 'Stucco' Walls

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This projected mosaic image, taken by the microscopic imager, an instrument located on the Mars Exploration Rover Opportunity 's instrument deployment device, or 'arm,' shows the partial clotting or cement-like properties of the sand-sized grains within the trench wall. The area in this image measures approximately 3 centimeters (1.2 inches) wide and 5 centimeters (2 inches) tall.(This image also appears as an inset on a separate image from the rover's navigation camera, showing the location of this particular spot within the trench wall.)

  17. 'Stucco' Walls

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This projected mosaic image, taken by the microscopic imager, an instrument located on the Mars Exploration Rover Opportunity 's instrument deployment device, or 'arm,' shows the partial clotting or cement-like properties of the sand-sized grains within the trench wall. The area in this image measures approximately 3 centimeters (1.2 inches) wide and 5 centimeters (2 inches) tall.(This image also appears as an inset on a separate image from the rover's navigation camera, showing the location of this particular spot within the trench wall.)

  18. Diaphragm assessment in mice overexpressing phospholamban in slow-twitch type I muscle fibers.

    PubMed

    Fajardo, Val Andrew; Smith, Ian Curtis; Bombardier, Eric; Chambers, Paige J; Quadrilatero, Joe; Tupling, Allan Russell

    2016-06-01

    Phospholamban (PLN) and sarcolipin (SLN) are small inhibitory proteins that regulate the sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA) pump. Previous work from our laboratory revealed that in the soleus and gluteus minimus muscles of mice overexpressing PLN (Pln (OE)), SERCA function was impaired, dynamin 2 (3-5 fold) and SLN (7-9 fold) were upregulated, and features of human centronuclear myopathy (CNM) were observed. Here, we performed structural and functional experiments to evaluate whether the diaphragm muscles of the Pln (OE) mouse would exhibit CNM pathology and muscle weakness. Diaphragm muscles from Pln (OE) and WT mice were subjected to histological/histochemical/immunofluorescent staining, Ca(2+)-ATPase and Ca(2+) uptake assays, Western blotting, and in vitro electrical stimulation. Our results demonstrate that PLN overexpression reduced SERCA's apparent affinity for Ca(2+) but did not reduce maximal SERCA activity or rates of Ca(2+) uptake. SLN was upregulated 2.5-fold, whereas no changes in dynamin 2 expression were found. With respect to CNM, we did not observe type I fiber predominance, central nuclei, or central aggregation of oxidative activity in diaphragm, although type I fiber hypotrophy was present. Furthermore, in vitro contractility assessment of Pln (OE) diaphragm strips revealed no reductions in force-generating capacity, maximal rates of relaxation or force development, but did indicate that ½ relaxation time was prolonged. Therefore, the effects of PLN overexpression on skeletal muscle phenotype differ between diaphragm and the postural soleus and gluteus minimus muscles. Our findings here point to differences in SLN expression and type I fiber distribution as potential contributing factors.

  19. Global Proteome Changes in the Rat Diaphragm Induced by Endurance Exercise Training

    PubMed Central

    Burniston, Jatin G.; Kavazis, Andreas N.; Morton, Aaron B.; Wiggs, Michael P.; Ahn, Bumsoo; Smuder, Ashley J.; Powers, Scott K.

    2017-01-01

    Mechanical ventilation (MV) is a life-saving intervention for many critically ill patients. Unfortunately, prolonged MV results in the rapid development of diaphragmatic atrophy and weakness. Importantly, endurance exercise training results in a diaphragmatic phenotype that is protected against ventilator-induced diaphragmatic atrophy and weakness. The mechanisms responsible for this exercise-induced protection against ventilator-induced diaphragmatic atrophy remain unknown. Therefore, to investigate exercise-induced changes in diaphragm muscle proteins, we compared the diaphragmatic proteome from sedentary and exercise-trained rats. Specifically, using label-free liquid chromatography-mass spectrometry, we performed a proteomics analysis of both soluble proteins and mitochondrial proteins isolated from diaphragm muscle. The total number of diaphragm proteins profiled in the soluble protein fraction and mitochondrial protein fraction were 813 and 732, respectively. Endurance exercise training significantly (P<0.05, FDR <10%) altered the abundance of 70 proteins in the soluble diaphragm proteome and 25 proteins of the mitochondrial proteome. In particular, key cytoprotective proteins that increased in relative abundance following exercise training included mitochondrial fission process 1 (Mtfp1; MTP18), 3-mercaptopyruvate sulfurtransferase (3MPST), microsomal glutathione S-transferase 3 (Mgst3; GST-III), and heat shock protein 70 kDa protein 1A/1B (HSP70). While these proteins are known to be cytoprotective in several cell types, the cyto-protective roles of these proteins have yet to be fully elucidated in diaphragm muscle fibers. Based upon these important findings, future experiments can now determine which of these diaphragmatic proteins are sufficient and/or required to promote exercise-induced protection against inactivity-induced muscle atrophy. PMID:28135290

  20. Reduced Diaphragm Excursion During Reflexive Citric Acid Cough Test in Subjects With Subacute Stroke.

    PubMed

    Choi, Yong-Min; Park, Geun-Young; Yoo, Yeonji; Sohn, Donggyun; Jang, YongJun; Im, Sun

    2017-09-12

    Diaphragm excursion is limited during respiratory maneuvers after a stroke. How the diaphragm is limited during reflexive coughs and affects the effectiveness of cough in stroke patients is unclear. This study aimed to measure reflexive cough strength by cough peak flow (CPF) induced by citric acid nebulization (2.8 mol/L), record diaphragm excursions during reflexive coughs in stroke subjects at risk of silent aspiration, and compare these values with those of stroke subjects without risk of aspiration or dysphagia. Twenty-one subjects with subacute stroke (mean stroke onset, 13.6 d) at risk of silent aspiration (penetration-aspiration scale, 8) and 21 stroke subjects without dysphagia or aspiration (controls) were included. Diaphragmatic excursions were assessed using real-time sonography in all subjects; the main outcome measure was reflexive CPF induced by citric acid nebulization. The median (interquartile range) values of citric acid-induced CPF values were significantly more reduced in the 21 subjects with silent aspiration (45 [0-83] L/min) than in the control subjects (97 [66-162] L/min) (P = .004). Diaphragmatic excursions during the reflexive coughs were also significantly reduced (P < .001), although both groups had a similar range in the initial National Institutes of Health Stroke Scale scores and level of disability, as measured by the modified Barthel index. Citric acid-induced CPF was significantly correlated with the number of generated coughs (rs = 0.69), voluntary cough CPF (rs = 0.85), and degree of diaphragm excursion on both sides (rs = 0.50 [hemiplegic] and rs = 0.55 [nonhemiplegic]) but not correlated with the degree of hemiparesis, National Institutes of Health Stroke Scale score, or modified Barthel index scores. The 6-month follow up revealed that 7 subjects in group A experienced aspiration pneumonia. Stroke subjects at risk of silent aspiration showed reduced CPF and more limited diaphragm excursion during the citric acid

  1. Role of adenosine in the depolarization of hypoxic hamster diaphragm membrane in vitro.

    PubMed

    Esau, S A

    1994-04-01

    The resting membrane potential of in vitro hamster diaphragm muscle fibers is depolarized on exposure to hypoxia. It was hypothesized that this depolarization was mediated by adenosine. It was predicted that the treatment of well-oxygenated hamster diaphragm muscle strips in vitro with adenosine or adenosine agonists would depolarize the diaphragm fiber membrane. Furthermore, resting membrane potential of hypoxic diaphragm fibers would be repolarized by (1) the removal of adenosine by the enzyme adenosine deaminase (ADA), or (2) the addition of an adenosine antagonist, BW A1433. Adenosine (10(-4) M) depolarized the membrane by 8 +/- 1 mV (p < 0.001). The adenosine agonist cyclopentyladenosine, which has predominantly A1 receptor affinity, depolarized the membrane from -75.4 +/- 5.6 mV to -68.9 +/- 5.7 mV (p < 0.001). The A2 adenosine receptor agonist 5'-N-ethylcarboxamide adenosine did not cause a significant depolarization. The addition of ADA (2 unit/ml) to hypoxic muscle returned the resting membrane potential to that of well-oxygenated fibers, p < 0.001 versus hypoxia. BW A1433 (3 x 10(-7)) also restored the membrane potential of hypoxic muscle fibers from -72 +/- 1 mV to -79 +/- 1 mV (p < 0.001). These observations suggest that adenosine via the A1 adenosine receptor mediates the hypoxic depolarization of in vitro hamster diaphragm muscle. A direct effect of adenosine on muscle membrane has not been described previously.

  2. Sleep-disordered breathing in unilateral diaphragm paralysis or severe weakness.

    PubMed

    Steier, J; Jolley, C J; Seymour, J; Kaul, S; Luo, Y M; Rafferty, G F; Hart, N; Polkey, M I; Moxham, J

    2008-12-01

    Few data exist concerning sleep in patients with hemidiaphragm paralysis or weakness. Traditionally, such patients are considered to sustain normal ventilation in sleep. In the present study, diaphragm strength was measured in order to identify patients with unilateral paralysis or severe weakness. Patients underwent polysomnography with additional recordings of the transoesophageal electromyogram (EMG) of the diaphragm and surface EMG of extra-diaphragmatic respiratory muscles. These data were compared with 11 normal, healthy subjects matched for sex, age and body mass index (BMI). In total, 11 patients (six males, mean+/-sd age 56.5+/-10.0 yrs, BMI 28.7+/-2.8 kg x m(-2)) with hemidiaphragm paralysis or severe weakness (unilateral twitch transdiaphragmatic pressure 3.3+/-1.7 cmH(2)O (0.33+/-0.17 kPa) were studied. They had a mean+/-sd respiratory disturbance index of 8.1+/-10.1 events x h(-1) during non-rapid eye movement (NREM) sleep and 26.0+/-17.8 events x h(-1) during rapid eye movement (REM) sleep (control groups 0.4+/-0.4 and 0.7+/-0.9 events x h(-1), respectively). The diaphragm EMG, as a percentage of maximum, was double that of the control group in NREM sleep (15.3+/-5.3 versus 8.9+/-4.9% max, respectively) and increased in REM sleep (20.0+/-6.9% max), while normal subjects sustained the same level of activation (6.2+/-3.1% max). Patients with unilateral diaphragm dysfunction are at risk of developing sleep-disordered breathing during rapid eye movement sleep. The diaphragm electromyogram, reflecting neural respiratory drive, is doubled in patients compared with normal subjects, and increases further in rapid eye movement sleep.

  3. Aerobic training attenuates nicotinic acethylcholine receptor changes in the diaphragm muscle during heart failure.

    PubMed

    de Souza, Paula Aiello Tomé; de Souza, Rodrigo Wagner Alves; Soares, Luana Campos; Piedade, Warlen Pereira; Campos, Dijon Henrique S; Carvalho, Robson Francisco; Padovani, Carlos Roberto; Okoshi, Katashi; Cicogna, Antônio Carlos; Matheus, Selma Maria Michelin; Dal-Pai-Silva, Maeli

    2015-07-01

    Heart failure (HF) is a progressive myopathy, with clinical signs of fatigue and limb weakness that can damage the nerve-muscle interaction, altering synaptic transmission and nicotinic acetylcholine receptors (nAChR) in neuromuscular junctions (NMJs). The diaphragm is composed of a mixed proportion of muscle fibres, and during HF, this muscle becomes slower and can alter its function. As exercise training is an accepted practice to minimise abnormalities of skeletal muscle during HF, in this study, we evaluated the hypothesis that aerobic training attenuates alterations in the expression of nAChR subunits in NMJs diaphragm during heart failure. The aim of this study was to evaluate the distribution and expression of nAChR subunits in the diaphragm muscle fibres of rats subjected to an aerobic training programme during HF. Control (Sham), control training (ShamTR), aortic stenosis (AS) and aortic stenosis training (ASTR) groups were evaluated. The expression of nAChR subunits (γ, α1, ε, β1 and δ) was determined by qRT-PCR, and NMJs were analysed using confocal microscopy. We observed increased expression of the γ, α1 and β1 subunits in the AS group compared with the ASTR group. The distribution of NMJs was modulated in these groups. HF alters the mRNA expression of nAChR subunits and the structural characteristics of diaphragm NMJs. In addition, aerobic training did not alter NMJs morphology but attenuated the alterations in heart structure and function and in nAChR subunit mRNA expression. Our findings demonstrate the beneficial effects of aerobic exercise training in maintaining the integrity of the neuromuscular system in the diaphragm muscle during HF and may be critical for non-pharmacological therapy to improve the quality of life for patients with this syndrome.

  4. Myosin heavy chain and physiological adaptation of the rat diaphragm in elastase-induced emphysema

    PubMed Central

    Kim, Dong Kwan; Zhu, Jianliang; Kozyak, Benjamin W; Burkman, James M; Rubinstein, Neal A; Lankford, Edward B; Stedman, Hansell H; Nguyen, Taitan; Levine, Sanford; Shrager, Joseph B

    2003-01-01

    Background Several physiological adaptations occur in the respiratory muscles in rodent models of elastase-induced emphysema. Although the contractile properties of the diaphragm are altered in a way that suggests expression of slower isoforms of myosin heavy chain (MHC), it has been difficult to demonstrate a shift in MHCs in an animal model that corresponds to the shift toward slower MHCs seen in human emphysema. Methods We sought to identify MHC and corresponding physiological changes in the diaphragms of rats with elastase-induced emphysema. Nine rats with emphysema and 11 control rats were studied 10 months after instillation with elastase. MHC isoform composition was determined by both reverse transcriptase polymerase chain reaction (RT-PCR) and immunocytochemistry by using specific probes able to identify all known adult isoforms. Physiological adaptation was studied on diaphragm strips stimulated in vitro. Results In addition to confirming that emphysematous diaphragm has a decreased fatigability, we identified a significantly longer time-to-peak-tension (63.9 ± 2.7 ms versus 53.9 ± 2.4 ms). At both the RNA (RT-PCR) and protein (immunocytochemistry) levels, we found a significant decrease in the fastest, MHC isoform (IIb) in emphysema. Conclusion This is the first demonstration of MHC shifts and corresponding physiological changes in the diaphragm in an animal model of emphysema. It is established that rodent emphysema, like human emphysema, does result in a physiologically significant shift toward slower diaphragmatic MHC isoforms. In the rat, this occurs at the faster end of the MHC spectrum than in humans. PMID:12617755

  5. Ultrasound assessment of the diaphragm: Preliminary study of a canine model of X-linked myotubular myopathy.

    PubMed

    Sarwal, Aarti; Cartwright, Michael S; Walker, Francis O; Mitchell, Erin; Buj-Bello, Anna; Beggs, Alan H; Childers, Martin K

    2014-10-01

    We tested the feasibility of using neuromuscular ultrasound for non-invasive real-time assessment of diaphragmatic structure and function in a canine model of X-linked myotubular myopathy (XLMTM). Ultrasound images in 3 dogs [wild-type (WT), n=1; XLMTM untreated, n=1; XLMTM post-AAV8-mediated MTM1 gene replacement, n=1] were analyzed for diaphragm thickness, change in thickness with respiration, muscle echogenicity, and diaphragm excursion amplitude during spontaneous breathing. Quantitative parameters of diaphragm structure were different among the animals. WT diaphragm was thicker and less echogenic than the XLMTM control, whereas the diaphragm measurements of the MTM1-treated XLMTM dog were comparable to those of the WT dog. This pilot study demonstrates the feasibility of using ultrasound for quantitative assessment of the diaphragm in a canine model. In the future, ultrasonography may replace invasive measures of diaphragm function in canine models and in humans for non-invasive respiratory monitoring and evaluation of neuromuscular disease. Copyright © 2014 Wiley Periodicals, Inc.

  6. An experimental evaluation of metallic diaphragms for positive fuel expulsion in the Atmosphere Explorer, hydrazine propulsion subsystem

    NASA Technical Reports Server (NTRS)

    Woodruff, W. L.

