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Sample records for ecc direct bypass

  1. 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

  2. Bias in peak clad temperature predictions due to uncertainties in modeling of ECC bypass and dissolved non-condensable gas phenomena

    SciTech Connect

    Rohatgi, U.S.; Neymotin, L.Y.; Jo, J.; Wulff, W. )

    1990-09-01

    This report describes a general method for estimating the effect on the Reflood Phase PCT from systematic errors (biases) associated with the modelling of the ECCS and dissolved nitrogen, and the application of this method in estimating biases in the Reflood Phase PCT (second PCT) predicted by the TRAC/PF1/MOD1, Version 14.3. The bias in the second PCT due to the uncertainty in the existing code models for ECCS related phenomena is {minus}19{degree}K ({minus}34{degree}F). The negative bias implies that the code models for this phenomena are conservative. The bias in the second PCT due to the lack of modelling of dissolved N{sub 2} in the code is estimated to be 9.9{degree}K (17.8{degree}F). The positive bias implies that the absence of dissolved N{sub 2} model makes the code prediction of PCT non-conservative. The bias estimation in this report is a major exception among all other uncertainty and bias assessments performed in conjunction with the CSAU methodology demonstration, because this bias estimation benefitted from using full-scale test data from the full-scale Upper Plenum Test Facility (UPTF). Thus, the bias estimates presented here are unaffected by scale distortions in test facilities. Data from small size facilities were also available and an estimate of bias based on these data will be conservative. 35 refs., 18 figs., 5 tabs.

  3. Direct Cannulation of the Infrahepatic Vena Cava for Emergent Cardiopulmonary Bypass Support

    PubMed Central

    Gopaldas, Raja R.; Patel, Kirti P.; Livesay, James J.; Cooley, Denton A.

    2009-01-01

    Cannulation for cardiopulmonary bypass, although seemingly routine, can pose technical challenges. In patients undergoing repeat sternotomy, for example, peripherally established cardiopulmonary bypass may be necessary to ensure safe entry into the chest; however, establishing bypass in this way can sometimes be complicated by patients' body habitus. We describe a technique for direct cannulation of the infrahepatic abdominal vena cava that was required for emergent cardiopulmonary bypass. The patient was a 62-year-old woman who had presented with severely symptomatic left main coronary stenosis 3 months after elective aortic valve replacement. She had gone into cardiogenic shock as general anesthesia was being induced for repeat sternotomy and myocardial revascularization. Emergent establishment of femorofemoral cardiopulmonary bypass was precluded by difficulties in advancing the femoral venous cannula beyond the pelvic brim. Hence, an emergent celiotomy was performed, and the abdominal vena cava was directly cannulated to establish venous drainage for cardiopulmonary bypass. The rest of the operation was uneventful. Our technique for direct cannulation of the infrahepatic abdominal vena cava may be used in exceptional circumstances. Necessary precautions and potential pitfalls are also presented. PMID:19693306

  4. Lung herniation secondary to minimally invasive direct coronary artery bypass grafting.

    PubMed

    Deeik, R K; Memon, M A; Sugimoto, J T

    1998-06-01

    Lung herniation after thoracotomy is rare. We report a 66-year-old man who presented with this complication after undergoing attempted minimally invasive direct coronary artery bypass grafting. The defect was repaired with a composite of Marlex mesh and methyl methacrylate. PMID:9647101

  5. Development of the Current Bypassing Methods into the Transverse Direction in Non-insulation HTS Coils

    NASA Astrophysics Data System (ADS)

    Tanaka, K.; Kim, S. B.; Ikoma, H.; Kanemoto, D.

    In the case of motors and generators, the benefits of using high temperature superconducting (HTS) coils can be represented by the reduction of 50% in both losses and sizes compared to conventional machines. However, it is hard to establish quench detection and protection devices for the HTS coils applied to the rotors of motors and generators. So, the stability of the coils is lower than for the quiescent coils applied to NMR, MRI and so on. Therefore, it is important to improve the self-protection ability of HTS coils. We have studied the methods to improve the self-protection ability of HTS coils by removing the layer-to-layer insulation and inserting metal tape instead of the electrical insulation. The operating current in the non-insulated HTS coil was bypassed into the transverse direction by the generated normal region because of their electrical contact among the winding. In this study, we examined the method to control the current bypassing on layer-to-layer for controlling the inductance of the non-insulated HTS coil. The current bypassing properties on non-insulated HTS coil wound with 2G wires will be discussed.

  6. Successful resection of thymoma directly invading the right atrium under cardiopulmonary bypass.

    PubMed

    De Giacomo, Tiziano; Patella, Miriam; Mazzesi, Giuseppe; Venuta, Federico

    2015-08-01

    We present the case of an invasive thymoma with severe compression of the right atrium, and infiltration of the atrial wall, causing a superior vena cava (SVC) syndrome. The tumour was resected under cardiopulmonary bypass en bloc with the atrial wall. A bovine pericardial patch was used for atrial reconstruction. We obtained a complete resection of the tumour and regression of symptoms, and, after 1 year of the follow-up, no signs of recurrence are evident. To our knowledge, this is the first case of thymoma directly invading the right atrium, without involvement of the SVC. In this setting, the aggressive surgical approach led to an immediate resolution of the symptoms and contributed to prolonged long-term survival. PMID:25293404

  7. Bypassing the Limitations of Directed C–H Functionalizations of Heterocycles

    PubMed Central

    Liu, Yue-Jin; Xu, Hui; Kong, Wei-Jun; Shang, Ming; Dai, Hui-Xiong; Yu, Jin-Quan

    2014-01-01

    In directed C–H activation reactions, nitrogen and sulfur atoms present in heterocyclic substrates coordinate strongly with metal catalysts. This coordination, which can lead to catalyst poisoning or C–H functionalization at an undesired position, limits the application of C–H activation reactions in heterocycle-based drug discovery.1–5 Herein, we report a robust and synthetically useful reaction that overcomes the complications associated with performing C–H functionalization reactions on heterocycles. Our approach employs a simple N-methoxy amide group, which serves as both a directing group and an anionic ligand to promote the in situ generation of the reactive PdX2 (X = ArCONOMe) species from a Pd(0) source using air as the sole oxidant. In this way, the PdX2 species is inherently anchored in close proximity with the target C–H bond adjacent to CONHOMe group, thus avoiding the interference from various heterocycles. Remarkably, this reaction overrides the conventional positional selectivity patterns observed with substrates containing strongly coordinating heteroatoms, including nitrogen, sulfur, and phosphorus. Thus, this operationally simple aerobic reaction demonstrates the feasibility of bypassing a fundamental limitation that has long plagued applications of directed C–H activation in medicinal chemistry. PMID:25383516

  8. Robot-assisted coronary artery bypass grafting improves short-term outcomes compared with minimally invasive direct coronary artery bypass grafting

    PubMed Central

    Gong, Wenhui; Cai, Junfeng; Wang, Zhe; Chen, Anqing; Ye, Xiaofeng; Li, Haiqing

    2016-01-01

    Background Robot-assisted coronary artery bypass grafts (RACAB) utilizing the da Vinci surgical system are increasingly used and allow the surgeon to conveniently harvest internal mammary arteries (IMAs). The aim of this study was to compare the outcomes of off-pump RACAB and minimally invasive direct coronary artery bypass grafting (MIDCAB) in the short and medium term. Methods We performed a retrospective review of 132 patients with single- or multiple-vessel coronary artery disease who underwent minimally invasive off-pump CABG (OPCAB) between May 2009 and May 2014. The patients were divided into two groups based on the surgical approach, MIDCAB and RACAB group. The anastomosis of the left internal mammary artery (LIMA) to the left anterior descending artery (LAD) was performed as regular OPCAB through the incision on the beating heart using regular stabilization devices (Genzyme Corporation). The preoperative, intraoperative, postoperative, and follow-up data, including major adverse cardiac and cerebrovascular events (MACCE), were compared. Results The preoperative data were similar. RACAB significantly shorten the intensive care unit (ICU) stay and postoperative compared with the MIDCAB group (P<0.05). There were 12 (19.7%) patients treated with a two-stage hybrid procedure in the MIDCAB group and 34 (47.9%) patients in the RACAB group (P=0.001). Thirty-day mortality was 1.6% in the MIDCAB group. There were 9 (14.7%) MIDCAB patients and 2 (2.8%) RACAB patients (P=0.013) that developed new arrhythmia. The two groups showed comparable mid-term survival (P=0.246), but the MACCEs were significantly different (P=0.038). Conclusions RACAB may be a valuable alternative for patients requiring single or simple multi-vessel coronary artery bypass grafting (CABG). Although the mid-term mortality outcomes are similar, RACAB improves short-term outcomes and mid-term MACCE-free survival compared with MIDCAB. PMID:27076941

  9. ECC (electrochemical concentration cell) ozonesonde observations at South Pole, Antarctica, during 1987. Data report

    SciTech Connect

    Komhyr, W.D.; Franchois, P.R.; Kuester, S.E.; Reitelback, P.J.; Fanning, M.L.

    1988-03-01

    Atmospheric ozone vertical distributions, air temperatures, and wind speed and wind direction data are presented for 76 balloon electrochemical concentration cell (ECC) ozonesonde soundings made at South Pole, Antarctica, in 1987.

  10. Heart bypass surgery - minimally invasive

    MedlinePlus

    ... in 30-day outcomes in high-risk patients randomized to off-pump versus on-pump coronary bypass ... Thiele H, Neumann-Schniedewind P, Jacobs S, et al. Randomized comparison of minimally invasive direct coronary artery bypass ...

  11. 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.

  12. 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.

  13. Off-pump minimally invasive direct coronary artery bypass in patients with cosmetic prosthesis for pectus excavatum.

    PubMed

    Massi, Francesco; Manca, Mario; Muretti, Mirko; Portoghese, Michele

    2016-08-01

    Pectus excavatum can be associated with coronary artery diseases that can become difficult to manage in urgent situations. We describe the use of an off-pump minimally invasive direct coronary artery bypass (MIDCAB) through the fourth intercostal space incision in a patient with pectus excavatum and acute coronary syndrome who previously underwent a cosmetic prosthesis implantation. The patient refused any surgical procedure that could compromise the integrity of his cosmetic prosthesis and a left mini-thoracotomy was a good option to avoid the removal of the prosthesis. The preservation of the integrity of the thoracic cage enhanced chest wall stability and pulmonary function and permitted avoidance of inadvertent cardiac structure iatrogenic injuries. MIDCAB was optimal for the exposure of the left internal thoracic artery and the left anterior descending artery. The deformity of the chest should not be considered as an absolute contraindication to off-pump MIDCAB when other surgical options are not viable, even in emergency situations. PMID:27170745

  14. 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

  15. Noise-based Stego-ECC

    NASA Astrophysics Data System (ADS)

    Rahardjo, Budi; Muchtadi-Alamsyah, Intan; Paryasto, Marisa

    2014-03-01

    A novel method of inserting noise into stream of ciphered text is proposed. The goal of inserting noise is to increase the level of uncertainty, thus making it harder for an attacker to detect data and noise. This form of steganography is implemented using Elliptic Curve Cryptography (ECC). The process of embedding the noise to the message in the encryption process and removing the noise from the message in the decryption process is proposed in this work by modifying ElGamal to allow auto detection of data and noise.

  16. 10 CFR Appendix K to Part 50 - ECCS Evaluation Models

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false ECCS Evaluation Models K Appendix K to Part 50 Energy NUCLEAR REGULATORY COMMISSION DOMESTIC LICENSING OF PRODUCTION AND UTILIZATION FACILITIES Pt. 50, App. K Appendix K to Part 50—ECCS Evaluation Models I. Required and Acceptable Features of Evaluation Models. II. Required Documentation. I. Required...

  17. The Status of ECCE Provision in Trinidad and Tobago.

    ERIC Educational Resources Information Center

    Logie, Carol

    This study examined the provision of early childhood care and education (ECCE) in Trinidad and Tobago, focusing on the educational environment and demographic factors within ECCE. A representative national sample of 2,370 children, 175 teachers, and 883 parents from 79 public and private centers across the country completed questionnaires or…

  18. Current status and future directions in computer-enhanced video- and robotic-assisted coronary bypass surgery.

    PubMed

    Boyd, W Douglas; Kodera, Kojiro; Stahl, Kenneth D; Rayman, Reiza

    2002-01-01

    Since 1997, both the Cleveland Clinic and London Health Sciences Centre groups have embraced robotic assistance and more recently demonstrated the efficacy of this technology in totally closed-chest, beating heart myocardial revascularization. This endeavor involved an orderly progression and the learning of new surgical skill sets. We review the evolution of robot-enhanced coronary surgery and forecast the future of endoscopic and computer-enhanced, robotic-enabling technology for coronary revascularization. This report describes a computer-assisted totally closed-chest coronary bypass operation, and preliminary results are discussed. The internal thoracic artery (ITA) was harvested through three 5-mm access ports and prepared and controlled endoscopically. A prototype sternal elevator was used to increase intrathoracic working space. A 10-mm endoscopic stabilizer was placed through the second intercostal space, and the left anterior descending coronary artery was controlled with silastic snares. Telerobotic anastomoses were completed end-to-side using custom-made, double-armed 8-0 polytetrafluroethylene sutures. To date, 84 patients have undergone successful myocardial revascularization with robotic assistance with a 0% surgical mortality rate. ITA harvest, anastomotic, and operating times for the entire group have been longer than for conventional surgery at 61.3 +/- 17.9 minutes, 28.5 +/- 28.2 minutes, and 368 +/- 129 minutes, respectively. Bleeding, ventilatory times, arrhythmias, hospital lengths of stay, and return to normal activity have been reduced. Recently, we have developed a new robotic revascularization strategy called Atraumatic Coronary Artery Bypass that is a promising mid-term step on the pathway to totally endoscopic, beating-heart coronary artery bypass. We conclude that computer-enhanced robotic techniques are safe, and further clinical studies are required to define the full potential of this evolving technology. PMID:11977023

  19. 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.

  20. 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

  1. Sensitivity of the ECC ozonesondes response to solution concentration

    NASA Astrophysics Data System (ADS)

    Stübi, R.; Levrat, G.; Viatte, P.

    2003-04-01

    The Electrochemical Concentration Cell (ECC) ozonesondes are commonly used to measure the ozone profiles during the aerological balloon ascents. Various experiments showed that the response of the ECC sondes are sensitive to a few factors like sensing solution concentration, supplier and preparation procedures. This sensitivity represents an important issue in case of comparison between stations or when a specific station changes its procedure. The simulator experiments during JOSIE campaigns have produced clear indications of those effects which have to be confirmed in atmospheric conditions. At the Payerne aerological station, a weekly dual ECC flight program is running since September 2002 in order to measure the difference between the 0.5% and 1% KI concentration solution for ENSCI sondes. Preliminary results of the first half of this one year program will be presented. The systematic difference profiles will be shown as well as the comparison of the ozone total ozone columns evaluated from the ballon soundings and the measurements of a Dobson spectrophotometer. In addition, laboratory experiments with different concentrations ranging from 0.1% to 2% KI buffered solutions have been conducted. Regular calibration of the sondes are performed with a UV photometer reference to evidence concentration sensitivity of the ECC sondes response in laboratory conditions and possible aging effect. These experiments should help to finalize Standard Operating Procedure (SOP) which are still to be set up by the ECC users community.

  2. 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.

  3. Heart bypass surgery

    MedlinePlus

    Heart bypass surgery creates a new route, called a bypass, for blood and oxygen to go around a blockage to reach your heart. ... heart is still beating. This is called off-pump coronary artery bypass, or OPCAB. To create the bypass graft: The doctor will take a ...

  4. Compact bypass-flow filter

    NASA Technical Reports Server (NTRS)

    Swift, W. G.; Ulanovsky, J. M.

    1979-01-01

    Annular filter consisting of stacked rings separates particulates from bypass fluid passing through it in radial direction without slowing down main flow across unimpeded flow of fluid through its center. Applications include fluidized bed reactors, equipment for catalyst operations, and water purification.

  5. Coronary Artery Bypass Surgery

    MedlinePlus

    ... t help, you may need coronary artery bypass surgery. The surgery creates a new path for blood to flow ... more than one bypass. The results of the surgery usually are excellent. Many people remain symptom-free ...

  6. Coronary Artery Bypass

    MedlinePlus

    ... to 3 days in the Intensive Care Unit (ICU). Life After Bypass After bypass surgery, your doctor will recommend that you join a cardiac rehabilitation program. These programs help you make lifestyle changes ...

  7. 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

  8. 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.

  9. 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.

  10. 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. PMID:26872706

  11. Clogging the enrichment bypass

    SciTech Connect

    1995-05-01

    The issue that has come to be known as the bypass is the latest dispute in the continuing saga of uranium trade between the United States and the Commonwealth of Indepenent States. Bypass deals now being conducted by US utilities have drawn heavy criticism from the US Department of Commerce but are perfectly legal under the terms of the Suspension Agreements. Urged on by the United States Enrichment Corporation, the US DOC intends to stop, or at least severely restrict, bypass deals. Using a recent agreement with Kazakhstan as a case study, this article reviews the implications of such bypass deals.

  12. Laparoscopic Revision of Jejunoileal Bypass to Gastric Bypass

    ClinicalTrials.gov

    2009-12-28

    Clinically Severe Obesity; Metabolic Complications After Jejunoileal Bypass; Nutritional Complications After Jejunoileal Bypass; Obesity Recidivism; Inadequate Initial Weight Loss; Intestinal Malabsorptive Syndrome; Protein Malnutrition

  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. 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 ...

  15. Flood Bypass Capacity Optimization

    NASA Astrophysics Data System (ADS)

    Siclari, A.; Hui, R.; Lund, J. R.

    2015-12-01

    Large river flows can damage adjacent flood-prone areas, by exceeding river channel and levee capacities. Particularly large floods are difficult to contain in leveed river banks alone. Flood bypasses often can efficiently reduce flood risks, where excess river flow is diverted over a weir to bypasses, that incur much less damage and cost. Additional benefits of bypasses include ecosystem protection, agriculture, groundwater recharge and recreation. Constructing or expanding an existing bypass costs in land purchase easements, and levee setbacks. Accounting for such benefits and costs, this study develops a simple mathematical model for optimizing flood bypass capacity using benefit-cost and risk analysis. Application to the Yolo Bypass, an existing bypass along the Sacramento River in California, estimates optimal capacity that economically reduces flood damage and increases various benefits, especially for agriculture. Land availability is likely to limit bypass expansion. Compensation for landowners could relax such limitations. Other economic values could affect the optimal results, which are shown by sensitivity analysis on major parameters. By including land geography into the model, location of promising capacity expansions can be identified.

  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. 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.

  18. 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

  19. Thrust reverser for high bypass turbofan engine

    SciTech Connect

    Matta, R.K.; Bhutiani, P.K.

    1990-05-08

    This patent describes a thrust reverser for a gas turbine engine of the type which includes an outer wall spaced from the center body of a core engine to define a bypass duct therebetween. The thrust reverser comprising: circumferentially displaced blocker doors, each of the doors being movable between a normal position generally aligned with the outer wall and a thrust reversing position extending transversely of the bypass duct for blocking the exhaust of air through the bypass duct and directing the air through an opening in the outer wall for thrust reversal; each of the blocker doors being of lightweight construction and including a pit in the inner surface thereof in the normal position; means for covering the pit during normal flow of air through the bypass duct to reduce the pressure drop in the bypass duct and to reduce noise. The covering means including a pit cover hingedly mounted at one end thereof on the blocker door and means of biasing the pit cover away from the blocker door to a position providing smooth flow of air through the bypass duct during normal operation.

  20. 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 ...

  1. Heart bypass surgery

    MedlinePlus Videos and Cool Tools

    ... of this great vein will be used to bypass the blocked arteries in the heart. The venous graft is sewn to the aorta and to the affected coronary artery past the blocked site. The internal mammary ...

  2. 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.

  3. Laparoscopic bypass pyeloureterostomy.

    PubMed

    Noh, Paul H; Shah, Anish K

    2013-02-01

    Minimally invasive surgery has been increasingly applied in paediatric urology, including the treatment of ureteropelvic junction obstruction. To the best of our knowledge, we describe the first laparoscopic bypass pyeloureterostomy in a 3-month-old male infant, with giant hydronephrosis and high insertion of the ureter into the renal pelvis. PMID:22889709

  4. Heart bypass surgery - discharge

    MedlinePlus

    ... Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Chest . 2012;141:e637S-e68S. Read More Angina Coronary heart disease Heart bypass surgery Heart failure - overview High blood cholesterol levels Smoking - ...

  5. Cardiopulmonary bypass in pregnancy.

    PubMed

    Pomini, F; Mercogliano, D; Cavalletti, C; Caruso, A; Pomini, P

    1996-01-01

    The cardiopathic patient can sustain acute heart failure during pregnancy. In such cases, if open heart operation is necessary to save the patient's life, the fetus could be seriously compromised after exposure to cardiopulmonary bypass. From 1958 to 1992, 69 reports of cardiac operations during pregnancy with the aid of cardiopulmonary bypass have been published. Maternal mortality was 2.9%. Embryofetal mortality was 20.2%. Examining only the last 40 patients, maternal and embryofetal mortality were 0.0% and 12.5%, respectively. Embryofetal mortality was 24.0% when hypothermia was used, compared with 0.0% while operating in normothermia. Maternal mortality did not change. The use of hypothermia during cardiopulmonary bypass provoked uterine contractions in several patients. Hypothermia decreases O2 exchange through the placenta. Pump flow and mean arterial pressure during cardiopulmonary bypass seem to be the most important parameters that influence fetal oxygenation. We speculate that cardiac operation is not a contraindication to pregnancy prolongation. PMID:8561577

  6. Analyses of 1/15 scale Creare bypass transient experiments. [PWR

    SciTech Connect

    Kmetyk, L.N.; Buxton, L.D.; Cole, R.K. Jr.

    1982-09-01

    RELAP4 analyses of several 1/15 scale Creare H-series bypass transient experiments have been done to investigate the effect of using different downcomer nodalizations, physical scales, slip models, and vapor fraction donoring methods. Most of the analyses were thermal equilibrium calculations performed with RELAP4/MOD5, but a few such calculations were done with RELAP4/MOD6 and RELAP4/MOD7, which contain improved slip models. In order to estimate the importance of nonequilibrium effects, additional analyses were performed with TRAC-PD2, RELAP5 and the nonequilibrium option of RELAP4/MOD7. The purpose of these studies was to determine whether results from Westinghouse's calculation of the Creare experiments, which were done with a UHI-modified version of SATAN, were sufficient to guarantee SATAN would be conservative with respect to ECC bypass in full-scale plant analyses.

  7. 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.

  8. 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. PMID:25096968

  9. 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.

  10. Low-Voltage Bypass Device

    NASA Technical Reports Server (NTRS)

    Wilson, J. P.

    1994-01-01

    Improved bypass device provides low-resistance current shunt around low-voltage power cell when cell fails in open-circuit condition during operation. In comparison with older bypass devices for same application, this one weighs less, generates less heat, and has lower voltage drop (less resistance). Bypass device connected in parallel with power cell. Draws very little current during normal operation of cell.

  11. 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. PMID:21785968

  12. A pedoprosthetic rehabilitation in patients with severe early childhood caries (S-ECC).

    PubMed

    Mishra, Apurva; Pandey, Ramesh; Pandey, Neelisha; Jain, Eesha

    2013-01-01

    Early childhood caries (ECC) is a rapid form of dental caries. ECC is the most common chronic childhood disease that can compromise a child's self-esteem, nutritional intake, oral development and quality of life, subsequently leading to malocclusion and psychological problems. The restoration of severely decayed primary teeth is often a difficult procedure that offers a great challenge to paediatric dentists. The present case series document the clinical management of patients suffering from severe early childhood caries using removable partial prosthesis restoring their masticatory function and aesthestics. The ultimate aim of the treatment was to improve psychological and physiological development leading to better functioning of the stomatognathic system. PMID:23843409

  13. 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. PMID:26003959

  14. 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…

  15. Force and Pressure Recovery Characteristics at Supersonic Speeds of a Conical Spike Inlet with a Bypass Discharging from the Top or Bottom of the Diffuser in an Axial Direction

    NASA Technical Reports Server (NTRS)

    Allen, J L; Beke, Andrew

    1953-01-01

    Force and pressure-recovery characteristics of a nacelle-type conical-spike inlet with a fixed-area bypass located in the top or bottom of the diffuser are presented for flight Mach numbers of 1.6, 1.8, and 2.0 for angles of attack from 0 degrees to 9 degrees. Top or bottom location of the bypass did not have significant effects on diffuser pressure-recovery, bypass mass-flow ratio, or drag coefficient over the range of angles of attack, flight Mach numbers, and stable engine mass-flow ratios investigated. A larger stable subcritical operating range was obtained with the bypass on the bottom at angles of attack from 3 degrees to 9 degrees at a flight Mach number of 2.0. At a flight Mach number of 2.0, the discharge of 14 percent of the critical mass flow of the inlet by means of a bypass increased the drag only one-fifth of the additive drag that would result for equivalent spillage behind an inlet normal shock without significant reductions in diffuser pressure recovery.

  16. Breathless after bypass

    PubMed Central

    Pearse, Simon G; Missouris, Constantinos; Qureshi, Muhammad Ali

    2014-01-01

    A 65-year-old normotensive, non-athletic man presented to the cardiology clinic with exertional dyspnoea and chest discomfort. Echocardiography revealed mild left ventricular hypertrophy with good systolic function but with regional wall motion abnormalities suggesting ischaemia. Coronary angiography showed significant three-vessel disease. He underwent coronary artery bypass surgery, which was complicated by recurrent pericardial and pleural effusions, requiring a pericardial window procedure. Over the following year he became increasingly oedematous and breathless. On ECG the complexes were low voltage with impaired R wave progression and atrial fibrillation. Echocardiography revealed progression of the left ventricular hypertrophy (LVH) with a bright myocardium and restrictive filling pattern. MRI scanning confirmed the diagnosis of cardiac amyloidosis. He was referred for transplant but was considered unsuitable due to extensive mediastinal scarring. This case demonstrates the importance of a high index of suspicion for amyloidosis, especially in patients with unexplained LVH. Cardiac MRI or biopsy may expedite the diagnosis. PMID:24895396

  17. 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.

  18. [Robot-assisted Coronary Artery Bypass Grafting].

    PubMed

    Ishikawa, Norihiko; Watanabe, Go

    2016-07-01

    The application for robot-assisted coronary surgery ranges from internal thoracic artery (ITA) harvesting with hand-sewn anastomoses to totally endoscopic coronary artery bypass grafting (TECAB), either on- or off-pump. The bilateral IMA can be harvested with the aid of a surgical robot and then multivessel bypass grafting can follow. Such robot-assisted minimally invasive direct coronary artery bypass grafting is called "ThoraCAB". Surgical robots cannot only endoscopically harvest the ITA but they can also anastomose the coronary artery in TECAB. But TECAB still has the difficulties, such as narrow surgical field in Japanese patients. Both procedures have the significant advantages of minimizing surgical trauma, such as reduced comlications, faster return back to normal activities and being improved cosmesis, and which have resulted in the development of minimally invasive surgery. Robot-assisted cardiac surgery for structural heart disease has been approved by the Ministry of Health, Labour and Welfare (MHLW) since December 2015, however, robot-assisted cardiac surgery for TECAB has not been approved yet in Japan. PMID:27440015

  19. 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.

  20. How to accurately bypass damage

    PubMed Central

    Broyde, Suse; Patel, Dinshaw J.

    2016-01-01

    Ultraviolet radiation can cause cancer through DNA damage — specifically, by linking adjacent thymine bases. Crystal structures show how the enzyme DNA polymerase η accurately bypasses such lesions, offering protection. PMID:20577203

  1. Heart bypass surgery - minimally invasive

    MedlinePlus

    ... MIDCAB; Robot assisted coronary artery bypass; RACAB; Keyhole heart surgery ... To perform this surgery: The heart surgeon will make a 3- to 5-inch-long surgical cut in the left part of your chest between your ribs ...

  2. 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. PMID:24997856

  3. The validation of LIMS ozone profiles using correlative rocket, ECC, and Dobson data sets

    NASA Technical Reports Server (NTRS)

    Remsberg, E. E.; Russell, J. M., III; Gordley, L. L.; Gille, J. C.; Bailey, P. L.

    1981-01-01

    The Limb Infrared Monitor of the Stratosphere (LIMS) experiment is a limb scanning infrared sounder designed to measure vertical temperature profiles and the concentrations of key chemical compounds which are important in the stratospheric ozone-nitrogen photochemistry. Preliminary ozone profiles are being intercompared with correlative rocket and balloonsonde ozone data sets as part of the Nimbus 7 LIMS data validation activity. The LIMS ozone retrievals extend from the lower mesosphere to the tropopause (or cloud-top altitudes). In this paper, preliminary statistics of comparisons of ECC (electrochemical concentration cell) ozonesonde and rocket ozone profiles with LIMS ozone profiles are presented. ECC ozonesonde data taken at times of LIMS overpasses are also used to extend the LIMS retrieval down to ground level. Each combined profile is then integrated to obtain total column ozone. These integrated results are compared to Dobson data obtained at approximately the same time and location.

  4. EPRI R and D contributions to the technical basis for revision of ECCS rules

    SciTech Connect

    Chexal, V.K.; Duffey, R.; Horowitz, J.

    1985-07-01

    EPRI research efforts over the last ten years in the area of ECCS methodology are summarized. The results when added to those of the NRC and others provide a technical basis to show that the regulatory requirements in 10CFR50 Appendix K, are very conservative. In addition, these research efforts allow quantification of that conservatism. The research experiments, computer code development, and code assessment efforts funded by EPRI or cofunded with others are described.

  5. A secure-enhanced data aggregation based on ECC in wireless sensor networks.

    PubMed

    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

  6. 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

  7. Quorum sensing in the plant pathogen Erwinia carotovora subsp. carotovora: the role of expR(Ecc).

    PubMed

    Andersson, R A; Eriksson, A R; Heikinheimo, R; Mäe, A; Pirhonen, M; Kõiv, V; Hyytiäinen, H; Tuikkala, A; Palva, E T

    2000-04-01

    The production of the main virulence determinants of the plant pathogen Erwinia carotovora subsp. carotovora, the extracellular cell wall-degrading enzymes, is partly controlled by the diffusible signal molecule N-(3-oxohexanoyl)-L-homoserine lactone (OHHL). OHHL is synthesized by the product of the expI/carI gene. Linked to expI we found a gene encoding a putative transcriptional regulator of the LuxR-family. This gene, expR(Ecc), is transcribed convergently to the expI gene and the two open reading frames are partially overlapping. The ExpR(Ecc) protein showed extensive amino acid sequence similarity to the repressor EsaR from Pantoea stewartii subsp. stewartii (formerly Erwinia stewartii subsp. stewartii) and to the ExpR(Ech) protein of Erwinia chrysanthemi. Inactivation of the E. carotovora subsp. carotovora expR(Ecc) gene caused no decrease in virulence or production of virulence determinants in vitro. In contrast, there was a slight increase in the maceration capacity of the mutant strain. The effects of ExpR(Ecc) were probably mediated by changes in OHHL levels. Inactivation of expR(Ecc) resulted in increased OHHL levels during early logarithmic growth. In addition, overexpression of expR(Ecc) caused a clear decrease in the production of virulence determinants and part of this effect was likely to be caused by OHHL binding to ExpR(Ecc). ExpR(Ecc) did not appear to exhibit transcriptional regulation of expI, but the effect on OHHL was apparently due to other mechanisms. PMID:10755301

  8. Bypass rewiring and robustness of complex networks.

    PubMed

    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. PMID:27627320

  9. Postoperative bypass bleeding: a bypass-associated dilutional (BAD) coagulopathy?

    PubMed

    Bull, Brian S; Hay, Karen L; Herrmann, Paul C

    2009-01-01

    A number of associations with post-bypass bleeding have been described in the accompanying paper. Herein we hypothesize that dilution is an underlying cause through a malign series of bypass-associated events. Heparinized blood behaves anomalously when diluted. Clotting times first shorten somewhat, then--as the dilution of whole blood approaches 50%--rapidly lengthen to unclottability. During cardiopulmonary bypass, low blood volume patients are at a significant risk of clotting factor dilution which will always be more severe than the level of whole blood dilution. If severe enough, this dilution may lower plasma clotting factors to a critical level and may result in excess protamine administration, secondary to overestimation of heparin. The presence of un-neutralized protamine combined with critically lowered clotting factors leads to marked coagulopathy. PMID:19699663

  10. 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. PMID:26566199

  11. Heat exchanger bypass test report

    SciTech Connect

    De Vries, M.L.

    1995-01-26

    This test report documents the results that were obtained while conducting the test procedure which bypassed the heat exchangers in the HC-21C sludge stabilization process. The test was performed on November 15, 1994 using WHC-SD-CP-TC-031, ``Heat Exchanger Bypass Test Procedure.`` The primary objective of the test procedure was to determine if the heat exchangers were contributing to condensation of moisture in the off-gas line. This condensation was observed in the rotameters. Also, a secondary objective was to determine if temperatures at the rotameters would be too high and damage them or make them inaccurate without the heat exchangers in place.

  12. Surgical cartographic navigation system for endoscopic bypass grafting.

    PubMed

    Voruganti, Arun; Mayoral, Rafael; Jacobs, Stephan; Grunert, Ronny; Moeckel, Hendrik; Korb, Werner

    2007-01-01

    Endoscopic bypass grafting with the da Vinci system is still challenging and needs high level of experience and skill of the surgeon. Therefore, it is necessary to support the surgeon with enhanced vision and augmented reality. The augmentation of the patient model into the view of the endoscope is a direct approach to enhance support. The results of a preclinical study are shown in this paper. The method applied is suitable for endoscopic bypass grafting and in general applicable to minimal invasive surgery. The system was designed as an open architecture to facilitate easy transfer of the methodology into other surgical domain applications. PMID:18002243

  13. 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.

  14. Technology Solutions Case Study: Preventing Thermal Bypass

    SciTech Connect

    none,

    2012-10-01

    This project highlights the importance of continuous air barriers in full alignment with insulation to prevent thermal bypasses and achieve high energy performance, and recommends use of ENERGY STAR's Thermal Bypass Inspection Checklist.

