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Sample records for ecc direct bypass

  1. ECC Water Film Spreading, ECC Water Bypass and Sweep-out Phenomena in the Downcomer with DVI of APR1400 under LBLOCA

    SciTech Connect

    Lee, Dong Won; No, Hee Cheon; Kim, Han Kon; Oh, Seung Jong

    2002-07-01

    In the present study, several experiments related to the thermal-hydraulic phenomena in downcomer with DVI under LBLOCA (Large Break Loss of Coolant Accident) were carried out using the experimental facility of plane-channel type scaled down as 1/7 ratio of prototype reactor (APR1400). Especially, phenomena such as ECC (Emergency Core Cooling) water entrainment and mixing in the downcomer were focused in the present study. Water film spreading was studied and compared with the full-scaled experiment and the experiment with a 1/7 scaled cylindrical-type test section to see the scaling effect and its curvature effect. It turns out that the curvature effect is negligible and the present modified linear scaling law is more appropriate than the linear scaling law. The water height and the amount of ECC water bypass by onset of sweep-out were measured from the visual observation of sweep-out in the downcomer. From this test, the onset of continuous sweep-out was used to analyze the water height in the downcomer. The amount of ECC water bypass by sweep-out was measured and compared with the UCB and KfK correlations. It is found that the best fit of the data from the present experiment lies between the predictions by the two correlations. ECC water mixing phenomena in downcomer were observed focusing on the ECC water film behavior. From the air and water mixing tests, it is concluded that ECC water bypass fraction is highly dependent on DVI position rather than gas flow rates and ECC water bypass fraction is less than 10% of injection ECC water. From the steam and water mixing tests, it is concluded that ECC bypass fraction with steam injection is under 1.5% and much less than that with an air injection because of the condensation in the downcomer. (authors)

  2. Progress on Complications of Direct Bypass for Moyamoya Disease

    PubMed Central

    Yu, Jinlu; Shi, Lei; Guo, Yunbao; Xu, Baofeng; Xu, Kan

    2016-01-01

    Moyamoya disease (MMD) involves progressive occlusion of the intracranial internal carotid artery resulting in formation of moyamoya-like vessels at the base of the brain. It can be characterized by hemorrhage or ischemia. Direct vascular bypass is the main and most effective treatment of MMD. However, patients with MMD differ from those with normal cerebral vessels. MMD patients have unstable intracranial artery hemodynamics and a poor blood flow reserve; therefore, during the direct bypass of superficial temporal artery (STA)-middle cerebral artery (MCA) anastomosis, perioperative risk factors and anesthesia can affect the hemodynamics of these patients. When brain tissue cannot tolerate a high blood flow rate, it becomes prone to hyperperfusion syndrome, which leads to neurological function defects and can even cause intracranial hemorrhage in severe cases. The brain tissue is prone to infarction when hemodynamic equilibrium is affected. In addition, bypass vessels become susceptible to occlusion or atrophy when blood resistance increases. Even compression of the temporalis affects bypass vessels. Because the STA is used in MMD surgery, the scalp becomes ischemic and is likely to develop necrosis and infection. These complications of MMD surgery are difficult to manage and are not well understood. To date, no systematic studies of the complications that occur after direct bypass in MMD have been performed, and reported complications are hidden among various case studies; therefore, this paper presents a review and summary of the literature in PubMed on the complications of direct bypass in MMD. PMID:27499690

  3. Bypassing primary sensory cortices--a direct thalamocortical pathway for transmitting salient sensory information.

    PubMed

    Liang, M; Mouraux, A; Iannetti, G D

    2013-01-01

    Detection and appropriate reaction to sudden and intense events happening in the sensory environment is crucial for survival. By combining Bayesian model selection with dynamic causal modeling of functional magnetic resonance imaging data, a novel analysis approach that allows inferring the causality between neural activities in different brain areas, we demonstrate that salient sensory information reaches the multimodal cortical areas responsible for its detection directly from the thalamus, without being first processed in primary and secondary sensory-specific areas. This direct thalamocortical transmission of multimodal salient information is parallel to the processing of finer stimulus attributes, which are transmitted in a modality-specific fashion from the thalamus to the relevant primary sensory areas. Such direct thalamocortical connections bypassing primary sensory cortices provide a fast and efficient way for transmitting information from subcortical structures to multimodal cortical areas, to allow the early detection of salient events and, thereby, trigger immediate and appropriate behavior.

  4. The ESX-5 associated eccB-EccC locus is essential for Mycobacterium tuberculosis viability.

    PubMed

    Di Luca, Mariagrazia; Bottai, Daria; Batoni, Giovanna; Orgeur, Mickael; Aulicino, Anna; Counoupas, Claudio; Campa, Mario; Brosch, Roland; Esin, Semih

    2012-01-01

    The recently described ESX-5 secretion system of Mycobacterium tuberculosis is one of the most important modulators of host-pathogen interactions due to its crucial impact on PPE protein secretion, cell wall stability and virulence. Although various components of the ESX-5 secretion machinery have been defined, other ESX-5 core components still remain to be characterized. In this study, we focused on EccB(5) and EccC(5), a transmembrane protein (EccB(5)) and a membrane-bound ATPase (EccC(5)), both predicted to be building blocks of the M. tuberculosis ESX-5 membrane-associated complex. In vitro expression studies demonstrated that EccB(5) and EccC(5) encoding genes constitute an operon. The expression of this operon is essential for M. tuberculosis, since the deletion of the eccB(5)-eccC(5) genomic segment at the ESX-5 locus is possible only after the integration of a second functional copy of eccB(5)-eccC(5) genes into the M. tuberculosis chromosome. The characterization of two M. tuberculosis conditional mutant strains (Mtb(Pptr)eccB(5) and Mtb(Pptr)eccC(5)), in which the eccB(5)-eccC(5) operon or the eccC(5) gene, respectively, were expressed under the control of an anhydrotetracycline-repressible promoter, confirmed that the repression of eccB(5)-eccC(5) genes is detrimental for growth of M. tuberculosis both in vitro and in THP-1 human macrophage cell line. Moreover, analysis of the secretome of Mtb(Pptr)eccB(5)-eccC(5) and Mtb(Pptr)eccC(5) strains revealed that both EccB(5) and EccC(5) are required for secretion of ESX-5 specific substrates, thus confirming that they are indeed components of the ESX-5 secretion machinery. Taken together these findings demonstrate the importance of an intact and functional ESX-5 system for viability of M. tuberculosis, thus opening new interesting options for alternative antimycobacterial control strategies.

  5. Clinical Effect and Prognosis of Off-Pump Minimally Invasive Direct Coronary Artery Bypass

    PubMed Central

    Yang, Ming; Xiao, Lian-Bo; Gao, Zhi-Sheng; Zhou, Ji-Wu

    2017-01-01

    Background Coronary artery bypass grafting (CABG) is a common procedure to circumvent the obstruction of coronary arteries when stents are unsuitable. CABG is a very traumatic surgery that requires redirecting blood flow to an external pump. Thus, this procedure has many risks during and after surgery, and minimizing these risks would greatly benefit the patients. Material/Methods We selected 126 patients with coronary artery syndrome and who were unsuitable for stent percutaneous coronary intervention. The observation group received minimally invasive direct coronary artery bypass (MIDCAB), while the control group was treated with off-pump CABG. Results Blood markers and echocardiography before and after treatment improved equally in both groups. Neither group exhibited obvious adverse reactions, or liver and kidney function damage. However, surgical bleeding and postoperative observation days were significantly reduced in the MIDCAB group. Death and cardiac shock at the end of follow-up were significantly lower in the MIDCAB group. Conclusions Overall, the clinical benefits of MIDCAB and OP-CABG were similar, but MIDCAB significantly reduced postoperative hospital stay and intraoperative blood transfusion, and improved clinical prognosis. PMID:28257412

  6. Osborne Reynolds' pipe flow: Direct computation from laminar through bypass transition to fully-developed turbulence

    NASA Astrophysics Data System (ADS)

    Wu, Xiaohua; Moin, Parviz; Adrian, Ronald; Baltzer, Jon; Hickey, Jean-Pierre

    2012-11-01

    The most fundamental internal flow, smooth pipe from a slightly perturbed laminar inlet state continuously through bypass transition to fully-developed turbulence, has been computed using DNS over an axial domain length of 250 pipe radii. In the fully-developed turbulent region, mean and second-order turbulent statistics including the rate of viscous dissipation show excellent agreement with those obtained from an additional simulation using the conventional streamwise periodic boundary condition over an axial domain length of 30 pipe radii. Friction factor follows analytical solution prior to breakdown, and agrees with Moody's correlation after the completion of transition. During transition it exhibits an overshoot. Breakdown of the laminar pipe flow is characterized by the formation of large Lambda-shaped vortices pointing upstream, followed by their subsequent generation of small hairpin packets inclined towards the downstream direction.

  7. ECC Ozonesonde Calibration and Observations: Satellite Validation

    NASA Technical Reports Server (NTRS)

    Schmidlin, Francis J.; Zukor, Dorothy (Technical Monitor)

    2001-01-01

    The reliability of the Electrochemical Concentration Cell (ECC) ozonesonde depends on the care exercised in preparing the instrument for use. Although the ECC can be quickly prepared and flown, generally within less then one day if necessary, it is best to prepare the instrument at least one week prior to use, and as our tests have confirmed even 2-3 weeks prior to use may actually be better. There are a number of factors that must be considered when preparing an ECC. These basically are the pump efficiency, volumetric flow rate, temperature of the air entering the pump, and the background current. Also of importance is the concentration of the potassium iodide solution. Tests conducted at Wallops Island (38 N) has enabled us to identify potential problem areas and ways to avoid them. The calibration and pre-flight preparation methods will be discussed. The method of calibrating the ECC also is used at Ascension Island (8 S) and Natal, Brazil (5 S). Comparisons between vertical profiles of the ECC instrument and satellites will be reviewed as well as comparison with ground based instruments, such as, the Dobson Spectrophotometer and hand held Microtops photometers.

  8. Nanoscale characterization of engineered cementitious composites (ECC)

    SciTech Connect

    Sakulich, Aaron Richard Li, Victor C.

    2011-02-15

    Engineered cementitious composites (ECC) are ultra-ductile fiber-reinforced cementitious composites. The nanoscale chemical and mechanical properties of three ECC formulae (one standard formula, and two containing nanomaterial additives) were studied using nanoindentation, electron microscopy, and energy dispersive spectroscopy. Nanoindentation results highlight the difference in modulus between bulk matrix ({approx} 30 GPa) and matrix/fiber interfacial transition zones as well as between matrix and unreacted fly ash ({approx} 20 GPa). The addition of carbon black or carbon nanotubes produced little variation in moduli when compared to standard M45-ECC. The indents were observed by electron microscopy; no trace of the carbon black particles could be found, but nanotubes, including nanotubes bridging cracks, were easily located in ultrafine cracks near PVA fibers. Elemental analysis failed to show a correlation between modulus and chemical composition, implying that factors such as porosity have more of an effect on mechanical properties than elemental composition.

  9. Patient directed perfusion pressure on bypass, an analogy from electrical engineering--a new concept.

    PubMed

    Warwick, Richard; Poole, Robert; Palmer, Kenneth; Johnson, Ian; Poullis, Michael

    2010-03-01

    Organ ischemia, particularly mesenteric and renal, can occur despite a seemingly adequate perfusion flow and pressure during a period of cardiopulmonary bypass. The blood pressure to run bypass at remains a contentious issue. We present the concept that perfusion pressure during cardiopulmonary bypass should be patient specific, depending on an individual's resting pre-procedural blood pressure. Four simulated arterial traces with variable morphology, but identical systolic and diastolic blood pressures, were analyzed to calculate the medical mean, arithmetic mean, and root mean square of the blood pressure tracing. Using the standard medical formula for calculation of mean blood pressure, you can potentially underestimate perfusion pressure by 12 mmHg in a normotensive subject. The root mean square pressure calculates the equivalent non pulsatile pressure that will deliver the same hydraulic power to the circulation as its pulsatile equivalent. Patient specific perfusion pressures, calculated via root mean square may potentially help reduce the incidence of organ ischemia during cardiopulmonary bypass. Clinical trials are needed to confirm or refute this concept.

  10. Patient Directed Perfusion Pressure on Bypass, an Analogy from Electrical Engineering—A New Concept

    PubMed Central

    Warwick, Richard; Poole, Robert; Palmer, Kenneth; Johnson, Ian; Poullis, Michael

    2010-01-01

    Abstract: Organ ischemia, particularly mesenteric and renal, can occur despite a seemingly adequate perfusion flow and pressure during a period of cardiopulmonary bypass. The blood pressure to run bypass at remains a contentious issue. We present the concept that perfusion pressure during cardiopulmonary bypass should be patient specific, depending on an individual’s resting pre-procedural blood pressure. Four simulated arterial traces with variable morphology, but identical systolic and diastolic blood pressures, were analyzed to calculate the medical mean, arithmetic mean, and root mean square of the blood pressure tracing. Using the standard medical formula for calculation of mean blood pressure, you can potentially underestimate perfusion pressure by 12 mmHg in a normotensive subject. The root mean square pressure calculates the equivalent non pulsatile pressure that will deliver the same hydraulic power to the circulation as its pulsatile equivalent. Patient specific perfusion pressures, calculated via root mean square may potentially help reduce the incidence of organ ischemia during cardiopulmonary bypass. Clinical trials are needed to confirm or refute this concept. PMID:20437793

  11. Fatigue enhancement of concrete beam with ECC layer

    SciTech Connect

    Leung, Christopher K.Y. . E-mail: ckleung@ust.hk; Cheung, Y.N.; Zhang Jun

    2007-05-15

    The pseudo strain-hardening behavior of Engineered Cementitious Composites (ECC) is a desirable characteristic for it to replace concrete to suppress brittle failure. This widespread use of ECC in the industry is, however, limited by its high cost. To achieve higher performance/cost, ECC can be strategically applied in parts of a structure that is under relatively high stress and strain. In this paper, layered ECC-concrete beams subjected to static and fatigue flexural loads were investigated by experiments. The static test results showed that the application of a layer of ECC on the tensile side of a flexural beam increased its flexural strength and the degree of improvement increased with the thickness of ECC applied. In addition, the layer of ECC enhanced the ductility of the beam and the failure mode changed from brittle to ductile. Under four-point cyclic loading, the ECC layer significantly improved the fatigue life of the beam. Moreover, in comparison to plain concrete beams, layered ECC beams could sustain fatigue loading at a larger deflection without failure. The great improvement in fatigue performance was attributed to the effectiveness of ECC in controlling the growth of small cracks. The experimental findings reflect the feasibility of using ECC strategically in critical locations for the control of fatigue crack growth.

  12. Effects of solution mass transport on the ECC ozonesonde background current. [Electrochemical Concentration Cell

    NASA Technical Reports Server (NTRS)

    Thornton, D. C.; Niazy, N.

    1983-01-01

    A technique is developed to measure the effective mass transport parameter for the electrochemical concentration cell (ECC) ozonesonde in order to determine the mass transport rate constant for the ECC as a function of pressure. It is shown that a pressure dependent factor in the background current originates in a convective mass transport parameter. It is determined that for atmospheric pressures greater than 100 mb the mass transport parameter is a constant, while at pressures less than 100 mb it decreases logarithmically with pressure. It is suggested that the background current correction is directly correlated to the mass transport parameter pressure dependence. The presently used background current correction, which is based on the partial pressure of oxygen, is found to lead to an overestimation of the integrated ozone value in the troposphere for the ECC ozonesonde data.

  13. [IVUS-controlled aorto-ostial directional coronary atherectomy in higher grade stenosis of the central anastomosis of a sequential triple venous bypass].

    PubMed

    Schiele, T M; Beauport, J; Niehues, R; Jacksch, R

    1998-12-01

    Following coronary artery bypass grafting repeat ischemia mandatory for reintervention occurs in 2 to 30% of cases, depending mainly on graft age. Selection of a suitable strategy for revascularisation--transcatheter angioplasty or reoperation--depends on various parameters including coronary morphology, left ventricular performance, comorbidity and availability of graft material. Catheter-based interventions on saphenous vein bypass grafts are feasible, but lower primary success rates and a higher incidence of restenosis--compared with native coronary arteries--have to be expected. Repeat coronary artery bypass graft operations are associated with a significantly higher perioperative morbidity and mortality, patency rates are lower and late clinical outcome is worse than in primary surgery. We report on a patient who underwent coronary artery bypass grafting 4 years ago revealing a high grade ostial stenosis in a jump-graft supplying RCA, LAD and Cx sequentially, making reintervention necessary. As a prerequisite serial balloon angioplasty of two native vessels was performed prior to ostial intervention. Intravascular-ultrasound guided directional coronary atherectomy was performed with good primary and long-term result. Our case demonstrates that, if all relevant clinical parameters and different therapeutic options are taken into account, complex transcatheter angioplasty procedures are feasible and associated with a reasonable amount of risk, thus avoiding repeat coronary artery bypass graft operations.

  14. Goal-directed Therapy Improves the Outcome of High-risk Cardiac Patients Undergoing Off-pump Coronary Artery Bypass

    PubMed Central

    Kapoor, Poonam Malhotra; Magoon, Rohan; Rawat, Rajinder Singh; Mehta, Yatin; Taneja, Sameer; Ravi, R; Hote, Milind P

    2017-01-01

    Background: There has been a constant emphasis on developing management strategies to improve the outcome of high-risk cardiac patients undergoing surgical revascularization. The performance of coronary artery bypass surgery on an off-pump coronary artery bypass (OPCAB) avoids the risks associated with extra-corporeal circulation. The preliminary results of goal-directed therapy (GDT) for hemodynamic management of high-risk cardiac surgical patients are encouraging. The present study was conducted to study the outcome benefits with the combined use of GDT with OPCAB as compared to the conventional hemodynamic management. Material and Method: Patients with the European System for Cardiac Operative Risk Evaluation ≥3 scheduled for OPCAB were randomly divided into two groups; the control and GDT groups. The GDT group included the monitoring and optimization of advanced parameters, including cardiac index (CI), systemic vascular resistance index, oxygen delivery index, stroke volume variation; continuous central venous oxygen saturation (ScVO2), global end-diastolic volume, and extravascular lung water (EVLW), using FloTrac™, PreSep™, and EV-1000® monitoring panels, in addition to the conventional hemodynamic management in the control group. The hemodynamic parameters were continuously monitored for 48 h in Intensive Care Unit (ICU) and corrected according to GDT protocol. A total of 163 patients consented for the study. Result: Seventy-five patients were assigned to the GDT group and 88 patients were in the control group. In view of 9 exclusions from the GDT group and 12 exclusions from control group, 66 patients in the GDT group and 76 patients in control group completed the study. Conclusion: The length of stay in hospital (LOS-H) (7.42 ± 1.48 vs. 5.61 ± 1.11 days, P < 0.001) and ICU stay (4.2 ± 0.82 vs. 2.53 ± 0.56 days, P < 0.001) were significantly lower in the GDT group as compared to control group. The duration of inotropes (3.24 ± 0.73 vs. 2.89

  15. ECCE Toolkit: Prototyping Sensor-Based Interaction.

    PubMed

    Bellucci, Andrea; Aedo, Ignacio; Díaz, Paloma

    2017-02-23

    Building and exploring physical user interfaces requires high technical skills and hours of specialized work. The behavior of multiple devices with heterogeneous input/output channels and connectivity has to be programmed in a context where not only the software interface matters, but also the hardware components are critical (e.g., sensors and actuators). Prototyping physical interaction is hindered by the challenges of: (1) programming interactions among physical sensors/actuators and digital interfaces; (2) implementing functionality for different platforms in different programming languages; and (3) building custom electronic-incorporated objects. We present ECCE (Entities, Components, Couplings and Ecosystems), a toolkit for non-programmers that copes with these issues by abstracting from low-level implementations, thus lowering the complexity of prototyping small-scale, sensor-based physical interfaces to support the design process. A user evaluation provides insights and use cases of the kind of applications that can be developed with the toolkit.

  16. ECCE Toolkit: Prototyping Sensor-Based Interaction

    PubMed Central

    Bellucci, Andrea; Aedo, Ignacio; Díaz, Paloma

    2017-01-01

    Building and exploring physical user interfaces requires high technical skills and hours of specialized work. The behavior of multiple devices with heterogeneous input/output channels and connectivity has to be programmed in a context where not only the software interface matters, but also the hardware components are critical (e.g., sensors and actuators). Prototyping physical interaction is hindered by the challenges of: (1) programming interactions among physical sensors/actuators and digital interfaces; (2) implementing functionality for different platforms in different programming languages; and (3) building custom electronic-incorporated objects. We present ECCE (Entities, Components, Couplings and Ecosystems), a toolkit for non-programmers that copes with these issues by abstracting from low-level implementations, thus lowering the complexity of prototyping small-scale, sensor-based physical interfaces to support the design process. A user evaluation provides insights and use cases of the kind of applications that can be developed with the toolkit. PMID:28241502

  17. Direct sGC Activation Bypasses NO Scavenging Reactions of Intravascular Free Oxy-Hemoglobin and Limits Vasoconstriction

    PubMed Central

    Tabima, D. Marcela; Specht, Patricia A.C.; Tejero, Jesús; Champion, Hunter C.; Kim-Shapiro, Daniel B.; Baust, Jeff; Mik, Egbert G.; Hildesheim, Mariana; Stasch, Johannes-Peter; Becker, Eva-Maria; Truebel, Hubert

    2013-01-01

    Abstract Aims: Hemoglobin-based oxygen carriers (HBOC) provide a potential alternative to red blood cell (RBC) transfusion. Their clinical application has been limited by adverse effects, in large part thought to be mediated by the intravascular scavenging of the vasodilator nitric oxide (NO) by cell-free plasma oxy-hemoglobin. Free hemoglobin may also cause endothelial dysfunction and platelet activation in hemolytic diseases and after transfusion of aged stored RBCs. The new soluble guanylate cyclase (sGC) stimulator Bay 41-8543 and sGC activator Bay 60-2770 directly modulate sGC, independent of NO bioavailability, providing a potential therapeutic mechanism to bypass hemoglobin-mediated NO inactivation. Results: Infusions of human hemoglobin solutions and the HBOC Oxyglobin into rats produced a severe hypertensive response, even at low plasma heme concentrations approaching 10 μM. These reactions were only observed for ferrous oxy-hemoglobin and not analogs that do not rapidly scavenge NO. Infusions of L-NG-Nitroarginine methyl ester (L-NAME), a competitive NO synthase inhibitor, after hemoglobin infusion did not produce additive vasoconstriction, suggesting that vasoconstriction is related to scavenging of vascular NO. Open-chest hemodynamic studies confirmed that hypertension occurred secondary to direct effects on increasing vascular resistance, with limited negative cardiac inotropic effects. Intravascular hemoglobin reduced the vasodilatory potency of sodium nitroprusside (SNP) and sildenafil, but had no effect on vasodilatation by direct NO-independent activation of sGC by BAY 41-8543 and BAY 60-2770. Innovation and Conclusion: These data suggest that both sGC stimulators and sGC activators could be used to restore cyclic guanosine monophosphate-dependent vasodilation in conditions where cell-free plasma hemoglobin is sufficient to inhibit endogenous NO signaling. Antioxid. Redox Signal. 19, 2232–2243. PMID:23697678

  18. Optimal preparation of the ECC ozonesonde. [electrochemical cells

    NASA Technical Reports Server (NTRS)

    Thornton, D. C.

    1982-01-01

    The ECC background current was identified as the removal of residual tri-iodide (iodine) as the cell approaches equilibrium. The altitude dependence of this source of the background current is expected to be only slowly changed in the troposphere with a more rapid decrease in the stratosphere. Oxygen does not play a role in the background current except in the unlikely situation where the electrodes have had all forms of iodine removed from them and the electrodes have not re-equilibrated with the sonde solutions before use. A solution mass transport parameter in the ECC was identified and its altitude dependence determined. The mass transport of tri-iodide dominates in the chemical transduction of ozone to electrical signal. The effect of the mass transport on the ECC background current is predicted. An electrochemical model of the ECC has been developed to predict the response of the ECC to various ozone vertical profiles. The model corresponds very closely to the performance of the ECC in the laboratory. Based on this model, an ECC with no background current is predicted to give total ozone values within 1% of the correct value, although the vertical profile may be in error by as much as + or - 15%.

  19. Electronic bypass of spinal lesions: activation of lower motor neurons directly driven by cortical neural signals

    PubMed Central

    2014-01-01

    Background Lower motor neurons in the spinal cord lose supraspinal inputs after complete spinal cord injury, leading to a loss of volitional control below the injury site. Extensive locomotor training with spinal cord stimulation can restore locomotion function after spinal cord injury in humans and animals. However, this locomotion is non-voluntary, meaning that subjects cannot control stimulation via their natural “intent”. A recent study demonstrated an advanced system that triggers a stimulator using forelimb stepping electromyographic patterns to restore quadrupedal walking in rats with spinal cord transection. However, this indirect source of “intent” may mean that other non-stepping forelimb activities may false-trigger the spinal stimulator and thus produce unwanted hindlimb movements. Methods We hypothesized that there are distinguishable neural activities in the primary motor cortex during treadmill walking, even after low-thoracic spinal transection in adult guinea pigs. We developed an electronic spinal bridge, called “Motolink”, which detects these neural patterns and triggers a “spinal” stimulator for hindlimb movement. This hardware can be head-mounted or carried in a backpack. Neural data were processed in real-time and transmitted to a computer for analysis by an embedded processor. Off-line neural spike analysis was conducted to calculate and preset the spike threshold for “Motolink” hardware. Results We identified correlated activities of primary motor cortex neurons during treadmill walking of guinea pigs with spinal cord transection. These neural activities were used to predict the kinematic states of the animals. The appropriate selection of spike threshold value enabled the “Motolink” system to detect the neural “intent” of walking, which triggered electrical stimulation of the spinal cord and induced stepping-like hindlimb movements. Conclusion We present a direct cortical “intent”-driven electronic spinal

  20. Condensation during gravity driven ECC: Experiments with PACTEL

    SciTech Connect

    Munther, R.; Kalli, H.; Kouhia, J.

    1995-09-01

    This paper provides the results of the second series of gravity driven emergency core cooling (ECC) experiments with PACTEL (Parallel Channel Test Loop). The simulated accident was a small break loss-of-coolant accident (SBLOCA) with a break in a cold leg. The ECC flow was provided from a core makeup tank (CMT) located at a higher elevation than the main part of the primary system. The CMT was pressurized with pipings from the pressurizer and a cold leg. The tests indicated that steam condensation in the CMT can prevent ECC and lead to core uncovery.

  1. Heart bypass surgery

    MedlinePlus

    Off-pump coronary artery bypass; OPCAB; Beating heart surgery; Bypass surgery - heart; CABG; Coronary artery bypass graft; Coronary artery bypass surgery; Coronary bypass surgery; Coronary artery disease - CABG; CAD - CABG; Angina - ...

  2. ECC Ozonesonde Reliability, Observations, and Comparisons with Satellite Ozone Instruments

    NASA Technical Reports Server (NTRS)

    Schmidlin, F. J.; Northam, E. T.; Ross, E. D.; Schauer, A. G.; Gerlach, John C. (Technical Monitor)

    2001-01-01

    Electrochemical Concentration Cell (ECC) ozone instruments depend on the quality of care exercised in their pre-flight preparation. The ozone-measuring project conducted at Goddard Space Flight Center's Wallops Flight Facility uses a number of mechanisms designed to inspect the ECC for anomalies that may interfere with the reception of valid ozone profiles. Complete electronic testing of the instrument, individually and when coupled to its radiosonde has led to exceptional monitoring of ozone for detecting long-term atmospheric changes. A number of factors are considered when preparing an ECC instrument for flight. These basically are specific calibrations of pump efficiency, volumetric flow rate, temperature of the air entering the pump, and background current. The concentration of the potassium iodide solution is also important. Wallops is the only site using a UV photometer (Dasibi) to compare ECC ozone output at various concentrations of ozone that allows adjustment to be made to offsets that may appear in the balloon-borne instrument prior to release. All of the above procedures allow identification of potential problems before release of the ECC instrument. Procedures followed at Wallops also are employed in Brazil, and Ascension Island where NASA has cooperative agreements in place to obtain ozonesondes data. All ECC instruments are prepared 3-4 weeks prior to the day of observation. We will briefly describe the instrumental tests employed. These tests have included simultaneous dual observations to compare the effect of different solution concentrations, comparison of sensors of different manufacturers, and comparisons with surface- and space-based instrumentation such as the Dobson Spectrophotometer and satellites. Vertical profiles of ozone from Arctic, mid-latitudes, and Antarctica will be discussed. Although not unusual, the data reveals ozone structure that correlate well with typical atmospheric temperatures and possibly relative humidity. Finally

  3. Coronary Artery Bypass Grafting

    MedlinePlus

    ... from the NHLBI on Twitter. What Is Coronary Artery Bypass Grafting? Coronary artery bypass grafting (CABG) is ... bypass multiple coronary arteries during one surgery. Coronary Artery Bypass Grafting Figure A shows the location of ...

  4. Intraocular pressure following ECCE, phacoemulsification, and PC-IOL implantation.

    PubMed

    Kooner, K S; Cooksey, J C; Perry, P; Zimmerman, T J

    1988-09-01

    Abnormal intraocular pressure (IOP), either transient or permanent, may follow extracapsular cataract extraction (ECCE) with phacoemulsification (PE) and posterior chamber intraocular lens (PC-IOL) implantation. We retrospectively studied IOP measurements at different intervals post ECCE and PE in 242 eyes of 211 patients: 105 males, 106 females, 198 Caucasians and 13 blacks. Elevated IOP (greater than 23 mm Hg) was observed in 20 eyes (8.2%). Only two patients (0.8%) had persistent (greater than 3 months) IOP elevation and needed antiglaucoma therapy. Six more eyes (2.5%), however, developed glaucoma after 1 year. Hence, the incidence of secondary pseudophakic glaucoma at the conclusion of this study was 3.3%. No patient required laser or other mechanical surgery for IOP control. ECCE and PE with PC-IOL does not appear to adversely affect IOP. Patients, however, must be followed closely, as some may develop glaucoma months after surgery.

  5. ECC ozonesonde performance at high altitudes: Pump efficiency

    NASA Technical Reports Server (NTRS)

    Torres, A. L.

    1981-01-01

    The ECC ozonesonde sampling behavior was examined at pressures ranging from 60 to 6 hPa with the objective of evaluating uncertainties in high altitude ozone data caused by variations in pumping efficiency. The averaged pump efficiency correction curve for a 43 sample set of 3A type ECC pumps showed a 2-3% bias from the curve provided by the manufacturer. In addition, random pump to pump variations (2 sigma) + or - were 5% at 6 hPa. These values probably represent minimum errors since the pumps were from the same production batch. A seven sample set of the newer 4A type ECC pumps was examined, with similar findings as for the 3A types.

  6. Acute Pre-operative Infarcts and Poor Cerebrovascular Reserve are Independent Risk Factors for Severe Ischemic Complications Following Direct Extracranial-Intracranial Bypass for Moyamoya Disease

    PubMed Central

    Pulling, T. Michael; Rosenberg, Jarrett; Marks, Michael P.; Steinberg, Gary K.; Zaharchuk, Greg

    2015-01-01

    Background and Purpose Severe ischemic changes are a rare but devastating complication following direct superficial temporal artery to middle cerebral artery (STA MCA) bypass in Moyamoya patients. This study was undertaken to determine whether pre-operative MR imaging and/or cerebrovascular reserve (CVR) assessment using reference standard stable xenon enhanced computed tomography (xeCT) could predict such complications. Materials and Methods Among all adult patients receiving direct bypass at our institution between 2005 and 2010 who received a clinically interpretable xeCT examination, we identified index cases (patients with >15 ml post-operative infarcts) and control cases (patients without post-operative infarcts and without transient or permanent ischemic symptoms). Differences between groups were evaluated using the Mann Whitney test. Univariate and multivariate generalized linear model regression were employed to test predictors of post-operative infarct. Results Six index cases were identified and compared with 25 controls. Infarct size in the index cases was 95±55 ml. Four of six index cases (67%), but no control patients, had pre-operative acute infarcts. Baseline CBF was similar, but CVR was significantly lower in the index cases compared with control cases. For example, in the anterior circulation, median CVR was 0.4% (range: −38.0% to 16.6%) in index vs. 26.3% (range: −8.2% to 60.5%) in control patients (p=0.003). Multivariate analysis demonstrated that the presence of a small pre-operative infarct (regardless of location) and impaired CVR were independent, significant predictors of severe post-operative ischemic injury. Conclusion Acute infarcts and impaired CVR on pre operative imaging are independent risk factors for severe ischemic complications following STA MCA bypass in Moyamoya disease. PMID:26564435

  7. Performance tests on the Kohmyr ECC ozone sonde

    NASA Technical Reports Server (NTRS)

    Bandy, A. R.; Torres, A. L.

    1975-01-01

    The reliability and accuracy of the Kohmyr ECC ozone sonde are determined. Emphasis is placed on establishing and testing for leak-free connections and stable pump flow rates as well as properly adjusting the pumping pressure. Calibration of the Kohmyr ECC ozone sondes and Dasibi monitors is described. Raw ordinate data and ozone connection data are presented in tabular form. The results of a linear regression treatment of the sonde-indicated ozone concentration vs. Dasibi readings for each switch position are included along with averages of the regression parameters over the six sequencing switch positions. It is suggested that sondes and Dasibi monitors be individually calibrated before flight.

  8. Urgent treatment of severe symptomatic direct carotid cavernous fistula caused by ruptured cavernous internal carotid artery aneurysm using high-flow bypass, proximal ligation, and direct distal clipping: Technical case report

    PubMed Central

    Hasegawa, Hirotaka; Inoue, Tomohiro; Tamura, Akira; Saito, Isamu

    2014-01-01

    Background: Direct carotid cavernous fistula (CCF) secondary to ruptured carotid cavernous aneurysms (CCAs) is rare, but patients with this condition who develop acutely worsening and severe neuro-ophthalmic symptoms require urgent treatment. Endovascular methods are the first-line option, but this modality may not be available on an urgent basis. Case Description: In this article, we report a 45-year-old female with severe direct CCF due to rupture of the CCA. She presented with intractable headache and acute worsening of double vision and visual acuity. Emergent radiographic study revealed high-flow fistula tracked from the CCA toward the contralateral cavernous sinus and drained into the engorged left superior orbital vein. To prevent permanent devastating neuro-ophthalmic damages, urgent high-flow bypass with placement of a radial artery graft was performed followed by right cervical internal carotid artery (ICA) ligation and the clipping of the ICA at the C3 portion, proximal to the ophthalmic artery. In the immediate postoperative period, her symptoms resolved and angiography confirmed patency of the high-flow bypass and complete occlusion of the CCF. Conclusion: With due consideration of strategy and techniques to secure safety, open surgical intervention with trapping and bypass is a good treatment option for direct severe CCF when the endovascular method is not available, not possible, or is unsuccessful. PMID:24818056

  9. Gastric bypass surgery - discharge

    MedlinePlus

    Bariatric surgery - gastric bypass - discharge; Roux-en-Y gastric bypass - discharge; Gastric bypass - Roux-en-Y - discharge; Obesity ... Gloy VL, Briel M, Bhatt DL, et al. Bariatric surgery versus non-surgical treatment for obesity: a systematic ...

  10. An overview of the BWR ECCS strainer blockage issues

    SciTech Connect

    Serkiz, A.W.; Marshall, M.L. Jr.; Elliott, R.

    1996-03-01

    This Paper provides a brief overview of actions taken in the mid 1980s to resolve Unresolved Safety Issue (USI) A-43, {open_quotes}Containment Emergency Sump Performance,{close_quotes} and their relationship to the BWR strainer blockage issue; the importance of insights gained from the Barseback-2 (a Swedish BWR) incident in 1992 and from ECCS strainer testing and inspections at the Perry nuclear power plant in 1992 and 1993; an analysis of an US BWR/4 with a Mark I containment; an international community sharing of knowledge relevant to ECCS strainer blockage, additional experimental programs; and identification of actions needed to resolve the strainer blockage issue and the status of such efforts.

  11. Considerations for realistic ECCS evaluation methodology for LWRs

    SciTech Connect

    Rohatgi, U.S.; Saha, P.; Chexal, V.K.

    1985-01-01

    This paper identifies the various phenomena which govern the course of large and small break LOCAs in LWRs, and affect the key parameters such as Peak Clad Temperature (PCT) and timing of the end of blowdown, beginning of reflood, PCT, and complete quench. A review of the best-estimate models and correlations for these phenomena in the current literature has been presented. Finally, a set of models have been recommended which may be incorporated in a present best-estimate code such as TRAC or RELAP5 in order to develop a realistic ECCS evaluation methodology for future LWRs and have also been compared with the requirements of current ECCS evaluation methodology as outlined in Appendix K of 10CFR50. 58 refs.

  12. Disease Management of Early Childhood Caries: ECC Collaborative Project.

    PubMed

    Ng, Man Wai; Ramos-Gomez, Francisco; Lieberman, Martin; Lee, Jessica Y; Scoville, Richard; Hannon, Cindy; Maramaldi, Peter

    2014-01-01

    Until recently, the standard of care for early childhood caries (ECC) has been primarily surgical and restorative treatment with little emphasis on preventing and managing the disease itself. It is now recognized that surgical treatment alone does not address the underlying etiology of the disease. Despite costly surgeries and reparative treatment, the onset and progression of caries are likely to continue. A successful rebalance of risk and protective factors may prevent, slow down, or even arrest dental caries and its progression. An 18-month risk-based chronic disease management (DM) approach to address ECC in preschool children was implemented as a quality improvement (QI) collaborative by seven teams of oral health care providers across the United States. In the aggregate, fewer DM children experienced new cavitation, pain, and referrals to the operating room (OR) for restorative treatment compared to baseline historical controls. The teams found that QI methods facilitated adoption of the DM approach and resulted in improved care to patients and better outcomes overall. Despite these successes, the wide scale adoption and spread of the DM approach may be limited unless health policy and payment reforms are enacted to compensate providers for implementing DM protocols in their practice.

  13. Disease Management of Early Childhood Caries: ECC Collaborative Project

    PubMed Central

    Lee, Jessica Y.

    2014-01-01

    Until recently, the standard of care for early childhood caries (ECC) has been primarily surgical and restorative treatment with little emphasis on preventing and managing the disease itself. It is now recognized that surgical treatment alone does not address the underlying etiology of the disease. Despite costly surgeries and reparative treatment, the onset and progression of caries are likely to continue. A successful rebalance of risk and protective factors may prevent, slow down, or even arrest dental caries and its progression. An 18-month risk-based chronic disease management (DM) approach to address ECC in preschool children was implemented as a quality improvement (QI) collaborative by seven teams of oral health care providers across the United States. In the aggregate, fewer DM children experienced new cavitation, pain, and referrals to the operating room (OR) for restorative treatment compared to baseline historical controls. The teams found that QI methods facilitated adoption of the DM approach and resulted in improved care to patients and better outcomes overall. Despite these successes, the wide scale adoption and spread of the DM approach may be limited unless health policy and payment reforms are enacted to compensate providers for implementing DM protocols in their practice. PMID:24723953

  14. Peripheral artery bypass - leg

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/007394.htm Peripheral artery bypass - leg To use the sharing features on this page, please enable JavaScript. Peripheral artery bypass is surgery to reroute the blood supply ...

  15. Endothelial Dysfunction of Bypass Graft: Direct Comparison of In Vitro and In Vivo Models of Ischemia-Reperfusion Injury

    PubMed Central

    Veres, Gábor; Hegedűs, Péter; Barnucz, Enikő; Zöller, Raphael; Klein, Stephanie; Schmidt, Harald; Radovits, Tamás; Korkmaz, Sevil; Karck, Matthias; Szabó, Gábor

    2015-01-01

    Background Although, ischemia/reperfusion induced vascular dysfunction has been widely described, no comparative study of in vivo- and in vitro-models exist. In this study, we provide a direct comparison between models (A) ischemic storage and in-vitro reoxygenation (B) ischemic storage and in vitro reperfusion (C) ischemic storage and in-vivo reperfusion. Methods and Results Aortic arches from rats were stored for 2 hours in saline. Arches were then (A) in vitro reoxygenated (B) in vitro incubated in hypochlorite for 30 minutes (C) in vivo reperfused after heterotransplantation (2, 24 hours and 7 days reperfusion). Endothelium-dependent and independent vasorelaxations were assessed in organ bath. DNA strand breaks were assessed by TUNEL-method, mRNA expressions (caspase-3, bax, bcl-2, eNOS) by quantitative real-time PCR, proteins by Western blot analysis and the expression of CD-31 by immunochemistry. Endothelium-dependent maximal relaxation was drastically reduced in the in-vivo models compared to ischemic storage and in-vitro reperfusion group, and no difference showed between ischemic storage and control group. CD31-staining showed significantly lower endothelium surface ratio in-vivo, which correlated with TUNEL-positive ratio. Increased mRNA and protein levels of pro- and anti-apoptotic gens indicated a significantly higher damage in the in-vivo models. Conclusion Even short-period of ischemia induces severe endothelial damage (in-vivo reperfusion model). In-vitro models of ischemia-reperfusion injury can be limitedly suited for reliable investigations. Time course of endothelial stunning is also described. PMID:25875813

  16. Combined group ECC protection and subgroup parity protection

    DOEpatents

    Gara, Alan; Cheng, Dong; Heidelberger, Philip; Ohmacht, Martin

    2016-02-02

    A method and system are disclosed for providing combined error code protection and subgroup parity protection for a given group of n bits. The method comprises the steps of identifying a number, m, of redundant bits for said error protection; and constructing a matrix P, wherein multiplying said given group of n bits with P produces m redundant error correction code (ECC) protection bits, and two columns of P provide parity protection for subgroups of said given group of n bits. In the preferred embodiment of the invention, the matrix P is constructed by generating permutations of m bit wide vectors with three or more, but an odd number of, elements with value one and the other elements with value zero; and assigning said vectors to rows of the matrix P.

  17. [Macular threshold after ECCE and posterior chamber IOL implantation].

    PubMed

    Baltatzis, S; Georgopoulos, G; Andreanos, D

    1989-01-01

    In the present paper, the macular threshold after ECCE and posterior chamber intraocular lens implantation, was studied in an effort to determine the time period needed for full postoperative recovery of macular function. We evaluated 22 eyes in 20 patients who underwent extracapsular cataract extraction and posterior chamber IOL implantation. There were 12 men and 8 women between the ages of 40 and 62 years with mean age of 53 years. Postoperative visual field testing was performed within the central 4 degrees with an automated static perimeter (Humphrey Visual Field Analyser), using a macular threshold test pattern. It has been established that central retinal sensitivity in pseudophakia shows a postoperative decrease and consequently recovers to almost normal levels within one month. The exact cause of this reduction remains under discussion and further control mainly with fluorescein angiography is necessary.

  18. [Combination surgery (ECCE+IOL+TE) and intraocular pressure levels].

    PubMed

    Hornová, J

    1997-08-01

    The authors investigated the effect of a combined operation, ECCE + TE + IOL, on reduction of intraocular pressure (IOP), changes in antiglaucomatous treatment and on vision six months after operation. In 1994 36 eyes were operated, 16 eyes with primary open angle glaucoma (POAG), 8 eyes with angular glaucoma (PACG) and 12 eyes with marked exfoliative syndrome (CG). Six months after operation the IOP declined from 26.4 mm Hg to 13.3 mm Hg (P 0.05), antiglaucomatous treatment was reduced from 2.55 to 1.11 (P 0.05), vision improved by 0.39, i.e. by 2-3 lines of optotypes (P 0.05). 89% of the operated patients have a vision better than 0.5. Comparison of values before and after operation revealed a more marked drop of IOP in CG (P 0.05) than in POAG.

  19. Combined group ECC protection and subgroup parity protection

    DOEpatents

    Gara, Alan G.; Chen, Dong; Heidelberger, Philip; Ohmacht, Martin

    2013-06-18

    A method and system are disclosed for providing combined error code protection and subgroup parity protection for a given group of n bits. The method comprises the steps of identifying a number, m, of redundant bits for said error protection; and constructing a matrix P, wherein multiplying said given group of n bits with P produces m redundant error correction code (ECC) protection bits, and two columns of P provide parity protection for subgroups of said given group of n bits. In the preferred embodiment of the invention, the matrix P is constructed by generating permutations of m bit wide vectors with three or more, but an odd number of, elements with value one and the other elements with value zero; and assigning said vectors to rows of the matrix P.

  20. Cardiopulmonary Bypass Without Heparin.

    PubMed

    Rehfeldt, Kent H; Barbara, David W

    2016-03-01

    Due to familiarity, short half-life, ease of monitoring, and the availability of a reversal agent, heparin remains the anticoagulant of choice for cardiac operations requiring cardiopulmonary bypass (CPB). However, occasionally patients require CPB but should not receive heparin, most often because of acute or subacute heparin-induced thrombocytopenia (HIT). In these cases, if it is not feasible to wait for the disappearance of HIT antibodies, an alternative anticoagulant must be selected. A number of non-heparin anticoagulant options have been explored. However, current recommendations suggest the use of a direct thrombin inhibitor such as bivalirudin. This review describes the use of heparin alternatives for the conduct of CPB with a focus on the direct thrombin inhibitors.

  1. Perioperative utility of goal-directed therapy in high-risk cardiac patients undergoing coronary artery bypass grafting: “A clinical outcome and biomarker-based study”

    PubMed Central

    Kapoor, Poonam Malhotra; Magoon, Rohan; Rawat, Rajinder; Mehta, Yatin

    2016-01-01

    Goal-directed therapy (GDT) encompasses guidance of intravenous (IV) fluid and vasopressor/inotropic therapy by cardiac output or similar parameters to help in early recognition and management of high-risk cardiac surgical patients. With the aim of establishing the utility of perioperative GDT using robust clinical and biochemical outcomes, we conducted the present study. This multicenter randomized controlled study included 130 patients of either sex, with European system for cardiac operative risk evaluation ≥3 undergoing coronary artery bypass grafting on cardiopulmonary bypass. The patients were randomly divided into the control and GDT group. All the participants received standardized care; arterial pressure monitored through radial artery, central venous pressure (CVP) through a triple lumen in the right internal jugular vein, electrocardiogram, oxygen saturation, temperature, urine output per hour, and frequent arterial blood gas (ABG) analysis. In addition, cardiac index (CI) monitoring using FloTrac™ and continuous central venous oxygen saturation (ScVO2) using PreSep™ were used in patients in the GDT group. Our aim was to maintain the CI at 2.5–4.2 L/min/m2, stroke volume index 30–65 ml/beat/m2, systemic vascular resistance index 1500–2500 dynes/s/cm5/m2, oxygen delivery index 450–600 ml/min/m2, continuous ScVO2 >70%, and stroke volume variation <10%; in addition to the control group parameters such as CVP 6–8 mmHg, mean arterial pressure 90–105 mmHg, normal ABG values, oxygen saturation, hematocrit value >30%, and urine output >1 ml/kg/h. The aims were achieved by altering the administration of IV fluids and doses of inotropes or vasodilators. The data of sixty patients in each group were analyzed in view of ten exclusions. The average duration of ventilation (19.89 ± 3.96 vs. 18.05 ± 4.53 h, P = 0.025), hospital stay (7.94 ± 1.64 vs. 7.17 ± 1.93 days, P = 0.025), and Intensive Care Unit (ICU) stay (3.74 ± 0.59 vs. 3.41 ± 0

  2. Structures of EccB1 and EccD1 from the core complex of the mycobacterial ESX-1 type VII secretion system

    SciTech Connect

    Wagner, Jonathan M.; Chan, Sum; Evans, Timothy J.; Kahng, Sara; Kim, Jennifer; Arbing, Mark A.; Eisenberg, David; Korotkov, Konstantin V.

    2016-02-27

    The ESX-1 type VII secretion system is an important determinant of virulence in pathogenic mycobacteria, including Mycobacterium tuberculosis. This complicated molecular machine secretes folded proteins through the mycobacterial cell envelope to subvert the host immune response. Despite its important role in disease very little is known about the molecular architecture of the ESX-1 secretion system. This study characterizes the structures of the soluble domains of two conserved core ESX-1 components – EccB1 and EccD1. The periplasmic domain of EccB1 consists of 4 repeat domains and a central domain, which together form a quasi 2-fold symmetrical structure. The repeat domains of EccB1 are structurally similar to a known peptidoglycan binding protein suggesting a role in anchoring the ESX-1 system within the periplasmic space. The cytoplasmic domain of EccD1 has a ubiquitin-like fold and forms a dimer with a negatively charged groove. In conclusion, these structures represent a major step towards resolving the molecular architecture of the entire ESX-1 assembly and may contribute to ESX-1 targeted tuberculosis intervention strategies.

  3. Structures of EccB1 and EccD1 from the core complex of the mycobacterial ESX-1 type VII secretion system

    DOE PAGES

    Wagner, Jonathan M.; Chan, Sum; Evans, Timothy J.; ...

    2016-02-27

    The ESX-1 type VII secretion system is an important determinant of virulence in pathogenic mycobacteria, including Mycobacterium tuberculosis. This complicated molecular machine secretes folded proteins through the mycobacterial cell envelope to subvert the host immune response. Despite its important role in disease very little is known about the molecular architecture of the ESX-1 secretion system. This study characterizes the structures of the soluble domains of two conserved core ESX-1 components – EccB1 and EccD1. The periplasmic domain of EccB1 consists of 4 repeat domains and a central domain, which together form a quasi 2-fold symmetrical structure. The repeat domains ofmore » EccB1 are structurally similar to a known peptidoglycan binding protein suggesting a role in anchoring the ESX-1 system within the periplasmic space. The cytoplasmic domain of EccD1 has a ubiquitin-like fold and forms a dimer with a negatively charged groove. In conclusion, these structures represent a major step towards resolving the molecular architecture of the entire ESX-1 assembly and may contribute to ESX-1 targeted tuberculosis intervention strategies.« less

  4. Pharmacodynamic and Efficacy Profile of TGN 255, a Novel Direct Thrombin Inhibitor, in Canine Cardiopulmonary Bypass and Simulated Mitral Valve Repair

    PubMed Central

    Nelson, David A.; Nelson, Katherine T.; Miller, Matthew W.; Dupe, Robert; Chahwala, Suresh B.; Kennedy, Anthony; Chander, Chaman; Fossum, Theresa W.

    2008-01-01

    Abstract: Heparin-induced thrombocytopenia can be a life-threatening sequel to conventional use of unfractionated heparin in cardiopulmonary bypass (CPB). This study evaluated the pharmacokinetic/pharmacodynamic (PK/PD) and efficacy profile of a novel direct thrombin inhibitor, TGN 255, during cardiac surgery in dogs. Point-of-care coagulation monitoring was also compared against the plasma concentrations of TRI 50c, the active metabolite of TGN 255. The study was conducted in three phases using 10 animals: phase 1 was a dose-ranging study in conscious animals (n = 6), phase 2 was a similar but terminal dose-ranging study in dogs undergoing CPB (n = 6), and phase 3 was with animals undergoing simulated mitral valve repair (terminal) using optimal TGN 255 dose regimens derived from phases I and II (n = 4). During the study, PD markers and drug plasma levels were determined. In addition, determinations of hematologic markers and blood loss were undertaken. Phase 1 studies showed that a high-dose regimen of a 5-mg/kg bolus and infusion of 20 mg/kg/h elevated PD markers in conscious animals, at which time there were no measured effects on platelet or red blood cell counts, and the mean plasma concentration of TRI 50C was 20.6 fg/mL. In the phase 2 CPB dose-ranging study, this dosing regimen significantly elevated all the PD markers and produced hemorrhagic and paradoxical thrombogenic effects. In the phase 3 surgical study, a lower TGN 255 dose regimen of a 2.5-mg/kg bolus plus 10 mg/kg/h produced anticoagulation, elevated PD markers, and produced minimal post-operative blood loss in the animals. Plasma levels of TRI 50C trended well with the conventional point-of-care coagulation monitoring. TGN 255 provided effective anticoagulation in a canine CPB procedure, enabling successful completion with minimal blood loss. These findings support further evaluation of TGN 255 as an anticoagulant for CPB. PMID:18705547

  5. Refractive results after phacoemulsification and ECCE. A comparative study.

    PubMed

    Dam-Johansen, M; Olsen, T

    1993-06-01

    The refractive results were evaluated in 79 patients undergoing cataract extraction by phacoemulsification using a 6-7 mm tunnel incision, and compared with a group of 77 patients undergoing planned extracapsular cataract extraction (ECCE) by the same surgeon. A mean increase in the keratometric cylinder of 0.05D and 0.52D was found in the phacoemulsification and the extracapsular cataract extraction group, respectively. This was significantly different from zero for the extracapsular cataract extraction group (p < 0.05) but not for the phacoemulsification group (p > 0.05). By vector analysis, the mean surgically induced astigmatism was 0.91D and 1.36D in the phacoemulsification and the extracapsular cataract extraction group, respectively (p < 0.01). The IOL power prediction error (spectacle plane) was found to be 0.17D (+/- 0.69 SD) in the phacoemulsification group and 0.02 D (+/- 0.79 SD) in the extracapsular cataract extraction group, respectively. We conclude that phacoemulsification improves the surgical control of the refractive outcome of cataract surgery.

  6. Allogeneic Blood Product Usage in Coronary Artery Bypass Grafting (CABG) with minimalized Extracorporeal Circulation System (MECC) Versus Standard On-Pump Coronary Artery Bypass Grafting

    PubMed Central

    Lisy, M.; Schmid, E.; Kozok, J.; Rosenberger, P.; Stock, U.A.; Kalender, G.

    2016-01-01

    Aim: Intraoperative allogeneic blood product transfusion (ABPT) in cardiac surgery is associated with worse overall outcome, including mortality. The objective of this study was to evaluate the ABPTs in minimalized extracorporeal cardiopulmonary (MECCTM) compared with standard open system on-pump coronary revascularization. Methods: Data of 156 patients undergoing myocardial revascularization between September 2008 and September 2010 were reviewed. 83 patients were operated by the MECC technique and 73 were treated by standard extracorporeal circulation (sECC). ABPT and overall early postoperative complications were analyzed. Results: Operative mortality and morbidity were similar in both groups. ABPT in the MECC group was significantly lower than in the sECC group both intraoperatively (7.2 vs. 60.3% of patients p<0.001) and during the first five postoperative days (19.3 vs. 57.5%; p<0.001). “Skin to skin”- (214 ± 45 vs. 232 ± 45 min; p=0.012), cardiopulmonary bypass (CPB) - (82 ± 25 vs. 95 ± 26 min; p=0.014), and X-clamp- times (50 ± 16 vs. 56 ± 17 min; p=0.024) were significantly lower in the MECC group than in the sECC group. Length of ICU (intensive care unit) - and hospital stay were also significantly lower in the MECC group vs. the sECC group (26.7 ± 20.2 vs. 54.5 ± 68.9 h; p<0.001, and 12.0 ± 4.1 vs. 14.5 ± 4.6 days; p<0.001). Conclusion: Application of MECC as on-pump coronary artery bypass graft (CABG) results in significantly lower ABPT as well as shorter ICU and in-hospital stay. In order to achieve these benefits of MECC autologous retrograde priming, Bispectral index (BIS) monitoring, intraoperative cell salvage, meticulous hemostasis and strict peri- and postoperative volume management are crucial. PMID:27499818

  7. Heart bypass surgery

    MedlinePlus Videos and Cool Tools

    Heart bypass surgery begins with an incision made in the chest, with the breastbone cut exposing the heart. Next, a portion of the saphenous vein is ... used to bypass the blocked arteries in the heart. The venous graft is sewn to the aorta ...

  8. Gastric bypass surgery

    MedlinePlus

    ... your legs to help prevent blood clots from forming. You will receive shots of medicine to prevent ... diversion with duodenal switch Dumping syndrome References Buchwald H. Laparoscopic Roux-en-Y gastric bypass. In: Buchwald ...

  9. Energy-dissipating and self-repairing SMA-ECC composite material system

    NASA Astrophysics Data System (ADS)

    Li, Xiaopeng; Li, Mo; Song, Gangbing

    2015-02-01

    Structural component ductility and energy dissipation capacity are crucial factors for achieving reinforced concrete structures more resistant to dynamic loading such as earthquakes. Furthermore, limiting post-event residual damage and deformation allows for immediate re-operation or minimal repairs. These desirable characteristics for structural ‘resilience’, however, present significant challenges due to the brittle nature of concrete, its deformation incompatibility with ductile steel, and the plastic yielding of steel reinforcement. Here, we developed a new composite material system that integrates the unique ductile feature of engineered cementitious composites (ECC) with superelastic shape memory alloy (SMA). In contrast to steel reinforced concrete (RC) and SMA reinforced concrete (SMA-RC), the SMA-ECC beams studied in this research exhibited extraordinary energy dissipation capacity, minimal residual deformation, and full self-recovery of damage under cyclic flexural loading. We found that the tensile strain capacity of ECC, tailored up to 5.5% in this study, allows it to work compatibly with superelastic SMA. Furthermore, the distributed microcracking damage mechanism in ECC is critical for sufficient and reliable recovery of damage upon unloading. This research demonstrates the potential of SMA-ECC for improving resilience of concrete structures under extreme hazard events.

  10. Seizures Following Cardiopulmonary Bypass

    PubMed Central

    Brouwer, Monique E.; McMeniman, William J.

