Pathway-related modules involved in the application of sevoflurane or propofol in off-pump coronary artery bypass graft surgery.

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Bu, Xiangmei; Wang, Bo; Wang, Yaoqi; Wang, Zhigang; Gong, Chunzhi; Qi, Feng; Zhang, Caixia

2017-07-01

Off-pump coronary artery bypass graft (CABG) surgery has recently emerged as a means to avoid the sequelae of extracorporeal circulation, including the whole-body inflammatory response, coagulation disorders and multiple organ dysfunction. At present, gas anesthesia, sevoflurane and intravenous anesthesia and propofol have been widely used during the CABG. To further understand the underlying mechanisms of these anesthetics on the gene level, the present study conducted pathway-related module analysis based on a co-expression network. This was performed in order to identify significant pathways in coronary artery disease patients who had undergone off-pump CABG surgery before and after applying sevoflurane or propofol. A total of 269 and 129 differentially expressed genes were obtained in the sevoflurane and propofol groups, respectively. In total, eight and seven pathways (P<0.05) in the sevoflurane and propofol groups were separately obtained via Kyoto Encyclopedia of Genes and Genome pathway analysis. Finally, eight and seven pathway-related modules in the sevoflurane and propofol groups were obtained, respectively. Furthermore, the mean degree of complement and coagulation cascades pathway-related module in both of the groups was the highest. It was predicted that during the CABG, the anesthetics might activate the complement and coagulation systems in order to possess some cardioprotective properties.

Study of perioperative extravascular lung water and intrathoracic blood volume in patients undergoing CABG surgery with or without cardiopulmonary bypass

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Samia Ragab El Azab

2014-10-01

Discussion and Conclusion: The clinical advantage of off-pump CABG surgery over standard extracorporeal circulation in regard to lung water content was not found in our study. In conclusion, the presumed superiority of off pump surgery for coronary artery bypass grafting could not be confirmed in our group of patients.

Frequency of Acute Kidney Injury in Patients Treated With Normal Saline after Off-Pump Coronary Artery Bypass Grafting

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Shima Sheybani

2017-03-01

Full Text Available Introduction: Acute kidney injury (AKI is a common postoperative complication of cardiac surgery, which is associated with an increased risk of morbidity and mortality. This study investigated the frequency of postoperative AKI in low risk adult patients undergoing off-pump coronary artery bypass grafting (CABG.Materials & Methods: All consecutive adult patients of American Society of Anesthesiologists (ASA class II and III, who were transferred to the post-operative cardiac surgery ICU after off-pump CABG and were low risk for AKI from October 2013 to September 2014 at Emam Reza Hospital, Mashhad, Iran were enrolled in this prospective cohort study at a teaching hospital. The patients were explored for AKI development, based on risk-injury-failure-loss- end stage kidney disease (RIFLE and acute kidney injury network (AKIN criteria, frequency of metabolic acidosis, hypernatremia, hyperchloremia, and length of stay in ICU.Results: According to the results of the present study, 479 patients with the mean age of 60.8±10.75 yrs were included. AKI occurred in 22 (4.4% and23 (4.8% patients, based on both the RIFLE and AKIN criteria, respectively with the highest rate of AKI, reported on the third and fourth post-operative days. Additionally, hyperchloremia and hypernatremia were observed in 71 (14.8% and 76 (15.9% patients, respectively. Only one case of mortality occurred during the study. Metabolic acidosis was reported in 112 (23.4% patients with a high anion gap in 60 (12.5% cases.Conclusion: The current study demonstrated that hypernatremia and metabolic acidosis but not AKI are frequently seen in patients receiving normal saline following off pump CABG with low risk for AKI.

Platelet hyperreactivity in response to on- and off-pump coronary artery bypass grafting

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Bochsen, Louise; Rosengaard, Lisbeth Bredahl; Nielsen, Allan Bybeck

2009-01-01

Hypercoagulability has been reported after off-pump coronary artery bypass grafting (OPCAB) compared with patients undergoing standard coronary artery bypass grafting (CABG) with cardiopulmonary bypass. The aim of this study was to evaluate the changes in platelet reactivity in response to cardiac...... and this study identified 23% of patients needing coronary bypass surgery to be at high risk for recurrent ischemic events at 1 month after surgery, based on the MA. These results suggest that a more aggressive antithrombotic treatment might be warranted for patients undergoing coronary artery bypass grafting...

Postoperative chest radiographic changes after on- and off-pump coronary surgery

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Narayan, P.; Caputo, M.; Jones, J.; Al-Tai, S.; Angelini, G.D.; Wilde, P.

2005-01-01

AIM: A variety of chest radiograph abnormalities are recognized after coronary artery bypass grafting (CABG). This study analyzes the appearance of preoperative and postoperative chest radiographs in two groups of patients undergoing myocardial revascularization with or without the use of cardiopulmonary bypass (CPB). METHODS: Chest radiographs (preoperative and at 1 day, 6 days and 6 to 8 weeks post operatively) were analyzed according to a detailed protocol in cases of conventional CABG on CPB (n=60) or off-pump coronary artery bypass (OPCAB) (n=60) surgery. On each film 17 different major potential postoperative abnormalities were analyzed. RESULTS: Clinical findings were similar in the two groups. Patients undergoing OPCAB surgery had decreased blood loss, decreased red cell and platelet transfusion, significantly lower intubation time and required less postoperative inotropic support compared with patients undergoing CPB. The CPB group had a significantly higher incidence of left band atelectasis than the OPCAB group (37.6% vs 17.5%, p=0.01) at 6 days postoperatively. There was no other statistically significant difference in any of the 16 remaining major chest radiograph findings between the two groups. CONCLUSION: Although OPCAB surgery is associated with improved clinical outcome compared with conventional CABG surgery, the analysis of postoperative chest radiographs demonstrated only a minor benefit as shown by a reduced degree of left band atelectasis in the OPCAB group

Postoperative chest radiographic changes after on- and off-pump coronary surgery

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Narayan, P. [Bristol Heart Institute, Bristol Royal Infirmary, Bristol (United Kingdom); Caputo, M. [Bristol Heart Institute, Bristol Royal Infirmary, Bristol (United Kingdom); Jones, J. [Department of Radiology, Bristol Royal Infirmary, Bristol (United Kingdom); Al-Tai, S. [Department of Radiology, Bristol Royal Infirmary, Bristol (United Kingdom); Angelini, G.D. [Bristol Heart Institute, Bristol Royal Infirmary, Bristol (United Kingdom); Wilde, P. [Department of Radiology, Bristol Royal Infirmary, Bristol (United Kingdom)]. E-mail: peter.wilde@ubht.swest.nhs.uk

2005-06-01

AIM: A variety of chest radiograph abnormalities are recognized after coronary artery bypass grafting (CABG). This study analyzes the appearance of preoperative and postoperative chest radiographs in two groups of patients undergoing myocardial revascularization with or without the use of cardiopulmonary bypass (CPB). METHODS: Chest radiographs (preoperative and at 1 day, 6 days and 6 to 8 weeks post operatively) were analyzed according to a detailed protocol in cases of conventional CABG on CPB (n=60) or off-pump coronary artery bypass (OPCAB) (n=60) surgery. On each film 17 different major potential postoperative abnormalities were analyzed. RESULTS: Clinical findings were similar in the two groups. Patients undergoing OPCAB surgery had decreased blood loss, decreased red cell and platelet transfusion, significantly lower intubation time and required less postoperative inotropic support compared with patients undergoing CPB. The CPB group had a significantly higher incidence of left band atelectasis than the OPCAB group (37.6% vs 17.5%, p=0.01) at 6 days postoperatively. There was no other statistically significant difference in any of the 16 remaining major chest radiograph findings between the two groups. CONCLUSION: Although OPCAB surgery is associated with improved clinical outcome compared with conventional CABG surgery, the analysis of postoperative chest radiographs demonstrated only a minor benefit as shown by a reduced degree of left band atelectasis in the OPCAB group.

Nonselective carotid artery ultrasound screening in patients undergoing coronary artery bypass grafting: Is it necessary?

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Masabni, Khalil; Sabik, Joseph F.; Raza, Sajjad; Carnes, Theresa; Koduri, Hemantha; Idrees, Jay J.; Beach, Jocelyn; Riaz, Haris; Shishehbor, Mehdi H.; Gornik, Heather L.; Blackstone, Eugene H.

2016-01-01

Objectives To determine whether nonselective preoperative carotid artery ultrasound screening alters management of patients scheduled for coronary artery bypass grafting (CABG), and whether such screening affects neurologic outcomes. Methods From March 2011 to September 2013, preoperative carotid artery ultrasound screening was performed on 1236 of 1382 patients (89%) scheduled to undergo CABG. Carotid artery stenosis (CAS) was classified as none or mild (any type 0%–59% stenosis), moderate (unilateral 60%-79% stenosis), or severe (bilateral 60%-79% stenosis or unilateral 80%–100% stenosis). Results A total of 1069 (86%) hadunderwent combined CABG + carotid endarterectomy (CEA); 11 (12%) had off-pump surgery. Of those with severe CAS, 18 (23%) had confirmatory testing, and 18 (23%) underwent combined CABG + CEA; 6 (7.8%) had off-pump surgery. Stroke occurred in 14 of 1069 (1.3%) patients with CABG + CEA and 3 of 148 (2.0%) undergoing CABG alone experienced stroke (P = .4). In patients with moderate CAS, stroke occurred in 1 of 11 (9.1%) off-pump and 1 of 79 (1.3%) on-pump patients (P = .2). In patients with severe CAS, stroke occurred in 1 of 6 (17%) off-pump and 1 of 71 (1.4%) on-pump patients (P = .15). Conclusions Routine preoperative carotid artery evaluation altered the management of a minority of patients undergoing CABG; this did not translate into perioperative stroke risk. Hence, a more targeted approach for preoperative carotid artery evaluation should be adopted. PMID:26586360

Outcomes of On-pump Coronary Artery Bypass Grafting in Patients with Metabolic Syndrome in Mashhad, Iran

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Aliasghar Moeinipour

2017-09-01

Full Text Available Introduction: Metabolic syndrome (MS is considered as an important risk factor for advanced coronary artery disease. This condition can increase the mortality and morbidity in the patients undergoing coronary artery bypass graft (CABG surgery. The aim of the study was compared mortality and morbidity after off Pump- CABG surgery between patients with and without the Metabolic syndrome. Materials & Methods: This prospective cross-sectional study was conducted on 120 patients, who underwent off-pump CABG surgery between October 2014-October 2016. The participants were equally divided into two groups including the patients with and without MS (MS and non-MS, respectively. Results: According to the results, 68 (56.6% patients were male. Furthermore, out of the 60 participants with MS, 36 (60% cases were male. The mean ages of the MS and non-MS groups were 64.96±9.6 and 65.62±10.6 P=0.6 years, respectively. No statistically significant difference was observed between the two groups in terms of the mortality and morbidity (e.g., surgical wound infection, length of Intensive Care Unit and hospital stay, atrial fibrillation rhythm, and bleeding in the first 24 h. The intubation time in patients with Metabolic Syndrome was significantly higher than patients without Metabolic Syndrome (6.66 ± 1.97 vs 5.83 ± 1.93 respectively; P=0.007 Conclusion: Metabolic syndrome was not associated with higher mortality and morbidity after CABG surgery compare to patients without Metabolic syndrome, although patients with Metabolic syndrome had higher risk for long intubation time.

Off-pump coronary artery bypass surgery in severe left ventricular dysfunction.

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Azarfarin, Rasoul; Pourafkari, Leili; Parvizi, Rezayat; Alizadehasl, Azin; Mahmoodian, Roghaiyeh

2010-02-01

Our aim was to examine hospital outcomes of coronary artery bypass surgery in patients with and without left ventricular dysfunction, with regard to the surgical technique (off- or on-pump). Between March 2007 and March 2008, 689 consecutive patients underwent isolated first-time coronary artery bypass; 127 had ejection fractions fractions >30% (group 2). Data of preoperative risk profiles and hospital outcomes were collected prospectively. Off-pump operations were performed in 49 (38.6%) patients in group 1 and 196 (34.9%) in group 2. The incidences of infectious, neurologic, and cardiac complications postoperatively were significantly higher in group 1. In multivariate analysis, preoperative ejection fraction operations, but no significant difference in mortality was observed between those undergoing off-pump or conventional surgery in either group. Off-pump surgery helped to limit the increased morbidity rate after coronary bypass in patients with ventricular dysfunction.

Revascularização miocárdica em pacientes octogenários: estudo retrospectivo e comparativo entre pacientes operados com e sem circulação extracorpórea Myocardial revascularization in octogenarian patients: retrospective and comparative study between patients operated on pump and off pump

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Ricardo Lima

2005-03-01

Full Text Available OBJETIVO: O objetivo do presente trabalho é comparar e analisar os benefícios da cirurgia com e sem CEC, em pacientes octogenários. MÉTODO: Foram analisados dados retrospectivos dos pacientes com 80 anos de idade ou mais, no período de dezembro 1995 a dezembro de 2003. Neste período, 73 pacientes foram submetidos à revascularização do miocárdio (RM, sendo 26 (35,6% com CEC e 47 (64,4%, sem CEC. Os dados demográficos, fatores de risco pré-operatório, comorbidades, classe da angina (CCVS, complicações pós-operatórias e resultados cirúrgicos foram comparados entre os dois grupos (com CEC e sem CEC. Utilizou-se o teste de "t de Student" na comparação entre os grupos e foi considerado um nível de significância de p OBJECTIVE: The purpose of the present study is to compare and analyze the benefits of this operation with and without cardiopulmonary bypass in octogenarian patients. METHOD: Retrospective data of the patients aged eighty years or more from December 1995 to December 2003 were analyzed. During this period 73 patients were submitted to coronary artery bypass grafting (CABG, 26 (35.6% on-pump and 47 (64.4% off-pump. A comparison was made of the demographic data, preoperative risks, concurrent morbid conditions, types of angina, postoperative complications and surgical outcomes between the on-pump and off-pump groups. The Student t-test was used to compare the groups and the level of significance was set at p-value < 0.05. RESULTS: Both groups showed a high preoperative risk, although the off-pump group presented less surgical mortality (11.5% vs 2.1%, p < 0.05. No strokes were observed in the patients operated on off-pump (11.5% vs 0.0%, p < 0.005. Atrial fibrillation (AF in the immediate postoperative period was present less often in the off-pump group (30.8% vs 12.8%, p < 0.005. The postoperative mechanical ventilation time and the presence of respiratory failure were less in the off-pump group (p < 0.005. The presence

Sequential Vein Bypass Grafting is Not Associated with an Increase of Either In-hospital or Mid-term Adverse Events in Off-pump Coronary Artery Bypass Grafting

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Fucheng Xiao

2015-01-01

Full Text Available Background: The impact of sequential vein bypass grafting on clinical outcomes is less known in off-pump coronary artery bypass grafting (CABG. We aimed to evaluate the effects of sequential vein bypass grafting on clinical outcomes in off-pump CABG. Methods: From October 2009 to September 2013 at the Fuwai Hospital, 127 patients with at least one sequential venous graft were matched with 127 patients of individual venous grafts only, using propensity score matching method to obtain risk-adjusted outcome comparison. In-hospital measurement was composite outcome of in-hospital death, myocardial infarction (MI, stroke, requirement for intra-aortic ballon pump (IABP assistance and prolonged ventilation. Major adverse cardiac events (MACEs: Death, MI or repeat revascularization and angina recurrence were considered as mid-term endpoints. Results: No significant difference was observed among the groups in baseline characteristics. Intraoperative mean blood flow per vein graft was 40.4 ml in individual venous grafts groups versus 59.5 ml in sequential venous grafts groups (P < 0.001. There were no differences between individual and sequential venous grafts groups with regard to composite outcome of in-hospital mortality, MI, stroke, IABP assistance and prolonged ventilation (11.0% vs. 14.2%, P = 0.45. Individual in-hospital measurement also did not differ significantly between the two groups. At about four years follow-up, the survival estimates free from MACEs (92.5% vs. 97.3%, P = 0.36 and survival rates free of angina recurrence (80.9% vs. 85.5%, P = 0.48 were similar among individual and sequential venous grafts groups with a mean follow-up of 22.5 months. In the Cox regression analysis, sequential vein bypass grafting was not identified as an independent predictor of both MACEs and angina recurrence. Conclusions: Compared to individual vein bypass grafting, sequential vein bypass grafting was not associated with an increase of either in

Off-pump myocardial revascularisation in an octogenarian patient with dextrocardia and situs inversus.

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Ennker, I C; Pietrowski, D; Ennker, J

2006-01-01

Dextrocardia associated with situs inversus totalis is a rare condition and there are few reports of myocardial revascularisation in such patients. An 82-year-old woman with dextrocardia and situs inversus totalis underwent successful off-pump coronary artery bypass grafting using internal mammary arteries. The operative technique was similar to that of off-pump coronary artery bypass grafting for situs solitus. However, for a right-handed surgeon the operation was easier standing on the left side of the patient.

Off-pump Coronary Artery Bypass Graft in a High Risk Patient ...

African Journals Online (AJOL)

On-pump coronary artery bypass graft (CABG) entails the use of cardiopulmonary bypass (CPB). The procedure is safe but it's not without complications like neurocognitive deficits, cerebrovascular accidents, myocardial ischemic injury and activation of inflammatory pathways that contribute to pulmonary, renal, hematologic ...

Target vessel detection by epicardial ultrasound in off-pump coronary bypass surgery.

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Hayakawa, Masato; Asai, Tohru; Kinoshita, Takeshi; Suzuki, Tomoaki; Shiraishi, Shoichiro

2013-01-01

The detection of embedded coronary arteries is difficult especially in off-pump coronary bypass surgery. From June 2010, we introduced high-frequency epicardial ultrasound (ECUS) to assess and evaluate embedded arteries during off-pump coronary bypass surgery. Between June 2010 and June 2011, a total of 89 consecutive patients underwent isolated coronary bypass surgery at our institution. The patients consisted of 72 men and 17 women with a mean age of 67.9 years. We routinely use the VeriQC system (MediStim, Oslo, Norway) to detect the target vessels in the operation. The patients were assigned to one of two groups, depending on whether ECUS was used in the operation (n = 10, ECUS group) or not (n = 79, non-ECUS group). We analyzed the impact of introducing the ECUS in terms of operative outcome. All patients underwent revascularization using the off-pump technique without emergent conversion to cardiopulmonary bypass during surgery. The total number of distal anastomoses was 299, and 12 target vessels could not be identified either visually or on palpation. Thus, the frequency of the embedded coronary arteries was 4.01% (12/299 cases). The preoperative profiles of the two groups were not significantly different. Operation time was significantly longer in the ECUS group (P = 0.02). There were no significant differences in postoperative outcome between the two groups. In the present study, in which the target coronary arteries could not be detected either visually or on palpation in 12 (4.01%) of 299 cases, the use of high-frequency ECUS allowed all patients to undergo off-pump coronary bypass surgery without conversion to cardiopulmonary bypass during the operation. High-frequency ECUS is therefore useful in off-pump coronary bypass surgery.

Effect of different dosages of nitroglycerin infusion on arterial blood gas tensions in patients undergoing on- pump coronary artery bypass graft surgery.

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Masoumi, Gholamreza; Pour, Evaz Hidar; Sadeghpour, Ali; Ziayeefard, Mohsen; Alavi, Mostapha; Anbardan, Sanam Javid; Shirani, Shahin

2012-02-01

On-pump coronary artery bypass graft (CABG) surgery impairs gas exchange in the early postoperative period. The main object on this study was evaluation of changes in arterial blood gas values in patients underwent on pump CABG surgery receiving different dose of intravenous nitroglycerin (NTG). sixty-seven consecutive patients undergoing elective on-pump CABG randomly enrolled into three groups receiving NTG 50 μg/min (Group N1, n =67), 100 μg/min (Group N2, n = 67), and 150 μg/min (Group N3, n = 67). Arterial blood gas (ABG) tensions were evaluated just before induction of anesthesia, during anesthesia, at the end of warming up period, and 6 h after admission to the intensive care unit. Pao2 and PH had the highest value during surgery in Group N1, Group N2, and Group N3. No significant difference was noted in mean values of Pao2 and PH during surgery between three groups (P > 0.05). There was no significant difference in HCO3 values in different time intervals among three groups (P > 0.05). our results showed that infusing three different dosage of NTG (50, 100, and 150 μg/min) had no significant effect on ABG tensions in patients underwent on-pump CABG surgery.

Effect of preoperatively continued aspirin use on early and mid-term outcomes in off-pump coronary bypass surgery: a propensity score-matched study of 1418 patients.

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Fucheng Xiao

Full Text Available To date, effect of preoperatively continued aspirin administration in off-pump coronary artery bypass grafting (CABG is less known. We aimed to assess the effect of preoperatively continued aspirin use on early and mid-term outcomes in patients receiving off-pump CABG.From October 2009 to September 2013 at the Fuwai Hospital, 709 preoperative aspirin users were matched with unique 709 nonaspirin users using propensity score matching to obtain risk-adjusted outcome comparisons between the two groups. Early outcomes were in-hospital death, stroke, intra- and post-operative blood loss, reoperation for bleeding and blood product transfusion. Major adverse cardiac events (death, myocardial infarction or repeat revascularization, angina recurrence and cardiogenic readmission were considered as mid-term endpoints.There were no significant differences among the groups in baseline characteristics after propensity score matching. The median intraoperative blood loss (600 ml versus 450 ml, P = 0.56, median postoperative blood loss (800 ml versus 790 ml, P = 0.60, blood transfusion requirements (25.1% versus 24.4%, P = 0.76 and composite outcome of in-hospital death, stroke and reoperation for bleeding (2.8% versus 1.6%, P = 0.10 were similar in aspirin and nonaspirin use group. At about 4 years follow-up, no significant difference was observed among the aspirin and nonaspirin use group in major adverse cardiac events free survival estimates (95.7% versus 91.5%, P = 0.23 and freedom from cardiogenic readmission (88.5% versus 85.3%, P = 0.77 whereas the angina recurrence free survival rates was 83.7% and 73.9% in the aspirin and nonaspirin use group respectively (P = 0.02, with odd ratio for preoperative aspirin estimated at 0.71 (95% confidence interval, 0.49-1.04, P = 0.08.Preoperatively continued aspirin use was not associated with increased risk of intra- and post-operative blood loss, blood transfusion requirements and composite outcome of in

Embracing the heart: perioperative management of patients undergoing off-pump coronary artery bypass grafting using the octopus tissue stabilizer.

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Nierich, A P; Diephuis, J; Jansen, E W; van Dijk, D; Lahpor, J R; Borst, C; Knape, J T

1999-04-01

To describe hemodynamic alterations during coronary artery bypass grafting (CABG) without extracorporeal circulation using the Octopus Tissue Stabilizer, and to describe the two anesthetic management protocols based on either general anesthesia with opioids (34 patients) or general anesthesia with high thoracic epidural anesthesia (TEA; 66 patients). A prospective observational report. An academic university heart center. First 100 patients undergoing CABG using the Octopus Tissue Stabilizer. None. Current management provided satisfactory results in preventing hypoperfusion of the heart and inadequate systemic circulation without the use of major pharmacologic interventions. Movement of the heart to reach the target site of anastomosis caused hemodynamic alterations. These could easily be corrected by anesthetic interventions, such as fluid load and low doses of inotropes. High TEA allows earlier extubation compared with the opioid anesthesia technique (0.9 v 4.5 hours). Perioperative management and the incidence of postoperative complications did not differ between anesthetic techniques. Major complications, such as death, intraoperative myocardial infarction, and stroke, did not occur. Both anesthetic protocols are safe and effective in handling these patients. Off-pump CABG surgery requires anesthetic interventions because hemodynamic alterations are caused by the presentation of the heart to the surgeon. The complication rate is low but needs to be evaluated, compared with conventional CABG, in a prospective randomized study. High thoracic epidural anesthesia allows early recovery, but improved outcome could not be proved in this patient group.

Influence of body size on outcomes of off-pump coronary artery bypass surgery.

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Yap, Alexander; Baladi, Naoum; Zapolanski, Alex; Pliam, Michael B; Shaw, Richard E

2005-01-01

Patients of small physical stature may be more likely selected for an on-pump coronary artery surgery (ONCAB) rather than an off-pump procedure (OPCAB). Small patients who do have OPCAB may do poorly. Our hospital demographics afford a unique opportunity to examine a group of small patients. Information was available over the past 4 years on 1015 patients who had isolated CABG and a calculable body surface area. Sixty-one patients had a body surface area of less than 1.5 m2 (SMALL). The 954 remaining patients were classed as larger (LARGER). Patients were compared with respect to preoperative risk factors, operative procedures, and postoperative results. Among SMALL patients, 59% were Asian, 89% female, averaged slightly older, had higher STS risk scores, lower hematocrits, more severe NYHA class ratings, and less elective surgical status (P < .05) than LARGER patients. Fifty-one percent of SMALL patients had OPCAB, 44.3% received blood, 90% had an event-free course, and 4.9% died postop (versus 1.2%, P < .05). OPCAB mortality was lower than ONCAB for both SMALL and nonsmall (P < .05). Blood use was greater for SMALL than for LARGER (44% versus 20%, P < .05) but less for SMALL OPCAB than SMALL ONCAB (27% versus 62%, P < .05). No differences were noted in postop MI, CVA, or length of stay, but 30-day readmission was lower for SMALL patients (5.0% versus 7.4%). Patients with small physical stature can be safely operated upon using off-pump techniques with good revascularization and postop results, despite apparently higher preop STS risk scores.

CABG Versus PCI

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Habib, Robert H.; Dimitrova, Kamellia R.; Badour, Sanaa A.; Yammine, Maroun B.; El-Hage-Sleiman, Abdul-Karim M.; Hoffman, Darryl M.; Geller, Charles M.; Schwann, Thomas A.; Tranbaugh, Robert F.

2017-01-01

BACKGROUND Treatment of multivessel coronary artery disease with traditional single-arterial coronary artery bypass graft (SA-CABG) has been associated with superior intermediate-term survival and reintervention compared with percutaneous coronary intervention (PCI) using either bare-metal stents (BMS) or drug-eluting stents (DES). OBJECTIVES This study sought to investigate longer-term outcomes including the potential added advantage of multiarterial coronary artery bypass graft (MA-CABG). METHODS We studied 8,402 single-institution, primary revascularization, multivessel coronary artery disease patients: 2,207 BMS-PCI (age 66.6 ± 11.9 years); 2,381 DES-PCI (age 65.9 ± 11.7 years); 2,289 SA-CABG (age 69.3 ± 9.0 years); and 1,525 MA-CABG (age 58.3 ± 8.7 years). Patients with myocardial infarction within 24 h, shock, or left main stents were excluded. Kaplan-Meier analysis and Cox regression were used to separately compare 9-year all-cause mortality and unplanned reintervention for BMS-PCI and DES-PCI to respective propensity-matched SA-CABG and MA-CABG cohorts. RESULTS BMS-PCI was associated with worse survival than SA-CABG, especially from 0 to 7 years (p = 0.015) and to a greater extent than MA-CABG was (9-year follow-up: 76.3% vs. 86.9%; p PCI hazard ratios (HR) were as follows: versus SA-CABG, HR: 0.87; and versus MA-CABG, HR: 0.38. DES-PCI showed similar survival to SA-CABG except for a modest 0 to 3 years surgery advantage (HR: 1.06; p = 0.615). Compared with MA-CABG, DES-PCI exhibited worse survival at 5 (86.3% vs. 95.6%) and 9 (82.8% vs. 89.8%) years (HR: 0.45; p PCI for all comparisons (all p PCI or DES-PCI, resulted in substantially enhanced death and reintervention-free survival. Accordingly, MA-CABG represents the optimal therapy for multivessel coronary artery disease and should be enthusiastically adopted by multidisciplinary heart teams as the best evidence-based therapy. PMID:26403338

Does Off-Pump Coronary Artery Bypass Grafting Negatively Impact Long-Term Survival and Freedom from Reintervention?

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Shahzad G. Raja

2013-01-01

Full Text Available Recently published evidence has raised concerns about worse late mortality and increasing need for reintervention after off-pump coronary artery bypass grafting. We undertook this study to assess the impact of off-pump coronary artery bypass grafting on survival and freedom from reintervention at 10 years. From January 2002 to December 2002, 307 consecutive patients who had isolated multivessel off-pump coronary artery bypass grafting at our institution were compared to a control group of 397 patients that underwent multivessel on-pump coronary artery bypass grafting during the same period. In addition, univariate and risk-adjusted comparisons between the two groups were performed at 10 years. Kaplan-Meier survival was similar for the two cohorts. After adjusting for clinical covariates, off-pump coronary artery bypass grafting did not emerge as a significant independent predictor of long-term mortality (Hazard Ratio 0.91; 95% Confidence Interval 0.70–1.12, readmission to hospital for cardiac cause (Hazard Ratio 0.96; 95% Confidence Interval 0.78–1.10, or the need for reintervention (Hazard Ratio 0.93; 95% Confidence Interval 0.87–1.05. Off-pump coronary artery bypass grafting compared with on-pump coronary artery bypass grafting does not adversely impact survival or freedom from reintervention at a 10-year follow-up.

DOES TRANEXAMIC ACID REDUCE BLOOD LOSS IN OFF-PUMP CORONARY ARTERY BYPASS?

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A. Mehr-Aein

2006-09-01

Full Text Available Tranexamic acid is now used on a routine basis for on-pump coronary artery bypass grafting (CABG. We assessed the hemostatic effects of tranexamic acid to decrease bleeding tendency and transfusion requirements in patients undergoing off-pump coronary artery bypass surgery (OPCAB. A total of 66 patients were enrolled to elective OPCAB in a double-blind, prospective randomized study. Of these, 33 patients received tranexamic acid (15 mg/kg before the infusion of heparin and 15 mg/kg after protamin infusion, and 33 patients received only saline. Preoperative hematologic variables, postoperative bleeding and allogeneic transfusions were considered. D-dimer plasma levels were also evaluated to monitor the activation of fibrinolysis. Postoperative bleeding was significantly lower in the tranexamic acid group compared with the control group (320 ± 38 mL vs. 480 ± 75 mL at 12 hour, P < 0.001. The tranexamic acid group had significantly lesser need for allogeneic blood products (0.46 units/patients vs. 0.94 units/patients, P < 0.001. They had also lower post-operative D-dimer plasma levels. No postoperative thrombotic complications were observed in either group. The defective hemostasis occurs even in the OPCABG. Tranexamic acid effectively reduces postoperative blood loss and the need for allogeneic blood products after OPCAB is decreased.

Prevalence and intensity of hyperglycemia in non-diabetic patients undergoing coronary artery bypass graft surgery with and without cardiopulmonary bypass

International Nuclear Information System (INIS)

Azarfarin, R.; Asl, Azin A.

2008-01-01

Objective was to study the prevalence and severity of hyperglycemia in nondiabetic patients undergoing cardiac operation. In an observational prospective study, 282 non-diabetic patients underwent elective off-pump (n=101) or non on-pump (n=181) coronary artery bypass grafting (CABG) surgery from March 2006 to July 2007 in Madani Heart Hospital, Tabriz, Iran. Blood glucose (BG) levels were measured during and 24 hours after operation. Frequencies of hyperglycemia (BG>-126 mg/dl) and severe hyperglycemia (BG>-180 mg/dl) and postoperative complications were compared in the 2 study groups. Prevalence of at least one episode of severe hyperglycemia was 54.6% (154/282) in our patients during and 24 hours after operation. Intra-operative hyperglycemia was slightly higher in on-pumping group. Frequency of post-operative hyperglycemia was higher, although not significantly different between the two groups. The 2 study groups were not significantly different in frequency of severe hyperglycemia during operation, although were different within 24 hours postoperative period. Prevalence of hyperglycemia especially severe hyperglycemia was high during, and after operation in both off-pump and on-pump CABG in non-diabetic patients. There was a borderline difference in blood glucose level between on-pump and off-pump CABG patients. It may be prudent to consider glycemic control protocols in these patients especially in early post-operative period. (author)

PCI Versus CABG in Patients With Type 1 Diabetes and Multivessel Disease.

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Nyström, Thomas; Sartipy, Ulrik; Franzén, Stefan; Eliasson, Björn; Gudbjörnsdottir, Soffia; Miftaraj, Mervete; Lagerqvist, Bo; Svensson, Ann-Marie; Holzmann, Martin J

2017-09-19

It is unknown if coronary artery bypass grafting (CABG) or percutaneous coronary intervention (PCI) may offer a survival benefit in patients with type 1 diabetes (T1D) in need of multivessel revascularization. This study sought to determine if patients with T1D and multivessel disease may benefit from CABG compared with PCI. In an observational cohort study, the authors included all patients with T1D who underwent a first multivessel revascularization in Sweden from 1995 to 2013. The authors used the SWEDEHEART (Swedish Web-system for Enhancement and Development of Evidence-based care in Heart disease Evaluated According to Recommended Therapies) register, the Swedish National Diabetes Register, and the Swedish National Patient Register to retrieve information about patient characteristics and outcomes. They estimated hazard ratios (HRs) adjusted for confounders with 95% confidence intervals (CIs) for all-cause and coronary heart disease mortality, myocardial infarction, repeat revascularization, stroke, and heart failure using inverse probability of treatment weighting based on propensity scores. In total, 683 patients who underwent CABG and 1,863 patients who underwent PCI were included. During a mean follow-up of 10.6 years, 53% of patients in the CABG group and 45% in the PCI group died. PCI, compared with CABG, was associated with a similar risk of all-cause mortality (HR: 1.14; 95% CI: 0.99 to 1.32), but higher risks of death from coronary heart disease (HR: 1.45; 95% CI: 1.21 to 1.74), myocardial infarction (HR: 1.47; 95% CI: 1.23 to 1.78), and repeat revascularization (HR: 5.64; 95% CI: 4.67 to 6.82). No differences in risks of stroke or heart failure were found. Notwithstanding the inclusion of patients with T1D who might not have been able to undergo CABG in the PCI group we found that PCI, compared with CABG, was associated with higher rates and risks of coronary heart disease mortality, myocardial infarction, and repeat revascularizations. Our

Peripheral tissue metabolism during off-pump versus on-pump coronary artery bypass graft surgery: the microdialysis study.

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Pojar, Marek; Mand'ák, Jirí; Cibícek, Norbert; Lonský, Vladimír; Dominik, Jan; Palicka, Vladimír; Kubícek, Jaroslav

2008-05-01

The aim of this study was to monitor and compare metabolic changes in the skeletal muscle during coronary artery bypass grafting surgery with and without cardiopulmonary bypass (CPB) by means of interstitial microdialysis. Glucose, lactate, pyruvate and glycerol were assessed as markers of basic metabolism and tissue perfusion. Twenty patients undergoing surgical myocardial revascularization were enrolled in this pilot study. Ten patients were operated on without CPB (group A, off-pump) and 10 patients using normothermic CPB (group B, on-pump). Interstitial microdialysis was performed by a CMA 60 (CMA/Microdialysis AB, Sweden) probe, inserted into the patient's left deltoid muscle. Microdialysis measurements were performed at 30 min intervals. Glucose, lactate, pyruvate and glycerol were measured in samples using a CMA 600 Analyser (CMA/Microdialysis AB, Sweden). Results in both groups were statistically processed and the groups were compared. Both groups were similar with regards to preoperative characteristics. Dynamic changes of interstitial concentrations of the measured analytes were found in off-pump (group A) and on-pump (group B) patients during the operation. There were no significant differences in dialysate concentrations of glucose and lactate between the groups. Significant differences were detected in pyruvate concentrations, lactate-pyruvate ratio and glycerol concentrations between off-pump versus on-pump patients. Pyruvate concentrations were higher in the off-pump group (plactate-pyruvate ratios indicating the aerobic/anaerobic metabolism status were lower in the off-pump group (pglucose, glycerol, pyruvate and lactate were found in both groups of patients (off-pump and on-pump). The presented preliminary results suggest that extracorporeal circulation during cardiac operations could compromise skeletal muscle energy metabolism.

Right atrium positioning for exposure of right pulmonary veins during off-pump atrial fibrillation ablation.

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Suwalski, Grzegorz; Emery, Robert; Mróz, Jakub; Kaczejko, Kamil; Gryszko, Leszek; Cwetsch, Andrzej; Skrobowski, Andrzej

2017-06-01

Concomitant surgical ablation of atrial fibrillation (AF) is recommended for patients undergoing off-pump coronary revascularization in the presence of this arrhythmia. Achievement of optimal visualization of pulmonary veins while maintaining stable haemodynamic conditions is crucial for proper completion of the ablation procedure. This study evaluates the safety and feasibility of right atrial positioning using a suction-based cardiac positioner as opposed to compressive manoeuvres for exposure during off-pump surgical ablation for AF. Thirty-four consecutive patients underwent pulmonary vein isolation, ganglionated plexi ablation and left atrial appendage occlusion during off-pump coronary artery bypass grafting. Right atrial suction positioning was used to visualize right pulmonary veins. Safety and feasibility end points were analysed intraoperatively and in the early postoperative course. In all patients, right atrial positioning created optimal conditions to complete transverse and oblique sinus blunt dissection, correct placement of a bipolar ablation probe, detection and ablation of ganglionated plexi and conduction block assessment. In all patients, this entire right-sided ablation procedure was completed with a single exposure manoeuvre. Feasibility end points were achieved in all study patients. This report documents the safety and feasibility of right atrial exposure using a suction-based cardiac positioner to complete ablation for AF concomitant with off-pump coronary revascularization. This technique may be widely adopted to create stable haemodynamic conditions and optimal visualization of the right pulmonary veins. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Predictors of early return to work after a coronary artery bypass graft surgery (CABG

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Ramin Mehrdad

2016-12-01

Full Text Available Objectives: Identifying factors predictive of early return to work in patients who underwent a coronary artery bypass graft surgery (CABG. Material and Methods: Two hundred twenty-six working patients who volunteered and underwent a primary coronary artery bypass surgery between September 2013 and May 2014 were selected for the study and followed up for 6 months. Predictors of early return to work (RTW (within 2 months were analyzed from variables in a prospectively collected database and the 36-Item Short Form Health Survey (SF-36 questionnaire carried out in the hospital and rehabilitation center as well as from the follow-up performed via the phone. Results: One hundred and two (45.1% and 155 (68.9% patients returned to work within 2 and 3 months after the surgery, respectively. Furthermore, 196 patients (87.1% returned to work within 6 months after the surgery. In the univariate analysis, demographic or socioeconomic factors (such as age, level of education, income, occupational factors (such as occupation type, working hours per week, duration of the preoperative absence from work, psychological factors (such as a patient’s concern about adverse health effects of RTW, feeling depressed, a patient’s attitude towards his/her ability to RTW and a patient’s perception of his/her job stress level and medical factors (such as serum troponin T and creatine kinase MB (CKMB level, pump time in surgery, co-surgery and dyslipidemia history had a statistically significant correlation with early return to work. The patients who early returned to work had significantly higher scores in 3 domains on the SF-36 questionnaire (used for assessing the patients’ quality of life, compared to those who did not return to work early (including physical functioning, role limitations due to physical health and pain. Conclusions: In the present study we identified 4 new medical factors that could be used as predictors of early return to work after CABG. These

Scrape-off profiles and effects of limiter pumping in Tore Supra

International Nuclear Information System (INIS)

Budny, R.

1986-11-01

A one dimensional plasma scrape-off model was used to simulate Tore Supra discharges which are limited by various combinations of the pumped and inner limiters. Scrape-off profiles of the electron density and temperature, ion temperature, and neutral density are given. For each case, various fractions of the ion flux to the neutralizers were assumed to be pumped. Modifications of the scrap-off profiles caused by pumping are predicted. Pumping efficiencies are calculated including the effects of flux amplification caused by recycling. The pumping efficiency is estimated to be 8% for low-power discharges formed on the outer pumped limiter, 7.5% for intermediate-power discharges formed on the seven-module pumped-limiter system, and 5% for full-power discharges formed on both the inner limiter and the pumped-limiter system. The maximum particle removal rate is estimated to be 150 Tl/s

On-pump versus off-pump coronary artery bypass surgery

DEFF Research Database (Denmark)

Houlind, Kim Christian

2013-01-01

Off pump coronary artery bypass surgery has been purported to be safer than conventional coronary artery bypass surgery performed using cardiopulmonary bypass. This theory was supported by a number of early series, but failed to be confirmed by a number of small, randomized controlled trials...

Heart bypass surgery

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

Investigation of Pumped Storage Hydropower Power-Off Transient Process Using 3D Numerical Simulation Based on SP-VOF Hybrid Model

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Daqing Zhou

2018-04-01

Full Text Available The transient characteristic of the power-off process is investigated due to its close relation to hydraulic facilities’ safety in a pumped storage hydropower (PSH. In this paper, power-off transient characteristics of a PSH station in pump mode was studied using a three-dimensional (3D unsteady numerical method based on a single-phase and volume of fluid (SP-VOF coupled model. The computational domain covered the entire flow system, including reservoirs, diversion tunnel, surge tank, pump-turbine unit, and tailrace tunnel. The fast changing flow fields and dynamic characteristic parameters, such as unit flow rate, runner rotate speed, pumping lift, and static pressure at measuring points were simulated, and agreed well with experimental results. During the power-off transient process, the PSH station underwent pump mode, braking mode, and turbine mode, with the dynamic characteristics and inner flow configurations changing significantly. Intense pressure fluctuation occurred in the region between the runner and guide vanes, and its frequency and amplitude were closely related to the runner’s rotation speed and pressure gradient, respectively. While the reversed flow rate of the PSH unit reached maximum, some parameters, such as static pressure, torque, and pumping lift would suddenly jump significantly, due to the water hammer effect. The moment these marked jumps occurred was commonly considered as the most dangerous moment during the power-off transient process, due to the blade passages being clogged by vortexes, and chaos pressure distribution on the blade surfaces. The results of this study confirm that 3D SP-VOF hybrid simulation is an effective method to reveal the hydraulic mechanism of the PSH transient process.

Superior long term outcome associated with native vessel versus graft vessel PCI following secondary PCI in patients with prior CABG.

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Mavroudis, Chrysostomos A; Kotecha, Tushar; Chehab, Omar; Hudson, Jonathan; Rakhit, Roby D

2017-02-01

Secondary percutaneous coronary intervention (PCI) in patients with prior coronary artery bypass graft surgery is increasingly common. Graft vessel PCI has higher rates of adverse events compared with native coronary vessel PCI. To investigate the clinical outcomes of patients with prior CABG who underwent secondary PCI of either a graft vessel (GV), a native coronary vessel (NV) or both graft and native (NG) vessels. 220 patients (84% male) who underwent PCI in our institution to either GV (n=89), NV (n=103) or both GV and NV (NG group) (n=28) were studied. The study population underwent 378 procedures (GV group; n=126, NV group; n=164 and NG group; n=88). Median follow up was for 36months [range 2-75months]. Target vessel revascularisation (TVR) occurred in 12.5% of the GV group and 3.6% in the NV group [p=0.0004], and was predominantly due to in-stent restenosis. Patients who had PCI due to TVR were more likely to suffer from diabetes and peripheral vascular disease. History of chronic renal failure was associated with higher risk (HR 2.21, p=0.005) whereas preserved left ventricular ejection fraction (LVEF) with lower risk (HR 0.17, p=0.0007) of death. The median survival (interval between CABG and end of follow-up period) was lower in the GV compared with the NV group (315 vs 372months p=0.005). This registry demonstrates inferior long term outcome for patients undergoing secondary PCI of GV versus NV. Where possible, a strategy of NV rather than GV target PCI should be considered in patients with prior CABG. Secondary PCI in patients with prior CABG surgery is increasingly common. Graft vessel PCI has inferior outcomes with high rates of restenosis and occlusion compared with native coronary vessel PCI. We studied the clinical outcomes of 220 patients with prior CABG who underwent secondary PCI to either a graft vessel (GV), a native coronary vessel (NV) or both graft and native (NG) vessels. Target vessel revascularisation was 5 times higher in the GV

Neurological complications are avoidable during CABG.

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Haider, Zulfiqar; Jalal, Anjum; Alamgir, Asif Rashid; Rasheed, Irfan

2018-01-01

To review the incidence of stroke in patients undergoing CABG and the impact of a preventive strategy adopted at tertiary care unit of cardiac surgery. The data of all patients who underwent isolated CABG (N= 722) from July 2016 to August 2017 at Faisalabad Institute of Cardiology was retrieved for this retrospective study. All operations were done on cardiopulmonary bypass and cold blood cardioplegia. Numeric data was summarized as Mean ± Standard Deviation while categoric variables were summarized into frequency and percentage. Mean age of patients was 53.83±8.8 years. Mean Parsonnet and Logistic EuroScore were 4.3±3.2 and 3.3±0.9 respectively. Forty nine patients (6.78%) had significant carotid artery disease. Mean number of grafts was 2.8±0.82. Diabetes was present in 27.8% patients. Neurological complications were noticed in 14 patients (1.94%) who included 12 permanent paralyses. Further subgroup analysis revealed that 67 patients who were operated by single clamp technique remained free of neurological complications. This is clinically remarkable finding but due to small population size it is statistically non- significant. The incidence of neurological complications can be reduced significantly by adopting the appropriate preventing measures. Use of Single Clamp technique may be the reasons of such a low incidence of stroke in this study.

The Influence of Comprehensive Cardiac Rehabilitation on Heart Rate Variability Indices after CABG is More Effective than after PCI.

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Szmigielska, Katarzyna; Szmigielska-Kapłon, Anna; Jegier, Anna

2018-02-01

The aim of this study was to evaluate the influence of cardiac rehabilitation (CR) on heart rate variability (HRV) indices in men with coronary artery disease (CAD) treated with percutaneous coronary intervention (PCI) or coronary artery bypass graft surgery (CABG). The study population consisted of 131 male patients with CAD prospectively and consecutively admitted to CR after PCI n = 72, or CABG n = 59. Participants performed cycle ergometer interval training for 45 min three times a week for 8 weeks. At baseline and after 8 weeks, all patients underwent the HRV assessment. HRV indices in CAGB survivals were significantly lower in comparison to PCI patients at baseline. Significant increases were seen for SDNN, rMSSD, and HF in the CABG group and only in HF component in PCI group after 8 weeks of CR. Eight weeks of CR seems to be more effective in CABG patients than patients after PCI.

Gender-linked impact of epicardial adipose tissue volume in patients who underwent coronary artery bypass graft surgery or non-coronary valve surgery.

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Maimaituxun, Gulinu; Shimabukuro, Michio; Salim, Hotimah Masdan; Tabata, Minoru; Yuji, Daisuke; Morimoto, Yoshihisa; Akasaka, Takeshi; Matsuura, Tomomi; Yagi, Shusuke; Fukuda, Daiju; Yamada, Hirotsugu; Soeki, Takeshi; Sugimoto, Takaki; Tanaka, Masashi; Takanashi, Shuichiro; Sata, Masataka

2017-01-01

Traditional and non-traditional risk factors for atherosclerotic cardiovascular disease (ASCVD) are different between men and women. Gender-linked impact of epicardial adipose tissue volume (EATV) in patients undergoing coronary artery bypass grafting (CABG) remains unknown. Gender-linked impact of EATV, abdominal fat distribution and other traditional ASCVD risk factors were compared in 172 patients (men: 115; women: 57) who underwent CABG or non-coronary valvular surgery (non-CABG). In men, EATV, EATV index (EATV/body surface area) and the markers of adiposity such as body mass index, waist circumference and visceral fat area were higher in the CABG group than in the non-CABG group. Traditional ASCVD risk factors were also prevalent in the CABG group. In women, EATV and EATV index were higher in the CABG group, but other adiposity markers were comparable between CABG and non-CABG groups. Multivariate logistic regression analysis showed that in men, CABG was determined by EATV Index and other ASCVD risk factors including hypertension, dyslipidemia, adiponectin, high sensitive C-reactive protein (hsCRP) and type 2 diabetes mellitus (Corrected R2 = 0.262, p EATV Index (Corrected R2 = 0.266, p = 0.005). Our study found that multiple risk factors, including epicardial adipose tissue volume and traditional ASCVD factors are determinants for CABG in men, but type 2 diabetes mellitus was the sole determinant in women. Gender-specific disparities in risk factors of CABG prompt us to evaluate new diagnostic and treatment strategies and to seek underlying mechanisms.

Transient post-operative atrial fibrillation predicts short and long term adverse events following CABG

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Becker, Matthew; Galla, John; Blackstone, Eugene; Kapadia, Samir R.

2014-01-01

Objective To assess the relationship between the development of transient post-operative atrial fibrillation (TPOAF) following coronary artery bypass graft (CABG) surgery and risk of long-term mortality. Background Atrial fibrillation (AF) following CABG is common and associated with increased morbidity and mortality in the perioperative period. However the impact of TPOAF and its management on long-term morbidity and mortality in patients undergoing first time, isolated CABG surgery remains unclear. Methods The Cleveland Clinic Cardiovascular Information Registry was used to identify 5,205 consecutive patients who underwent CABG between January 1993 and December 2005. Patients with TPOAF (n=1,490) were compared to those without post-operative AF (n=3,645) for the endpoints of death, myocardial infarction (MI), or stroke at 1 year. Results Overall rates of 1-year mortality, MI and stroke were 3.7%, 0.8%, and 2.6%, respectively. Patients with TPOAF had an increased risk of death at 1 year as compared to patients without POAF (6.4% vs. 2.7%; P<0.001), but there was not an increased risk of stroke or MI. Multivariate analysis identified TPOAF as an independent predictor of death at 1 year (HR 1.89, 95% CI, 1.42-2.53; P<0.001). After propensity matching, patients who developed TPOAF experienced a significantly increased risk of death compared with those without TPOAF (HR 1.96, 95% CI, 1.34-2.86; P<0.001). Conclusions In patients undergoing first time, isolated CABG, the presence of TPOAF identifies a subgroup of patients at increased risk for all-cause mortality. Future prospective studies to determine potential beneficial interventions in this large population are warranted. PMID:25414823

Off-pump coronary artery bypass surgery in selected patients is superior to the conventional approach for patients with severely depressed left ventricular function

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Caputti, Guido Marco; Palma, José Honório; Gaia, Diego Felipe; Buffolo, Enio

2011-01-01

OBJECTIVES: Patients with coronary artery disease and left ventricular dysfunction have high mortality when kept in clinical treatment. Coronary artery bypass grafting can improve survival and the quality of life. Recently, revascularization without cardiopulmonary bypass has been presented as a viable alternative. The aim of this study is to compare patients with left ventricular ejection fractions of less than 20% who underwent coronary artery bypass graft with or without cardiopulmonary bypass. METHODS: From January 2001 to December 2005, 217 nonrandomized, consecutive, and nonselected patients with an ejection fraction less than or equal to 20% underwent coronary artery bypass graft surgery with (112) or without (off-pump) (105) the use of cardiopulmonary bypass. We studied demographic, operative, and postoperative data. RESULTS: There were no demographic differences between groups. The outcome variables showed similar graft numbers in both groups. Mortality was 12.5% in the cardiopulmonary bypass group and 3.8% in the off-pump group. Postoperative complications were statistically different (cardiopulmonary bypass versus off-pump): total length of hospital stay (days)—11.3 vs. 7.2, length of ICU stay (days)—3.7 vs. 2.1, pulmonary complications—10.7% vs. 2.8%, intubation time (hours)—22 vs. 10, postoperative bleeding (mL)—654 vs. 440, acute renal failure—8.9% vs. 1.9% and left-ventricle ejection fraction before discharge—22% vs. 29%. CONCLUSION: Coronary artery bypass grafting without cardiopulmonary bypass in selected patients with severe left ventricular dysfunction is valid and safe and promotes less mortality and morbidity compared with conventional operations. PMID:22189729

Off-pump coronary artery bypass surgery in selected patients is superior to the conventional approach for patients with severely depressed left ventricular function

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Guido Marco Caputti

2011-01-01

Full Text Available OBJECTIVES: Patients with coronary artery disease and left ventricular dysfunction have high mortality when kept in clinical treatment. Coronary artery bypass grafting can improve survival and the quality of life. Recently, revascularization without cardiopulmonary bypass has been presented as a viable alternative. The aim of this study is to compare patients with left ventricular ejection fractions of less than 20% who underwent coronary artery bypass graft with or without cardiopulmonary bypass. METHODS: From January 2001 to December 2005, 217 nonrandomized, consecutive, and nonselected patients with an ejection fraction less than or equal to 20% underwent coronary artery bypass graft surgery with (112 or without (off-pump (105 the use of cardiopulmonary bypass. We studied demographic, operative, and postoperative data. RESULTS: There were no demographic differences between groups. The outcome variables showed similar graft numbers in both groups. Mortality was 12.5% in the cardiopulmonary bypass group and 3.8% in the off-pump group. Postoperative complications were statistically different (cardiopulmonary bypass versus off-pump: total length of hospital stay (days-11.3 vs. 7.2, length of ICU stay (days-3.7 vs. 2.1, pulmonary complications-10.7% vs. 2.8%, intubation time (hours-22 vs. 10, postoperative bleeding (mL-654 vs. 440, acute renal failure-8.9% vs. 1.9% and left-ventricle ejection fraction before discharge-22% vs. 29%. CONCLUSION: Coronary artery bypass grafting without cardiopulmonary bypass in selected patients with severe left ventricular dysfunction is valid and safe and promotes less mortality and morbidity compared with conventional operations.

Comparative study of short-term cardiovascular autonomic control in cardiac surgery patients who underwent coronary artery bypass grafting or correction of valvular heart disease.

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Shvartz, Vladimir A; Kiselev, Anton R; Karavaev, Anatoly S; Vulf, Kristina A; Borovkova, Ekaterina I; Prokhorov, Mikhail D; Petrosyan, Andrey D; Bockeria, Olga L

2018-01-01

Introduction: Our aim was to perform a comparative study of short-term cardiovascular autonomic control in cardiac surgery patients who underwent coronary artery bypass grafting (CABG) or surgical correction of valvular heart disease (SCVHD ). Methods: The synchronous 15 minutes records of heart rate variability (HRV) and finger's photoplethysmographic waveform variability (PPGV) were performed in 42 cardiac surgery patients (12 women) aged 61.8 ± 8.6 years (mean ± standard deviation), who underwent CABG, and 36 patients (16 women) aged 54.2 ± 14.9 years, who underwent SCVHD , before surgery and in 5-7 days after surgery. Conventional time and frequency domain measures of HRV and index S of synchronization between the slow oscillations in PPGV and HRV were analyzed. We also calculated personal dynamics of these indices after surgery. Results: We found no differences ( Р > 0.05) in all studied autonomic indices (preoperative and post-surgery) between studied patients' groups, except for the preoperative heart rate, which was higher in patients who underwent SCVHD ( P = 0.013). We have shown a pronounced preoperative and post-surgery variability (magnitude of inter-quartile ranges) of all autonomic indices in studied patients. In the cluster analysis based on cardiovascular autonomic indices (preoperative and post-surgery), we divided all patients into two clusters (38 and 40 subjects) which did not differ in all clinical characteristics (except for the preoperative hematocrit, P = 0.038), index S, and all post-surgery HRV indices. First cluster (38 patients) had higher preoperative values of the HR, TP, HF, and HF%, and lower preoperative values of the LF% and LF/HF. Conclusion: The variability of cardiovascular autonomic indices in on-pump cardiac surgery patients (two characteristic clusters were identified based on preoperative indices) was not associated with their clinical characteristics and features of surgical procedure (including cardioplegia).

Gender-linked impact of epicardial adipose tissue volume in patients who underwent coronary artery bypass graft surgery or non-coronary valve surgery.

Directory of Open Access Journals (Sweden)

Gulinu Maimaituxun

Full Text Available Traditional and non-traditional risk factors for atherosclerotic cardiovascular disease (ASCVD are different between men and women. Gender-linked impact of epicardial adipose tissue volume (EATV in patients undergoing coronary artery bypass grafting (CABG remains unknown.Gender-linked impact of EATV, abdominal fat distribution and other traditional ASCVD risk factors were compared in 172 patients (men: 115; women: 57 who underwent CABG or non-coronary valvular surgery (non-CABG.In men, EATV, EATV index (EATV/body surface area and the markers of adiposity such as body mass index, waist circumference and visceral fat area were higher in the CABG group than in the non-CABG group. Traditional ASCVD risk factors were also prevalent in the CABG group. In women, EATV and EATV index were higher in the CABG group, but other adiposity markers were comparable between CABG and non-CABG groups. Multivariate logistic regression analysis showed that in men, CABG was determined by EATV Index and other ASCVD risk factors including hypertension, dyslipidemia, adiponectin, high sensitive C-reactive protein (hsCRP and type 2 diabetes mellitus (Corrected R2 = 0.262, p < 0.0001, while in women, type 2 diabetes mellitus is a single strong predictor for CABG, excluding EATV Index (Corrected R2 = 0.266, p = 0.005.Our study found that multiple risk factors, including epicardial adipose tissue volume and traditional ASCVD factors are determinants for CABG in men, but type 2 diabetes mellitus was the sole determinant in women. Gender-specific disparities in risk factors of CABG prompt us to evaluate new diagnostic and treatment strategies and to seek underlying mechanisms.

Pulmonary hemodynamics and gas exchange in off pump coronary artery bypass grafting.

Science.gov (United States)

Vedin, Jenny; Jensen, Ulf; Ericsson, Anders; Samuelsson, Sten; Vaage, Jarle

2005-10-01

To investigate the influence of cardiopulmonary bypass on pulmonary hemodynamics and gas exchange. Low risk patients admitted for elective coronary artery bypass grafting were randomized to either on (n=25) or off pump (n=25) surgery. Central hemodynamics, gas exchange, and venous admixture were studied during and up to 20 h after surgery. There was no difference in pulmonary vascular resistance index (P=0.16), right ventricular stroke work index (P>0.2), mean pulmonary artery pressure (P>0.2) or pulmonary capillary wedge pressure (P>0.2) between groups. Soon after surgery there was a tendency towards higher cardiac index (P=0.07) in the off pump group. Arterial oxygen tension (P>0.2), hematocrit (P>0.2), venous admixture (P>0.2), and arterial-venous oxygen content difference (P=0.12) did not differ between groups. This prospective, randomized study showed no difference in pulmonary hemodynamics, pulmonary gas exchange, and venous admixture, in low risk patients undergoing off pump compared to on pump coronary artery bypass surgery.

Re-OPCAB vs. Re-CABG for myocardial revascularization.

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Schütz, A; Mair, H; Wildhirt, S M; Gillrath, G; Lamm, P; Kilger, E; Reichart, B

2001-06-01

The present study compared redo coronary artery bypass grafting (Re-OPCAB) techniques with conventional redo coronary artery bypass grafting (Re-CABG) with particular focus on myocardial damage and clinical outcome parameters. Redo OPCAB (Re-OPCAB) was performed on 20 consecutive patients (15 males, mean age 63.2 +/- 9.3 years) using either the anterolateral approach for minimally invasive direct coronary artery bypass (n = 4) or the Octopus technique with regular sternotomy (n = 16). The Re-CABG group consisted of 20 consecutive patients (18 males, mean age 67.1 +/- 6.6 years). Groups did not differ in the number of atherosclerotic risk factors, or left ventricular, renal or liver function. Duration of surgery, number of bypass grafts and amount of transfused red blood cells did not differ significantly between both groups. Requirement of epinephrine (mg/h) within the first 24 h was lower in the Re-OPCAB group (Re-OPCAB: 0.14 +/- 0.22 vs. CABG: 0.88 +/- 0.97; p<0.01). In addition, CKMB levels at 24 h after operation were lower in the Re-OPCAB group (Re-OPCAB: 10.0 +/- 10.1 vs. Re-CABG: 38.7 +/- 28.1 U/l, p<0.001). There were no acute myocardial infarctions or deaths in the perioperative period. In the CABG group, there was a longer time period to extubation (hours) (Re-OPCAB: 9.8 +/- 3.9 vs. Re-CABG: 28.7 +/- 25.5; p<0.001), and the length of ICU stay was significantly prolonged (OPCAB: 1.3 +/- 0.5 versus Re-CABG: 4.4 +/- 8.7; p<0.001). The graft patency rate at follow-up was 95% in the Re-OPCAB group. Re-OPCAB results in decreased cardiac specific enzyme release, reduced requirement of inotropes and comparable clinical outcome in the early postoperative period. It is an appropriate alternative to conventional Re-CABG in selected patients awaiting reoperation for myocardial revascularization. Larger prospective and randomized trials are required to select the appropriate patient who benefits most from one or the other treatment regime.