  15. POST CORONARY ARTERY BYPASS GRAFT STUDY (CABG)

    EPA Science Inventory

    Relative effectiveness of moderate versus more aggressive lipid lowering, and of low dose anticoagulation versus placebo, in delaying saphenous vein coronary bypass graft atherosclerosis and preventing occlusion of saphenous grafts of patients with saphenous vein coronary bypass ...

  16. 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)

  17. MedlinePlus: Coronary Artery Bypass Surgery

    MedlinePlus

    ... and Blood Institute Start Here Coronary Artery Bypass (Texas Heart Institute) Also in Spanish Coronary Artery Bypass ... and Blood Institute) Specifics Limited-Access Heart Surgery (Texas Heart Institute) Also in Spanish Types of Coronary ...

  18. Impact of di-ethylhexylphthalate exposure on metabolic programming in P19 ECC-derived cardiomyocytes.

    PubMed

    Schaedlich, Kristina; Schmidt, Juliane-Susanne; Kwong, Wing Yee; Sinclair, Kevin D; Kurz, Randy; Jahnke, Heinz-Georg; Fischer, Bernd

    2015-07-01

    Di(2-ethylhexyl)phthalate (DEHP) is the most common plasticizer in plastic devices of everyday use. It is a ubiquitous environmental contaminant and primarily known to impair male gonadal development and fertility. Studies concerning the long-term effects of prenatal DEHP exposure on certain diseases [The Developmental Origins of Health and Disease paradigm (DOHaD) hypothesis] are scarce although it is proven that DEHP crosses the placenta. Rising environmental pollution during the last centuries coincides with an increasing prevalence of cardiovascular and metabolic diseases. We have investigated the effects of an early embryonic DEHP exposure at different developmental stages on cardiomyogenesis. We used an in-vitro model, the murine P19 embryonic carcinoma cell line (P19 ECC), mimicking early embryonic stages up to differentiated beating cardiomyocytes. P19 ECC were exposed to DEHP (5, 50, 100 µg ml(-1)) at the undifferentiated stage for 5 days and subsequently differentiated to beating cardiomyocytes. We analyzed the expression of metabolic (Pparg1, Fabp4 and Glut4), cardiac (Myh6, Gja1) and methylation (Dnmt1, Dnmt3a) marker genes by quantitative real-time PCR (qRT-PCR), beating rate and the differentiation velocity of the cells. The methylation status of Pparg1, Ppara and Glut4 was investigated by pyrosequencing. DEHP significantly altered the expression of all investigated genes. The beating rate and differentiation velocity were accelerated. Exposure to DEHP led to small but statistically significant increases in methylation of specific CpGs within Ppara and Pparg1, which otherwise were generally hypomethylated, but methylation of Glut4 was unaltered. Early DEHP exposure of P19 ECC alters the expression of genes associated with cellular metabolism and the functional features of cardiomyocytes. PMID:25351189

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

    PubMed

    Windstar, Kimberly; Dunlap, Corina; Zwickey, Heather

    2014-04-01

    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

  20. 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.

  1. 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.

  2. Clinical Evaluation of Poly(2-methoxyethylacrylate) in Primary Coronary Artery Bypass Grafting

    PubMed Central

    Vang, See N.; Brady, Chad P.; Christensen, Kevin A.; Isler, Jack R.; Allen, Keith R.

    2005-01-01

    Abstract: In an attempt to make cardiopulmonary bypass (CPB) less traumatic for patients undergoing cardiac surgery, extracorporeal circuits (ECC) have been modified to achieve this goal. Poly(2-methoxyethylacrylate) (PMEA, X-coating™) is a new polymer coating used in the ECC. PMEA studies have shown excellent biocompatibility with the components of blood. In this evaluation, PMEA-coated ECC were compared with control (CTR) circuits with emphasis on hematological parameters, perioperative homologous blood product usage, and clinical outcomes. Patients undergoing elective coronary artery bypass grafting were randomized to either a PMEA group (n = 30) or a CTR group (n = 30). Extracorporeal circuit components in the PMEA group were coated except for the cardioplegia delivery device and cannulas. Patients in the CTR group had just the arterial line filter coated. The following hematological parameters were measured: platelet count (PLT), white blood cell count (WBC), red blood cell count (RBC), and hematocrit (Hct). Blood product usage was observed along with clinical outcomes for the following parameters: ventilation time, mediastinal tube output, intensive care unit (ICU) and hospital lengths of stay. The preoperative patient profiles were comparable between the two groups. The PMEA group had marginally higher CPB times (134 ± 31.9 vs. 118 ± 33.7 minutes) and cross clamp times (83.9 ± 21.3 vs. 73.7 ± 21.6 minutes), however no significant differences were reached. Platelet count, RBC, and Hct levels were also comparable between groups with no significant differences. However, there was a significant difference in WBC between groups (p = 0.041). Less platelets were administered both intraoperatively and 48 hours postoperatively in the PMEA group. The authors evaluated PMEA-coating by measuring clinical outcomes, such as ventilation time, ICU and hospital lengths of stay, and homologous blood utilization. PMEA patients trended towards less homologous blood

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

    PubMed

    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

  4. 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. PMID:26551361

  5. 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

  6. 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.

  7. Sediment Bypassing of River Mouths: Mechanisms and Effects on Delta Evolution

    NASA Astrophysics Data System (ADS)

    Nienhuis, J.; Ashton, A. D.; Giosan, L.; Nardin, W.; Fagherazzi, S.

    2014-12-01

    Wave-influenced deltas are shaped by wave-driven transport of river-borne sediments. Near the river mouth, combined jet and wave dynamics, along with morphodynamic feedbacks, control the fraction of sediment transported alongshore by littoral currents that can bypass the river channel. Here we study how different bypassing rates influence large-scale delta evolution and examine the effect of waves and the river mouth jet on alongshore sediment bypassing. First, we use a modified version of the Coastline Evolution Model (CEM) to look at the effects of wave climate, fluvial sediment supply, and alongshore sediment bypassing rates on channel orientation. This modified version of CEM progrades the channel in a direction perpendicular to the local shoreline orientation at the river mouth, allowing feedbacks between alongshore sediment transport and fluvial sediment delivery to steer the river channel. Additionally, we allow a prescribed fraction of littoral sediment to bypass the river mouth. We find that deltas that have a large fluvial sediment flux can orient themselves into the direction of dominant wave approach. Lower fluvial inputs result in channels that are deflected downdrift, with increasing deflection as bypassing is reduced. In contrast, channels do not deflect downdrift (but can reorient themselves updrift for large fluvial fluxes) when full bypassing is allowed. These results demonstrate the importance of river mouth sediment bypassing on delta growth patterns, but, as we explore arbitrary bypassing laws, the simulations cannot help us constrain natural bypassing fluxes. To further investigate the natural extent and mechanisms of bypassing, we use the coupled hydrodynamic and morphodynamic model Delft3D-SWAN. With a simplified shoreface and river channel, the model is able to construct river mouth morphology from the combined action of alongshore transport and a river mouth jet. Exploring river mouth morphology and sediment bypassing under various wave

  8. Quantitative and qualitative evaluation of blood salvaged after extracorporeal circulation (ECC) in paediatric heart surgery. Study of biochemical, morphological and structural variations of RBC after ECC and after salvaging of ECC circuit priming blood.

    PubMed

    Calza, G; Zannini, L; Lerzo, F; Nitti, P; Mangraviti, S; Perutelli, P; Porlezza, M

    2000-06-01

    The salvaging of ECC circuit priming blood is essential for reducing the morbidity related to homologous blood transfusions and the importance of this technique is inversely proportionate to the age and weight of the child. In infants, the washing and centrifugation of blood not only drastically reduce the risk of contracting blood-transmitted diseases and cut management costs, but are also of considerable hemodynamic importance, producing a rapid normalization of the patient's hematocrit and hemoglobin and balancing the O2 consumption/demand ratio. The marketing of miniaturized salvagin devices with 55 ml bowls by Dideco has made possible the recovery of small quantities of blood, so as to normalise the hematic crisis and permit the application of total hemodilution in low-weight patients. The salvaged blood shows an average hematocrit of 52.7+/-9.7% (max 68.1%) and an average hemoglobin of 17.6 +/- 2.9 g/dl (max 20.7 g/dl), and maintains its structural components, osmotic resistance, concentration of intraerythrocytic hemoglobin and mean corpuscular hemoglobin all intact. Washing with isoosmotic and isoionic hydroelectrolytic solutions normalizes the ionic situation in the post-operative period and activated blood salvaging after Extracorporeal Circulation. The use of solutions without nutritional substances results however in a considerable fall in the number of enzymes in the intraerythrocytic metabolic glucide chain (G6PDH: -40.7 +/- 14.3% p<0.001), (PK: -23.8 +/- 20.5% p<0.03). This drop may be responsible for erythrocytic morphological alterations (echinocytic change) and probably for the release of hemoglobin from the red blood cells. Washing with isoionic, isoosmotic solutions containing G5% and adenine could, at least in theory, improve the quality of the salvaged blood, by normalizing the morphology and the volume of the RBC and by increasing the hematocrit. PMID:10919757

  9. 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

  10. 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

  11. 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.

  12. Hypoglycaemia after gastric bypass: mechanisms and treatment.

    PubMed

    Ritz, P; Vaurs, C; Barigou, M; Hanaire, H

    2016-03-01

    Hypoglycaemia after gastric bypass can be severe, but is uncommon, and is sometimes only revealed through monitoring glucose concentrations. The published literature is limited by the heterogeneity of the criteria used for diagnosis, arguing in favour of the Whipple triad with a glycaemia threshold of 55 mg/dl as the diagnostic reference. Women who lost most of their excess weight after gastric bypass, long after the surgery was performed, and who did not have diabetes before surgery are at the greatest risk. In this context, hypoglycaemia results from hyperinsulinism, which is either generated by pancreas anomalies (nesidioblastosis) and/or caused by an overstimulation of β cells by incretins, mainly glucagon-like peptide-1 (GLP-1). Glucose absorption is both accelerated and increased because of the direct communication between the gastric pouch and the jejunum. This is a post-surgical exaggeration of a natural adaptation that is seen in patients who have not undergone surgery in whom glucose is infused directly into the jejunum. There is not always a correspondence between symptoms and biological traits; however, hyperinsulinism is constant if hypoglycaemia is severe and there are neuroglucopenic symptoms. The treatment relies firstly on changes in eating habits, splitting food intake into five to six daily meals, slowing gastric emptying, reducing the glycaemic load and glycaemic index of foods, using fructose and avoiding stress at meals. Pharmacological treatment with acarbose is efficient, but other drugs still need to be validated in a greater number of subjects (insulin, glucagon, calcium channel blockers, somatostatin analogues and GLP-1 analogues). Lastly, if the surgical option has to be used, the benefits (efficient symptom relief) and the risks (weight regain, diabetes) should be weighed carefully. PMID:26508374

  13. 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. PMID:26573649

  14. 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.

  15. 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.

  16. 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…

  17. Bypass transition to turbulence and research Desiderata

    NASA Technical Reports Server (NTRS)

    Morkovin, M. V.

    1985-01-01

    Bypass transitions are seldom mentioned in texts or meetings on instability and transition to wall turbulence. The nature of a number of bypass transitions is illustrated by example. Until this characteristics is truly understood predicting transition on the basis of theory or statistically inadequate correlations (as they all are) entails risks that should be considered in justifying any design involving transition. A historical overview of bypass transition identified on blunt bodies is given.

  18. 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.

  19. Heart bypass surgery - minimally invasive - discharge

    MedlinePlus

    ... Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Chest . ... bypass surgery - minimally invasive Heart failure - overview High blood cholesterol ...

  20. 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.

  1. 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).

  2. Electroencephalographic seizures during cardiopulmonary bypass

    PubMed Central

    Stockard, J.; Calanchini, P.; Bickford, R.; Billinger, T.

    1974-01-01

    Eleven cardiac operations are reported in which there was electroencephalographic and/or clinical evidence of seizure activity during cardiopulmonary bypass (CPB). In four patients seizure activity appeared after acute episodes of cerebral ischaemia resulting from either hypotension or pump-generated emboli occurring at the beginning of CPB, or from air embolism occurring at the end of CPB when the myocardium was closed and defibrillated. In the remaining seven patients the seizures appeared to result from the synergistic action of a toxic substance in the perfusate with pre-existing or CPB-induced alterations in cerebral physiology. Images PMID:4819907

  3. Bypassing An Open-Circuit Power Cell

    NASA Technical Reports Server (NTRS)

    Wannemacher, Harry E.

    1994-01-01

    Collection of bypass circuits enables battery consisting series string of cells to continue to function when one of its cells fails in open-circuit (high-resistance) condition. Basic idea simply to shunt current around defective cell to prevent open circuit from turning off battery altogether. Bypass circuits dissipate little power and are nearly immune to false activation.

  4. 40 CFR 403.17 - Bypass.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 29 2014-07-01 2012-07-01 true Bypass. 403.17 Section 403.17 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GENERAL PRETREATMENT REGULATIONS FOR EXISTING AND NEW SOURCES OF POLLUTION § 403.17 Bypass....

  5. 40 CFR 403.17 - Bypass.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 30 2013-07-01 2012-07-01 true Bypass. 403.17 Section 403.17 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GENERAL PRETREATMENT REGULATIONS FOR EXISTING AND NEW SOURCES OF POLLUTION § 403.17 Bypass....

  6. 40 CFR 403.17 - Bypass.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 30 2012-07-01 2012-07-01 false Bypass. 403.17 Section 403.17 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GENERAL PRETREATMENT REGULATIONS FOR EXISTING AND NEW SOURCES OF POLLUTION § 403.17 Bypass....

  7. 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....

  8. 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....

  9. 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 M.

    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

  10. Post-Gastric Bypass Hypoglycemia.

    PubMed

    Rariy, Chevon M; Rometo, David; Korytkowski, Mary

    2016-02-01

    Obesity is a major public health problem worldwide. Obesity-related illnesses, such as coronary heart disease, type 2 diabetes, hypertension, dyslipidemia, stroke, sleep apnea, and several forms of cancer (endometrial, breast, and colon), contribute to a significant number of deaths in the USA. Bariatric surgery, including the Roux-en-Y gastric bypass (RYGB) procedure, has demonstrated significant improvements in obesity and obesity-related co-morbidities and is becoming more popular as the number of obese individuals rises. Despite the reported benefits of bariatric surgery, there are potential complications that physicians need to be aware of as the number of patients undergoing these procedures continues to increase. One challenging and potentially life-threatening complication that to date is not well understood is post-RYGB surgery hypoglycemia (PGBH). In this review, we will present the definition, historical perspective, diagnostic approach, currently available treatment options, and anecdotal assessment and treatment algorithm for this disorder. PMID:26868861

  11. 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.

  12. 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.

  13. 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)

  14. 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. PMID:25732081

  15. 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.

  16. ECC ozonesonde observations at Point Barrow, Alaska during January 16-April 19, 1989. Data report

    SciTech Connect

    Komhyr, W.D.; Wendell, J.; Lathrop, J.A.

    1991-03-01

    Measurements of the vertical distribution of ozone and air temperature were made with ECC ozonesondes January 16-April 19, 1989, at Point Barrow, Alaska, in an attempt to detect whether the stratospheric ozone depletion that occurs during the austral winter and spring in Antarctica also occurs during the winter and spring in the Arctic. Of 33 soundings made, 17 measured total ozone amounts of 400-531 Dobson units (DU), 13 measured 350-399 DU total ozone, and 1 measured 304 DU total ozone. (Two soundings did not attain high enough altitudes for estimates of total ozone to be made.) In contrast, total ozone amounts in winter and spring in Antarctica in recent years have ranged from about 125 to 275 DU. Stratospheric air temperatures over Point Barrow were never colder than -70 C and were often as warm as -50 C. No unequivocal evidence of photochemical ozone destruction such as that which occurs in Antarctica in the presence of polar stratospheric clouds appears on the ozone profiles presented here. Neither is there any evidence in the profiles of stratospheric transport to Point Barrow of partially depleted ozone from the eastern Arctic.

  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. 21 CFR 870.4310 - Cardiopulmonary bypass coronary pressure gauge.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 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 perfusing... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass coronary pressure...

  19. 21 CFR 870.4205 - Cardiopulmonary bypass bubble detector.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Cardiopulmonary bypass bubble detector. 870.4205... bypass bubble detector. (a) Identification. A cardiopulmonary bypass bubble detector is a device used to detect bubbles in the arterial return line of the cardiopulmonary bypass circuit. (b)...

  20. 21 CFR 870.4205 - Cardiopulmonary bypass bubble detector.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Cardiopulmonary bypass bubble detector. 870.4205... bypass bubble detector. (a) Identification. A cardiopulmonary bypass bubble detector is a device used to detect bubbles in the arterial return line of the cardiopulmonary bypass circuit. (b)...

  1. 21 CFR 870.4205 - Cardiopulmonary bypass bubble detector.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass bubble detector. 870.4205... bypass bubble detector. (a) Identification. A cardiopulmonary bypass bubble detector is a device used to detect bubbles in the arterial return line of the cardiopulmonary bypass circuit. (b)...

  2. 21 CFR 870.4205 - Cardiopulmonary bypass bubble detector.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Cardiopulmonary bypass bubble detector. 870.4205... bypass bubble detector. (a) Identification. A cardiopulmonary bypass bubble detector is a device used to detect bubbles in the arterial return line of the cardiopulmonary bypass circuit. (b)...

  3. 21 CFR 870.4205 - Cardiopulmonary bypass bubble detector.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Cardiopulmonary bypass bubble detector. 870.4205... bypass bubble detector. (a) Identification. A cardiopulmonary bypass bubble detector is a device used to detect bubbles in the arterial return line of the cardiopulmonary bypass circuit. (b)...

  4. 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...

  5. 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...

  6. Isopentenyl diphosphate (IPP)-bypass mevalonate pathways for isopentenol production.

    PubMed

    Kang, Aram; George, Kevin W; Wang, George; Baidoo, Edward; Keasling, Jay D; Lee, Taek Soon

    2016-03-01

    Branched C5 alcohols are promising biofuels with favorable combustion properties. A mevalonate (MVA)-based isoprenoid biosynthetic pathway for C5 alcohols was constructed in Escherichia coli using genes from several organisms, and the pathway was optimized to achieve over 50% theoretical yield. Although the MVA pathway is energetically less efficient than the native methylerythritol 4-phosphate (MEP) pathway, implementing the MVA pathway in bacterial hosts such as E. coli is advantageous due to its lack of endogenous regulation. The MVA and MEP pathways intersect at isopentenyl diphosphate (IPP), the direct precursor to isoprenoid-derived C5 alcohols and initial precursor to longer chain terpenes, which makes independent regulation of the pathways difficult. In pursuit of the complete "decoupling" of the MVA pathway from native cellular regulation, we designed novel IPP-bypass MVA pathways for C5 alcohol production by utilizing promiscuous activities of two enzymes, phosphomevalonate decarboxylase (PMD) and an E. coli-endogenous phosphatase (AphA). These bypass pathways have reduced energetic requirements, are further decoupled from intrinsic regulation, and are free from IPP-related toxicity. In addition to these benefits, we demonstrate that reduced aeration rate has less impact on the bypass pathway than the original MVA pathway. Finally, we showed that performance of the bypass pathway was primarily determined by the activity of PMD. We designed PMD mutants with improved activity and demonstrated titer increases in the mutant strains. These modified pathways would be a good platform for industrial production of isopentenol and related chemicals such as isoprene. PMID:26708516

  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. 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.

  9. Bypass diode for a solar cell

    SciTech Connect

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

    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.

  10. Absence of a role for DNA polymerase II in SOS-induced translesion bypass of phi X174.

    PubMed Central

    Kow, Y W; Faundez, G; Hays, S; Bonner, C A; Goodman, M F; Wallace, S S

    1993-01-01

    In order to examine the possible role of Escherichia coli DNA polymerase II in SOS-induced translesion bypass, Weigle reactivation and mutation induction were measured with single-stranded phi X174 transfecting DNA containing individual lesions. No decrease in bypass of thymine glycol or cyclobutane pyrimidine dimers in the absence of DNA polymerase II was observed. Furthermore, DNA polymerase II did not affect bypass of abasic sites when either survival or mutagenesis was the endpoint. Lastly, repair of gapped DNA molecules, intermediates in methyl-directed mismatch repair, was also unaffected by the presence or absence of DNA polymerase II. PMID:8419305

  11. 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

  12. Oxidative stress in coronary artery bypass surgery

    PubMed Central

    Dias, Amaury Edgardo Mont’Serrat Ávila Souza; Melnikov, Petr; Cônsolo, Lourdes Zélia Zanoni

    2015-01-01

    Objective The aim of this prospective study was to assess the dynamics of oxidative stress during coronary artery bypass surgery with cardiopulmonary bypass. Methods Sixteen patients undergoing coronary artery bypass grafting were enrolled. Blood samples were collected from the systemic circulation during anesthesia induction (radial artery - A1), the systemic venous return (B1 and B2) four minutes after removal of the aortic cross-clamping, of the coronary sinus (CS1 and CS2) four minutes after removal of the aortic cross-clamping and the systemic circulation four minutes after completion of cardiopulmonary bypass (radial artery - A2). The marker of oxidative stress, malondialdehyde, was measured using spectrophotometry. Results The mean values of malondialdehyde were (ng/dl): A1 (265.1), B1 (490.0), CS1 (527.0), B2 (599.6), CS2 (685.0) and A2 (527.2). Comparisons between A1/B1, A1/CS1, A1/B2, A1/CS2, A1/A2 were significant, with ascending values (P<0.05). Comparisons between the measurements of the coronary sinus and venous reservoir after the two moments of reperfusion (B1/B2 and CS1/CS2) were higher when CS2 (P<0.05). Despite higher values ​​after the end of cardiopulmonary bypass (A2), when compared to samples of anesthesia (A1), those show a downward trend when compared to the samples of the second moment of reperfusion (CS2) (P<0.05). Conclusion The measurement of malondialdehyde shows that coronary artery bypass grafting with cardiopulmonary bypass is accompanied by increase of free radicals and this trend gradually decreases after its completion. Aortic clamping exacerbates oxidative stress but has sharper decline after reperfusion when compared to systemic metabolism. The behavior of thiobarbituric acid species indicates that oxidative stress is an inevitable pathophysiological component. PMID:27163415

  13. "Orpheus" cardiopulmonary bypass simulation system.

    PubMed

    Morris, Richard W; Pybus, David A

    2007-12-01

    In this paper we describe a high-fidelity perfusion simulation system intended for use in the training and continuing education of perfusionists. The system comprises a hydraulic simulator, an electronic interface unit and a controlling computer with associated real-time computer models. It is designed for use within an actual operating theatre, or within a specialized simulation facility. The hydraulic simulator can be positioned on an operating table and physically connected to the circuit of the institutional heart-lung machine. The institutional monitoring system is used to display the arterial and central venous pressures, the ECG and the nasopharyngeal temperature using appropriate connections. The simulator is able to reproduce the full spectrum of normal and abnormal events that may present during the course of cardiopulmonary bypass. The system incorporates a sophisticated blood gas model that accurately predicts the behavior of a modern, hollow-fiber oxygenator. Output from this model is displayed in the manner of an in-line blood gas electrode and is updated every 500 msecs. The perfusionist is able to administer a wide variety of drugs during a simulation session including: vasoconstrictors (metaraminol, epinephrine and phenylephrine), a vasodilator (sodium nitroprusside), chronotropes (epinephrine and atropine), an inotrope (epinephrine) and modifiers of coagulation (heparin and protamine). Each drug has a pharmacokinetic profile based on a three-compartment model plus an effect compartment. The simulation system has potential roles in the skill training of perfusionists, the development of crisis management protocols, the certification and accreditation of perfusionists and the evaluation of new perfusion equipment and/or techniques. PMID:18293807

  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., Jr.

    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. Battery Cell By-Pass Circuit

    NASA Technical Reports Server (NTRS)

    Mumaw, Susan J. (Inventor); Evers, Jeffrey (Inventor); Craig, Calvin L., Jr. (Inventor); Walker, Stuart D. (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.

  16. 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.

  17. 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.

  18. Coronary artery bypass surgery without cardiopulmonary bypass: short- and mid-term results.

    PubMed

    Mishra, Y; Mehta, Y; Kohli, V M; Kohli, V; Mairal, M; Mishra, A; Bapna, R K; Trehan, N

    1997-01-01

    From March 1994 to April 1997, 433 patients had undergone coronary artery bypass grafting without cardiopulmonary bypass in our institute. Sixty-eight patients had various organ dysfunctions and/or aortic atheroma or calcification and were regarded as high risk for cardiopulmonary bypass. In 277 patients surgery was performed through midline sternotomy, while in 156 minithoracotomy approach was used. In 361 patients single coronary artery bypass grafting was done, and in 72 two-coronary arteries were bypassed. In 63 patients who had graftable vessels in anterior wall and diffusely diseased ungraftable vessels in posterolateral and/or inferior wall, transmyocardial laser revascularisation was also done along with coronary artery bypass grafting to achieve complete myocardial revascularisation. Nine patients in this series were also subjected to simultaneous carotid endarterectomy along with myocardial revascularisation. In two patients complementary percutaneous transluminal coronary angioplasty of left circumflex coronary artery was done five days after minithoracotomy and left internal mammary artery to left anterior descending coronary artery bypass grafting. Forty-two cases were extubated in operating room. Average blood loss was 260 ml. Six patients were reexplored for postoperative bleeding. Seven patients had perioperative myocardial infarction. One developed neurological complication. Hospital mortality was 2.3 percent (10/433 cases) and four deaths were due to malignant ventricular arrhythmias. Nine patients developed chest wound complications. Average hospital stay after operation was six days, 423 patients were discharged from hospital and all of them were asymptomatic. During three years follow-up (range 3 to 38 months) there were three known cardiac deaths. Ninety percent (391) patients reported to the follow-up clinic and 91 percent of them were angina-free. In patients who were subjected to transmyocardial laser revascularisation along with coronary

  19. 20 CFR 631.18 - Federal by-pass authority.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Secretary's intent to exercise by-pass authority and an opportunity to request and to receive a hearing.... (c) The Secretary will exercise by-pass authority only until such time as the affected State has...

  20. 21 CFR 870.4350 - Cardiopulmonary bypass oxygenator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... bypass oxygenator. (a) Identification. A cardiopulmonary bypass oxygenator is a device used to exchange gases between blood and a gaseous environment to satisfy the gas exchange needs of a patient during...

  1. The role of extra- and intracranial bypass in the treatment of complex aneurysms.

    PubMed

    Cenzato, Marco; Bortolotti, Carlo

    2016-03-01

    The availability of flow diverters and new endovascular techniques has greatly reduced the need and indications for bypass surgery. Nevertheless, there are situations where a bypass is the best option for a complex cerebrovascular problem. Generally, typical indications are giant aneurysms with a wide neck and/or partially calcified aneurysms with main branches or perforating arteries arising directly from the sac or from the neck itself, or fusiform aneurysms, partially calcified aneurysms. In this paper we discuss the following issues as they apply to the modern use of bypass techniques. In case of fusiform aneurysms involving the proximal bifurcations of the media or the internal carotid artery combined and coordinated evaluations and efforts by a team which includes neurosurgeons and endovascular specialists is essential. Treatment with bypass alone may not be sufficient and the combination of one or more bypasses with an endovascular treatment of occlusion, partial aneurysm embolization or flow diversion may be the best strategy. Addressing complex and fusiform aneurysm surgery requires a problem solving attitude and in this lies both the challenging and the fun side of this surgery. PMID:26947783

  2. 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

  3. (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

  4. (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

  5. 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.

  6. 46 CFR 56.20-20 - Valve bypasses.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Valves § 56.20-20 Valve bypasses. (a) Sizes of bypasses shall be in accordance with MSS SP-45 (incorporated by reference; see 46 CFR 56.01-2). (b) Pipe for bypasses should be at least Schedule 80 seamless... 46 Shipping 2 2011-10-01 2011-10-01 false Valve bypasses. 56.20-20 Section 56.20-20 Shipping...

  7. 46 CFR 56.20-20 - Valve bypasses.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Valves § 56.20-20 Valve bypasses. (a) Sizes of bypasses shall be in accordance with MSS SP-45 (incorporated by reference; see 46 CFR 56.01-2). (b) Pipe for bypasses should be at least Schedule 80 seamless... 46 Shipping 2 2014-10-01 2014-10-01 false Valve bypasses. 56.20-20 Section 56.20-20 Shipping...

  8. 46 CFR 56.20-20 - Valve bypasses.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Valves § 56.20-20 Valve bypasses. (a) Sizes of bypasses shall be in accordance with MSS SP-45 (incorporated by reference; see 46 CFR 56.01-2). (b) Pipe for bypasses should be at least Schedule 80 seamless... 46 Shipping 2 2012-10-01 2012-10-01 false Valve bypasses. 56.20-20 Section 56.20-20 Shipping...

  9. 46 CFR 56.20-20 - Valve bypasses.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Valves § 56.20-20 Valve bypasses. (a) Sizes of bypasses shall be in accordance with MSS SP-45 (incorporated by reference; see 46 CFR 56.01-2). (b) Pipe for bypasses should be at least Schedule 80 seamless... 46 Shipping 2 2013-10-01 2013-10-01 false Valve bypasses. 56.20-20 Section 56.20-20 Shipping...

  10. Effect of sucrose concentration on sucrose-dependent adhesion and glucosyltransferase expression of S. mutans in children with severe early-childhood caries (S-ECC).

    PubMed

    Zhao, Wei; Li, Wenqing; Lin, Jiacheng; Chen, Zhuoyu; Yu, Dongsheng

    2014-09-01

    Sucrose, extracellular polysaccharide, and glucosyltransferases (GTFs) are key factors in sucrose-dependent adhesion and play important roles in the process of severe early-childhood caries (S-ECC). However, whether sucrose concentration regulates gtf expression, extracellular polysaccharide synthesis, and sucrose-dependent adhesion is related to the different genotypes of S. mutans isolated from ECC in children and still needs to be investigated. In this study, 52 strains of S. mutans were isolated from children with S-ECC and caries-free (CF) children. Water-insoluble glucan (WIG) synthesis was detected by the anthrone method, adhesion capacity by the turbidimetric method, and expression of gtf by RT-PCR in an in vitro model containing 1%-20% sucrose. The genotypes of S. mutans were analyzed by AP-PCR. The results showed that WIG synthesis, adhesion capacity, and gtf expression increased significantly when the sucrose concentration was from 1% to 10%. WIG synthesis and gtfB as well as gtfC expression of the 1% and 5% groups were significantly lower than those of the 10% and 20% groups (p < 0.05). There were no significant differences between the 10% and 20% groups. The fingerprints of S. mutans detected from individuals in the S-ECC group exhibited a significant difference in diversity compared with those from CF individuals (p < 0.05). Further, the expression of gtfB and gtfC in the S-ECC group was significantly different among the 1- to 5-genotype groups (p < 0.05). It can be concluded that sucrose-dependent adhesion might be related to the diversity of genotypes of S. mutans, and the 10% sucrose level can be seen as a "turning point" and essential factor for the prevention of S-ECC. PMID:25207825

  11. Beating heart mitral valve repair for a patient with previous coronary bypass: a case report and review of the literature

    PubMed Central

    2013-01-01

    Mitral valve reoperation, through a median sternotomy, for a patient with patent coronary bypass grafts is technically challenging and carries higher postoperative morbidity and mortality than a primary operation. We present a case of mitral valve repair using a beating heart technique under normothermic cardiopulmonary bypass that was performed 3 years after a coronary artery bypass operation. A limited (10 cm) right thoracotomy was made and cardiopulmonary bypass was conducted using the ascending aortic and femoral venous cannulation. The left atrium was opened while beating was maintained. Triangular resection of the prolapsed portion of the posterior leaflet and ring annuloplasty were performed. Completeness of the repair was verified by direct visualization under beating condition and transesophageal echocardiogram. This technique is a safe and feasible option for a mitral valve reoperation that excludes re-sternotomy, extensive pericardial dissection and aortic clamping, thereby minimizes risks of bleeding, graft injury and myocardial damage. PMID:24128131

  12. 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....

  13. 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 conjunction with short-term extracorporeal circulation devices to hold a reserve supply of blood in the...

  14. 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...

  15. 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 conjunction with short-term extracorporeal circulation devices to hold a reserve supply of blood in the...

  16. 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 conjunction with short-term extracorporeal circulation devices to hold a reserve supply of blood in the...

  17. 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 conjunction with short-term extracorporeal circulation devices to hold a reserve supply of blood in the...

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

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3545 Ventricular bypass (assist) device. (a) Identification. A ventricular bypass (assist) device is a device that assists... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Ventricular bypass (assist) device....

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

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3545 Ventricular bypass (assist) device. (a) Identification. A ventricular bypass (assist) device is a device that assists... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ventricular bypass (assist) device....

  20. 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....

  1. 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....

  2. 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....

  3. 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....

  4. 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 Section 870.4390 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... bypass pump tubing. (a) Identification. A cardiopulmonary bypass pump tubing is polymeric tubing which...

  5. 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 Section 870.4390 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... bypass pump tubing. (a) Identification. A cardiopulmonary bypass pump tubing is polymeric tubing which...

  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 Section 870.4390 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... bypass pump tubing. (a) Identification. A cardiopulmonary bypass pump tubing is polymeric tubing which...

  7. 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 Section 870.4390 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... bypass pump tubing. (a) Identification. A cardiopulmonary bypass pump tubing is polymeric tubing which...

  8. 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 Section 870.4390 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... bypass pump tubing. (a) Identification. A cardiopulmonary bypass pump tubing is polymeric tubing which...

  9. 21 CFR 870.3545 - Ventricular bypass (assist) device.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3545 Ventricular bypass (assist) device. (a) Identification. A ventricular bypass (assist) device is a device that assists... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Ventricular bypass (assist) device....

  10. 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....

  11. 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... 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....

  12. 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....

  13. 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.

  14. 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

  15. Gastric infarction following gastric bypass surgery

    PubMed Central

    Do, Patrick H; Kang, Young S; Cahill, Peter

    2016-01-01

    Gastric infarction is an extremely rare occurrence owing to the stomach’s extensive vascular supply. We report an unusual case of gastric infarction following gastric bypass surgery. We describe the imaging findings and discuss possible causes of this condition. PMID:27200168

  16. Analysis and testing of electrorheological bypass dampers

    NASA Astrophysics Data System (ADS)

    Lindler, Jason E.; Wereley, Norman M.