    2016-01-01

    Abstract: Seizures following cardiopulmonary bypass are an immediate and alarming indication that a neurologic event has occurred. A case report of a 67-year-old man undergoing aortic valve surgery who unexpectedly experiences seizures following cardiopulmonary bypass is outlined. Possible contributing factors including atheromatous disease in the aorta, low cerebral perfusion pressures, an open-chamber procedure, and the use of tranexamic acid are identified. PMID:27729707

  11. Intraocular pressure following ECCE and IOL implantation in patients with glaucoma.

    PubMed

    Kooner, K S; Dulaney, D D; Zimmerman, T J

    1988-08-01

    Patients with glaucoma may suffer optic nerve head damage due to elevated intraocular pressure (IOP) after any intraocular procedure. We retrospectively reviewed the IOP data in 82 consecutive patients (103 eyes) with glaucoma after extracapsular cataract extraction (ECCE) and posterior chamber intraocular lens (PC-IOL) implantation. Nine eyes had previous trabeculectomy and three eyes required combined trabeculectomy with ECCE and PC-IOL. The average follow-up period is 1.5 years (range 0.5 to 6 years). The postoperative IOP rise of 8 mm Hg over baseline or above 23 mm Hg was observed in 45 eyes (49.5%). Two eyes needed argon laser trabeculoplasty and one required trabeculectomy to control postoperative IOP elevation. Most of the patients required the same or lesser number of medications for IOP control after surgery. Results suggest that ECCE with PC-IOL may be a relatively safe procedure in cataract patients with preexisting glaucoma.

  12. Lightweight ECC based RFID authentication integrated with an ID verifier transfer protocol.

    PubMed

    He, Debiao; Kumar, Neeraj; Chilamkurti, Naveen; Lee, Jong-Hyouk

    2014-10-01

    The radio frequency identification (RFID) technology has been widely adopted and being deployed as a dominant identification technology in a health care domain such as medical information authentication, patient tracking, blood transfusion medicine, etc. With more and more stringent security and privacy requirements to RFID based authentication schemes, elliptic curve cryptography (ECC) based RFID authentication schemes have been proposed to meet the requirements. However, many recently published ECC based RFID authentication schemes have serious security weaknesses. In this paper, we propose a new ECC based RFID authentication integrated with an ID verifier transfer protocol that overcomes the weaknesses of the existing schemes. A comprehensive security analysis has been conducted to show strong security properties that are provided from the proposed authentication scheme. Moreover, the performance of the proposed authentication scheme is analyzed in terms of computational cost, communicational cost, and storage requirement.

  13. An evaluation of electrochemical concentration Cell (ECC) sonde measurements of atmospheric ozone

    NASA Technical Reports Server (NTRS)

    Geraci, M. J.; Luers, J. K.

    1978-01-01

    Using Dobson spectrophotometer measurements of total ozone as a comparison, an analysis of the electrochemical concentration cell (ECC) ozonesonde's measurement accuracy is presented. Days of conjunctive ECC-Dobson observations (from 1970 to 1976 at Wallops Flight Center) provide a set of 123 pairs of total ozone values. Sample set statistics are generated with means and standard deviations of total ozone values and differences being noted. An in-depth study of factors such as time assumptions used in calculating residual ozone, and other possible sources of errors are examined. A study of ECC ozone profiles is also presented with an evaluation of sonde measurement of seasonal trends, altitude or peak ozone concentration, and other important ozone parameters. Short-period changes in total ozone using Dobson data during the observational period are also described.

  14. ECC-based grouping-proof RFID for inpatient medication safety.

    PubMed

    Lin, Qiping; Zhang, Fangguo

    2012-12-01

    Several papers were proposed in which symmetric cryptography was used to design RFID grouping-proof for medication safety in the Journal of Medical Systems. However, if we want to ensure privacy, authentication and protection against the tracking of RFID-tags without losing system scalability, we must design an asymmetric cryptography-based RFID. This paper will propose a new ECC-based grouping-proof for RFID. Our ECC-based grouping-proof reduces the computation of tags and prevents timeout problems from occurring in n-party grouping-proof protocol. Based on asymmetric cryptography, the proposed scheme is practical, secure and efficient for medication applications.

  15. Bypass Flow Study

    SciTech Connect

    Richard Schultz

    2011-09-01

    The purpose of the fluid dynamics experiments in the MIR (Matched Index of-Refraction) flow system at Idaho National Laboratory (INL) is to develop benchmark databases for the assessment of Computational Fluid Dynamics (CFD) solutions of the momentum equations, scalar mixing, and turbulence models for the flow ratios between coolant channels and bypass gaps in the interstitial regions of typical prismatic standard fuel element (SFE) or upper reflector block geometries of typical Modular High-temperature Gas-cooled Reactors (MHTGR) in the limiting case of negligible buoyancy and constant fluid properties. The experiments use Particle Image Velocimetry (PIV) to measure the velocity fields that will populate the bypass flow study database.

  16. Peripheral artery bypass - leg - discharge

    MedlinePlus

    ... page: //medlineplus.gov/ency/patientinstructions/000239.htm Peripheral artery bypass - leg - discharge To use the sharing features ... this page, please enable JavaScript. You had peripheral artery bypass surgery to re-route the blood supply ...

  17. Zirconia crowns--an esthetic and resistant restorative alternative for ECC affected primary teeth.

    PubMed

    Planells del Pozo, P; Fuks, A B

    2014-01-01

    The present report discusses briefly the problem of ECC in very young children and the recommended approaches for prevention and treatment. The esthetic restoration of the maxillary incisors with Zirconia Nu Smile crowns is described. It is also stressed that the luxation injury two months after placement did not damage the appearance nor the stability of the crowns.

  18. Superior Vena Cava Bypass

    PubMed Central

    Trainini, Jorge Carlos; Auricchio, Renato; Del Bagno, Horacio Augusto; Federico, Vicente; Acrich, Mario Willie; Osorio, Julio Nestor

    1983-01-01

    A case of superior vena cava obstruction due to carcinoma of unknown origin is reported. A superior vena cava bypass with polytetrafluoroethylene was performed by suturing the prosthesis to the left innominate vein and the right atrium, respectively. Long-term satisfactory results were achieved. Images PMID:15227139

  19. [ECCE with self-sealing cataract incision. Technique and clinical results].

    PubMed

    Pham, D T; Wollensak, J; Drosch, S

    1995-06-01

    We present of modified technique for sutureless ECCE with a trapezoidal tunnel incision of 11 mm. The operation can be performed in a closed system because of the self-sealing wound construction. Compared to the sutured corneoscleral ECCE the new procedure has important advantages: the procedure is safe even during the critical phase following nucleus extraction. The procedure is therefore safer, faster, more economical and suture-induced astigmatism is avoided. Clinical experience after 2 years showed that postoperative complications were reduced significantly. Iris prolapse, wound dehiscens and hyphema occurred at a rate of 2%. The astigmatism (Jaffe analysis) was at a rate of 2 D, stable within 4 weeks after surgery, and did not change up to 2 years postoperatively. The astigmatism induced was then reduced about 0.5 D by a radical suture.

  20. Modifying the ECC-based grouping-proof RFID system to increase inpatient medication safety.

    PubMed

    Ko, Wen-Tsai; Chiou, Shin-Yan; Lu, Erl-Huei; Chang, Henry Ker-Chang

    2014-09-01

    RFID technology is increasingly used in applications that require tracking, identification, and authentication. It attaches RFID-readable tags to objects for identification and execution of specific RFID-enabled applications. Recently, research has focused on the use of grouping-proofs for preserving privacy in RFID applications, wherein a proof of two or more tags must be simultaneously scanned. In 2010, a privacy-preserving grouping proof protocol for RFID based on ECC in public-key cryptosystem was proposed but was shown to be vulnerable to tracking attacks. A proposed enhancement protocol was also shown to have defects which prevented proper execution. In 2012, Lin et al. proposed a more efficient RFID ECC-based grouping proof protocol to promote inpatient medication safety. However, we found this protocol is also vulnerable to tracking and impersonation attacks. We then propose a secure privacy-preserving RFID grouping proof protocol for inpatient medication safety and demonstrate its resistance to such attacks.

  1. Candida albicans Carriage in Children with Severe Early Childhood Caries (S-ECC) and Maternal Relatedness

    PubMed Central

    Xiao, Jin; Moon, Yonghwi; Li, Lihua; Rustchenko, Elena; Wakabayashi, Hironao; Zhao, Xiaoyi; Feng, Changyong; Gill, Steven R.; McLaren, Sean; Malmstrom, Hans; Ren, Yanfang; Quivey, Robert

    2016-01-01

    Introduction Candida albicans has been detected together with Streptococcus mutans in high numbers in plaque-biofilm from children with early childhood caries (ECC). The goal of this study was to examine the C. albicans carriage in children with severe early childhood caries (S-ECC) and the maternal relatedness. Methods Subjects in this pilot cross-sectional study were recruited based on a convenient sample. DMFT(S)/dmft(s) caries and plaque scores were assessed during a comprehensive oral exam. Social-demographic and related background information was collected through a questionnaire. Saliva and plaque sample from all children and mother subjects were collected. C. albicans were isolated by BBL™ CHROMagar™ and also identified using germ tube test. S. mutans was isolated using Mitis Salivarius with Bacitracin selective medium and identified by colony morphology. Genetic relatedness was examined using restriction endonuclease analysis of the C. albicans genome using BssHII (REAG-B). Multilocus sequence typing was used to examine the clustering information of isolated C. albicans. Spot assay was performed to examine the C. albicans Caspofungin susceptibility between S-ECC children and their mothers. All statistical analyses (power analysis for sample size, Spearman’s correlation coefficient and multiple regression analyses) were implemented with SAS 9.4 Results A total of 18 S-ECC child-mother pairs and 17 caries free child-mother pairs were enrolled in the study. Results indicated high C. albicans carriage rate in the oral cavity (saliva and plaque) of both S-ECC children and their mothers (>80%). Spearman’s correlation coefficient also indicated a significant correlation between salivary and plaque C. albicans and S. mutans carriage (p<0.01) and caries severity (p<0.05). The levels of C. albicans in the prepared saliva and plaque sample (1ml resuspension) of S-ECC children were 1.3 ± 4.5 x104 cfu/ml and 1.2 ± 3.5 x104 cfu/ml (~3-log higher vs. caries

  2. Prosthetic Oral Rehabilitation of a Child With S-ECC: A Case Report with Histopathologic Analysis.

    PubMed

    Tannure, P N; Moraes, G G; Borba, McU; Abrahão, A; Andrade, Mtrc; Fidalgo, Tks

    2015-01-01

    The aim of this case report is to describe the treatment planning of a young child with severe early childhood caries (S-ECC) as well as the prosthetic rehabilitation technique. A 3-year-old female child was referred to the pediatric dentistry clinic with the chief complaint of tooth pain, difficulty in eating and recurrent hospitalizations caused by dental infections. The mother reported intermittent episodes of fever and recurrent swelling of child's face. The girl presented angular cheilitis and was referred to a dietitian. The treatment plain consisted on a behavior changes in oral hygiene habits, exodontias of all primary teeth and oral rehabilitation with a prosthesis. The extracted teeth with periapical lesions were submitted to histopathologic analysis (hematoxilin and eosin staining) and revealed an inflammatory infiltrate. The aesthetic requirement of children with S-ECC has been a challenge to pediatric dentists. In the present case, the oral rehabilitation provided for the children better aesthetic, nutrition, phonation, and functional conditions.

  3. Access to the bypassed stomach after gastric bypass.

    PubMed

    Fobi, M A; Chicola, K; Lee, H

    1998-06-01

    The gastric bypass (GBP) Operation is progressively being widely used to treat severe obesity. One problem with this operation is that it leaves the bypassed segment of the gastrointestinal tract not readily available for either mechanical, radiological or endoscopic evaluation. We have addressed this problem by putting a gastrostomy tube in the bypassed stomach at the time of the GBP. A radio-opaque marker placed around the gastrostomy site enables easy radiological localization of and thus easy percutaneous access to the bypassed stomach. The surgical technique is presented.

  4. A Secure-Enhanced Data Aggregation Based on ECC in Wireless Sensor Networks

    PubMed Central

    Zhou, Qiang; Yang, Geng; He, Liwen

    2014-01-01

    Data aggregation is an important technique for reducing the energy consumption of sensor nodes in wireless sensor networks (WSNs). However, compromised aggregators may forge false values as the aggregated results of their child nodes in order to conduct stealthy attacks or steal other nodes' privacy. This paper proposes a Secure-Enhanced Data Aggregation based on Elliptic Curve Cryptography (SEDA-ECC). The design of SEDA-ECC is based on the principles of privacy homomorphic encryption (PH) and divide-and-conquer. An aggregation tree disjoint method is first adopted to divide the tree into three subtrees of similar sizes, and a PH-based aggregation is performed in each subtree to generate an aggregated subtree result. Then the forged result can be identified by the base station (BS) by comparing the aggregated count value. Finally, the aggregated result can be calculated by the BS according to the remaining results that have not been forged. Extensive analysis and simulations show that SEDA-ECC can achieve the highest security level on the aggregated result with appropriate energy consumption compared with other asymmetric schemes. PMID:24732099

  5. Direct reperfusion of the right common carotid artery prior to cardiopulmonary bypass in patients with brain malperfusion complicated with acute aortic dissection.

    PubMed

    Okita, Yutaka; Matsumori, Masamichi; Kano, Hiroya

    2016-04-01

    The cases of 3 patients with brain malperfusion secondary to acute aortic dissection who underwent preoperative perfusion of the right common carotid artery are presented. The patients were 64, 65 and 72 years old and 2 were female. All were in a comatose or semi-comatose state with left hemiplegia. The right common carotid artery was exposed and directly cannulated, using a 12-Fr paediatric arterial cannula. The right common femoral artery was chosen for arterial drainage, using a 14-Fr double-lumen cannula. The circuit contained a small roller pump and heat exchanger coil. Target flow was set at 90 ml/min and blood temperature at 30 °C. Durations of right carotid perfusion were 120, 100 and 45 min, respectively. All underwent partial arch replacement and survived. Postoperative neurological sequelae were minimal in all cases.

  6. Bypass surgery for lower extremity limb salvage: vein bypass.

    PubMed

    El-Sayed, Hosam F

    2012-01-01

    Bypass surgery for limb salvage in cases of chronic limb ischemia is a well-established treatment modality. Use of an autogenous vein provides the best conduit for infrainguinal arterial bypass procedures, particularly for bypass to the infrapopliteal arteries. In this article, we discuss infrainguinal vein bypass surgery including indications, perioperative care, and long-term follow up. We also discuss the outcomes of the procedure with regard to patient survival and limb salvage. The autogenous vein continues to be the best available conduit with the highest patency rate and the best treatment option. Compared to all other revascularization options for infrainguinal disease, the vein bypass has the best limb salvage and long-term survival in patients appropriately selected for the procedure.

  7. Spiritual Bypass: A Preliminary Investigation

    ERIC Educational Resources Information Center

    Cashwell, Craig S.; Glosoff, Harriet L.; Hammond, Cheree

    2010-01-01

    The phenomenon of spiritual bypass has received limited attention in the transpersonal psychology and counseling literature and has not been subjected to empirical inquiry. This study examines the phenomenon of spiritual bypass by considering how spirituality, mindfulness, alexithymia (emotional restrictiveness), and narcissism work together to…

  8. The CSNI/PWG-1 international task group on ECCS reliability

    SciTech Connect

    Sandervag, O.; Riekert, T.; Serkiz, A.; Hyvarinen, J.

    1996-03-01

    A steam line loss-of-coolant accident (LOCA) occurred when a safety relief valve inadvertently opened in the Barseback-2 nuclear power plant. The steam jet stripped fibrous insulation from adjacent pipework. Part of that insulation debris was transported to the wetwell pool and clogged the intake strainers for the drywell spray system after about one hour. Although the incident in itself was not very serious, it revealed a weakness in the defense-in-depth concept which under other circumstances could have led to failure of the emergency core cooling system (ECCS) to provide water to the core. Before the Barseback-2 LOCA, international regulators of nuclear power plants and the nuclear power plant industry had considered safety questions related to strainer clogging as resolved. Many European countries had followed the guidance for strainers in pressurized water reactors (PWRs) contained in United States Nuclear Regulatory Commission`s (USNRC) Regulatory Guide 1.82, Water Sources for Long Term Recirculation Cooling Following a Loss-of-Coolant Accident, 1974. However, data obtained from European experimental programs carried out in the late seventies to determine the performance of strainers indicated that this guide was not adequate. In addition, Swedish plant owners had used this guidance to judge performance of emergency core cooling systems (ECCS) in their plants. Analyses at that time had indicated that strainer clogging, if occurring at all, would at least not occur during the first ten hours after a LOCA. Since operation of the ECCS would be needed for a long time, backflushing capabilities and monitors of pressure drop across the strainers were installed in older Swedish BWR plants with small strainer areas. These actions were judged to be adequate compliance with the revised USNRC Regulatory Guide 1.82, Rev. 1, issued in 1985. Safety questions related to strainer clogging were considered to have been resolved until the incident happened in Barseback-2.

  9. Monitoring the conjunctiva for carbon dioxide and oxygen tensions and pH during cardiopulmonary bypass.

    PubMed

    Weiss, Irwin K; Isenberg, Sherwin J; McArthur, David L; Del Signore, Madeline; McDonald, John S

    2011-03-01

    The purpose of this study was to measure, for the first time, multiple physiologic parameters of perfusion (pH, PCO2, PO2, and temperature) from the conjunctiva of adult patients during cardiopulmonary bypass while undergoing cardiothoracic surgery. Ten patients who underwent either intracardiac valve repair, atrial septal defect repair, or coronary artery bypass graft surgery had placement of a sensor which directly measured pH, PCO2, PO2, and temperature from the conjunctiva. Data were stratified into seven phases (0-5 minutes prior to bypass; 0-5, 6-10, and 11-15 minutes after initiation of bypass; 0-5 minutes prior to conclusion of bypass; and 0-5 and 6-10 minutes after bypass) and analyzed using a mixed model analysis.The change in conjunctival pH over the course of measurement was not statistically significant (p = .56). The PCO2 level followed a quadratic pattern, decreasing from a mean pre-bypass level of 37.7 mmHg at baseline prior to the initiation of cardiopulmonary bypass to a nadir of 33.2 mmHg, then increasing to a high of 39.4 mmHg at 6-10 minutes post bypass (p < .01). The PO2 declined from a mean pre-bypass level of 79.5 mmHg to 31.3 mmHg by 6-10 minutes post bypass and even post-bypass, it never returned to baseline values (p < .01). Temperature followed a pattern similar to PCO2 by returning to baseline levels as the patient was re-warmed following bypass (p < .01). There was no evidence of any eye injury or inflammation following the removal of the sensor. In the subjects studied, the conjunctival sensor yielded reproducible measurements during the various phases of cardiopulmonary bypass without ocular injury. Further study is necessary to determine the role of conjunctival measurements in critical settings.

  10. Microorganisms found in secondary cataract material of ECCE patients, a study with SEM and TEM.

    PubMed

    Kalicharan, D; Jongebloed, W L; Los, L I; Worst, J G

    1993-01-01

    Globular secondary cataract material, removed from 24 patients with ECCE after ophthalmic cleaning of the anterior capsule, were investigated with SEM and TEM. Besides spherical, somewhat oval shaped bodies of various shape and size comparable with those found in cataractous lenses, (an)aerobic bacteria and yeast cells were found in approximately 70% of the cases, all of them in eyes without intra-ocular inflammation. Probably these bacteria have been transferred from the conjunctiva during IOL.-implantation and were encapsulated without starting an inflammation.

  11. [Extracapsular cataract extraction (ECCE) with posterior chamber IOL implantation in the very elderly].

    PubMed

    Gao, Y; Zhang, Y Z

    1992-07-01

    A study of the operations of ECCE with posterior chamber IOL implantation in 30 eyes of 25 patients aged 75-86 years showed that the average postoperative corrected visual acuity was 18/20, the average corrective spherical lens power was -0.70D and those of cylindrical power 1.18D(AR) and 1.33D(WR). There was no difference in operative complications between these very old and general elderly patients. However, since the health state was often compromised in the very old, to ensure uneventful operations, the ophthalmic surgeon should solicit advice from geriatricians, in addition to his own meticulous perioperative and postoperative care.

  12. The course of nonproliferative diabetic retinopathy following ECCE with posterior chamber IOL implantation.

    PubMed

    Raniel, Y; Teichner, Y; Friedman, Z

    1994-01-01

    A prospective study on the effect of ECCE + IOL implantation on the course of diabetic retinopathy (DR) in 59 eyes showed that in one to three years following surgery, progression of DR, including the development of newly formed one, occurred in 28.8% of the eyes. This was more marked in patient with IDDM (IDDM-46%, NIDDM-24%) as well as in eyes with pre-operative BDR (pre-operative BDR-62.5%, no pre-operative BDR-16.3%). Final visual acuity was better in eyes without pre-operative DR as well as in eyes that did not show progression of the retinopathy.

  13. Predicting Clearance Mechanism in Drug Discovery: Extended Clearance Classification System (ECCS).

    PubMed

    Varma, Manthena V; Steyn, Stefanus J; Allerton, Charlotte; El-Kattan, Ayman F

    2015-12-01

    Early prediction of clearance mechanisms allows for the rapid progression of drug discovery and development programs, and facilitates risk assessment of the pharmacokinetic variability associated with drug interactions and pharmacogenomics. Here we propose a scientific framework--Extended Clearance Classification System (ECCS)--which can be used to predict the predominant clearance mechanism (rate-determining process) based on physicochemical properties and passive membrane permeability. Compounds are classified as: Class 1A--metabolism as primary systemic clearance mechanism (high permeability acids/zwitterions with molecular weight (MW) ≤400 Da), Class 1B--transporter-mediated hepatic uptake as primary systemic clearance mechanism (high permeability acids/zwitterions with MW >400 Da), Class 2--metabolism as primary clearance mechanism (high permeability bases/neutrals), Class 3A--renal clearance (low permeability acids/zwitterions with MW ≤400 Da), Class 3B--transporter mediated hepatic uptake or renal clearance (low permeability acids/zwitterions with MW >400 Da), and Class 4--renal clearance (low permeability bases/neutrals). The performance of the ECCS framework was validated using 307 compounds with single clearance mechanism contributing to ≥70% of systemic clearance. The apparent permeability across clonal cell line of Madin - Darby canine kidney cells, selected for low endogenous efflux transporter expression, with a cut-off of 5 × 10(-6) cm/s was used for permeability classification, and the ionization (at pH7) was assigned based on calculated pKa. The proposed scheme correctly predicted the rate-determining clearance mechanism to be either metabolism, hepatic uptake or renal for ~92% of total compounds. We discuss the general characteristics of each ECCS class, as well as compare and contrast the framework with the biopharmaceutics classification system (BCS) and the biopharmaceutics drug disposition classification system (BDDCS

  14. Bypass diode integration

    NASA Technical Reports Server (NTRS)

    Shepard, N. F., Jr.

    1981-01-01

    Protective bypass diodes and mounting configurations which are applicable for use with photovoltaic modules having power dissipation requirements in the 5 to 50 watt range were investigated. Using PN silicon and Schottky diode characterization data on packaged diodes and diode chips, typical diodes were selected as representative for each range of current carrying capacity, an appropriate heat dissipating mounting concept along with its environmental enclosure was defined, and a thermal analysis relating junction temperature as a function of power dissipation was performed. In addition, the heat dissipating mounting device dimensions were varied to determine the effect on junction temperature. The results of the analysis are presented as a set of curves indicating junction temperature as a function of power dissipation for each diode package.

  15. Post-manufacturing, 17-times acceptable raw bit error rate enhancement, dynamic codeword transition ECC scheme for highly reliable solid-state drives, SSDs

    NASA Astrophysics Data System (ADS)

    Tanakamaru, Shuhei; Fukuda, Mayumi; Higuchi, Kazuhide; Esumi, Atsushi; Ito, Mitsuyoshi; Li, Kai; Takeuchi, Ken

    2011-04-01

    A dynamic codeword transition ECC scheme is proposed for highly reliable solid-state drives, SSDs. By monitoring the error number or the write/erase cycles, the ECC codeword dynamically increases from 512 Byte (+parity) to 1 KByte, 2 KByte, 4 KByte…32 KByte. The proposed ECC with a larger codeword decreases the failure rate after ECC. As a result, the acceptable raw bit error rate, BER, before ECC is enhanced. Assuming a NAND Flash memory which requires 8-bit correction in 512 Byte codeword ECC, a 17-times higher acceptable raw BER than the conventional fixed 512 Byte codeword ECC is realized for the mobile phone application without an interleaving. For the MP3 player, digital-still camera and high-speed memory card applications with a dual channel interleaving, 15-times higher acceptable raw BER is achieved. Finally, for the SSD application with 8 channel interleaving, 13-times higher acceptable raw BER is realized. Because the ratio of the user data to the parity bits is the same in each ECC codeword, no additional memory area is required. Note that the reliability of SSD is improved after the manufacturing without cost penalty. Compared with the conventional ECC with the fixed large 32 KByte codeword, the proposed scheme achieves a lower power consumption by introducing the "best-effort" type operation. In the proposed scheme, during the most of the lifetime of SSD, a weak ECC with a shorter codeword such as 512 Byte (+parity), 1 KByte and 2 KByte is used and 98% lower power consumption is realized. At the life-end of SSD, a strong ECC with a 32 KByte codeword is used and the highly reliable operation is achieved. The random read performance is also discussed. The random read performance is estimated by the latency. The latency is below 1.5 ms for ECC codeword up to 32 KByte. This latency is below the average latency of 15,000 rpm HDD, 2 ms.

  16. [Comparison of corneal endothelial cells after ECCE and phacoemulsification of the lens].

    PubMed

    Trnavec, B; Cuvala, J; Cernák, A; Vodrázková, E

    1997-08-01

    The authors evaluate the finding on the corneal endothelium before and after operation of cataract. For examination of the endothelium they used a specular microscope SP 1.000 of Topcon Co. The group comprised 64 eyes of 64 patients. The patients were divided at random into two groups. The first group comprised 26 patients, where ECCE was performed. The second group comprised 38 patients and the opaque lens was removed by phacoemulsification. The mean age in the first group was 69.3 years and in the second group 70.7 years. The same viscoelastic material (methylcellulose) was used and the same synthetic lens from PMMA material was implanted into the capsule. The endothelium was examined one day after operation and on the 7th to 10th day after operation. The following parameters were evaluated: density of the endothelial cells in the centre, mean cell size, polymegethism, coefficient of variation, pleomorphism. In the group of patients who had ECCE the loss of endothelial cells was 18.53%, in the group with phacoemulsification of the nucleus the loss was 16.43%. This difference is not statistically significant. After operation in both groups enlargement of the minimal, maximal as well as mean cell size was observed, the coefficient of variation increased while the grade of cell hexagonality decreased. However these differences in endothelial cells were not statistically significant. After operation of cataract not only endothelial cells are lost but also significant changes in cell morphology occur.

  17. [3 1/2 years experiences with ECCE with tunnel incision].

    PubMed

    Häberle, H; Anders, N; Antoni, H J; Pham, D T; Wollensak, J

    1997-01-01

    Since January 1992 planned extracapsular cataract extraction (ECCE) is performed routinely with the no-stitch technique at our clinic. To minimize surgically induced astigmatism further, modified wound constructions for planned ECCE with on 1.1-mm tunnel width were evaluated. The follow-up time was up to 3 years postoperatively. For 250 eyes wound closure was performed prospectively either sutureless (n = 70), with a single perpendicular suture (n = 100) or cross sutures (n = 40) at the 12 o'clock position or sutureless in the temporal position (n = 40). The complication rate was 4% (filtering bleb, iris prolapse or transient hypotonia). There were no wound ruptures, but once endophthalmitis was observed. Late mean astigmatism after up to 3 years follow-up for vertical incision was 2.05 +/- 1.16 D (1.01 +/- 0.96 D preoperatively) for sutureless wound closure, 1.63 +/- 1.08 D (0.86 +/- 0.95 D) for perpendicular and 1.76 +/- 0.88 D (0.73 +/- 0.55 D) for cross-sutures. A temporal incision resulted in 0.78 +/- 0.52 D (1.0 +/- 0.69 D) of astigmatism and was only performed on eyes with against the rule astigmatism preoperatively. Surgically induced astigmatism was stabilized early. For with the rule astigmatism preoperatively, a 12 o'clock incision with a perpendicular single suture is recommended and for against the rule astigmatism, a temporal incision.

  18. A provably-secure ECC-based authentication scheme for wireless sensor networks.

    PubMed

    Nam, Junghyun; Kim, Moonseong; Paik, Juryon; Lee, Youngsook; Won, Dongho

    2014-11-06

    A smart-card-based user authentication scheme for wireless sensor networks (in short, a SUA-WSN scheme) is designed to restrict access to the sensor data only to users who are in possession of both a smart card and the corresponding password. While a significant number of SUA-WSN schemes have been suggested in recent years, their intended security properties lack formal definitions and proofs in a widely-accepted model. One consequence is that SUA-WSN schemes insecure against various attacks have proliferated. In this paper, we devise a security model for the analysis of SUA-WSN schemes by extending the widely-accepted model of Bellare, Pointcheval and Rogaway (2000). Our model provides formal definitions of authenticated key exchange and user anonymity while capturing side-channel attacks, as well as other common attacks. We also propose a new SUA-WSN scheme based on elliptic curve cryptography (ECC), and prove its security properties in our extended model. To the best of our knowledge, our proposed scheme is the first SUA-WSN scheme that provably achieves both authenticated key exchange and user anonymity. Our scheme is also computationally competitive with other ECC-based (non-provably secure) schemes.

  19. A Provably-Secure ECC-Based Authentication Scheme for Wireless Sensor Networks

    PubMed Central

    Nam, Junghyun; Kim, Moonseong; Paik, Juryon; Lee, Youngsook; Won, Dongho

    2014-01-01

    A smart-card-based user authentication scheme for wireless sensor networks (in short, a SUA-WSN scheme) is designed to restrict access to the sensor data only to users who are in possession of both a smart card and the corresponding password. While a significant number of SUA-WSN schemes have been suggested in recent years, their intended security properties lack formal definitions and proofs in a widely-accepted model. One consequence is that SUA-WSN schemes insecure against various attacks have proliferated. In this paper, we devise a security model for the analysis of SUA-WSN schemes by extending the widely-accepted model of Bellare, Pointcheval and Rogaway (2000). Our model provides formal definitions of authenticated key exchange and user anonymity while capturing side-channel attacks, as well as other common attacks. We also propose a new SUA-WSN scheme based on elliptic curve cryptography (ECC), and prove its security properties in our extended model. To the best of our knowledge, our proposed scheme is the first SUA-WSN scheme that provably achieves both authenticated key exchange and user anonymity. Our scheme is also computationally competitive with other ECC-based (non-provably secure) schemes. PMID:25384009

  20. Photovoltaic module bypass diode encapsulation

    NASA Technical Reports Server (NTRS)

    Shepard, N. J., Jr.

    1983-01-01

    The design and processing techniques necessary to incorporate bypass diodes within the module encapsulant are presented. The Semicon PN junction diode cells were selected. Diode junction to heat spreader thermal resistance measurements, performed on a variety of mounted diode chip types and sizes, have yielded values which are consistently below 1 deg C per watt, but show some instability when thermally cycled over the temperature range from -40 to 150 deg C. Three representative experimental modules, each incorporating integral bypass diode/heat spreader assemblies of various sizes, were designed. Thermal testing of these modules enabled the formulation of a recommended heat spreader plate sizing relationship. The production cost of three encapsulated bypass diode/heat spreader assemblies were compared with similarly rated externally mounted packaged diodes. It is concluded that, when proper designed and installed, these bypass diode devices will improve the overall reliability of a terrestrial array over a 20 year design lifetime.

  1. Modified ECC ozone sonde for long-duration flights aboard isopicnic drifting balloons

    NASA Astrophysics Data System (ADS)

    Gheusi, Francois; Durand, Pierre; Verdier, Nicolas; Dulac, François; Attié, Jean-Luc; Commun, Philippe; Barret, Brice; Basdevant, Claude; Clénet, Antoine; Fontaine, Alain; Jambert, Corinne; Meyerfeld, Yves; Roblou, Laurent; Tocquer, Flore

    2015-04-01

    Since few years, the French space agency CNES has developed boundary-layer pressurized balloons (BLPB) with the capability to transport scientific payloads at isopicnic level over very long distances and durations (up to several weeks in absence of navigation limits). However, the autonomy of conventional electrochemical concentration cell (ECC) ozone sondes, that are widely used for tropospheric and stratospheric soundings, is limited to few hours due to power consumption and electrolyte evaporation (owing to air bubbling in the cathode solution). In collaboration with the French research community, CNES has developed a new ozone payload suited for long duration flights aboard BLPB. The mechanical elements (Teflon pump and motor) and the electrochemical cell of conventional ECC sondes have been kept but the electronic implementation is entirely new. The main feature is the possibility of programming periodic measurement sequences -- with possible remote control during the flight. To increase the ozone sonde autonomy, a strategy has been adopted of short measurement sequences (typically 2-3 min) regularly spaced in time (e.g. every 15 min, which is usually sufficient for air quality studies). The rest of the time, the sonde is at rest (pump motor off). The response time of an ECC sonde to an ozone concentration step is below one minute. Consequently, the measurement sequence is typically composed of a one-minute spin-up period after the pump has been turned on, followed by a one- to two-minute acquisition period. All time intervals can be adjusted before and during the flight. Results of a preliminary ground-based test in spring 2012 are first presented. The sonde provided correct ozone concentrations against a reference UV analyzer every 15 minutes during 4 days. Then we illustrate results from 16 BLBP flights launched in the low troposphere over the Mediterranean during summer field campaings in 2012 and 2013 (TRAQA and ChArMEx programmes). BLPB drifting

  2. Escharotic Treatment for ECC-positive CIN3 in Childbearing Years: A Case Report

    PubMed Central

    Windstar, Kimberly; Dunlap, Corina; Zwickey, Heather

    2014-01-01

    A persistent human papillomavirus (HPV) infection of a high-risk type is necessary for cervical cancer to develop. The severity of the diagnosis, together with colposcopy findings, determines the standard for treatment, and ablative or excisional options may be recommended. Escharotic treatment, together with an oral, anticarcinogenic HPV protocol and a vaginal-suppository protocol, is an alternative treatment, especially for those women of childbearing age who are concerned about the possibility of obstetrical complications associated with the use of loop electrosurgical excision (LEEP). The aim of the current case study was to observe the effect of an ablative escharotic treatment for a woman with severe dysplasia, cervical intraepithelial neoplasia grade 3 (CIN3). A 28-y-old female visited the National College of Natural Medicine clinic to obtain suggestions for alternative treatments following a satisfactory colposcopy and a biopsy revealing a high-risk HPV effect, severe dysplasia CIN3, and a positive endocervical curettage (ECC). She refused the recommended standard of care, a LEEP, because of concerns about the potential for future obstetrical complications. As an alternative, she elected to receive an escharotic treatment at a frequency of 2 treatments/wk for 5 wk. In addition to the escharotic treatment, she followed an oral protocol consisting of vitamins and botanical medicine for 1 y and she completed a 12-wk regime of vaginal suppositories following the escharotic. The authors followed her for 2 y. The woman’s Papanicolaou (Pap) test at the 6-mo follow-up revealed negative cervical cytology for intraepithelial lesion or malignancy, and her follow-up ECC was negative. Liquid-based Pap results were normal, and HPV testing was negative at her 1-y follow-up. Her Pap continued to remain normal at her 2-y follow-up. For women with high-grade cervical neoplasias and positive ECCs, with satisfactory colposcopies, escharotic treatment, accompanied by oral

  3. Adapted ECC ozonesonde for long-duration flights aboard boundary-layer pressurised balloons

    NASA Astrophysics Data System (ADS)

    Gheusi, François; Durand, Pierre; Verdier, Nicolas; Dulac, François; Attié, Jean-Luc; Commun, Philippe; Barret, Brice; Basdevant, Claude; Clenet, Antoine; Derrien, Solène; Doerenbecher, Alexis; El Amraoui, Laaziz; Fontaine, Alain; Hache, Emeric; Jambert, Corinne; Jaumouillé, Elodie; Meyerfeld, Yves; Roblou, Laurent; Tocquer, Flore

    2016-12-01

    Since the 1970s, the French space agency CNES has developed boundary-layer pressurised balloons (BLPBs) with the capability to transport lightweight scientific payloads at isopycnic level and offer a quasi-Lagrangian sampling of the lower atmosphere over very long distances and durations (up to several weeks).

    Electrochemical concentration cell (ECC) ozonesondes are widely used under small sounding balloons. However, their autonomy is limited to a few hours owing to power consumption and electrolyte evaporation. An adaptation of the ECC sonde has been developed specifically for long-duration BLPB flights. Compared to conventional ECC sondes, the main feature is the possibility of programming periodic measurement sequences (with possible remote control during the flight). To increase the ozonesonde autonomy, the strategy has been adopted of short measurement sequences (2-3 min) regularly spaced in time (e.g. every 15 min). The rest of the time, the sonde pump is turned off. Results of preliminary ground-based tests are first presented. In particular, the sonde was able to provide correct ozone concentrations against a reference UV-absorption ozone analyser every 15 min for 4 days. Then we illustrate results from 16 BLBP flights launched over the western Mediterranean during three summer field campaigns of the ChArMEx project (http://charmex.lsce.ipsl.fr): TRAQA in 2012, and ADRIMED and SAFMED in 2013. BLPB drifting altitudes were in the range 0.25-3.2 km. The longest flight lasted more than 32 h and covered more than 1000 km. Satisfactory data were obtained when compared to independent ozone measurements close in space and time. The quasi-Lagrangian measurements allowed a first look at ozone diurnal evolution in the marine boundary layer as well as in the lower free troposphere. During some flight segments, there was indication of photochemical ozone production in the marine boundary layer or even

  4. Bypass rewiring and robustness of complex networks

    NASA Astrophysics Data System (ADS)

    Park, Junsang; Hahn, Sang Geun

    2016-08-01

    A concept of bypass rewiring is introduced, and random bypass rewiring is analytically and numerically investigated with simulations. Our results show that bypass rewiring makes networks robust against removal of nodes including random failures and attacks. In particular, random bypass rewiring connects all nodes except the removed nodes on an even degree infinite network and makes the percolation threshold 0 for arbitrary occupation probabilities. In our example, the even degree network is more robust than the original network with random bypass rewiring, while the original network is more robust than the even degree networks without random bypass. We propose a greedy bypass rewiring algorithm which guarantees the maximum size of the largest component at each step, assuming which node will be removed next is unknown. The simulation result shows that the greedy bypass rewiring algorithm improves the robustness of the autonomous system of the Internet under attacks more than random bypass rewiring.

  5. Cost-minimization analysis of capsulotomy after ECCE and IOL implantation.

    PubMed

    Lertsumitkul, S; La Nauze, J

    1996-06-01

    An economic evaluation of capsulotomy for posterior capsular opacification after extracapsular cataract extraction (ECCE) and intraocular lens (IOL) implantation was carried out using a cost minimization model. This model demonstrates the use of cost comparison to aid the decision making process. A flow-chart of capsulotomy mode, with associated complications, is illustrated. Costs of complications are calculated using assigned probability for each tree. Overall comparative costs are displayed graphically Further, the model is presented using a computer-assisted spreadsheet with an added calculation program. Variables can therefore be adjusted with instantaneous outcomes visually displayed. We present several examples with different sets of variables and find that, in most instances, YAG capsulotomy is a more economical option than surgical capsulotomy. This finding is a relevant finding in planning for eye health programs, particularly in developing countries. We suggest that the model be modified using local parameters in order to provide optimal benefits in similar health programs.

  6. On the Quality of ECC Ozonesondes Data: Improvements of the Ground Based Data for Satellites Validation

    NASA Astrophysics Data System (ADS)

    Stubi, R.; Levrat, G.; Romanens, G.; Deshler, T.; Kivi, R.; Davis, J.; Schmidlin, F.; Johnson, B.

    2010-12-01

    The ozonesondes networks play an important role in the validation of the satellites instruments because of their high altitude resolution from the ground up to the mid-stratosphere and the very long term record starting in the late 70-ies. However, there is a lack of homogeneity of the ECC ozonesondes data from the various stations around the world. Progresses have been made over the last 10 years to identify the major source of biases affecting the ozonesondes profiles (see [1] and [2]), in particular regarding the sensing solution composition, the back-ground current and the sonde provider. To illustrate these effects on real data comparison and to test first order correction procedures, SCIAMACHY ozone columns are compared to three different processings of the Nairobi and Payerne aerological stations data.

  7. A Secure ECC-based RFID Mutual Authentication Protocol to Enhance Patient Medication Safety.

    PubMed

    Jin, Chunhua; Xu, Chunxiang; Zhang, Xiaojun; Li, Fagen

    2016-01-01

    Patient medication safety is an important issue in patient medication systems. In order to prevent medication errors, integrating Radio Frequency Identification (RFID) technology into automated patient medication systems is required in hospitals. Based on RFID technology, such systems can provide medical evidence for patients' prescriptions and medicine doses, etc. Due to the mutual authentication between the medication server and the tag, RFID authentication scheme is the best choice for automated patient medication systems. In this paper, we present a RFID mutual authentication scheme based on elliptic curve cryptography (ECC) to enhance patient medication safety. Our scheme can achieve security requirements and overcome various attacks existing in other schemes. In addition, our scheme has better performance in terms of computational cost and communication overhead. Therefore, the proposed scheme is well suitable for patient medication systems.

  8. Intracranial-to-intracranial bypass for posterior inferior cerebellar artery aneurysms: options, technical challenges, and results in 35 patients.

    PubMed

    Abla, Adib A; McDougall, Cameron M; Breshears, Jonathan D; Lawton, Michael T

    2016-05-01

    -quarter of all PICA aneurysms treated microsurgically at our center requiring bypass without a single EC-IC bypass. The selection of PICA bypass is almost algorithmic: trapped aneurysms at the PICA origin or p1 segment are revascularized with a PICA-PICA bypass, with PICA reimplantation as an alternative; trapped p2 segment aneurysms are reanastomosed, bypassed in situ, or reimplanted; distal p3 segment aneurysms are reanastomosed or revascularized with a PICA-PICA bypass; and aneurysms of the p4 segment that are too distal for PICA-PICA bypass are reanastomosed. Interposition grafts are reserved for when these 3 primary options are unsuitable. A constructive approach that preserves the PICA with direct clipping or replaces flow with a bypass when sacrificed should remain an alternative to deconstructive PICA occlusion and endovascular coiling when complete aneurysm occlusion is unlikely.

  9. Experiments of ECCS strainer blockage and debris settling in suppression pools

    SciTech Connect

    Hecker, G.E.; Johnson, A.B.; Murthy, P.; Padmanabhan

    1996-03-01

    If a rupture occurs in a nuclear power station pipe that leads to or from the reactor pressure vessel, the resultant Loss of Coolant Accident (LOCA) would initiate a chain of events involving complex flow phenomena. In a Boiling Water Reactor (BWR), the steam or liquid pipe break pressurizes the dry well, forcing the inert containment gases and steam through downcomers into the suppression pool, thoroughly mixing any particulates and pipe insulation debris carried with the gas flow to the pool. As the steam flow decreases, its unsteady condensation at the end of the downcomers (Condensation Oscillation and Chugging) produces continued water motion in the suppression pool and downcomers. During the blowdown event, high pressure and then low pressure pumps automatically start injecting water from the suppression pool into the reactor to keep its temperature under control. Proper functioning of this Emergency Core Cooling System (ECCS) is critical for the first 30 minutes or so, before operators have time to consider and align alternative sources of cooling water. A major concern for proper operation of the ECCS is the effect of fragmented insulation and plant particulates on the head loss at pump suction strainers. Sufficient loss could exceed the NPSH margin, causing cavitation with a resultant loss of pump capacity and longevity. The bead loss increases with the mass of debris accumulated on the pump strainers, which in turn is dependent on the debris concentration versus time in the suppression pool. This paper describes two sets of experiments that quantified the strainer head loss. One set of experiments considered the mixing and settling of fibrous insulation debris and fine iron oxide particles in the suppression pool during and after chugging. These tests used a reduced scale facility which duplicated the kinetic energy per unit water volume to define the concentration of the actual materials in the pool versus time.

  10. Interference of sulphur dioxide to balloon-borne ECC ozone sensors over the Valley of Mexico

    NASA Astrophysics Data System (ADS)

    Kanda, I.; Basaldud, R.; Horikoshi, N.; Okazaki, Y.; Benítez Garcia, S. E.; Ortínez, A.; Ramos Benítez, V. R.; Cárdenas, B.; Wakamatsu, S.

    2014-01-01

    Abnormal decrease in the ozonesonde sensor signal occurred during air-pollution study campaigns in November 2011 and March 2012 in Mexico City. Sharp drops around 5 km a.s.l. and above were observed in November 2011, and a broad deficit in the convective boundary layer in March 2012. Various circumstantial evidence indicates that the decrease was due to interference of SO2 gas to Electrochemical Concentration Cell (ECC) ozone sensors. The sharp drops in November 2011 are considered to be caused by the SO2 plume from the Popocatépetl volcano to the south-east of Mexico City. Response experiments of the ECC sensor to representative atmospheric trace gases showed that only SO2 could generate the observed abrupt drops. The vertical structure of the plume reproduced by a Lagrangian particle diffusion simulation also supported this assumption. The near-ground deficit in March 2012 is considered to be generated by the SO2 plume from the Tula industrial complex to the north-west of Mexico City. Sporadic large SO2 emission is known to occur from this region, and before and at the ozonesonde launching time, large intermittent peaks of SO2 concentration were recorded at the ground-level monitoring stations. The difference between the O3 concentration obtained by ozonesonde and that by UV-based O3 monitor was consistent with the SO2 concentration measured by a UV-based monitor on the ground. The plume vertical profiles estimated by the Lagrangian particle diffusion simulation agreed fairly well with the observed profile. Statistical analysis of the wind field in Mexico City revealed that the Popocatépetl effect is most likely to occur from June to October, and the Tula effect all the year.

  11. Incorporating Indigenous Knowledge and Practice into ECCE: A Comparison of Programs in The Gambia, Senegal and Mali

    ERIC Educational Resources Information Center

    Soudee, Alicia Ranck

    2009-01-01

    Early Childhood Development (ECD) has emerged as a theme in international and African dialogue on education in recent years. UNESCO's Division of Basic Education Early Childhood promotes an integrated approach to Early Childhood Care and Education (ECCE) policy development and review. The study examines how this is implemented in three West…

  12. Bypass surgery versus medical treatment for symptomatic moyamoya disease in adults.

    PubMed

    Jang, Dong-Kyu; Lee, Kwan-Sung; Rha, Hyoung Kyun; Huh, Pil-Woo; Yang, Ji-Ho; Park, Ik Seong; Ahn, Jae-Geun; Sung, Jae Hoon; Han, Young-Min

    2016-11-11

    OBJECTIVE In this study the authors evaluated whether extracranial-intracranial bypass surgery can prevent stroke occurrence and decrease mortality in adult patients with symptomatic moyamoya disease (MMD). METHODS The medical records of 249 consecutive adult patients with symptomatic MMD that was confirmed by digital subtraction angiography between 2002 and 2011 at 8 institutions were retrospectively reviewed. The study outcomes of stroke recurrence as a primary event and death during the 6-year follow-up and perioperative complications within 30 days as secondary events were compared between the bypass and medical treatment groups. RESULTS The bypass group comprised 158 (63.5%) patients, and the medical treatment group comprised 91 (36.5%) patients. For 249 adult patients with MMD, bypass surgery showed an HR of 0.48 (95% CI 0.27-0.86, p = 0.014) for stroke recurrence calculated by Cox regression analysis. However, for the 153 patients with ischemic MMD, the HR of bypass surgery for stroke recurrence was 1.07 (95% CI 0.43-2.66, p = 0.887). For the 96 patients with hemorrhagic MMD, the multivariable adjusted HR of bypass surgery for stroke recurrence was 0.18 (95% CI 0.06-0.49, p = 0.001). For the treatment modality, indirect bypass and direct bypass (or combined bypass) did not show any significant difference for stroke recurrence, perioperative stroke, or mortality (log rank; p = 0.524, p = 0.828, and p = 0.616, respectively). CONCLUSIONS During the treatment of symptomatic MMD in adults, bypass surgery reduces stroke recurrence for the hemorrhagic type, but it does not do so for the ischemic type. The best choice of bypass methods in adult patients with MMD is uncertain. In adult ischemic MMD, a prospective randomized study to evaluate the effectiveness and safety of bypass surgery to prevent recurrent stroke is necessary.

  13. Parametric study of the potential for BWR ECCS strainer blockage due to LOCA generated debris. Final report

    SciTech Connect

    Zigler, G.; Brideau, J.; Rao, D.V.; Shaffer, C.; Souto, F.; Thomas, W.

    1995-10-01

    This report documents a plant-specific study for a BWR/4 with a Mark I containment that evaluated the potential for LOCA generated debris and the probability of losing long term recirculation capability due ECCS pump suction strainer blockage. The major elements of this study were: (1) acquisition of detailed piping layouts and installed insulation details for a reference BWR; (2) analysis of plant specific piping weld failure probabilities to estimate the LOCA frequency; (3) development of an insulation and other debris generation and drywell transport models for the reference BWR; (4) modeling of debris transport in the suppression pool; (5) development of strainer blockage head loss models for estimating loss of NPSH margin; (6) estimation of core damage frequency attributable to loss of ECCS recirculation capability following a LOCA. Elements 2 through 5 were combined into a computer code, BLOCKAGE 2.3. A point estimate of overall DEGB pipe break frequency (per Rx-year) of 1.59E-04 was calculated for the reference plant, with a corresponding overall ECCS loss of NPSH frequency (per Rx-year) of 1.58E-04. The calculated point estimate of core damage frequency (per Rx-year) due to blockage related accident sequences for the reference BWR ranged from 4.2E-06 to 2.5E-05. The results of this study show that unacceptable strainer blockage and loss of NPSH margin can occur within the first few minutes after ECCS pumps achieve maximum flows when the ECCS strainers are exposed to LOCA generated fibrous debris in the presence of particulates (sludge, paint chips, concrete dust). Generic or unconditional extrapolation of these reference plant calculated results should not be undertaken.

  14. Carotid bypass for carotid occlusion.

    PubMed

    Hage, Ziad A; Behbahani, Mandana; Amin-Hanjani, Sepideh; Charbel, Fady T

    2015-07-01

    The 2-year risk of ipsilateral ischemic stroke following internal carotid artery occlusion (ICAO) in a patient undergoing maximal medical therapy is 5-8% per year. While medical therapy may reduce the risk of stroke, it does not completely eliminate it. Since the 1985 extracranial-intracranial (EC-IC) bypass study, additional trials have been conducted to further investigate the usefulness of EC-IC bypass surgery in more selected patients with cerebral ischemia and impaired hemodynamic reserve. These important studies will be briefly reviewed in this article, as well as a discussion regarding the utility of bypass surgery for ICAO in current clinical practice. In addition, a short discussion regarding the pathophysiology of carotid occlusion will be presented. We will also highlight our own institutional patient selection criteria based on the latest methods for hemodynamic assessment, as well as our intraoperative flow assisted surgical techniques (FAST), and post-operative patient follow-up.

  15. Cycling firing method for bypass operation of bridge converters

    DOEpatents

    Zabar, Zivan

    1982-01-01

    The bridge converter comprises a number of switching elements and an electronic logic system which regulated the electric power levels by controlling the firing, i.e., the initiation of the conduction period of the switching elements. Cyclic firing of said elements allows the direct current to bypass the alternating current system with high power factor and negligible losses.

  16. Secondary and College LD Bypass Strategies.

    ERIC Educational Resources Information Center

    Mosby, Robert J.

    1981-01-01

    The author describes the Developmental By-Pass (DBP) Instructional technology for teaching secondary and college learning disabled (LD) students by allowing students to bypass ordering and organizational deficits. (SB)

  17. 40 CFR 403.17 - Bypass.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... loss of natural resources which can reasonably be expected to occur in the absence of a bypass. Severe... essential maintenance to assure efficient operation. These bypasses are not subject to the provision...

  18. Types of Coronary Artery Bypass Grafting

    MedlinePlus

    ... from the NHLBI on Twitter. Types of Coronary Artery Bypass Grafting There are several types of coronary ... for you based on your needs. Traditional Coronary Artery Bypass Grafting Traditional CABG is used when at ...

  19. Who Needs Coronary Artery Bypass Grafting?

    MedlinePlus

    ... from the NHLBI on Twitter. Who Needs Coronary Artery Bypass Grafting? Coronary artery bypass grafting (CABG) is used to treat people ... or after a heart attack to treat blocked arteries. Your doctor may recommend CABG if other treatments, ...

  20. Coronary Artery Disease: Angioplasty or Bypass Surgery?

    MedlinePlus

    Coronary artery disease: Angioplasty or bypass surgery? I'm getting a cardiac catheterization. If blockages are found, ... angioplasty or bypass surgery? Answers from Rekha Mankad, M.D. During cardiac catheterization, your doctor will examine ...

  1. Psychological Effects of Intestinal Bypass Surgery.

    ERIC Educational Resources Information Center

    Wampler, Richard S.; And Others

    1980-01-01

    Preoperative and postoperative intestinal bypass patients were evaluated. Results suggest that postoperative bypass patients have improved psychological health and an increased sense of freedom and well-being but may need assistance in improving self-concepts. (Author)

  2. Heart bypass surgery - minimally invasive

    MedlinePlus

    ... MIDCAB; Robot-assisted coronary artery bypass; RACAB; Keyhole heart surgery; CAD - MIDCAB; Coronary artery disease - MIDCAB ... To perform this surgery: The heart surgeon will make a 3- to 5-inch (8 to 13 centimeters) surgical cut in the left part of your chest ...

  3. Interventions in Infrainguinal Bypass Grafts

    SciTech Connect

    Mueller-Huelsbeck, S. Order, B.-M.; Jahnke, T.

    2006-02-15

    The interventional radiologist plays an important role in the detection and prevention of infrainguinal bypass failure. Early detection and evaluation of flow-limiting lesions effectively preserve graft (venous bypass and polyester or expanded polytetrafluoroethylene bypass) patency by identifying stenoses before occlusion occurs. Delay in treatment of the at-risk graft may result in graft failure and a reduced chance of successful revascularization. For this reason, surveillance protocols form an important part of follow-up after infrainguinal bypass surgery. As well as having an understanding of the application of imaging techniques including ultrasound, MR angiography, CT angiography and digital subtraction angiography, the interventional radiologist should have detailed knowledge of the minimally invasive therapeutic options. Percutaneous transluminal angioplasty (PTA), or alternatively cutting balloon angioplasty, is the interventional treatment of choice in prevention of graft failure and occlusion. Further alternatives include metallic stent placement, fibrinolysis, and mechanical thrombectomy. Primary assisted patency rates following PTA can be up to 65% at 5 years. When the endovascular approach is unsuccessful, these therapeutic options are complemented by surgical procedures including vein patch revision, jump grafting, or placement of a new graft.

  4. Turbine bypass turbofan with mid-turbine reingestion and method of operating the same

    SciTech Connect

    Klees, G.W.

    1984-03-13

    A supersonic two spool turbofan engine is disclosed capable not only of developing sufficient power to accelerate up to supersonic cruise and maintain efficient operation at supersonic cruise, but also arranged to cruise at subsonic velocities with a relatively low specific fuel consumption. The engine is provided with a variable bypass passageway downstream of the compressor. Flow into the bypass passageway is controlled so that during low power setting the bypass passageway is closed so that all the gaseous flow is directed through the turbine. During higher power settings, the bypass passageway is opened to the extent that a selected portion of the gaseous flow is directed through the bypass passageway to bypass the first stage of the turbine section so that the corrected flow to the first turbine stage remains substantially constant for high and low power setting of the engine. The bypass flow is then directed into the area between the first and second turbine to combine with the gaseous flow passing through the first turbine and pass through the second turbine.

  5. Pre-test CFD Calculations for a Bypass Flow Standard Problem

    SciTech Connect

    Rich Johnson

    2011-11-01

    The bypass flow in a prismatic high temperature gas-cooled reactor (HTGR) is the flow that occurs between adjacent graphite blocks. Gaps exist between blocks due to variances in their manufacture and installation and because of the expansion and shrinkage of the blocks from heating and irradiation. Although the temperature of fuel compacts and graphite is sensitive to the presence of bypass flow, there is great uncertainty in the level and effects of the bypass flow. The Next Generation Nuclear Plant (NGNP) program at the Idaho National Laboratory has undertaken to produce experimental data of isothermal bypass flow between three adjacent graphite blocks. These data are intended to provide validation for computational fluid dynamic (CFD) analyses of the bypass flow. Such validation data sets are called Standard Problems in the nuclear safety analysis field. Details of the experimental apparatus as well as several pre-test calculations of the bypass flow are provided. Pre-test calculations are useful in examining the nature of the flow and to see if there are any problems associated with the flow and its measurement. The apparatus is designed to be able to provide three different gap widths in the vertical direction (the direction of the normal coolant flow) and two gap widths in the horizontal direction. It is expected that the vertical bypass flow will range from laminar to transitional to turbulent flow for the different gap widths that will be available.