    1973-01-01

    Four Arde conospheroid metallic diaphragms were tested at NASA to evaluate their capability for use in the orbit adjust propulsion subsystem (OAPS) of the Atmosphere Explorer spacecraft (AE's C, D, and E). The diaphragms will be used for positive propellant expulsion and spacecraft center of mass (c.m.) control. A leak-free cycle life capability of nine reversals was demonstrated. The diaphragms rolled smoothly from ring to ring in a predictable manner on the first reversal. Varying amounts of diaphragm cocking and ring skipping were observed on subsequent reversals. The diaphragm pressure differential did not exceed 10 psid during any reversal. Cycle life capability, reversal mode, and pressure differential were not affected by sudden reversals, environmental tests, or 18,000 partial reversals. An expulsion efficiency of approximately 97 percent was demonstrated. The results of these tests show that metallic diaphragms can be used as an effective means of positive fuel expulsion; however, to achieve spacecraft c.m. control, the diaphragm must not be reversed prior to flight.

  7. Wall Art

    ERIC Educational Resources Information Center

    McGinley, Connie Q.

    2004-01-01

    The author of this article, an art teacher at Monarch High School in Louisville, Colorado, describes how her experience teaching in a new school presented an exciting visual challenge for an art teacher--monotonous brick walls just waiting for decoration. This school experienced only minimal instances of graffiti, but as an art teacher, she did…

  8. Wall Art

    ERIC Educational Resources Information Center

    McGinley, Connie Q.

    2004-01-01

    The author of this article, an art teacher at Monarch High School in Louisville, Colorado, describes how her experience teaching in a new school presented an exciting visual challenge for an art teacher--monotonous brick walls just waiting for decoration. This school experienced only minimal instances of graffiti, but as an art teacher, she did…

  9. Wall Covering

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The attractive wall covering shown below is one of 132 styles in the Mirror Magic II line offered by The General Tire & Rubber Company, Akron, Ohio. The material is metallized plastic fabric, a spinoff from space programs. Wall coverings are one of many consumer applications of aluminized plastic film technology developed for NASA by a firm later bought by King-Seeley Thermos Company, Winchester, Massachusetts, which now produces the material. The original NASA use was in the Echo 1 passive communications satellite, a "space baloon" made of aluminized mylar; the high reflectivity of the metallized coating enabled relay of communications signals from one Earth station to another by "bouncing" them off the satellite. The reflectivity feature also made the material an extremely efficient insulator and it was subsequently widely used in the Apollo program for such purposes as temperature control of spacecraft components and insulation of tanks for fuels that must be maintained at very low temperatures. I Used as a wall covering, the aluminized material offers extra insulation, reflects light and I resists cracking. In addition to General Tire, King-Seeley also supplies wall covering material to Columbus Coated Fabrics Division of Borden, Incorporated, Columbus, Ohio, among others.

  10. A successful early gore-tex reconstruction of an abdominal wall defect in a neonate with Cantrell pentalogy: a case report and literature review

    PubMed Central

    Divkovic, Dalibor; Kvolik, Slavica; Sipl, Mirna; Sego, Krunoslav; Puseljic, Silvija; Rakipovic-Stojanovic, Andreja; Kovacic, Borna

    2015-01-01

    Key Clinical Message A surgical technique, materials used for abdominal wall reconstruction, and postoperative care are important for patient outcomes. We report the first case of neonate with Cantrell's pentalogy surviving early reconstruction of abdominal, diaphragmal and pericardial defects. Several recent investigations suggest that intraabdominal pressure monitoring may improve outcomes in this patient category. PMID:25678967

  11. Modeling and analysis of a novel combined peninsula-island structure diaphragm for ultra-low pressure sensing with high sensitivity

    NASA Astrophysics Data System (ADS)

    Xu, Tingzhong; Zhao, Libo; Jiang, Zhuangde; Xu, Yu; Zhao, Yulong

    2016-02-01

    A novel combined peninsula-island structure diaphragm has been developed with four pairs of peninsula and island structures as well as four gaps between them. When a pressure is applied to the diaphragm, the major strain energy of the diaphragm is locked in the position above each gap, which is called the stress concentration region (SCR). Also, minimal strain energy is wasted outside the SCR. Therefore, this novel diaphragm is favorable in obtaining high sensitivity for a micro-electromechanical system piezoresistive ultra-low pressure sensor. In order to optimize the diaphragm structure, the partial differential equation governing the diaphragm deflection has been given under pressure. The theoretical analysis solutions are obtained based on the theory of the Navier trigonometric series and the mirror image method, and in accordance with the finite element method simulation results. Finally, a sensor with the proposed diaphragm is designed with the working range of 0-500 Pa and has sensitivity above 0.055 mV V-1 Pa-1. In comparison to a flat diaphragm with the same dimensions, this novel diaphragm achieves a sensitivity level increased by 256%, a nonlinearity reduced by 79%, and a resonance frequency increased by 5.5%. In addition, the proposed theoretical analysis solution of the diaphragm can also be applied to other kinds of diaphragm with different islands to achieve optimization.

  12. Depletion of Pax7+ satellite cells does not affect diaphragm adaptations to running in young or aged mice.

    PubMed

    Murach, Kevin A; Confides, Amy L; Ho, Angel; Jackson, Janna R; Ghazala, Lina S; Peterson, Charlotte A; Dupont-Versteegden, Esther E

    2017-10-01

    Satellite cell depletion does not affect diaphragm adaptations to voluntary wheel running in young or aged mice. Satellite cell depletion early in life (4 months of age) has minimal effect on diaphragm phenotype by old age (24 months). Prolonged satellite cell depletion in the diaphragm does not result in excessive extracellular matrix accumulation, in contrast to what has been reported in hind limb muscles. Up-regulation of Pax3 mRNA+ cells after satellite cell depletion in young and aged mice suggests that Pax3+ cells may compensate for a loss of Pax7+ satellite cells in the diaphragm. Future investigations should focus on the role of Pax3+ cells in the diaphragm during adaptation to exercise and ageing. Satellite cell contribution to unstressed diaphragm is higher compared to hind limb muscles, which is probably attributable to constant activation of this muscle to drive ventilation. Whether satellite cell depletion negatively impacts diaphragm quantitative and qualitative characteristics under stressed conditions in young and aged mice is unknown. We therefore challenged the diaphragm with prolonged running activity in the presence and absence of Pax7+ satellite cells in young and aged mice using an inducible Pax7(CreER) -R26R(DTA) model. Mice were vehicle (Veh, satellite cell-replete) or tamoxifen (Tam, satellite cell-depleted) treated at 4 months of age and were then allowed to run voluntarily at 6 months (young) and 22 months (aged). Age-matched, cage-dwelling, Veh- and Tam-treated mice without wheel access served as activity controls. Diaphragm muscles were analysed from young (8 months) and aged (24 months) mice. Satellite cell depletion did not alter diaphragm mean fibre cross-sectional area, fibre type distribution or extracellular matrix content in young or aged mice, regardless of running activity. Resting in vivo diaphragm function was also unaffected by satellite cell depletion. Myonuclear density was maintained in young satellite cell

  13. Wall Turbulence

    DTIC Science & Technology

    1992-04-01

    Doppler velocimeter, computer experiments, and pulsed-laser velocimetry. External influences to be studied are imposed flow oscillations , wavy walls...imposed flow oscillations Studies of the effect of imposed small amplitude flow oscillations have shown no effect on the time mean flow. Work was...undertaken to see if imposed large amplitude oscillations can affect drag. The system used was water flow through a two inch pipe. The flow oscillations

  14. Sub-micron silica diaphragm-based fiber-tip Fabry-Perot interferometer for pressure measurement.

    PubMed

    Liao, Changrui; Liu, Shen; Xu, Lei; Wang, Chao; Wang, Yiping; Li, Zhengyong; Wang, Qiao; Wang, D N

    2014-05-15

    We demonstrate a sub-micron silica diaphragm-based fiber-tip Fabry-Perot interferometer for pressure sensing applications. The thinnest silica diaphragm, with a thickness of ∼320  nm, has been achieved by use of an improved electrical arc discharge technique. Such a sub-micron silica diaphragm breaks the sensitivity limitation imposed by traditional all-silica Fabry-Perot interferometric pressure sensors and, as a result, a high pressure sensitivity of ∼1036  pm/MPa at 1550 nm and a low temperature cross-sensitivity of ∼960  Pa/°C are achieved when a silica diaphragm of ∼500  nm in thickness is used. Moreover, the all-silica spherical structure enhanced the mechanical strength of the micro-cavity sensor, making it suitable for high sensitivity pressure sensing in harsh environments.

  15. Dynamic Strain on Thin Diaphragms of a Mercury Target During 800-MeV Proton Thermal Shock Tests

    SciTech Connect

    Allison, S.W.; Andriulli, J.B.; Cates, M.R.; Earl, D.D.; Haines, J.R.; Morrissey, F.X.; Tsai, C.C.; Wender, S.

    1999-11-13

    Extrinsic Fabry-Perot Interferometric fiber optic sensors were used to measure dynamic strains on thin diaphragms of a liquid mercury target, which was subjected to intense 800-MeV proton thermal shock tests. The mercury target is engineered with very thin end plates or diaphragms (either 0.6 mm or 1.9 mm) for studying large strain effects. During thermal shock tests, the mercury in the target interacted with an intense pulsed beam of 2.4x10{sup 13 protons}. The resulting pressure waves lead to large strains exceeding 250 microstrains on a 0.6-mm diaphragm. Significant factors relative to the accuracy of strain measurements are emphasized, such as the sensor air gap, alignment of sensors, and frequency response of the strain instrument. In this paper, dynamic strains measured on thin diaphragms are described and discussed.

  16. A qualitative study of obstacles to diaphragm and condom use in an HIV prevention trial in sub-Saharan Africa.

    PubMed

    Kacanek, Deborah; Dennis, Amanda; Sahin-Hodoglugil, Nuriye Nalan; Montgomery, Elizabeth T; Morar, Neetha; Mtetwa, Sibongile; Nkala, Busi; Phillip, Jessica; Watadzaushe, Connie; van der Straten, Ariane

    2012-02-01

    Consistent condom use and the substitution of condoms with potential HIV prevention methods of lower or unknown effectiveness are important concerns in the development of new prevention technologies. This qualitative study explored obstacles to consistent condom use with the diaphragm in MIRA, an HIV prevention trial in South Africa and Zimbabwe. We conducted 26 focus group discussions (FGDs) with 206 women and 7 FGDs and 10 in-depth interviews with 41 male partners of intervention-arm women. The belief that the diaphragm/gel prevented HIV, women's difficulties negotiating condom use, and men's unawareness that using the products together was recommended were obstacles to consistent condom use with the diaphragm/gel. Concerns about protection from HIV and pregnancy, recognition that the diaphragm was not yet proven to prevent HIV or sexually transmitted infections, and the trial context were facilitators. Understanding selective study product use in HIV prevention trials may inform improved adherence counseling and male involvement strategies.

  17. The Effects of Phrenic Nerve Degeneration by Axotomy and Crush on the Electrical Activities of Diaphragm Muscles of Rats.

    PubMed

    Alkiş, Mehmet Eşref; Kavak, Servet; Sayır, Fuat; Him, Aydin

    2016-03-01

    The aim of this study was to investigate the effect of axotomy and crush-related degeneration on the electrical activities of diaphragm muscle strips of experimental rats. In the present study, twenty-one male Wistar-albino rats were used and divided into three groups. The animals in the first group were not crushed or axotomized and served as controls. Phrenic nerves of the rats in the second and third groups were crushed or axotomized in the diaphragm muscle. Resting membrane potential (RMP) was decreased significantly in both crush and axotomy of diaphragm muscle strips of experimental rats (p < 0.05). Depolarization time (T DEP) and half-repolarization (1/2 RT) time were significantly prolonged in crush and axotomy rats (p < 0.05). Crushing or axotomizing the phrenic nerves may produce electrical activities in the diaphragm muscle of the rat by depolarization time and half-repolarization time prolonged in crush and axotomy rats.

  18. Realization of a High Sensitivity Microphone for a Hearing Aid Using a Graphene-PMMA Laminated Diaphragm.

    PubMed

    Woo, SeongTak; Han, Jae-Hyung; Lee, Jyung Hyun; Cho, Sunghun; Seong, Ki-Woong; Choi, Muhan; Cho, Jin-Ho

    2017-01-18

    Microphones for hearing aid systems are required to have high sensitivity, an appropriate bandwidth, and a wide dynamic range. In this paper, a high sensitivity microphone, 4 mm in diameter and using a multilayer graphene-PMMA laminated diaphragm that can be applied in hearing aids, is designed, optimized, and implemented. Typically, polyphenylene sulfide (PPS) has been used for the diaphragm of electret condenser microphones (ECM), and this method provides simple, low cost mass production. Generally, the sensitivity of the commercial 4 mm diameter ECM is about -30 to 35 dB (0 dB = 1 V/Pa). A microphone using a nanometer-thick graphene diaphragm has been found to have higher sensitivity than the conventional ECM. However, nanometer-thick multilayer graphene is vulnerable to large mechanical shocks or high sound pressures, and the practical production of nanometer-thick diaphragms also poses a challenge. However, if a multilayer graphene diaphragm of the same thickness as the conventional ECM is used, displacement during diaphragm vibration will be severely attenuated due to the high elastic modulus of graphene, and the microphone sensitivity will be greatly reduced. In this paper, we fabricate a multilayer graphene/poly(methyl methacrylate) (PMMA) laminated diaphragm with sensitivity higher than that of any other microphones currently available for hearing aids, with the appropriate bandwidth in the auditory range. The high sensitivity arises from the laminated structure of the thin graphene membrane with high elastic modulus and from the PMMA membrane with lower elastic modulus and higher dielectric constant. The optimal thickness ratio of the graphene-PMMA layered diaphragm was studied by both analytical and experimental methods, and then a fabricated diaphragm was assembled in a 4 mm diameter microphone package. The performance of the implemented microphone was evaluated, including the sensitivity and total harmonic distortion. It is demonstrated that the

  19. Enhanced Transmissions Through Three-dimensional Cascade Sharp Waveguide Bends Using C-slit Diaphragms

    PubMed Central

    Yang, Rui; Hu, Bowei; Zhang, Aofang; Gao, Dongxing; Wang, Hui; Shi, Ayuan; Lei, Zhenya; Yang, Pei

    2017-01-01

    Transmission properties through sharp rectangular waveguide bends are investigated to determine the cut-off bending angles of the wave propagation. We show that a simple metallic diaphragm at the bending corner with properly devised sub-wavelength defect apertures of C-slits would be readily to turn on the transmissions with scarce reflections of the propagating modes, while preserving the integrity of the transmitting fields soon after the bends. In particularly, our design also demonstrates the capability of eliminating all the unwanted cavity resonant transmissions that exist in the three-dimensional cascade sharp waveguide bends, and solely let the desired signals travel along the whole passage of the waveguide. The present approach, using C-slit diaphragms to support the sharp bending behaviors of the guided waves with greatly enhanced transmissions, would be especially effective in constructing novel waveguides and pave the way for the development of more compact and miniaturized electromagnetic systems that exploit these waveguide bends. PMID:28322344

  20. Enhanced Transmissions Through Three-dimensional Cascade Sharp Waveguide Bends Using C-slit Diaphragms.

    PubMed

    Yang, Rui; Hu, Bowei; Zhang, Aofang; Gao, Dongxing; Wang, Hui; Shi, Ayuan; Lei, Zhenya; Yang, Pei

    2017-03-21

    Transmission properties through sharp rectangular waveguide bends are investigated to determine the cut-off bending angles of the wave propagation. We show that a simple metallic diaphragm at the bending corner with properly devised sub-wavelength defect apertures of C-slits would be readily to turn on the transmissions with scarce reflections of the propagating modes, while preserving the integrity of the transmitting fields soon after the bends. In particularly, our design also demonstrates the capability of eliminating all the unwanted cavity resonant transmissions that exist in the three-dimensional cascade sharp waveguide bends, and solely let the desired signals travel along the whole passage of the waveguide. The present approach, using C-slit diaphragms to support the sharp bending behaviors of the guided waves with greatly enhanced transmissions, would be especially effective in constructing novel waveguides and pave the way for the development of more compact and miniaturized electromagnetic systems that exploit these waveguide bends.