    1998-06-01

    We experimentally validate nonlinear quasi-steady electrorheological (ER) and magnetorheological (MR) damper models, using an idealized Bingham plastic shear flow mechanism, for the flow mode of damper operation. An electrorheological valve or bypass damper was designed, and fabricated using predominantly commercial off-the-shelf hydraulic components. Both the hydraulic cylinder and the bypass duct have cylindrical geometry, and damping forces are developed in the annular bypass via Poiseuille (flow mode) flow. Damper models assume parallel plate geometry. Three nondimensional groups are used for damper analysis, namely, the Bingham number, Bi, the nondimensional plug thickness, (delta) , and the area coefficient defined as the ratio of the piston head area, A(rho ), to the cross-sectional area of the annular bypass, Ad. In the flow mode case, the damping coefficient, which is defined as the ratio of equivalent viscous damping of the Bingham plastic material, Ceq, to the Newtonian viscous damping, C, is a function of the nondimensional plug thickness only. The damper was tested using a mechanical damper dynamometer for sinusoidal stroke of 2 inches, over a range of frequencies below 0.63 Hz. The damping coefficient vs. nondimensional plug thickness diagram was experimentally validated using these data over a range of damper shaft velocities and applied electric field. Because the behaviors of ER and MR fluid are qualitatively similar, these ER damper modeling results may be extended to analysis of flow mode MR dampers.

  17. 30 CFR 77.302 - Bypass stacks.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Bypass stacks. 77.302 Section 77.302 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS, SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Thermal Dryers §...

  18. 30 CFR 77.302 - Bypass stacks.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Bypass stacks. 77.302 Section 77.302 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS, SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Thermal Dryers §...

  19. 30 CFR 77.302 - Bypass stacks.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Bypass stacks. 77.302 Section 77.302 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS, SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Thermal Dryers §...

  20. 30 CFR 77.302 - Bypass stacks.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Bypass stacks. 77.302 Section 77.302 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS, SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Thermal Dryers §...

  1. 30 CFR 77.302 - Bypass stacks.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Bypass stacks. 77.302 Section 77.302 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS, SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Thermal Dryers §...

  2. Fluid distribution kinetics during cardiopulmonary bypass

    PubMed Central

    Törnudd, Mattias; Hahn, Robert G.; Zdolsek, Joachim H.

    2014-01-01

    OBJECTIVE: The purpose of this study was to examine the isovolumetric distribution kinetics of crystalloid fluid during cardiopulmonary bypass. METHODS: Ten patients undergoing coronary artery bypass grafting participated in this prospective observational study. The blood hemoglobin and the serum albumin and sodium concentrations were measured repeatedly during the distribution of priming solution (Ringer's acetate 1470 ml and mannitol 15% 200 ml) and initial cardioplegia. The rate of crystalloid fluid distribution was calculated based on 3-min Hb changes. The preoperative blood volume was extrapolated from the marked hemodilution occurring during the onset of cardiopulmonary bypass. Clinicaltrials.gov: NCT01115166. RESULTS: The distribution half-time of Ringer's acetate averaged 8 minutes, corresponding to a transcapillary escape rate of 0.38 ml/kg/min. The intravascular albumin mass increased by 5.4% according to mass balance calculations. The preoperative blood volume, as extrapolated from the drop in hemoglobin concentration by 32% (mean) at the beginning of cardiopulmonary bypass, was 0.6-1.2 L less than that estimated by anthropometric methods (p<0.02). The mass balance of sodium indicated a translocation from the intracellular to the extracellular fluid space in 8 of the 10 patients, with a median volume of 236 ml. CONCLUSIONS: The distribution half-time of Ringer's solution during isovolumetric cardiopulmonary bypass was 8 minutes, which is the same as for crystalloid fluid infusions in healthy subjects. The intravascular albumin mass increased. Most patients were hypovolemic prior to the start of anesthesia. Intracellular edema did not occur. PMID:25141112

  3. 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.

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

    PubMed Central

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

    2016-01-01

    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. PMID:27428541

  5. An update on coronary bypass graft intervention

    PubMed Central

    Dash, Debabrata

    2014-01-01

    Coronary artery bypass grafting (CABG) remains one of the most common surgical procedures. In spite of great advancements like arterial grafts and off-pump bypass procedure, recurrent ischaemia may ensue with the lesions of the graft. Early postoperative ischaemia (<30 days) is due to graft occlusion or stenosis, and percutaneous coronary intervention (PCI) is frequently feasible. Late postoperative ischaemia (>3 years) is most often due to a saphenous vein graft (SVG) lesion. Multiple diseased grafts, reduced left ventricular function, and available arterial conduits favour repeat CABG, whereas, a patent left internal mammary artery to left anterior descending favours PCI. Embolic protection reduces atheroembolic myocardial infarction during PCI of SVG and should be routinely used in treatment of SVG lesions. A variety of vasodilators may reduce the risk of or mitigate the consequences of no-reflow. Drug-eluting stents reduce restenosis in SVG grafts, and have become the default strategy for many interventionalists. PMID:27326165

  6. A variable current bypass shunt for electromagnets

    SciTech Connect

    Berndt, M.M.; Lipari, J.J.

    1992-11-01

    An IGBT is used to control the current in bypass circuits that vary the relative strength of magnets connected in series. Each circuit consists of a water cooled assembly rated for continuous operation at 70 Volts and 0--50 Amperes DC, with 1 KV insulation between control/monitoring elements and magnets. The circuit operates as a 10KHz PWM switcher that includes filters and transient protection.

  7. TRAS principles blight arterial bypass and plasty.

    PubMed

    Kothari, M V; Mehta, L A; Kothari, V M

    1997-01-01

    A new concept--Tissue Requisitions (Principle I)/Relinquishes (Principle II) Arterial Supply--of TRAS principles is introduced to help appreciate the failures/successes of modern medicine's attempts at restoring arterial flow in luminally compromised coronary/carotid fields, an invasive branch rightly called vascular ReRheology, which comprises diagnosing/treating arterial blocks. The technical wizardry of arterial reconstruction (bypass) or lumen--restoration (plasty) has to reckon with the TRAS principles all the time. PMID:10740714

  8. Vein harvesting and techniques for infrainguinal bypass.

    PubMed

    Albäck, Anders; Saarinen, Eva; Venermo, Maarit

    2016-04-01

    In order to achieve good long term results after bypass surgery, alongside with good inflow and outflow arteries, the bypass graft material also has an important role. The best patency and limb salvage rates are achieved with autologous vein. If great saphenous vein is not available, acceptable long-term results can be achieved with arm veins and lesser saphenous vein. The quality and size of the vein are important. A small-caliber vein, increased wall thickness, postphlebitic changes and varicosities are associated with a risk of early failure. Preoperative vein mapping with ultrasound reduces readmissions and postoperative surgical site infections. During the mapping, the vein to be used and its main tributaries are marked with a permanent marker pen. To reduce wound complication rates we recommend bridged incisions in vein harvesting. Endoscopic vein harvesting seems to have no benefit compared to open techniques in lower limb bypasses, and has been associated with higher risk of primary patency loss at one year. With deep tunneling of the graft the problems caused by wound infection can be avoided. PMID:26837257

  9. Force and pressure-recovery characteristics at supersonic speeds of a conical nose inlet with bypasses discharging outward from the body axis

    NASA Technical Reports Server (NTRS)

    Beke, Andrew; Allen, J L

    1953-01-01

    Aerodynamic and performance characteristics of a conical spike nacelle-type inlet with two bypasses are presented at Mach numbers of 1.6, 1.8, and 2.0 for angles of attach up to 90 degrees. The bypasses were located 6 inlet diameters downstream of the inlet and were designed to discharge the bypass mass flow outward from the body axis. The inlet was designed to attain a mass-flow ratio of unity at a Mach number of 2.0. It is shown that discharging the bypass mass flow outward from the body nearly doubles the critical drag of a similar configuration but with bypass discharge in an axial direction. As a result of this greater drag, the net force on the model in the flight direction is reduced when comparison is made with the axial discharge case. The lift and pitching-moment coefficients are slightly higher than those for a configuration without bypasses. Approximately 25 % of the maximum inlet mass flow was discharged through the bypasses, and the pressure-recovery and mass-flow characteristics were in qualitative and quantitative agreement with the results of an investigation of a similar configuration with axial discharge.

  10. VAV/bypass filtration system controls VOCs, particulates

    SciTech Connect

    Meckler, M. )

    1994-03-01

    This article describes how a proprietary demand control ventilation system equipped with an IAQ sensor helps provide acceptable air quality, comfort, and cost effectiveness, especially with VAV systems. Properly implemented demand control ventilation (DCV) strategies can provide the opportunity to maintain acceptable indoor air quality (IAQ) in accordance with ASHRAE Standard 62-1989 while offering significant energy savings. This article will introduce a proprietary DCV system already equipped with an IAQ sensor that directly measures the concentration of VOCs in an occupied space and accordingly modulates supply air rates to provide acceptable IAQ, comfort, and cost effectiveness, especially for variable air volume (VAV) systems. In addition, system filter and bypass filter selection criteria for both retrofit and new building applications will be outlined.

  11. PEEP therapy for patients with pleurotomy during coronary artery bypass grafting.

    PubMed

    Ishikawa, S; Ohtaki, A; Takahashi, T; Sakata, K; Koyano, T; Kano, M; Ohki, S; Kawashima, O; Hamada, Y; Morishita, Y

    2000-01-01

    Severe pulmonary oxygenation impairment resulting from peripheral lung atelectasis occurred in some patients with pleurotomy during the harvest of the internal mammary artery graft followed by coronary artery bypass grafting (CABG). We studied the efficacy of intraoperative positive end-expiratory airway pressure (PEEP) therapy for the prevention of postoperative pulmonary oxygenation impairment. A total of 66 patients with solitary CABG procedure were included in this study. The pleural cavity was intraoperatively opened in 44 patients and not opened in 22. PEEP therapy was not used in any patient before May 1996 (referred to herein as the former period) and was used more recently in eight patients with pleurotopmy (referred to herein as the latter period). PEEP was initiated immediately after pleurotomy during the harvest of the internal mammary artery graft. Without PEEP therapy, values of PaO2, A-aDO2, and respiratory index (RI) were worse in patients with pleurotomy than in those without pleurotomy. Meanwhile, there were no major differences in these values between patients with or without pleurotomy after the induction of PEEP therapy. Respiratory insufficiency (A-aDO2 > 400 mmHg and RI > 1.5) was detected in six patients with pleurotomy in the former period. Three of these six patients required over 1 week of long-term mechanical respiratory support. No respiratory insufficiency occurred in patients of the latter period. In conclusion, PEEP therapy, which is initiated just after pleurotomy, may prevent oxygen impairment and pulmonary atelectasis after extracorporeal circulation (ECC) and is recommended for patients with pleurotomy, especially for patients with preoperative low respiratory function. PMID:11414602

  12. 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. PMID:25164136

  13. Repeated vital capacity manoeuvres after cardiopulmonary bypass: effects on lung function in a pig model.

    PubMed

    Magnusson, L; Wicky, S; Tydén, H; Hedenstierna, G

    1998-05-01

    Respiratory failure following cardiopulmonary bypass (CPB) is a major complication after cardiac surgery. A vital capacity inflation of the lungs, performed before the end of CPB, may improve gas exchange, but the necessity to repeat it is unclear. Therefore, we studied 18 pigs undergoing hypothermic CPB. A vital capacity manoeuvre (VCM) was performed in two groups and consisted of inflating the lungs for 15 s to 40 cm H2O at the end of CPB. In one group, VCM was repeated every hour. The third group served as controls. Atelectasis was studied by CT scan. Intrapulmonary shunt increased after bypass in the controls and improved spontaneously 3 h later without returning to baseline values. From 3 to 6 h after CPB, there was no more improvement and more than 10% atelectasis remained at 6 h. In contrast, the two groups treated before termination of CPB with VCM showed only minor atelectasis and no abnormal changes in gas exchange directly after bypass or later. We conclude that the protective effect of VCM remained for 6 h after bypass, and there was no extra benefit on gas exchange by repeating the VCM. PMID:9691879

  14. Jet-Pylon Interaction of High Bypass Ratio Separate Flow Nozzle Configurations

    NASA Technical Reports Server (NTRS)

    Thomas, Russell H.; Kinzie, Kevin W.

    2004-01-01

    NASA Langley Research Center, Hampton, Virginia, 23681-0001 USA An experimental investigation was performed of the acoustic effects of jet-pylon interaction for separate flow and chevron nozzles of both bypass ratio five and eight. The models corresponded to an approximate scale factor of nine. Cycle conditions from approach to takeoff were tested at wind tunnel free jet Mach numbers of 0.1, 0.2 and 0.28. An eight-chevron core nozzle, a sixteen chevron fan nozzle, and a pylon were primary configuration variables. In addition, two orientations of the chevrons relative to each other and to the pylon were tested. The effect of the pylon on the azimuthal directivity was investigated for the baseline nozzles and the chevron nozzles. For the bypass ratio five configuration, the addition of the pylon reduces the noise by approximately 1 EPNdB compared to the baseline case and there is little effect of azimuthal angle. The core chevron produced a 1.8 EPNdB reduction compared to the baseline nozzle. Adding a pylon to the chevron core nozzle produces an effect that depends on the orientation of the chevron relative to the pylon. The azimuthal directivity variation remains low at less than 0.5 EPNdB. For the bypass ratio eight configuration the effect of adding a pylon to the baseline nozzle is to slightly increase the noise at higher cycle points and for the case with a core chevron the pylon has little additional effect. The azimuthal angle effect continues to be very small for the bypass ratio eight configurations. A general impact of the pylon was observed for both fan and core chevrons at both bypass ratios. The pylon reduces the typical low frequency benefit of the chevrons, even eliminating it in some cases, while not impacting the high frequency. On an equal ideal thrust basis, the bypass ratio eight baseline nozzle was about 5 EPNdB lower than the bypass ratio five baseline nozzle at the highest cycle condition, however, with a pylon installed the difference

  15. 34 CFR 300.191 - Provisions for services under a by-pass.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 34 Education 2 2011-07-01 2010-07-01 true Provisions for services under a by-pass. 300.191 Section... Provisions for services under a by-pass. (a) Before implementing a by-pass, the Secretary consults with... under the by-pass. (b) After determining that a by-pass is required, the Secretary arranges for...

  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... Provisions for services under a by-pass. (a) Before implementing a by-pass, the Secretary consults with... under the by-pass. (b) After determining that a by-pass is required, the Secretary arranges for...

  17. 34 CFR 300.191 - Provisions for services under a by-pass.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 34 Education 2 2012-07-01 2012-07-01 false Provisions for services under a by-pass. 300.191... Provisions for services under a by-pass. (a) Before implementing a by-pass, the Secretary consults with... under the by-pass. (b) After determining that a by-pass is required, the Secretary arranges for...

  18. 34 CFR 300.191 - Provisions for services under a by-pass.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 34 Education 2 2013-07-01 2013-07-01 false Provisions for services under a by-pass. 300.191... Provisions for services under a by-pass. (a) Before implementing a by-pass, the Secretary consults with... under the by-pass. (b) After determining that a by-pass is required, the Secretary arranges for...

  19. 34 CFR 300.191 - Provisions for services under a by-pass.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 34 Education 2 2014-07-01 2013-07-01 true Provisions for services under a by-pass. 300.191 Section... Provisions for services under a by-pass. (a) Before implementing a by-pass, the Secretary consults with... under the by-pass. (b) After determining that a by-pass is required, the Secretary arranges for...

  20. 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.

  1. Jejunioleal Bypass Procedures in Morbid Obesity: Preoperative Psychological Findings

    ERIC Educational Resources Information Center

    Webb, Warren W.; And Others

    1976-01-01

    Seventy patients who averaged 155 percent overweight and requested jejunioleal bypass surgery as a treatment intervention for morbid obesity were studied preoperatively for prominent psychological characteristics. (Author)

  2. 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

  3. 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.

  4. 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.

  5. Demonstration of a Hitless Bypass Switch Using Nanomechanical Perturbation for High-bitrate Transparent Networks

    SciTech Connect

    Chatterjee, R.; Stein, A.; Yu, M.; Kwong, D.-L.; Kimerling, L.C.; Wong, C.W.

    2010-01-01

    We demonstrate an optical hitless bypass switch based on nanomechanical proximity perturbation for high-bitrate transparent networks. Embedded in a single-level {pi}-imbalanced Mach-Zehnder interferometer, the two nanomechanical-based {Delta}{beta}-directional couplers permit broadband signal rerouting on-chip, while the selected wavelength remains unaffected at all times for optical filter reconfiguration. The optical hitless switch is implemented in the silicon nanophotonics platform, with experimental measurements matching well with numerical and theoretical modeling.

  6. Tissue Oxygenation Response to Mild Hypercapnia during Cardiopulmonary Bypass with Constant Pump Output

    PubMed Central

    Akça, Ozan; Sessler, Daniel I; DeLong, Diane; Keijner, Raymond; Ganzel, Brian; Doufas, Anthony G

    2006-01-01

    Background Tissue oxygenation is the primary determinant of wound infection risk. Mild hypercapnia markedly improves cutaneous, subcutaneous, and muscular tissue oxygenation in volunteers and patients. However, relative contributions of increased cardiac output and peripheral vasodilation to this response remains unknown. We thus tested the hypothesis that increased cardiac output is the dominant mechanism. Methods We recruited 10 ASA III patients, aged 40–65 years, undergoing cardiopulmonary bypass for this crossover trial. After induction of anaesthesia, a Silastic tonometer was inserted subcutaneously in the upper arm. Subcutaneous tissue oxygen tension was measured with both polarographic electrode and fluorescence-based systems. Oximeter probes were placed bilaterally on the forehead to monitor cerebral oxygenation. After initiation of cardiopulmonary bypass, in random order patients were exposed to two arterial CO2 partial pressures for 30 minutes each: 35 (normocapnia) or 50 mmHg (hypercapnia). Bypass pump flow was kept constant throughout the measurement periods. Results Hypercapnia during bypass had essentially no effect on PaO2, mean arterial pressure, or tissue temperature. PaCO2 and pH differed significantly. Subcutaneous tissue oxygenation was virtually identical during the two PaCO2 periods (139 [50,163] vs. 145 [38,158], P=0.335) (median [range]). In contrast, cerebral oxygen saturation (our positive control measurement) was significantly less during normocapnia (57 [28,67]%) than hypercapnia (64 [37,89]%, P=0.025). Conclusions Mild hypercapnia, which normally markedly increases tissue oxygenation, did not do so during cardiopulmonary bypass with fixed pump output. This suggests that hypercapnia normally increases tissue oxygenation by increasing cardiac output rather than direct dilation of peripheral vessels. PMID:16675511

  7. Bypassing genomic imprinting allows seed development.

    PubMed

    Nowack, Moritz K; Shirzadi, Reza; Dissmeyer, Nico; Dolf, Andreas; Endl, Elmar; Grini, Paul E; Schnittger, Arp

    2007-05-17

    In developing progeny of mammals the two parental genomes are differentially expressed according to imprinting marks, and embryos with only a uniparental genetic contribution die. Gene expression that is dependent on the parent of origin has also been observed in the offspring of flowering plants, and mutations in the imprinting machinery lead to embryonic lethality, primarily affecting the development of the endosperm-a structure in the seed that nourishes the embryo, analogous to the function of the mammalian placenta. Here we have generated Arabidopsis thaliana seeds in which the endosperm is of uniparental, that is, maternal, origin. We demonstrate that imprinting in developing seeds can be bypassed and viable albeit smaller seedlings can develop from seeds lacking a paternal contribution to the endosperm. Bypassing is only possible if the mother is mutant for any of the FIS-class genes, which encode Polycomb group chromatin-modifying factors. Thus, these data provide functional evidence that the action of the FIS complex balances the contribution of the paternal genome. As flowering plants have evolved a special reproduction system with a parallel fusion of two female with two male gametes, our findings support the hypothesis that only with the evolution of double fertilization did the action of the FIS genes become a requirement for seed development. Furthermore, our data argue for a gametophytic origin of endosperm in flowering plants, thereby supporting a hypothesis raised in 1900 by Eduard Strasburger. PMID:17468744

  8. 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. PMID:25738720

  9. 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

  10. Coronary Artery Bypass Surgery - Multiple Languages: MedlinePlus

    MedlinePlus

    ... Are Here: Home → Multiple Languages → All Health Topics → Coronary Artery Bypass Surgery URL of this page: https://www.nlm. ... V W XYZ List of All Topics All Coronary Artery Bypass Surgery - Multiple Languages To use the sharing features ...

  11. 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 SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Surgical Devices § 870.4420 Cardiopulmonary bypass cardiotomy...

  12. 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...

  13. 46 CFR 154.550 - Excess flow valve: Bypass.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 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...

  14. 46 CFR 154.550 - Excess flow valve: Bypass.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 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...

  15. 46 CFR 154.550 - Excess flow valve: Bypass.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 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...

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

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 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. 46 CFR 56.20-20 - Valve bypasses.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... (incorporated by reference; see 46 CFR 56.01-2). (b) Pipe for bypasses should be at least Schedule 80 seamless... 46 Shipping 2 2010-10-01 2010-10-01 false Valve bypasses. 56.20-20 Section 56.20-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PIPING SYSTEMS AND...

  18. 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.

  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. Hypocupremia-related myeloneuropathy following gastrojejunal bypass surgery.

    PubMed

    Choi, Eric H; Strum, Williamson

    2010-01-01

    Gastrojejunal bypass surgery may be complicated by nutritional deficiencies, including trace elements. Copper, which is absorbed in the duodenum and proximal jejunum, is poorly absorbed when a significant portion of the proximal small intestine is bypassed. However, despite this theoretical risk of hypocupremia in the gastrojejunal bypass patient, reports of symptomatic copper deficiency are very rare, and even then the deficiency is often potentiated by an accelerant, such as concomitant zinc ingestion. We report a case of hypocupremia resulting in hematologic abnormalities and myeloneuropathy after gastrojejunal bypass surgery for morbid obesity. It stresses the importance of recognizing nutritional deficiencies, particularly copper deficiency, because of the possible and serious sequelae of bone marrow suppression and myeloneuropathy. The early recognition and treatment of the symptoms of hypocupremia is emphasized to avoid these long-term sequelae. With the rapidly growing number of patients undergoing gastrojejunal bypass surgery for morbid obesity, the index of suspicion for hypocupremia must be heightened. PMID:21088385

  2. One sided bypass for bilateral Moyamoya disease, a case report and review of the literatures

    PubMed Central

    Li, Xuhui; Zhao, Ninghui; Yang, P. Zichu

    2016-01-01

    Background Moyamoya disease (MMD) is a rare condition, where the most appropriate treatment for it is yet to be determined. Surgery remains an important method of choice although it is considered a form of palliative care. The outcome following surgery is very difficult to judge, and there is no standardised measurement to assess it. It is therefore important to know which approach for such patient is adequate. Clinical presentation A 21-year-old male patient presented with signs and symptoms of intracranial haemorrhage. Upon investigation, a diagnosis of bilateral MMD was made, and one sided direct bypass surgery was subsequently performed. At 3-year follow-up, there is no evidence of recurrent cerebral vascular event. Conclusion This case provided further evidence that direct bypass surgery is beneficial for patient in terms of blood flow improvement and symptom relieve. Although there is no consensus on whether bilateral surgical intervention is mandatory for patient with bilateral MMD, unilateral bypass might be sufficient enough. Further study is required to evaluate the best approach for such group of patient. PMID:27016648

  3. Can pregnant women be safely placed on cardiopulmonary bypass?

    PubMed Central

    Sepehripour, Amir H.; Lo, Tammy T.; Shipolini, Alex R.; McCormack, David J.

    2012-01-01

    A best evidence topic was written according to a structured protocol. The question addressed was whether cardiopulmonary bypass can be used safely with satisfactory maternal and foetal outcomes in pregnant patients undergoing cardiac surgery. A total of 679 papers were found using the reported searches of which 14 represented the best evidence to answer the clinical question. The authors, date, journal, study type, population, main outcome measures and results are tabulated. Reported measures were maternal and foetal mortality and complications, mode of delivery, cardiopulmonary bypass and aortic cross-clamp times, perfusate flow rate and temperature and maternal NYHA functional class. The most recent of the best evidence studies, a retrospective observational study of 21 pregnant patients reported early and late maternal mortalities of 4.8 and 14.3%, respectively, and a foetal mortality of 14.3%. Median cardiopulmonary bypass and aortic cross-clamp times were 53 and 35 min, respectively, and the median bypass temperature was 37°C. Three larger retrospective reviews of the literature reported maternal mortality rates of 2.9–5.1% and foetal mortality rates of 19–29%. Mean cardiopulmonary bypass times ranged from 50.5 to 77.8 min. Another retrospective observational study reported maternal mortality of 13.3% and foetal mortality of 38.5%. Mean cardiopulmonary bypass and aortic cross-clamp times were 89.1 and 62.8 min, respectively, with a mean bypass temperature of 31.8°C. A retrospective case series reported no maternal mortality and one case of foetal mortality. Median cardiopulmonary bypass and aortic cross-clamp times were 101 and 88 min, respectively. Eight case reports described 10 patients undergoing cardiopulmonary bypass. There were no reports of maternal mortality and one report of foetal mortality. Mean cardiopulmonary bypass and aortic cross-clamp times were 105 and 50 min, respectively. We conclude that while the use of cardiopulmonary bypass

  4. Early outcomes of coronary artery bypass with and without cardiopulmonary bypass in octogenarians

    PubMed Central

    Nagpal, AD; Bhatnagar, G; Cutrara, CA; Ahmed, SM; McKenzie, N; Quantz, M; Kiaii, B; Menkis, A; Fox, S; Stitt, L; Novick, RJ

    2006-01-01

    BACKGROUND Off-pump coronary artery bypass (OPCAB) surgery has been successfully used in diverse patient populations and has been postulated to be safer than conventional coronary artery bypass (CCAB) surgery in some high-risk patients, including the elderly. OBJECTIVE To compare the safety of OPCAB surgery versus CCAB surgery in the octogenarian population of two large southwestern Ontario cardiac surgical units. RESULTS Two hundred thirty-six consecutive octogenarians underwent primary isolated coronary artery bypass sugery from November 2000 to March 2005. Patients undergoing OPCAB surgery tended to have higher Parsonnet scores, while patients undergoing CCAB surgery had a greater number of emergent operations. The Canadian Cardiovascular Network predicted that mortality risk was similar in both groups. In-hospital mortality was similar between groups, as was postoperative myocardial infarction and new onset of renal dysfunction. However, in the OPCAB group, there was a decreased incidence of postoperative neurological dysfunction (2.3% in the OPCAB group versus 10.5% in the CCAB group, P=0.01), in particular cerebrovascular accidents (1.5% in the OPCAB group versus 7.6% in the CCAB group, P=0.05), and a decreased incidence of prolonged intubation (5.3% in the OPCAB group versus 13.3% in the CCAB group, P=0.04). Multivariable analysis found that cardiopulmonary bypass had no significant impact on mortality or length of stay. CONCLUSIONS In octogenarian patients, OPCAB surgery is as safe as CCAB surgery in terms of mortality and major morbidity. Furthermore, a significant reduction in neurological dysfunction and prolonged intubation was seen in the OPCAB group compared with the CCAB group. PMID:16957802

  5. Trilinolein improves erythrocyte deformability during cardiopulmonary bypass.

    PubMed Central

    Tsai, S K; Chan, P; Lee, T Y; Yung, J M; Hong, C Y

    1994-01-01

    The in vitro effect of trilinolein, a triglyceride with linoleic acid as the major fatty acid residue in the esterified positions of glycerol, on erythrocyte deformability was studied in blood samples collected from 12 patients before and after cardiopulmonary bypass (CPB). Erythrocyte deformability was measured with a filtration method and expressed as red cell filtration rate (RFR). RFR was reduced after CPB and the reduction was time dependent. Trilinolein at a concentration of 10(-7) M significantly reversed the CPB-induced reduction of RFR when it was mixed with blood samples collected 30, 60 and 90 min from the start of CPB. This study confirmed the effect of CPB on erythrocyte deformability and showed that this damage could be significantly improved by mixing blood with trilinolein. PMID:8054252

  6. Factor V Leiden and Cardiopulmonary Bypass

    PubMed Central

    Uppal, Victor; Rosin, Mark; Marcoux, Jo-Anne; Olson, Marnie; Bezaire, Jennifer; Dalshaug, Gregory

    2015-01-01

    Abstract: We present a case of a patient with factor V Leiden with an antithrombin III activity of 67% who received a successful aortic valve replacement supported by cardiopulmonary bypass (CPB). A safe level of anticoagulation was achieved by monitoring activated clotting time (ACT) and heparin concentration ensuring adequate anticoagulation throughout the procedure. Results from ACT, heparin dose response, heparin protamine titration, and thrombelastography are given. Factor V Leiden patients can be safely anti-coagulated using heparin for CPB procedures when monitored with ACT, heparin protamine titration, and thrombelastography. Postoperative chest tube losses were 360 mL, less than half our institutional average. Anticoagulation for the pre-and post-operative phase is also discussed. PMID:26834284

  7. Innovative Double Bypass Engine for Increased Performance

    NASA Astrophysics Data System (ADS)

    Manoharan, Sanjivan

    Engines continue to grow in size to meet the current thrust requirements of the civil aerospace industry. Large engines pose significant transportation problems and require them to be split in order to be shipped. Thus, large amounts of time have been spent in researching methods to increase thrust capabilities while maintaining a reasonable engine size. Unfortunately, much of this research has been focused on increasing the performance and efficiencies of individual components while limited research has been done on innovative engine configurations. This thesis focuses on an innovative engine configuration, the High Double Bypass Engine, aimed at increasing fuel efficiency and thrust while maintaining a competitive fan diameter and engine length. The 1-D analysis was done in Excel and then compared to the results from Numerical Propulsion Simulation System (NPSS) software and were found to be within 4% error. Flow performance characteristics were also determined and validated against their criteria.

  8. 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

  9. 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

  10. 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

  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. Monitoring microemboli during cardiopulmonary bypass with the EDAC quantifier.

    PubMed

    Lynch, John E; Wells, Christopher; Akers, Tom; Frantz, Paul; Garrett, Donna; Scott, M Lance; Williamson, Lisa; Agnew, Barbara; Lynch, John K

    2010-09-01

    Gaseous emboli may be introduced into the bypass circuit both from the surgical field and during perfusionist interventions. While circuits provide good protection against massive air embolism, they do not remove gaseous microemboli (GME) from the bypass circuit. The purpose of this preliminary study is to assess the incidence of GME during bypass surgery and determine if increased GME counts were associated with specific events during bypass surgery. In 30 cases divided between 15 coronary artery bypass grafts and 15 valve repairs, GME were counted and sizedt the three locations on the bypass circuit using the EDAC" Quantifier (Luna Innovations, Roanoke, VA). A mean of 45,276 GME were detected after the arterial line filter during these 30 cases, with significantly more detected (p = .04) post filter during valve cases (mean = 72,137 +/- 22,113) than coronary artery bypass graft cases (mean = 18,416 +/- 7831). GME detected post filter were significantly correlated in time with counts detected in the venous line (p < .001). Specific events associated with high counts included the initiation of cardiopulmonary bypass, heart manipulations, insertion and removal of clamps, and the administration of drugs. Global factors associated with increased counts post filter included higher venous line counts and higher post reservoir/bubble trap counts. The mean number of microemboli detected during bypass surgery was much higher than reported in other studies of emboli incidence, most likely due to the increased sensitivity of the EDAC Quantifier compared to other detection modalities. The results furthermore suggest the need for further study of the clinical significance of these microemboli and what practices may be used to reduce GME incidence. Increased in vitro testing of the air handling capability of different circuit designs, along with more clinical studies assessing best clinical practices for reducing GME activity, is recommended. PMID:21114224

  13. 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.

  14. Coronary bypass using bilateral internal mammary arteries in an achondroplast.

    PubMed

    Alassal, Mohamed Abdulwahab; Youssef, Mostafa; Koudieh, Mohammed

    2015-01-01

    Coronary bypass grafting for ischemic heart disease in achondroplastic dwarfs is very rare. Shortage of veins and inadequate vein quality may cause difficulties during surgery. Only 2 cases of coronary bypass surgery in an achondroplastic dwarf, in which the left internal mammary artery and vein grafts were used, have been reported. We describe the case of a 55-year-old male achondroplastic dwarf who had triple-vessel coronary disease and underwent successful coronary bypass surgery using one saphenous vein graft and bilateral internal mammary artery grafts. The anatomic and surgical challenges in achondroplasia are highlighted. PMID:24887865

  15. Impact of cardiopulmonary bypass on acute kidney injury following coronary artery bypass grafting: a matched pair analysis

    PubMed Central

    2014-01-01

    Background Postoperative Acute Kidney Injury (AKI) after coronary artery bypass grafting (CABG) is a common complication associated with significant morbidity and mortality. Cardiopulmonary bypass (CPB) is accepted to contribute to the occurrence of AKI and is of particular importance as it can be avoided by using the off-pump technique. However the renoprotective properties of off-pump (CABG) are controversial. This analysis evaluates the impact of cardiopulmonary bypass on renal function. Methods A matched-pair analysis of 1428 patients undergoing coronary artery bypass grafting was conducted. The patients were stratified according to their preoperative renal function and to risk factors for postoperative AKI. The development of the glomerular filtration rate (GFR) from before surgery until hospital discharge was analyzed. Incidence of AKI were analyzed. Furthermore the impact of CPB duration on postoperative GFR was assessed. Results The occurrence of AKI increases the risk of thirty-day mortality (odds ratio of 4.3). The postoperative GFR decreases significantly after coronary artery bypass grafting but does not differ between onpump and offpump CABG (60.2 ± 24.5 vs 60.7 ± 24.8; p = 0.54). No difference regarding the incidence (26.6% vs 25%) and severity of AKI between cardiopulmonary bypass and the off-pump technique could be found. Duration of cardiopulmonary bypass does not correlate with the decline in postoperative glomerular filtration rate (Pearson Product Moment Correlation; p > 0.050). Conclusion Neither the mere use nor duration of cardiopulmonary bypass proofed to be a risk factor for developing postoperative AKI in CABG patients with a comparable preoperative risk profile for postoperative renal dysfunction. Furthermore, the severity of postoperative AKI is not affected by the use of cardiopulmonary bypass. PMID:24438155

  16. Hypothermia During Cardiopulmonary Bypass Increases Need for Inotropic Support but Does Not Impact Inflammation in Children Undergoing Surgical Ventricular Septal Defect Closure.