  6. Ageing and COPD affect different domains of nutritional status: the ECCE study.

    PubMed

    Battaglia, S; Spatafora, M; Paglino, G; Pedone, C; Corsonello, A; Scichilone, N; Antonelli-Incalzi, R; Bellia, V

    2011-06-01

    Chronic obstructive pulmonary disease (COPD) and ageing may contribute to malnutrition. We aimed to explore whether COPD and ageing determine malnutrition in different manners. 460 stable COPD outpatients (376 males and 84 females) from the Extrapulmonary Consequences of COPD in the Elderly (ECCE) study database were investigated (age 75.0±5.9 yrs; forced expiratory volume in 1 s 54.7±18.3% predicted). Nutritional status was evaluated using the Mini Nutritional Assessment® (MNA) questionnaire. From the MNA, three scores exploring the domains of the nutritional status were calculated: body composition, energy intake and body functionality scores. Global Initiative for Chronic Obstructive Lung Disease (GOLD) stages were negatively correlated with five MNA items exploring mobility, patient's perception of own nutrition and health status, and arm and calf circumferences (lowest Spearman's rho (rs)=-0.011; highest p=0.039). GOLD stages were independently correlated with body composition and body functionality scores (model r2=0.073). Age was negatively correlated with four MNA items exploring loss of appetite, fluid intake, mobility and autonomy in daily life (lowest rs=-0.013; highest p=0.030). Age was independently correlated with body functionality score (model r2=0.037). Severe COPD and ageing are independent and probably concurrent conditions leading to malnutrition. The MNA questionnaire allows a valuable insight into the complexity of components of nutritional status and may provide useful clues for treatment strategies.

  7. Estimated net value and uncertainty for automating ECCS switchover at PWRs

    SciTech Connect

    Walsh, B.; Brideau, J.; Comes, L.; Darby, J.; Guttmann, H.; Sciacca, F.; Souto, F.; Thomas, W.; Zigler, G.

    1996-02-01

    Question for resolution of Generic Safety Issue No. 24 is whether or not PWRs that currently rely on a manual system for ECCS switchover to recirculation should be required to install an automatic system. Risk estimates are obtained by reevaluating the contributions to core damage frequencies (CDFs) associated with failures of manual and semiautomatic switchover at a representative PWR. This study considers each separate instruction of the corresponding emergency operating procedures (EOPs), the mechanism for each control, and the relation of each control to its neighbors. Important contributions to CDF include human errors that result in completely coupled failure of both trains and failure to enter the required EOP. It is found that changeover to a semiautomatic system is not justified on the basis of cost-benefit analysis: going from a manual to a semiautomatic system reduces the CDF by 1.7 {times} 10{sup {minus}5} per reactor-year, but the probability that the net cost of the modification being less than $1, 000 per person-rem is about 20% without license renewal. Scoping analyses, using optimist assumptions, were performed for a changeover to a semiautomatic system with automatic actuation and to a fully automatic system; in these cases the probability of a net cost being less than $1,000/person-rem is about 50% without license renewal and over 95% with license renewal.

  8. Water-hammer in the cold leg during an SBLOCA due to cold ECCS injection

    SciTech Connect

    Ortiz, M.G.; Ghan, L.S.

    1991-12-01

    Water-hammer might occur in the cold leg of pressurized water reactors (PWR) during small break loss-of-coolant accidents (SBLOCA`s), when cold emergency core cooling system (ECCS) water is injected into a pipe that may be partially filled with saturated steam. The water may mix with the steam and cause it to condense abruptly. Depending on the flow regime present, slugs of liquid may then be accelerated towards each other or against the piping structure. The possibility of this phenomenon is of concern to us because it may become a dominant phenomenon and change the character of the transient. In performing the code scaling, applicability, and uncertainty study (CSAU) on a SBLOCA scenario, we had to examine the possibility that the transient being analyzed could experience water-hammer and thus depart from the scope of the study. Two criteria for water-hammer initiation were investigated and tested using a RELAP5/MOD3 simulation of the transient. Our results indicated a very low likelihood of occurrence of the phenomenon. 8 refs., 6 figs.

  9. Water-hammer in the cold leg during an SBLOCA due to cold ECCS injection

    SciTech Connect

    Ortiz, M.G.; Ghan, L.S.

    1991-01-01

    Water-hammer might occur in the cold leg of pressurized water reactors (PWR) during small break loss-of-coolant accidents (SBLOCA's), when cold emergency core cooling system (ECCS) water is injected into a pipe that may be partially filled with saturated steam. The water may mix with the steam and cause it to condense abruptly. Depending on the flow regime present, slugs of liquid may then be accelerated towards each other or against the piping structure. The possibility of this phenomenon is of concern to us because it may become a dominant phenomenon and change the character of the transient. In performing the code scaling, applicability, and uncertainty study (CSAU) on a SBLOCA scenario, we had to examine the possibility that the transient being analyzed could experience water-hammer and thus depart from the scope of the study. Two criteria for water-hammer initiation were investigated and tested using a RELAP5/MOD3 simulation of the transient. Our results indicated a very low likelihood of occurrence of the phenomenon. 8 refs., 6 figs.

  10. Robust ECC-based authenticated key agreement scheme with privacy protection for Telecare medicine information systems.

    PubMed

    Zhang, Liping; Zhu, Shaohui

    2015-05-01

    To protect the transmission of the sensitive medical data, a secure and efficient authenticated key agreement scheme should be deployed when the healthcare delivery session is established via Telecare Medicine Information Systems (TMIS) over the unsecure public network. Recently, Islam and Khan proposed an authenticated key agreement scheme using elliptic curve cryptography for TMIS. They claimed that their proposed scheme is provably secure against various attacks in random oracle model and enjoys some good properties such as user anonymity. In this paper, however, we point out that any legal but malicious patient can reveal other user's identity. Consequently, their scheme suffers from server spoofing attack and off-line password guessing attack. Moreover, if the malicious patient performs the same time of the registration as other users, she can further launch the impersonation attack, man-in-the-middle attack, modification attack, replay attack, and strong replay attack successfully. To eliminate these weaknesses, we propose an improved ECC-based authenticated key agreement scheme. Security analysis demonstrates that the proposed scheme can resist various attacks and enables the patient to enjoy the remote healthcare services with privacy protection. Through the performance evaluation, we show that the proposed scheme achieves a desired balance between security and performance in comparisons with other related schemes.

  11. The latitudinal distribution of ozone to 35 km altitude from ECC ozonesonde observations, 1982-1990

    NASA Technical Reports Server (NTRS)

    Komhyr, W. D.; Oltmans, S. J.; Lathrop, J. A.; Kerr, J. B.; Matthews, W. A.

    1994-01-01

    Electrochemical concentration cell (ECC) ozone-sonde observations, made in recent years at ten stations whose locations range from the Arctic to Antarctica, have yielded a self-consistent ozone data base from which mean seasonal and annual latitudinal ozone vertical distributions to 35 km have been derived. Ozone measurement uncertainties are estimated, and results are presented in the Bass-Paur (1985) ozone absorption coefficient scale adopted for use with Dobson ozone spectrophotometers January 1, 1992. The data should be useful for comparison with model calculations of the global distribution of atmospheric ozone, for serving as apriori statistical information in deriving ozone vertical distributions from satellite and Umkehr observations, and for improving the satellite and Umkehr ozone inversion algorithms. Attention is drawn to similar results based on a less comprehensive data set published in Ozone in the Atmosphere, Proceedings of the 1988 Quadrennial Ozone Symposium where errors in data tabulations occurred for three of the stations due to inadvertent transposition of ozone partial pressure and air temperature values.

  12. Implementation and verification of different ECC mitigation designs for BRAMs in flash-based FPGAs

    NASA Astrophysics Data System (ADS)

    Yang, Zhen-Lei; Wang, Xiao-Hui; Zhang, Zhan-Gang; Liu, Jie; Su, Hong

    2016-04-01

    Embedded RAM blocks (BRAMs) in field programmable gate arrays (FPGAs) are susceptible to single event effects (SEEs) induced by environmental factors such as cosmic rays, heavy ions, alpha particles and so on. As technology scales, the issue will be more serious. In order to tackle this issue, two different error correcting codes (ECCs), the shortened Hamming codes and shortened BCH codes, are investigated in this paper. The concrete design methods of the codes are presented. Also, the codes are both implemented in flash-based FPGAs. Finally, the synthesis report and simulation results are presented in the paper. Moreover, heavy-ion experiments are performed, and the experimental results indicate that the error cross-section of the device using the shortened Hamming codes can be reduced by two orders of magnitude compared with the device without mitigation, and no errors are discovered in the experiments for the device using the shortened BCH codes. Supported by National Natural Science Foundation of China (11079045, 11179003 and 11305233)

  13. Comparison of Long Term Tropospheric Ozone Trends Measured by Lidar and ECC Ozonesondes from 1991 to 2010 in Southern France

    NASA Astrophysics Data System (ADS)

    Ancellet, G.; Gaudel, A.; Godin-Beekmann, S.

    2016-06-01

    ECC (Electrochemical Concentration Cell) ozonesondes and UV DIAL (Differential Absorption Lidar) measurements have been carried out simultaneously at OHP (Observatoire de Haute Provence, 44°N, 6.7°E, 690 m) since 1991. A unique long-term trend assessment by two different instruments operated routinely at the same location is possible. Air mass trajectories have been calculated for all the ozone observations available at OHP. The bias between the seasonal mean calculated with lidar and ECC ozone vertical profiles for 4 timeperiods of 5 years is 0.6 ppbv in the free troposphere (4-8 km). Larger differences (> 10 ppbv) are explained by the need for clear sky conditions during lidar observations. The measurements of both instruments have been combined to decrease the impact of short-term atmospheric variability on the trend estimate.

  14. Modified Ultrafiltration During Cardiopulmonary Bypass and Postoperative Course of Pediatric Cardiac Surgery

    PubMed Central

    Ziyaeifard, Mohsen; Alizadehasl, Azin; Massoumi, Gholamreza

    2014-01-01

    Context: The use of cardiopulmonary bypass (CPB) provokes the inflammatory responses associated with ischemic/reperfusion injury, hemodilution and other agents. Exposure of blood cells to the bypass circuit surface starts a systemic inflammatory reaction that may causes post-CPB organ dysfunction, particularly in lungs, heart and brain. Evidence Acquisition: We investigated in the MEDLINE, PUBMED, and EMBASE databases and Google scholar for every available article in peer reviewed journals between 1987 and 2013, for related subjects to CPB with conventional or modified ultrafiltration (MUF) in pediatrics cardiac surgery patients. Results: MUF following separation from extracorporeal circulation (ECC) provides well known advantages in children with improvements in the hemodynamic, pulmonary, coagulation and other organs functions. Decrease in blood transfusion, reduction of total body water, and blood loss after surgery, are additional benefits of MUF. Conclusions: Consequently, MUF has been associated with attenuation of morbidity after pediatric cardiac surgery. In this review, we tried to evaluate the current evidence about MUF on the organ performance and its effect on post-CPB morbidity in pediatric patients. PMID:25478538

  15. Mini cardiopulmonary bypass: Anesthetic considerations

    PubMed Central

    Alsatli, Raed A.

    2012-01-01

    This review article is going to elaborate on the description, components, and advantages of mini-cardiopulmonary bypass (mini-CPB), with special reference to the anesthetic management and fast track anesthesia with mini-CPB. There are several clinical advantages of mini-CPB like, reduced inflammatory reaction to the pump, reduced need for allogenic blood transfusion and lower incidence of postoperative neurological complications. There are certainly important points that have to be considered by anesthesiologists to avoid sever perturbation in the cardiac output and blood pressure during mini-CPB. Fast-track anesthesia provides advantages regarding fast postoperative recovery from anesthesia, and reduction of postoperative ventilation time. Mini bypass offers a sound alternative to conventional CPB, and has definite advantages. It has its limitations, but even with that it has a definite place in the current practice of cardiac surgery. PMID:25885494

  16. Characterization of EccA3, a CbbX family ATPase from the ESX-3 secretion pathway of M. tuberculosis.

    PubMed

    Gaur, Amit; Sharma, Vijay Kumar; Shree, Sonal; Rai, Niyati; Ramachandran, Ravishankar

    2017-04-08

    EccA family proteins are conserved components of ESX secretion pathways in M. tuberculosis H37Rv. Here, we report the characterization of EccA3 (Rv0282), a CbbX family AAA (ATPases Associated with diverse cellular Activities) protein from the ESX-3 pathway that is required for in vitro growth of mycobacteria, secretion of virulence factors, and acquisition of iron and zinc. EccA3 is a thermostable ATPase with a molecular weight of ~68kDa. It exists as a dodecamer in the apo form and associates as a hexamer in the presence of ATP. Its C-terminal region consists of a CbbX-like AAA-domain while the N-terminal region contains a tetratricopeptide repeat (TPR) domain with lower homology to other EccA-type proteins. Further, the C-terminal domain functions as the oligomerization domain and also exhibits ATPase activity. Mutational analysis, steady state kinetics and molecular docking studies identify R573 as the important 'sensor arginine' and R505 as an 'arginine finger' in EccA3. Dynamic fluorescence quenching experiments suggest that the N-terminal domain moves closer to the C-terminal domain upon ATP-binding. The ATP-dependent 'open-close' relative movements of the two domains might help EccA3 interaction and secretion of essential virulence factors.

  17. Bypass system modification at Bonneville Dam on the Columbia River improved the survival of juvenile salmon

    USGS Publications Warehouse

    Ferguson, J.W.; Sandford, B.P.; Reagan, R.E.; Gilbreath, L.G.; Meyer, E.B.; Ledgerwood, R.D.; Adams, N.S.

    2007-01-01

    From 1987 to 1992, we evaluated a fish bypass system at Bonneville Dam Powerhouse 2 on the Columbia River. The survival of subyearling Chinook salmon Oncorhynchus tshawytscha released into the system ranged from 0.774 to 0.911 and was significantly lower than the survival of test fish released into turbines and the area immediately below the powerhouse where bypass system flow reentered the river. Yearling and subyearling Chinook salmon and yearling coho salmon O. kisutch released into the bypass system were injured or descaled. Also, levels of blood plasma cortisol and lactate were significantly higher in yearling and subyearling Chinook salmon that passed through the bypass system than in fish released directly into a net located over the bypass exit. This original system was then extensively modified using updated design criteria, and the site where juvenile fish reentered the river was relocated 2.8 km further downstream to reduce predation on bypassed fish by northern pikeminnow Ptychocheilus oregonensis. Based on studies conducted from 1999 to 2001, the new bypass system resulted in high fish survival, virtually no injuries to fish, fish passage times that were generally similar to water travel times, and mild stress responses from which fish recovered quickly. The mean estimated survival of subyearling Chinook salmon passing through the new bypass system was 0.946 in 2001, which was an usually low-flow year. Survival, physical condition, passage timing, and blood physiological indicators of stress were all useful metrics for assessing the performance of both bypass systems and are discussed. The engineering and hydraulic criteria used to design the new bypass system that resulted in improved fish passage conditions are described.

  18. Cardiopulmonary bypass with bivalirudin in type II heparin-induced thrombocytopenia.

    PubMed

    Clayton, Stephanie B; Acsell, Jeffrey R; Crumbley, Arthur J; Uber, Walter E

    2004-12-01

    Cardiopulmonary bypass in patients with type II heparin induced-thrombocytopenia poses significant challenges. Inadequate pharmacokinetic profiles, monitoring, reversibility, and availability often limit alternative anticoagulation strategies. Bivalirudin, a semisynthetic direct thrombin inhibitor, was recently approved for use in patients undergoing percutaneous coronary interventions. Its unique properties, including a relatively short half-life, an anticoagulation effect that closely correlates with activated clotting time, and an alternate metabolic pathway for elimination, make bivalirudin an attractive agent for cardiopulmonary bypass in patients with type II heparin induced-thrombocytopenia. We report our experience using bivalirudin in 2 patients undergoing coronary artery bypass grafting.

  19. Ramjet bypass duct and preburner configuration

    NASA Technical Reports Server (NTRS)

    Orlando, Robert J. (Inventor)

    1994-01-01

    A combined turbofan and ramjet aircraft engine includes a forward bypass duct which allows the engine to operate more efficiently during the turbofan mode of operation. By mounting a ramjet preburner in the forward duct and isolating this duct from the turbofan bypass air, a transition from turbofan operation to ramjet operation can take place at lower flight Mach numbers without incurring pressure losses or blockage in the turbofan bypass air.

  20. Ultra High Bypass Ratio Low Noise Engine Study

    NASA Technical Reports Server (NTRS)

    Dalton, W. N., III

    2003-01-01

    A study was conducted to identify engine cycle and technologies needed for a regional aircraft which could be capable of achieving a 10 EPNdB reduction in community noise level relative to current FAR36 Stage 3 limits. The study was directed toward 100-passenger regional aircraft with engine configurations in the 15,000 pound thrust class. The study focused on Ultra High Bypass Ratio (UHBR) cycles due to low exhaust jet velocities and reduced fan tip speeds. The baseline engine for this study employed a gear-driven, 1000 ft/sec tip speed fan and had a cruise bypass ratio of 14:1. A revised engine configuration employing fan and turbine design improvements are predicted to be 9.2 dB below current takeoff limits and 12.8 dB below current approach limits. An economic analysis was also done by estimating Direct Operating Cost (DOC).

  1. History of cardiopulmonary bypass (CPB).

    PubMed

    Hessel, Eugene A

    2015-06-01

    The development of cardiopulmonary bypass (CPB), thereby permitting open-heart surgery, is one of the most important advances in medicine in the 20th century. Many currently practicing cardiac anesthesiologists, cardiac surgeons, and perfusionists are unaware of how recently it came into use (60 years) and how much the practice of CPB has changed during its short existence. In this paper, the development of CPB and the many changes and progress that has taken place over this brief period of time, making it a remarkably safe endeavor, are reviewed. The many as yet unresolved questions are also identified, which sets the stage for the other papers in this issue of this journal.

  2. Prevalence and socio-behavioral influence of early childhood caries, ECC, and feeding habits among 6 – 36 months old children in Uganda and Tanzania

    PubMed Central

    2012-01-01

    Background Early childhood caries (ECC) is a serious problem that has remained unexplored in sub-Saharan Africa. This study aimed to identify possible socio-behavioral correlates of ECC focusing 6–36 months old children and their caretakers. Methods Cross sectional studies were conducted in a high fluoride rural area, Manyara, Tanzania and a low fluoride urban area, Kampala, Uganda. Totals of 1221 and 816 child - caretaker pairs attending health care facilities for growth monitoring were recruited in Manyara and Kampala, respectively. All caretakers completed face to face interviews at the health care facility. Children underwent oral clinical examination whereby ECC and Enamel hypoplasia were recorded using the dmft (WHO 1997) and the DDE index (FDI 1992). Results The prevalence of ECC was 3.7% in Manyara and 17.6% in Kampala. According to multiple logistic regression analyses, received oral health information from health worker was the strongest determinant of ECC in Manyara, adjusted OR 0.3, 95% CI 0.09 – 0.93. In Kampala, visible plaque, high sugar intake and presence of enamel hypoplasia associated with ECC, adjusted ORs 2.8 (95% CI 1.61- 4.95), 3.0 (95% CI 1.39 – 6.34) and 2.3 (95% CI 1.36 - 3.95). Conclusion Oral health education aimed at caretakers of 6–36 months, including health care workers’ information regarding the detrimental consequences for oral health of frequent sugar consumption and poor oral hygiene is important for prevention of ECC in Tanzania and Uganda. PMID:22834770

  3. What to Expect during Coronary Artery Bypass Grafting

    MedlinePlus

    ... NHLBI on Twitter. What To Expect During Coronary Artery Bypass Grafting Coronary artery bypass grafting (CABG) requires ... surgery to newer, less-invasive methods. Traditional Coronary Artery Bypass Grafting This type of surgery usually lasts ...

  4. Coronary Artery Bypass Surgery: MedlinePlus Health Topic

    MedlinePlus

    ... arteries from becoming clogged again. NIH: National Heart, Lung, and Blood Institute Start Here Coronary Artery Bypass (Texas Heart ... in Spanish Coronary Artery Bypass Grafting (National Heart, Lung, and Blood Institute) What Is Coronary Bypass Surgery? (American Heart ...

  5. R&D Plan for RISMC Industry Application #1: ECCS/LOCA Cladding Acceptance Criteria

    SciTech Connect

    Szilard, Ronaldo Henriques; Zhang, Hongbin; Epiney, Aaron Simon; Tu, Lei

    2016-04-01

    The Nuclear Regulatory Commission (NRC) is finalizing a rulemaking change that would revise the requirements in 10 CFR 50.46. In the proposed new rulemaking, designated as 10 CFR 50.46c, the NRC proposes a fuel performance-based equivalent cladding reacted (ECR) criterion as a function of cladding hydrogen content before the accident (pre-transient) in order to include the effects of higher burnup on cladding performance as well as to address other technical issues. A loss of operational margin may result due to the more restrictive cladding embrittlement criteria. Initial and future compliance with the rule may significantly increase vendor workload and licensee costs as a spectrum of fuel rod initial burnup states may need to be analyzed to demonstrate compliance. The Idaho National Laboratory (INL) has initiated a project, as part of the DOE Light Water Reactor Sustainability Program (LWRS), to develop analytical capabilities to support the industry in the transition to the new rule. This project is called the Industry Application 1 (IA1) within the Risk-Informed Safety Margin Characterization (RISMC) Pathway of LWRS. The general idea behind the initiative is the development of an Integrated Evaluation Model (IEM). The motivation is to develop a multiphysics framework to analyze how uncertainties are propagated across the stream of physical disciplines and data involved, as well as how risks are evaluated in a LOCA safety analysis as regulated under 10 CFR 50.46c. This IEM is called LOTUS which stands for LOCA Toolkit for US, and it represents the LWRS Program’s response to the proposed new rule making. The focus of this report is to complete an R&D plan to describe the demonstration of the LOCA/ECCS RISMC Industry Application # 1 using the advanced RISMC Toolkit and methodologies. This report includes the description and development plan for a RISMC LOCA tool that fully couples advanced MOOSE tools already in development in order to characterize and optimize

  6. 40 CFR 403.17 - Bypass.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 28 2010-07-01 2010-07-01 true Bypass. 403.17 Section 403.17 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GENERAL PRE-TREAT-MENT REGULATIONS FOR EXIST-ING AND NEW SOURCES OF POLLUTION § 403.17 Bypass....

  7. 40 CFR 403.17 - Bypass.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 29 2011-07-01 2009-07-01 true Bypass. 403.17 Section 403.17 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GENERAL PRE-TREAT-MENT REGULATIONS FOR EXIST-ING AND NEW SOURCES OF POLLUTION § 403.17 Bypass....

  8. 40 CFR 403.17 - Bypass.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., damage to the treatment facilities which causes them to become inoperable, or substantial and permanent... does not cause Pretreatment Standards or Requirements to be violated, but only if it also is for... a description of the bypass and its cause; the duration of the bypass, including exact dates...

  9. 40 CFR 403.17 - Bypass.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) Definitions. (1) Bypass means the intentional diversion of wastestreams from any portion of an Industrial User... applicable Pretreatment Standards or Requirements. An Industrial User may allow any bypass to occur which... paragraphs (c) and (d) of this section. (c) Notice. (1) If an Industrial User knows in advance of the...

  10. Analysis of pesticides in surface water and sediment from Yolo Bypass, California, 2004-2005

    USGS Publications Warehouse

    Smalling, Kelly L.; Orlando, James L.; Kuivila, Kathryn

    2005-01-01

    Inputs to the Yolo Bypass are potential sources of pesticides that could impact critical life stages of native fish. To assess the direct inputs during inundation, pesticide concentrations were analyzed in water, in suspended and bed-sediment samples collected from six source watersheds to the Yolo Bypass, and from three sites within the Bypass in 2004 and 2005. Water samples were collected in February 2004 from the six input sites to the Bypass during the first flood event of the year representing pesticide inputs during high-flow events. Samples were also collected along a transect across the Bypass in early March 2004 and from three sites within the Bypass in the spring of 2004 under low-flow conditions. Low-flow data were used to understand potential pesticide contamination and its effects on native fish if water from these areas were used to flood the Bypass in dry years. To assess loads of pesticides to the Bypass associated with suspended sediments, large-volume water samples were collected during high flows in 2004 and 2005 from three sites, whereas bed sediments were collected from six sites in the fall of 2004 during the dry season. Thirteen current-use pesticides were detected in surface water samples collected during the study. The highest pesticide concentrations detected at the input sites to the Bypass corresponded to the first high-flow event of the year. The highest pesticide concentrations at the two sites sampled within the Bypass during the early spring were detected in mid-April following a major flood event as the water began to subside. The pesticides detected and their concentrations in the surface waters varied by site; however, hexazinone and simazine were detected at all sites and at some of the highest concentrations. Thirteen current-use pesticides and three organochlorine insecticides were detected in bed and suspended sediments collected in 2004 and 2005. The pesticides detected and their concentrations varied by site and sediment

  11. Satellite and correlative measurements of stratospheric ozone - Comparison of measurements made by SAGE, ECC balloons, chemiluminescent, and optical rocketsondes

    NASA Technical Reports Server (NTRS)

    Mccormick, M. P.; Swissler, T. J.; Osborn, M. T.; Hilsenrath, E.; Krueger, A. J.

    1984-01-01

    The validity of ozone-profile data from the satellite sensor SAGE was tested in a series of correlative experiments conducted at five fixed sites between 6 deg S and 65 deg N during 1979-1980. The intercomparisons included data taken with electrochemical ozone (ECC) balloonsondes and chemiluminescent and optical rocketsondes. The average mean difference for 17 separate comparisons between the SAGE and ECC balloonsonde observations over the altitudes 18-28 km was 9.3 percent with a standard deviation of 2.8 percent. Excluding comparisons separated by greater than 500 km reduces the average mean difference to 8.9 percent and the standard deviation to 2.1 percent. The average mean difference between SAGE and three optical rocketsonde observations over the altitudes 25-50 km was 11 percent, and between SAGE and two chemiluminescent rocketsondes over the altitudes 20-60 km it was 13.5 percent. Considering the differences in vertical resolution, experimental errors, and ozone time and space gradients, the agreement between SAGE-derived ozone profiles and these correlative measurements is considered very good. In addition, isopleths of ozone mixing ratio versus latitude and altitude are in good agreement with previously published results.

  12. Interpositional carotid artery bypass strategies in the surgical management of aneurysms and tumors of the skull base.

    PubMed

    Liu, James K; Couldwell, William T

    2003-03-15

    Cerebral revascularization is an important component in the surgical management of complex skull base tumors and aneurysms. Patients who harbor complex aneurysms that cannot be clipped directly and in whom parent vessel occlusion cannot be tolerated may require cerebrovascular bypass surgery. In cases in which skull base tumors encase the carotid artery (CA) and a resection is desired, a cerebrovascular bypass may be necessary in planned CA occlusion or sacrifice. In this review the authors discuss options for performing high-flow anterograde interposition CA bypass for lesions of the skull base. The authors review three important bypass techniques involving saphenous vein grafts: the cervical-to-petrous internal carotid artery (ICA), petrous-to-supraclinoid ICA, and cervical-to-supraclinoid ICA bypass. These revascularization techniques are important tools in the surgical treatment of complex aneurysms and tumors of the skull base and cavernous sinus.

  13. 21 CFR 870.4380 - Cardiopulmonary bypass pump speed control.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Cardiopulmonary bypass pump speed control. 870... Cardiopulmonary bypass pump speed control. (a) Identification. A cardiopulmonary bypass pump speed control is a... control the speed of blood pumps used in cardiopulmonary bypass surgery. (b) Classification. Class...

  14. 21 CFR 870.4380 - Cardiopulmonary bypass pump speed control.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Cardiopulmonary bypass pump speed control. 870... Cardiopulmonary bypass pump speed control. (a) Identification. A cardiopulmonary bypass pump speed control is a... control the speed of blood pumps used in cardiopulmonary bypass surgery. (b) Classification. Class...

  15. 21 CFR 870.4380 - Cardiopulmonary bypass pump speed control.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Cardiopulmonary bypass pump speed control. 870... Cardiopulmonary bypass pump speed control. (a) Identification. A cardiopulmonary bypass pump speed control is a... control the speed of blood pumps used in cardiopulmonary bypass surgery. (b) Classification. Class...

  16. 21 CFR 870.4380 - Cardiopulmonary bypass pump speed control.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Cardiopulmonary bypass pump speed control. 870... Cardiopulmonary bypass pump speed control. (a) Identification. A cardiopulmonary bypass pump speed control is a... control the speed of blood pumps used in cardiopulmonary bypass surgery. (b) Classification. Class...

  17. 21 CFR 870.4310 - Cardiopulmonary bypass coronary pressure gauge.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Cardiopulmonary bypass coronary pressure gauge... Cardiopulmonary bypass coronary pressure gauge. (a) Identification. A cardiopulmonary bypass coronary pressure gauge is a device used in cardiopulmonary bypass surgery to measure the pressure of the blood...

  18. 30 CFR 56.19018 - Overtravel by-pass switches.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Overtravel by-pass switches. 56.19018 Section... Hoisting Hoists § 56.19018 Overtravel by-pass switches. When an overtravel by-pass switch is installed, the... switch is held in the closed position by the hoistman. The overtravel by-pass switch shall...

  19. 30 CFR 57.19018 - Overtravel by-pass switches.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Overtravel by-pass switches. 57.19018 Section... Hoisting Hoists § 57.19018 Overtravel by-pass switches. When an overtravel by-pass switch is installed, the... switch is held in the closed position by the hoistman. The overtravel by-pass switch shall...

  20. 21 CFR 870.4380 - Cardiopulmonary bypass pump speed control.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass pump speed control. 870... Cardiopulmonary bypass pump speed control. (a) Identification. A cardiopulmonary bypass pump speed control is a... control the speed of blood pumps used in cardiopulmonary bypass surgery. (b) Classification. Class...

  1. Comparison of direct and enrichment methods for the selective isolation of vancomycin-resistant enterococci from feces of pigs and poultry.

    PubMed

    Butaye, P; Devriese, L A; Haesebrouck, F

    1999-01-01

    Isolation results of vancomycin-resistant enterococci (VRE) of fecal samples from pigs and broiler and layer chickens obtained with two vancomycin-supplemented enrichment media, kanamycin aesculin azide (KAA) broth and Enterococcosel (ECC) broth, and three isolation media, KAA agar, ECC agar, and Slanetz and Bartley (SL) agar, were compared. Direct isolation on vancomycin-containing agar plates was not efficient in swine and layer chickens, which had only low numbers of VRE. In broilers chickens, the VRE content of the samples was high, and SL as well as ECC were found to perform better than KAA agar. The same three agar media were used as selective plating media after 1 and 2 days incubation of the samples in KAA and ECC enrichment broths. Sensitivities of the 12 different enrichment-plate combinations tested ranged from 0 to 81% in layer chickens and from 5 to 44% in samples from pigs. In the high prevalence type of samples from broilers, sensitivities still varied substantially from 52 to 78%. Incubating vancomycin-containing enrichment broths for 2 days compared with 1 day was favorable for the isolation of vancomycin-resistant Enterococcus faecalis, E. gallinarum, and E. casseliflavus but not for E. faecium and E. hirae/E. durans. ECC broth and ECC plates yielded the highest number of E. gallinarum and E. casseliflavus. In layer as well as in broiler chickens, ECC broth incubated for 2 days and plated on ECC agar was the most sensitive method. In pigs, however, KAA broth incubated for 2 days and plated on ECC medium yielded the highest number of VRE.

  2. Frataxin-bypassing Isu1: characterization of the bypass activity in cells and mitochondria.

    PubMed

    Yoon, Heeyong; Knight, Simon A B; Pandey, Alok; Pain, Jayashree; Zhang, Yan; Pain, Debkumar; Dancis, Andrew

    2014-04-01

    Frataxin is a conserved mitochondrial protein, and deficiency underlies the neurodegenerative disease Friedreich's ataxia. Frataxin interacts with the core machinery for Fe-S cluster assembly in mitochondria. Recently we reported that in frataxin-deleted yeast strains, a spontaneously occurring mutation in one of two genes encoding redundant Isu scaffold proteins, bypassed the mutant phenotypes. In the present study we created strains expressing a single scaffold protein, either Isu1 or the bypass mutant M107I Isu1. Our results show that in the frataxin-deletion strain expressing the bypass mutant Isu1, cell growth, Fe-S cluster protein activities, haem proteins and iron homoeostasis were restored to normal or close to normal. The bypass effects were not mediated by changes in Isu1 expression level. The persulfide-forming activity of the cysteine desulfurase was diminished in the frataxin deletion (∆yfh1 ISU1) and was improved by expression of the bypass Isu1 (∆yfh1 M107I ISU1). The addition of purified bypass M107I Isu1 protein to a ∆yfh1 lysate conferred similar enhancement of cysteine desulfurase as did frataxin, suggesting that this effect contributed to the bypass mechanism. Fe-S cluster-forming activity in isolated mitochondria was stimulated by the bypass Isu1, albeit at a lower rate. The rescuing effects of the bypass Isu1 point to ways that the core defects in Friedreich's ataxia mitochondria can be restored.

  3. A systematic review on robotic coronary artery bypass graft surgery

    PubMed Central

    Indraratna, Praveen; Doyle, Mathew; Tian, David H.; Liou, Kevin; Munkholm-Larsen, Stine; Uys, Ciska; Virk, Sohaib

    2016-01-01

    Background Robotic-assisted coronary artery bypass graft surgery (CABG) has been performed over the past decade. Despite encouraging results from selected centres, there is a paucity of robust clinical data to establish its clinical safety and efficacy. The present systematic review aimed to identify all relevant clinical data on robotic CABG. The primary endpoint was perioperative mortality, and secondary endpoints included perioperative morbidities, anastomotic complications, and long-term survival. Methods Electronic searches were performed using three online databases from their dates of inception to 2016. Relevant studies fulfilling the predefined search criteria were categorized according to surgical techniques as (I) totally endoscopic coronary artery bypass without cardiopulmonary bypass (TECAB off-pump); (II) TECAB on-pump; and robotic-assisted mammary artery harvesting followed by minimally invasive direct coronary artery bypass (robotic MIDCAB). Results The present systematic review identified 44 studies that fulfilled the study selection criteria, including nine studies in the TECAB off-pump group and 16 studies in the robotic MIDCAB group. Statistical analysis reported a pooled mortality of 1.7% for the TECAB off-pump group and 1.0% for the robotic MIDCAB group. Intraoperative details such as the number and location of grafts performed, operative times and conversion rates, as well as postoperative secondary endpoints such as morbidities, anastomotic complications and long-term outcomes were also summarized for both techniques. Conclusions A number of technical, logistic and cost-related issues continue to hinder the popularization of the robotic CABG procedure. Current clinical evidence is limited by a lack of randomized controlled trials, heterogeneous definition of techniques and complications, as well as a lack of robust clinical follow-up with routine angiography. Nonetheless, the present systematic review reported acceptable perioperative

  4. Heart bypass surgery - minimally invasive - discharge

    MedlinePlus

    ... thrombosis, 9th ed: American College of Chest Physicians evidence-based clinical practice guidelines. Chest . 2012;141(2 ... bypass surgery - minimally invasive Heart failure - overview High blood cholesterol ...

  5. Exhaust gas bypass valve control for thermoelectric generator

    SciTech Connect

    Reynolds, Michael G; Yang, Jihui; Meisner, Greogry P.; Stabler, Francis R.; De Bock, Hendrik Pieter Jacobus; Anderson, Todd Alan

    2012-09-04

    A method of controlling engine exhaust flow through at least one of an exhaust bypass and a thermoelectric device via a bypass valve is provided. The method includes: determining a mass flow of exhaust exiting an engine; determining a desired exhaust pressure based on the mass flow of exhaust; comparing the desired exhaust pressure to a determined exhaust pressure; and determining a bypass valve control value based on the comparing, wherein the bypass valve control value is used to control the bypass valve.

  6. Leading-edge effects in bypass transition

    NASA Astrophysics Data System (ADS)

    Nagarajan, S.; Lele, S. K.; Ferziger, J. H.

    The effect of a blunt leading edge on bypass transition is studied by numerical simulation. A mixed direct and large-eddy simulation of a flat plate with a super-ellipse leading edge is carried out at various conditions. Onset and completion of transition is seen to move upstream with increasing bluntness. For sharper leading edges, at lower levels of turbulence, transition usually occurs through instabilities on low-speed streaks as observed by Jacobs & Durbin (2001) and Brandt et al. (2004) whereas increasing either the turbulence intensity or the leading-edge bluntness brings into play another mechanism. Free-stream vortices are amplified at the leading edge because of stretching. In the case of particularly strong vortices, this interaction induces a localized streamwise vortical disturbance in the boundary layer which then grows as it convects downstream and eventually breaks down to form a turbulent spot. These disturbances, which are localized and hence wavepacket-like, move at speeds in the range 0.55 U_{infty} 0.65 U_{infty} and occur in the lower portion of the boundary layer. Simulations conducted with isolated vortices confirm such a response of the boundary layer.

  7. MHD Energy Bypass Scramjet Engine

    NASA Technical Reports Server (NTRS)

    Mehta, Unmeel B.; Bogdanoff, David W.; Park, Chul; Arnold, Jim (Technical Monitor)

    2001-01-01

    Revolutionary rather than evolutionary changes in propulsion systems are most likely to decrease cost of space transportation and to provide a global range capability. Hypersonic air-breathing propulsion is a revolutionary propulsion system. The performance of scramjet engines can be improved by the AJAX energy management concept. A magneto-hydro-dynamics (MHD) generator controls the flow and extracts flow energy in the engine inlet and a MHD accelerator downstream of the combustor accelerates the nozzle flow. A progress report toward developing the MHD technology is presented herein. Recent theoretical efforts are reviewed and ongoing experimental efforts are discussed. The latter efforts also include an ongoing collaboration between NASA, the US Air Force Research Laboratory, US industry, and Russian scientific organizations. Two of the critical technologies, the ionization of the air and the MHD accelerator, are briefly discussed. Examples of limiting the combustor entrance Mach number to a low supersonic value with a MHD energy bypass scheme are presented, demonstrating an improvement in scramjet performance. The results for a simplified design of an aerospace plane show that the specific impulse of the MHD-bypass system is better than the non-MHD system and typical rocket over a narrow region of flight speeds and design parameters. Equilibrium ionization and non-equilibrium ionization are discussed. The thermodynamic condition of air at the entrance of the engine inlet determines the method of ionization. The required external power for non-equilibrium ionization is computed. There have been many experiments in which electrical power generation has successfully been achieved by magneto-hydrodynamic (MHD) means. However, relatively few experiments have been made to date for the reverse case of achieving gas acceleration by the MHD means. An experiment in a shock tunnel is described in which MHD acceleration is investigated experimentally. MHD has several

  8. Bypass diode for a solar cell

    DOEpatents

    Rim, Seung Bum [Palo Alto, CA; Kim, Taeseok [San Jose, CA; Smith, David D [Campbell, CA; Cousins, Peter J [Menlo Park, CA

    2012-03-13

    Bypass diodes for solar cells are described. In one embodiment, a bypass diode for a solar cell includes a substrate of the solar cell. A first conductive region is disposed above the substrate, the first conductive region of a first conductivity type. A second conductive region is disposed on the first conductive region, the second conductive region of a second conductivity type opposite the first conductivity type.

  9. Monsanto may bypass NIH in microbe test.

    PubMed

    Sun, Marjorie

    1985-01-11

    The Monsanto Company is planning to ask the Environmental Protection Agency for clearance to field test a genetically engineered microbial pesticide, bypassing the traditional approval process of the National Institutes of Health. Although only federally funded institutions are required to obtain NIH approval for genetic engineering tests, Monsanto is the first company to bypass the NIH regulatory process, which has become mired in a lawsuit brought by Jeremy Rifkin.

  10. Prophylactic digitalization for coronary artery bypass surgery.

    PubMed

    Johnson, L W; Dickstein, R A; Fruehan, C T; Kane, P; Potts, J L; Smulyan, H; Webb, W R; Eich, R H

    1976-05-01

    One hundred and twenty patients undergoing aortocoronary bypass procedures were randomly placed into control and digitalized groups. All were initially in normal sinus rhythm and without evidence of congestive heart failure. Supraventricular arrhythmias occurred in 17 of 66 controls and in only three of 54 digitalized patients (P less than 0.01). There was no evidence of digitals toxicity. Based on this evidence we recommend prophylactic digitalization for patients having aortocoronary bypass operations.

  11. The Dalles Dam juvenile bypass electrical systems

    SciTech Connect

    Bannister, B.D.; Luck, B.

    1995-12-31

    The Corps of Engineers is in the process of providing a juvenile fish bypass system at The Dalles Lock and Dam project on the lower Columbia River. This system is intended to preserve and enhance the dwindling stocks of wild anadromous fish. The impact of the proposed facilities on the electrical systems and on plant operations are developed along with descriptions of the special bypass features including the incorporation of provisions for a future small hydropower generator.

  12. ECC (Electrochemical Concentration Cell) ozonesonde observations at Mirny, Antarctica, during 1988

    NASA Technical Reports Server (NTRS)

    Komhyr, W. D.; Lathrop, J. A.; Arbuzova, V. N.; Khattatov, V. U.; Nureyev, P. G.; Rudakov, V. V.; Zamyshlayev, I. V.

    1989-01-01

    Atmospheric ozone vertical distributions, air temperatures, and wind speed and direction data are presented for 40 balloon electrochemical concentration cell ozone soundings made at Mirny, Antarctica, in 1988.

  13. Brain microvascular function during cardiopulmonary bypass

    SciTech Connect

    Sorensen, H.R.; Husum, B.; Waaben, J.; Andersen, K.; Andersen, L.I.; Gefke, K.; Kaarsen, A.L.; Gjedde, A.

    1987-11-01

    Emboli in the brain microvasculature may inhibit brain activity during cardiopulmonary bypass. Such hypothetical blockade, if confirmed, may be responsible for the reduction of cerebral metabolic rate for glucose observed in animals subjected to cardiopulmonary bypass. In previous studies of cerebral blood flow during bypass, brain microcirculation was not evaluated. In the present study in animals (pigs), reduction of the number of perfused capillaries was estimated by measurements of the capillary diffusion capacity for hydrophilic tracers of low permeability. Capillary diffusion capacity, cerebral blood flow, and cerebral metabolic rate for glucose were measured simultaneously by the integral method, different tracers being used with different circulation times. In eight animals subjected to normothermic cardiopulmonary bypass, and seven subjected to hypothermic bypass, cerebral blood flow, cerebral metabolic rate for glucose, and capillary diffusion capacity decreased significantly: cerebral blood flow from 63 to 43 ml/100 gm/min in normothermia and to 34 ml/100 gm/min in hypothermia and cerebral metabolic rate for glucose from 43.0 to 23.0 mumol/100 gm/min in normothermia and to 14.1 mumol/100 gm/min in hypothermia. The capillary diffusion capacity declined markedly from 0.15 to 0.03 ml/100 gm/min in normothermia but only to 0.08 ml/100 gm/min in hypothermia. We conclude that the decrease of cerebral metabolic rate for glucose during normothermic cardiopulmonary bypass is caused by interruption of blood flow through a part of the capillary bed, possibly by microemboli, and that cerebral blood flow is an inadequate indicator of capillary blood flow. Further studies must clarify why normal microvascular function appears to be preserved during hypothermic cardiopulmonary bypass.

  14. Massive sediment bypassing on the lower shoreface offshore of a wide tidal inlet - Cat Island Pass, Louisiana

    USGS Publications Warehouse

    Jaffe, B.E.; List, J.H.; Sallenger, A.H.

    1997-01-01

    Analysis of a series of historical bathymetric and shoreline surveys along the Louisiana coast west of the Mississippi River mouth detected a large area of deposition in water depths of 2.0-8.5 m offshore of a 9-km- wide tidal inlet, the Cat Island Pass/Wine Island Pass system. A 59.9 ?? 106 m3 sandy deposit formed from the 1930s-1980s, spanning 27 km in the alongshore direction, delineating the transport pathway for sediment bypassing offshore of the inlet on the shoreface. Bypassing connected the shorefaces of two barrier island systems, the Isles Dernieres and the Bayou Lafourche. The processes responsible for formation of this deposit are not well understood, but sediment-transport modeling suggests that sediment is transported primarily by wind-driven coastal currents during large storms and hurricanes. Deposition appears to be related to changes in shoreline orientation, closing of transport pathways into a large bay to the east and the presence of tidal inlets. This newly documented type of bypassing, an offshore bypassing of the inlet system, naturally nourished the immediate downdrift area, the eastern Isles Dernieres, where shoreface and shoreline erosion rates are about half of pre-bypassing rates. Erosion rates remained the same farther downdrift, where bypassing has not yet reached. As this offshore bypassing continues, the destruction of the Isles Dernieres will be slowed.

  15. Experimental Investigation of By-pass Transition

    NASA Astrophysics Data System (ADS)

    Sengupta, Tapan; Lim, T. T.; Chattopadhyay, Manojit

    2000-11-01

    By-pass transition, a phenomenon often encountered in nature and engineering devices, is a complex flow instability caused by moving disturbances over bodies. To date this phenomenon is not fully explained. In the present research a controlled experiment is performed to show that the violent breakdown during by-pass transition is dominated by a two-dimensional mechanism and the resultant broadband energy spectrum of the corresponding turbulent flow is excited at the receptivity stage itself by the primary instability. The experiment is conducted in a water tunnel using dye visualisation technique, and the by-pass transition is created by controlled motion of captive vortices. In the presentation, apart from showing video images of the phenomenon, the similarity of the observed events with secondary instability and fully developed turbulent flows will be discussed.

  16. Battery Cell By-Pass Circuit

    NASA Technical Reports Server (NTRS)

    Evers, Jeffrey (Inventor); Gelger, Ronald V. (Inventor)

    2001-01-01

    The invention is a circuit and method of limiting the charging current voltage from a power supply net work applied to an individual cell of a plurality of cells making up a battery being charged in series. It is particularly designed for use with batteries that can be damaged by overcharging, such as Lithium-ion type batteries. In detail. the method includes the following steps: 1) sensing the actual voltage level of the individual cell; 2) comparing the actual voltage level of the individual cell with a reference value and providing an error signal representative thereof; and 3) by-passing the charging current around individual cell necessary to keep the individual cell voltage level generally equal a specific voltage level while continuing to charge the remaining cells. Preferably this is accomplished by by-passing the charging current around the individual cell if said actual voltage level is above the specific voltage level and allowing the charging current to the individual cell if the actual voltage level is equal or less than the specific voltage level. In the step of bypassing the charging current, the by-passed current is transferred at a proper voltage level to the power supply. The by-pass circuit a voltage comparison circuit is used to compare the actual voltage level of the individual cell with a reference value and to provide an error signal representative thereof. A third circuit, designed to be responsive to the error signal, is provided for maintaining the individual cell voltage level generally equal to the specific voltage level. Circuitry is provided in the third circuit for bypassing charging current around the individual cell if the actual voltage level is above the specific voltage level and transfers the excess charging current to the power supply net work. The circuitry also allows charging of the individual cell if the actual voltage level is equal or less than the specific voltage level.

  17. [Simplified laparoscopic gastric bypass. Initial experience].

    PubMed

    Hernández-Miguelena, Luis; Maldonado-Vázquez, Angélica; Cortes-Romano, Pablo; Ríos-Cruz, Daniel; Marín-Domínguez, Raúl; Castillo-González, Armando

    2014-01-01

    Antecedentes: la cirugía de la obesidad comprende diversos procedimientos gastrointestinales. El bypass gástrico en Y de Roux es el prototipo de los procedimientos mixtos y el más practicado en el mundo en sus diversas variedades. Una técnica similar y novedosa es la adoptada por Cardoso-Ramos y Galvao denominada "bypass simplificado" que rápidamente se aceptó por la mayor facilidad y resultados muy parecidos a la técnica convencional. Objetivo: describir los resultados a un año del bypass gástrico simplificado para el tratamiento de la obesidad mórbida. Material y métodos: estudio retrospectivo y descriptivo de todos los pacientes a quienes se realizó bypass gástrico de enero de 2008 a julio de 2012, en la clínica de obesidad de un hospital privado de la Ciudad de México. Resultados: se estudiaron 90 pacientes con diagnóstico de obesidad mórbida, con límites de edad de 18 y 65 años, operados para bypass gástrico simplificado. En 10% de los pacientes hubo complicaciones, las más frecuentes fueron: hemorragia y hernia interna. Durante el periodo de estudio la mortalidad fue de 0%. La pérdida de peso promedio a los 12 meses fue de 72.7%. Conclusión: el bypass gástrico simplificado laparoscópico es una cirugía segura, con buenos resultados a mediano plazo, y con una pérdida del exceso de peso adecuada en 71% de los casos.

  18. Gas Turbine Engine Having Fan Rotor Driven by Turbine Exhaust and with a Bypass

    NASA Technical Reports Server (NTRS)

    Suciu, Gabriel L. (Inventor); Chandler, Jesse M. (Inventor)

    2016-01-01

    A gas turbine engine has a core engine incorporating a core engine turbine. A fan rotor is driven by a fan rotor turbine. The fan rotor turbine is in the path of gases downstream from the core engine turbine. A bypass door is moveable from a closed position at which the gases from the core engine turbine pass over the fan rotor turbine, and moveable to a bypass position at which the gases are directed away from the fan rotor turbine. An aircraft is also disclosed.

  19. Polymorphous ventricular tachycardia following cardiopulmonary bypass.

    PubMed Central

    Thompson, L. D.; Cohen, A. J.; Bellasis, R. M.

    1996-01-01

    A 62-year-old African-American man who underwent coronary artery bypass surgery was found to have repetitive ventricular tachycardia of the "Torsade des pointes" type. The arrhythmia was resistant to bretylium, lidocaine, and pacing, but was controlled by intravenous magnesium sulfate. The recurrent attacks were abolished by a bolus of 1 g magnesium sulfate and controlled using a 1 mg/minute drip for 12 hours. This case shows the effectiveness of intravenous magnesium in controlling Torsade des pointes in postoperative coronary bypass patients. PMID:8583493

  20. Redox-mediated bypass of restriction point via skipping of G1pm

    PubMed Central

    Hoffman, Arnold; Greene, James J; Spetner, Lee M; Burke, Michael

    2006-01-01

    Background It is well known that cancer cells bypass the restriction point, R, and undergo uncontrolled cell proliferation. Hypothesis and evidence We suggest here that fibrosarcoma cells enter G1ps directly from M, skipping G1pm, hence bypassing R, in response to redox modulation. Evidence is presented from the published literature that demonstrate a shortening of the cycle period of transformed fibroblasts (SV-3T3) compared to the nontransformed 3T3 fibroblasts, corresponding to the duration of G1pm in the 3T3 fibroblasts. Evidence is also presented that demonstrate that redox modulation can induce the CUA-4 fibroblasts to bypass R, resulting in a cycle period closely corresponding to the cycle period of fibrosarcoma cells (HT1080). Conclusion The evidence supports our hypothesis that a low internal redox potential can cause fibrosarcoma cells to skip the G1pm phase of the cell cycle. PMID:16867189

  1. A review of the iStent® trabecular micro-bypass stent: safety and efficacy

    PubMed Central

    Wellik, Sarah R; Dale, Elizabeth A

    2015-01-01

    There is a significant demand for procedures that can effectively treat glaucoma with low risk and good visual outcomes. To fill this void, procedures termed “minimally invasive glaucoma surgery”, are gaining in popularity. This review will focus on the safety and efficacy of one such minimally invasive glaucoma surgery procedure, the trabecular micro-bypass stent. This stent is intended to lower intraocular pressure by directly cannulating Schlemm’s canal and thereby enhancing aqueous outflow. Recent randomized controlled trials and case series have demonstrated the micro-bypass stent to be a relatively safe procedure, with limited complications and no serious adverse sequelae. The most common complication across all studies was stent obstruction or malposition, which generally did not result in any adverse outcome in vision or pressure control. In addition, increased rates of hypotony, choroidal hemorrhage, or infection were not seen with the micro-bypass stent in comparison to cataract surgery alone. PMID:25931808

  2. (Updated) NCI Fiscal 2016 Bypass Budget Proposes $25 Million for Frederick National Lab | Poster

    Cancer.gov

    By Nancy Parrish, Staff Writer; image by Richard Frederickson, Staff Photographer The additional funding requested for Frederick National Laboratory for Cancer Research (FNLCR) in the Fiscal 2016 Bypass Budget was $25 million, or approximately 3.5 percent of the total additional funding request of $715 million. Officially called the Professional Judgment Budget, the Bypass Budget is a result of the National Cancer Act of 1971, which authorizes NCI to submit a budget directly to the president, to send to Congress. With a focus on NCI’s research priorities and areas of cancer research with potential for investment, the Bypass Budget specifies additional funding, over and above the current budget, that is needed to advance

  3. Stress analysis method for clearance-fit joints with bearing-bypass loads

    NASA Technical Reports Server (NTRS)

    Naik, R. A.; Crews, J. H., Jr.

    1989-01-01

    A simple direct stress analysis method is proposed for a laminate with a clearance-fit fastener subjected to combined bearing and bypass loads in tension or compression, including bearing and bypass loads on bolt-hole contact and local stresses. The approach uses a linear-elastic finite element analysis with an inverse formulation; conditions along the bolt-hole interface are specified by constraint equations that limit nodal displacements to a circular arc corresponding to the bolt diameter. The application of the method to the analysis of the effects of bearing-bypass loading on bolt-hole contact angles and local stresses, with the plate material properties representing a quasi-isotropic T300/5208 graphite/epoxy laminate, is discussed.

  4. Variable volume combustor with an air bypass system

    DOEpatents

    Johnson, Thomas Edward; Ziminsky, Willy Steve; Ostebee, Heath Michael; Keener, Christopher Paul

    2017-02-07

    The present application provides a combustor for use with flow of fuel and a flow of air in a gas turbine engine. The combustor may include a number of micro-mixer fuel nozzles positioned within a liner and an air bypass system position about the liner. The air bypass system variably allows a bypass portion of the flow of air to bypass the micro-mixer fuel nozzles.

  5. 21 CFR 870.4390 - Cardiopulmonary bypass pump tubing.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Cardiopulmonary bypass pump tubing. 870.4390... bypass pump tubing. (a) Identification. A cardiopulmonary bypass pump tubing is polymeric tubing which is used in the blood pump head and which is cyclically compressed by the pump to cause the blood to...

  6. 21 CFR 870.4390 - Cardiopulmonary bypass pump tubing.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Cardiopulmonary bypass pump tubing. 870.4390... bypass pump tubing. (a) Identification. A cardiopulmonary bypass pump tubing is polymeric tubing which is used in the blood pump head and which is cyclically compressed by the pump to cause the blood to...

  7. 21 CFR 870.4390 - Cardiopulmonary bypass pump tubing.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Cardiopulmonary bypass pump tubing. 870.4390... bypass pump tubing. (a) Identification. A cardiopulmonary bypass pump tubing is polymeric tubing which is used in the blood pump head and which is cyclically compressed by the pump to cause the blood to...

  8. 21 CFR 870.4390 - Cardiopulmonary bypass pump tubing.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Cardiopulmonary bypass pump tubing. 870.4390... bypass pump tubing. (a) Identification. A cardiopulmonary bypass pump tubing is polymeric tubing which is used in the blood pump head and which is cyclically compressed by the pump to cause the blood to...

  9. Bypass apparatus and method for series connected energy storage devices

    DOEpatents

    Rouillard, Jean; Comte, Christophe; Daigle, Dominik

    2000-01-01

    A bypass apparatus and method for series connected energy storage devices. Each of the energy storage devices coupled to a common series connection has an associated bypass unit connected thereto in parallel. A current bypass unit includes a sensor which is coupled in parallel with an associated energy storage device or cell and senses an energy parameter indicative of an energy state of the cell, such as cell voltage. A bypass switch is coupled in parallel with the energy storage cell and operable between a non-activated state and an activated state. The bypass switch, when in the non-activated state, is substantially non-conductive with respect to current passing through the energy storage cell and, when in the activated state, provides a bypass current path for passing current to the series connection so as to bypass the associated cell. A controller controls activation of the bypass switch in response to the voltage of the cell deviating from a pre-established voltage setpoint. The controller may be included within the bypass unit or be disposed on a control platform external to the bypass unit. The bypass switch may, when activated, establish a permanent or a temporary bypass current path.

  10. 30 CFR 57.19018 - Overtravel by-pass switches.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Overtravel by-pass switches. 57.19018 Section... Hoisting Hoists § 57.19018 Overtravel by-pass switches. When an overtravel by-pass switch is installed, the switch shall function so as to allow the conveyance to be moved through the overtravel position when...

  11. 30 CFR 56.19018 - Overtravel by-pass switches.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Overtravel by-pass switches. 56.19018 Section... Hoisting Hoists § 56.19018 Overtravel by-pass switches. When an overtravel by-pass switch is installed, the switch shall function so as to allow the conveyance to be moved through the overtravel position when...

  12. 30 CFR 56.19018 - Overtravel by-pass switches.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Overtravel by-pass switches. 56.19018 Section... Hoisting Hoists § 56.19018 Overtravel by-pass switches. When an overtravel by-pass switch is installed, the switch shall function so as to allow the conveyance to be moved through the overtravel position when...

  13. 30 CFR 57.19018 - Overtravel by-pass switches.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Overtravel by-pass switches. 57.19018 Section... Hoisting Hoists § 57.19018 Overtravel by-pass switches. When an overtravel by-pass switch is installed, the switch shall function so as to allow the conveyance to be moved through the overtravel position when...

  14. 30 CFR 56.19018 - Overtravel by-pass switches.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Overtravel by-pass switches. 56.19018 Section... Hoisting Hoists § 56.19018 Overtravel by-pass switches. When an overtravel by-pass switch is installed, the switch shall function so as to allow the conveyance to be moved through the overtravel position when...