  1. Successful use of the diaphragm and jelly by a young population: report of a clinical study.

    PubMed

    Lane, M E; Arceo, R; Sobrero, A J

    1976-01-01

    In the largest contemporary study of diaphragm use in the United States, the authors examine the experience of 2,168 women who selected this method of contraception at the Margaret Sanger Research Bureau over a recent two-year period. Eight in 10 of the study group were younger than 30 years and three in 10 were aged 21-24. Seven in 10 had never been married and the same proportion had never been pregnant. Accidental pregnancies in the first 12 months of use ranged from a low of 1.9 per 100 users younger than 18 years old to a high of 3.0 among 30-34-year-olds; and more than eight in 10 were still using the diaphragm at the year's end. These rates compare favorably with those reported for the pill and IUD in other clinical studies.

  2. All-fiber high-sensitivity pressure sensor with SiO2 diaphragm.

    PubMed

    Donlagic, Denis; Cibula, Edvard

    2005-08-15

    The design and fabrication of a miniature fiber Fabry-Perot pressure sensor with a diameter of 125 microm are presented. The essential element in the process is a thin SiO2 diaphragm that is fusion spliced at the hollow end of an optical fiber. Good repeatability and high sensitivity of the sensor are achieved by on-line tuning of the diaphragm thickness during the sensor fabrication process. Various sensor prototypes were fabricated, demonstrating pressure ranges of from 0 to 40 kPa to 0 to 1 MPa. The maximum achieved sensitivity was 1.1 rad/40 kPa at 1550 nm, and a pressure resolution of 300 Pa was demonstrated in practice. The presented design and fabrication technique offers a means of simple and low-cost disposable pressure sensor production.

  3. Diaphragm based long cavity Fabry-Perot fiber acoustic sensor using phase generated carrier

    NASA Astrophysics Data System (ADS)

    Liu, Bin; Lin, Jie; Liu, Huan; Ma, Yuan; Yan, Lei; Jin, Peng

    2017-01-01

    A diaphragm based long cavity Fabry-Perot interferometric fiber acoustic sensor is proposed. The Fabry-Perot cavity is formed by a flat fiber facet and an ultra-thin silver diaphragm with a 6-meter long fiber inserted in the cavity. A narrow-linewidth ring-cavity erbium-doped fiber laser is applied to demodulate the sensing signal in the phase generated carrier algorithm. Experimental results have demonstrated that the phase sensitivity is about -140 dB re 1 rad/μPa at 2 kHz. The noise equivalent acoustic signal level is 60.6 μPa/Hz1/2 and the dynamic range is 65.1 dB-SPL at 2 kHz. The sensor is suitable for sensing of weak acoustic signals.

  4. Initial Pulmonary Respiration Causes Massive Diaphragm Damage and Hyper-CKemia in Duchenne Muscular Dystrophy Dog

    PubMed Central

    Nakamura, Akinori; Kobayashi, Masanori; Kuraoka, Mutsuki; Yuasa, Katsutoshi; Yugeta, Naoko; Okada, Takashi; Takeda, Shin'ichi

    2013-01-01

    The molecular mechanism of muscle degeneration in a lethal muscle disorder Duchene muscular dystrophy (DMD) has not been fully elucidated. The dystrophic dog, a model of DMD, shows a high mortality rate with a marked increase in serum creatine kinase (CK) levels in the neonatal period. By measuring serum CK levels in cord and venous blood, we found initial pulmonary respiration resulted in massive diaphragm damage in the neonates and thereby lead to the high serum CK levels. Furthermore, molecular biological techniques revealed that osteopontin was prominently upregulated in the dystrophic diaphragm prior to the respiration, and that immediate-early genes (c-fos and egr-1) and inflammation/immune response genes (IL-6, IL-8, COX-2, and selectin E) were distinctly overexpressed after the damage by the respiration. Hence, we segregated dystrophic phases at the molecular level before and after mechanical damage. These molecules could be biomarkers of muscle damage and potential targets in pharmaceutical therapies. PMID:23851606

  5. Anesthetic management of staged thoracoscopic repair of bilateral eventration of diaphragm in a neonate

    PubMed Central

    Rao, Subramanian Hari; Natarajan, Saravanan; Pallavi, Vyapaka

    2016-01-01

    Congenital eventration of the diaphragm is a rare disorder, the perioperative management of which is challenging. The introduction of thoracoscopic repair of these defects has considerably reduced the perioperative morbidity and mortality in these patients. In spite of the advantages of thoracoscopy which include smaller chest incisions, reduced postoperative pain, and more rapid postoperative recovery compared with thoracotomy, it is still inherent with complications unique to it. A clear understanding of the pathophysiologic changes, potential complications and institution of appropriate monitoring and good planning is essential for the safe conduct of thoracoscopic procedures in neonates. We describe the anesthetic management of staged thoracoscopic repair of bilateral congenital eventration of the diaphragm in a neonate. PMID:26957704

  6. Variation compensation and analysis on diaphragm curvature analysis for emphysema quantification on whole lung CT scans

    NASA Astrophysics Data System (ADS)

    Keller, Brad M.; Reeves, Anthony P.; Barr, R. Graham; Yankelevitz, David F.; Henschke, Claudia I.

    2010-03-01

    CT scans allow for the quantitative evaluation of the anatomical bases of emphysema. Recently, a non-density based geometric measurement of lung diagphragm curvature has been proposed as a method for the quantification of emphysema from CT. This work analyzes variability of diaphragm curvature and evaluates the effectiveness of a compensation methodology for the reduction of this variability as compared to emphysema index. Using a dataset of 43 scan-pairs with less than a 100 day time-interval between scans, we find that the diaphragm curvature had a trend towards lower overall variability over emphysema index (95% CI:-9.7 to + 14.7 vs. -15.8 to +12.0), and that the variation of both measures was reduced after compensation. We conclude that the variation of the new measure can be considered comparable to the established measure and the compensation can reduce the apparent variation of quantitative measures successfully.

  7. Enhanced Transmissions Through Three-dimensional Cascade Sharp Waveguide Bends Using C-slit Diaphragms

    NASA Astrophysics Data System (ADS)

    Yang, Rui; Hu, Bowei; Zhang, Aofang; Gao, Dongxing; Wang, Hui; Shi, Ayuan; Lei, Zhenya; Yang, Pei

    2017-03-01

    Transmission properties through sharp rectangular waveguide bends are investigated to determine the cut-off bending angles of the wave propagation. We show that a simple metallic diaphragm at the bending corner with properly devised sub-wavelength defect apertures of C-slits would be readily to turn on the transmissions with scarce reflections of the propagating modes, while preserving the integrity of the transmitting fields soon after the bends. In particularly, our design also demonstrates the capability of eliminating all the unwanted cavity resonant transmissions that exist in the three-dimensional cascade sharp waveguide bends, and solely let the desired signals travel along the whole passage of the waveguide. The present approach, using C-slit diaphragms to support the sharp bending behaviors of the guided waves with greatly enhanced transmissions, would be especially effective in constructing novel waveguides and pave the way for the development of more compact and miniaturized electromagnetic systems that exploit these waveguide bends.

  8. Training-induced alterations in young and senescent rat diaphragm muscle

    NASA Technical Reports Server (NTRS)

    Gosselin, Luc E.; Betlach, Michael; Vailas, Arthur C.; Thomas, D. P.

    1992-01-01

    The effect of progressive treadmill exercise on oxidative capacity in three specific diaphragm muscle fiber types and on the capillary density of known fiber types was investigated in young (5 month) and senescent (23 months or older) rats. All animals were trained for 1 hr/day, 5 days weekly, for 10 weeks. Measurements of succinate dehydrogenase activity showed significant increases in all three fiber types in both the young and the senescent trained animals, compared with their sedentary controls. Fiber size and capillary density were not affected by exercise or age. The results demonstrate that the senescent costal diaphragm maintains its ability to adapt to an increased metabolic demand brought about by locomotor exercises.

  9. [A rare case of metastases in the diaphragm in a patient with gastric cancer].

    PubMed

    Vasil'ev, A Iu; Maev, I V; Penkina, T V; Dicheva, D T; Bulanova, T V; Buragina, T A

    2006-01-01

    In spite of the general affection of the greater curvature of the stomach, there were no dyspeptic manifestations, pains in the upper half of the stomach were not related to meals, 'and the stool remained unchanged. The main characteristic of the clinical picture was the distribution of the tumor process to the diaphragm, which was a reason explaining the complaints about acute pains in the right flank enhancing in the course of movements or deep breaths. No data about any metastatic affection of the skeleton bones, lungs or pleura were received. This case shows the need in the close examination of the diaphragm in the case of the pain syndrome in the right hypochondrium in patients with generalized tumor diseases.

  10. Telomere shortening in diaphragm and tibialis anterior muscles of aged mdx mice.

    PubMed

    Lund, Troy C; Grange, Robert W; Lowe, Dawn A

    2007-09-01

    The progression of Duchenne muscular dystrophy (DMD) is, in part, due to satellite cell senescence driven by high replicative pressure as these muscle stem cells repeatedly divide and fuse to damaged muscle fibers. We hypothesize that telomere shortening in satellite cells underlies their senescence. To test this hypothesis, we evaluated the diaphragm and a leg muscle from dystrophic mice of various ages for telomere dynamics. We found 30% telomere shortening in tibialis anterior muscles from 600-day-old mdx mice relative to age-matched wildtype mice. We also found a more severe shortening of telomere length in diaphragm muscles of old mdx mice. In those muscles, telomeres were shortened by approximately 15% and 40% in 100- and 600-day-old mdx mice, respectively. These findings indicate that satellite cells undergo telomere erosion, which may contribute to the inability of these cells to perpetually repair DMD muscle.

  11. Measurement of the frequency response of a diaphragm-based pressure sensor by use of a pulsed excimer laser.

    PubMed

    Shen, Fabin; Xu, Juncheng; Wang, Anbo

    2005-08-01

    We present a novel method for measuring the frequency response of a diaphragm-based optical fiber Fabry-Perot interferometric pressure sensor. The impulse response of the sensor to the radiation pressure generated by an excimer laser pulse is measured. The Fourier transform of the impulse response yields the frequency response of the pressure sensor. Experimental results show that it is a convenient and efficient method for measurement of the frequency response of diaphragm-based pressure sensors.

  12. Diaphragm Pacing as a Rehabilitative Tool for Patients With Pompe Disease Who Are Ventilator-Dependent: Case Series

    PubMed Central

    Fuller, David D.; Martin, A. Daniel; Lottenberg, Lawrence; Islam, Saleem; Lawson, Lee Ann; Onders, Raymond P.; Byrne, Barry J.

    2016-01-01

    Background and Purpose Pompe disease is an inherited disorder notable for severe, progressive ventilatory compromise. Although ventilatory failure has been attributed to myofiber dysfunction secondary to diaphragmatic glycogen accumulation, neural involvement of the phrenic motor system is also a prominent feature. Direct diaphragm pacing supplements respiratory function in other disorders of the phrenic motor system. Accordingly, it is hypothesized that augmented neuromuscular activity via diaphragm pacing would promote weaning from mechanical ventilation in patients with Pompe disease who are unresponsive to conventional, muscle-directed treatments. Case Description Three patients with Pompe disease developed diaphragm paresis that resulted in chronic mechanical ventilation dependence. After preoperative inspiratory muscle strengthening exercises failed to improve function, fine-wire pacing electrodes were laparoscopically implanted into the diaphragm. Diaphragm conditioning was initiated the first postoperative week and consisted of gradual increases in stimulation parameters, lengthening of stimulation sessions, and ventilator weaning. Ventilation and intramuscular electromyographic activity were recorded periodically during conditioning to quantify diaphragm neuromuscular function. Outcomes During paced breathing without mechanical ventilation, tidal volumes increased, and 2 patients were weaned from daytime ventilator dependence within the first 3 months of pacing, which has been sustained over the long-term. A third patient reduced reliance on daytime ventilation, but weaning was delayed by malacia of the large airways. In all patients, pacing appeared to facilitate spontaneous phrenic motor unit activity during independent breathing without ventilator or pacer support. Discussion The findings are consistent with the view that diaphragm pacing has potential rehabilitative value to reduce reliance on mechanical ventilation in people with Pompe disease, but

  13. Partial Support Ventilation and Mitochondrial-Targeted Antioxidants Protect against Ventilator-Induced Decreases in Diaphragm Muscle Protein Synthesis.

    PubMed

    Hudson, Matthew B; Smuder, Ashley J; Nelson, W Bradley; Wiggs, Michael P; Shimkus, Kevin L; Fluckey, James D; Szeto, Hazel H; Powers, Scott K

    2015-01-01

    Mechanical ventilation (MV) is a life-saving intervention in patients in respiratory failure. Unfortunately, prolonged MV results in the rapid development of diaphragm atrophy and weakness. MV-induced diaphragmatic weakness is significant because inspiratory muscle dysfunction is a risk factor for problematic weaning from MV. Therefore, developing a clinical intervention to prevent MV-induced diaphragm atrophy is important. In this regard, MV-induced diaphragmatic atrophy occurs due to both increased proteolysis and decreased protein synthesis. While efforts to impede MV-induced increased proteolysis in the diaphragm are well-documented, only one study has investigated methods of preserving diaphragmatic protein synthesis during prolonged MV. Therefore, we evaluated the efficacy of two therapeutic interventions that, conceptually, have the potential to sustain protein synthesis in the rat diaphragm during prolonged MV. Specifically, these experiments were designed to: 1) determine if partial-support MV will protect against the decrease in diaphragmatic protein synthesis that occurs during prolonged full-support MV; and 2) establish if treatment with a mitochondrial-targeted antioxidant will maintain diaphragm protein synthesis during full-support MV. Compared to spontaneously breathing animals, full support MV resulted in a significant decline in diaphragmatic protein synthesis during 12 hours of MV. In contrast, diaphragm protein synthesis rates were maintained during partial support MV at levels comparable to spontaneous breathing animals. Further, treatment of animals with a mitochondrial-targeted antioxidant prevented oxidative stress during full support MV and maintained diaphragm protein synthesis at the level of spontaneous breathing animals. We conclude that treatment with mitochondrial-targeted antioxidants or the use of partial-support MV are potential strategies to preserve diaphragm protein synthesis during prolonged MV.

  14. Partial Support Ventilation and Mitochondrial-Targeted Antioxidants Protect against Ventilator-Induced Decreases in Diaphragm Muscle Protein Synthesis

    PubMed Central

    Hudson, Matthew B.; Smuder, Ashley J.; Nelson, W. Bradley; Wiggs, Michael P.; Shimkus, Kevin L.; Fluckey, James D.; Szeto, Hazel H.; Powers, Scott K.

    2015-01-01

    Mechanical ventilation (MV) is a life-saving intervention in patients in respiratory failure. Unfortunately, prolonged MV results in the rapid development of diaphragm atrophy and weakness. MV-induced diaphragmatic weakness is significant because inspiratory muscle dysfunction is a risk factor for problematic weaning from MV. Therefore, developing a clinical intervention to prevent MV-induced diaphragm atrophy is important. In this regard, MV-induced diaphragmatic atrophy occurs due to both increased proteolysis and decreased protein synthesis. While efforts to impede MV-induced increased proteolysis in the diaphragm are well-documented, only one study has investigated methods of preserving diaphragmatic protein synthesis during prolonged MV. Therefore, we evaluated the efficacy of two therapeutic interventions that, conceptually, have the potential to sustain protein synthesis in the rat diaphragm during prolonged MV. Specifically, these experiments were designed to: 1) determine if partial-support MV will protect against the decrease in diaphragmatic protein synthesis that occurs during prolonged full-support MV; and 2) establish if treatment with a mitochondrial-targeted antioxidant will maintain diaphragm protein synthesis during full-support MV. Compared to spontaneously breathing animals, full support MV resulted in a significant decline in diaphragmatic protein synthesis during 12 hours of MV. In contrast, diaphragm protein synthesis rates were maintained during partial support MV at levels comparable to spontaneous breathing animals. Further, treatment of animals with a mitochondrial-targeted antioxidant prevented oxidative stress during full support MV and maintained diaphragm protein synthesis at the level of spontaneous breathing animals. We conclude that treatment with mitochondrial-targeted antioxidants or the use of partial-support MV are potential strategies to preserve diaphragm protein synthesis during prolonged MV. PMID:26361212

  15. Sedation using propofol induces similar diaphragm dysfunction and atrophy during spontaneous breathing and mechanical ventilation in rats.