SmartHeart CABG Edu

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Gabriele DI GIAMMARCO

2015-12-01

Full Text Available The paper reports on the SmartHeart CABG Edu Android app. The app was conceived to be an innovative and up-to-date tool for patient education, the first of its kind in the Italian context. In particular, the app was developed to provide educational material for patients about to undergo Coronary Artery Bypass Graft (CABG surgery, a set of self-assessment tools concerning health status (i.e., BMI calculator, LDL cholesterol calculator and anxiety assessment tool and usability questionnaires (i.e., SEQ and SUS. The paper initially describes the app, then reports on its evaluation, concerning both the app usability and the pre-operative anxiety, and ends by showing the improvements -- derived from the usability evaluation -- put into practice.

Does transfusion of residual cardiopulmonary bypass circuit blood increase postoperative bleeding? A prospective randomized study in patients undergoing on pump cardiopulmonary bypass

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Duara, Rajnish; Misra, Manoranjan; Bhuyan, Ritwick Raj; Sarma, P. Sankara; Jayakumar, Karunakaran

2008-01-01

Objective: Homologous blood transfusion after open heart surgery puts a tremendous load on the blood banks. This prospective randomized study evaluates the efficacy of infusing back residual cardiopulmonary bypass (CPB) circuit i.e., pump blood as a means to reduce homologous transfusion after coronary artery bypass surgery (CABG) and whether its use increases postoperative drainage. Materials and Methods: Sixty-seven consecutive patients who underwent elective CABGs under CPB were randomized into 2 groups: (1) cases where residual pump blood was used and (2) controls where residual pump blood was not used. Patients were monitored for hourly drainage on the day of surgery and the 1st postoperative day and the requirements of homologous blood and its products. Data were matched regarding change in Hemoglobin, Packed Cell Volume and coagulation parameters till 1st postoperative day. All cases were followed up for three years. Results: There was a marginal reduction in bleeding pattern in the early postoperative period in the cases compared to controls. The requirement of homologous blood and its products were also reduced in the cases. Conclusions: The use of CPB circuit blood is safe in the immediate postoperative period. The requirement of homologous blood transfusion can come down if strict transfusion criteria are maintained. PMID:20041077

Does transfusion of residual cardiopulmonary bypass circuit blood increase postoperative bleeding? A prospective randomized study in patients undergoing on pump cardiopulmonary bypass

Directory of Open Access Journals (Sweden)

Duara Rajnish

2008-01-01

Full Text Available Objective: Homologous blood transfusion after open heart surgery puts a tremendous load on the blood banks. This prospective randomized study evaluates the efficacy of infusing back residual cardiopulmonary bypass (CPB circuit i.e., pump blood as a means to reduce homologous transfusion after coronary artery bypass surgery (CABG and whether its use increases postoperative drainage. Materials and Methods: Sixty-seven consecutive patients who underwent elective CABGs under CPB were randomized into 2 groups: (1 cases where residual pump blood was used and (2 controls where residual pump blood was not used. Patients were monitored for hourly drainage on the day of surgery and the 1 st postoperative day and the requirements of homologous blood and its products. Data were matched regarding change in Hemoglobin, Packed Cell Volume and coagulation parameters till 1st postoperative day. All cases were followed up for three years. Results: There was a marginal reduction in bleeding pattern in the early postoperative period in the cases compared to controls. The requirement of homologous blood and its products were also reduced in the cases. Conclusions: The use of CPB circuit blood is safe in the immediate postoperative period. The requirement of homologous blood transfusion can come down if strict transfusion criteria are maintained.

Gender-linked impact of epicardial adipose tissue volume in patients who underwent coronary artery bypass graft surgery or non-coronary valve surgery

OpenAIRE

Maimaituxun, Gulinu; Shimabukuro, Michio; Salim, Hotimah Masdan; Tabata, Minoru; Yuji, Daisuke; Morimoto, Yoshihisa; Akasaka, Takeshi; Matsuura, Tomomi; Yagi, Shusuke; Fukuda, Daiju; Yamada, Hirotsugu; Soeki, Takeshi; Sugimoto, Takaki; Tanaka, Masashi; Takanashi, Shuichiro

2017-01-01

Background Traditional and non-traditional risk factors for atherosclerotic cardiovascular disease (ASCVD) are different between men and women. Gender-linked impact of epicardial adipose tissue volume (EATV) in patients undergoing coronary artery bypass grafting (CABG) remains unknown. Methods Gender-linked impact of EATV, abdominal fat distribution and other traditional ASCVD risk factors were compared in 172 patients (men: 115; women: 57) who underwent CABG or non-coronary valvular surgery ...

Ischemia monitoring in off-pump coronary artery bypass surgery using intravascular near-infrared spectroscopy

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Zerkowski Hans-Reinhard

2006-05-01

Full Text Available Abstract Background In off-pump coronary artery bypass surgery, manipulations on the beating heart can lead to transient interruptions of myocardial oxygen supply, which can generate an accumulation of oxygen-dependent metabolites in coronary venous blood. The objective of this study was to evaluate the reliability of intravascular near-infrared spectroscopy as a monitoring method to detect possible ischemic events in off-pump coronary artery bypass procedures. Methods In 15 elective patients undergoing off-pump myocardial revascularization, intravascular near-infrared spectroscopic analysis of coronary venous blood was performed. NIR signals were transferred through a fiberoptic catheter for signal emission and collection. For data analysis and processing, a miniature spectrophotometer with multivariate statistical package was used. Signal acquisition and analysis were performed before and after revascularization. Spectroscopic data were compared with hemodynamic parameters, electrocardiogram, transesophageal echocardiography and laboratory findings. Results A conversion to extracorporeal circulation was not necessary. The mean number of grafts per patient was 3.1 ± 0.6. An intraoperative myocardial ischemia was not evident, as indicated by electrocardiogram and transesophageal echocardiography. Continuous spectroscopic analysis showed reproducible absorption spectra of coronary sinus blood. Due to uneventful intraoperative courses, clear ischemia-related changes could be detected in none of the patients. Conclusion Our initial results show that intravascular near-infrared spectroscopy can reliably be used for an online intraoperative ischemia monitoring in off-pump coronary artery bypass surgery. However, the method has to be further evaluated and standardized to determine the role of spectroscopy in off-pump coronary artery bypass surgery.

CABG in 2012: Evidence, practice and the evolution of guidelines

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David P Taggart

2012-12-01

Full Text Available In the management of coronary artery disease (CAD it is important to ensure that all patients are receiving optimal medical therapy irrespective of whether any intervention, by stents or surgery, is planned. Furthermore it is important to establish if a proposed intervention is for symptomatic and/or prognostic reasons. The latter can only be justified if there is demonstration of a significant volume of ischaemia (>10% of myocardial mass. Taking together evidence from the most definitive randomized trial and its registry component (SYNTAX, almost 79% of patients with three vessel CAD and almost two thirds of patients with LMS disease have a survival benefit and marked reduction in the need for repeat revascularisation with CABG in comparison to stents, implying that CABG is still the treatment of choice for most of these patients. This conclusion which is apparently at odds with the results of most previous trials of stenting and surgery but entirely consistent with the findings of large propensity matched registries can be explained by the fact that SYNTAX enrolled ‘real life’ patients rather than the highly select patients usually enrolled in previous trials. SYNTAX also shows that for patients with less severe coronary artery disease there is no difference in survival between CABG and stents but a lower incidence of repeat revascularisation with CABG. At three years, SYNTAX shows no difference in stroke between CABG and stents for three-vessel disease but a higher incidence of stroke with CABG in patients with left main stem disease. In contrast the PRECOMBAT trial of stents and CABG in patients with left main stem disease showed no excess of mortality or stroke with CABG in comparison to stents in relatively low risk patients. Finally the importance of guidelines and multidisciplinary/heart teams in making recommendations for interventions is emphasised.

Assessment of the effect of revascularization early after CABG using ECG-gated perfusion single-photon emission tomography

International Nuclear Information System (INIS)

Kubo, Shigeto; Tadamura, Eiji; Kudoh, Takashi; Inubushi, Masayuki; Konishi, Junji; Ikeda, Tadashi; Koshiji, Takaaki; Nishimura, Kazunobu; Komeda, Masashi; Tamaki, Nagara

2001-01-01

When an arterial graft is used, reversible perfusion defects on single-photon emission tomography (SPET) perfusion images are occasionally observed early after coronary artery bypass graft surgery (CABG), owing to the restricted flow capacity. The purpose of this study was to determine whether the functional information obtained with electrocardiography (ECG)-gated perfusion SPET could be helpful in evaluating the effect of revascularization early after CABG. Twenty-three patients (18 men and 5 women, mean age 65±9 years) underwent stress/re-injection thallium-201 ECG-gated SPET before and 4 weeks after CABG (13 with exercise and 10 with dipyridamole). Patency of all grafts was confirmed by coronary angiography 1 month after CABG. Cardiac functional data including the left ventricular ejection fraction (LVEF) and the transient ischaemic dilatation (TID) ratio were analysed using a commercially available automated program. The conventional stress and re-injection tomograms were interpreted by means of a five-point scoring system in a nine-segment model. Stress-induced reversible 201 Tl perfusion defects were present in 64% of the myocardial segments bypassed by patent arterial grafts, in contrast to 42% of the myocardial segments bypassed by patent venous grafts (χ 2 =7.8, P=0.005). Of the 23 patients, 12 showed improvement in summed ischaemic scores (group 1), while 11 had no change or deterioration (group 2), although all grafts were patent on postoperative catheterization. The TID ratio improved in both group 1 and group 2 before and after CABG (1.14±0.13 vs 0.99±0.07, P=0.001 and 1.09±0.07 vs 0.94±0.05, P=0.002, respectively). However, LVEF did not significantly improve in group 1 or group 2 after CABG (42.5%±9.9% vs 47.5%±11.8%, and 52.1%±7.5% vs 53.1%±5.9%, respectively). Perfusion imaging or LVEF assessment is of limited value early after CABG. The TID ratio obtained with ECG-gated perfusion SPET may be a useful marker to evaluate the effect of

Graft patency after off-pump coronary artery bypass surgery is inferior even with identical heparinization protocols

DEFF Research Database (Denmark)

Houlind, Kim; Fenger-Grøn, Morten; Holme, Susanne J

2014-01-01

OBJECTIVE: To determine whether graft patency after on-pump and off-pump coronary artery bypass surgery is similar when performed using the same heparinization protocol. METHODS: In a randomized, controlled, multicenter trial, 900 patients more than 70 years of age received either on-pump or off......-pump coronary artery bypass surgery. Heparin was given to achieve an activated clotting time of 400 seconds before arteriotomy in both groups. After the procedure, protamine sulfate was given to revert the activated clotting time to less than 120 seconds. Coronary angiography was performed 6 months after...

Distinct alterations in sublingual microcirculatory blood flow and hemoglobin oxygenation in on-pump and off-pump coronary artery bypass graft surgery

NARCIS (Netherlands)

Atasever, Bektaş; Boer, Christa; Goedhart, Peter; Biervliet, Jules; Seyffert, Jan; Speekenbrink, Ron; Schwarte, Lothar; de Mol, Bas; Ince, Can

2011-01-01

The authors hypothesized that cardiopulmonary bypass (CPB) (on-pump) is associated with more severe changes in the microcirculatory blood flow and tissue oxygenation as compared with off-pump coronary artery bypass surgery. An observational study. A university hospital and teaching hospital.

Results of completion arteriography after minimally invasive off-pump coronary artery bypass.

Science.gov (United States)

Hoff, Steven J; Ball, Stephen K; Leacche, Marzia; Solenkova, Natalia; Umakanthan, Ramanan; Petracek, Michael R; Ahmad, Rashid; Greelish, James P; Walker, Kristie; Byrne, John G

2011-01-01

The benefits of a minimally invasive approach to off-pump coronary artery bypass remain controversial. The value of completion arteriography in validating this technique has not been investigated. From April 2007 to October 2009, fifty-six patients underwent isolated minimally invasive coronary artery bypass grafting through a left thoracotomy without cardiopulmonary bypass. Forty-three of these patients underwent completion arteriography. Sixty-five grafts were performed in these 56 patients, (average, 1.2 grafts per patient; range, 1 to 3). Forty-eight grafts were studied in the 43 patients undergoing completion arteriography. There were 4 findings on arteriogram leading to further immediate intervention (8.3%). These included 3 grafts with anastomotic stenoses or spasm requiring stent placement, and 1 patient who had limited dissection in the left internal mammary artery graft and underwent placement of an additional vein graft. These findings were independent of electrocardiographic changes or hemodynamic instability. The remainder of the studies showed no significant abnormalities. There were no deaths. One patient who did not have a completion arteriogram suffered a postoperative myocardial infarction requiring stent placement for anastomotic stenosis. Patients were discharged home an average of 6.8 days postoperatively. There were no instances of renal dysfunction postoperatively attributable to catheterization. Minimally invasive coronary artery bypass is safe and effective. Findings of completion arteriography occasionally reveal previously under-recognized findings that, if corrected in a timely fashion, could potentially impact graft patency and clinical outcomes. Our experience validates this minimally invasive technique. Copyright © 2011 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Evaluation of Factors Influencing Liver Function Test in On-Pump Coronary Artery Bypass Graft Surgery

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Shahrbano Shahbazi

2013-12-01

Full Text Available Background: Liver dysfunction during on-pump coronary artery bypass graft surgery (CABG is a rare complication but is associated with significant morbidity and mortality. The ability to identify high-risk patients may be helpful in planning appropriate management strategies. We aimed to evaluate the factors influencing liver function tests during on-pump CABG. Methods: In 146 patients scheduled for on-pump CABG, the liver function test was done preoperatively and on the first postoperative day. Some preoperative and intraoperative risk factors were checked and then the postoperative liver function tests were compared with the preoperative ones. Probable relationships between these changes and the preoperative and intraoperative risk factors were studied. Results: A medical history of diabetes had a significant relationship with the changes in direct bilirubin. Preoperative central venous pressure had a significant relationship with the changes in aspartate aminotransferase and alanine aminotransferase. Use of intra-aortic balloon pump and duration of aortic cross-clamp were significantly related to the changes in the liver function tests except for alanine aminotransferase and alkaline phosphatase. Conclusion: It seems that the techniques for the reduction of cardiopulmonary bypass and aortic cross-clamp duration may be useful to protect liver function. We recommend that a larger population of patients be studied to confirm these findings.

The impact of aortic manipulation on neurologic outcomes after coronary artery bypass surgery: a risk-adjusted study.

Science.gov (United States)

Kapetanakis, Emmanouil I; Stamou, Sotiris C; Dullum, Mercedes K C; Hill, Peter C; Haile, Elizabeth; Boyce, Steven W; Bafi, Ammar S; Petro, Kathleen R; Corso, Paul J

2004-11-01

Cerebral embolization of atherosclerotic plaque debris caused by aortic manipulation during conventional coronary artery bypass grafting (CABG) is a major mechanism of postoperative cerebrovascular accidents (CVA). Off-pump CABG (OPCABG) reduces stroke rates by minimizing aortic manipulation. Consequently, the effect of different levels of aortic manipulation on neurologic outcomes after CABG surgery was examined. From January 1998 to June 2002, 7,272 patients underwent isolated CABG surgery through three levels of aortic manipulation: full plus tangential (side-biting) aortic clamp application (on-pump surgery; n = 4,269), only tangential aortic clamp application (OPCABG surgery; n = 2,527) or an "aortic no-touch" technique (OPCABG surgery; n = 476). A risk-adjusted logistic regression analysis was performed to establish the likelihood of postoperative stroke with each technique. Preoperative risk factors for stroke from the literature, and those found significant in a univariable model were used. A significant association for postoperative stroke correspondingly increasing with the extent of aortic manipulation was demonstrated by the univariable analysis (CVA incidence respectively increasing from 0.8% to 1.6% to a maximum of 2.2%, p < 0.01). In the logistic regression model, patients who had a full and a tangential aortic clamp applied were 1.8 times more likely to have a stroke versus those without any aortic manipulation (95% confidence interval: 1.15 to 2.74, p < 0.01) and 1.7 times more likely to develop a postoperative stroke than those with only a tangential aortic clamp applied (95% confidence interval: 1.11 to 2.48, p < 0.01). Aortic manipulation during CABG is a contributing mechanism for postoperative stroke. The incidence of postoperative stroke increases with increased levels of aortic manipulation.

Significant reduction in blood loss in patients undergoing minimal extracorporeal circulation

NARCIS (Netherlands)

Gerritsen, W. B.; van Boven, W. J.; Smelt, M.; Morshuis, W. J.; van Dongen, H. P.; Haas, F. J.; Aarts, L. P.

2006-01-01

Several recent studies have shown differences in blood loss and allogeneic transfusion requirements between on-pump and off-pump coronary artery bypass grafting (CABG). Recently a new concept, the mini-extracorporeal circulation, was introduced to minimize the side effects of extracorporeal

Pleurotomy with subxyphoid pleural drain affords similar effects to pleural integrity in pulmonary function after off-pump coronary artery bypass graft.

Science.gov (United States)

Guizilini, Solange; Bolzan, Douglas W; Faresin, Sonia M; Ferraz, Raquel F; Tavolaro, Kelly; Cancio, Andrea A; Gomes, Walter J

2012-01-25

Exacerbation of pulmonary dysfunction has been reported in patients receiving a pleural drain inserted through the intercostal space in comparison to patients with an intact pleura undergoing coronary artery bypass grafting (CABG). Evidence suggests that shifting the site of pleural drain insertion to the subxyphoid position minimizes chest wall trauma and preserves respiratory function in the early postoperative period. The aim of this study was to compare the pulmonary function parameters, clinical outcomes, and pain score between patients undergoing pleurotomy with pleural drain placed in the subxyphoid position and patients with intact pleural cavity after off-pump CABG (OPCAB) using left internal thoracic artery (LITA). Seventy-one patients were allocated into two groups: I (n = 38 open left pleural cavity and pleural drain inserted in the subxyphoid position); II (n = 33 intact pleural cavity). Pulmonary function tests and clinical parameters were recorded preoperatively and on postoperative days (POD) 1, 3 and 5. Arterial blood gas analysis and shunt fraction were evaluated preoperatively and in POD1. Pain score was assessed on POD1. To monitor pleural effusion and atelectasis chest radiography was performed routinely 1 day before operation and until POD5. In both groups a significant impairment was found in lung function parameters until on POD5. However, no significant difference in forced vital capacity and forced expiratory volume in 1 second were seen between groups. A significant decrease in partial pressure of arterial oxygen and an increase in shunt fraction values were observed on POD1 in both groups, but no statistical difference was found when the groups were compared. Pleural effusion and atelectasis until on POD5 were similar in both groups. There were no statistical differences in pain score, duration of mechanical ventilation and postoperative hospital stay between groups. Subxyphoid insertion of pleural drain provides similar effects to

CABG Versus PCI: Greater Benefit in Long-Term Outcomes With Multiple Arterial Bypass Grafting.

Science.gov (United States)

Habib, Robert H; Dimitrova, Kamellia R; Badour, Sanaa A; Yammine, Maroun B; El-Hage-Sleiman, Abdul-Karim M; Hoffman, Darryl M; Geller, Charles M; Schwann, Thomas A; Tranbaugh, Robert F

2015-09-29

Treatment of multivessel coronary artery disease with traditional single-arterial coronary artery bypass graft (SA-CABG) has been associated with superior intermediate-term survival and reintervention compared with percutaneous coronary intervention (PCI) using either bare-metal stents (BMS) or drug-eluting stents (DES). This study sought to investigate longer-term outcomes including the potential added advantage of multiarterial coronary artery bypass graft (MA-CABG). We studied 8,402 single-institution, primary revascularization, multivessel coronary artery disease patients: 2,207 BMS-PCI (age 66.6 ± 11.9 years); 2,381 DES-PCI (age 65.9 ± 11.7 years); 2,289 SA-CABG (age 69.3 ± 9.0 years); and 1,525 MA-CABG (age 58.3 ± 8.7 years). Patients with myocardial infarction within 24 h, shock, or left main stents were excluded. Kaplan-Meier analysis and Cox regression were used to separately compare 9-year all-cause mortality and unplanned reintervention for BMS-PCI and DES-PCI to respective propensity-matched SA-CABG and MA-CABG cohorts. BMS-PCI was associated with worse survival than SA-CABG, especially from 0 to 7 years (p = 0.015) and to a greater extent than MA-CABG was (9-year follow-up: 76.3% vs. 86.9%; p PCI hazard ratios (HR) were as follows: versus SA-CABG, HR: 0.87; and versus MA-CABG, HR: 0.38. DES-PCI showed similar survival to SA-CABG except for a modest 0 to 3 years surgery advantage (HR: 1.06; p = 0.615). Compared with MA-CABG, DES-PCI exhibited worse survival at 5 (86.3% vs. 95.6%) and 9 (82.8% vs. 89.8%) years (HR: 0.45; p PCI for all comparisons (all p PCI or DES-PCI, resulted in substantially enhanced death and reintervention-free survival. Accordingly, MA-CABG represents the optimal therapy for multivessel coronary artery disease and should be enthusiastically adopted by multidisciplinary heart teams as the best evidence-based therapy. Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

A comparison of hybrid coronary revascularization and off-pump coronary revascularization.

Science.gov (United States)

Umakanthan, Ramanan; Leacche, Marzia; Gallion, Anna H; Byrne, John G

2013-04-01

Minimally invasive approaches to treat vascular disease have been accruing significant popularity over the last several decades. Due to progressive advances in technology, a variety of techniques are being now utilized in the field of cardiovascular surgery. The objectives of minimally invasive techniques are to curtail operative trauma and minimize perioperative morbidity without decreasing the quality of the treatment. The standard surgical approach for the treatment of coronary artery disease has traditionally been coronary artery bypass grafting surgery via median sternotomy. Off-pump coronary artery bypass grafting surgery offers a less invasive alternative and enables coronary revascularization to be performed without cardiopulmonary bypass. Hybrid coronary revascularization offers an even less invasive option in which minimally invasive direct coronary artery bypass can be combined with percutaneous coronary intervention. In this article, the authors review a recent publication comparing hybrid coronary revascularization and off-pump coronary artery bypass grafting surgery.

Effects of ionizing scrape-off layers on local recycling in Tore Supra pump limiter experiments

International Nuclear Information System (INIS)

Owen, L.W.; Hogan, J.T.; Klepper, C.C.; Mioduszewski, P.K.; Uckan, T.; Chatelier, M.; Loarer, T.

1992-01-01

A series of ohmic discharges with active pumping in the Tore Supra outboard pump limiter has been analyzed with the DEGAS neutrals transport code and an analysis scrape-off layer (SOL) plasma model. Pumping speed and plenum pressure measurements indicated 5--10 torr-L/s throughput with only modest effects on density (dN core /dt + source rate from ionization and dissociation of wall-desorbed molecules is seen to peak very near the radial position of the limiter throat. Consequently, a strong recycling vortex is created in the region of the limiter, with the ion flux amplified by factors of ∼2 at the outer limiter surfaces and >3 within the limiter throat. The calculations indicate that less than 30% of the pump throughput is due to first-generation ions from the core efflux, with the balance from local recycling in the strongly ionizing scrape-off layer

No major differences in 30-day outcomes in high-risk patients randomized to off-pump versus on-pump coronary bypass surgery: the best bypass surgery trial

DEFF Research Database (Denmark)

Møller, Christian H; Perko, Mario J; Lund, Jens T

2010-01-01

Off-pump coronary artery bypass grafting compared with coronary revascularization with cardiopulmonary bypass seems safe and results in about the same outcome in low-risk patients. Observational studies indicate that off-pump surgery may provide more benefit in high-risk patients. Our objective...... was to compare 30-day outcomes in high-risk patients randomized to coronary artery bypass grafting without or with cardiopulmonary bypass....

TRADING-OFF CONSTRAINTS IN THE PUMP SCHEDULING OPTIMIZATION OF WATER DISTRIBUTION NETWORKS

Directory of Open Access Journals (Sweden)

Gencer Genço\\u011Flu

2016-01-01

Full Text Available Pumps are one of the essential components of water supply systems. Depending of the topography, a water supply system may completely rely on pumping. They may consume non-negligible amount of water authorities' budgets during operation. Besides their energy costs, maintaining the healthiness of pumping systems is another concern for authorities. This study represents a multi-objective optimization method for pump scheduling problem. The optimization objective contains hydraulic and operational constraints. Switching of pumps and usage of electricity tariff are assumed to be key factors for operational reliability and energy consumption and costs of pumping systems. The local optimals for systems operational reliability, energy consumptions and energy costs are investigated resulting from trading-off pump switch and electricity tariff constraints within given set of boundary conditions. In the study, a custom made program is employed that combines genetic algorithm based optimization module with hydraulic network simulation software -EPANET. Developed method is applied on the case study network; N8-3 pressure zone of the Northern Supply of Ankara (Turkey Water Distribution Network. This work offers an efficient method for water authorities aiming to optimize pumping schedules considering expenditures and operational reliability mutually.

CArbon dioxide surgical field flooding and aortic NO-touch off-pump coronary artery bypass grafting to reduce Neurological injuries after surgical coronary revascularisation (CANON): protocol for a randomised, controlled, investigator and patient blinded single-centre superiority trial with three parallel arms

Science.gov (United States)

Szwed, Krzysztof; Pawliszak, Wojciech; Serafin, Zbigniew; Kowalewski, Mariusz; Tomczyk, Remigiusz; Perlinski, Damian; Szwed, Magdalena; Tomaszewska, Marta; Anisimowicz, Lech; Borkowska, Alina

2017-01-01

Introduction Neurological injuries remain a major concern following coronary artery bypass grafting (CABG) that offsets survival benefit of CABG over percutaneous coronary interventions. Among numerous efforts to combat this issue is the development of off-pump CABG (OPCABG) that obviates the need for extracorporeal circulation and is associated with improved neurological outcomes. The objective of this study is to examine whether the neuroprotective effect of OPCABG can be further pronounced by the use of two state-of-the-art operating techniques. Methods and analysis In this randomised, controlled, investigator and patient blinded single-centre superiority trial with three parallel arms, a total of 360 patients will be recruited. They will be allocated in a 1:1:1 ratio to two treatment arms and one control arm. Treatment arms undergoing either aortic no-touch OPCABG or OPCABG with partial clamp applying carbon dioxide surgical field flooding will be compared against control arm undergoing OPCABG with partial clamp. The primary endpoint will be the appearance of new lesions on control brain MRI 3 days after surgery. Secondary endpoints will include the prevalence of new focal neurological deficits in the first 7 days after surgery, the occurrence of postoperative cognitive dysfunction at either 1 week or 3 months after surgery and the incidence of delirium in the first 7 days after surgery. Data will be analysed on intention-to-treat principles and a per protocol basis. Ethics and dissemination Ethical approval has been granted for this study. Results will be disseminated through peer-reviewed media. Trial registration number NCT03074604; Pre-results. Date and version identifier 10-Mar-2017 Original PMID:28698347

Can perioperative C-reactive protein and interleukin-6 levels predict atrial fibrillation after coronary artery bypass surgery?

International Nuclear Information System (INIS)

Ziabaksh-Tabari, S.

2008-01-01

Objective was to examine the relationship between proinflammatory cytokines such as interleukin-6 (IL-6) and C-reactive protein (CRP) and atrial fibrillation and after on-pump coronary artery bypass grafting (CABG). Fifty-four patients with coronary artery disease undergoing elective CABG at the Mazandaran Medical University, Mazandaran, Iran were enrolled in our prospective study in the year 2007. Postoperatively, heart rate and rhythm were continuously monitored for 5 days. Fasting blood samples were taken from all patients to examine quantities of CRP and IL-6 the day before surgery and on the second postoperative day in the intensive care unit. From 54 patients, 11 patients (20.4%) developed atrial fibrillation (AF) after CABG. The median age of patients with AF was 51.45+/-10.74 compared with 57.28+/-9.04 for patients with sinus rhythm (p=0.072). Cardioplegic time, cross clamp time and pump time were higher in the AF group but there was no significant difference between the 2 groups. Preoperative CRP and IL-6 levels were higher in patients with AF. The CRP and IL-6 increased after CABG in all patients but it increased more in the AF group. There was a significant relationship between preoperative IL-6 and AF in patients who underwent on-pump CABG, but there was no relationship between CRP and AF. Therefore, administration of glucocordicoids which significantly reduce plasma levels of IL-6 can reduce the incidence of AF after on-pump CABG. (author)

Cognitive outcomes in elderly high-risk patients after off-pump versus conventional coronary artery bypass grafting

DEFF Research Database (Denmark)

Jensen, Birte Ostergaard; Hughes, Pia; Rasmussen, Lars S

2006-01-01

It has been suggested that the risk of cerebral dysfunction is less with off-pump coronary artery bypass grafting (OPCAB) than with conventional coronary artery bypass grafting (CCAB). However, evidence for this statement is preliminary, and additional insight is needed.......It has been suggested that the risk of cerebral dysfunction is less with off-pump coronary artery bypass grafting (OPCAB) than with conventional coronary artery bypass grafting (CCAB). However, evidence for this statement is preliminary, and additional insight is needed....

A new beating-heart off-pump coronary artery bypass grafting training model

NARCIS (Netherlands)

Bouma, Wobbe; Kuijpers, Michiel; Bijleveld, Aanke; De Maat, Gijs E.; Koene, Bart M.; Erasmus, Michiel E.; Natour, Ehsan; Mariani, Massimo A.

OBJECTIVES: Training models are essential in mastering the skills required for off-pump coronary artery bypass grafting (OPCAB). We describe a new, high-fidelity, effective and reproducible beating-heart OPCAB training model in human cadavers. METHODS: Human cadavers were embalmed according to the

Effects of continuous administration of clopidogrel before off-pump coronary artery bypass grafting in patients with acute coronary syndrome. A propensity score analysis

International Nuclear Information System (INIS)

Song, Suk-Won; Youn, Young-Nam; Yi, Gijong; Lee, Sak; Yoo, Kyung-Jong

2008-01-01

Clopidogrel has become standard treatment after urgent percutaneous coronary revascularization. Due to its enhanced and irreversible platelet inhibition, patients undergoing urgent surgical revascularization have a higher risk of bleeding complications and transfusions. Therefore, the effect of preoperative continuous administration of clopidogrel on the incidence of hemorrhagic complications in patients undergoing off-pump coronary artery bypass surgery with acute coronary syndrome was evaluated. From March 2004 to September 2006, 172 patients with acute coronary syndrome underwent isolated off-pump coronary artery bypass surgery; 70 (40.7%) and 102 (59.3%) of these patients did or did not take clopidogrel before surgery respectively. Seventy patients in each group were matched using propensity scores and associations between preoperative continuous administration of clopidogrel and postoperative bleeding, hemostatic reoperation, blood products received, the need for multiple transfusions and early graft patency by coronary computed tomography were assessed. Univariate analysis showed the continuous clopidogrel group had similar levels of postoperative bleeding for 24 h (601.4±312.6 ml vs 637.2±452.4 ml, p=0.616) and rates of reexploration (1.4% vs 1.4%), perioperative blood transfusion (33.3% vs 34.3%, p>0.05) and platelet transfusion (2.9% vs 7.1%, p=0.44) compared with the non-continuous group. Preoperative continuous administration of clopidogrel did not increase the risk of hemorrhagic complications in patients with acute coronary syndrome undergoing isolated off-pump coronary artery bypass surgery. These findings indicate that surgery after clopidogrel treatment in patients with acute coronary syndrome should not be delayed until platelet function returns to normal because they may have a higher risk of recurrent myocardial ischemic events. (author)

CArbon dioxide surgical field flooding and aortic NO-touch off-pump coronary artery bypass grafting to reduce Neurological injuries after surgical coronary revascularisation (CANON): protocol for a randomised, controlled, investigator and patient blinded single-centre superiority trial with three parallel arms.

Science.gov (United States)

Krzysztof, Szwed; Wojciech, Pawliszak; Zbigniew, Serafin; Mariusz, Kowalewski; Remigiusz, Tomczyk; Damian, Perlinski; Magdalena, Szwed; Marta, Tomaszewska; Lech, Anisimowicz; Alina, Borkowska

2017-07-10

Neurological injuries remain a major concern following coronary artery bypass grafting (CABG) that offsets survival benefit of CABG over percutaneous coronary interventions. Among numerous efforts to combat this issue is the development of off-pump CABG (OPCABG) that obviates the need for extracorporeal circulation and is associated with improved neurological outcomes. The objective of this study is to examine whether the neuroprotective effect of OPCABG can be further pronounced by the use of two state-of-the-art operating techniques. In this randomised, controlled, investigator and patient blinded single-centre superiority trial with three parallel arms, a total of 360 patients will be recruited. They will be allocated in a 1:1:1 ratio to two treatment arms and one control arm. Treatment arms undergoing either aortic no-touch OPCABG or OPCABG with partial clamp applying carbon dioxide surgical field flooding will be compared against control arm undergoing OPCABG with partial clamp. The primary endpoint will be the appearance of new lesions on control brain MRI 3 days after surgery. Secondary endpoints will include the prevalence of new focal neurological deficits in the first 7 days after surgery, the occurrence of postoperative cognitive dysfunction at either 1 week or 3 months after surgery and the incidence of delirium in the first 7 days after surgery. Data will be analysed on intention-to-treat principles and a per protocol basis. Ethical approval has been granted for this study. Results will be disseminated through peer-reviewed media. NCT03074604; Pre-results. 10-Mar-2017 Original. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Analysis of off-grid hybrid wind turbine/solar PV water pumping systems

Science.gov (United States)

While many remote water pumping systems exist (e.g. mechanical windmills, solar photovoltaic , wind-electric, diesel powered), very few combine both the wind and solar energy resources to possibly improve the reliability and the performance of the system. In this paper, off-grid wind turbine (WT) a...

Pleurotomy with subxyphoid pleural drain affords similar effects to pleural integrity in pulmonary function after off-pump coronary artery bypass graft

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Guizilini Solange

2012-01-01

Full Text Available Abstract Background Exacerbation of pulmonary dysfunction has been reported in patients receiving a pleural drain inserted through the intercostal space in comparison to patients with an intact pleura undergoing coronary artery bypass grafting (CABG. Evidence suggests that shifting the site of pleural drain insertion to the subxyphoid position minimizes chest wall trauma and preserves respiratory function in the early postoperative period. The aim of this study was to compare the pulmonary function parameters, clinical outcomes, and pain score between patients undergoing pleurotomy with pleural drain placed in the subxyphoid position and patients with intact pleural cavity after off-pump CABG (OPCAB using left internal thoracic artery (LITA. Methods Seventy-one patients were allocated into two groups: I (n = 38 open left pleural cavity and pleural drain inserted in the subxyphoid position; II (n = 33 intact pleural cavity. Pulmonary function tests and clinical parameters were recorded preoperatively and on postoperative days (POD 1, 3 and 5. Arterial blood gas analysis and shunt fraction were evaluated preoperatively and in POD1. Pain score was assessed on POD1. To monitor pleural effusion and atelectasis chest radiography was performed routinely 1 day before operation and until POD5. Results In both groups a significant impairment was found in lung function parameters until on POD5. However, no significant difference in forced vital capacity and forced expiratory volume in 1 second were seen between groups. A significant decrease in partial pressure of arterial oxygen and an increase in shunt fraction values were observed on POD1 in both groups, but no statistical difference was found when the groups were compared. Pleural effusion and atelectasis until on POD5 were similar in both groups. There were no statistical differences in pain score, duration of mechanical ventilation and postoperative hospital stay between groups. Conclusion Subxyphoid

Hemoglobin Level to Facilitate Off-Pump Coronary Artery Bypass without Transfusion.

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Kim, Kun Il; Lee, Won Yong; Ko, Ho Hyun; Kim, Hyoung Soo; Jeong, Jae Han

2014-08-01

Conservation of blood during cardiac surgery is important because of the shortage of donor blood, risks associated with transfusion, and the costs of allogeneic blood products. This retrospective study explored the feasibility of off-pump coronary artery bypass (OPCAB) without transfusion. One hundred and two consecutive patients underwent OPCAB from January 2007 to June 2012 at Hallym University Sacred Heart Hospital. Excluding 10 chronic renal failures patients, 102 patients were enrolled. Their characteristics, clinical data, and laboratory data were analyzed. We investigated the success rate of OPCAB without transfusion according to pre-operative hemoglobin (Hb), and the cutoff point of the Hb level and the risk factors for transfusion. We implemented multidisciplinary blood-saving protocols. The overall operative mortality and the success rate of OPCAB without transfusion were 2.9% (3/102) and 73.5% (75/102). The success rates in patients with Hb70 years, diagnosis of acute myocardial infarction, preoperative Hb and creatinine levels, and operation time. The events precipitating the need for transfusion were low Hb level in 9 patients and hypotension or excessive bleeding in 18 patients. The preoperative Hb level of >11 facilitates OPCAB without transfusion. These results suggest that transfusion-free OPCAB can be performed by modifying the risk factors and correctable causes of transfusion and improving various blood salvage methods.

Coronary artery bypass grafting-related bleeding complications in patients treated with dual antiplatelet treatment

NARCIS (Netherlands)

Tomšič, Anton; Schotborgh, Mark A.; Manshanden, Johan S. J.; Li, Wilson W. L.; de Mol, Bas A. J. M.

2016-01-01

To evaluate the relationship between the timing of either ticagrelor or clopidogrel discontinuation and bleeding-related complications in patients undergoing isolated on-pump coronary artery bypass grafting (CABG). Between January 2012 and December 2014, 705 consecutive patients underwent isolated

Off-pump transapical implantation of artificial neo-chordae to correct mitral regurgitation: the TACT Trial (Transapical Artificial Chordae Tendinae) proof of concept.

Science.gov (United States)

Seeburger, Joerg; Rinaldi, Mauro; Nielsen, Sten Lyager; Salizzoni, Stefano; Lange, Ruediger; Schoenburg, Markus; Alfieri, Ottavio; Borger, Michael Andrew; Mohr, Friedrich Wilhelm; Aidietis, Audrius

2014-03-11

The goal of this study was to evaluate the safety and performance of the NeoChord DS1000 system (NeoChord, Inc., Minneapolis, Minnesota). There is an increasing interest in transcatheter mitral valve (MV) treatment. The NeoChord DS 1000 system enables off-pump beating heart transapical MV repair with implantation of artificial neo-chordae. Patients with severe mitral regurgitation (MR) due to isolated posterior prolapse were included in this TACT (Transapical Artificial Chordae Tendinae) trial. All patients were scheduled for off-pump transapical implantation of neo-chordae. Thirty patients at 7 centers were enrolled. Major adverse events included 1 death due to post-cardiotomy syndrome and concomitant sepsis and 1 minor stroke with the patient fully recovered at the 30-day follow-up visit. Additional patients experienced procedural major adverse events related to a reoperation or conversion to standard of care. Acute procedural success (placement of at least 1 neo-chord and reduction of MR from 3+ or 4+ to ≤2+) was achieved in 26 patients (86.7%). In 4 patients neo-chordae were not placed for technical and/or patient-specific reasons. These patients underwent intraoperative (3 patients) or post-operative (1 patient) standard MV repair. At 30 days, 17 patients maintained an MR grade ≤2+. Four patients who developed recurrent MR were successfully treated with open MV repair during 30-day follow-up. Results improved with experience: durable reduction in MR to ≤2+ at 30 days was achieved in 5 (33.3%) of the first 15 patients and 12 (85.7%) of the last 14 patients. Off-pump transapical implantation of artificial chordae to correct MR is technically safe and feasible; however, it yields further potential for improvement of efficacy and durability. (Safety and Performance Study of the NeoChord Device [TACT]; NCT01777815). Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

On-Pump Versus Off-Pump Coronary Artery Bypass Surgery in Elderly Patients

DEFF Research Database (Denmark)

Houlind, Kim; Kjeldsen, Bo Juul; Madsen, Susanne Nørgaard

2012-01-01

BACKGROUND: Conventional coronary artery bypass grafting performed with the use of cardiopulmonary bypass is a well-validated treatment for patients with ischemic heart disease. Off-pump coronary artery bypass grafting (OPCAB) has been suggested to reduce the number of perioperative complications......, especially in elderly patients. METHODS AND RESULTS: In a multicenter, randomized trial, we assigned 900 patients >70 years of age to conventional coronary artery bypass grafting or OPCAB surgery. After 30 days, a blinded end-point committee assessed whether a combined end point of death, stroke...... experiencing the combined end point within 30 days was 10.2% for conventional coronary artery bypass grafting and 10.7% for OPCAB. Implied risk difference of 0.4% (with a 95% confidence interval, -3.6 to 4.4) showed nonsignificance in a standard test for equality (P=0.83) and for noninferiority...

SheppHeartCABG trial-comprehensive early rehabilitation after coronary artery bypass grafting

DEFF Research Database (Denmark)

Hojskov, Ida Elisabeth; Moons, Philip; Hansen, Niels Viggo

2017-01-01

rehabilitation. The SheppHeartCABG trial will investigate the effect of early comprehensive rehabilitation in early phase rehabilitation versus usual care. The aim of this paper is to present the protocol for the SheppHeartCABG trial. METHODS/ANALYSIS: SheppHeartCABG is an investigator-initiated randomised...... clinical superiority trial with blinded outcome assessment, employing 1:1 central randomisation to rehabilitation plus usual care versus usual care alone. On the basis of a sample size calculation, 326 patients undergoing coronary artery bypass grafting will be included from two clinical sites. All...... patients receive usual care and patients allocated to the experimental intervention follow 4 weeks rehabilitation consisting of an exercise programme, psycho-educative consultations and a compact mindfulness programme. The primary outcome is physical function measured by the 6-min walk test. The secondary...

Anesthesia for off-pump coronary artery bypass surgery

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Thomas M Hemmerling

2013-01-01

Full Text Available The evolution of techniques and knowledge of beating heart surgery has led anesthesia toward the development of new procedures and innovations to promote patient safety and ensure high standards of care. Off-pump coronary artery bypass (OPCAB surgery has shown to have some advantages compared to on-pump cardiac surgery, particularly the reduction of postoperative complications including systemic inflammation, myocardial injury, and cerebral injury. Minimally invasive surgery for single vessel OPCAB through a limited thoracotomy incision can offer the advantage of further reduction of complications. The anesthesiologist has to deal with different issues, including hemodynamic instability and myocardial ischemia during aorto-coronary bypass grafting. The anesthesiologist and surgeon should collaborate and plan the best perioperative strategy to provide optimal care and ensure a rapid and complete recovery. The use of high thoracic epidural analgesia and fast-track anesthesia offers particular benefits in beating heart surgery. The excellent analgesia, the ability to reduce myocardial oxygen consumption, and the good hemodynamic stability make high thoracic epidural analgesia an interesting technique. New scenarios are entering in cardiac anesthesia: ultra-fast-track anesthesia with extubation in the operating room and awake surgery tend to be less invasive, but can only be performed on selected patients.

Off-pump coronary bypass surgery adversely affects alveolar gas exchange.

Science.gov (United States)

Gasparović, Hrvoje; Unić, Daniel; Sutlić, Zeljko; Husedzinović, Ino; Biocina, Bojan; Rudez, Igor; Nikić, Nada; Jelić, Ivan

2008-03-01

While the introduction of off-pump myocardial revascularization (OPCAB) has initially shown promise in reducing respiratory complications inherent to conventional coronary surgery, it has failed to eradicate them. Our study focused on quantifying the lactate release from the lungs and the dysfunction at the level of the alveolar-capillary membrane precipitated by OPCAB at different time points after the insult. Furthermore, we aimed to determine the impact of pulmonary lactate production on systemic lactic acid concentrations. The study was conducted in a prospective observational fashion. Forty consecutive patients undergoing OPCAB were analyzed. The mean patient age was 60 +/- 10 years. The mean EUROScore was 3.8 +/- 2.9. The alveolar-arterial O2 gradient increased from 19 [range 9 to 30] to 26 [range 20 to 34] kPa (P pump myocardial revascularization was evidenced by a prompt increase in the alveolar-arterial oxygen gradient. The alveolar-arterial O2 gradient correlated with the duration of mechanical ventilation.

Improved Approach With Subcostal Exchange of the HeartMate II Left Ventricular Assist Device: Difference in On and Off Pump?

Science.gov (United States)

Gaffey, Ann C; Chen, Carol W; Chung, Jennifer J; Phillips, Emily; Wald, Joyce; Williams, Matthew L; Low, David W; Acker, Michael A; Atluri, Pavan

2017-11-01

The HeartMate II (St. Jude Medical, Inc, St. Paul, MN [previously Thoratec]) left ventricular assist device (LVAD) exchange has traditionally involved a redo sternotomy. Alternate minimally invasive subcostal approaches have the advantage of avoiding sternal reentry, excessive bleeding, and prolonged recovery. This retrospective review included patients who underwent an exchange from May 2009 to March 2016. The patients were divided into three cohorts: (1) redo sternotomy, (2) subcostal approach involving cardiopulmonary bypass (CPB) (ON-CPB SC), and (3) subcostal approach off the CPB pump (OFF-CPB SC). Data pertaining to patients' baseline characteristics and outcomes were collected and analyzed. From May 1, 2009 to July 31, 2016, 33 HeartMate II LVAD exchanges were performed. There were 11 redo sternotomies and 22 subcostal exchanges, 12 of which were in the OFF-CPB SC group. There was no significant difference among the groups in terms of age (p = 0.75), sex (p = 0.95), and indication for exchange (p = 0.94). There was a higher red blood cell transfusion requirement within the sternotomy cohort (p rates were equivalent among the cohorts. Exchange of the HeartMate II LVAD can be accomplished with significantly improved recovery time and transfusion requirement through a less invasive subcostal approach when compared with sternotomy. The subcostal approach can be performed safely both on and off cardiopulmonary bypass. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Effect of Cryoanalgesia on Post Midsternotomy Pain and Paresthesia Following CABG

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H Hosseini

2009-07-01

Full Text Available Introduction: Control of post thoracotomy pain is particularly important in prevention of post operative respiratory complications. Several methods are proposed for control of postoperative pain. Cryoanalgesia by freezing of intercostal nerves is able to providing long term pain relief in post operative period which probably results in cutaneous sensory changes. Methods: This clinical trial study was done on 124 patients who underwent CABG surgery. Patients were randomly divided in two groups; control group (group I and study group (group II. In study group cryoanalgesia was applied intraoperatively on the intercostal nerves. All of the patients received appropriate analgesia on demand in postoperative period. Pain in LIMA harvesting site and sternum was measured by visual analogue pain score before discharge, one and three months following cryoanalgesia. In all of the patient’s, presence of paresthesia was evaluated. The amount of administered analgesics (narcotic, opium, indomethacin was noted daily. Data of this investigation was analyzed and evaluated using SPSS 11.5 software. Results: Pain score of sternum was higher in study group before discharge and was lower at one and three months after operation than the control group that was statistically significant (P=0.01. Pain score of LIMA region before discharge was higher, at one month post operation was equal and at three months post operative was lower than the control group (P=0.045. Use of morphine and opium was lower (P=0.017 and use of indomethacin was higher in the cryoanalgesia group that was statistically significant (P=0.001. Incidence of paresthesia was lower in the study group (P=0.001. Conclusion: It is proposed that cryoanalgesia is a safe and effective method for reduction of pain and paresthesia and need for analgesics following CABG operation.

An information-motivation-behavioral skills (IMB) model-based intervention for CABG patients.

Science.gov (United States)

Zarani, Fariba; Besharat, Mohammad Ali; Sarami, Gholamreza; Sadeghian, Saeed

2012-12-01

In order to benefit from a coronary artery bypass graft (CABG) surgery, patients must adhere to medical recommendations and health advices. Despite the importance of adherence in CABG patients, adherence rates are disappointingly low. Despite the low adherence rates, very few articles regarding adherence-enhancing intervention among heart patients have been published. The goal of this study was to assess the effects of the Information-Motivation-Behavioral Skills (IMB) model-based intervention on the IMB model constructs among patients undergoing CABG and to evaluate the relationship of information, motivation, and behavioral skills with adherence. A total of 152 CABG patients were randomly assigned to either an intervention group or to a standard care control group. Participants completed pretest measures and were reassessed 1 month later. Findings showed mixed support for the effectiveness of the intervention. There was a significant effect of IMB intervention on information and motivation of patients, but no significant effect on behavioral skills. Furthermore, the results revealed that intervention constructs (information, motivation, and behavioral skills) were significantly related to patients' adherence. Findings provided initial evidence for the effectiveness of IMB-based interventions on the IMB constructs and supported the importance of these constructs to improve adherence; however, there are additional factors that need to be identified in order to improve behavioral skills more effectively.

Perioperative outcomes in minimally invasive direct coronary artery bypass versus off-pump coronary artery bypass with sternotomy.

Science.gov (United States)

Tekin, Ali İhsan; Arslan, Ümit

2017-09-01

Surgical treatment of isolated left anterior descending coronary artery disease can be performed with either minimally invasive direct coronary artery bypass via a left anterior thoracotomy (MIDCAB) or off-pump coronary artery bypass via a median sternotomy (OPCAB). To compare the perioperative outcomes of patients undergoing MIDCAB or OPCAB surgery. Patients who underwent either MIDCAB or OPCAB for isolated left anterior descending (LAD) coronary artery disease between October 2013 and December 2015 were retrospectively evaluated. Operations were carried out by the same surgical team. Preoperative, intraoperative and postoperative data of the patients were recorded for analyses. Twenty-three patients (7 females, 16 males) underwent MIDCAB surgery, and 24 patients (4 female, 20 males) underwent OPCAB surgery. The two groups were comparable regarding preoperative patient characteristics. Duration of mechanical ventilation (5.1 ±0.7 h vs. 6.6 ±0.9 h), intensive care unit stay (19.4 ±2.5 h vs. 45.8 ±5.4 h) and hospital stay (4.3 ±0.4 days vs. 5.6 ±0.8 days) were significantly shorter in the MIDCAB group (p < 0.01). Patients in the OPCAB group required significantly more blood transfusions (1.83 ±0.38 units vs. 0.17 ±0.38 units) and fresh frozen plasma use (2.33 ±0.96 units vs. 0.69 ±0.76 units) (p < 0.01). Conversion to sternotomy was not required in the MIDCAB group. There was no mortality, conversion to cardiopulmonary bypass or serious complication in either group. We believe that the MIDCAB technique is more advantageous than the OPCAB technique in the treatment of patients with a critical LAD lesion.

Sodium bicarbonate does not prevent postoperative acute kidney injury after off-pump coronary revascularization: a double-blinded randomized controlled trial.

Science.gov (United States)

Soh, S; Song, J W; Shim, J K; Kim, J H; Kwak, Y L

2016-10-01

Acute kidney injury (AKI) is a common morbidity after off-pump coronary revascularization. We investigated whether perioperative administration of sodium bicarbonate, which might reduce renal injury by alleviating oxidative stress in renal tubules, prevents postoperative AKI in off-pump coronary revascularization patients having renal risk factors. Patients (n=162) having at least one of the following AKI risk factors were enrolled: (i) age >70 yr; (ii) diabetes mellitus; (iii) chronic renal disease; (iv) congestive heart failure or left ventricular ejection fraction 24 h) relative to the control group (20 vs 6, P=0.003). Perioperative sodium bicarbonate administration did not decrease the incidence of AKI after off-pump coronary revascularization in high-risk patients and might even be associated with a need for prolonged ventilatory care. NCT01840241. © The Author 2016. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Transient simulation of coolant peak temperature due to prolonged fan and/or water pump operation after the vehicle is keyed-off

Science.gov (United States)

Pang, Suh Chyn; Masjuki, Haji Hassan; Kalam, Md. Abul; Hazrat, Md. Ali

2014-01-01

Automotive designers should design a robust engine cooling system which works well in both normal and severe driving conditions. When vehicles are keyed-off suddenly after some distance of hill-climbing driving, the coolant temperature tends to increase drastically. This is because heat soak in the engine could not be transferred away in a timely manner, as both the water pump and cooling fan stop working after the vehicle is keyed-off. In this research, we aimed to visualize the coolant temperature trend over time before and after the vehicles were keyed-off. In order to prevent coolant temperature from exceeding its boiling point and jeopardizing engine life, a numerical model was further tested with prolonged fan and/or water pump operation after keying-off. One dimensional thermal-fluid simulation was exploited to model the vehicle's cooling system. The behaviour of engine heat, air flow, and coolant flow over time were varied to observe the corresponding transient coolant temperatures. The robustness of this model was proven by validation with industry field test data. The numerical results provided sensible insights into the proposed solution. In short, prolonging fan operation for 500 s and prolonging both fan and water pump operation for 300 s could reduce coolant peak temperature efficiently. The physical implementation plan and benefits yielded from implementation of the electrical fan and electrical water pump are discussed.

Simulation in transient regime of a heat pump with closed-loop and on-off control

Energy Technology Data Exchange (ETDEWEB)

Vargas, J.V.C. [Duke Univ., Durham, NC (United States). Dept. of Mechanical Engineering and Materials Science; Parise, J.A.R. [Pontificia Univ. Catolica do Rio de Janeiro, RJ (Brazil). Dept. de Engenharia Mecanica

1995-05-01

The present work introduces a mathematical model for a heat pump with a variable-speed compressor, driven by a d.c. servomotor, operating either in closed loop by a power law control action or by the traditional on-off basis. The resulting differential and algebraic equations are integrated in time for a specified period of simulation in both designs. The results show that the closed-loop system presents significant savings in energy consumption when compared with the on-off system, under the same environmental conditions. (author)

Preoperative factors affecting cost and length of stay for isolated off-pump coronary artery bypass grafting: hierarchical linear model analysis.

Science.gov (United States)

Shinjo, Daisuke; Fushimi, Kiyohide

2015-11-17

To determine the effect of preoperative patient and hospital factors on resource use, cost and length of stay (LOS) among patients undergoing off-pump coronary artery bypass grafting (OPCAB). Observational retrospective study. Data from the Japanese Administrative Database. Patients who underwent isolated, elective OPCAB between April 2011 and March 2012. The primary outcomes of this study were inpatient cost and LOS associated with OPCAB. A two-level hierarchical linear model was used to examine the effects of patient and hospital characteristics on inpatient costs and LOS. The independent variables were patient and hospital factors. We identified 2491 patients who underwent OPCAB at 268 hospitals. The mean cost of OPCAB was $40 665 ±7774, and the mean LOS was 23.4±8.2 days. The study found that select patient factors and certain comorbidities were associated with a high cost and long LOS. A high hospital OPCAB volume was associated with a low cost (-6.6%; p=0.024) as well as a short LOS (-17.6%, pcost and LOS. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Influence of isoflurane on the diastolic pressure-flow relationship and critical occlusion pressure during arterial CABG surgery: a randomized controlled trial

OpenAIRE

Hinz, Jos?; Mansur, Ashham; Hanekop, Gerd G.; Weyland, Andreas; Popov, Aron F.; Schmitto, Jan D.; Gr?ne, Frank F. G.; Bauer, Martin; Kazmaier, Stephan

2016-01-01

The effects of isoflurane on the determinants of blood flow during Coronary Artery Bypass Graft (CABG) surgery are not completely understood. This study characterized the influence of isoflurane on the diastolic Pressure-Flow (P-F) relationship and Critical Occlusion Pressure (COP) during CABG surgery. Twenty patients undergoing CABG surgery were studied. Patients were assigned to an isoflurane or control group. Hemodynamic and flow measurements during CABG surgery were perf...

Health-related quality of life following off-pump versus on-pump coronary artery bypass grafting in elderly moderate to high-risk patients

DEFF Research Database (Denmark)

Jensen, Birte Østergaard; Hughes, Pia; Rasmussen, Lars S

2006-01-01

Previous trials comparing coronary artery bypass grafting (CABG) with or without extracorporeal circulation have mainly enrolled selected patients at younger age and low risk. Patient-reported health-related quality of life has not been significantly different. We compared health-related quality...

Role of Acid and Weakly Acidic Reflux in Gastroesophageal Reflux Disease Off Proton Pump Inhibitor Therapy

OpenAIRE

Sung, Hea Jung; Cho, Yu Kyung; Moon, Sung Jin; Kim, Jin Su; Lim, Chul Hyun; Park, Jae Myung; Lee, In Seok; Kim, Sang Woo; Choi, Myung-Gye

2012-01-01

Background/Aims Available data about reflux patterns and symptom determinants in the gastroesophageal reflux disease (GERD) subtypes off proton pump inhibitor (PPI) therapy are lacking. We aimed to evaluate reflux patterns and determinants of symptom perception in patients with GERD off PPI therapy by impedance-pH monitoring. Methods We retrospectively reviewed the impedance-pH data in patients diagnosed as GERD based on results of impedance-pH monitoring, endoscopy and/or typical symptoms. T...

Numerical investigation of solid-liquid two phase flow in a non-clogging centrifugal pump at off-design conditions

International Nuclear Information System (INIS)

Zhao, B J; Chen, H L; Hou, D H; Huang, Z F

2012-01-01

The solid-liquid two-phase flow fields in the non-clogging centrifugal pump with a double-channel impeller have been investigated numerically for the design condition and also off-design conditions, in order to study the solid-liquid two-phase flow pattern and non-clogging mechanism in non-clogging centrifugal pumps. The main conclusions include: The sand volume fraction distribution is extremely inhomogeneous in the whole flow channel of the pump at off-design conditions. In the impeller, particles mainly flow along the pressure surface and hub; In the volute, particles mainly accumulate in the region near to the exit of volute, the largest sand volume fraction is observed at the tongue, and a large number of particles collide with volute wall and exit the volute after circling around the volute for several times. When the particle diameter increases, particles tend to accumulate on the pressure side of the impeller, and more particles crash with the pressure side of the blade. And larger sand volume fraction gratitude is also observed in the whole flow channel of the pump. With the decrease of the inlet sand volume fraction, particles tend to accumulate on the suction side of the blade. Compared with the particle diameter, the inlet sand volume fraction has less influence on the sand volume fraction gratitude in the whole channel of the pump. At the large flow rate, the minimum and maximum sand volume fraction in the whole flow channel of the model pump tends to be smaller than that at the small flow rate. Thus, it is concluded that the water transportation capacity increases with the flow rate. This research will strengthen people's understanding of the multiphase flow pattern in non-clogging centrifugal pumps, thus provides a theoretical basis for the optimal design of non-clogging centrifugal pumps.

Effects of ionizing scrape-off layers on local recycling in Tore Supra pump limiter experiments

International Nuclear Information System (INIS)

Chatelier, M.; Loarer, T.

1992-01-01

A series of ohmic discharges with active pumping in the Tore Supra outboard pump limiter has been analyzed with the DEGAS neutrals transport code and an analytic scrape-off layer (SOL) plasma model. Pumping speed and plenum pressure measurements indicated 5-10 torr.L/s throughput with only modest effects on density. A model is developed in which large exhaust fluxes, with little attendant effect on core plasma density, are explained in terms of SOL ionization of recycled and wall-desorbed neutrals. Particle balance with active pumping and constant line density requires that the wall return flux exceed the incident flux by approximately the pump throughput in the absence of external fueling. The radial profile of the H + source rate from ionization and dissociation of wall-desorbed molecules is seen to peak very near the radial position of the limiter throat. Consequently, a strong recycling vortex is created in the region of the limiter, with the ion flux amplified by factors of 2 at the outer limiter surfaces and > 3 within the limiter throat. The calculations indicate that less than 30% of the pump throughput is due to first-generation ions from the core efflux, with the balance from local recycling in the strongly ionizing SOL

Off-Pump Repair of a Post Myocardial Infarction Ventricular Septal Defect

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Feridoun Sabzi

2014-01-01

Full Text Available Refractory cardiogenic shock meant that traditional patch repairs requiring cardiopulmonary bypass would be poorly tolerated and external sandwich closure of post myocardial ventricular septal defect (VSD appears to be simple and effective after initial myocardial infarction (MI. The three cases presented with a VSD after of acute MI with or without thrombolysed with streptokinase during patient admission. The general condition of the three patients was poor with pulmonary edema, low cardiac output and renal failure. The heart was approached through a median sternotomy. Off-pump coronary artery bypass grafting of the coronary artery lesion was done first using octopus and beating heart surgery method and latero - lateral septal plication was performed using sandwich technique. Low cardiac output managed with intra-aortic balloon pump in these patients accompanied with inotropic drugs. Post-operative transesophageal echocardiography revealed that VSD was closed completely in one patient and in two patients small residual VSD remained. More experience is required to ascertain whether this technique will become an accepted alternative to patch repairs.