  15. 30 CFR 57.19018 - Overtravel by-pass switches.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Overtravel by-pass switches. 57.19018 Section... Hoisting Hoists § 57.19018 Overtravel by-pass switches. When an overtravel by-pass switch is installed, the switch shall function so as to allow the conveyance to be moved through the overtravel position when...

  16. 21 CFR 870.4250 - Cardiopulmonary bypass temperature controller.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Cardiopulmonary bypass temperature controller. 870... Cardiopulmonary bypass temperature controller. (a) Identification. A cardiopulmonary bypass temperature controller is a device used to control the temperature of the fluid entering and leaving a heat exchanger....

  17. 21 CFR 870.4250 - Cardiopulmonary bypass temperature controller.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Cardiopulmonary bypass temperature controller. 870... Cardiopulmonary bypass temperature controller. (a) Identification. A cardiopulmonary bypass temperature controller is a device used to control the temperature of the fluid entering and leaving a heat exchanger....

  18. 21 CFR 870.4250 - Cardiopulmonary bypass temperature controller.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass temperature controller. 870... Cardiopulmonary bypass temperature controller. (a) Identification. A cardiopulmonary bypass temperature controller is a device used to control the temperature of the fluid entering and leaving a heat exchanger....

  19. 21 CFR 870.4250 - Cardiopulmonary bypass temperature controller.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Cardiopulmonary bypass temperature controller. 870... Cardiopulmonary bypass temperature controller. (a) Identification. A cardiopulmonary bypass temperature controller is a device used to control the temperature of the fluid entering and leaving a heat exchanger....

  20. 21 CFR 870.4250 - Cardiopulmonary bypass temperature controller.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Cardiopulmonary bypass temperature controller. 870... Cardiopulmonary bypass temperature controller. (a) Identification. A cardiopulmonary bypass temperature controller is a device used to control the temperature of the fluid entering and leaving a heat exchanger....

  1. 21 CFR 870.4400 - Cardiopulmonary bypass blood reservoir.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass blood reservoir. 870.4400... bypass blood reservoir. (a) Identification. A cardiopulmonary bypass blood reservoir is a device used in conjunction with short-term extracorporeal circulation devices to hold a reserve supply of blood in the...

  2. 21 CFR 870.4240 - Cardiopulmonary bypass heat exchanger.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Cardiopulmonary bypass heat exchanger. 870.4240... bypass heat exchanger. (a) Identification. A cardiopulmonary bypass heat exchanger is a device, consisting of a heat exchange system used in extracorporeal circulation to warm or cool the blood...

  3. 21 CFR 870.4240 - Cardiopulmonary bypass heat exchanger.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass heat exchanger. 870.4240... bypass heat exchanger. (a) Identification. A cardiopulmonary bypass heat exchanger is a device, consisting of a heat exchange system used in extracorporeal circulation to warm or cool the blood...

  4. 20 CFR 631.18 - Federal by-pass authority.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Federal by-pass authority. 631.18 Section 631... Procedures § 631.18 Federal by-pass authority. (a) In the event that a State fails to submit a biennial State... Secretary's intent to exercise by-pass authority and an opportunity to request and to receive a...

  5. 21 CFR 870.4400 - Cardiopulmonary bypass blood reservoir.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Cardiopulmonary bypass blood reservoir. 870.4400... bypass blood reservoir. (a) Identification. A cardiopulmonary bypass blood reservoir is a device used in... circulation. (b) Classification. Class II (performance standards), except that a reservoir that contains...

  6. 21 CFR 870.4400 - Cardiopulmonary bypass blood reservoir.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Cardiopulmonary bypass blood reservoir. 870.4400... bypass blood reservoir. (a) Identification. A cardiopulmonary bypass blood reservoir is a device used in... circulation. (b) Classification. Class II (performance standards), except that a reservoir that contains...

  7. 21 CFR 870.4400 - Cardiopulmonary bypass blood reservoir.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Cardiopulmonary bypass blood reservoir. 870.4400... bypass blood reservoir. (a) Identification. A cardiopulmonary bypass blood reservoir is a device used in... circulation. (b) Classification. Class II (performance standards), except that a reservoir that contains...

  8. 21 CFR 870.4400 - Cardiopulmonary bypass blood reservoir.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Cardiopulmonary bypass blood reservoir. 870.4400... bypass blood reservoir. (a) Identification. A cardiopulmonary bypass blood reservoir is a device used in... circulation. (b) Classification. Class II (performance standards), except that a reservoir that contains...

  9. 30 CFR 56.19018 - Overtravel by-pass switches.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Overtravel by-pass switches. 56.19018 Section... Hoisting Hoists § 56.19018 Overtravel by-pass switches. When an overtravel by-pass switch is installed, the switch shall function so as to allow the conveyance to be moved through the overtravel position when...

  10. 30 CFR 57.19018 - Overtravel by-pass switches.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Overtravel by-pass switches. 57.19018 Section... Hoisting Hoists § 57.19018 Overtravel by-pass switches. When an overtravel by-pass switch is installed, the switch shall function so as to allow the conveyance to be moved through the overtravel position when...

  11. 21 CFR 870.4390 - Cardiopulmonary bypass pump tubing.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass pump tubing. 870.4390... bypass pump tubing. (a) Identification. A cardiopulmonary bypass pump tubing is polymeric tubing which is used in the blood pump head and which is cyclically compressed by the pump to cause the blood to...

  12. 21 CFR 870.4320 - Cardiopulmonary bypass pulsatile flow generator.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Cardiopulmonary bypass pulsatile flow generator... Cardiopulmonary bypass pulsatile flow generator. (a) Identification. A cardiopulmonary bypass pulsatile flow generator is an electrically and pneumatically operated device used to create pulsatile blood flow....

  13. 21 CFR 870.4320 - Cardiopulmonary bypass pulsatile flow generator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass pulsatile flow generator... Cardiopulmonary bypass pulsatile flow generator. (a) Identification. A cardiopulmonary bypass pulsatile flow generator is an electrically and pneumatically operated device used to create pulsatile blood flow....

  14. 21 CFR 870.4320 - Cardiopulmonary bypass pulsatile flow generator.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Cardiopulmonary bypass pulsatile flow generator... Cardiopulmonary bypass pulsatile flow generator. (a) Identification. A cardiopulmonary bypass pulsatile flow generator is an electrically and pneumatically operated device used to create pulsatile blood flow....

  15. Investigation on the Core Bypass Flow in a Very High Temperature Reactor

    SciTech Connect

    Hassan, Yassin

    2013-10-22

    Uncertainties associated with the core bypass flow are some of the key issues that directly influence the coolant mass flow distribution and magnitude, and thus the operational core temperature profiles, in the very high-temperature reactor (VHTR). Designers will attempt to configure the core geometry so the core cooling flow rate magnitude and distribution conform to the design values. The objective of this project is to study the bypass flow both experimentally and computationally. Researchers will develop experimental data using state-of-the-art particle image velocimetry in a small test facility. The team will attempt to obtain full field temperature distribution using racks of thermocouples. The experimental data are intended to benchmark computational fluid dynamics (CFD) codes by providing detailed information. These experimental data are urgently needed for validation of the CFD codes. The following are the project tasks: • Construct a small-scale bench-top experiment to resemble the bypass flow between the graphite blocks, varying parameters to address their impact on bypass flow. Wall roughness of the graphite block walls, spacing between the blocks, and temperature of the blocks are some of the parameters to be tested. • Perform CFD to evaluate pre- and post-test calculations and turbulence models, including sensitivity studies to achieve high accuracy. • Develop the state-of-the art large eddy simulation (LES) using appropriate subgrid modeling. • Develop models to be used in systems thermal hydraulics codes to account and estimate the bypass flows. These computer programs include, among others, RELAP3D, MELCOR, GAMMA, and GAS-NET. Actual core bypass flow rate may vary considerably from the design value. Although the uncertainty of the bypass flow rate is not known, some sources have stated that the bypass flow rates in the Fort St. Vrain reactor were between 8 and 25 percent of the total reactor mass flow rate. If bypass flow rates are on the

  16. [Pre- and postoperative corneal topography after combined single suture and running suture in ECCE. An analysis using the video keratoscope].

    PubMed

    Schickel, B; Holschbach, A; Strobel, J

    1993-12-01

    In a prospective study with 45 patients undergoing extracapsular cataract extraction (ECCE) with implantation of posterior chamber lens, curvature measurements of the cornea by means of computerized videokeratoscope were taken postoperatively. Analysis of the corneal shape on color-coded topographic maps of astigmatism showed an hourglass-shaped formation in all patients with a main axis in the sense of general astigmatism. Within a 3-mm zone (optical zone) the steepest meridian in all eyes was 96.1 +/- 13.3 degrees with an astigmatism of +4.4 +/- 2.1 D (1st postoperative day). Postoperatively we found that 35.6% of the patients examined had irregular astigmatism that could not be corroborated by the readings from the Javal ophthalmometer. An irregular astigmatism, corneal topographic analysis reveals regions peripheral to the center with a peak corneal refractive power of +43.8 +/- 1.4 D. In contrast to the conventional methods (for example, Javal ophthalmometer, autokeratometer), computerized videokeratoscope analysis provides additional and useful information on the corneal topography after intraocular operations.

  17. Educational Programs for By-Passed Populations.

    ERIC Educational Resources Information Center

    Morgan, Don A., Ed.

    The objective of the symposium from which this document resulted was to give visibility to some worthwhile programs for mobile and "by-passed" populations, in order to allow those in attendance at the symposium and those exposed to the published proceedings to capitalize on what has been learned through these programs. The conference report points…

  18. Continuous mode interaction and the bypass route to transition

    NASA Astrophysics Data System (ADS)

    Zaki, Tamer A.

    Boundary layer transition to turbulence, without the intervention of Tollmien-Schlichting instability waves, is designated 'bypass transition'. That terminology is all-encompassing; many bypass mechanisms are possible, for example transition due to surface roughness, acoustic perturbations, or free-stream vortical disturbances. It is the last that has become synonymous with the term bypass, and is the focus of this work. The perspective that bypass is the complement to orderly transition suggests that it be studied by starting from the complement to Tollmien-Schlichting waves. The latter are the discrete modes of the Orr-Sommerfeld operator; their complement is the continuous spectrum. An examination of mode shapes sheds light on boundary layer receptivity to vortical disturbances: Low-frequency modes penetrate the boundary layer, while high frequencies are expelled---a result referred to as shear sheltering. Low frequency penetration can be characterized by a coupling coefficient. Large coupling, Orr-Sommerfeld modes resonantly force the Squire operator. The response is a superposition of Squire modes, and their incomplete cancellation gives rise to Klebanoff modes, which resemble jets in the perturbation field. While this is a route into the boundary layer, transition subsequently involves an inter-action between low and high frequency modes. The lifted, low-frequency perturbation jets are susceptible to a Kelvin-Helmholtz type instability that marks the onset of breakdown and turbulent spots. Continuous mode transition is illustrated by numerical simulations of pairwise mode interaction. Only two modes, one low-frequency penetrating and one high-frequency sheltered eigenfunction, can induce transition in a manner that emulates the influence of a spectrum of vortical disturbances. This new framework provides a link between the continuous eigenmodes from linear theory, and the non-linear interaction that causes transition to turbulence. The role of pressure

  19. Functional Dissection of the Blocking and Bypass Activities of the Fab-8 Boundary in the Drosophila Bithorax Complex.

    PubMed

    Kyrchanova, Olga; Mogila, Vladic; Wolle, Daniel; Deshpande, Girish; Parshikov, Alexander; Cléard, Fabienne; Karch, Francois; Schedl, Paul; Georgiev, Pavel

    2016-07-01

    Functionally autonomous regulatory domains direct the parasegment-specific expression of the Drosophila Bithorax complex (BX-C) homeotic genes. Autonomy is conferred by boundary/insulator elements that separate each regulatory domain from its neighbors. For six of the nine parasegment (PS) regulatory domains in the complex, at least one boundary is located between the domain and its target homeotic gene. Consequently, BX-C boundaries must not only block adventitious interactions between neighboring regulatory domains, but also be permissive (bypass) for regulatory interactions between the domains and their gene targets. To elucidate how the BX-C boundaries combine these two contradictory activities, we have used a boundary replacement strategy. We show that a 337 bp fragment spanning the Fab-8 boundary nuclease hypersensitive site and lacking all but 83 bp of the 625 bp Fab-8 PTS (promoter targeting sequence) fully rescues a Fab-7 deletion. It blocks crosstalk between the iab-6 and iab-7 regulatory domains, and has bypass activity that enables the two downstream domains, iab-5 and iab-6, to regulate Abdominal-B (Abd-B) transcription in spite of two intervening boundary elements. Fab-8 has two dCTCF sites and we show that they are necessary both for blocking and bypass activity. However, CTCF sites on their own are not sufficient for bypass. While multimerized dCTCF (or Su(Hw)) sites have blocking activity, they fail to support bypass. Moreover, this bypass defect is not rescued by the full length PTS. Finally, we show that orientation is critical for the proper functioning the Fab-8 replacement. Though the inverted Fab-8 boundary still blocks crosstalk, it disrupts the topology of the Abd-B regulatory domains and does not support bypass. Importantly, altering the orientation of the Fab-8 dCTCF sites is not sufficient to disrupt bypass, indicating that orientation dependence is conferred by other factors.

  20. Prevalence of candida albicans in dental plaque and caries lesion of early childhood caries (ECC) according to sampling site

    PubMed Central

    Ghasempour, Maryam; Sefidgar, Seyed Ali Asghar; Eyzadian, Haniyeh; Gharakhani, Samaneh

    2011-01-01

    Background: Candida albicans may have cariogenic potential but its role in caries etiology has not been established. The aim of this study was to determine candida albicans in supragingival dental plaque and infected dentine of cervical and proximal in early childhood caries (ECC). Methods: This cross-sectional study was carried out on 6o children aged 2-5 years, which were divided into 3 groups: children with at least one cervical caries; children with at least one proximal caries and caries-free. The infected dentine was collected from cervical and proximal caries lesions and plaque samples were collected from the three groups in order to compare the frequency of candida albicans in the collected sites. All samples were cultured in Sabouraud and CHROMagar medium and the cases that were positive for candida albicans were cultured in germ tube. Data were collected and analyzed. Results: The mean age of the children was 3.9 years. From 100 samples, candida albicans samples were isolated in 55%, mold fungi were found in 29% cases and there was no fungal growth in 16% of the samples. In plaque samples, candida albicans were found in 15% of caries-free samples, 20% of the proximal and 80% of the cervical caries. In samples extracted from the caries, candida albicans were found in 60% of the proximal and 100% of the cervical caries. Mothers with university educational level had children with more cervical decays, caries free and proximal caries, respectively. Conclusion: The results showed that prevalence of Candida albicans in dental plaque and caries lesions of children with early childhood caries were relatively high and the prevalence was higher in cervical caries group. PMID:24551436

  1. Bypass surgery in limb salvage: inflow procedures.

    PubMed

    Bismuth, Jean; Duran, Cassidy

    2013-04-01

    Proper management of lower-extremity inflow vessel disease is critical to the success of distal interventions. Aortobifemoral bypass is the most effective means of treating aortoiliac disease, but this invasive procedure is not always ideal for a patient population that often has diffuse vascular disease and multiple comorbidities. Technologic advances and increasing experience have fundamentally altered the management algorithm for lower-extremity vascular lesions, and endovascular options have become the first-line therapy for Trans-Atlantic Inter-Society Guidelines (TASC) class A and B lesions. In fact, an endovascular first approach is being endorsed even for highly complex TASC C and even TASC D lesions. Other alternatives include minimally invasive (laparoscopic or robotic) options or extra-anatomic bypass procedures. Inadequate outflow can compromise any inflow procedure, but inflow treatment failures are the crux of all limb salvage in patients with lower-extremity vascular disease.

  2. Coronary artery bypass surgery in elderly people

    PubMed Central

    Natarajan, Arun; Samadian, Samad; Clark, Stephen

    2007-01-01

    An increasing number of elderly individuals are now undergoing coronary artery bypass surgery. Elderly patients, compared with patients of a younger age group, present for surgery with a greater burden of risk factors and reduced functional levels. Short‐term outcomes are hence poorer in them. But symptom relief occurs in most survivors and is accompanied by excellent rates of long‐term survival and a good quality of life. Therefore, an individualised risk–benefit profile must be carefully constructed by clinicians, taking into account several different factors and not just age alone. This review summarises the current concepts of coronary artery bypass surgery from the perspective of the very old. PMID:17344568

  3. The Golden bypass landslide, Golden, Colorado

    USGS Publications Warehouse

    Highland, L.M.; Brown, W. M.

    1993-01-01

    Slope instability along a new highway bypass in Golden, Colorado, became a major concern in 1993. Rains and snowmelt accelerated movement of a landslide that had begun to develop before the bypass was opened to traffic in July of 1991. The downslope movement of earth materials increased significantly in 1993. During the first few months of the year, the landslide pushed onto the west shoulder of the road and crumpled the pavement beneath the south-bound lane. As we prepare this article (September, 1993), the slide continues to encroach onto the highway, posing a persistent problem despite repeated efforts to slow or stop its movement. As this article will show, permanent solutions to landslide problems of this kind are difficult to obtain. 

  4. Altered coronary microvascular serotonin receptor expression after coronary artery bypass grafting utilizing cardiopulmonary bypass

    PubMed Central

    Robich, Michael P.; Araujo, Eugenio G.; Feng, Jun; Osipov, Robert M.; Clements, Richard T.; Bianchi, Cesario; Sellke, Frank W.

    2009-01-01

    Objectives Evaluate the role of serotonin receptors 1B and 2A, thromboxane synthase and receptor and phospholipases A2 and C in response to cardiopulmonary bypass in patients. Methods Atrial tissue was harvested from patients before and after cardiopulmonary bypass with cardioplegia (n=13). Coronary microvessels were assessed for vasoactive response to serotonin with and without inhibitors of 5-HT1B and 5-HT2A receceptors, phospholipase A2 and C. Expression of 5-HT1B and 5-HT2A mRNA was determined by RT-PCR. Expression of 5-HT1B, 5-HT2A, Thromboxane A2 receptor and synthase protein was determined by immunoblotting and immunohistochemistry. Results Exposure of microvessels to serotonin elicited a 7.3 ± 2% relaxation response pre-bypass, changing to a strong contraction response of -19.2 ± 2% after bypass (p<0.001). Addition of either a specific 5-HT1B antagonist or inhibitor of PLA2 resulted in a significant decrease in the contractile response to -8.6 ±1% (p<0.001) and 2.8 ± 3% (p= 0.001), respectively. 5-HT1B receptor mRNA expression increased 1.82 ± 0.34 fold after bypass (p=0.044), while 5-HT2A mRNA expression did not change. 5-HT1B receptor, but not 5-HT2A, protein expression increased after bypass by 1.35 ± 0.7 fold (p=0.0413). Neither thromboxane synthase nor thromboxane receptor expression changed after bypass. Immunohistochemistry demonstrated 5-HT1B receptor increased mainly in the arterial smooth muscle. There was no appreciable difference in arterial expression of either thromboxane synthase or receptor. Conclusion These data indicate that 5-HT-induced vascular dysfunction after cardiopulmonary bypass with cardioplegia may be mediated by increased expression of 5-HT1B receptor and subsequent PLA2 activation in myocardial coronary smooth muscle. Mini Abstract The expression of 5-HT1B receptor protein and mRNA were increased in the atrial myocardium after cardioplegia and cardiopulmonary bypass (CP-CPB). Serotonin elicited a strong contraction

  5. Effects of Cardiopulmonary Bypass on Hemostasis

    DTIC Science & Technology

    2007-11-02

    agents as possible alternatives to heparin anticoagulation during CPB. Some of the agents mat have been found to be promising in these studies...67-76. 22Q. Terrell MR, Walenga JM, Koza MJ, et al. Efficacy of aprotinin with various anticoagulant agents in cardiopulmonary bypass. AnnThorac Surg...procedures, systemic anticoagulation with 3mg/kg of heparin prior to the institution of CPB elicits a modest but significant prolongation of the

  6. Control of Bypass Transition for Textile Surface

    NASA Astrophysics Data System (ADS)

    Kikuchi, Satoshi; Shimoji, Masayuki; Watanabe, Hideo; Kohama, Yasuaki

    The present research deals with turbulent friction reduction for bypass transition on a flat plate with a textile surface. Unique boundary layers such as those found in swimsuits, sail wings, or skiwear, where certain boundary layer trip structure-like folded edges or masts of a sailboat exist, contain limited turbulence level in the boundary layer even under laminar conditions. A turbulent transition delay in such boundary layers is observed for textile surfaces.

  7. Histoplasma infection of aortofemoral bypass graft.

    PubMed

    Patel, Nishit; Bronze, Michael S

    2014-05-01

    Histoplasma infection of vascular grafts is extremely rare. To our knowledge, there are only 4 cases reported with Histoplasma capsulatum infection of the aortic graft. All had previous disseminated histoplasmosis and atherosclerotic peripheral vascular disease. They were treated surgically with explantation of the infected graft and reimplantation of new graft in extra-anatomic uninfected site. The authors present a new case of H capsulatum infection of aortofemoral bypass graft, but unlike the other cases, this case was managed without surgical intervention.

  8. Percutaneous venovenous bypass in orthotopic liver transplantation.

    PubMed

    Washburn, W K; Lewis, W D; Jenkins, R L

    1995-11-01

    Since January 1994, we have used percutaneous placement of both the subclavian and femoral cannulae to establish access for venovenous bypass during orthotopic liver transplantation. Percutaneous subclavian and femoral cannulae were used in 36 patients of which 5 had portal decompression by placement of a cannula in inferior mesenteric vein percutaneously through the abdominal wall. Intraoperative placement of the subclavian cannula is facilitated by placing a subclavian central venous line before the abdominal incision. One patient underwent exploration for femoral vein bleeding early in our experience. Another patient sustained hypotension as a result of a kinked subclavian cannula. In 4 patients, early in this experience, we had difficulty placing the subclavian cannula and resorted to axillary vein cut-down. There were no episodes of deep venous thrombosis detected by routine postoperative duplex ultrasonography. Minimum and maximum flow rates were significantly better (P < .01), with percutaneously placed cannulae in comparison to a control group of patients who underwent transplantation in whom we used the standard venous cut-down approach with a #7 Gott shunt (2.14 and 3.17 L/min v 1.65 and 2.41 L/min, respectively). Percutaneous placement of cannulae for venovenous bypass during liver transplantation is quick, safe, and effective. We would advocate this technique as an alternative approach for patients in whom bypass is deemed necessary.

  9. Temperature inaccuracies during cardiopulmonary bypass.

    PubMed

    Salah, Mohammad; Sutton, Robin; Tsarovsky, Gary; Djuric, Michael

    2005-03-01

    Cerebral hyperthermia caused by perfusate temperature greater than 37 degrees C during the rewarming phase of CPB has been linked to postoperative neurologic deficits. The purpose of this study was to determine the accuracy of the coupled temperature measurement system and the CDI 500 arterial temperature sensor. Seventeen patients undergoing CPB were divided into four groups, each with a different temperature probe coupled to the oxygenator. The coupled temperature measurement system and CDI temperature sensors were compared with an indwelling probe placed in direct contact with the arterial perfusate. Blood, bladder, room and water temperatures, arterial line pressure, blood flow, and hemoglobin were recorded while the patients were supported with CPB. The actual blood temperature was significantly higher than the coupled temperature measurement system for two of the four groups (mean = 1.61 degrees C and 0.91 degrees C, p < 0.0001). A significant positive correlation between the actual temperature and the coupled temperature measurement system error was observed for the same two groups (r = 0.44, p < 0.0001). The actual temperature was significantly higher than the CDI temperature in all patients (mean = 1.2 degrees C, p < 0.0001). The coupling mechanism on the oxygenator generates inconsistent temperature readings. The perfusionist should consider these inconsistencies when using coupled temperature measurements and may consider the use of a direct temperature measurement system. The CDI temperature error is probably the result of inadequate flow through the sensor. On the test circuit, the flow of 170 mL/min was inadequate for circuit temperature accuracy. The accuracy of the CDI temperature drastically improved when the flow-through the sensor was increased to approximately 400 mL/min. Thus, the perfusionist must ensure adequate flow through the sensor in order for the temperature mechanism to function properly. Finally, the perfusionist can prevent cerebral

  10. A patent ductus arteriosus complicating cardiopulmonary bypass for combined coronary artery bypass grafting and aortic valve replacement only discovered by computed tomography 3D reconstruction.

    PubMed

    van Middendorp, Lars B; Maessen, Jos G; Sardari Nia, Peyman

    2014-12-01

    We describe the case of a 59-year old male patient undergoing combined coronary artery bypass grafting and aortic valve replacement. Manipulation of the heart during cardiopulmonary bypass significantly decreased venous return. Several measures were necessary to improve venous return to a level at which continuation of the procedure was safe. Based on the initial troubles with venous return, we decided to selectively cross-clamp the aorta. This resulted in a large amount of backflow of oxygenated blood from the left ventricle, necessitating additional vents in the pulmonary artery and directly in the left ventricle. The procedure was continued uneventfully, and postoperative recovery was without significant complications. Postoperative 2D computed tomography did not show any signs of a shunt, but 3D reconstruction showed a small patent ductus arteriosus.

  11. Giant and complex aneurysms treatment with preservation of flow via bypass technique.

    PubMed

    Thines, L; Proust, F; Marinho, P; Durand, A; van der Zwan, A; Regli, L; Lejeune, J-P

    2016-02-01

    Due to their anatomical characteristics and the complexity of the procedures required to obtain their complete occlusion, the treatment of giant intracranial aneurysms is a real challenge. Direct reconstructive strategies, whether by interventional neuroradiology (coils, stents) or microsurgical (clipping) means, are not always applicable and, in patients that would not tolerate parent or collateral artery sacrifice, the adjunction of a revascularization procedure using a bypass technique might be necessary. Cerebral arterial bypasses can be classified according to their function (3 types: flow replacement, flow reversal or protective), the branching mode of the graft used (3 types: pedicled, interpositional or in situ), the sites of anastomosis (2 types: extracranial-intracranial or intracranial-intracranial) and the class of flow they are supposed to provide (3 types: low-, intermediate- or high-flow). In this article, the authors review the different aspects in the management of patients with a giant intracranial aneurysm using a bypass: preoperative work-up, types of bypass and indications, surgical techniques and results.

  12. Ply-level failure analysis of a graphite/epoxy laminate under bearing-bypass loading

    NASA Technical Reports Server (NTRS)

    Naik, R. A.; Crews, J. H., Jr.

    1988-01-01

    A combined experimental and analytical study was conducted to investigate and predict the failure modes of a graphite/epoxy laminate subjected to combined bearing and bypass loading. Tests were conducted in a test machine that allowed the bearing-bypass load ratio to be controlled while a single-fastener coupon was loaded to failure in either tension or compression. Onset and ultimate failure modes and strengths were determined for each test case. The damage-onset modes were studied in detail by sectioning and micrographing the damaged specimens. A two-dimensional, finite-element analysis was conducted to determine lamina strains around the bolt hole. Damage onset consisted of matrix cracks, delamination, and fiber failures. Stiffness loss appeared to be caused by fiber failures rather than by matrix cracking and delamination. An unusual offset-compression mode was observed for compressive bearing-bypass laoding in which the specimen failed across its width along a line offset from the hole. The computed lamina strains in the fiber direction were used in a combined analytical and experimental approach to predict bearing-bypass diagrams for damage onset from a few simple tests.

  13. Ply-level failure analysis of a graphite/epoxy laminate under bearing-bypass loading

    NASA Technical Reports Server (NTRS)

    Naik, R. A.; Crews, J. H., Jr.

    1990-01-01

    A combined experimental and analytical study was conducted to investigate and predict the failure modes of a graphite/epoxy laminate subjected to combined bearing and bypass loading. Tests were conducted in a test machine that allowed the bearing-bypass load ratio to be controlled while a single-fastener coupon was loaded to failure in either tension or compression. Onset and ultimate failure modes and strengths were determined for each test case. The damage-onset modes were studied in detail by sectioning and micrographing the damaged specimens. A two-dimensional, finite-element analysis was conducted to determine lamina strains around the bolt hole. Damage onset consisted of matrix cracks, delamination, and fiber failures. Stiffness loss appeared to be caused by fiber failures rather than by matrix cracking and delamination. An unusual offset-compression mode was observed for compressive bearing-bypass loading in which the specimen failed across its width along a line offset from the hole. The computed lamina strains in the fiber direction were used in a combined analytical and experimental approach to predict bearing-bypass diagrams for damage onset from a few simple tests.

  14. Hypopotassemia following open heart surgery by cardio-pulmonary bypass.

    PubMed

    Abe, T; Nagata, Y; Yoshioka, K; Iyomasa, Y

    1977-01-01

    1. In this study where potassium concentration of perfusate of heart-lung machine was made high and no potassium was given until two hours after by-pass, the fall of plasma potassium level due to heart-lung bypass occurred in two stages, namely one hour of complete bypass and two hours after the end of bypass. 2. Regarding to the decrease of these plasma potassium level, increase of potassium excretion into urine and the movement of potassium from extracellular fluid into cells are presumed to be causes. Their genesis was discussed. 3. To prevent hypopotassemia following bypass, it is recommended to add KCl in the perfusate of heart-lung machine and to give intravenous drip of KCl immediately after bypass.

  15. Considerations for Probabilistic Analyses to Assess Potential Changes to Large-Break LOCA Definition for ECCS Requirements

    SciTech Connect

    Wilkowski, G.; Rudland, D.; Wolterman, R.; Krishnaswamy, P.; Scott, P.; Rahman, S.; Fairbanks, C.

    2002-07-01

    The U.S.NRC has undertaken a study to explore changes to the body of Part 50 of the U.S. Federal Code of Regulations, to incorporate risk-informed attributes. One of the regulations selected for this study is 10 CFR 50.46, {sup A}cceptance Criteria for Emergency Core Cooling Systems for Light-Water Nuclear Power Reactors{sup .} These changes will potentially enhance safety and reduce unnecessary burden on utilities. Specific attention is being paid to redefining the maximum pipe break size for LB-LOCA by determining the spectrum of pipe diameter (or equivalent opening area) versus failure probabilities. In this regard, it is necessary to ensure that all contributors to probabilistic failures are accounted for when redefining ECCS requirements. This paper describes initial efforts being conducted for the U.S.NRC on redefining the LB-LOCA requirements. Consideration of the major contributors to probabilistic failure, and deterministic aspects for modeling them, are being addressed. At this time three major contributors to probabilistic failures are being considered. These include: (1) Analyses of the failure probability from cracking mechanisms that could involve rupture or large opening areas from either through-wall or surface flaws, whether the pipe system was approved for leak-before-break (LBB) or not. (2) Future degradation mechanisms, such as recent occurrence of PWSCC in PWR piping need to be included. This degradation mechanism was not recognized as being an issue when LBB was approved for many plants or when the initial risk-informed inspection plans were developed. (3) Other indirect causes of loss of pressure-boundary integrity than from cracks in the pipe system also should be included. The failure probability from probabilistic fracture mechanics will not account for these other indirect causes that could result in a large opening in the pressure boundary: i.e., failure of bolts on a steam generator manway, flanges, and valves; outside force damage from

  16. Heat exchanger bypass system for an absorption refrigeration system

    DOEpatents

    Reimann, Robert C.

    1984-01-01

    A heat exchanger bypass system for an absorption refrigeration system is disclosed. The bypass system operates to pass strong solution from the generator around the heat exchanger to the absorber of the absorption refrigeration system when strong solution builds up in the generator above a selected level indicative of solidification of strong solution in the heat exchanger or other such blockage. The bypass system includes a bypass line with a gooseneck located in the generator for controlling flow of strong solution into the bypass line and for preventing refrigerant vapor in the generator from entering the bypass line during normal operation of the refrigeration system. Also, the bypass line includes a trap section filled with liquid for providing a barrier to maintain the normal pressure difference between the generator and the absorber even when the gooseneck of the bypass line is exposed to refrigerant vapor in the generator. Strong solution, which may accumulate in the trap section of the bypass line, is diluted, to prevent solidification, by supplying weak solution to the trap section from a purge system for the absorption refrigeration system.

  17. Embolic Activity During In Vivo Cardiopulmonary Bypass

    PubMed Central

    DeFoe, Gordon R.; Dame, Norman A.; Farrell, Mark S.; Ross, Cathy S.; Langner, Craig W.; Likosky, Donald S.

    2014-01-01

    Abstract: Neurologic injury after cardiac surgery is principally associated with emboli. Although much work has focused on surgical sources of emboli, less attention has been focused on emboli associated with the heart–lung machine. We tested whether emboli are associated with discrete processes during cardiopulmonary bypass (CPB). One hundred patients undergoing cardiothoracic surgery were enrolled between April 2008 and May 2011 at a single medical center. During each surgical procedure, emboli were counted in three CPB locations: the venous side (Channel 1), before the arterial line filter (Channel 2), and after the arterial line filter (Channel 3). We used prespecified event markers to identify perfusionist interventions. Identical circuits were used on all patients. Of the 100 patients enrolled, 62 underwent isolated coronary artery bypass grafting (CABG), 17 underwent isolated valve operations, and 21 underwent CABG plus valve. Median counts across Channels 1, 2, and 3 were 69,853, 3,017, and 1,251, respectively. The greatest contributor to emboli in Channels 1, 2, and 3, respectively, were achieving the calculated CPB flow, opening of the electronic arterial line clamp, and introducing a hemofilter. The circuit technology was efficient in reducing total emboli counts from Channels 1–2 irrespective of the size of the emboli. Nearly 71% of all emboli 30–100 mm in size were removed from the circuit between Channels 2 and 3. No significant association was found between emboli counts and S100B release. Emboli occur frequently during CPB and are predominantly associated with the initiation of bypass, operation of the electronic arterial line clamp, and the initiation of a hemofilter. Continued work to reduce the occurrence of emboli is warranted. PMID:25208432

  18. Preoperative graft assessment in aortocoronary bypass surgery

    PubMed Central

    Tinica, Grigore; Vartic, Cristina Luca; Mocanu, Veronica; Baran, Dana; Butcovan, Doina

    2016-01-01

    Coronary artery bypass graft (CABG) is a surgical procedure able to improve the blood supply to the myocardium. In the present study, the distal segments of grafts taken from the internal thoracic artery (ITA), radial artery (RA) and saphenous vein (SV) for use in aortocoronary bypass surgery were examined. The morphologies of the grafts were investigated in order to draw conclusions concerning their patency and viability. In addition, clinical and laboratory risk factors considered to be significant predictors of lesion severity in graft vessels used in CABGs were investigated. In total, 54 distal graft segments of ITAs, RAs and SVs from 20 men and 6 women aged between 42 and 78 years, were evaluated. Histological analyses were used to visualize graft lesions. Morphometrically, the intimal thickness index (ITI) and luminal narrowing were assessed as an indication of graft patency. The histological changes observed in the graft vessel walls included the presence of distinct atheromatous plaques (fatty streaks in 2 cases) or thickening of the intima (20 cases) and media (17 cases). Morphometric analysis showed that the mean ITI of the vessel conduits was 0.37 in the SVs, 0.95 in the RAs, and 1.66 in the ITAs. No patient had >50% conduit stenosis. By assessing the association between risk factors and graft lesions, it was found that all the patients showed risk factors for atherosclerosis, such as age (61.54%), arterial hypertension (65.38%), hyperlipidemia (65.38%), smoking (34.61%), diabetes mellitus (38.46%) and obesity (15.38%). The presence of pre-existing lesions in bypass grafts may contribute to a reduction in their viability, particularly in the case of venous grafts. Further long-term follow-ups are mandatory to evaluate the consequences of such lesions upon the patency of the grafts. PMID:27446279

  19. [Repeat bypass surgery for intracranial hemorrhage 30 years after indirect bypass for moyamoya disease].

    PubMed

    Hori, Satoshi; Kashiwazaki, Daina; Akioka, Naoki; Hamada, Hideo; Kuwayama, Naoya; Kuroda, Satoshi

    2014-04-01

    A 39-year-old man had been diagnosed with moyamoya disease and underwent a bilateral encephalo-duro-arterio-synangiosis(EDAS)intervention at the age of 9 years. During the 30 years after his bilateral EDAS, he experienced no cerebrovascular events. However, at age 39, he suddenly presented with mild consciousness disturbance and vomiting and was transferred to a local hospital. Brain CT showed an intracerebral hemorrhage associated with ventricular hematoma. He was referred to our hospital for further investigation and treatment. Cerebral angiography showed faint collaterals through the site of the bilateral EDAS and development of basal moyamoya vessels. SPECT showed decreased cerebral blood flow(CBF)and cerebrovascular reactivity(CVR)in the right frontal lobe. We diagnosed him with delayed cerebral hemorrhage due to delayed rupturing of fragile moyamoya vessels after indirect bypass. The patient underwent a repeat bypass surgery(STA-MCA anastomosis and encephalo-duro-myo-arterio-pericranial synangiosis;EDMAPS)on the right side. He showed improvement in cerebral hemodynamics after surgery, and has since remained free from cerebrovascular events. Hemorrhagic events occurring a very long time after indirect bypass surgery in pediatric-onset moyamoya disease are rare. In such cases, a lifelong follow-up strategy may be necessary. Repeat bypass surgery may be a powerful tool to prevent such hemorrhagic events.

  20. Conduits for Coronary Bypass: Vein Grafts

    PubMed Central

    Farkas, Emily A

    2012-01-01

    The saphenous vein has been the principal conduit for coronary bypass grafting from the beginning, circa 1970. This report briefly traces this history and concomitantly presents one surgeons experience and personal views on use of the vein graft. As such it is not exhaustive but meant to be practical with a modest number of references. The focus is that of providing guidance and perspective which may be at variance with that of others and recognizing that there may be many ways to accomplish the task at hand. Hopefully the surgeon in training/early career may find this instructive on the journey to surgical maturity. PMID:23130300

  1. Bypass diode for a solar cell

    DOEpatents

    Rim, Seung Bum; Kim, Taeseok; Smith, David D; Cousins, Peter J

    2013-11-12

    Methods of fabricating bypass diodes for solar cells are described. In once embodiment, a method includes forming a first conductive region of a first conductivity type above a substrate of a solar cell. A second conductive region of a second conductivity type is formed on the first conductive region. In another embodiment, a method includes forming a first conductive region of a first conductivity type above a substrate of a solar cell. A second conductive region of a second conductivity type is formed within, and surrounded by, an uppermost portion of the first conductive region but is not formed in a lowermost portion of the first conductive region.

  2. Flow characteristics in narrowed coronary bypass graft

    NASA Astrophysics Data System (ADS)

    Bernad, S. I.; Bosioc, A.; Bernad, E. S.; Petre, I.; Totorean, A. F.

    2016-06-01

    Tortuous saphenous vein graft (SVG) hemodynamics was investigated using computational fluid dynamics (CFD) techniques. Computed tomography (CT) technology is used for non-invasive bypass graft assessment 7 days after surgery. CT investigation shown two regions with severe shape remodelling first is an elbow type contortion and second is a severe curvature with tortuous area reduction. In conclusion, the helical flow induced by vessel torsion may stabilize the blood flow in the distal part of the SVG, reducing the flow disturbance and suppressing the flow separation, but in the distal end of the graft, promote the inflammatory processes in the vessels.

  3. Secondary structure of bacteriophage T4 gene 60 mRNA: implications for translational bypassing.

    PubMed

    Todd, Gabrielle C; Walter, Nils G

    2013-05-01

    Translational bypassing is a unique phenomenon of bacteriophage T4 gene 60 mRNA wherein the bacterial ribosome produces a single polypeptide chain from a discontinuous open reading frame (ORF). Upon reaching the 50-nucleotide untranslated region, or coding gap, the ribosome either dissociates or bypasses the interruption to continue translating the remainder of the ORF, generating a subunit of a type II DNA topoisomerase. Mutational and computational analyses have suggested that a compact structure, including a stable hairpin, forms in the coding gap to induce bypassing, yet direct evidence is lacking. Here we have probed the secondary structure of gene 60 mRNA with both Tb³⁺ ions and the selective 2'-hydroxyl acylation analyzed by primer extension (SHAPE) reagent 1M7 under conditions where bypassing is observed. The resulting experimentally informed secondary structure models strongly support the presence of the predicted coding gap hairpin and highlight the benefits of using Tb³⁺ as a second, complementary probing reagent. Contrary to several previously proposed models, however, the rest of the coding gap is highly reactive with both probing reagents, suggesting that it forms only a short stem-loop. Mutational analyses coupled with functional assays reveal that two possible base-pairings of the coding gap with other regions of the mRNA are not required for bypassing. Such structural autonomy of the coding gap is consistent with its recently discovered role as a mobile genetic element inserted into gene 60 mRNA to inhibit cleavage by homing endonuclease MobA.

  4. Conduit options in coronary artery bypass surgery.

    PubMed

    Canver, C C

    1995-10-01

    The choice of graft conduit is crucial to the success of coronary artery bypass grafting (CABG) because the patency of a coronary conduit is closely associated with an uneventful postoperative course and a better long-term patient survival. The standard conduits used for CABG are the greater saphenous vein (GSV) and the internal thoracic artery (ITA). An excellent substitute conduit for coronary bypass operations that can be taken "off the shelf" is certainly the dream of every practicing cardiac surgeon. However, virtually every synthetic and biologic alternative to arterial conduits or autologous fresh saphenous vein has proved disappointing. Fortunately, patients with absolutely no autologous conduit alternatives are uncommon. Circumstances exist, however, that often necessitate the use of alternative conduits such as young hyperlipemic patients, absent or unsuitable autologous ITAs and GSV as a result of previous myocardial revascularization, peripheral arterial reconstruction, and varicose vein ligation procedures. This review provides an update on the clinical work done with all coronary conduits available for myocardial surgical revascularization.

  5. Jet noise from ultrahigh bypass turbofan engines

    NASA Astrophysics Data System (ADS)

    Posey, Joe W.; Norum, Thomas D.; Brown, Martha C.; Bhat, Thonse R. S.

    2002-05-01

    Modern commercial jet transport aircraft are powered by turbofan engines. Thrust from a turbofan engine is derived in part from the exhaust of a ducted fan, which may or may not be mixed with the core exhaust before exiting the nacelle. The historical trend has been toward ever higher bypass ratios (BPRs). The BPR is the ratio of air mass passing through the fan to that going through the core. The higher BPR engines can be more efficient and quieter. In general, a higher BPR results in lower average exhaust velocities and less jet noise. In order to address a scarcity of noise data for BPRs greater than 6, an extensive database collection effort was undertaken using the Jet Engine Simulator in NASA Langley's Low Speed Aeroacoustic Wind Tunnel. Forward flight simulations of Mach 0.1, 0.2, and 0.28 were used with BPRs of 5, 8, 11, and 14. Data was taken over the entire operating line of the simulated engines along with parametric deviations to provide a complete set of sensitivity measurements. The results will be used to develop an empirical jet noise prediction capability for ultrahigh bypass engines.

  6. Previous gastric bypass surgery complicating total thyroidectomy.

    PubMed

    Alfonso, Bianca; Jacobson, Adam S; Alon, Eran E; Via, Michael A

    2015-03-01

    Hypocalcemia is a well-known complication of total thyroidectomy. Patients who have previously undergone gastric bypass surgery may be at increased risk of hypocalcemia due to gastrointestinal malabsorption, secondary hyperparathyroidism, and an underlying vitamin D deficiency. We present the case of a 58-year-old woman who underwent a total thyroidectomy for the follicular variant of papillary thyroid carcinoma. Her history included Roux-en-Y gastric bypass surgery. Following the thyroid surgery, she developed postoperative hypocalcemia that required large doses of oral calcium carbonate (7.5 g/day), oral calcitriol (up to 4 μg/day), intravenous calcium gluconate (2.0 g/day), calcium citrate (2.0 g/day), and ergocalciferol (50,000 IU/day). Her serum calcium levels remained normal on this regimen after hospital discharge despite persistent hypoparathyroidism. Bariatric surgery patients who undergo thyroid surgery require aggressive supplementation to maintain normal serum calcium levels. Preoperative supplementation with calcium and vitamin D is strongly recommended.

  7. At 1050 Gallery, Block 65, view of coaster gate bypass ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    At 1050 Gallery, Block 65, view of coaster gate bypass valve (for turbine-generator unit G-10, this bypass-valve unit manufactured by Western Koppers Co., Fort Wayne, Ind., 1938), looking southeast. - Columbia Basin Project, Grand Coulee Dam & Franklin D. Roosevelt Lake, Across Columbia River, Southeast of Town of Grand Coulee, Grand Coulee, Grant County, WA

  8. Bearing-Bypass Loading On Bolted Composite Joints

    NASA Technical Reports Server (NTRS)

    Crews, John H.; Naik, Rajiv-Vikas A.

    1989-01-01

    Unexpected interaction between effects of bypass and bearing loads reported. Combined experimental and analytical study described in NASA technical memorandum conducted to investigate effects of simultaneous bearing and bypass loading on graphite/epoxy laminate. Results important in emerging technology of composites for use in wide range of applications. Includes applications in aircraft, boats, and automobiles, in which bolted connections to composites increasingly important.

  9. 20 CFR 631.38 - State by-pass authority.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false State by-pass authority. 631.38 Section 631.38 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR PROGRAMS UNDER TITLE III OF THE JOB TRAINING PARTNERSHIP ACT State Administration § 631.38 State by-pass authority....

  10. The in situ saphenous vein bypass graft: radiologic aspects.

    PubMed

    Schwarz, W; Nozick, J; Richmand, D; Rodgers, B; Simpson, A; Argila, C; Honickman, S

    1986-03-01

    The use of the in situ saphenous vein for bypassing arterial occlusions in the lower extremities appears to have a higher patency rate than other bypass procedures but presents unique technical problems, such as lysing valves and occluding venous tributaries. Forty-four patients undergoing in situ bypasses had preoperative arteriograms. Special attention was paid to the small runoff vessels around the ankle, which are not suitable for reversed bypass procedures but may be adequate for in situ bypasses. Eight patients also had preoperative saphenous venograms, which revealed surgically important abnormalities in six cases. Postoperative arteriograms obtained within 2 weeks in 10 patients and within 2-12 months in 15 patients revealed persistent arteriovenous fistulas in four patients, stenoses in nine, occlusions in five, and progressive disease in the nonbypassed arteries in five patients. Early recognition of these problems led to 11 surgical repairs; nine repairs used the interventional radiologic procedures of balloon angioplasty, transcatheter embolization, and catheter thrombolysis. In this group of 44 patients, five patients died with patent bypasses and three patients required amputation despite functioning bypasses. Only four amputations were attributed to bypass failure. This low figure may be due to the close cooperation of the vascular surgeons and the vascular radiologists in dealing with these complicated cases.

  11. 21 CFR 870.4420 - Cardiopulmonary bypass cardiotomy return sucker.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Cardiopulmonary bypass cardiotomy return sucker. 870.4420 Section 870.4420 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... from the chest or heart during cardiopulmonary bypass surgery. (b) Classification. Class...

  12. 21 CFR 870.4420 - Cardiopulmonary bypass cardiotomy return sucker.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Cardiopulmonary bypass cardiotomy return sucker. 870.4420 Section 870.4420 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... from the chest or heart during cardiopulmonary bypass surgery. (b) Classification. Class...

  13. 21 CFR 870.4420 - Cardiopulmonary bypass cardiotomy return sucker.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Cardiopulmonary bypass cardiotomy return sucker. 870.4420 Section 870.4420 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... from the chest or heart during cardiopulmonary bypass surgery. (b) Classification. Class...

  14. 21 CFR 870.4420 - Cardiopulmonary bypass cardiotomy return sucker.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass cardiotomy return sucker. 870.4420 Section 870.4420 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... from the chest or heart during cardiopulmonary bypass surgery. (b) Classification. Class...

  15. Reverse bias protected solar array with integrated bypass battery

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A (Inventor)

    2012-01-01

    A method for protecting the photovoltaic cells in a photovoltaic (PV) array from reverse bias damage by utilizing a rechargeable battery for bypassing current from a shaded photovoltaic cell or group of cells, avoiding the need for a bypass diode. Further, the method mitigates the voltage degradation of a PV array caused by shaded cells.

  16. 46 CFR 154.550 - Excess flow valve: Bypass.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Excess flow valve: Bypass. 154.550 Section 154.550 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY... and Process Piping Systems § 154.550 Excess flow valve: Bypass. If the excess flow valve allowed...

  17. Combined use of phenoxybenzamine and dopamine for low cardiac output syndrome in children at withdrawal from cardiopulmonary bypass.

    PubMed

    Kawamura, M; Minamikawa, O; Yokochi, H; Maki, S; Yasuda, T; Mizukawa, Y

    1980-04-01

    The combined use of phenoxybenzamine and dopamine was applied in infants and children when it was difficult to come off cardiopulmonary bypass for low cardiac output. The rationale of this method is to prevent the alpha-adrenergic action of dopamine by phenoxybenzamine and to encourage the beta-adrenergic and direct specific action of dopamine. Dopamine was used in dosage of 10 to 30 micrograms/kg per min after the additional administration of a half of the initial dosage of phenoxybenzamine; this was infused by drip always in a dosage of 0.5 to 1.0 mg/kg during the first half of cardiopulmonary bypass. It was possible to come off cardiopulmonary bypass with a stable haemodynamic state (mean arterial pressure more than 60 mmHg and total peripheral vascular resistance less than 2000 bynes s cm-5) and a good urinary output.

  18. Combined use of phenoxybenzamine and dopamine for low cardiac output syndrome in children at withdrawal from cardiopulmonary bypass.

    PubMed Central

    Kawamura, M; Minamikawa, O; Yokochi, H; Maki, S; Yasuda, T; Mizukawa, Y

    1980-01-01

    The combined use of phenoxybenzamine and dopamine was applied in infants and children when it was difficult to come off cardiopulmonary bypass for low cardiac output. The rationale of this method is to prevent the alpha-adrenergic action of dopamine by phenoxybenzamine and to encourage the beta-adrenergic and direct specific action of dopamine. Dopamine was used in dosage of 10 to 30 micrograms/kg per min after the additional administration of a half of the initial dosage of phenoxybenzamine; this was infused by drip always in a dosage of 0.5 to 1.0 mg/kg during the first half of cardiopulmonary bypass. It was possible to come off cardiopulmonary bypass with a stable haemodynamic state (mean arterial pressure more than 60 mmHg and total peripheral vascular resistance less than 2000 bynes s cm-5) and a good urinary output. PMID:7397040

  19. Predicting Functional Status Following Amputation After Lower Extremity Bypass

    PubMed Central

    Suckow, Bjoern D.; Goodney, Philip P.; Cambria, Robert A.; Bertges, Daniel J.; Eldrup-Jorgensen, Jens; Indes, Jeffrey E.; Schanzer, Andres; Stone, David H.; Kraiss, Larry W.; Cronenwett, Jack L.

    2012-01-01

    differ compared with no amputation (BK amputation 87%, p = 0.14, AK amputation 89%, p = 0.27); however, this part of the analysis was limited by its sample size (n = 212). In multivariable analysis, we found that the patients most likely to remain ambulatory and live independently despite undergoing a lower extremity amputation were those living at home preoperatively (hazard ratio [HR]: 6.8, 95% confidence interval [CI]: 0.94–49, p = 0.058) and those with preoperative statin use (HR: 1.6, 95% CI: 1.2–2.1, p = 0.003), whereas the presence of several comorbidities identified patients less likely to achieve a good functional outcome: coronary disease (HR: 0.6, 95% CI: 0.5–0.9, p = 0.003), dialysis (HR: 0.5, 95% CI: 0.3–0.9, p = 0.02), and congestive heart failure (HR: 0.5, 95% CI: 0.3–0.8, p = 0.005). Conclusions A postoperative amputation at any level impacts functional outcomes following LEB surgery, and the extent of amputation is directly related to the effect on functional outcome. It is possible, based on preoperative patient characteristics, to identify patients undergoing LEB who are most or least likely to achieve good functional outcomes even if a major amputation is ultimately required. These findings may assist in patient education and surgical decision making in patients who are poor candidates for lower extremity bypass. PMID:22176876

  20. Cardiopulmonary bypass: development of John Gibbon's heart-lung machine

    PubMed Central

    Passaroni, Andréia Cristina; Silva, Marcos Augusto de Moraes; Yoshida, Winston Bonetti

    2015-01-01

    Objective To provide a brief review of the development of cardiopulmonary bypass. Methods A review of the literature on the development of extracorporeal circulation techniques, their essential role in cardiovascular surgery, and the complications associated with their use, including hemolysis and inflammation. Results The advancement of extracorporeal circulation techniques has played an essential role in minimizing the complications of cardiopulmonary bypass, which can range from various degrees of tissue injury to multiple organ dysfunction syndrome. Investigators have long researched the ways in which cardiopulmonary bypass may insult the human body. Potential solutions arose and laid the groundwork for development of safer postoperative care strategies. Conclusion Steady progress has been made in cardiopulmonary bypass in the decades since it was first conceived of by Gibbon. Despite the constant evolution of cardiopulmonary bypass techniques and attempts to minimize their complications, it is still essential that clinicians respect the particularities of each patient's physiological function. PMID:26107456

  1. 75 FR 71145 - San Joaquin River Restoration Program: Reach 4B, Eastside Bypass, and Mariposa Bypass Channel and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-22

    ... bypasses and maintain the current flood operations and conveyance capacity of the system. Additionally, the Proposed Action may result in an opportunity for improvements to the existing flood system. These..., and the Mariposa Bypass. The planning and environmental review for the Proposed Action is...

  2. Hypomethylated Pollen Bypasses the Interploidy Hybridization Barrier in Arabidopsis[C][W

    PubMed Central

    Schatlowski, Nicole; Wolff, Philip; Santos-González, Juan; Schoft, Vera; Siretskiy, Alexey; Scott, Rod; Tamaru, Hisashi; Köhler, Claudia

    2014-01-01

    Plants of different ploidy levels are separated by a strong postzygotic hybridization barrier that is established in the endosperm. Deregulated parent-of-origin specific genes cause the response to interploidy hybridizations, revealing an epigenetic basis of this phenomenon. In this study, we present evidence that paternal hypomethylation can bypass the interploidy hybridization barrier by alleviating the requirement for the Polycomb Repressive Complex 2 (PRC2) in the endosperm. PRC2 epigenetically regulates gene expression by applying methylation marks on histone H3. Bypass of the barrier is mediated by suppressed expression of imprinted genes. We show that the hypomethylated pollen genome causes de novo CHG methylation directed to FIS-PRC2 target genes, suggesting that different epigenetic modifications can functionally substitute for each other. Our work presents a method for the generation of viable triploids, providing an impressive example of the potential of epigenome manipulations for plant breeding. PMID:25217506

  3. [Nutritional follow-up after gastric bypass].

    PubMed

    Gasteyger, C; Giusti, V

    2006-03-29

    Roux-en-Y gastric bypass has become one of the main bariatric procedures. This surgical operation shows excellent results in weight evolution and quality of life and allows a decrease of mortality. However, it leads, relatively often, to nutritional deficiencies which need an effective post-operative follow-up. This follow-up includes not only medical and dietetic encounters but also regular blood analyses made every 3 months during the first post-operative year, every 6 months the second year, then each year. The most frequent deficiencies are those in vitamin B12, iron and folic acid. The secondary hyperparathyroidism characterized by an increase of PTH associated to a low vitamin D and a normal calcium, is quite frequent.

  4. Outcomes of coronary artery bypass graft surgery

    PubMed Central

    Hawkes, Anna Louise; Nowak, Madeleine; Bidstrup, Benjamin; Speare, Richard

    2006-01-01

    This review article summarizes the major studies that have investigated the outcomes of coronary artery bypass graft surgery (CABG). The article includes a review of the literature in the areas of: history of CABG; indications for CABG; and measurement of quality of life following CABG, including prolongation of life, physical functioning (ie, relief from angina and dyspnea, physical activity, as well as complications of surgery and re-hospitalization), psychological functioning, and social functioning. Overall, the literature demonstrates that the outcomes of CABG have historically been measured in terms of mortality and morbidity; however, it has now been well recognized that adjustment to CABG is a multidimensional phenomenon that is not fully explained by medical factors. Therefore, in addition to studying mortality and morbidity outcomes following CABG, many recent studies have identified that it is important to investigate various physical, psychological, and social variables that have a significant impact on post-operative adjustment to CABG. PMID:17323602

  5. Transient Diabetes Insipidus Following Cardiopulmonary Bypass.

    PubMed

    Ekim, Meral; Ekim, Hasan; Yilmaz, Yunus Keser; Bolat, Ali

    2015-04-01

    Diabetes insipidus (DI) results from inadequate output of Antidiuretic Hormone (ADH) from the pituitary gland (central DI) or the inability of the kidney tubules to respond to ADH (nephrogenic DI). ADH is an octapeptide produced in the supraoptic and paraventricular nuclei of the hypothalamus and stored in the posterior lobe of the pituitary gland. Cardiopulmonary Bypass (CPB) has been shown to cause a six-fold increased circulating ADH levels 12 hours after surgery. However, in some cases, ADH release may be transiently suppressed due to cardioplegia (cardiac standstill) or CPB leading to DI. We present the postoperative course of a 60-year-old man who developed transient DI after CPB. He was successfully treated by applying nasal desmopressin therapy. Relevant biochemical parameters should be monitored closely in patients who produce excessive urine after open heart surgery.