    PubMed

    Bruells, Christian S; Maes, Karen; Rossaint, Rolf; Thomas, Debby; Cielen, Nele; Bergs, Ingmar; Bleilevens, Christian; Weis, Joachim; Gayan-Ramirez, Ghislaine

    2014-03-01

    Mechanical ventilation is crucial for patients with respiratory failure. The mechanical takeover of diaphragm function leads to diaphragm dysfunction and atrophy (ventilator-induced diaphragmatic dysfunction), with an increase in oxidative stress as a major contributor. In most patients, a sedative regimen has to be initiated to allow tube tolerance and ventilator synchrony. Clinical data imply a correlation between cumulative propofol dosage and diaphragm dysfunction, whereas laboratory investigations have revealed that propofol has some antioxidant properties. The authors hypothesized that propofol reduces markers of oxidative stress, atrophy, and contractile dysfunction in the diaphragm. Male Wistar rats (n = 8 per group) were subjected to either 24 h of mechanical ventilation or were undergone breathing spontaneously for 24 h under propofol sedation to test for drug effects. Another acutely sacrificed group served as controls. After sacrifice, diaphragm tissue was removed, and contractile properties, cross-sectional areas, oxidative stress, and proteolysis were examined. The gastrocnemius served as internal control. Propofol did not protect against diaphragm atrophy, oxidative stress, and protease activation. The decrease in tetanic force compared with controls was similar in the spontaneous breathing group (31%) and in the ventilated group (34%), and both groups showed the same amount of muscle atrophy. The gastrocnemius muscle fibers did not show atrophy. Propofol does not protect against ventilator-induced diaphragmatic dysfunction or oxidative injury. Notably, spontaneous breathing under propofol sedation resulted in the same amount of diaphragm atrophy and dysfunction although diaphragm activation per se protects against ventilator-induced diaphragmatic dysfunction. This makes a drug effect of propofol likely.

  16. Diaphragm Pacing as a Rehabilitative Tool for Patients With Pompe Disease Who Are Ventilator-Dependent: Case Series.

    PubMed

    Smith, Barbara K; Fuller, David D; Martin, A Daniel; Lottenberg, Lawrence; Islam, Saleem; Lawson, Lee Ann; Onders, Raymond P; Byrne, Barry J

    2016-05-01

    Pompe disease is an inherited disorder notable for severe, progressive ventilatory compromise. Although ventilatory failure has been attributed to myofiber dysfunction secondary to diaphragmatic glycogen accumulation, neural involvement of the phrenic motor system is also a prominent feature. Direct diaphragm pacing supplements respiratory function in other disorders of the phrenic motor system. Accordingly, it is hypothesized that augmented neuromuscular activity via diaphragm pacing would promote weaning from mechanical ventilation in patients with Pompe disease who are unresponsive to conventional, muscle-directed treatments. Three patients with Pompe disease developed diaphragm paresis that resulted in chronic mechanical ventilation dependence. After preoperative inspiratory muscle strengthening exercises failed to improve function, fine-wire pacing electrodes were laparoscopically implanted into the diaphragm. Diaphragm conditioning was initiated the first postoperative week and consisted of gradual increases in stimulation parameters, lengthening of stimulation sessions, and ventilator weaning. Ventilation and intramuscular electromyographic activity were recorded periodically during conditioning to quantify diaphragm neuromuscular function. During paced breathing without mechanical ventilation, tidal volumes increased, and 2 patients were weaned from daytime ventilator dependence within the first 3 months of pacing, which has been sustained over the long-term. A third patient reduced reliance on daytime ventilation, but weaning was delayed by malacia of the large airways. In all patients, pacing appeared to facilitate spontaneous phrenic motor unit activity during independent breathing without ventilator or pacer support. The findings are consistent with the view that diaphragm pacing has potential rehabilitative value to reduce reliance on mechanical ventilation in people with Pompe disease, but further study is needed. Diaphragm pacing represents a

  17. Analytical comparison of circular diaphragm based simple, single and double touch mode - MEMS capacitive pressure sensor

    NASA Astrophysics Data System (ADS)

    Jindal, Sumit Kumar; Raghuwanshi, Sanjeev Kumar

    2016-03-01

    In this paper a comparative study is done between normal capacitive pressure sensor, a touch mode capacitive pressure sensor and a double touch mode capacitive pressure sensor. The diaphragm in use is of circular shape. The theory and underlying equations has been described for the said devices and then simulations have been done for different performance parameters to understand the advantage of one over the other.

  18. Combined pars plana vitrectomy and artificial iris diaphragm implant after globe rupture.

    PubMed

    Rossi, Tommaso; Boccassini, Barbara; Iossa, Mario; Lesnoni, Guido; Mutolo, Maria Giulia; Mutolo, P Alessandro

    2009-04-01

    Retinal detachment (RD) associated with aniridia due to globe rupture (GR) is an uncommon condition with a severe prognosis. Surgical technique must address anterior and posterior segment issues secondary to the altered compartmentalization and increased risk for corneal toxicity. The purpose of this paper is to report a series of GR patients undergoing combined pars plana vitrectomy (PPV) and artificial iris diaphragm (AID) implant for the repair of RD associated to aniridia. The authors retrospectively reviewed 12 consecutive patients operated on by a single surgeon. Surgery consisted of a standard three-port PPV with extensive bimanual dissection of vitreous base and ciliary body membrane and combined AID implant. Office visits included Snellen visual acuity (VA), intraocular pressure measurement, biomicroscopy and indirect ophthalmoscopy. AID prosthesis included aniridic IOLs, Heimann's PMMA and silicone diaphragm. Mean age was 53 years and mean follow-up was 19 months. At the end of follow-up, seven patients gained more than two lines (58.3%), two lost their vision (16.6%) and three were unchanged (25%). Seven patients (58.3%) had a VA better than 20/400 and one (8%) 20/40 vision. Eight patients (66.6%) retained a clear cornea, two (16.6%) had minimal corneal oedema and two (16.6%) corneal decompensation. Implanted prosthesis included two silicone diaphragms, four PMMA diaphragms and six aniridic IOLs. After an average 1.6 operations, the retina was completely attached in six patients (50%), partially attached in four (33.3%) and detached in two (16.6%). RD associated to GR carries a guarded prognosis both due to RD complexity and hypotony. The combined repair of RD and aniridia after GR offers the advantage of addressing all issues at one time allowing correct eye compartmentalization and better tamponade effect. Successful anatomical and functional results can be achieved although multiple surgeries are often needed.

  19. Pseudo-shear universal actuator driving flextensional-panel-diaphragm low-frequency acoustic source

    NASA Astrophysics Data System (ADS)

    Liu, Ruibin; Wang, Qing-Ming; Zhang, Qi Ming; Kugel, Valery D.; Cross, Leslie E.

    1998-07-01

    Acoustic source used for Active Noise Control at low frequency (80 - 250 Hz) is designed and developed by using a piezoelectric ceramic actuator and a flextensional panel diaphragm. In order to reach the vibration magnitude and radiation area needed for high and flat sound pressure level in the low frequency range. Pseudo-Shear Universal (PSU) actuator has been used as the driving part which is a new type of multilayer piezoelectric actuator originated from MRL offering the advantages of large displacement and high blocking force; on the other hand, Carbon Fiber Reinforced Composite has been used as the diaphragm material which provides a more rigid structure than conventional loudspeaker paper. A prototype device was fabricated which has the following characterizations: 40 layers PSU actuator with a compact dimension: 38 mm X 50 mm X 23.6 mm. Two of them are needed for a device. Diaphragm area is 126 mm X 152 mm. At quasistatic condition (5 Hz) and at the 0.84 kV/cm electric field, 344 micrometers displacement could be achieved at the apex of the diaphragm resulted from the flextensional amplifying mechanism with an amplification factor more than 11. The sound passive level in the frequency range 100 - 250 Hz shows better flat behavior than the acoustic sources studied earlier such as Double Amplifier and PANEL air transducers which exhibit a significant reduction of sound pressure level in the low frequency range. By a slight modification, it is likely to make this device in a total thickness of 10 - 15 mm range. High and stable sound pressure level as well as thin flat structure make it much more competitive in the whole area of applications for low frequency active noise control.

  20. Oxidative damage induced by cigarette smoke exposure in mice: impact on lung tissue and diaphragm muscle*,**

    PubMed Central

    de Carlos, Samanta Portão; Dias, Alexandre Simões; Forgiarini, Luiz Alberto; Patricio, Patrícia Damiani; Graciano, Thaise; Nesi, Renata Tiscoski; Valença, Samuel; Chiappa, Adriana Meira Guntzel; Cipriano, Gerson; de Souza, Claudio Teodoro; Chiappa, Gaspar Rogério da Silva

    2014-01-01

    OBJECTIVE: To evaluate oxidative damage (lipid oxidation, protein oxidation, thiobarbituric acid-reactive substances [TBARS], and carbonylation) and inflammation (expression of phosphorylated AMP-activated protein kinase and mammalian target of rapamycin [p-AMPK and p-mTOR, respectively]) in the lung parenchyma and diaphragm muscles of male C57BL-6 mice exposed to cigarette smoke (CS) for 7, 15, 30, 45, or 60 days. METHODS: Thirty-six male C57BL-6 mice were divided into six groups (n = 6/group): a control group; and five groups exposed to CS for 7, 15, 30, 45, and 60 days, respectively. RESULTS: Compared with control mice, CS-exposed mice presented lower body weights at 30 days. In CS-exposed mice (compared with control mice), the greatest differences (increases) in TBARS levels were observed on day 7 in diaphragm-muscle, compared with day 45 in lung tissue; the greatest differences (increases) in carbonyl levels were observed on day 7 in both tissue types; and sulfhydryl levels were lower, in both tissue types, at all time points. In lung tissue and diaphragm muscle, p-AMPK expression exhibited behavior similar to that of TBARS. Expression of p-mTOR was higher than the control value on days 7 and 15 in lung tissue, as it was on day 45 in diaphragm muscle. CONCLUSION: Our data demonstrate that CS exposure produces oxidative damage, not only in lung tissue but also (primarily) in muscle tissue, having an additional effect on respiratory muscle, as is frequently observed in smokers with COPD. PMID:25210964

  1. Inspiratory muscle conditioning exercise and diaphragm gene therapy in Pompe disease: Clinical evidence of respiratory plasticity.

    PubMed

    Smith, Barbara K; Martin, A Daniel; Lawson, Lee Ann; Vernot, Valerie; Marcus, Jordan; Islam, Saleem; Shafi, Nadeem; Corti, Manuela; Collins, Shelley W; Byrne, Barry J

    2017-01-01

    Pompe disease is an inherited disorder due to a mutation in the gene that encodes acid α-glucosidase (GAA). Children with infantile-onset Pompe disease develop progressive hypotonic weakness and cardiopulmonary insufficiency that may eventually require mechanical ventilation (MV). Our team conducted a first in human trial of diaphragmatic gene therapy (AAV1-CMV-GAA) to treat respiratory neural dysfunction in infantile-onset Pompe. Subjects (aged 2-15years, full-time MV: n=5, partial/no MV: n=4) underwent a period of preoperative inspiratory muscle conditioning exercise. The change in respiratory function after exercise alone was compared to the change in function after intramuscular delivery of AAV1-CMV-GAA to the diaphragm with continued exercise. Since AAV-mediated gene therapy can reach phrenic motoneurons via retrograde transduction, we hypothesized that AAV1-CMV-GAA would improve dynamic respiratory motor function to a greater degree than exercise alone. Dependent measures were maximal inspiratory pressure (MIP), respiratory responses to inspiratory threshold loads (load compensation: LC), and physical evidence of diaphragm activity (descent on MRI, EMG activity). Exercise alone did not change function. After AAV1-CMV-GAA, MIP was unchanged. Flow and volume LC responses increased after dosing (p<0.05 to p<0.005), but only in the subjects with partial/no MV use. Changes in LC tended to occur on or after 180days. At Day 180, the four subjects with MRI evidence of diaphragm descent had greater maximal voluntary ventilation (p<0.05) and tended to be younger, stronger, and use fewer hours of daily MV. In conclusion, combined AAV1-CMV-GAA and exercise training conferred benefits to dynamic motor function of the diaphragm. Children with a higher baseline neuromuscular function may have greater potential for functional gains. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Investigation of geometric design in piezoelectric microelectromechanical systems diaphragms for ultrasonic energy harvesting

    NASA Astrophysics Data System (ADS)

    Shi, Qiongfeng; Wang, Tao; Kobayashi, Takeshi; Lee, Chengkuo

    2016-05-01

    Acoustic energy transfer (AET) has been widely used for contactless energy delivery to implantable devices. However, most of the energy harvesters (ultrasonic receivers) for AET are macro-scale transducers with large volume and limited operation bandwidth. Here, we propose and investigate two microelectromechanical systems diaphragm based piezoelectric ultrasonic energy harvesters (PUEHs) as an alternative for AET. The proposed PUEHs consist of micro-scale diaphragm array with different geometric parameter design. Diaphragms in PUEH-1 have large length to width ratio to achieve broadband property, while its energy harvesting performance is compromised. Diaphragms in PUEH-2 have smaller length to width ratio and thinner thickness to achieve both broadband property and good energy harvesting performance. Both PUEHs have miniaturized size and wide operation bandwidth that are ideally suitable to be integrated as power source for implantable biomedical devices. PUEH-1 has a merged -6 dB bandwidth of 74.5% with a central frequency of 350 kHz. PUEH-2 has two separate -6 dB bandwidth of 73.7%/30.8% with central frequencies of 285 kHz/650 kHz. They can adapt to various ultrasonic sources with different working frequency spectrum. Maximum output power is 34.3 nW and 84.3 nW for PUEH-1 and PUEH-2 at 1 mW/cm2 ultrasound intensity input, respectively. The associated power density is 0.734 μW/cm2 and 4.1 μW/cm2, respectively. Better energy harvesting performance is achieved for PUEH-2 because of the optimized length to width ratio and thickness design. Both PUEHs offer more alignment flexibility with more than 40% power when they are in the range of the ultrasound transmitter.

  3. Acoustic emission (AE) health monitoring of diaphragm type couplings using neural network analysis

    NASA Astrophysics Data System (ADS)

    Godinez-Azcuaga, Valery F.; Shu, Fong; Finlayson, Richard D.; O'Donnell, Bruce

    2005-05-01

    This paper presents the latest results obtained from Acoustic Emission (AE) monitoring and detection of cracks and/or damage in diaphragm couplings, which are used in some aircraft and engine drive systems. Early detection of mechanical failure in aircraft drive train components is a key safety and economical issue with both military and civil sectors of aviation. One of these components is the diaphragm-type coupling, which has been evaluated as the ideal drive coupling for many application requirements such as high speed, high torque, and non-lubrication. Its flexible axial and angular displacement capabilities have made it indispensable for aircraft drive systems. However, diaphragm-type couplings may develop cracks during their operation. The ability to monitor, detect, identify, and isolate coupling cracks on an operational aircraft system is required in order to provide sufficient advance warning to preclude catastrophic failure. It is known that metallic structures generate characteristic Acoustic Emission (AE) during crack growth/propagation cycles. This phenomenon makes AE very attractive among various monitoring techniques for fault detection in diaphragm-type couplings. However, commercially available systems capable of automatic discrimination between signals from crack growth and normal mechanical noise are not readily available. Positive classification of signals requires experienced personnel and post-test data analysis, which tend to be a time-consuming, laborious, and expensive process. With further development of automated classifiers, AE can become a fully autonomous fault detection technique requiring no human intervention after implementation. AE has the potential to be fully integrated with automated query and response mechanisms for system/process monitoring and control.