Rare case-series of electrocautery burn following off-pump coronary artery bypass grafting

Science.gov (United States)

Sabzi, Feridoun; Niazi, Mojtaba; Ahmadi, Alireza

2014-01-01

Abstract: With an increasing number of off-pump coronary artery surgery procedures in high-risk patients with coagulopathy, including renal failure, hepatic failure and anticoagulant drug-using patients, the frequency of related complications such as repeated exploration for bleeding is also increasing. The associated co-morbidity and repeated use of electrocautery in postoperative bleeding leaves patients susceptible to electrocautery ulcers. In this case series, rare cases of cautery burn with unique causative mechanisms are described. PMID:23669602

Mechanical design and modeling of a single-piston pump for the novel power take-off system of a wave energy converter

NARCIS (Netherlands)

Vakis, Antonis I.; Anagnostopoulos, John S.

2016-01-01

A multi-pump, multi-piston power take-off wave energy converter ((MPPTO)-P-2 WEC) has been proposed for use with a novel renewable energy harvester termed the Ocean Grazer. The (MPPTO)-P-2 WEC utilizes wave motion to pump via buoys connected to pistons working fluid within a closed circuit and store

Identifying patients at risk of intraoperative and postoperative transfusion in isolated CABG: toward selective conservation strategies.

Science.gov (United States)

Arora, Rakesh C; Légaré, Jean-Francois; Buth, Karen J; Sullivan, John A; Hirsch, Gregory M

2004-11-01

Allogeneic blood product use during cardiac operation is often reported to exceed 40% despite published guidelines and costly blood conservation strategies. We developed a predictive model, based on eight preoperative risk factors, of allogeneic blood product transfusion rates in patients undergoing a cardiac procedure. All 3,046 consecutive, isolated coronary artery bypass graft (CABG) procedures at a university hospital from 1995 to 1998 were included. A logistic regression model was created to identify independent predictors of allogeneic blood product transfusion. This model was validated using a prospective patient sample. Overall use of allogeneic blood products was 23% with a crude operative mortality of 2.1%. In isolated, elective, first-time CABG cases, 16.9% received allogeneic blood products. Independent predictors of blood product usage in CABG patients were preoperative hemoglobin 12.0 or less, emergent operation, renal failure, female sex, age 70 years or older, left ventricular ejection fraction 0.40 or less, redo procedure, and low body surface area. Prospective validation of this model on 2,117 consecutive isolated CABG patients demonstrated an observed-to-expected allogeneic blood product transfusion rate ratio of 1.06. This internally validated logistic regression risk model is a sensitive and specific predictor of allogeneic blood product use in patients undergoing isolated CABG. Utilization of this model allows for preoperative risk stratification and may allow for more rational resource allocation of costly blood conservation strategies and blood bank resources.

Mid-term results of off-pump coronary artery bypass grafting assessed by multi-slice computed tomography

International Nuclear Information System (INIS)

Yoshida, Seijiro; Nitta, Yoshio; Oda, Katsuhiko

2004-01-01

Off-pump coronary artery bypass (OPCAB) has recently increased in popularity, but the long-term results are still unknown. We evaluated the mid-term results of OPCAB surgery using multi-slice computed tomography (MSCT), which is a non-invasive postoperative evaluation method. Thirty-one consecutive patients who underwent OPCAB surgery at least 2 years prior to the study were selected. The age was 50 to 79 years (66.9±6.5) and the ratio of men to women was 26:5. Coronary angiography was performed in all patients at 2 weeks postoperatively. The follow-up was complete, and mean follow-up was 30.9 months. There were no hospital deaths and 1 non-cardiac late death. The graft patency rate in coronary angiography was left internal thoracic artery (LITA) 30/30 (100%), right internal thoracic artery (RITA) 2/2 (100%), radial artery (RA) 14/15 (93%), saphenous vein graft (SVG) 15/17 (88%). No graft became occluded on MSCT study and all patients have been angina-free during the follow-up period. We suggest that OPCAB is feasible in most patients with good patency and low mortality. MSCT is an effective follow up method for the morphological findings and noninvasive quantitative evaluation of the bypass grafts. (author)

Development and evaluation of cryosorption pump and cryotrapping pump for CTR applications

International Nuclear Information System (INIS)

Kuribayashi, S.; Ota, H.; Sato, H.

1986-01-01

In order to obtain the engineering data to design compound cryopump for CTR, the authors tested the cryosorption pump and cryotrapping pump. The cryosorption panel was consisted of coconut charcoal metallically bonded to 4.2K cryopanel by brazing. The initial pumping speed of helium of cryosorption pump was found to be ≅2.2 iota/scm/sup 2/. The speed dropped off with loading (about 8 Torr iota/cm/sup 2/) to 1.5 iota/scm/sup 2/. The initial helium pumping speed of the 4.2K cryotrapping pump by argon spray was found to be ≅6 iota/scm/sup 2/. The speed, however, dropped off with loading (≅0.3 Torr iota/cm/sup 2/) to less than 5%. These results indicate that the cryosorption pump by coconut charcoal is superior to the cryotrapping pump, because the capacity of the former is larger than the latter

Effect of on/off pumping strategy on sewer sediment behvaviour elucidated by high frequecny monitoring at the treatment plan inlte

DEFF Research Database (Denmark)

Sharma, Anitha Kumari; Alferes, J.; Vezzaro, Luca

study illustrates how data with high temporal resolution and advanced DQC tools can be used to: (i) detect unexpected shock loads during dry weather due to an on/off pumping strategy, (ii) understand the processes in upstream sewer systems under wet weather, and (iii) take the necessary actions...... to reduce the shock loads at the WWTP. The results for a selected week show that the on/off pumping strategy creates unnecessary peaks with 50-200% increased flows. This affects the water quality arriving at the WWTP, particularly with respect to the total suspended solids concentrations, which increased...... understand the processes taking place upstream the plant and to reduce their impact on the performance of the WWTP....

Effects of preoperative aspirin and clopidogrel therapy on perioperative blood loss and blood transfusion requirements in patients undergoing off-pump coronary artery bypass graft surgery.

Science.gov (United States)

Shim, Jae Kwang; Choi, Yong Seon; Oh, Young Jun; Bang, Sou Ouk; Yoo, Kyung Jong; Kwak, Young Lan

2007-07-01

Preoperative exposure to clopidogrel and aspirin significantly increases postoperative bleeding in patients undergoing on-pump coronary artery bypass graft surgery. Off-pump coronary bypass grafting has been proposed as an alternative technique to attenuate postoperative bleeding associated with clopidogrel. This study aimed to determine the effects of aspirin and clopidogrel therapy on perioperative blood loss and blood transfusion requirements in off-pump coronary artery bypass grafting. One hundred six patients scheduled for off-pump coronary artery bypass grafting were divided into three groups: aspirin and clopidogrel discontinued more than 6 days before surgery (group 1, n = 35), aspirin and clopidogrel continued until 3 to 5 days before surgery (group 2, n = 51), and both medications continued within 2 days of surgery (group 3, n = 20). Thromboelastographic tracings were analyzed before induction of anesthesia. Routine coagulation profiles were measured before and after surgery. A cell salvage device was used during surgery and salvaged blood was reinfused. Chest tube drainage and blood transfusion requirement were recorded postoperatively. Patient characteristics, operative data, and thromboelastographic tracings were similar among the groups. There were significant decreases in hematocrit level and platelet count and prolongation in prothrombin time postoperatively in all groups without any intergroup differences. The amounts of perioperative blood loss and blood transfusion required were all similar among the groups. Preoperative clopidogrel and aspirin exposure even within 2 days of surgery does not increase perioperative blood loss and blood transfusion requirements in patients undergoing elective off-pump coronary artery bypass grafting.

Causes of Death Following PCI Versus CABG in Complex CAD: 5-Year Follow-Up of SYNTAX.

Science.gov (United States)

Milojevic, Milan; Head, Stuart J; Parasca, Catalina A; Serruys, Patrick W; Mohr, Friedrich W; Morice, Marie-Claude; Mack, Michael J; Ståhle, Elisabeth; Feldman, Ted E; Dawkins, Keith D; Colombo, Antonio; Kappetein, A Pieter; Holmes, David R

2016-01-05

There are no data available on specific causes of death from randomized trials that have compared coronary artery bypass grafting (CABG) with percutaneous coronary intervention (PCI). The purpose of this study was to investigate specific causes of death, and its predictors, after revascularization for complex coronary disease in patients. An independent Clinical Events Committee consisting of expert physicians who were blinded to the study treatment subclassified causes of death as cardiovascular (cardiac and vascular), noncardiovascular, or undetermined according to the trial protocol. Cardiac deaths were classified as sudden cardiac, related to myocardial infarction (MI), and other cardiac deaths. In the randomized cohort, there were 97 deaths after CABG and 123 deaths after PCI during a 5-year follow-up. After CABG, 49.4% of deaths were cardiovascular, with the greatest cause being heart failure, arrhythmia, or other causes (24.6%), whereas after PCI, the majority of deaths were cardiovascular (67.5%) and as a result of MI (29.3%). The cumulative incidence rates of all-cause death were not significantly different between CABG and PCI (11.4% vs. 13.9%, respectively; p = 0.10), whereas there were significant differences in terms of cardiovascular (5.8% vs. 9.6%, respectively; p = 0.008) and cardiac death (5.3% vs. 9.0%, respectively; p = 0.003), which were caused primarily by a reduction in MI-related death with CABG compared with PCI (0.4% vs. 4.1%, respectively; p PCI versus CABG was an independent predictor of cardiac death (hazard ratio: 1.55; 95% confidence interval: 1.09 to 2.33; p = 0.045). The difference in MI-related death was seen largely in patients with diabetes, 3-vessel disease, or high SYNTAX (TAXUS Drug-Eluting Stent Versus Coronary Artery Bypass Surgery for the Treatment of Narrowed Arteries) trial scores. During a 5-year follow-up, CABG in comparison with PCI was associated with a significantly reduced rate of MI-related death, which was the

The clinical research of off-pump coronary artery bypass grafting by small incision at the left chest.

Science.gov (United States)

Xiao, L-B; Zhang, Y-H; Zhou, J-W; Yang, M; Ling, Y-P; Gao, Z-S; Wang, Y-S

2016-01-01

To explore the clinical value of off-pump coronary artery bypass grafting by small incision at the left chest, and develop a better surgical regimen for coronary heart disease patients. 201 coronary heart disease patients who need coronary artery bypass grafting were required and randomly divided into 2 groups including a control group and an observation group. There were 107 cases in the control group who received coronary bypass grafting by extracorporeal circulation; there were 103 cases in the observation group who received off-pump coronary bypass grafting by small incision at the left chest. The duration of the mechanism ventilation, length of stay in ICU, hospitalization time, postoperative drainage volume, and the occurrence rate of complications were recorded and compared. The duration of mechanism ventilation, length of stay in ICU, hospitalization time and postoperative drainage volume in the control group were (19.21 ± 1.33) hours, (5.08 ± 0.57) days, (21.20 ± 2.34) days and (997.68 ± 96.35) mL, which were (7.73 ± 0.74) hours, (2.83 ± 0.16) days, (15.67 ± 1.18) days and (901.53 ± 89.32) mL in the observation group respectively, with statistical difference between the two groups (pdisease, pulmonary infection, perioperative cardiac infarction and mortality did not display a significant difference between the two groups (p > 0.05). Off-pump coronary artery bypass grafting by small incision at the left chest is a surgical method with less injury and fast recovery, which can be used as the preferred therapeutical method for the coronary heart disease patients who need coronary artery bypass grafting.

Aprotinin decreases the incidence of cognitive deficit following CABG and cardiopulmonary bypass: a pilot randomized controlled study.

LENUS (Irish Health Repository)

Harmon, Dominic C

2012-02-03

PURPOSE: Cognitive deficit after coronary artery bypass surgery (CABG) has a high prevalence and is persistent. Meta-analysis of clinical trials demonstrates a decreased incidence of stroke after CABG when aprotinin is administrated perioperatively. We hypothesized that aprotinin administration would decrease the incidence of cognitive deficit after CABG. METHODS: Thirty-six ASA III-IV patients undergoing elective CABG were included in a prospective, randomized, single-blinded pilot study. Eighteen patients received aprotinin 2 x 10(6) KIU (loading dose), 2 x 10(6) KIU (added to circuit prime) and a continuous infusion of 5 x 10(5) KIU.hr(-1). A battery of cognitive tests was administered to patients and spouses (n = 18) the day before surgery, four days and six weeks postoperatively. RESULTS: Four days postoperatively new cognitive deficit (defined by a change in one or more cognitive domains using the Reliable Change Index method) was present in ten (58%) patients in the aprotinin group compared to 17 (94%) in the placebo group [95% confidence interval (CI) 0.10-0.62, P = 0.005); (P = 0.01)]. Six weeks postoperatively, four (23%) patients in the aprotinin group had cognitive deficit compared to ten (55%) in the placebo group (95% CI 0.80-0.16, P = 0.005); (P = 0.05). CONCLUSION: In this prospective pilot study, the incidence of cognitive deficit after CABG and cardiopulmonary bypass is decreased by the administration of high-dose aprotinin.

Preoperative values of inflammatory markers predict clinical outcomes in patients after CABG, regardless of the use of cardiopulmonary bypass

Directory of Open Access Journals (Sweden)

Dariusz Plicner

2016-12-01

Conclusion: Links between preoperative 8-iso-PGF2α, ADMA and β-TG and unfavorable early post-CABG outcomes suggest that these markers could be useful in identifying patients with increased risk of LCOS, PMI and in-hospital cardiovascular death following elective CABG.

Fibrinolytic Inhibitors in Off-pump Coronary Surgery: A Prospective, Randomized, Double-Blind TAP Study (Tranexamic Acid, Aprotinin, Placebo)

Czech Academy of Sciences Publication Activity Database

Vaněk, T.; Jareš, M.; Fajt, R.; Straka, Z.; Jirásek, K.; Kolesár, M.; Brůček, P.; Malý, Marek

2005-01-01

Roč. 28, č. 4 (2005), s. 563-568 ISSN 1010-7940 Source of funding: V - iné verejné zdroje Keywords : tranexamic acid * protinin * off-pump coronary artery bypass * hemostasis Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 1.802, year: 2005

The Bypassing the Blues treatment protocol: stepped collaborative care for treating post-CABG depression.

Science.gov (United States)

Rollman, Bruce L; Belnap, Bea Herbeck; LeMenager, Michelle S; Mazumdar, Sati; Schulberg, Herbert C; Reynolds, Charles F

2009-02-01

To present the design of the Bypassing the Blues (BtB) study to examine the impact of a collaborative care strategy for treating depression among patients with cardiac disease. Coronary artery bypass graft (CABG) surgery is one of the most common and costly medical procedures performed in the US. Up to half of post-CABG patients report depressive symptoms, and they are more likely to experience poorer health-related quality of life (HRQoL), worse functional status, continued chest pains, and higher risk of cardiovascular morbidity independent of cardiac status, medical comorbidity, and the extent of bypass surgery. BtB was designed to enroll 450 post-CABG patients from eight Pittsburgh-area hospitals including: (1) 300 patients who expressed mood symptoms preceding discharge and at 2 weeks post hospitalization (Patient Health Questionnaire (PHQ-9) >or=10); and (2) 150 patients who served as nondepressed controls (PHQ-9 Depressed patients were randomized to either an 8-month course of nurse-delivered telephone-based collaborative care supervised by a psychiatrist and primary care expert, or to their physicians' "usual care." The primary hypothesis will test whether the intervention can produce an effect size of >or=0.5 improvement in HRQoL at 8 months post CABG, as measured by the SF-36 Mental Component Summary score. Secondary hypotheses will examine the impact of our intervention on mood symptoms, cardiovascular morbidity, employment, health services utilization, and treatment costs. Not applicable. This effectiveness trial will provide crucial information on the impact of a widely generalizable evidence-based collaborative care strategy for treating depressed patients with cardiac disease.

High efficiency, variable geometry, centrifugal cryogenic pump

International Nuclear Information System (INIS)

Forsha, M.D.; Nichols, K.E.; Beale, C.A.

1994-01-01

A centrifugal cryogenic pump has been developed which has a basic design that is rugged and reliable with variable speed and variable geometry features that achieve high pump efficiency over a wide range of head-flow conditions. The pump uses a sealless design and rolling element bearings to achieve high reliability and the ruggedness to withstand liquid-vapor slugging. The pump can meet a wide range of variable head, off-design flow requirements and maintain design point efficiency by adjusting the pump speed. The pump also has features that allow the impeller and diffuser blade heights to be adjusted. The adjustable height blades were intended to enhance the pump efficiency when it is operating at constant head, off-design flow rates. For small pumps, the adjustable height blades are not recommended. For larger pumps, they could provide off-design efficiency improvements. This pump was developed for supercritical helium service, but the design is well suited to any cryogenic application where high efficiency is required over a wide range of head-flow conditions

Comparative effectiveness of coronary artery bypass grafting (CABG) surgery and percutaneous coronary intervention (PCI) in elderly patients with diabetes.

Science.gov (United States)

Shah, Ruchit; Yang, Yi; Bentley, John P; Banahan, Benjamin F

2016-11-01

To compare the relative effectiveness of coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) among elderly patients with diabetes regarding acute myocardial infarction (AMI), stroke, repeat revascularization, and all-cause mortality. A retrospective cohort study was conducted using the 2006-2008 5% national sample of Medicare claims data. Elderly (≥65 years) beneficiaries with at least two claims of diabetes separated by ≥30 days and who had at least one inpatient claim for multi-vessel CABG or PCI between 1 July 2006 and 30 June 2008 were identified. The date of beneficiary's first CABG or PCI was defined as the index date. All patients were followed from the index date to 31 December 2008 for outcomes. CABG and PCI patients were 1:1 matched on propensity scores and index dates. Cox proportional hazards models were used to compare postoperative outcomes between patients undergoing CABG versus PCI. The matched sample consisted of 4430 patients (2215 in each group). The Cox proportional hazards models showed that, compared to patients undergoing PCI, CABG was associated with a lower risk of postoperative AMI (hazard ratio [HR]: 0.494; 95% CI: 0.396-0.616; p < .0001), repeat revascularization (HR: 0.194; 95% CI: 0.149-0.252; p < .0001), the composite outcome (HR: 0.523; 95% CI: 0.460-0.595; p < .0001), and all-cause mortality (HR: 0.775; 95% CI: 0.658-0.914; p = .0024); postoperative risk of stroke was not significantly different between the two groups (HR: 0.965; 95% CI: 0.812-1.148; p = .691). CABG appears to be the preferred revascularization strategy for elderly patients with diabetes and coronary heart disease. However, this result should be interpreted considering study limitations, for example, several patient clinical variables and physician-related factors which may affect procedure outcomes are not available in the data. Clinical decisions should be individualized considering all patient- and physician

Numerical simulation of hydrodynamics in a pump-turbine at off-design operating conditions in turbine mode

International Nuclear Information System (INIS)

Yan, J P; Seidel, U; Koutnik, J

2012-01-01

The hydrodynamics of a reduced-scaled model of a radial pump-turbine is investigated under off-design operating conditions, involving runaway and 'S-shape' turbine brake curve at low positive discharge. It is a low specific speed pump-turbine machine of Francis type with 9 impeller blades and 20 stay vanes as well as 20 guide vanes. The computational domain includes the entire water passage from the spiral casing inlet to the draft tube outlet. Completely structured hexahedral meshes generated by the commercial software ANSYS-ICEM are employed. The unsteady incompressible simulations are performed using the commercial code ANSYS-CFX13. For turbulence modeling the standard k-ε model is applied. The numerical results at different operating points are compared to the experimental results. The predicted pressure amplitude is in good agreement with the experimental data and the amplitude of normal force on impeller is in reasonable range. The detailed analysis reveals the onset of the flow instabilities when the machine is brought from a regular operating condition to runaway and turbine break mode. Furthermore, the rotating stall phenomena are well captured at runaway condition as well as low discharge operating condition with one stall cell rotating inside and around the impeller with about 70% of its frequency. Moreover, the rotating stall is found to be the effect of rotating flow separations developed in several consecutive impeller channels which lead to their blockage. The reliable simulation of S-curve characteristics in pump-turbines is a basic requirement for design and optimization at off-design operating conditions.

Five-year outcomes of percutaneous versus surgical coronary revascularization in patients with diabetes mellitus (from the CREDO-Kyoto PCI/CABG Registry Cohort-2).

Science.gov (United States)

Marui, Akira; Kimura, Takeshi; Nishiwaki, Noboru; Mitsudo, Kazuaki; Komiya, Tatsuhiko; Hanyu, Michiya; Shiomi, Hiroki; Tanaka, Shiro; Sakata, Ryuzo

2015-04-15

We investigated the impact of diabetes mellitus on long-term outcomes of percutaneous coronary intervention (PCI) in the drug-eluting stent era versus coronary artery bypass grafting (CABG) in a real-world population with advanced coronary disease. We identified 3,982 patients with 3-vessel and/or left main disease of 15,939 patients with first coronary revascularization enrolled in the Coronary Revascularization Demonstrating Outcome Study in Kyoto PCI/CABG Registry Cohort-2 (patients without diabetes: n = 1,984 [PCI: n = 1,123 and CABG: n = 861], and patients with diabetes: n = 1,998 [PCI: n = 1,065 and CABG: n = 933]). Cumulative 5-year incidence of all-cause death after PCI was significantly higher than after CABG both in patients without and with diabetes (19.8% vs 16.2%, p = 0.01, and 22.9% vs 19.0%, p = 0.046, respectively). After adjusting confounders, the excess mortality risk of PCI relative to CABG was no longer significant (hazard ratio [HR] 1.16; 95% confidence interval [CI] 0.88 to 1.54; p = 0.29) in patients without diabetes, whereas it remained significant (HR 1.31; 95% CI 1.01 to 1.70; p = 0.04) in patients with diabetes. The excess adjusted risks of PCI relative to CABG for cardiac death, myocardial infarction (MI), and any coronary revascularization were significant in both patients without (HR 1.59, 95% CI 1.01 to 2.51, p = 0.047; HR 2.16, 95% CI 1.20 to 3.87, p = 0.01; and HR 3.30, 95% CI 2.55 to 4.25, p PCI relative to CABG for all-cause death, cardiac death, MI, and any revascularization. In conclusion, in both patients without and with diabetes with 3-vessel and/or left main disease, CABG compared with PCI was associated with better 5-year outcomes in terms of cardiac death, MI, and any coronary revascularization. There was no difference in the direction and magnitude of treatment effect of CABG relative to PCI regardless of diabetic status. Copyright © 2015 Elsevier Inc. All rights reserved.

Prophylactic dialysis in non-dialysis-dependent patients with renal failure after CABG

Directory of Open Access Journals (Sweden)

Roghayyeh Borji

2014-03-01

Conclusion: According the results of this study, prophylactic dialysis, before conduct-ing CABG, does not have any significant effect on mortality and other complications. The only exception is lung complications in non-dialysis-dependent patients with renal failure.

EFFECT OF SUPERVISED MODERATE INTENSITY EXERCISE PROGRAM IN PHASE ONE CARDIAC REHABILITATION OF POST OPERATIVE CABG PATIENTS - A RANDOMIZED CONTROLLED TRAIL

Directory of Open Access Journals (Sweden)

Rajan Modi

2014-10-01

Full Text Available Background: With the increasing number of cases for CABG, the cardiac rehabilitation has gained importance. The trends in rehabilitation of a coronary artery disease patient are changing by incorporating a variety of aerobic exercises and resisted training in to their rehabilitation program. The outcome of any exercise chiefly depends on the training parameters like intensity, frequency and duration. Hence the present study focused to know the effects of supervised moderate intensity exercises on patients during hospital discharge following CABG. The objective of is to study the effectiveness of supervised moderate intensity exercise on distance walked and Quality of Life at hospital discharge following CABG. Methods: Study recruited randomly 46 patients between age group 40-65 years who were posted for non-emergency CABG for the first time. Pre-operative assessment was done thoroughly and was divided in to two groups, Group A conventional treatment and Group B Moderate intensity exercise group. The patients were treated using different protocols in terms of intensity for 8-10 days immediate post CABG. Then the outcome parameters of 6MWT and sf-36 were compared for analysis. Results: Both groups individually showed extremely significant results for two outcome measures. 6 MWD difference between two treatment groups showed significant results with unpaired t test (t = 8.5720,p<0.001. Quality of life score difference within group showed very significant results but there is no difference found between both groups. Conclusion: Moderate intensity exercises can also be included in the immediate post-operative phase of CABG, as they reduce the length of hospital stay and quicken the cardiac rehabilitation process. But there need to be a lot of randomized control trails to confirm the benefits of moderate intensity exercises in phase one rehabilitation program after CABG.

Influence of isoflurane on the diastolic pressure-flow relationship and critical occlusion pressure during arterial CABG surgery: a randomized controlled trial.

Science.gov (United States)

Hinz, José; Mansur, Ashham; Hanekop, Gerd G; Weyland, Andreas; Popov, Aron F; Schmitto, Jan D; Grüne, Frank F G; Bauer, Martin; Kazmaier, Stephan

2016-01-01

The effects of isoflurane on the determinants of blood flow during Coronary Artery Bypass Graft (CABG) surgery are not completely understood. This study characterized the influence of isoflurane on the diastolic Pressure-Flow (P-F) relationship and Critical Occlusion Pressure (COP) during CABG surgery. Twenty patients undergoing CABG surgery were studied. Patients were assigned to an isoflurane or control group. Hemodynamic and flow measurements during CABG surgery were performed twice (15 minutes after the discontinuation of extracorporeal circulation (T15) and again 15 minutes later (T30)). The zero flow pressure intercept (a measure of COP) was extrapolated from a linear regression analysis of the instantaneous diastolic P-F relationship. In the isoflurane group, the application of isoflurane significantly increased the slope of the diastolic P-F relationship by 215% indicating a mean reduction of Coronary Vascular Resistance (CVR) by 46%. Simultaneously, the Mean Diastolic Aortic Pressure (MDAP) decreased by 19% mainly due to a decrease in the systemic vascular resistance index by 21%. The COP, cardiac index, heart rate, Left Ventricular End-Diastolic Pressure (LVEDP) and Coronary Sinus Pressure (CSP) did not change significantly. In the control group, the parameters remained unchanged. In both groups, COP significantly exceeded the CSP and LVEDP at both time points. We conclude that short-term application of isoflurane at a sedative concentration markedly increases the slope of the instantaneous diastolic P-F relationship during CABG surgery implying a distinct decrease with CVR in patients undergoing CABG surgery.

99Tcm-MIBI and 18F-FDG DISA imaging in the evaluation of CABG combined with autologous bone marrow mononuclear cell transplantation in patients with myocardial infarction

International Nuclear Information System (INIS)

Zhang Fuqiang; Chen Xianying; Zhang Guoxu; Wang Zhiguo; Ma Dongchu; Wang Huishan

2009-01-01

Objective: Autologous bone marrow mononuclear cell transplantation is a treatment modality under investigation for severe coronary heart disease. Its beneficial effects on ventricular function, myocardial perfusion and metabolism remain to be evaluated. The present study proposed a 18 F-fluorodeoxyglucose (FDG) and 99 Tc m -methoxyisobutylisinitrile (MIBI) dual-isotope simultaneous acquisition (DISA) imaging technique to assess the effects of coronary artery bypass grafting (CABG) combined with autologous bone marrow mononuclear cell transplantation in patients with old myocardial infarction (OMI). Methods: Twenty patients with OMI, whose diagnosis was confirmed with angiography. were divided into a convention. al CABG group (group A, n=11) and CABG+ autologous bone marrow mononuclear cell transplantation group (group B, n=9). All subjects underwent gated cardiac DISA tomography at one week preoperatively and four months postoperatively. The segmental myocardial uptake of the tracers was scored as 3, 2, 1 and 0. Paired-samples t test was used to compare data of the two groups. Results In group A, there were 52 perfusion/metabolism mismatched segments, 99 Tc m -MIBI and 18 F-FDG uptake scores of these segments in-creased from preoperatively 1.48 ± 0.75( 99 Tc m -MIBI)and 1.90 ± 0.75( 18 F-FDG) to postoperatively 1.75 ± 0.68 and 2.13 ± 0.74 (t=3.25 and 2.37, both P 0.05). However, in group B, there was significant increase of the myocardial uptake scores both in mismatched segments and matched segments. In the 45 mismatched segments of this group,preoperative and postoperative 99 Tc m -MIBI/ 18 F-FDG uptake scores were 1.24 ± 0.68/1.71 ± 0.76 and 1.53 ± 0.66/2.00 ± 0.64, respectively (t=2.93 and 2.56. both P 99 Tc m -MIBI/ 18 F-FDG uptake scores were 0.94 ± 0.75/1.50 ± 0.74 and 1.22 ± 0.76/1.78 ± 0.64. respectively (t=2.71 and 3.37. both P 0.05). Conclusions: CABG combined with autologous bone marrow mononuclear cell transplantation may improve myocardial

Investigating the adaptability of the multi-pump multi-piston power take-off system for a novel wave energy converter

NARCIS (Netherlands)

Wei, Y.; Barradas Berglind, J.J; van Rooij, M.; Prins, WA; Jayawardhana, B.; Vakis, A. I.

2017-01-01

In this work, a numerical model is developed in order to investigate the adaptability of the multi-pump multi-piston power take-off ((MPPTO)-P-2) system of a novel wave energy converter (WEC). This model is realized in the MATLAB/SIMULINK environment, using the multi-body dynamics solver Multibody

65. Impact of focused echocardiography in clinical decision of patients presented with STMI, underwent primary percutenouse angioplasty

Directory of Open Access Journals (Sweden)

M. Qasem

2016-07-01

Full Text Available Echocardiography in coronary artery diseases is an essential, routine echocardiography prior to primary percutaneous angioplasty is not clear. In our clinical practice in primary angioplasty we faced lots of complications either before or during or after the procedure. Moreover, lots of incidental findings that discovered after the procedure which if known will affect the plan of management. One-hundred-nineteen consecutive underwent primary angioplasty. All patients underwent FE prior to the procedure in catheterization lab while the patient was preparing for the procedure. FE with 2DE of LV at base, mid and apex, and apical stander views. Diastology grading, E/E′ and color doppler of mitral and aortic valve were performed. (N = 119 case of STMI were enrolled, mean age 51 ± 12 year. Eleven cases (9.2% had normal coronary and normal LV function. Twenty cases (17% of MI complication detected before the procedures: RV infarction 8.4% (5.1% asymptomatic and 3.3% symptomatic, ischemic MR (8.4%, LV apical aneurysm (0.8%, significant pericardial effusion (0.80%. Acute pulmonary edema in 17 cases (14.3%: six cases (5.1% developed acute pulmonary edema on the cath lab with grade 3 diastolic dysfunction and E/E ′  >20, 9 cases (7.6% develop acute pulmonary edema in CCU with grade 2–3 diastolic dysfunction and E/E′ 15–20. 2 cases (2.7% develop acute pulmonary in CCU with grade 1–2 diastolic dysfunction and E/E′ 9–14. One case (0.8% presented cardiac tamponade 2 h post PCI. Incidental finding not related to STMI were as follow: 2 cases (1.7% with severe fibro degenerative MR, 2 cases (1.7% with mild to moderate AR and 2 cases (1.7% with mild to moderate AS. Isoled CABG 5/4.2% and CABG and MVR 2/1.7%. FE play an important role in guiding the management, early detection the incidental findings and complication post PCI.

SheppHeartCABG trial-comprehensive early rehabilitation after coronary artery bypass grafting

DEFF Research Database (Denmark)

Hojskov, Ida Elisabeth; Moons, Philip; Hansen, Niels Viggo

2017-01-01

Quality Index, pain measured by the Örebro Musculoskeletal Screening Questionnaire and muscle endurance measured by the sit-to-stand test. A number of explorative analyses will also be conducted. ETHICS AND DISSEMINATION: SheppHeartCABG is approved by the regional ethics committee (no. H-4...

CABG Surgery Remains the best Option for Patients with Left Main Coronary Disease in Comparison with PCI-DES: Meta-Analysis of Randomized Controlled Trials

Science.gov (United States)

Sá, Michel Pompeu Barros Oliveira; Soares, Artur Freire; Miranda, Rodrigo Gusmão Albuquerque; Araújo, Mayara Lopes; Menezes, Alexandre Motta; Silva, Frederico Pires Vasconcelos; Lima, Ricardo Carvalho

2017-01-01

Objective To compare the safety and efficacy of coronary artery bypass grafting (CABG) with percutaneous coronary intervention (PCI) using drug-eluting stents (DES) in patients with unprotected left main coronary artery (ULMCA) disease. Methods MEDLINE, EMBASE, CENTRAL/CCTR, SciELO, LILACS, Google Scholar and reference lists of relevant articles were searched for clinical studies that reported outcomes at 1-year follow-up after PCI with DES and CABG for the treatment of ULMCA stenosis. Five studies fulfilled our eligibility criteria and they included a total of 4.595 patients (2.298 for CABG and 2.297 for PCI with DES). Results At 1-year follow-up, there was no significant difference between CABG and DES groups concerning the risk for death (risk ratio [RR] 0.973, P=0.830), myocardial infarction (RR 0.694, P=0.148), stroke (RR 1.224, P=0.598), and major adverse cerebrovascular and cardiovascular events (RR 0.948, P=0.680). The risk for target vessel revascularization (TVR) was significantly lower in the CABG group compared to the DES group (RR 0.583, P<0.001). It was observed no publication bias regarding the outcomes, but only the outcome TVR was free from substantial statistical heterogeneity of the effects. In the meta-regression, there was evidence that the factor "female gender" modulated the effect regarding myocardial infarction rates, favoring the CABG strategy. Conclusion CABG surgery remains the best option of treatment for patients with ULMCA disease, with lower TVR rates. PMID:29211222

Presentation of a quality management program in off-pump coronary bypass surgery.

Science.gov (United States)

Bougioukakis, Petros; Kluegl, Stefan J; Babin-Ebell, Joerg; Tagarakis, Giorgios I; Mandewirth, Martin; Zacher, Michael; Diegeler, Anno

2014-01-01

To increase the number of off-pump coronary procedures at our institution, a new surgical team was formed. The first 3 years of "learning period" were accompanied by a quality management program aimed to control and adjust the surgical process and to ensure the safety and quality of the procedure. All patients were operated on by the same surgeon between January 2004 and December 2006; all procedures were performed under the following quality management protocol. First, a flow chart regulated surgical and anesthetic details. Second, an online file, named "disturbance file," was used to report work flow interruption, disturbance, and intraoperative events, that is, myocardial ischemia, hypotension, conversion to cardiopulmonary bypass, and any violation of the protocol. Each event was coded with 1 point and added to a score (the higher the score is, the greater the disturbance). Outcome parameters known as major events-major cardiac and cerebral events: mortality within 30 days/myocardial infarction confirmed by electrocardiogram or significantly high levels of total creatine kinase-myocardial muscle creatine kinase/reintervention within 30 days/stroke--and new-onset dialysis were also measured. Success was defined as freedom from any of those events and depicted in a cumulative sum control (CUSUM) chart. Outcome data and CUSUM were correlated with the intraoperative Disturbance Index. In total, 490 off-pump coronary bypass operations were performed by the named surgeon during the study period. The 30-day mortality was reduced from 4.0% to 1.9%. Disturbance Index score of greater than 1 declined from 41.6% to 23.3%. All major cardiac and cerebral events declined. The CUSUM chart showed two critical periods during the learning period, which made an adjustment of the protocol necessary. Quality management control is efficient in improving the postoperative results of a surgical procedure. A learning period is of cardinal importance for any new team wishing to engage

Comparison of two doses of heparin on outcome in off-pump coronary artery bypass surgery patients: A prospective randomized control study

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Murali Chakravarthy

2017-01-01

Full Text Available Introduction: While off pump coronary artery bypass surgery is practiced with an intention to reduce the morbidity associated with cardiopulmonary bypass, the resultant ′hypercoagulability′ needs to be addressed. Complications such as cavitary thrombus possibly due to the hyper coagulability after off pump coronary artery bypass surgery have been described. Many clinicians use higher doses of heparin - up to 5 mg/kg in order to thwart this fear. Overall, there appears to be no consensus on the dose of heparin in off pump coronary artery bypass surgeries. Aim of the Study: The aim of the study was understand the differences in outcome of such as transfusion requirement, myocardial ischemia, and morbidity when two different doses were used for systemic heparinization. Methods: Elective patients scheduled for off pump coronary artery bypass surgery were included. Ongoing anti platelet medication was not an exclusion criteria, however, anti platelet medications were ceased about a week prior to surgery when possible. Thoracic epidural anesthesia was administered as an adjunct in patients who qualified for it. By computer generated randomization chart, patients were chosen to receive either 2 or 3 mg/kg of intravenous unfractioned heparin to achieve systemic heparinization with activated clotting time targeted at >240 secs. Intraoperative blood loss, postoperative blood loss, myocardial ischemic episodes, requirement of intraaortic balloon counter pulsation and transfusion requirement were analyzed. Results: Sixty two patients participated in the study. There was one conversion to cardiopulmonary bypass. The groups had comparable ACT at baseline (138.8 vs. 146.64 seconds, P = 0.12; 3 mg/kg group had significantly higher values after heparin, as expected. But after reversal with protamine, ACT and need for additional protamine was similar among the groups. Intraoperative (685.56 ± 241.42 ml vs. 675.15 ± 251.86 ml, P = 0.82 and postoperative

Off-pump coronary artery bypass grafting or percutaneous transluminal coronary angioplasty with stenting for proximal left anterior descending coronary artery disease?

NARCIS (Netherlands)

Drenth, Derk Jan

2005-01-01

This thesis describes and discusses the results of a prospective randomized controlled clinical trial comparing percutaneous coronary angioplasty with stenting (stenting) and off-pump coronary artery bypass grafting with a left internal mammary artery (surgery) in patients with a high-grade stenosis

Subxyphoid pleural drain confers lesser impairment in respiratory muscle strength, oxygenation and lower chest pain after off-pump coronary artery bypass grafting: a randomized controlled trial.

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Cancio, Andreia S A; Guizilini, Solange; Bolzan, Douglas W; Dauar, Renato B; Succi, José E; de Paola, Angelo A V; Carvalho, Antonio C de Camargo; Gomes, Walter J

2012-01-01

To evaluate respiratory muscle strength, oxygenation and chest pain in patients undergoing off-pump coronary artery bypass (OPCAB) using internal thoracic artery grafts comparing pleural drain insertion site at the subxyphoid region versus the lateral region. Forty patients were randomized into two groups in accordance with the pleural drain site. Group II (n = 19) -pleural drain exteriorized in the intercostal space; group (SI) (n = 21) chest tube exteriorized at the subxyphoid region. All patients underwent assessment of respiratory muscle strength (inspiratory and expiratory) on the pre, 1, 3 and 5 postoperative days (POD). Arterial blood gas analysis was collected on the pre and POD1. The chest pain sensation was measured 1, 3 and 5 POD. A significant decrease in respiratory muscle strength (inspiratory and expiratory) was seen in both groups until POD5 (P pleural drainage showed less decrease in respiratory muscle strength, better preservation of blood oxygenation and reduced thoracic pain compared to patients with intercostal drain on early OPCAB postoperative.

Numerical study on the selective excitation of Helmholtz-Gauss beams in end-pumped solid-state digital lasers with the control of the laser gain transverse position provided by off-axis end pumping

Science.gov (United States)

Tsai, Ko-Fan; Chu, Shu-Chun

2018-03-01

This study proposes a complete and unified method for selective excitation of any specified nearly nondiffracting Helmholtz-Gauss (HzG) beam in end-pumped solid-state digital lasers. Four types of the HzG beams: cosine-Gauss beams, Bessel-Gauss beams, Mathieu-Gauss beams, and, in particular, parabolic-Gauss beams are successfully demonstrated to be generated with the proposed methods. To the best of the authors’ knowledge, parabolic-Gauss beams have not yet been directly generated from any kind of laser system. The numerical results of this study show that one can successfully achieve any lasing HzG beams directly from the solid-state digital lasers with only added control of the laser gain transverse position provided by off-axis end pumping. This study also presents a practical digital laser set-up for easily manipulating off-axis pumping in order to achieve the control of the laser gain transverse gain position in digital lasers. The reported results in this study provide advancement of digital lasers in dynamically generating nondiffracting beams. The control of the digital laser cavity gain position creates the possibility of achieving real-time selection of more laser modes in digital lasers, and it is worth further investigation in the future.

Percutaneous coronary intervention versus coronary artery bypass grafting in patients with end-stage renal disease requiring dialysis (5-year outcomes of the CREDO-Kyoto PCI/CABG Registry Cohort-2).

Science.gov (United States)

Marui, Akira; Kimura, Takeshi; Nishiwaki, Noboru; Mitsudo, Kazuaki; Komiya, Tatsuhiko; Hanyu, Michiya; Shiomi, Hiroki; Tanaka, Shiro; Sakata, Ryuzo

2014-08-15

Ischemic heart disease is a major risk factor for morbidity and mortality in patients with end-stage renal disease. However, long-term benefits of percutaneous coronary intervention (PCI) relative to coronary artery bypass grafting (CABG) in those patients is still unclear in the drug-eluting stent era. We identified 388 patients with multivessel and/or left main disease with end-stage renal disease requiring dialysis among 15,939 patients undergoing first coronary revascularization enrolled in the Coronary REvascularization Demonstrating Outcome Study in Kyoto PCI/CABG Registry Cohort-2 (PCI: 258 patients and CABG: 130 patients). The CABG group included more patients with 3-vessel (38% vs 57%, p PCI group (23.5 ± 8.7 vs 29.4 ± 11.0, p PCI and 5.4% for CABG. Cumulative 5-year all-cause mortality was 52.3% for PCI and 49.9% for CABG. Propensity score-adjusted all-cause mortality was not different between PCI and CABG (hazard ratio [HR] 1.33, 95% confidence interval [CI] 0.85 to 2.09, p = 0.219). However, the excess risk of PCI relative to CABG for cardiac death was significant (HR 2.10, 95% CI 1.11 to 3.96, p = 0.02). The risk of sudden death was also higher after PCI (HR 4.83, 95% CI 1.01 to 23.08, p = 0.049). The risk of myocardial infarction after PCI tended to be higher than after CABG (HR 3.30, 95% CI 0.72 to 15.09, p = 0.12). The risk of any coronary revascularization after PCI was markedly higher after CABG (HR 3.78, 95% CI 1.91 to 7.50, p PCI reduced the risk of cardiac death, sudden death, myocardial infarction, and any revascularization. However, the risk of all-cause death was not different between PCI and CABG. Copyright © 2014 Elsevier Inc. All rights reserved.

Effect of clopidogrel premedication in off-pump cardiac surgery: are we forfeiting the benefits of reduced hemorrhagic sequelae?

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Kapetanakis, Emmanouil I; Medlam, Diego A; Petro, Kathleen R; Haile, Elizabeth; Hill, Peter C; Dullum, Mercedes K C; Bafi, Ammar S; Boyce, Steven W; Corso, Paul J

2006-04-04

Premedication with clopidogrel has reduced thrombotic complications after percutaneous coronary revascularization procedures. However, because of the enhanced and irreversible platelet inhibition by clopidogrel, patients requiring surgical revascularization have a higher risk of bleeding complications and transfusion requirements. A principal benefit of surgical coronary revascularization without cardiopulmonary bypass is its lower hemorrhagic sequelae. The purpose of this study was to evaluate the effect of preoperative clopidogrel administration in the incidence of hemostatic reexploration, blood product transfusion rates, morbidity, and mortality in patients undergoing off-pump coronary artery bypass graft surgery using a large patient sample and a risk-adjusted approach. Two hundred eighty-one patients (17.9%) did and 1291 (82.1%) did not receive clopidogrel before their surgery, for a total of 1572 patients undergoing isolated off-pump coronary artery bypass graft surgery between January 2000 and June 2002. Risk-adjusted logistic regression analyses and a matched pair analyses by propensity scores were used to assess the association between clopidogrel administration and reoperation as a result of bleeding, intraoperative and postoperative blood transfusions received, and the need for multiple transfusions. Hemorrhage-related preoperative risk factors identified in the literature and those found significant in a univariate model were used. The clopidogrel group had a higher likelihood of hemostatic reoperations (odds ratio [OR], 5.1; 95% confidence interval [CI], 2.47 to 10.47; P<0.01) and an increased need in overall packed red blood cell (OR, 2.6; 95% CI, 1.94 to 3.60; P<0.01), multiple unit (OR, 1.6; 95% CI, 1.07 to 2.48; P=0.02), and platelet (OR, 2.5; 95% CI, 1.77 to 3.66; P<0.01) transfusions. Surgical outcomes and operative mortality (1.4% versus 1.4%; P=1.00) were not statistically different. Clopidogrel administration in the cardiology suite increases

Revascularização miocárdica com circulação extracorpórea: aspectos bioquímicos, hormonais e celulares On-pump coronary artery bypass graft surgery: biochemical, hormonal and cellular features

Directory of Open Access Journals (Sweden)

Edmo Atique Gabriel

2011-12-01

artery bypass graft (CABG surgery. METHODS: Eighteen patients underwent on-pump CABG surgery. Mean time of CPB was 80.3 minutes. Hormonal, biochemical and cellular measurements were taken in some time points - preoperatively, immediately after coming off CPB, 24 and 48 hours postoperatively. Friedman and Wilcoxon tests were applied based on significance level of 5%. RESULTS: There was activation and significant elevation of total leukocytes and neutrophils count over CPB, remaining this way up to 48 hours postoperatively. Total platelets count, in turn, was marked by relevant reduction immediately after coming off CPB as well as in two postoperative time points. Serum levels of total proteins and albumin, immediately after coming off CPB and also in two postoperative time points, were significantly decreased comparing with preoperative status. There was remarkable reduction of total T3, free T3 and total T4 particularly up to first 24 hours postoperatively. CONCLUSION: In on-pump CABG surgery, inflammatory effects encompass activation of total leukocytes, neutrophils and platelets, reduction of serum level of total proteins and albumin and decreased thyroid hormones levels, especially within first postoperative 24 hours.

Long‐Term Post‐CABG Survival: Performance of Clinical Risk Models Versus Actuarial Predictions

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Carr, Brendan M.; Romeiser, Jamie; Ruan, Joyce; Gupta, Sandeep; Seifert, Frank C.; Zhu, Wei

2015-01-01

Abstract Background/aim Clinical risk models are commonly used to predict short‐term coronary artery bypass grafting (CABG) mortality but are less commonly used to predict long‐term mortality. The added value of long‐term mortality clinical risk models over traditional actuarial models has not been evaluated. To address this, the predictive performance of a long‐term clinical risk model was compared with that of an actuarial model to identify the clinical variable(s) most responsible for any differences observed. Methods Long‐term mortality for 1028 CABG patients was estimated using the Hannan New York State clinical risk model and an actuarial model (based on age, gender, and race/ethnicity). Vital status was assessed using the Social Security Death Index. Observed/expected (O/E) ratios were calculated, and the models' predictive performances were compared using a nested c‐index approach. Linear regression analyses identified the subgroup of risk factors driving the differences observed. Results Mortality rates were 3%, 9%, and 17% at one‐, three‐, and five years, respectively (median follow‐up: five years). The clinical risk model provided more accurate predictions. Greater divergence between model estimates occurred with increasing long‐term mortality risk, with baseline renal dysfunction identified as a particularly important driver of these differences. Conclusions Long‐term mortality clinical risk models provide enhanced predictive power compared to actuarial models. Using the Hannan risk model, a patient's long‐term mortality risk can be accurately assessed and subgroups of higher‐risk patients can be identified for enhanced follow‐up care. More research appears warranted to refine long‐term CABG clinical risk models. doi: 10.1111/jocs.12665 (J Card Surg 2016;31:23–30) PMID:26543019

Demographic determinants and effect of pre-operative angiotensin converting enzyme inhibitors and angiotensin receptor blockers on the occurrence of atrial fibrillation after CABG surgery

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Weiss Michael J

2010-02-01

Full Text Available Abstract Background Atrial fibrillation (AF occurs in about 27% to 40% of post cardiac surgery patients. AF following coronary artery bypass graft surgery (CABG is associated with a two-fold increase in morbidity and mortality. Various demographic risk factors and medications have been studied to predict the occurrence of this arrhythmia. The role of angiotensin related medications on the occurrence of AF in CABG patients is not determined. Methods Retrospective clinical and statistical analysis was made of all the patients who had undergone CABG surgery at Lehigh Valley Hospital during the years 2005 and 2006. Patients with chronic AF and those undergoing valvular surgery with CABG were excluded. Statistic analysis included chi-square test for categorical and student t-test for continuous variables. Results 757 patients (560 males and 197 females were studied. AF occurred in 19% of the patients. Age (70.5 vs. 65.1, p Conclusions Advanced age and presence of hypertension were independent predictors of post-CABG AF. Patients with post operative AF had significantly longer hospital stay. Neither ARBs nor ACE inhibitors were associated with reduction of post-surgical AF. Further studies are needed to better delineate the role of angiotensin related medications on reduction of post-surgical AF.

Pumping behavior of ion pump elements at high and misaligned magnetic fields

Energy Technology Data Exchange (ETDEWEB)

Hseuh, H. C.; Jiang, W. S.; Mapes, M.

1994-11-01

The pumping speeds of several diode type ion pump elements with cell radii of 5 mm, 5.5 mm, 6 mm, 9 mm and 12 mm were measured while being subjected to a magnetic field B, ranging from 500 Gauss up to 15 KG, and misalignment angles (angles between the direction of B and the anode axis) from 0 to 13 degrees. The pumping speeds of elements with the 9 mm and 12 mm cells peaked around 1--2 KG, then dropped off rapidly with an increasing magnetic field. The pumping speeds of the smaller cell elements remained constant with an increasing magnetic field. The pumping speeds of all the elements decreased with increasing misalignment. The measured pumping speeds from this study are 3--4 times lower than the calculated pumping, speeds using previously reported empirical formulae.

Pumping behavior of ion pump elements at high and misaligned magnetic fields

International Nuclear Information System (INIS)

Hseuh, H.C.; Jiang, W.S.; Mapes, M.

1994-01-01

The pumping speeds of several diode type ion pump elements with cell radii of 5 mm, 5.5 mm, 6 mm, 9 mm and 12 mm were measured while being subjected to a magnetic field B, ranging from 500 Gauss up to 15 KG, and misalignment angles (angles between the direction of B and the anode axis) from 0 to 13 degrees. The pumping speeds of elements with the 9 mm and 12 mm cells peaked around 1--2 KG, then dropped off rapidly with an increasing magnetic field. The pumping speeds of the smaller cell elements remained constant with an increasing magnetic field. The pumping speeds of all the elements decreased with increasing misalignment. The measured pumping speeds from this study are 3--4 times lower than the calculated pumping, speeds using previously reported empirical formulae

Pump efficiency in solar-energy systems

Science.gov (United States)

1978-01-01

Study investigates characteristics of typical off-the-shelf pumping systems that might be used in solar systems. Report includes discussion of difficulties in predicting pump efficiency from manufacturers' data. Sample calculations are given. Peak efficiencies, flow-rate control, and noise levels are investigated. Review or theory of pumps types and operating characteristics is presented.

Weaning mechanical ventilation after off-pump coronary artery bypass graft procedures directed by noninvasive gas measurements.

Science.gov (United States)

Chakravarthy, Murali; Narayan, Sandeep; Govindarajan, Raghav; Jawali, Vivek; Rajeev, Subramanyam

2010-06-01

Partial pressure of carbon dioxide and oxygen were transcutaneously measured in adults after off-pump coronary artery bypass (OPCAB) surgery. The clinical use of such measurements and interchangeability with arterial blood gas measurements for weaning patients from postoperative mechanical ventilation were assessed. This was a prospective observational study. Tertiary referral heart hospital. Postoperative OPCAB surgical patients. Transcutaneous oxygen and carbon dioxide measurements. In this prospective observational study, 32 consecutive adult patients in a tertiary care medical center underwent OPCAB surgery. Noninvasive measurement of respiratory gases was performed during the postoperative period and compared with arterial blood gases. The investigator was blinded to the reports of arterial blood gas studies and weaned patients using a "weaning protocol" based on transcutaneous gas measurement. The number of patients successfully weaned based on transcutaneous measurements and the number of times the weaning process was held up were noted. A total of 212 samples (pairs of arterial and transcutaneous values of oxygen and carbon dioxide) were obtained from 32 patients. Bland-Altman plots and mountain plots were used to analyze the interchangeability of the data. Twenty-five (79%) of the patients were weaned from the ventilator based on transcutaneous gas measurements alone. Transcutaneous carbon dioxide measurements were found to be interchangeable with arterial carbon dioxide during 96% of measurements, versus 79% for oxygen measurements. More than three fourths of the patients were weaned from mechanical ventilation and extubated based on transcutaneous gas values alone after OPCAB surgery. The noninvasive transcutaneous carbon dioxide measurement can be used as a surrogate for arterial carbon dioxide measurement to manage postoperative OPCAB patients. Copyright 2010 Elsevier Inc. All rights reserved.

Study of Stage-wise Pressure Pulsation in an Electric Submersible Pump under Variable Frequency Operation at Shut-off Condition

Science.gov (United States)

Dhanasekaran, A.; Kumaraswamy, S.

2018-01-01

Pressure pulsation causes vibration in the Electric Submersible Pump (ESP) and affects the life and performance of its system. ESP systems are installed at depths ranging from a few meters to several hundred meters. Unlike pumps used on the surface, once they are installed they become inaccessible for maintenance or for any kind of diagnostic measurement that might be taken directly on them. Therefore a detailed knowledge of mean and fluctuating pressures is required to achieve an optimal pressure distribution inside the ESP. This paper presents the results of an experimental investigation of the stage-wise pulsating pressure in ESP at shut-off condition at different speeds. Experiments were conducted on a pump having five stages. A variable frequency drive was used to operate the pump at five different speeds. Piezoresistive transducers were mounted at each stage of ESP to capture the unsteady pressure signals. Fast Fourier Transformation was carried out on the pressure signals to convert into frequency domain and the spectra of pressure pulsation signals were analyzed. The obtained results indicated the existence of fundamental frequency corresponding to the speed of rotation times the number of impeller blades and of the whole series of harmonics of higher frequencies.

The Predictive Value of Integrated Pulmonary Index after Off-Pump Coronary Artery Bypass Grafting: A Prospective Observational Study

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Evgenia V. Fot

2017-08-01

Full Text Available BackgroundThe early warning scores may increase the safety of perioperative period. The objective of this study was to assess the diagnostic and predictive role of Integrated Pulmonary Index (IPI after off-pump coronary artery bypass grafting (OPCAB.Materials and MethodsForty adult patients undergoing elective OPCAB were enrolled into a single-center prospective observational study. We assessed respiratory function using IPI that includes oxygen saturation, end-tidal CO2, respiratory rate, and pulse rate. In addition, we evaluated blood gas analyses and hemodynamics, including ECG, invasive arterial pressure, and cardiac index. The measurements were performed after transfer to the intensive care unit, after spontaneous breathing trial and at 2, 6, 12, and 18 h after extubation.Results and DiscussionThe value of IPI registered during respiratory support correlated weakly with cardiac index (rho = 0.4; p = 0.04 and ScvO2 (rho = 0.4, p = 0.02. After extubation, IPI values decreased significantly, achieving a minimum by 18 h. The IPI value ≤9 at 6 h after extubation was a predictor of complicated early postoperative period (AUC = 0.71; p = 0.04 observed in 13 patients.ConclusionIn off-pump coronary surgery, the IPI decreases significantly after tracheal extubation and may predict postoperative complications.

Effects of dexmedetomidine on heart arrhythmia prevention in off-pump coronary artery bypass surgery: A randomized clinical trial.

Science.gov (United States)

Soltani, Ghasem; Jahanbakhsh, Saeed; Tashnizi, Mohammad Abbasi; Fathi, Mehdi; Amini, Shahram; Zirak, Nahid; Sheybani, Shima

2017-10-01

Arrhythmia occurring during and after surgery is one of the major complications in open-heart surgery. Dexmedetomidine is an intravenous alpha-2 agonist and very specific short-acting drug to protect the various organs against ischemic injuries and blood reflow. However, the effect of dexmedetomidine for preventing intraoperative heart arrhythmias has not been recognized. This study aimed to determine the effect of dexmedetomidine on the incidence rate of heart arrhythmias and anesthetic required in off-pump coronary artery bypass surgery. This randomized clinical trial was conducted on patients who were candidates for off-pump coronary artery bypass referring to Imam Reza Hospital of Mashhad, Iran, from July 2016 through January 2017. The patients were randomly assigned to two groups of intervention (infusion of 0.5 mcg/kg/h dexmedetomidine together with induction followed by infusion of 0.5 mcg/kg/h by the end of the surgery) or control (saline infusion). Mean arterial pressure (MAP) and heart rate (HR) were measured before induction, during surgery operation and ICU admission. Data were analyzed by SPSS version 18 using Chi Square and independent-samples t-test. A total of 76 patients with a mean age of 59.8 ± 8.2 years (in two groups of 38) were studied. The two groups had no statistically significant difference in terms of background variables. The MAP and HR values before induction, during surgery and ICU admission were significantly higher in the control group than in the intervention group (p=0.001). Out of the studied arrhythmias, the values of PAC (55.2% vs. 15.7%), PVC (81.5% vs. 21.0%), AF (26.3% vs. 7.8%), VTAC (21.0% vs. 2.6%) were significantly lower in dexmedetomidine group (p=0.001). It seems that dexmedetomidine administration during induction and surgery can cause significant reduction in most of the common arrhythmias in off-pump coronary bypass surgery. The use of dexmedetomidine maintains MAP and HR at significantly lower values, and changes

Flow Rate In Microfluidic Pumps As A Function Of Tension and Pump Motor Head Speed

Science.gov (United States)

Irwin, Anthony; McBride, Krista

2015-03-01

As the use of microfluidic devices has become more common in recent years the need for standardization within the pump systems has grown. The pumps are ball bearing rotor microfluidic pumps and work off the idea of peristalsis. The rapid contraction and relaxation propagating down a tube or a microfluidic channel. The ball bearings compress the tube (occlusion) and move along part of the tube length forcing fluid to move inside of the tube in the same direction of the ball bearings. When the ball bearing rolls off the area occupied by the microfluidic channel, its walls and ceiling undergo restitution and a pocket of low pressure is briefly formed pulling more of the liquid into the pump system. Before looking to standardize the pump systems it must be known how the tension placed by the pumps bearing heads onto the PDMS inserts channels affect the pumps performance (mainly the flow rate produced). The relationship of the speed at which the bearings on the motor head spin and the flow rate must also be established. This research produced calibration curves for flow rate vs. tension and rpm. These calibration curves allow the devices to be set to optimal user settings by simply varying either the motor head tension or the motor head speed. I would like to acknowledge the help and support of Vanderbilt University SyBBURE program, Christina Marasco, Stacy Sherod, Franck Block and Krista McBride.

Mitral valve repair for ischemic moderate mitral regurgitation in patients undergoing coronary artery bypass grafting

Science.gov (United States)

Toktas, Faruk; Yavuz, Senol; Ozsin, Kadir K.; Sanri, Umut S.