  6. Comparison of neutrophil:lymphocyte ratios following coronary artery bypass surgery with or without cardiopulmonary bypass

    PubMed Central

    Aldemir, Mustafa; Adalı, Fahri; Çarşanba, Görkem; Tecer, Evren; Bakı, Elif Doğan; Taş, Hanife Uzel

    2015-01-01

    Objective Coronary artery bypass graft (CABG) surgery may induce postoperative systemic changes in leukocyte counts, including leukocytosis, neutrophilia or lymphopenia. This retrospective clinical study investigated whether offpump coronary artery bypass (OPCAB) surgery working on the beating heart without extracorporeal circulation could favourably affect leukocyte counts, including neutrophil-tolymphocyte (N:L) ratio, after CABG. Methods In this study, 30 patients who underwent isolated CABG with cardiopulmonary bypass (CPB), and another 30 patients who underwent the same operation without CPB between May 2010 and May 2013, were screened from the computerised database of our hospital. Pre-operative, and first and fifth postoperative day differential counts of leukocytes with the N:L ratio of peripheral blood were obtained. Results A significant increase in total leukocyte and neutrophil counts and N:L ratio, and a decrease in lymphocyte counts were observed at all time points after surgery in both groups. N:L ratio was significantly higher in the CPB group compared with the OPCAB group on the first postoperative day (20.73 ± 13.85 vs 10.19 ± 4.55, p < 0.001), but this difference disappeared on the fifth postoperative day. Conclusion CPB results in transient but significant changes in leukocyte counts in the peripheral blood stream in terms of N:L ratio compared with the off-pump technique of CABG. PMID:25903477

  7. Miniaturized cardiopulmonary bypass: the Hammersmith technique

    PubMed Central

    2013-01-01

    Background Conventional Cardiopulmonary Bypass (cCPB) is a trigger of systemic inflammatory reactions, hemodilution, coagulopathy, and organ failure. Miniaturised Cardiopulmonary Bypass (mCPB) has the potential to reduce these deleterious effects. Here, we describe our standardised ‘Hammersmith’ mCPB technique, used in all types of adult cardiac operations including major aortic surgery. Methods The use of mCPB remains limited by the diversity of technologies which range from extremely complex, micro systems to ones very similar to cCPB. Our approach is designed around the principle of balancing the benefits of miniaturisation; reducing foreign surface area while maintaining patient safety. Results From January 2010 to March 2011, a single surgeon performed 184 consecutive operations (Euro score Logistic 8.4+/-9.9): 61 aortic valve replacements, 78 CABGs, 25 aortic valve replacement and CABG and 17 other procedures (major aortic surgery, re-do operations or double/triple valve replacements). Our clinical experience suggests that: i. Venous drainage is optimally maintained using kinetic energy. ii. Venous collapse pressure depends on the patient’s anatomy and cannula size, but most importantly on the negative pressure generated by venous drainage. iii. The patient-prime interaction is optimised with antegrade and retrograde autologous priming, which mixes the blood and prime away from the tissues and results in a reduced oncotic destabilization. iv. mCPB is a safe and reproducible technique Conclusion The Hammersmith mCPB is a “next generation” system which uses standard commercially available components. It aims to maintain safety margin and the benefit of miniaturised system whilst reducing the human factor demands. PMID:23731623

  8. CFD Analysis of Core Bypass Phenomena

    SciTech Connect

    Richard W. Johnson; Hiroyuki Sato; Richard R. Schultz

    2010-03-01

    The U.S. Department of Energy is exploring the potential for the VHTR which will be either of a prismatic or a pebble-bed type. One important design consideration for the reactor core of a prismatic VHTR is coolant bypass flow which occurs in the interstitial regions between fuel blocks. Such gaps are an inherent presence in the reactor core because of tolerances in manufacturing the blocks and the inexact nature of their installation. Furthermore, the geometry of the graphite blocks changes over the lifetime of the reactor because of thermal expansion and irradiation damage. The existence of the gaps induces a flow bias in the fuel blocks and results in unexpected increase of maximum fuel temperature. Traditionally, simplified methods such as flow network calculations employing experimental correlations are used to estimate flow and temperature distributions in the core design. However, the distribution of temperature in the fuel pins and graphite blocks as well as coolant outlet temperatures are strongly coupled with the local heat generation rate within fuel blocks which is not uniformly distributed in the core. Hence, it is crucial to establish mechanistic based methods which can be applied to the reactor core thermal hydraulic design and safety analysis. Computational Fluid Dynamics (CFD) codes, which have a capability of local physics based simulation, are widely used in various industrial fields. This study investigates core bypass flow phenomena with the assistance of commercial CFD codes and establishes a baseline for evaluation methods. A one-twelfth sector of the hexagonal block surface is modeled and extruded down to whole core length of 10.704m. The computational domain is divided vertically with an upper reflector, a fuel section and a lower reflector. Each side of the sector grid can be set as a symmetry boundary

  9. CFD Analysis of Core Bypass Phenomena

    SciTech Connect

    Richard W. Johnson; Hiroyuki Sato; Richard R. Schultz

    2009-11-01

    The U.S. Department of Energy is exploring the potential for the VHTR which will be either of a prismatic or a pebble-bed type. One important design consideration for the reactor core of a prismatic VHTR is coolant bypass flow which occurs in the interstitial regions between fuel blocks. Such gaps are an inherent presence in the reactor core because of tolerances in manufacturing the blocks and the inexact nature of their installation. Furthermore, the geometry of the graphite blocks changes over the lifetime of the reactor because of thermal expansion and irradiation damage. The existence of the gaps induces a flow bias in the fuel blocks and results in unexpected increase of maximum fuel temperature. Traditionally, simplified methods such as flow network calculations employing experimental correlations are used to estimate flow and temperature distributions in the core design. However, the distribution of temperature in the fuel pins and graphite blocks as well as coolant outlet temperatures are strongly coupled with the local heat generation rate within fuel blocks which is not uniformly distributed in the core. Hence, it is crucial to establish mechanistic based methods which can be applied to the reactor core thermal hydraulic design and safety analysis. Computational Fluid Dynamics (CFD) codes, which have a capability of local physics based simulation, are widely used in various industrial fields. This study investigates core bypass flow phenomena with the assistance of commercial CFD codes and establishes a baseline for evaluation methods. A one-twelfth sector of the hexagonal block surface is modeled and extruded down to whole core length of 10.704m. The computational domain is divided vertically with an upper reflector, a fuel section and a lower reflector. Each side of the one-twelfth grid can be set as a symmetry boundary

  10. The reliability of bypass diodes in PV modules

    NASA Astrophysics Data System (ADS)

    Dhere, Neelkanth G.; Shiradkar, Narendra; Schneller, Eric; Gade, Vivek

    2013-09-01

    The operating conditions of bypass diodes in PV modules deployed in the field are considerably harsher than the conditions at which the diode manufacturers test the diodes. This has a potential to significantly reduce the operating life of bypass diodes and has raised concerns about the safety and reliability of PV modules as a whole. The study of modes and mechanisms of the failures encountered in bypass diodes used in PV modules can provide important information which would be useful to predict the module lifetime. This paper presents the review of the failure modes and mechanisms observed in bypass diodes and current work related to reliability testing of bypass diodes. The International PV Module Quality Assurance Task Force has recommended following four potential areas of research to understand the reliability issues of bypass diodes: Electrostatic Discharge, reverse bias thermal runaway testing, forward bias overheating and transition testing of forward bias to reverse bias. As a joint collaborative effort between Florida Solar Energy Center and Solar and Environmental Test Laboratory at Jabil Inc., laboratory testing of bypass diodes on the guidelines provided by the International PV Module Quality Assurance Task Force has been initiated. Preliminary results from this work are presented in this paper.

  11. Alongshore sediment bypassing as a control on river mouth morphodynamics

    NASA Astrophysics Data System (ADS)

    Nienhuis, Jaap H.; Ashton, Andrew D.; Nardin, William; Fagherazzi, Sergio; Giosan, Liviu

    2016-04-01

    River mouths, shoreline locations where fluvial and coastal sediments are partitioned via erosion, trapping, and redistribution, are responsible for the ultimate sedimentary architecture of deltas and, because of their dynamic nature, also pose great management and engineering challenges. To investigate the interaction between fluvial and littoral processes at wave-dominated river mouths, we modeled their morphologic evolution using the coupled hydrodynamic and morphodynamic model Delft3D-SWAN. Model experiments replicate alongshore migration of river mouths, river mouth spit development, and eventual spit breaching, suggesting that these are emergent phenomena that can develop even under constant fluvial and wave conditions. Furthermore, we find that sediment bypassing of a river mouth develops though feedbacks between waves and river mouth morphology, resulting in either continuous bypassing pathways or episodic bar bypassing pathways. Model results demonstrate that waves refracting into the river mouth bar create a zone of low alongshore sediment transport updrift of the river mouth, which reduces sediment bypassing. Sediment bypassing, in turn, controls the river mouth migration rate and the size of the river mouth spit. As a result, an intermediate amount of river discharge maximizes river mouth migration. The fraction of alongshore sediment bypassing can be predicted from the balance between the jet and the wave momentum flux. Quantitative comparisons show a match between our modeled predictions of river mouth bypassing and migration rates observed in natural settings.

  12. Mechanically fastened composite laminates subjected to combined bearing-bypass and shear loading

    NASA Technical Reports Server (NTRS)

    Madenci, Erdogan

    1993-01-01

    contact stress distribution and the contact region are not known a priori, they did not directly impose the boundary conditions appropriate for modelling the contact and on-contact regions between the fastener and the hole. Furthermore, finite element analysis is not suitable for iterative design calculations for optimizing laminate construction in the presence of fasteners under complex loading conditions. In this study, the solution method developed by Madenci and Ileri (1992a,b) has been extended to determine the contact stresses in mechanical joints under combined bearing-bypass and shear loading, and bearing-bypass loading in compression resulting in dual contact regions.

  13. Coronary artery bypass grafting in an achondroplastic dwarf.

    PubMed

    Balaguer, J M; Perry, D; Crowley, J; Moran, J M

    1995-01-01

    To our knowledge, coronary bypass for complications of coronary artery disease in achondroplasia has not previously been described. Achondroplasia, in and of itself, is not a contraindication to coronary bypass. Although the anatomic reserve of saphenous vein is less in achondroplastic dwarfs than in people of normal stature, that vessel and the internal mammary artery can be harvested in routine fashion. A 60-year-old woman with several risk factors for coronary artery disease underwent successful bypass surgery, which included the use of both a saphenous vein and the left internal mammary artery.

  14. [Bypass spanning the knee joint with synthetic prosthesis].

    PubMed

    Müller-Wiefel, H

    1989-01-01

    Synthetic tubes are the second choice for below-knee bypass materials. The ring-reinforced thin-walled Goretex-PTFE graft is an approved material which was tested in a multicenter study. The primary 3 years patency for below-knee femoral-popliteal bypass was 64%, for crural bypass 39%. A total of 195 grafts have been implanted. Long-term patency depends very much on the run-off conditions (81% in good and 43% in bad cases). The over-all limb salvage rate was 80% after 3 years.

  15. Beating heart versus conventional cardiopulmonary bypass: the octopus experience: a randomized comparison of 281 patients undergoing coronary artery bypass surgery with or without cardiopulmonary bypass.

    PubMed

    van Dijk, Diederik; Diephuis, Jan C; Nierich, Arno P; Keizer, Annemieke M A; Kalkman, Cor J

    2006-06-01

    In the Octopus Study, 281 coronary artery bypass surgery patients were randomized to surgery with or without cardiopulmonary bypass. The primary objective was to compare cognitive outcome between off-pump and on-pump coronary artery bypass surgery. Before and after surgery, psychologists administered a battery of 10 neuropsychological tests to the patients. Cognitive decline was defined as a decrease in an individual's performance of at least 20% from baseline, in at least 20% of the main variables. According to this definition, cognitive decline was present in 21% in the off-pump group and 29% in the on-pump group, 3 months after the procedure (P = .15). At 12 months, cognitive decline was present in 31% in the off-pump group and 34% in the on-pump group (P = .69). These results indicated that patients undergoing coronary artery bypass surgery without cardiopulmonary bypass had improved cognitive outcomes 3 months after the procedure, but the effects were limited and became negligible at 12 months. The same definition of cognitive decline was also applied to 112 volunteers not undergoing surgery. The definition labeled 28% of the control subjects as suffering from cognitive decline, 3 months after their first assessment. This suggests that the natural fluctuations in performance during repeated neuropsychological testing should be included in the statistical analysis of cognitive decline. Using an alternative definition of cognitive decline that takes these natural fluctuations in performance into account, the proportions of coronary artery bypass surgery patients displaying cognitive decline were substantially lower. This indicates that the incidence of cognitive decline after coronary artery bypass surgery has been overestimated.

  16. 34 CFR 300.191 - Provisions for services under a by-pass.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 2 2010-07-01 2010-07-01 false Provisions for services under a by-pass. 300.191... EDUCATION OF CHILDREN WITH DISABILITIES State Eligibility By-Pass for Children in Private Schools § 300.191 Provisions for services under a by-pass. (a) Before implementing a by-pass, the Secretary consults...

  17. 34 CFR 300.198 - Continuation of a by-pass.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 2 2010-07-01 2010-07-01 false Continuation of a by-pass. 300.198 Section 300.198... CHILDREN WITH DISABILITIES State Eligibility By-Pass for Children in Private Schools § 300.198 Continuation of a by-pass. The Secretary continues a by-pass until the Secretary determines that the SEA, LEA...

  18. 34 CFR 300.192 - Notice of intent to implement a by-pass.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 2 2010-07-01 2010-07-01 false Notice of intent to implement a by-pass. 300.192... EDUCATION OF CHILDREN WITH DISABILITIES State Eligibility By-Pass for Children in Private Schools § 300.192 Notice of intent to implement a by-pass. (a) Before taking any final action to implement a by-pass,...

  19. Effects of coronary artery bypass grafting on cellular immunity with or without cardiopulmonary bypass: changes in lymphocytes subsets.

    PubMed

    Akbas, Haluk; Erdal, A Cenk; Demiralp, Emel; Alp, Mete

    2002-12-01

    Cell-mediated immunity responses decrease after all kinds of surgical procedures. Either anesthesia or surgical trauma plays an important role in this effect. Identification of functional lymphocyte subsets, by using appropriate monoclonal antibodies and analysis of flow cytometry data, appears to provide an accurate measurement of cellular immune competence. We found a significant decrease in the total number of T helper/inducer cells (p<0.035), B cells (p<0.043) and natural killer cells (NK) (p<0.018) but in contrast, increase in NK cell activity (p<0.012) in the peripheral arterial blood of ten patients undergoing coronary artery bypass grafting with cardiopulmonary bypass (group 1) immediately after surgery and postoperative day 1 (POD1). On the other hand, there was no significant change of these parameters occurred in the peripheral arterial blood of ten patients (group 2) who were undergoing coronary artery bypass grafting without cardiopulmonary bypass. Therefore, we conclude that coronary artery bypass grafting (CABG) with cardiopulmonary bypass induce a greater decrease in immunologic response than CABG without cardiopulmonary bypass (off pump) operations. Nevertheless, off pump CABG operations do not induce a greater decrease in immunologic response than other surgical operations.

  20. Linitis Plastica of the bypassed stomach 7 years after Roux-en-Y gastric bypass. A Case Report.

    PubMed

    Haenen, Filip Wn; Gys, Ben; Moreels, Tom; Michielsen, Maartje; Gys, Tobie; Lafullarde, Thierry

    2016-06-03

    Laparoscopic Roux-en-Y gastric bypass (RYGB) is currently the preferred surgical procedure to treat morbid obesity. It has proven its effects on excess weight loss and its positive effect on comorbidities. One of the main issues, however, is the postoperative evaluation of the bypassed gastric remnant. In literature, cancer of the excluded stomach after RYGB is rare. We describe the case of a 52-year-old woman with gastric linitis plastica in the bypassed stomach after Roux-en-Y gastric bypass, diagnosed by means of laparoscopy and Single-Balloon enteroscopy, and it's clinical importance. Linitis plastica of the excluded stomach after RYGB is a very rare entity. This case report shows the importance of long-term postoperative follow-up, and the importance of Single-Balloon enteroscopy for visualization of the bypassed stomach remnant, when other investigations remain without results. This case report is only the second report of a linitis plastica in the bypassed stomach after Roux-en-Y gastric bypass.

  1. Vitamin a deficiency after gastric bypass surgery: an underreported postoperative complication.

    PubMed

    Zalesin, Kerstyn C; Miller, Wendy M; Franklin, Barry; Mudugal, Dharani; Rao Buragadda, Avdesh; Boura, Judith; Nori-Janosz, Katherine; Chengelis, David L; Krause, Kevin R; McCullough, Peter A

    2011-01-01

    Introduction. Few data are available on vitamin A deficiency in the gastric bypass population. Methods. We performed a retrospective chart review of gastric bypass patients (n = 69, 74% female). The relationship between serum vitamin A concentration and markers of protein metabolism at 6-weeks and 1-year post-operative were assessed. Results. The average weight loss at 6-weeks and 1-year following surgery was 20.1 ± 9.1 kg and 44.1 ± 17.1 kg, respectively. At 6 weeks and 1 year after surgery, 35% and 18% of patients were vitamin A deficient, (<325 mcg/L). Similarly, 34% and 19% had low pre-albumin levels (<18 mg/dL), at these time intervals. Vitamin A directly correlated with pre-albumin levels at 6 weeks (r = 0.67, P < 0.001) and 1-year (r = 0.67,  P < 0.0001). There was no correlation between the roux limb length measurement and pre-albumin or vitamin A serum concentrations at these post-operative follow-ups. Vitamin A levels and markers of liver function testing were also unrelated. Conclusion. Vitamin A deficiency is common after bariatric surgery and is associated with a low serum concentration of pre-albumin. This fat-soluble vitamin should be measured in patients who have undergone gastric bypass surgery and deficiency should be suspected in those with evidence of protein-calorie malnutrition.

  2. Shunt for bypass graft of the cavernous carotid artery: an anatomical and technical study.

    PubMed

    al-Mefty, O; Khalil, N; Elwany, M N; Smith, R R

    1990-11-01

    During direct surgery of neoplastic and vascular lesions of the cavernous sinus, the intracavernous carotid artery may be injured beyond repair, or its total isolation may be necessary for surgical management of these lesions. The newly developed procedure of a saphenous vein graft bypass of the cavernous carotid artery allows re-establishment of carotid circulation. Patients with poor collateral circulation are at high risk for ischemic complications induced by the prolonged temporary occlusion required to perform the bypass graft. Optimal management of these patients is to perform the venous bypass graft for permanent vascularization while maintaining carotid cerebral circulation through an intraoperative shunt. We studied this procedure in cadavers, and three shunt types were evaluated: the external intrapetrous-supraclinoid shunt (Type A), the internal intrapetrous-supraclinoid shunt (Type B), and the neck internal carotid-supraclinoid shunt (Type C). Anatomical landmarks, techniques, distances, caliber, and materials used are presented. The rationale and candidates for such a procedure are discussed. The specifications of an optimal balloon shunt are presented, and the three procedures are compared.

  3. Does extubation result in haemodynamic instability in patients following coronary artery bypass grafts?

    PubMed

    Walthall, H; Ray, S; Robson, D

    2001-10-01

    Coronary heart disease and its management continue to be at the centre of Government health policy. The present political climate demands clinical effectiveness and best practice should be established, while maintaining the philosophy of cost-effectiveness and resource management. These directives have led practitioners to question the care of patients following coronary artery bypass surgery, in particular the role of mechanical ventilation and the subsequent act of extubation. A retrospective study of 89 patients who had coronary artery bypass grafts (emergency and elective) was undertaken, to establish if extubation had a significant effect on the haemodynamic status of patients with variable degrees of left ventricular function (19% with poor left ventricular function). The study found that extubation was achieved within a mean time of 4.97 hours following return from surgery. Extubation resulted in a significant increase in heart rate (P = 0.001), as well as a respiratory acidosis (pCO2: P = 0.000; pH: P = 0.000). However, the stability of the patient was not compromised, with neither mean arterial blood pressure (P = 0.825) nor oxygenation levels (P = 0.267) being significantly altered by extubation. On multivariate analysis, the act of extubation had no significant effect on any of the dependent variables. These results suggest that it is not extubation alone that has an impact on the haemodynamic stability of patients following coronary artery bypass grafts, but that this is indeed multifactorial. Therefore extubation is 'safe' practice for patients with varying degrees of left ventricular function following coronary artery bypass grafts. Limitations of the study are acknowledged.

  4. 14. DRAGLINE BEGINNING CONSTRUCTION OF THE BYPASS CHANNEL CONNECTING THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. DRAGLINE BEGINNING CONSTRUCTION OF THE BY-PASS CHANNEL CONNECTING THE DIVERSION GATE ALONG THE OUTLET CHANNEL WITH THE ORIGINAL CHANNEL OF THE SOURIS RIVER - Upper Souris National Wildlife Refuge, Dam 83, Souris River Basin, Foxholm, Surrey (England), ND

  5. What to Expect After Coronary Artery Bypass Grafting

    MedlinePlus

    ... What To Expect After Coronary Artery Bypass Grafting Recovery in the Hospital After surgery, you'll typically ... for 3 to 5 days before going home. Recovery at Home Your doctor will give you specific ...

  6. Oil Bypass Filter Technology Performance Evaluation - January 2003 Quarterly Report

    SciTech Connect

    Laurence R. Zirker; James E. Francfort

    2003-01-01

    This report details the initial activities to evaluate the performance of the oil bypass filter technology being tested by the Idaho National Engineering and Environmental Laboratory (INEEL) for the U.S. Department of Energy's FreedomCAR & Vehicle Technologies Program. Eight full-size, four-cycle diesel-engine buses used to transport INEEL employees on various routes have been equipped with oil bypass systems from the puraDYN Corporation. Each bus averages about 60,000 miles a year. The evaluation includes an oil analysis regime to monitor the presence of necessary additives in the oil and to detect undesirable contaminants. Very preliminary economic analysis suggests that the oil bypass system can reduce life-cycle costs. As the evaluation continues and oil avoidance costs are quantified, it is estimated that the bypass system economics may prove increasingly favorable, given the anticipated savings in operational costs and in reduced use of oil and waste oil avoidance.

  7. Oil Bypass Filter Technology Performance Evaluation - First Quarterly Report

    SciTech Connect

    Zirker, L.R.; Francfort, J.E.

    2003-01-31

    This report details the initial activities to evaluate the performance of the oil bypass filter technology being tested by the Idaho National Engineering and Environmental Laboratory (INEEL) for the U.S. Department of Energy's FreedomCAR & Vehicle Technologies Program. Eight full-size, four-cycle diesel-engine buses used to transport INEEL employees on various routes have been equipped with oil bypass systems from the puraDYN Corporation. Each bus averages about 60,000 miles a year. The evaluation includes an oil analysis regime to monitor the presence of necessary additives in the oil and to detect undesirable contaminants. Very preliminary economic analysis suggests that the oil bypass system can reduce life-cycle costs. As the evaluation continues and oil avoidance costs are quantified, it is estimated that the bypass system economics may prove increasingly favorable, given the anticipated savings in operational costs and in reduced use of oil and waste oil avoidance.

  8. Spasm in Arterial Grafts in Coronary Artery Bypass Grafting Surgery.

    PubMed

    He, Guo-Wei; Taggart, David P

    2016-03-01

    Spasm of arterial grafts in coronary artery bypass grafting surgery is still a clinical problem, and refractory spasm can occasionally be lethal. Perioperative spasm in bypass grafts and coronary arteries has been reported in 0.43% of all coronary artery bypass grafting surgery, but this may be an underestimate. Spasm can develop not only in the internal mammary artery but more frequently in the right gastroepiploic and radial artery. The mechanism of spasm can involve many pathways, particularly those involving regulation of the intracellular calcium concentration. Endothelial dysfunction also plays a role in spasm. Depending on the clinical scenario, the possibility of spasm during and after coronary artery bypass grafting should be confirmed by angiography. If present, immediate intraluminal injection of vasodilators is often effective, although other procedures such as an intraaortic balloon pump or extracorporeal membrane oxygenation may also become necessary to salvage the patient. Prevention of spasm involves many considerations, and the principles are discussed in this review article.

  9. Protection of semiconductor converters for controlled bypass reactors

    SciTech Connect

    Dolgopolov, A. G.; Akhmetzhanov, N. G.; Karmanov, V. F.

    2010-05-15

    Possible ways of protecting thyristor converters in systems for magnetizing 110 - 500 kV controlled bypass reactors during switching and automatic reclosing are examined based on experience with the development of equipment, line tests, and mathematical modelling.

  10. Subarachnoid-subarachnoid bypass for spinal adhesive arachnoiditis.

    PubMed

    Tachibana, Toshiya; Moriyama, Tokuhide; Maruo, Keishi; Inoue, Shinichi; Arizumi, Fumihiro; Yoshiya, Shinichi

    2014-11-01

    The authors report a case of adhesive arachnoiditis (AA) and arachnoid cyst successfully treated by subarachnoid to subarachnoid bypass (S-S bypass). Arachnoid cysts or syringes sometimes compress the spinal cord and cause compressive myelopathy that requires surgical treatment. However, surgical treatment for AA is challenging. A 57-year-old woman developed leg pain and gait disturbance. A dorsal arachnoid cyst compressed the spinal cord at T7-9, the spinal cord was swollen, and a small syrinx was present at T9-10. An S-S bypass was performed from T6-7 to T11-12. The patient's gait disturbance resolved immediately after surgery. Two years later, a small arachnoid cyst developed. However, there was no neurological deterioration. The myelopathy associated with thoracic spinal AA, subarachnoid cyst, and syrinx improved after S-S bypass.

  11. [Psychoprophylaxis in patients after coronary artery bypass graft operations].

    PubMed

    Rymaszewska, Joanna; Chładzińska-Kiejna, Sylwia; Górna, Renata; Kustrzycki, Wojciech

    2004-05-01

    The paper presented problems of quality of life and psychosocial functioning of patients following coronary artery bypass grafting operations. Possibilities of psychoprophylactic effects towards these patients and its efficacy were described.

  12. 1. PLENUM INTERIOR, SHOWING HEATING COILS AND BYPASS Hot ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. PLENUM INTERIOR, SHOWING HEATING COILS AND BY-PASS - Hot Springs National Park, Bathhouse Row, Fordyce Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

  13. [Preliminary study of colloid osmotic pressure for cardiopulmonary bypass].

    PubMed

    Wang, D; Xiang, L; Luo, J

    1996-12-01

    The ideal colloid osmotic pressure is beneficial to decrease the fluid accumulated in the pulmonary and other tissue during cardiopulmonary bypass. Schupbach reported the proper colloidosmotic pressure for cardiopulmonary bypass was 2.1 kPa (16 mmHg). Colloid osmotic pressures of blood and priming fluid during cardiopulmonary bypass were measured in 28 patients with heart disease by using colloid osmotic pressure detection apparatus. The value of colloid osmotic pressure suitable for the designed standard was apparently different among the Gelofusine group and other groups. P value was 0.005. Priming fluid for cardiopulmonary bypass needs to satisfy the quality and the quantity of colloid osmotic pressure. Using Albumin isn't economical. Whole blood and plazma are not suitable for increasing colloid osmotic pressure. Hydroxyethyl starch or Gelofusine is best choice in priming to get designed standard of colloid osmotic pressure. The ratio of hydroxyethyl starch or Gelofusine in priming fluid should beyond 1/2.

  14. Off-pump coronary artery bypass: techniques, pitfalls, and results.

    PubMed

    Hoff, Steven J

    2009-01-01

    In an attempt to advance the surgical treatment of coronary artery disease, surgeons sought a way to offer the proven benefits of coronary revascularization and avoid the side effects of cardiopulmonary bypass by performing revascularization in the beating heart (off-pump coronary artery bypass). This review will describe the development and refinement of the technique, pitfalls to its widespread adoption, and an up-to-date assessment of current results.

  15. Method of treating emissions of a hybrid vehicle with a hydrocarbon absorber and a catalyst bypass system

    SciTech Connect

    Roos, Bryan Nathaniel; Gonze, Eugene V; Santoso, Halim G; Spohn, Brian L

    2014-01-14

    A method of treating emissions from an internal combustion engine of a hybrid vehicle includes directing a flow of air created by the internal combustion engine when the internal combustion engine is spinning but not being fueled through a hydrocarbon absorber to collect hydrocarbons within the flow of air. When the hydrocarbon absorber is full and unable to collect additional hydrocarbons, the flow of air is directed through an electrically heated catalyst to treat the flow of air and remove the hydrocarbons. When the hydrocarbon absorber is not full and able to collect additional hydrocarbons, the flow of air is directed through a bypass path that bypasses the electrically heated catalyst to conserve the thermal energy stored within the electrically heated catalyst.

  16. How safe is it to train residents to perform off-pump coronary artery bypass surgery?

    PubMed

    Smith, Tanya A; Asimakopoulos, George

    2015-05-01

    A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was, in [patients undergoing off-pump CABG] are [postoperative mortality and morbidity outcomes] acceptable when performed by [trainees]? Altogether more than 597 papers were found using the reported search, of which 8 represented the best evidence to answer the clinical question. Six retrospective cohort studies directly compared the performance of trainees and experienced surgeons in off-pump coronary artery bypass graft surgery. Of the remaining papers, one recorded the performance of trainees in on- and off-pump operations and finally one paper evaluated a single trainee's performance in off-pump coronary artery bypass graft surgery, both supervised and unsupervised, over a 1-year period. It is important to note that the two respective cohort studies included in our analysis compared similar cohorts of patients. However, both studies were included in our paper as they provide additional information regarding trainee performance. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. Although a heterogeneous range of postoperative complications were recorded in the identified studies, we were able to determine that, overall, there was no significant difference in the 30-day mortality seen in operations performed by trainees or experienced surgeons. The incidence of myocardial infarction and stroke were also similar among cases performed by both groups. However, senior surgeons were more likely to operate on patients with more complex or severe disease, or those requiring more urgent operations. Therefore, it was not possible to directly compare outcomes between trainees and experienced surgeons in operations of similar complexity. However, we conclude that despite the absence of randomized controlled trials comparing the performance of trainees and

  17. Current status of mini-gastric bypass

    PubMed Central

    Mahawar, Kamal K.; Kumar, Parveen; Carr, William RJ; Jennings, Neil; Schroeder, Norbert; Balupuri, Shlok; Small, Peter K.

    2016-01-01

    Mini-gastric bypass (MGP) is a promising bariatric procedure. Tens of thousands of this procedure have been performed throughout the world since Rutledge performed the first procedure in the United States of America in 1997. Several thousands of these have even been documented in the published scientific literature. Despite a proven track record over nearly two decades, this operation continues to polarise the bariatric community. A large number of surgeons across the world have strong objections to this procedure and do not perform it. The risk of symptomatic (bile) reflux, marginal ulceration, severe malnutrition, and long-term risk of gastric and oesophageal cancers are some of the commonly voiced concerns. Despite these expressed fears, several advantages such as technical simplicity, shorter learning curve, ease of revision and reversal, non-inferior weight loss and comorbidity resolution outcomes have prompted some surgeons to advocate a wider adoption of this procedure. This review examines the current status of these controversial aspects in the light of the published academic literature in English. PMID:27251826

  18. Evaluation of intracardiac recordings in diagnosis of impulse formation and concealed conduction in atrioventricular nodal bypass tracts.

    PubMed Central

    Castellanos, A; Agha, A S; Mendoza, I J; Sung, R J

    1977-01-01

    Invasive electrophysiological studies were performed in 2 symptomatic patients with recurrent arrhythmias in which impulse formation presumably occured within atrioventricular nodal bypass tracts. Case 1 had ectopic beats arising within, or close to, the upper end of a left-sided atrioventricular nodal bypass tract of the type described by Brechenmacher. In addition, this conduction was 'concealed' during sinus rhythm and right atrial pacing because the relatively prolonged right-to-left atrial conduction time allowed right atrial impulses to reach the His bundle via the atrioventricular node before they could do so through the atrioventricular nodal bypass tract. Case 2 had ectopic beats arising in a right-sided atrioventricular nodal bypass tract which did not conduct in either forward or retrograde directions, its presence being detected only when initiating impulses. However, it could not be determined whether this tract was an 'abnormal' atrio-His connection or a 'normal' transitional (atrio-atrioventricular nodal) tract. Though intracardiac studies complement body surface recordings, they should be interpreted with knowledge of their inherent limitations. PMID:884022

  19. [The peculiarties of nitric oxide synthesis in patients after coronary bypass surgery].

    PubMed

    Bulanova, E L; Drapkina, O M; Kutepov, Iu S; Ivashkin, V T

    2007-01-01

    Nitric oxide (NO) participates in many physiological processes including those taking place in the cardiovascular system. The peculiarities of NO synthesis in patients after coronary bypass surgery were studied. The systems of NO generation responded in different ways. Changes in the levels of end-products of NO metabolism may be used as an additional prognostic criterion of the course of the postoperative period. The study found a direct correlation between the levels of end-products of NO metabolism and left ventricular ejection fraction as well as a reverse correlation between the level of end-products of NO metabolism and atherogenic lipids.

  20. [Palliative biliary-digestive bypass with a Kehr tube for neoplastic surgical cholestatic jaundice].

    PubMed

    Revetria, P; Bonardi, L; Gambetta, G; Ferro, A; Bertino, C

    1993-03-31

    The authors, in some rare cases of surgical neoplastic icterus operation, had to adopt a technique of biliary-digestive bypass with prosthesis on account of the technical-anatomical and general conditions of the patients. That prosthesis has been made out of the typical Keher's duct which can be generally found in every general surgery. The above mentioned authors describe the operations they have carried out, their directions and the results of six cases which have been treated with a technique similar to Kron's.

  1. Annular MHD Physics for Turbojet Energy Bypass

    NASA Technical Reports Server (NTRS)

    Schneider, Steven J.

    2011-01-01

    The use of annular Hall type MHD generator/accelerator ducts for turbojet energy bypass is evaluated assuming weakly ionized flows obtained from pulsed nanosecond discharges. The equations for a 1-D, axisymmetric MHD generator/accelerator are derived and numerically integrated to determine the generator/accelerator performance characteristics. The concept offers a shockless means of interacting with high speed inlet flows and potentially offers variable inlet geometry performance without the complexity of moving parts simply by varying the generator loading parameter. The cycle analysis conducted iteratively with a spike inlet and turbojet flying at M = 7 at 30 km altitude is estimated to have a positive thrust per unit mass flow of 185 N-s/kg. The turbojet allowable combustor temperature is set at an aggressive 2200 deg K. The annular MHD Hall generator/accelerator is L = 3 m in length with a B(sub r) = 5 Tesla magnetic field and a conductivity of sigma = 5 mho/m for the generator and sigma= 1.0 mho/m for the accelerator. The calculated isentropic efficiency for the generator is eta(sub sg) = 84 percent at an enthalpy extraction ratio, eta(sub Ng) = 0.63. The calculated isentropic efficiency for the accelerator is eta(sub sa) = 81 percent at an enthalpy addition ratio, eta(sub Na) = 0.62. An assessment of the ionization fraction necessary to achieve a conductivity of sigma = 1.0 mho/m is n(sub e)/n = 1.90 X 10(exp -6), and for sigma = 5.0 mho/m is n(sub e)/n = 9.52 X 10(exp -6).

  2. Natural Product Screening Reveals Naphthoquinone Complex I Bypass Factors

    PubMed Central

    Mevers, Emily; Higgins, Kathleen W.; Fomina, Yevgenia; Zhang, Jianming; Mandinova, Anna; Newman, David; Shaw, Stanley Y.; Clardy, Jon; Mootha, Vamsi K.

    2016-01-01

    Deficiency of mitochondrial complex I is encountered in both rare and common diseases, but we have limited therapeutic options to treat this lesion to the oxidative phosphorylation system (OXPHOS). Idebenone and menadione are redox-active molecules capable of rescuing OXPHOS activity by engaging complex I-independent pathways of entry, often referred to as “complex I bypass.” In the present study, we created a cellular model of complex I deficiency by using CRISPR genome editing to knock out Ndufa9 in mouse myoblasts, and utilized this cell line to develop a high-throughput screening platform for novel complex I bypass factors. We screened a library of ~40,000 natural product extracts and performed bioassay-guided fractionation on a subset of the top scoring hits. We isolated four plant-derived 1,4-naphthoquinone complex I bypass factors with structural similarity to menadione: chimaphilin and 3-chloro-chimaphilin from Chimaphila umbellata and dehydro-α-lapachone and dehydroiso-α-lapachone from Stereospermum euphoroides. We also tested a small number of structurally related naphthoquinones from commercial sources and identified two additional compounds with complex I bypass activity: 2-methoxy-1,4-naphthoquinone and 2-methoxy-3-methyl-1,4,-naphthoquinone. The six novel complex I bypass factors reported here expand this class of molecules and will be useful as tool compounds for investigating complex I disease biology. PMID:27622560

  3. Natural Product Screening Reveals Naphthoquinone Complex I Bypass Factors.

    PubMed

    Vafai, Scott B; Mevers, Emily; Higgins, Kathleen W; Fomina, Yevgenia; Zhang, Jianming; Mandinova, Anna; Newman, David; Shaw, Stanley Y; Clardy, Jon; Mootha, Vamsi K

    2016-01-01

    Deficiency of mitochondrial complex I is encountered in both rare and common diseases, but we have limited therapeutic options to treat this lesion to the oxidative phosphorylation system (OXPHOS). Idebenone and menadione are redox-active molecules capable of rescuing OXPHOS activity by engaging complex I-independent pathways of entry, often referred to as "complex I bypass." In the present study, we created a cellular model of complex I deficiency by using CRISPR genome editing to knock out Ndufa9 in mouse myoblasts, and utilized this cell line to develop a high-throughput screening platform for novel complex I bypass factors. We screened a library of ~40,000 natural product extracts and performed bioassay-guided fractionation on a subset of the top scoring hits. We isolated four plant-derived 1,4-naphthoquinone complex I bypass factors with structural similarity to menadione: chimaphilin and 3-chloro-chimaphilin from Chimaphila umbellata and dehydro-α-lapachone and dehydroiso-α-lapachone from Stereospermum euphoroides. We also tested a small number of structurally related naphthoquinones from commercial sources and identified two additional compounds with complex I bypass activity: 2-methoxy-1,4-naphthoquinone and 2-methoxy-3-methyl-1,4,-naphthoquinone. The six novel complex I bypass factors reported here expand this class of molecules and will be useful as tool compounds for investigating complex I disease biology.

  4. Bearing-Bypass Loading on Bolted Composite Joints

    NASA Technical Reports Server (NTRS)

    Crews, J. H., Jr.; Naik, R. A.

    1988-01-01

    A combined experimental and analytical study has been conducted to investigate the effects of simultaneous bearing and bypass loading on a graphite/epoxy (T300/5208) laminate. Tests were conducted with a test machine that allows the bearing-bypass load ratio to be controlled while a single-fastener coupon is loaded to failure in either tension or compression. Test coupons consisted of 16-ply quasi-isotropic graphite/epoxy laminates with a centrally-located 6.35 mm bolt having a clearance fit. Onset-damage and ultimate strengths were determined for each test case. Next, a finite element stress analysis was conducted for each test case. The computed local stresses were used with appropriate failure criteria to analyze the observed failure modes and strengths. An unexpected interaction of the effect of the bypass and bearing loads was found for the onset of compression-reacted bearing damage. This interaction was caused by a decrease in the bolt-hole contact arc and a corresponding increase in the severity of the bearing loads. The amount of bolt-hole contact had a significant effect on local stresses and, thus, on the calculated damage-onset and ultimate strengths. An offset-compressible failure mode was identified for laminate failure under compression bearing-bypass loading. This failure mode appears to be unique to compression bearing-bypass loading and, therefore, cannot be predicted from simple tests.

  5. Neuroprotective Strategies during Cardiac Surgery with Cardiopulmonary Bypass

    PubMed Central

    Salameh, Aida; Dhein, Stefan; Dähnert, Ingo; Klein, Norbert

    2016-01-01

    Aortocoronary bypass or valve surgery usually require cardiac arrest using cardioplegic solutions. Although, in principle, in a number of cases beating heart surgery (so-called off-pump technique) is possible, aortic or valve surgery or correction of congenital heart diseases mostly require cardiopulmonary arrest. During this condition, the heart-lung machine also named cardiopulmonary bypass (CPB) has to take over the circulation. It is noteworthy that the invention of a machine bypassing the heart and lungs enabled complex cardiac operations, but possible negative effects of the CPB on other organs, especially the brain, cannot be neglected. Thus, neuroprotection during CPB is still a matter of great interest. In this review, we will describe the impact of CPB on the brain and focus on pharmacological and non-pharmacological strategies to protect the brain. PMID:27879647

  6. Rankine cycle load limiting through use of a recuperator bypass

    DOEpatents

    Ernst, Timothy C.

    2011-08-16

    A system for converting heat from an engine into work includes a boiler coupled to a heat source for transferring heat to a working fluid, a turbine that transforms the heat into work, a condenser that transforms the working fluid into liquid, a recuperator with one flow path that routes working fluid from the turbine to the condenser, and another flow path that routes liquid working fluid from the condenser to the boiler, the recuperator being configured to transfer heat to the liquid working fluid, and a bypass valve in parallel with the second flow path. The bypass valve is movable between a closed position, permitting flow through the second flow path and an opened position, under high engine load conditions, bypassing the second flow path.

  7. Bearing-bypass loading on bolted composite joints

    NASA Technical Reports Server (NTRS)

    Crews, J. H., Jr.; Naik, R. A.

    1987-01-01

    The effects of simultaneous bearing and bypass loading on a graphite-epoxy (T300/5208) laminate were investigated. Onset damage and ultimate strengths were determined for each test case. A finite element stress analysis was conducted for each test case. The computed local stresses were used with appropriate failure criteria to analyze the observed failure modes and strengths. An unexpected interaction of the effect of the bypass and bearing loads was found for the onset of compression reacted bearing damage. The interaction was caused by a decrease in the bolt-hole contact arc and a corresponding increase in the severity of the bearing loads. The amount of bolt-hole contact had a significant effect on local stresses and, thus, on the calculated damage-onset and ultimate strengths. An offset-compression failure mode was identified for laminate failure under compression bearing-bypass loading.

  8. Vitamin deficiency after gastric bypass surgery: a review.

    PubMed

    Matrana, Marc R; Davis, William E

    2009-10-01

    More than 60% of the adult US population now meets the criteria for being overweight or obese. Gastric bypass surgery has become a popular and effective way to combat this medical problem. Despite the success of these procedures, they are associated with many complications, including malnutrition, neurological compromise, and vitamin deficiency. Research has determined that even with multivitamin supplementation for life, a large percentage of bypass patients develop vitamin deficiencies. We present a case of beriberi after Roux-en-Y bypass that illustrates the importance of close follow up. A thorough review of vitamin deficiencies in this unique patient population is explored. Vitamin supplementation and treatment recommendations are compiled from the most up-to-date sources. Even patients on regular supplements should be closely monitored for vitamin deficiencies. Patient education regarding vitamin supplementation is vital; it should begin prior to surgery and continue throughout the postoperative period and beyond.

  9. Luxury perfusion syndrome confirmed by sequential studies of regional cerebral blood flow and volume after extracranial to intracranial bypass surgery: case report.

    PubMed

    Higashi, S; Matsuda, H; Fujii, H; Ito, H; Yamashita, J

    1989-07-01

    We report a case of luxury perfusion syndrome with temporary neurological deterioration after extracranial to intracranial bypass surgery. A preoperative computed tomographic scan showed no detectable infarct, and the measurement of regional cerebral blood flow showed severe depression of ipsilateral hemispheric perfusion. The patient developed temporary neurological deterioration after bypass surgery, with no recognizable pathological signs on postoperative computed tomographic and angiographic studies. Regional cerebral blood flow and volume were more elevated during the period of neurological deterioration than after the subsequent recovery. This strongly suggests that excessive blood flow directed into chronically ischemic brain through a graft may induce a luxury perfusion syndrome resulting in neurological deterioration.

  10. Cavo-atrial bypass with a polytetrafluoroethylene graft for the treatment of a complete, traumatic transection of the suprahepatic inferior vena cava.

    PubMed

    Prevot, Flavien; Berna, Pascal; Badoux, Louise; Regimbeau, Jean-Marc

    2016-09-27

    In the event of injury to the vena cava, the surgeon's goal is to control the bleeding and then repair the vascular damage. Given the wide range of lesions observed, the repair step has not been standardized. There are a few case reports of simple venoplasty or cavocaval bypass with a polytetrafluoroethylene graft. The present report introduces another treatment option for total avulsion of the suprahepatic inferior vena cava when a lack of remnant venous tissue below the heart prevents direct repair: cavo-atrial bypass with a polytetrafluoroethylene graft.

  11. By-pass hydrocarbon absorber system for ULEV

    SciTech Connect

    Williams, J.L.; Patil, M.D.; Hertl, W.

    1996-09-01

    A by-pass zeolite adsorber system consisting of a first catalyst, a by-pass loop containing the zeolite adsorbers followed by a downstream second catalyst was FTP tested using a US vehicle equipped with a 3.8 L, V6 engine. The system exhibited ULEV emissions performance with hydrocarbon adsorption and regeneration (desorption and oxidation) within the FTP cycle and required only a single diversion valve within the exhaust line. Adsorption takes place during the initial 70 seconds of the FTP cycle. The adsorbers were regenerated with the exhaust gas plus injected air.

  12. Management of a malignant hyperthermia patient during cardiopulmonary bypass.

    PubMed

    Byrick, R J; Rose, D K; Ranganathan, N

    1982-01-01

    The anaesthetic management of cardiopulmonary bypass (CPB) for a patient with biopsy-proven malignant hyperthermia is reported. Specific changes in the technique used, such as venting the oxygenator before use, monitoring mixed venous PO2 and PCO2, as well as the safety of cold hyperkalaemic cardioplegia are described. Controversial aspects of malignant hyperthermia management such as the safety of calcium and catechol inotropes are discussed in relationship to the successful use of cardio-pulmonary bypass in our patient. We chose to treat left ventricular dysfunction by aggressive vasodilator (nitroglycerine) therapy. We detected no myocardial or respiratory depression secondary to dantrolene therapy either before or after operation.

  13. Lattice and bypass design for a coherent xuv facility

    SciTech Connect

    Jackson, A.; Garren, A.A.; Vignola, G.

    1985-05-01

    The design of a magnet lattice and bypass for a coherent radiation facility is discussed. The lattice is the missing magnet FODO structure first proposed by Vignola for a 6 GeV light source. This has been adapted for a 750-1300 MeV electron storage ring for use with both conventional insertion devices and a high gain FEL optimized for output at 400 A. The latter device requires that the electron bunch be deflected into a small aperture bypass, then reinjected into the ring where the perturbing effects of the FEL are damped out. 8 refs., 7 figs.

  14. Fibrin Adhesive: Clinical Application in Coronary Artery Bypass Graft Surgery

    PubMed Central

    Fundaró, Pino; Velardi, Antonio R.; Santoli, Carmine

    1985-01-01

    Fibrin adhesive was used 72 times in a group of 67 patients undergoing elective coronary artery bypass graft surgery. The indications were prophylactic sealing of potential sources of bleeding, topical hemostasis (control of bleeding sites dangerous or difficult to suture), and fixation of the graft in the optimal position. The method of glue application under varying circumstances is described and the results are reported. This experience suggests that in some cases the glue expedites the operation and makes it safer. We conclude that the fibrin sealing represents a valid aid in coronary artery bypass graft surgery. PMID:15227018

  15. [Prevalence of early and late dumping after gastric bypass].

    PubMed

    Héraïef, R; Giusti, V

    2014-03-26

    Gastric bypass surgery is an effective treatment of obesity, bringing a significant weight loss and a major improvement of carbohydrate profile. However, in some patients, a deregulation in carbohydrate metabolism between insulin secretion and sensitivity is observed, whereupon early and late dumping happen. Their prevalence isn't well studied, although it seems that 10 to 20% of patients are affected. We've studied a cohort of 70 patients who undergone gastric bypass surgery at the CHUV. 18 (25.7%) patients have a positive anamnesis for early dumping and 10 (14.3%) for late dumping, being it superior as what is described in the literature.

  16. CT scan diagnosis of bleeding peptic ulcer after gastric bypass.

    PubMed

    Husain, Syed; Ahmed, Ahmed R; Johnson, Joseph; Boss, Thad; O'Malley, William

    2007-11-01

    Investigation of the bypassed stomach in patients with suspected peptic ulcer disease presents a major challenge to bariatric surgeons. Various methods have been suggested for visualization of the duodenum and bypassed stomach. These include endoscopy via percutaneous gastrostomy access, retrograde endoscopy and virtual gastroscopy using CT scan. We present a case of peptic ulcer bleeding diagnosed with the help of conventional CT scan. To the best of our knowledge, this is the second such case reported in the literature and the first in the bariatric population.

  17. A Bypass Program of Supportive Instruction for Secondary Students with Learning Disabilities.

    ERIC Educational Resources Information Center

    Mosby, Robert J.

    1979-01-01

    The developmental bypass teaching technique (which provides students an opportunity to bypass their learning deficits) was studied with regard to social studies achievement and classroom behaviors in 50 learning disabled junior high school students. (Author/PHR)

  18. Hereditary spherocytosis in a patient undergoing coronary artery bypass grafting with cardiopulmonary bypass--a case report.

    PubMed

    Spegar, J; Riha, H; Kotulak, T; Vanek, T

    2015-01-01

    Hereditary spherocytosis is a genetically determined abnormality of red blood cells. It is the most common cause of inherited haemolysis in Europe and North America within the Caucasian population. We document a patient who underwent an aortocoronary bypass procedure on cardiopulmonary bypass. In view of the uncertain tolerance of the abnormal red cells in hereditary spherocytosis to cardiopulmonary bypass, we reviewed the patient's chart and analyzed recorded values of these parameters: free plasma haemoglobin, renal parameters, cystatin C, bilirubin, liver tests, urine samples. From the results, we can see that slight haemolysis-elevated bilirubin in the blood sample and elevated bilirubin and urobilinogen in the urine sample occurred on the first postoperative day. The levels of these parameters slowly decreased during the next postoperative days. There was no real clinical effect of this haemolysis on renal functions.

  19. On Pump Coronary Artery Bypass Graft Surgery Versus Off Pump Coronary Artery Bypass Graft Surgery: A Review

    PubMed Central

    Islam, Mohammad Yousuf-ul; Ahmed, Muhammad Umer; Khan, Muhammad Shahzeb; Bawany, Faizan Imran; Khan, Asadullah; Arshad, Mohammad Hussham

    2014-01-01

    There are two basic ways of performing coronary artery bypass graft surgery (CABG): on pump CABG and off pump CABG. Off pump CABG is relatively a newer procedure to on-pump CABG and does not require the use of the cardiopulmonary bypass machine. On pump CABG is the more traditional method of performing bypass surgery. However its resultant inflammatory effects cause renal dysfunction, gastrointestinal distress and cardiac abnormalities which have forced the surgeons to look for alternatives to the procedure. An extensive literature search revealed that on pump CABG causes better revascularization as compared to off pump CABG while off pump CABG has a much lower post operative morbidity and mortality especially in high risk patients. We suggest that the technique used should depend on the ease of the surgeon doing the operation as both the methods seem almost equally efficient according to the review. PMID:24762361

  20. Percutaneous gastric drainage as a treatment for small bowel obstruction after gastric bypass.

    PubMed

    Hamoui, Nahid; Crookes, Peter F; Kaufman, Howard S

    2007-10-01

    The authors report the case of a patient who developed small bowel obstruction after laparoscopic gastric bypass. Imaging revealed an obstruction at the enteroenterostomy resulting in dilation of the bypassed stomach and proximal small bowel. The bypassed stomach was percutaneously drained using CT guidance, leading to resolution of the small bowel obstruction. Biliopancreatic limb obstructions can be successfully treated non-operatively after gastric bypass.

  1. Outcomes of lower extremity bypass performed for acute limb ischemia

    PubMed Central

    Baril, Donald T.; Patel, Virendra I.; Judelson, Dejah R.; Goodney, Philip P.; McPhee, James T.; Hevelone, Nathanael D.; Cronenwett, Jack L.; Schanzer, Andres

    2013-01-01

    Objective Acute limb ischemia remains one of the most challenging emergencies in vascular surgery. Historically, outcomes following interventions for acute limb ischemia have been associated with high rates of morbidity and mortality. The purpose of this study was to determine contemporary outcomes following lower extremity bypass performed for acute limb ischemia. Methods All patients undergoing infrainguinal lower extremity bypass between 2003 and 2011 within hospitals comprising the Vascular Study Group of New England were identified. Patients were stratified according to whether or not the indication for lower extremity bypass was acute limb ischemia. Primary end points included bypass graft occlusion, major amputation, and mortality at 1 year postoperatively as determined by Kaplan-Meier life table analysis. Multivariable Cox proportional hazards models were constructed to evaluate independent predictors of mortality and major amputation at 1 year. Results Of 5712 lower extremity bypass procedures, 323 (5.7%) were performed for acute limb ischemia. Patients undergoing lower extremity bypass for acute limb ischemia were similar in age (66 vs 67; P = .084) and sex (68% male vs 69% male; P = .617) compared with chronic ischemia patients, but were less likely to be on aspirin (63% vs 75%; P < .0001) or a statin (55% vs 68%; P < .0001). Patients with acute limb ischemia were more likely to be current smokers (49% vs 39%; P < .0001), to have had a prior ipsilateral bypass (33% vs 24%; P = .004) or a prior ipsilateral percutaneous intervention (41% vs 29%; P = .001). Bypasses performed for acute limb ischemia were longer in duration (270 vs 244 minutes; P = .007), had greater blood loss (363 vs 272 mL; P < .0001), and more commonly utilized prosthetic conduits (41% vs 33%; P = .003). Acute limb ischemia patients experienced increased in-hospital major adverse events (20% vs 12%; P < .0001) including myocardial infarction, congestive heart failure exacerbation

  2. 21 CFR 870.4370 - Roller-type cardiopulmonary bypass blood pump.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Roller-type cardiopulmonary bypass blood pump. 870... Roller-type cardiopulmonary bypass blood pump. (a) Identification. A roller-type cardiopulmonary bypass blood pump is a device that uses a revolving roller mechanism to pump the blood through...

  3. 21 CFR 870.4360 - Nonroller-type cardiopulmonary bypass blood pump.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Nonroller-type cardiopulmonary bypass blood pump... Nonroller-type cardiopulmonary bypass blood pump. (a) Identification. A nonroller-type cardiopulmonary bypass blood pump is a device that uses a method other than revolving rollers to pump the blood...

  4. 21 CFR 870.4360 - Nonroller-type cardiopulmonary bypass blood pump.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Nonroller-type cardiopulmonary bypass blood pump... Nonroller-type cardiopulmonary bypass blood pump. (a) Identification. A nonroller-type cardiopulmonary bypass blood pump is a device that uses a method other than revolving rollers to pump the blood...

  5. 21 CFR 870.4370 - Roller-type cardiopulmonary bypass blood pump.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Roller-type cardiopulmonary bypass blood pump. 870... Roller-type cardiopulmonary bypass blood pump. (a) Identification. A roller-type cardiopulmonary bypass blood pump is a device that uses a revolving roller mechanism to pump the blood through...

  6. 21 CFR 870.4370 - Roller-type cardiopulmonary bypass blood pump.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Roller-type cardiopulmonary bypass blood pump. 870... Roller-type cardiopulmonary bypass blood pump. (a) Identification. A roller-type cardiopulmonary bypass blood pump is a device that uses a revolving roller mechanism to pump the blood through...

  7. 21 CFR 870.4360 - Nonroller-type cardiopulmonary bypass blood pump.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Nonroller-type cardiopulmonary bypass blood pump... Nonroller-type cardiopulmonary bypass blood pump. (a) Identification. A nonroller-type cardiopulmonary bypass blood pump is a device that uses a method other than revolving rollers to pump the blood...

  8. 21 CFR 870.4370 - Roller-type cardiopulmonary bypass blood pump.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Roller-type cardiopulmonary bypass blood pump. 870... Roller-type cardiopulmonary bypass blood pump. (a) Identification. A roller-type cardiopulmonary bypass blood pump is a device that uses a revolving roller mechanism to pump the blood through...

  9. 21 CFR 870.4360 - Nonroller-type cardiopulmonary bypass blood pump.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Nonroller-type cardiopulmonary bypass blood pump... Nonroller-type cardiopulmonary bypass blood pump. (a) Identification. A nonroller-type cardiopulmonary bypass blood pump is a device that uses a method other than revolving rollers to pump the blood...

  10. 21 CFR 870.4220 - Cardiopulmonary bypass heart-lung machine console.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Cardiopulmonary bypass heart-lung machine console... Cardiopulmonary bypass heart-lung machine console. (a) Identification. A cardiopulmonary bypass heart-lung machine... heart-lung machine. The console is designed to interface with the basic units used in a gas...

  11. 21 CFR 870.4220 - Cardiopulmonary bypass heart-lung machine console.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Cardiopulmonary bypass heart-lung machine console... Cardiopulmonary bypass heart-lung machine console. (a) Identification. A cardiopulmonary bypass heart-lung machine... heart-lung machine. The console is designed to interface with the basic units used in a gas...

  12. 21 CFR 870.4220 - Cardiopulmonary bypass heart-lung machine console.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Cardiopulmonary bypass heart-lung machine console... Cardiopulmonary bypass heart-lung machine console. (a) Identification. A cardiopulmonary bypass heart-lung machine... heart-lung machine. The console is designed to interface with the basic units used in a gas...