  4. Diaphragm and Lung Ultrasound to Predict Weaning Outcome: Systematic Review and Meta-Analysis.

    PubMed

    Llamas-Álvarez, Ana M; Tenza-Lozano, Eva M; Latour-Pérez, Jaime

    2017-08-31

    Deciding the optimal timing for extubation in patients who are mechanically ventilated can be challenging, and traditional weaning predictor tools are not very accurate. The aim of this systematic review and meta-analysis was to assess the accuracy of lung and diaphragm ultrasound for predicting weaning outcomes in critically ill adults. MEDLINE, the Cochrane Library, Web of Science, Scopus, LILACS, Teseo, Tesis Doctorales en Red, and OpenGrey were searched, and the bibliographies of relevant studies were reviewed. Two researchers independently selected studies that met the inclusion criteria and assessed study quality in accordance with the Quality Assessment of Diagnostic Accuracy Studies-2 tool. The summary receiver-operating characteristic curve and pooled diagnostic OR (DOR) were estimated by using a bivariate random effects analysis. Sources of heterogeneity were explored by using predefined subgroup analyses and bivariate meta-regression. Nineteen studies involving 1,071 people were included in the study. For diaphragm thickening fraction, the area under the summary receiver-operating characteristic curve was 0.87, and DOR was 21 (95% CI, 11-40). Regarding diaphragmatic excursion, pooled sensitivity was 75% (95% CI, 65-85); pooled specificity, 75% (95% CI, 60-85); and DOR, 10 (95% CI, 4-24). For lung ultrasound, the area under the summary receiver-operating characteristic curve was 0.77, and DOR was 38 (95% CI, 7-198). Based on bivariate meta-regression analysis, a significantly higher specificity for diaphragm thickening fraction and higher sensitivity for diaphragmatic excursion was detected in studies with applicability concerns. Lung and diaphragm ultrasound can help predict weaning outcome, but its accuracy may vary depending on the patient subpopulation. Copyright © 2017 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

  5. Eventration with diaphragm perforation leading to secondary diaphragmatic hernia and intestinal strangulation.

    PubMed

    Kanojia, R P; Shanker, R; Menon, P; Rao, K L N

    2010-10-01

    We report a rare occurrence of a previously asymptomatic eventration that presented with intestinal obstruction followed by respiratory distress. The thinned out diaphragm had a nontraumatic perforation with herniation of the small bowel through the narrow defect. The herniated gut became strangulated and dilated inside the thorax, resulting in respiratory compromise. The rare occurrence of this vicious cycle of obstruction and respiratory failure leading to a sudden clinical deterioration in a previously stable patient is described.

  6. Role of intrinsic aerobic capacity and ventilator-induced diaphragm dysfunction

    PubMed Central

    Sollanek, Kurt J.; Smuder, Ashley J.; Wiggs, Michael P.; Morton, Aaron B.; Koch, Lauren G.; Britton, Steven L.

    2015-01-01

    Prolonged mechanical ventilation (MV) leads to rapid diaphragmatic atrophy and contractile dysfunction, which is collectively termed “ventilator-induced diaphragm dysfunction” (VIDD). Interestingly, endurance exercise training prior to MV has been shown to protect against VIDD. Further, recent evidence reveals that sedentary animals selectively bred to possess a high aerobic capacity possess a similar skeletal muscle phenotype to muscles from endurance trained animals. Therefore, we tested the hypothesis that animals with a high intrinsic aerobic capacity would naturally be afforded protection against VIDD. To this end, animals were selectively bred over 33 generations to create two divergent strains, differing in aerobic capacity: high-capacity runners (HCR) and low-capacity runners (LCR). Both groups of animals were subjected to 12 h of MV and compared with nonventilated control animals within the same strains. As expected, contrasted to LCR animals, the diaphragm muscle from the HCR animals contained higher levels of oxidative enzymes (e.g., citrate synthase) and antioxidant enzymes (e.g., superoxide dismutase and catalase). Nonetheless, compared with nonventilated controls, prolonged MV resulted in significant diaphragmatic atrophy and impaired diaphragm contractile function in both the HCR and LCR animals, and the magnitude of VIDD did not differ between strains. In conclusion, these data demonstrate that possession of a high intrinsic aerobic capacity alone does not afford protection against VIDD. Importantly, these results suggest that endurance exercise training differentially alters the diaphragm phenotype to resist VIDD. Interestingly, levels of heat shock protein 72 did not differ between strains, thus potentially representing an important area of difference between animals with intrinsically high aerobic capacity and exercise-trained animals. PMID:25571991

  7. Concomitant ventilatory and circulatory functions of the diaphragm and abdominal muscles.

    PubMed

    Aliverti, Andrea; Uva, Barbara; Laviola, Marianna; Bovio, Dario; Lo Mauro, Antonella; Tarperi, Cantor; Colombo, Edoardo; Loomas, Bryan; Pedotti, Antonio; Similowski, Thomas; Macklem, Peter T

    2010-11-01

    Expulsive maneuvers (EMs) caused by simultaneous contraction of diaphragm and abdominal muscles shift substantial quantities of blood from the splanchnic circulation to the extremities. This suggests that the diaphragm assisted by abdominal muscles might accomplish ventilation and circulation simultaneously by repeated EMs. We tested this hypothesis in normal subjects by measuring changes (Δ) in body volume (Vb) by whole body plethysmography simultaneously with changes in trunk volume (Vtr) by optoelectronic plethysmography, which measures the same parameters as whole body plethysmography plus the volume of blood shifts (Vbs) between trunk and extremities: Vbs = ΔVtr-ΔVb. We also measured abdominal pressure, pleural pressure, the arterial pressure wave, and cardiac output (Qc). EMs with abdominal pressure ~100 cmH(2)O for 1 s, followed by 2-s relaxations, repeated over 90 s, produced a "stroke volume" from the splanchnic bed of 0.35 ± 0.07 (SD) liter, an output of 6.84 ± 0.75 l/min compared with a resting Qc of 5.59 ± 1.14 l/min. Refilling during relaxation was complete, and the splanchnic bed did not progressively empty. Diastolic pressure increased by 25 mmHg during each EM. Between EMs, Qc increased to 7.09 ± 1.14 l/min due to increased stroke volume and heart rate. The circulatory function of the diaphragm assisted by simultaneous contractions of abdominal muscles with appropriate pressure and duration at 20 min(-1) can produce a circulatory output as great as resting Qc, as well as ventilation. These combined functions of the diaphragm have potential for cardiopulmonary resuscitation. The abdominal circulatory pump can act as an auxiliary heart.

  8. Electrical activity of the diaphragm during nCPAP and high flow nasal cannula.

    PubMed

    de Waal, C G; Hutten, G J; Kraaijenga, J V; de Jongh, F H; van Kaam, A H

    2017-09-01

    To determine if the electrical activity of the diaphragm, as measure of neural respiratory drive and breathing effort, changes over time in preterm infants transitioned from nasal continuous positive airway pressure (nCPAP) to high flow nasal cannula (HFNC). Prospective observational study. Neonatal intensive care unit. Stable preterm infants transitioned from nCPAP to HFNC using a 1:1 pressure to flow ratio. The electrical activity of the diaphragm was measured by transcutaneous electromyography (dEMG) from 30 min before until 3 hours after the transition. At eight time points after the transition to HFNC, diaphragmatic activity was compared with the baseline on nCPAP. Percentage change in amplitudedEMG, peakdEMG and tonicdEMG were calculated. Furthermore, changes in respiratory rate, heart rate and fraction of inspired oxygen (FiO2) were analysed. Thirty-two preterm infants (mean gestational age: 28.1±2.2 weeks, mean birth weight: 1118±368 g) were included. Compared with nCPAP, the electrical activity of the diaphragm did not change during the first 3 hours on HFNC (median (IQR) change in amplitudedEMG at t=180 min: 2.81% (-21.51-14.10)). The respiratory rate, heart rate and FiO2 remained stable during the 3-hour measurement. Neural respiratory drive and breathing effort assessed by electrical activity of the diaphragm is similar in the first 3 hours after transitioning stable preterm infants from nCPAP to HFNC with a 1:1 pressure-to-flow ratio. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  9. Laparoscopic vs computerized tomography-guided radiofrequency ablation for large hepatic hemangiomas abutting the diaphragm

    PubMed Central

    Gao, Jun; Kong, Jian; Ding, Xue-Mei; Ke, Shan; Niu, Hai-Gang; Xin, Zong-Hai; Ning, Chun-Min; Guo, Shi-Gang; Li, Xiao-Long; Zhang, Long; Dong, Yong-Hong; Sun, Wen-Bing

    2015-01-01

    AIM: To compare safety and therapeutic efficacy of laparoscopic radiofrequency (RF) ablation vs computed tomography (CT)-guided RF ablation for large hepatic hemangiomas abutting the diaphragm. METHODS: We retrospectively reviewed our sequential experience of treating 51 large hepatic hemangiomas abutting the diaphragm in 51 patients by CT-guided or laparoscopic RF ablation due to either the presence of symptoms and/or the enlargement of hemangioma. Altogether, 24 hemangiomas were ablated via a CT-guided percutaneous approach (CT-guided ablation group), and 27 hemangiomas were treated via a laparoscopic approach (laparoscopic ablation group). RESULTS: The mean diameter of the 51 hemangiomas was 9.6 ± 1.8 cm (range, 6.0-12.0 cm). There was no difference in the diameter of hemangiomas between the two groups (P > 0.05). RF ablation was performed successfully in all patients. There was no difference in ablation times between groups (P > 0.05). There were 23 thoracic complications in 17 patients: 15 (62.5%, 15/24) in the CT-guided ablation group and 2 (7.4%, 2/27) in the laparoscopic ablation group (P < 0.05). According to the Dindo-Clavien classification, two complications (pleural effusion and diaphragmatic rupture grade III) were major in two patients. All others were minor (grade I). Both major complications occurred in the CT-guided ablation group. The minor complications were treated successfully with conservative measures, and the two major complications underwent treatment by chest tube drainage and thoracoscopic surgery, respectively. Complete ablation was achieved in 91.7% (22/24) and 96.3% (26/27) in the CT-guided and the laparoscopic ablation groups, respectively (P > 0.05). CONCLUSION: Laparoscopic RF ablation therapy should be used as the first-line treatment option for large hepatic hemangiomas abutting the diaphragm. It avoids thermal injury to the diaphragm and reduces thoracic complications. PMID:26019459

  10. Diaphragm pacing stimulation system for tetraplegia in individuals injured during childhood or adolescence.

    PubMed

    Onders, Raymond P; Elmo, Mary Jo; Ignagni, Anthony R

    2007-01-01

    Children with cervical spinal cord injury and chronic respiratory insufficiency face the risks and stigma associated with mechanical ventilators. The Diaphragm Pacing Stimulation (DPS) System for electrical activation of the diaphragm is a minimally invasive alternative to mechanical ventilation. Review of patients in a prospective Food and Drug Administration trial of the DPS System in individuals who were injured at age 18 years or younger. The procedure involved laparoscopic mapping to locate the diaphragm motor points with electrode implantation. Two weeks after surgery, stimulus/output characteristics of each electrode were determined to obtain an adequate tidal volume for ventilation. A home-based weaning protocol from the ventilator was used. Of 28 patients implanted with the DPS System, 10 had sustained cervical SCI as children or adolescents. Average age at injury was 13 years (range 1.5 to 17 y). Age at implantation ranged from 18 to 34 years. Length of time from injury to implantation averaged 9.7 years (0.8 to 19 y). All patients tolerated the implantation procedure. Four patients utilize DPS continuously (24/7), 4 patients pace daytime only, and 2 patients are still actively conditioning their diaphragms. Two patients required surgical correction of scoliosis prior to implantation. All patients prefer breathing with the DPS and would recommend it to others; 4 patients specifically identified that attending college or church without a ventilator eases their integration into society. The results show that the laparoscopic DPS system can be safely implanted in tetraplegics injured as children and used in a home-based environment to wean them off of mechanical ventilation.

  11. Implications for Cardiac Function Following Rescue of the Dystrophic Diaphragm in a Mouse Model of Duchenne Muscular Dystrophy.

    PubMed

    Betts, Corinne A; Saleh, Amer F; Carr, Carolyn A; Muses, Sofia; Wells, Kim E; Hammond, Suzan M; Godfrey, Caroline; McClorey, Graham; Woffindale, Caroline; Clarke, Kieran; Wells, Dominic J; Gait, Michael J; Wood, Matthew J A

    2015-06-26

    Duchenne muscular dystrophy (DMD) is caused by absence of the integral structural protein, dystrophin, which renders muscle fibres susceptible to injury and degeneration. This ultimately results in cardiorespiratory dysfunction, which is the predominant cause of death in DMD patients, and highlights the importance of therapeutic targeting of the cardiorespiratory system. While there is some evidence to suggest that restoring dystrophin in the diaphragm improves both respiratory and cardiac function, the role of the diaphragm is not well understood. Here using exon skipping oligonucleotides we predominantly restored dystrophin in the diaphragm and assessed cardiac function by MRI. This approach reduced diaphragmatic pathophysiology and markedly improved diaphragm function but did not improve cardiac function or pathophysiology, with or without exercise. Interestingly, exercise resulted in a reduction of dystrophin protein and exon skipping in the diaphragm. This suggests that treatment regimens may require modification in more active patients. In conclusion, whilst the diaphragm is an important respiratory muscle, it is likely that dystrophin needs to be restored in other tissues, including multiple accessory respiratory muscles, and of course the heart itself for appropriate therapeutic outcomes. This supports the requirement of a body-wide therapy to treat DMD.

  12. Diaphragm Muscle Adaptation to Sustained Hypoxia: Lessons from Animal Models with Relevance to High Altitude and Chronic Respiratory Diseases

    PubMed Central

    Lewis, Philip; O'Halloran, Ken D.

    2016-01-01

    The diaphragm is the primary inspiratory pump muscle of breathing. Notwithstanding its critical role in pulmonary ventilation, the diaphragm like other striated muscles is malleable in response to physiological and pathophysiological stressors, with potential implications for the maintenance of respiratory homeostasis. This review considers hypoxic adaptation of the diaphragm muscle, with a focus on functional, structural, and metabolic remodeling relevant to conditions such as high altitude and chronic respiratory disease. On the basis of emerging data in animal models, we posit that hypoxia is a significant driver of respiratory muscle plasticity, with evidence suggestive of both compensatory and deleterious adaptations in conditions of sustained exposure to low oxygen. Cellular strategies driving diaphragm remodeling during exposure to sustained hypoxia appear to confer hypoxic tolerance at the expense of peak force-generating capacity, a key functional parameter that correlates with patient morbidity and mortality. Changes include, but are not limited to: redox-dependent activation of hypoxia-inducible factor (HIF) and MAP kinases; time-dependent carbonylation of key metabolic and functional proteins; decreased mitochondrial respiration; activation of atrophic signaling and increased proteolysis; and altered functional performance. Diaphragm muscle weakness may be a signature effect of sustained hypoxic exposure. We discuss the putative role of reactive oxygen species as mediators of both advantageous and disadvantageous adaptations of diaphragm muscle to sustained hypoxia, and the role of antioxidants in mitigating adverse effects of chronic hypoxic stress on respiratory muscle function. PMID:28018247

  13. Diaphragm Muscle Adaptation to Sustained Hypoxia: Lessons from Animal Models with Relevance to High Altitude and Chronic Respiratory Diseases.

    PubMed

    Lewis, Philip; O'Halloran, Ken D

    2016-01-01

    The diaphragm is the primary inspiratory pump muscle of breathing. Notwithstanding its critical role in pulmonary ventilation, the diaphragm like other striated muscles is malleable in response to physiological and pathophysiological stressors, with potential implications for the maintenance of respiratory homeostasis. This review considers hypoxic adaptation of the diaphragm muscle, with a focus on functional, structural, and metabolic remodeling relevant to conditions such as high altitude and chronic respiratory disease. On the basis of emerging data in animal models, we posit that hypoxia is a significant driver of respiratory muscle plasticity, with evidence suggestive of both compensatory and deleterious adaptations in conditions of sustained exposure to low oxygen. Cellular strategies driving diaphragm remodeling during exposure to sustained hypoxia appear to confer hypoxic tolerance at the expense of peak force-generating capacity, a key functional parameter that correlates with patient morbidity and mortality. Changes include, but are not limited to: redox-dependent activation of hypoxia-inducible factor (HIF) and MAP kinases; time-dependent carbonylation of key metabolic and functional proteins; decreased mitochondrial respiration; activation of atrophic signaling and increased proteolysis; and altered functional performance. Diaphragm muscle weakness may be a signature effect of sustained hypoxic exposure. We discuss the putative role of reactive oxygen species as mediators of both advantageous and disadvantageous adaptations of diaphragm muscle to sustained hypoxia, and the role of antioxidants in mitigating adverse effects of chronic hypoxic stress on respiratory muscle function.