    PubMed

    Schmitt, Katharina Rose Luise; Fedarava, Katsiaryna; Justus, Georgia; Redlin, Mathias; Böttcher, Wolfgang; Delmo Walter, Eva Maria; Hetzer, Roland; Berger, Felix; Miera, Oliver

    2016-05-01

    Minimizing the systemic inflammatory response caused by cardiopulmonary bypass is a major concern. It has been suggested that the perfusion temperature affects the inflammatory response. The aim of this prospective study was to compare the effects of moderate hypothermia (32°C) and normothermia (36°C) during cardiopulmonary bypass on markers of the inflammatory response and clinical outcomes (time on ventilator) after surgical closure of ventricular septal defects. During surgical closure of ventricular septal defects under cardiopulmonary bypass, 20 children (median age 4.9 months, range 2.3-38 months; median weight 7.2 kg, range 5.2-11.7 kg) were randomized to a perfusion temperature of either 32°C (Group 1, n = 10) or 36°C (Group 2, n = 10). The clinical data and blood samples were collected before cardiopulmonary bypass, directly after aortic cross-clamp release, and 4 and 24 h after weaning from cardiopulmonary bypass. Time on ventilation as primary outcome did not differ between the two groups. Other clinical outcome parameters like fluid balance or length of stay in the intensive care were also similar in the two groups. Compared with Group 2, Group 1 needed significantly higher and longer inotropic support (P < 0.001). In Group 1, two infants had junctional ectopic tachycardia, and another had a pulmonary hypertensive crisis. Perfusion temperature did not influence cytokine release, organ injury, or coagulation. Cardiopulmonary bypass temperature does not influence time on ventilation or inflammatory marker release. However, in the present study, with a small patient cohort, patients operated under hypothermic bypass needed higher and longer inotropic support. The use of hypothermic cardiopulmonary bypass in infants and children should be approached with care. PMID:26581834

  17. What to Expect during Coronary Artery Bypass Grafting

    MedlinePlus

    ... support from an anesthesiologist, perfusionist (heart-lung bypass machine specialist), other surgeons, and nurses. There are several ... The tube will connect to a ventilator (a machine that supports breathing). The surgeon will make an ...

  18. Many Heart Bypass Patients Don't Take Needed Meds

    MedlinePlus

    ... need to continue appropriate prevention measures after successful heart surgery," said Savage, who is director of the Angioplasty ... More Health News on: Coronary Artery Bypass Surgery Heart Surgery Medicines Recent Health News Related MedlinePlus Health Topics ...

  19. [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. PMID:9590779

  20. 21 CFR 870.4320 - Cardiopulmonary bypass pulsatile flow generator.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    .... Class III (premarket approval). (c) Date PMA or notice of completion of PDP is required. A PMA or notice... May 28, 1976. Any other cardiopulmonary bypass pulsatile flow generator shall have an approved PMA...

  1. 21 CFR 870.4320 - Cardiopulmonary bypass pulsatile flow generator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    .... Class III (premarket approval). (c) Date PMA or notice of completion of PDP is required. A PMA or notice... May 28, 1976. Any other cardiopulmonary bypass pulsatile flow generator shall have an approved PMA...

  2. 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.

  3. Left Subclavian Artery Occlusion: Femoro-Axillary Artery Retrograde Bypass

    PubMed Central

    Nakashima, Masaya; Kobayashi, Hideaki; Kobayashi, Masayoshi

    2016-01-01

    The treatment tactics for subclavian artery occlusion include the more commonly used endovascular therapy rather than surgical intervention. We present a case of a 61-year-old woman with dialysis-dependent chronic renal failure who experienced left finger necrosis in the left upper extremity. To salvage the limb, we performed femoro-axillary (fem-ax) artery bypass using an autologous saphenous vein graft. However, 10 months later, she experienced coldness in the left forearm. Angiography revealed chronic total occlusion of the venous bypass. Despite emergent thrombectomy, redo fem-ax artery bypass operation was performed using a prosthetic graft. Upper limb salvage can be achieved by fem-ax artery retrograde bypass. PMID:27386454

  4. VIEW OF ONEONTA TUNNEL, CURRENT BYPASS ROAD IS ON THE ...

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

    VIEW OF ONEONTA TUNNEL, CURRENT BYPASS ROAD IS ON THE LEFT - Historic Columbia River Highway, Oneonta Tunnel, Adjacent to Historic Columbia River Highway through Oneonta Point, Troutdale, Multnomah County, OR

  5. 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

  6. 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.

  7. 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.

  8. 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

  9. 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

  10. Measurement of entropy generation within bypass transitional flow

    NASA Astrophysics Data System (ADS)

    Skifton, Richard; Budwig, Ralph; McEligot, Donald; Crepeau, John

    2013-11-01

    A flat plate made from quartz was submersed in the Idaho National Laboratory's Matched Index of Refraction flow facility. Particle Image Velocimetry and Particle Tracking Velocimetry were utilized to capture spatial vector maps at near wall locations within a transitional boundary layer. Entropy generation was then calculated directly from measured velocity vector fields using an integral approach. Two flows were studied: a Zero Pressure Gradient (ZPG) and an Adverse Pressure Gradient (APG), with β ~ -0.039. Near the leading edge of the plate, the free stream turbulence intensity (FSTI) to drive bypass transition was 7.5% and 4.25% for the ZPG and APG, respectively. Towards the downstream side of the plate, the FSTI was 2.5% and 3% for ZPG and APG, respectively. The integral approach for entropy generation rate, within the transitional region of flow, will be utilized as a design parameter to systematically reduce losses. As a second observation, the entropy generation can be shown to predict the onset of transitional flow. This research was funded by the DOE EPSCoR program No. DE-SC0004751, and by funding received from the DOE Office of Nuclear Energy's Nuclear Energy University Programs

  11. Surviving the sun: Repair and bypass of DNA UV lesions

    PubMed Central

    Yang, Wei

    2011-01-01

    Structural studies of UV-induced lesions and their complexes with repair proteins reveal an intrinsic flexibility of DNA at lesion sites. Reduced DNA rigidity stems primarily from the loss of base stacking, which may manifest as bending, unwinding, base unstacking, or flipping out. The intrinsic flexibility at UV lesions allows efficient initial lesion recognition within a pool of millions to billions of normal DNA base pairs. To bypass the damaged site by translesion synthesis, the specialized DNA polymerase η acts like a molecular “splint” and reinforces B-form DNA by numerous protein–phosphate interactions. Photolyases and glycosylases that specifically repair UV lesions interact directly with UV lesions in bent DNA via surface complementation. UvrA and UvrB, which recognize a variety of lesions in the bacterial nucleotide excision repair pathway, appear to exploit hysteresis exhibited by DNA lesions and conduct an ATP-dependent stress test to distort and separate DNA strands. Similar stress tests are likely conducted in eukaryotic nucleotide excision repair. PMID:21898645

  12. Immunocytochemical features of obstructed saphenous vein coronary artery bypass grafts.

    PubMed Central

    Brody, J I; Pickering, N J; Fink, G B

    1989-01-01

    The peroxidase-immunoperoxidase immunocytochemical method was used on 27 saphenous vein coronary artery bypass grafts, which had been resected because of recurrent angina, to identify in situ cellular and humoral elements possibly associated with graft occlusion. Immunostaining was performed on paraffin wax embedded control saphenous vein and graft sections incubated directly with primary antibodies against von Willebrand antigen (vWFAg), fibronectin, fibrinogen, leucocyte common antigen (LCA), lysozyme, vimentin, desmin, platelet factor 4, and thrombospondin. Antigens were visualised by a chromogen providing an orange-red immunoprecipitate at the site of epitope localisation. The intraluminal, amorphous exudate present in most grafts was not composed simply of fibrin or fibrinogen, as previously thought, but was a multiprotein complex including wWFAg, fibronectin, thrombospondin and platelet factor 4. Along with macrophages, these components probably enter the graft after haemodynamic, physical, and chemical injury to, and disruption of, the endothelial cell. Progressive myointimal proliferation and fibrosis of these grafts may be local repetitive responses to macrophages and platelets, cells previously known to participate in vascular disease. Images Fig 1 Fig 2 Fig 3 Fig 4 Fig 5 PMID:2659629

  13. Carburetor by-pass and fuel control system

    SciTech Connect

    Deboynton, W.L.

    1983-01-04

    A fuel-saving and emission reduction system for internal combustion engines includes electronic carburetor controlling circuitry and a carburetor by-pass system which stops fuel flow to the engine when power from combustion is not required. A normally open by-pass control butterfly valve in the fuel/air passage between the throttle valve and the engine intake manifold is operated by a motor, such as a solenoid or the like, under control of the controlling circuitry and is closed only upon release of the engine throttle and during the period that the vehicle has sufficient speed to assure restart upon reapplication of the fuel/air flow. A carburetor by-pass valve is held in a normally closed position by the combined effects of spring bias and the normal vacuum in the fuel/air passage. When the normally open by-pass control butterfly is closed, the fuel/air vacuum is reduced to permit the spring biased normally closed selfregulating carburetor by-pass valve to admit filtered air at a predetermined reduced vacuum to the engine manifold for continued operation of vacuum accessories and also for reducing the amount of oil drawn past combustion chamber seals and valve guides. Associated with the carburetor by-pass valve is a carburetor vent valve which is simultaneously opened to admit filtered air to the fuel/air passage between the throttle valve and the by-pass control butterfly to thereby eliminate all vacuum that will draw fuel from the carburetor. As a further feature, the electronic controlling circuitry operates to close the by-pass control butterfly for about one-half second upon the opening of the ignition switch to thereby eliminate self-ignition or dieseling and reduced hydrocarbon emissions.

  14. Electrical failure during cardiopulmonary bypass: a critical moment.

    PubMed

    Durukan, Ahmet Baris; Gurbuz, Hasan Alper; Ozcelik, Gokhan; Yorgancioglu, Cem

    2016-06-01

    Electrical failure during cardiopulmonary bypass is a crisis situation for the cardiac surgical team. Fortunately, it has a low incidence with low morbidity and mortality rates. Notwithstanding, institutional preventative and management measures should be taken. Here, we report a case of electrical failure during cardiopulmonary bypass, which was successfully managed during the surgery, allowing the patient to recover uneventfully. These unwanted complications can only be managed by promoting awareness and putting in place strategies against them. PMID:27516788

  15. Scintigraphic documentation of hemorrhage from coronary artery bypass graft

    SciTech Connect

    Orzel, J.A.; Baisden, C.E.

    1986-11-01

    Tc-99m labeled RBC imaging was used to conclusively demonstrate continuing intrathoracic hemorrhage from the anastomotic site of a coronary artery bypass graft. Demonstration of continuing hemorrhage and localization of the most likely site of bleeding resulted in timely and appropriate surgical intervention, which resulted in hemostasis and eventual patient recovery. Tc-99m RBC imaging may be an ideal noninvasive technique to investigate the site and activity of intrathoracic hemorrhage after coronary bypass surgery and other thoracic procedures.

  16. Electrical failure during cardiopulmonary bypass: a critical moment

    PubMed Central

    Gurbuz, Hasan Alper; Ozcelik, Gokhan; Yorgancioglu, Cem

    2016-01-01

    Electrical failure during cardiopulmonary bypass is a crisis situation for the cardiac surgical team. Fortunately, it has a low incidence with low morbidity and mortality rates. Notwithstanding, institutional preventative and management measures should be taken. Here, we report a case of electrical failure during cardiopulmonary bypass, which was successfully managed during the surgery, allowing the patient to recover uneventfully. These unwanted complications can only be managed by promoting awareness and putting in place strategies against them. PMID:27516788

  17. Bypass flow computations on the LOFA transient in a VHTR

    SciTech Connect

    Tung, Yu-Hsin; Johnson, Richard W.; Ferng, Yuh-Ming; Chieng, Ching-Chang

    2014-01-01

    Bypass flow in the prismatic gas-cooled very high temperature reactor (VHTR) is not intentionally designed to occur, but is present in the gaps between graphite blocks. Previous studies of the bypass flow in the core indicated that the cooling provided by flow in the bypass gaps had a significant effect on temperature and flow distributions for normal operating conditions. However, the flow and heat transports in the core are changed significantly after a Loss of Flow Accident (LOFA). This study aims to study the effect and role of the bypass flow after a LOFA in terms of the temperature and flow distributions and for the heat transport out of the core by natural convection of the coolant for a 1/12 symmetric section of the active core which is composed of images and mirror images of two sub-region models. The two sub-region models, 9 x 1/12 and 15 x 1/12 symmetric sectors of the active core, are employed as the CFD flow models using computational grid systems of 70.2 million and 117 million nodes, respectively. It is concluded that the effect of bypass flow is significant for the initial conditions and the beginning of LOFA, but the bypass flow has little effect after a long period of time in the transient computation of natural circulation.

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

    DOEpatents

    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.

  19. Ultra-High Bypass Ratio Jet Noise

    NASA Technical Reports Server (NTRS)

    Low, John K. C.

    1994-01-01

    The jet noise from a 1/15 scale model of a Pratt and Whitney Advanced Ducted Propulsor (ADP) was measured in the United Technology Research Center anechoic research tunnel (ART) under a range of operating conditions. Conditions were chosen to match engine operating conditions. Data were obtained at static conditions and at wind tunnel Mach numbers of 0.2, 0.27, and 0.35 to simulate inflight effects on jet noise. Due to a temperature dependence of the secondary nozzle area, the model nozzle secondary to primary area ratio varied from 7.12 at 100 percent thrust to 7.39 at 30 percent thrust. The bypass ratio varied from 10.2 to 11.8 respectively. Comparison of the data with predictions using the current Society of Automotive Engineers (SAE) Jet Noise Prediction Method showed that the current prediction method overpredicted the ADP jet noise by 6 decibels. The data suggest that a simple method of subtracting 6 decibels from the SAE Coaxial Jet Noise Prediction for the merged and secondary flow source components would result in good agreement between predicted and measured levels. The simulated jet noise flight effects with wind tunnel Mach numbers up to 0.35 produced jet noise inflight noise reductions up to 12 decibels. The reductions in jet noise levels were across the entire jet noise spectra, suggesting that the inflight effects affected all source noise components.

  20. Post-gastric bypass hypoglycaemia: a review.

    PubMed

    Shantavasinkul, Prapimporn C; Torquati, Alfonso; Corsino, Leonor

    2016-07-01

    Bariatric surgery is a highly effective treatment for severe obesity, resulting in substantial weight loss and normalizing obesity-related comorbidities. However, long-term consequences can occur, such as postbariatric surgery hypoglycaemia. This is a challenging medical problem, and the number of patients presenting with it has been increasing. Roux-en-Y gastric bypass (RYGB) is the most popular bariatric procedure, and it is the surgery most commonly associated with the development of postbariatric surgery hypoglycaemia. To date, the pathogenesis of this condition has not been completely established. However, various factors - particularly increased postprandial glucagon-like peptide (GLP)-1 secretion - have been considered as crucial mediator. The mechanisms responsible for diabetic remission after bariatric surgery may be responsible for the development of hypoglycaemia, which typically occurs 1-3 h after a meal and is concurrent with inappropriate hyperinsulinaemia. Carbohydrate-rich foods usually provoke hypoglycaemic symptoms, which can typically be alleviated by strict dietary modifications, including carbohydrate restriction and avoidance of high glycaemic index foods and simple sugars. Few patients require further medical intervention, such as medications, but some patients have required a pancreatectomy. Because this option is not always successful, it is no longer routinely recommended. Clinical trials are needed to further determine the pathophysiology of this condition as well as the best diagnostic and treatment approaches for these patients. PMID:26840207

  1. Variations of Weight Loss Following Gastric Bypass and Gastric Band

    PubMed Central

    Puzziferri, Nancy; Nakonezny, Paul A.; Livingston, Edward H.; Carmody, Thomas J.; Provost, David A.; Rush, A. John

    2016-01-01

    Objective To compare and describe the weight loss outcomes from gastric bypass and gastric band so as to define the variation of excess weight loss (EWL) among individual patients, the time to onset of effect, and the durability of weight loss in severely obese adults. Summary Background Data Gastric bypass and gastric band are the most common operations for obesity performed in the United States, but few reports have compared these 2 procedures. Methods Patients (N = 1733, aged 18–65 years) met National Institutes of Health criteria for obesity surgery and underwent either gastric bypass or gastric band between March 1997 and November 2006. The selection of bypass versus band was based on patient/surgeon discussion. The evaluable sample consisted of 1518 patients. The percentage of EWL was assessed over 2 years. Successful weight loss was defined a priori as ≥40% EWL in each of four 6-month postoperative measurement periods. The analyses included a mixed model and generalized estimating equation (GEE) model with repeated measures. Odds ratios and descriptive analyses were also provided. Results Gastric bypass was associated with less individual variation in weight loss than gastric band. Both procedures were associated with a significant EWL benefit (Treatment Group effect P < 0.0001), but they differed in terms of time to effect (Treatment Group × Period interaction effect P < 0.0001). The mean EWL for gastric bypass was greater at each measurement period (6, 12, 18, 24 months) compared with gastric band (P < 0.0001). Furthermore, at each of the postoperative measurement periods within each treatment group (bypass and band), the mean EWL was greater for those who had preoperative body mass index (BMI) ≤50 kg/m2 than for those who had preoperative BMI >50 kg/m2 (P < 0.0001). Gastric bypass was consistently associated with a greater likelihood of at least a 40% EWL in each of the 6-month postoperative measurement periods (GEE, P < 0.0001). The odds ratio

  2. By-pass pigs for two-phase flow pipelines

    SciTech Connect

    Wu, H.L.; Spronsen, G. van; Klaus, E.H.; Stewart, D.M.

    1996-12-31

    Pigging two-phase pipelines normally leads to the generation of large liquid slug volumes in front of the pig requiring excessively large separators or slug catchers. The concept of using a high by-pass pig to disperse the liquid and reduce the maximum liquid production rate prior to pig arrival is under investigation by Shell Exploration and Production companies. A simulation model of the dynamics of the pig and related two-phase flow behavior in the pipeline was used to predict the performance of by-pass pigs. Field trials in a dry gas pipeline were carried out to provide friction data and to validate the model. It was then used to explore operating possibilities in a two-phase lie which led to the follow-up trial in a 15.6 km, 20 inch OD two-phase offshore interfield pipeline with risers. Whereas the volume of liquid swept in front of the pig would be 179 m{sup 3} if the by-pass fraction were zero, a reduction of 70% to 53m{sup 3} was achieved in the field with a by-pass fraction of 10%. The predicted mobility of the high by-pass pig in the pipeline and risers was verified and the beneficial effects due to the by-pass concept exceeded the prediction of the simplified model. The significant gains of using a by-pass pig in modifying gas and liquid production rates during pigging operation have been demonstrated. The method can widen the possibility of applying two-phase flow pipeline transportation to cases where separator or slug catcher capacity are limited for reasons of practicality or cost.

  3. The quorum sensing negative regulators EsaR and ExpR(Ecc), homologues within the LuxR family, retain the ability to function as activators of transcription.

    PubMed

    von Bodman, Susanne B; Ball, Jessica K; Faini, Marie A; Herrera, Carmen M; Minogue, Timothy D; Urbanowski, Mark L; Stevens, Ann M

    2003-12-01

    Most LuxR homologues function as activators of transcription during the process of quorum sensing, but a few, including EsaR and ExpR(Ecc), negatively impact gene expression. The LuxR-activated luxI promoter and LuxR binding site, the lux box, were used in artificial contexts to assess the potential for transcriptional activation and DNA binding by EsaR and ExpR(Ecc). Although the acyl-homoserine lactone responsiveness of both proteins is the opposite of that shown by most LuxR family members, EsaR and ExpR(Ecc) have preserved the ability to interact with RNA polymerase and activate transcription despite their low affinity for the lux box DNA. PMID:14617666

  4. 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).

  5. Hypogammaglobulinemia After Cardiopulmonary Bypass in Infants

    PubMed Central

    Rhodes, Leslie A; Robert, Stephen M; Atkinson, T. Prescott; Dabal, Robert J; Mahdi, Alla M.; Alten, Jeffrey A

    2014-01-01

    Background Hypogammaglobulinemia has been reported after cardiac surgery and may be associated with adverse outcomes. We sought to define baseline immunoglobulin (Ig) concentration in neonates and infants with congenital heart disease, determine its course following cardiopulmonary bypass (CPB), and determine if post-CPB hypogammaglobulinemia was associated with increased morbidity. Methods Single center, retrospective analysis of infants who underwent cardiac surgery with CPB between June 2010 and December 2011. Ig concentration obtained from banked plasma of 47 patients from a prior study (pre-CPB, immediately post-CPB, and 24- and 48-hours post-CPB). Additionally, any Ig levels drawn for clinical purposes after CPB were included. Ig levels were excluded if drawn after chylothorax diagnosis or intravenous immunoglobulin G administration. Results Median age was 7 days. Preoperative Ig concentration was similar to that described in healthy children. IgG level fell to less than 50% of preoperative concentration by 24-hr post-CPB and failed to recover by 7 days. 25/47 (53%) patients had low IgG after CPB (<248 mg/dl). Despite no difference in demographics or risk factors between patients with low and normal IgG, low IgG patients had more positive fluid balance at 24-hours, increased pro-inflammatory plasma cytokine levels, duration of mechanical ventilation, and CICU length of stay. Additionally, low IgG patients had increased incidence of post-operative infections (40% vs. 14%, p=0.056). Conclusions Hypogammaglobulinemia occurs in half of infants after CPB. Its association with fluid overload and increased inflammatory cytokines suggests it may result from capillary leak. Postoperative hypogammaglobulinemia is associated with increased morbidity, including more secondary infections. PMID:24035378

  6. A Snapshot of Coagulopathy After Cardiopulmonary Bypass.

    PubMed

    Höfer, Judith; Fries, Dietmar; Solomon, Cristina; Velik-Salchner, Corinna; Ausserer, Julia

    2016-09-01

    Cardiac surgery involving cardiopulmonary bypass (CPB) is often associated with important blood loss, allogeneic blood product usage, morbidity, and mortality. Coagulopathy during CPB is complex, and the current lack of uniformity for triggers and hemostatic agents has led to a wide variability in bleeding treatment. The aim of this review is to provide a simplified picture of the data available on patients' coagulation status at the end of CPB in order to provide relevant information for the development of tailored transfusion algorithms. A nonsystematic literature review was carried out to identify changes in coagulation parameters during CPB. Both prothrombin time and activated partial thromboplastin time increased during CPB, by a median of 33.3% and 17.9%, respectively. However, there was marked variability across the published studies, indicating these tests may be unreliable for guiding hemostatic therapy. Some thrombin generation (TG) parameters were affected, as indicated by a median increase in TG lag time of 55.0%, a decrease in TG peak of 17.5%, and only a slight decrease in endogenous thrombin potential of 7%. The most affected parameters were fibrinogen levels and platelet count/function. Both plasma fibrinogen concentration and FIBTEM maximum clot firmness decreased during CPB (median change of 36.4% and 33.3%, respectively) as did platelet count (44.5%) and platelet component (34.2%). This review provides initial information regarding changes in coagulation parameters during CPB but highlights the variability in the reported results. Further studies are warranted to guide physicians on the parameters most appropriate to guide hemostatic therapy. PMID:27268940

  7. A numerical analysis of the aortic blood flow pattern during pulsed cardiopulmonary bypass.

    PubMed

    Gramigna, V; Caruso, M V; Rossi, M; Serraino, G F; Renzulli, A; Fragomeni, G

    2015-01-01

    In the modern era, stroke remains a main cause of morbidity after cardiac surgery despite continuing improvements in the cardiopulmonary bypass (CPB) techniques. The aim of the current work was to numerically investigate the blood flow in aorta and epiaortic vessels during standard and pulsed CPB, obtained with the intra-aortic balloon pump (IABP). A multi-scale model, realized coupling a 3D computational fluid dynamics study with a 0D model, was developed and validated with in vivo data. The presence of IABP improved the flow pattern directed towards the epiaortic vessels with a mean flow increase of 6.3% and reduced flow vorticity. PMID:24962383

  8. Vascularized lymph node transfer and lymphovenous bypass: Novel treatment strategies for symptomatic lymphedema.

    PubMed

    Silva, Amanda K; Chang, David W

    2016-06-01

    Lymphedema is a debilitating disease that is commonly caused by cancer and it is treatments in the developed world. Surgery is an option for refractory disease. Lymphovenous bypass and vascularized lymph node transfer are newer modalities that show great promise. Further work is necessary to determine proper patient selection and ensure minimum donor site morbidity. Liposuction and direct excision still have a role, especially in advanced cases. Further investigations into prevention of iatrogenic lymphedema are underway. J. Surg. Oncol. 2016;113:932-939. © 2016 Wiley Periodicals, Inc. PMID:26846735

  9. Minimally invasive coronary artery bypass grafting: initial Connecticut experience.

    PubMed

    Tellides, G; Maragh, M R; Smith, J M; Kopf, G S; Ezekowitz, M; Remetz, M; Elefteriades, J A

    1997-03-01

    We report the initial Connecticut experience with minimally invasive coronary artery bypass grafting. This procedure allows bypass grafting to the left anterior descending coronary artery utilizing the internal mammary artery as the conduit. The procedure is minimally invasive because it is performed through a mini-thoracotomy incision in the fourth anterior intercostal space and it is conducted without the use of cardiopulmonary bypass. The procedure has been applied to 13 patients operated between February and October 1996. All but one patient selected were poor candidates for conventional coronary artery bypass surgery because of advanced age (6), chronic renal failure/dialysis/kidney transplant (4), redo status with vulnerable grafts (1), severe peripheral vascular disease (6), severe chronic obstructive pulmonary disease (4). All patients survived operation and were discharged in good condition. Mean postoperative intubation time was seven hours and mean hospital stay was 4.5 days despite the very high pre-existing comorbidity of these patients. All patients are alive at the current follow-up time. Two patients required a conventional bypass procedure for occlusion of the minimally invasive graft, the first because of diffuse disease in the target artery and the second attributable to the technical limitations of minimally invasive coronary artery bypass grafting; both tolerated the subsequent procedure well. All patients are now angina-free. All four grafts studied by routine postoperative angiography were widely patent. Routine post-operative exercise nuclear imaging was normal in an additional patient. This procedure of minimally invasive coronary artery bypass grafting offers significant advantages compared to the conventional bypass procedure (short hospital stay, quick recovery, and, especially, avoidance of cerebrovascular accidents caused by the heart-lung machine). This minimally invasive procedure is expected to apply to a growing percentage of

  10. Entry overload, emergency department overcrowding, and ambulance bypass

    PubMed Central

    Fatovich, D; Hirsch, R

    2003-01-01

    Objectives: To describe an experience of emergency department (ED) overcrowding and ambulance bypass. Methods: A prospective observational study at Royal Perth Hospital, a major teaching hospital. Episodes of ambulance bypass and their characteristics were recorded. Results: From 1 July 1999 to 30 June 2001, there were 141 episodes of ambulance bypass (mean duration 187 min, range 35–995). Monday was the most common day with 39 (28%) episodes. Entry block alone was the most common reason bypass was activated (n=38, 30.4%). The mean number of patients in ED at these times was 40 (occupancy 174%), including nine in the corridor, seven awaiting admission, and 14 waiting to be seen. Episodes attributable to entry block were typically preceded by a presentation rate of ⩾10 patients per hour for ⩾2 hours (OR 6.2, 95% CI 4.3 to 8.5). Mid-afternoon to early evening was the most common time for activation. Ambulance bypass is increasing in frequency and duration. Conclusions: Entry overload resulting in entry block results from overwhelming numbers of patients presenting to the ED in a short space of time. Entry block impairs access to emergency care. Unless something is done in the near future, the general public may no longer be able to rely on EDs for quality and timely emergency care. A "whole of system" approach is necessary to tackle the problem. PMID:12954675

  11. Emergency conversion in off-pump coronary artery bypass grafting.

    PubMed

    Tabata, Minoru; Takanashi, Shuichiro; Horai, Tetsuya; Fukui, Toshihiro; Hosoda, Yasuyuki

    2006-10-01

    Emergency conversion to cardiopulmonary bypass in off-pump coronary artery bypass grafting is recognized to increase operative mortality and morbidity. We conducted a retrospective review of 616 consecutive patients who were planned for off-pump coronary artery bypass grafting from April 2001 to July 2004. Fourteen patients (2.3%) required emergency conversion to cardiopulmonary bypass. Operative mortality was 13.3% in the conversion group and 1.2% in the non-conversion group (P<0.001). The incidence of reoperation for bleeding was 7.1% and 1.0%, respectively (P=0.032) and that of respiratory failure was 35.7% and 3.3%, respectively (P<0.001). Multivariable analysis showed that mitral regurgitation and chronic obstructive pulmonary disease were predictors of emergency conversion with all causes except for bleeding, and that mitral regurgitation and no use of a heart positioning device were predictors of emergency conversion due to hemodynamic compromise during distal anastomosis of the circumflex artery territory. In conclusion, emergency conversion in off-pump coronary artery bypass grafting increases operative mortality and morbidity. Mitral regurgitation and chronic obstructive pulmonary disease are risk factors for emergency conversion. Use of a heart positioning device decreases hemodynamic compromise during anastomosis of the circumflex artery territory. PMID:17670644

  12. Photovoltaic-module bypass-diode encapsulation. Annual report

    SciTech Connect

    Not Available

    1983-06-20

    The design and processing techniques necessary to incorporate bypass diodes within the module encapsulant are presented in this annual report. A comprehensive survey of available pad-mounted PN junction and Schottky diodes led to the selection of Semicon PN junction diode cells for this application. 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/sup 0/C per watt, but show some instability when thermally cycled over the temperature range from -40 to 150/sup 0/C. Based on the results of a detailed thermal analysis, which covered the range of bypass currents from 2 to 20 amperes, three representative experimental modules, each incorporating integral bypass diode/heat spreader assemblies of various sizes, were designed and fabricated. Thermal testing of these modules has enabled the formation 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. An assessment of bypass diode reliability, which relies heavily on rectifying diode failure rate data, leads to the general conclusion that, when proper designed and installed, these devices will improve the overall reliability of a terrestrial array over a 20 year design lifetime.

  13. A remote augmentor lift system with a turbine bypass engine

    NASA Technical Reports Server (NTRS)

    Fishbach, L. H.; Franciscus, L. C.

    1982-01-01

    Two supersonic vertical takeoff or landing (VTOL) aircraft engine types, a conventional medium bypass ratio turbofan, and a turbine bypass turbojet were studied. The aircraft assumed was a clipped delta wing with canard configuration. A VTOL deck launched intercept, DLI, mission with Mach 1.6 dash and cruise segments was used as the design mission. Several alternate missions requiring extended subsonic capabilities were analyzed. Comparisons were made between the turbofan (TF) and the turbine bypass turbojet (TBE) engines in airplane types using a Remote Augmented Lift Systems, RALS and a Lift plus Lift Cruise system (L+LC). The figure of merit was takeoff gross weight for the VTOL DLI mission. The results of the study show that the turbine bypass turbojet and the conventional turbofan are competitive engines for both type of aircraft in terms of takeoff gross weight and range. However, the turbine bypass turbojet would be a simpler engine and may result in more attractive life cycle costs and reduced maintenance. The RALS and L+LC airplane types with either TBE or TF engines have approximately the same aircraft takeoff gross weight.

  14. 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. PMID:27622560

  15. Robotically assisted totally endoscopic coronary artery bypass surgery

    PubMed Central

    Canale, Leonardo Secchin; Mick, Stephanie; Mihaljevic, Tomislav; Nair, Ravi

    2013-01-01

    Robotically assisted totally endoscopic coronary artery bypass surgery has emerged as a feasible and efficient alternative to conventional full sternotomy coronary artery bypass graft surgery in selected patients. This minimally invasive approach using the daVinci robotic system allows fine intrathoracic maneuvers and excellent view of the coronary arteries. Both on-pump and off-pump operations can be performed to treat single and multivessel disease. Hybrid approaches have the potential of offering complete revascularization with the “best of both worlds” from surgery (internal mammary artery anastomosis in less invasive fashion) and percutaneous coronary intervention (least invasive approach). In this article we review the indications, techniques, short and long term results, as well as current developments in totally endoscopic robotic coronary artery bypass operations. PMID:24251021

  16. 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.

  17. Proposal of bypass in heat recovery system with sucking air

    NASA Astrophysics Data System (ADS)

    Siažik, Ján; Malcho, Milan; Rezničák, Štefan

    2016-06-01

    Waste heat is utilized in a wide variety of technologies for a number of reasons. But the significant one such reason is use of the energy contained for example in waste water or waste heat that would otherwise left unused. Other considerable reason it is also reduces primary costs to operate the technology. The article deals with the arrangement section of the unit in heat recovery systems where the entry of waste gases into defluorinastion device. The technologies re-use heat often use the bypass. Bypass fulfill their duty in equipment failures, for example heat exchanger where it is not possible to stop the operationimmediately and the hot combustion gases can flow bypass without interrupting operation.