  13. 21 CFR 870.4220 - Cardiopulmonary bypass heart-lung machine console.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Cardiopulmonary bypass heart-lung machine console... Cardiopulmonary bypass heart-lung machine console. (a) Identification. A cardiopulmonary bypass heart-lung machine... heart-lung machine. The console is designed to interface with the basic units used in a gas...

  14. 21 CFR 870.4220 - Cardiopulmonary bypass heart-lung machine console.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass heart-lung machine console... Cardiopulmonary bypass heart-lung machine console. (a) Identification. A cardiopulmonary bypass heart-lung machine... heart-lung machine. The console is designed to interface with the basic units used in a gas...

  15. 21 CFR 870.4410 - Cardiopulmonary bypass in-line blood gas sensor.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Cardiopulmonary bypass in-line blood gas sensor... Cardiopulmonary bypass in-line blood gas sensor. (a) Identification. A cardiopulmonary bypass in-line blood gas sensor is a transducer that measures the level of gases in the blood. (b) Classification. Class...

  16. 21 CFR 870.4330 - Cardiopulmonary bypass on-line blood gas monitor.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Cardiopulmonary bypass on-line blood gas monitor... Cardiopulmonary bypass on-line blood gas monitor. (a) Identification. A cardiopulmonary bypass on-line blood gas monitor is a device used in conjunction with a blood gas sensor to measure the level of gases in the...

  17. 21 CFR 870.4260 - Cardiopulmonary bypass arterial line blood filter.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Cardiopulmonary bypass arterial line blood filter... Cardiopulmonary bypass arterial line blood filter. (a) Identification. A cardiopulmonary bypass arterial line blood filter is a device used as part of a gas exchange (oxygenator) system to filter...

  18. 21 CFR 870.4330 - Cardiopulmonary bypass on-line blood gas monitor.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Cardiopulmonary bypass on-line blood gas monitor... Cardiopulmonary bypass on-line blood gas monitor. (a) Identification. A cardiopulmonary bypass on-line blood gas monitor is a device used in conjunction with a blood gas sensor to measure the level of gases in the...

  19. 21 CFR 870.4410 - Cardiopulmonary bypass in-line blood gas sensor.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Cardiopulmonary bypass in-line blood gas sensor... Cardiopulmonary bypass in-line blood gas sensor. (a) Identification. A cardiopulmonary bypass in-line blood gas sensor is a transducer that measures the level of gases in the blood. (b) Classification. Class...

  20. 21 CFR 870.4260 - Cardiopulmonary bypass arterial line blood filter.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Cardiopulmonary bypass arterial line blood filter... Cardiopulmonary bypass arterial line blood filter. (a) Identification. A cardiopulmonary bypass arterial line blood filter is a device used as part of a gas exchange (oxygenator) system to filter...

  1. 21 CFR 870.4330 - Cardiopulmonary bypass on-line blood gas monitor.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Cardiopulmonary bypass on-line blood gas monitor... Cardiopulmonary bypass on-line blood gas monitor. (a) Identification. A cardiopulmonary bypass on-line blood gas monitor is a device used in conjunction with a blood gas sensor to measure the level of gases in the...

  2. 21 CFR 870.4330 - Cardiopulmonary bypass on-line blood gas monitor.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Cardiopulmonary bypass on-line blood gas monitor... Cardiopulmonary bypass on-line blood gas monitor. (a) Identification. A cardiopulmonary bypass on-line blood gas monitor is a device used in conjunction with a blood gas sensor to measure the level of gases in the...

  3. 21 CFR 870.4410 - Cardiopulmonary bypass in-line blood gas sensor.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Cardiopulmonary bypass in-line blood gas sensor... Cardiopulmonary bypass in-line blood gas sensor. (a) Identification. A cardiopulmonary bypass in-line blood gas sensor is a transducer that measures the level of gases in the blood. (b) Classification. Class...

  4. 21 CFR 870.4260 - Cardiopulmonary bypass arterial line blood filter.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Cardiopulmonary bypass arterial line blood filter... Cardiopulmonary bypass arterial line blood filter. (a) Identification. A cardiopulmonary bypass arterial line blood filter is a device used as part of a gas exchange (oxygenator) system to filter...

  5. 21 CFR 870.4410 - Cardiopulmonary bypass in-line blood gas sensor.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Cardiopulmonary bypass in-line blood gas sensor... Cardiopulmonary bypass in-line blood gas sensor. (a) Identification. A cardiopulmonary bypass in-line blood gas sensor is a transducer that measures the level of gases in the blood. (b) Classification. Class...

  6. 21 CFR 870.4260 - Cardiopulmonary bypass arterial line blood filter.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Cardiopulmonary bypass arterial line blood filter... Cardiopulmonary bypass arterial line blood filter. (a) Identification. A cardiopulmonary bypass arterial line blood filter is a device used as part of a gas exchange (oxygenator) system to filter...

  7. 21 CFR 870.4360 - Nonroller-type cardiopulmonary bypass blood pump.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Nonroller-type cardiopulmonary bypass blood pump... Nonroller-type cardiopulmonary bypass blood pump. (a) Identification. A nonroller-type cardiopulmonary bypass blood pump is a device that uses a method other than revolving rollers to pump the blood...

  8. 21 CFR 870.4260 - Cardiopulmonary bypass arterial line blood filter.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass arterial line blood filter... Cardiopulmonary bypass arterial line blood filter. (a) Identification. A cardiopulmonary bypass arterial line blood filter is a device used as part of a gas exchange (oxygenator) system to filter...

  9. 21 CFR 870.4370 - Roller-type cardiopulmonary bypass blood pump.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Roller-type cardiopulmonary bypass blood pump. 870... Roller-type cardiopulmonary bypass blood pump. (a) Identification. A roller-type cardiopulmonary bypass blood pump is a device that uses a revolving roller mechanism to pump the blood through...

  10. 21 CFR 870.4330 - Cardiopulmonary bypass on-line blood gas monitor.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass on-line blood gas monitor... Cardiopulmonary bypass on-line blood gas monitor. (a) Identification. A cardiopulmonary bypass on-line blood gas monitor is a device used in conjunction with a blood gas sensor to measure the level of gases in the...

  11. Routine preoperative insertion of IABP in high-risk off-pump coronary artery bypass grafting.

    PubMed

    Vohra, Hunaid A; Briffa, Norman P

    2005-01-01

    The beneficial effects of intraaortic balloon pump (IABP) in coronary artery bypass graft surgery with cardiopulmonary bypass have been reported. However, whether preoperative insertion of IABP in high-risk off-pump coronary artery bypass grafting (OPCAB) has any beneficial effects remains to be established. We report our experience of preoperative insertion of IABP in OPCAB.

  12. 21 CFR 870.4410 - Cardiopulmonary bypass in-line blood gas sensor.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass in-line blood gas sensor... Cardiopulmonary bypass in-line blood gas sensor. (a) Identification. A cardiopulmonary bypass in-line blood gas sensor is a transducer that measures the level of gases in the blood. (b) Classification. Class...

  13. Bivalirudin as an adjunctive anticoagulant to heparin in the treatment of heparin resistance during cardiopulmonary bypass-assisted cardiac surgery.

    PubMed

    McNair, E; Marcoux, J-A; Bally, C; Gamble, J; Thomson, D

    2016-04-01

    Heparin resistance (unresponsiveness to heparin) is characterized by the inability to reach acceptable activated clotting time values following a calculated dose of heparin. Up to 20% of the patients undergoing cardiothoracic surgery with cardiopulmonary bypass using unfractionated heparin (UFH) for anticoagulation experience heparin resistance. Although UFH has been the "gold standard" for anticoagulation, it is not without its limitations. It is contraindicated in patients with confirmed heparin-induced thrombocytopenia (HIT) and heparin or protamine allergy. The safety and efficacy of the use of the direct thrombin inhibitor bivalirudin for anticoagulation during cardiac surgery has been reported. However, there have been no reports on the treatment of heparin resistance with bivalirudin during CPB. In this review, we report the favorable outcome of our single-center experience with the alternative use of bivalirudin in the management of anticoagulation of heparin unresponsive patients undergoing coronary artery bypass graft surgery.

  14. Emergency EC-IC bypass for symptomatic atherosclerotic ischemic stroke.

    PubMed

    Horiuchi, Tetsuyoshi; Nitta, Junpei; Ishizaka, Shigetoshi; Kanaya, Kohei; Yanagawa, Takao; Hongo, Kazuhiro

    2013-10-01

    Previous studies have shown that extracranial-intracranial (EC-IC) bypass surgery has no preventive effect on subsequent ipsilateral ischemic stroke in patients with symptomatic atherosclerotic internal carotid occlusion and hemodynamic cerebral ischemia. A few studies have assessed whether an urgent EC-IC bypass surgery is an effective treatment for main trunk stenosis or occlusion in acute stage. The authors retrospectively reviewed 58 consecutive patients who underwent urgent EC-IC bypass for symptomatic internal carotid artery or the middle cerebral artery stenosis or occlusion between January 2003 and December 2011. Clinical characteristics and neuroimagings were evaluated and analyzed. Based on preoperative angiogram, responsible lesions were the internal carotid artery in 19 (32.8%) patients and the middle cerebral artery in 39 (67.2%). No hemorrhagic complication occurred. Sixty-nine percent of patients showed improvement of neurological function after surgery, and 74.1% of patients had favorable outcome. Unfavorable outcome was associated with insufficient collateral flow and new infarction after bypass surgery.

  15. 21 CFR 870.4430 - Cardiopulmonary bypass intracardiac suction control.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Cardiopulmonary bypass intracardiac suction control. 870.4430 Section 870.4430 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND... intracardiac suction control is a device which provides the vacuum and control for a cardiotomy return...

  16. 21 CFR 870.4430 - Cardiopulmonary bypass intracardiac suction control.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Cardiopulmonary bypass intracardiac suction control. 870.4430 Section 870.4430 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND... intracardiac suction control is a device which provides the vacuum and control for a cardiotomy return...

  17. Plutonium Finishing Plant assessment of confinement system bypass leakage

    SciTech Connect

    Dick, J.D.

    1996-09-30

    The purpose of this report is to document walk-through`s of the safety class confinement systems at the Plutonium Finishing Plant (PFP). In addition this document outlines the actions taken to assess the confinement system for bypass leakage as well as establishing disposition for discovered deficiencies at the PFP.

  18. 21 CFR 870.3545 - Ventricular bypass (assist) device.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Ventricular bypass (assist) device. 870.3545 Section 870.3545 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... partially implanted in the body. (b) Classification. Class III (premarket approval). (c) Date PMA or...

  19. 21 CFR 870.3545 - Ventricular bypass (assist) device.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Ventricular bypass (assist) device. 870.3545 Section 870.3545 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... partially implanted in the body. (b) Classification. Class III (premarket approval). (c) Date PMA or...

  20. Step by Step: Avoiding Spiritual Bypass in 12-Step Work

    ERIC Educational Resources Information Center

    Cashwell, Craig S.; Clarke, Philip B.; Graves, Elizabeth G.

    2009-01-01

    With spirituality as a cornerstone, 12-step groups serve a vital role in the recovery community. It is important for counselors to be mindful, however, of the potential for clients to be in spiritual bypass, which likely will undermine the recovery process.

  1. Thermal Reliability Study of Bypass Diodes in Photovoltaic Modules (Poster)

    SciTech Connect

    Zhang, Z.; Wohlgemuth, J.; Kurtz, S.

    2013-05-01

    This paper presents the result of high-temperature durability and thermal cycling testing and analysis for the selected diodes to study the detail of the thermal design and relative long-term reliability of the bypass diodes used to limit the detrimental effects of module hot-spot susceptibility.

  2. 21 CFR 870.3545 - Ventricular bypass (assist) device.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ventricular bypass (assist) device. 870.3545 Section 870.3545 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3545...

  3. 21 CFR 870.3545 - Ventricular bypass (assist) device.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Ventricular bypass (assist) device. 870.3545 Section 870.3545 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3545...

  4. 21 CFR 870.3545 - Ventricular bypass (assist) device.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Ventricular bypass (assist) device. 870.3545 Section 870.3545 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3545...

  5. Integral bypass diodes in an amorphous silicon alloy photovoltaic module

    NASA Technical Reports Server (NTRS)

    Hanak, J. J.; Flaisher, H.

    1991-01-01

    Thin-film, tandem-junction, amorphous silicon (a-Si) photovoltaic modules were constructed in which a part of the a-Si alloy cell material is used to form bypass protection diodes. This integral design circumvents the need for incorporating external, conventional diodes, thus simplifying the manufacturing process and reducing module weight.

  6. Bypassing the Local Rural Hospital for Outpatient Procedures

    ERIC Educational Resources Information Center

    Saunders, Charles; Bellamy, Gail R.; Menachemi, Nir; Chukmaitov, Askar S.; Brooks, Robert G.

    2009-01-01

    Purpose: To assess the amount of local rural hospital outpatient department (HOPD) bypass for outpatient procedures. Methods: We analyzed data on colonoscopies and upper gastrointestinal endoscopies performed in the state of Florida over the period 1997-2004. Findings: Approximately, 53% of colonoscopy and 45% of upper gastrointestinal endoscopy…

  7. 21 CFR 870.4320 - Cardiopulmonary bypass pulsatile flow generator.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Cardiopulmonary bypass pulsatile flow generator. 870.4320 Section 870.4320 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... of completion of a PDP is required to be filed with the Food and Drug Administration on or...

  8. 21 CFR 870.4320 - Cardiopulmonary bypass pulsatile flow generator.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Cardiopulmonary bypass pulsatile flow generator. 870.4320 Section 870.4320 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... of completion of a PDP is required to be filed with the Food and Drug Administration on or...

  9. Successful kinase bypass with new acyclovir phosphoramidate prodrugs.

    PubMed

    McGuigan, Christopher; Derudas, Marco; Bugert, Joachim J; Andrei, Graciela; Snoeck, Robert; Balzarini, Jan

    2008-08-01

    Novel phosphoramidates of acyclovir have been prepared and evaluated in vitro against acyclovir-sensitive and -resistant herpes simplex virus (HSV) types 1 and 2 and varicella-zoster virus (VZV). Unlike the parent nucleoside these novel phosphate prodrugs retain antiviral potency versus the ACV-resistant virus strain, suggesting an efficient bypass of the viral thymidine kinase.

  10. 21 CFR 870.4350 - Cardiopulmonary bypass oxygenator.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Cardiopulmonary bypass oxygenator. 870.4350 Section 870.4350 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES...-heart surgery. (b) Classification. Class II (special controls). The special control for this device...

  11. 21 CFR 870.4350 - Cardiopulmonary bypass oxygenator.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Cardiopulmonary bypass oxygenator. 870.4350 Section 870.4350 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES...-heart surgery. (b) Classification. Class II (special controls). The special control for this device...

  12. 21 CFR 870.4350 - Cardiopulmonary bypass oxygenator.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Cardiopulmonary bypass oxygenator. 870.4350 Section 870.4350 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES...-heart surgery. (b) Classification. Class II (special controls). The special control for this device...

  13. 21 CFR 870.4350 - Cardiopulmonary bypass oxygenator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass oxygenator. 870.4350 Section 870.4350 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES...-heart surgery. (b) Classification. Class II (special controls). The special control for this device...

  14. 21 CFR 870.4200 - Cardiopulmonary bypass accessory equipment.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Cardiopulmonary bypass accessory equipment. 870.4200 Section 870.4200 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN..., and (ii) The guidance document entitled “Guidance on the Performance Standard for Electrode Lead...

  15. 21 CFR 870.4200 - Cardiopulmonary bypass accessory equipment.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Cardiopulmonary bypass accessory equipment. 870.4200 Section 870.4200 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN..., and (ii) The guidance document entitled “Guidance on the Performance Standard for Electrode Lead...

  16. Coronary Artery Bypass Surgery - Multiple Languages: MedlinePlus

    MedlinePlus

    ... Artery Bypass Surgery Операция шунтирования коронарной ... displaying correctly on this page? See language display issues . Return to the MedlinePlus Health Information ...

  17. 46 CFR 56.20-20 - Valve bypasses.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Valve bypasses. 56.20-20 Section 56.20-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PIPING SYSTEMS AND APPURTENANCES..., and of a material of the same nominal chemical composition and physical properties as that used...

  18. Computer-assisted LAD bypass grafting at the open heart

    NASA Astrophysics Data System (ADS)

    Hartung, Christine; Gnahm, Claudia; Friedl, Reinhard; Hoffmann, Martin; Dietmayer, Klaus

    2009-02-01

    Open heart bypass surgery is the standard treatment in advanced coronary heart diseases. For an effective revascularization procedure, optimal placement of the bypass is very important. To accelerate the intraoperative localization of the anastomosis site and to increase the precision of the procedure, a concept for computer assistance in open heart bypass surgery has been developed comprising the following steps: 1. Preprocedural planning: A patient-specific coronary map with information on vessel paths and wall plaque formations is extracted from a multi-slice computed tomography (MSCT). On this basis, the heart surgeon and the cardiac radiologist define the optimal anastomosis site prior to surgery. 2. Intraoperative navigation: During surgery, data are recorded at the beating heart using a stereo camera system. After registering the pre- and intraoperative data sets, preprocedural information can be transferred to the surgical site by overlaying the coronary map and the planned anastomosis site on the live video stream. With this visual guidance system, the surgeon can navigate to the planned anastomosis site. In this work, the proposed surgical assistance system has been validated for the left anterior descending coronary artery (LAD). The accuracy of the registration mechanism has been evaluated in retrospective on patient data sets and the effects of breathing motion were quantified. The promising results of the retrospective evaluation led to the in-vivo application of the computer assistance system during several bypass grafting procedures. Intraoperative navigation has been performed successfully and postoperative evaluation confirms that the bypass grafts were accurately positioned to the preoperatively planned anastomosis sites.

  19. Atrial Fibrillation, Neurocognitive Decline and Gene Expression After Cardiopulmonary Bypass

    PubMed Central

    Dalal, Rahul S.; Sabe, Ashraf A.; Elmadhun, Nassrene Y.; Ramlawi, Basel; Sellke, Frank W.

    2015-01-01

    OBJECTIVE Atrial fibrillation and neurocognitive decline are common complications after cardiopulmonary bypass. By utilizing genomic microarrays we investigate whether gene expression is associated with postoperative atrial fibrillation and neurocognitive decline. METHODS Twenty one cardiac surgery patients were prospectively matched and underwent neurocognitive assessments pre-operatively and four days postoperatively. The whole blood collected in the pre-cardiopulmonary bypass, 6 hours after-cardiopulmonary bypass, and on the 4th postoperative day was hybridized to Affymetrix Gene Chip U133 Plus 2.0 Microarrays. Gene expression in patients who developed postoperative atrial fibrillation and neurocognitive decline (n=6; POAF+NCD) was compared with gene expression in patients with postoperative atrial fibrillation and normal cognitive function (n=5; POAF+NORM) and patients with sinus rhythm and normal cognitive function (n=10; SR+NORM). Regulated genes were identified using JMP Genomics 4.0 with a false discovery rate of 0.05 and fold change of >1.5 or <-1.5. RESULTS Eleven patients developed postoperative atrial fibrillation. Six of these also developed neurocognitive decline. Of the 12 patients with sinus rhythm, only 2 developed neurocognitive decline. POAF+NCD patients had unique regulation of 17 named genes preoperatively, 60 named genes six hours after cardiopulmonary bypass, and 34 named genes four days postoperatively (P<0.05) compared with normal patients. Pathway analysis demonstrated that these genes are involved in cell death, inflammation, cardiac remodeling and nervous system function. CONCLUSION Patients who developed postoperative atrial fibrillation and neurocognitive decline after cardiopulmonary bypass may have differential genomic responses compared to normal patients and patients with only postoperative atrial fibrillation, suggesting common pathophysiology for these conditions. Further exploration of these genes may provide insight into the

  20. Mass transfer from bypassed zones during gas injection

    SciTech Connect

    Burger, J.E.; Mohanty, K.K.

    1995-12-31

    Gasflooding in oil reservoirs leads to bypassing of the oil due to gravitational, viscous and/or heterogeneity effects. The bypassed oil can be recovered by the flowing solvent by pressure-driven, gravity-driven, dispersion/diffusion-driven and capillarity-driven crossflow/mass transfer. It is difficult to represent all of these mechanisms explicitly in large-scale simulations. In this work, we have studied the effect of the orientation of the bypassed region and the enrichment of the solvent on the mass transfer. Laboratory-scale mass transfer and coreflood experiments were conducted. Numerical simulation was used to identify the role of the different mechanisms. Results indicate that the mass transfer is the least for the vertical orientation, intermediate for the inverted orientation and the highest for the horizontal orientation. The mass transfer increases with enrichment for all orientations. Liquid phase diffusion controls vertical orientation mass transfer for the fluids studied. Phase behavior determines the liquid phase saturation. Capillary pumping does not contribute to the mass transfer of oil because the interfacial tension decreases towards the flowing region. Gravity-driven flow contributes the most to the mass transfer in the horizontal and the inverted orientations. The gravity-driven flow, however, is impeded by the capillarity whose magnitude decreases with solvent enrichment. Oil recovery in the horizontal gasfloods is nonmonotonic with enrichment for this fluid system in an almost homogeneous Berea core. Multiphase flow in the near-miscible floods leads to less gravity override compared to the FCM floods. In the heterogeneous core studied, the heterogeneity is very strong and the capillary forces do not prevent bypassing. The capillary forces, in fact, reduce oil recovery by diminishing mass transfer from the bypassed regions.

  1. Impact of top end anastomosis design on patency and flow stability in coronary artery bypass grafting.

    PubMed

    Koyama, Sachi; Kitamura, Tadashi; Itatani, Keiichi; Yamamoto, Tadashi; Miyazaki, Shohei; Oka, Norihiko; Nakashima, Kouki; Horai, Tetsuya; Ono, Minoru; Miyaji, Kagami

    2016-05-01

    For coronary artery bypass grafting (CABG), free grafts such as a saphenous vein or radial artery are often used for grafts to the lateral and posterior walls. However, the relationship between top-end anastomosis design and long-term patency remains unknown. Because coronary artery blood flow is dominant during diastole, top-end anastomosis may work better if the graft is directed towards the apex, whereas the shortest graft pathway appears to be most efficient. Using computational fluid dynamic models, we evaluated the hemodynamic variables that were affected by the angle of the top-end anastomosis. We created three-dimensional geometries of the aortic root with coronary arteries that involved 75 % stenosis in the obtuse marginal and postero-lateral branches. Two bypass models under vasodilator administration were created: in a"Model A", the top-end anastomosis is parallel to the long axis of the ascending aorta and the graft passed over the conus directed towards the apex; in a "Model B", the top-end anastomosis is directed toward the shortest pathway, and form near the right angles to the long axis of the ascending aorta. Wall shear stress (WSS) and its fluctuation, an oscillatory shear index (OSI) were evaluated to predict fibrosis progression at the anastomosis site and graft flow. Graft flow was 197.3 ml/min and 207.3 ml/min in the "Model A" and "Model B", respectively. The minimal WSS value inside the graft with the "Model A" and "Model B" was 0.53 Pa and 4.09 Pa, respectively, and the OSI value was 0.46 and 0.04, respectively. The top-end anastomosis of a free graft should be directed vertically towards the aorta to achieve the shortest graft pathway to maintain a high graft flow rate and to avoid the risks of endothelial fibrosis and plaque progression over the long-term after CABG.

  2. Nonlinear optimal control of bypass transition in a boundary layer flow

    NASA Astrophysics Data System (ADS)

    Xiao, Dandan; Papadakis, George

    2016-11-01

    Bypass transition is observed in a flat-plate boundary-layer flow when high levels of free stream turbulence are present. This scenario is characterized by the formation of streamwise elongated streaks inside the boundary layer, their break down into turbulent spots and eventually fully turbulent flow. In the current work, we perform DNS simulations of control of bypass transition in a zero-pressure-gradient boundary layer. A non-linear optimal control algorithm is developed that employs the direct-adjoint approach to minimise a quadratic cost function based on the deviation from the Blasius velocity profile. Using the Lagrange variational approach, the distribution of the blowing/suction control velocity is found by solving iteratively the non-linear Navier-Stokes and its adjoint equations in a forward/backward loop. The optimisation is performed over a finite time horizon during which the Lagrange functional is to be minimised. Large values of optimisation horizon result in instability of the adjoint equations. The results show that the controller is able to reduce the turbulent kinetic energy of the flow in the region where the objective function is defined and the velocity profile is seen to approach the Blasius solution. Significant drag reduction is also achieved.

  3. iStent trabecular micro-bypass stent for open-angle glaucoma

    PubMed Central

    Le, Kim; Saheb, Hady

    2014-01-01

    Trabecular micro-bypass stents, commonly known as iStents, are micro-invasive glaucoma surgery (MIGS) devices used to treat open-angle glaucoma. Like other MIGS procedures that enhance trabecular outflow, the iStent lowers intraocular pressure (IOP) by creating a direct channel between the anterior chamber and Schlemm’s canal. iStents are typically implanted at the time of phacoemulsification for patients with open-angle glaucoma and visually significant cataracts. This review summarizes the published data regarding the efficacy, safety, and cost considerations of trabecular micro-bypass stents. Most studies found statistically significant reductions in mean IOP and ocular medication use after combined phacoemulsification with single or double iStent implantation. The devices were found to be very safe, with a safety profile similar to that of cataract surgery. Complications were infrequent, with the most common complications being temporary stent obstruction or malposition, which resolved with observation or secondary procedures. Future studies are needed to evaluate long-term outcomes, patient satisfaction, cost effectiveness, and expanded indications. PMID:25284980

  4. Bypass balloon pumping: a newly developed device for mechanical circulatory support in heart failure.

    PubMed

    Hoshino, M; Asakura, T; Yasuura, K; Ogawa, Y; Okamoto, H; Matsuura, A

    2003-02-01

    Various types of assist devices have been developed for severe heart failures. Among them, intra-aortic balloon pumping (IABP) has achieved popularity, mainly in the treatment of patients with either severe cardiac infarction or low cardiac output syndrome (LOS) after open-heart surgery. However, IABP has a limitation in that although it acts as a pressure support, it cannot directly support flow volume. In cases of severe pump failure, stronger pump support would be required. However, there is a limit in the clinical use of temporary mechanical support using a pump because of the costs of the expensive equipment. With this in mind, we came up with a new idea in which the motion of a balloon in IABP system is converted into a power source for creating a one-way stream. In order to realize our idea, we made a J-shaped sample model of pulsating chamber incorporating two ball valves. In the hydrodynamic experiment using our new device, flows over 2500 ml/min (Max. 3475 ml/min) were obtained. The percent changes in parameters such as TTI, DPTI and bypass flows obtained by the experiment of left ventricular bypass have demonstrated that our assist system is effective for reducing cardiac work.

  5. Factors associated with mortality in patients undergoing coronary artery bypass grafting 1

    PubMed Central

    Koerich, Cintia; Lanzoni, Gabriela Marcellino de Melo; Erdmann, Alacoque Lorenzini

    2016-01-01

    ABSTRACT Objective: to investigate the factors associated with mortality in patients undergoing coronary artery bypass grafting in a cardiovascular referral hospital in Santa Catarina. Method: quantitative, exploratory, descriptive and retrospective study. The medical records of 1447 patients, from 2005 to 2013, were analyzed for statistically related variables, these being: profile, hospitalization diagnosis, risk factors for coronary artery disease, complications recorded during the hospitalization, length of hospitalization and cause of death. Results: the mortality rate was 5.3% during the study period. Death was more common in females and those of black skin color, with a mean age of 65 years. Acute myocardial infarction was the most common hospitalization diagnosis. The majority of the complications recorded during hospitalization were characterized by changes in the cardiovascular system, with longer hospitalization periods being directly related to death from septic shock. Conclusion: the data provide subsidies for nursing work with preventive measures and early detection of complications associated with coronary artery bypass grafting. This reinforces the importance of using the data as quality indicators, aiming to guarantee care guided by reliable information to guide managers in planning patient care and high complexity health services. PMID:27508918

  6. [Increased fibrinolytic activity during cardiopulmonary bypass is caused by activated protein C system].

    PubMed

    Gando, S; Tedo, I; Masio, H; Goda, Y; Kawahigashi, H

    1994-06-01

    To examine the hypothesis that activated protein C system during cardiopulmonary bypass surgery may increase fibrinolytic activity during cardiopulmonary bypass, protein C activity, protein C antigen and thrombomodulin of sixteen patients undergoing elective cardiopulmonary bypass surgery were investigated after induction of anesthesia, before and after cardiopulmonary bypass, and at the end of operation. Protein C activity decreased and thrombomodulin increased significantly after the cardiopulmonary bypass. There were no significant correlations of thrombomodulin with protein C activity and protein C antigen. In conclusion, we have demonstrated that protein C system is activated and circulating thrombomodulin appears in the systemic circulation during cardiopulmonary bypass surgery and this enhanced activation of protein C system is possibly related to the reported increase of fibrinolytic activity during cardiopulmonary bypass.

  7. The Platelet Function Defect of Cardiopulmonary Bypass.

    DTIC Science & Technology

    1992-11-24

    fibrinolytic and coagulation systems occur during CPB,1 a platelet function defect is generally considered to be the primary CPB-induced hemostatic...platelets.39 OKM5 (provided by Dr. Patricia Rao, Ortho Diagnostic Systems , Raritan, NJ) is directed against platelet membrane GPIV.40 Flow Cytometric...22 after degranulation.7-14-16-18 Utilizing washed platelet systems , Nieuwenhuis et al.14 found a modest increase during CPB of the platelet

  8. Anesthetic implications of subxiphoid coronary artery bypass surgery

    PubMed Central

    Chakravarthy, Murali; Veerappa, Muralimanohar; Jawali, Vivek; Pandya, Nischal; Krishnamoorthy, Jayaprakash; Muniraju, Geetha; George, Antony; Baishya, Jitumoni

    2016-01-01

    Background: Minimal invasive surgeries are carried out to benefit the patient with less pain, blood loss, mechanical ventilation and hospital stay; a smaller scar is not the aim. Minimal invasive cardiac surgeries are carried out via small sternotomy, small thoracotomy and via robotic arms. Subxiphoid route is a novel method and avoids sternotomy. Aim: This case series is an attempt to understand the anesthetic modifications required. Secondly, whether it is feasible to carry out subxiphoid coronary artery bypass surgery. Methods: Elective patients scheduled to undergo subxiphoid coronary artery bypass surgery were chosen. The surgeries were conducted under general anesthesia with left lung isolation via either endobronchial tube or bronchial blocker. Results: We conducted ten (seven males and 3 females) coronary artery bypass graft surgeries via subxiphoid technique. The mean EuroSCORE was 1.7 and the mean ejection fraction was 53.6. Eight patients underwent surgery via endobronchial tube, while, in the remaining two lung isolation was obtained using bronchial blocker. Mean blood loss intraoperatively was 300 ± 42 ml and postoperatively 2000 ± 95 ml. The pain score on the postoperative day ‘0’ was 4.3 ± 0.6 and 2.3 ± 0.7 on the day of discharge. Length of stay in the hospital was 4.8 ± 0.9 days. There were no complications, blood transfusions, conversion to cardiopulmonary bypass. The modifications in the anesthetic and surgical techniques are, use of left lung isolation using either endobronchial tube or bronchial blocker, increased duration for conduit harvesting, grafting, requirement of transesophageal echocardiography monitoring in addition to hemodynamic monitoring. Other minor requirements are transcutaneous pacing and defibrillator pads, a wedge under the chest to ‘lift’ up the chest, sparing right femoral artery and vein (to serve as vascular access) for an unlikely event of conversion to cardiopulmonary bypass. Any anesthesiologist wishing

  9. Brain machine interface and limb reanimation technologies: restoring function after spinal cord injury through development of a bypass system.

    PubMed

    Lobel, Darlene A; Lee, Kendall H

    2014-05-01

    Functional restoration of limb movement after traumatic spinal cord injury (SCI) remains the ultimate goal in SCI treatment and directs the focus of current research strategies. To date, most investigations in the treatment of SCI focus on repairing the injury site. Although offering some promise, these efforts have met with significant roadblocks because treatment measures that are successful in animal trials do not yield similar results in human trials. In contrast to biologic therapies, there are now emerging neural interface technologies, such as brain machine interface (BMI) and limb reanimation through electrical stimulators, to create a bypass around the site of the SCI. The BMI systems analyze brain signals to allow control of devices that are used to assist SCI patients. Such devices may include a computer, robotic arm, or exoskeleton. Limb reanimation technologies, which include functional electrical stimulation, epidural stimulation, and intraspinal microstimulation systems, activate neuronal pathways below the level of the SCI. We present a concise review of recent advances in the BMI and limb reanimation technologies that provides the foundation for the development of a bypass system to improve functional outcome after traumatic SCI. We also discuss challenges to the practical implementation of such a bypass system in both these developing fields.

  10. Variation of Binge Eating One Year after Roux-en-Y Gastric Bypass and Its Relationship with Excess Weight Loss

    PubMed Central

    Brito, César Luis de Souza; Debon, Letícia Manoel; Brandalise, Lívia Nora; de Azevedo, Juliana Tainski; Monbach, Karin Daniele; Heberle, Luísa Schmidt; Mottin, Cláudio Corá

    2016-01-01

    Background Bariatric surgery is the most effective treatment for obesity classes II and III. However, some patients do not get the desired results or initially lose and then regain the lost weight. Identifying these individuals early on and treating them adequately remains a challenge. As binge eating directly affects food intake, the study of this symptom and its relation to bariatric surgery and its results is increasing, because it appears to have an influence on the results of surgery. Objectives This study aimed to see how binge eating changes, measured with the Binge Eating Scale, interferes in the % excess weight loss one year after Roux-en-Y gastric bypass. Methods We conducted a cross-sectional study with 149 patients older than 18 years who were evaluated one year after undergoing Roux-en-Y gastric bypass. The variation in the intensity of binge eating was measured with the pre- and postoperative Binge Eating Scale scores. Results The variation of one unit in the Binge Eating Scale implied an inverse variation of 0.41% of % excess weight loss (p<0.05). The correlation coefficient between the variation of binge eating and the % excess weight loss was -0.186 (p = 0.033). The correlation coefficient between the binge eating symptoms one year after surgery and the % excess weight loss was -0.353 (p<0.001). Conclusions There was a correlation between the variation of binge eating one year after gastric bypass and the % excess weight loss. The correlation between binge eating and the % excess weight loss was greater after the surgery than it was at the preoperative stage. This study provides new, valuable information on the intensity and variation of binge eating symptoms one year after gastric bypass, which, to the best of our knowledge, have not been studied in depth earlier. PMID:27992541

  11. Distinctive striatal dopamine signaling after dieting and gastric bypass.

    PubMed

    Hankir, Mohammed K; Ashrafian, Hutan; Hesse, Swen; Horstmann, Annette; Fenske, Wiebke K

    2015-05-01

    Highly palatable and/or calorically dense foods, such as those rich in fat, engage the striatum to govern and set complex behaviors. Striatal dopamine signaling has been implicated in hedonic feeding and the development of obesity. Dieting and bariatric surgery have markedly different outcomes on weight loss, yet how these interventions affect central homeostatic and food reward processing remains poorly understood. Here, we propose that dieting and gastric bypass produce distinct changes in peripheral factors with known roles in regulating energy homeostasis, resulting in differential modulation of nigrostriatal and mesolimbic dopaminergic reward circuits. Enhancement of intestinal fat metabolism after gastric bypass may also modify striatal dopamine signaling contributing to its unique long-term effects on feeding behavior and body weight in obese individuals.

  12. Fault detection and bypass in a sequence information signal processor

    NASA Technical Reports Server (NTRS)

    Peterson, John C. (Inventor); Chow, Edward T. (Inventor)

    1992-01-01

    The invention comprises a plurality of scan registers, each such register respectively associated with a processor element; an on-chip comparator, encoder and fault bypass register. Each scan register generates a unitary signal the logic state of which depends on the correctness of the input from the previous processor in the systolic array. These unitary signals are input to a common comparator which generates an output indicating whether or not an error has occurred. These unitary signals are also input to an encoder which identifies the location of any fault detected so that an appropriate multiplexer can be switched to bypass the faulty processor element. Input scan data can be readily programmed to fully exercise all of the processor elements so that no fault can remain undetected.

  13. Modelling of natural and bypass transition in aerodynamics

    NASA Astrophysics Data System (ADS)

    Fürst, Jiří; Straka, Petr; Příhoda, Jaromír

    2014-03-01

    Most of transition models are proposed for modelling of the bypass transition common in the internal aerodynamics especially in turbomachinery where free stream turbulence is the dominant parameter affecting the transition onset. Free-stream turbulence level in the external aerodynamics is usually noticeably lower and so the natural transition often occurs in flows around airfoils. The transition model with the algebraic equation for the intermittency coefficient proposed originally by Straka and Příhoda [3] for the bypass transition was modified for modelling of the transition at low free-stream turbulence. The modification is carried out using experimental data of Schubauer and Skramstad [18]. Further, the three-equation k-kL-ω model proposed by Walters and Cokljat [10] was used for the modelling of the transition at low free-stream turbulence. Both models were tested by means of the incompressible flow around airfoils at moderate and very low free-stream turbulence.

  14. Glycemic control and outcome related to cardiopulmonary bypass.

    PubMed

    Thiessen, Steven; Vanhorebeek, Ilse; Van den Berghe, Greet

    2015-06-01

    Perioperative hyperglycemia, aggravated by cardiopulmonary bypass, is associated with adverse outcome in adult and pediatric patients. Whereas hyperglycemia was originally perceived as an adaptive response to surgical stress, it is now clear that glycemic control is a strategy to reduce adverse outcomes after cardiac surgery and cardiopulmonary bypass. The optimal blood glucose target, whether or not glycemic control should be initiated already intraoperatively, and whether or not perioperative glucose administration affects the impact of glycemic control on ischemia-reperfusion damage remain open questions. Hypoglycemia, the risk of which is increased with glycemic control, is also associated with adverse outcomes. However, it remains controversial whether brief episodes of hypoglycemia, rapidly corrected during glycemic control, have adverse effects on outcome. This review gives an overview of the currently available literature on glycemic control during and after cardiac surgery and focuses on the indicated open questions about this intervention for this specific patient population.

  15. Fatal pyoderma gangrenosum with pathergy after coronary artery bypass grafting.

    PubMed

    Bryan, Charles S

    2012-01-01

    Surgeons and others who perform invasive procedures should be aware of the possibility of pyoderma gangrenosum and the risk of pathergy in patients who have a history of unexplained skin ulcers or poor wound-healing. We report the case of a 70-year-old man in whom diffuse erythema over the anterior chest wall and marked leukocytosis developed after coronary artery bypass grafting. This prompted débridement and opening of the sternotomy wound. The cause of the erythema was pyoderma gangrenosum that expressed the pathergy phenomenon. The pyoderma gangrenosum subsequently involved the saphenous vein harvest site, a chest-tube site, and a previously healed abdominal scar. The patient died when an exposed saphenous vein graft was perforated. To our knowledge, this is the 9th reported case of pathergy due to pyoderma gangrenosum after coronary artery bypass grafting and the first with a fatal outcome.

  16. Coronary artery bypass grafting in a patient with organophosphate poisoning.

    PubMed

    Pieris, Rajeeva R; Fernando, Ravindra

    2015-08-30

    A 43-year-old male, with no previous history of mental illness, was diagnosed with coronary heart disease, after which he became acutely depressed and attempted suicide by ingesting an organophosphate pesticide. He was admitted to an intensive care unit and treated with pralidoxime, atropine, and oxygen. His coronary occlusion pattern required early coronary artery bypass grafting (CABG) surgery. His family, apprehensive of a repeat suicidal attempt, requested surgery be performed as soon as possible. He recovered well from the OP poisoning and was mentally fit to express informed consent 2 weeks after admission. Seventeen days after poisoning, he underwent coronary artery bypass grafting and recovered uneventfully. Six years later, he remains in excellent health. We report this case because to the best of our knowledge there is no literature regarding CABG performed soon after organophosphate poisoning.

  17. Pharmacological Bypass of Cockayne Syndrome B Function in Neuronal Differentiation

    PubMed Central

    Wang, Yuming; Jones-Tabah, Jace; Chakravarty, Probir; Stewart, Aengus; Muotri, Alysson; Laposa, Rebecca R.; Svejstrup, Jesper Q.

    2016-01-01

    Summary Cockayne syndrome (CS) is a severe neurodevelopmental disorder characterized by growth abnormalities, premature aging, and photosensitivity. Mutation of Cockayne syndrome B (CSB) affects neuronal gene expression and differentiation, so we attempted to bypass its function by expressing downstream target genes. Intriguingly, ectopic expression of Synaptotagmin 9 (SYT9), a key component of the machinery controlling neurotrophin release, bypasses the need for CSB in neuritogenesis. Importantly, brain-derived neurotrophic factor (BDNF), a neurotrophin implicated in neuronal differentiation and synaptic modulation, and pharmacological mimics such as 7,8-dihydroxyflavone and amitriptyline can compensate for CSB deficiency in cell models of neuronal differentiation as well. SYT9 and BDNF are downregulated in CS patient brain tissue, further indicating that sub-optimal neurotrophin signaling underlies neurological defects in CS. In addition to shedding light on cellular mechanisms underlying CS and pointing to future avenues for pharmacological intervention, these data suggest an important role for SYT9 in neuronal differentiation. PMID:26972010

  18. Human gut microbiota in obesity and after gastric bypass.

    PubMed

    Zhang, Husen; DiBaise, John K; Zuccolo, Andrea; Kudrna, Dave; Braidotti, Michele; Yu, Yeisoo; Parameswaran, Prathap; Crowell, Michael D; Wing, Rod; Rittmann, Bruce E; Krajmalnik-Brown, Rosa

    2009-02-17

    Recent evidence suggests that the microbial community in the human intestine may play an important role in the pathogenesis of obesity. We examined 184,094 sequences of microbial 16S rRNA genes from PCR amplicons by using the 454 pyrosequencing technology to compare the microbial community structures of 9 individuals, 3 in each of the categories of normal weight, morbidly obese, and post-gastric-bypass surgery. Phylogenetic analysis demonstrated that although the Bacteria in the human intestinal community were highly diverse, they fell mainly into 6 bacterial divisions that had distinct differences in the 3 study groups. Specifically, Firmicutes were dominant in normal-weight and obese individuals but significantly decreased in post-gastric-bypass individuals, who had a proportional increase of Gammaproteobacteria. Numbers of the H(2)-producing Prevotellaceae were highly enriched in the obese individuals. Unlike the highly diverse Bacteria, the Archaea comprised mainly members of the order Methanobacteriales, which are H(2)-oxidizing methanogens. Using real-time PCR, we detected significantly higher numbers of H(2)-utilizing methanogenic Archaea in obese individuals than in normal-weight or post-gastric-bypass individuals. The coexistence of H(2)-producing bacteria with relatively high numbers of H(2)-utilizing methanogenic Archaea in the gastrointestinal tract of obese individuals leads to the hypothesis that interspecies H(2) transfer between bacterial and archaeal species is an important mechanism for increasing energy uptake by the human large intestine in obese persons. The large bacterial population shift seen in the post-gastric-bypass individuals may reflect the double impact of the gut alteration caused by the surgical procedure and the consequent changes in food ingestion and digestion.

  19. Human gut microbiota in obesity and after gastric bypass

    PubMed Central

    Zhang, Husen; DiBaise, John K.; Zuccolo, Andrea; Kudrna, Dave; Braidotti, Michele; Yu, Yeisoo; Parameswaran, Prathap; Crowell, Michael D.; Wing, Rod; Rittmann, Bruce E.; Krajmalnik-Brown, Rosa

    2009-01-01

    Recent evidence suggests that the microbial community in the human intestine may play an important role in the pathogenesis of obesity. We examined 184,094 sequences of microbial 16S rRNA genes from PCR amplicons by using the 454 pyrosequencing technology to compare the microbial community structures of 9 individuals, 3 in each of the categories of normal weight, morbidly obese, and post-gastric-bypass surgery. Phylogenetic analysis demonstrated that although the Bacteria in the human intestinal community were highly diverse, they fell mainly into 6 bacterial divisions that had distinct differences in the 3 study groups. Specifically, Firmicutes were dominant in normal-weight and obese individuals but significantly decreased in post-gastric-bypass individuals, who had a proportional increase of Gammaproteobacteria. Numbers of the H2-producing Prevotellaceae were highly enriched in the obese individuals. Unlike the highly diverse Bacteria, the Archaea comprised mainly members of the order Methanobacteriales, which are H2-oxidizing methanogens. Using real-time PCR, we detected significantly higher numbers of H2-utilizing methanogenic Archaea in obese individuals than in normal-weight or post-gastric-bypass individuals. The coexistence of H2-producing bacteria with relatively high numbers of H2-utilizing methanogenic Archaea in the gastrointestinal tract of obese individuals leads to the hypothesis that interspecies H2 transfer between bacterial and archaeal species is an important mechanism for increasing energy uptake by the human large intestine in obese persons. The large bacterial population shift seen in the post-gastric-bypass individuals may reflect the double impact of the gut alteration caused by the surgical procedure and the consequent changes in food ingestion and digestion. PMID:19164560

  20. Experiments on bypassing during gasfloods in heterogeneous porous media

    SciTech Connect

    Burger, J.E.; Springate, G.S.; Mohanty, K.K.

    1996-05-01

    Mass transfer from a bypassed region to a flowing region is a very strong function of the solvent phase behavior. Diffusion, dispersion, and capillarity-driven crossflow can contribute to this mass transfer in addition to pressure- and buoyancy-driven crossflow. The authors experiments indicated that the mass transfer rate increased with enrichment. Liquid phase diffusion played a significant role and capillary pumping did not contribute to mass transfer in the cases studied.

  1. Jejunal bypass stimulation of pancreatic growth and cholecystokinin secretion in rats: importance of luminal nutrients.

    PubMed Central

    Levan, V H; Liddle, R A; Green, G M

    1987-01-01

    The effect of jejunal bypass on pancreatic growth and plasma cholecystokinin (CCK) was investigated in rats. Rats underwent bypass of jejunum or sham operation. Rats with jejunal bypass were further divided into three groups; one group received a continuous infusion of a partially hydrolysed liquid diet (Vital) into the bypassed jejunum; a second group received the nutrient solution mixed with trypsin and infused into the bypassed jejunum; the third bypass group did not receive infusion of nutrient or trypsin into the jejunum. Jejunal bypass alone did not significantly stimulate pancreatic growth or DNA content at one or two weeks postoperative. Infusion of nutrient solution into the bypassed jejunum stimulated pancreatic growth and DNA content, with maximal increases of 185% and 181% for pancreatic weight and DNA content, respectively, at two weeks. This coincided with significant increases in postabsorptive plasma CCK concentrations. Infusion of pancreatic proteases into the bypassed jejunum partially reversed the effects of nutrient infusion. These results suggest that exclusion of bile-pancreatic juice or pancreatic proteases from the jejunum does not lead to maximal release of CCK unless the jejunum receives luminal nutrients. It is proposed that CCK release from rat jejunum occurs spontaneously in the absence of pancreatic proteases, and that luminal nutrients in bypassed jejunum increase plasma CCK and stimulate pancreatic growth by maintaining synthesis of CCK. PMID:3692314

  2. [Return to work after coronary artery bypass surgery].

    PubMed

    Vasiliauskas, Donatas; Raugaliene, Rasa; Grizas, Vytautas; Marcinkeviciene, Jolanta; Jasiukeviciene, Lina; Kubilius, Raimondas; Barsys, Vygantas

    2008-01-01

    The aim of this study was to assess the possible reasons for not returning to work after coronary artery bypass surgery. A total of 134 patients (aged 65 years and younger) who underwent coronary bypass surgery in 2003 were examined. The analysis was performed in three groups of the patients: Group I, patients who were employed before surgery and returned to work after it (n=51); Group II, patients who were employed before surgery but did not return to work after surgery (n=55); and Group III, patients who were unemployed before and remained unemployed after surgery due to health problems (n=28). Number of injured coronary arteries, the extent of operation, postoperative complications, risk factors for ischemic heart disease, clinical status of patients (angina pain and heart failure), physical tolerance, and return to work within one year after coronary bypass surgery were analyzed. It was found that 48.1% of patients who were employed before surgery returned to work after myocardial revascularization. About 30% of patients experienced recurrent symptoms of angina after 12 months. Logistic regression analysis revealed that return to work was significantly influenced by female gender, physical pattern of work, age, and severity of heart failure.

  3. Off-pump coronary artery bypass grafting in octogenarians

    PubMed Central

    2016-01-01

    Enhanced life expectancy has confronted cardiac surgery with a rapidly growing population of octogenarians needing coronary artery bypass grafting (CABG). Octogenarians are deemed a high-risk patient population with increased postoperative morbidity and mortality following conventional CABG using cardiopulmonary bypass (CPB). In such patients reducing the invasiveness of the surgical procedure by avoiding CPB may be tried in an attempt to improve outcomes. The increasing performance of off-pump coronary artery bypass (OPCAB) grafting within certain centers reflects surgeon preference to avoid the inherent risks of CPB and cardioplegic arrest including hemodilution, nonpulsatile arterial flow, global myocardial ischemia, atherosclerotic embolization from aortic manipulation, and systemic inflammatory response. Although OPCAB grafting is a well-established surgical myocardial revascularization strategy, its actual benefits in terms of morbidity and mortality remain questionable in the general population. In the higher risk octogenarian patients, however, there is a potential for more tangible clinical benefits when CPB is avoided. This review article provides an overview of the impact of OPCAB grafting on postoperative mortality and morbidity in octogenarians. PMID:27942398

  4. Thermodynamic Cycle Analysis of Magnetohydrodynamic-Bypass Airbreathing Hypersonic Engines

    NASA Technical Reports Server (NTRS)

    Litchford, Ron J.; Bityurin, Valentine A.; Lineberry, John T.

    1999-01-01

    Established analyses of conventional ramjet/scramjet performance characteristics indicate that a considerable decrease in efficiency can be expected at off-design flight conditions. This can be explained, in large part, by the deterioration of intake mass flow and limited inlet compression at low flight speeds and by the onset of thrust degradation effects associated with increased burner entry temperature at high flight speeds. In combination, these effects tend to impose lower and upper Mach number limits for practical flight. It has been noted, however, that Magnetohydrodynamic (MHD) energy management techniques represent a possible means for extending the flight Mach number envelope of conventional engines. By transferring enthalpy between different stages of the engine cycle, it appears that the onset of thrust degradation may be delayed to higher flight speeds. Obviously, the introduction of additional process inefficiencies is inevitable with this approach, but it is believed that these losses are more than compensated through optimization of the combustion process. The fundamental idea is to use MHD energy conversion processes to extract and bypass a portion of the intake kinetic energy around the burner. We refer to this general class of propulsion system as an MHD-bypass engine. In this paper, we quantitatively assess the performance potential and scientific feasibility of MHD-bypass airbreathing hypersonic engines using ideal gasdynamics and fundamental thermodynamic principles.

  5. Thermodynamic Cycle Analysis of Magnetohydrodynamic-Bypass Hypersonic Airbreathing Engines

    NASA Technical Reports Server (NTRS)

    Litchford, R. J.; Cole, J. W.; Bityurin, V. A.; Lineberry, J. T.

    2000-01-01

    The prospects for realizing a magnetohydrodynamic (MHD) bypass hypersonic airbreathing engine are examined from the standpoint of fundamental thermodynamic feasibility. The MHD-bypass engine, first proposed as part of the Russian AJAX vehicle concept, is based on the idea of redistributing energy between various stages of the propulsion system flow train. The system uses an MHD generator to extract a portion of the aerodynamic heating energy from the inlet and an MHD accelerator to reintroduce this power as kinetic energy in the exhaust stream. In this way, the combustor entrance Mach number can be limited to a specified value even as the flight Mach number increases. Thus, the fuel and air can be efficiently mixed and burned within a practical combustor length, and the flight Mach number operating envelope can be extended. In this paper, we quantitatively assess the performance potential and scientific feasibility of MHD-bypass engines using a simplified thermodynamic analysis. This cycle analysis, based on a thermally and calorically perfect gas, incorporates a coupled MHD generator-accelerator system and accounts for aerodynamic losses and thermodynamic process efficiencies in the various engin components. It is found that the flight Mach number range can be significantly extended; however, overall performance is hampered by non-isentropic losses in the MHD devices.

  6. Helical type coronary bypass graft performance: Experimental investigations.

    PubMed

    Bernad, Sandor I; Bosioc, Alin I; Bernad, Elena S; Craina, Marius L

    2015-01-01

    Optimal graft design has been an objective of many researchers to find correlations between hemodynamics and graft failure. Compared to planar grafts, the helical graft configurations improve hemodynamic performance including the promotion of flow mixing and reduction of flow stagnation regions. In order to evaluate the advantages and disadvantages of the suggested helical type bypass graft model in comparison to a conventional bypass graft configuration, three experimental models were designed and evaluated. The character of complex vortex structures created in the area between the heel and the occluded section depends on the flow parameters (in the case of the straight graft). We have identified two vortices in the symmetrical plane (proximal and distal to the anastomosis). In the new design of the two-turn helical graft, the stagnation point is eliminated from the anastomoses at different time intervals compared to the conventional straight bypass model The present study indicated that the magnitude of the pressure drop along a helical graft was considerably increased compared to a traditional graft which, while still physiologically advantageous, can be surpassed by an optimal geometry model.

  7. EARLY POSTOPERATIVE COMPLICATIONS IN ROUX-EN-Y GASTRIC BYPASS

    PubMed Central

    STOLL, Aluisio; ROSIN, Leandro; DIAS, Mariana Fernandes; MARQUIOTTI, Bruna; GUGELMIN, Giovana; STOLL, Gabriela Fanezzi

    2016-01-01

    ABSTRACT Background: Roux-en-Y gastric bypass is one of the most common bariatric surgery and leads to considerable weight loss in the first months. Aim: To quantify the main early postoperative complications in patients submitted to the gastric bypass. Method: Observational retrospective cohort. Data of 1051 patients with class II obesity associated with comorbidities or class III obesity submitted to the gastric bypass with 30 days of follow-up starting from the date of the surgery. Results: The age average was 36 years with a predominance of females (81.1%). The mean preoperative body mass index was 43 kg/m². The major complication was fistula (2.3%), followed by intestinal obstruction (0.5%) and pulmonary embolism (0.5%). Death occurred in 0.6% of the cases. Conclusion: In the period of 30 days after surgery the overall complication rate was 3.8%; reoperation was necessary in 2.6% and death occurred in 0.6%. Fistula was the main complication and the leading cause of hospitalization in intensive care unit, reoperation and death. PMID:27683781

  8. Flow Simulation of Supersonic Inlet with Bypass Annular Duct

    NASA Technical Reports Server (NTRS)

    Kim, HyoungJin; Kumano, Takayasu; Liou, Meng-Sing; Povinelli, Louis A.; Conners, Timothy R.

    2011-01-01

    A relaxed isentropic compression supersonic inlet is a new concept that produces smaller cowl drag than a conventional inlet, but incurs lower total pressure recovery and increased flow distortion in the (radially) outer flowpath. A supersonic inlet comprising a bypass annulus to the relaxed isentropic compression inlet dumps out airflow of low quality through the bypass duct. A reliable computational fluid dynamics solution can provide considerable useful information to ascertain quantitatively relative merits of the concept, and further provide a basis for optimizing the design. For a fast and reliable performance evaluation of the inlet performance, an equivalent axisymmetric model whose area changes accounts for geometric and physical (blockage) effects resulting from the original complex three-dimensional configuration is proposed. In addition, full three-dimensional calculations are conducted for studying flow phenomena and verifying the validity of the equivalent model. The inlet-engine coupling is carried out by embedding numerical propulsion system simulation engine data into the flow solver for interactive boundary conditions at the engine fan face and exhaust plane. It was found that the blockage resulting from complex three-dimensional geometries in the bypass duct causes significant degradation of inlet performance by pushing the terminal normal shock upstream.

  9. A randomized trial of the topical effect of antifibrinolytic epsilon aminocaproic Acid on coronary artery bypass surgery without cardiopulmonary bypass.

    PubMed

    Gurian, Danilo Bortolotto; Meneghini, Adriano; Abreu, Luiz Carlos de; Murad, Neif; Matos, Leandro Luongo de; Pires, Adilson Casemiro; Valenti, Vitor E; Breda, João Roberto

    2014-09-01

    We assessed the effect of the topical application of epsilon-aminocaproic antifibrinolytic acid (EACA) on the pericardium of patients submitted to coronary artery bypass graft (CABG) without the use of cardiopulmonary bypass (CPB). This is a prospective, randomized, and double-blind study. We evaluated 26 patients with chronic coronary heart disease indicated for CABG without CPB (EACA and placebo groups). The analysis of the postoperative hematological results showed no difference between groups in hemoglobin and hematocrit. There was no difference between the groups regarding the postoperative bleeding through the drains in the first 24 hours, 48 hours, and accumulated loss until removal of drains. The use of EACA in patients undergoing CABG without CPB presented no difference in the reduction of the amount of bleeding and the need for blood transfusions.