  14. Down-regulation of insulin-like growth factor I (IGF-I) in the mouse diaphragm during sepsis.

    PubMed

    Lin, Meng-Chih; Leung, Sum Yee; Fang, Wen-Feng; Chin, Chien-Hung; Chung, Kian Fan

    2010-01-01

    Diaphragmatic muscle impairment is an important cause of respiratory failure during sepsis. Insulin-like growth factor I (IGF-I) is an anabolic growth factor which prevents muscle degradation and wasting during sepsis, but its role in the diaphragmatic muscle during sepsis is unknown. The aim of this study was to investigate the expression of IGF-I in the diaphragmatic muscle in a murine model of sepsis induced by lipopolysaccharide (LPS). Male B57 mice were peritoneally injected with LPS, and were killed and studied at different time-points, 24 h, 48 h, 72 h, and 96 h after injection. Diaphragm sarcolemmal damage was visualized by orange tracer dye infusion, and the expression of IGF-I, interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in diaphragm tissue extracts were measured using ELISA. LPS induced sarcolemmal damage in diaphragm myofibers from 24 h to 96 h, which was accompanied by a significant increase in IL-1β expression in the tissues while IGF-I levels were down-regulated. No change in TNF-α was observed. Body weights of animals were also reduced, especially at 96 h. The expression of IGF-I in diaphragm tissues was down-regulated during sepsis- induced diaphragm myofiber damage, suggesting that IGF-I may be an important factor in the regulation of diaphragm myofiber repair. Further studies are needed to examine the mechanisms involved.

  15. Superoxide dismutase/catalase mimetic EUK-134 prevents diaphragm muscle weakness in monocrotalin-induced pulmonary hypertension.

    PubMed

    Himori, Koichi; Abe, Masami; Tatebayashi, Daisuke; Lee, Jaesik; Westerblad, Håkan; Lanner, Johanna T; Yamada, Takashi

    2017-01-01

    Patients with pulmonary hypertension (PH) suffer from inspiratory insufficiency, which has been associated with intrinsic contractile dysfunction in diaphragm muscle. Here, we examined the role of redox stress in PH-induced diaphragm weakness by using the novel antioxidant, EUK-134. Male Wistar rats were randomly divided into control (CNT), CNT + EUK-134 (CNT + EUK), monocrotaline-induced PH (PH), and PH + EUK groups. PH was induced by a single intraperitoneal injection of monocrotaline (60 mg/kg body weight). EUK-134 (3 mg/kg body weight/day), a cell permeable mimetic of superoxide dismutase (SOD) and catalase, was daily intraperitoneally administered starting one day after induction of PH. After four weeks, diaphragm muscles were excised for mechanical and biochemical analyses. There was a decrease in specific tetanic force in diaphragm bundles from the PH group, which was accompanied by increases in: protein expression of NADPH oxidase 2/gp91phox, SOD2, and catalase; 3-nitrotyrosine content and aggregation of actin; glutathione oxidation. Treatment with EUK-134 prevented the force decrease and the actin modifications in PH diaphragm bundles. These data show that redox stress plays a pivotal role in PH-induced diaphragm weakness. Thus, antioxidant treatment can be a promising strategy for PH patients with inspiratory failure.

  16. Ultrasound evaluation of diaphragm function and its application in critical patients, mechanical ventilation and brachial plexus block.

    PubMed

    de la Quintana Gordon, F de B; Nacarino Alcorta, B; Fajardo Pérez, M

    2017-03-23

    Before diaphragm ultrasonography, assessment of diaphragm function was very difficult due to the complex nature of its exploration. The use of this new technique has shed light on diagnostic problems and treatment with an improvement in final outcomes for critically ill patients, in whom the incidence of diaphragm weakness or dysfunction has been underestimated. Better knowledge of diaphragm function enables us earlier diagnosis by quantification of diaphragm contractile activity or evaluation of functional status after delivery of plexus block anaesthesia, facilitating therapeutic decisions. It is also being used as a guide in the process of weaning from mechanical ventilation or as the safest approach for braquial plexus block. In this review we present how to perform a systematic exploration of diaphragm function and its clinical implications. Copyright © 2017 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

  17. Superoxide dismutase/catalase mimetic EUK-134 prevents diaphragm muscle weakness in monocrotalin-induced pulmonary hypertension

    PubMed Central

    Tatebayashi, Daisuke; Lee, Jaesik; Westerblad, Håkan; Lanner, Johanna T.

    2017-01-01

    Patients with pulmonary hypertension (PH) suffer from inspiratory insufficiency, which has been associated with intrinsic contractile dysfunction in diaphragm muscle. Here, we examined the role of redox stress in PH-induced diaphragm weakness by using the novel antioxidant, EUK-134. Male Wistar rats were randomly divided into control (CNT), CNT + EUK-134 (CNT + EUK), monocrotaline-induced PH (PH), and PH + EUK groups. PH was induced by a single intraperitoneal injection of monocrotaline (60 mg/kg body weight). EUK-134 (3 mg/kg body weight/day), a cell permeable mimetic of superoxide dismutase (SOD) and catalase, was daily intraperitoneally administered starting one day after induction of PH. After four weeks, diaphragm muscles were excised for mechanical and biochemical analyses. There was a decrease in specific tetanic force in diaphragm bundles from the PH group, which was accompanied by increases in: protein expression of NADPH oxidase 2/gp91phox, SOD2, and catalase; 3-nitrotyrosine content and aggregation of actin; glutathione oxidation. Treatment with EUK-134 prevented the force decrease and the actin modifications in PH diaphragm bundles. These data show that redox stress plays a pivotal role in PH-induced diaphragm weakness. Thus, antioxidant treatment can be a promising strategy for PH patients with inspiratory failure. PMID:28152009

  18. Recovery of PdiTwitch following the induction of diaphragm fatigue in normal subjects.

    PubMed

    Travaline, J M; Sudarshan, S; Criner, G J

    1997-11-01

    Low frequency diaphragm fatigue (LFF) may play a major role in the pathogenesis of ventilatory failure; however, recovery from LFF is not well studied. We measured transdiaphragmatic twitch pressure (PdiT) at FRC (using a reduction of PdiT as an index of LFF) and maximum transdiaphragmatic pressure (Pdimax) before and after the induction of diaphragm fatigue in seven normal subjects, age 31 +/- 3 yr (mean +/- SD). Fatigue was induced by breathing through an inspiratory resistive load. PdiT produced by bilateral transcutaneous supramaximal electrophrenic stimulation was measured at baseline, 15, 30 min, 1, 2, 3, 4 h, and then 1 to 3 times between hour 20-25 post-fatigue. Pdimax estimated by twitch occlusion was measured at baseline, 30 min, 2-3, and 20-25 h post-fatigue. Pre-fatigue values (mean +/- SE) were: PdiT 23.6 +/- 2.5 cm H2O. The mean +/- SD time to fatigue was 25.3 +/- 12.3 min. Post-fatigue PdiT was reduced to 50%, and by 3 h was 72% of the initial value; 100% by 25 h. Pdimax was reduced to 75% post-fatigue, but recovered to 87% by 3 h, and 100% by 25 h. We concluded that recovery of PdiT and Pdimax in normal subjects starts to occur within the first few hours following diaphragm fatigue, and is complete by 25 h.

  19. Age-related remodeling of neuromuscular junctions on type-identified diaphragm fibers.

    PubMed

    Prakash, Y S; Sieck, G C

    1998-07-01

    Previous studies have reported fiber-type differences in the morphological adaptations of neuromuscular junctions (NMJs) to aging by comparing limb muscles consisting of predominantly type I or II fibers. A confounding factor in these studies is age-related change in activity, which may differ between muscles. In the present study, we assessed age-related changes of the NMJ in type-identified fibers of the rat diaphragm muscle, which maintains consistent inspiratory-related activation throughout life. In 6- and 24-month-old rats, a fluorescent triple-labeling technique was used to visualize phrenic axons, presynaptic nerve terminals, and postsynaptic acetylcholine receptors (end-plates) on type-identified fibers. The NMJs were then imaged using three-dimensional (3D) confocal microscopy. On type IIx and IIb fibers, nerve terminal and end-plate 2D planar and 3D surface areas expanded, and the number of nerve terminal and end-plate branches increased, indicating fragmentation of the NMJ with aging. On the other hand, NMJs on type I and IIa fibers displayed little adaptation. These morphological adaptations may be geared toward maintaining the efficacy of inspiratory-related activity of the diaphragm muscle, but may affect the functional reserve of the aging diaphragm.

  20. Improving accuracy of markerless tracking of lung tumours in fluoroscopic video by incorporating diaphragm motion

    NASA Astrophysics Data System (ADS)

    Schwarz, M.; Teske, H.; Stoll, M.; Bendl, Rolf

    2014-03-01

    Purpose: Conformal radiation of moving tumours is a challenging task in radiotherapy. Tumour motion induced by respiration can be visualized in fluoroscopic images recorded during patients breathing. Markerless methods making use of registration techniques can be used to estimate tumour motion. However, registration methods might fail when the tumour is hidden by ribs. Using motion of anatomical surrogates, like the diaphragm, is promising to model tumour motion. Methods: A sequence of 116 fluoroscopic images was analyzed and the tumour positions were manually defined by three experts. A block matching (BM) technique is used to calculate the displacement vector relatively to a selected reference image of the first breathing cycle. An enhanced method was developed: Positions, when the tumour is not located behind a rib, are taken as valid estimations of the tumour position. Furthermore, these valid estimations are used to establish a linear model of tumour position and diaphragm motion. For invalid estimations the calculated tumour positions are not taken into consideration, and instead the model is used to determine tumour motion. Results: Enhancing BM with a model of tumour motion from diaphragm motion improves the tracking accuracy when the tumour moves behind a rib. The error (mean ± SD) in longitudinal dimension was 2.0 ± 1.5mm using only BM and 1.0 ± 1.1mm when the enhanced approach was used. Conclusion: The enhanced tracking technique is capable to improve tracking accuracy compared to BM in the case that the tumour is occluded by ribs.

  1. The effect of theophylline on hypoxic, hypercapnic hamster diaphragm muscle in vitro.

    PubMed

    Esau, S A

    1991-05-01

    Hypoxic, hypercapnic acidosis (HHA) decreases tension and enhances fatigue in hamster diaphragm in vitro. We hypothesized that theophylline would decrease the harmful effect of HHA. Hamster diaphragm strips were studied in Krebs solution aerated with 21% O2 and 12% CO2. The force-frequency responses and the tension and relaxation of brief, submaximal contractions were studied. Mild fatigue was produced by a series of 45 submaximal contractions, after which recovery of force was followed for 15 min. Theophylline (0.55 mM) was added at the time of exposure to HHA (early theophylline) in half the strips and at the end of the fatigue run (late theophylline) in the others. In contrast to our hypothesis, early theophylline had a limited effect on force production in unfatigued HHA diaphragm strips and resulted in lower force production in the recovery period. Late theophylline improved force in the recovery period for low-frequency contractions. Thus the effect of theophylline in the setting of HHA depended on the time it was added and was beneficial only if added after the muscle stopped contracting.

  2. Targeting Heat Shock Proteins Mitigates Ventilator Induced Diaphragm Muscle Dysfunction in an Age-Dependent Manner

    PubMed Central

    Ogilvie, Hannah; Cacciani, Nicola; Akkad, Hazem; Larsson, Lars

    2016-01-01

    Intensive care unit (ICU) patients are often overtly subjected to mechanical ventilation and immobilization, which leads to impaired limb and respiratory muscle function. The latter, termed ventilator-induced diaphragm dysfunction (VIDD) has recently been related to compromised heat shock protein (Hsp) activation. The administration of a pharmacological drug BGP-15 acting as a Hsp chaperone co-inducer has been found to partially alleviate VIDD in young rats. Considering that the mean age in the ICU is increasing, we aimed to explore whether the beneficial functional effects are also present in old rats. For that, we exposed young (7–8 months) and old (28–32 months) rats to 5-day controlled mechanical ventilation and immobilization with or without systemic BGP-15 administration. We then dissected diaphragm muscles, membrane–permeabilized bundles and evaluated the contractile function at single fiber level. Results confirmed that administration of BGP-15 restored the force-generating capacity of isolated muscle cells from young rats in conjunction with an increased expression of Hsp72. On the other hand, our results highlighted that old rats did not positively respond to the BGP-15 treatment. Therefore, it is of crucial importance to comprehend in more depth the effect of VIDD on diaphragm function and ascertain any further age-related differences. PMID:27729867

  3. Incorporation of beams into bossed diaphragm for a high sensitivity and overload micro pressure sensor.

    PubMed

    Yu, Zhongliang; Zhao, Yulong; Sun, Lu; Tian, Bian; Jiang, Zhuangde

    2013-01-01

    The paper presents a piezoresistive absolute micro pressure sensor, which is of great benefits for altitude location. In this investigation, the design, fabrication, and test of the sensor are involved. By analyzing the stress distribution of sensitive elements using finite element method, a novel structure through the introduction of sensitive beams into traditional bossed diaphragm is built up. The proposed configuration presents its advantages in terms of high sensitivity and high overload resistance compared with the conventional bossed diaphragm and flat diaphragm structures. Curve fittings of surface stress and deflection based on ANSYS simulation results are performed to establish the equations about the sensor. Nonlinear optimization by MATLAB is carried out to determine the structure dimensions. The output signals in both static and dynamic environments are evaluated. Silicon bulk micromachining technology is utilized to fabricate the sensor prototype, and the fabrication process is discussed. Experimental results demonstrate the sensor features a high sensitivity of 11.098 μV/V/Pa in the operating range of 500 Pa at room temperature, and a high overload resistance of 200 times overpressure to promise its survival under atmosphere. Due to the excellent performance above, the sensor can be applied in measuring the absolute micro pressure lower than 500 Pa.

  4. Micromachined flexible diaphragm backed PZT ultrasonic transducer with a controllable self-focused acoustic beam

    NASA Astrophysics Data System (ADS)

    Feng, Guo-Hua; Lin, Zhi-Dian

    2011-12-01

    This paper presents novel self-focused ultrasonic transducers batch-produced by microfabrication. A PZT film, tens of microns thick, can be deposited on an engineered flexible substrate composed of an F-number controllable parylene shaped diaphragm and heat resistant RTV material, with no fractures after thermal annealing. The residual stress of the PZT film is released through the curvature change of the fabricated parylene/RTV, spherically shaped diaphragm. The experimental relationship between the designed and resultant F-number of the fabricated transducer is discussed. The shaped PZT electromechanical coupling coefficient kt is determined as 0.41. A pulse-echo experiment is performed directly using the parylene/RTV curved diaphragm as the backing of the device. The outcome displays a central frequency of 50 MHz and a -6 dB bandwidth of 30% as well as a lateral resolution of 40 µm. An experiment for measuring the averaged acoustic intensity generated by the transducer in air is designed and tested. The result shows a maximum value of 43 µW mm-2 at the focus when the transducer is driven by an 11 MHz continuous sinusoidal wave of 3 Vpp.

  5. High temperature energy harvesters utilizing ALN/3C-SiC composite diaphragms

    NASA Astrophysics Data System (ADS)

    Lai, Yun-Ju; Li, Wei-Chang; Felmetsger, Valery V.; Senesky, Debbie G.; Pisano, Albert P.

    2014-06-01

    Microelectromechanical systems (MEMS) energy harvesting devices aiming at powering wireless sensor systems for structural health monitoring in harsh environments are presented. For harsh environment wireless sensor systems, sensor modules are required to operate at elevated temperatures (> 250°C) with capabilities to resist harsh chemical conditions, thereby the use of battery-based power sources becomes challenging and not economically efficient if considering the required maintenance efforts. To address this issue, energy harvesting technology is proposed to replace batteries and provide a sustainable power source for the sensor systems towards autonomous harsh environment wireless sensor networks. In particular, this work demonstrates a micromachined aluminum nitride/cubic silicon carbide (AlN/3C-SiC) composite diaphragm energy harvester, which enables high temperature energy harvesting from ambient pulsed pressure sources. The fabricated device yields an output power density of 87 μW/cm2 under 1.48-psi pressure pulses at 1 kHz while connected to a 14.6-kΩ load resistor. The effects of pulse profile on output voltage have been studied, showing that the output voltage can be maximized by optimizing the diaphragm resonance frequency based on specific pulse characteristics. In addition, temperature dependence of the diaphragm resonance frequency over the range of 20°C to 600°C has been investigated and the device operation at temperatures as high as 600°C has been verified.