2016-01-01

Objectives: To investigate whether mitral valve repair (MVR) at the time of coronary artery bypass grafting (CABG) in patients with ischemic moderate mitral regurgitation (MR) and coronary artery disease could improve short- and mid-term postoperative outcomes. Methods: Between March 2013 and December 2015, 90 patients with moderate ischemic MR underwent first-time CABG in Bursa Yuksek Ihtisas Training and Research Hospital, Bursa, Turkey. Out of 90 patients, 44 (48.9%) underwent combined CABG+MVR. The remaining 46 (51.1%) underwent CABG alone. Ventricular functions and effort capacities of patients in both groups were evaluated echocardiographically and clinically in the preoperative period, and in the first postoperative year. Results: Postoperative regurgitant volume changes according to preoperative values were -24.76±19 ml/beat in the combined CABG+MVR group, and -8.70±7.2 ml/beat in the CABG alone group (p=0.001). The change of vena contracta width was -3.40±0.2 mm in the combined CABG+MVR group whereas in the CABG alone -1.45±0.7 mm (p=0.019). The changes of left ventricular end-systolic volume index were -30.77±25.9 ml/m2 in the combined CABG+MVR group and -15.6±9.4 ml/m2 in the CABG alone group (p=0.096). Ejection fraction changes in the combined CABG+MVR group was +1.51±5.3% and in the CABG alone group was +1.15±4.3%. No statistically significant difference was found between both groups (p=0.604). Preoperative New York Heart Association class values in the combined CABG+MVR group was 2.18±0.45, and in the CABG alone group was 2.13±0.54. Conclusions: Moderate MR in patients undergoing CABG affects the outcome adversely and it does not reliably improve after CABG alone. Therefore, patients with ischemic moderate MR should undergo simultaneous MVR at the time of CABG. PMID:27464861

Predictive Model for Blood Product Use in Coronary Artery Bypass Grafting

International Nuclear Information System (INIS)

Sharif, H.; Ansari, H.Z.; Ashfaq, A.; Rawasia, W.F.; Bano, G.; Hashmi, S.

2016-01-01

Objective: To build a clinical predictive model to determine the need for transfusing blood and its products in coronary artery bypass grafting (CABG) procedures in South East Asian population. Study Design: Analytical study. Place and Duration of Study: Section of Cardiothoracic Surgery, Aga Khan University Hospital, Karachi, from January 2006 to October 2014. Methodology: Information on pre-, intra- and postoperative variables were collected for all adult patients who underwent on-pump CABG. The patients grouped into those who received blood and its components, and those who did not. A univariate as well as multivariate logistic model was built to determine the predictors of transfusion. Result: A total of 3,550 patients underwent CABG and males were dominant in both groups (75 vs. 93 percent). The transfusion rate was 56.4 percent (n=2001). Age (adjusted OR 1.03, p < 0.001), obesity (1.50, p=0.001), tobacco use (1.29, p=0.001), and male gender (4.51, p < 0.001) found to be a stronger predictor. Among preoperative comorbidities, diabetes (1.20, p=0.016), myocardial infarction (1.22, p=0.009), preoperative creatinine (1.12, p=0.033), and left main vessel disease of > 50 percent (1.49, p < 0.001) were independently associated with the outcome. Compared to elective cases, transfusion rates were high in urgent and emergent cases (OR: 1.93 and 3.36 respectively, p < 0.001 for both). Conclusion: Age, male gender, obesity, tobacco use, diabetes, myocardial infarction, high creatinine, urgent and emergent cases were independent predictors of transfusion in CABG procedure. This model can be utilized for preoperative risk stratification of patients and their management to improve the outcomes. (author)

Pump system characterization and reliability enhancement

International Nuclear Information System (INIS)

Staunton, R.H.

1998-01-01

Pump characterization studies were performed at the Oak Ridge National Laboratory (ORNL) to review and analyze six years (1990-1995) of data from pump systems at domestic nuclear plants. The studies considered not only pumps and pump motors but also pump-related circuit breakers and turbine drives (i.e., the pump system). One significant finding was that the number of 'significant' failures of the pump circuit breaker exceeds the number of significant failures of the pump itself. The study also shows how regulatory code testing was designed for the pump only and therefore did not lead to the discovery of other significant pump system failures. Potential diagnostic technologies, both experimental and mature, suitable for on-line and off-line pump testing were identified. The study does not select or recommend technologies but proposes diagnostic technologies and monitoring techniques that should be further evaluated/developed for making meaningful and critically-needed improvements in the reliability of the pump system. (author)

High-speed flow visualization in a pump-turbine under off-design operating conditions

International Nuclear Information System (INIS)

Hasmatuchi, V; Roth, S; Botero, F; Avellan, F; Farhat, M

2010-01-01

The flow hydrodynamics in a low specific speed radial pump-turbine reduced scale model is experimentally investigated under off-design operating conditions in generating mode. Wall pressure measurements, in the stator, synchronized with high-speed flow visualizations in the vaneless space between the impeller and the guide vanes using air bubbles injection are performed. When starting from the best efficiency point and increasing the runner speed, a significant increase of the pressure fluctuations is observed mainly in channels between wicket gates. The spectral analysis shows a rise of one stall cell, rotating with about 70% of the impeller frequency, at runaway, which further increases as the zero discharge condition is approached. Then a specific image processing technique is detailed and applied to create a synthetic instantaneous view of the flow pattern on the entire guide vanes circumference for an operating point in turbine-brake mode, where backflow and vortices accompany the stall passage.

Comparison of Five-Year Outcome of Percutaneous Coronary Intervention With Coronary Artery Bypass Grafting in Triple-Vessel Coronary Artery Disease (from the Coronary Revascularization Demonstrating Outcome Study in Kyoto PCI/CABG Registry Cohort-2).

Science.gov (United States)

Shiomi, Hiroki; Morimoto, Takeshi; Furukawa, Yutaka; Nakagawa, Yoshihisa; Tazaki, Junichi; Sakata, Ryuzo; Okabayashi, Hitoshi; Hanyu, Michiya; Shimamoto, Mitsuomi; Nishiwaki, Noboru; Komiya, Tatsuhiko; Kimura, Takeshi

2015-07-01

Studies evaluating long-term (≥5 years) outcomes of percutaneous coronary intervention (PCI) using drug-eluting stents compared with coronary artery bypass grafting (CABG) in patients with triple-vessel coronary artery disease (TVD) are still limited. We identified 2,978 patients with TVD (PCI: n = 1,824, CABG: n = 1,154) of 15,939 patients with first coronary revascularization enrolled in the Coronary Revascularization Demonstrating Outcome Study in Kyoto PCI/CABG Registry Cohort-2. The primary outcome measure in the present analysis was a composite of death, myocardial infarction (MI), and stroke. Median follow-up duration for the surviving patients was 1,973 days (interquartile range 1,700 to 2,244). The cumulative 5-year incidence of death/MI/stroke was significantly higher in the PCI group than in the CABG group (28.2% vs 24.0%, log-rank p = 0.006). After adjusting for confounders, the excess risk of PCI relative to CABG for death/MI/stroke remained significant (hazard ratio [HR] 1.38, 95% confidence interval [CI] 1.13 to 1.68, p = 0.002). The excess risks of PCI relative to CABG for all-cause death, MI, and any coronary revascularization were also significant (HR 1.38, 95% CI 1.10 to 1.74, p = 0.006; HR 2.81, 95% CI 1.69 to 4.66, p PCI and CABG groups (HR 0.88, 95% CI 0.61 to 1.26, p = 0.48). There were no interactions for the primary outcome measure between the mode of revascularization (PCI or CABG) and the subgroup factors such as age, diabetes, and Synergy Between PCI With Taxus and Cardiac Surgery score. In conclusion, CABG compared with PCI was associated with better long-term outcome in patients with TVD. Copyright © 2015 Elsevier Inc. All rights reserved.

Combining PCI and CABG: the role of hybrid revascularization.

Science.gov (United States)

Green, Kelly D; Lynch, Donald R; Chen, Tyffany P; Zhao, David

2013-04-01

Hybrid coronary revascularization combines the benefits of both percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) in the treatment of multivessel coronary artery disease (CAD) by combining the benefits of the LIMA-to-LAD graft and drug eluting stent (DES) to non-LAD regions. Through this approach, a patient receives the long-term benefit of the LIMA graft and avoids the morbidity of a full sternotomy and saphenous vein grafts. Available data related to outcomes following hybrid revascularization is limited to small studies. In this review we seek to provide an overview of hybrid revascularization in the era of modern drug eluting stent technology, discuss appropriate patient selection, and comment on future trial design. Additionally, we review the recent literature pertaining to the hybrid approach.

Can preoperative serum level of creatinine predict new-onset atrial fibrillation in non-diabetic male patients undergoing open heart surgery? A retrograde view.

Directory of Open Access Journals (Sweden)

Seyed Jalil Mirhosseini

2013-12-01

Full Text Available Renal dysfunction is a risk marker in patients who candidate for coronary artery bypass graft (CABG. Renal disorder is associated with prolonged stays in intensive care unit and hospital, morbidity and mortality. Aim of this study is specific evaluation of association between preoperative creatinine (Cr with atrial fibrillation (AF after elective off-pump CABG in non-diabetic male patients with normal ejection fraction. Two hundred non-diabetic male patients with normal ejection fraction undergoing elective off pump CABG surgery enrolled in this cross-sectional study and were stratified by present or absence of postoperative atrial fibrillation: patients with postoperative new-onset atrial fibrillation (n=100 as group 1 and patients without new-onset postoperative atrial fibrillation as group 2 (n=100. Preoperative serological test of the participants, such as serum creatinine, were recorded in their medical dossiers. Data were analyzed in SPSS-16 software and tested for association between atrial fibrillation with creatinine level by using student t test, chi-square test or logistic regression. Cr level in patients with and without AF three days before surgery were 1.8±0.3 and 1.0±0.4 respectively (P value for Cr=0.00. On surgical day, mean Cr level in patients with and without AF were 1.6±0.2 and 1.1±0.5 respectively (P value for Cr = 0.00. Of the 100, male patients with postoperative AF, duration and frequency of recurrence of AF were not associated with Cr at three days before surgery and on surgical days (P>0.05. Patients with postoperative AF had unsuitable status of renal function compare to patients without AF; however, preoperative serum creatinine cannot associate with duration and frequency of recurrence of AF.

Process review of a departmental change from conventional coronary artery bypass grafting to totally arterial coronary artery bypass and its effects on the incidence and severity of postoperative stroke.

Science.gov (United States)

Albert, Alexander; Sergeant, Paul; Florath, Ines; Ismael, Mohammed; Rosendahl, Ulrich; Ennker, Jürgen

2011-04-01

We evaluated the process of changing from conventional coronary artery bypass grafting (CABG) to totally arterial off-pump coronary artery bypass (TOPCAB) at a single heart center in Germany. We (1) used multivariate statistical methods to assess real-time monitoring of OPCAB effects, (2) conducted a case review to assess preventable deaths and identify areas of improvement, (3) conducted a team survey, and (4) evaluated benchmarking results. All surgeons and assistants (n = 18) at this center were involved and were guided by the department head and one of the consultants, who was trained in this procedure in 2004 at the Leuven OPCAB school. The frequency of OPCAB operations increased abruptly in 2005 from 5% to 43% and then increased gradually to 67% (n = 546) by 2008 (total, 1781 OPCAB cases and 1563 on-pump cases). The in-hospital and 30-day mortality rates for OPCAB surgeries (n = 10 [0.6%] and 21 [1.2%], respectively) were lower than for on-pump surgeries (n = 27 [1.7%] and 26 [1.7%], respectively). Stroke rates were also lower for OPCAB surgeries (7 cases [0.4%] versus 15 cases [1%]). The lower risk of stroke in the OPCAB group was significant (P popularity, and a top national rank). The change from conventional CABG to TOPCAB was effective in decreasing the incidence and severity of stroke, in developing a team routine and a positive team attitude, and in producing excellent benchmarking results. The presence of a training and communication deficiency at the beginning of the study suggested an area for further improvement. After 6 years TOPCAB had largely replaced conventional CABG.

Mold Heating and Cooling Pump Package Operator Interface Controls Upgrade

Energy Technology Data Exchange (ETDEWEB)

Josh A. Salmond

2009-08-07

The modernization of the Mold Heating and Cooling Pump Package Operator Interface (MHC PP OI) consisted of upgrading the antiquated single board computer with a proprietary operating system to off-the-shelf hardware and off-the-shelf software with customizable software options. The pump package is the machine interface between a central heating and cooling system that pumps heat transfer fluid through an injection or compression mold base on a local plastic molding machine. The operator interface provides the intelligent means of controlling this pumping process. Strict temperature control of a mold allows the production of high quality parts with tight tolerances and low residual stresses. The products fabricated are used on multiple programs.

Bistable direction switching in an off-axis pumped continuous wave ruby laser

Science.gov (United States)

Afzal, R. Sohrab; Lawandy, N. M.

1988-01-01

A report is presented of the observation of hysteretic bistable direction switching in a single-mode CW ruby laser system. This effect is only observed when the pump beam which is focused into the ruby rod is misaligned with respect to the rod end faces. At low pump powers, the ruby lases in a mode nearly collinear with the pump axis. At a higher pump power the ruby switches to a mode that is collinear with the rod end faces and preserves the original polarization. The effect is large enough to switch the beam by an angle equal to twice the diffraction angle. The observations show that under steady-state pumping, a CW ruby laser can exhibit bistable operation in its output direction and power. A calculation using the heat equation with two concentric cylinders with one as a heat source (pump laser) and the outer wall of the other held at 77 K, gives an increase in core temperature of about 0.01 K. Therefore, the increase in temperature is not large enough to change the index of refraction to account for such large macroscopic effects.

Impeller radial force evolution in a large double-suction centrifugal pump during startup at the shut-off condition

International Nuclear Information System (INIS)

Zou, Zhichao; Wang, Fujun; Yao, Zhifeng; Tao, Ran; Xiao, Ruofu; Li, Huaicheng

2016-01-01

Highlights: • Conclude the characteristics of transient radial force in the startup process for a large double-suction centrifugal pump. • The overall direction of the radial force during startup process is also confirmed. • A formula used to calculate the transient radial force during startup process is proposed. • A relationship between radial force variation and axial vortex development in blade channel during the startup process is established. The mechanism of the radial force evolution is revealed. - Abstract: Double-suction centrifugal pumps play an important role in the main feedwater systems of nuclear power plant. The impeller radial force in a centrifugal pump varies dramatically during startup at the shut-off condition. In this study, the startup process of a large double-suction centrifugal pump is investigated using CFD. During testing, the impeller speed is accelerated from zero to its rated speed in 1.0 s (marked as t_0) and is then maintained at the rated speed. The results show that the radial force increase lags behind the impeller speed increase. At 0–0.4t_0, the radial force is small (approaching zero). At 0.4–1.4t_0, the radial force increases rapidly. After 1.4t_0, the average radial force stabilizes and reaches its maximum value of 55,619 N. The observed maximum radial force value during startup is approximately nine times as high as the radial force under rated condition. During startup, the overall radial force direction is proximate to the radial line located 25° from the volute tongue along circumferential direction. A transient radial force formula is proposed to evaluate the changes in radial force during startup. The streamline distribution in impeller passages and the impeller outlet pressure profile varying over time are produced. The relationship between radial force evolution and the varying axial-to-spiral vortex structure is analyzed. The radial force change mechanism is revealed. This research provides a scientific

Impeller radial force evolution in a large double-suction centrifugal pump during startup at the shut-off condition

Energy Technology Data Exchange (ETDEWEB)

Zou, Zhichao [College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083 (China); Wang, Fujun, E-mail: wangfj@cau.edu.cn [College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083 (China); Beijing Engineering Research Center of Safety and Energy Saving Technology for Water Supply Network System, China Agricultural University, Beijing 100083 (China); Yao, Zhifeng [College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083 (China); Beijing Engineering Research Center of Safety and Energy Saving Technology for Water Supply Network System, China Agricultural University, Beijing 100083 (China); Tao, Ran [College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083 (China); Xiao, Ruofu [College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083 (China); Beijing Engineering Research Center of Safety and Energy Saving Technology for Water Supply Network System, China Agricultural University, Beijing 100083 (China); Li, Huaicheng [Shanghai Liancheng (Group) Co., Ltd., Shanghai 201812 (China)

2016-12-15

Highlights: • Conclude the characteristics of transient radial force in the startup process for a large double-suction centrifugal pump. • The overall direction of the radial force during startup process is also confirmed. • A formula used to calculate the transient radial force during startup process is proposed. • A relationship between radial force variation and axial vortex development in blade channel during the startup process is established. The mechanism of the radial force evolution is revealed. - Abstract: Double-suction centrifugal pumps play an important role in the main feedwater systems of nuclear power plant. The impeller radial force in a centrifugal pump varies dramatically during startup at the shut-off condition. In this study, the startup process of a large double-suction centrifugal pump is investigated using CFD. During testing, the impeller speed is accelerated from zero to its rated speed in 1.0 s (marked as t{sub 0}) and is then maintained at the rated speed. The results show that the radial force increase lags behind the impeller speed increase. At 0–0.4t{sub 0}, the radial force is small (approaching zero). At 0.4–1.4t{sub 0}, the radial force increases rapidly. After 1.4t{sub 0}, the average radial force stabilizes and reaches its maximum value of 55,619 N. The observed maximum radial force value during startup is approximately nine times as high as the radial force under rated condition. During startup, the overall radial force direction is proximate to the radial line located 25° from the volute tongue along circumferential direction. A transient radial force formula is proposed to evaluate the changes in radial force during startup. The streamline distribution in impeller passages and the impeller outlet pressure profile varying over time are produced. The relationship between radial force evolution and the varying axial-to-spiral vortex structure is analyzed. The radial force change mechanism is revealed. This research

Development of ANC-type empirical two-phase pump model for full size CANDU primary heat transport pump

International Nuclear Information System (INIS)

Chan, A.M.C.; Huynh, H.M.

2004-01-01

The development of an ANC-type empirical two-phase pump model for CANDU (Canadian Deuterium) reactor primary heat transport pumps is described in the present paper. The model was developed based on Ontario Hydro Technologies' full scale Darlington pump first quadrant test data. The functional form of the ANC model which is widely used was chosen to facilitate the implementation of the model into existing computer codes. The work is part of a bigger test program with the aims: (1) to produce high quality pump performance data under off-normal operating conditions using both full-size and model scale pumps; (2) to advance our basic understanding of the dominant mechanisms affecting pump performance based on more detailed local measurements; and (3) to develop a 'best-estimate' or improved pump model for use in reactor licensing and safety analyses. (author)

Designs for a TFTR full-power pumped limiter

International Nuclear Information System (INIS)

Budny, R.

1986-10-01

A pumped-limiter system which would provide increased particle control and enhance the performance of full-power discharges is being considered for TFTR. The system consists of two toroidal belts located near the Zirconium-Aluminium (ZrAl) getter panels. The limiter blades would be made of carbon/carbon composite in order to have a very thin profile, allowing a large fraction of the scrape-off flux to be pumped. Simulations of the plasma scrape-off and neutral transport indicate that the limiter pumping should reduce the recycling coefficient by 10 to 25%. Simulations of central plasma processes indicate that the lowered recycling could increase Q/sub fusion/ by more than 100%. This paper discusses the designs and the performance predictions for the system

Particle removal with pump limiters in ISX-B

International Nuclear Information System (INIS)

Mioduszewski, P.; Emerson, L.C.; Simpkins, J.E.

1983-01-01

First pump limiter experiments were performed on ISX-B. Two pump limiter modules were installed in the top and bottom of one toroidal sector of the tokamak. The modules consist of inertia cooled, TiC coated graphite heads and Zr-Al getter pumps each with a pumping speed of 1000 to 2000 l/s. The objective of the initial experiments was the demonstration of plasma particle control with pump limiters. The first set of experiments were performed in ohmic discharges (OH) in which the effect of the pump limiters on the plasma density was clearly demonstrated. In discharges characterized by: I/sub p/ = 110 kA, B/sub T/ = 15 kG, anti n/sub e/ = 1 - 5 x 10 13 cm -3 and t = 0.3 s the pressure rise in the pump limiters was typically 2 mTorr with the pumps off and 0.7 mTorr after activating the pumps. When the pumps were activated, the line-average plasma density decreased by up to a factor 2 at identical gas flow rates. The second set of measurements were performed in neutral beam heated discharges (NBI) with injected powers between 0.6 MW and 1.0 MW. Due to a cooling problem on one of the Zr-Al pumps the NBI experiments were carried out with one limiter only. The maximum pressure observed in NBI-discharges was 5 mTorr without activating the pumps, i.e., approximately twice as high as in OH-discharges. The exhaust efficiency, which is defined as the removed particle flux over the total particle flux in the scrape-off layer is estimated to be 5%

The effects of cardiac rehabilitation program on exercise capacity and coronary risk factors in CABG Patients aged 45-65

Directory of Open Access Journals (Sweden)

rahim Mirnasuri

2014-03-01

Full Text Available Background : Cardiovascular diseases (CVD are the most common cause of mortalily and inability. In Iran, one third of mortality causes are coronary heart diseases. So, the aim of the present study was to evaluate the effects of a Cardiac Rehabilitation program (CR on exercise capacity (VO2max and coronary risk factors in CABG patients aged 45-65 . Materials and Methods: Of 36 CABG patients randomly selected from Hamadan Shahid Beheshti hospital, 18 subjects as experimental group (with mean age 54.57±6.26 years and weight 72.14±10.83 kg participated in CR program, and 18 subjects as control group (with mean age 57.64±4.75 years and weight 76.5±12 kg without participation in any exercise and CR program participated in this study based on inclusion and exclusion criteria. CR program was an eight-week involving warm-up, aerobic exercises and cool-down. Variables including: anthropometrics measurements and exercise capacity (VO2max, and also coronary risk factors such as body mass index (BMI, waist-hip ratio (WHR, systolic blood pressure (SBP, diastolic blood pressure (DBP, fasting blood sugar (FBS, total cholesterol (TC, triglyceride (TG, low-density lipoprotein (LDL, high-density lipoprotein (HDL, LDL-HDL ratio (LHR, body fat percent (BFP were determined at the first and the last week of CR program in both groups. Results: Statistical analysis by independent t-test indicated that after program, there was a significant difference between 2 groups in VO2max, BMI, WHR, SBP, DBP, TC, TG, LDL, LHR (P<0.05, but there was no significant difference between the 2 groups in FBS, HDL, BFP. Conclusion: The CR program of the present study indicated a significant effect on exercise capacity and some coronary risk factors profile in CABG patients of 45-65 and can it be considered as a suitable program for CABG patients.

Pumping of methane by an ionization assisted Zr/Al getter pump

International Nuclear Information System (INIS)

Shen, G.L.

1987-01-01

The pumping of methane by an ionization assisted Zr/Al getter pump has been investigated. This pump consists of 12 pieces of ring getters. A spiral shape W filament is located within the ring getters. A bias voltage is applied across the filament and the getter itself. The experiments have shown that (1) when the bias voltage is turned off, the pumping speed of the getter pump for methane increases exponentially with the filament temperature; (2) when the filament temperature is held constant, its pumping speed varies directly with the ionization electron current; (3) when the filament temperature is 2063 0 C and the electron current is 57 mA, the pumping speed of the Zr/Al getter pump is 475 ml/s, and the specific speed is 16.8 ml/s cm 2 ; and (4) an activation energy and critical temperature measured for methane molecules decomposition are, respectively, 47.4 kcal/mol and about 1700 0 C. Analysis of the results indicates that methane is pumped by an ionization assisted Zr/Al getter pump not because of the adsorption and the diffusion of methane molecules directly, but because methane molecules are decomposed as C and H 2 through a catalysis of the hot W filament, carbon is adsorbed on the surface of the W filament, and is diffused into the interior of the W lattice. H 2 is immediately absorbed by the Zr/Al getters. Besides, electron impact with CH 4 would result in the additional decomposition and ionization, then the effect of electron bombardment enhances methane pumping by the Zr/Al getters

Incidence and outcome of surgical procedures after coronary artery bypass grafting compared with those after percutaneous coronary intervention: a report from the Coronary Revascularization Demonstrating Outcome Study in Kyoto PCI/CABG Registry Cohort-2.

Science.gov (United States)

Tokushige, Akihiro; Shiomi, Hiroki; Morimoto, Takeshi; Ono, Koh; Furukawa, Yutaka; Nakagawa, Yoshihisa; Kadota, Kazushige; Ando, Kenji; Shizuta, Satoshi; Tada, Tomohisa; Tazaki, Junichi; Kato, Yoshihiro; Hayano, Mamoru; Abe, Mitsuru; Hamasaki, Shuichi; Ohishi, Mitsuru; Nakashima, Hitoshi; Mitsudo, Kazuaki; Nobuyoshi, Masakiyo; Kita, Toru; Imoto, Yutaka; Sakata, Ryuzo; Okabayashi, Hitoshi; Hanyu, Michiya; Shimamoto, Mitsuomi; Nishiwaki, Noboru; Komiya, Tatsuhiko; Kimura, Takeshi

2014-08-01

Noncardiac surgery after percutaneous coronary intervention (PCI) has been reported to be carrying high risk for both ischemic and bleeding complications. However, there has been no report comparing the incidence and outcomes of surgical procedures after coronary artery bypass grafting (CABG) with those after PCI. Among 14 383 patients undergoing first coronary revascularization (PCI, n=12 207; CABG, n=2176) enrolled in the Coronary Revascularization Demonstrating Outcome Study in Kyoto (CREDO-Kyoto) PCI/CABG Registry Cohort-2, surgical procedures were performed more frequently after CABG (n=560) than after PCI (n=2398; cumulative 3-year incidence: 27% versus 22%; unadjusted PPCI groups (cumulative incidence: 3.1% versus 3.2%; unadjusted P=0.9; adjusted hazard ratio, 0.97; 95% confidence interval, 0.47-1.89; P=0.9). The risk for the primary bleeding outcome measure (moderate or severe bleeding by Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries classification) was lower in the CABG groups than in the PCI group (cumulative incidence: 1.3% versus 2.6%; unadjusted P=0.07; adjusted hazard ratio, 0.36; 95% confidence interval, 0.12-0.87; P=0.02). There were no interactions between the timing of surgery and the types of coronary revascularization (CABG/PCI) for both ischemic and bleeding outcomes. Surgical procedures were performed significantly more frequently after CABG than after PCI, particularly PCI were associated with similar risk for ischemic events and lower risk for bleeding events, regardless of the timing after coronary revascularization. © 2014 American Heart Association, Inc.

News from heat-pump research - Large-scale heat pumps, components, heat pumps and solar heating; News aus der Waermepumpen-Forschung - Gross-Waermepumpen, Komponenten, Waermepumpe und Solar

Energy Technology Data Exchange (ETDEWEB)

NONE

2010-06-15

These proceedings summarise the presentations made at the 16{sup th} annual meeting held by the Swiss Federal Office of Energy's Heat Pump Research Program in Burgdorf, Switzerland. The proceedings include contributions on large-scale heat pumps, components and the activities of the heat pump promotion society. A summary of targets and trends in energy research in general is presented and an overview of the heat pump market in 2009 and future perspectives is given. International work within the framework of the International Energy Agency's heat pump group is reviewed, including solar - heat pump combinations. Field-monitoring and the analysis of large-scale heat pumps are discussed and the importance of the use of correct concepts in such installations is stressed. Large-scale heat pumps with carbon dioxide as working fluid are looked at, as are output-regulated air/water heat pumps. Efficient system solutions with heat pumps used both to heat and to cool are discussed. Deep geothermal probes and the potential offered by geothermal probes using carbon dioxide as a working fluid are discussed. The proceedings are rounded off with a list of useful addresses.

Hydrostatic radial bearing of centrifugal pump

International Nuclear Information System (INIS)

Skalicky, A.

1976-01-01

A hydrostatic radial pump is described characterized by the fact that part of the medium off-taken from delivery is used as a lubricating medium. Two additional bodies are placed alongside a hydrostatic bearing with coils in between them and the pump shaft; the coils have an opposite pitch. The feed channel for the hydrostatic bearing pocket is linked to delivery. The coil outlets are connected to the pump suction unit. Two rotating coils placed alongside the hydrostatic bearing will considerably simplify the communication channel design and reduce the dependence on the pump shaft deflections. The addition of another rotating coil in the close vicinity of the pump shaft or directly on the shaft further increases the efficiency. The bearing can be used in designing vertical circulating pumps for the cooling circuits of nuclear reactors. (J.B.)

Investigation of the effect of Acute Normovolemic Hemodilution and Tranexamic Acid on the amount of bleeding during off-pump coronary artery bypass graft surgery: a systematic review

Directory of Open Access Journals (Sweden)

Reza Jalaeian Taghadoomi

2017-01-01

Full Text Available Introduction: Postoperative bleeding and transfusion remain a source of morbidity and cost after open heart operations . To evaluate the effect of ANH method and tranexamic acid on blood transfusion requirements and blood loss after off pump coronary artery bypass surgery (OPCAB. Materials and Methods: The Cochrane Central Register of Controlled Trials, MEDLINE, and EMBASE from inception to December 2014; reference lists of published guidelines, reviews, and associated articles, as well as conference proceedings.We included articles with available abstract in English language. Manual searching was done within the reference list of articles. Three reviewers independently reviewed and assessed eligibility criteria, assessed quality, and extracted data. Results: Bleeding and hemorrhagic complications and the consequent need for allogeneic transfusion are still major problems after off-pump coronary artery bypass surgery that can reduced in combination of ANH method and tranexamic acid. Conclusion: Tranexamic acid and ANH appear to be effective in reducing postoperative bleeding and the need for allogeneic blood products.

Continuous Perfusion of Saphenous Vein by Oxygenated Blood during Beating Coronary Surgery

Directory of Open Access Journals (Sweden)

Mohammad Hossein Mandegar

2015-09-01

Full Text Available Background: The saphenous vein remains the most commonly used conduit for coronary artery bypass surgery (CABG. However, the long-term success of surgical revascularization is largely limited by development of occlusion in vein grafts. Objectives: We sought to reduce graft ischemia by maintaining the blood flow into the harvested vein throughout surgery at lowest costs and without special devices. Patients and Methods: This study was conducted on three hundred patients aged 58.5 ± 8 years undergoing elective first-time off-pump CABG with saphenous veins. Results: In addition to preserving nutritional materials and oxygen, the veins harvested via this novel technique did not go into spasm and were not subjected to high-pressure distension, eventually resulting in minimal damage to the endothelium. Conclusions: This technique confers favorable myocardial function and protection in the presence of left ventricular dysfunction, especially in elderly patients.

Mid-term follow-up outcomes of 2-staged hybrid coronary revascularization compared with off-pump coronary artery bypass for patients with multivessel coronary artery disease.

Science.gov (United States)

Wu, Song; Ling, Yunpeng; Fu, Yuanhao; Zhang, Lufeng; Yang, Hang; Guo, Lijun; Gao, Wei; Wan, Feng

2017-06-01

Two-staged hybrid coronary revascularization (HCR) is a novel procedure in selected patients with multivessel coronary artery disease. However, few studies are available on the mid-term or long-term outcomes of this 2-staged procedure as compared to off-pump coronary artery bypass (OPCAB). To compare in-hospital and mid-term follow-up outcomes of 2-staged HCR with OPCAB in patients with multivessel coronary artery disease. The present retrospective study analyzed the data from 73 patients who underwent the 2-staged HCR (HCR group) during 2012-2014 at the heart center. Three hundred and eighty-three patients who underwent conventional OPCAB by the same surgeon were selected for the comparative analysis performed on in-hospital and mid-term follow-up outcomes between the two groups. No significant difference was observed in the preoperative outcome between the two groups. The HCR group had a shorter operation duration (152.9 ±43.8 vs. 262.6 ±51.8 min, p < 0.05), less bleeding (558.6 ±441.3 vs. 1035.5 ±613.3 ml, p < 0.05), shorter mechanical ventilation (9.4 ±7.4 vs. 19.0 ±18.3 h, p < 0.05), and less blood transfusion (12 (16.4%) vs. 200 (52.2%), p < 0.05). The mean follow-up duration was 25.0 ±9.6 months in the HCR group and 22.8 ±10.6 months in the OPCAB group. The incidence of major adverse cardiac or cerebrovascular events (MACCE) was similar in both groups (4 (5.5%) vs. 10 (2.8%), p = 0.408). The estimated 3-year survival was similar in both groups (log-rank χ 2 = 1.041, p = 0.308). The 2-staged HCR is a safe and effective surgical procedure and may offer similar mid-term follow-up outcomes to OPCAB.

Transcatheter aortic valve implantation and off-pump coronary artery bypass surgery: an effective hybrid procedure in selected patients.

Science.gov (United States)

Mayr, Benedikt; Firschke, Christian; Erlebach, Magdalena; Bleiziffer, Sabine; Krane, Markus; Joner, Michael; Herold, Ulf; Nöbauer, Christian; Lange, Rüdiger; Deutsch, Marcus-André

2018-02-26

Simultaneous surgical off-pump coronary revascularization and transcatheter aortic valve implantation (TAVI) as a hybrid procedure may be a therapeutic option for patients with a TAVI indication who are not suitable for percutaneous coronary intervention and for patients who have an indication for combined surgical aortic valve implantation and coronary artery bypass grafting but present with a porcelain aorta. Early outcomes of these patients are analysed in this study. From February 2011 to April 2017, hybrid TAVI/off-pump coronary artery bypass (OPCAB) was performed in 12 (60%) patients, hybrid TAVI/minimally invasive direct coronary artery bypass in 6 (30%) patients and staged TAVI/OPCAB in 2 (10%) patients. Endpoints of this study were 30-day mortality, device success and postoperative adverse events as defined by the updated Valve Academic Research Consortium (VARC-2). The median age at the time of surgery was 77 years [interquartile range (IQR), 70-81] with a median logistic EuroSCORE and Society of Thoracic Surgeons' Predicted Risk score of 16.1% (IQR, 9.3-28.1) and 3.9% (IQR, 2.2-5.6), respectively. The median Synergy between PCI with Taxus and Cardiac Surgery score was 16.5 (IQR, 9.8-22.8). TAVI implantation routes were transaortic in 9 (45%) patients, transapical and transfemoral in 5 (25%) patients each and transsubclavian in 1 (5%) patient. Complete myocardial revascularization was achieved in 75% of patients. Device success rate was 100%. Paravalvular aortic regurgitation did not exceed mild in any patient. Stroke/transient ischaemic attack, vascular complications and myocardial infarction were not observed. Re-exploration for bleeding was required in 1 (5%) patient. Thirty-day mortality was 0%. Hybrid OPCAB/MIDCAB and TAVI prove to be a safe and effective alternative treatment option in selected higher risk patients.

The role of capacitance in a wind-electric water pumping system

Energy Technology Data Exchange (ETDEWEB)

Ling, Shitao [West Texas A& M Univ., Canyon, TX (United States); Clark, R.N. [Conservation and Production Research Lab., Bushland, TX (United States)

1997-12-31

The development of controllers for wind-electric water pumping systems to enable the use of variable voltage, variable frequency electricity to operate standard AC submersible pump motors has provided a more efficient and flexible water pumping system to replace mechanical windmills. A fixed capacitance added in parallel with the induction motor improves the power factor and starting ability of the pump motor at the lower cut-in frequency. The wind-electric water pumping system developed by USDA-Agricultural Research Service, Bushland, TX, operated well at moderate wind speeds (5-12 m/s), but tended to lose synchronization in winds above 12 m/s, especially if they were gusty. Furling generally did not occur until synchronization had been lost and the winds had to subside before synchronization could be reestablished. The frequency needed to reestablish synchronization was much lower (60-65 Hz) than the frequency where synchronization was lost (70-80 Hz). As a result, the load (motor and pump) stayed off an excessive amount of time thus causing less water to be pumped and producing a low system efficiency. The controller described in this paper dynamically connects additional capacitance of the proper amount at the appropriate time to keep the system synchronized (running at 55 to 60 Hz) and pumping water even when the wind speed exceeds 15 m/s. The system efficiency was improved by reducing the system off-line time and an additional benefit was reducing the noise caused by the high speed blade rotation when the load was off line in high winds.

Coupled plasma-neutral transport model for the scrape-off region

International Nuclear Information System (INIS)

Galambos, J.D.; Peng, Y.K.M.; Heifetz, D.

1985-03-01

Analysis of the scrape-off region requires treatment of the plasma transport along and across the field lines and inclusion of the neutral transport effects. A method for modeling the scrape-off region that is presented here uses separate models for each of these aspects that are coupled together through an iteration procedure that requires only minimal numerical effort. The method is applied here to estimate the neutral pumping rates in the pump-limiter and divertor options for a proposed deuterium-tritium (D-T) ignition experiment. High neutral recycling in the vicinity of the neutralizer plate dramatically affects pumping rates for both the pump-limiter and divertor. In both cases, the plasma flow into the channel surrounding the neutralizer plate is greatly reduced by the neutral recycling. The fraction of this flow that is pumped can be large (> 50%), but in general it is dependent on the particular geometry and plasma conditions. It is estimated that pumping speeds approximately greater than 10 5 L/s are adequate for the exhaust requirements in the pump-limiter and the divertor cases. Also, high neutral recycling on the front surface of the limiter tends to increase the neutral pumping rate

Cryogenic storage tank with built-in pump

International Nuclear Information System (INIS)

Zwick, E.B.

1984-01-01

A cryogenic storage tank with a built-in pump for pumping cryogen directly from the primary storage container consistent with low boil-off losses of cryogen has an outer vessel, an inner vessel and an evacuated insulation space therebetween. A pump mounting tube assembly extends into the interior of the inner vessel and includes an inner pump mounting tube and an outer pump mounting tube joined at their lower rims to define an insulating jacket between the two tubes. The inner pump mounting tube is affixed at its upper end to the outer vessel while the outer pump mounting tube is affixed at its upper end to the inner vessel. The inner pump mounting tube defines a relatively long heat path into the cryogenic container and is itself insulated from the liquid cryogen by a pocket of trapped gas formed within the inner pump mounting tube by heated cryogen. A pump may be introduced through the inner pump mounting tube and is also insulated against contact with liquid cryogen by the trapped gas such that only the lowermost end of the pump is immersed in cryogen thereby minimizing heat leakage into the tank

Prospective randomized study comparing coronary artery bypass grafting with the new mini-extracorporeal circulation Jostra System or with a standard cardiopulmonary bypass.

Science.gov (United States)

Remadi, Jean Paul; Rakotoarivelo, Zava; Marticho, Paul; Benamar, Amar

2006-01-01

To assess the potential benefits of a new concept of cardiopulmonary bypass (CPB), the mini-extracorporeal circulation (MECC) Jostra System, we conducted a prospective randomized study among patients who underwent coronary artery bypass grafting (CABG) with a MECC Jostra System or with a standard CPB. In a prospective randomized study, 400 patients underwent elective CABG using a standard CPB (200 patients) or a Jostra MECC System (200 patients). The patients were randomly assigned to have preoperative data similar for both groups. The operative mortality rate (system is a new concept of CPB that seems to be reliable and safe. To perform CABG, the MECC provides an excellent surgical exposure like a standard CPB and a better biologic profile like CABG without CPB.

Study of High Sensitive C-Reactive Protein (HS-CRP) After Cardiac Rehabilitation Program in Patients Undergoing Isolated CABG.

Science.gov (United States)

Johari Moghadam, Adel; Azizinejad, Saied

2016-12-01

Although cardiac rehabilitation is known as a tool to reduce the overall risk of cardiovascular complications, its specific role in the reduction of hs-CRP as a marker of inflammation and a proven marker of cardiovascular risk needs further investigation. The present study aims at elucidating the effects of a full course of conventional cardiac rehabilitation program for the period of eight weeks, on the levels of hs-CRP in patients who underwent isolated coronary artery bypass surgery. In this case study, 30 consecutive patients who underwent isolated coronary artery bypass surgery (isolated CABGS), and a full 8-week cardiac rehabilitation program in Tehran Heart Center, were investigated. A group of 30 similar patients, who enrolled in the same period of rehabilitation program but did not participate in practice, was considered as a control group. Serum levels of hs-CRP in both groups were measured retrospectively and in similar days before the start of rehabilitation program and at the end of it (or 8 weeks after initial registration for the control group). Levels of hs-CRP in the rehabilitation group and control group were 5.9 7.7 and 6.3 6.9 respectively before start of the program which was not statistically meaningful ( P -Value = 0.833). However, after the program, level of hs-CRP in the two tested groups changed to 2.3 5.1 and 5.7 6.1 respectively which showed a meaningful correlation ( P -Value = 0.023). These results also showed that decrease in hs-CRP level in the rehabilitated group but not in the control group was statistically meaningful (with P -Value of 0.037 and 0.0723 respectively). In patients undergoing coronary bypass surgery, participating in a full course of cardiac rehabilitation for 8 weeks has resulted in a significant reduction in hs-CRP levels as a marker of cardiovascular risk.

Pleurotomy with subxyphoid pleural drain affords similar effects to pleural integrity in pulmonary function after off-pump coronary artery bypass graft

OpenAIRE

Guizilini, Solange; Bolzan, Douglas W; Faresin, Sonia M; Ferraz, Raquel F; Tavolaro, Kelly; Cancio, Andrea A; Gomes, Walter J

2012-01-01

Abstract Background Exacerbation of pulmonary dysfunction has been reported in patients receiving a pleural drain inserted through the intercostal space in comparison to patients with an intact pleura undergoing coronary artery bypass grafting (CABG). Evidence suggests that shifting the site of pleural drain insertion to the subxyphoid position minimizes chest wall trauma and preserves respiratory function in the early postoperative period. The aim of this study was to compare the pulmonary f...

LD pumped Nd: YLF amplification technology

International Nuclear Information System (INIS)

Qin Xingwu; Li Mingzhong; Luo Yiming; Sui Zhan; Ding Lei; Liang Yue; Zhao Runchang; Chen Lianming

2003-01-01

A Ring-LD-pumped Nd: YLF laser amplifier system is theoretically and experimentally discussed. A structure of off-axes double passes amplifier is used. The results of experiment shown that 109 mJ output energy with a net gain of 1115 is obtained under 150 μJ input energy; a compact side-pumped structure is used to obtain a high transferring efficiency of LD array, 1.01 J output energy is achieved at 1053 nm. (authors)

Comparison of five-year outcomes of coronary artery bypass grafting versus percutaneous coronary intervention in patients with left ventricular ejection fractions≤50% versus >50% (from the CREDO-Kyoto PCI/CABG Registry Cohort-2).

Science.gov (United States)

Marui, Akira; Kimura, Takeshi; Nishiwaki, Noboru; Mitsudo, Kazuaki; Komiya, Tatsuhiko; Hanyu, Michiya; Shiomi, Hiroki; Tanaka, Shiro; Sakata, Ryuzo

2014-10-01

Coronary heart disease is a major risk factor for left ventricular (LV) systolic dysfunction. However, limited data are available regarding long-term benefits of percutaneous coronary intervention (PCI) in the era of drug-eluting stent or coronary artery bypass grafting (CABG) in patients with LV systolic dysfunction with severe coronary artery disease. We identified 3,584 patients with 3-vessel and/or left main disease of 15,939 patients undergoing first myocardial revascularization enrolled in the CREDO-Kyoto PCI/CABG Registry Cohort-2. Of them, 2,676 patients had preserved LV systolic function, defined as an LV ejection fraction (LVEF) of >50% and 908 had impaired LV systolic function (LVEF≤50%). In patients with preserved LV function, 5-year outcomes were not different between PCI and CABG regarding propensity score-adjusted risk of all-cause and cardiac deaths. In contrast, in patients with impaired LV systolic function, the risks of all-cause and cardiac deaths after PCI were significantly greater than those after CABG (hazard ratio 1.49, 95% confidence interval 1.04 to 2.14, p=0.03 and hazard ratio 2.39, 95% confidence interval 1.43 to 3.98, pPCI was significantly greater than that after CABG (hazard ratio 2.25, 95% confidence interval 1.15 to 4.40, p=0.02 and hazard ratio 4.42, 95% confidence interval 1.48 to 13.24, p=0.01). Similarly, the risk of all-cause death tended to be greater after PCI than after CABG in both patients with moderate and severe LV systolic dysfunction without significant interaction (hazard ratio 1.57, 95% confidence interval 0.96 to 2.56, p=0.07 and hazard ratio 1.42, 95% confidence interval 0.71 to 2.82, p=0.32; interaction p=0.91). CABG was associated with better 5-year survival outcomes than PCI in patients with impaired LV systolic function (LVEF≤50%) with complex coronary disease in the era of drug-eluting stents. In both patients with moderate (35%PCI. Copyright © 2014 Elsevier Inc. All rights reserved.

Clinicopathological comparisons of open vein harvesting and endoscopic vein harvesting in coronary artery bypass grafting patients in Mashhad.

Science.gov (United States)

Amouzeshi, Ahmad; Teshnisi, Mohamad Abbassi; Zirak, Nahid; Shamloo, Alireza Sepehri; Hoseinikhah, Hamid; Alizadeh, Behzad; Moeinipour, Aliasghar

2016-01-01

Harvesting of the greater saphenous vein is almost an inevitable part of coronary artery bypass grafting (CABG) operations, and it is done by two main techniques, i.e., conventional or open vein harvesting (OVH) and the minimally-invasive endoscopic vein harvesting (EVH). This study aimed to compare these two techniques in off-pump CABG procedures with respect to clinical and pathological outcomes. This cohort study was conducted on CABG candidates during a one-year period from October 2013 through September 2014 in the Department of Cardiac Surgery at Mashhad University of Medical Sciences. Eighty-seven patients voluntarily underwent EVH, and another 86 patients matched for age, gender, and other cardiovascular risk factors were selected for OVH. They were followed up for six weeks, and the main outcome measures were infections of the wound, pain, duration of hospital stay, and the costs of hospitalization. Paired sample t-test, independent t-test, or their non-parametric equivalents and the chi-squared test were used by SPSS version 17.0 for data analysis. The mean duration of time for vein harvesting was shorter in the EVH group (p < 0.001), and the pain score was lower (p = 0.04). No infections occurred at the site of the wound. The length of hospital stay was not significantly different for the two groups (OVH versus EVH: 8.5 ± 3.3 versus 8.4 ± 3.2 days; p-value: 0.08). Hospitalization costs were significantly higher in the EVH group (OVH versus EVH: 5.8 ± 4.7 versus 7.3 ± 2.0 million Tomman; p-value: 0.008), yet no difference was diagnosed with respect to endothelial damage in the vein grafts harvested by the EVH and OVH techniques. EVH is considered as a minimally invasive and safe vein harvesting technique in our Center, and it can reduce the harvesting time and post-operative pain. In addition, its efficiency was similar to that of OVH.

Pleural subxyphoid drain confers better pulmonary function and clinical outcomes in chronic obstructive pulmonary disease after off-pump coronary artery bypass grafting: a randomized controlled trial.

Science.gov (United States)

Guizilini, Solange; Viceconte, Marcela; Esperança, Gabriel Tavares da M; Bolzan, Douglas W; Vidotto, Milena; Moreira, Rita Simone L; Câncio, Andréia Azevedo; Gomes, Walter J

2014-01-01

To evaluate the lung function and clinical outcome in severe chronic obstructive pulmonary disease in patients undergoing off-pump coronary artery bypass grafting with left internal thoracic artery graft, comparing the pleural drain insertion in the intercostal versus subxyphoid region. A randomized controlled trial. Chronic obstructive pulmonary disease patients were randomized into two groups according pleural drain site: II group (n=27) - pleural drain in intercostal space; SI group (n=29) - pleural drain in the subxyphoid region. Spirometry values (Forced Vital Capacity - and Forced expiratory volume in 1 second) were obtained on preoperative and 1, 3 and 5 postoperative days. Chest x-ray from preoperative until postoperative day 5 (POD5) was performed for monitoring respiratory events, such as atelectasis and pleural effusion. Pulmonary shunt fraction and pain score was evaluate preoperatively and on postoperative day 1. In both groups there was a significant decrease of the spirometry values (Forced Vital Capacity and Forced expiratory volume in 1 second) until POD5 (Ppleural drainage in severe Chronic obstructive pulmonary disease patients determined better preservation and recovery of pulmonary capacity and volumes with lower pulmonary shunt fraction and better clinical outcomes on early postoperative off-pump coronary artery bypass grafting.

Tokamak pump limiters

International Nuclear Information System (INIS)

Conn, R.W.

1984-05-01

Recent experiments with a scoop limiter without active internal pumping have been carried out in the PDX tokamak with up to 6MW of auxiliary neutral beam heating. Experiments have also been done with a rotating head pump limiter in the PLT tokamak in conjunction with RF plasma heating. Extensive experiments have been done in the ISX-B tokamak and first experiments have been completed with the ALT-I limiter in TEXTOR. The pump limiter modules in these latter two machines have internal getter pumping. Experiments in ISX-B are with ohmic and auxiliary neutral beam heating. The results in ISX-B and TEXTOR show that active density control and particle removal is achieved with pump limiters. In ISX-B, the boundary layer (or scape-off layer) plasma partially screens the core plasma from gas injection. In both ISX-B and TEXTOR, the pressure internal to the module scales linearly with plasma density but in ISX-B, with neutral beam injection, a nonlinear increase is observed at the highest densities studied. Plasma plugging is the suspected cause. Results from PDX suggest that a region may exist in which core plasma energy confinement improves using a pump limiter during neutral beam injection. Asymmetric radial profiles and an increased edge electron temperature are observed in discharges with improved confinement. The injection of small amounts of neon into ISX-B has more clearly shown an improved electron core energy confinement during neutral beam injection. While carried out with a regular limiter, this Z-mode of operation is ideal for use with pump limiters and should be a way to achieve energy confinement times similar to values for H-mode tokamak plasmas. The implication of all these results for the design of a reactor pump limiter is described

Tokamak pump limiters

International Nuclear Information System (INIS)

Conn, R.W.; California Univ., Los Angeles

1984-01-01

Recent experiments with a scoop limiter without active internal pumping have been carried out in the PDX tokamak with up to 6 MW of auxiliary neutral beam heating. Experiments have also been performed with a rotating head pump limiter in the PLT tokamak in conjunction with RF plasma heating. Extensive experiments have been done in the ISX-B tokamak and first experiments have been completed with the ALT-I limiter in TEXTOR. The pump limiter modules in these latter two machines have internal getter pumping. Experiments in ISX-B are with ohmic and auxiliary neutral beam heating. The results in ISX-B and TEXTOR show that active density control and particle removal is achieved with pump limiters. In ISX-B, the boundary layer (or scrape-off layer) plasma partially screens the core plasma from gas injection. In both ISX-B and TEXTOR, the pressure internal to the module scales linearly with plasma density but in ISX-B, with neutral beam injection, a nonlinear increase is observed at the highest densities studied. Plasma plugging is the suspected cause. Results from PDX suggest that a regime may exist in which core plasma energy confinement improves using a pump limiter during neutral beam injection. Asymmetric radial profiles and an increased edge electron temperature are observed in discharges with improved confinement. The injection of small amounts of neon into ISX-B has more clearly shown an improved electron core energy confinement during neutral beam injection. While carried out with a regular limiter, this 'Z-mode' of operation is ideal for use with pump limiters and should be a way to achieve energy confinement times similar to values for H-mode tokamak plasmas. The implication of all these results for the design of a reactor pump limiter is described. (orig.)

Analytical studies on pump-induced optical resonances in an M-type six-level system

International Nuclear Information System (INIS)

Ghosh, Saswata; Mandal, Swapan

2010-01-01

In the domain of semiclassical formulation and for the Doppler-free atom-field interaction, we construct the optical Bloch equations involving an M-type six-level system coupled to two pump fields and a probe field. The response of the system is probed for different pump-induced transitions in double and triple-resonance situations. In order to obtain the coherent lineshapes (absorptive and dispersive), we use the usual perturbation method for obtaining the approximate analytical solutions to these coupled optical Bloch equations for the density matrix elements. The interferences between the probability amplitudes for different energy levels (dipole allowed and dipole forbidden) are taken care of. For off-resonance pump positions, the linewidths of the three probe transitions are insensitive to the pump Rabi frequencies. On the other hand, the shifts of the three resonance peaks are extremely sensitive to the pump Rabi frequencies. However, for on-resonance pump conditions, the sensitivities of pump Rabi frequencies on the linewidths of the resonance peaks and on the shifts of the resonance peak positions are opposite to those of their off-resonance counterparts. In particular, we have shown the asymmetric and symmetric Rabi splittings under different physical conditions, for non-zero and near-zero probe detuning, respectively. The Rabi splitting under triple-resonance conditions, significantly, modifies the dispersive lineshape at the centre of the absorption line. The two- and three-photon absorptions are also reported for different off-resonant pump positions.

Heat pumps: planning, optimisation, operation and maintenance; Waermepumpen. Planung - Optimierung - Betrieb - Wartung

Energy Technology Data Exchange (ETDEWEB)

Kunz, P. [Kunz-Beratungen, Dietlikon (Switzerland); Afjei, T. [Fachhochschule Nordwestschweiz, Institut fuer Energie am Bau, Muttenz (Switzerland); Betschart, W.; Prochaska, V. [Hochschule Luzern, Technik und Architektur, Horw (Switzerland); Hubacher, P. [Hubacher Engineering, Engelburg (Switzerland); Loehrer, R. [Scheco AG, Winterthur (Switzerland); Mueller, A. [Mueller und Pletscher AG, Winterthur (Switzerland)

2008-01-15

This handbook issued by the Swiss Federal Office of Energy (SFOE) in co-operation with a trade publication takes a look at the planning, optimisation, operation and maintenance of heat pumps. First of all, the basics of heat pump technology, heat pump components and refrigerants are discussed. Then, heat sources and heat distribution are looked at, followed by chapters on the integration of heat pumps into heating systems and noise protection topics. The definition of projects, commissioning and operation of heat pump systems are then discussed. Examples of installations round off the handbook.

Hourly simulation of a Ground-Coupled Heat Pump system

Science.gov (United States)

Naldi, C.; Zanchini, E.

2017-01-01

In this paper, we present a MATLAB code for the hourly simulation of a whole Ground-Coupled Heat Pump (GCHP) system, based on the g-functions previously obtained by Zanchini and Lazzari. The code applies both to on-off heat pumps and to inverter-driven ones. It is employed to analyse the effects of the inverter and of the total length of the Borehole Heat Exchanger (BHE) field on the mean seasonal COP (SCOP) and on the mean seasonal EER (SEER) of a GCHP system designed for a residential house with 6 apartments in Bologna, North-Center Italy, with dominant heating loads. A BHE field with 3 in line boreholes is considered, with length of each BHE either 75 m or 105 m. The results show that the increase of the BHE length yields a SCOP enhancement of about 7%, while the SEER remains nearly unchanged. The replacement of the on-off heat pump by an inverter-driven one yields a SCOP enhancement of about 30% and a SEER enhancement of about 50%. The results demonstrate the importance of employing inverter-driven heat pumps for GCHP systems.

Short-term results of a randomized trial examining timing of carotid endarterectomy in patients with severe asymptomatic unilateral carotid stenosis undergoing coronary artery bypass grafting.

Science.gov (United States)

Illuminati, Giulio; Ricco, Jean-Baptiste; Caliò, Francesco; Pacilè, Maria Antonietta; Miraldi, Fabio; Frati, Giacomo; Macrina, Francesco; Toscano, Michele

2011-10-01

This study evaluated the timing of carotid endarterectomy (CEA) in the prevention of stroke in patients with asymptomatic carotid stenosis >70% receiving a coronary artery bypass graft (CABG). From January 2004 to December 2009, 185 patients with unilateral asymptomatic carotid artery stenosis >70%, candidates for CABG, were randomized into two groups. In group A, 94 patients received a CABG with previous or simultaneous CEA. In group B, 91 patients underwent CABG, followed by CEA. All patients underwent preoperative helical computed tomography scans, excluding significant atheroma of the ascending aorta or aortic arch. Baseline characteristics of the patients, type of coronary artery lesion, and preoperative myocardial function were comparable in the two groups. In group A, all patients underwent CEA under general anesthesia with the systematic use of a carotid shunt, and 79 patients had a combined procedure and 15 underwent CEA a few days before CABG. In group B, all patients underwent CEA, 1 to 3 months after CABG, also under general anesthesia and with systematic carotid shunting. Two patients (one in each group) died of cardiac failure in the postoperative period. Operative mortality was 1.0% in group A and 1.1% in group B (P = .98). No strokes occurred in group A vs seven ipsilateral ischemic strokes in group B, including three immediate postoperative strokes and four late strokes, at 39, 50, 58, and 66 days, after CABG. These late strokes occurred in patients for whom CEA was further delayed due to an incomplete sternal wound healing or because of completion of a cardiac rehabilitation program. The 90-day stroke and death rate was 1.0% (one of 94) in group A and 8.8% (eight of 91) in group B (odds ratio [OR], 0.11; 95% confidence interval [CI], 0.01-0.91; P = .02). Logistic regression analysis showed that only delayed CEA (OR, 14.2; 95% CI, 1.32-152.0; P = .03) and duration of cardiopulmonary bypass (OR, 1.06; 95% CI, 1.02-1.11; P = .004) reliably predicted

Endovascular approach to treat ascending aortic pseudoaneurysm in a patient with previous CABG and very high surgical risk.

Science.gov (United States)

Zago, Alexandre C; Saadi, Eduardo K; Zago, Alcides J

2011-10-01

Pseudoaneurysm of the ascending aorta is an uncommon pathology and a challenge in high-risk patients who undergo conventional surgery because of high operative morbidity and mortality. Endovascular exclusion of an aortic pseudoaneurysm using an endoprosthesis is a less invasive approach, but few such cases have been reported. Moreover, the use of this approach poses unique therapeutic challenges because there is no specific endoprosthesis for ascending aortic repair, particularly to treat patients with previous coronary artery bypass graft (CABG). We describe the case of a 74-year-old patient who had undergone CABG and later presented with an iatrogenic ascending aortic pseudoaneurysm that occurred during an angiography. This patient was at very high risk for surgical treatment and, therefore, an endovascular approach was adopted: percutaneous coronary intervention for the left main coronary artery, left anterior descending and left circumflex native coronary arteries followed by endovascular endoprosthesis deployment in the ascending aorta to exclude the pseudoaneurysm. Both procedures were successfully performed, and the patient was discharged without complications 4 days later. At 5 months' clinical follow-up, his clinical condition was good and he had no complications. Copyright © 2011 Wiley-Liss, Inc.

Particles pumping in Tore Supra

International Nuclear Information System (INIS)

Bonnel, P.; Chappuis, P.; Lipa, M.

1989-01-01

TORE SUPRA and its peripheral equipments are provided with routine clean high vacuum by turbomolecular pumping. During plasma discharges large quantity of very hot gases activating at plasma edge and plasma density in scrape off layer has to be controlled before they strike violently solid wall provoking increase in impurities content and make density up to disruptive level. A Magnetic Ergodic Divertor made of six winding structures - MED - six Vertical Pumped Limiters - VPL - and one Horizontal Pumped Limiter - HPL - are set in the vacuum chamber in order to cope with plasma-wall interactions and neutral gas recycling. Each apparatus is equipped at front side with thermal shield respectively made of polycristallin and pyrolitic graphite bolted on stainless steel support for MED and HPL whereas for VPL it is made of CFC Aerolor 05 brazed on hardened copper. The total heat removal capacity of these plasma facing components is 12 MW. Design of particles collection openings and ducts conductance allow 10% of capture efficiency, that means for TORE SUPRA a flux of 3 x 10 21 particles/second has to be sorbed by water cooled titanium getter pumps, settled at rear side. All those facilities were put into plasma operation at the beginning of 1989 for a short time. Preliminary observations go along with theoretical predictions, that actions in scrappe-off layer may provoke effects in bulk plasma. Very first results drawn out, show that particle collection and heat removal were effective by MED, VPL and HPL and that plasma behaviour was not disturbed by their presence and actions but instead tendency to improvement was observed

Energy Efficient Pump Control for an Offshore Oil Processing System

DEFF Research Database (Denmark)

Yang, Zhenyu; Soleiman, Kian; Løhndorf, Bo

2012-01-01

The energy efficient control of a pump system for an offshore oil processing system is investigated. The seawater is lifted up by a pump system which consists of three identical centrifugal pumps in parallel, and the lifted seawater is used to cool down the crude oil flowing out of a threephase...... separator on one of the Danish north-sea platform. A hierarchical pump-speed control strategy is developed for the considered system by minimizing the pump power consumption subject to keeping a satisfactory system performance. The proposed control strategy consists of online estimation of some system...... operating parameters, optimization of pump configurations, and a real-time feedback control. Comparing with the current control strategy at the considered system, where the pump system is on/off controlled, and the seawater flows are controlled by a number of control valves, the proposed control strategy...