  18. Refractory Vascular Spasm Associated with Coronary Bypass Grafting

    PubMed Central

    Kim, Young Sam; Yoon, Yong Han; Kim, Jeoung Taek; Shinn, Helen Ki; Woo, Seong Ill; Baek, Wan Ki

    2014-01-01

    Diffuse refractory vascular spasms associated with coronary bypass artery grafting (CABG) are rare but devastating. A 42-year-old male patient with a past history of stent insertion was referred for the surgical treatment of a recurrent left main coronary artery disease. A hemodynamic derangement developed during graft harvesting, necessitating a hurried initiation of cardiopulmonary bypass (CPB). Although CABG was carried out as planned, the patient could not be weaned from the bypass. An emergency coronary angiography demonstrated a diffuse spasm of both native coronary arteries and grafts. CPB was switched to the femorofemoral extracorporeal membrane oxygenator (ECMO). Although he managed to recover from heart failure, his discharge was delayed due to the ischemic injury of the lower limb secondary to cannulation for ECMO. We reviewed the case and literature, placing emphasis on the predisposing factors and appropriate management. PMID:25346903

  19. Smokers' rights to coronary artery bypass graft surgery.

    PubMed

    Heath, Janie; Braun, Mary Ann; Brindle, Margaret

    2002-06-01

    Imagine a health maintenance organization creating a policy to deny all smokers access to nonemergent coronary artery bypass graft surgery. The cost savings to the organization and society would be potentially significant. Now envision the smoker, a hardworking father with daily angina, and the provider, writing costly prescriptions to manage the angina. What ethical and legal questions do you suppose would present in that setting? Now imagine how you would respond if given this scenario of denying smokers access to nonemergent coronary artery bypass graft. This article discusses the implications of resource allocation with self-inflicted health behaviors such as smoking. Tough questions are raised that explore both the pros and the cons of smokers' rights to coronary artery bypass graft. PMID:12042677

  20. Coronary artery bypass grafting in cold-induced urticaria.

    PubMed

    Bakay, Cihat; Onan, Burak; Onan, Ismihan Selen; Ozkara, Ahmet

    2010-03-01

    Cold-induced urticaria is an unusual systemic disorder that develops in response to exposures to cold temperatures in susceptible individuals. Patients with cold urticaria are potentially at risk of severe systemic anaphylactic shock-like reactions. This disorder is of unique clinical importance in cardiac surgery, considering the use of cardiopulmonary bypass and hypothermia. Contact of blood with hypothermia and subsequent warming can be associated with hemodynamic instability, hypotension, and cardiovascular collapse, mainly during the period of rewarming. We report the case of a 41-year-old woman with chronic cold-induced urticaria, who underwent a successful coronary bypass grafting, and describe perioperative management of this rare disorder. PMID:20172161

  1. Exercise thallium-201 scintigraphy in evaluating aortocoronary bypass surgery

    SciTech Connect

    Iskandrian, A.S.; Haaz, W.; Segal, B.L.; Kane, S.A.

    1981-07-01

    Thirty patients with recurrent symptoms after aortocoronary bypass graft surgery underwent angiography as well as exercise thallium 201 imaging. Exercise imaging has been shown to be highly specific (100 percent in our study) in evaluating patients after bypass surgery. Patients with complete revascularization have normal thallium 201 images. Similarly, exercise-induced defects are seen only in the presence of incomplete revascularization. There are patients, however, with incomplete revascularization with normal exercise images, but these generally limited to the right coronary artery or the diagonal vessels or their grafts.

  2. Divertor bypass in the Alcator C-Mod tokamak

    NASA Astrophysics Data System (ADS)

    Pitcher, C. S.; LaBombard, B.; Danforth, R.; Pina, W.; Silveira, M.; Parkin, B.

    2001-01-01

    The Alcator C-Mod divertor bypass has for the first time allowed in situ variations to the mechanical baffle design in a tokamak. The design utilizes small coils which interact with the ambient magnetic field inside the vessel to provide the torque required to control small flaps of a Venetian blind geometry. Plasma physics experiments with the bypass have revealed the importance of the divertor baffling to maintain high divertor gas pressures. These experiments have also indicated that the divertor baffling has only a limited effect on the main chamber pressure in C-Mod.

  3. Cerebral blood flow and autoregulation during hypothermic cardiopulmonary bypass

    SciTech Connect

    Johnsson, P.; Messeter, K.; Ryding, E.; Nordstroem, L.S.; Stahl, E.

    1987-04-01

    Mean hemispheric cerebral blood flow (CBF) was studied following intravenous or intraarterial administration of xenon-133, in 10 men admitted for coronary artery bypass grafting. Repeated CBF measurements were performed to evaluate autoregulation before, during, and after cardiopulmonary bypass (CPB). During CPB mean CBF remained unchanged compared with the pre-CPB level, without evidence of cerebral hyperemia or impairment of autoregulation. A marked increase in CBF occurred after CPB and was followed by a time-dependent reduction toward the pre-CPB level. The data support the alpha-stat regulation theory but cannot explain the cerebral vasodilation observed after CPB.

  4. Off-pump coronary artery bypass grafting in patients with mirror-imaging dextrocardia.

    PubMed

    Yuan, Xin; Sun, Hansong; Wang, Xianqiang

    2015-08-01

    Dextrocardia requires alterations in techniques during coronary artery bypass graft (CABG) surgery. We report two cases undergoing off-pump coronary artery bypass graft (OPCAB) surgery and discuss techniques for the operative management of these patients. PMID:26059016

  5. Anesthetic vaporizer mount malfunction resulting in oxygenation failure after initiating cardiopulmonary bypass: specific recommendations for the pre-bypass checklist.

    PubMed

    Gautam, Nischal K; Schmitz, Michael L; Zabala, Luis M; White, Michael W; Mckamie, Wesley A; Lutz, Alyssa; Johnson, Charles E

    2009-09-01

    Modern technologic advances in medicine have allowed commonly used machines to perform safely with very low risk and a high degree of success. To detect or prevent potential malfunctions, professionals routinely perform pre-use checks for equipment such as anesthesia machines and cardiopulmonary bypass (CPB) machines. These machine checklists are not only critical for a safe operation but also have large impacts on outcomes. For example, when malfunctions are encountered that could have potential negative ramifications or adverse outcomes, multi-approach strategies should be used to identify rectifiable causes and find solutions that are practical. This information can be used to promulgate safe practice guidelines. This case report identifies a machine-based contributing factor to precipitous hypoxia on initiation of bypass in one of our patients. After a detailed approach to identify preventable root causes, we made simple additions to our pre-bypass checklist and recommend these changes to other institutions. PMID:19806803

  6. 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

  7. Internal Maxillary Artery-Middle Cerebral Artery Bypass: Infratemporal Approach for Subcranial-Intracranial (SC-IC) Bypass

    PubMed Central

    Nossek, Erez; Costantino, Peter D.; Eisenberg, Mark; Dehdashti, Amir R.; Setton, Avi; Chalif, David J.; Ortiz, Rafael A.

    2014-01-01

    BACKGROUND: Internal maxillary artery (IMax)–middle cerebral artery (MCA) bypass has been recently described as an alternative to cervical extracranial-intracranial bypass. This technique uses a “keyhole” craniectomy in the temporal fossa that requires a technically challenging end-to-side anastomosis. OBJECTIVE: To describe a lateral subtemporal craniectomy of the middle cranial fossa floor to facilitate wide exposure of the IMax to facilitate bypass. METHODS: Orbitozygomatic osteotomy is used followed by frontotemporal craniotomy and subsequently laterotemporal fossa craniectomy, reaching its medial border at a virtual line connecting the foramen rotundum and foramen ovale. The IMax was identified by using established anatomic landmarks, neuronavigation, and micro Doppler probe (Mizuho Inc. Tokyo, Japan). Additionally, we studied the approach in a cadaveric specimen in preparation for microsurgical bypass. RESULTS: There were 4 cases in which the technique was used. One bypass was performed for flow augmentation in a hypoperfused hemisphere. The other 3 were performed as part of treatment paradigms for giant middle cerebral artery aneurysms. Vein grafts were used in all patients. The proximal anastomosis was performed in an end-to-side fashion in 1 patient and end-to-end in 3 patients. Intraoperative graft flow measured with the Transonic flow probe ranged from 20 to 60 mL/min. Postoperative angiography demonstrated good filling of the graft with robust distal flow in all cases. All patients tolerated the procedure well. CONCLUSION: IMax to middle cerebral artery subcranial-intracranial bypass is safe and efficacious. The laterotemporal fossa craniectomy technique resulted in reliable identification and wide exposure of the IMax, facilitating the proximal anastomosis. ABBREVIATIONS: EC-IC, extracranial-intracranial IMax, internal maxillary artery MCA, middle cerebral artery SC-IC, subcranial-intracranial STA, superficial temporal artery PMID:24618804

  8. Retinal Blood Vessel Distribution Correlates With the Peripapillary Retinal Nerve Fiber Layer Thickness Profile as Measured With GDx VCC and ECC

    PubMed Central

    Resch, Hemma; Pereira, Ivania; Weber, Stephanie; Holzer, Stephan; Fischer, Georg

    2015-01-01

    Purpose: Aim of the present study was to evaluate whether there is a correlation between retinal blood vessel density (RVD) and the peripapillary retinal nerve fiber layer (RNFL) thickness profile. Methods: RNFL thickness of 106 healthy subjects was measured using scanning laser polarimetry, GDx variable corneal compensation (VCC), and GDx enhanced corneal compensation (ECC). A proprietary software was developed in MATLAB to measure the peripapillary retinal vessels using scanning laser ophthalmoscopy fundus images, centered on the optic disc measured by Cirrus spectral domain optical coherence tomography. The individual retinal vessel positions and thickness values were integrated in a 64-sector RVD profile and intrasubject and intersubject correlations were calculated. Results: The mean R value±SD for intrasubject correlation between RVD and RNFL thickness measured with GDx VCC and GDx ECC was 0.714±0.157 and 0.629±0.140, with 105 of 106 subjects presenting significant correlations. In the intersubject linear regression analysis for GDx VCC, 33 of 64 (52%) sectors presented a significant Pearson correlation coefficient between RNFL thickness and RVD values, with a mean R value of 0.187±0.135 (P<0.05). Conclusions: Peripapillary RNFL thickness profiles correlate with the RVD over 50% of the sectors and might explain up to 26% of the interindividual variance of the peripapillary RNFL thickness values as measured with GDx VCC. To our opinion, taking into account RVD might reduce interindividual variation in peripapillary RNFL thickness profiles measured with scanning laser polarimetry. PMID:25719231

  9. Idiopathic hypertrophic subaortic stenosis and coronary atherosclerosis. Results of coronary artery bypass alone and myectomy combined with coronary artery bypass.

    PubMed

    Gill, C C; Duda, A M; Kitazume, H; Kramer, J R; Loop, F D

    1982-12-01

    Twenty-one patients with combined coronary artery disease and idiopathic hypertrophic subaortic stenosis (IHSS) have had coronary artery bypass grafting alone (Group I, n = 7) or in combination with left ventricular septal myectomy (Group II, n = 14). Patients ranged in age from 46 to 73 years (mean 59 years). There were no operative deaths, but one Group I patient died 16 months after operation. Patients in Group I have had continuing symptoms after the operation, whereas Group II patients have had consistent relief of symptoms. Patients with documented IHSS and coronary atherosclerosis should undergo combined coronary bypass and septal myectomy if symptoms recur with medical management. PMID:6983006

  10. 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...

  11. 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...

  12. 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...

  13. 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...

  14. 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...

  15. 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...

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. 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...

  5. 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...

  6. 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...

  7. 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...

  8. 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...

  9. 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...

  10. 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...

  11. 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...

  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, 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...

  14. 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...

  15. 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...

  16. 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...

  17. 21 CFR 870.4340 - Cardiopulmonary bypass level sensing monitor and/or control.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Cardiopulmonary bypass level sensing monitor and... Devices § 870.4340 Cardiopulmonary bypass level sensing monitor and/or control. (a) Identification. A cardiopulmonary bypass level sensing monitor and/or control is a device used to monitor and/or control the...

  18. 21 CFR 870.4340 - Cardiopulmonary bypass level sensing monitor and/or control.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass level sensing monitor and... Devices § 870.4340 Cardiopulmonary bypass level sensing monitor and/or control. (a) Identification. A cardiopulmonary bypass level sensing monitor and/or control is a device used to monitor and/or control the...

  19. 21 CFR 870.4340 - Cardiopulmonary bypass level sensing monitor and/or control.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Cardiopulmonary bypass level sensing monitor and... Devices § 870.4340 Cardiopulmonary bypass level sensing monitor and/or control. (a) Identification. A cardiopulmonary bypass level sensing monitor and/or control is a device used to monitor and/or control the...

  20. 21 CFR 870.4340 - Cardiopulmonary bypass level sensing monitor and/or control.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Cardiopulmonary bypass level sensing monitor and... Devices § 870.4340 Cardiopulmonary bypass level sensing monitor and/or control. (a) Identification. A cardiopulmonary bypass level sensing monitor and/or control is a device used to monitor and/or control the...

  1. 21 CFR 870.4340 - Cardiopulmonary bypass level sensing monitor and/or control.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Cardiopulmonary bypass level sensing monitor and... Devices § 870.4340 Cardiopulmonary bypass level sensing monitor and/or control. (a) Identification. A cardiopulmonary bypass level sensing monitor and/or control is a device used to monitor and/or control the...

  2. 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...

  3. 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...

  4. 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...

  5. Patient Bypass Behavior and Critical Access Hospitals: Implications for Patient Retention

    ERIC Educational Resources Information Center

    Liu, Jiexin (Jason); Bellamy, Gail R.; McCormick, Melissa

    2007-01-01

    Purpose: To assess the extent of bypass for inpatient care among patients living in Critical Access Hospital (CAH) service areas, and to determine factors associated with bypass, the reasons for bypass, and what CAHs can do to retain patients locally. Methods: Six hundred and forty-seven subjects, aged 18 years and older, who had been admitted to…

  6. 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.

  7. Bypass control valve seal and bearing life cycle test report

    NASA Technical Reports Server (NTRS)

    Lundback, A. V.

    1972-01-01

    The operating characteristics of a bypass control valve seal and bearing life cycle tests are reported. Data from the initial assembly, leak, torque, and deflection tests are included along with the cycle life test results and conclusions. The equipment involved was to be used in the nuclear engine for the rocket vehicles program.

  8. 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.

  9. A device for a noninvasive evaluation of coronary bypass grafts.

    PubMed

    McInerney, J J; Lamser, D G; Herr, M D

    1994-01-01

    A new device is presented for evaluating the patency of coronary bypass grafts. Bypass grafts are located within the chest cavity using a Compton backscatter imaging (CBI) technique that creates frontal plane tomographic images. The tomographic image pixels are mapped into computer memory and displayed. A display pointer is used to mark the position of the bypass graft. The computer uses that information to subsequently position a radiation detector, such that it "looks" at the location of the bypass graft within the closed chest. The patency of the graft is then evaluated by monitoring an X-ray induced iodine fluorescence transient in the graft, subsequent to a peripheral intravenous contrast injection. This imaging and graft evaluation device is relatively inexpensive and its application does not require cutdowns or catheterization. The associated radiation dose is 1/10 to 1/50 of that associated with alternative X-ray graft patency evaluation techniques. Preliminary testing has been performed on mechanical and animal models. PMID:18218544

  10. Off-pump coronary artery bypass grafting: a case report.

    PubMed

    Behny, Leanne R

    2006-02-01

    It is easy to take for granted the seemingly effortless way cardiovascular surgeons are able to bypass atherosclerotic coronary arteries. The process used today was developed over many years of rigorous study, experimentation, success, and failure. Early cardiac surgery was performed blindly, through small incisions, on a beating heart. Advances in medicine allowed surgery to be performed on hearts stilled by cardioplegic arrest, while the circulation was continued through the use of a cardiopulmonary bypass (CPB) machine. The development of the CPB machine allowed surgeons to perform the delicate work of coronary artery bypass grafting (CABG), first attempted on dogs, and then humans. This article briefly outlines the historical evolution of cardiac surgery that led to the development of the technology necessary to perform off-pump coronary artery bypass grafting (OPCAB). A case report of a 72-year-old female who underwent OPCAB is outlined. Included is a discussion of some of the benefits and potential complications of CABG and OPCAB. Anesthetic considerations for OPCAB procedures also are presented. PMID:16483067

  11. Role of radionuclide cardiac imaging in coronary artery bypass surgery

    SciTech Connect

    Iskandrian, A.S.; Heo, J.; Mostel, E.

    1987-01-01

    The main applications of cardiac nuclear imaging in coronary artery bypass surgery include: patient selection, prediction of improvement in resting LV function after revascularization, diagnosis of perioperative myocardial infarction, assessment of the results of revascularization, evaluation of new or recurrent symptoms, and in risk stratification. Proper understanding of which test to be used, when, and why may be important to optimize patient management.

  12. Esophageal exclusion and bypass for corrosive injury: The lessons learnt

    PubMed Central

    Lal, Richa; Behari, Anu; Reddy, Jayanth; Poddar, Banani

    2014-01-01

    While it is always preferable to excise and replace the diseased esophagus in corrosive injuries, the surgeon may be compelled to exclude and bypass it by a substernal conduit in select situations wherein excision is technically hazardous. This case illustrates the lessons learnt from a potentially life-threatening complication of bipolar esophageal exclusion. PMID:24604986

  13. 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…

  14. Psychological Adjustment Following Coronary Artery Bypass Graft Surgery.

    ERIC Educational Resources Information Center

    Hagen, Janet W.

    1991-01-01

    Identified patterns of psychological adjustment following coronary bypass surgery in 100 individuals, 1 to 2 years postsurgery. Profiles were clustered into three groups based on level of distress (low, moderate, high). Findings revealed that over one-half of participants reported levels of psychological distress following surgery that were one or…

  15. 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...

  16. 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 (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3545...

  17. Intravascular stenting following bypass grafting in terminal coronary artery disease.

    PubMed Central

    Vecht, R J; Sigwart, U

    1995-01-01

    Reoperation after coronary artery bypass grafting in terminal coronary artery disease is associated with a substantial risk. Advances in coronary artery angioplasty offer alternative treatment with low morbidity and acceptable mortality. Images Figure 1 (a) Figure 1 (b) Figure 2 (a) Figure 2 (b) Figure 1 PMID:7884772

  18. [Coronary artery bypass graft for Bland-White-Garland syndrome in an old age; report of a case].

    PubMed

    Komagamine, Masahide; Saito, Satoshi; Nishinaka, Tomohiro; Katsube, Ken; Yamazaki, Kenji

    2010-12-01

    We report a case of Bland-White-Garland syndrome with advanced age. The patient, a 67-year-old women, presented with a history of congestive heart failure. Coronary catheterization revealed an anomalous origin of the left coronary artery (LCA) from the trunk of the pulmonary artery and huge right coronary aneurysm. Myocardial single photon emission computed tomography (SPECT) showed previous myocardial infarction with reversible ischemia in left anterior descending (LAD) region. We performed LCA direct closure and coronary artery bypass graft. The patient recovered uneventfully without signs of ischemia. Although a bypass graft was patent, left ventricular function had not been improved immediately probably due to the coronary flow pattern changes. PMID:21174671

  19. 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. PMID:25934498

  20. 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

  1. 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.

  2. 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.

  3. Bypassing Bypass Surgery and Other Success Stories from the National Institutes of Health.

    PubMed

    Nijhara, Ruchika; Tidwell, J Lille; Ferguson, Steven; Balakrishnan, Krishna

    2005-01-01

    After a heart attack, patients often undergo a procedure to open up the clogged artery and install a tiny meshlike device called a stent to keep the artery propped open. In most cases, the body reacts to this foreign object with scar-tissue formation, and the artery narrows again. To combat this re-clogging process, National Institutes of Health inventors developed paclitaxel-coated stents and later licensed it to Angiotech. Approved by the Food and Drug Administration in March 2004, these stents are expected to substantially reduce the use of coronary artery bypass surgery, an expensive operation now performed annually on 350,000-plus Americans. This and three other examples of NIH licensing success stories are described in this paper: (a) Kepivance, which improves the quality of life for cancer patients by eliminating mouth sores, (b) AIDS drug ddI, an important component of many combination drug therapies, and (c) Vitravene, the first and only antisense drug to be approved by FDA. These four examples will illustrate the success not only of the NIH licensing program, but also the innovative approaches taken by NIH inventors and the persistence of its commercial partners. This paper also highlights the business and legal lessons learned from these four cases. PMID:23730679

  4. Reusing the patent internal mammary artery as a conduit in redo coronary artery bypass surgery.

    PubMed

    Nwaejike, Nnamdi; Tennyson, Charlene; Mosca, Roberto; Venkateswaran, Rajamiyer

    2016-03-01

    mortality and satisfactory follow-up at up to 29 months. Evidently, the recycled ITA can be used in redo coronary artery bypass grafting. Papers found were retrospective series or case reports. As such, there is no direct comparison in outcomes between the recycled ITA and first-time ITA harvest or any other conduit for CABG. In conclusion, we find that when it is possible to harvest a previously used ITA, studies have shown it to be a safe and viable conduit in redo CABG with good long-term outcomes. PMID:26669852

  5. 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

    ... Bureau of Reclamation San Joaquin River Restoration Program: Reach 4B, Eastside Bypass, and Mariposa... the San Joaquin River Restoration Program. The original notice of intent was published in the Federal Register on September 9, 2009 (74 FR 46453). This revised proposal would include measures for...

  6. 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

  7. 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

  8. Ultra-High Bypass Engine Aeroacoustic Study

    NASA Technical Reports Server (NTRS)

    Gliebe, Philip R.; Janardan, Bangalore A.

    2003-01-01

    A system study was carried out to identify potential advanced aircraft engine concepts and cycles which could be capable of achieving a 5 to 10 EPNdB reduction in community noise level relative to current FAR36 Stage 3 limits for a typical large-capacity commercial transport aircraft. The study was directed toward large twin-engine aircraft applications in the 400,000 to 500,000 pound take-off gross weight class. Four single rotation fan engine designs with fan pressure ratios from 1.3 to 1.75, and two counter-rotating fan engine configurations were studied. Several engine configurations were identified which, with further technology development, could achieve the objective of 5 to 10 EPNdB noise reduction. Optimum design fan pressure ratio is concluded to be in the range of 1.4 to 1.55 for best noise reduction with acceptable weight and Direct Operating Cost (DOC) penalties.

  9. 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

  10. Development of a multiplexed bypass control system for aerospace batteries

    NASA Technical Reports Server (NTRS)

    Frank, H. A.

    1977-01-01

    A breadboard bypass control system was developed to control a battery comprised of 26 JPL-developed negative limited Ni-Cd cells. The system was designed to automatically remove cells from the circuit when their voltages exceeded a fixed limit on charge and fell below a fixed limit on discharge. Major components of the system consisted of a cell voltage monitor, a multiplexing circuit, and individual electromechanical relays for each cell. The system was found to function well in controlling the battery during a simulated 10-month MM-71 mission and a 2-month simulated low earth orbit cycling mission. A flight version of the bypass system was estimated to have a total parts count of 150 and total weight of 1.63 kg. When fully developed, the system shows promise for improving life and reliability of spacecraft batteries.

  11. Changes in Reward after Gastric Bypass: the Advantages and Disadvantages.

    PubMed

    Scholtz, Samantha; Goldstone, Anthony P; le Roux, Carel W

    2015-10-01

    Gastric bypass surgery is an effective long-term weight loss intervention. Key to its success appears a putative shift in food preference away from high-energy-density foods associated with a reduced appetitive drive and loss of neural reactivity in the reward system of the brain towards food. Post-prandial exaggerated satiety gut hormone responses have been implicated as mediators. Whilst the positive impact of bariatric surgery on both physical and psychological outcomes for many patients is clearly evident, a subset of patients appear to be detrimentally affected by this loss of reward from food and by a lack of alternative strategies for regulating affect after surgery. Mindfulness training has emerged as a potential tool in reducing the need for immediate reward that underpins much of eating behaviour. Further research is needed to help identify patients who may be more vulnerable after gastric bypass and which forms of support may be most beneficial. PMID:26358733

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

    PubMed

    Pieris, Rajeeva R; Fernando, Ravindra

    2015-01-01

    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. PMID:26334855

  13. Advanced magnetorheological damper with a spiral channel bypass valve

    NASA Astrophysics Data System (ADS)

    McLaughlin, G.; Hu, W.; Wereley, N. M.

    2014-05-01

    Magnetorheological (MR) fluid has a yield stress that is readily controllable using an applied magnetic field. MR dampers adjust this yield stress in a magnetic valve to accommodate a wide range of shock or vibration loads. In this study, the performance of an MR damper with a spiral channel bypass valve is examined. Three bypass damper configurations, i.e., a spiral channel, a spiral channel with beads, and a straight channel with beads, are subject to sinusoidal forcing at constant amplitude, while varying frequency, and applied field (current). These configurations are characterized using tortuosity and porosity parameters. The spiral channel without beads had the largest porosity and smallest tortuosity, which produced the smallest damper force, but the widest controllable damping range. The spiral channel with beads had the smallest porosity, and a comparable tortuosity, which produced the largest damping force, but similar controllable damping range to the straight channel with beads.

  14. 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. PMID:25887491

  15. 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

  16. Aspirin use and survival after coronary bypass surgery.

    PubMed

    Johnson, W D; Kayser, K L; Hartz, A J; Saedi, S F

    1992-03-01

    From Jan. 1, 1968, through Dec. 31, 1981, 5618 patients in a single cardiovascular surgery practice underwent coronary bypass surgery. Detailed clinical information was obtained during hospitalization and entered into a data base. All surviving patients were surveyed for aspirin use four times: in 1984, 1985, 1986, and 1987. A subgroup of 2395 patients gave consistent answers on every returned survey. The group that answered consistently "yes" had a 5-year survival rate of 79%; those who answered consistently "no" had a 5-year survival rate of 67%. Stepwise logistic regression showed that, after adjusting for patient characteristics, the relative risk of death was 58% (confidence interval 47% to 70%) for consistent aspirin users compared with consistent non-aspirin users. This study provides evidence that regular aspirin use after bypass surgery may enhance survival. PMID:1539511

  17. 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. PMID:26060029

  18. 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.

  19. The future of the Roux-en-Y gastric bypass.

    PubMed

    Lim, Chin Hong; Jahansouz, Cyrus; Abraham, Anasooya A; Leslie, Daniel B; Ikramuddin, Sayeed

    2016-07-01

    Archaic surgical procedures such as the jejunoileal bypass, vertical banded gastroplasty and duodenal switch have contributed to the current best practice of Roux-en-Y gastric bypass (RYGB) procedure for the treatment of obesity and its consequences. Despite this, RYGB has been blighted with late occurring adverse events such as severe malnutrition, marginal ulcer and reactive hypoglycemia. Despite this, RYGB has given us an opportunity to examine the effect of surgery on gut hormones and the impact on metabolic syndrome which in turn has allowed us to carry out a lower impact but equally, if not more effective, procedure - the vertical sleeve gastrectomy (VSG). We examine the benefits of sleeve gastrectomy from the less challenging technical aspect to the effect on obesity and its metabolic syndrome long-term and have concluded that sleeve gastrectomy is possibly the next current best practice. PMID:27027414

  20. Performance of Scramjet Engine with MHD Energy Bypass System

    NASA Astrophysics Data System (ADS)

    Kaminaga, Susumu; Tomioka, Sadatake; Yamasaki, Hiroyuki

    Flow behavior and thrust performance of MHD energy bypass scramjet engine was examined numerically. MHD generator was placed at the isolator to enhance the flow compression. Kinetic energy was converted to electrical energy in the MHD generator. Extracted electrical energy was consumed at the MHD accelerator placed at the downstream of the combustor. When MHD energy bypass system was used, the flow was decelerated and compressed in the MHD generator. Effect of velocity and Mach number on wall friction was analyzed and decrease of friction force was pointed out. Also, high pressure in the combustor resulted in increase of pressure contribution to net thrust. Despite of positive effects, decelerating Lorentz force in the MHD generator was comparably large and no significant difference in net thrust performance is observed.

  1. Fatal Pyoderma Gangrenosum with Pathergy after Coronary Artery Bypass Grafting

    PubMed Central

    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. PMID:23304049

  2. Arrhythmias in two patients with left ventricular bypass transplants.

    PubMed Central

    Kennelly, B M; Corte, P; Losman, J; Barnard, C N

    1976-01-01

    Two patients who underwent left ventricular bypass transplants are described. Both patients sustained postoperative rhythm disturbances of their own hearts during sinus rhythm of the donor hearts. Illustrative examples of atrial flutter, ventricular flutter, ventricular fibrillation, blocked atrial extrasystoles, and double ventricular parasystole in the recipient hearts are presented. The patients tolerated all these arrhythmias well during uninterrupted sinus rhythm in the donor heart. The problems in interpretation of arrhythmias in the presence of two hearts are discussed. Images PMID:788729

  3. [Staged reconstruction of brachiocephalic arteries and coronary artery bypass grafting].

    PubMed

    Lysenko, A V; Belov, Iu V; Stonogin, A V

    2015-01-01

    It is presented the results of staged treatment of 28 patients with lesion of brachiocephalic arteries and ischemic heart disease. Patients underwent reconstructive surgery on brachiocephalic arteries (n=34) and coronary artery bypass grafting (n=28). Diagnostic and surgical features are described and indications for this technique are defined. The authors studied Russian and international experience, described postoperative complications and suggested ways to improve the results of simultaneous interventions. PMID:26081182

  4. Inflammatory reaction as an occlusive mechanism in aortocoronary bypass grafts?

    PubMed

    Svendsen, E; Dalen, H; Moland, J; Engedal, H

    1986-01-01

    Morphological changes in aortocoronary vein grafts are described in two cases; one dying 5 hours post operatively and the other reoperated 8 months after aortocoronary bypass surgery for graft occlusion. Occlusive thrombi and fibrin deposition on the intimal surface and a focal inflammatory process in the wall of the vein grafts were found in the former. Thrombotic encrustation and organization similar to the manifestations of the thrombogenic theory of atherosclerosis were demonstrated in the latter. PMID:3489720

  5. 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.

  6. Risk factors for low colloid osmotic pressure during infant cardiopulmonary bypass with a colloidal prime.

    PubMed

    Golab, Hanna D; Takkenberg, Johanna J M; Bogers, Ad J J C

    2009-05-01

    Extensive variations of colloid osmotic pressure (COP) measured in the priming as well as during infant cardiopulmonary bypass motivated us to audit clinical and laboratory data to identify the risk factors for low COP at the end of bypass. Data of 73 consecutive infant patients with body weight <10 kg, who underwent elective, first time open-heart surgery between March 2005 and December 2006 were examined. The following variables were analyzed: COP, blood loss, transfusion requirements and hematological data. Univariate and multivariate analysis of risk factors for low COP (<15 mmHg) was performed. Forty-eight percent of patients had COP <15 mmHg at the end of bypass. Those patients had significantly lower COP before start of bypass, during, and at the end of the operation. Significant univariate predictors of low COP at the end of bypass were: lower patient weight; lower COP before start of bypass, lower priming COP and larger volume of cardioplegia received into the circulation. After multivariable analysis, lower patient COP before bypass remained the only significant predictor for low COP at the end of bypass. Pre-bypass crystalloid dilution during induction should be avoided, as this is the most important cause of low COP during the bypass. Priming COP and COP management strategy should be adapted to the individual patient demand. PMID:19188213

  7. Colonic pseudo-obstruction: a new complication of jejunoileal bypass.

    PubMed Central

    Barry, R E; Benfield, J R; Nicell, P; Bray, G A

    1975-01-01

    Five female patients ranging in age from 25 to 44 years are reported in whom jejunoileal bypass (three end-to-side and two end-to end), performed for morbid obesity, was complicated 1 1/2 to three years later by symptoms of colonic pseudo-obstruction. In each size, the colon was markedly elongated, dilated, and atonic but with no demonstrate organic obstruction. The cause of this complication is not known. Full thickness rectal biopsy in one case showed normal intrinsic nervous plexuses and ganglia. Serum electrolytes were normal. Functional and defunctionalized small bowel were not involved. Symptoms varied from complete colonic paralysis to incapacitating crampy abdominal pain and distention. In the three patients with end-to-side bypass, dilatation affected the entire colon, while, in the two patients with end-to-end bypass, the dilatation was localized to colon distal to the anastomosis with the defunctionalized small bowel. Resection of the affected portion of colon in one case resulted in recurrence distal to the new site of drainage of defunctioned bowel. Treatment with anti-anaerobe antibiotics in two cases produced dramatic but temporary relief of symptoms. PMID:1238312

  8. [Forefoot gangrene and infra-crural bypass: simultaneous amputation].

    PubMed

    Jacobs, M J

    1996-01-01

    Patients presented for amputation mostly have chronic limb ischaemia caused by atherosclerosis, with signs of severe arterial insufficiency including rest pain, non-healing skin lesions, ulceration or gangrene. Foot infections, especially in diabetic patients, are often multimicrobial, deeply invasive and frequently require aggressive measures, like debridement and drainage or partial open forefoot amputation in addition to broad-spectrum antibiotics, in patients with critical limb ischaemia and limited necrosis and forefoot gangrene, distal bypass surgery is the treatment of choice. The main question is whether amputation should be performed simultaneously or in a secondary stage. Our own experience deals with 342 femorocrural and femoropedal bypass grafts for the treatment of critical limb ischaemia. The results showed no significant difference in graft patency between crural and pedal grafts. Clinical factors like diabetes mellitus, poor distal run-off and site of the distal anastomosis had no adverse effect on the functioning and patency of the graft. In this series we found that in diabetic patients significantly more amputations were required because of persistent foot infection. Since in these patients amputation was performed in a secondary stage, we changed our policy to simultaneous amputation. After completion of the bypass, closure and coverage of all the wounds, the gangrenous part is amputated. In case of deep, wet or infectious gangrene of the forefoot, an open transmetatarsal amputation is performed. Using this approach we have further increased limb-salvage and especially the number of usuable limbs. PMID:8713389

  9. 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.

  10. Blood gas strategies and management during pediatric cardiopulmonary bypass.

    PubMed

    Griffin, Dee Ann

    2005-01-01

    Blood gas management during hypothermic cardiopulmonary bypass may be corrected by pH stat or alpha stat strategy. The pH stat philosophy is to maintain the blood pH constant at any temperature. Carbon dioxide must be introduced to the oxygenator in order to maintain the pH and pCO2 during hypothermic cardiopulmonary bypass. Conversely, during alpha stat blood gas management pH is maintained according to 37 degrees C despite the patient temperature. Alpha stat management preserves intracellular pH and autoregulation of cerebral vasculature by following the natural shift of the oxyhemoglobin dissociation curve. In-line blood gas analysis is a practical tool in assessing adequate blood gas management, because this technology provides immediate detection for modification of air/oxygen/carbon dioxide parameters. Results from several studies favor the pH stat strategy during neonatal cardiopulmonary bypass. This strategy increases tissue oxygenation and cerebral blood flow while cooling. Data also suggest that pH stat management results in better outcomes with shorter ventilation times and intensive care unit stays after pediatric cardiac surgery. PMID:16322734

  11. Perioperative complications of in-situ vein bypass.

    PubMed Central

    Gannon, M. X.; Goldman, M. D.; Simms, M. H.; Ruddock, S.; Ashton, F.; Slaney, G.