  6. Electro-active device using radial electric field piezo-diaphragm for sonic applications

    NASA Technical Reports Server (NTRS)

    Bryant, Robert G. (Inventor); Fox, Robert L. (Inventor)

    2005-01-01

    An electro-active transducer for sonic applications includes a ferroelectric material sandwiched by first and second electrode patterns to form a piezo-diaphragm coupled to a mounting frame. When the device is used as a sonic actuator, the first and second electrode patterns are configured to introduce an electric field into the ferroelectric material when voltage is applied to the electrode patterns. When the device is used as a sonic sensor, the first and second electrode patterns are configured to introduce an electric field into the ferroelectric material when the ferroelectric material experiences deflection in a direction substantially perpendicular thereto. In each case, the electrode patterns are designed to cause the electric field to: i) originate at a region of the ferroelectric material between the first and second electrode patterns, and ii) extend radially outward from the region of the ferroelectric material (at which the electric field originates) and substantially parallel to the plane of the ferroelectric material. The mounting frame perimetrically surrounds the peizo-diaphragm and enables attachment of the piezo-diaphragm to a housing.

  7. Piston diaphragm pumps: An economic and reliable tool for slurry pipeline transportation

    SciTech Connect

    Broek, B. van den

    1998-07-01

    Slurry transportation systems by means of pumps and pipelines has been in use now for over 100 years. Hydraulic transportation of slurries is defined as a two-phase transportation of a mixture of a fluid carrier and solids, mainly in enclosed pipelines. In the mid fifties, slurry transportation techniques became more sophisticated, resulting in the design and operation of long distance pipelines for raw materials, such as coal, copper concentrate, iron concentrate, kaolin and phosphate. Nowadays, slurry transportation through pipelines has become a generally accepted means of solids transportation. A major contribution to its acceptance was the development of reliable and efficient high pressure positive displacement piston diaphragm slurry pumps. This paper will deal with the latest development in this field, namely, the high pressure GEHO piston diaphragm pump. In order to create more understanding for the possible applications and use of such piston diaphragm pumps in relation to minerals and waste transportation through pipelines, a number of typical examples will be discussed.

  8. The effect of theophylline on the prevention of mechanical ventilation-induced diaphragm atrophy in rats.

    PubMed

    Aydin, Nihal Bakirkalay; Teke, Turgut; Toy, Hatice; Uzun, Kursat

    2014-01-01

    Movement disorders and atrophy occur in the diaphragm, the most important muscle of respiration, because of mechanical ventilation (MV). In this animal model, we aimed to evaluate the effect of intravenous theophylline administration on the prevention of mechanical ventilation-induced diaphragmatic atrophy. In our study, 30 healthy male Sprague-dawley rats were used. They were divided into 3 equal groups. Group 1: the control group (no MV); group 2: the placebo group that received MV; Group 3: the theophylline group composed of rats that received both MV and theophylline therapy. In all 3 groups, the diaphragmatic atrophy was evaluated histopathologically. In the histopathological examination, no macroscopic thickening and microscopic atrophy were observed in the diaphragm in the control group. In the placebo group (group 2), macroscopically definite thickening was observed in all rats, and microscopically, heavy (+++) atrophy was observed. In the theophylline group (group 3), there was no atrophy in one rat. In 8 rats, light (+), and in 1 rat medium (++) atrophy was observed. In our study, it was shown that atrophy occurred in the diaphragms of rats after MV, and the atrophy was decreased after theophylline administration.

  9. Comparison of stethoscope bell and diaphragm, and of stethoscope tube length, for clinical blood pressure measurement.

    PubMed

    Liu, Chengyu; Griffiths, Clive; Murray, Alan; Zheng, Dingchang

    2016-06-01

    This study investigated the effect of stethoscope side and tube length on auscultatory blood pressure (BP) measurement. Thirty-two healthy participants were studied. For each participant, four measurements with different combinations of stethoscope characteristics (bell or diaphragm side, standard or short tube length) were each recorded at two repeat sessions, and eight Korotkoff sound recordings were played twice on separate days to one experienced listener to determine the systolic and diastolic BPs (SBP and DBP). Analysis of variance was carried out to study the measurement repeatability between the two repeat sessions and between the two BP determinations on separate days, as well as the effects of stethoscope side and tube length. There was no significant paired difference between the repeat sessions and between the repeat determinations for both SBP and DBP (all P-values>0.10, except the repeat session for SBP using short tube and diaphragm). The key result was that there was a small but significantly higher DBP on using the bell in comparison with the diaphragm (0.66 mmHg, P=0.007), and a significantly higher SBP on using the short tube in comparison with the standard length (0.77 mmHg, P=0.008). This study shows that stethoscope characteristics have only a small, although statistically significant, influence on clinical BP measurement. Although this helps understand the measurement technique and resolves questions in the published literature, the influence is not clinically significant.

  10. Molecular, cellular, and muscle strip mechanics of the mdx mouse diaphragm.

    PubMed

    Bates, Genevieve; Sigurdardottir, Sara; Kachmar, Linda; Zitouni, Nedjma B; Benedetti, Andrea; Petrof, Basil J; Rassier, Dilson; Lauzon, Anne-Marie

    2013-05-01

    Duchenne muscular dystrophy (DMD) is a lethal disorder caused by defects in the dystrophin gene, which leads to respiratory or cardiac muscle failure. Lack of dystrophin predisposes the muscle cell sarcolemmal membrane to mechanical damage. However, the role of myosin in this muscle weakness has been poorly addressed. In the current study, in addition to measuring the velocity of actin filament propulsion (υmax) of mdx myosin molecules purified from 3- and 12-mo-old control (C57Bl/10) and mdx (C57Bl/10mdx) mouse diaphragms, we also measured myosin force production. Furthermore, we measured cellular and muscle strip force production at three mo of age. Stress (force/cross-sectional area) was smaller for mdx than control at the muscle strip level but was not different at the single fiber level. υmax of mdx myosin was not different from control at either 3 or 12 mo nor was their relative myosin force. The type I and IIb myosin heavy chain composition was not different between control and mdx diaphragms at 3 or 12 mo. These results suggest that the myosin function, as well as the single fiber mechanics, do not underlie the weakness of the mdx diaphragm. This weakness was only observed at the level of the intact muscle bundle and could not be narrowed down to a specific mechanical impairment of its individual fibers or myosin molecules.

  11. Targeting Heat Shock Proteins Mitigates Ventilator Induced Diaphragm Muscle Dysfunction in an Age-Dependent Manner.

    PubMed

    Ogilvie, Hannah; Cacciani, Nicola; Akkad, Hazem; Larsson, Lars

    2016-01-01

    Intensive care unit (ICU) patients are often overtly subjected to mechanical ventilation and immobilization, which leads to impaired limb and respiratory muscle function. The latter, termed ventilator-induced diaphragm dysfunction (VIDD) has recently been related to compromised heat shock protein (Hsp) activation. The administration of a pharmacological drug BGP-15 acting as a Hsp chaperone co-inducer has been found to partially alleviate VIDD in young rats. Considering that the mean age in the ICU is increasing, we aimed to explore whether the beneficial functional effects are also present in old rats. For that, we exposed young (7-8 months) and old (28-32 months) rats to 5-day controlled mechanical ventilation and immobilization with or without systemic BGP-15 administration. We then dissected diaphragm muscles, membrane-permeabilized bundles and evaluated the contractile function at single fiber level. Results confirmed that administration of BGP-15 restored the force-generating capacity of isolated muscle cells from young rats in conjunction with an increased expression of Hsp72. On the other hand, our results highlighted that old rats did not positively respond to the BGP-15 treatment. Therefore, it is of crucial importance to comprehend in more depth the effect of VIDD on diaphragm function and ascertain any further age-related differences.

  12. Monte Carlo analysis of thermal transpiration effects in capacitance diaphragm gauges with helicoidal baffle system

    NASA Astrophysics Data System (ADS)

    Vargas, M.; Wüest, M.; Stefanov, S.

    2012-05-01

    The Capacitance Diaphragm Gauge (CDG) is one of the most widely used vacuum gauges in low and middle vacuum ranges. This device consists basically of a very thin ceramic or metal diaphragm which forms one of the electrodes of a cap acitor. The pressure is determined by measuring the variation in the capacitance due to the deflection of the diaphragm caused by the pressure difference established across the membrane. In order to minimize zero drift, some CDGs are operated keeping the sensor at a higher temperature. This difference in the temperature between the sensor and the vacuum chamber makes the behaviour of the gauge non-linear due to thermal transpiration effects. This effect becomes more significant when we move from the transitional flow to the free molecular regime. Besides, CDGs may incorporate different baffle systems to avoid the condensation on the membrane or its contamination. In this work, the thermal transpiration effect on the behaviour of a rarefied gas and on the measurements in a CDG with a helicoidal baffle system is investigated by using the Direct Simulation Monte Carlo method (DSMC). The study covers the behaviour of the system under the whole range of rarefaction, from the continuum up to the free molecular limit and the results are compared with empirical results. Moreover, the influence of the boundary conditions on the thermal transpiration effects is investigated by using Maxwell boundary conditions.

  13. Contractile function is unaltered in diaphragm from mice lacking calcium release channel isoform 3

    NASA Technical Reports Server (NTRS)

    Clancy, J. S.; Takeshima, H.; Hamilton, S. L.; Reid, M. B.

    1999-01-01

    Skeletal muscle expresses at least two isoforms of the calcium release channel in the sarcoplasmic reticulum (RyR1 and RyR3). Whereas the function of RyR1 is well defined, the physiological significance of RyR3 is unclear. Some authors have suggested that RyR3 participates in excitation-contraction coupling and that RyR3 may specifically confer resistance to fatigue. To test this hypothesis, we measured contractile function of diaphragm strips from adult RyR3-deficient mice (exon 2-targeted mutation) and their heterozygous and wild-type littermates. In unfatigued diaphragm, there were no differences in isometric contractile properties (twitch characteristics, force-frequency relationships, maximal force) among the three groups. Our fatigue protocol (30 Hz, 0.25 duty cycle, 37 degrees C) depressed force to 25% of the initial force; however, lack of RyR3 did not accelerate the decline in force production. The force-frequency relationship was shifted to higher frequencies and was depressed in fatigued diaphragm; lack of RyR3 did not exaggerate these changes. We therefore provide evidence that RyR3 deficiency does not alter contractile function of adult muscle before, during, or after fatigue.

  14. Contractile function is unaltered in diaphragm from mice lacking calcium release channel isoform 3

    NASA Technical Reports Server (NTRS)

    Clancy, J. S.; Takeshima, H.; Hamilton, S. L.; Reid, M. B.

    1999-01-01

    Skeletal muscle expresses at least two isoforms of the calcium release channel in the sarcoplasmic reticulum (RyR1 and RyR3). Whereas the function of RyR1 is well defined, the physiological significance of RyR3 is unclear. Some authors have suggested that RyR3 participates in excitation-contraction coupling and that RyR3 may specifically confer resistance to fatigue. To test this hypothesis, we measured contractile function of diaphragm strips from adult RyR3-deficient mice (exon 2-targeted mutation) and their heterozygous and wild-type littermates. In unfatigued diaphragm, there were no differences in isometric contractile properties (twitch characteristics, force-frequency relationships, maximal force) among the three groups. Our fatigue protocol (30 Hz, 0.25 duty cycle, 37 degrees C) depressed force to 25% of the initial force; however, lack of RyR3 did not accelerate the decline in force production. The force-frequency relationship was shifted to higher frequencies and was depressed in fatigued diaphragm; lack of RyR3 did not exaggerate these changes. We therefore provide evidence that RyR3 deficiency does not alter contractile function of adult muscle before, during, or after fatigue.

  15. Changes in types of muscle fibers induced by transcutaneous electrical stimulation of the diaphragm of rats.

    PubMed

    Costa, D; Cancelliero, K M; Campos, G E R; Salvini, T F; Silva, C A da

    2008-09-01

    The objective of the present study was to assess the effect of transcutaneous electrical diaphragmatic stimulation (TEDS) on different types of diaphragm muscle fibers. Male Wistar rats (8-12 weeks old) were divided into 2 experimental groups (N = 8 in each group): 1) control, 2) animals submitted to TEDS [frequency = 50 Hz; T(ON)/T(OFF) (contraction/relaxation time) = 2/2 s; pulse duration = 0.4 ms, intensity = 5 mA with a 1 mA increase every 3 min for 20 min] for 7 days. After completing this treatment period, the I, IIA, IIB, and IID diaphragm muscle fibers were identified using the mATPase technique. Statistical analysis consisted of the normality, homoscedasticity and t-tests (P < 0.05). There was a 19.6% (P < 0.05) reduction in the number of type I fibers and a 49.7% increase (P < 0.05) in type IID fibers in the TEDS group compared with the control group. An important result of the present study was that electrical stimulation with surface electrodes was efficient in altering the distribution of fibers in diaphragm muscle. This therapeutic resource could be used in the treatment of respiratory muscle alterations.

  16. Vibration and sound radiation of an electrostatic speaker based on circular diaphragm.

    PubMed

    Chiang, Hsin-Yuan; Huang, Yu-Hsi

    2015-04-01

    This study investigated the lumped parameter method (LPM) and distributed parameter method (DPM) in the measurement of vibration and prediction of sound pressure levels (SPLs) produced by an electrostatic speaker with circular diaphragm. An electrostatic speaker with push-pull configuration was achieved by suspending the circular diaphragm (60 mm diameter) between two transparent conductive plates. The transparent plates included a two-dimensional array of holes to enable the visualization of vibrations and avoid acoustic distortion. LPM was used to measure the displacement amplitude at the center of the diaphragm using a scanning vibrometer with the aim of predicting symmetric modes using Helmholtz equations and SPLs using Rayleigh integral equations. DPM was used to measure the amplitude of displacement across the entire surface of the speaker and predict SPL curves. LPM results show that the prediction of SPL associated with the first three symmetric resonant modes is in good agreement with the results of DPM and acoustic measurement. Below the breakup frequency of 375 Hz, the SPL predicted by LPM and DPM are identical with the results of acoustic measurement. This study provides a rapid, accurate method with which to measure the SPL associated with the first three symmetric modes using semi-analytic LPM.

  17. Thoracoabdominal wall defect with complete ectopia cordis and gastroschisis: a case report and review of the literature.

    PubMed

    Pepper, Michael A; Fishbein, Gregory A; Teitell, Michael A

    2013-01-01

    Ventral wall defects are extremely rare anomalies that are likely caused by the failure of the ventral wall to close during week 4 of development. We report a case of severe thoracoabdominal wall defect including complete thoracic ectopia cordis and gastroschisis. This combination represents a novel constellation of findings in a single patient. This unique case further demonstrates an anatomically normal heart with age-appropriate development and an intact diaphragm. We review the literature of other reports and discussions of entities that share overlapping features with this case.

  18. Cooling wall

    SciTech Connect

    Nosenko, V.I.

    1995-07-01

    Protecting the shells of blast furnaces is being resolved by installing cast iron cooling plates. The cooling plates become non-operational in three to five years. The problem is that defects occur in manufacturing the cooling plates. With increased volume and intensity of work placed on blast furnaces, heat on the cast iron cooling plates reduces their reliability that limits the interim repair period of blast furnaces. Scientists and engineers from the Ukraine studied this problem for several years, developing a new method of cooling the blast furnace shaft called the cooling wall. Traditional cast iron plates were replaced by a screen of steel tubes, with the area between the tubes filled with fireproof concrete. Before placing the newly developed furnace shaft into operation, considerable work was completed such as theoretical calculations, design, research of temperature fields and tension. Continual testing over many years confirms the value of this research in operating blast furnaces. The cooling wall works with water cooling as well as vapor cooling and is operating in 14 blast furnaces in the Ukraine and two in Russia, and has operated for as long as 14 years.