Age-dependent trends in postoperative mortality and preoperative comorbidity in isolated coronary artery bypass surgery

DEFF Research Database (Denmark)

Thorsteinsson, Kristinn; Fonager, Kirsten; Mérie, Charlotte

2016-01-01

OBJECTIVES: An increasing number of octogenarians are being subjected to coronary artery bypass grafting (CABG). The purpose of this study was to examine age-dependent trends in postoperative mortality and preoperative comorbidity over time following CABG. METHODS: All patients who underwent isol...

Selective Retrograde Venous Revascularization of the Myocardium when PCI or CABG Is Impossible: Investigation in a Porcine Model

DEFF Research Database (Denmark)

Møller, Christian H; Nørgaard, Martin A; Gøtze, Jens P

2008-01-01

We investigated the possibility of nourishing the myocardium through selective retrograde coronary venous bypass grafting (CVBG) with an off-pump technique and evaluated various methods of monitoring the physiological effects of this procedure. In a porcine model, the left internal mammary artery...... tension decreased, but with time some recovery was seen. Cardiac troponin T was elevated. Histological analysis showed ischemic changes. In control pigs, microdialysis was performed for 1.5 hours up to LAD artery ligation, after which all pigs died in ventricular fibrillation arrest. No increase...

Flue gas condensing with heat pump; Roekgaskondensering med vaermepump

Energy Technology Data Exchange (ETDEWEB)

Axby, Fredrik; Pettersson, Camilla [Carl Bro Energikonsult AB, Malmoe (Sweden)

2004-11-01

Flue gas condensing is often both a technically and economically efficient method to increase the thermal efficiency in a plant using fuels with high moisture and/or high hydrogen content. The temperature of the return water in district heating systems in Sweden is normally 50 deg C, which gives quite high efficiency for a flue gas condenser. The flue gas after the flue gas condenser still contains energy that to some extent can be recovered by a combustion air humidifier or a heat pump. The object of this project is to technically and economically analyse flue gas condensing with heat pump. The aim is that plant owners get basic data to evaluate if a coupling between a flue gas condenser and a heat pump could be of interest for their plant. With a heat pump the district heating water can be 'sub cooled' to increase the heat recover in the flue gas condenser and thereby increase the total efficiency. The project is set up as a case study of three different plants that represent different types of technologies and sizes; Aabyverket in Oerebro, Amagerforbraending in Copenhagen and Staffanstorp district heating central. In this report a system with a partial flow through the condenser of the heat pump is studied. For each plant one case with the smallest heat pump and a total optimization regarding total efficiency and cost for investment has been calculated. In addition to the optimizations sensitivity analyzes has been done of the following parameters: Moisture in fuel; Type of heat pump; Temperature of the return water in the district heating system; and, Size of plant. The calculations shows that the total efficiency increases with about 6 % by the installation of the heat pump at a temperature of the return water in the district heating system of 50 deg C at Aabyverket. The cost for production of heat is just below 210 kr/MWh and the straight time for pay-off is 5,4 years at 250 kr/MWh in heat credit and at 300 kr/MWh in basic price for electricity. The

Pressurizer pump reliability analysis high flux isotope reactor

International Nuclear Information System (INIS)

Merryman, L.; Christie, B.

1993-01-01

During a prolonged outage from November 1986 to May 1990, numerous changes were made at the High Flux Isotope Reactor (HFIR). Some of these changes involved the pressurizer pumps. An analysis was performed to calculate the impact of these changes on the pressurizer system availability. The analysis showed that the availability of the pressurizer system dropped from essentially 100% to approximately 96%. The primary reason for the decrease in availability comes because off-site power grid disturbances sometimes result in a reactor trip with the present pressurizer pump configuration. Changes are being made to the present pressurizer pump configuration to regain some of the lost availability

A Fourier Approximation Method for the Multi-Pump Multi-Piston Power Take-Off System

NARCIS (Netherlands)

Wei, Yanji; Barradas Berglind, Jose de Jesus; Muhammad Zaki Almuzakki, M.; van Rooij, Marijn; Wang, Ruoqi; Jayawardhana, Bayu; Vakis, Antonis I.

2018-01-01

In this work, a frequency-domain method for the numerical solution of the nonlinear dynamics of a wave energy converter with a pumping system is presented. To this end, a finite Fourier series is used to describe the nonlinear force components, i.e., the pumping force. The dynamics of the buoy and

Off-design performance analysis of Kalina cycle for low temperature geothermal source

International Nuclear Information System (INIS)

Li, Hang; Hu, Dongshuai; Wang, Mingkun; Dai, Yiping

2016-01-01

Highlights: • The off-design performance analysis of Kalina cycle is conducted. • The off-design models are established. • The genetic algorithm is used in the design phase. • The sliding pressure control strategy is applied. - Abstract: Low temperature geothermal sources with brilliant prospects have attracted more and more people’s attention. Kalina cycle system using ammonia water as working fluid could exploit geothermal energy effectively. In this paper, the quantitative analysis of off-design performance of Kalina cycle for the low temperature geothermal source is conducted. The off-design models including turbine, pump and heat exchangers are established preliminarily. Genetic algorithm is used to maximize the net power output and determine the thermodynamic parameters in the design phase. The sliding pressure control strategy applied widely in existing Rankine cycle power plants is adopted to response to the variations of geothermal source mass flow rate ratio (70–120%), geothermal source temperature (116–128 °C) and heat sink temperature (0–35 °C). In the off-design research scopes, the guidance for pump rotational speed adjustment is listed to provide some reference for off-design operation of geothermal power plants. The required adjustment rate of pump rotational speed is more sensitive to per unit geothermal source temperature than per unit heat sink temperature. Influence of the heat sink variation is greater than that of the geothermal source variation on the ranges of net power output and thermal efficiency.

Surgery of abdominal aortic aneurysm associated with coronary artery disease. Simultaneous or two staged operation

International Nuclear Information System (INIS)

Tanaka, Hiroyuki; Narisawa, Takashi; Mori, Takanobu; Masuda, Mikio; Kishi, Daijirou; Suzuki, Takashi; Takaba, Toshihiro

2003-01-01

Coronary artery disease (CAD) was evaluated by noninvasive examination in abdominal aortic aneurysm (AAA) patients. A simultaneous operation or a 2-staged operation was performed depending on the seriousness of the condition when both diseases were combined. A total of 36 patients underwent elective repair of AAA between 1996 and 2001. Coronary angiography (CAG) was performed only in patients with suspected CAD by dipyridamole myocardial scintigraphy. Significant CAD was found in 8 patients. Simultaneous operation was performed in 4 patients, and off-pump coronary artery bypass grafting (OPCAB) was performed in all cases of simultaneous operation. In 4 patients receiving 2-staged operations, 1 standard coronary artery bypass grafting (CABG), 1 OPCAB and 2 percutaneous transluminal coronary angioplasties (PTCA) were performed prior to AAA surgery. Twenty-eight patients underwent only AAA operation. Though there were no incidents of perioperative myocardial infarction or cardiac related deaths in this group, 2 patients died due to other causes (hemorrhage and duodenal perforation). In the 8 patients associated with CAD, 1 patient died of myonephrotic metabolic syndrome (MNMS) after simultaneous operation. The other 7 patients revived their social function soon of the discharge. Dipyridamole cardiac scintigraphy was considered to be an effective examination for evaluation of CAD in AAA patients. There was no need to perform CAG in all AAA patients. The policy of choosing simultaneous operation or 2-staged operation according to the seriousness of the 2 diseases seemed to be appropriate. (author)

Design and optimisation of dual-mode heat pump systems using natural fluids

International Nuclear Information System (INIS)

Zhang Wenling; Klemeš, Jiří Jaromír; Kim, Jin-Kuk

2012-01-01

The paper introduces new multi-period modelling and design methodology for dual-mode heat pumps using natural fluids. First, a mathematical model is developed to capture thermodynamic and operating characteristics of dual-mode heat pump systems, subject to different ambient temperatures. The multi-period optimisation framework has been developed to reflect different ambient conditions and its influences on heat pump performance, as well as to determine a system capacity of heat pump which allows systematic economic trade-offs between supplementary heating (or cooling) and operating cost for heat pump. Case study considering three geographical locations with different heating and cooling demands is presented to illustrate the importance of using multi-period optimisation for the design of heat pump systems.

Partial revascularization plus medical treatment versus medical treatment alone in patients with multivessel coronary artery disease not eligible for CABG

Directory of Open Access Journals (Sweden)

M. Sadaka

2013-06-01

Conclusion: In patients with MVD who were not eligible for CABG; IR plus OMT was not superior to OMT alone in improving the 1year clinical outcomes except the improvement in the level of angina class, which could be the adopted strategy to improve the quality of life in such patients but with close follow up.

Utility of pulmonary venous flow diastolic deceleration time in an adult patient undergoing surgical closure of atrial septal defect and coronary artery bypass grafting

Directory of Open Access Journals (Sweden)

Dharmesh R Agrawal

2013-01-01

Full Text Available Acute left ventricular (LV failure has been reported after surgical closure of atrial septal defect (ASD in adult patients. We report acute LV failure in a 56 year old gentleman following coronary artery bypass grafting (CABG and surgical closure of ASD. Transesophageal echocardiography examination of the patient following closure of ASD and CABG showed a residual ASD and a shunt (Qp :Qs = 1.5. The residual ASD was closed after re-institution of cardiopulmonary bypass (CPB under cardioplegic cardiac arrest. However, the patient did not tolerate closure of the residual ASD. The CPB was re-established and under cardioplegic cardiac arrest residual ASD was reopened to create a fenestration. This time patient was weaned easily from CPB. Postoperatively, 16 hours after extubation, patient became hemodynamically unstable, the patient was electively put on ventilator and intra-aortic balloon pump. Later the patient was weaned off successfully from ventilator. Retrospective analysis of pulmonary venous flow diastolic deceleration time (PVDT D recorded during prebypass period measured 102 msec suggestive of high left atrial pressure which indicate possibility of LV failure after ASD closure.

[Clinical research of minimal extracorporeal circulation in perioperative blood conservation of coronary artery bypass graft].

Science.gov (United States)

Liu, Yan; Cui, Hu-jun; Tao, Liang; Chen, Xu-fa

2011-04-01

To analyze the clinical effect of minimal extracorporeal circulation (MECC) in blood conservation perioperatively coronary artery bypass graft (CABG). The data of 120 cases received simple CABG since August 2006 to October 2009 was analyzed retrospectively. All the patients were divided to three groups according to the mode of circulation support in-operation: MECC, conventional extracorporeal circulation (cECC) or off-pump, 40 cases in each group. Jostra MECC system with normal temperature was used in MECC group, and common membrane oxygenator with moderate hypo-temperature was used in cECC group. Collect the data of coagulation and the blood cytological examination perioperatively, the draining volume during the first 24 h after operation, and consumption of blood products perioperatively. Standard and logistic EuroSCORE were higher in MECC group than the others (P blood products in cECC group, but no difference among the three groups. MECC could reduce the ruin to blood cell and interfere to coagulation function during the conventional ECC procedure, decrease the postoperative draining volume and requirement of blood products.

Ultrastructural investigations for reducing endothelial cell damage of vein grafts during CABG-operation and practical consequences.

Science.gov (United States)

Hickethier, T; Dämmrich, J; Silber, R E; Finster, S; Elert, O

1999-02-01

In the present study the influence of different storage solutions on endothelial integrity or damage was investigated with direct methods particularly with transmission electron microscopy (TEM), scanning electron microscopy (SEM) and immunohistochemistry. Saphenous vein segments of 10 cm in length were taken surgically from 6 male CABG-patients (aged 60-70) under standardized conditions. Each vein segment was cut into rings, which were incubated at room temperature for 45 minutes in different storage solutions, particularly in 0.9% sodium chloride solution and in buffered solution (M 199) with 5% human serum albumin respectively. Then, the vein segments were fixed in 3.5% glutaraldehyde and prepared for scanning and transmission electron microscopy to evaluate the endothelial damage. In addition, immunohistochemical staining (CD34, PECAM and Factor VIII) was performed. When using 0.9% sodium chloride solution, the SEM-examination revealed that 55% of the cell population was destroyed. In comparison to these findings only 26% of the endothelial cell population was damaged when the venous segment was stored in buffered solution with 5% albumin (p<0.01). In immunohistochemistry (CD34, PECAM, Factor VIII) these findings were supported. This study demonstrates the importance of storage solutions in regard to endothelial integrity. For best preservation of endothelium it is necessary to modify conventional storage methods. So, storage in buffered solution with albumin has shown much better endothelial cell preservation compared with physiological saline which might reduce the obliteration rate of CABG in future.

Domestic demand-side management (DSM): Role of heat pumps and thermal energy storage (TES) systems

International Nuclear Information System (INIS)

Arteconi, A.; Hewitt, N.J.; Polonara, F.

2013-01-01

Heat pumps are seen as a promising technology for load management in the built environment, in combination with the smart grid concept. They can be coupled with thermal energy storage (TES) systems to shift electrical loads from high-peak to off-peak hours, thus serving as a powerful tool in demand-side management (DSM). This paper analyzes heat pumps with radiators or underfloor heating distribution systems coupled with TES with a view to showing how a heat pump system behaves and how it influences the building occupants' thermal comfort under a DSM strategy designed to flatten the shape of the electricity load curve by switching off the heat pump during peak hours (16:00–19:00). The reference scenario for the analysis was Northern Ireland (UK). The results showed that the heat pump is a good tool for the purposes of DSM, also thanks to the use of TES systems, in particular with heating distribution systems that have a low thermal inertia, e.g. radiators. It proved possible to achieve a good control of the indoor temperature, even if the heat pump was turned off for 3 h, and to reduce the electricity bill if a “time of use” tariff structure was adopted. -- Highlights: ► Heat pump heating systems with thermal energy storage are considered. ► System behavior is investigated during a DSM strategy for reducing peak energy demand. ► Heat pump heating systems demonstrate to be able to have an active role in DSM programs. ► A TES system must be coupled with the heat pump in presence of low thermal inertia heating distribution systems. ► Central role played by incentives schemes to promote this technology

Concomitant coronary artery revascularization and right pneumonectomy without cardiopulmonary bypass

NARCIS (Netherlands)

Hensens, AG; Zeebregts, C.J.A.M.; Liem, TH; Gehlmann, H; Lacquet, LK

Combined coronary artery bypass grafting (CABG) and pneumonectomy has a high morbidity and mortality rate, especially when the right lung has to be removed. A patient is described who underwent a CABG operation through a midline sternotomy without the use of cardiopulmonary bypass (CPB), and a right

Role of Acid and Weakly Acidic Reflux in Gastroesophageal Reflux Disease Off Proton Pump Inhibitor Therapy

Science.gov (United States)

Sung, Hea Jung; Moon, Sung Jin; Kim, Jin Su; Lim, Chul Hyun; Park, Jae Myung; Lee, In Seok; Kim, Sang Woo; Choi, Myung-Gye

2012-01-01

Background/Aims Available data about reflux patterns and symptom determinants in the gastroesophageal reflux disease (GERD) subtypes off proton pump inhibitor (PPI) therapy are lacking. We aimed to evaluate reflux patterns and determinants of symptom perception in patients with GERD off PPI therapy by impedance-pH monitoring. Methods We retrospectively reviewed the impedance-pH data in patients diagnosed as GERD based on results of impedance-pH monitoring, endoscopy and/or typical symptoms. The characteristics of acid and weakly acidic reflux were evaluated. Symptomatic and asymptomatic reflux were compared according to GERD subtypes and individual symptoms. Results Forty-two patients (22 males, mean age 46 years) were diagnosed as GERD (17 erosive reflux disease, 9 pH(+) non-erosive reflux disease [NERD], 9 hypersensitive esophagus and 7 symptomatic NERD). A total of 1,725 reflux episodes were detected (855 acid [50%], 857 weakly acidic [50%] and 13 weakly alkaline reflux [reflux was more frequently symptomatic and bolus clearance was longer compared with weakly acidic reflux. In terms of globus, weakly acidic reflux was more symptomatic. Symptomatic reflux was more frequently acid and mixed reflux; these associations were more pronounced in erosive reflux disease and symptomatic NERD. The perception of regurgitation was related to acid reflux, while that of globus was more related to weakly acidic reflux. Conclusions In patients not taking PPI, acid reflux was more frequently symptomatic and had longer bolus clearance. Symptomatic reflux was more frequently acid and mixed type; however, weakly acidic reflux was associated more with globus. These data suggest a role for impedance-pH data in the evaluation of globus. PMID:22837877

Role of Acid and weakly acidic reflux in gastroesophageal reflux disease off proton pump inhibitor therapy.

Science.gov (United States)

Sung, Hea Jung; Cho, Yu Kyung; Moon, Sung Jin; Kim, Jin Su; Lim, Chul Hyun; Park, Jae Myung; Lee, In Seok; Kim, Sang Woo; Choi, Myung-Gye

2012-07-01

Available data about reflux patterns and symptom determinants in the gastroesophageal reflux disease (GERD) subtypes off proton pump inhibitor (PPI) therapy are lacking. We aimed to evaluate reflux patterns and determinants of symptom perception in patients with GERD off PPI therapy by impedance-pH monitoring. We retrospectively reviewed the impedance-pH data in patients diagnosed as GERD based on results of impedance-pH monitoring, endoscopy and/or typical symptoms. The characteristics of acid and weakly acidic reflux were evaluated. Symptomatic and asymptomatic reflux were compared according to GERD subtypes and individual symptoms. Forty-two patients (22 males, mean age 46 years) were diagnosed as GERD (17 erosive reflux disease, 9 pH(+) non-erosive reflux disease [NERD], 9 hypersensitive esophagus and 7 symptomatic NERD). A total of 1,725 reflux episodes were detected (855 acid [50%], 857 weakly acidic [50%] and 13 weakly alkaline reflux [Acid reflux was more frequently symptomatic and bolus clearance was longer compared with weakly acidic reflux. In terms of globus, weakly acidic reflux was more symptomatic. Symptomatic reflux was more frequently acid and mixed reflux; these associations were more pronounced in erosive reflux disease and symptomatic NERD. The perception of regurgitation was related to acid reflux, while that of globus was more related to weakly acidic reflux. In patients not taking PPI, acid reflux was more frequently symptomatic and had longer bolus clearance. Symptomatic reflux was more frequently acid and mixed type; however, weakly acidic reflux was associated more with globus. These data suggest a role for impedance-pH data in the evaluation of globus.

Tokamak advanced pump limiter experiments and analysis

International Nuclear Information System (INIS)

Conn, R.W.

1983-06-01

Experiments with pump limiter modules on several operating tokamaks establish such limiters as efficient collectors of particles and has demonstrated the importance of ballistic scattering as predicted theoretically. Plasma interaction with recycling neutral gas appears to become important as the plasma density increases and the effective ionization mean free path within the module decreases. In limiters with particle collection but without active internal pumping, the neutral gas pressure is found to vary nonlinearly with the edge plasma density at the highest densities studies. Both experiments and theory indicate that the energy spectrum of gas atoms in the pump ducting is non-thermal, consistent with the results of Monte Carlo neutral atom transport calculations. The distribution of plasma power over the front surface of such modules has been measured and appears to be consistent with the predictions of simple theory. Initial results from the latest experiment on the ISX-B tokamak with an actively pumped limiter module demonstrates that the core plasma density can be controlled with a pump limiter and that the scrape-off layer plasma can partially screen the core plasma from gas injection. The results from module pump limiter experiments and from the theory and design analysis of advanced pump limiters for reactors are used to suggest the major features of a definitive, axisymmetric, toroidal belt pump limiter experiment

The economics of supplying the supplementary heat in a closed loop water source heat pump system

International Nuclear Information System (INIS)

Johnson, R.P.; Bartkus, V.E.; Singh, J.B.

1993-01-01

The paper describes the details of a research and demonstration project that will be completed in August 1992 at a healthcare facility in northeastern Pennsylvania. The purpose of the project is to compare the economics of several methods of supplying the supplementary heating in a facility served by a closed loop water source heat pump system. The systems being tested include a storage hot water tank with electric resistance heaters and three air source heat pumps that have the ability to supply the same heat during on-peak hours as well as off-peak hours. The paper compares the projected operating costs of the following: (1) Gas boiler supplying the supplementary heat. (2) Stored hot water supplying the supplementary heat which is generated and stored during off-peak hours using resistance heat on PP ampersand L's offpeak rate. (3) Stored hot water supplying the supplementary heat generated during off-peak hours using the air source heat pumps on PP ampersand L's off-peak rate. (4) Hot water generated by the air source heat pumps supplying the supplementary loop heating on PP ampersand L's general service and time-of-day electric rates. It is generally known in the HVAC industry that a closed loop water source heat pump system can provide one of the most efficient means of space conditioning to a building with high internal gains by transferring the excess heat available in one part of the building to another part of the building where it may be needed for heating. The following flow diagram depicts the relationship of the air source heat pumps with the storage tanks and the building closed water loop

Effects of the reactor coolant pumps following a small break in a Westinghouse PWR

International Nuclear Information System (INIS)

Koenig, J.E.

1983-10-01

Numerical simulations of the thermal-hydraulic events following a small cold-leg break in a Westinghouse pressurized water reactor were performed to address the pumps-on/off issue. The mode of pump operation was varied in each calculation to ascertain the optimum mode. It was found that pump operation was not critical for this break size and location because the fuel rods remained cool in all accidents analyzed. In terms of system mass, however, it was preferable to leave the pumps in operation

Longevity and admission to nursing home according to age after isolated coronary artery bypass surgery

DEFF Research Database (Denmark)

Thorsteinsson, Kristinn; Andreasen, Jan; Mortensen, Rikke N

2016-01-01

OBJECTIVES: Data on nursing home admission in patient's ≥80 years after isolated coronary artery bypass grafting (CABG) are scarce. The purpose of this study was to evaluate longevity and subsequent admission to a nursing home stratified by age in a nationwide CABG cohort. METHODS: All patients who...... underwent isolated CABG from 1996 to 2012 in Denmark were identified through nationwide registers. The cumulative incidence of admission to a nursing home after CABG was estimated. A Cox regression model was constructed to identify predictors for living in a nursing home 1 year after CABG. Kaplan.......1% of patients ≥80 years had received home care. The proportion of patients admitted to a nursing home at 1, 5 and 10 years after CABG was 0.1, 0.4 and 1.0% (nursing home 1 year postoperatively were: age ≥80 years...

Off-stream Pumped Storage Hydropower plant to increase renewable energy penetration in Santiago Island, Cape Verde

Science.gov (United States)

Barreira, Inês; Gueifão, Carlos; Ferreira de Jesus, J.

2017-04-01

In order to reduce the high dependence on imported fuels and to meet the ongoing growth of electricity demand, Cape Verde government set the goal to increase renewable energy penetration in Santiago Island until 2020. To help maximize renewable energy penetration, an off-stream Pumped Storage Hydropower (PSH) plant will be installed in Santiago, in one of the following locations: Chã Gonçalves, Mato Sancho and Ribeira dos Picos. This paper summarizes the studies carried out to find the optimal location and connection point of the PSH plant in Santiago’s electricity network. This goal was achieved by assessing the impact of the PSH plant, in each location, on power system stability. The simulation tool PSS/E of Siemens was used to study the steady-state and dynamic behavior of the future (2020) Santiago MV grid. Different scenarios of demand and renewable resources were created. Each hydro unit of the PSH plant was modeled as an adjustable speed reversible turbine employing a DFIM. The results show that Santiago’s grid with the PSH plant in Chã Gonçalves is the one that has the best performance.

Study of Pumping Capacity of Pitched Blade Impellers

Directory of Open Access Journals (Sweden)

I. Fořt

2002-01-01

Full Text Available A study was made of the pumping capacity of pitched blade impellers in a cylindrical pilot plant vessel with four standard radial baffles at the wall under a turbulent regime of flow. The pumping capacity was calculated from the radial profile of the axial flow, under the assumption of axial symmetry of the discharge flow. The mean velocity was measured using laser Doppler anemometry in a transparent vessel of diameter T = 400 mm, provided with a standard dished bottom. Three and six blade pitched blade impellers (the pitch angle varied within the interval a Îá24°; 45°ń of impeller/vessel diameter ratio D/T = 0.36, as well as a three blade pitched blade impeller with folded blades of the same diameter, were tested. The calculated results were compared with the results of experiments mentioned in the literature, above all in cylindrical vessels with a flat bottom. Both arrangements of the agitated system were described by the impeller energetic efficiency, i.e, a criterion including in dimensionless form both the impeller energy consumption (impeller power input and the impeller pumping effect (impeller pumping capacity. It follows from the results obtained with various geometrical configurations that the energetic efficiency of pitched blade impellers is significantly lower for configurations suitable for mixing solid-liquid suspensions (low impeller off bottom clearances than for blending miscible liquids in mixing (higher impeller off bottom clearances.

Assessment of feasibility of helium ash exhaust and heat removal by pumped-limiter in tokamak fusion reactor

International Nuclear Information System (INIS)

Hitoki, Shigehisa; Sugihara, Masayoshi; Saito, Seiji; Fujisawa, Noboru

1985-01-01

A detailed calculation of the behavior of fuel and He particles in tokamak reactor with pumped-limiter is performed by one-dimensional tokamak transport code. Energy of neutral particles flowing back from limiter chamber is calculated by two-dimensional Monte Carlo neutral code. Feasibility of He ash exhaust and heat removal by the pumped-limiter are analyzed. Following features of the pumped-limiter are clarified: (1) Electron temperature decays rapidly in radial direction in scrape-off layer, while density profile is broader than that of temperature. (2) Helium accumulation in main plasma can be kept at desired level by rather short limiter and moderate pumping system. (3) Minimum amount of tritium pumped out little depends on limiter length. (4) Although high temperature plasma in scrape-off layer could be realized by large pumping and ideal pellet injection, it is not sufficiently high to reduce the erosion of the limiter surface and the leading edge. In conclusion, He ash exhaust may be possible by the pumped-limiter, while the heat load and erosion will be so high that the pumped-limiter may not be applicable unless the boundary plasma is cooled by radiation or by some other means. (author)

Study on cavitation in centrifugal sodium pumps for FBTR and PFBR

International Nuclear Information System (INIS)

Rao, A.S.L.K.; Prabhakar, R.; Prakash, V.; Paranjpe, S.R.

2002-01-01

Fast Breeder Test Reactor (FBTR) which is expected to become critical shortly is a loop type reactor of 40 MW thermal capacity and has two primary and two secondary centrifugal pumps for heat removal. During the initial periods of reactor operation, the steam generator is bypassed and the secondary sodium pumps are required to operate at flows less than that at best efficiency point. This paper deals with the cavitation problems associated with operation at partial f lows, theoretical estimations and experimental cavitation measurements carried out on FBTR secondary sodium pumps. These investigations revealed that operation of FBTR pumps at this off design condition is free from cavitation damage. Cavitation experiments on a model pump for the development of large sodium pumps for a 500 MWe Prototype Fast Breeder Reactor (PFBR) are described in this paper

Depression and Geographic Status as Predictors for Coronary Artery Bypass Surgery Outcomes

Science.gov (United States)

Dao, Tam K.; Chu, Danny; Springer, Justin; Hiatt, Emily; Nguyen, Quang

2010-01-01

Purpose: To examine the relationships between depression, geographic status, and clinical outcomes following a coronary artery bypass grafting (CABG) surgery. Methods: Using the 2004 Nationwide Inpatient Sample database, we identified 63,061 discharge records of patients who underwent a primary CABG surgery (urban 57,247 and rural 5,814). We…

Design technology development of the main coolant pump for an integral reactor

International Nuclear Information System (INIS)

Park, J. S.; Lee, J. S.; Kim, M. H.; Kim, D. W.; Kim, J. I.

2004-01-01

All of the reactor coolant pump currently used in commercial nuclear power plant were imported from foreign country. Now, the developing program of design technology for the reactor coolant pump will be started in a few future by domestic researchers. At this stage, the design technology of the main coolant pump for an integral reactor is developed based on the regulation of domestic nuclear power plant facilities. The main coolant pump is a canned motor axial pump, which accommodates all constraints required from the integral reactor system. The main coolant pump does not have mechanical seal device because the rotor of motor and the shaft of impeller are the same one. There is no flywheel on the rotating shaft of main coolant pump so that the coastdown duration time is short when the electricity supply is cut off

Capacitive-discharge-pumped copper bromide vapour laser

International Nuclear Information System (INIS)

Sukhanov, V B; Fedorov, V F; Troitskii, V O; Gubarev, F A; Evtushenko, Gennadii S

2007-01-01

A copper bromide vapour laser pumped by a high-frequency capacitive discharge is developed. It is shown that, by using of a capacitive discharge, it is possible to built a sealed off metal halide vapour laser of a simple design allowing the addition of active impurities into the working medium. (letters)

Electromagnetically powered electrolytic pump and thermo-responsive valve for drug delivery

KAUST Repository

Yi, Ying; Zaher, Amir; Yassine, Omar; Buttner, Ulrich; Kosel, Jü rgen; Foulds, Ian G.

2015-01-01

A novel drug delivery device is presented, implementing an electrolytic pump and a thermo-responsive valve. The device is remotely operated by an AC electromagnetic field (40.5∼58.5 mT, 450 kHz) that provides the power for the pump and the valve. It is suitable for long-term therapy applications, which use a solid drug in reservoir (SDR) approach and avoids unwanted drug diffusion. When the electromagnetic field is on, the electrolytic pump drives the drug towards the valve. The valve is made of a magnetic composite consisting of a smart hydrogel: Poly (N-Isopropylacrylamide) (PNIPAm) and iron powder. The heat generated in the iron powder via magnetic losses causes the PNIPAm to shrink, allowing the drug to flow past it. When the electromagnetic field is off, the PNIPAm swells, sealing the outlet. In the meantime, the bubbles generated by electrolysis recombine into water, causing a pressure reduction in the pumping chamber. This draws fresh fluid from outside the pump into the drug reservoir before the valve is fully sealed. The recombination can be accelerated by a platinum (Pt) coated catalytic reformer, allowing more fluid to flow back to the drug reservoir and dissolve the drug. By repeatedly turning on and off the magnetic field, the drug solution can be delivered cyclically. © 2015 IEEE.

Electromagnetically powered electrolytic pump and thermo-responsive valve for drug delivery

KAUST Repository

Yi, Ying

2015-04-01

A novel drug delivery device is presented, implementing an electrolytic pump and a thermo-responsive valve. The device is remotely operated by an AC electromagnetic field (40.5∼58.5 mT, 450 kHz) that provides the power for the pump and the valve. It is suitable for long-term therapy applications, which use a solid drug in reservoir (SDR) approach and avoids unwanted drug diffusion. When the electromagnetic field is on, the electrolytic pump drives the drug towards the valve. The valve is made of a magnetic composite consisting of a smart hydrogel: Poly (N-Isopropylacrylamide) (PNIPAm) and iron powder. The heat generated in the iron powder via magnetic losses causes the PNIPAm to shrink, allowing the drug to flow past it. When the electromagnetic field is off, the PNIPAm swells, sealing the outlet. In the meantime, the bubbles generated by electrolysis recombine into water, causing a pressure reduction in the pumping chamber. This draws fresh fluid from outside the pump into the drug reservoir before the valve is fully sealed. The recombination can be accelerated by a platinum (Pt) coated catalytic reformer, allowing more fluid to flow back to the drug reservoir and dissolve the drug. By repeatedly turning on and off the magnetic field, the drug solution can be delivered cyclically. © 2015 IEEE.

The quality of life of patients developed delirium after coronary artery bypass grafting is determined by cognitive function after discharge: A cross-sectional study.

Science.gov (United States)

Chen, Yuling; Ding, Shu; Tao, Xiangjun; Feng, Xinwei; Lu, Sai; Shen, Yuzhi; Wu, Ying; An, Xiangguang

2017-10-01

Postoperative delirium (POD) and declined cognitive function were common in patients (especially elderly patients) who underwent coronary artery bypass grafting (CABG), which may affect quality of life (QoL). The aim of this study was to determine the relationships among age, POD, declined cognitive function, and QoL in patients who underwent CABG. Consecutive patients who underwent first time elective CABG and assessed for POD using Confusion Assessment Method for intensive care unit for 5 postoperative days from November 2013 to March 2015 were recruited. A cross-sectional study was conducted during April 2015 to assess their cognitive function and QoL, using the Telephone Interview for Cognitive Status Scale and Medical Outcomes Study 36-Item Short Form Health Survey. The relationships among age, POD, declined cognitive function, and QoL were tested using path analysis. Declined cognitive function was associated with poorer QoL. POD was associated with declined cognitive function but was not associated with poorer QoL. Ageing was not associated with QoL but was associated with POD and declined cognitive function. The QoL of patients developed delirium after CABG is determined by cognitive function after discharge. Necessary strategies should be implemented to prevent POD and declined cognitive function, especially in elderly patients. © 2017 John Wiley & Sons Australia, Ltd.

A mitral annulus tracking approach for navigation of off-pump beating heart mitral valve repair.

Science.gov (United States)

Li, Feng P; Rajchl, Martin; Moore, John; Peters, Terry M

2015-01-01

To develop and validate a real-time mitral valve annulus (MVA) tracking approach based on biplane transesophageal echocardiogram (TEE) data and magnetic tracking systems (MTS) to be used in minimally invasive off-pump beating heart mitral valve repair (MVR). The authors' guidance system consists of three major components: TEE, magnetic tracking system, and an image guidance software platform. TEE provides real-time intraoperative images to show the cardiac motion and intracardiac surgical tools. The magnetic tracking system tracks the TEE probe and the surgical tools. The software platform integrates the TEE image planes and the virtual model of the tools and the MVA model on the screen. The authors' MVA tracking approach, which aims to update the MVA model in near real-time, comprises of three steps: image based gating, predictive reinitialization, and registration based MVA tracking. The image based gating step uses a small patch centered at each MVA point in the TEE images to identify images at optimal cardiac phases for updating the position of the MVA. The predictive reinitialization step uses the position and orientation of the TEE probe provided by the magnetic tracking system to predict the position of the MVA points in the TEE images and uses them for the initialization of the registration component. The registration based MVA tracking step aims to locate the MVA points in the images selected by the image based gating component by performing image based registration. The validation of the MVA tracking approach was performed in a phantom study and a retrospective study on porcine data. In the phantom study, controlled translations were applied to the phantom and the tracked MVA was compared to its "true" position estimated based on a magnetic sensor attached to the phantom. The MVA tracking accuracy was 1.29 ± 0.58 mm when the translation distance is about 1 cm, and increased to 2.85 ± 1.19 mm when the translation distance is about 3 cm. In the study on

Sub-xyphoid pleural drain as a determinant of functional capacity and clinical results after off-pump coronary artery bypass surgery: a randomized clinical trial.

Science.gov (United States)

Guizilini, Solange; Alves, Daniel F; Bolzan, Douglas W; Cancio, Andreia S A; Regenga, Marisa M; Moreira, Rita S L; Trimer, Renata; Gomes, Walter J

2014-09-01

The aim of this trial was to compare functional capacity, pulmonary shunt fraction and clinical outcomes between patients undergoing pleurotomy with a pleural drain inserted in the sub-xyphoid position and patients with a pleural drain placed in the intercostal position after off-pump coronary artery bypass surgery. Patients were randomized into two groups according to the pleural drain site: Group II (n = 33 intercostal pleural drain); and Group SI (n = 35 sub-xyphoid pleural drain). Functional capacity was assessed by the distance covered on the 6-min walking test performed preoperatively and on postoperative day (POD) 5; in addition, pulmonary function test was determined preoperatively and on POD 1 and 5. Pulmonary shunt fraction was evaluated preoperatively and on POD 1, and clinical outcomes were recorded throughout the study. Group SI had better preservation of lung volumes and capacities in POD compared with Group II (P Pulmonary shunt fraction increased in both groups postoperatively; however, Group SI showed a smaller pulmonary shunt fraction (0.26 ± 0.04 vs 0.21 ± 0.04%; P = 0.0014). Functional capacity was significantly reduced in both groups on POD 5; however, Group SI showed better preservation of functional capacity (P = 0.0001). Group SI had better postoperative clinical results, with lower incidence of atelectasis and pleural effusion (P capacity and exercise tolerance with a smaller pulmonary shunt fraction and improved clinical outcomes compared with intercostal pleural drainage after off-pump coronary artery bypass surgery. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Giant narrowband twin-beam generation along the pump-energy propagation direction

Science.gov (United States)

Pérez, Angela M.; Spasibko, Kirill Yu; Sharapova, Polina R.; Tikhonova, Olga V.; Leuchs, Gerd; Chekhova, Maria V.

2015-07-01

Walk-off effects, originating from the difference between the group and phase velocities, limit the efficiency of nonlinear optical interactions. While transverse walk-off can be eliminated by proper medium engineering, longitudinal walk-off is harder to avoid. In particular, ultrafast twin-beam generation via pulsed parametric down-conversion and four-wave mixing is only possible in short crystals or fibres. Here we show that in high-gain parametric down-conversion, one can overcome the destructive role of both effects and even turn them into useful tools for shaping the emission. In our experiment, one of the twin beams is emitted along the pump Poynting vector or its group velocity matches that of the pump. The result is markedly enhanced generation of both twin beams, with the simultaneous narrowing of angular and frequency spectrum. The effect will enable efficient generation of ultrafast twin photons and beams in cavities, waveguides and whispering-gallery mode resonators.

Remote Ischemic Preconditioning and Outcomes of Cardiac Surgery.

OpenAIRE

Hausenloy, DJ; Candilio, L; Evans, R; Ariti, C; Jenkins, DP; Kolvekar, S; Knight, R; Kunst, G; Laing, C; Nicholas, J; Pepper, J; Robertson, S; Xenou, M; Clayton, T; Yellon, DM

2015-01-01

: Whether remote ischemic preconditioning (transient ischemia and reperfusion of the arm) can improve clinical outcomes in patients undergoing coronary-artery bypass graft (CABG) surgery is not known. We investigated this question in a randomized trial. : We conducted a multicenter, sham-controlled trial involving adults at increased surgical risk who were undergoing on-pump CABG (with or without valve surgery) with blood cardioplegia. After anesthesia induction and before surgical incision, ...

Sodium pumping: pump problems

International Nuclear Information System (INIS)

Guer, M.; Guiton, P.

Information on sodium pumps for LMFBR type reactors is presented concerning ring pump design, pool reactor pump design, secondary pumps, sodium bearings, swivel joints of the oscillating annulus, and thermal shock loads

Performance of a solar augmented heat pump

Science.gov (United States)

Bedinger, A. F. G.; Tomlinson, J. J.; Reid, R. L.; Chaffin, D. J.

Performance of a residential size solar augmented heat pump is reported for the 1979-1980 heating season. The facility located in Knoxville, Tennessee, has a measured heat load coefficient of 339.5 watt/C (644 BTU/hr- F). The solar augmented heat pump system consists of 7.4 cu m of one inch diameter crushed limestone. The heat pump is a nominal 8.8 KW (2 1/2 ton) high efficiency unit. The system includes electric resistance heaters to give the option of adding thermal energy to the pebble bed storage during utility off-peak periods, thus offering considerable load management capability. A 15 KW electric resistance duct heater is used to add thermal energy to the pebble bin as required during off-peak periods. Hourly thermal performance and on site weather data was taken for the period November 1, 1979, to April 13, 1980. Thermal performance data consists of heat flow summations for all modes of the system, pebble bed temperatures, and space temperature. Weather data consists of dry bulb temperature, dew point temperature, total global insolation (in the plane of the collector), and wind speed and direction. An error analysis was performed and the least accurate of the measurements was determined to be the heat flow at 5%. Solar system thermal performance factor was measured to be 8.77. The heat pump thermal performance factor was 1.64. Total system seasonal performance factor was measured to be 1.66. Using a modified version of TRNSYS, the thermal performance of this system was simulated. When simulation results were compared with data collected onsite, the predicted heat flow and power consumption generally were within experimental accuracy.

Effect of Body Mass Index on Postoperative Transfusions and 24-Hour Chest-Tube Output

Science.gov (United States)

Nolan, Heather R.; Ramaiah, Chandrashekhar

2011-01-01

An increasing obese population in the United States focuses attention on the effect of obesity on surgical outcomes. Our objective was to see if obesity, determined by body mass index (BMI), contributed to bleeding in coronary artery bypass graft (CABG) surgery as measured by intraoperative and postoperative packed red blood cell transfusion frequency and amount and 24-hour chest-tube output. A retrospective chart review examined 150 subjects undergoing single-surgeon off-pump or on-pump CABG surgery between September 2006 and April 2009. BMI groups included normal-weight (BMI trend based on BMI group (p = 0.054). The percentage of subjects receiving transfusions in the combined intraoperative or 72-hour postoperative period showed a decreasing linear trend based on BMI group (p = 0.054). The transfusion amount during the 72-hour postoperative period varied significantly between BMI groups (p = 0.021), and the test for a linear decrease across groups was significant (p = 0.020). Twenty-four hour chest-tube output showed variation across all three BMI categories (p = 0.018) with chest-tube output decreasing with increasing obesity in a linear fashion (p = 0.006). Transfusion rate and amount indicate total blood loss is decreased in the obese, and chest-tube output findings give a direct measurable indicator of blood loss from the surgical site indicating increasing BMI is linearly correlated with decreasing postoperative bleeding. PMID:22654469

Pumps and pump facilities. 2. ed.

International Nuclear Information System (INIS)

Bohl, W.; Bauerfeind, H.; Gutmann, G.; Leuschner, G.; Matthias, H.B.; Mengele, R.; Neumaier, R.; Vetter, G.; Wagner, W.

1981-01-01

This book deals with the common fundamental aspects of liquid pumps and gives an exemplary choice of the most important kinds of pumps. The scientific matter is dealt with by means of practical mathematical examples among other ways of presenting the matter. Survey of contents: Division on main operational data of pumps - pipe characteristics - pump characteristics - suction behaviour of the pumps - projecting and operation of rotary pumps - boiler feed pumps - reactor feed pumps - oscillating positive-displacement pumps - eccentric spiral pumps. (orig./GL) [de

Does topical tranexamic acid reduce postcoronary artery bypass graft bleeding?

Directory of Open Access Journals (Sweden)

Amir Mirmohammadsadeghi

2018-01-01

Full Text Available Background: Postoperative bleeding is a common problem in cardiac surgery. We tried to evaluate the effect of topical tranexamic acid (TA on reducing postoperative bleeding of patients undergoing on-pump coronary artery bypass graft (CABG surgery. Materials and Methods: One hundred and twenty-six isolated primary CABG patients were included in this clinical trial. They were divided blindly into two groups; Group 1, patients receiving 1 g TA diluted in 100 ml normal saline poured into mediastinal cavity before closing the chest and Group 2, patients receiving 100 ml normal saline at the end of operation. First 24 and 48 h chest tube drainage, hemoglobin decrease and packed RBC transfusion needs were compared. Results: Both groups were the same in baseline characteristics including gender, age, body mass index, ejection fraction, clamp time, bypass time, and operation length. During the first 24 h postoperatively, mean chest tube drainage in intervention group was 567 ml compared to 564 ml in control group (P = 0.89. Mean total chest tube drainage was 780 ml in intervention group and 715 ml in control group (P = 0.27. There was no significant difference in both mean hemoglobin decrease (P = 0.26 and packed RBC transfusion (P = 0.7. Topical application of 1 g TA diluted in 100 ml normal saline does not reduce postoperative bleeding of isolated on-pump CABG surgery. Conclusion: We do not recommend topical usage of 1 g TA diluted in 100 ml normal saline for decreasing blood loss in on-pump CABG patients.

Pleural subxyphoid drain confers better pulmonary function and clinical outcomes in chronic obstructive pulmonary disease after off-pump coronary artery bypass grafting: a randomized controlled trial

Directory of Open Access Journals (Sweden)

Solange Guizilini

2014-12-01

Full Text Available Objective: To evaluate the lung function and clinical outcome in severe chronic obstructive pulmonary disease in patients undergoing off-pump coronary artery bypass grafting with left internal thoracic artery graft, comparing the pleural drain insertion in the intercostal versus subxyphoid region. Methods: A randomized controlled trial. Chronic obstructive pulmonary disease patients were randomized into two groups according pleural drain site: II group (n=27 - pleural drain in intercostal space; SI group (n=29 - pleural drain in the subxyphoid region. Spirometry values (Forced Vital Capacity - and Forced expiratory volume in 1 second were obtained on preoperative and 1, 3 and 5 postoperative days. Chest x-ray from preoperative until postoperative day 5 (POD5 was performed for monitoring respiratory events, such as atelectasis and pleural effusion. Pulmonary shunt fraction and pain score was evaluate preoperatively and on postoperative day 1. Results: In both groups there was a significant decrease of the spirometry values (Forced Vital Capacity and Forced expiratory volume in 1 second until POD5 (P<0.05. However, when compared, SI group presented less decrease in these parameters (P<0.05. Pulmonary shunt fraction was significantly lower in SI group (P<0.05. Respiratory events, pain score, orotracheal intubation time and postoperative length of hospital stay were lower in the SI group (P<0.05. Conclusion: Subxyphoid pleural drainage in severe Chronic obstructive pulmonary disease patients determined better preservation and recovery of pulmonary capacity and volumes with lower pulmonary shunt fraction and better clinical outcomes on early postoperative off-pump coronary artery bypass grafting.

River Debris Management System using Off-Grid Photovoltaic Module

Directory of Open Access Journals (Sweden)

Saadon Intan Mastura

2017-01-01

Full Text Available In Malaysia, Malacca River has long been the tourism attraction in Malacca. However, due to negligence, the river has been polluted by the litters thrown by tourists and even local residents, thus reflects a negative perception on Malacca. Therefore, this paper discusses about a fully automated river debris management system development using a stand-alone photovoltaic system. The concept design is to be stand alone in the river and automatically pull debris towards it for disposal. An off-grid stand-alone photovoltaic solar panel is used as renewable energy source connected to water pump and Arduino Uno microcontroller. The water pump rotates a water wheel and at the same time moves a conveyor belt; which is connected to the water wheel by a gear for debris collection. The solar system sizing suitable for the whole system is shown in this paper. The dumpster barge is equipped with an infrared sensor to monitor maximum height for debris, and instruct Arduino Uno to turn off the water pump. This system is able to power up using solar energy on sunny days and using battery otherwise.

Impact Of Secondary-Primary Pumps Operating Sequence On The Electrical Power Supply System

International Nuclear Information System (INIS)

Suwoto; Rusdiyanto; Kiswanto

2001-01-01

The operating procedure of the reactor cooling system has decided that the primary cooling pump should be operated before secondary cooling pump as known primary-secondary pumps operating sequence. This decision is based on consideration that starting current of the primary pump is higher than secondary pump. Therefore, the primary-secondary pumps operating sequence can avoid the power supply system failure. However, this operating procedure has to take a consequence that in case of primary pump failure, the shutdown time period of the reaktor to be longer caused to re operate the primary pump has required that the running secondary pump should be shutted off. To solve this problem, an impact analysis of the secondary-primary pumps operating sequence on the electric power supply system was carried out to identify the revision possibility of the cooling pump operating procedure. The analysis by discussion of the measuring results of the secondary and primary pump starting current related to another electrical loads has been measured. From discussion it can be concluded that secondary-primary pumps operating sequence has no impact to failure in electric power supply system

Affordable Hybrid Heat Pump Clothes Dryer

Energy Technology Data Exchange (ETDEWEB)

TeGrotenhuis, Ward E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Butterfield, Andrew [Jabil, St. Petersburg, FL (United States); Caldwell, Dustin D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Crook, Alexander [Jabil, St. Petersburg, FL (United States)

2016-06-30

This project was successful in demonstrating the feasibility of a step change in residential clothes dryer energy efficiency by demonstrating heat pump technology capable of 50% energy savings over conventional standard-size electric dryers with comparable drying times. A prototype system was designed from off-the-shelf components that can meet the project’s efficiency goals and are affordable. An experimental prototype system was built based on the design that reached 50% energy savings. Improvements have been identified that will reduce drying times of over 60 minutes to reach the goal of 40 minutes. Nevertheless, the prototype represents a step change in efficiency over heat pump dryers recently introduced to the U.S. market, with 30% improvement in energy efficiency at comparable drying times.

Time trends in coronary revascularization procedures among people with COPD: analysis of the Spanish national hospital discharge data (2001–2011

Directory of Open Access Journals (Sweden)

de Miguel-Díez J

2015-10-01

Full Text Available Javier de Miguel-Díez,1 Rodrigo Jiménez-García,2 Valentín Hernández-Barrera,2 Pilar Carrasco-Garrido,2 Héctor Bueno,3 Luis Puente-Maestu,1 Isabel Jimenez-Trujillo,2 Alejandro Alvaro-Meca,2 Jesús Esteban-Hernandez,2 Ana López de Andrés21Pneumology Department, Hospital General Universitario Gregorio Marañón, Universidad Complutense de Madrid, Madrid, Spain; 2Preventive Medicine and Public Health Teaching and Research Unit, Department of Health Sciences, Health Sciences Faculty, Rey Juan Carlos University, Alcorcón, Madrid, Spain; 3Centro Nacional de Investigaciones Cardiovasculares, Instituto de investigación i+12, Cardiology Department, Hospital Universitario 12 de Octubre, Universidad Complutense de Madrid, Madrid, SpainBackground: People with COPD suffering from coronary artery disease are frequently treated with revascularization procedures. We aim to compare trends in the use and outcomes of these procedures in COPD and non-COPD patients in Spain between 2001 and 2011.Methods: We identified all patients who had undergone percutaneous coronary interventions (PCIs and coronary artery bypass graft (CABG surgeries, using national hospital discharge data. Discharges were grouped into: COPD and no COPD.Results: From 2001 to 2011, 428,516 PCIs and 79,619 CABGs were performed. The sex and age-adjusted use of PCI increased by 21.27% per year from 2001 to 2004 and by 5.47% per year from 2004 to 2011 in patients with COPD. In-hospital mortality (IHM among patients with COPD who underwent a PCI increased significantly from 2001 to 2011 (odds ratio 1.11; 95% confidence interval 1.03–1.20. Among patients with COPD who underwent a CABG, the sex and age-adjusted CABG incidence rate increased by 9.77% per year from 2001 to 2003, and then decreased by 3.15% through 2011. The probability of dying during hospitalization in patients who underwent a CABG did not change significantly in patients with and without COPD (odds ratio, 1.06; 95

Parallel pumping of a ferromagnetic nanostripe: Confinement quantization and off-resonant driving

Science.gov (United States)

Yarbrough, P. M.; Livesey, K. L.

2018-01-01

The parametric excitation of spin waves in a rectangular, ferromagnetic nanowire in the parallel pump configuration and with an applied field along the long axis of the wire is studied theoretically, using a semi-classical and semi-analytic Hamiltonian approach. We find that as a function of static applied field strength, there are jumps in the pump power needed to excite thermal spin waves. At these jumps, there is the possibility to non-resonantly excite spin waves near kz = 0. Spin waves with negative or positive group velocity and with different standing wave structures across the wire width can be excited by tuning the applied field. By using a magnetostatic Green's function that depends on both the nanowire's width and thickness—rather than just its aspect ratio—we also find that the threshold field strength varies considerably for nanowires with the same aspect ratio but of different sizes. Comparisons between different methods of calculations are made and the advantages and disadvantages of each are discussed.

Pump-To-Signal Intensity Modulation Transfer Characteristics in FOPAs: Modulation Frequency and Saturation Effect

DEFF Research Database (Denmark)

Lali-Dastjerdi, Zohreh; Cristofori, Valentina; Lund-Hansen, Toke

2012-01-01

This paper reports a comprehensive study of pump- to-signal intensity modulation transfer (IMT) in single-pump fiber optic parametric amplifiers (FOPAs). In particular, the IMT is studied for the first time for high-frequency fluctuations of the pump as well as in the saturated gain regime. The IMT...... cut-off frequency in typical single-pump FOPAs is around 100–200 GHz. The possibilities to shift this frequency based on dispersion and nonlinearities involved in the parametric gain are discussed. The severe IMT to the signal at low modulation frequencies can be suppressed by more than 50...

Tolerance of centrifuge-simulated suborbital spaceflight in subjects with implanted insulin pumps.

Science.gov (United States)

Levin, Dana R; Blue, Rebecca S; Castleberry, Tarah L; Vanderploeg, James M

2015-04-01

With commercial spaceflight comes the possibility of spaceflight participants (SFPs) with significant medical conditions. Those with previously untested medical conditions, such as diabetes mellitus (DM) and the use of indwelling medical devices, represent a unique challenge. It is unclear how SFPs with such devices will react to the stresses of spaceflight. This case report describes two subjects with Type I DM using insulin pumps who underwent simulated dynamic phases of spaceflight via centrifuge G force exposure. Two Type I diabetic subjects with indwelling Humalog insulin pumps, a 23-yr-old man averaging 50 u of Humalog daily and a 27-yr-old man averaging 60 u of Humalog daily, underwent seven centrifuge runs over 48 h. Day 1 consisted of two +Gz runs (peak = +3.5 Gz, run 2) and two +Gx runs (peak = +6.0 Gx, run 4). Day 2 consisted of three runs approximating suborbital spaceflight profiles (combined +Gx and +Gz). Data collected included blood pressure, electrocardiogram, pulse oximetry, neurovestibular evaluation, and questionnaires regarding motion sickness, disorientation, greyout, and other symptoms. Neither subject experienced adverse clinical responses to the centrifuge exposure. Both maintained blood glucose levels between 110-206 mg · dl(-1). Potential risks to SFPs with insulin pump dependent DM include hypo/hyperglycemia, pump damage, neurovestibular dysfunction, skin breakdown, and abnormal stress responses. A search of prior literature did not reveal any previous studies of individuals with DM on insulin pumps exposed to prolonged accelerations. These cases suggest that individuals with conditions dependent on continuous medication delivery might tolerate the accelerations anticipated for commercial spaceflight.

Effect of milrinone on short term outcome of patients with myocardial dysfunction undergoing off-pump coronary artery bypass graft: a randomized clinical trial.

Science.gov (United States)

Hadadzadeh, Mehdi; Hosseini, Seyed Habib; Mostafavi Pour Manshadi, Seyed Mohammad Yousof; Naderi, Nafiseh; Emami Meybodi, Mahmood

2013-01-01

Myocardial dysfunction is a major complication in cardiac surgery that needs inotropic support. This study evaluates the effect of milrinone on patients with low ventricular ejection fraction undergoing off- pump coronary artery bypass graft (OPCAB). The present study is designed to evaluate the effect of milrinone on myocardial dysfunction. Eighty patients with low ventricular ejection fraction (milrinone (50 μg/kg) intravenously and another group received a saline as placebo followed by 24 hours infusion of each agent (0.5 μg/kg/min). Short outcome of patients such as hemodynamic parameters and left ventricular ejection fraction were variables evaluated. Serum levels of creatine phosphokinase, the MB isoenzyme of creatine kinase, occurrence of arrhythmias and mean duration of mechanical ventilation were significantly lower in milrinone group (P<0.05). The mean post operative left ventricular ejection fraction was significantly higher in milrinone group (P=0.031). There were no statistical significant differences between the two groups in terms of intra-aortic balloon pump, inotropic support requirement, myocardial ischemia, myocardial infarction, duration of inotropic support, duration of intensive care unit stay, mortality and morbidity rate. Administration of milrinone in patients undergoing OPCAB with low ventricular ejection fraction is useful and effective.

Hydraulic design and optimization of a modular pump-turbine runner

International Nuclear Information System (INIS)

Schleicher, W.C.; Oztekin, A.

2015-01-01

Highlights: • A modular pumped-storage scheme using elevated water storage towers is investigated. • The pumped-storage scheme also aides in the wastewater treatment process. • A preliminary hydraulic pump-turbine runner design is created based on existing literature. • The preliminary design is optimized using a response surface optimization methodology. • The performance and flow fields between preliminary and optimized designs are compared. - Abstract: A novel modular pumped-storage scheme is investigated that uses elevated water storage towers and cement pools as the upper and lower reservoirs. The scheme serves a second purpose as part of the wastewater treatment process, providing multiple benefits besides energy storage. A small pumped-storage scheme has been shown to be a competitive energy storage solution for micro renewable energy grids; however, pumped-storage schemes have not been implemented on scales smaller than megawatts. Off-the-shelf runner designs are not available for modular pumped-storage schemes, so a custom runner design is sought. A preliminary hydraulic design for a pump-turbine runner is examined and optimized for increased pumping hydraulic efficiency using a response surface optimization methodology. The hydraulic pumping efficiency was found to have improved by 1.06% at the best efficiency point, while turbine hydraulic efficiency decreased by 0.70% at the turbine best efficiency point. The round-trip efficiency for the system was estimated to be about 78%, which is comparable to larger pumped-storage schemes currently in operation

The assessment of neural injury following open heart surgery by physiological tremor analysis.

Science.gov (United States)

Németh, Adám; Hejjel, László; Ajtay, Zénó; Kellényi, Lóránd; Solymos, Andor; Bártfai, Imre; Kovács, Norbert; Lenkey, Zsófia; Cziráki, Attila; Szabados, Sándor

2013-02-21

The appearance of post-operative cognitive dysfunction as a result of open heart surgery has been proven by several studies. Focal and/or sporadic neuron damage emerging in the central nervous system may not only appear as cognitive dysfunction, but might strongly influence features of physiological tremor. We investigated 110 patients (age: 34-73 years; 76 male, 34 female; 51 coronary artery bypass grafting (CABG), 25 valve replacement, 25 combined open heart surgery, 9 off-pump CABG) before surgery and after open-heart surgery on the 3(rd) to 5(th) post-operative day. The assessment of the physiological tremor analysis was performed with our newly developed equipment based on the Analog Devices ADXL 320 JPC integrated accelerometer chip. Recordings were stored on a PC and spectral analysis was performed by fast Fourier transformation (FFT). We compared power integrals in the 1-4 Hz, 4-8 Hz and 8-12 Hz frequency ranges and these were statistically assessed by the Wilcoxon rank correlation test. We found significant changes in the power spectrum of physiological tremor. The spectrum in the 8-12 Hz range (neuronal oscillation) decreased and a shift was recognised to the lower spectrum (p open heart surgery.

Saltwater Upconing and Decay Beneath a Well Pumping Above an Interface Zone

Energy Technology Data Exchange (ETDEWEB)

Zhou, Quanlin; Bear, Jacob; Bensabat, Jacob

2004-04-20

Saltwater, or brine, underlies fresh water in many aquifers, with a transition zone separating them. Pumping fresh water by wells located above the transition zone produces upconing of the latter, eventually salinizing the pumped water, forcing shut-off. The salinity of the pumped water depends on the pumping rate, on the location of the well's screen, on the fresh water flow regime, and on the difference in density between fresh and salt water, expressed as a dimensionless factor called density difference factor (DDF). Following the well's shut-off, the upconed saltwater mound undergoes decay, tending to return to the pre-pumping regime. In this paper, the upconing-decay processes in an axially symmetrical system are investigated to discover how they are affected by the DDF and by the dispersivities. The code FEAS-Brine, developed for the simulation of coupled density-dependent flow and salt transport, is used. In this code, the flow equation is solved by the Galer:wqkin finite element method (FEM), while the advective-dispersive salt transport equation is solved in the Eulerian-Lagrangian framework. This code does not suffer from the instability constraint on the Peclet number in the vicinity of the pumping well, where advection dominates the salt transport. Simulation results show that upconing is very sensitive to the DDF, which, in our work, is in the range from 0 (for ideal tracer) to 0.2 (for brine). It is shown that for the DDF of 0.025 (for seawater), local upconing occurs only for low iso-salinity surfaces, while those of high salt concentration, practically, do not shift toward the pumping well. For an ideal tracer, all iso-salinity surfaces rise toward the pumping well. For brine, however, only iso-salinity surfaces of very low salinity upcone towards the pumping well. The decay process is lengthy; it takes a long time for the upconed saltwater to migrate back to the original horizontal transition zone prior to pumping. However, the wider

Comparison of different lubricating oil pump systems for combustion engines. Vergleich verschiedener Schmieroelpumpen-Systeme bei Verbrennungsmotoren

Energy Technology Data Exchange (ETDEWEB)

Eisenmann, S; Haerle, C; Schreiber, B

1994-10-01

The present day and future legislative requirements with regard to fuel consumption and improvement of emission values are forcing the automotive industry to continually improve its technology. However, the investments made in such technical innovations should be set-off by the results. The lubricating oil pump can make an important contribution with optimum design and through the choice of the most adequate pump system. Over the last 17 years, SHW has worked very closely with the automotive industry on the development of lubricating oil pumps. One of the results of this research work is a Suction Regulated Pump (SRP) which distinguishes itself from conventional pumps through its lower drive power. We will proceed to explain this pump system, comparing it with the present day pump systems. (orig.)