  10. A practical approach to MRI of coronary artery bypass graft patency and flow.

    PubMed

    van Rossum, A C; Galjee, M A; Post, J C; Visser, C A

    1997-06-01

    Direct visualization of coronary artery bypass grafts can be obtained non-invasively by magnetic resonance imaging. Several studies demonstrated a high sensitivity and somewhat lower specificity for detection of vein-graft patency, using the conventional spin-echo and gradient-echo techniques. In addition, the true functional status can be assessed by determining the flowrate within the graft using phase velocity mapping. Important limitations of the previously applied techniques include the inability to accurately evaluate the different segments of jump grafts and the presence of graft stenoses. Further improvement is to be expected from the recent introduction of breath-hold imaging sequences and the forthcoming introduction of bloodpool-avid contrast agents.

  11. [Results of using composite bypass grafts with infragenicular distal anastomosis].

    PubMed

    Pokrovskiĭ, A V; Iakhontov, D I

    2014-01-01

    The authors share herein their experience with composite bypass grafts and PTFE synthetic prostheses used for treatment of obliterating diseases of the infrainguinal-segment arteries. The data of the study were based on the outcomes obtained in 92 patients. The authors assessed the condition of the outflow pathways and their effect on patency of composite bypass grafts in the immediate and remote postoperative periods, followed by comparative analysis of the short- and long-term therapeutic outcomes after using composite bypass grafts and PTFE synthetic prostheses in the infragenicular position for femoropopliteal and femorotibial reconstructions, also assessing the effect of the localization of the distal anastomosis on the immediate and remote therapeutic outcomes. Based on the obtained findings it was determined that the immediate results of patency depended upon the state of the outflow pathways and localization of the distal anastomosis. Thus, by the 1st, 3rd and 5th year of follow up patency of transplants in patients with the runoff score less than 7.0 amounted to 78.3, 21.7 and 4.3%, respectively. Analogous indices of patency in patients with the runoff score equalling or greater than 7.0 amounted to 60.7 and 3.6% for the 1st and 3rd year, respectively. The remote results of patency turned out to depend on the type of a vascular transplant and the state of the outflow pathways and did not depend on the localization of the distal anastomosis. Thus, the remote results of patency for the composite bypass graft for the 1st, 3rd and 5th year of follow up amounted to 74.5, 19.6 and 5.9%, respectively, versus 60.8 and 8.6% by the first and third year for the PTFE prosthesis. The limb salvage rate at the same terms for the composite bypass graft amounted to 94.1, 84.3 and 78.4% versus 73.9, 56.5 and 52.2% for the PTFE prosthesis.

  12. Passage of downstream migrant American eels through an airlift-assisted deep bypass

    USGS Publications Warehouse

    Haro, Alexander J.; Watten, Barnaby J.; Noreika, John

    2016-01-01

    Traditional downstream guidance and bypass facilities for anadromous fishes (i.e., surface bypasses, surface guidance structures, and behavioral barriers) have frequently been ineffective for anguillid eels. Because eels typically spend the majority of their time near the bottom in the vicinity of intake structures, deep bypass structures with entrances near the bottom hold promise for increased effectiveness, thereby aiding in the recovery of this important species. A new design of a deep bypass system that uses airlift technology (the Conte Airlift Bypass) to induce flow in a bypass pipe was tested in a simulated intake entrance environment under controlled laboratory conditions. Water velocities of 0.9–1.5 m s−1 could be generated at the bypass entrance (opening with 0.073 m2 area), with corresponding flows through the bypass pipe of 0.07–0.11 m3 s−1. Gas saturation and hydrostatic pressure within the bypass pipe did not vary appreciably from a control (no air) condition under tested airflows. Migratory silver-phase American eels (Anguilla rostrata) tested during dark conditions readily located, entered, and passed through the bypass; initial avoidance rates (eels approaching but not entering the bypass entrance) were lower at higher entrance velocities. Eels that investigated the bypass pipe entrance tended to enter headfirst, but those that then exited the pipe upstream did so more frequently at lower entrance velocities. Eels appeared to swim against the flow while being transported downstream through the pipe; median transit times through the bypass for each test velocity ranged from 5.8 to 12.2 s, with transit time decreasing with increasing entrance velocity. Eels did not show strong avoidance of the vertical section of the pipe which contained injected air. No mortality or injury of bypassed eels was observed, and individual eels repeatedly passed through the bypass at rates of up to 40 passes per hour, suggesting that individuals do not

  13. Optimal viral strategies for bypassing RNA silencing.

    PubMed

    Rodrigo, Guillermo; Carrera, Javier; Jaramillo, Alfonso; Elena, Santiago F

    2011-02-06

    The RNA silencing pathway constitutes a defence mechanism highly conserved in eukaryotes, especially in plants, where the underlying working principle relies on the repressive action triggered by the intracellular presence of double-stranded RNAs. This immune system performs a post-transcriptional suppression of aberrant mRNAs or viral RNAs by small interfering RNAs (siRNAs) that are directed towards their target in a sequence-specific manner. However, viruses have evolved strategies to escape from silencing surveillance while promoting their own replication. Several viruses encode suppressor proteins that interact with different elements of the RNA silencing pathway and block it. The different suppressors are not phylogenetically nor structurally related and also differ in their mechanism of action. Here, we adopt a model-driven forward-engineering approach to understand the evolution of suppressor proteins and, in particular, why viral suppressors preferentially target some components of the silencing pathway. We analysed three strategies characterized by different design principles: replication in the absence of a suppressor, suppressors targeting the first protein component of the pathway and suppressors targeting the siRNAs. Our results shed light on the question of whether a virus must opt for devoting more time into transcription or into translation and on which would be the optimal step of the silencing pathway to be targeted by suppressors. In addition, we discussed the evolutionary implications of such designing principles.

  14. Contrast-enhanced cardiac MRI before coronary artery bypass surgery: impact of myocardial scar extent on bypass flow.

    PubMed

    Hunold, Peter; Massoudy, Parwis; Boehm, Claudia; Schlosser, Thomas; Nassenstein, Kai; Knipp, Stephan; Eggebrecht, Holger; Thielmann, Matthias; Erbel, Raimund; Jakob, Heinz; Barkhausen, Jörg

    2008-12-01

    The aim of the study was to relate the extent of myocardial late gadolinium enhancement (LGE) in cardiac MRI to intraoperative graft flow in patients undergoing coronary artery bypass graft (CABG) surgery. Thirty-three CAD patients underwent LGE MRI before surgery using an inversion-recovery GRE sequence (turboFLASH). Intraoperative graft flow in Doppler ultrasonography was compared with the scar extent in each coronary vessel territory. One hundred and fourteen grafts were established supplying 86 of the 99 vessel territories. A significant negative correlation was found between scar extent and graft flow (r = -0.4, p < 0.0001). Flow in grafts to territories with no or small subendocardial scar was significantly higher than in grafts to territories with broad nontransmural or transmural scar (75 +/- 39 vs. 38 +/- 26 cc min(-1); p < 0.0001). In summary, the extent of myocardial scar as defined by contrast-enhanced MRI predicts coronary bypass graft flow. Beyond the probability of functional recovery, preoperative MRI might add value to surgery planning by predicting midterm bypass graft patency.

  15. Aerodynamic/acoustic performance of YJ101/double bypass VCE with coannular plug nozzle

    NASA Technical Reports Server (NTRS)

    Vdoviak, J. W.; Knott, P. R.; Ebacker, J. J.

    1981-01-01

    Results of a forward Variable Area Bypass Injector test and a Coannular Nozzle test performed on a YJ101 Double Bypass Variable Cycle Engine are reported. These components are intended for use on a Variable Cycle Engine. The forward Variable Area Bypass Injector test demonstrated the mode shifting capability between single and double bypass operation with less than predicted aerodynamic losses in the bypass duct. The acoustic nozzle test demonstrated that coannular noise suppression was between 4 and 6 PNdB in the aft quadrant. The YJ101 VCE equipped with the forward VABI and the coannular exhaust nozzle performed as predicted with exhaust system aerodynamic losses lower than predicted both in single and double bypass modes. Extensive acoustic data were collected including far field, near field, sound separation/ internal probe measurements as Laser Velocimeter traverses.

  16. Novel blood sampling method of an artificial endocrine pancreas via the cardiopulmonary bypass circuit.

    PubMed

    Kawahito, Shinji; Higuchi, Seiichi; Mita, Naoji; Kitagawa, Tetsuya; Kitahata, Hiroshi

    2013-12-01

    We tried to perform continuous blood glucose monitoring during cardiovascular surgery involving cardiopulmonary bypass using an artificial endocrine pancreas (STG-22 or -55; Nikkiso, Tokyo, Japan); however, we often encountered problems during these procedures because insufficient blood was obtained for monitoring. Thus, we started performing the blood sampling via the venous side of the cardiopulmonary bypass circuit. As a result, continuous blood glucose monitoring using an artificial endocrine pancreas was proven to be stable and reliable during cardiovascular surgery involving cardiopulmonary bypass.

  17. Hybrid procedure for celiac trunk aneurysm repair via left reno-splenic bypass and stent-graft deployment.

    PubMed

    Gabrielli, Roberto; Rosati, Maria Sofia; Siani, Andrea; Chiappa, Roberto; Caselli, Giovanni

    2012-01-01

    Celiac trunk aneurysm is one of the rarest forms of splanchnic artery aneurysm. Conventional open vascular surgery is associated with increased rates of morbidity and mortality and can require complex vascular reconstruction.We describe the case of a 42-year-old patient with celiac trunk aneurysm whom we treated by means of a hybrid surgical-endovascular procedure. We performed a left reno-splenic bypass, after which we used a direct splenic artery approach to deploy a self-expandable 6 × 50-mm stent-graft across the splenic and hepatic arteries. One year later, the stability of the repair was confirmed.

  18. Hybrid Procedure for Celiac Trunk Aneurysm Repair via Left Reno-Splenic Bypass and Stent-Graft Deployment

    PubMed Central

    Gabrielli, Roberto; Rosati, Maria Sofia; Siani, Andrea; Chiappa, Roberto; Caselli, Giovanni

    2012-01-01

    Celiac trunk aneurysm is one of the rarest forms of splanchnic artery aneurysm. Conventional open vascular surgery is associated with increased rates of morbidity and mortality and can require complex vascular reconstruction. We describe the case of a 42-year-old patient with celiac trunk aneurysm whom we treated by means of a hybrid surgical-endovascular procedure. We performed a left reno-splenic bypass, after which we used a direct splenic artery approach to deploy a self-expandable 6 × 50-mm stent-graft across the splenic and hepatic arteries. One year later, the stability of the repair was confirmed. PMID:22719156

  19. Experiences with ACE inhibitors early after acute myocardial infarction. Rationale and design of the German Multicenter Study on the Effects of Captopril on Cardiopulmonary Exercise parameters post myocardial infarction (ECCE).

    PubMed

    Kleber, F X; Reindl, I; Wenzel, M; Rodewyk, P; Beil, S; Kosloswki, B; Doering, W; Sabin, G V; Hinzmann, S; Winter, U J

    1993-12-01

    Left ventricular damage by necrosis of myocardial tissue can lead to compromise of left ventricular function, to left ventricular volume increase and ultimately to development of heart failure. This sequence in the pathophysiology has been shown to be blunted by ACE inhibitors. Volume increase, however, can also be helpful in restoring stroke volume and ameliorate elevation of filling pressures. Furthermore, very early institution of ACE inhibition has failed to improve short-term mortality after myocardial infarction in one large trial. The aim of the ECCE trial therefore is, to investigate the early effects of the ACE inhibitor captopril on compromise of exercise capacity, thought to be a first measurable sign of developing heart failure. The ECCE trial is a randomized, seven-center investigation, studying the effects of ACE inhibition on oxygen uptake in a double blind, placebo controlled design in a group of 204 patients. Sample size was calculated on the basis of a pilot trial. The study design and first not unblinded data of 104 patients are presented. The population consists of predominantly male patients with mostly first myocardial infarction. They were admitted to hospital within five hours of onset of chest pain. End-diastolic volumes were normal, but ejection fraction was moderately compromised. ACE inhibition was started after the first day, but within 72 hours of onset of chest pain. After four and after twelve weeks, oxygen uptake was considerably below expected values and one third of the patients had severe compromise of exercise capacity.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. Effect of pre-bypass methylprednisolone on post-operative renal function following correction of atrial septal defect under cardiopulmonary bypass.

    PubMed

    Dhar, S; Rahman, Z; Hasan, K; Hoque, M F; Sultana, A

    2012-01-01

    Conventional open heart surgery with cardiopulmonary bypass (CPB) are associated with transient post-operative renal dysfunction which is caused by systemic inflammatory response induced by CPB. Corticosteroids are administered to attenuate the systemic inflammatory response. The purpose of this study was to compare the effects of pre-bypass and post-bypass methylprednisolone on postoperative renal function after correction of ASD under CPB. Forty (40) patients were selected in the University cardiac centre of BSMMU undergoing ASD correction under CPB. Patients were randomized into two group to receive pre-bypass (Group A) or post-bypass (Group B) methylprednisolone 30mg/kg. Markers of glomerular function (BUN, serum creatinine, creatinine clearance) and damage (micro-albuminuria) and tubular function (glucosuria) were evaluated 24 hours after operation. Transient impairment of glomerular and tubular function of kidney was observed in patients those received post-bypass metylprednisolone (Group B) while Group A patients shown no significant difference between baseline and post-operative renal function. Use of pre-bypass methylprednisolone has a protective effect on post-operative renal function after correction of ASD under CPB.

  1. An MDOE Assessment of Nozzle Vanes for High Bypass Ratio Jet Noise Reduction

    NASA Technical Reports Server (NTRS)

    Henderson, Brenda; Norum, Thomas; Bridges, James

    2006-01-01

    The effect of airfoil-shaped vanes placed in the fan stream of a BPR 8 coannular nozzle model system on the resulting jet noise was investigated. The experiments used a Modern Design of Experiments approach to investigate the impact of a range of vane parameters on the noise reduction achieved at representative takeoff conditions. The experimental results showed that the installation of the vanes decreased low frequency noise radiation in the downstream peak-noise direction and increased high frequency noise in the upstream direction. Results also showed that improper selection of the vane configuration resulted in increased low frequency noise radiation in the upstream direction. Large angles of attack are shown to reduce noise near the peak jet noise angle and increase noise in the upstream direction. The MDOE analysis yields an optimum design that minimizes perceived noise levels. Limited data taken with a BPR 5 nozzle system showed that the vanes result in better effective perceived noise reduction for lower bypass ratio nozzles than for the BPR 8 model.

  2. Cardiovascular devices; reclassification of nonroller-type cardiopulmonary bypass blood pumps for cardiopulmonary and circulatory bypass; effective date of requirement for premarket approval for nonroller-type cardiopulmonary bypass blood pumps for temporary ventricular support. Final order.

    PubMed

    2015-06-08

    The Food and Drug Administration (FDA) is issuing a final order to reclassify nonroller-type cardiopulmonary bypass blood pump (NRP) devices for cardiopulmonary and circulatory bypass, a preamendments class III device, into class II (special controls), and to require the filing of a premarket approval application (PMA) for NRP devices for temporary ventricular support. FDA is also revising the title and identification of the regulation for NRP devices in this order.

  3. [Cognitive functions in elderly high-risk patients after off-pump coronary artery bypass grafting versus conventional bypass grafting - a randomised study - Secondary publication].

    PubMed

    Jensen, Birte Østergaard; Hughest, Pia; Rasmussen, Lars S; Pedersen, Preben U; Steinbrüchel, Daniel A

    2006-10-30

    It has been suggested that the risk of cerebral dysfunction is less with off-pump coronary artery bypass grafting (OPCAB) than with conventional coronary artery bypass grafting (CCAB). The study is a part of the Best Bypass Surgery Trial. A total of 120 elderly patients underwent psychometric testing with a neuropsychological test battery before as well as 3 months after surgery. Cognitive dysfunction was identified in 7.4% of the patients in the OPCAB group and 9.8% in the CCAB group. We found no significant difference after either OPCAB or CCAB.

  4. Acetaminophen Attenuates Lipid Peroxidation in Children Undergoing Cardiopulmonary Bypass

    PubMed Central

    Simpson, Scott A.; Zaccagni, Hayden; Bichell, David P.; Christian, Karla G.; Mettler, Bret A.; Donahue, Brian S.; Roberts, L. Jackson; Pretorius, Mias

    2014-01-01

    Objective Hemolysis, occurring during cardiopulmonary bypass (CPB), is associated with lipid peroxidation and postoperative acute kidney injury (AKI). Acetaminophen (ApAP) inhibits lipid peroxidation catalyzed by hemeproteins and in an animal model attenuated rhabdomyolysis-induced AKI. This pilot study tests the hypothesis that ApAP attenuates lipid peroxidation in children undergoing CPB. Design Single center prospective randomized double blinded study. Setting University-affiliated pediatric hospital. Patients Thirty children undergoing elective surgical correction of a congenital heart defect. Interventions Patients were randomized to ApAP (OFIRMEV® (acetaminophen) injection, Cadence Pharmaceuticals, San Diego, CA) or placebo every 6 hours for 4 doses starting before the onset of CPB. Measurement and Main Results Markers of hemolysis, lipid peroxidation (isofurans and F2-isoprostanes) and AKI were measured throughout the perioperative period. CPB was associated with a significant increase in free hemoglobin (from a pre-bypass level of 9.8±6.2 mg/dl to a peak of 201.5±42.6 mg/dl post-bypass). Plasma and urine isofuran and F2-isoprostane concentrations increased significantly during surgery. The magnitude of increase in plasma isofurans was greater than the magnitude in increase in plasma F2-isoprostanes. ApAP attenuated the increase in plasma isofurans compared to placebo (P=0.02 for effect of study drug). There was no significant effect of ApAP on plasma F2-isoprostanes or urinary makers of lipid peroxidation. ApAP did not affect postoperative creatinine, urinary neutrophil gelatinase-associated lipocalin or prevalence of AKI. Conclusion CPB in children is associated with hemolysis and lipid peroxidation. ApAP attenuated the increase in plasma isofuran concentrations. Future studies are needed to establish whether other therapies that attenuate or prevent the effects of free hemoglobin result in more effective inhibition of lipid peroxidation in patients

  5. Metabolic Complications of Bypass Surgery for Morbid Obesity

    PubMed Central

    Richard-Devantoy, S.; Garré, J.B.; Gohier, B.

    2009-01-01

    Postoperative complications resulting from bariatric surgery can lead to severe vitamin-deficiency states. A patient who underwent bariatric bypass surgery and later developed Wernicke’s encephalopathy prompted us to present her interesting case history for discussion. Although bariatric surgery is known to be a risk factor for Wernicke’s encephalopathy, this diagnosis is only rarely evoked in the postoperative course. We recommend that the occurrence of digestive, psychiatric or neurological symptoms after bariatric surgery should suggest a thiamine deficiency that must be promptly assessed. Without waiting for the results, thiamine supplementation should be initiated. PMID:24179375

  6. Transient cortical blindness and successful recovery after coronary bypass surgery.

    PubMed

    Tasdemir, Kutay; Evereklioglu, Cem; Kaya, Mehmet G

    2011-10-01

    Left ventricular injury has a bad prognosis, especially when a coronary artery is involved. After perforation of the left cardiac ventricle by a knife, a 19-year-old male patient presented with: (i) complete bilateral visual loss; (ii) left anterior descending (LAD) artery injury; (iii) severe systemic hypotension. Under emergency conditions and cardiopulmonary bypass, the LAD artery was revascularized by a saphenous vein graft. Bilateral blindness recovered within several days. Cerebral hypoxia as a result of severe systemic hypotension was the most likely underlying mechanism.

  7. Popular Hybrid Congenital Heart Procedures without Cardiopulmonary Bypass

    PubMed Central

    Gupta, Aamisha; Amin, Zahid

    2017-01-01

    As surgical and catheter interventions advance, patients with congenital heart disease are now offered alternative treatment options that cater to their individual needs. Furthermore, collaboration between interventional cardiologists and cardiac surgeons have led to the development of hybrid procedures, using the best techniques of each respective field to treat these complex cardiac entities from initial treatment in the pediatric patient to repeat intervention in the adult. We present a review of the increased popularity and trend in hybrid procedures in congenital heart disease without the use of cardiopulmonary bypass. PMID:28321396

  8. Gust erosion chamber data, Yolo Bypass, CA (2015-16)

    USGS Publications Warehouse

    Work, Paul; Schoellhamer, David H.; Weidich, Kurt

    2016-01-01

    A Gust erosion chamber was used to apply horizontal shear stress to sediment cores obtained at selected locations within the Yolo Bypass near Sacramento, California. The locations correspond to different land uses; two cores were taken at each site. The shear stress was increased in stepwise fashion, and turbidity of the effluent monitored. From this, two quantities are calculated: 1) critical shear stress required to initiate erosion, and 2) soil mass eroded per square meter at an applied shear stress of 0.4 Pa. So for each core we have a date, land use or site, core number, latitude, longitude, critical shear stress, and eroded mass at tau = 0.4 Pa.

  9. Induced mild hypothermia in post-cardiopulmonary bypass vasoplegia syndrome.

    PubMed

    Tripathi, Mukesh; Singh, Prabhat Kumar; Kumar, Naresh; Pant, Kailash Chandra

    2009-01-01

    The state of vasoplegia in immediate post-cardiopulmonary bypass period is characterized by severe hypotension, supranormal cardiac output, low systemic vascular resistance (SVR), and resistance to vasoconstrictors. We could successfully use induced mild hypothermia to increase SVR, and could avoid very high doses of nor-epinephrine (>0.3 mcg/kg/min) in the background of severe pulmonary hypertension (systolic pulmonary pressure> 90 mmHg). Its effects such as decreased oxygen demand, positive inotropy and better right ventricle performance probably helped to improve oxygenation in presence of pulmonary oedema.

  10. Red Blood Cell Transfusions Impact Pneumonia Rates After Coronary Artery Bypass Grafting Surgery

    PubMed Central

    Likosky, Donald S.; Paone, Gaetano; Zhang, Min; Rogers, Mary A.M.; Harrington, Steven D.; Theurer, Patricia F.; DeLucia, Alphonse; Fishstrom, Astrid; Camaj, Anton; Prager, Richard L.

    2016-01-01

    Background Pneumonia, a known complication of coronary artery bypass (CABG) surgery, significantly increases a patient’s risk of morbidity and mortality. While not well characterized, red blood cell transfusions (RBC) may increase a patient’s risk of pneumonia. We describe the relationship between RBC transfusion and post-operative pneumonia after CABG surgery. Methods A total of 16,182 consecutive patients underwent isolated CABG surgery between 2011 and 2013 at one of 33 hospitals in the state of Michigan. We used multivariable logistic regression to estimate the odds of pneumonia associated with the use or number (0, 1, 2, 3, 4, 5, >6) of RBC units. We adjusted for predicted risk of mortality, pre-operative hematocrit, history of pneumonia, cardiopulmonary bypass duration and medical center. We confirmed the strength and direction of these relationships among selected clinical subgroups in a secondary analysis. Results 576 (3.6%) patients developed pneumonia and 6,451 (39.9%) received RBC transfusions. There was a significant association between any RBC transfusion and pneumonia (ORadj 3.4, p<0.001). There was a dose-response between number of units and odds of pneumonia, ptrend<0.001. Patients receiving only 2 units of RBCs had twofold (ORadj 2.1, p<0.001) increased odds of pneumonia. These findings were consistent across clinical subgroups. Conclusions We found a significant, volume-dependent association between an increasing number of RBCs and odds of pneumonia, which persisted after adjusting for pre-operative patient characteristics. Clinical teams should explore opportunities for preventing a patient’s risk of RBC transfusions, including reducing hemodilution or adopting a lower transfusion threshold in a stable patient. PMID:26209489

  11. Complex Blunt Aortic Injury or Repair: Beneficial Effects of Cardiopulmonary Bypass Use

    PubMed Central

    Miller, Preston R.; Kortesis, Bill G.; McLaughlin, Charles A.; Chen, Michael Y. M.; Chang, Michael C.; Kon, Neal D.; Meredith, J. Wayne

    2003-01-01

    Objective To compare the outcomes and associated morbidity in patients with blunt aortic injury (BAI) repaired using cardiopulmonary bypass versus no bypass. Special consideration is given to the influence of bypass in the outcome of complex injuries or repair circumstances. Summary Background Data There are conflicting data concerning the utility of bypass techniques in the operative management of BAI, and controversy over the subject persists. During the last decade, surgeons at the authors’ institution have undergone a change in philosophy concerning management of these injuries and began almost exclusively using cardiopulmonary bypass for the repair in 1996. This project explores the effects of this change in the management of BAI. Methods The records of all patients with BAI admitted to a level 1 trauma center over a period of 12 years were reviewed for demographics, injury characteristics, operative technique, and outcome. The bypass group was compared to the no bypass group with respect to morbidity and mortality. Those with a complex injury or repair (CI/R) were examined as a subgroup. CI/R was defined as the presence of an injury with extension proximal to the subclavian artery, involvement of branch vessels, or requirement of maneuvers interfering with anastomosis construction, such as cardiac massage. Results From January 1, 1990, to December 31, 2001, 91 patients were admitted to Wake Forest University Baptist Medical Center with BAI. Sixty-five of these underwent operative repair. Sixty (32 no bypass, 28 bypass) survived to the immediate postoperative period. Injury Severity Score was similar (33 no bypass, 31 bypass, P = .48), as was admission base deficit (−9.2 m Eq/L no bypass vs. −7.0 mEq/L B, P = .13). Paraplegia occurred in four (12%) of the no bypass group as opposed to 0 of the bypass group (P = .05). No patient in the bypass group experienced complications related to heparinization, and two (7%) experienced bypass-related complications

  12. Quadratus lumborum block for femoral–femoral bypass graft placement

    PubMed Central

    Watanabe, Kunitaro; Mitsuda, Shingo; Tokumine, Joho; Lefor, Alan Kawarai; Moriyama, Kumi; Yorozu, Tomoko

    2016-01-01

    Abstract Introduction: Atherosclerosis has a complex etiology that leads to arterial obstruction and often results in inadequate perfusion of the distal limbs. Patients with atherosclerosis can have severe complications of this condition, with widespread systemic manifestations, and the operations undertaken are often challenging for anesthesiologists. Case report: A 79-year-old woman with chronic heart failure and respiratory dysfunction presented with bilateral gangrene of the distal lower extremities with obstruction of the left common iliac artery due to atherosclerosis. Femoral–femoral bypass graft and bilateral foot amputations were planned. Spinal anesthesia failed due to severe scoliosis and deformed vertebrae. General anesthesia was induced after performing multiple nerve blocks including quadratus lumborum, sciatic nerve, femoral nerve, lateral femoral cutaneous nerve, and obturator nerve blocks. However, general anesthesia was abandoned because of deterioration in systemic perfusion. The surgery was completed; the patient remained comfortable and awake without the need for further analgesics. Conclusion: Quadratus lumborum block may be a useful anesthetic technique to perform femoral–femoral bypass. PMID:27583851

  13. Overview of ERA Ultra High Bypass Propulsor Technology Development

    NASA Technical Reports Server (NTRS)

    Hughes, Christopher

    2011-01-01

    A review of the current research being conducted under the Environmentally Responsible Aviation (ERA) Ultra High Bypass (UHB) Testing subelement is presented. The four exiting tasks under the subelement, a description of each task, and the current status of each are given. The four tasks are: 1. Collaborate with P&W to design, fabricate and test a second generation of Geared Turbofan 2. Design, fabricate and test advanced Over the Rotor acoustic treatment and acoustically treated Soft Vanes 3. Develop a Shape Memory Alloy Variable Area Nozzle concept and demonstrate prototype 4. Refurbish and update the GRC Ultra High Bypass Drive Rig Following the current task updates, an overview of three proposed additional tasks to support the existing tasks is presented. The additional tasks would allow noise reduction and noise diagnostic testing technologies to be demonstrated at TRL 4 as part of existing planned fan model testing in the NASA Glenn 9 x15 Low Speed Wind Tunnel under the ERA UHB Testing subelement.

  14. Weight regain after gastric bypass: etiology and treatment options

    PubMed Central

    Gudaitytė, Rita; Petereit, Rūta; Venclauskas, Linas; Veličkienė, Džilda

    2016-01-01

    Roux-en-Y gastric bypass (RYGB) is one of the most common operations performed for the patients with morbid obesity. Weight regain (WR) is a complication that may decrease efficiency of the surgical treatment and demand further interventions. Different factors including lifestyle, mental health, hormonal/metabolic and surgical plays role in WR after RYGB. Various treatment options have been proposed for WR. Conservative treatment is less effective than surgery. Endoscopic refashioning of gastric pouch/stoma fails to achieve sustainable weight loss. Surgical reduction of pouch has acceptable short-term results, but WR after 3 years is substantial. Banded gastric bypass achieves good short-term results, but long-term follow-up data are needed. Distalization of RYGB has a high risk of protein calorie malnutrition (PCM) and conversion to BP diversion (BPD)/duodenal switch (DS) is a technically demanding procedure. Both procedures achieve sustainable long-term weight loss. More studies are needed to explore long-term results of various surgical interventions for WR after RYGB. PMID:28149808

  15. Hemodynamic Conditions in a Failing Peripheral Artery Bypass Graft

    PubMed Central

    McGah, Patrick M.; Leotta, Daniel F.; Beach, Kirk W.; Zierler, R. Eugene; Riley, James J.; Aliseda, Alberto

    2012-01-01

    Objective The mechanisms of restenosis in autogenous vein bypass grafts placed for peripheral artery disease are not completely understood. We seek to investigate the role of hemodynamic stress in a case study of a revised bypass graft that failed due to restenosis. Methods The morphology of the lumen is reconstructed from a custom 3D ultrasound system. Scans were taken at one, six, and sixteen months after a patch angioplasty procedure. Computational hemodynamic simulations of the patient-specific model provide the blood flow features and the hemodynamic stresses on the vessel wall at the three time points studied. Results The vessel was initially free of any detectable lesions, but a 60% diameter reducing stenosis developed over the 16 month interval of study. As determined from the simulations, chaotic and recirculating flow occurred downstream of the stenosis due to the sudden widening of the lumen at the patch location. Curvature and a sudden increase in the lumen cross-sectional area induce these flow features that are hypothesized to be conducive to intimal hyperplasia. Favorable agreement was found between simulation results and in vivo Doppler ultrasound velocity measurements. Conclusions Transitional and chaotic flow occurs at the site of the revision, inducing a complex pattern of wall shear are computed with the hemodynamic simulations. This supports the hypothesis that the hemodynamic stresses in the revised segment, produced by the coupling of vessel geometry and chaotic flow, led to the intimal hyperplasia and restenosis of the graft. PMID:22551907

  16. Kron's biliary prosthetic bypass in the treatment of neoplastic jaundice.

    PubMed

    Kron, B; Reynier, J

    1985-01-01

    After experimental study in the dog, which showed the material to be highly reliable, an original method of biliary bypass using a silicone prosthesis in the treatment of neoplastic jaundice is introduced. This prosthesis allows the bile duct to be bypassed regardless of the location of the obstacle. This method was used in 150 patients; recession was sufficiently good in 84 of them to confirm good tolerance and the excellence of the results. In fact, good results were recorded in 95% of cases of cancer of the hilum, which is all the more remarkable in consideration of the difficulties involved in these operations. The main postoperative complications are bile fistulas which resolve spontaneously if the precaution of extensively draining the zones of intubation is taken; postoperative comfort is excellent; no constraint is necessary and the operative risk is moderate, this is particularly desirable in patients in a poor general condition. A short prosthesis makes transtumoral intubation possible, and a long prosthesis allows implantation in the digestive tract: stomach, duodenum or first intestinal loop. Postoperative persistence of jaundice is rare if a prosthesis of sufficient diameter is used and if no major bile duct or part of the liver is excluded. Cholangitis is exceptional and indicative of an excluded biliary area.

  17. Hypoplastic left heart syndrome: palliation without cardiopulmonary bypass.

    PubMed

    Tucker, W Y; McKone, R C; Weesner, K M; Kon, N D

    1990-05-01

    Our 100% mortality rate with first-stage palliation of hypoplastic left heart syndrome performed with cardiopulmonary bypass led us to a procedure not necessitating bypass. In nine neonates with this congenital heart defect, a woven Dacron graft was placed from the main pulmonary artery to the descending thoracic aorta. The patent ductus arteriosus was ligated and the main pulmonary artery banded distal to the graft and proximal to the bifurcation. Five patients were extubated within 4 days. Only low-dose inotropic support was required in eight of the nine. There were no bleeding problems. Four patients died in the hospital: one of Candida sepsis at 81 days, one of low cardiac output at 2 days, and two of restrictive atrial septal defect at 3 and 5 days. The five living patients were discharged 11 to 80 days postoperatively (mean 38 days). We now perform balloon septostomies preoperatively in all patients and believe that this will improve the survival rate. We believe this simpler approach to the treatment of hypoplastic left heart syndrome may allow survival for a cardiac transplant or a staged Fontan procedure at a later date for more definitive treatment.

  18. Simulation of flow through a Miller cuff bypass graft.

    PubMed

    Henry, F S; Küpper, C; Lewington, N P

    2002-06-01

    Unnatural temporal and spatial distributions of wall shear stress in the anastomosis of distal bypass grafts have been identified as possible factors in the development of anastomotic intimal hyperplasia in these grafts. Distal bypass graft anastomoses with an autologus vein cuff (a Miller cuff) interposed between the graft and artery have been shown to alleviate the effects of intimal hyperplasia. In this study, pulsatile flow through models of a standard end-to-side anastomosis and a Miller cuff anastomosis are computed and the resulting wall shear stress and pressure distributions analysed. The results are inconclusive, and could be taken to suggest that the unnatural distributions of shear stress that do occur along the anastomosis floor may not be particularly important in the development of intimal hyperplasia. However, it seems more likely that the positive effects of the biological and material properties of the vein cuff, which are not considered in this study, somehow outweigh the negative effects of the shear stress distributions predicted to occur on the floor of the Miller-cuff graft.

  19. Genetic therapy for vein bypass graft disease: current perspectives.

    PubMed

    Simosa, Hector F; Conte, Michael S

    2004-01-01

    Although continued progress in endovascular technology holds promise for less invasive approaches to arterial diseases, surgical bypass grafting remains the mainstay of therapy for patients with advanced coronary and peripheral ischemia. In the United States, nearly 400,000 coronary and 100,000 lower extremity bypass procedures are performed annually. The autogenous vein, particularly the greater saphenous vein, has proven to be a durable and versatile arterial substitute, with secondary patency rates at 5 years of 70 to 80% in the extremity. However, vein graft failure is a common occurrence that incurs significant morbidity and mortality, and, to date, pharmacologic approaches to prolong vein graft patency have produced limited results. Dramatic advances in genetics, coupled with a rapidly expanding knowledge of the molecular basis of vascular diseases, have set the stage for genetic interventions. The attraction of a genetic approach to vein graft failure is based on the notion that the tissue at risk is readily accessible to the clinician prior to the onset of the pathologic process and the premise that genetic reprogramming of cells in the wall of the vein can lead to an improved healing response. Although the pathophysiology of vein graft failure is incompletely understood, numerous relevant molecular targets have been elucidated. Interventions designed to influence cell proliferation, thrombosis, inflammation, and matrix remodeling at the genetic level have been described, and many have been tested in animal models. Both gene delivery and gene blockade strategies have been investigated, with the latter reaching the stage of advanced clinical trials.

  20. MHD Energy Bypass Scramjet Performance with Real Gas Effects

    NASA Technical Reports Server (NTRS)

    Park, Chul; Mehta, Unmeel B.; Bogdanoff, David W.

    2000-01-01

    The theoretical performance of a scramjet propulsion system incorporating an magneto-hydro-dynamic (MHD) energy bypass scheme is calculated. The one-dimensional analysis developed earlier, in which the theoretical performance is calculated neglecting skin friction and using a sudden-freezing approximation for the nozzle flow, is modified to incorporate the method of Van Driest for turbulent skin friction and a finite-rate chemistry calculation in the nozzle. Unlike in the earlier design, in which four ramp compressions occurred in the pitch plane, in the present design the first two ramp compressions occur in the pitch plane and the next two compressions occur in the yaw plane. The results for the simplified design of a spaceliner show that (1) the present design produces higher specific impulses than the earlier design, (2) skin friction substantially reduces thrust and specific impulse, and (3) the specific impulse of the MHD-bypass system is still better than the non-MHD system and typical rocket over a narrow region of flight speeds and design parameters. Results suggest that the energy management with MHD principles offers the possibility of improving the performance of the scramjet. The technical issues needing further studies are identified.

  1. Anesthesia for off-pump coronary artery bypass surgery.

    PubMed

    Hemmerling, Thomas M; Romano, Gianmarco; Terrasini, Nora; Noiseux, Nicolas

    2013-01-01

    The evolution of techniques and knowledge of beating heart surgery has led anesthesia toward the development of new procedures and innovations to promote patient safety and ensure high standards of care. Off-pump coronary artery bypass (OPCAB) surgery has shown to have some advantages compared to on-pump cardiac surgery, particularly the reduction of postoperative complications including systemic inflammation, myocardial injury, and cerebral injury. Minimally invasive surgery for single vessel OPCAB through a limited thoracotomy incision can offer the advantage of further reduction of complications. The anesthesiologist has to deal with different issues, including hemodynamic instability and myocardial ischemia during aorto-coronary bypass grafting. The anesthesiologist and surgeon should collaborate and plan the best perioperative strategy to provide optimal care and ensure a rapid and complete recovery. The use of high thoracic epidural analgesia and fast-track anesthesia offers particular benefits in beating heart surgery. The excellent analgesia, the ability to reduce myocardial oxygen consumption, and the good hemodynamic stability make high thoracic epidural analgesia an interesting technique. New scenarios are entering in cardiac anesthesia: ultra-fast-track anesthesia with extubation in the operating room and awake surgery tend to be less invasive, but can only be performed on selected patients.

  2. Implementation of magnetohydrodynamic energy bypass process for hypersonic vehicles

    NASA Astrophysics Data System (ADS)

    Lee, Ying Ming; Czysz, Paul A.; Bruno, Claudio

    2004-08-01

    The global political structure has changed dramatically since the breakup of the former Soviet Union, and world changes have caused the United States to reprioritize its national hypersonic needs. The US Government has looked at the needs of the future, and the hypersonic aerospace plane is one of the systems included in alternative force structures. One hypersonic aerospace plane concept would involve magnetohydrodynamic (MHD) technology (i.e., the AJAX hypersonic flight vehicle concept) originally proposed by Russian scientist Vladimir Fraishtadt. This paper reports on the current progress and findings of an air-breathing horizontal takeoff and landing design concept using an MHD energy bypass injector ramjet engine being studied at MSE Technology Applications, Inc., HyperTech Concepts, and several universities for the National Aeronautics and Space Administration Langley Research Center under a Phase II Small Business Innovation Research project. The areas that are addressed in this paper include: (1) ionization required to achieve the required energy bypass, (2) utilization of a nonequilibrium model to calculate nonequilibrium engine ionization conditions, (3) hydrocarbon fuel reforming, and (4) vehicle performance and sizing. A quasi-onedimensional electromagnetic code combined with a new scramjet model, as well as other tools, were used to examine total system performance.

  3. Computational study of the risk of restenosis in coronary bypasses.

    PubMed

    Guerciotti, Bruno; Vergara, Christian; Ippolito, Sonia; Quarteroni, Alfio; Antona, Carlo; Scrofani, Roberto

    2017-02-01

    Coronary artery disease, caused by the buildup of atherosclerotic plaques in the coronary vessel wall, is one of the leading causes of death in the world. For high-risk patients, coronary artery bypass graft is the preferred treatment. Despite overall excellent patency rates, bypasses may fail due to restenosis. In this context, the purpose of this work was to perform a parametric computational study of the fluid dynamics in patient-specific geometries with the aim of investigating a possible relationship between coronary stenosis degree and risk of graft failure. Firstly, we propose a strategy to prescribe realistic boundary conditions in the absence of measured data, based on an extension of Murray's law to provide the flow division at bifurcations in case of stenotic vessels and non-Newtonian blood rheology. Then, we carry out numerical simulations in three patients affected by severe coronary stenosis and treated with a graft, in which the stenosis degree is virtually varied in order to compare the resulting fluid dynamics in terms of hemodynamic indices potentially involved in restenosis development. Our findings suggest that low degrees of coronary stenosis produce a more disturbed fluid dynamics in the graft, resulting in hemodynamic conditions that may promote a higher risk of graft failure.

  4. Percutaneous mechanical thrombectomy for treatment of acute femoropopliteal bypass occlusion.

    PubMed

    Lichtenberg, Michael; Käunicke, Matthias; Hailer, Birgit

    2012-01-01

    Acute and subacute ischemia of the legs in acute and subacute femoropopliteal bypass occlusion is a dramatic situation that endangers the survival of the limbs, depending on the severity of the ischemia. Different therapy options like percutaneous mechanical thrombectomy procedures, which include rotational thrombectomy, have become available in recent years, in addition to local lysis and surgical thrombectomy. Surgical thrombectomy using the Fogarty catheter technique, in particular, shows an increased incidence of perioperative complications but only small technical success rates in randomized trials. On the other hand, local lysis is associated with increased costs due to resource-consuming measures, such as intensive monitoring and repeat angiographies, in addition to bleeding complications. In the past, further development of the Straub Rotarex(®) system as an endovascular therapy option has demonstrated good success leading to amputation-free survival in multiple studies. At the same time, a low rate of complications with use has been documented. Most examinations have been conducted in the thigh. To date, there are little investigational data on its use in acutely and subacutely occluded femoropopliteal bypasses. In this paper, the current study-based significance of the Rotarex system for this indication is analyzed based on the existing literature and the authors' own experiences with 22 patients.

  5. Percutaneous mechanical thrombectomy for treatment of acute femoropopliteal bypass occlusion

    PubMed Central

    Lichtenberg, Michael; Käunicke, Matthias; Hailer, Birgit

    2012-01-01

    Acute and subacute ischemia of the legs in acute and subacute femoropopliteal bypass occlusion is a dramatic situation that endangers the survival of the limbs, depending on the severity of the ischemia. Different therapy options like percutaneous mechanical thrombectomy procedures, which include rotational thrombectomy, have become available in recent years, in addition to local lysis and surgical thrombectomy. Surgical thrombectomy using the Fogarty catheter technique, in particular, shows an increased incidence of perioperative complications but only small technical success rates in randomized trials. On the other hand, local lysis is associated with increased costs due to resource-consuming measures, such as intensive monitoring and repeat angiographies, in addition to bleeding complications. In the past, further development of the Straub Rotarex® system as an endovascular therapy option has demonstrated good success leading to amputation-free survival in multiple studies. At the same time, a low rate of complications with use has been documented. Most examinations have been conducted in the thigh. To date, there are little investigational data on its use in acutely and subacutely occluded femoropopliteal bypasses. In this paper, the current study-based significance of the Rotarex system for this indication is analyzed based on the existing literature and the authors’ own experiences with 22 patients. PMID:22661895

  6. Long-term results after robotically assisted coronary bypass surgery

    PubMed Central

    Ramahi, Jehad; Hasan, Faisal; Edris, Ahmad; Bartel, Thomas; Nair, Ravi; Tuzcu, Murat; Suri, Rakesh; Mihaljevic, Tomislav

    2016-01-01

    Background Robotically-assisted coronary bypass grafting (CABG) was introduced in 1998 and dedicated centers have continuously applied and developed this minimally invasive method of coronary bypass surgery. While short-term results are relatively well published, data on long-term outcome are limited. In this literature review, we assessed the outcomes after robotic CABG following the first postoperative year. Methods We searched PubMed for articles containing the terms “robotic” or “robotically assisted” and “coronary bypass”. A total of 11 papers contained long-term results. We specifically investigated survival, graft patency, freedom from angina and re-intervention, as well as freedom from major adverse cardiac and cerebrovascular events (MACCE). Results Five-year survival after robotic CABG was consistently consistently greater than 90% and graft patency between 3 and 5 years was reported to be above 90%. Fifteen percent to 26% of patients re-experienced angina at 3 to 5 years postoperatively. Long-term freedom from re-intervention reached the range and the 5-year freedom from MACCE rate was approximately 75%. Conclusions According to data in the literature, long-term results after CABG carried out with the assistance of a surgical robot appear to be in line with results achieved after conventional CABG. PMID:27942487

  7. Silent meningioma - a rare cause of stroke in post-cardiopulmonary bypass patients.

    PubMed

    Chow, Hon K; Yousafzai, Sajjad M; Ugurlucan, Murat; Canver, Charles C

    2010-04-30

    Stroke in cardiac patients undergoing surgery is usually attributed to the use of cardiopulmonary bypass. In this report, we present an unusual cause of cerebral dysfunction: a meningioma leading to stroke, following coronary artery bypass grafting in a 62-year-old patient. Diagnosis and treatment options of the pathology are discussed with the guidance of the literature.

  8. Silent meningioma – a rare cause of stroke in post-cardiopulmonary bypass patients

    PubMed Central

    Chow, Hon K.; Yousafzai, Sajjad M.; Canver, Charles C.

    2010-01-01

    Stroke in cardiac patients undergoing surgery is usually attributed to the use of cardiopulmonary bypass. In this report, we present an unusual cause of cerebral dysfunction: a meningioma leading to stroke, following coronary artery bypass grafting in a 62-year-old patient. Diagnosis and treatment options of the pathology are discussed with the guidance of the literature. PMID:22371743

  9. 40 CFR 63.307 - Standards for bypass/bleeder stacks.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... National Emission Standards for Coke Oven Batteries § 63.307 Standards for bypass/bleeder stacks. (a)(1.... (2) Coke oven emissions shall not be vented to the atmosphere through bypass/bleeder stacks, except.... (3) The owner or operator of a brownfield coke oven battery or a padup rebuild shall install such...

  10. 40 CFR 63.307 - Standards for bypass/bleeder stacks.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... National Emission Standards for Coke Oven Batteries § 63.307 Standards for bypass/bleeder stacks. (a)(1.... (2) Coke oven emissions shall not be vented to the atmosphere through bypass/bleeder stacks, except.... (3) The owner or operator of a brownfield coke oven battery or a padup rebuild shall install such...

  11. Contrast MR of the brain after high-perfusion cardiopulmonary bypass

    SciTech Connect

    Simonson, T.M.; Yuh, W.T.C.; Hindman, B.J.; Embrey, R.P.; Halloran, J.I.; Behrendt, D.M. )

    1994-01-01

    To study the efficacy of contrast MR imaging in the evaluation of central nervous system complications in the cardiopulmonary bypass patient and attempt to explain their pathophysiology based on the MR appearance and the cardiopulmonary bypass protocol. Nineteen patients were prospectively studied with contrast MR examinations the day before and 3 to 7 days after cardiopulmonary bypass, to determine the nature, extent, and number of new postoperative MR abnormalities. Cardiopulmonary bypass parameters used in our institution included: membrane oxygenation, arterial filtration with a pore size of 25 [mu]m, and a relatively high perfusion rate to produce a cardiac index of 2.0 to 2.5 L min per m[sup 2]. The preoperative noncontrast MR examination showed age-related changes and/or signs of ischemia in 60% of patients on the day before surgery. However, there was no abnormal enhancement or new T2 abnormalities on any postoperative MR examination to suggest hypoperfusion or emboli. None of the 19 patients developed overt neurologic deficits postoperatively. Review of the cardiopulmonary bypass protocol used indicated significant variations in technique at different institutions. Contrast MR imaging demonstrated no new abnormalities in patients after cardiopulmonary bypass performed with strict in-line arterial filtration and relatively high perfusion. MR imaging is feasible in the early postoperative period after cardiopulmonary bypass and may offer a convenient method for evaluation of the neurologic impact of technical factors associated with cardiopulmonary bypass. 17 refs.

  12. 21 CFR 870.4270 - Cardiopulmonary bypass cardiotomy suction line blood filter.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... blood filter. 870.4270 Section 870.4270 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Devices § 870.4270 Cardiopulmonary bypass cardiotomy suction line blood filter. (a) Identification. A cardiopulmonary bypass cardiotomy suction line blood filter is a device used as part of a gas exchange...

  13. 21 CFR 870.4270 - Cardiopulmonary bypass cardiotomy suction line blood filter.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... blood filter. 870.4270 Section 870.4270 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Devices § 870.4270 Cardiopulmonary bypass cardiotomy suction line blood filter. (a) Identification. A cardiopulmonary bypass cardiotomy suction line blood filter is a device used as part of a gas exchange...

  14. 21 CFR 870.4270 - Cardiopulmonary bypass cardiotomy suction line blood filter.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... blood filter. 870.4270 Section 870.4270 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Devices § 870.4270 Cardiopulmonary bypass cardiotomy suction line blood filter. (a) Identification. A cardiopulmonary bypass cardiotomy suction line blood filter is a device used as part of a gas exchange...

  15. 21 CFR 870.4270 - Cardiopulmonary bypass cardiotomy suction line blood filter.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... blood filter. 870.4270 Section 870.4270 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Devices § 870.4270 Cardiopulmonary bypass cardiotomy suction line blood filter. (a) Identification. A cardiopulmonary bypass cardiotomy suction line blood filter is a device used as part of a gas exchange...

  16. Effect of shading on the switching of bypass diodes in PV modules

    NASA Astrophysics Data System (ADS)

    Shiradkar, Narendra; Schneller, Eric; Dhere, Neelkanth; Gade, Vivek

    2014-10-01

    Bypass diodes are installed in Photovoltaic (PV) modules in order to prevent the application of high reverse voltage across the shaded cells in the event of partial shading of the module. Crystalline silicon (c-Si) modules have one bypass diode per 18-20 cells while thin film modules have at most one bypass diode per module. Ideally, bypass diodes are expected to turn on as soon as a current mismatch is detected between various strings of cells inside the module, which typically occurs in the event of partial shading. However, limited information is available on the actual switching characteristics of bypass diodes in field. In this paper, effect of incremental shading of various cells on the flasher I-V curve of a commercial 60-cell c-Si module was studied. Cell combinations in various strings were shaded with operational bypass diodes in the module and effect on module performance parameters such as Voc, Isc, Pmax and Fill Factor was discussed. Consequently one bypass diode in the module was short circuited and open circuited respectively and again the effect of shading on the I-V curve was investigated. Techniques for identifying short circuited and open circuited bypass diodes from I-V curve are presented.

  17. Fatal air embolism during cardiopulmonary bypass: analysis of an incident and prevention measures.

    PubMed

    van der Zee, Michiel P; Koene, Bart M; Mariani, Massimo A

    2014-11-01

    Air embolism is a life-threatening complication during cardiopulmonary bypass. We present a case of a patient who suffered an air embolism during coronary bypass surgery, despite standard safety features and procedures. The patient died 3 days after surgery due to massive cerebral oedema. This case report gives a reconstruction of the event and the countermeasures undertaken to minimize the risk of recurrence.

  18. 21 CFR 870.4290 - Cardiopulmonary bypass adaptor, stopcock, manifold, or fitting.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ..., or fitting. 870.4290 Section 870.4290 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Devices § 870.4290 Cardiopulmonary bypass adaptor, stopcock, manifold, or fitting. (a) Identification. A cardiopulmonary bypass adaptor, stopcock, manifold, or fitting is a device used in cardiovascular...

  19. 21 CFR 870.4270 - Cardiopulmonary bypass cardiotomy suction line blood filter.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... blood filter. 870.4270 Section 870.4270 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Devices § 870.4270 Cardiopulmonary bypass cardiotomy suction line blood filter. (a) Identification. A cardiopulmonary bypass cardiotomy suction line blood filter is a device used as part of a gas exchange...

  20. The Straight Path to Healing: Using Motivational Interviewing to Address Spiritual Bypass

    ERIC Educational Resources Information Center

    Clarke, Philip B.; Giordano, Amanda L.; Cashwell, Craig S.; Lewis, Todd F.

    2013-01-01

    Spiritual bypass is the avoidance of underlying emotional issues by focusing solely on spiritual beliefs, practices, and experiences. Motivational interviewing (MI) is a client-centered, compassionate approach to effectively addressing resistance among those who present with spiritual bypass. In this article, the authors provide background…

  1. The Only Way out Is through: The Peril of Spiritual Bypass

    ERIC Educational Resources Information Center

    Cashwell, Craig S.; Bentley, Paige B.; Yarborough, J. Preston

    2007-01-01

    Given the increased attention to spirituality in the counseling literature, with a primary emphasis on helping clients find their spiritual path, it is important for counselors to be aware of one potential pitfall of the spiritual path, namely spiritual bypass. Spiritual bypass occurs when clients seek to use their spiritual beliefs, practices,…

  2. Coronary artery surgery without cardiopulmonary bypass: usefulness of the surgical blower-humidifier.

    PubMed

    Maddaus, M; Ali, I S; Birnbaum, P L; Panos, A L; Salerno, T A

    1992-12-01

    Coronary artery bypass surgery can be performed without cardiopulmonary bypass (CPB). Bleeding obscuring the operative field and hemodilution of shed blood with irrigating saline are some of the drawbacks of this technique. We report the use of a newly developed surgical blower-humidifier (custom made [Research Medical, Inc.]) for improved visualization and facilitation of coronary artery surgery without CPB.

  3. Coronary artery bypass surgery with heparin-coated perfusion circuits and low-dose heparinization

    PubMed Central

    Mullen, John C.; Bentley, Michael J.; Gelfand, Elliot T.; Koshal, Arvind; Modry, Dennis L.; Guenther, Craig R.; Etches, Wai S.; Stang, Linda J.; Lopushinsky, Steven R.

    2002-01-01

    Objective To evaluate the safety and efficacy of heparin-coated perfusion circuits with low-dose heparinization and centrifugal pumping compared with the standard method during coronary artery bypass grafting. Design Prospective, randomized, single-blind clinical trial. Setting A primary care institution. Patients Ninety patients who underwent first-time elective coronary artery bypass grafting were eligible for the study. After giving informed consent, they were randomly assigned to 1 of 3 groups (30/group). Interventions Perfusion on regular uncoated bypass equipment with a roller pump and full-dose heparinization (300 IU/kg bolus, activated clotting time [ACT] > 400 s) (group 1), on a heparin-coated oxygenator with a centrifugal pump and full-dose heparinization (group 2) and on fully heparin-coated bypass equipment with a centrifugal pump and low-dose heparinization (100 IU/kg bolus, ACT of 180–400 s) (group 3). Standard coronary artery bypass grafting was performed. Outcome measures Postoperative bleeding, transfusion requirements and clinical outcomes. Results There were no complications related to the study protocol. Study groups were similar in terms of postoperative bleeding, transfusion requirements and clinical outcomes. Conclusions Heparin-coated cardiopulmonary bypass with low-dose heparinization and centrifugal pumping is a safe practice but showed no advantages over the use of regular uncoated bypass circuits for coronary bypass surgery. PMID:12067167

  4. IMPACT ON DISINFECTION AT PEAK FLOWS DURING BLENDING/PARTIAL BYPASSING OF SECONDARY TREATMENT

    EPA Science Inventory

    A U.S EPA study evaluated the impact on disinfection during peak flows when a portion of the flow to the wastewater treatment plant (WWTP) bypasses secondary treatment prior to disinfection. The practice of bypassing secondary treatment during peak flows, referred to as “blending...

  5. [Serum immune complexes and cardiopulmonary bypass. A review of thirty-four cases (author's transl)].

    PubMed

    Herreman, G; Poisson-Lespassailles, C; Puech, H; Vanetti, A; Delaunay, L; Yvart, J; Fermé, I

    1982-05-20

    The immunologic status of patients undergoing cardiopulmonary bypass as investigated. Rheumatoid factor, cryoglobulinemia and serum immune complexes were looked for. Studies were performed before the operation and eight or fifteen days later. From the results, it is concluded that the immunologic changes that occur in the immediate postoperative period cannot be interpreted because of the profound modifications resulting from cardiopulmonary bypass.

  6. Haptic Distal Spatial Perception Mediated by Strings: Point of Closest Approach and Bypass Distance

    ERIC Educational Resources Information Center

    Cabe, Patrick A.; Hofman, L. Leigh

    2012-01-01

    Four experiments examined haptic perception of two distal spatial properties in a bypass event. A hook suspended a string held taut between the participant's finger and a weight. Moving their fingers laterally beneath the hook, participants estimated the finger's point of closest approach (PCA) to the hook and bypass distance (BPD; i.e., hook…

  7. A Rare Case of Plastic Bronchitis in an Adult Patient After Cardiopulmonary Bypass.

    PubMed

    Sheikh, Ahmad Y; Ahmadi-Kashani, Mastaneh; Mohindra, Vibha; Friedenberg, Allison; Pramanik, Sharmila B; Ogden, William D

    2016-03-01

    Plastic bronchitis is a rare life-threatening complication observed after cardiopulmonary bypass (CPB). We describe a case of a 54-year-old man in whom a fulminant case of plastic bronchitis developed after coronary artery bypass grafting (CABG) and mitral valve repair. A brief review of the literature is also presented.

  8. A Longitudinal Study of Remodeling in a Revised Peripheral Artery Bypass Graft Using 3D Ultrasound Imaging and Computational Hemodynamics

    PubMed Central

    Leotta, Daniel F.; Beach, Kirk W.; Riley, James J.; Aliseda, Alberto

    2011-01-01

    We report a study of the role of hemodynamic shear stress in the remodeling and failure of a peripheral artery bypass graft. Three separate scans of a femoral to popliteal above-knee bypass graft were taken over the course of a 16 month period following a revision of the graft. The morphology of the lumen is reconstructed from data obtained by a custom 3D ultrasound system. Numerical simulations are performed with the patient-specific geometries and physiologically realistic flow rates. The ultrasound reconstructions reveal two significant areas of remodeling: a stenosis with over 85% reduction in area, which ultimately caused graft failure, and a poststenotic dilatation or widening of the lumen. Likewise, the simulations reveal a complicated hemodynamic environment within the graft. Preliminary comparisons with in vivo velocimetry also showed qualitative agreement with the flow dynamics observed in the simulations. Two distinct flow features are discerned and are hypothesized to directly initiate the observed in vivo remodeling. First, a flow separation occurs at the stenosis. A low shear recirculation region subsequently develops distal to the stenosis. The low shear region is thought to be conducive to smooth muscle cell proliferation and intimal growth. A poststenotic jet issues from the stenosis and subsequently impinges onto the lumen wall. The lumen dilation is thought to be a direct result of the high shear stress and high frequency pressure fluctuations associated with the jet impingement. PMID:21428682

  9. A longitudinal study of remodeling in a revised peripheral artery bypass graft using 3D ultrasound imaging and computational hemodynamics.