  19. Different tissue reaction of oesophagus and diaphragm after mesh hiatoplasty. Results of an animal study

    PubMed Central

    Otto, Jens; Kämmer, Daniel; Jansen, Petra Lynen; Anurov, Michael; Titkova, Svetlana; Öttinger, Alexander; Rosch, Raphael; Schumpelick, Volker; Jansen, Marc

    2008-01-01

    Background Laparoscopic mesh-reinforcement of the hiatal region in the treatment of gastroesophageal reflux disease (GERD) and paraesophageal hernia (PEH) reduces the risk of recurrence. However, there are still controversies about the technique of mesh placement, shape, structure and material. We therefore compared tissue integration and scar formation after implantation of two different polypropylene-meshes in a rabbit model. Methods A total of 20 female chinchilla rabbits were included in this study. Two different meshes (Polypropylene PP, Polyglecaprone 25 Composite PP-PG) were implanted on the abdominal diaphragm around the oesophagus. After 3 months the implanted meshes were excised en-bloc. Histological and morphological analyses were carried out accordingly proliferation rate, apoptosis and collagen type I/III ratio. Results Regarding proliferation rate of oesophagus PP (9.31 ± 3.4%) and PP-PG (13.26 ± 2.54%) differ in a significant (p = 0.0097) way. In the diaphragm we found a significant (p = 0.00066) difference between PP (9.43 ± 1.45%) and PP-PG (18.73 ± 5.92%) respectively. Comparing oesophagus and diaphragm we could prove a significant difference within PP-PG-group (p = 0.0195). Within PP-group the difference reached no statistical significance (p = 0.88). We found analogous results regarding apoptosis. Furthermore, there is a significant (p = 0.00013) difference of collagen type I/III ratio in PP-PG (12.28 ± 0.8) compared to PP (8.44 ± 1,63) in case of oesophageal tissue. Concerning diaphragm we found a significant difference (p = 0.000099) between PP-PG (8.85 ± 0.81) and PP (6.32 ± 1.07) as well. Conclusion The histologic and morphologic characteristics after prosthetic enforcement of the hiatus in this animal model show a more distinct tissue integration using PP-PG compared to PP. Additionally, different wound healing and remodelling capability influence tissue integration of the mesh in diaphragm and oesophagus. PMID:18405386

  20. Automatic assessment of average diaphragm motion trajectory from 4DCT images through machine learning

    PubMed Central

    Li, Guang; Wei, Jie; Huang, Hailiang; Gaebler, Carl Philipp; Yuan, Amy; Deasy, Joseph O

    2016-01-01

    To automatically estimate average diaphragm motion trajectory (ADMT) based on four-dimensional computed tomography (4DCT), facilitating clinical assessment of respiratory motion and motion variation and retrospective motion study. We have developed an effective motion extraction approach and a machine-learning-based algorithm to estimate the ADMT. Eleven patients with 22 sets of 4DCT images (4DCT1 at simulation and 4DCT2 at treatment) were studied. After automatically segmenting the lungs, the differential volume-per-slice (dVPS) curves of the left and right lungs were calculated as a function of slice number for each phase with respective to the full-exhalation. After 5-slice moving average was performed, the discrete cosine transform (DCT) was applied to analyze the dVPS curves in frequency domain. The dimensionality of the spectrum data was reduced by using several lowest frequency coefficients (fv) to account for most of the spectrum energy (Σfv2). Multiple linear regression (MLR) method was then applied to determine the weights of these frequencies by fitting the ground truth—the measured ADMT, which are represented by three pivot points of the diaphragm on each side. The ‘leave-one-out’ cross validation method was employed to analyze the statistical performance of the prediction results in three image sets: 4DCT1, 4DCT2, and 4DCT1 + 4DCT2. Seven lowest frequencies in DCT domain were found to be sufficient to approximate the patient dVPS curves (R = 91%−96% in MLR fitting). The mean error in the predicted ADMT using leave-one-out method was 0.3 ± 1.9 mm for the left-side diaphragm and 0.0 ± 1.4 mm for the right-side diaphragm. The prediction error is lower in 4DCT2 than 4DCT1, and is the lowest in 4DCT1 and 4DCT2 combined. This frequency-analysis-based machine learning technique was employed to predict the ADMT automatically with an acceptable error (0.2 ± 1.6 mm). This volumetric approach is not affected by the presence of the lung tumors

  1. Proportionality between chest wall resistance and elastance.

    PubMed

    Barnas, G M; Stamenović, D; Fredberg, J J

    1991-02-01

    Fredberg and Stamenovic (J. Appl. Physiol. 67: 2408-2419, 1989) demonstrated a relatively robust phenomenological relationship between resistance (R) and elastance (E) of lung tissue during external forcing. The relationship can be expressed as omega R = eta E, where omega = 2 pi times forcing frequency and eta is hysteresivity; they found eta to be remarkably invariant under a wide range of circumstances. From data gathered in previous experiments, we have tested the adequacy and utility of this phenomenological description for the chest wall (eta w) and its major compartments, the rib cage (eta rc), diaphragm-abdomen (eta d-a), and belly wall (eta bw+). For forcing frequencies and tidal volumes within the normal range of breathing, we found that eta w remained in a relatively narrow range (0.27-0.37) and that neither eta w nor the compartmental eta's changed much with frequency or tidal volume. Compared with eta w, eta rc tended to be slightly low, whereas eta d-a tended to be slightly higher than eta w. However, at higher frequencies (greater than 1 Hz) all eta's increased appreciably with frequency. During various static nonrespiratory maneuvers involving use of respiratory muscles, eta w increased up to twofold. We conclude that in the normal ranges of breathing frequency and tidal volume 1) elastic and dissipative processes within the chest wall appear to be coupled, 2) eta's of the various component parts of the chest wall are well matched, 3) respiratory muscle contraction increases the ratio of cyclic dissipative losses to energy storage, and 4) R of the relaxed chest wall can be estimated from E.(ABSTRACT TRUNCATED AT 250 WORDS)

  2. Wall to Wall Optimal Transport

    NASA Astrophysics Data System (ADS)

    Chini, Gregory P.; Hassanzadeh, Pedram; Doering, Charles R.

    2013-11-01

    How much heat can be transported between impermeable fixed-temperature walls by incompressible flows with a given amount of kinetic energy or enstrophy? What do the optimal velocity fields look like? We employ variational calculus to address these questions in the context of steady 2D flows. The resulting nonlinear Euler-Lagrange equations are solved numerically, and in some cases analytically, to find the maximum possible Nusselt number Nu as a function of the Péclect number Pe , a measure of the flow's energy or enstrophy. We find that in the fixed-energy problem Nu ~ Pe , while in the fixed-enstrophy problem Nu ~ Pe 10 / 17 . In both cases, the optimal flow consists of an array of convection cells with aspect ratio Γ (Pe) . Interpreting our results in terms of the Rayleigh number Ra for relevant buoyancy-driven problems, we find Nu <= 1 + 0 . 035 Ra and Γ ~ Ra - 1 / 2 for porous medium convection (which occurs with fixed energy), and Nu <= 1 + 0 . 115 Ra 5 / 12 and Γ ~ Ra - 1 / 4 for Rayleigh-Bénard convection (which occurs with fixed enstrophy and for free-slip walls). This work was supported by NSF awards PHY-0855335, DMS-0927587, and PHY-1205219 (CRD) and DMS-0928098 (GPC). Much of this work was completed at the 2012 Geophysical Fluid Dynamics (GFD) Program at Woods Hole Oceanographic Institution.

  3. SU-D-BRA-04: Improvement of Diaphragm Motion Reproducibility in MRI Using Audiovisual Biofeedback for Lung Cancer Radiotherapy.

    PubMed

    Kim, Taeho

    2012-06-01

    Previous studies have investigated the effect of AV biofeedback on the external respiratory signal reproducibility. This is the first study investigating the effect of AV biofeedback to improve the motion reproducibility of the internal anatomy. The aim of the project is to test the hypothesis that AV biofeedback improves the diaphragm motion reproducibility. An AV biofeedback system has been employed with MRI acquisitions. The AV biofeedback system utilized (1) the external marker position on the abdomen using an RPM system (Real-time Position Management, Varian) to audio-visually guide a human subject for regular breathing and (2) a fast Gradient-Recalled-Echo (fGRE) MR pulse sequence of 3 Tesla GE MRI (GE Healthcare) to monitor the diaphragm motion (200ms). The improvement in the diaphragm motion reproducibility using the AV biofeedback system combined with MRI has been assessed in 26 studies with 13 healthy human subjects. Each subject underwent two studies for assessment of the diaphragm motion reproducibility both with AV biofeedback and without (free breathing). The second study features a reversed order of breathing conditions. The total MRI acquisitions across the 26 studies are 202 measurements including sagittal and coronal planes. Average RMSE (root mean square error) of diaphragm displacement obtained from MRI analysis has been reduced from 2.7mm of free breathing to 1.6mm of AV biofeedback breathing (p-value < 0.05). Additionally, the average RMSE of diaphragm motion period was reduced from 1.84s with free breathing to 0.34s with AV biofeedback breathing (p- value < 0.05). 22% of average displacement error was reduced using AV biofeedback in the first study, and 47% reduction in the second study. The study demonstrated the improvement in the diaphragm motion reproducibility using AV biofeedback. This system can provide clinically applicable motion management of the internal anatomy in MRI and for Image Guided Radiotherapy (IGRT). © 2012 American

  4. Diaphragm muscle weakness in mice is early-onset post-myocardial infarction and associated with elevated protein oxidation.

    PubMed

    Bowen, T Scott; Mangner, Norman; Werner, Sarah; Glaser, Stefanie; Kullnick, Yvonne; Schrepper, Andrea; Doenst, Torsten; Oberbach, Andreas; Linke, Axel; Steil, Leif; Schuler, Gerhard; Adams, Volker

    2015-01-01

    Heart failure induced by myocardial infarction (MI) causes diaphragm muscle weakness, with elevated oxidants implicated. We aimed to determine whether diaphragm muscle weakness is 1) early-onset post-MI (i.e., within the early left ventricular remodeling phase of 72 h); and 2) associated with elevated protein oxidation. Ligation of the left coronary artery to induce MI (n = 10) or sham operation (n = 10) was performed on C57BL6 mice. In vitro contractile function of diaphragm muscle fiber bundles was assessed 72 h later. Diaphragm mRNA and protein expression, enzyme activity, and individual carbonylated proteins (by two-dimensional differential in-gel electrophoresis and mass spectrometry) were subsequently assessed. Infarct size averaged 57 ± 1%. Maximal diaphragm function was reduced (P < 0.01) by 20% post-MI, with the force-frequency relationship depressed (P < 0.01) between 80 and 300 Hz. The mRNA expression of inflammation, atrophy, and regulatory Ca(2+) proteins remained unchanged post-MI, as did the protein expression of key contractile proteins. However, enzyme activity of the oxidative sources NADPH oxidase and xanthine oxidase was increased (P < 0.01) by 45 and 33%, respectively. Compared with sham, a 57 and 45% increase (P < 0.05) was observed in the carbonylation of sarcomeric actin and creatine kinase post-MI, respectively. In conclusion, diaphragm muscle weakness was rapidly induced in mice during the early left ventricular remodeling phase of 72 h post-MI, which was associated with increased oxidation of contractile and energetic proteins. Collectively, these findings suggest diaphragm muscle weakness may be early onset in heart failure, which is likely mediated in part by posttranslational oxidative modifications at the myofibrillar level. Copyright © 2015 the American Physiological Society.

  5. Diaphragm muscle weakness in mice is early-onset post-myocardial infarction and associated with elevated protein oxidation

    PubMed Central

    Mangner, Norman; Werner, Sarah; Glaser, Stefanie; Kullnick, Yvonne; Schrepper, Andrea; Doenst, Torsten; Oberbach, Andreas; Linke, Axel; Steil, Leif; Schuler, Gerhard; Adams, Volker

    2014-01-01

    Heart failure induced by myocardial infarction (MI) causes diaphragm muscle weakness, with elevated oxidants implicated. We aimed to determine whether diaphragm muscle weakness is 1) early-onset post-MI (i.e., within the early left ventricular remodeling phase of 72 h); and 2) associated with elevated protein oxidation. Ligation of the left coronary artery to induce MI (n = 10) or sham operation (n = 10) was performed on C57BL6 mice. In vitro contractile function of diaphragm muscle fiber bundles was assessed 72 h later. Diaphragm mRNA and protein expression, enzyme activity, and individual carbonylated proteins (by two-dimensional differential in-gel electrophoresis and mass spectrometry) were subsequently assessed. Infarct size averaged 57 ± 1%. Maximal diaphragm function was reduced (P < 0.01) by 20% post-MI, with the force-frequency relationship depressed (P < 0.01) between 80 and 300 Hz. The mRNA expression of inflammation, atrophy, and regulatory Ca2+ proteins remained unchanged post-MI, as did the protein expression of key contractile proteins. However, enzyme activity of the oxidative sources NADPH oxidase and xanthine oxidase was increased (P < 0.01) by 45 and 33%, respectively. Compared with sham, a 57 and 45% increase (P < 0.05) was observed in the carbonylation of sarcomeric actin and creatine kinase post-MI, respectively. In conclusion, diaphragm muscle weakness was rapidly induced in mice during the early left ventricular remodeling phase of 72 h post-MI, which was associated with increased oxidation of contractile and energetic proteins. Collectively, these findings suggest diaphragm muscle weakness may be early onset in heart failure, which is likely mediated in part by posttranslational oxidative modifications at the myofibrillar level. PMID:25359720

  6. The effect of progressive high-intensity inspiratory muscle training and fixed high-intensity inspiratory muscle training on the asymmetry of diaphragm thickness in stroke patients.

    PubMed

    Jung, Ju-Hyeon; Kim, Nan-Soo

    2015-10-01

    [Purpose] This study investigated the effects of progressive load and fixed load high-intensity inspiratory muscle training on the asymmetry of diaphragm thickness in stroke patients. [Subjects] Twenty-one stroke patients were assigned to one of three groups: progressive load high-intensity inspiratory muscle training (n = 8), fixed load high-intensity inspiratory muscle training (n = 6), and controls (n = 7). [Methods] The progressive load and fixed load high-intensity inspiratory muscle training participants undertook an exercise program for 20 minutes, three times weekly, for 6 weeks. After each session, diaphragm thickness was measured using ultrasonography. The diaphragm asymmetry ratio and diaphragm thickening ratio were standardized using a formula. [Results] After intervention, the diaphragm asymmetry ratio significantly differed among the three groups, and the diaphragm asymmetry ratio significantly increased in the control group. A significant increase was identified in the diaphragm thickening ratio within the progressive load and fixed load high-intensity inspiratory muscle training groups. [Conclusion] Progressive load and fixed load high-intensity inspiratory muscle training decreased the asymmetry of diaphragm thickness in stroke patients; this effect, in turn, increased the diaphragm thickening ratio in stroke patients. The two interventions examined here should be selectively applied to individuals in the clinical field.

  7. Instantaneous changes in respiratory function induced by passive pelvic suspension in the supine position in relation to increased diaphragm excursion

    PubMed Central

    Ishizuka, Tatsuya; Nishida, Naoya; Homma, Yuuki; Hirayama, Tetsuro; Ishida, Yukisato; Kakizaki, Fujiyasu; Konishi, Masato

    2017-01-01

    [Purpose] This study aimed to introduce an approach of pelvic suspension (PS) using sling cords and to obtain evidence for changes in respiratory function of healthy subjects. [Subjects and Methods] Subjects were 25 healthy men. In the supine position, with hip and knee joints flexed at 90°, the subjects’ pelvises were suspended with sling belts. Diaphragm excursion, respiratory function, and respiratory comfort in these postures were measured using ultrasonography, respirometry, and visual analog scale (VAS), respectively. [Results] When the pelvis was passively suspended with sling cords, the diaphragm moved 5 mm cranially and diaphragm excursion showed an instantaneous increase compared with the control. The tidal volume (VT) showed an increase and the respiration rate (RR) showed a decrease. The extent of diaphragm excursion was correlated with changes in VT under the control and PS conditio