    1986-01-01

    Experience with 146 in-situ vein bypass procedures for obliterative arterial disease are reviewed to determine the specific complication of the technique. Vein wall injury with the Hall valvulotome occurred in 6 patients (4%) and vein patching of a stenosed femoral vein was required in 2 patients. Residual arteriovenous fistulae occurred in 24 patients (16.5%) of whom 9 had an associated graft thrombosis distal to the fistula of which 6 were corrected by thrombectomy and fistula ligation. Perioperative thrombosis occurred in 29 grafts (20%) and was more common in the femoropopliteal group (23/80) than in the femorocrural group (6/66) (P less than 0.01, X2 = 7.55). Fourteen of the femoropopliteal and two of the femorocrural thromboses were corrected resulting in an immediate patency of 89% and 94% respectively with the cumulative patency at one year being 77.5% and 79%. Complications of the in-situ bypass technique remain despite having largely overcome the problems of valve disruption. However, until a standard method emerges careful note must be made of technique and complications when considering reports of in-situ bypass patency. Images Fig. 1 PMID:3729260

  12. Patient’s Perception About Coronary Artery Bypass Grafting

    PubMed Central

    Mendonça, Kelminda Maria Bulhões; de Andrade, Tarcisio Matos

    2015-01-01

    OBJECTIVE The diagnosis of coronary artery disease referred for heart surgery has an important psychological component. The purpose of this study was to access the difficulties experienced by individuals awaiting coronary artery bypass grafting and to determine strategies that facilitate adaptation to a new lifestyle, modified by the disease. METHODS A qualitative, exploratory study involving patients admitted to a university teaching hospital in the city of Salvador, Bahia, Brazil, awaiting coronary artery bypass grafting. Semi-structured interviews were performed in accordance with a previously defined script based on the study objective. Each transcription was read in its entirety to verify the representativeness, homogeneity and pertinence of the data obtained (pre-analysis), followed by separation of categories of analysis. RESULTS The descriptions of this study show that patients admitted to the completion of coronary artery bypass grafting experience a wide range of psychological difficulties, considering that surgery acquires interpretations that vary according to individuals' subjectivity. The patients recognized the benefit of being able to discuss their feelings as a means of diminishing their fear and anxiety. CONCLUSION Helping patients find resources to confront more positively the daily hospitalization is an important aspect for the health care professionals who assist them. This goal can be achieved through modification of the biomedical model of care for a biopsychosocial view. The investment of time and attention is of fundamental importance and aims to overcome existing deficiencies that interfere with the outcome of patients after cardiac surgery. PMID:26735601

  13. 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.

  14. 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.

  15. Racial Disparities in Outcomes Following Coronary Artery Bypass Grafting

    PubMed Central

    Hravnak, Marilyn; Ibrahim, Said; Kaufer, Abigail; Sonel, Ali; Conigliaro, Joseph

    2013-01-01

    More than 12 million people in the United States have coronary heart disease, the second leading cause of hospitalization in the United States. It is known that persons within racial minorities, specifically African Americans, have a higher prevalence of coronary heart disease, yet are much less likely to undergo invasive cardiac treatment interventions. An invasive intervention commonly used to treat coronary heart disease is coronary artery bypass grafting, with over 140,000 operations performed annually in the United States. However, blacks are known to experience higher post–coronary artery bypass graft morbidity and mortality. The causes for racial disparities in post–coronary artery bypass graft outcomes are not well known but may include factors related to the individual, provider, system, and society/environment, either alone or in combination. The purpose of this article is to provide an overview of the literature regarding disparities in the health and healthcare of black patients with coronary heart disease with respect to CABG, and examine potential hypotheses for variant outcomes after surgery. PMID:16966914

  16. Simultaneous “hybrid” percutaneous coronary intervention and minimally invasive surgical bypass grafting: Feasibility, safety, and clinical outcomes

    PubMed Central

    Reicher, Barry; Poston, Robert S.; Mehra, Mandeep R.; Joshi, Ashish; Odonkor, Patrick; Kon, Zachary; Reyes, Peter A.; Zimrin, David A.

    2009-01-01

    Surgical and percutaneous coronary artery intervention revascularization are traditionally considered isolated options. A simultaneous hybrid approach may allow an opportunity to match the best strategy for a particular anatomic lesion. Concerns regarding safety and feasibility of such an approach exist. We examined the safety, feasibility, and early outcomes of a simultaneous hybrid revascularization strategy (minimally invasive direct coronary bypass grafting of the left anterior descending [LAD] artery and drug-eluting stent [DES] to non-LAD lesions) in 13 patients with multivessel coronary artery disease that underwent left internal mammary artery to LAD minimally invasive direct coronary bypass performed through a lateral thoracotomy, followed by stenting of non-LAD lesions, in a fluoroscopy-equipped operating room. Assessment of coagulation parameters was also undertaken. Inhospital and postdischarge outcomes of these patients were compared to a group of 26 propensity score matched parallel controls that underwent standard off-pump coronary artery bypass. Baseline characteristics were similar in both groups. All hybrid patients were successfully treated with DES and no inhospital mortality occurred in either group. Hybrid patients had a shorter length of stay (3.6 ± 1.5 vs 6.3 ± 2.3 days, P < .0001) and intubation times (0.5 ± 1.3 vs 11.7 ± 9.6 hours, P < .02). Despite aggressive anticoagulation and confirmed platelet inhibition, hybrid patients had less blood loss (581 ± 402 vs 1242 ± 941 mL, P < .05) and decreased transfusions (0.33 ± 0.49 vs 1.47 ± 1.53 U, P < .01). Six-month angiographic vessel patency and major adverse cardiac events were similar in the hybrid and off-pump coronary artery bypass groups. A simultaneous hybrid approach consisting of minimally invasive coronary artery bypass grafting with left internal mammary artery to LAD combined with revascularization of the remaining coronary targets using percutaneous coronary artery

  17. Laparoscopic gastric bypass to robotic gastric bypass: time and cost commitment involved in training and transitioning an academic surgical practice.

    PubMed

    Lyn-Sue, Jerome R; Winder, Josh S; Kotch, Shannon; Colello, Jacob; Docimo, Salvatore

    2016-06-01

    The Roux-en-Y gastric bypass is the gold standard procedure for weight loss. This relatively complex procedure has excellent outcomes when performed via laparoscopy. The advent of the DaVinci robotic platform has been a technological advancement. Our goal is to provide information regarding the cost, time commitment, and advantages of transitioning an LRYGB program to an RRYGB program in an academic setting. We retrospectively reviewed the last 25 laparoscopic gastric bypass procedures and the first 25 robotic gastric bypass procedures performed by a single surgeon. We compared clinical outcomes and focused on time and hospital cost during this transition phase. There was no significant demographic difference between the groups. The mean age was 41.7 (RRYGB) years vs 43.4 (LRYGM) years. The mean BMI were similar between groups, 45.3 vs 46.5 kg/m(2) for RRYGB and LRYGB. No anastomotic leaks or mortalities were noted. There was one anastomotic stricture in both groups. Excess weight loss was similar in both groups at 1 year. There was a significant increase in operative time with RRYGB, mean 241 min vs mean 174 min (p = 0.0005). Operative time fell by 25 min after the first 10 cases. The hospital cost was also increased with RRYGB mean $5922 vs $4395 (p = 0.03). Transitioning from a laparoscopic to a robotic practice can be done safely, however, the initial operative times were longer and the hospital cost was higher for robotic gastric bypass. We hope in the future that these will decrease after overcoming the learning and as the technology becomes widespread. PMID:26983848

  18. The potential of the novel leukocyte removal filter in cardiopulmonary bypass.

    PubMed

    Fujii, Yutaka

    2016-01-01

    Cardiopulmonary bypass (CPB) is indispensable for cardiac surgery but leads to systemic inflammatory responses and leukocyte activation, possibly due to blood contact with the surface of the CPB unit, surgical, ischemic reperfusion injury, etc. Systemic inflammatory responses during CPB result in increased morbidity and mortality. Activation of leukocytes is an important part of this process and directly contributes to coagulopathy and hemorrhage. This inflammatory response may contribute to the development of postoperative complications, including myocardial dysfunction, respiratory failure, renal and neurologic dysfunction, altered liver function and ultimately, multiple organ failure. Various pharmacologic and mechanical strategies have been developed to minimize the systemic inflammatory response during CPB. For example, leukocyte removal filters were developed in the 1990s for incorporation into the CPB circuit. However, studies of this approach have yielded conflicting findings. The purpose of this was to review the studies of a novel leukocyte removal filter in patients undergoing CPB. PMID:26613267

  19. 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

  20. Perioperative risk factors for prolonged mechanical ventilation and tracheostomy in women undergoing coronary artery bypass graft with cardiopulmonary bypass

    PubMed Central

    Faritous, Zahra S.; Aghdaie, Nahid; Yazdanian, Forouzan; Azarfarin, Rasoul; Dabbagh, Ali

    2011-01-01

    Background: Prolonged mechanical ventilation is an important recognized complication occurring during cardiovascular surgery procedures. This study was done to assess the perioperative risk factors related to postoperative pulmonary complications and tracheostomy in women undergoing coronary artery bypass graft with cardiopulmonary bypass. Methods: It was a retrospective study on 5,497 patients, including 31 patients with prolonged ventilatory support and 5,466 patients without it; from the latter group, 350 patients with normal condition (extubated in 6-8 hours without any complication) were selected randomly. Possible perioperative risk factors were compared between the two groups using a binary logistic regression model. Results: Among the 5,497 women undergoing coronary artery bypass graft (CABG), 31 women needed prolonged mechanical ventilation (PMV), and 15 underwent tracheostomy. After logistic regression, 7 factors were determined as being independent perioperative risk factors for PMV. Discussion: Age ≥70 years old, left ventricular ejection fraction (LVEF) ≤30%, preexisting respiratory or renal disease, emergency or re-do operation and use of preoperative inotropic agents are the main risk factors determined in this study on women undergoing CABG. PMID:21804797

  1. 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.

  2. Indications and Outcomes of Prophylactic and Therapeutic Extracranial-to-intracranial Arterial Bypass for Cerebral Revascularization

    PubMed Central

    Gazyakan, Emre; Lee, Ching-Yi; Wu, Chieh-Tsai; Tsao, Chung-Kan; Craft, Randall; Henry, Steven L.; Lee, Shih-Tseng

    2015-01-01

    Background: Extracranial-to-intracranial (EC-IC) arterial bypass is a technically demanding procedure used to treat complex cerebral artery diseases. The indications, proper surgical techniques, and outcomes of this procedure have been under debate over the recent decades. Methods: Between January 2004 and December 2012, 28 patients, including patients with cerebral artery occlusion, intracranial aneurysm, cranial base tumor, and Moyamoya disease, underwent EC-IC bypass. Patients’ records were retrospectively reviewed for demography, indications, complications, high-flow versus low-flow bypass, patency rate of bypass, and neurological outcome. The patients were sorted into prophylactic (n = 16) and therapeutic (n = 12) groups based on the preoperative presentation of their neurological symptoms. Follow-up evaluation was performed at a mean of 32.7 ± 24.3 months. Results: The overall patency rate of bypass was 100%, the postoperative stroke rate was zero, and the surgical complication rate was 14.3%. There was no significant difference in the bypass patency rate between the 2 groups or between the high-flow and low-flow bypass patients. Patients who underwent prophylactic bypass had minimal surgical and total complications (P = 0.03 and P < 0.01, respectively) and a better neurological outcome. Surgical complications were more common in patients who underwent therapeutic bypass (25%). Conclusions: The collaboration of neurosurgeons and plastic surgeons in performing EC-IC bypass can result in excellent outcomes with a high bypass patency rate and few complications, particularly for prophylactic EC-IC bypass. PMID:25973350

  3. Bypass transition in boundary layers including curvature and favorable pressure gradient effects

    NASA Technical Reports Server (NTRS)

    Volino, R. J.; Simon, T. W.

    1991-01-01

    Recent studies of 2-D boundary layers undergoing bypass transition were reviewed. Bypass transition is characterized by the sudden appearance of turbulent spots in boundary layer without first the regular, observable growth of disturbances predicted by linear stability theory. There are no standard criteria or parameters for defining bypass transition, but it is known to be the mode of transition when the flow is disturbed by perturbations of sufficient amplitude.

  4. Genome wide interactions of wild-type and activator bypass forms of σ54.

    PubMed

    Schaefer, Jorrit; Engl, Christoph; Zhang, Nan; Lawton, Edward; Buck, Martin

    2015-09-01

    Enhancer-dependent transcription involving the promoter specificity factor σ(54) is widely distributed amongst bacteria and commonly associated with cell envelope function. For transcription initiation, σ(54)-RNA polymerase yields open promoter complexes through its remodelling by cognate AAA+ ATPase activators. Since activators can be bypassed in vitro, bypass transcription in vivo could be a source of emergent gene expression along evolutionary pathways yielding new control networks and transcription patterns. At a single test promoter in vivo bypass transcription was not observed. We now use genome-wide transcription profiling, genome-wide mutagenesis and gene over-expression strategies in Escherichia coli, to (i) scope the range of bypass transcription in vivo and (ii) identify genes which might alter bypass transcription in vivo. We find little evidence for pervasive bypass transcription in vivo with only a small subset of σ(54) promoters functioning without activators. Results also suggest no one gene limits bypass transcription in vivo, arguing bypass transcription is strongly kept in check. Promoter sequences subject to repression by σ(54) were evident, indicating loss of rpoN (encoding σ(54)) rather than creating rpoN bypass alleles would be one evolutionary route for new gene expression patterns. Finally, cold-shock promoters showed unusual σ(54)-dependence in vivo not readily correlated with conventional σ(54) binding-sites. PMID:26082500

  5. Pregnancy management for a patient with graft occlusion after right iliac artery bypass surgery.

    PubMed

    Nakae, Ruriko; Matsuzaki, Shinya; Egawa-Takata, Tomomi; Mimura, Kazuya; Kanagawa, Takeshi; Kimura, Tadashi

    2015-06-01

    We describe an extremely rare case of a pregnant woman who had a successful delivery despite developing bypass graft occlusion after right external iliac bypass surgery. External and common iliac artery bypass surgery is often performed when arteriosclerosis obliterans or thromboangiitis obliterans result in iliac artery occlusion or when revascularization is required because of iliac artery injury. Because arteriosclerosis obliterans and thromboangiitis obliterans rarely develop in young women or girls, most physicians have little experience with graft occlusion after iliac artery bypass surgery. Here we describe and discuss the published work pertaining to this extremely rare case. PMID:25511914

  6. Robotic totally endoscopic triple coronary artery bypass grafting on the arrested heart: report of the first successful clinical case.

    PubMed

    Bonatti, Johannes; Rehman, Atiq; Schwartz, Kimberly; Deshpande, Seema; Kon, Zachary; Lehr, Eric; Zimrin, David; Griffith, Bartley

    2010-12-01

    Robotic technology enables "port only" totally endoscopic coronary artery bypass grafting (TECAB). During early procedure development only single bypass grafts were feasible. Because current referral practice for coronary bypass surgery mostly includes multivessel disease, performance of multiple endoscopic bypass grafts is desirable. We report a case in which a patient received a right internal mammary artery bypass graft to the left anterior descending artery and a left internal mammary artery jump graft to 2 obtuse marginal branches. The procedure was performed through 5 ports on the arrested heart using the daVinci S robotic surgical system. This is the first reported triple bypass grafting procedure using an arrested heart approach. PMID:21169151

  7. 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

    2015-06-01

    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. PMID:26054096

  8. 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

  9. Laser Doppler imaging of myocardial perfusion during coronary bypass surgery

    NASA Astrophysics Data System (ADS)

    Wardell, Karin; Hermansson, Ulf; Nilsson, Gert E.; Casimir-Ahn, Henrik

    2000-05-01

    Laser Doppler perfusion imaging has been used to assess the myocardium perfusion on the arrested heart during bypass surgery. Twenty-two patients undergoing coronary artery bypass grafting, including usage of the left internal thoracic artery, were included in the study. The anticipated perfusion increase following declamping of the internal thoracic artery was investigated by mapping areas at the size of 10 cm X 11 cm, (n equals 11) and 7 cm X 5 cm (n equals 11). The larger images allowed quantification of blood flow in different regions of the myocardium. The size of the affected area was 32.2 +/- 12.9 cm2 with a total increase of 3.17 +/- 0.75 a.u. (range 0 - 10 a.u.). Corresponding values for areas surrounding the vessels and areas defined as the larger vessels in the myocardium were 29.0 +/- 10.9 cm2 (2.85 +/- 0.57 a.u.) and 3.5 +/- 2.8 cm2 (6.78 +/- 0.18 a.u.). All subjects but two showed a substantial blood flow increase (> 2 a.u.) after release of the clamp. Six subjects had a total increase of at least 4 a.u. Correlation analysis between areas including various number of sites showed an r equals 0.91 (p < 0,0001) or better. In conclusion, laser Doppler perfusion imaging can easily be used intraoperatively in conjunction with bypass surgery. It enables immediate assessment of both the increase and spatial distribution of myocardial perfusion following declamping of an arterial graft.

  10. Hospitalization before and after mini-gastric bypass surgery.

    PubMed

    Rutledge, Robert

    2007-02-01

    The mini-gastric bypass (MGB) was developed to address some of the limitations of the Roux-en-Y gastric bypass ("RNY"). The RNY has recently been reported to increase the need for hospitalization for complications after RNY surgery. To determine the rates and indications for inpatient hospital use before and after MGB in comparison to similar rates in RNY. The study is a self reported retrospective study of patients from across the United States receiving MGB in Centers for Excellence in Laparoscopic Obesity Surgery ("CELOS") hospitals from 2000 to 2005. Complications and hospitalization in the year before and in the 1 to 5 years after MGB. 1069 patients who underwent MGB were selected for study. The rate of hospitalization in the year following MGB was 67% of the rate in the year preceding MGB (11% vs. 17%, P<0.001). The most common reasons for admission prior to MGB were general medical problems (38%) obstetric and Gynecological issues (36%), orthopedic problems (16%), gallbladder surgery (9%) and renal stones in 2%. The most common reasons for hospital admission after MGB were complications from surgery (29%), gallbladder surgery (20%), renal stones (14%), plastic surgery procedures (11%), appendectomy (9%), Gynecologic issues (9%) and orthopedic problems (6%). Thus while MGB complications made up a third of hospital readmissions following MGB surgery the over all hospitalization rates declined significantly. Previous studies have demonstrated that hospitalization after RNY gastric bypass increases remarkably (20% per year). The present study shows that hospitalization following MGB instead of rising, as reported with RNY, decreases by a third. The MGB has been shown to be a short, safe successful weight loss surgery in previous work. The present study supports the MGB as a low risk procedure that decreases the need for hospitalization. PMID:17386913

  11. [Dealing with surgical complications after bariatric gastric bypass surgery].

    PubMed

    Schlesinger, Nis Hallundbæk; Naver, Lars

    2013-11-25

    The subject of this article is surgical complications to Roux-en-Y-gastric bypass and how to deal with them. The article addresses doctors, who are on duty in hospitals without bariatric surgery and who often deal with this patient category in the acute situation. Managing complications is challenging due to both the patient's physiognomy and the wide-ranged change in anatomy. The article gives a review of the literature and hands-on-recommendations for treating anastomotic leak, post-operative bleeding, internal herniation, bowel obstruction and biliary complications. PMID:24629437

  12. Incidental invasive thymoma during coronary artery bypass surgery.

    PubMed

    Al-Smady, Moaath; Hammdan, Farouq F; Abu-Abeeleh, Mahmood M; Massad, Islam M

    2009-01-01

    We encountered 2 incidental cases of invasive thymomas at Jordan University Hospital, Amman, Jordan; during routine coronary artery bypass graft surgery between 2005 and 2008 with an incidence of 0.6%. Both patients presented with angina pain. None of the 2 patients had pressure symptoms (cough, shortness of breath or superior vena cava syndrome) or Myasthenia Gravis symptoms. Total thymectomy with dissection of perithymic fat was performed on both cases. No radiotherapy was given. No recurrence of the tumor was seen in 2 years follow up. These cases are presented to emphasize the occurrence of this tumor. PMID:19139788

  13. Esophageal perforation during gastric bypass: delayed diagnosis and management.

    PubMed

    Endara, Santiago A; Serrano, Armando J; Sandoval, Bernardo A; Davalos, Gerardo A

    2007-07-01

    Mediastinitis secondary to esophageal perforation is usually a life-threatening problem associated with high morbidity and mortality. We present a 44-year-old morbidly obese female who underwent laparoscopic gastric bypass, during which she suffered perforation of the distal thoracic esophagus diagnosed 5 days later during progression of mediastinitis. She was treated with left posterolateral thoracotomy, drainage of a peri-esophageal abscess and primary repair of the esophagus with intercostal muscle reinforcement, and cervical esophagostomy. Thereafter, she had an uneventful hospital course, and remains well on 12-month follow-up. PMID:17894163

  14. Extreme distal bypass to improve wound healing in Buerger's disease.

    PubMed

    De Caridi, Giovanni; Massara, Mafalda; Villari, Simona; Martelli, Eugenio; Spinelli, Francesco; Grande, Raffaele; Butrico, Lucia; de Franciscis, Stefano; Serra, Raffaele

    2016-02-01

    Thromboangiitis obliterans or Buerger's disease is a rare non-atherosclerotic segmental inflammatory vasculitis that most commonly involves small and medium-sized arteries, veins and nerves of the extremities, and generally affects young tobacco smokers. A 53-year-old man was found to have critical ischaemia of his left lower limb with foot gangrene. He underwent extremely distal surgical revascularisation using a great saphenous vein bypass graft. The choice of a very distal artery as run-off vessel promoted a faster wound healing and pain relief, with improvement in quality of life. PMID:24612761

  15. Fetal monitoring during maternal cardiac surgery with cardiopulmonary bypass.

    PubMed Central

    Koh, K. S.; Friesen, R. M.; Livingstone, R. A.; Peddle, L. J.

    1975-01-01

    Fetal cardiac activity was monitored with an external ultrasound transducer in two patients with clinical class III heart disease due to severe mitral stenosis complicated by pulmonary hypertension, undergoing open heart surgery with cardiopulmonary bypass in the 2nd trimester of pregnancy. Fetal distress was detected in one patient, who had mitral valvuloplasty, and was corrected by increasing the rate of blood flow, and the other patient had a mitral valve replacement but no fetal distress was noted. The postoperative course of both mothers and fetuses was uneventful. Images FIG. 1 FIG. 2 FIG. 3 FIG. 4 FIG. 5 FIG. 6 FIG. 7 PMID:1125921

  16. Coronary Artery Bypass Surgery - Multiple Languages: MedlinePlus

    MedlinePlus

    ... 繁體中文) French (français) Hindi (हिन्दी) Japanese (日本語) Korean (한국어) Russian (Русский) Somali (af Soomaali) Spanish (español) ... 冠動脈バイパス手術 - 日本語 (Japanese) Bilingual PDF Health Information Translations Korean (한국어) Coronary Artery Bypass Surgery 관상동맥 우회 수술 - ...

  17. Simultaneous off-pump coronary artery bypass graft and nephrectomy.

    PubMed

    Dedeilias, Panagiotis; Roussakis, Antonios; Koletsis, Efstratios N; Kouerinis, Ilias; Balaka, Christina; Apostolakis, Efstratios; Malovrouvas, Dimitrios

    2008-01-01

    We report the one-stage surgical management of a 68-year-old patient with renal cell carcinoma and serious hematuria combined with coronary artery disease and unstable angina. After the accomplishment of coronary revascularization without cardiopulmonary bypass, we proceeded to nephrectomy and resection of the renal tumor at the same time. The patient's postoperative course was uneventful, and at 17 months of follow-up, the patient showed no signs of recurrence. To the best of our knowledge, such a case has never been reported before in the literature. PMID:19017005

  18. 2005 American Heart Association (AHA) guidelines for cardiopulmonary resuscitation (CPR) and emergency cardiovascular care (ECC) of pediatric and neonatal patients: pediatric basic life support.

    PubMed

    2006-05-01

    This publication presents the 2005 American Heart Association (AHA) guidelines for cardiopulmonary resuscitation (CPR) and emergency cardiovascular care (ECC) of the pediatric patient and the 2005 American Academy of Pediatrics/AHA guidelines for CPR and ECC of the neonate. The guidelines are based on the evidence evaluation from the 2005 International Consensus Conference on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations, hosted by the American Heart Association in Dallas, Texas, January 23-30, 2005. The "2005 AHA Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care" contain recommendations designed to improve survival from sudden cardiac arrest and acute life-threatening cardiopulmonary problems. The evidence evaluation process that was the basis for these guidelines was accomplished in collaboration with the International Liaison Committee on Resuscitation (ILCOR). The ILCOR process is described in more detail in the "International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations." The recommendations in the "2005 AHA Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care" confirm the safety and effectiveness of many approaches, acknowledge that other approaches may not be optimal, and recommend new treatments that have undergone evidence evaluation. These new recommendations do not imply that care involving the use of earlier guidelines is unsafe. In addition, it is important to note that these guidelines will not apply to all rescuers and all victims in all situations. The leader of a resuscitation attempt may need to adapt application of the guidelines to unique circumstances. The following are the major pediatric advanced life support changes in the 2005 guidelines: There is further caution about the use of endotracheal tubes. Laryngeal mask airways are acceptable when used by experienced

  19. Feasibility and safety of minimized cardiopulmonary bypass in major aortic surgery

    PubMed Central

    Momin, Aziz U.; Sharabiani, Mansour T. A.; Kidher, Emadin; Najefi, Ali; Mulholland, John W.; Reeves, Barnaby C.; Angelini, Gianni D.; Anderson, Jon R.

    2013-01-01

    OBJECTIVES Conventional cardiopulmonary bypass causes haemodilution and is a trigger of systemic inflammatory reactions, coagulopathy and organ failure. Miniaturized cardiopulmonary bypass has been proposed as a way to reduce these deleterious effects of conventional cardiopulmonary bypass and to promote a more physiological state. The use of miniaturized cardiopulmonary bypass has been reported in low-risk patients undergoing valve and coronary artery bypass graft (CABG) surgery. However, little is known about its application in major aortic surgery. METHODS From February 2007 to September 2010, 49 patients underwent major aortic surgery using the Hammersmith miniaturized cardiopulmonary bypass (ECCO, Sorin). Data were extracted from medical records to characterize preoperative comorbidities (EuroSCORE), perioperative complications and the use of blood products. The same data were collected and described for 328 consecutive patients having similar surgery with conventional cardiopulmonary bypass at the Bristol Heart Institute, our twinned centre, during the same period. RESULTS The miniaturized cardiopulmonary bypass group had a median EuroSCORE of 8 [inter-quartile range (IQR): 5–11], 13% had preoperative renal dysfunction and 20% of operations were classified as emergency or salvage. Thirty-day mortalities were 6.4; and 69, 67 and 74% had ≥1 unit of red cells, fresh frozen plasma (FFP) and platelets transfused, respectively. Eight percent of patients experienced a renal complication, and 8% a neurological complication. The conventional cardiopulmonary bypass group was similar, with a EuroSCORE of 8 (IQR: 6–10); 30-day mortalities were 9.4; and 68, 62 and 74% had ≥1 unit of red cells, FFP and platelets transfused, respectively. The proportions experiencing renal and neurological complications were 14 and 5%. CONCLUSIONS Our experience suggests that miniaturized cardiopulmonary bypass is safe and feasible for use in major aortic cardiac surgery. A

  20. 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

  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. PMID:25910614

  2. 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.

  3. A bypass transition in the Lamb-Oseen vortex

    NASA Astrophysics Data System (ADS)

    Bisanti, Luigi; Brancher, Pierre; Airiau, Christophe

    2012-11-01

    Transient energy growth in the short-time linear dynamics of a Lamb-Oseen monopole is a potential mechanism for nonlinear bypass transition, a phenomenon already observed in both experiments and numerical simulations. In the present study, we investigate this scenario by means of a nonlinear optimal perturbation approach, i.e. by looking for the initial perturbation whose evolution satisfies the fully nonlinear Navier-Stokes equations and maximizes the energy gain at a given time horizon. Preliminary two-dimensional results show that, for small initial amplitudes, the optimal perturbation and growth mechanisms observed in the linear regime are recovered. More particularly, the time evolution of the m = 2 optimal perturbation leads to an elliptical core deformation of the monopole, which suggests a potential bypass scenario driven by the non-linear dynamics. This is confirmed by computations for larger initial perturbation amplitudes: the optimal perturbation is similar to that of the linear regime but a subcritical bifurcation to a quasi-steady, high-energy, rotating tripole is observed.

  4. Phrenic and diaphragm function after coronary artery bypass grafting.

    PubMed Central

    Estenne, M; Yernault, J C; De Smet, J M; De Troyer, A

    1985-01-01

    We studied respiratory mechanics and phrenic nerve and diaphragm function in 12 patients on the day before and eight to 13 days after coronary artery bypass grafting. The average vital capacity, functional residual capacity, and total lung capacity decreased by 20.5%, 9.5%, and 14.7% respectively after operation. Eleven patients showed less negative maximum inspiratory mouth pressures at any given lung volume after surgery and the magnitude of the change correlated with the reduction in total lung capacity. In 11 of the 12 patients the conduction times of the right and left phrenic nerves did not change substantially after operation and the ratio of inspiratory electrical activity (Edi) of left and right hemidiaphragms was similar before and after the procedure. One patient, however, showed a considerable increase in left phrenic nerve conduction time and a reduction in the left to right Edi ratio postoperatively. In three patients diaphragm function was also assessed by changes in transdiaphragmatic pressure during supramaximal phrenic nerve stimulation and voluntary increase in inspired volume; in none of the three patients did the transdiaphragmatic pressure swings show any significant change in the postoperative period. These data indicate that phrenic nerve paralysis only occasionally accounts for the postoperative loss of lung volume after coronary artery bypass grafting surgery. The mechanism of these abnormalities therefore remains to be determined. PMID:3875161

  5. [Issues in Coronary Artery Bypass Grafting for Kawasaki Disease].

    PubMed

    Katahira, Shintaro; Kawamoto, Shunsuke; Hosoyama, Katsuhiro; Masaki, Naoki; Kanda, Keisuke; Suzuki, Tomoyuki; Kawatsu, Satoshi; Yoshioka, Ichiro; Fujiwara, Hidenori; Kumagai, Kiichiro; Adachi, Osamu; Akiyama, Masatoshi; Saiki, Yoshikatsu

    2016-05-01

    Progressive narrowing at the entrance and exit of coronary artery aneurysm can develop at late phase of Kawasaki disease (KD). Evaluation and prediction of progressive coronary lesions remain a challenge in the treatment of post-KD coronary artery disease. We aimed to elucidate long-standing issues imposed on the patients who underwent coronary artry bypass grafting(CABG) for coronary artery lesions associated with KD. Between January, 2000 and December, 2013, CABG for coronary artery lesions associated with KD were performed in 6 patients (male/female:5/1, mean age 14.5±10.0). There was no operative mortality. Follow-up for the 6 patients has been performed with the average period of 5 years(1~9 years). Cardiac events occurred in 2 patients during follow-up. In 1patient, left internal thoracic artery( LITA) occluded due to flow competition between the native artery and LITA graft after LITA to LAD bypass grafting. The other patient required a re-do CABG using the free right internal thoracic artery to the circumflex branch because of occlusion at the coronary artery aneurysms after 4 years postoperatively. Meticulous preoperative diagnostic evaluations of coronary artery aneurysm may further improve the long-term outcome after surgical intervention for coronary lesions in conjunction with an aneurysm. PMID:27220919

  6. [Reoperative cardiac surgery after previous coronary artery bypass grafting].

    PubMed

    Hayashi, Yasunari; Ito, Toshiaki; Maekawa, Atsuo; Sawaki, Sadanari; Hoshino, Satoshi; Tokoro, Masayoshi; Yanagisawa, Junji

    2014-06-01

    Reoperative cardiac surgery after coronary artery bypass grafting( CABG) has been increasing. We reviewed 25 cases of reoperative cardiac surgery after CABG. Re-CABG was not included in this study. The patients consisted of 15 men and 10 women. The mean patient age was 74.4±6.3 years old. The reoperations were performed 6.3±5.1 years after CABG. They consisted of 7 aortic valve surgeries, 2 double valve surgeries, 12 mitral valve surgeries, and 4 total arch replacements. Resternotomy was performed in 20 cases, while right thoracotomy was performed in 5 cases. Internal thoracic artery( ITA)grafts had been used in 24 cases, and 22 of them were patent. Fifteen operations were performed under cardioplegic arrest with the patent ITA graft clamped from the left pleural space, while 5 operations were performed under perfused ventricular fibrillation with hypothermia. No differences were observed between the 2 groups in terms of cardiopulmonary bypass (CPB) time and peak creatine kinase MB (CK-MB). Operative mortality was 4% (1/25). To clamp left internal thoracic artery (LITA) graft from the left pleural space is easy and safe. In case clamping the patent graft is difficult, perfused ventricular fibrillation with hypothermia is a useful alternative. PMID:24917396

  7. Effects of inosine on reperfusion injury after cardiopulmonary bypass

    PubMed Central

    2010-01-01

    Objective Inosine, a break-down product of adenosine has been recently shown to exert inodilatory and anti-inflammatory properties. Furthermore inosine might be a key substrate of pharmacological post-conditioning. In the present pre-clinical study, we investigated the effects of inosine on cardiac function during reperfusion in an experimental model of cardioplegic arrest and extracorporal circulation. Methods Twelve anesthetized dogs underwent hypothermic cardiopulmonary bypass. After 60 minutes of hypothermic cardiac arrest, reperfusion was started after application of either saline vehicle (control, n = 6), or inosine (100 mg/kg, n = 6). Left ventricular end-systolic pressure volume relationship (ESPVR) was measured by a combined pressure-volume-conductance catheter at baseline and after 60 minutes of reperfusion. Left anterior descendent coronary blood flow (CBF), endothelium-dependent vasodilatation to acetylcholine (ACh) and endothelium-independent vasodilatation to sodium nitroprusside (SNP) were also determined. Results The administration of inosine led to a significantly better recovery (given as percent of baseline) of ESPVR 90 ± 9% vs. 46 ± 6%, p < 0.05. CBF and was also significantly higher in the inosine group (56 ± 8 vs. 23 ± 4, ml/min, p < 0.05). While the vasodilatatory response to SNP was similar in both groups, ACh resulted in a significantly higher increase in CBF (58 ± 6% vs. 25 ± 5%, p < 0.05) in the inosine group. Conclusions Application of inosine improves myocardial and endothelial function after cardiopulmonary bypass with hypothermic cardiac arrest. PMID:21059208

  8. Bypass transition of the bottom boundary layer under solitary wave

    NASA Astrophysics Data System (ADS)

    Sadek, Mahmoud; Diamessis, Peter; Parras, Luis; Liu, Philip

    2015-11-01

    The transition to turbulence in the bottom boundary layer (BBL) flow driven by a soliton-like pressure gradient in an oscillating water tunnel (an approximation for the BBL under solitary waves) is investigated using hydrodynamic linear stability theory and DNS. As observed in the laboratory experiment by Sumer et al. (2010), two possible transition scenarios exist. The first scenario is associated with the classical transition resulting from the breakdown of the exponentially growing 2-D Tollmien-Schlichting waves. The alternative scenario; i.e., bypass transition; takes place through formation of localized turbulent spots. The investigation of the latter transition scenario is performed in two steps. The first step consists of reformulating the linear stability analysis in the non-modal framework for the purpose of finding the optimum disturbance characteristics which lead to the formation of those turbulent spots. In the second step, the computed optimum noise structure is inserted in the 3D DNS in order to induce the formation of the turbulent spots and effectively simulate the bypass transition observed experimentally.