    PubMed

    McGah, Patrick M; Leotta, Daniel F; Beach, Kirk W; Riley, James J; Aliseda, Alberto

    2011-04-01

    We report a study of the role of hemodynamic shear stress in the remodeling and failure of a peripheral artery bypass graft. Three separate scans of a femoral to popliteal above-knee bypass graft were taken over the course of a 16 month period following a revision of the graft. The morphology of the lumen is reconstructed from data obtained by a custom 3D ultrasound system. Numerical simulations are performed with the patient-specific geometries and physiologically realistic flow rates. The ultrasound reconstructions reveal two significant areas of remodeling: a stenosis with over 85% reduction in area, which ultimately caused graft failure, and a poststenotic dilatation or widening of the lumen. Likewise, the simulations reveal a complicated hemodynamic environment within the graft. Preliminary comparisons with in vivo velocimetry also showed qualitative agreement with the flow dynamics observed in the simulations. Two distinct flow features are discerned and are hypothesized to directly initiate the observed in vivo remodeling. First, a flow separation occurs at the stenosis. A low shear recirculation region subsequently develops distal to the stenosis. The low shear region is thought to be conducive to smooth muscle cell proliferation and intimal growth. A poststenotic jet issues from the stenosis and subsequently impinges onto the lumen wall. The lumen dilation is thought to be a direct result of the high shear stress and high frequency pressure fluctuations associated with the jet impingement.

  10. Rankine cycle condenser pressure control using an energy conversion device bypass valve

    DOEpatents

    Ernst, Timothy C; Nelson, Christopher R; Zigan, James A

    2014-04-01

    The disclosure provides a waste heat recovery system and method in which pressure in a Rankine cycle (RC) system of the WHR system is regulated by diverting working fluid from entering an inlet of an energy conversion device of the RC system. In the system, an inlet of a controllable bypass valve is fluidly coupled to a working fluid path upstream of an energy conversion device of the RC system, and an outlet of the bypass valve is fluidly coupled to the working fluid path upstream of the condenser of the RC system such that working fluid passing through the bypass valve bypasses the energy conversion device and increases the pressure in a condenser. A controller determines the temperature and pressure of the working fluid and controls the bypass valve to regulate pressure in the condenser.

  11. Coronary artery bypass is superior to drug-eluting stents in multivessel coronary artery disease.

    PubMed

    Guyton, Robert A

    2006-06-01

    Percutaneous intervention for the treatment of multivessel coronary artery disease continues to displace coronary artery bypass graft surgery. But controlled trials of percutaneous intervention versus coronary bypass, in meta-analysis, have shown a significant survival advantage for coronary bypass. Studies of bare metal stents have not presented any data to prompt reversal of this conclusion for all but the small portion of patients most suited for stenting. Drug-eluting stents have no survival advantage compared with bare metal stents. Data from real-world registries have shown that the current therapy of multivessel disease patients has resulted in a relative excess mortality of as much as 46% in patients with initial stenting compared with patients with initial coronary bypass. Ethical considerations demand that patients with multivessel disease be informed of the documented mortality benefit of coronary bypass graft surgery.

  12. Temporary diabetes insipidus in 2 men after on-pump coronary artery bypass grafting.

    PubMed

    Uyar, Ihsan Sami; Sahin, Veysel; Akpinar, Besir; Yurtman, Volkan; Abacilar, Feyzi; Okur, Faik Fevzi; Ates, Mehmet

    2013-01-01

    Many complications have been reported after cardiopulmonary bypass. A common physiologic change during the early postoperative period after cardiopulmonary bypass is increased diuresis. In patients whose urine output is increased, postoperative diabetes insipidus can develop, although reports of this are rare. We present the cases of 2 patients who underwent on-pump coronary artery bypass grafting (with cardiopulmonary bypass). Each was diagnosed with diabetes insipidus postoperatively: a 54-year-old man on the 3rd day, and a 66-year-old man on the 4th day. Each patient recovered from the condition after 6 hours of intranasal therapy with synthetic vasopressin (antidiuretic hormone). The diagnosis of diabetes insipidus should be considered in patients who produce excessive urine early after cardiac surgery in which cardiopulmonary bypass has been used.

  13. Active bypass flow control for a seal in a gas turbine engine

    DOEpatents

    Ebert, Todd A.; Kimmel, Keith D.

    2017-01-10

    An active bypass flow control system for controlling bypass compressed air based upon leakage flow of compressed air flowing past an outer balance seal between a stator and rotor of a first stage of a gas turbine in a gas turbine engine is disclosed. The active bypass flow control system is an adjustable system in which one or more metering devices may be used to control the flow of bypass compressed air as the flow of compressed air past the outer balance seal changes over time as the outer balance seal between the rim cavity and the cooling cavity wears. In at least one embodiment, the metering device may include a valve formed from one or more pins movable between open and closed positions in which the one pin at least partially bisects the bypass channel to regulate flow.

  14. A Novel Endoscopic Technique to Diagnose Gastric Cancer in Excluded Stomach after Roux-en-Y Gastric Bypass

    PubMed Central

    Pitea, Teodor C.

    2017-01-01

    Access to the bypassed portion of the stomach after Roux-en-Y gastric bypass remains a challenge. We present a case of 64-year-old woman who presented with gastric outlet obstruction. We used a novel endoscopic technique to access the bypassed stomach by creating a jejunogastrostomy using a specialized stent, which allowed the insertion of a pediatric gastroscope to examine the bypassed portion of the stomach. Stomach biopsies revealed poorly differentiated adenocarcinoma with signet cell features. PMID:28331875

  15. 40 CFR 75.18 - Specific provisions for monitoring emissions from common and by-pass stacks for opacity.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... emissions from common and by-pass stacks for opacity. 75.18 Section 75.18 Protection of Environment... Provisions § 75.18 Specific provisions for monitoring emissions from common and by-pass stacks for opacity... emissions pass through the bypass stack. Method 9 shall be used in accordance with the applicable...

  16. Minimally invasive coronary artery bypass grafting versus stenting for patients with proximal left anterior descending coronary artery disease.

    PubMed

    Shirai, Kazuyuki; Lansky, Alexandra J; Mehran, Roxana; Dangas, George D; Costantini, Costantino O; Fahy, Martin; Slack, Steven; Mintz, Gary S; Stone, Gregg W; Leon, Martin B

    2004-04-15

    The purpose of this study was to compare the clinical outcomes of stenting and minimally invasive coronary artery bypass grafting (MIDCAB) in patients with proximal left anterior descending (LAD) coronary artery disease. The Patency, Outcome, Economics of Minimally invasive direct coronary bypass (POEM) study demonstrated that MIDCAB had similar safety and long-term efficacy for LAD revascularization compared with conventional coronary artery bypass grafting. Although LAD stenting is superior to conventional balloon angioplasty, whether it is comparable to MIDCAB is not known. We identified a matched population of 429 consecutive patients with 1-vessel disease who underwent elective proximal LAD stenting and compared their clinical outcomes with those of the 152 patients in the MIDCAB group of the POEM study. The in-hospital event rate was similar in both groups, except for a shorter length of hospital stay with LAD stenting compared with MIDCAB (2.68 vs 4.07 days, p <0.0001). At 6-month follow-up, the incidence of death and Q-wave myocardial infarction or that of cerebrovascular accident was not significantly different between these 2 groups. However, target vessel revascularization was significantly higher with LAD stenting than MIDCAB (13.3% vs 6.6%, p = 0.045). In the subgroup of patients without diabetes, all clinical events were similar in both groups, and the benefit of a shorter hospital stay associated with stenting was maintained. Compared with MIDCAB, LAD stenting is associated with higher repeat revascularization rates but offers the advantage of shorter hospitalization. For nondiabetics with proximal LAD disease, stenting may be the revascularization strategy of choice.

  17. Splenorenal Arterial Bypass: Description of Technique and Case Example in an Instance of Renal Revascularization during Adrenalectomy for Adrenocortical Carcinoma.

    PubMed

    Yozawitz, J; Kissin, M; Szuchmacher, M; Sullivan, J; Nicastro, J; Coppa, G; Molmenti, E

    2016-12-01

    We present a patient with a 16 cm adrenocortical carcinoma that underwent a left adrenalectomy en bloc with resection of the involved segment of the left renal artery. A splenectomy and splenorenal bypass was performed to revascularize the left kidney. To our knowledge, this is the first instance in the literature of a splenorenal arterial bypass being reported for renal revascularization during an extirpative oncologic procedure. A 64-year-old male patient, with history significant for adrenocortical carcinoma, status post prior right adrenalectomy with partial right nephrectomy, presented for an elective left adrenalectomy. Preoperative work-up revealed an 11.4 × 13.2 × 16 cm left adrenal mass, most consistent with an adrenocortical carcinoma. At the time of surgery, the mass was found to be intimately adherent to the aorta at the takeoff of the left renal artery. Moreover, the left renal artery appeared to be coursing directly through the mass. The involved segment of the left renal artery was resected en bloc with the tumor. Because of concerns for a small and likely poorly functioning right renal remnant, a decision was made to attempt to salvage the left kidney. This was accomplished by performing a splenectomy and constructing a splenorenal bypass. Serial Duplex Doppler renal ultrasound studies were obtained over the first three postoperative days and demonstrated improved arterial waveforms. Serum creatinine reached a peak level of 3.76 mg/dL on postoperative day 3, and then began to slowly trend down to 3.37 mg/dL on the day of discharge (postoperative day7).

  18. Mortality risk is dose-dependent on the number of packed red blood cell transfused after coronary artery bypass graft

    PubMed Central

    dos Santos, Antônio Alceu; Sousa, Alexandre Gonçalves; Piotto, Raquel Ferrari; Pedroso, Juan Carlos Montano

    2013-01-01

    Introduction Transfusions of one or more packed red blood cells is a widely strategy used in cardiac surgery, even after several evidences of increased morbidity and mortality. The world's blood shortage is also already evident. Objective To assess whether the risk of mortality is dose-de>pendent on the number of packed red blood cells transfused after coronary artery bypass graft. Methods Between June 2009 and July 2010, were analyzed 3010 patients: transfused and non-transfused. Transfused patients were divided into six groups according to the number of packed red blood cells received: one, two, three, four, five, six or more units, then we assess the mortality risk in each group after a year of coronary artery bypass graft. To calculate the odds ratio was used the multivariate logistic regression model. Results The increasing number of allogeneic packed red blood cells transfused results in an increasing risk of mortality, highlighting a dose-dependent relation. The odds ratio values increase with the increased number of packed red blood cells transfused. The death's gross odds ratio was 1.42 (P=0.165), 1.94 (P=0.005), 4.17; 4.22, 8.70, 33.33 (P<0.001) and the adjusted death's odds ratio was 1.22 (P=0.43), 1.52 (P=0.08); 2.85; 2.86; 4.91 and 17.61 (P<0.001), as they received one, two, three, four, five, six or more packed red blood cells, respectively. Conclusion The mortality risk is directly proportional to the number of packed red blood cells transfused in coronary artery bypass graft. The greater the amount of allogeneic blood transfused the greater the risk of mortality. The current transfusion practice needs to be reevaluated. PMID:24598957

  19. Risk factors for in-hospital mortality after coronary artery bypass grafting in patients 80 years old or older: a retrospective case-series study

    PubMed Central

    Konstanty-Kalandyk, Janusz; Kiełbasa, Grzegorz; Olszewska, Marta; Song, Bryan HyoChan; Wierzbicki, Karol; Milaniak, Irena; Darocha, Tomasz; Sobczyk, Dorota; Kapelak, Bogusław

    2016-01-01

    Background Age remains a significant and unmodifiable risk factor for cardiovascular diseases, and an increasing number of patients older than 80 years of age undergo Coronary Artery Bypass Grafting (CABG). Old age is also an independent risk factor for postoperative complications. The aim of this study is to describe the population of patients 80 years of age or older who underwent CABG procedure and to assess the mortality rate and risk factors for in-hospital mortality. Methods A retrospective case-series study analyzing 388 consecutive patients aged 80 years of age or older who underwent isolated CABG procedure between 2010 and 2014 in the Department of Cardiovascular Surgery and Transplantology, John Paul II Hospital, Krakow. Results In-hospital mortality stood at 7%, compared to 3.4% for all isolated CABG procedures at our Institution. In an univariate logistic regression analysis, risk factors for in-hospital mortality were as follows: NYHA class (p = 0.005, OR 1.95, 95% CI [1.23–3.1]), prolonged mechanical ventilation (p < 0.001, OR 7.08, 95% CI [2.47–20.3]), rethoracotomy (p = 0.04, OR 3.31, 95% CI [1.04–10.6]), duration of the procedure and ECC (for every 10 min p = 0.01, OR 1.01, 95% CI [1.0–1.01]; p = 0.03, OR 1.01, 95% CI [1.0–1.02], respectively), PRBC, FFP, and PLT transfusion (for every unit transfused p = 0.004, OR 1.42, 95% CI [1.12–1.8]; p = 0.002, OR 1.55, 95% CI [1.18–2.04]; p = 0.009, OR 1.93, 95% CI [1.18–3.14], respectively). Higher LVEF (p = 0.02, OR 0.97, 95% CI [0.94–0.99]) and LIMA graft implantation (p = 0.04, OR 0.36, 95% CI [0.13–0.98) decreased the in-hospital mortality. Death before discharge was more often observed in patients with multiple risk factors for cardiovascular diseases (0–2 –5.7%; 3–7.4%, 4–26.6%; p = 0.03). Conclusions Older age is associated with higher in-hospital mortality after isolated CABG at our Institution. Risk stratification scores and individualized risk

  20. Ozone profiles obtained by DIAL technique at Maïdo Observatory in La Reunion Island: comparisons with ECC ozone-sondes, ground-based FTIR spectrometer and microwave radiometer measurements

    NASA Astrophysics Data System (ADS)

    Portafaix, T.; Godin-Beekmann, S.; Payen, G.; de Mazière, M.; Langerock, B.; Fernandez, S.; Posny, F.; Cammas, J. P.; Metzger, J. M.; Bencherif, H.; Vigouroux, C.; Marquestaut, N.

    2016-06-01

    A DIAL lidar system performing stratospheric ozone profile measurements from 15 to 45 km is installed at Reunion Island (southwest of Indian Ocean). The purpose of this communication is to present this DIAL system mounted now at the new Maïdo Observatory since February 2013, and the ozone profile retrieval. The first stratospheric ozone profiles obtained during 2013 and 2014 will be presented and discussed. Inter-comparison and differences observed with other high vertical resolution ozone profiles performed by ECC ozonesonde will be shown. Finally, comparisons with low vertical resolution ozone profiles retrieved from microwave and FTIR remote sensing measurements performed at Maïdo will be carried out, making appropriate use of the associated averaging kernels

  1. Characterization and modeling of screen-printed metal insulator semiconductor tunnel junctions for integrated bypass functionality in crystalline silicon solar cells

    NASA Astrophysics Data System (ADS)

    Thaidigsmann, Benjamin; Lohmüller, Elmar; Fertig, Fabian; Clement, Florian; Wolf, Andreas

    2013-06-01

    This work investigates sintered, screen-printed silver contacts on lowly doped p-type silicon with different intermediate dielectric layer systems using scanning electron microscopy and dark current-voltage measurements. The data reveal electron tunneling through a thin insulating layer as the most probable transport mechanism. A model based on Fowler-Nordheim and direct tunneling is presented that allows for the description of reverse current-voltage characteristics and the extraction of effective contact properties. The investigated screen-printed metal insulator semiconductor structures are proposed as solar cell integrated bypass that reduces the risk of hot spot generation and power loss during partial shading of a module. Furthermore, the integrated bypass approach enables the fabrication of solar cells from silicon material that tends to show early breakdown of the p-n-junction.

  2. Diabetic patients have abnormal cerebral autoregulation during cardiopulmonary bypass

    SciTech Connect

    Croughwell, N.; Lyth, M.; Quill, T.J.; Newman, M.; Greeley, W.J.; Smith, L.R.; Reves, J.G. )

    1990-11-01

    We tested the hypothesis that insulin-dependent diabetic patients with coronary artery bypass graft surgery experience altered coupling of cerebral blood flow and oxygen consumption. In a study of 23 patients (11 diabetics and 12 age-matched controls), cerebral blood flow was measured using 133Xe clearance during nonpulsatile, alpha-stat blood gas managed cardiopulmonary bypass at the conditions of hypothermia and normothermia. In diabetic patients, the cerebral blood flow at 26.6 +/- 2.42 degrees C was 25.3 +/- 14.34 ml/100 g/min and at 36.9 +/- 0.58 degrees C it was 27.3 +/- 7.40 ml/100 g/min (p = NS). The control patients increased cerebral blood flow from 20.7 +/- 6.78 ml/100 g/min at 28.4 +/- 2.81 degrees C to 37.6 +/- 8.81 ml/100 g/min at 36.5 +/- 0.45 degrees C (p less than or equal to 0.005). The oxygen consumption was calculated from jugular bulb effluent and increased from hypothermic values of 0.52 +/- 0.20 ml/100 g/min in diabetics to 1.26 +/- 0.28 ml/100 g/min (p = 0.001) at normothermia and rose from 0.60 +/- 0.27 to 1.49 +/- 0.35 ml/100 g/min (p = 0.0005) in the controls. Thus, despite temperature-mediated changes in oxygen consumption, diabetic patients did not increase cerebral blood flow as metabolism increased. Arteriovenous oxygen saturation gradients and oxygen extraction across the brain were calculated from arterial and jugular bulb blood samples. The increase in arteriovenous oxygen difference between temperature conditions in diabetic patients and controls was significantly different (p = 0.01). These data reveal that diabetic patients lose cerebral autoregulation during cardiopulmonary bypass and compensate for an imbalance in adequate oxygen delivery by increasing oxygen extraction.

  3. Vacuum-assisted drainage in cardiopulmonary bypass: advantages and disadvantages

    PubMed Central

    de Carvalho Filho, Élio Barreto; Marson, Fernando Augusto de Lima; da Costa, Loredana Nilkenes Gomes; Antunes, Nilson

    2014-01-01

    Systematic review of vacuum assisted drainage in cardiopulmonary bypass, demonstrating its advantages and disadvantages, by case reports and evidence about its effects on microcirculation. We conducted a systematic search on the period 1997-2012, in the databases PubMed, Medline, Lilacs and SciELO. Of the 70 selected articles, 26 were included in the review. Although the vacuum assisted drainage has significant potential for complications and requires appropriate technology and professionalism, prevailed in literature reviewed the concept that vacuum assisted drainage contributed in reducing the rate of transfusions, hemodilutions, better operative field, no significant increase in hemolysis, reduced complications surgical, use of lower prime and of smaller diameter cannulas. PMID:25140478

  4. Interdisciplinary Simulation Using the Cardiopulmonary Bypass Simulator (CPBS)©

    PubMed Central

    Mendel, Shaun

    2014-01-01

    Abstract: Interdisciplinary education offerings between students of cardiovascular science and nurse anesthesia are uncommon despite the collaborative nature of these disciplines. The dual purpose of this article is to describe a method for interdisciplinary simulation and to report survey responses provided by participants. An interdisciplinary simulation session using concurrent use of the cardiopulmonary bypass simulator and the emergency care simulator is described. Interdisciplinary perceptions before and after the event were surveyed using the revised Interdisciplinary Education Perception Scale. Statistically significant differences between baseline and final survey responses were observed in the total score and within the areas of competency and perception of cooperation. Emerging simulation technologies and novel combinations of existing devices can facilitate meaningful interdisciplinary educational opportunities for health science students. PMID:26357799

  5. CFD Design for Bypass Ratio 15 Nacelle Integration

    NASA Technical Reports Server (NTRS)

    Milholen, William E., II

    2001-01-01

    A computational study is being conducted to evaluate the installation effects of ultra-high bypass ratio (BPR) nacelles on conventional twin-engine transonic transport aircraft. An unstructured Navier-Stokes flow solver, USM3D, is being utilized for the study. The results have been compared to wind tunnel data obtained in the NASA LaRC 16-Foot Transonic Tunnel, for nacelle BPRs of nine and twelve. The USM3D flow solver was found to adequately predict the flows of interest, and has subsequently been used to analyze the installation effects of a theoretical BPR-15 nacelle. In addition, a design code is being used in conjunction with USM3D to redesign the wing in the presence of the BPR-15 nacelle. The preliminary design results will be presented.

  6. [Percutaneous transluminal angioplasty in vascular by-passes].

    PubMed

    Rodríguez, J E; Fernández Guinea, O; López, V; Suárez Pereiro, M J; Reimunde, E; Cosío, J M; Barreiro, A

    1993-01-01

    Results from 21 cases of percutaneous transluminal angioplasties as a treatment of stenosed vascular by-pass from 16 patients, are presented. The technique took place in 10 cases at the aorto-femoral area, in others 10 cases at the popliteal-femoral area and, in the last one, at the carotid-subclavian area. Preliminary results were successful in all cases (100%). Follow-up showed a better long-term results at the aorto-femoral level. Considering the satisfactory results and also considering that, in case of negative results or re-stenosis, other surgical techniques could be performed, we conclude that the percutaneous transluminal angioplasty should be the first treatment for such of injuries.

  7. Lithium-induced nephrogenic diabetes insipidus after coronary artery bypass.

    PubMed

    Leeman, Matthew F; Vuylsteke, Alain; Ritchie, Andrew J

    2007-08-01

    We present a case of nephrogenic diabetes insipidus that occurred after on-pump coronary artery bypass grafting in a patient taking long-term lithium carbonate. Lithium toxicity (2.79 mmol/L) was identified on postoperative day 9. Serum sodium peaked at 175 mmol/L on postoperative day 21. Serum osmolality peaked at 384 mOsm/kg H2O, with a urinary osmolality of 403 mOsm/kg H2O. The patient was ultimately managed with hemofiltration and high-dose 1-desamino-8-D-arginine-vasopressin. Recommendations are made based on our experience of this case. In patients on long-term lithium therapy, the potentially life-threatening complication of lithium-induced nephrogenic diabetes insipidus should be specifically anticipated and managed.

  8. Patient-controlled analgesia after coronary artery bypass grafting.

    PubMed

    Dawkins, Sarah

    Patient-controlled analgesia is a method of pain control that allows the patient to self-administer opioid medication as and when it is needed. Pain is a personal experience and one pain-relieving intervention may not be effective for all patients. This article reviews the literature on patient-controlled analgesia, particularly with reference to patients after coronary artery bypass grafting. Pain policies and education programmes need to be proactive in addressing staff and patient gaps in knowledge and misconceptions about pain assessment and management. Nurses need to appreciate the nature and importance of research in promoting a more critical approach to patient care and the development of quality nursing practice.

  9. Integrated Bypass Battery for ReverseBias Protection

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A,

    2002-01-01

    When a single solar cell of a series-connect string is placed in shadow, the entire array current is forced through that cell in reverse bias. Reverse bias current can lead to "hot-spot" heating, where the power produced by the unshadowed cells is dissipated as heat in the shadowed cell. Since occasional shadows are unavoidable in most applications, most solar arrays include shadow protection to prevent damage. In current practice, shadow protection is done with a "bypass diode" on each cell, to shunt the reverse bias current if a cell is shadowed. A new method of reverse bias protection is to use an Integral thin-film battery to provide voltage in the case of a shadowed cell. In this case, the shadowed cell continues to provide voltage during the transient shadow.

  10. Noise barrier for the Temuco ByPass Highway

    NASA Astrophysics Data System (ADS)

    Gerard, Christian; Campos, Aldo; Belfiore, Sergio

    2002-11-01

    Increases in traffic and the emergent Highway Concession Program created by the Public Works Ministry of the Chilean government, have led to the necessity of providing acoustic protection in inhabited areas in which the level of noise exceeds that allowed by the standard. Around the world, the installation of acoustic barriers has been one of the main measures of the controlling traffic noise. This is the case with the Temuco ByPass Highway, an extension of 21 km, located in a rural area typical of the environment and landscape of the South of Chile. A total of 6000 lineal meters of transparent acoustic barrier (Methacrylate) was installed. This barrier is the first one of its type to be installed in South America, and theoretical calculations and practical results are analyzed in this work. (To be presented in Spanish.)

  11. Hiatal hernia causing extrapericardial tamponade after coronary bypass surgery.

    PubMed

    Papoulidis, Pavlos; Beatty, Jasmine Winter; Dandekar, Uday

    2014-10-01

    Cardiac tamponade is defined as compression of the heart due to accumulation of fluid in the pericardial sac, leading to raised pericardial pressures with haemodynamic compromise. We describe the case of a 76-year old female patient who underwent a routine off-pump coronary artery bypass graft operation and within 48 h developed classic signs of cardiac tamponade. The perioperative echocardiogram and operative findings at re-exploration revealed no clots or fluid collection. A giant hiatus hernia was found to be responsible for the tamponade through extrinsic compression. After insertion of a nasogastric tube and decompression of the stomach, there was a rapid improvement of the clinical picture. The remaining postoperative course was uneventful and the patient was discharged 5 days later, with referral to the general surgeon for further management. We conclude that, in cases of tamponade post-cardiac surgery, extrapericardial pathologies should be considered.

  12. Photovoltaic power generation system free of bypass diodes

    SciTech Connect

    Lentine, Anthony L.; Okandan, Murat; Nielson, Gregory N.

    2015-07-28

    A photovoltaic power generation system that includes a solar panel that is free of bypass diodes is described herein. The solar panel includes a plurality of photovoltaic sub-modules, wherein at least two of photovoltaic sub-modules in the plurality of photovoltaic sub-modules are electrically connected in parallel. A photovoltaic sub-module includes a plurality of groups of electrically connected photovoltaic cells, wherein at least two of the groups are electrically connected in series. A photovoltaic group includes a plurality of strings of photovoltaic cells, wherein a string of photovoltaic cells comprises a plurality of photovoltaic cells electrically connected in series. The strings of photovoltaic cells are electrically connected in parallel, and the photovoltaic cells are microsystem-enabled photovoltaic cells.

  13. Vanishing Venous Coronary Artery Bypass Grafts after Sepsis

    PubMed Central

    Park, Soo Jin; Park, Ji Ye; Jung, Joonho; Hong, You Sun; Lee, Cheol Joo; Lim, Sang Hyun

    2016-01-01

    The dehiscence of saphenous vein grafts (SVGs) is a rare, often fatal, complication of coronary artery bypass grafting (CABG). We present the case of a 57-year-old man who underwent hemiarch graft interposition and CABG for a Stanford type A aortic dissection. Five months after discharge, the patient developed streptococcal sepsis caused by a hemodialysis catheter. Complete rupture of the proximal anastomoses of the saphenous veins and containment by the obliterated pericardial cavity was observed 25 months after the initial operation. The patient was successfully treated surgically. This report describes a patient who developed potentially fatal dehiscence of SVGs secondary to infection and outlines preventive and management strategies for this complication. PMID:27734001

  14. [Qualitative analysis of factors supporting the motivation for gastric bypass].

    PubMed

    Mboyato, S; Somasse, E; Coppieters, Y

    2012-01-01

    Half of Belgium's adult population is overweight and approximately 14% are obese. Apart from organic diseases associated with obesity, the psychological repercussion is very important and requires a specific caring. Conservative treatments containing diet, physical-activity and drugs often show limits in particular when the patient presents food behavioural disorders. The bariatric surgery is presented like an ultimate therapy. It is a specific treatment which involves risks and high cost for the patient. This study is based on a qualitative study including patients coming to a gastric bypass in order to appreciate the surgical indications and to describe the individual motivations which lead the patients to request this intervention. The study consists of semi-structured interviews with hospitalized patients. The majority of the patients do not correspond to the criteria defined by the law. The psychological repercussion of obesity compared to the family sight and the society seems to constitute a crucial factor in the recourse to the gastric bypass. The motivations to undergo this intervention are: importance attached to the physique, need for being with the mode, for answering at the request of a spouse or for decreasing health risks. The social support of the family and friends, during and after the intervention is a key component of the success and the acceptability of the intervention. This study proposes to re-examine the criteria of access to the bariatric surgery and to ensure a psychological accompaniment before and after the intervention. That is important for patients who are badly informed about conditions and consequences of the intervention.

  15. Hyperparathyroidism and vitamin D deficiency after laparoscopic gastric bypass.

    PubMed

    Clements, Ronald H; Yellumahanthi, Kishore; Wesley, Mary; Ballem, Naveen; Bland, Kirby I

    2008-06-01

    Hyperparathyroidism (HPT) can occur after gastric bypass because of the alteration in vitamin D and calcium absorption. Adequate serum vitamin D concentrations have not been clearly defined in this patient population. Vitamin D (Vit D) and parathyroid hormone (PTH) were assessed 1 year after laparoscopic gastric bypass (LGB). The prevalence of HPT and Vit D deficiency were determined and their association was evaluated using Fisher's exact test. Ninety-three patients (aged 44 +/- 1.1 years, 49.6 +/- 0.67 Kg/m2 body mass index, 79.6% female, 69.6% white) were evaluated. The prevalence of Vit D deficiency (less than 20 ng/mL) and HPT (greater than 65 pg/mL) was 23.6 per cent (n = 22) and 25.7 per cent (n = 28), respectively. Among patients with HPT, only eight of 28 (28.6%) had Vit D deficiency, and of those with Vit D deficiency, only eight of 22 (36.4%) had HPT. There was a weak inverse correlation (r = -0.37) between PTH and Vit D. Blacks are at higher risk for Vit D deficiency. There was no significant association between Vit D deficiency and HPT, Vit D deficiency and Roux limb length, or HPT and Roux limb length. After LGB, Vit D deficiency and hyperparathyroidism occur commonly. Body mass index and Roux limb length are not associated with these two conditions, but racial differences do exist. There is a weak inverse correlation between Vit D and PTH. Further research is needed to elucidate the causes, treatments, and significance of HPT after LGB.

  16. Management of Failing Prosthetic Bypass Grafts with Metallic Stent Placement

    SciTech Connect

    Siskin, Gary P.; Stainken, Brian F.; Mandell, Valerie S.; Darling, R. Clement; Dowling, Kyran; Herr, Allen

    1999-09-15

    Purpose: To evaluate the role of metallic stents in treating stenoses involving prosthetic arterial bypass grafts. Methods: Patients undergoing stent placement within a failing prosthetic bypass graft, during a 41-month period, were reviewed for treatment outcome and complications. The indications for stent placement in 15 patients included severe claudication (n= 3), rest pain (n= 9), and minor or major tissue loss (n= 3). Lesions were at the proximal anastomosis (n= 6), the distal anastomosis (n= 3), or within the graft (n= 6). Results: Treatment with metallic stents was successful in all patients. There was one acute stent thrombosis, successfully treated with thrombolytic therapy. Follow-up data are available for a mean duration of 12.3 months. The mean duration of primary patency was 9.4 months with 6- and 12-month primary patency rates of 51.9% and 37.0%, respectively. The mean duration of secondary patency was 12.1 months with 6- and 12-month secondary patency rates of 80.0% and 72.7%, respectively. Two patients with discontinuous runoff and preexisting gangrene required a below-knee amputation. Six patients were revised surgically after stent placement (at a mean of 10.8 months). Three late deaths occurred during follow-up. Conclusion: Given the mortality risks of surgical revision and the reduced life expectancy of this patient population, metallic stent placement represents a viable, short-term treatment option for stenoses within or at the anastomoses of prosthetic grafts. Further evaluation is warranted to compare intragraft stent placement with surgical graft revision.

  17. Do Advance Directives Direct?

    PubMed

    Shapiro, Susan P

    2015-06-01

    Resolution of long-standing debates about the role and impact of advance directives - living wills and powers of attorney for health care - has been hampered by a dearth of appropriate data, in particular data that compare the process and outcomes of end-of-life decision making on behalf of patients with and without advance directives. Drawing on a large ethnographic study of patients in two intensive care units in a large urban teaching hospital, this article compares aspects of the medical decision-making process and outcomes by advance-directive status. Controlling for demographic characteristics and severity of illness, the study finds few significant differences between patients without advance directives and those who claim to have them. Surprisingly, these few differences hold only for those whose directives are in their hospital chart. There are no significant differences between those with no directive and those claiming to have a copy at home or elsewhere. The article considers the implications if directives seemingly must be in hand to show even modest effects. Do advance directives direct? The intensive care unit data provide far more support for the growing body of literature that casts doubt on their impact than studies that promote the use of them.

  18. Left ventricular mechanics of counterpulsation and left heart bypass, individually and in combination.

    PubMed

    Rose, E A; Marrin, C A; Bregman, D; Spotnitz, H M

    1979-01-01

    Counterpulsation and left heart bypass devices have been successfully used to salvage patients with severe left ventricular power failure following cardiopulmonary bypass. Each of these techniques is believed to reduce or minimize myocardial work, yet the effects of these devices on the force of myocardial contraction have not been defined. In the present investigation the effects of counterpulsation produced by intravascular (intra-aortic balloon pumping) and extravascular (pulsatile assist device) balloon devices, partial left atrial-aortic bypass, and total bypass on left ventricular mechanics were examined. The devices were studied individually and in combination in 10 anesthetized open-chest dogs. Left ventricular wall stress, external work, and contractility indices were calculated by computer using a changing volume spherical model of the left ventricle. Results indicate that although all currently available circulatory assist devices reduced peak left ventricular wall stress, a spectrum of relative effectiveness progressed from intra-aortic balloon pumping or pulsatile assist device alone through the combination intra-aortic balloon pumping plus the pulsatile assist device. Partial left heart bypass was more effective than intra-aortic balloon pumping plus the pulsatile assist device in reducing peak wall stress, but the difference was small. Total left heart bypass was vastly superior to any of the other modalities tested in its effects on peak wall stress as well as external work. The addition of counterpulsation to partial or total left heart bypass produced minimal changes in left ventricular systolic mechanics.

  19. Value of tomographic thallium-201 imaging in patients with chest pain following coronary artery bypass grafting

    SciTech Connect

    Starling, M.R.; Walsh, R.A.; Dehmer, G.J.; Lasher, J.C.; Blumhardt, R.

    1987-02-01

    To determine whether thallium-201 washout profile analysis can detect regional myocardial ischemia caused by coronary artery bypass graft occlusion or progression of disease in nonbypassed coronary arteries, 19 consecutive patients with chest pain following bypass grafting were evaluated with coronary arteriography and thallium-201 scintigraphy. Twenty of the 55 coronary artery regions were perfused by an occluded bypass graft or a significantly stenosed (greater than or equal to 70% diameter narrowing) nonbypassed coronary artery, while 35 coronary regions were perfused by patent bypass grafts or insignificantly diseased coronary arteries. The tomographic thallium-201 washout profile results correlated with the bypass graft and coronary arteriographic findings. The sensitivity of tomographic thallium-201 washout profile abnormalities for arteriographic abnormalities was 75%, while the specificity was 86%. The authors conclude that tomographic thallium-201 washout profile analysis may be very useful in the evaluation of patients with chest pain following coronary artery bypass grafting by detecting regional myocardial ischemia caused by occlusion of specific bypass grafts or progression of disease in nonbypassed coronary arteries.

  20. Measurement of hepatic insulin sensitivity early after the bypass of the proximal small bowel in humans

    PubMed Central

    Herring, R.; Vusirikala, A.; Shojaee‐Moradi, F.; Jackson, N. C.; Chandaria, S.; Jackson, S. N.; Goldstone, A. P.; Hakim, N.; Patel, A. G.; Umpleby, A. M.; Le Roux, C. W.

    2016-01-01

    Summary Objective Unlike gastric banding or sleeve gastrectomy procedures, intestinal bypass procedures, Roux‐en‐Y gastric bypass in particular, lead to rapid improvements in glycaemia early after surgery. The bypass of the proximal small bowel may have weight loss and even caloric restriction‐independent glucose‐lowering properties on hepatic insulin sensitivity. In this first human mechanistic study, we examined this hypothesis by investigating the early effects of the duodeno‐jejunal bypass liner (DJBL; GI Dynamics, USA) on the hepatic insulin sensitivity by using the gold standard euglycaemic hyperinsulinaemic clamp methodology. Method Seven patients with obesity underwent measurement of hepatic insulin sensitivity at baseline, 1 week after a low‐calorie liquid diet and after a further 1 week following insertion of the DJBL whilst on the same diet. Results Duodeno‐jejunal bypass liner did not improve the insulin sensitivity of hepatic glucose production beyond the improvements achieved with caloric restriction. Conclusions Caloric restriction may be the predominant driver of early increases in hepatic insulin sensitivity after the endoscopic bypass of the proximal small bowel. The same mechanism may be at play after Roux‐en‐Y gastric bypass and explain, at least in part, the rapid improvements in glycaemia.

  1. Noise predictions of a high bypass turbofan engine using the Lockheed Near-Field Noise Prediction Program

    NASA Technical Reports Server (NTRS)

    Rawls, J. W., Jr.

    1986-01-01

    The prediction of engine noise during cruise using the Near-Field Noise Prediction Program developed by Lockheed is examined. Test conditions were established which simulate the operation of a high bypass turbofan engine under a wide range of operating conditions. These test conditions include variations in altitude, flight Mach number and thrust setting. Based on the results of noise prediction made using the Lockheed program, an evaluation of the impact of these test conditions on the overall sound pressure level(OASPL)and the one-third octave band spectra is made. An evaluation of the sensitivity of flight condition parameters is also made. The primary noise source from a high bypass turbofan was determined to be fan broadband shock noise. This noise source can be expected to be present during normal cruising conditions. When present, fan broadband shock noise usually dominates at all frequencies and all directivity angles. Other noise sources of importance are broadband shock noise from the primary jet, fan noise, fan mixing noise and turbine noise.

  2. Stent graft repair of anastomotic pseudoaneurysm of femoral–popliteal bypass graft following patch angioplasty

    PubMed Central

    Carollo, Andrea; Gagliardo, Giovanni; DeVito, Peter M.; Cicchillo, Michael

    2016-01-01

    Pseudoaneurysm (PA) following vascular reconstruction is a complication of bypass surgery. Historically, the mainstay of treatment was an open repair; the surgical management consisted of resection of the initial graft with reimplantation of a new bypass either into the original arteriotomy or to a more distal target. Placement of a stent graft to exclude the PA is a viable option. We present a case of an 85-year-old man with prior history of polytetrafluoroethylene femoral–popliteal bypass now with an 8 × 5.6 cm PA of the distal anastomosis site treated with endovascular placement of a Viabahn stent. PMID:27994009

  3. Evaluation of a Stirling engine heater bypass with the NASA Lewis nodal-analysis performance code

    SciTech Connect

    Sullivan, T.J.

    1986-05-01

    In support of the US Department of Energy's Stirling Engine Highway Vehicle Systems program, the NASA Lewis Research Center investigated whether bypassing the P-40 Stirling engine heater during regenerative cooling would improve the engine thermal efficiency. The investigation was accomplished by using the Lewis nodal-analysis Stirling engine computer model. Bypassing the P-40 Stirling engine heater at full power resulted in a rise in the indicated thermal efficiency from 40.6 to 41.0 percent. For the idealized (some losses not included) heater bypass that was analyzed, this benefit is not considered significant.

  4. By-Pass Diode Temperature Tests of a Solar Array Coupon under Space Thermal Environment Conditions

    NASA Technical Reports Server (NTRS)

    Wright, Kenneth H.; Schneider, Todd A.; Vaughn, Jason A.; Hoang, Bao; Wong, Frankie; Wu, Gordon

    2016-01-01

    By-Pass diodes are a key design feature of solar arrays and system design must be robust against local heating, especially with implementation of larger solar cells. By-Pass diode testing was performed to aid thermal model development for use in future array designs that utilize larger cell sizes that result in higher string currents. Testing was performed on a 56-cell Advanced Triple Junction solar array coupon provided by SSL. Test conditions were vacuum with cold array backside using discrete by-pass diode current steps of 0.25 A ranging from 0 A to 2.0 A.

  5. Effect of ischemic postconditioning on myocardial protection in patients undergoing coronary artery bypass grafting surgery with cardiopulmonary bypass

    PubMed Central

    Safaei, Nasser; Sheikhalizadeh, Mohammad Ali; Badalzadeh, Reza

    2016-01-01

    Introduction: Reperfusion injury is a well-known phenomenon following restoration of the coronary circulation after coronary artery bypass grafting (CABG) that impairs myocardial function. In order to control the severity of this injury, we aimed to investigate the effect of a new conditioning strategy namely ischemic postconditioning (IPOC) along with controlled aortic root reperfusion (CARR) on myocardial protection in CABG surgery with cardiopulmonary bypass. Methods: In a doubled blind clinical trial study, 51 patients undergoing first-time elective CABG were randomly divided in three groups: CARR, IPOC, and combination of IPOC and CARR. At the end of procedure and just before aortic cross-clamp removal, reperfusion was started as following: In CARR-receiving groups, the reperfusion was started with low perfusion pressures for 10 minutes, and in IPOC-receiving groups, three cycles of 1 minute episodes of ischemia separated by 1 minute episodes of reperfusion was applied as postconditioning protocol. Left ventricular ejection fraction (EF) (by echocardiography), inotrope requirement index, and myocardial arrhythmias were measured up to 72 hours after operation. Results: Echocardiography revealed that the recovery of EF after operation in IPOC group was significantly higher than those of two other groups (P < 0.05). Inotropic support requirement was significantly lower in IPOC groups. In addition, the incidence of atrial and ventricular arrhythmias after opening of aortic clamp and in intensive care unit (ICU) as well as recovery time of cardiac rhythm upon reperfusion were lowered by administration of IPOC, as compared with CARR group. Conclusion: The study suggests that IPOC may provide clinical benefits against reperfusion injury in patients undergoing CABG surgery and maintain the post ischemic left ventricular performance. PMID:27489599

  6. Malabsorptive procedures for severe obesity: comparison of pancreaticobiliary bypass and very very long limb Roux-en-Y gastric bypass.

    PubMed

    Murr, M M; Balsiger, B M; Kennedy, F P; Mai, J L; Sarr, M G

    1999-01-01

    The aim of this study was to determine the efficacy and safety of two malabsorptive procedures for severe obesity. Prospectively collected data from eight men and three women who underwent partial biliopancreatic bypass (PBB) and 19 men and seven women who underwent very very long limb Roux-en-Y gastric bypass (VVLGB) for superobesity (preoperative weight >225% above ideal body weight) were evaluated. Age (42 +/- 3 years and 40 +/- 2 years), body mass index (64 +/- 4 kg/m(2) and 67 +/- 3 kg/m(2)), and percentage of excess body weight (183% +/- 17% and 203% +/- 12%) were similar (mean +/- standard error of the mean). Median follow-up was 96 months (range 72 to 108 months) and 24 months (range 18 to 60 months) for the PBB and VVLGB groups, respectively. Weight loss expressed as percentage of excess body weight was 68% +/- 4% 2 years and 71% +/- 5% 4 years after PBB, and 53% +/- 7% 2 years and 57% +/- 5% 4 years after VVLGB. Current body mass indexes are 37 +/- 2 kg/m(2) and 42 +/- 2 kg/m(2) in the PBB and VVLGB groups, respectively. Hospital mortality was zero. Morbidity occurred in five patients after VVLGB (wound infection in four, wound seroma in one, and pulmonary embolus in one) and in two patients after PBB (abscess in two, anastomotic leak in one, and gastrointestinal bleeding in one). After PBB, one woman died of refractory liver failure 18 months postoperatively and two other patients developed metabolic bone disease. No such known complications have occurred to date after VVLGB. We conclude that VVLGB is safe and effective for clinically significant obesity, results in sustained weight loss, and improves quality of life.

  7. The Effects of Levosimendan and Sodium Nitroprusside Combination on Left Ventricular Functions After Surgical Ventricular Reconstruction in Coronary Artery Bypass Grafting Patients

    PubMed Central

    Temizturk, Zeki; Azboy, Davut; Atalay, Atakan; Atalay, Hakan; Dogan, Omer Faruk

    2016-01-01

    Objective: The aim of our study was to research the effects of levosimendan (LS) and sodium nitroprusside (SNP) combination on systolic and diastolic ventricular function after coronary artery bypass grafting (CABG) who required endoventricular patch repair (EVPR). Patients and Methods: We studied 70 patients with ischemic dilated cardiomyopathy. LS and SNP combination was administered in 35 patients (study group, SG). In the remaining patients, normal saline solution was given (placebo group, PG). Levosimendan (10µgr/kg) started 4 h prior to operation and we stopped LS before the initiation of extracorporeal circulation (ECC). During the rewarming period, we started again levosimendan (10µgr/kg) in combination with SNP (0.1-0.2 µgr/kg/min). If mean blood pressure decreased by more than 25% compared with pre-infusion values, for corrected of mean arterial pressure, the volume loading was performed using a 500 ml ringer lactate. Hemodynamic variables, inotrophyc requirement, and laboratory values were recorded. Results: Five patients died (7.14%) post-surgery (one from SG and 4 from PG) due to low cardiac out-put syndrome (LOS). At the postoperative period, cardiac output and stroke volume index was higher in SG (mean±sd;29.1±6.3 vs. 18.4±4.9 mL/min−1/m−2 (P<0.0001)). Stroke volume index (SVI) decreased from 29±10mL/m2 preoperatively to 22±14mL/m2 in the early postoperative period in group 1. This difference was statistically significant (P=0.002). Cardiac index was higher in SG (320.7±37.5 vs. 283.0±83.9 mL/min−1/m−2 (P=0.009)). The postoperative inotrophyc requirement was less in SG (5.6±2.7 vs. 10.4±2.0 mg/kg, P< 0.008), and postoperative cardiac enzyme levels were less in SG (P< 0.01). Ten patients (28.5%) in SG and 21 patients (60%) in PG required inotrophyc support (P<0.001). We used IABP in eight patients (22.8%) in SG and 17 patients (48.5%) in CG (P=0.0001). Conclusion: This study showed that LS and SNP combination impressive increase in

  8. Diabetes surgery in type 2 BMI 24-29 vs IMC 30-34 diabetic patients: is there differences among restrictive, malabsorptive and gastric bypass procedures?

    PubMed

    Garciacaballero, M; Navarrete, S; Favretti, F; Celik, A; Del Castillo, D

    2013-03-01

    Diabetes mellitus (DM) is a public health problem with a prevalence of 345 million people worldwide that it may double by the year 2030 and have a high costs and mortality. Gastrointestinal surgery is accepted as a form of treatment that was already suggested for obese in 1987 by Pories, confirmed for obese patients by the metaanalysis of Buchwald and the direct comparison of gastric bypass with medical treatment in the study of Schauer that demonstrate a 4 fold greater resolution rate of DM with surgery. Improvement occurs immediately after surgery, before the patients lose weight in with BMI > 35; but there is doubt if the existent evidence is enough to extrapolate these results to patients with BMI < 35 and especially with BMI < 30, in spite that four reviews in patients with this BMI and DM2 demonstrated the same results when stomach, duodenum and part of jejunum is bypassed as happen gastric bypass (better results with this of one anastomosis than of two anastomosis, Roux-en-Y) BPD. For patients with a BMI between 30 and 35 restrictive techniques: LAGB and SGL are good but not better than the mixed: RYGB, BAGUA, or SG-DJB with remission from 60 to 100%, minor in the derivative: BPD and above on the IID with a 81% of remission. There are no differences in the metabolic control in comparison to the obese, It is progressively better with DJB, SDS, IID and BAGUA especially in patients who do not require insulin, have less time with disease, have normal C peptide levels, and not so much relation with the initial BMI that is only important to decide the degree of restriction. Although several mechanisms has been suggested for explaining these results such as caloric intake, hormonal changes, bypass of the anterior or early stimulation of posterior intestine, fundectomy, intestinal gluconeogenesis and others, new ones will appear in the near future.

  9. Requirements for bypass of UV-induced lesions in single-stranded DNA of bacteriophage phi X174 in Salmonella typhimurium.

    PubMed Central

    Slater, S C; Maurer, R

    1991-01-01

    According to the current model for mutagenic bypass of UV-induced lesions, efficient bypass requires three proteins: activated RecA (RecA*) and either activated UmuD (UmuD') and UmuC or their plasmid-encoded analogues, MucA' and MucB. RecA* aids synthesis of UmuD' and UmuC (and MucA'/MucB) at two levels: by inactivation of the LexA transcriptional repressor of these genes and by cleavage of UmuD (and MucA) to produce the active fragments, UmuD' (MucA'). A third role for RecA is revealed when these two roles are otherwise satisfied in a suitably engineered strain. An often-suggested possible role for RecA in bypass is inhibition of editing by the epsilon subunit of DNA polymerase III. Here, by demonstrating that elimination of epsilon by deletion of its gene, dnaQ, does not relieve the requirement for the third function of RecA, we show that RecA must perform some function other than, or in addition to, inhibition of epsilon. We also show that elimination of epsilon does not relieve the requirement for either Muc protein. Moreover, we observed reactivation of irradiated phi X174 in unirradiated cells expressing MucA' and MucB. This finding makes it unlikely that the additional role of recA involves derepression of an unidentified gene or cleavage of an unidentified protein and makes it more likely that RecA participates directly in bypass. PMID:1847514

  10. Requirements for bypass of UV-induced lesions in single-stranded DNA of bacteriophage phi X174 in Salmonella typhimurium

    SciTech Connect

    Slater, S.C.; Maurer, R. )

    1991-02-15

    According to the current model for mutagenic bypass of UV-induced lesions, efficient bypass requires three proteins: activated RecA (RecA*) and either activated UmuD (UmuD') and UmuC or their plasmid-encoded analogues, MucA' and MucB. RecA* aids synthesis of UmuD' and UmuC (and MucA'/MucB) at two levels: by inactivation of the LexA transcriptional repressor of these genes and by cleavage of UmuD (and MucA) to produce the active fragments, UmuD' (MucA'). A third role for RecA is revealed when these two roles are otherwise satisfied in a suitably engineered strain. An often-suggested possible role for RecA in bypass is inhibition of editing by the epsilon subunit of DNA polymerase III. Here, by demonstrating that elimination of epsilon by deletion of its gene, dnaQ, does not relieve the requirement for the third function of RecA, we show that RecA must perform some function other than, or in addition to, inhibition of epsilon. We also show that elimination of epsilon does not relieve the requirement for either Muc protein. Moreover, we observed reactivation of irradiated phi X174 in unirradiated cells expressing MucA' and MucB. This finding makes it unlikely that the additional role of recA involves derepression of an unidentified gene or cleavage of an unidentified protein and makes it more likely that RecA participates directly in bypass.

  11. Quadruple valve replacement and bypass surgery 23 years after the Ross operation†.

    PubMed

    Oeser, Claudia; Andreas, Martin; Habertheuer, Andreas; Kocher, Alfred

    2015-07-01

    This report describes a case of simultaneous quadruple valve replacement, coronary artery bypass surgery and reconstruction of one aortic sinus performed in a patient who had undergone the Ross operation 23 years previously.

  12. Development of design criteria and a qualification test for bypass diodes

    NASA Astrophysics Data System (ADS)

    Otth, D. H.

    1985-06-01

    The development of a qualification test for modules bypass diodes is reviewed. Diode junction temperature is measured, indirectly, under laboratory ambient conditions, and extrapolated to field conditions. Criteria are given for diode reliability.

  13. Paraplegia Due to Spinal Cord Infarction After Coronary Artery Bypass Graft Surgery.

    PubMed

    Sevuk, Utkan; Kaya, Sedat; Ayaz, Firat; Aktas, Ulas

    2016-01-01

    Paraplegia is an extremely rare complication after coronary artery bypass grafting (CABG) and the underlying mechanisms remain poorly understood. We report a patient who developed paraplegia after CABG and review the literature on spinal cord ischemia following CABG surgery.

  14. Cefepime-induced neurotoxicity in a patient with coronary artery bypass

    PubMed Central

    Shah, Megha; Shah, Hetalkumar; Maslekar, Atul

    2016-01-01

    We present here a case of 58-year-old male operated for coronary artery bypass graft surgery with four grafts. He developed neurologic symptoms with injection cefepime which recovered after withdrawal of the drug. PMID:27721551

  15. Bypass Transitional Flow Calculations Using a Navier-Stokes Solver and Two-Equation Models

    NASA Technical Reports Server (NTRS)

    Liuo, William W.; Shih, Tsan-Hsing; Povinelli, L. A. (Technical Monitor)

    2000-01-01

    Bypass transitional flows over a flat plate were simulated using a Navier-Stokes solver and two equation models. A new model for the bypass transition, which occurs in cases with high free stream turbulence intensity (TI), is described. The new transition model is developed by including an intermittency correction function to an existing two-equation turbulence model. The advantages of using Navier-Stokes equations, as opposed to boundary-layer equations, in bypass transition simulations are also illustrated. The results for two test flows over a flat plate with different levels of free stream turbulence intensity are reported. Comparisons with the experimental measurements show that the new model can capture very well both the onset and the length of bypass transition.

  16. The Benefits of Photorespiratory Bypasses: How Can They Work?1[OPEN

    PubMed Central

    Xin, Chang-Peng; Tholen, Danny; Devloo, Vincent; Zhu, Xin-Guang

    2015-01-01

    Bypassing the photorespiratory pathway is regarded as a way to increase carbon assimilation and, correspondingly, biomass production in C3 crops. Here, the benefits of three published photorespiratory bypass strategies are systemically explored using a systems-modeling approach. Our analysis shows that full decarboxylation of glycolate during photorespiration would decrease photosynthesis, because a large amount of the released CO2 escapes back to the atmosphere. Furthermore, we show that photosynthesis can be enhanced by lowering the energy demands of photorespiration and by relocating photorespiratory CO2 release into the chloroplasts. The conductance of the chloroplast membranes to CO2 is a key feature determining the benefit of the relocation of photorespiratory CO2 release. Although our results indicate that the benefit of photorespiratory bypasses can be improved by increasing sedoheptulose bisphosphatase activity and/or increasing the flux through the bypass, the effectiveness of such approaches depends on the complex regulation between photorespiration and other metabolic pathways. PMID:25516604

  17. Active bypass flow control for a seal in a gas turbine engine

    DOEpatents

    Ebert, Todd A.; Kimmel, Keith D.

    2017-03-14

    An active bypass flow control system for controlling bypass compressed air based upon leakage flow of compressed air flowing past an outer balance seal between a stator and rotor of a first stage of a gas turbine in a gas turbine engine is disclosed. The active bypass flow control system is an adjustable system in which one or more metering devices may be used to control the flow of bypass compressed air as the flow of compressed air past the outer balance seal changes over time as the outer balance seal between the rim cavity and the cooling cavity wears In at least one embodiment, the metering device may include an annular ring having at least one metering orifice extending therethrough, whereby alignment of the metering orifice with the outlet may be adjustable to change a cross-sectional area of an opening of aligned portions of the outlet and the metering orifice.

  18. Small Bowel Limb Lengths and Roux-en-Y Gastric Bypass: a Systematic Review.

    PubMed

    Mahawar, Kamal K; Kumar, Parveen; Parmar, Chetan; Graham, Yitka; Carr, William R J; Jennings, Neil; Schroeder, Norbert; Balupuri, Shlok; Small, Peter K

    2016-03-01

    There is currently no consensus on the combined length of small bowel that should be bypassed as biliopancreatic or alimentary limb for optimum results with Roux-en-Y gastric bypass. A number of different limb lengths exist, and there is significant variation in practice amongst surgeons. Inevitably, this means that some patients have too much small bowel bypassed and end up with malnutrition and others end up with a less effective operation. Lack of standardisation poses further problems with interpretation and comparison of scientific literature. This systematic review concludes that a range of 100-200 cm for combined length of biliopancreatic or alimentary limb gives optimum results with Roux-en-Y gastric bypass in most patients.

  19. Bearing-bypass loading in composite joints - Testing and stress analysis

    NASA Technical Reports Server (NTRS)

    Crews, John H., Jr.; Naik, Rajiv A.

    1989-01-01

    A combined experimental and analytical study of bearing and bypass loading on single-fastener specimens of a 16-ply, quasi-isotropic T300/5208 graphite/epoxy laminate with a centrally located hole is reported. The specimens were loaded in either tension or compression, and onset damage, ultimate strengths, and corresponding failure modes were determined. The tension data showed the expected linear interaction for combined bearing-bypass loading with damage developing in the net-section tension mode. However, the bearing-onset strengths showed an unexpected interaction of the bearing and compressive bypass loads in which the latter reduced the bearing-onset strength. A linear finite element analysis showed that bearing-bypass loading had a marked influence on the bolt-hole contact which in turn had a significant effect on local stresses.

  20. Building America Top Innovations 2012: Thermal Bypass Air Barriers in the 2009 International Energy Conservation Code

    SciTech Connect

    none,

    2013-01-01

    This Building America Top Innovations profile describes Building America research supporting Thermal Bypass Air Barrier requirements. Since these were adopted in the 2009 IECC, close to one million homes have been mandated to include this vitally important energy efficiency measure.