Rock bed storage with heat pump. Final report

Energy Technology Data Exchange (ETDEWEB)

Remmers, H.E.; Mills, G.L.

1979-05-01

The study, Rock Bed Storage with Heat Pump, established the feasibility of mating a heat pump to a rock bed storage to effect optimal performance at the lowest cost in single family residences. The operating characteristics of off-the-shelf components of heat pump/rock bed storage systems were studied, and the results were used to formulate configurations of representative systems. These systems were modeled and subsequently analyzed using the TRNSYS computer program and a life cycle cost analysis program called LCCA. A detailed load model of a baseline house was formulated as part of the TRNSYS analysis. Results of the analysis involved the development of a technique to confine the range of heat pump/rock bed storage systems to those systems which are economical for a specific location and set of economic conditions. Additionally, the results included a comparison of the detailed load model with simple UA models such as the ASHRAE bin method. Several modifications and additions were made to the TRNSYS and LCCA computer programs during the course of the study.

Leukocyte filtration and miniature perfusion during arrested heart CABG on a Jehovah's Witness patient.

Science.gov (United States)

Sutton, Steven W; Duncan, Michael A; Chase, Virginia A; Cheung, Edson H; Hamman, B L

2004-11-01

Bloodless surgery and a reduction in the use of allogeneic blood products has long been the standard of care in medicine. Many individuals in our communities have demanded this form of surgical treatment for personal and religious reasons. On 6 December 2002, a 72-year-old male patient was admitted to our institution as a critical air flight transfer. The patient's height was 190.5 cm and weight was 59.3 kg (body surface area 1.83 m2). His preliminary diagnosis was chest pain with myocardial infarction as evidenced by elevated blood cardiac isoenzymes. His principle diagnosis was subendocardial infarction with paroxysmal ventricular tachycardia. Cardiac catheterization was performed and demonstrated severe triple vessel disease with an ejection fraction of 30%. He was evaluated and accepted as a candidate for coronary artery bypass grafting. Multidisciplinary consultation concluded that a safe and effective method of perioperative treatment would involve the use of arrested heart support with cold blood cardioplegia using a low prime miniature perfusion circuit as no blood products would be considered for use. Additionally, the combined modalities of perfusion interventions to minimize hemodilution consisted of intraoperative autologous blood collection totaling 500 mL and rapid autologous priming of the miniature perfusion circuit. The miniature perfusion system was a low prime Cardiovention (Santa Clara, CA) CORx device which includes a hollow-fiber oxygenator and integral centrifugal pump with a surface area of 1.2 m2. This system also incorporates an air sensing solenoid which triggers rapid air evacuation in a bolus range of 1 mL or greater. Kinetic venous drainage is another feature of this device as the centrifugal pump is integrated into the oxygenator. We believed that a miniature extracorporeal circuit would enhance the desired clinical outcome as opposed to the risk of: (1) off-pump coronary artery bypass (OPCAB) approach and the concern of emergent

Power deposition to the pump limiters in Tore-Supra with ohmic plasmas

International Nuclear Information System (INIS)

Guilhem, D.; Chatelier, M.; Chappuis Fleury, I.; Klepper, C.

1990-01-01

The modification of power scrape-off-length, λq, and power deposition are studied both with the horizontal limiter alone and with the full set of 7 pump limiters for 1MW ohmic plasmas in TORE-SUPRA. By making spatially resolved infrared surface temperature measurements during the plasma discharge, the magnitude and distribution of the energy flux can be derived. For comparison, the surface temperature of the horizontal pump limiter is calculated with a finite element code using a 3D description of the field lines, an exponential scrape-off-layer, and the pump limiter geometry. From comparison of the infrared images of the limiter we derived that the λq for power deposition was slightly less than 9 mm (±1mm) which is in agreement with the predicted design value of 10 mm. For an 8 seconds discharge, the maximum surface temperature on the horizontal limiter is 450 0 C. Inserting the 7 limiters does not modify λq (which becomes 10 mm). The power is shared by all the limiters and the maximum surface temperature on the horizontal limiter decreased to 320 0 C. These λq values have been independently measured by the integrated energy deposition on the horizontal limiter and other internal structures 5 cm into the scrape-off layer. These values agree with the infrared measurements in the two cases

Impact of Spatial Pumping Patterns on Groundwater Management

Science.gov (United States)

Yin, J.; Tsai, F. T. C.

2017-12-01

Challenges exist to manage groundwater resources while maintaining a balance between groundwater quantity and quality because of anthropogenic pumping activities as well as complex subsurface environment. In this study, to address the impact of spatial pumping pattern on groundwater management, a mixed integer nonlinear multi-objective model is formulated by integrating three objectives within a management framework to: (i) maximize total groundwater withdrawal from potential wells; (ii) minimize total electricity cost for well pumps; and (iii) attain groundwater level at selected monitoring locations as close as possible to the target level. Binary variables are used in the groundwater management model to control the operative status of pumping wells. The NSGA-II is linked with MODFLOW to solve the multi-objective problem. The proposed method is applied to a groundwater management problem in the complex Baton Rouge aquifer system, southeastern Louisiana. Results show that (a) non-dominated trade-off solutions under various spatial distributions of active pumping wells can be achieved. Each solution is optimal with regard to its corresponding objectives; (b) operative status, locations and pumping rates of pumping wells are significant to influence the distribution of hydraulic head, which in turn influence the optimization results; (c) A wide range of optimal solutions is obtained such that decision makers can select the most appropriate solution through negotiation with different stakeholders. This technique is beneficial to finding out the optimal extent to which three objectives including water supply concern, energy concern and subsidence concern can be balanced.

Performance of a 10 kilowatt wind-electric water pumping system for irrigating crops

Energy Technology Data Exchange (ETDEWEB)

Vick, B.D.; Clark, R.N. [Conservation and Production Research Lab., Bushland, TX (United States); Molla, S. [Texas A& M Univ., College Station, TX (United States)

1997-12-31

A 10 kW wind-electric water pumping system was tested for field crop irrigation at pumping depths from 50 to 120 m. The wind turbine for this system used a permanent magnet alternator that powered off-the-shelf submersible motors and pumps without the use of an inverter. Pumping performance was determined at the USDA-Agricultural Research Service (ARS), Wind Energy Laboratory in Bushland, TX for the 10 kW wind turbine using a pressure valve and a pressure tank to simulate different pumping depths. Pumping performance was measured for two 10 kW wind turbines of the same type at farms near the cities of Garden City, TX and Stiles, TX. The pumping performance data collected at these actual wells compared favorably with the data collected at the USDA-ARS, Wind Energy Laboratory. If utility generated electricity was accessible, payback on the wind turbine depended on the cost of utility generated electricity and the transmission line extension cost.

Automated Weaning from Mechanical Ventilation after Off-Pump Coronary Artery Bypass Grafting.

Science.gov (United States)

Fot, Evgenia V; Izotova, Natalia N; Yudina, Angelika S; Smetkin, Aleksei A; Kuzkov, Vsevolod V; Kirov, Mikhail Y

2017-01-01

The discontinuation of mechanical ventilation after coronary surgery may prolong and significantly increase the load on intensive care unit personnel. We hypothesized that automated mode using INTELLiVENT-ASV can decrease duration of postoperative mechanical ventilation, reduce workload on medical staff, and provide safe ventilation after off-pump coronary artery bypass grafting (OPCAB). The primary endpoint of our study was to assess the duration of postoperative mechanical ventilation during different modes of weaning from respiratory support (RS) after OPCAB. The secondary endpoint was to assess safety of the automated weaning mode and the number of manual interventions to the ventilator settings during the weaning process in comparison with the protocolized weaning mode. Forty adult patients undergoing elective OPCAB were enrolled into a prospective single-center study. Patients were randomized into two groups: automated weaning ( n  = 20) using INTELLiVENT-ASV mode with quick-wean option; and protocolized weaning ( n  = 20), using conventional synchronized intermittent mandatory ventilation (SIMV) + pressure support (PS) mode. We assessed the duration of postoperative ventilation, incidence and duration of unacceptable RS, and the load on medical staff. We also performed the retrospective analysis of 102 patients (standard weaning) who were weaned from ventilator with SIMV + PS mode based on physician's experience without prearranged algorithm. Realization of the automated weaning protocol required change in respiratory settings in 2 patients vs. 7 (5-9) adjustments per patient in the protocolized weaning group. Both incidence and duration of unacceptable RS were reduced significantly by means of the automated weaning approach. The FiO 2 during spontaneous breathing trials was significantly lower in the automated weaning group: 30 (30-35) vs. 40 (40-45) % in the protocolized weaning group ( p  ventilation in a more protective way, reduces the

Large-scale integration of off-shore wind power and regulation strategies of cogeneration plants in the Danish electricity system

DEFF Research Database (Denmark)

Østergaard, Poul Alberg

2005-01-01

The article analyses how the amount of a small-scale CHP plants and heat pumps and the regulation strategies of these affect the quantity of off-shore wind power that may be integrated into Danish electricity supply......The article analyses how the amount of a small-scale CHP plants and heat pumps and the regulation strategies of these affect the quantity of off-shore wind power that may be integrated into Danish electricity supply...

Magnetic heat pumping near room temperature

Science.gov (United States)

Brown, G. V.

1976-01-01

It is shown that magnetic heat pumping can be made practical at room temperature by using a ferromagnetic material with a Curie point at or near operating temperature and an appropriate regenerative thermodynamic cycle. Measurements are performed which show that gadolinium is a resonable working material and it is found that the application of a 7-T magnetic field to gadolinium at the Curie point (293 K) causes a heat release of 4 kJ/kg under isothermal conditions or a temperature rise of 14 K under adiabatic conditions. A regeneration technique can be used to lift the load of the lattice and electronic heat capacities off the magnetic system in order to span a reasonable temperature difference and to pump as much entropy per cycle as possible

Renal Dysfunction after Off-Pump Coronary Artery Bypass Surgery- Risk Factors and Preventive Strategies

Directory of Open Access Journals (Sweden)

Gaurab Maitra

2009-01-01

Full Text Available Postoperative renal dysfunction is a relatively common and one of the serious complications of cardiac surgery. Though off-pump coronary artery bypass surgery technique avoids cardiopulmonary bypass circuit induced adverse effects on renal function, multiple other factors cause postoperative renal dysfunction in these groups of patients. Acute kidney injury is generally defined as an abrupt and sustained decrease in kidney function. There is no consen-sus on the amount of dysfunction that defines acute kidney injury, with more than 30 definitions in use in the literature today. Although serum creatinine is widely used as a marker for changes in glomerular filtration rate, the criteria used to define renal dysfunction and acute renal failure is highly variable. The variety of definitions used in clinical studies may be partly responsible for the large variations in the reported incidence. Indeed, the lack of a uniform definition for acute kidney injury is believed to be a major impediment to research in the field. To establish a uniform definition for acute kidney injury, the Acute Dialysis Quality Initiative formulated the Risk, Injury, Failure, Loss, and End-stage Kidney (RIFLE classification. RIFLE , defines three grades of increasing severity of acute kidney injury -risk (class R, injury (class I and failure (class F - and two outcome classes (loss and end-stage kidney disease. Various perioperative risk factors for postoperative renal dysfunction and failure have been identified. Among the important preoperative factors are advanced age, reduced left ventricular function, emergency surgery, preoperative use of intraaortic balloon pump, elevated preoperative serum glucose and creatinine. Most important intraoperative risk factor is the intraoperative haemodynamic instability and all the causes of postoperative low output syndrome com-prise the postoperative risk factors. The most important preventive strategies are the identification of the

WEXA: exergy analysis for increasing the efficiency of air/water heat pumps - Final report

Energy Technology Data Exchange (ETDEWEB)

Gasser, L.; Wellig, B.; Hilfiker, K.

2008-04-15

This comprehensive final report for the Swiss Federal Office of Energy (SFOE) presents the results of a study at the made by the Engineering and Architecture department at the Lucerne University of Applied Sciences and Arts. The subject of the WEXA study (Waermepumpen-Exergie-Analyse - heat pump exergy analysis) is the analysis of the operation of air/water heat-pumps using exergy analysis methods. The basic thermodynamics of heating systems using heat-pumps is discussed. The exergy analyses and exergy balances for the various components and processes of an air/water heat-pump are presented and discussed. Comparisons are presented for heat-pumps with on/off and continuous control systems for their compressors and fans. The paper is concluded with a collection of appendices on the subject.

Pumping behavior of sputter ion pumps

International Nuclear Information System (INIS)

Chou, T.S.; McCafferty, D.

The ultrahigh vacuum requirements of ISABELLE is obtained by distributed pumping stations. Each pumping station consists of 1000 l/s titanium sublimation pump for active gases (N 2 , H 2 , O 2 , CO, etc.), and a 20 l/s sputter ion pump for inert gases (methane, noble gases like He, etc.). The combination of the alarming production rate of methane from titanium sublimation pumps (TSP) and the decreasing pumping speed of sputter ion pumps (SIP) in the ultrahigh vacuum region (UHV) leads us to investigate this problem. In this paper, we first describe the essential physics and chemistry of the SIP in a very clean condition, followed by a discussion of our measuring techniques. Finally measured methane, argon and helium pumping speeds are presented for three different ion pumps in the range of 10 -6 to 10 -11 Torr. The virtues of the best pump are also discussed

Numerical Simulation of Tubular Pumping Systems with Different Regulation Methods

Science.gov (United States)

Zhu, Honggeng; Zhang, Rentian; Deng, Dongsheng; Feng, Xusong; Yao, Linbi

2010-06-01

Since the flow in tubular pumping systems is basically along axial direction and passes symmetrically through the impeller, most satisfying the basic hypotheses in the design of impeller and having higher pumping system efficiency in comparison with vertical pumping system, they are being widely applied to low-head pumping engineering. In a pumping station, the fluctuation of water levels in the sump and discharge pool is most common and at most time the pumping system runs under off-design conditions. Hence, the operation of pump has to be flexibly regulated to meet the needs of flow rates, and the selection of regulation method is as important as that of pump to reduce operation cost and achieve economic operation. In this paper, the three dimensional time-averaged Navier-Stokes equations are closed by RNG κ-ɛ turbulent model, and two tubular pumping systems with different regulation methods, equipped with the same pump model but with different designed system structures, are numerically simulated respectively to predict the pumping system performances and analyze the influence of regulation device and help designers make final decision in the selection of design schemes. The computed results indicate that the pumping system with blade-adjusting device needs longer suction box, and the increased hydraulic loss will lower the pumping system efficiency in the order of 1.5%. The pumping system with permanent magnet motor, by means of variable speed regulation, obtains higher system efficiency partly for shorter suction box and partly for different structure design. Nowadays, the varied speed regulation is realized by varied frequency device, the energy consumption of which is about 3˜4% of output power of the motor. Hence, when the efficiency of variable frequency device is considered, the total pumping system efficiency will probably be lower.

Development and Evaluation of Care Programs for the Delirium Management in Patients after Coronary Artery Bypass Graft Surgery (CABG

Directory of Open Access Journals (Sweden)

Safoora Fallahpoor

2016-07-01

Full Text Available Delirium is one of the common problems of cognitive impairment after coronary artery bypass graft surgery (CABG that its prevention, timely detection, and treatment require a care and management program to be controlled. The present research has studied a care program for the management of delirium in patients after coronary artery bypass graft surgery. This research was performed by action research methodology during a fivestage cycle in two groups of 50 persons (without interference and with intervention. In both groups, the patients were evaluated every 8 hours by CAM-ICU tool in hours (6, 14 and 22 for the occurrence of delirium after surgery until they were in Intensive Care Unit (ICU. In the intervention group, the developed program was implemented in three areas of delirium management before, during, and after the surgery. Then, the collected information was analyzed in two groups using descriptive and analytical statistics in SPSS 20 software. Delirium was observed at least once in 68% of patients without the intervention and 38% of patients with intervention after surgery. The ratio of delirium incidence was significantly lower in the intervention group (P<0.05. In addition, the total number of delirium in ICU was significantly lower for patients in the intervention group (P<0.05.The developed program for reducing the incidence of delirium in hospitalized patients after coronary artery bypass graft surgery (CABG was confirmed. This means that its applying will lead to a reduction in delirium.

Laser Diode Pumped Solid State Lasers

Science.gov (United States)

1987-01-01

Report N66001-83-C-0071, 17 April 1986, prepared for NOSC. 4.6 W.T. Welford, R. Winston , "The Option of Nonimaging Concentrators ," Academic Press, 1978...by non-imac optics such as reflective or refractive flux concentrators . Simple considerations regarding the optimum pumping configuration, high marks...reduced if the arrays can stand-off from the Nd:YAG laser. As mentioned before, compound parabolic concentrators or refractive optics cat employed to

Influencing factors for early acute cerebrovascular accidents in patients with stroke history following off-pump coronary artery bypass grafting.

Science.gov (United States)

Wang, Bin; Jia, Ming; Jia, Shijie; Wan, Jiuhe; Zhou, Xiao; Luo, Zhimin; Zhou, Ye; Zhang, Jianqun

2014-06-01

To analyse risk factors for early acute cerebrovascular accidents following off-pump coronary artery bypass grafting (OPCAB) in patients with stroke history, and to propose preventive measures to reduce the incidence of these events. A total of 468 patients with a history of stroke underwent OPCAB surgery in Beijing Anzhen Hospital of China from January 2010 to September 2012. They were retrospectively divided into two groups according to the occurrence of early acute cerebrovascular accidents within 48 hours following OPCAB. Multivariate logistic regression analysis was used to find risk or protective factors for early acute cerebrovascular accidents following the OPCAB. Fifty-two patients (11.1%) suffered from early acute cerebrovascular accidents in 468 patients, including 39 cases of cerebral infarction, two cases of cerebral haemorrhage, 11 cases of transient ischaemic attack (TIA). There were significant differences between the two groups in preoperative left ventricular ejection fraction ≤ 35%, severe bilateral carotid artery stenosis, poorly controlled hypertension, intraoperative application of Enclose® II proximal anastomotic device, postoperative acute myocardial infarction, atrial fibrillation, hypotension, ventilation time > 48h, ICU duration >48h and mortality. Multivariate logistic regression analysis showed that preoperative severe bilateral carotid stenosis (OR=6.378, 95%CI: 2.278-20.987) and preoperative left ventricular ejection fraction ≤ 35% (OR=2.737, 95%CI: 1.267-6.389), postoperative acute myocardial infarction (OR=3.644, 95%CI: 1.928-6.876), postoperative atrial fibrillation (OR=3.104, 95%CI:1.135∼8.016) and postoperative hypotension (OR=4.173, 95%CI: 1.836∼9.701) were independent risk factors for early acute cerebrovascular accidents in patients with a history of stroke following OPCAB procedures, while intraoperative application of Enclose® II proximal anastomotic device was protective factor (OR=0.556, 95%CI: 0.337-0.925). This

Photonic crystal fibers for supercontinuum generation pumped by a gain-switched CW fiber laser

DEFF Research Database (Denmark)

Larsen, Casper; Noordegraaf, Danny; Hansen, Kim P.

2012-01-01

Supercontinuum generation in photonics crystal fibers (PCFs) pumped by CW lasers yields high spectral power density and average power. However, such systems require very high pump power and long nonlinear fibers. By on/off modulating the pump diodes of the fiber laser, the relaxation oscillations...... of the laser can be exploited to enhance the broadening process. The physics behind the supercontinuum generation is investigated by sweeping the fiber length, the zero dispersion wavelength, and the fiber nonlinearity. We show that by applying gain-switching a high average output power of up to 30 W can...

Relationship between Angiotensin Converting Enzyme, Apelin, and New-Onset Atrial Fibrillation after Off-Pump Coronary Artery Bypass Grafting

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Shu Xu

2017-01-01

Full Text Available It has been shown that inflammation and oxidative stress are important factors in postoperative atrial fibrillation (POAF. Angiotensin converting enzyme (ACE and apelin have a close relationship with inflammation and oxidative stress. The effect of ACE and apelin on POAF after off-pump coronary artery bypass grafting (OPCABG remains a question. The concentrations of serum ACE, angiotensin II (Ang II, apelin, bradykinin (BK, malondialdehyde (MDA, and C reactive protein (CRP were measured in the perioperative period of OPCABG. The levels of serum ACE in the POAF group were higher than in the no POAF group both preoperatively and postoperatively. Apelin in the POAF group was lower than in the no POAF group. There was a correlation between serum ACE and apelin. Postoperatively, CRP and MDA in the POAF group were higher than in the no POAF group; however, there was no difference before the operation. Preoperative ACE and apelin were both significant and independent risk factors for POAF. In conclusion, the high ACE and low apelin preoperatively led to CRP and MDA being increased postoperatively, which was probably associated with POAF after OPCABG. Apelin may be a new predictor for POAF.

Open-Lung Ventilation Improves Clinical Outcomes in Off-Pump Coronary Artery Bypass Surgery: A Randomized Controlled Trial.

Science.gov (United States)

Bolzan, Douglas W; Trimer, Renata; Begot, Isis; Nasrala, Mara L S; Forestieri, Patricia; Mendez, Vanessa M F; Arena, Ross; Gomes, Walter J; Guizilini, Solange

2016-06-01

To compare pulmonary function, functional capacity, and clinical outcomes among conventional mechanical ventilation (CMV), early open-lung (EOL), and late open-lung (LOL) strategies after off-pump coronary artery bypass surgery (OPCAB). Prospective, randomized, and double-blinded study. Two hospitals of the Federal University of Sao Paulo, Brazil. Ninety-three patients undergoing elective first-time OPCAB. Patients were randomized into 3 groups: CMV (n=31); LOL (n=32) initiated upon intensive care unit (ICU) arrival; EOL (n = 30) initiated after intubation. Spirometry was performed at bedside preoperatively and on postoperative days (PODs) 1, 3, and 5. Partial pressure of arterial oxygen (PaO2) and pulmonary shunt fraction were evaluated presurgically and on POD 1; 6-minute walk test (6MWT) was performed presurgically and on POD 5. Both open-lung groups demonstrated higher forced vital capacity and forced expiratory volume in 1 second on PODs 1, 3 and 5 compared to the CMV group (pLOL groups were compared. Both open-lung strategies were able to promote higher pulmonary function preservation and greater recovery of functional capacity with better clinical outcomes after OPCAB. No difference in outcome was found when comparing initiation of OLS intraoperatively or after ICU arrival. Copyright © 2016 Elsevier Inc. All rights reserved.

Clinical utility of carotid duplex ultrasound prior to cardiac surgery.

Science.gov (United States)

Lin, Judith C; Kabbani, Loay S; Peterson, Edward L; Masabni, Khalil; Morgan, Jeffrey A; Brooks, Sara; Wertella, Kathleen P; Paone, Gaetano

2016-03-01

Clinical utility and cost-effectiveness of carotid duplex examination prior to cardiac surgery have been questioned by the multidisciplinary committee creating the 2012 Appropriate Use Criteria for Peripheral Vascular Laboratory Testing. We report the clinical outcomes and postoperative neurologic symptoms in patients who underwent carotid duplex ultrasound prior to open heart surgery at a tertiary institution. Using the combined databases from our clinical vascular laboratory and the Society of Thoracic Surgery, a retrospective analysis of all patients who underwent carotid duplex ultrasound within 13 months prior to open heart surgery from March 2005 to March 2013 was performed. The outcomes between those who underwent carotid duplex scanning (group A) and those who did not (group B) were compared. Among 3233 patients in the cohort who underwent cardiac surgery, 515 (15.9%) patients underwent a carotid duplex ultrasound preoperatively, and 2718 patients did not (84.1%). Among the patients who underwent carotid screening vs no screening, there was no statistically significant difference in the risk factors of cerebrovascular disease (10.9% vs 12.7%; P = .26), prior stroke (8.2% vs 7.2%; P = .41), and prior transient ischemic attack (2.9% vs 3.3%; P = .24). For those undergoing isolated coronary artery bypass grafting (CABG), 306 (17.8%) of 1723 patients underwent preoperative carotid duplex ultrasound. Among patients who had carotid screening prior to CABG, the incidence of carotid disease was low: 249 (81.4%) had minimal or mild stenosis (duplex scanning and those who did not. Primary outcomes of patients who underwent open heart surgery also showed no difference in the perioperative mortality (5.1% vs 6.9%; P = .14) and stroke (2.6% vs 2.4%; P = .85) between patients undergoing preoperative duplex scanning and those who did not. Operative intervention of severe carotid stenosis prior to isolated CABG occurred in 2 of the 17 patients (11.8%) identified who

An analytical model for neutral and charged particles in closed pump limiter

International Nuclear Information System (INIS)

Tokar, M.Z.

1990-01-01

In number of modern tokamaks pump limiters are used for control of the edge plasma parameters. In thermonuclear reactor projects pump limiters are considered as a possible alternative or additional for divertor configuration of magnetic field method for unburnt fuel, helium ash and other impurity exhaust. From the point of view of limiter operation efficiency the dependence of neutral particle pressure P g in pumping system on the plasma parameters in the scrape-off layer (SOL) is of importance since an increase of P g will permit to decrease needed pump rate and facilitate solution of reactor technological problems. In connection with this the experimentally observed mode of closed pump limiter operation with strong neutral compression is of great interest. In such a mode P g sharply grows up when the SOL plasma density n s exceeds some critial level. (author) 6 refs., 2 figs

Evaluation of load case ''switch-off of the high pressure pump of the emergency core cooling system'', measures of verification and in situ-test

International Nuclear Information System (INIS)

Trobitz, M.; Mattheis, A.; Kerkhof, K.; Hippelein, K.; Hofstoetter, P.

1998-01-01

Within the framework of periodic safety inspection of the Gundremmingen power station (RWE-Bayernwerk - KRB II), the load collectives used for the design of safety-relevant systems and components were checked for their consistency with latest updates of the design basis. It was found that there was no analytical information or study available describing a particular process and its effects, namely switch-off of the high-pressure feedwater pump of the emergency core cooling system. The paper reports the work performed for closing the gap, including preparatory analyses, accompanying measures such as vibration measurements during plant shut-down, as well as the preparation and performance of the in-situ test. The experimental results and the comparative evaluation of calculated and experimental data are presented. (orig./CB) [de

Relationship of plasma level of NT- ProBNP with development of AF in CABG patients

Directory of Open Access Journals (Sweden)

Tanaray B

2010-10-01

Full Text Available "nBackground: Studies of the association between post operative AF and Plasma level of NT- Pro BNP have reported conflicting findings. The aim of the present study was evaluation of the association between post coronary bypass graft- Atrial Fibrillation (AF and Plasma level of NT- ProBNP as an independent risk factor of AF development in patients undergoing coronary artery bypass graft."n "nMethods: In a cohort study, 79 patients with sinus rhythm who admitted in Imam Khomeini Hospital in Tehran, Iran, during February 2009 and February 2010 for CABG are included the study and followed for developing post operative AF rhythm."n "nResults: Post operative AF was found in 17.7% of patients. The peak time from the operation to the first AF episode was in second post op day in ten patients (71.4%. The serum level of ProBNP in patients with AF was significantly higher (1624± 647 versus 221± 238 pg/ml, p< 0/0001. Increased age, Increased LA size and high plasma level of ProBNP were associated with increased risk for post op AF. After adjustment of risk factors, plasma level of ProBNP was the most important risk factor with odds ratio of 15.34 with CI 95% 1.77-132.95 and then LA diameter with odds ratio of 6.11 with CI 95% 0.99-37.42 was independently correlated with post op AF. Correlation between plasma level of ProBNP with age and LA size was seen too (LA size r = 0.0281, p= 0.012. Between age and ProBNP (r= 0.337, p= 0.002. The best cut off point for plasma ProBNP as a predictor of post op AF was 854 pg/ml."n "nConclusion: Increased level of preoperative ProBNP levels could be an independent predictor of post operative Atrial Fibrillation.

National trends in utilization and outcomes of coronary revascularization procedures among people with and without type 2 diabetes in Spain (2001–2011)

Science.gov (United States)

2014-01-01

Background Diabetes is associated with a high risk of death due to coronary artery disease (CAD). People with diabetes suffering from CAD are frequently treated with revascularization procedures. We aim to compare trends in the use and outcomes of coronary revascularization procedures in diabetic and non-diabetic patients in Spain between 2001 and 2011. Methods We identified all patients who had undergone coronary revascularization procedures, percutaneous coronary interventions (PCI) and coronary artery bypass graft (CABG) surgeries, using national hospital discharge data. Discharges were grouped by diabetes status: type 2 diabetes and no diabetes. The incidence of discharges attributed to coronary revascularization procedures were calculated stratified by diabetes status. We calculated length of stay and in-hospital mortality (IHM). We apply joinpoint log-linear regression to identify the years in which changes in tendency occurred in the use of PCI and CABG in diabetic and non-diabetic patients. Multivariate analysis was adjusted by age, sex, year and comorbidity (Charlson comorbidity index). Results From 2001 to 2011, 434,108 PCIs and 79,986 CABGs were performed. According to the results of the joinpoint analysis, we found that sex and age-adjusted use of PCI increased by 31.4% per year from 2001 to 2003, by 15.9% per year from 2003 to 2006 and by 3.8% per year from 2006 to 2011 in patients with diabetes. IHM among patients with diabetes who underwent a PCI did not change significantly over the entire study period (OR 0.99; 95% CI 0.97-1.00). Among patients with diabetes who underwent a CABG, the sex and age-adjusted CABG incidence rate increased by 10.4% per year from 2001 to 2003, and then decreased by 1.1% through 2011. Diabetic patients who underwent a CABG had a 0.67 (95% CI 0.63-0.71) times lower probability of dying during hospitalization than those without diabetes. Conclusions The annual percent change in PCI procedures increased in diabetic and non

National trends in utilization and outcomes of coronary revascularization procedures among people with and without type 2 diabetes in Spain (2001-2011).

Science.gov (United States)

Lopez-de-Andres, Ana; Jimenez-García, Rodrigo; Hernandez-Barrera, Valentin; Perez-Farinos, Napoleon; de Miguel-Yanes, Jose M; Mendez-Bailon, Manuel; Jimenez-Trujillo, Isabel; de Miguel, Angel Gil; Pino, Carmen Gallardo; Carrasco-Garrido, Pilar

2014-01-03

Diabetes is associated with a high risk of death due to coronary artery disease (CAD). People with diabetes suffering from CAD are frequently treated with revascularization procedures. We aim to compare trends in the use and outcomes of coronary revascularization procedures in diabetic and non-diabetic patients in Spain between 2001 and 2011. We identified all patients who had undergone coronary revascularization procedures, percutaneous coronary interventions (PCI) and coronary artery bypass graft (CABG) surgeries, using national hospital discharge data. Discharges were grouped by diabetes status: type 2 diabetes and no diabetes. The incidence of discharges attributed to coronary revascularization procedures were calculated stratified by diabetes status. We calculated length of stay and in-hospital mortality (IHM). We apply joinpoint log-linear regression to identify the years in which changes in tendency occurred in the use of PCI and CABG in diabetic and non-diabetic patients. Multivariate analysis was adjusted by age, sex, year and comorbidity (Charlson comorbidity index). From 2001 to 2011, 434,108 PCIs and 79,986 CABGs were performed. According to the results of the joinpoint analysis, we found that sex and age-adjusted use of PCI increased by 31.4% per year from 2001 to 2003, by 15.9% per year from 2003 to 2006 and by 3.8% per year from 2006 to 2011 in patients with diabetes. IHM among patients with diabetes who underwent a PCI did not change significantly over the entire study period (OR 0.99; 95% CI 0.97-1.00).Among patients with diabetes who underwent a CABG, the sex and age-adjusted CABG incidence rate increased by 10.4% per year from 2001 to 2003, and then decreased by 1.1% through 2011. Diabetic patients who underwent a CABG had a 0.67 (95% CI 0.63-0.71) times lower probability of dying during hospitalization than those without diabetes. The annual percent change in PCI procedures increased in diabetic and non-diabetic patients. Higher comorbidity and

Experimental Study of Unshrouded Impeller Pump Stage Sensitivity to Tip Clearance

Science.gov (United States)

Williams, Robert W.; Zoladz, Thomas; Storey, Anne K.; Skelley, Stephen E.

2002-01-01

This viewgraph presentation provides information on an experiment. Its objective is to experimentally determine unshrouded impeller performance sensitivity to tip clearance. The experiment included: Determining impeller efficiency at scaled operating conditions in water at MSFC's Pump Test Equipment (PTE) Facility; Testing unshrouded impeller at three different tip clearances; Testing each tip clearance configuration at on- and off-design conditions, and collecting unsteady- and steady-state data in each configuration; Determining impeller efficiency directly using drive line torquemeter and pump inlet and exit total pressure measurements.

Effect of milrinone on short term outcome of patients with myocardial dysfunction undergoing off-pump coronary artery bypass graft: a randomized clinical trial.

Directory of Open Access Journals (Sweden)

Mehdi Hadadzadeh

2013-10-01

Full Text Available Myocardial dysfunction is a major complication in cardiac surgery that needs inotropic support. This study evaluates the effect of milrinone on patients with low ventricular ejection fraction undergoing off- pump coronary artery bypass graft (OPCAB. The present study is designed to evaluate the effect of milrinone on myocardial dysfunction. Eighty patients with low ventricular ejection fraction (<35%, candidate for elective OPCAB, were enrolled in this study. They were randomly assigned to two groups. One group received milrinone (50 μg/kg intravenously and another group received a saline as placebo followed by 24 hours infusion of each agent (0.5 μg/kg/min. Short outcome of patients such as hemodynamic parameters and left ventricular ejection fraction were variables evaluated. Serum levels of creatine phosphokinase, the MB isoenzyme of creatine kinase, occurrence of arrhythmias and mean duration of mechanical ventilation were significantly lower in milrinone group (P<0.05. The mean post operative left ventricular ejection fraction was significantly higher in milrinone group (P=0.031. There were no statistical significant differences between the two groups in terms of intra-aortic balloon pump, inotropic support requirement, myocardial ischemia, myocardial infarction, duration of inotropic support, duration of intensive care unit stay, mortality and morbidity rate. Administration of milrinone in patients undergoing OPCAB with low ventricular ejection fraction is useful and effective.

Delay in admission for elective coronary-artery bypass grafting is associated with increased in-hospital mortality

Directory of Open Access Journals (Sweden)

Levy Adrian R

2008-09-01

Full Text Available Abstract Background Many health care systems now use priority wait lists for scheduling elective coronary artery bypass grafting (CABG surgery, but there have not yet been any direct estimates of reductions in in-hospital mortality rate afforded by ensuring that the operation is performed within recommended time periods. Methods We used a population-based registry to identify patients with established coronary artery disease who underwent isolated CABG in British Columbia, Canada. We studied whether postoperative survival during hospital admission for CABG differed significantly among patients who waited for surgery longer than the recommended time, 6 weeks for patients needing semi-urgent surgery and 12 weeks for those needing non-urgent surgery. Results Among 7316 patients who underwent CABG, 97 died during the same hospital admission, for a province-wide death rate at discharge of 1.3%. The observed proportion of patients who died during the same admission was 1.0% (27 deaths among 2675 patients for patients treated within the recommended time and 1.5% (70 among 4641 for whom CABG was delayed. After adjustment for age, sex, anatomy, comorbidity, calendar period, hospital, and mode of admission, patients with early CABG were only 2/3 as likely as those for whom CABG was delayed to experience in-hospital death (odds ratio 0.61; 95% confidence interval [CI] 0.39 to 0.96. There was a linear trend of 5% increase in the odds of in-hospital death for every additional month of delay before surgery, adjusted OR = 1.05 (95% CI 1.00 to 1.11. Conclusion We found a significant survival benefit from performing surgical revascularization within the time deemed acceptable to consultant surgeons for patients requiring the treatment on a semi-urgent or non-urgent basis.

Pre-operative high sensitive C-reactive protein predicts cardiovascular events after coronary artery bypass grafting surgery: A prospective observational study

Directory of Open Access Journals (Sweden)

Balciunas Mindaugas

2009-01-01

Full Text Available C-reactive protein is a powerful independent predictor of cardiovascular events in patients with coronary artery disease. The relation between C-reactive protein (CRP concentration and in-hospital outcome, after coronary artery bypass grafting (CABG, has not yet been established. The study aims to evaluate the predictive value of pre-operative CRP for in-hospital cardiovascular events after CABG surgery. High-sensitivity CRP (hs-CRP levels were measured pre-operatively on the day of surgery in 66 patients scheduled for elective on pump CABG surgery. Post-operative cardiovascular events such as death from cardiovascular causes, ischemic stroke, myocardial damage, myocardial infarction and low output heart failure were recorded. During the first 30 days after surgery, 54 patients were free from observed events and 14 developed the following cardiovascular events: 10 (15% had myocardial damage, four (6% had low output heart failure and two (3% suffered stroke. No patients died during the follow-up period. Serum concentration of hs-CRP ≥ 3.3 mg/l (cut-off point obtained by ROC analysis was related to higher risk of post-operative cardiovascular events (36% vs 6%, P = 0.01, myocardial damage (24% vs 6%, P = 0.04 and low output heart failure (12% vs 0%, P = 0.04. Multivariate logistic regression analysis showed that hs-CRP ≥ 3.3 mg/l ( P = 0.002, O.R.: 19.3 (95% confidence interval (CI 2.9-128.0, intra-operative transfusion of red blood cells ( P = 0.04, O.R.: 9.9 (95% C.I. 1.1-85.5 and absence of diuretics in daily antihypertensive treatment ( P = 0.02, O.R.: 15.1 (95% C.I. 1.4-160.6 were independent predictors of combined cardiovascular event. Patients having hs-CRP value greater or equal to 3.3 mg/l pre-operatively have an increased risk of post-operative cardiovascular events after on pump coronary artery bypass grafting surgery.

A Phase-Controlled Optical Parametric Amplifier Pumped by Two Phase-Distorted Laser Beams

International Nuclear Information System (INIS)

Hong-Yan, Ren; Lie-Jia, Qian; Peng, Yuan; He-Yuan, Zhu; Dian-Yuan, Fan

2010-01-01

We theoretically study the phase characteristic of optical parametric amplification (OPA) or chirped pulse OPA (OPCPA) pumped by two phase-distorted laser beams. In the two-beam-pumped optical parametric amplification (TBOPA), due to spatial walk-off, both of the pump phase distortions will be partly transferred to signal in a single crystal so as to degrade the signal beam-quality, which will be more serious in high-energy OPCPA. An OPA configuration with a walkoff-compensated crystal pair is demonstrated for reducing the signal phase distortion experienced in the first stage and ensuring the signal phase independent of two pump phase distortions through the second crystal, hence maintaining the signal beam-quality. Such a TBOPA is similar to the conventional quantum laser amplifier by means of eliminating its sensitivity to the phase and number of the pump beams

REMOTE CONTROLLING OF AN AGRICULTURAL PUMP SYSTEM BASED ON THE DUAL TONE MULTI-FREQUENCY (DTMF TECHNIQUE

Directory of Open Access Journals (Sweden)

BEZA N. GETU

2015-10-01

Full Text Available In modern days, as a result of advances in technology, human beings are interested to remotely control different systems and applications. In this work, telephone signalling technique using Dual Tone Multi-Frequency (DTMF signalling, is used to control switching of electrical loads such as agricultural pumps located in remote areas. A DTMF tone command sent from a transmitting fixed or mobile phone terminal will be used to SWITCH ON/OFF the motors used to pump water for agricultural fields. A processing electronic system at the receiving side is designed to interpret the tone commands and sends an appropriate signal to the motor driving circuit to complete the pump switching states. In the design methodology, it is possible to control several water pumps distributed in a certain agricultural site, however, in this work we considered four pumps and the paper presents the complete electronic design and simulation results at the different stages of the design. The electronic design is based on discrete passive and active electronic components and the system is tested and simulated using Multism program. The results of the simulation show that the design is capable of controlling the switching state of the motors. For a certain DTMF command, it is possible to switch ON/OFF a specific motor pump or all of the four motors.

On the relationship between competitive flow and FFT analysis of the flow waves in the left internal mammary artery graft in the process of CABG.

Science.gov (United States)

Mao, Boyan; Wang, Wenxin; Zhao, Zhou; Zhao, Xi; Li, Lanlan; Zhang, Huixia; Liu, Youjun

2016-12-28

During coronary artery bypass grafting (CABG), the ratio of powers of the fundamental frequency and its first harmonic (F0/H1) in fast Fourier transformation (FFT) analysis of the graft's flow waves has been used in the field of evaluation of the patency in anastomosis. But there is no report about using the FFT method to evaluate the magnitude of competitive flow. This study is aiming at exploring the relationship between competitive flow and FFT analysis of the flow waves in left internal mammary artery (LIMA) graft, and finding a new method to evaluate the magnitude of competitive flow. At first, establishing the CABG multiscale models of different stenosis in left anterior descending artery (LAD) to get different magnitude of competitive flows. Then, calculating the models by ANSYS-CFX and getting the flow waves in LIMA. Finally, analyzing the flow waves by FFT method and comparing the FFT results with the magnitude of competitive flow. There is no relationship between competitive flow and F0/H1. As for F0/H2 and F0/H3, they both increase with the reduction of the stenosis in LAD. But the increase of F0/H3 is not obviously enough and it can't identify the significant competitive flow clearly, so it can't be used as the evaluation index. It is found that F0/H2 increases obviously with the increase of the competitive flow and can identify the significant competitive flow. The FFT method can be used in the evaluation of competitive flow and the F0/H2 is the ideal index. High F0/H2 refers to the significant competitive flow. This method can be used during CABG to avoid the risk of competitive flow.

Design and development of a split-evaporator heat-pump system

Energy Technology Data Exchange (ETDEWEB)

Somerville, M.H.; Penoncello, S.G.

1981-12-01

The designs and experimental results of three types of multiple source heat pumps are presented. The three designs are the parallel evaporator, the series evaporator, and the parallel evaporator with active subcooling, with the parallel evaporator with the active subcooling showing the most promise for solving the problem of defrosting of air evaporators. Three design procedures for multiple source heat pumps were developed. One of these is a hand calculational procedure, the others are computer based. The models are based upon the refrigerant flow rate, rather than the refrigeration effect of the evaporator. The technical results of a detailed analytical and experimental model of the heat transfer rates on a flat plate ice maker are presented. It is shown, both analytically and experimentally, that the temperature of the air surrounding the flat plate ice maker can play a dominant role in the rate of ice formation. A detailed weather analysis for forty cities located throughout the nation was completed. These data were processed to allow easy computation of thermal storage requirements for full, partial, or minimum ACES systems, or upon other design requirements, such as off-peak air conditioning. The results of an innovative ice storage system that is thermally coupled to the earth are described. This system has the potential for meeting both the off-peak air conditioning needs and the thermal storage requirements for the heating cycle. An economic and energy comparison of multiple source heat pumps with ACES, and air-to-air heat pump systems is presented.

Improvement of exercise ventricular function in patients of coronary artery bypass surgery

International Nuclear Information System (INIS)

Kawasuji, Michio; Sawa, Shigeharu; Tedoriya, Takeo; Iwa, Takashi; Taki, Jun-ichi; Bunkou, Hisashi

1989-01-01

Thirty-five patients underwent exercise blood pool scintigraphy before and 4 weeks after coronary artery bypass graft (CABG). Left ventricular ejection fraction (EF), peak ejection rate (PER), peak filling rate (PFR), and one third peak filling rate (1/3 FR) were calculated. Exercise-induced EF was significantly higher after than before CABG (+2.4±6.1% vs -3.9±7.3%). Irrespective of exercise, preoperative PER was unchanged. Postoperative exercise significantly increased PER from 2.88±0.71 sec -1 to 3.85±0.85 sec -1 (p<0.01). Exercise also significantly increased PFR after GABG when compared with that before GABF. 1/3FR did not differ before and after CABG. Exercise blood pool scintigraphy was useful in evaluating ventricular function before and after CABG. (Namekawa, K)

The efficacy of a lidocaine-infused pain pump for postoperative analgesia following elective augmentation mammaplasty or abdominoplasty.

Science.gov (United States)

Chavez-Abraham, Victor; Barr, Jason S; Zwiebel, Paul C

2011-08-01

Postoperative pain management following aesthetic plastic surgery traditionally has been achieved by systemic administration of several narcotic pain medications. Because this method can lead to undesirable side effects such as sedation, nausea, vomiting, and respiratory depression, a more efficacious method of postoperative analgesia with fewer side effects needs to be implemented in outpatient cosmetic surgery. From March of 2003 until December of 2008, 690 patients underwent augmentation mammaplasty and 215 patients underwent abdominoplasty. All of these patients were equipped with an elastomeric continuous infusion pump postoperatively and were prescribed oral narcotics. Prior to 2003, patients were prescribed only oral narcotics postoperatively. A retrospective chart review of patients before and after implementation of the pain pump was undertaken to review the perceived pain patients experienced postoperatively with and without the pump. The self-administration of oral narcotics was also assessed. Patients equipped with the pain pump experienced a statistically significant decrease in perceived pain compared to those without the pump (augmentation mammaplasty: 2.27 vs. 3.68, p use of the oral narcotic Vicodin™ at 72 h postoperatively (5 mg hydrocodone/500 mg acetaminophen, Abbott Laboratories, Abbott Park, IL) (augmentation mammaplasty: 26.5 mg/2650 mg vs. 49 mg/4900 mg, p reduce both the amount of pain patients experience and the quantity of narcotics used postoperatively.

Low plasma edge temperatures for the self-pumped limiter

International Nuclear Information System (INIS)

Terry, W.K.; Brooks, J.N.

1985-03-01

Transport code calculations have been performed to study the operation of an INTOR-like tokamak plasma from which helium is removed by a self-pumped limiter, which traps helium, but not hydrogen, in its surface layers. To prevent saturation by helium, the surface is renewed by continuous injection of the surface material (vanadium in this study) into the scrape-off layer. The presence of the injected vanadium leads to plasma temperatures well below 50 eV in the scrape-off layer, with supplementary rf heating. Operation in this edge temperature regime is essential for the use of medium- and high-Z limiter coatings

Criteria for definition of regional functional improvement on quantitative post-stress gated myocardial SPET after bypass surgery in patients with ischaemic cardiomyopathy

International Nuclear Information System (INIS)

Lee, Dong Soo; Cheon, Gi Jeong; Paeng, Jin Chul; Chung, June-Key; Lee, Myung Chul; Kim, Ki Bong

2002-01-01

Myocardial viability can be defined as functional improvement of dysfunctional myocardium after revascularization. The purpose of this study was to define the optimal criteria for definition of regional functional improvement after coronary artery bypass graft (CABG) surgery on quantitative gated single-photon emission tomography (SPET). Thirty-two patients (26 men, 6 women; age 56±13 years) with coronary artery disease (three-vessel disease, 17; two-vessel disease, 15; previous history of myocardial infarction, 9) and severe left ventricular dysfunction (LVEF≤35%) underwent CABG. Rest thallium-201/dipyridamole stress technetium-99m methoxyisobutylisonitrile gated myocardial SPET was performed before and 3 months after CABG. Global LV functional improvement was defined as either an improvement in LVEF of 10% (n=15) or an improvement in LVEF of 5% combined with a decrease in end-systolic volume of 10 ml (n=2) after CABG on quantitative gated SPET. Postoperative regional wall thickening improvement (ΔRWT), regional wall motion improvement (ΔRWM) and regional resting (ΔRP) and stress perfusion improvement (ΔRstrP) were used to determine global functional improvement by ROC curve analysis, and the optimal criteria for definition of viable regional dysfunctional myocardium were defined on the ROC curves. Correlations were verified by determining the number of improved myocardial regions and LVEF improvement. LVEF was improved from 25%±6% to 34%±11% after CABG. A total of 229 segments were dysfunctional (wall motion ≤2 mm, thickening ≤20%) before CABG. On ROC curve analysis using global functional improvement as an indicator of viability, the areas under the ROC curves (AUCs) of ΔRWT and ΔRWM were 0.717 and 0.620, respectively. The AUC of ΔRWT was significantly larger than that of ΔRWM (P=0.009) and the optimal cut-off value of ΔRWT was 15%. The AUCs of ΔRP and ΔRstrP were not significant. The correlation coefficients between summed ΔRWT and �

Design of a high-pressure circulating pump for viscous liquids.

Science.gov (United States)

Seifried, Bernhard; Temelli, Feral

2009-07-01

The design of a reciprocating dual action piston pump capable of circulating viscous fluids at pressures of up to 34 MPa (5000 psi) and temperatures up to 80 degrees C is described. The piston of this pump is driven by a pair of solenoids energized alternatively by a 12 V direct current power supply controlled by an electronic controller facilitating continuously adjustable flow rates. The body of this seal-less pump is constructed using off-the-shelf parts eliminating the need for custom made parts. Both the electronic controller and the pump can be assembled relatively easily. Pump performance has been evaluated at room temperature (22 degrees C) and atmospheric pressure using liquids with low and moderately high viscosities, such as ethanol and corn oil, respectively. At ambient conditions, the pump delivered continuous flow of ethanol and corn oil at a flow rate of up to 170 and 17 cm3/min, respectively. For pumping viscous fluids comparable to corn oil, an optimum reciprocation frequency was ascertained to maximize flow rate. For low viscosity liquids such as ethanol, a linear relationship between the flow rate and reciprocation frequency was determined up to the maximum reciprocation frequency of the pump. Since its fabrication, the pump has been used in our laboratory for circulating triglycerides in contact with supercritical carbon dioxide at pressures of up to 25 MPa (3600 psi) and temperatures up to 70 degrees C on a daily basis for a total of more than 1500 h of operation functioning trouble free.

Making effective use of rod pumping systems in coalbed methane applications

Energy Technology Data Exchange (ETDEWEB)

Crivello, A. [eProduction Solutions Inc., Kingwood, TX (United States)

2003-07-01

The advantages of optimizing coalbed methane (CBM) operations are increased production, reduced expenses, improved efficiency, and better inventory. The author discussed the CBM production cycle and the possible artificial lift options, including electric submersible pump (ESP), plunger lift, primary coolant pump (PCP), and reciprocating rod lift. The presentation focused on the rod lift, as it represents a low to moderate capital expenditure, has good system efficiency, an excellent fluid volume range, an excellent salvage value, excellent familiarity with equipment, and has readily available parts and service. The major disadvantage of the rod lift is that the fixed operating range does not adapt to changing reservoir characteristics. A comparison between the rod pump controller and the variable speed drive was presented. The well can be operated at or near the pumped off condition with variable speed drives with rod pumping intelligence. The author provided a closer examination of the variable frequency drive and the vector flux drive. The presentation also included a discussion of prime movers, drive and inclinometer, gearbox loading, rod load limiter, and dynamometer cards. Three case studies were presented: CSW1, CSW2, and CSW3. It was concluded that wells must be kept pumping, and that a Flux Vector Drive should be used along with an NEMA B motor and properly sized pumping unit and pump. tabs., figs.

Resonantly cladding-pumped Yb-free Er-doped LMA fiber laser with record high power and efficiency.

Science.gov (United States)

Zhang, Jun; Fromzel, Viktor; Dubinskii, Mark

2011-03-14

We report the results of our power scaling experiments with resonantly cladding-pumped Er-doped eye-safe large mode area (LMA) fiber laser. While using commercial off-the-shelf LMA fiber we achieved over 88 W of continuous-wave (CW) single transverse mode power at ~1590 nm while pumping at 1532.5 nm. Maximum observed optical-to-optical efficiency was 69%. This result presents, to the best of our knowledge, the highest power reported from resonantly-pumped Yb-free Er-doped LMA fiber laser, as well as the highest efficiency ever reported for any cladding-pumped Er-doped laser, either Yb-co-doped or Yb-free.

Adsorption pump for helium pumping out

International Nuclear Information System (INIS)

Donde, A.L.; Semenenko, Yu.E.

1981-01-01

Adsorption pump with adsorbent cooling by liquid helium is described. Shuttered shield protecting adsorbent against radiation is cooled with evaporating helium passing along the coil positioned on the shield. The pump is also equipped with primed cylindrical shield, cooled with liquid nitrogen. The nitrogen shield has in the lower part the shuttered shield, on the pump casing there is a valve used for pump pre-burning, and valves for connection to recipient as well. Pumping- out rates are presented at different pressures and temperatures of adsorbent. The pumping-out rate according to air at absorbent cooling with liquid nitrogen constituted 5x10 -4 Pa-3000 l/s, at 2x10 -2 Pa-630 l/s. During the absorbent cooling with liquid hydrogen the pumping-out rate according to air was at 4x10 -4 Pa-580 l/s, at 2x10 -3 Pa-680 l/s, according to hydrogen - at 8x10 -5 Pa-2500 l/s, at 5x10 -3 Pa-4200 l/s. During adsorbent cooling with liquid helium the rate of pumping-out according to hydrogen at 3x10 5 Pa-2400% l/s, at 6x10 3 Pa-1200 l/s, and according to helium at 3.5x10 -5 Pa-2800 l/s, at 4x10 -3 Pa-1150 l/s. The limit vacuum is equal to 1x10 -7 Pa. The volume of the vessel with liquid helium is equal to 3.5 l. Helium consumption is 80 cm 3 /h. Consumption of liquid nitrogen from the shield is 400 cm 3 /h. The limit pressure in the pump is obtained after forevacuum pumping-out (adsorbent regeneration) at 300 K temperature. The pump is made of copper. The pump height together with primed tubes is 800 mm diameter-380 mm [ru

A cryocondensation pump for the DIII-D Advanced Divertor Program

International Nuclear Information System (INIS)

Smith, J.P.; Baxi, C.; Reis, E.; Sevier, L.

1992-03-01

A cryocondensation pump was designed for the baffle chamber of General Atomics DIII-D tokamak and will be installed in the fall of 1992. The purpose of the pump is to study plasma density control by pumping the divertor. The pump is toroidally continuous, approximately 10 m long and located in the lower outer corner of the vacuum chamber of the machine. It consists of a 1 m 2 liquid helium-cooled surface surrounded by a liquid nitrogen-cooled shield to limit the heat load on the helium-cooled surface. The liquid nitrogen-cooled surface is surrounded by a radiation/particle shield to prevent energetic particles from impacting and releasing condensed water molecules. A thermal enhancement coating was applied to the nitrogen shell to lower the maximum temperature of the shell. The coating is non-continuous to keep the toroidal electrical resistance high. The whole pump is supported off the water-cooled vacuum vessel wall. Supports for the pump were designed to accommodate the thermal differences between the 4 K helium surface, the 77 K nitrogen shells, and the 300 K vacuum vessel supporting the pump and to provide a low heat leak structural support. Disruption loading on the pump was analyzed and a finite element structural analysis of the pump was completed. A testing program was completed to evaluate coating techniques to enhance heat transfer and emissivity of the various surfaces. Fabrication tests were performed to determine the best method of attaching the liquid nitrogen flow tubes to their shield surfaces and to determine the best alternative to fabricating the different shells of the pump. A prototype sector of the pump was built to verify fabrication and assembly techniques

Validating the EXCEL hypothesis: a propensity score matched 3-year comparison of percutaneous coronary intervention versus coronary artery bypass graft in left main patients with SYNTAX score ≤32.

Science.gov (United States)

Capodanno, Davide; Caggegi, Anna; Capranzano, Piera; Cincotta, Glauco; Miano, Marco; Barrano, Gionbattista; Monaco, Sergio; Calvo, Francesco; Tamburino, Corrado

2011-06-01

The aim of this study is to verify the study hypothesis of the EXCEL trial by comparing percutaneous coronary intervention (PCI) and coronary artery bypass graft (CABG) in an EXCEL-like population of patients. The upcoming EXCEL trial will test the hypothesis that left main patients with SYNTAX score ≤ 32 experience similar rates of 3-year death, myocardial infarction (MI), or cerebrovascular accidents (CVA) following revascularization by PCI or CABG. We compared the 3-year rates of death/MI/CVA and death/MI/CVA/target vessel revascularization (MACCE) in 556 patients with left main disease and SYNTAX score ≤ 32 undergoing PCI (n = 285) or CABG (n = 271). To account for confounders, outcome parameters underwent extensive statistical adjustment. The unadjusted incidence of death/MI/CVA was similar between PCI and CABG (12.7% vs. 8.4%, P = 0.892), while MACCE were higher in the PCI group compared to the CABG group (27.0% vs. 11.8%, P EXCEL-like cohort of patients with left main disease, there seems to be a clinical equipoise between PCI and CABG in terms of death/MI/CVA. However, even in patients with SYNTAX score ≤ 32, CABG is superior to PCI when target vessel revascularization is included in the combined endpoint. Copyright © 2011 Wiley-Liss, Inc.

Numerical study of pressure fluctuations in different guide vanes' opening angle in pump mode of a pump turbine

International Nuclear Information System (INIS)

Sun, Y K; Zuo, Z G; Liu, S H; Wu, Y L; Liu, J T

2012-01-01

A numerical model based on a pumped storage power station was built to develop the numerical simulation, to analyze the pressure fluctuations in a pump turbine in different guide vanes' opening angle. The different guide vanes' opening angles were simulated using the SST k-ω turbulence model and SIMPLEC Pressure-Velocity coupling scheme. The pressure sensor were placed in mainly three positions, they are: bottom ring between runner and the wicket gates, downstream and left side in the draft tube cone below the runner. All the peak to peak values of pressure fluctuation meet signal probability of 97%. The frequency is gained by Fast Fourier Transform. The pressure fluctuations in different positions of the model in pump condition were showed when the guide vanes' opening angels were different. The simulation results confirmed the results gained in model tests. The results show that pressure fluctuations in design opening angle were much lower than those in off design opening angle. The main source of pressure fluctuations between runner and guide vanes is rotor stator interaction. While a lower frequency is the main frequency of the pressure fluctuation in draft tube.

Predictive Factors for Delayed Extubation in the Intensive Care Unit after Coronary Artery Bypass Grafting; A Southern Iranian Experience

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Shahrbanoo Shahbazi

2012-12-01

Full Text Available Background: Early extubation is implemented in cardiothoracic units worldwide for its advantages such as decreased mortality, morbidity, and hospitalization costs. We conducted a retrospective study to evaluate potential factors which may affect extubation time. Methods: The records of 334 eligible patients who underwent elective coronary artery bypass grafting (CABG in 2008 in Kowsar Hospital in Shiraz, southern Iran were evaluated to find the factors that can affect the extubation time. The patients were divided to early (equal or less than 6 hours and late extubation groups. The patients’ demographic data and operative variables were extracted from the records. We excluded patients with difficult intubation, severe acid base disturbance, neurological problems, and cardiovascular instability; and those who used intra-aortic balloon pump, had underwent emergency operation, or had another concomitant surgery. Results: Multiple logistic regressions comparing age, sex, number of grafts, ejection fraction, pump time, hematocrit, number of risk factors, and number of inotropic drugs, identified only age as a predictor of delayed extubation (odds ratio=1.07, CI 95%=1.04-1.10, P<0.001. Also, in both studied groups the men to women ratio was higher (P<0.05.Conclusion: Although in our study age was the only predictive factor for delayed extubation, a comprehensive study including preoperative, perioperative, and postoperative factors is recommended in our area.

Pumping mechanisms in sputter-ion pumps low pressure operation

International Nuclear Information System (INIS)

Welch, K.M.

1991-01-01

It is shown that significant H 2 pumping occurs in the walls of triode pumps. Also, H 2 is pumped in the anode cells of sputter-ion pumps. This pumping occurs in a manner similar to that by which the inert gases are pumped. That is, H 2 is pumped in the walls of the anode cells by high energy neutral burial. Hydrogen in the pump walls and anodes limits the base pressure of the pump

Automated surveillance of reactor coolant pump performance

International Nuclear Information System (INIS)

Gross, K.C.; Singer, R.M.; Humenik, K.E.