  9. 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

  10. [Proximal anastomotic marker use in coronary artery bypass operations].

    PubMed

    Cikirikçioğlu, Mustafa; Ozbay, Gültaç; Duran, Enver

    2002-06-01

    Detection and evaluation of aorto-to-saphenous vein anastomosis sites (proximal anastomoses) in patients who had undergone coronary artery bypass surgery are comparatively harder than native coronary orifices during follow-up re-angiography procedures. Placement of a radioopaque proximal anastomotic graft marker during coronary artery bypass procedure poses medical and economical advantages in case of postoperative re-angiography during follow-up of these patients. Indication of whether or not to use a proximal anastomotic marker is in general decide on by the operating surgeon. However, coronary angiography is a task of interventional cardiologist. Difference of the teams performing catheterization and the surgical procedure may rise some inconsistencies in terms of requirements for these markers. In order for these dilemmas to be prevented, surgical team should be informed of the complication re-angiography procedure. Proper strategy for the implantation of this technique, which is convenient not only for cardiologist and surgeon but also in economic terms, should be decided on with collaboration of cardiology and cardiovascular surgery teams. In this article, advantages of the proximal anastomotic markers during the postoperative follow-up and re-angiography have been presented with the related literature review. PMID:12134539

  11. Postoperative physical therapy after coronary artery bypass surgery.

    PubMed

    Johnson, D; Kelm, C; To, T; Hurst, T; Naik, C; Gulka, I; Thomson, D; East, K; Osachoff, J; Mayers, I

    1995-09-01

    Coronary artery bypass surgery is frequently complicated by postoperative atelectasis. Although routinely prescribed, the efficacy of any specific chest physical therapy is not well established. We studied patients at a university center undergoing elective coronary artery bypass surgery. Based upon chest X-ray criteria at extubation, patients (n = 228) were classified as demonstrating greater or lesser degrees of atelectasis. Those with a lesser degree of atelectasis were randomized to receive either early mobilization or sustained maximal inflations (SMI). Those with greater a degree of atelectasis were separately randomized to receive either SMI or single-handed percussions (SSP). We found the extent of atelectasis at extubation did not predict the risk of developing pneumonia. Hospital stays and intensive care unit stays were similar regardless of treatment. Physical therapy costs were highest in the most labor-intensive therapy group (SSP). We conclude that postoperative respiratory dysfunction is common but does not commonly cause significant morbidity or prolong hospital stay. Adding SMI to patients with minimal atelectasis at extubation does not improve clinical outcomes. Similarly, adding SSP to patients with marked atelectasis does not improve outcomes over those obtained with SMI and early ambulation. PMID:7663809

  12. A new screening technique for salinity resistance in rice (Oryza sativa L.) seedlings using bypass flow.

    PubMed

    Faiyue, Bualuang; Al-Azzawi, Mohammed J; Flowers, Timothy J

    2012-06-01

    A lack of screening techniques delays progress in research on salinity resistance in rice. In this study, we report our test of the hypothesis that an apoplastic pathway (the so-called bypass flow) causes a difference in salt resistance between rice genotypes and can be used in screening for salinity resistance. Fourteen-day-old seedlings of low- and high-Na(+) -transporting recombinant inbred lines (10 of each) of rice IR55178 were treated with 50 mm NaCl and 0.2 mm trisodium-8-hydroxy-1,3,6-pyrenetrisulphonic acid (PTS), a bypass flow tracer, for short (4 d) and long (90 d) periods of time. The results showed that the average shoot Na(+) concentration and bypass flow for high-Na(+) -transporting lines were 1.4 and 2.4 times higher than those of low-Na(+) -transporting lines, respectively. There was a positive linear correlation between the percentage of bypass flow and Na(+) concentrations in the shoots, suggesting that the difference in Na(+) transport in rice is a consequence of different degrees of bypass flow. Moreover, a high correlation was found between bypass flow and seedling survival after prolonged salt stress: the lower the magnitude of bypass flow, the greater the seedling survival. We conclude that bypass flow could be used as a new screening technique for salt resistance in rice. PMID:22171658

  13. 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…

  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, 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...

  16. 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...

  17. 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...

  18. 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...

  19. 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…

  20. 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...

  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. Facility S17A, interior view of underground room showing bypass valves ...

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

    Facility S17A, interior view of underground room showing by-pass valves standing in a row along edge of wall, view facing southeast - U.S. Naval Base, Pearl Harbor, Dry Dock No. 1, Pumpwell, By-Pass Valve & Saltwater Pumphouse, North end of Fifth Street, between Dry Dock No. 1 & Facility GD2 , Pearl City, Honolulu County, HI

  3. Facility S17A, closeup of bypass valve, entry door on right, ...

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

    Facility S17A, close-up of by-pass valve, entry door on right, vent opening above door, view facing southwest - U.S. Naval Base, Pearl Harbor, Dry Dock No. 1, Pumpwell, By-Pass Valve & Saltwater Pumphouse, North end of Fifth Street, between Dry Dock No. 1 & Facility GD2 , Pearl City, Honolulu County, HI

  4. 21 CFR 870.4210 - Cardiopulmonary bypass vascular catheter, cannula, or tubing.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ..., or tubing. 870.4210 Section 870.4210 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Devices § 870.4210 Cardiopulmonary bypass vascular catheter, cannula, or tubing. (a) Identification. A cardiopulmonary bypass vascular catheter, cannula, or tubing is a device used in cardiopulmonary surgery...

  5. 21 CFR 870.4210 - Cardiopulmonary bypass vascular catheter, cannula, or tubing.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ..., or tubing. 870.4210 Section 870.4210 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Devices § 870.4210 Cardiopulmonary bypass vascular catheter, cannula, or tubing. (a) Identification. A cardiopulmonary bypass vascular catheter, cannula, or tubing is a device used in cardiopulmonary surgery...

  6. 21 CFR 870.4210 - Cardiopulmonary bypass vascular catheter, cannula, or tubing.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ..., or tubing. 870.4210 Section 870.4210 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Devices § 870.4210 Cardiopulmonary bypass vascular catheter, cannula, or tubing. (a) Identification. A cardiopulmonary bypass vascular catheter, cannula, or tubing is a device used in cardiopulmonary surgery...

  7. 21 CFR 870.4210 - Cardiopulmonary bypass vascular catheter, cannula, or tubing.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ..., or tubing. 870.4210 Section 870.4210 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Devices § 870.4210 Cardiopulmonary bypass vascular catheter, cannula, or tubing. (a) Identification. A cardiopulmonary bypass vascular catheter, cannula, or tubing is a device used in cardiopulmonary surgery...

  8. 21 CFR 870.4210 - Cardiopulmonary bypass vascular catheter, cannula, or tubing.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ..., or tubing. 870.4210 Section 870.4210 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Devices § 870.4210 Cardiopulmonary bypass vascular catheter, cannula, or tubing. (a) Identification. A cardiopulmonary bypass vascular catheter, cannula, or tubing is a device used in cardiopulmonary surgery...

  9. 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

  10. Rankine cycle condenser pressure control using an energy conversion device bypass valve

    SciTech Connect

    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. Malabsorption and intestinal adaptation after one anastomosis gastric bypass compared with Roux-en-Y gastric bypass in rats.

    PubMed

    Cavin, Jean-Baptiste; Voitellier, Eglantine; Cluzeaud, Françoise; Kapel, Nathalie; Marmuse, Jean-Pierre; Chevallier, Jean-Marc; Msika, Simon; Bado, André; Le Gall, Maude

    2016-09-01

    The technically easier one-anastomosis (mini) gastric bypass (MGB) is associated with similar metabolic improvements and weight loss as the Roux-en-Y gastric bypass (RYGB). However, MGB is controversial and suspected to result in greater malabsorption than RYGB. In this study, we compared macronutrient absorption and intestinal adaptation after MGB or RYGB in rats. Body weight and food intake were monitored and glucose tolerance tests were performed in rats subjected to MGB, RYGB, or sham surgery. Carbohydrate, protein, and lipid absorption was determined by fecal analyses. Intestinal remodeling was evaluated by histology and immunohistochemistry. Peptide and amino acid transporter mRNA levels were measured in the remodeled intestinal mucosa and those of anorexigenic and orexigenic peptides in the hypothalamus. The MGB and RYGB surgeries both resulted in a reduction of body weight and an improvement of glucose tolerance relative to sham rats. Hypothalamic orexigenic neuropeptide gene expression was higher in MGB rats than in RYGB or sham rats. Fecal losses of calories and proteins were greater after MGB than RYGB or sham surgery. Intestinal hyperplasia occurred after MGB and RYGB with increased jejunum diameter, higher villi, and deeper crypts than in sham rats. Peptidase and peptide or amino acid transporter genes were overexpressed in jejunal mucosa from MGB rats but not RYGB rats. In rats, MGB led to greater protein malabsorption and energy loss than RYGB. This malabsorption was not compensated by intestinal overgrowth and increased expression of peptide transporters in the jejunum. PMID:27418681

  12. Alterations of sucrose preference after Roux-en-Y gastric bypass.

    PubMed

    Bueter, M; Miras, A D; Chichger, H; Fenske, W; Ghatei, M A; Bloom, S R; Unwin, R J; Lutz, T A; Spector, A C; le Roux, C W

    2011-10-24

    Roux-en-Y gastric bypass (gastric bypass) patients reportedly have changes in perception and consumption of sweet-tasting foods. This study aimed to further investigate alterations in sweet food intake in rats and sucrose detection in humans after gastric bypass. Wistar rats were randomized to gastric bypass or sham-operations and preference for sucrose (sweet), sodium chloride (salty), citric acid (sour) and quinine hydrochloride (bitter) was assessed with standard two-bottle intake tests (vs. water). Intestinal T1R2 and T1R3 expression and plasma levels of glucagon-like-peptide 1 (GLP-1) and peptide YY (PYY) were measured. Furthermore, obese patients and normal weight controls were tested for sucrose taste detection thresholds pre- and postoperatively. Visual analogue scales measuring hedonic perception were used to determine the sucrose concentration considered by patients and controls as "just about right" pre- and postoperatively. Gastric bypass reduced the sucrose intake relative to water in rats (p<0.001). Preoperative sucrose exposure reduced this effect. Preference or aversion for compounds representative of other taste qualities in naïve rats remained unaffected. Intestinal T1R2 and T1R3 expression was significantly decreased in the alimentary limb while plasma levels of GLP-1 and PYY were elevated after bypass in rats (p=0.01). Bypass patients showed increased taste sensitivity to low sucrose concentrations compared with controls (p<0.05), but both groups considered the same sucrose concentration as "just about right" postoperatively. In conclusion, gastric bypass reduces sucrose intake relative to water in sucrose-naïve rats, but preoperative sucrose experience attenuates this effect. Changes in sucrose taste detection do not predict hedonic taste ratings of sucrose in bypass patients which remain unchanged. Thus, factors other than the unconditional affective value of the taste may also play a role in determining food preferences after gastric bypass

  13. 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.

  14. 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.

  15. Perioperative ischemic injury after coronary bypass graft surgery

    SciTech Connect

    Li, W.; Hanelin, L.G.; Riggins, R.C.; Agnew, R.C.; Annest, L.S.; Anderson, R.P.

    1985-07-01

    Two hundred twelve patients who underwent isolated coronary bypass graft surgery were prospectively evaluated for perioperative ischemic injury. All patients underwent preoperative and postoperative testing with technetium 99m pyrophosphate first-pass ventriculography combined with myocardial uptake scans, 12-lead electrocardiography, and serial creatinine phosphokinase MB determination. Fifteen percent of the patients had ischemic injury with at least two test results positive, but only 4 percent had positive results of all three tests. No single test proved adequate. Enzyme levels were highly sensitive and had value as a screening test. The electrocardiogram was specific but only moderately sensitive. The single best test was the radionuclide scan with good sensitivity and no false-positive results. All three tests are required to rigorously diagnose ischemic injury.

  16. 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

  17. Clinical value of coronary bypass graft evaluation with CT

    SciTech Connect

    Godwin, J.D.; Califf, R.M.; Korobkin, M.; Moore, A.V.; Breiman, R.S.; Kong, Y.

    1983-04-01

    Computed tomography (CT) has a reported accuracy of 45%-97% in assessment of patency of coronary artery bypass grafts. Dynamic CT was done in 26 patients (47 grafts) with recurrent cardiac symptoms after graft surgery. Although CT was 79% accurate (with selective angiography as the standard), the authors do not believe that it provides sufficient information for the assessment of symptomatic patients. Four patients had high-grade stenoses in their grafts, and 50% of patients had significant progression of atherosclerosis in their native coronary arteries. Neither of these conditions could be detected by CT. The clinical contribution of CT will probably be greatest for routine screening of asymptomatic patients soon after operation. Technical problems with CT scanning for graft patency are discussed.

  18. No ethical bypass of moral status in stem cell research.

    PubMed

    Brown, Mark

    2013-01-01

    Recent advances in reprogramming technology do not bypass the ethical challenge of embryo sacrifice. Induced pluripotent stem cell (iPS) research has been and almost certainly will continue to be conducted within the context of embryo sacrifice. If human embryos have moral status as human beings, then participation in iPS research renders one morally complicit in their destruction; if human embryos have moral status as mere precursors of human beings, then advocacy of iPS research policy that is inhibited by embryo sacrifice concerns renders one morally complicit in avoidable harms to persons. Steps may be taken to address these complicity concerns, but in the final analysis there is no alternative to achieving clarity with respect to the moral status of the human embryo. PMID:21726260

  19. 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

  20. 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.

  1. Interdisciplinary Simulation Using the Cardiopulmonary Bypass Simulator (CPBS)?

    PubMed

    Mendel, Shaun

    2014-12-01

    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

  2. Hydrogel-electrospun mesh composites for coronary artery bypass grafts.

    PubMed

    McMahon, Rebecca E; Qu, Xin; Jimenez-Vergara, Andrea Carolina; Bashur, Chris A; Guelcher, Scott A; Goldstein, Aaron S; Hahn, Mariah S

    2011-04-01

    The aim of the present study was to investigate the potential of hydrogel-electrospun mesh hybrid scaffolds as coronary artery bypass grafts. The circumferential mechanical properties of blood vessels modulate a broad range of phenomena, including vessel stress and mass transport, which, in turn, have a critical impact on cardiovascular function. Thus, coronary artery bypass grafts should mimic key features of the nonlinear stress-strain behavior characteristic of coronary arteries. In native arteries, this J-shaped circumferential stress-strain curve arises primarily from initial load transfer to low stiffness elastic fibers followed by progressive recruitment and tensing of higher stiffness arterial collagen fibers. This nonlinear mechanical response is difficult to achieve with a single-component scaffold while simultaneously meeting the suture retention strength and tensile strength requirements of an implantable graft. For instance, although electrospun scaffolds have a number of advantages for arterial tissue engineering, including relatively high tensile strengths, tubular mesh constructs formed by conventional electrospinning methods do not generally display biphasic stress-strain curves. In the present work, we demonstrate that a multicomponent scaffold comprised of polyurethane electrospun mesh layers (intended to mimic the role of arterial collagen fibers) bonded together by a fibrin hydrogel matrix (designed to mimic the role of arterial elastic fibers) results in a composite construct which retains the high tensile strength and suture retention strength of electrospun mesh but which displays a J-shaped mechanical response similar to that of native coronary artery. Moreover, we show that these hybrid constructs support cell infiltration and extracellular matrix accumulation following 12-day exposure to continuous cyclic distension. PMID:21083438

  3. Bilateral Internal Thoracic Artery Configuration for Coronary Artery Bypass Surgery

    PubMed Central

    Boodhwani, Munir; Hanet, Claude; de Kerchove, Laurent; Navarra, Emiliano; Astarci, Parla; Noirhomme, Philippe; El Khoury, Gebrine

    2016-01-01

    Background— Bilateral internal thoracic arteries (BITA) have demonstrated superior patency and improved survival in patients undergoing coronary artery bypass grafting. However, the optimal configuration for BITA utilization and its effect on long-term outcome remains uncertain. Methods and Results— We randomly assigned 304 patients undergoing coronary artery bypass grafting using BITA to either in situ or Y grafting configurations. The primary end point was 3-year angiographic patency. Secondary end points included major adverse cardiac and cerebrovascular events (ie, death from any cause, stroke, myocardial infarction, or repeat revascularization) at 7 years. More coronary targets were able to be revascularized using internal thoracic arteries in patients randomized to Y grafting versus in situ group (3.2±0.8 versus 2.4±0.5 arteries/patient; P<0.01). The primary end point did not show significant differences in graft patency between groups. Secondary end points occurred more frequently in the in situ group (P=0.03), with 7-year rates of 34±10% in the in situ and 25±12% in the Y grafting groups, driven largely by a higher incidence of repeat revascularization in the in situ group (14±4.5% versus 7.4±3.2% at 7 years; P=0.009). There were no significant differences in hospital mortality or morbidity or in late survival, myocardial infarction, or stroke between groups. Conclusions— Three-year systematic angiographic follow-up revealed no significant difference in graft patency between the 2 BITA configurations. However, compared with in situ configuration, the use of BITA in a Y grafting configuration results in lower rates of major adverse cardiovascular and cerebrovascular events at 7 years. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT01666366. PMID:27406988

  4. Effects of Gastric Bypass Surgery on Female Reproductive Function

    PubMed Central

    Dodson, William C.; Gnatuk, Carol L.; Estes, Stephanie J.; Kunselman, Allen R.; Meadows, Juliana W.; Kesner, James S.; Krieg, Edward F.; Rogers, Ann M.; Haluck, Randy S.; Cooney, Robert N.

    2012-01-01

    Context: Reproductive function may improve after bariatric surgery, although the mechanisms and time-related changes are unclear. Objective: The objective of the study was to determine whether ovulation frequency/quality as well as associated reproductive parameters improve after Roux en Y gastric bypass surgery. Design: This was a prospective cohort study that enrolled female subjects from 2005 to 2008 with study visits at baseline and then 1, 3, 6, 12, and up to 24 months after surgery. Setting: The study was conducted at an academic health center. Patients: Twenty-nine obese, reproductive-aged women not using confounding medications participated in the study. Main Outcome Measures: The primary outcome was integrated levels of urinary progestin (pregnanediol 3-glururonide) from daily urinary collections at 12 months postoperatively. Secondary outcomes were changes in vaginal bleeding, other biometric, hormonal, ultrasound, dual-energy x-ray absorptiometry measures, and Female Sexual Function Index. Results: Ninety percent of patients with morbid obesity had ovulatory cycles at baseline, and the ovulatory frequency and luteal phase quality (based on integrated pregnanediol 3-glururonide levels) were not modified by bariatric surgery. The follicular phase was shorter postoperatively [6.5 d shorter at 3 months and 7.9–8.9 d shorter at 6–24 months (P < 0.01)]. Biochemical hyperandrogenism improved, largely due to an immediate postoperative increase in serum SHBG levels(P < 0.01), with no change in clinical hyperandrogenism (sebum production, acne, hirsutism). Bone density was preserved, contrasting with a significant loss of lean muscle mass and fat (P < 0.001), reflecting preferential abdominal fat loss (P < 0.001). Female sexual function improved 28% (P = 0.02) by 12 months. Conclusions: Ovulation persists despite morbid obesity and the changes from bypass surgery. Reproductive function after surgery is characterized by a shortened follicular phase and improved

  5. 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.

  6. Proliferative and morphologic changes in rat colon following bypass surgery.

    PubMed Central

    Barkla, D. H.; Tutton, P. J.

    1985-01-01

    In this study the proliferative and morphologic changes that occur in the colon of normal and dimethylhydrazine-treated rats following surgical bypass of the middle third of the colon are reported. Proliferative changes were measured by estimating accumulated mitotic indexes following vinblastine treatment and morphologic changes were observed with the use of light microscopy and scanning electron microscopy. Data were collected on Days 0, 7, 14, 30, and 72 after surgery. The results show that surgical bypass produces contrasting effects in the segments proximal to and distal to the suture line. In the proximal segment there was morphologic evidence of hyperplasia, although proliferative activity was unchanged except for an increase at 7 days in normal rats. In the distal segment there was a long-lived increase in the mitotic index, although morphologic changes were not seen. The results for DMH-treated rats were similar to those in normal rats. Groups of isolated dysplastic epithelial cells were often seen in the submucosa adjacent to sutures up to 72 days after surgery. Increased lymphoid infiltration was seen in segments proximal to but not distal to the suture line. It is hypothesized that the different responses of the proximal and distal segments may be related to the different embryologic origins of those segments. It is also hypothesized that the seeding of the submucosa with epithelial cells during suturing may be a factor in tumor recurrence. Images Figure 19 Figure 20 Figure 21 Figure 22 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 Figure 17 Figure 18 PMID:4014432

  7. Early and Midterm Outcome of Redo Coronary Artery Bypass Grafting: On-Pump versus Off-Pump Bypass

    PubMed Central

    Shin, Yu Rim; Lee, Sak; Joo, Hyun Chel; Youn, Young-Nam; Kim, Jong Gun; Yoo, Kyung-Jong

    2014-01-01

    Background Redo coronary artery bypass grafting (CABG) is still associated with increased morbidity and mortality as compared to the first-time operation. Further, the application of the off-pump technique to redo CABG is limited due to technical difficulties. The aim of this retrospective study was to analyze early and midterm results after redo CABG and compare the outcome of redo on-pump and off-pump CABG. Methods From June 1996 to October 2011, elective redo CABG was performed in 32 patients. Mean age was 64.8 years (on pump 64.3 years vs. off pump 65.5 years; p=0.658), and 21 patients were male. Among these patients, 14 (43.8%) underwent on-pump CABG, and 18 (56.2%) underwent off-pump CABG. Results Internal thoracic artery was used in 22 patients (68.8%), and total arterial revascularization was achieved in 17 patients (53.1%). The average number of distal anastomoses was 2.13, and the rate of incomplete revascularization was 43.8%. The rate of total arterial revascularization was higher in the off-pump group (14.3% vs. 83.3%, p<0.001), and the use of saphenous vein graft was more in the on-pump group (78.6% vs. 16.7%, p<0.001). Overall hospital mortality was 3.1% (n=1) and was comparable in both groups (on pump 7.1% vs. off pump 0%; p=0.249). Postoperative complications occurred in 9 patients (64.2%), and the rate of complications was high in the on-pump group without statistical significance (64.2% vs. 33.3%, p=0.082). The mean follow-up duration was 5.4 years, and overall survival at 10 years was 86.0%±10.5%. There was no significant difference in the 10-year survival rate between the two groups (79.6% vs. 100%, p=0.225). Conclusion Redo CABG can be safely performed with acceptable mortality. Redo off-pump coronary artery bypass is feasible with low mortality and morbidity, comparable target vessel bypass grafting, and long-term survival. The off-pump technique might be considered a safe option for redo CABG in high-risk patients. PMID:25207219

  8. 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.

  9. Myocardial edema and compromised left ventricular function attributable to dirofilariasis and cardiopulmonary bypass in dogs.

    PubMed

    Rohn, D A; Davis, K L; Mehlhorn, U; Allen, S J; Laine, G A

    1995-02-01

    We investigated the relation between left ventricular dysfunction and myocardial edema in dogs with heartworm (Dirofilaria immitis) infection that were undergoing cardiopulmonary bypass. Dogs with and without D immitis were anesthetized by continuous thiopental infusion and were mechanically ventilated. Sonomicrometry crystals were placed on the long and short axes of the left ventricle, and a Millar pressure transducer was placed in the left ventricular chamber. Pressure-volume loops were digitized and continuously recorded. Dogs with and without D immitis were placed on standard hypothermic cardiopulmonary bypass, with 1 hour of aortic cross-clamp. Wet-to-dry weight ratio corrected for residual blood volume was used to quantitate the volume of myocardial edema. Preload recruitable stroke work was used as a preload-independent index of systolic function. Tau, the isovolumic relaxation time constant, was determined to assess diastolic relaxation. Dogs with D immitis had increased baseline myocardial wet-to-dry weight ratio. After cardiopulmonary bypass, myocardial edema increased in all dogs. Acute edema attributable to cardiopulmonary bypass decreased preload recruitable stroke work in all dogs of both groups, and dogs with D immitis could not be weaned from cardiopulmonary bypass. Myocardial edema increased diastolic relaxation times (tau) in dogs with and without D immitis. We conclude that cardiopulmonary bypass and heartworm infection induce myocardial edema. This edema compromises left ventricular systolic and diastolic function making D immitis an important confounding factor in weaning dogs from cardiopulmonary bypass. PMID:7717590

  10. 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.

  11. Improvements in the metabolic milieu following Roux-en-Y gastric bypass and the arrest of diabetic kidney disease.

    PubMed

    Docherty, Neil G; le Roux, Carel W

    2014-09-01

    Roux-en-Y gastric bypass (RYGB) is an efficacious intervention for morbid obesity and has a diabetes-remitting effect in patients with obesity and type 2 diabetes mellitus, which occurs prior to significant weight loss. Roux-en-Y gastric bypass is also associated with early and sustained reductions in the risk factor profile for the progression of diabetic complications. Attention is therefore now being placed on RYGB as a metabolic intervention with the capacity to yield therapeutic benefit in relation to the progression of diabetic complications, such as diabetic kidney disease. As alterations in gut anatomy following RYGB coincide with attendant shifts in downstream enteroendocrine signals with direct and indirect resolutionary effects on the kidney, the concept of an endocrine gut-kidney axis post-RYGB is growing. With the model of a gut-kidney axis in mind, this article summarizes emerging data on the effects of RYGB on risk factors for diabetic kidney disease (hyperglycaemia, dyslipidaemia and hypertension), highlighting a potential role for glucagon-like peptide 1 in risk factor reduction. PMID:25085842

  12. A simple technique can reduce cardiopulmonary bypass use during lung transplantation

    PubMed Central

    Samano, Marcos N; Iuamoto, Leandro R; Fonseca, Hugo V S; Fernandes, Lucas M; Abdalla, Luis G; Jatene, Fabio B; Pêgo-Fernandes, Paulo M

    2016-01-01

    Cardiopulmonary bypass causes an inflammatory response and consumption of coagulation factors, increasing the risk of bleeding and neurological and renal complications. Its use during lung transplantation may be due to pulmonary hypertension or associated cardiac defects or just for better exposure of the pulmonary hilum. We describe a simple technique, or open pericardium retraction, to improve hilar exposure by lifting the heart by upward retraction of the pericardial sac. This technique permits lung transplantation without cardiopulmonary bypass when bypass use is recommended only for better exposure. PMID:27166775

  13. Simulating nitrate leaching under winter wheat grown on a structured clay soil considering bypass flow

    NASA Astrophysics Data System (ADS)

    Ragab, R.; Coopers, D. M.; Harris, G. L.; Catt, J. A.

    1996-07-01

    Nitrate leaching from drained plots of structured clay soil under winter wheat is simulated for one growing season using the SOILN model. Results are compared with field measurements from two replicate plots. Soil water movement is simulated both with and without a bypass flow component using the SOIL model. Flow to field drains and soil water content in the root zone are simulated better when bypass flow is included. The results emphasise the importance of considering bypass flow in modelling leaching from structured clay soils. Simulations of nitrate leaching using the SOILN model show that the model captures the main features of the cumulative loss of nitrate over the year.

  14. [Ways to improve patency of the femoral-popliteal-crural bypass grafts].

    PubMed

    Sazhinov, A P; Lukinskiĭ, A V; Chupin, A V

    2014-01-01

    Chronic obliterating diseases of lower-limb arteries account for more than 20% of all manifestations of cardiovascular pathology. A surgical method of treatment for this pathology remains most effective. The types of operations below the inguinal fold currently used are as follows: bypass grafting, endarterectomy, and angioplasty. The vein is the material of choice and if it is not easily available allografts may be used. Differing elastic properties of the artery and prosthesis lead to progression of the neointima thus negatively affecting patency of bypass grafts. This article describes venous bypass grafts, their efficacy, methods of improving patency of allografts, as well as variants of combined operations. PMID:24722032

  15. 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.

  16. 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.

  17. A simple technique can reduce cardiopulmonary bypass use during lung transplantation.

    PubMed

    Samano, Marcos N; Iuamoto, Leandro R; Fonseca, Hugo V S; Fernandes, Lucas M; Abdalla, Luis G; Jatene, Fabio B; Pêgo-Fernandes, Paulo M

    2016-04-01

    Cardiopulmonary bypass causes an inflammatory response and consumption of coagulation factors, increasing the risk of bleeding and neurological and renal complications. Its use during lung transplantation may be due to pulmonary hypertension or associated cardiac defects or just for better exposure of the pulmonary hilum. We describe a simple technique, or open pericardium retraction, to improve hilar exposure by lifting the heart by upward retraction of the pericardial sac. This technique permits lung transplantation without cardiopulmonary bypass when bypass use is recommended only for better exposure. PMID:27166775

  18. What could the impact be on the market if the enrichment bypass is closed?

    SciTech Connect

    1995-05-01

    This article is a continuation of the discussion on the changing nuclear trade status with the Commonwealth of Independent States, and it reviews the impact on the US market if the enrichment bypass were to be closed. No one doubts that the closing of the bypass will impact the uranium market... the US market in particular. The question is: How will closing of the bypass manifest itself with respect to uranium and enrichment prices? It is conclued that the ratepayers will be the real losers.

  19. Evaluation of a Stirling engine heater bypass with the NASA Lewis nodal-analysis performance code

    NASA Technical Reports Server (NTRS)

    Sullivan, T. J.

    1986-01-01

    In support of the U.S. 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 engine performance. The Lewis nodal-analysis Stirling engine computer simulation was used for this investigation. Results for the heater-bypass concept showed no significant improvement in the indicated thermal efficiency for the P-40 Stirling engine operating at full-power and part-power conditions. Optimizing the heater tube length produced a small increase in the indicated thermal efficiency with the heater-bypass concept.

  20. Off-Pump Coronary Artery Bypass Grafting and Transaortic Transcatheter Aortic Valve Replacement.

    PubMed

    Dellis, Sophia L; Akujuo, Adanna C; Bennett, Edward V; Britton, Lewis W

    2016-07-01

    We sought to demonstrate the effectiveness of off-pump coronary artery bypass grafting and transcatheter aortic valve replacement in two patients with porcelain aortas and lesions that could not be optimally treated with percutaneous coronary intervention. Patients with aortic stenosis and coronary artery disease who are too high-risk for conventional surgical aortic valve replacement and coronary artery bypass grafting due to comorbidities and porcelain aorta, and who do not have the appropriate anatomy for percutaneous coronary intervention should be considered for concomitant transcatheter aortic valve replacement and off-pump coronary artery bypass grafting. doi: 10.1111/jocs.12762 (J Card Surg 2016;31:435-438). PMID:27196956

  1. Aortic Root Enlargement with Ascending-to-Descending Aortic Bypass in Repair of Coarctation.

    PubMed

    Perry, Paul A; Young, Nilas

    2015-07-01

    Ascending-to-descending aortic bypass is a valuable technique for addressing coarctation of the aorta when additional cardiac procedures are indicated in adults. Among these, aortic valve replacement is one of the most commonly performed concomitant procedures, and there are instances in which aortic root enlargement is required. Herein, a novel technique is described for performing simultaneous ascending-to-descending aortic bypass in conjunction with aortic root enlargement which incorporates the bypass graft as part of the aortic root enlargement. PMID:26897826

  2. Severe Scurvy After Gastric Bypass Surgery and a Poor Postoperative Diet

    PubMed Central

    Hansen, Esben P.K.; Metzsche, Carsten; Henningsen, Emil; Toft, Palle

    2012-01-01

    After bariatric gastric bypass surgery patients are at risk of developing micronutrient deficiencies. If gastric bypass surgery is followed by a vitamin deficient diet the patients have a risk of developing vitamin-C deficiency. When spontaneous ecchymosis is observed in the skin, in at-risk patients, scurvy must be considered. When treated with large doses of vitamin-C the symptoms of scurvy rapidly improve even if the patient has developed multiple organ dysfunction syndrome. Keywords Scurvy; Gastric bypass surgery; Multiorgan dysfunction PMID:22505988

  3. Myocardial Revascularization for Patients With Diabetes: Coronary Artery Bypass Grafting or Percutaneous Coronary Intervention?

    PubMed

    Castelvecchio, Serenella; Menicanti, Lorenzo; Garatti, Andrea; Tramarin, Roberto; Volpe, Marianna; Parolari, Alessandro

    2016-09-01

    Patients affected by diabetes usually have extensive coronary artery disease. Coronary revascularization has a prominent role in the treatment of coronary artery disease in the expanding diabetic population. However, diabetic patients undergoing coronary artery bypass grafting or percutaneous coronary intervention experience worse outcomes than nondiabetic patients. Several studies comparing coronary artery bypass grafting vs percutaneous coronary intervention in subgroups of diabetic patients demonstrated a survival advantage and fewer repeat revascularization procedures with an initial surgical strategy. This review summarizes the current state of evidence comparing the effectiveness and safety of coronary artery bypass grafting and percutaneous coronary intervention in diabetic patients. PMID:27217297

  4. 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

  5. Comparison of two technics of cardiopulmonary bypass (conventional and mini CPB) in the trans-and postoperative periods of cardiac surgery

    PubMed Central

    Pereira, Sergio Nunes; Zumba, Izabelle Balta; Batista, Micheline Sulzbacher; Pieve, Daniela Da; dos Santos, Elisandra; Stuermer, Ralf; de Oliveira, Gerson Pereira; Senger, Roberta

    2015-01-01

    Objective This study aimed to compare the effects of two different perfusion techniques: conventional cardiopulmonary bypass and miniature cardiopulmonary bypass in patients undergoing cardiac surgery at the University Hospital of Santa Maria - RS. Methods We perform a retrospective, cross-sectional study, based on data collected from the patients operated between 2010 and 2013. We analyzed the records of 242 patients divided into two groups: Group I: 149 patients undergoing cardiopulmonary bypass and Group II - 93 patients undergoing the miniature cardiopulmonary bypass. Results The clinical profile of patients in the preoperative period was similar in the cardiopulmonary bypass and miniature cardiopulmonary bypass groups without significant differences, except in age, which was greater in the miniature cardiopulmonary bypass group. The perioperative data were significant of blood collected for autotransfusion, which were higher in the group with miniature cardiopulmonary bypass than the cardiopulmonary bypass and in transfusion of packed red blood cells, which was higher in cardiopulmonary bypass than in miniature cardiopulmonary bypass. In the immediate, first and second postoperative period the values of hematocrit and hemoglobin were higher and significant in miniature cardiopulmonary bypass than in the cardiopulmonary bypass, although the bleeding in the first and second postoperative days was higher and significant in miniature cardiopulmonary bypass than in the cardiopulmonary bypass. Conclusion The present results suggest that the miniature cardiopulmonary bypass was beneficial in reducing the red blood cell transfusion during surgery and showed slight but significant increase in hematocrit and hemoglobin in the postoperative period. PMID:27163417

  6. 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.

  7. 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.

  8. [A clinical experience of V-A bypass using a new antithrombotic coating material].

    PubMed

    Kawahito, K; Ino, T; Ide, H; Adachi, H; Mizuhara, A; Yamaguchi, A

    1992-07-01

    To perform V-A bypass with minimal systemically administered heparin, we used a equipment coated by fluorine-acryl-styrene-urethane-silicone graft copolymer. A 67 year old woman developed right heart failure after CABG was treated for 25 hours on V-A bypass without oxygenator by using this new antithrombotic coating material. During V-A bypass, hemodynamics were stable. Not coagulative nor hemolytic disorder was observed. And she did not suffer from thrombotic nor hemorrhagic complications. Scanning electron microscopy of coated equipment demonstrated only minor deposits on the surface, and morphologic study of platelet was almost normal. By using this new antithrombotic material it is possible to perform V-A bypass with minimal heparinization, thus avoiding the risk of major coagulation complications. PMID:1506705

  9. 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

  10. Partial flow compensation by transverse bypass configuration in multi-channel cryogenic compact heat exchanger

    NASA Astrophysics Data System (ADS)

    Jung, Jeheon; Hwang, Gyuwan; Baek, Seungwhan; Jeong, Sangkwon; Rowe, Andrew M.

    2012-01-01

    High-performance multi-channel heat exchangers are vulnerable to small defects such as ill-manufacture or contamination in flow channels. Even slight flow mal-distribution may result in drastic reduction of their thermal performance. In order to accommodate such performance reduction in multi-channel heat exchangers, transverse bypass structure among the channels of hot stream or cold stream is proposed. Since transverse bypass structure enables voluntary flow re-distribution among the channels, detrimental effect of flow defects can be partially reduced and flow mal-distribution can be locally relieved. The lower the flow resistance of transverse bypass is, the more substantial the flow re-distribution is and the larger its effect can be. Quantitative analysis and experimental verification on the effect of transverse bypass is carried out, and the results are presented in this paper.

  11. Quality of Life After Bypass Surgery in Patients with Chest Pain and Heart Failure

    MedlinePlus

    ... Bypass Surgery in Patients With Chest Pain and Heart Failure The full report is titled “Quality-of-Life ... in patients who have coronary artery disease plus heart failure, which can cause additional symptoms, such as shortness ...

  12. Electrocardiogram in a 39-Year-Old Woman After Coronary Artery Bypass Grafting.

    PubMed

    Glancy, David L

    2016-08-15

    After coronary arterial bypass operation for angina pectoris without prior myocardial infarction, a 39-year-old woman has an electrocardiogram during right ventricular pacing that is highly specific for anterior myocardial infarction. PMID:27328957

  13. Vascularized Nerve Bypass Graft: A Case Report of an Additional Treatment for Poor Sensory Recovery.

    PubMed

    Usami, Satoshi; Tanaka, Kentaro; Ohkubo, Alisa; Okazaki, Mutsumi

    2016-04-01

    End-to-side neurorrhaphy has proven effective in basic research and in clinical application. One of the methods of end-to-side neurorrhaphy, nerve bypass technique, has been reported and axon regeneration has been proven. In clinical application, the utility of the nerve bypass technique has been revealed in some cases; however, these bypasses were performed using nonvascularized nerves. We initially used the vascularized nerve bypass graft technique with the sural nerve as a secondary clinical procedure after median nerve injury in a 61-year-old patient and achieved motor and sensory nerve regeneration, as supported by a nerve conduction study and clinical sensory test. This technique has the potential to become one of the choices for salvage procedure of severe nerve injury. PMID:27200248

  14. Vascularized Nerve Bypass Graft: A Case Report of an Additional Treatment for Poor Sensory Recovery

    PubMed Central

    Tanaka, Kentaro; Ohkubo, Alisa; Okazaki, Mutsumi

    2016-01-01

    Summary: End-to-side neurorrhaphy has proven effective in basic research and in clinical application. One of the methods of end-to-side neurorrhaphy, nerve bypass technique, has been reported and axon regeneration has been proven. In clinical application, the utility of the nerve bypass technique has been revealed in some cases; however, these bypasses were performed using nonvascularized nerves. We initially used the vascularized nerve bypass graft technique with the sural nerve as a secondary clinical procedure after median nerve injury in a 61-year-old patient and achieved motor and sensory nerve regeneration, as supported by a nerve conduction study and clinical sensory test. This technique has the potential to become one of the choices for salvage procedure of severe nerve injury. PMID:27200248

  15. An experimental study on minimally occlusive laser-assisted vascular anastomosis in bypass surgery: the importance of temperature monitoring during laser welding procedures.

    PubMed

    Esposito, G; Rossi, F; Puca, A; Albanese, A; Sabatino, G; Matteini, P; Lofrese, G; Maira, G; Pini, R

    2010-01-01

    Laser welding has been proposed as an alternative technique to conventional stitching in microvascular anastomosis, with the advantages of improving the vascular healing process and reducing the risk of malfunction of a bypass. Our group recently proposed a laser-assisted end-to-side anastomotic technique, providing the advantages of laser welding and reducing the occlusion time of the recipient vessel, that is important in neurosurgical bypass procedures, in order to reduce the risk of cerebral ischemia. This in vivo study focuses on the control of the temperature dynamics developing in the welded tissue. A jugular vein graft was harvested and implanted on the rabbit carotid artery by means of two end-to-side anastomosis. Laser welding procedure was then carried out to implant the bypass. A real-time monitoring of the temperature during welding was performed with an infrared thermocamera, in order to control the laser-induced heating effect on the external surface of the vessel walls. The temperature analysis highlighted the dynamic of the heating effect in space and time and enabled us to define an optimal temperature range in operative conditions. The temperature control provided safe tissue heating confined within the directly irradiated area, with negligible damage to surrounding tissues, as well as effective sealing and welding of the vessel edges at the anastomotic sites. The average occlusion time of the carotid artery was about 11 minutes. After a follow-up of 30 days, all the bypasses were patent and no signs of thrombosis or leak point pressure were present, thus confirming the safety of this laser-assisted anastomotic procedure. PMID:20846478

  16. Reduction of intimal hyperplasia and enhanced reactivity of experimental vein bypass grafts with verapamil treatment.

    PubMed Central

    el-Sanadiki, M N; Cross, K S; Murray, J J; Schuman, R W; Mikat, E; McCann, R L; Hagen, P O

    1990-01-01

    in platelet or endothelium function between untreated and verapamil-treated animals, we examined the direct effect of verapamil on smooth muscle. Verapamil significantly inhibited [3H]-thymidine incorporation into DNA in vascular smooth muscle cells in culture in a dose-dependent manner. Verapamil treatment significantly reduces intimal hyperplasia in experimental vein grafts and inhibits smooth muscle cell proliferation in culture. Furthermore the enhanced reactivity to norepinephrine and histamine in the verapamil-treated vessels has no detrimental effect on the patency rate at 4 weeks. Thus by inhibiting intimal hyperplasia, calcium antagonists may improve the long-term patency of vein bypass grafts. Images Figs. 1A-C. PMID:2363608

  17. Flow Behavior in the Left Heart Ventricle Following Apico-Aortic Bypass Surgery

    NASA Astrophysics Data System (ADS)

    Shahriari, Shahrokh; Jeyhani, Morteza; Labrosse, Michel; Kadem, Lyes

    2013-11-01

    Apico-aortic bypass (AAB) surgery is an alternative for transcatheter aortic valve implantation (TAVI) to reduce left ventricle (LV) overload in patients with severe aortic stenosis (AS). It consists in connecting the apex of the LV to the descending thoracic aorta with a valved conduit. Postoperative flow assessments show that two thirds of the outflow is conducted from the LV apex to the conduit, while only one third crosses the native aortic valve. In this study, we performed high speed particle image velocimetry (PIV) measurements of flow pattern within an in vitro elastic model of LV in the presence of a very severe AS, before and after AAB. Results indicate that AAB effectively relieves the LV outflow obstruction; however, it also leads to abnormal ventricular flow patterns. Normal LV flow dynamics is characterized by an emerging mitral jet flow followed by the development of a vortical flow with velocities directed towards the aortic valve, while measurements in the presence of AAB show systolic flow bifurcating to the apical conduit and to the aortic valve outflow tract. This study provides the first insight into the LV flow structure after AAB including outflow jets and disturbed stagnation regions.

  18. Intestinal adaptations in chronic kidney disease and the influence of gastric bypass surgery.

    PubMed

    Hatch, Marguerite

    2014-09-01

    Studies have shown that compensatory adaptations in gastrointestinal oxalate transport can impact the amount of oxalate excreted by the kidney. Hyperoxaluria is a major risk factor in the formation of kidney stones, and oxalate is derived from both the diet and the liver metabolism of glyoxylate. Although the intestine generally absorbs oxalate from dietary sources and can contribute as much as 50% of urinary oxalate, enteric oxalate elimination plays a significant role when renal function is compromised. While the mechanistic basis for these changes in the direction of intestinal oxalate movements in chronic renal failure involves an upregulation of angiotensin II receptors in the large intestine, enteric secretion/excretion of oxalate can also occur by mechanisms that are independent of angiotensin II. Most notably, the commensal bacterium Oxalobacter sp. interacts with the host enterocyte and promotes the movement of oxalate from the blood into the lumen, resulting in the beneficial effect of significantly lowering urinary oxalate excretion. Changes in the passive permeability of the intestine, such as in steatorrhoea and following gastric bypass, also promote oxalate absorption and hyperoxaluria. In summary, this report highlights the two-way physiological signalling between the gut and the kidney, which may help to alleviate the consequences of certain kidney diseases. PMID:24951497

  19. Mutations that bypass tRNA binding activate the intrinsically defective kinase domain in GCN2

    PubMed Central

    Qiu, Hongfang; Hu, Cuihua; Dong, Jinsheng; Hinnebusch, Alan G.

    2002-01-01

    The protein kinase GCN2 is activated in amino acid-starved cells on binding of uncharged tRNA to a histidyl-tRNA synthetase (HisRS)-related domain. We isolated two point mutations in the protein kinase (PK) domain, R794G and F842L, that permit strong kinase activity in the absence of tRNA binding. These mutations also bypass the requirement for ribosome binding, dimerization, and association with the GCN1/GCN20 regulatory complex, suggesting that all of these functions facilitate tRNA binding to wild-type GCN2. While the isolated wild-type PK domain was completely inert, the mutant PK was highly active in vivo and in vitro. These results identify an inhibitory structure intrinsic to the PK domain that must be overcome on tRNA binding by interactions with a regulatory region, most likely the N terminus of the HisRS segment. As Arg 794 and Phe 842 are predicted to lie close to one another and to the active site, they may participate directly in misaligning active site residues. Autophosphorylation of the activation loop was stimulated by R794G and F842L, and the autophosphorylation sites remained critical for GCN2 function in the presence of these mutations. Our results imply a two-step activation mechanism involving distinct conformational changes in the PK domain. PMID:12023305

  20. Patient Specific Multiscale Simulations of Blood Flow in Coronary Artery Bypass Surgery

    NASA Astrophysics Data System (ADS)

    Bangalore Ramachandra, Abhay; Sankaran, Sethuraman; Kahn, Andrew M.; Marsden, Alison L.

    2013-11-01

    Coronary artery bypass surgery is performed to revascularize blocked coronary arteries in roughly 400,000 patients per year in the US.While arterial grafts offer superior patency, vein grafts are used in more than 70% of procedures, as most patients require multiple grafts. Vein graft failure (approx. 50% within 10 years) remains a major clinical issue. Mounting evidence suggests that hemodynamics plays a key role as a mechano-biological stimulus contributing to graft failure. However, quantifying relevant hemodynamic quantities (e.g. wall shear stress) invivo is not possible directly using clinical imaging techniques. We numerically compute graft hemodynamics in a cohort of 3-D patient specific models using a stabilized finite element method. The 3D flow domain is coupled to a 0D lumped parameter circulatory model. Boundary conditions are tuned to match patient specific blood pressures, stroke volumes & heart rates. Results reproduce clinically observed coronary flow waveforms. We quantify differences in multiple hemodynamic quantities between arterial & venous grafts & discuss possible correlations between graft hemodynamics & clinically observed graft failure.Such correlations will provide further insight into mechanisms of graft failure and may lead to improved clinical outcomes.

  1. Homogeneous shear turbulence – bypass concept via interplay of linear transient growth and nonlinear transverse cascade

    NASA Astrophysics Data System (ADS)

    Mamatsashvili, George; Dong, Siwei; Khujadze, George; Chagelishvili, George; Jiménez, Javier; Foysi, Holger

    2016-04-01

    We performed direct numerical simulations of homogeneous shear turbulence to study the mechanism of the self-sustenance of subcritical turbulence in spectrally stable (constant) shear flows. For this purpose, we analyzed the turbulence dynamics in Fourier/wavenumber/spectral space based on the simulation data for the domain aspect ratio 1 : 1 : 1. Specifically, we examined the interplay of linear transient growth of Fourier harmonics and nonlinear processes. The transient growth of harmonics is strongly anisotropic in spectral space. This, in turn, leads to anisotropy of nonlinear processes in spectral space and, as a result, the main nonlinear process appears to be not a direct/inverse, but rather a transverse/angular redistribution of harmonics in Fourier space referred to as the nonlinear transverse cascade. It is demonstrated that the turbulence is sustained by the interplay of the linear transient, or nonmodal growth and the transverse cascade. This course of events reliably exemplifies the wellknown bypass scenario of subcritical turbulence in spectrally stable shear flows. These processes mainly operate at large length scales, comparable to the box size. Consequently, the central, small wavenumber area of Fourier space (the size of which is determined below) is crucial in the self-sustenance and is labeled the vital area. Outside the vital area, the transient growth and the transverse cascade are of secondary importance - Fourier harmonics are transferred to dissipative scales by the nonlinear direct cascade. The number of harmonics actively participating in the self-sustaining process (i.e., the harmonics whose energies grow more than 10% of the maximum spectral energy at least once during evolution) is quite large - it is equal to 36 for the considered box aspect ratio - and obviously cannot be described by low-order models.

  2. High Frequency Single-Stage Multi-Bypass Pulse Tube Cryocooler for 23.8K

    NASA Astrophysics Data System (ADS)

    Yang, Junling; Hou, Xiaofeng; Yang, Luwei; Zhou, Yuan; Zhang, Liang

    2008-03-01

    A below 30K single-stage high-frequency multi-bypass pulse tube cryocooler(PTC) is introduced in this paper. At present, the lowest temperature of 27.46K has been achieved with input power of 100W and 23.8K with input power of 200W. Experiments show that if the area of multi-bypass and the length of inertance tube matching well, a better performance of PTC will be obtained.

  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

    Within a multi-fastener joint, fastener holes may be subjected to the combined effects of bearing loads and loads that bypass the hole to be reacted elsewhere in the joint. The analysis of a joint subjected to search combined bearing and bypass loads is complicated by the usual clearance between the hole and the fastener. A simple analysis method for such clearance-fit joints subjected to bearing-bypass loading has been developed in the present study. It uses an inverse formulation with a linear elastic finite-element analysis. Conditions along the bolt-hole contact arc are specified by displacement constraint equations. The present method is simple to apply and can be implemented with most general purpose finite-element programs since it does not use complicated iterative-incremental procedures. The method was used to study the effects of bearing-bypass loading on bolt-hole contact angles and local stresses. In this study, a rigid, frictionless bolt was used with a plate having the properties of a quasi-isotropic graphite/epoxy laminate. Results showed that the contact angle as well as the peak stresses around the hole and their locations were strongly influenced by the ratio of bearing and bypass loads. For single contact, tension and compression bearing-bypass loading had opposite effects on the contact angle. For some compressive bearing-bypass loads, the hole tended to close on the fastener leading to dual contact. It was shown that dual contact reduces the stress concentration at the fastener and would, therefore, increase joint strength in compression. The results illustrate the general importance of accounting for bolt-hole clearance and contact to accurately compute local bolt-hole stresses for combined bearings and bypass loading.

  4. Total i.v. anaesthesia with propofol and alfentanil for coronary artery bypass grafting.

    PubMed

    Manara, A R; Monk, C R; Bolsin, S N; Prys-Roberts, C

    1991-06-01

    The haemodynamic effects of total i.v. anaesthesia with a combination of propofol and alfentanil infusions were studied in eight patients with good left ventricular function undergoing coronary artery bypass surgery. Haemodynamic indices were measured before anaesthesia and at specified intervals before cardiopulmonary bypass. The technique resulted in haemodynamic changes comparable to those reported with opioid-based anaesthesia for coronary artery surgery, and has potential advantages. PMID:2064887

  5. Experimental and Analytic Study on the Core Bypass Flow in a Very High Temperature Reactor

    SciTech Connect

    Richard Schultz

    2012-04-01

    Core bypass flow has been one of key issues in the very high temperature reactor (VHTR) design for securing core thermal margins and achieving target temperatures at the core exit. The bypass flow in a prismatic VHTR core occurs through the control element holes and the radial and axial gaps between the graphite blocks for manufacturing and refueling tolerances. These gaps vary with the core life cycles because of the irradiation swelling/shrinkage characteristic of the graphite blocks such as fuel and reflector blocks, which are main components of a core's structure. Thus, the core bypass flow occurs in a complicated multidimensional way. The accurate prediction of this bypass flow and counter-measures to minimize it are thus of major importance in assuring core thermal margins and securing higher core efficiency. Even with this importance, there has not been much effort in quantifying and accurately modeling the effect of the core bypass flow. The main objectives of this project were to generate experimental data for validating the software to be used to calculate the bypass flow in a prismatic VHTR core, validate thermofluid analysis tools and their model improvements, and identify and assess measures for reducing the bypass flow. To achieve these objectives, tasks were defined to (1) design and construct experiments to generate validation data for software analysis tools, (2) determine the experimental conditions and define the measurement requirements and techniques, (3) generate and analyze the experimental data, (4) validate and improve the thermofluid analysis tools, and (5) identify measures to control the bypass flow and assess its performance in the experiment.

  6. A cryogenic heat exchanger with bypass and throttling and its thermodynamic analysis

    NASA Astrophysics Data System (ADS)

    Tao, X.; Liu, D. L.; Wang, L. Y.; Shen, J.; Gan, Z. H.

    2015-12-01

    A precooled Joule-Thomson (J-T) cooler refrigerates at liquid helium temperature. Its third stage heat exchanger works below 20 K. Hot fluid cannot be sufficiently cooled due to nonidealism of the heat exchanger and helium-4 properties. In a J-T cycle of low pressure ratio, the heat exchanger with bypass and throttling improves the refrigeration capacity. Bypass and throttling reduces the temperature difference and entropy generation within the heat exchanger.

  7. [THE COGNITIVE STATUS OF PATIENTS WITH TYPE 2 DIABETES MELLITUS AFTER CORONARY BYPASS SURGERY].

    PubMed

    Trubnikova, O A; Mamontova, A S; Syrova, I D; Kukhareva, I N; Maleva, O V; Barbarash, O L

    2015-01-01

    The aim of the study was to evaluate the neuropsychological status of patients with type 2 diabetes mellitus (DM2) before and I year after coronary bypass surgery performed under conditions of artificial circulation. It included 114 patients (54 with and 60 without DM2). Prior to surgery, the patients with DM2 had positive characteristics of neurodynamics and attention. They deteriorated 1 year after coronary bypass surgery, but improved in the patients without DM2. PMID:26669030

  8. Timing of Coronary Bypass Surgery in Patients Receiving Clopidogrel: The Role of VerifyNow.

    PubMed

    Bedeir, Kareem; Bliden, Kevin; Tantry, Udaya; Gurbel, Paul A; Mahla, Elisabeth

    2016-06-01

    We briefly report for the first time the association between a point of care platelet recovery test and the timing of coronary artery bypass grafting after clopidogrel withdrawal. We observe an association between suggested wait days and platelet recovery unit values that might potentially allow for safe shorter wait times before coronary artery bypass grafting without increased bleeding. Our results represent an observation and should prompt further validation. PMID:27094125

  9. Cardiopulmonary Bypass Strategy for a Cyanotic Child With Hemoglobin SC Disease.

    PubMed

    Machovec, Kelly A; Jaquiss, Robert D B; Kaemmer, David D; Ames, Warwick A; Homi, Hercilia M; Walczak, Richard J; Lodge, Andrew J; Jooste, Edmund H

    2016-06-01

    Hemoglobin SC (HbSC) disease is a hemoglobinopathy that may produce sickling under conditions of hypoxemia, dehydration, and acidosis. We present a case of HbSC disease and tricuspid atresia, type IB. We describe management by cardiopulmonary bypass CPB using exchange transfusion at initiation of bypass and fractionation of collected blood, allowing platelet and plasma apheresis, as an option for patients unable to undergo this procedure off pump. PMID:27211949

  10. Imaging of coronary artery bypass grafts by computed tomography coronary angiography.

    PubMed

    Laspas, Fotios; Roussakis, Arkadios; Kritikos, Nikolaos; Mourmouris, Christos; Efthimiadou, Roxani; Andreou, John

    2013-01-01

    In recent years, computed tomography coronary angiography is commonly performed as a follow-up examination after coronary artery bypass graft surgery. Coronary grafts owing to their minimal motion are well visualized by computed tomography coronary angiography, allowing radiologists to assess their patency noninvasively with very high diagnostic accuracy. The purpose of this pictorial essay is to provide an excellent overview of the anatomy and findings concerning coronary artery bypass grafts. PMID:24159923

  11. Combined bearing and bypass loading on a graphite/epoxy laminate

    NASA Technical Reports Server (NTRS)

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

    1986-01-01

    A combined experimental and analytical study was conducted to determine the behavior of a graphite/epoxy laminate subjected to combined bearing and bypass loading. Single-fastener quasi-isotropic specimens were loaded at various bearing-bypass ratios until damage was produced at the fastener hole. Damage-onset strengths and damage modes were then analyzed using local hole-boundary stresses calculated by a finite-element analysis. The tension data showed the expected linear interaction for combined bearing and bypass loading with damage developing in the net-section tension mode. However, the compression bearing-bypass strengths showed an unexpected interaction involving the bearing mode. Compressive bypass loads reduced the bearing strength by decreasing the bolt-hole contact arc and thus increasing the severity of the bearing loads. The bearing stresses at the hole boundary were not accurately estimated by superposition of the stress components for separate bearing and bypass loading. However, superposition produced reasonably accurate estimates for tangential stresses especially near the specimen net-section.

  12. 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

  13. Deoxypyrimidine monophosphate bypass therapy for thymidine kinase 2 deficiency

    PubMed Central

    Garone, Caterina; Garcia-Diaz, Beatriz; Emmanuele, Valentina; Lopez, Luis C; Tadesse, Saba; Akman, Hasan O; Tanji, Kurenai; Quinzii, Catarina M; Hirano, Michio

    2014-01-01

    Autosomal recessive mutations in the thymidine kinase 2 gene (TK2) cause mitochondrial DNA depletion, multiple deletions, or both due to loss of TK2 enzyme activity and ensuing unbalanced deoxynucleotide triphosphate (dNTP) pools. To bypass Tk2 deficiency, we administered deoxycytidine and deoxythymidine monophosphates (dCMP+dTMP) to the Tk2 H126N (Tk2−/−) knock-in mouse model from postnatal day 4, when mutant mice are phenotypically normal, but biochemically affected. Assessment of 13-day-old Tk2−/− mice treated with dCMP+dTMP 200 mg/kg/day each (Tk2−/−200dCMP/dTMP) demonstrated that in mutant animals, the compounds raise dTTP concentrations, increase levels of mtDNA, ameliorate defects of mitochondrial respiratory chain enzymes, and significantly prolong their lifespan (34 days with treatment versus 13 days untreated). A second trial of dCMP+dTMP each at 400 mg/kg/day showed even greater phenotypic and biochemical improvements. In conclusion, dCMP/dTMP supplementation is the first effective pharmacologic treatment for Tk2 deficiency. Subject Categories Genetics, Gene Therapy & Genetic Disease; Metabolism PMID:24968719

  14. In situ saphenous vein bypass for limb salvage.

    PubMed

    Sarcina, A; Carlesi, R; Bellosta, R; Agrifoglio, G

    1993-02-01

    A total of 130 infrapopliteal in situ saphenous vein bypasses were performed in 128 patients between January 1980 and June 1991. The indication for surgery was critical ischaemia with impending limb loss in 121 patients; seven suffered from severe claudication. The distal anastomosis was to the popliteal artery below the knee in 60 cases (46.2%) and in 70 (53.8%) to the tibioperoneal arteries. The results, in terms of secondary patency and limb salvage rates, of the first 68 procedures (1980-1985) and subsequent 62 (1986-June 1991) were compared. In the first period, a secondary patency rate of 42.6% and a limb salvage rate of 67.0% were obtained, compared with 71.3 and 80.8% respectively in the second. These differences are significant for patency (P < 0.005) and limb salvage (P < 0.01). These results show that the in situ technique can give acceptable results but a learning period with a high percentage of early failures is to be expected. PMID:8075993

  15. Coronary risk factors in patients underwent coronary artery bypass grafting.

    PubMed

    Safaei, Nasser; Alikhah, Hossein; Abadan, Younes

    2011-01-01

    Coronary Artery Disease (CAD) risk increases with increasing number of risk factors. This study was aimed to assess different coronary risk factors among Coronary Artery Bypass Grafting (CABG) surgery patients. A total of 700 patients younger than 45 or older than 65 years and underwent CABG in Tabriz Shahid Madani Heart Center since 2003 to 2007 were enrolled. We examined the probable differences of CAD risk factors between male and female groups and age groups. We also assessed the change of risk factors presentation in last 5 years. There was not significant difference between risk factor numbers in <45 and >65 years groups, but smoking and dyslipidemia was more prevalent in patients < 45 than > 65 years old. Hypertension and diabetes mellitus was more prevalent in patients > 65 old than < 45 years old; also differences were found between males and females patients, so that dyslipidemia, diabetes and hypertension were more prevalent in women than men. Some risk factors were recognized as acting more on one gender than the other. Also, the majority of patients have one or more risk factors, but different age and gender groups may have different risk factors that suggest the need for exact programming for appropriate prophylactic and therapeutic interventions in all groups. PMID:21913494

  16. A Novel Rotary Pulsatile Flow Pump for Cardiopulmonary Bypass

    PubMed Central

    Teman, Nicholas R.; Mazur, Daniel E.; Toomasian, John; Jahangir, Emilia; Alghanem, Fares; Goudie, Marcus; Rojas-Peña, Alvaro; Haft, Jonathan W.

    2014-01-01

    It has been suggested that pulsatile blood flow is superior to continuous flow in cardiopulmonary bypass (CPB). However, adoption of pulsatile flow (PF) technology has been limited due to practically and complexity of creating a consistent physiologic pulse. A pediatric pulsatile rotary ventricular pump (PRVP) was designed to address this problem. We evaluated the PRVP in an animal model, and determined its ability to generate PF during CPB. The PRVP (modified peristaltic pump, with tapering of the outlet of the pump chamber) was tested in 4 piglets (10-12kg). Cannulation was performed with right atrial and aortic cannulae, and pressure sensors were inserted into the femoral arteries. Pressure curves were obtained at different levels of flow and compared with both the animal's baseline physiologic function and a continuous flow (CF) roller pump. Pressure and flow waveforms demonstrated significant pulsatility in the PRVP setup compared to CF at all tested conditions. Measurement of hemodynamic energy data, including the percent pulsatile energy and the surplus hydraulic energy, also revealed a significant increase in pulsatility with the PRVP (p <0.001). PRVP creates physiologically significant PF, similar to the pulsatility of a native heart, and has the potential to be easily implemented in pediatric CPB. PMID:24625536

  17. Rplp1 bypasses replicative senescence and contributes to transformation

    SciTech Connect

    Artero-Castro, A.; Kondoh, H.; Fernandez-Marcos, P.J.; Serrano, M.; Ramon y Cajal, S.; LLeonart, M.E.

    2009-05-01

    To determine whether genes expressed by embryonic stem cells have a proliferative effect in primary cells, primary mouse embryonic fibroblasts were infected with an ES cell cDNA library. This led to identification of the ribosomal protein, Rplp1, a member of the P group of ribosomal proteins, whose putative role for bypassing replicative senescence in MEFs was investigated. Our results show that Rplp1 produces a two-fold increase in the expression of an E2F1 promoter and upregulation of cyclin E in MEFs. Therefore, this study is the first to show that overexpression of a single ribosomal protein, Rplp1, is a cause and not a consequence of cell proliferation. In addition, co-expression of Rplp1 with mutant ras{sup Val12} contributed to transformation in NIH3T3 cells, as was evidenced by colony production in soft-agar assays. Moreover, the Rplp1 protein was upregulated in MEFs and NIH3T3 cells upon expression of a p53 dominant negative mutant gene designated p53R175H. Hence, mutation of p53 may facilitate immortalization in vitro by upregulating Rplp1. Lastly, Rplp1 mRNA was found to be upregulated in 16 of 26 human colon cancer biopsy specimens, a finding that may be of relevance to cancer research.

  18. A pulsatile pump for cardiopulmonary bypass and its clinical use.

    PubMed

    Sasaki, Y; Kawai, T; Nishiyama, K; Murayama, Y; Toda, S; Wada, T; Kitaura, K; Sato, S; Kadowaki, M; Kanki, Y

    1988-09-01

    A pulsatile pump driven by a coil spring, which was designed and constructed by us, is described in this report. It consists of two main parts, a disposable blood chamber and a driving section. The blood chamber has two leaflet valves and a piston, which is covered with two bellofram rolling diaphragms and moves into the housing to draw in and eject the blood. The driving section consists of three cams, an electric motor and a coil spring. The ejection force is wholly produced by the compressed coil spring and is transmitted to the piston in the blood chamber by a rod. This pump allows the ejection pressure, the beat rates, and the stroke volume all to be changed independently. The performance of the pump was tested by using a circulation model where the beat rate was adjusted from 30 to 250 bpm. The output subsequently increased from 0.8 l/min to 5.7 l/min and the stroke volume, from 20.4 ml to 36.7 ml. This new pump has been used for clinical cardiopulmonary bypasses in 24 patients of open heart surgery and the pressure traces during perfusion resembled those of the patients' own hearts. PMID:3230723

  19. Chronic Severe Hyponatremia and Cardiopulmonary Bypass: Avoiding Osmotic Demyelination Syndrome.

    PubMed

    Canaday, Susan; Rompala, John; Rowles, John; Fisher, Josh; Holt, David

    2015-12-01

    Serum sodium concentration affects every cell in the body with respect to cellular tonicity. Hyponatremia is the most frequent electrolyte abnormality encountered, occurring at clinical admission in 22% of elderly patients. Any rapid correction of chronic severe hyponatremia can result in rapid cellular shrinking due to loss of intracellular free water. This is commonly associated with paralysis and severe brain damage due to osmotic demyelination syndrome (ODS). ODS occurs because the body has the ability to compensate for cellular fluid shifts due to chronic hyponatremia (by a decrease in brain concentration of several ions, amino acids, and organic osmolytes). Thus, the neurons are often at a functional state of fluid balance despite the sodium imbalance. The initiation of cardiopulmonary bypass (CPB) can introduce between 1 and 2 L of priming solution containing a normal sodium concentration creating a rapid rise in sodium concentration within the extracellular fluid. This abrupt change establishes a situation where intracellular free water can be lost resulting in cellular shrinking and ODS. In presenting this case study, we hope to add to the current literature with a specific isotonic approach to treating the chronically severe hyponatremic patient pre-CPB, during CPB, and post-CPB. PMID:26834285

  20. Bypassing the Pentose Phosphate Pathway: Towards Modular Utilization of Xylose

    PubMed Central

    Chomvong, Kulika; Bauer, Stefan; Benjamin, Daniel I.; Li, Xin; Nomura, Daniel K.; Cate, Jamie H. D.

    2016-01-01

    The efficient use of hemicellulose in the plant cell wall is critical for the economic conversion of plant biomass to renewable fuels and chemicals. Previously, the yeast Saccharomyces cerevisiae has been engineered to convert the hemicellulose-derived pentose sugars xylose and arabinose to d-xylulose-5-phosphate for conversion via the pentose phosphate pathway (PPP). However, efficient pentose utilization requires PPP optimization and may interfere with its roles in NADPH and pentose production. Here, we developed an alternative xylose utilization pathway that largely bypasses the PPP. In the new pathway, d-xylulose is converted to d-xylulose-1-phosphate, a novel metabolite to S. cerevisiae, which is then cleaved to glycolaldehyde and dihydroxyacetone phosphate. This synthetic pathway served as a platform for the biosynthesis of ethanol and ethylene glycol. The use of d-xylulose-1-phosphate as an entry point for xylose metabolism opens the way for optimizing chemical conversion of pentose sugars in S. cerevisiae in a modular fashion. PMID:27336308