1992-01-01

An artificial intelligence based expert system has been developed for continuous surveillance and diagnosis of centrifugal-type reactor coolant pump (RCP) performance and operability. The expert system continuously monitors digitized signals from a variety of physical variables (speed, vibration level, motor power, discharge pressure) associated with RCP performance for annunciation of the incipience or onset of off-normal operation. The system employs an extremely sensitive pattern-recognition technique, the sequential probability ratio test (SPRT) for rapid identification of pump operability degradation. The sequential statistical analysis of the signal noise has been shown to provide the theoretically shortest sampling time to detect disturbances and thus has the potential of providing incipient fault detection information to operators sufficiently early to avoid forced plant shutdowns. The sensitivity and response time of the expert system are analyzed in this paper using monte carlo simulation techniques

Pumping mechanisms in sputter-ion pumps low pressure operation

International Nuclear Information System (INIS)

Welch, K.M.

1991-01-01

It is shown that significant H 2 pumping occurs in the walls of triode pumps. Also, H 2 is pumped in the anode cells of sputter-ion pumps. This pumping occurs in a manner similar to that by which the inert gases are pumped. That is, H 2 pumped in the walls of the anode cells by high energy neutral burial. Hydrogen in the pump walls and anodes limits the base pressure of the pump. 13 refs., 5 figs., 1 tab

Comprehensive experimental and numerical analysis of instability phenomena in pump turbines

International Nuclear Information System (INIS)

Gentner, Ch; Sallaberger, M; Widmer, Ch; Bobach, B-J; Jaberg, H; Schiffer, J; Senn, F; Guggenberger, M

2014-01-01

The changes in the electricity market have led to changed requirements for the operation of pump turbines. Utilities need to change fast and frequently between pumping and generating modes and increasingly want to operate at off-design conditions for extended periods. Operation of the units in instable areas of the machine characteristic is not acceptable and may lead to self-excited vibration of the hydraulic system. In turbine operation of pump turbines unstable behaviour can occur at low load off-design operation close to runaway conditions (S-shape of the turbine characteristic). This type of instability may impede the synchronization of the machine in turbine mode and thus increase start-up and switch over times. A pronounced S-shaped instability can also lead to significant drop of discharge in the event of load rejection. Low pressure on the suction side and in the tail-race tunnel could cause dangerous separation of the water column. Understanding the flow features that lead to the instable behaviour of pump turbines is a prerequisite to the design of machines that can fulfil the growing requirements relating to operational flexibility. Flow simulation in these instability zones is demanding due to the complex and highly unsteady flow patterns. Only unsteady simulation methods are able to reproduce the governing physical effects in these operating regions. ANDRITZ HYDRO has been investigating the stability behaviour of pump turbines in turbine operation in cooperation with several universities using simulation and measurements. In order to validate the results of flow simulation of unstable operating points, the Graz University of Technology (Austria) performed detailed experimental investigations. Within the scope of a long term research project, the operating characteristics of several pump turbine runners have been measured and flow patterns in the pump turbine at speed no load and runaway have been examined by 2D Laser particle image velocimetry (PIV

System transient response to loss of off-site power

International Nuclear Information System (INIS)

Sozer, A.

1990-01-01

A simultaneous trip of the reactor, main circulation pumps, secondary coolant pumps, and pressurizer pump due to loss of off-site power at the High Flux Isotope Reactor (HFIR) located at the Oak Ridge National Laboratory (ORNL) has been analyzed to estimate available safety margin. A computer model based on the Modular Modeling System code has been used to calculate the transient response of the system. The reactor depressurizes from 482.7 psia down to about 23 psia in about 50 seconds and remains stable thereafter. Available safety margin has been estimated in terms of the incipient boiling heat flux ratio. It is a conservative estimate due to assumed less than available primary and secondary flows and higher than normal depressurization rate. The ratio indicates no incipient boiling conditions at the hot spot. No potential damage to the fuel is likely to occur during this transient. 2 refs., 6 figs

Clinical safety of magnetic resonance imaging in patients with implanted SynchroMed EL infusion pumps

International Nuclear Information System (INIS)

Diehn, Felix E.; Wood, Christopher P.; Watson, Robert E.; Hunt, Christopher H.; Mauck, William D.; Burke, Michelle M.

2011-01-01

Patients with implanted SynchroMed spinal infusion pumps (Medtronic, Inc., Minneapolis, MN) routinely undergo magnetic resonance imaging at our institution. In August 2008, Medtronic issued an urgent medical device correction report regarding several pumps. Because of the rare potential ''for a delay in the return of proper drug infusion'' and ''for a delay in the logging of motor stall events,'' ''a patient's pump must be interrogated after MRI exposure in order to confirm proper pump functionality.'' This is particularly important in patients receiving intrathecal baclofen, for whom a delay in return of proper pump infusion could lead to life-threatening baclofen withdrawal syndrome. The objective of this report is to present our experience and protocol of performing magnetic resonance imaging in patients with implanted SynchroMed EL pumps. We retrospectively reviewed records of 86 patients with implanted SynchroMed EL spinal infusion pumps who underwent 112 examinations on 1.5-T magnetic resonance imaging scanners from September 1, 1998 to July 7, 2004. No SynchroMed EL pumps were damaged by magnetic resonance imaging, and the programmable settings remained unchanged in all patients. Our data suggest that SynchroMed EL pump malfunction is indeed rare after routine clinical 1.5-T magnetic resonance imaging examinations. However, based on the Medtronic correction report, we perform pump interrogation before and after imaging. (orig.)

Benefits of ambulatory axillary intra-aortic balloon pump for circulatory support as bridge to heart transplant.

Science.gov (United States)

Umakanthan, Ramanan; Hoff, Steven J; Solenkova, Natalia; Wigger, Mark A; Keebler, Mary E; Lenneman, Andrew; Leacche, Marzia; Disalvo, Thomas G; Ooi, Henry; Naftilan, Allen J; Byrne, John G; Ahmad, Rashid M

2012-05-01

Axillary intra-aortic balloon pump therapy has been described as a bridge to transplant. Advantages over femoral intra-aortic balloon pump therapy include reduced incidence of infection and enhanced patient mobility. We identified the patients who would benefit most from this therapy while awaiting heart transplantation. We conducted a single-center, retrospective observational study to evaluate outcomes from axillary intra-aortic balloon pump therapy. These included hemodynamic parameters, duration of support, and success in bridging to transplant. We selected patients on the basis of history of sternotomy, elevated panel-reactive antibody, and small body habitus. Patients were made to ambulate aggressively beginning on postoperative day 1. Between September 2007 and September 2010, 18 patients underwent axillary intra-aortic balloon pump therapy. All patients had the devices placed through the left axillary artery with a Hemashield side graft (Boston Scientific, Natick, Mass). Before axillary placement, patients underwent femoral placement to demonstrate hemodynamic benefit. Duration of support ranged from 5 to 63 days (median = 19 days). There was marked improvement in ambulatory potential and hemodynamic parameters, with minimal blood transfusion requirements. There were no device-related infections. Some 72% of the patients (13/18) were successfully bridged to transplantation. Axillary intra-aortic balloon pump therapy provides excellent support for selected patients as a bridge to transplant. The majority of the patients were successfully bridged to transplant and discharged. Although this therapy has been described in previous studies, this is the largest series to incorporate a regimen of aggressive ambulation with daily measurements of distances walked. Copyright © 2012. Published by Mosby, Inc.

Post CABG Psychological Disorder: New Update for Surgeons and Nursing Groups

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Amanollah Heidari

2016-07-01

Full Text Available Atherosclerosis a type of arteries’ hardening that is caused by the formation of atheromatous plaque in the vessel wall. CABG is proposed as a standard of care for patients with coronary artery disease. This method besides its advantages has a variety of side effects that in addition to physiological mortality and morbidity suffers from psychological effects that are reviewed in this paper. The surgery is associated with multiple psychiatric symptoms for patients. Among them the pre and post-surgical mental problems and disorders are more important. Also As mentioned before depression is commonly reported as a consequence of coronary artery bypass surgery and it is associated with a great risk of mortality, morbidity, increased medical care and reduced performance in daily activities. Quality of life means the ability to perform daily affairs satisfactorily that includes a wide range of features and physical and mental factors. Scientific evidence suggests that 32% of heart patients in hospitals have severe depression that is continued after a year. However, it has been more than 40 years that delirium has been reported as an adverse postoperative cardiac surgery event. The analysis of the relief and relaxation method used by the nurses and its relationship with the incidence of post-surgical delirium helps to identify the areas that require training and practical changes.

Sevoflurane causes less arrhythmias than desflurane after off-pump coronary artery bypass grafting: A pilot study

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Hemmerling Thomas

2010-01-01

Full Text Available Background: Volatile anesthetics provide myocardial protection during cardiac surgery. Sevoflurane and desflurane are both efficient agents that allow immediate extubation after off-pump coronary artery bypass grafting (OPCABG. This study compared the incidence of arrhythmias after OPCABG with the two agents. Materials and Methods: Forty patients undergoing OPCABG with immediate extubation and perioperative high thoracic analgesia were included in this controlled, double-blind study; anesthesia was either provided using 1 MAC of sevoflurane (SEVO-group or desflurane (DES-group. Monitoring of perioperative arrhythmias was provided by continuous monitoring of the EKG up to 72 hours after surgery, and routine EKG monitoring once every day, until time of discharge. Patient data, perioperative arrhythmias, and myocardial protection (troponin I, CK, CK-MB-ratio, and transesophageal echocardiography examinations were compared using t-test, Fisher′s exact test or two-way analysis of variance for repeated measurements; P < 0.05. Results: Patient data and surgery-related data were similar between the two groups; all the patients were successfully extubated immediately after surgery, with similar emergence times. Supraventricular tachycardia occurred only in the DES-group (5 of 20 patients, atrial fibrillation was significantly more frequent in the DES group versus SEVO-group, at five out of 20 versus one out of 20 patients, respectively. Myocardial protection was equally achieved in both groups. Discussion: Ultra-fast track anesthesia using sevoflurane seems more advantageous than desflurane for anesthesia, for OPCABG, as it is associated with significantly less atrial fibrillation or supraventricular arrhythmias after surgery.

Infrared-x-ray pump-probe spectroscopy of the NO molecule

International Nuclear Information System (INIS)

Guimaraes, F.F.; Felicissimo, V.C.; Kimberg, V.; Gel'mukhanov, F.; Aagren, H.; Cesar, A.

2005-01-01

Two color infrared-x-ray pump-probe spectroscopy of the NO molecule is studied theoretically and numerically in order to obtain a deeper insight of the underlying physics and of the potential of this suggested technology. From the theoretical investigation a number of conclusions could be drawn: It is found that the phase of the infrared field strongly influences the trajectory of the nuclear wave packet, and hence, the x-ray spectrum. The trajectory experiences fast oscillations with the vibrational frequency with a modulation due to the anharmonicity of the potential. The dependences of the x-ray spectra on the delay time, the duration, and the shape of the pulses are studied in detail. It is shown that the x-ray spectrum keep memory about the infrared phase after the pump field left the system. This memory effect is sensitive to the time of switching-off the pump field and the Rabi frequency. The phase effect takes maximum value when the duration of the x-ray pulse is one-fourth of the infrared field period, and can be enhanced by a proper control of the duration and intensity of the pump pulse. The manifestation of the phase is different for oriented and disordered molecules and depends strongly on the intensity of the pump radiation

Infrared x-ray pump-probe spectroscopy of the NO molecule

Science.gov (United States)

Guimarães, F. F.; Kimberg, V.; Felicíssimo, V. C.; Gel'Mukhanov, F.; Cesar, A.; Ågren, H.

2005-07-01

Two color infrared x-ray pump-probe spectroscopy of the NO molecule is studied theoretically and numerically in order to obtain a deeper insight of the underlying physics and of the potential of this suggested technology. From the theoretical investigation a number of conclusions could be drawn: It is found that the phase of the infrared field strongly influences the trajectory of the nuclear wave packet, and hence, the x-ray spectrum. The trajectory experiences fast oscillations with the vibrational frequency with a modulation due to the anharmonicity of the potential. The dependences of the x-ray spectra on the delay time, the duration, and the shape of the pulses are studied in detail. It is shown that the x-ray spectrum keep memory about the infrared phase after the pump field left the system. This memory effect is sensitive to the time of switching-off the pump field and the Rabi frequency. The phase effect takes maximum value when the duration of the x-ray pulse is one-fourth of the infrared field period, and can be enhanced by a proper control of the duration and intensity of the pump pulse. The manifestation of the phase is different for oriented and disordered molecules and depends strongly on the intensity of the pump radiation.

Aprotinin vs. tranexamic acid in isolated coronary artery bypass surgery: A multicentre observational study.

Science.gov (United States)

Deloge, Elsa; Amour, Julien; Provenchère, Sophie; Rozec, Bertrand; Scherrer, Bruno; Ouattara, Alexandre

2017-05-01

Aprotinin appears to be more efficacious than lysine analogues to reduce bleeding and transfusion of blood products in high-transfusion-risk cardiac surgical patients. However, in isolated coronary artery bypass graft (CABG) surgery, the results from head-to-head trials remain less conclusive. Our objective was to compare the efficacies and safety of aprotinin and tranexamic acid (TXA) in patients undergoing isolated on-pump CABG. A multicentre before-and-after study pooling individual data from published trials and unpublished data from three other databases. Four tertiary care teaching hospitals (Haut-Lévêque Hospital in Bordeaux, Pitié-Salpêtrière Hospital and Bichat-Claude Bernard Hospital in Paris, and Laennec Hospital in Nantes). We included data of 2496 isolated on-pump CABG surgery patients who received either aprotinin between November 2003 and May 2008 (n = 1267) or TXA between November 2007 and November 2013 (n = 1229). The primary outcome was total blood loss within 24 h after operation. Secondary outcomes were transfusion of blood products, reoperation for bleeding, renal replacement therapy, ICU length of stay and in-hospital mortality. Adjusted mean (SEM) 24-h blood loss after surgery [483 (11) vs. 634 (11) ml, P < 0.0001] and the proportion of patients requiring intraoperative blood product transfusion (32.7 vs. 46.5%, P = 0.01) were lower in aprotinin-treated patients. No difference was observed with regard to reoperations for bleeding, renal replacement therapy and in-hospital mortality. However, patients receiving aprotinin had a significantly shorter adjusted ICU length of stay. In patients undergoing isolated CABG, aprotinin was more effective than TXA in reducing postoperative blood loss, and no safety concerns were identified. The benefits of aprotinin should be considered when evaluating the risk of major blood loss and transfusion in patients scheduled for isolated CABG surgery.

Coronary artery bypass grafting-related bleeding complications in patients treated with dual antiplatelet treatment.

NARCIS (Netherlands)

Tomsic, A.; Schotborgh, M.A.; Manshanden, J.S.; Li, W.W.L.; Mol, B.A. de

2016-01-01

OBJECTIVES: To evaluate the relationship between the timing of either ticagrelor or clopidogrel discontinuation and bleeding-related complications in patients undergoing isolated on-pump coronary artery bypass grafting (CABG). METHODS: Between January 2012 and December 2014, 705 consecutive patients

The development of a cavitation free sodium pump for the breeder reactor

International Nuclear Information System (INIS)

Baladi, J.Y.; Nyilas, C.P.

1986-01-01

The sodium pumps for a liquid metal fast breeder reactor must be designed for exceptionally high reliability and long life. The principal adverse factor which tends to limit the primary pump life is cavitation which becomes potentially severe under off-design flow conditions caused by the requirement of two loop operations which resulted in a large operating flow range. This problem prompted an extensive study which included experimental investigations of scaled down and full size pumps. The investigations involved visual observations, acoustic signature recordings, and physical characteristic measurements of the model and full size impellers. The blade configuration of the model was modified several times. This paper describes the test facilities erected for this study, discusses the experimental techniques employed, and presents a sample of the experimental results

Reversible pumped hydro - benefits and challenges

Energy Technology Data Exchange (ETDEWEB)

Nielsen, Torbjoern K.; Walseth, Eve C.

2010-07-01

Full text: The Norwegian hydro power system is dominated with high head turbines, Pelton and Francis with high capacity in the reservoirs. Originally they were built for secure energy supply. In the system there are also reversible pump turbine (RPT) plants where in times with spare energy, made it possible to pump water from the lower reservoir to the higher. Again the idea was to secure energy supply, which meant pumping in early autumn to fill the reservoirs for winter. In the recent years, a more active use of the RPT plants has been actualized. The free market made price difference between night and day interesting, hence a more frequent pumping was desirable. In the coming years, new-renewable energy sources will utterly enhance a more active use of the RPT plants. More active use of the RPT plants means more frequent starts and stops, both in pumping and in turbine mode. There are a lot of challenges in adopting a new strategy for operating the machinery. More effective start equipment is required. The machinery will be exposed to more frequent dynamic loads; the turbines will be run at part- and full load. The existing RPT plants are connected to huge reservoirs. That means the RPTs are not only for short sighted power regulations, as many RPT-plants in Europe, but are also capable for a substantial energy production. In Norway, the nature is very suitable for RPT plants, both in connection with existing power plants, were reservoirs and conduits are already established, and standing alone with a minimum of energy production. RPTs are, as a design, a compromise between effective generating and stable as well as effective pumping. Stable pumping often results in very steep flow-speed characteristics when operating as a turbine. When dealing with hydraulic transients these characteristics cause a higher change in flow and torque leading to instability during start-up and possible off-design operation point. The instability slows down the synchronization

Centrifugal pumps

CERN Document Server

Anderson, HH

1981-01-01

Centrifugal Pumps describes the whole range of the centrifugal pump (mixed flow and axial flow pumps are dealt with more briefly), with emphasis on the development of the boiler feed pump. Organized into 46 chapters, this book discusses the general hydrodynamic principles, performance, dimensions, type number, flow, and efficiency of centrifugal pumps. This text also explains the pumps performance; entry conditions and cavitation; speed and dimensions for a given duty; and losses. Some chapters further describe centrifugal pump mechanical design, installation, monitoring, and maintenance. The

Right pleural versus mediastinal drainage following elective off-pump coronary artery bypass

Directory of Open Access Journals (Sweden)

Forouzan nia SKh

2011-03-01

Full Text Available "n Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;} Background: Proper drainage of the mediastinal and pleural spaces following Off-Pump Coronary Artery Bypass (OPCAB surgery is essential for the prevention of pleural and pericardial effusions, cardiac tamponade and late complications such as constrictive pericarditis. Drainage tubes themselves may induce some complications which can negatively affect the result of the surgery. In this study we assessed a new technique for chest drainage following OPCAB."n"nMethods: In this clinical trial, 171 patients were allocated to two groups. In the control group, the drainage technique included one drain in the left pleural cavity and another in the mediastinum, while in the case group; the drainage technique included one drain in the left plural and one in the right pleural cavity."n"nResults: The amount of drainage in the case group was more than the control group (p=0.001. We found significant reductions in the incidence of arrhythmias in the case group (p=0.005. While one patient (1.2% needed reoperation for bleeding control in the control group, no patients needed reexploration in the case group (p=0.497. The duration of hospital (p=0.022 and ICU (p=0.002 stays was shorter in the case group."n"nConclusions: Based on the

High-speed off-axis holographic cinematography with a copper-vapor-pumped dye laser.

Science.gov (United States)

Lauterborn, W; Judt, A; Schmitz, E

1993-01-01

A series of coherent light pulses is generated by pumping a dye laser with the pulsed output of a copper-vapor laser at rates of as much as 20 kHz. Holograms are recorded at this pulse rate on a rotating holographic plate. This technique of high-speed holographic cinematography is demonstrated by viewing the bubble filaments that appear in water under the action of a sound field of high intensity.

Mitral Valve Structure in Addition to Myocardial Viability Determines the Outcome of Functional Mitral Regurgitation After Coronary Artery Bypass Grafting.

Science.gov (United States)

Yoshida, Shohei; Fukushima, Satsuki; Miyagawa, Shigeru; Nakamura, Teruya; Yoshikawa, Yasushi; Hata, Hiroki; Saito, Shunsuke; Yoshioka, Daisuke; Domae, Keitaro; Kashiyama, Noriyuki; Yamamoto, Kouji; Shintani, Ayumi; Nakatani, Satoshi; Toda, Koichi; Sawa, Yoshiki

2017-10-25

Coronary artery bypass grafting (CABG) reduces functional mitral regurgitation (MR) associated with ischemic heart disease, although the predictive factors or mechanisms of reversibility of functional MR after CABG are not fully understood.We investigated whether mitral valve structure is associated with the outcome of functional MR after CABG.Methods and Results:From a consecutive series of 98 patients with mild-moderate functional MR preoperatively who underwent isolated CABG, we enrolled 66 patients who were followed up for >1 year postoperatively using echocardiography. The degree of MR was reduced in 34 patients (52%) postoperatively, in association with a lower rate of in-hospital treatment for cardiac failure in the long term, compared with the 32 patients (48%) with residual MR postoperatively. The patients with reduced MR postoperatively had longer estimated coaptation length and more anteriorly or centrally directed MR jets than those without reduced MR. On statistical analysis, the addition of estimated coaptation length and jet direction to the reported predictors (ejection fraction, left ventricular end-diastolic dimension, and tenting height) more accurately predicted changes in post-CABG MR than the reported 3 factors alone. Residual MR was associated with the emergence of congestive heart failure in the long term after CABG. A specific mitral valve structure, such as large mitral leaflet size or predominant tethering of the posterior leaflet, was a predictive factor for the reversibility of post-CABG functional MR.

LMFBR with booster pump in pumping loop

International Nuclear Information System (INIS)

Rubinstein, H.J.

1975-01-01

A loop coolant circulation system is described for a liquid metal fast breeder reactor (LMFBR) utilizing a low head, high specific speed booster pump in the hot leg of the coolant loop with the main pump located in the cold leg of the loop, thereby providing the advantages of operating the main pump in the hot leg with the reliability of cold leg pump operation

Nuclear radiation detected optical pumping of neutron deficient Hg isotopes

International Nuclear Information System (INIS)

Bonn, J.

1975-01-01

The extension of the Nuclear Radiation Detected Optical Pumping method to mass-separated samples of isotopes far off stability is presented for a series of light Hg isotopes produced at the ISOLDE facility at CERN. The isotope under investigation is transferred by an automatic transfer system into the optical pumping apparatus. Zeeman scanning of an isotopically pure Hg spectral lamp is used to reach energetic coincidence with the hyperfine structure components of the 6s 2 1 S 0 -6s6p 3 P 1 (lambda = 2537 A) resonance line of the investigated isotope and the Hg lamp. The orientation build up by optical pumping is monitored via the asymmetry or anisotropy of the nuclear radiation. Nuclear spins, magnetic moments, electric quadrupole moments and isotopic shift are obtained for 181 Hg- 191 Hg using the β-asymmetry as detector. The extension of the method using the γ-anisotropy is discussed and measurements on 193 Hg are presented. (orig./HK)

Experimental and numerical investigation of centrifugal pumps with asymmetric inflow conditions

Science.gov (United States)

Mittag, Sten; Gabi, Martin

2015-11-01

Most of the times pumps operate off best point states. Reasons are changes of operating conditions, modifications, pollution and wearout or erosion. As consequences non-rotational symmetric flows, transient operational conditions, increased risk of cavitation, decrease of efficiency and unpredictable wearout can appear. Especially construction components of centrifugal pumps, in particular intake elbows, contribute to this matter. Intake elbows causes additional losses and secondary flows, hence non-rotational velocity distributions as intake profile to the centrifugal pump. As a result the impeller vanes experience permanent changes of the intake flow angle and with it transient flow conditions in the blade channels. This paper presents the first results of a project, experimentally and numerically investigating the consequences of non-rotational inflow to leading edge flow conditions of a centrifugal pump. Therefore two pumpintake- elbow systems are compared, by only altering the intake elbow geometry: a common single bended 90° elbow and a numerically optimized elbow (improved regarding rotational symmetric inflow conditions and friction coefficient). The experiments are carried out, using time resolved stereoscopic PIV on a full acrylic pump with refractions index matched (RIM) working fluid. This allows transient investigations of the flow field simultaneously for all blade leading edges. Additional CFD results are validated and used to further support the investigation i.e. for comparing an analog pump system with ideal inflow conditions.

A Linear Electromagnetic Piston Pump

Science.gov (United States)

Hogan, Paul H.

Advancements in mobile hydraulics for human-scale applications have increased demand for a compact hydraulic power supply. Conventional designs couple a rotating electric motor to a hydraulic pump, which increases the package volume and requires several energy conversions. This thesis investigates the use of a free piston as the moving element in a linear motor to eliminate multiple energy conversions and decrease the overall package volume. A coupled model used a quasi-static magnetic equivalent circuit to calculate the motor inductance and the electromagnetic force acting on the piston. The force was an input to a time domain model to evaluate the mechanical and pressure dynamics. The magnetic circuit model was validated with finite element analysis and an experimental prototype linear motor. The coupled model was optimized using a multi-objective genetic algorithm to explore the parameter space and maximize power density and efficiency. An experimental prototype linear pump coupled pistons to an off-the-shelf linear motor to validate the mechanical and pressure dynamics models. The magnetic circuit force calculation agreed within 3% of finite element analysis, and within 8% of experimental data from the unoptimized prototype linear motor. The optimized motor geometry also had good agreement with FEA; at zero piston displacement, the magnetic circuit calculates optimized motor force within 10% of FEA in less than 1/1000 the computational time. This makes it well suited to genetic optimization algorithms. The mechanical model agrees very well with the experimental piston pump position data when tuned for additional unmodeled mechanical friction. Optimized results suggest that an improvement of 400% of the state of the art power density is attainable with as high as 85% net efficiency. This demonstrates that a linear electromagnetic piston pump has potential to serve as a more compact and efficient supply of fluid power for the human scale.

Clinical safety of magnetic resonance imaging in patients with implanted SynchroMed EL infusion pumps

Energy Technology Data Exchange (ETDEWEB)

Diehn, Felix E.; Wood, Christopher P.; Watson, Robert E.; Hunt, Christopher H. [Mayo Clinic, Department of Radiology, Rochester, MN (United States); Mauck, William D. [Mayo Clinic, Department of Anesthesiology, Rochester, MN (United States); Burke, Michelle M. [Mayo Clinic, Department of Psychiatry and Psychology, Rochester, MN (United States)

2011-02-15

Patients with implanted SynchroMed spinal infusion pumps (Medtronic, Inc., Minneapolis, MN) routinely undergo magnetic resonance imaging at our institution. In August 2008, Medtronic issued an urgent medical device correction report regarding several pumps. Because of the rare potential ''for a delay in the return of proper drug infusion'' and ''for a delay in the logging of motor stall events,'' ''a patient's pump must be interrogated after MRI exposure in order to confirm proper pump functionality.'' This is particularly important in patients receiving intrathecal baclofen, for whom a delay in return of proper pump infusion could lead to life-threatening baclofen withdrawal syndrome. The objective of this report is to present our experience and protocol of performing magnetic resonance imaging in patients with implanted SynchroMed EL pumps. We retrospectively reviewed records of 86 patients with implanted SynchroMed EL spinal infusion pumps who underwent 112 examinations on 1.5-T magnetic resonance imaging scanners from September 1, 1998 to July 7, 2004. No SynchroMed EL pumps were damaged by magnetic resonance imaging, and the programmable settings remained unchanged in all patients. Our data suggest that SynchroMed EL pump malfunction is indeed rare after routine clinical 1.5-T magnetic resonance imaging examinations. However, based on the Medtronic correction report, we perform pump interrogation before and after imaging. (orig.)

Gender Differences in Major Dietary Patterns and Their Relationship with Cardio-Metabolic Risk Factors in a Year before Coronary Artery Bypass Grafting (CABG) Surgery Period.

Science.gov (United States)

Abbasalizad Farhangi, Mahdieh; Ataie-Jafari, Asal; Najafi, Mahdi; Sarami Foroushani, Gholamreza; Mohajeri Tehrani, Mohammad Reza; Jahangiry, Leila

2016-07-01

Previous studies reported the association between dietary patterns and prevalence of diabetes, cardiovascular disease and other chronic disease. However, there are no studies reporting major dietary patterns in patients awaiting coronary artery bypass graft surgery (CABG). The aim of this study was to obtain the major dietary patterns and their association with demographic, dietary factors and biochemical parameters in these patients. This was a cross-sectional study on 454 patients aged 35 - 80 years as candidates of CABG and hospitalized in the Tehran Heart Center. Anthropometric and demographic characteristics were obtained from all participants and a 138-item semi-quantitative food frequency questionnaire (FFQ) was used to evaluate dietary patterns by factor analysis. Biochemical parameters including HbA1c, serum lipids, hematocrit (HCT), albumin, creatinine and CRP were assessed by commercial laboratory methods. Five major dietary patterns, including: healthy, intermediate, neo-traditional, western and semi-Mediterranean patterns were extracted. Top quartile of healthy pattern was associated with higher educational attainment and lower serum low-density lipoprotein cholesterol (LDL), and total cholesterol (TC) in men, as well as  higher high-density lipoprotein cholesterol (HDL) concentrations in women (P habits, as well as the lower prevalence of diabetes, hyperlipidemia and hypertension (P eating patterns were associated with lower cardio-metabolic risk factors.

Is the number of microembolic signals related to neurologic outcome in coronary bypass surgery?

Directory of Open Access Journals (Sweden)

Malheiros Suzana M. F.

2001-01-01

Full Text Available Coronary artery bypass surgery (CABG without cardiopulmonary bypass (CPB may potentially reduce the number of microembolic signals (MES associated with aortic manipulation or generated by the pump circuit, resulting in a better neurologic outcome after surgery. Our aim was to compare the frequency of MES and neurologic complications in CABG with and without CPB. Twenty patients eligible to routine CABG without CPB were randomized to surgery with CPB and without CPB and continuously monitored by transcranial Doppler. Neurologic examination was performed in all patients before and after surgery. The two groups were similar with respect to demographics, risk factors, grade of aortic atheromatous disease and number of grafts. The frequency of MES in the nonCPB group was considerably lower than in CPB patients, however, we did not observe any change in the neurologic examination during the early postoperative period. Neurologic complications after CABG may be related to the size and composition of MES rather than to their absolute numbers. A large prospective multicentric randomized trial may help to elucidate this complex issue.

The pumping of hydrogen and helium by sputter-ion pumps

International Nuclear Information System (INIS)

Welch, K.M.; Pate, D.J.; Todd, R.J.

1992-01-01

The pumping of hydrogen in diode and triode sputter-ion pumps is discussed. The type of cathode material used in these pumps is shown to have a significant impact on the effectiveness with which hydrogen is pumped. Examples of this include data for pumps with aluminum and titanium-alloy cathodes. Diode pumps with aluminum cathodes are shown to be no more effective in the pumping of hydrogen than in the pumping of helium. The use of titanium or titanium alloy anodes is also shown to measurably impact on the speed of these pumps at.very low pressures. This stems from the fact that hydrogen is x10 6 more soluble in titanium than in stainless steel. Hydrogen becomes resident in the anodes because of fast neutral burial. Lastly, quantitative data are given for the He speeds and capacities of both noble and conventional diode and triode pumps. The effectiveness of various pump regeneration procedures, subsequent to the pumping of He, is reported.These included bakeout and N 2 glow discharge cleaning. The comparative desorption of He with the subsequent pumping of N 2 is reported on. The N 2 speed of these pumps was used as the benchmark for defining the size of the pumps vs. their respective He speeds

Liquid metals pumping

International Nuclear Information System (INIS)

Le Frere, J.P.

1984-01-01

Pumps used to pump liquid metals depend on the liquid metal and on the type of application concerned. One deals more particularly with electromagnetic pumps, the main pumps used with mechanical pumps. To pump sodium in the nuclear field, these two types of pumps are used; the pumps of different circuits of Super Phenix are presented and described [fr

Implementation of Wolsong Pump Model, Pressure Tube Deformation Model and Off-take Model into MARS Code for Regulatory Auditing of CANDU Reactors

Energy Technology Data Exchange (ETDEWEB)

Yoon, C.; Rhee, B. W.; Chung, B. D. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Cho, Y. J.; Kim, M. W. [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

2008-05-15

Korea currently has four operating units of the CANDU-6 type reactor in Wolsong. However, the safety assessment system for CANDU reactors has not been fully established due to lack of self-reliance technology. Although the CATHENA code had been introduced from AECL, it is undesirable to use vendor's code for regulatory auditing analysis. In Korea, the MARS code has been developed for decades and is being considered by KINS as a thermal hydraulic regulatory auditing tool for nuclear power plants. Before this decision, KINS (Korea Institute of Nuclear Safety) had developed RELAP5/MOD3/CANDU code for CANDU safety analyses by modifying the model of existing PWR auditing tool, RELAP5/MOD3. The main purpose of this study is to transplant the CANDU models of RELAP5/MOD3/CANDU code to MARS code including quality assurance of the developed models. This first part of the research series presents the implementation and verification of the Wolsong pump model, the pressure tube deformation model, and the off-take model for arbitrary-angled branch pipes.

Implementation of Wolsong Pump Model, Pressure Tube Deformation Model and Off-take Model into MARS Code for Regulatory Auditing of CANDU Reactors

International Nuclear Information System (INIS)

Yoon, C.; Rhee, B. W.; Chung, B. D.; Cho, Y. J.; Kim, M. W.

2008-01-01

Korea currently has four operating units of the CANDU-6 type reactor in Wolsong. However, the safety assessment system for CANDU reactors has not been fully established due to lack of self-reliance technology. Although the CATHENA code had been introduced from AECL, it is undesirable to use vendor's code for regulatory auditing analysis. In Korea, the MARS code has been developed for decades and is being considered by KINS as a thermal hydraulic regulatory auditing tool for nuclear power plants. Before this decision, KINS (Korea Institute of Nuclear Safety) had developed RELAP5/MOD3/CANDU code for CANDU safety analyses by modifying the model of existing PWR auditing tool, RELAP5/MOD3. The main purpose of this study is to transplant the CANDU models of RELAP5/MOD3/CANDU code to MARS code including quality assurance of the developed models. This first part of the research series presents the implementation and verification of the Wolsong pump model, the pressure tube deformation model, and the off-take model for arbitrary-angled branch pipes

Survival results of postoperative coronary angiogram for treatment of perioperative myocardial ischaemia following coronary artery bypass grafting: a single-centre experience.

Science.gov (United States)

Preußer, Maximilian J; Landwehrt, Jan; Mastrobuoni, Stefano; Biancari, Fausto; Dakkak, Abdul R; Alshakaki, Mosab; Martens, Sven; Dell'Aquila, Angelo M

2018-02-01

Although perioperative myocardial ischaemia (PMI) is a well-known complication following coronary artery bypass grafting (CABG), standard strategies for its diagnosis and treatment are so far not defined. In this study, we sought to evaluate the impact on survival of postoperative coronary angiogram for management of patients with PMI after CABG. Overall, 4028 patients underwent isolated CABG in a single-centre institution between January 2006 and September 2013. A total of 168 (4.2%) patients received postoperative coronary angiogram because of diagnosis of PMI. These patients were matched on the basis of gender, age at surgery and date of surgery, with 336 (1:2 ratio) CABG patients without PMI to determine the impact of the PMI management. A total of 476 grafts were examined (263 venous grafts, 196 internal mammary artery grafts and 17 radial artery grafts). Almost three-quarters of the 168 PMI (74.4%) patients underwent postoperative coronary angiogram within 24 h of surgery. Normal postoperative coronary angiogram, graft failure and new native vessels occlusion were observed in 23.2%, 52.4% and 24.4% of patients, respectively. A total of 30 (17.9%) patients underwent surgical revision of grafts, whereas 60 (35.7%) patients were treated with percutaneous coronary intervention. Eighteen (10.7%) PMI patients died during the hospital stay compared with 6 (1.8%) patients in the non-PMI group. Survival rates at 7 years were 62.5% in the PMI group and 81.1% in non-PMI group (P PMI (P 24 h after surgery) was an independent predictor of poorer mid-term survival (P = 0.008; hazard ratio 3.62, 95% confidence interval 1.41-9.33). PMI after CABG is associated with a significantly poorer survival. A prompt postoperative management must always be considered. Further prospective studies are required to confirm our results. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights

Impact of surgeon experience on the rate of blood transfusion in off-pump coronary artery bypass.

Science.gov (United States)

Chen, Jeng-Wei; Hsu, Ron-Bin

2016-03-01

Off-pump coronary artery bypass (OPCAB) reduces the rate of blood transfusion. No studies have focused on the effect of surgeon experience on the transfusion rate. We sought to assess the transfusion rate in OPCAB and to evaluate the effect of surgeon experience. Retrospective review of 1055 consecutive patients undergoing OPCAB between 2000 and 2012. Patients were divided into tripartites by the year of operation (2000-2004, 2005-2008, and 2009-2012). Surgeon experience was evaluated with revascularization index and conversion rate. Mode of intervention was elective in 768, urgency in 185, and emergency in 102 patients (10%). Blood transfusion was associated with increased rates of hospital mortality and sternal wound/bloodstream infections. Revascularization index was 1.22 ± 0.29 per patient and increased over time, from 1.05 ± 0.21 in 2000-2004 to 1.39 ± 0.26 in 2009-2012. Conversion rate was 10% and decreased over time, from 17% in 2000-2004 to 6% in 2009-2012. The average rate of blood transfusion was 58% and decreased over time, from 74% in 2000-2004 to 41% in 2009-2012. Rate of red blood cell transfusion was 56% and decreased from 72% in 2000-2004 to 40% in 2009-2012. Rate of platelet transfusion was 21% and decreased from 25% in 2000-2004 to 15% in 2009-2012.The most significant decrease in the transfusion rate was observed in nonemergency cases. Surgeon experience reduced the need of blood transfusion after OPCAB. Increasing surgeon experience was associated with a 33% reduction in blood transfusion rate. Copyright © 2015. Published by Elsevier B.V.

Nigerian Medical Journal - Vol 53, No 4 (2012)

African Journals Online (AJOL)

Intra‑operative grading of coronary artery atherosclerosis associated with homocysteine levels in postmenopausal women undergoing elective off‑pump CABG surgery · EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. Seyed Jalil Mirhosseini, Seyed Khalil Forouzannia, Seyed Ali ...

Precatheterization Use of P2Y12 Inhibitors in Non-ST-Elevation Myocardial Infarction Patients Undergoing Early Cardiac Catheterization and In-Hospital Coronary Artery Bypass Grafting: Insights From the National Cardiovascular Data Registry®.

Science.gov (United States)

Badri, Marwan; Abdelbaky, Amr; Li, Shuang; Chiswell, Karen; Wang, Tracy Y

2017-09-22

Current guidelines recommend early P2Y 12 inhibitor administration in non-ST-elevation myocardial infarction, but it is unclear if precatheterization use is associated with longer delays to coronary artery bypass grafting (CABG) or higher risk of post-CABG bleeding and transfusion. This study examines the patterns and outcomes of precatheterization P2Y 12 inhibitor use in non-ST-elevation myocardial infarction patients who undergo CABG. Retrospective analysis was done of 20 304 non-ST-elevation myocardial infarction patients in the ACTION (Acute Coronary Treatment and Intervention Outcomes Network) Registry (2009-2014) who underwent catheterization within 24 hours of admission and CABG during the index hospitalization. Using inverse probability-weighted propensity adjustment, we compared time from catheterization to CABG, post-CABG bleeding, and transfusion rates between patients who did and did not receive precatheterization P2Y 12 inhibitors. Among study patients, 32.9% received a precatheterization P2Y 12 inhibitor (of these, 2.2% were given ticagrelor and 3.7% prasugrel). Time from catheterization to CABG was longer among patients who received precatheterization P2Y 12 inhibitor (median 69.9 hours [25th, 75th percentiles 28.2, 115.8] versus 43.5 hours [21.0, 71.8], P ST-elevation myocardial infarction patients who undergo early catheterization and in-hospital CABG. Despite longer delays to surgery, the majority of pretreated patients proceed to CABG <3 days postcatheterization. Precatheterization P2Y 12 inhibitor use is associated with higher risks of postoperative bleeding and transfusion. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Continuously pumping and reactivating gas pump

International Nuclear Information System (INIS)

Batzer, T.H.; Call, W.R.

1984-01-01

Apparatus for continuous pumping using cycling cyropumping panels. A plurality of liquid helium cooled panels are surrounded by movable nitrogen cooled panels the alternatively expose or shield the helium cooled panels from the space being pumped. Gases condense on exposed helium cooled panels until the nitrogen cooled panels are positioned to isolate the helium cooled panels. The helium cooled panels are incrementally warmed, causing captured gases to accumulate at the base of the panels, where an independent pump removes the gases. After the helium cooled panels are substantially cleaned of condensate, the nitrogen cooled panels are positioned to expose the helium cooled panels to the space being pumped

Continuously pumping and reactivating gas pump

Science.gov (United States)

Batzer, Thomas H.; Call, Wayne R.

1984-01-01

Apparatus for continuous pumping using cycling cyropumping panels. A plurality of liquid helium cooled panels are surrounded by movable nitrogen cooled panels the alternatively expose or shield the helium cooled panels from the space being pumped. Gases condense on exposed helium cooled panels until the nitrogen cooled panels are positioned to isolate the helium cooled panels. The helium cooled panels are incrementally warmed, causing captured gases to accumulate at the base of the panels, where an independent pump removes the gases. After the helium cooled panels are substantially cleaned of condensate, the nitrogen cooled panels are positioned to expose the helium cooled panels to the space being pumped.

A Comparative Assessment of Spalart-Shur Rotation/Curvature Correction in RANS Simulations in a Centrifugal Pump Impeller

Directory of Open Access Journals (Sweden)

Ran Tao

2014-01-01

Full Text Available RANS simulation is widely used in the flow prediction of centrifugal pumps. Influenced by impeller rotation and streamline curvature, the eddy viscosity models with turbulence isotropy assumption are not accurate enough. In this study, Spalart-Shur rotation/curvature correction was applied on the SST k-ω turbulence model. The comparative assessment of the correction was proceeded in the simulations of a centrifugal pump impeller. CFD results were compared with existing PIV and LDV data under the design and low flow rate off-design conditions. Results show the improvements of the simulation especially in the situation that turbulence strongly produced due to undesirable flow structures. Under the design condition, more reasonable turbulence kinetic energy contour was captured after correction. Under the low flow rate off-design condition, the prediction of turbulence kinetic energy and velocity distributions became much more accurate when using the corrected model. So, the rotation/curvature correction was proved effective in this study. And, it is also proved acceptable and recommended to use in the engineering simulations of centrifugal pump impellers.

Design and Thermodynamic Analysis of a Steam Ejector Refrigeration/Heat Pump System for Naval Surface Ship Applications

Directory of Open Access Journals (Sweden)

Cüneyt Ezgi

2015-12-01

Full Text Available Naval surface ships should use thermally driven heating and cooling technologies to continue the Navy’s leadership role in protecting the marine environment. Steam ejector refrigeration (SER or steam ejector heat pump (SEHP systems are thermally driven heating and cooling technologies and seem to be a promising technology to reduce emissions for heating and cooling on board naval surface ships. In this study, design and thermodynamic analysis of a seawater cooled SER and SEHP as an HVAC system for a naval surface ship application are presented and compared with those of a current typical naval ship system case, an H2O-LiBr absorption heat pump and a vapour-compression heat pump. The off-design study estimated the coefficient of performances (COPs were 0.29–0.11 for the cooling mode and 1.29–1.11 for the heating mode, depending on the pressure of the exhaust gas boiler at off-design conditions. In the system operating at the exhaust gas boiler pressure of 0.2 MPa, the optimum area ratio obtained was 23.30.

Localization of fluctuation measurement by wave scattering close to a cut off layer

International Nuclear Information System (INIS)

Zou, X.L.; Laurent, L.; Rax, J.M.; Lehner, T.

1990-01-01

The diagnostic of plasma fluctuations in tokamaks based on the scattering of an electromagnetic wave close to a cut off layer is investigated. A linear density profile is considered. An one-dimensional exact analysis is performed. Spatial and spectral localization of scattering process close to the cut off layer is studied and a modified Bragg rule is derived. The structure of pump and of scattered waves is analyzed. The diagnostic seems to be local and sensitive for low R fluctuations

Effect of pump limiter throat on pumping efficiency

International Nuclear Information System (INIS)

Ghendrih, P.; Grosman, A.; Samain, A.; Capes, H.; Morera, J.P.

1988-01-01

The necessary control of plasma edge density has led to the development of pump limiters to achieve this task. On Tore Supra, where a large part of the program is devoted to plasma edge studies, two types of such density control apparatus have been implemented, a set of pump limiters and the pumps associated to the ergodic divertor (magnetically assisted pump limiters). Generally two different kinds of pump limiters can be used, those with a throat which drives the plasma from the open edge plasma (SOL) to the neutralizer plate, and those without or with a very short throat. We are interested here in this aspect of the pump limiter concept, i.e. on the throat effect on neutral density build-up in the vicinity of the pumping plates (and hence on pumping efficieny). The underlying idea of this throat effect can be readily understood; indeed while the neutral capture in pump limiters without throats is only a ballistic effect, on expects the plasma to improve the efficiency of pump-limiters via plasma-neutral-sidewall interactions in the throat. This problem has been studied both numerically and analytically. The paper is divided as follows. In section 2, we describe the basic features of pump-limiters which are modelized by the numerical code Cezanne. Section 3 is devoted to the throat length effect considering in particular the neutral density profile in the throat and the neutral density buil-up as a function of the throat lenght. In section 4, we show that the plugging effect occurs for reasonnable values of throat lengths. An analytical value of the plugging length is discussed and compared to the values obtained numerically

Low-Level Laser and Light-Emitting Diode Therapy for Pain Control in Hyperglycemic and Normoglycemic Patients Who Underwent Coronary Bypass Surgery with Internal Mammary Artery Grafts: A Randomized, Double-Blind Study with Follow-Up.

Science.gov (United States)

Lima, Andréa Conceição Gomes; Fernandes, Gilderlene Alves; Gonzaga, Isabel Clarisse; de Barros Araújo, Raimundo; de Oliveira, Rauirys Alencar; Nicolau, Renata Amadei

2016-06-01

This study aimed to evaluate the efficacy of low-level laser therapy (LLLT) and light-emitting diodes (LEDs) for reducing pain in hyperglycemic and normoglycemic patients who underwent coronary artery bypass surgery with internal mammary artery grafts. This study was conducted on 120 volunteers who underwent elective coronary artery bypass graft (CABG) surgery. The volunteers were randomly allocated to four different groups of equal size (n = 30): control, placebo, LLLT [λ = 640 nm and spatial average energy fluence (SAEF) = 1.06 J/cm(2)], and LED (λ = 660 ± 20 nm and SAEF = 0.24 J/cm(2)). Participants were also divided into hyperglycemic and normoglycemic subgroups, according to their fasting blood glucose test result before surgery. The outcome assessed was pain during coughing by a visual analog scale (VAS) and the McGill Pain Questionnaire. The patients were followed for 1 month after the surgery. The LLLT and LED groups showed a greater decrease in pain, with similar results, as indicated by both the VAS and the McGill questionnaire (p ≤ 0.05), on the 6th and 8th postoperative day compared with the placebo and control groups. The outcomes were also similar between hyperglycemic and normoglycemic patients. One month after the surgery, almost no individual reported pain during coughing. LLLT and LED had similar analgesic effects in hyperglycemic and normoglycemic patients, better than placebo and control groups.

Finite-momentum condensation in a pumped microcavity

International Nuclear Information System (INIS)

Brierley, R. T.; Eastham, P. R.

2010-01-01

We calculate the absorption spectra of a semiconductor microcavity into which a nonequilibrium exciton population has been pumped. We predict strong peaks in the spectrum corresponding to collective modes analogous to the Cooper modes in superconductors and fermionic atomic gases. These modes can become unstable, leading to the formation of off-equilibrium quantum condensates. We calculate a phase diagram for condensation and show that the dominant instabilities can be at a finite momentum. Thus we predict the formation of inhomogeneous condensates, similar to Fulde-Ferrel-Larkin-Ovchinnikov states.

Study of Hydrogen Pumping through Condensed Argon in Cryogenic pump

International Nuclear Information System (INIS)

Jadeja, K A; Bhatt, S B

2012-01-01

In ultra high vacuum (UHV) range, hydrogen is a dominant residual gas in vacuum chamber. Hydrogen, being light gas, pumping of hydrogen in this vacuum range is limited with widely used UHV pumps, viz. turbo molecular pump and cryogenic pump. Pre condensed argon layers in cryogenic pump create porous structure on the surface of the pump, which traps hydrogen gas at a temperature less than 20° K. Additional argon gas injection in the cryogenic pump, at lowest temperature, generates multiple layers of condensed argon as a porous frost with 10 to 100 A° diameters pores, which increase the pumping capacity of hydrogen gas. This pumping mechanism of hydrogen is more effective, to pump more hydrogen gas in UHV range applicable in accelerator, space simulation etc. and where hydrogen is used as fuel gas like tokamak. For this experiment, the cryogenic pump with a closed loop refrigerator using helium gas is used to produce the minimum cryogenic temperature as ∼ 14° K. In this paper, effect of cryosorption of hydrogen is presented with different levels of argon gas and hydrogen gas in cryogenic pump chamber.

Hybrid lasers produced in potassium vapor by off-resonance pumping

International Nuclear Information System (INIS)

Clark, B.K.; Stack, C.A.; Muehsler, H.E.

1993-01-01

Pulsed amplified emissions are observed at or near atomic transitions cascading down from the K(6S) and K(4D 5/2 ) states, when a pulsed dye laser is tuned near the K(6S left-arrow 4 3/2,1/2 ) and the K(4D 5/2 left-arrow 4P 3/2 ) transitions. Emissions are suppressed when the pulsed dye laser is tuned to the K(4D 3/2 left-arrow 4P 5/3,3/2 ) transitions. The pulsed dye laser is used to excite molecules in a heat-pipe oven from high-bring ro-vibrational levels in the K 2 (X 1 Σ g + ) ground state to ro-vibrational levels in the K 2 (B 1 product u ) state that predissociate to K(4S) and K(4P) atoms. The transitions can be pumped when the laser is tuned sufficiently close to the atomic resonances. We discuss the non-linear mechanisms responsible for the observed emissions. Emissions cascading down from the K(4S) state were first reported by Wang et al

Author Details

African Journals Online (AJOL)

Mirhosseini, Seyed Jalil. Vol 53, No 4 (2012) - Articles Intra‑operative grading of coronary artery atherosclerosis associated with homocysteine levels in postmenopausal women undergoing elective off‑pump CABG surgery. Abstract. ISSN: 2229-774X. AJOL African Journals Online. HOW TO USE AJOL... for Researchers ...

Bose-Einstein condensation in an ultra-hot gas of pumped magnons.

Science.gov (United States)

Serga, Alexander A; Tiberkevich, Vasil S; Sandweg, Christian W; Vasyuchka, Vitaliy I; Bozhko, Dmytro A; Chumak, Andrii V; Neumann, Timo; Obry, Björn; Melkov, Gennadii A; Slavin, Andrei N; Hillebrands, Burkard

2014-03-11

Bose-Einstein condensation of quasi-particles such as excitons, polaritons, magnons and photons is a fascinating quantum mechanical phenomenon. Unlike the Bose-Einstein condensation of real particles (like atoms), these processes do not require low temperatures, since the high densities of low-energy quasi-particles needed for the condensate to form can be produced via external pumping. Here we demonstrate that such a pumping can create remarkably high effective temperatures in a narrow spectral region of the lowest energy states in a magnon gas, resulting in strikingly unexpected transitional dynamics of Bose-Einstein magnon condensate: the density of the condensate increases immediately after the external magnon flow is switched off and initially decreases if it is switched on again. This behaviour finds explanation in a nonlinear 'evaporative supercooling' mechanism that couples the low-energy magnons overheated by pumping with all the other thermal magnons, removing the excess heat, and allowing Bose-Einstein condensate formation.

Revascularização do miocárdio sem circulação extracorpórea em idosos: análise da morbidade e mortalidade Off-pump myocardial revascularization in the elderly: analysis of morbidity and mortality

Directory of Open Access Journals (Sweden)

Ana Maria Rocha Pinto e Silva

2008-03-01

Full Text Available OBJETIVO: Analisar a evolução intra-hospitalar de doentes com 70 anos de idade ou mais, submetidos a revascularização do miocárdio sem circulação extracorpórea, com uso de shunt intracoronário, operados na urgência, emergência e eletivamente. MÉTODOS: Foram submetidos à cirurgia 87 doentes com idade entre 70 e 92 anos de julho de 1989 a julho de 2005. Dos 87 doentes, 50 (57,5% eram portadores de angina instável, sendo três (3,4% na vigência de infarto agudo do miocárdio. Foram operados em caráter de emergência e urgência 31 (35,6% doentes. De todo o grupo, havia 13 (14,9% doentes com infarto ocorrido em até 30 dias e 34 (39,1% com infarto ocorrido há mais de 30 dias. RESULTADOS: As complicações mais freqüentes foram: fibrilação atrial (32,2%, insuficiência cardíaca congestiva (12,6%, broncopneumonia (10,3%, sepse (3,4%, infarto agudo do miocárdio peri-operatório (2,3%, mediastinite (1,1%, acidente isquêmico transitório (1,1%, pneumotórax (1,1%. O tempo médio de intubação foi de 18,50±19,09 horas; permanência em UTI, 2,92±2,03 dias, e hospitalar, 10,55±7,16 dias. Apenas nove (10,3% doentes receberam concentrado de hemácias no pós-operatório e nenhum foi reoperado por sangramento. A mortalidade hospitalar foi de 4,6%. CONCLUSÃO: Em doentes acima de 70 anos, operados na emergência, urgência e eletivamente, a revascularização do miocárdio sem extracorpórea com shunt intracoronário apresentou adequada evolução pós-operatória e baixos índices de complicações e mortalidade em relação à população estudada.OBJECTIVE: To analyze the in-hospital outcome of elderly patients aged 70 years and older who underwent off-pump coronary artery bypass graft surgery with an intraluminal shunt in urgent, emergent, and elective coronary revascularizations. METHODS: From July 1989 to July 2005, we analyzed 87 patients ranging in age from 70 to 92 years. Of the 87 patients enrolled, 50 (57.5% patients had

Intraoperative coronary grafts flow measurement using the TTFM flowmeter: results from a domestic sample.

Science.gov (United States)

Succi, José Ernesto; Gerola, Luis Roberto; Succi, Guilherme de Menezes; Kim, Hyong Chun; Paredes, Jorge Edwin Morocho; Bufollo, Enio

2012-01-01

To evaluate intraoperative graft patency and identify grafts under risk of early occlusion. Fifty four patients were submitted to coronary artery bypass surgery and the graft flow was assessed by the Flowmeter (Medtronic Medistim), which utilizes the TTFM method. Three patients had left main disease and 48 had normal or mildly reduced left ventricular function. In hospital mortality was 3.7% (two patients), one for mesenteric thrombosis and one due to cardiogenic chock. Seventeen patients (34%) were submitted to off pump CABG. Arterial Graft flow measures ranged from 8 to 106 ml/min (average 31.14 ml/min), and venous grafts flow ranged from 9 to 149 ml/min (average 50.42 ml/min). Flowmeter use represents higher safety both for patients and surgeons. Even under legal aspects, the documentation provided by the device can avoid future questionings.

Parametric studies and optimisation of pumped thermal electricity storage

International Nuclear Information System (INIS)

McTigue, Joshua D.; White, Alexander J.; Markides, Christos N.

2015-01-01

Highlights: • PTES is modelled by cycle analysis and a Schumann-style model of the thermal stores. • Optimised trade-off surfaces show a flat efficiency vs. energy density profile. • Overall roundtrip efficiencies of around 70% are not inconceivable. - Abstract: Several of the emerging technologies for electricity storage are based on some form of thermal energy storage (TES). Examples include liquid air energy storage, pumped heat energy storage and, at least in part, advanced adiabatic compressed air energy storage. Compared to other large-scale storage methods, TES benefits from relatively high energy densities, which should translate into a low cost per MW h of storage capacity and a small installation footprint. TES is also free from the geographic constraints that apply to hydro storage schemes. TES concepts for electricity storage rely on either a heat pump or refrigeration cycle during the charging phase to create a hot or a cold storage space (the thermal stores), or in some cases both. During discharge, the thermal stores are depleted by reversing the cycle such that it acts as a heat engine. The present paper is concerned with a form of TES that has both hot and cold packed-bed thermal stores, and for which the heat pump and heat engine are based on a reciprocating Joule cycle, with argon as the working fluid. A thermodynamic analysis is presented based on traditional cycle calculations coupled with a Schumann-style model of the packed beds. Particular attention is paid to the various loss-generating mechanisms and their effect on roundtrip efficiency and storage density. A parametric study is first presented that examines the sensitivity of results to assumed values of the various loss factors and demonstrates the rather complex influence of the numerous design variables. Results of an optimisation study are then given in the form of trade-off surfaces for roundtrip efficiency, energy density and power density. The optimised designs show a

Operation and control strategies in pre-series testing of cold circulating pumps for ITER

International Nuclear Information System (INIS)

Bhattacharya, R.; Vaghela, H.; Sarkar, B.; Srinivas, M.; Choukekar, K.

2013-01-01

Cryo-distribution system of ITER is responsible for the distribution and control of forced-flow supercritical helium for cooling of the superconducting magnets and the cryo-pumps. The requirements of cold circulating pumps (CCP) for mass flow rates and performance are much higher than presently existing and commercially available one used at 4.0 K helium. Design up-scaling with pre-series test of CCP has been proposed including test infrastructure. Operation and control strategies for the test distribution box (TDB) of test infrastructure have been developed and analyzed using steady state and dynamic process simulation to cope with the functional requirements of CCPs. Off-normal scenario with CCP inlet pressure variation is an important concern, dynamic process responses during such scenario have been evaluated to verify the operability of CCP. The paper describes process simulation to cope with the functional requirements of CCPs along with evaluation of off-normal scenario to verify the operability of CCP. (author)

Aortic valve replacement with or without coronary artery bypass graft surgery: the risk of surgery in patients > or =80 years old.

Science.gov (United States)

Maslow, Andrew; Casey, Paula; Poppas, Athena; Schwartz, Carl; Singh, Arun

2010-02-01

The purpose of this study was to evaluate the outcomes for elderly (> or =80 years) patients undergoing aortic valve replacement (AVR) with or without coronary artery bypass graft surgery (AVR/CABG). The authors hypothesized that the mortalities of AVR and AVR/CABG are lower than that predicted by published risk scores. A retrospective analysis of data from a single-hospital database. Single tertiary care, private practice. Consecutive patients undergoing AVR or AVR/CABG. Two hundred sixty-one elderly (> or =80 years) patients undergoing isolated AVR (145) or AVR/CABG (116) were evaluated. The majority (94.6%) underwent AVR for aortic valve stenosis. Outcomes were recorded and compared between the 2 surgical procedures with predicted mortalities based on published risk assessment scoring systems. The overall short-term mortality for the elderly group was 6.1% (AVR 5.5% and AVR/CABG 6.9%). The median long-term survival was 6.8 years. There were no significant differences in either morbidity or mortality between the AVR and AVR/CABG groups. Although predicted mortalities were similar for each surgical procedure, they overestimated observed outcome by up to 4-fold. Short- and long-term mortality was low for this group of elderly patients undergoing AVR or AVR/CABG and not significantly different between the 2 surgical groups. Predicted outcomes were worse than that observed, consistent with the hypothesis, and supportive of a more aggressive surgical treatment for aortic valve disease in the elderly patient. Copyright 2010 Elsevier Inc. All rights reserved.

Dry vacuum pumps

International Nuclear Information System (INIS)

Sibuet, R

2008-01-01

For decades and for ultimate pressure below 1 mbar, oil-sealed Rotary Vane Pumps have been the most popular solution for a wide range of vacuum applications. In the late 80ies, Semiconductor Industry has initiated the development of the first dry roughing pumps. Today SC applications are only using dry pumps and dry pumping packages. Since that time, pumps manufacturers have developed dry vacuum pumps technologies in order to make them attractive for other applications. The trend to replace lubricated pumps by dry pumps is now spreading over many other market segments. For the Semiconductor Industry, it has been quite easy to understand the benefits of dry pumps, in terms of Cost of Ownership, process contamination and up-time. In this paper, Technology of Dry pumps, its application in R and D/industries, merits over conventional pumps and future growth scope will be discussed

A New Risk Factor Profile for Contrast-Induced Acute Kidney Injury in Patients Who Underwent an Emergency Percutaneous Coronary Intervention.

Science.gov (United States)

Yuan, Ying; Qiu, Hong; Song, Lei; Hu, Xiaoying; Luo, Tong; Zhao, Xueyan; Zhang, Jun; Wu, Yuan; Qiao, Shubin; Yang, Yuejin; Gao, Runlin

2018-07-01

We developed a new risk factor profile for contrast-induced acute kidney injury (CI-AKI) under a new definition in patients who underwent an emergency percutaneous coronary intervention (PCI). Consecutive patients (n = 1061) who underwent an emergency PCI were divided into a derivation group (n = 761) and a validation group (n = 300). The rates of CI-AKI were 23.5% (definition 1: serum creatinine [SCr] increase ≥25% in 72 hours), 4.3% (definition 2: SCr increase ≥44.2 μmol/L in 72 hours), and 7.0% (definition 3: SCr increase ≥44.2 μmol/L in 7 days). Due to the high sensitivity of definition 1 and the high rate of missed cases for late diagnosis of CI-AKI under definition 2, definition 3 was used in the study. The risk factor profile included body surface area 15.00 × 10 9 /L ( P = .047), estimated glomerular filtration rate 133 μmol/L ( P = .007), intra-aortic balloon pump application ( P = .006), and diuretics administration ( P risk factor profile of CI-AKI under a new CI-AKI definition in emergency PCI patients is easily applicable with a useful predictive value.

Prediction of Hydraulic Performance of a Scaled-Down Model of SMART Reactor Coolant Pump

Energy Technology Data Exchange (ETDEWEB)

Kwon, Sun Guk; Park, Jin Seok; Yu, Je Yong; Lee, Won Jae [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2010-08-15

An analysis was conducted to predict the hydraulic performance of a reactor coolant pump (RCP) of SMART at the off-design as well as design points. In order to reduce the analysis time efficiently, a single passage containing an impeller and a diffuser was considered as the computational domain. A stage scheme was used to perform a circumferential averaging of the flux on the impeller-diffuser interface. The pressure difference between the inlet and outlet of the pump was determined and was used to compute the head, efficiency, and break horse power (BHP) of a scaled-down model under conditions of steady-state incompressible flow. The predicted curves of the hydraulic performance of an RCP were similar to the typical characteristic curves of a conventional mixed-flow pump. The complex internal fluid flow of a pump, including the internal recirculation loss due to reverse flow, was observed at a low flow rate.

Dual light-activated microfluidic pumps based on an optopiezoelectric composite

International Nuclear Information System (INIS)

Wang, Hsin-Hu; Lee, Chih-Kung; Hsu, Yu-Hsiang; Wu, Ting-Jui; Cheng, I-Chun; Lin, Shih-Jue; Gu, Jen-Tau

2017-01-01

In this paper, a new type of microfluidic pump that can be activated and controlled by a masked light source is presented. The actuation of this micropump is based on an optopiezoelectric composite. This composite is constructed by having one of the electrodes of a piezoelectric PVDF (polyvinylidene fluoride) polymer replaced by a layer of TiOPc (titanyl phthalocyanine) photoconductive coating and an ITO (indium-tin-oxide) transparent electrode. This layer of photoconductive electrode provides the capability to activate multiple locations of this optopiezoelectric composite independently using a masked light source and a single voltage source. To verify the feasibility of this concept, dual light-activated microfluidic pumps based on this optopiezoelectric composite are implemented and studied. Experimental results verify that two microfluidic pumps can be created by one optopiezoelectric composite and that each pump can be optically turned on and off independently or be turned on simultaneously. These results suggest that integrating an optopiezoelectric composite into a lab-on-a-chip system can reduce the size and the number of driving units significantly, since every operation can be done optically and only one driving source is needed. The equivalent circuit, design, and implementation of dual light-activated optopiezoelectric micropumps are discussed in this paper. (paper)

A Novel Algorithm (G-JPSO and Its Development for the Optimal Control of Pumps in Water Distribution Networks

Directory of Open Access Journals (Sweden)

Rasoul Rajabpour

2017-01-01

Full Text Available Recent decades have witnessed growing applications of metaheuristic techniques as efficient tools for solving complex engineering problems. One such method is the JPSO algorithm. In this study, innovative modifications were made in the nature of the jump algorithm JPSO to make it capable of coping with graph-based solutions, which led to the development of a new algorithm called ‘G-JPSO’. The new algorithm was then used to solve the Fletcher-Powell optimal control problem and its application to optimal control of pumps in water distribution networks was evaluated. Optimal control of pumps consists in an optimum operation timetable (on and off for each of the pumps at the desired time interval. Maximum number of on and off positions for each pump was introduced into the objective function as a constraint such that not only would power consumption at each node be reduced but such problem requirements as the minimum pressure required at each node and minimum/maximum storage tank heights would be met. To determine the optimal operation of pumps, a model-based optimization-simulation algorithm was developed based on G-JPSO and JPSO algorithms. The model proposed by van Zyl was used to determine the optimal operation of the distribution network. Finally, the results obtained from the proposed algorithm were compared with those obtained from ant colony, genetic, and JPSO algorithms to show the robustness of the proposed algorithm in finding near-optimum solutions at reasonable computation costs.

Deposition of hematite particles on alumina seal faceplates of nuclear reactor coolant pumps: Laboratory experiments and industrial feedback

OpenAIRE

Lefèvre, Grégory; Živković, Ljiljana S.; Jaubertie, Anne

2012-01-01

In the primary circuit of pressurized water reactors (PWR), the dynamic sealing system in reactor coolant pumps is ensured by mechanical seals whose ceramic parts are in contact with the cooling solution. During the stretch-out phase in reactor operation, characterized by low boric acid concentration, the leak-off flow has been observed to abnormally evolve in industrial plants. The deposition of hematite particles, originating from corrosion, on alumina seals of coolant pumps is suspec...

Heat pump technology

CERN Document Server

Von Cube, Hans Ludwig; Goodall, E G A

2013-01-01

Heat Pump Technology discusses the history, underlying concepts, usage, and advancements in the use of heat pumps. The book covers topics such as the applications and types of heat pumps; thermodynamic principles involved in heat pumps such as internal energy, enthalpy, and exergy; and natural heat sources and energy storage. Also discussed are topics such as the importance of the heat pump in the energy industry; heat pump designs and systems; the development of heat pumps over time; and examples of practical everyday uses of heat pumps. The text is recommended for those who would like to kno

Liquid metal pump

Science.gov (United States)

Pennell, William E.

1982-01-01

The liquid metal pump comprises floating seal rings and attachment of the pump diffuser to the pump bowl for isolating structural deflections from the pump shaft bearings. The seal rings also eliminate precision machining on large assemblies by eliminating the need for a close tolerance fit between the mounting surfaces of the pump and the seals. The liquid metal pump also comprises a shaft support structure that is isolated from the pump housing for better preservation of alignment of shaft bearings. The shaft support structure also allows for complete removal of pump internals for inspection and repair.

Liquid metal pump

International Nuclear Information System (INIS)

Pennell, W.E.

1982-01-01

The liquid metal pump comprises floating seal rings and attachment of the pump diffuser to the pump bowl for isolating structural deflections from the pump shaft bearings. The seal rings also eliminate precision machining on large assemblies by eliminating the need for a close tolerance fit between the mounting surfaces of the pump and the seals. The liquid metal pump also comprises a shaft support structure that is isolated from the pump housing for better preservation of alignment of shaft bearings. The shaft support structure also allows for complete removal of pump internals for inspection and repair

Heat pumps

CERN Document Server

Brodowicz, Kazimierz; Wyszynski, M L; Wyszynski

2013-01-01

Heat pumps and related technology are in widespread use in industrial processes and installations. This book presents a unified, comprehensive and systematic treatment of the design and operation of both compression and sorption heat pumps. Heat pump thermodynamics, the choice of working fluid and the characteristics of low temperature heat sources and their application to heat pumps are covered in detail.Economic aspects are discussed and the extensive use of the exergy concept in evaluating performance of heat pumps is a unique feature of the book. The thermodynamic and chemical properties o

Indication and short-term clinical outcomes of high-risk percutaneous coronary intervention with microaxial Impella® pump: results from the German Impella® registry.

Science.gov (United States)

Baumann, Stefan; Werner, Nikos; Ibrahim, Karim; Westenfeld, Ralf; Al-Rashid, Fadi; Sinning, Jan-Malte; Westermann, Dirk; Schäfer, Andreas; Karatolios, Konstantinos; Bauer, Timm; Becher, Tobias; Akin, Ibrahim

2018-03-08

Percutaneous coronary intervention (PCI) is an alternative strategy to coronary artery bypass grafting (CABG) in patients with high perioperative risk. The microaxial Impella ® pump (Abiomed, Danvers, MA, USA), used as prophylactic and temporary support, is currently the most common device for "protected high-risk PCI" to ensure hemodynamic stability during complex coronary intervention. The study is an observational, retrospective multi-center registry. Patients from nine tertiary hospitals in Germany, who have undergone protected high-risk PCI, are included in the present study. A total of 154 patients (mean age 72.6-10.8 years, 75.3% male) were enrolled. The majority were at a high operative risk illustrated by a logistic EuroSCORE of 14.7-17.4. The initial SYNTAX score was 32.0-13.3, indicating very complex CAD and could be reduced to 14.1-14.3 (p study show that protected PCI is a safe and effective approach to revascularize high-risk patients with complex coronary anatomy and comorbidities.

Experimental Study on Series Operation of Sliding Vane Pump and Centrifugal Pump

OpenAIRE

Li, Tao; Zhang, Weiming; Jiang, Ming; Li, Zhengyang

2013-01-01

A platform for sliding vane pump and centrifugal pump tests is installed to study the series operation of them under different characteristics of pipeline. Firstly, the sliding vane pump and the centrifugal pump work independently, and the performance is recorded. Then, the two types of pumps are combined together, with the sliding vane pump acting as the feeding pump. Comparison is made between the performance of the independently working pump and the performance of series operation pump. Re...

Centrifugal pump handbook

CERN Document Server

Pumps, Sulzer

2010-01-01

This long-awaited new edition is the complete reference for engineers and designers working on pump design and development or using centrifugal pumps in the field. This authoritative guide has been developed with access to the technical expertise of the leading centrifugal pump developer, Sulzer Pumps. In addition to providing the most comprehensive centrifugal pump theory and design reference with detailed material on cavitation, erosion, selection of materials, rotor vibration behavior and forces acting on pumps, the handbook also covers key pumping applications topics and operational

Practical and efficient magnetic heat pump

Science.gov (United States)

Brown, G. V.

1978-01-01

Method for pumping heat magnetically at room temperature is more economical than existing refrigeration systems. Method uses natural magneto-thermal effect of gadolinium metal to establish temperature gradient across length of tube. Regenerative cyclic process in which gadolinium sample is magnetized and gives off heat at one end of tube, and then is demagnetized at other end to absorb heat has established temperature gradients of 144 degrees F in experiments near room temperature. Other materials with large magnetothermal effects can be used below room temperature. Possible commercial applications include freeze-drying and food processing, cold storage, and heating and cooling of buildings, plants, and ships.

Investigation of CFD calculation method of a centrifugal pump with unshrouded impeller

Science.gov (United States)

Wu, Dazhuan; Yang, Shuai; Xu, Binjie; Liu, Qiaoling; Wu, Peng; Wang, Leqin

2014-03-01

Currently, relatively large errors are found in numerical results in some low-specific-speed centrifugal pumps with unshrouded impeller because the effect of clearances and holes are not accurately modeled. Establishing an accurate analytical model to improve performance prediction accuracy is therefore necessary. In this paper, a three-dimensional numerical simulation is conducted to predict the performance of a low-specific-speed centrifugal pump, and the modeling, numerical scheme, and turbulent selection methods are discussed. The pump performance is tested in a model pump test bench, and flow rate, head, power and efficiency of the pump are obtained. The effect of taking into consideration the back-out vane passage, clearance, and balance holes is analyzed by comparing it with experimental results, and the performance prediction methods are validated by experiments. The analysis results show that the pump performance can be accurately predicted by the improved method. Ignoring the back-out vane passage in the calculation model of unshrouded impeller is found to generate better numerical results. Further, the calculation model with the clearances and balance holes can obviously enhance the numerical accuracy. The application of disconnect interface can reduce meshing difficulty but increase the calculation error at the off-design operating point at the same time. Compared with the standard k-ɛ, renormalization group k-ɛ, and Spalart-Allmars models, the Realizable k-ɛ model demonstrates the fastest convergent speed and the highest precision for the unshrouded impeller flow simulation. The proposed modeling and numerical simulation methods can improve the performance prediction accuracy of the low-specific-speed centrifugal pumps, and the modeling method is especially suitable for the centrifugal pump with unshrouded impeller.

Causes and indications for reoperation in valve replacement and coronary artery bypass graft (CABG in 915 patients in cardiac surgery department in Imam Khomeini Hospital, 1374-77

Directory of Open Access Journals (Sweden)

Radmehr H

2001-08-01

Full Text Available Valvular and coronary artery disease are among the most important causes of disability and death in the world and Iran as well. Every year, half a million death because of these diseases is reported in United State. The incidence of degenerative and valvular diseases of heart is increasing. Considering the industrialization of our country, the incidence of these kind of problems are increasing as well. In this study, there is an attempt to recognize the causes of cardiac surgery. We conducted a retrospective study in 915 cardiac surgery patients (630 CABG and 285 valve replacement from 1374 to 1377. In CABG patients, there were 46 cases of reoperation (78.3 percent male 21.7 percent female. The most reoperations for bleeding was less than 24 hours in 90.3 percent. In valvular patients the causes of reoperation were: A Valvular complications (female/male=3/1, B Non valvular complications (female/male=1/3. The most common nonvalvular complication was bleeding (66.6 percent. The most common valvular complication was bioprosthetic valve degeneration. The meantime between two operation in valvular complications was 11.8 years. In all cases (915 the incidence of bleeding was 3.8 percent, mediastinitis 0.8 percent, cardiac tamponade 0.8 percent and GI bleeding 0.5 percent.

Evaluating the pacemaker effect with the pump parameter of gated blood-pool imaging

International Nuclear Information System (INIS)

Cheng Muhua

1995-01-01

13 normal controls and 27 patients with ventricular pacemaker had undergone planar gated blood-pool imaging in different conditions. Result shows: (1) Pump parameters can successfully reflect therapeutic effect of pacemaker among them EMP is the most valuable parameter for evaluating the cardiac pumping effect. (2) After implantation of the ventricular pacemaker, the LVEF did not increase, but the CO and EMP was significantly increased. (3) Compared with right ventricular demand pacemaker, the rate-responsive ventricular pacemaker give better hemodynamic benefit at exercise condition. (4) Through restrained cardiac pacemaker the functional change was analyzed on or off pace, and monitoring the cardiac function itself after the pacemaker was implanted

Penis Pump

Science.gov (United States)

... your appointment might be less involved. Choosing a penis pump Some penis pumps are available without a ... it doesn't get caught in the ring. Penis pumps for penis enlargement Many advertisements in magazines ...

Pumping characteristics of sputter ion pump (SIP) and titanium sublimation pump (TSP) combination

International Nuclear Information System (INIS)

Ratnakala, K.C.; Patel, R.J.; Bhavsar, S.T.; Pandiyar, M.L.; Ramamurthi, S.S.

1995-01-01

For achieving hydrocarbon free, clean ultra high vacuum, SIP-TSP combination is one of the ideal choice for pumping. For the SRS facility in Centre for Advanced Technology (CAT), we are utilising this combination, enmass. For this purpose, two modules of these combination set-ups are assembled, one with the TSP as an integral part of SIP and the other, with TSP as a separate pump mounted on the top of SIP. The pump bodies were vacuum degassed at 700 degC at 10 -5 mbar for 3 hrs. An ultimate vacuum of 3 x 10 -11 mbar was achieved, after a bake-out at 250 degC for 4 hrs, followed by continuous SIP pumping for 48 hrs, with two TSP flashing at approximately 10 hrs interval. The pump-down patterns as well as the pressure-rise patterns are studied. (author). 2 refs., 5 figs

Kinetic energy storage of off-peak electricity

International Nuclear Information System (INIS)

Simpson, L.A.; Oldaker, I.E.; Stermscheg, J.

1975-09-01

The concept of using large flywheels to store off-peak electricity has been considered. The development of high strength composite materials has made possible improvements in the energy storage capacity of such devices. The problems involved in designing large flywheels and their economic advantages over alternative means of energy storage are discussed. The economic arguments are based on the present or near future capabilities and costs of structural composite materials. The flywheel costs turn out to be considerably higher than for many alternative schemes including advanced batteries, gas turbine generators and pumped storage schemes. (author)

Pulsed and cw laser oscillations in LiF:F-2 color center crystal under laser diode pumping.

Science.gov (United States)

Basiev, Tasoltan T; Vassiliev, Sergey V; Konjushkin, Vasily A; Gapontsev, Valentin P

2006-07-15

Continuous-wave laser oscillations in LiF:F-2 crystal optically pumped by a laser diode at 970 nm were demonstrated for what is believed to be the first time. The slope efficiency of 14% and conversion efficiency of 5.5% were achieved for 80 micros pump pulse duration and 5 Hz pulse repetition rate. An efficiency twice as low was measured at a 6.25 kHz pulse repetition rate (50% off-duty factor) and in cw mode of laser operation.

The control of convection by fuelling and pumping in the JET pumped divertor

Energy Technology Data Exchange (ETDEWEB)

Harbour, P J; Andrew, P; Campbell, D; Clement, S; Davies, S; Ehrenberg, J; Erents, S K; Gondhalekar, A; Gadeberg, M; Gottardi, N; Von Hellermann, M; Horton, L; Loarte, A; Lowry, C; Maggi, C; McCormick, K; O` Brien, D; Reichle, R; Saibene, G; Simonini, R; Spence, J; Stamp, M; Stork, D; Taroni, A; Vlases, G [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking

1994-07-01

Convection from the scrape-off layer (SOL) to the divertor will control core impurities, if it retains them in a cold, dense, divertor plasma. This implies a high impurity concentration in the divertor, low at its entrance. Particle flux into the divertor entrance can be varied systematically in JET, using the new fuelling and pumping systems. The convection ratio has been estimated for various conditions of operation. Particle convection into the divertor should increase thermal convection, decreasing thermal conduction, and temperature and density gradients along the magnetic field, hence increasing the frictional force and decreasing the thermal force on impurities. Changes in convection in the SOL, caused by gaseous fuelling, have been studied, both experimentally in the JET Mk I divertor and with EDGE2/NIMBUS. 1 ref., 4 figs., 1 tab.

Generalizability of EXCEL and NOBLE results to a large registry population with unprotected left main coronary artery disease.

Science.gov (United States)

Lee, Pil Hyung; Kang, Se Hun; Han, Seungbong; Ahn, Jung-Min; Bae, Jae Seok; Lee, Cheol Hyun; Kang, Soo-Jin; Lee, Seung-Whan; Kim, Young-Hak; Lee, Cheol Whan; Park, Seong-Wook; Park, Duk-Woo; Park, Seung-Jung

2017-12-01

The aim of this study was to determine how trial-based findings of EXCEL and NOBLE might be interpreted and generalizable in 'real-world' settings with comparison of data from the large-scaled, all-comer Interventional Research Incorporation Society-Left MAIN Revascularization (IRIS-MAIN) registry. We compared baseline clinical and procedural characteristics and also determined how the relative treatment effect of percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) was different in EXCEL and NOBLE, compared with those of the multicenter, IRIS-MAIN registry (n=2481). The primary outcome for between-study comparison was a composite of death, myocardial infarction (MI), or stroke. There were between-study differences in patient risk profiles (age, BMI, diabetes, and clinical presentation), lesion complexities, and procedural characteristics (stent type, the use of off-pump surgery, and radial artery); the proportion of diabetes and acute coronary syndrome was particularly lower in NOBLE than in other studies. Although there was interstudy heterogeneity for the protocol definition of MI, the risks for serious composite outcome of death, MI, or stroke were similar between PCI and CABG in EXCEL [hazard ratio (HR): 1.00; 95% confidence interval (CI): 0.79-1.26; P=0.98] and in the matched cohort of IRIS-MAIN (HR: 1.08; 95%CI: 0.85-1.38; P=0.53), whereas it was significantly higher after PCI than after CABG in NOBLE (HR: 1.47; 95%CI: 1.06-2.05; P=0.02), which was driven by more common MI and stroke after PCI. In the comparison of a large-sized, all-comer registry, the EXCEL trial might represent better generalizability with respect to baseline characteristics and observed clinical outcomes compared with the NOBLE trial.

New concepts and new design of permanent maglev rotary artificial heart blood pumps.

Science.gov (United States)

Qian, K X; Zeng, P; Ru, W M; Yuan, H Y

2006-05-01

According to tradition, permanent maglev cannot achieve stable equilibrium. The authors have developed, to the contrary, two stable permanent maglev impeller blood pumps. The first pump is an axially driven uni-ventricular assist pump, in which the rotor with impeller is radially supported by two passive magnetic bearings, but has one point contact with the stator axially at standstill. As the pump raises its rotating speed, the increasing hydrodynamic force of fluid acting on the impeller will make the rotor taking off from contacting point and disaffiliate from the stator. Then the rotor becomes fully suspended. The second pump is a radially driven bi-ventricular assist pump, i.e., an impeller total artificial heart. Its rotor with two impellers on both ends is supported by two passive magnetic bearings, which counteract the attractive force between rotor magnets and stator coil iron core. The rotor is affiliated to the stator radially at standstill and becomes levitated during rotation. Therefore, the rotor keeps concentric with stator during rotation but eccentric at standstill, as is confirmed by rotor position detection with Honeywell sensors. It concludes that the permanent maglev needs action of a non-magnetic force to achieve stability but a rotating magnetic levitator with high speed and large inertia can maintain its stability merely with passive magnetic bearings.

Consequences in the pumps operation during a large loss of coolant accident

International Nuclear Information System (INIS)

Santos, G.A. dos; Sabundjian, G.

1991-08-01

The event of living on or turning off the operation of the Reactor Cooling Pumps - RCPs, in the case of a Loss of Coolant Accident - LOCA, has been a reason of a lot of studies after the Three Mile Island 2 accident. Thus, it was investigated a large break LOCA in the cold leg of Angra 1, with the RELAP4/MOD5 Code during the blowdown. The attained results indicated that the best performance of the core was in the case where the RCPs had been turned off in the beginning of the transient, when compared with different operation conditions of the RCPs. (author)

Cirurgia coronária com condutos arteriais múltiplos sem circulação extracorpórea Off-pump coronary artery bypass with multiple arterial conduits

Directory of Open Access Journals (Sweden)

Daniel Navia

2005-03-01

circulação extracorpórea utilizando condutos arteriais para a doença de múltiplos vasos é factível com baixa morbimortalidade em 30 dias.OBJECTIVE: To analyze intra-hospital results in patients undergoing elective off-pump total arterial revascularization and identify morbidity and mortality predictors using this surgical strategy. METHOD: From May 1999 to February 2004, 203 myocardial revascularization procedures with total arterial revascularization without cardiopulmonary bypass (off-pump were carried out in patients with multivessel disease (three vessels 81.7 %, one vessel disease was excluded. We report pre-surgical variables and co-morbidities: average age 63.9 ± 9.13 years, men 182 (89.5%, hypertension 132 (65%, smokers 125 (61%, hypercholesterolemia 152 (74.8%, previous myocardial infarction (> 30 days 73 (35%, moderate to severe ventricular dysfunction 31 (15%, redo five (2.5%. Total arterial revascularization included T-grafts and sequential grafts with left internal mammary (100%, right internal mammary (56.6% and radial (63% arteries. The total number of distal anastomosis was 576 (mean of three grafts/patient, all carried out with external mechanical stabilizers. There were no proximal aortic anastomoses. Conversion to on-pump surgery occurred in three (1.5% patients; 90% of the patients was extubated in the operating room. The multiple logistic regression test was used for statistical analysis. RESULTS: The postoperative incidence of atrial fibrillation was 12.8% (26, oligoanuric renal failure 3% (six, dialysis 0.49% (one, postoperative myocardial infarction 1.47% (three, low cardiac output 4% (eight, Redo for bleeding 1.47% (three, mediastinitis 1.47% (three, stroke 1.47% (three. Intra-hospital mortality was 2.45% (five. The only independent 30 day morbidity predictor was age (p=0.033; OR 1.04; IC 95%: 1-1.08. CONCLUSION: Off-pump myocardial revascularization with arterial conduits for multiple vessel disease is feasible with a low 30-day morbidity

Centrifugal pumps

CERN Document Server

Gülich, Johann Friedrich

2014-01-01

This book gives an unparalleled, up-to-date, in-depth treatment of all kinds of flow phenomena encountered in centrifugal pumps including the complex interactions of fluid flow with vibrations and wear of materials. The scope includes all aspects of hydraulic design, 3D-flow phenomena and partload operation, cavitation, numerical flow calculations, hydraulic forces, pressure pulsations, noise, pump vibrations (notably bearing housing vibration diagnostics and remedies), pipe vibrations, pump characteristics and pump operation, design of intake structures, the effects of highly viscous flows, pumping of gas-liquid mixtures, hydraulic transport of solids, fatigue damage to impellers or diffusers, material selection under the aspects of fatigue, corrosion, erosion-corrosion or hydro-abrasive wear, pump selection, and hydraulic quality criteria. As a novelty, the 3rd ed. brings a fully analytical design method for radial impellers, which eliminates the arbitrary choices inherent to former design procedures. The d...

Effect of Exogenous Albumin on the Incidence of Postoperative Acute Kidney Injury in Patients Undergoing Off-pump Coronary Artery Bypass Surgery with a Preoperative Albumin Level of Less Than 4.0 g/dl.

Science.gov (United States)

Lee, Eun-Ho; Kim, Wook-Jong; Kim, Ji-Yeon; Chin, Ji-Hyun; Choi, Dae-Kee; Sim, Ji-Yeon; Choo, Suk-Jung; Chung, Cheol-Hyun; Lee, Jae-Won; Choi, In-Cheol

2016-05-01

Hypoalbuminemia may increase the risk of acute kidney injury (AKI). The authors investigated whether the immediate preoperative administration of 20% albumin solution affects the incidence of AKI after off-pump coronary artery bypass surgery. In this prospective, single-center, randomized, parallel-arm double-blind trial, 220 patients with preoperative serum albumin levels less than 4.0 g/dl were administered 100, 200, or 300 ml of 20% human albumin according to the preoperative serum albumin level (3.5 to 3.9, 3.0 to 3.4, or less than 3.0 g/dl, respectively) or with an equal volume of saline before surgery. The primary outcome measure was AKI incidence after surgery. Postoperative AKI was defined by maximal AKI Network criteria based on creatinine changes. Patient characteristics and perioperative data except urine output during surgery were similar between the two groups studied, the albumin group and the control group. Urine output (median [interquartile range]) during surgery was higher in the albumin group (550 ml [315 to 980]) than in the control group (370 ml [230 to 670]; P = 0.006). The incidence of postoperative AKI in the albumin group was lower than that in the control group (14 [13.7%] vs. 26 [25.7%]; P = 0.048). There were no significant between-group differences in severe AKI, including renal replacement therapy, 30-day mortality, and other clinical outcomes. There were no significant adverse events. Administration of 20% exogenous albumin immediately before surgery increases urine output during surgery and reduces the risk of AKI after off-pump coronary artery bypass surgery in patients with a preoperative serum albumin level of less than 4.0 g/dl.

Tritium system for a tokamak reactor with a self-pumped limiter

International Nuclear Information System (INIS)

Hassanein, A.M.; Sze, D.K.

1986-01-01

Benefits of the self-pumping system are the elimination of vacuum ducts, pumps, and penetration shielding (except for a very small startup system), and the reduction of tritium recycle and refueling. In addition, a self-pumped system may perform better and last longer than alternative systems such as a pumped limiter. The reference case here is a self-cooled lithium/vanadium blanket with a first wall/limiter. This concept combines the functions of first wall and limiter into a single first-wall structure. The wall is shaped in accordance with the outermost plasma flux surface. Trapping material is added to the plasma scrape-off or edge region where it is transported to the wall. The entire wall area is used for helium trapping. The tritium inventory, tritium permeation rate, and plasma protium concentration for the vanadium wall as a function of the number of years of operation are calculated. The tritium inventory is acceptable, the protium concentration in the plasma is acceptably small, and the tritium permeation rate is moderate. At the start of operation, it is equal to about five times the tritium burnup rate. This tritium will enter the coolant and the cost of the blanket tritium recovery system will be higher

Pumping characteristics of roots blower pumps for light element gases

International Nuclear Information System (INIS)

Hiroki, Seiji; Abe, Tetsuya; Tanzawa, Sadamitsu; Nakamura, Jun-ichi; Ohbayashi, Tetsuro

2002-07-01

The pumping speed and compression ratio of the two-stage roots blower pumping system were measured for light element gases (H 2 , D 2 and He) and for N 2 , in order to assess validity of the ITER torus roughing system as an ITER R and D task (T234). The pumping system of an Edwards EH1200 (nominal pumping speed of 1200 m 3 /s), two EH250s (ibid. 250 m 3 /s) and a backing pump (ibid. 100 m 3 /s) in series connection was tested under PNEUROP standards. The maximum pumping speeds of the two-stage system for D 2 and N 2 were 1200 and 1300 m 3 /h, respectively at 60 Hz, which satisfied the nominal pumping speed. These experimental data support the design validity of the ITER torus roughing system. (author)

PUMPS

Science.gov (United States)

Thornton, J.D.

1959-03-24

A pump is described for conveving liquids, particure it is not advisable he apparatus. The to be submerged in the liquid to be pumped, a conduit extending from the high-velocity nozzle of the injector,and means for applying a pulsating prcesure to the surface of the liquid in the conduit, whereby the surface oscillates between positions in the conduit. During the positive half- cycle of an applied pulse liquid is forced through the high velocity nozzle or jet of the injector and operates in the manner of the well known water injector and pumps liquid from the main intake to the outlet of the injector. During the negative half-cycle of the pulse liquid flows in reverse through the jet but no reverse pumping action takes place.

Comparison of heat pump performance using fin-and-tube and microchannel heat exchangers under frost conditions

International Nuclear Information System (INIS)

Shao, Liang-Liang; Yang, Liang; Zhang, Chun-Lu

2010-01-01

Vapor compression heat pumps are drawing more attention in energy saving applications. Microchannel heat exchangers can provide higher performance via less core volume and reduce system refrigerant charge, but little is known about their performance in heat pump systems under frosting conditions. In this study, the system performance of a commercial heat pump using microchannel heat exchangers as evaporator is compared with that using conventional finned-tube heat exchangers numerically and experimentally. The microchannel and finned-tube heat pump system models used for comparison of the microchannel and finned-tube evaporator performance under frosting conditions were developed, considering the effect of maldistribution on both refrigerant and air sides. The quasi-steady-state modeling results are in reasonable agreement with the test data under frost conditions. The refrigerant-side maldistribution is found remarkable impact on the microchannel heat pump system performance under the frost conditions. Parametric study on the fan speed and the fin density under frost conditions are conducted as well to figure out the best trade-off in the design of frost tolerant evaporators. (author)

Cryosorption pumping of deuterium by MS-5A at temperatures above 4.2 K for fusion reactor applications

International Nuclear Information System (INIS)

Fisher, P.W.; Watson, J.S.

1977-01-01

An Excalibur CVR-1106 cryosorption pump was fitted with a special cooling system to permit measurement of deuterium pumping speeds at temperatures between 6 and 20 0 K. Pumping speeds were found to be a function of feed rate, loading prior to each run, loading during runs, and thermal treatment between runs. At feed rates -4 Torr-l s -1 cm -2 , speeds were near 1 l s -1 cm -2 initially and declined monotonically with loading. At high feed rates, speeds reached a higher maximum (approx. 3 l s -1 cm -2 ) but also generally declined with loading; however, after 50 to 100 Torr l had accumulated, the pump underwent a spontaneous transition which effected a return to the original (high) pumping speed. This transition was accompanied by pressure spikes in the test chamber and temperature spikes in the sieve panel. Initial speeds for each consecutive run equaled the final speed for the preceding run if the pump was maintained at operating temperature; however, if it was warmed to 77 0 K and recooled, a restoration to the maximum speed was observed at the beginning of the next run

Regulatory analysis for Generic Issue 23: Reactor coolant pump seal failure. Draft report for comment

Energy Technology Data Exchange (ETDEWEB)

Shaukat, S K; Jackson, J E; Thatcher, D F

1991-04-01

This report presents the regulatory/backfit analysis for Generic Issue 23 (GI-23), 'Reactor Coolant Pump Seal Failure'. A backfit analysis in accordance with 10 CFR 50.109 is presented in Appendix E. The proposed resolution includes quality assurance provisions for reactor coolant pump seals, instrumentation and procedures for monitoring seal performance, and provisions for seal cooling during off-normal plant conditions involving loss of all seal cooling such as station blackout. Research, technical data, and other analyses supporting the resolution of this issue are summarized in the technical findings report (NUREG/CR-4948) and cost/benefit report (NUREG/CR-5167). (author)

An enhancement of spin polarization by multiphoton pumping in semiconductors

Energy Technology Data Exchange (ETDEWEB)

Miah, M. Idrish, E-mail: m.miah@griffith.edu.au [Queensland Micro- and Nanotechnology Centre, Griffith University, Nathan, Brisbane, QLD 4111 (Australia); Department of Physics, University of Chittagong, Chittagong 4331 (Bangladesh)

2011-08-15

Highlights: {yields} Multiphoton pumping and spin generation in semiconductors. {yields} Optical selection rules for inter-band transitions. {yields} Calculations of spin polarization using band-energy model and the second order perturbation theory. {yields} Enhancement of the electronic spin polarization. - Abstract: A pump-probe spectroscopic study has been carried out in zinc-blende bulk semiconductors. In the semiconductor samples, a spin-polarized carrier population is produced by the absorption of a monochromatic circularly polarized light beam with two-photon energy above the direct band gap in bulk semiconductors. The production of a carrier population with a net spin is a consequence of the optical selection rules for the heavy-hole and light-hole valence-to-conduction band transitions. This production is probed by the spin-dependent transmission of the samples in the time domain. The spin polarization of the conduction-band-electrons in dependences of delay of the probe beam as well as of pumping photon energy is estimated. The spin polarization is found to depolarize rapidly for pumping energy larger than the energy gap of the split-off band to the conduction band. From the polarization decays, the spin relaxation times are also estimated. Compared to one-photon pumping, the results, however, show that an enhancement of the spin-polarization is achieved by multiphoton excitation of the samples. The experimental results are compared with those obtained in calculations using second order perturbation theory of the spin transport model. A good agreement between experiment and theory is obtained. The observed results are discussed in details.

An enhancement of spin polarization by multiphoton pumping in semiconductors

International Nuclear Information System (INIS)

Miah, M. Idrish

2011-01-01

Highlights: → Multiphoton pumping and spin generation in semiconductors. → Optical selection rules for inter-band transitions. → Calculations of spin polarization using band-energy model and the second order perturbation theory. → Enhancement of the electronic spin polarization. - Abstract: A pump-probe spectroscopic study has been carried out in zinc-blende bulk semiconductors. In the semiconductor samples, a spin-polarized carrier population is produced by the absorption of a monochromatic circularly polarized light beam with two-photon energy above the direct band gap in bulk semiconductors. The production of a carrier population with a net spin is a consequence of the optical selection rules for the heavy-hole and light-hole valence-to-conduction band transitions. This production is probed by the spin-dependent transmission of the samples in the time domain. The spin polarization of the conduction-band-electrons in dependences of delay of the probe beam as well as of pumping photon energy is estimated. The spin polarization is found to depolarize rapidly for pumping energy larger than the energy gap of the split-off band to the conduction band. From the polarization decays, the spin relaxation times are also estimated. Compared to one-photon pumping, the results, however, show that an enhancement of the spin-polarization is achieved by multiphoton excitation of the samples. The experimental results are compared with those obtained in calculations using second order perturbation theory of the spin transport model. A good agreement between experiment and theory is obtained. The observed results are discussed in details.

Solar-based groundwater pumping for irrigation: Sustainability, policies, and limitations

International Nuclear Information System (INIS)

Closas, Alvar; Rap, Edwin

2017-01-01

The increasing demand for solar-powered irrigation systems in agriculture has spurred a race for projects as it potentially offers a cost-effective and sustainable energy solution to off-grid farmers while helping food production and sustaining livelihoods. As a result, countries such as Morocco and Yemen have been promoting this technology for farmers and national plans with variable finance and subsidy schemes like in India have been put forward. By focusing on the application of solar photovoltaic (PV) pumping systems in groundwater-fed agriculture, this paper highlights the need to further study the impacts, opportunities and limitations of this technology within the Water-Energy-Food (WEF) nexus. It shows how most policies and projects promoting solar-based groundwater pumping for irrigation through subsidies and other incentives overlook the real financial and economic costs of this solution as well as the availability of water resources and the potential negative impacts on the environment caused by groundwater over-abstraction. There is a need to monitor groundwater abstraction, targeting subsidies and improving the knowledge and monitoring of resource use. Failing to address these issues could lead to further groundwater depletion, which could threaten the sustainability of this technology and dependent livelihoods in the future. - Highlights: • Solar pumping projects require assessing environmental and financial sustainability. • Subsidies for solar pumping need to be tied to groundwater pumping regulations. • Solar irrigation projects need to consider groundwater availability and depletion. • Data and monitoring are needed to improve water resource impact assessments.

Pump characteristics and applications

CERN Document Server

Volk, Michael

2013-01-01

Providing a wealth of information on pumps and pump systems, Pump Characteristics and Applications, Third Edition details how pump equipment is selected, sized, operated, maintained, and repaired. The book identifies the key components of pumps and pump accessories, introduces the basics of pump and system hydraulics as well as more advanced hydraulic topics, and details various pump types, as well as special materials on seals, motors, variable frequency drives, and other pump-related subjects. It uses example problems throughout the text, reinforcing the practical application of the formulae

A finite element model for temperature induced electrohydrodynamic pumping horizontal pipes

International Nuclear Information System (INIS)

Kuo, B.S.; Chato, J.C.; Crowley, J.M.

1984-01-01

The electrohydrodynamic (EHD) pumping created by an axially traveling electric wave superimposed on a dielectric fluid with a transverse temperature field has abeen investigated using a finite element technique. Both forward wave (cooled wall) and backward wave (heated wall) modes of operation have been considered. The secondary flow generated by buoyancy effects in the cross section were included in the calculations. The driving effects of the traveling wave were calculated by assuming that only the average electric shear stress produced movement while the sinusoidally varying transient effects cancelled out. The results show that effective pumping can be achieved without the use of a grounding electrode along the axis of the tube but the design parameters have to be carefully selected. Increasing the diameter-to-wavelength ratios increases the velocities. The flow rate is maximum at an optimum frequency, about 0.8 Hz in our typical cases, but it drops off rather quickly as he frequency is either decreased or increased. The velocities were much less sensitive to heating/cooling rates (i.e., Rayleigh numbers) or changes in the magnitude of the electrical conductivity values. Although the pumping effect increases approximately as the square of the maximum applied electric potential, in practice, the electric gradients are limited by the dielectric strength of the fluid. The results indicate the EHD heat exchanger/pumps can be feasible alternatives to mechanical pumps in certain circumstances when dielectric liquids require both heat transfer and circulation

Pump element for a tube pump

DEFF Research Database (Denmark)

2011-01-01

The invention relates to a tube pump comprising a tube and a pump element inserted in the tube, where the pump element comprises a rod element and a first and a second non-return valve member positioned a distance apart on the rod element. The valve members are oriented in the same direction...... relative to the rod element so as to allow for a fluid flow in the tube through the first valve member, along the rod element, and through the second valve member. The tube comprises an at least partly flexible tube portion between the valve members such that a repeated deformation of the flexible tube...... portion acts to alternately close and open the valve members thereby generating a fluid flow through the tube. The invention further relates to a pump element comprising at least two non-return valve members connected by a rod element, and for insertion in an at least partly flexible tube in such tube...

Pumping behavior of sputtering ion pump

Energy Technology Data Exchange (ETDEWEB)

Chou, T.S.; Bittner, J.; Schuchman, J.

1991-12-31

To optimize the design of a distributed ion pump (DIP) for the Superconducting X-Ray Lithography Source (SXLS) the stability of the rotating electron cloud at very high magnetic field beyond transition, must be re-examined. In this work the pumping speed and frequency spectrum of a DIP at various voltages (1 to 10 KV) and various magnetic fields (0.1 to 4 Tesla) are measured. Three cell diameters 10 mm, 5 mm and 2.5 mm, each 8 mm long, and with 3 or 4 mm gaps between anode and cathode are investigated. In this study both the titanium cathodes and the stainless steel anode plates are perforated with holes comparable in size to the anode cell diameters. Only the partially saturated pumping behavior is under investigation. The ultimate pressure and conditioning of the pump will be investigated at a later date when the stability criterion for the electron cloud is better understood.

Pumping behavior of sputtering ion pump

Energy Technology Data Exchange (ETDEWEB)

Chou, T.S.; Bittner, J.; Schuchman, J.

1991-01-01

To optimize the design of a distributed ion pump (DIP) for the Superconducting X-Ray Lithography Source (SXLS) the stability of the rotating electron cloud at very high magnetic field beyond transition, must be re-examined. In this work the pumping speed and frequency spectrum of a DIP at various voltages (1 to 10 KV) and various magnetic fields (0.1 to 4 Tesla) are measured. Three cell diameters 10 mm, 5 mm and 2.5 mm, each 8 mm long, and with 3 or 4 mm gaps between anode and cathode are investigated. In this study both the titanium cathodes and the stainless steel anode plates are perforated with holes comparable in size to the anode cell diameters. Only the partially saturated pumping behavior is under investigation. The ultimate pressure and conditioning of the pump will be investigated at a later date when the stability criterion for the electron cloud is better understood.

Analysis of pumping tests: Significance of well diameter, partial penetration, and noise

Science.gov (United States)

Heidari, M.; Ghiassi, K.; Mehnert, E.

1999-01-01

The nonlinear least squares (NLS) method was applied to pumping and recovery aquifer test data in confined and unconfined aquifers with finite diameter and partially penetrating pumping wells, and with partially penetrating piezometers or observation wells. It was demonstrated that noiseless and moderately noisy drawdown data from observation points located less than two saturated thicknesses of the aquifer from the pumping well produced an exact or acceptable set of parameters when the diameter of the pumping well was included in the analysis. The accuracy of the estimated parameters, particularly that of specific storage, decreased with increases in the noise level in the observed drawdown data. With consideration of the well radii, the noiseless drawdown data from the pumping well in an unconfined aquifer produced good estimates of horizontal and vertical hydraulic conductivities and specific yield, but the estimated specific storage was unacceptable. When noisy data from the pumping well were used, an acceptable set of parameters was not obtained. Further experiments with noisy drawdown data in an unconfined aquifer revealed that when the well diameter was included in the analysis, hydraulic conductivity, specific yield and vertical hydraulic conductivity may be estimated rather effectively from piezometers located over a range of distances from the pumping well. Estimation of specific storage became less reliable for piezemeters located at distances greater than the initial saturated thickness of the aquifer. Application of the NLS to field pumping and recovery data from a confined aquifer showed that the estimated parameters from the two tests were in good agreement only when the well diameter was included in the analysis. Without consideration of well radii, the estimated values of hydraulic conductivity from the pumping and recovery tests were off by a factor of four.The nonlinear least squares method was applied to pumping and recovery aquifer test data in

Multiple pump housing

Science.gov (United States)

Donoho, II, Michael R.; Elliott; Christopher M.

2010-03-23

A fluid delivery system includes a first pump having a first drive assembly, a second pump having a second drive assembly, and a pump housing. At least a portion of each of the first and second pumps are located in the housing.

Assessing the energy efficiency of pumps and pump units background and methodology

CERN Document Server

Bernd Stoffel, em Dr-Ing

2015-01-01

Assessing the Energy Efficiency of Pumps and Pump Units, developed in cooperation with Europump, is the first book available providing the background, methodology, and assessment tools for understanding and calculating energy efficiency for pumps and extended products (pumps+motors+drives). Responding to new EU requirements for pump efficiency, and US DOE exploratory work in setting pump energy efficiency guidelines, this book provides explanation, derivation, and illustration of PA and EPA methods for assessing energy efficiency. It surveys legislation related to pump energy eff

Effect of Non-linear Velocity Loss Changes in Pumping Stage of Hydraulic Ram Pumps on Pumping Discharge Rate

Directory of Open Access Journals (Sweden)

Reza Fatahialkouhi

2018-03-01

Full Text Available The ram pump is a device which pumps a portion of input discharge to the pumping system in a significant height by using renewable energy of water hammer. The complexities of flow hydraulic on one hand and on the other hand the use of simplifying assumptions in ram pumps have caused errors in submitted analytical models for analyzing running cycle of these pumps. In this study it has been tried to modify the governing analytical model on hydraulic performance of these pumps in pumping stage. In this study by creating a logical division, the cycle of the ram pump was divided into three stages of acceleration, pumping and recoil and the governing equations on each stage of cycling are presented by using method of characteristics. Since the closing of impulse valve is nonlinear, velocity loss in pumping stage is considered nonlinearly. Also the governing equations in pumping stage were modified by considering disc elasticity of impulse valve and changing volume of the pump body when the water hammer phenomenon is occurred. In order to evaluate results and determine empirical factors of the proposed analytical model, a physical model of the ram pump is made with internal diameter of 51 mm. Results of this study are divided into several parts. In the first part, loss coefficients of the impulse valve were measured experimentally and empirical equations of drag coefficient and friction coefficient of the impulse valve were submitted by using nonlinear regression. In the second part, results were evaluated by using experimental data taken from this study. Evaluation of statistical error functions showed that the proposed model has good accuracy for predicting experimental observations. In the third part, in order to validate the results in pumping stage, the analytical models of Lansford and Dugan (1941 and Tacke (1988 were used and the error functions resulted from prediction of experimental observations were investigated through analytical models of

Revisiting blood transfusion and predictors of outcome in cardiac surgery patients: a concise perspective [version 1; referees: 2 approved

Directory of Open Access Journals (Sweden)

Carlos E Arias-Morales

2017-02-01

Full Text Available In the United States, cardiac surgery-related blood transfusion rates reached new highs in 2010, with 34% of patients receiving blood products. Patients undergoing both complex (coronary artery bypass grafting [CABG] plus valve repair or replacement and non-complex (isolated CABG cardiac surgeries are likely to have comorbidities such as anemia. Furthermore, the majority of patients undergoing isolated CABG have a history of myocardial infarction. These characteristics may increase the risk of complications and blood transfusion requirement. It becomes difficult to demonstrate the association between transfusions and mortality because of the fact that most patients undergoing cardiac surgery are also critically ill. Transfusion rates remain high despite the advances in perioperative blood conservation, such as the intraoperative use of cell saver in cardiac surgery. Some recent prospective studies have suggested that the use of blood products, even in low-risk patients, may adversely affect clinical outcomes. In light of this information, we reviewed the literature to assess the clinical outcomes in terms of 30-day and 1-year morbidity and mortality in transfused patients who underwent uncomplicated CABG surgery.

Revisiting blood transfusion and predictors of outcome in cardiac surgery patients: a concise perspective.

Science.gov (United States)

Arias-Morales, Carlos E; Stoicea, Nicoleta; Gonzalez-Zacarias, Alicia A; Slawski, Diana; Bhandary, Sujatha P; Saranteas, Theodosios; Kaminiotis, Eva; Papadimos, Thomas J

2017-01-01

In the United States, cardiac surgery-related blood transfusion rates reached new highs in 2010, with 34% of patients receiving blood products. Patients undergoing both complex (coronary artery bypass grafting [CABG] plus valve repair or replacement) and non-complex (isolated CABG) cardiac surgeries are likely to have comorbidities such as anemia. Furthermore, the majority of patients undergoing isolated CABG have a history of myocardial infarction. These characteristics may increase the risk of complications and blood transfusion requirement. It becomes difficult to demonstrate the association between transfusions and mortality because of the fact that most patients undergoing cardiac surgery are also critically ill. Transfusion rates remain high despite the advances in perioperative blood conservation, such as the intraoperative use of cell saver in cardiac surgery. Some recent prospective studies have suggested that the use of blood products, even in low-risk patients, may adversely affect clinical outcomes. In light of this information, we reviewed the literature to assess the clinical outcomes in terms of 30-day and 1-year morbidity and mortality in transfused patients who underwent uncomplicated CABG surgery.

Effect of thoracic epidural anesthesia on oxygen delivery and utilization in cardiac surgical patients scheduled to undergo off-pump coronary artery bypass surgery: a prospective study.

Science.gov (United States)

Suryaprakash, Sharadaprasad; Chakravarthy, Murali; Gautam, Mamatha; Gandhi, Anurag; Jawali, Vivek; Patil, Thimmannagowda; Jayaprakash, Krishnamoorthy; Pandey, Saurabh; Muniraju, Geetha

2011-01-01

To evaluate the effect of thoracic epidural anesthesia (TEA) on tissue oxygen delivery and utilization in patients undergoing cardiac surgery. This prospective observational study was conducted in a tertiary referral heart hospital. A total of 25 patients undergoing elective off-pump coronary artery bypass surgery were enrolled in this study. All patients received thoracic epidural catheter in the most prominent inter-vertebral space between C7 and T3 on the day before operation. On the day of surgery, an arterial catheter and Swan Ganz catheter (capable of measuring cardiac index) was inserted. After administering full dose of local anesthetic in the epidural space, serial hemodynamic and oxygen transport parameters were measured for 30 minute prior to administration of general anesthesia, with which the study was culminated. A significant decrease in oxygen delivery index with insignificant changes in oxygen extraction and consumption indices was observed. We conclude that TEA does not affect tissue oxygenation despite a decrease in arterial pressures and cardiac output.

Effect of thoracic epidural anesthesia on oxygen delivery and utilization in cardiac surgical patients scheduled to undergo off-pump coronary artery bypass surgery: A prospective study

Directory of Open Access Journals (Sweden)

Suryaprakash Sharadaprasad

2011-01-01

Full Text Available To evaluate the effect of thoracic epidural anesthesia (TEA on tissue oxygen delivery and utilization in patients undergoing cardiac surgery. This prospective observational study was conducted in a tertiary referral heart hospital. A total of 25 patients undergoing elective off-pump coronary artery bypass surgery were enrolled in this study. All patients received thoracic epidural catheter in the most prominent inter-vertebral space between C7 and T3 on the day before operation. On the day of surgery, an arterial catheter and Swan Ganz catheter (capable of measuring cardiac index was inserted. After administering full dose of local anesthetic in the epidural space, serial hemodynamic and oxygen transport parameters were measured for 30 minute prior to administration of general anesthesia, with which the study was culminated. A significant decrease in oxygen delivery index with insignificant changes in oxygen extraction and consumption indices was observed. We conclude that TEA does not affect tissue oxygenation despite a decrease in arterial pressures and cardiac output.

Performance Analysis Of Single-Pumped And Dual-Pumped Parametric Optical Amplifier

Directory of Open Access Journals (Sweden)

Sandar Myint

2015-06-01

Full Text Available Abstract In this study we present a performance analysis of single-pumped and dual- pumped parametric optical amplifier and present the analysis of gain flatness in dual- pumped Fiber Optical Parametric Amplifier FOPA based on four-wave mixing FWM. Result shows that changing the signal power and pump power give the various gains in FOPA. It is also found out that the parametric gain increase with increase in pump power and decrease in signal power. .Moreover in this paper the phase matching condition in FWM plays a vital role in predicting the gain profile of the FOPAbecause the parametric gain is maximum when the total phase mismatch is zero.In this paper single-pumped parametric amplification over a 50nm gain bandwidth is demonstrated using 500 nm highly nonlinear fiber HNLF and signal achieves about 31dB gain. For dual-pumped parametric amplification signal achieves 26.5dB gains over a 50nm gain bandwidth. Therefore dual-pumped parametric amplifier can provide relatively flat gain over a much wider bandwidth than the single-pumped FOPA.

Residual heat removal pump and low pressure safety injection pump retrofit program

International Nuclear Information System (INIS)

Dudiak, J.G.; McKenna, J.M.

1992-01-01

Residual Heat Removal (RHR) and low pressure safety injection (LPSI) pumps installed in pressurized water-to-reactor power plants are used to provide low-head safety injection in the event of loss of coolant in the reactor coolant system. Because these pumps are subjected to rather severe temperature and pressure transients, the majority of pumps installed in the RHR service are vertical pumps with a single stage impeller. Typically the pump impeller is mounted on an extended motor shaft (close-coupled configuration) and a mechanical seal is employed at the pump end of the shaft. Traditionally RHR and LPSI pumps have been a significant maintenance item for many utilities. Periodic mechanical seal of motor bearing replacement often is considered routine maintenance. The closed-coupled pump design requires disassembly of the casing cover from the lower pump casing while performing these routine maintenance tasks. This paper introduces a design modification developed to convert the close-coupled RHR and LPSI pumps to a coupled configuration

FACTORS ASSOCIATED WITH VISUAL OUTCOME AFTER MACULA-OFF RHEGMATOGENOUS RETINAL DETACHMENT SURGERY.

Science.gov (United States)

Park, Dae Hyun; Choi, Kyung Seek; Sun, Hae Jung; Lee, Sung Jin

2018-01-01

To evaluate preoperative factors influencing the visual outcome and postoperative factors associated with the changes in visual acuity, after reattachment surgery to treat macula-off rhegmatogenous retinal detachment. A total of 180 eyes of 180 patients who underwent reattachment surgery to treat macula-off rhegmatogenous retinal detachment, and who were followed up for more than 12 months, were reviewed retrospectively. Preoperative and postoperative characteristics, including optical coherence tomography findings, were comprehensively analyzed using univariate and multivariate models to evaluate preoperative factors influencing best-corrected visual acuity 12 months after macula-off rhegmatogenous retinal detachment surgery and postoperative factors associated with changes in best-corrected visual acuity after surgery. Preoperatively, the extent of detachment (P = 0.037), macula-off duration (P macula-off rhegmatogenous retinal detachment surgery were the extent of detachment, macula-off duration, and external limiting membrane integrity. Postoperatively, predictive factors were the outer retinal microstructures, particularly the photoreceptor outer segment layer.

Pump Application as Hydraulic Turbine – Pump as Turbine (PaT)

OpenAIRE

Rusovs, D

2009-01-01

The paper considers pump operation as hydraulic turbine with purpose to produce mechanical power from liquid flow. The Francis hydraulic turbine was selected for comparison with centrifugal pump in reverse operation. Turbine and centrifugal pump velocity triangles were considered with purpose to evaluate PaT efficiency. Shape of impeller blades for turbine and pumps was analysed. Specific speed calculation is carried out with purpose to obtain similarity in pump and turbine description. For ...

Heat pumps

CERN Document Server

Macmichael, DBA

1988-01-01

A fully revised and extended account of the design, manufacture and use of heat pumps in both industrial and domestic applications. Topics covered include a detailed description of the various heat pump cycles, the components of a heat pump system - drive, compressor, heat exchangers etc., and the more practical considerations to be taken into account in their selection.

Reactor coolant purification system circulation pumps (CUW pumps)

International Nuclear Information System (INIS)

Tsutsui, Toshiaki

1979-01-01

Coolant purification equipments for BWRs have been improved, and the high pressure purifying system has become the main type. The quantity of purifying treatment also changed to 2% of the flow rate of reactor feed water. As for the circulation pumps, canned motor pumps are adopted recently, and the improvements of reliability and safety are attempted. The impurities carried in by reactor feed water and the corrosion products generated in reactors and auxiliary equipments are activated by neutron irradiation or affect heat transfer adversely, adhering to fuel claddings are core structures. Therefore, a part of reactor coolant is led to the purification equipments, and returned to reactors after the impurities are eliminated perfectly. At the time of starting and stopping reactors, excess reactor water and the contaminated water from reactors are transferred to main condenser hot wells or waste treatment systems. Thus the prescribed water quality is maintained. The operational modes of and the requirements for the CUW pumps, the construction and the features of the canned motor type CUW pumps are explained. Recently, a pump operated for 11 months without any maintenance has been disassembled and inspected, but the wear of bearings has not been observed, and the high reliability of the pump has been proved. (Kako, I.)

In reply to: "Intra-aortic balloon pump protects against hydrostatic pulmonary oedema during peripheral venoarterial-extracorporeal membrane oxygenation".

Science.gov (United States)

Privratsky, Jamie R; Diaz, Sebastian; Nicoara, Alina; Daneshmand, Mani A

2018-05-01

Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is an increasingly utilized life-saving measure. However, left-ventricular distention from inadequate left-ventricular off-loading can lead to unwanted pulmonary and cardiac complications. We are writing to indicate our agreement with a recent article by Brechot et al. published in the June 2017 issue where the authors demonstrated that intra-aortic balloon pump provides mechanical support to off-load the left ventricle during VA-ECMO, which prevents pulmonary edema.

Frequency and Predictors of Cognitive Decline in Patients Undergoing Coronary Artery Bypass Graft Surgery

International Nuclear Information System (INIS)

Habib, S.; Khan, A. R.; Afridi, M. I.; Saeed, A.; Jan, A. F.; Amjad, N.

2014-01-01

Objective: To determine the frequency of cognitive impairment and its predictors in patients, who underwent first time coronary artery bypass graft surgery (CABGS). Study Design: An observational study. Place and Duration of Study: The National Institute of Cardiovascular Diseases (NICVD), Karachi, from December 2008 to December 2009. Methodology: Study included patients > 18 years, who underwent first-time elective CABGS. Emergency CABGS, with additional cardiac procedures, myocardial infarction (MI) within one month and known psychiatric illness were excluded. Patients were evaluated for their socio-demographic profile, medical history, intra-operative, anesthetic and surgical techniques and postoperative complications/therapy in ICU. Cognitive functioning, before the surgery, at discharge, 6 weeks and 6 months post-CABG was evaluated by McNair's and MMSE scales. HDRS was added to see if depression was a confounding factor for cognitive decline. Results: One hundred and thirty four patients were followed-up at discharge, 74 at 6 weeks and 73 at 6 months. There were 113 (84.3%) males and 21 (15.7%) females, with mean age of 53.7 +- 8.36 years. Prevalence of cognitive disturbance at baseline was 44.8%, which increased to 54.5% at discharge, and improvement was seen at 6 months, it was 39.7%. Older age, female gender, higher bleeding episodes, and high post-surgery creatinine level were more frequently associated with cognitive decline. Conclusion: Postoperative cognitive deficit was common and remained persistent at short-term. Older age, females and high postoperative creatinine were identified as its important predictors. There was high frequency of acute depression before surgery with significant reduction over time. (author)

Work plan, AP-102 mixer pump removal and pump replacement

International Nuclear Information System (INIS)

Jimenez, R.F.

1994-01-01

The objective of this work plan is to plan the steps and estimate the costs required to remove the failed AP-102 mixer pump, and to plan and estimate the cost of the necessary design and specification work required to order a new, but modified, mixer pump including the pump and pump pit energy absorbing design. The main hardware required for the removal of the mixer is as follows: a flexible receiver and blast shield; a metal container for the pulled mixer pump; and a trailer and strongback to haul and manipulate the container. Additionally: a gamma scanning device will be needed to detect the radioactivity emanating from the mixer as it is pulled from the tank; a water spray system will be required to remove tank waste from the surface of the mixer as it is pulled from the AP-102 tank; and a lifting yoke to lift the mixer from the pump pit (the SY-101 Mixer Lifting Yoke will be used). A ''green house'' will have to be erected over the AP-102 pump pit and an experienced Hoisting and Rigging crew must be assembled and trained in mixer pump removal methods before the actual removal is undertaken

Particle exhaust scheme using an in-vessel cryocondensation pump in the advanced divertor configuration of the DIII-D tokamak

International Nuclear Information System (INIS)

Menon, M.M.; Mioduszewski, P.K.; Owen, L.W.; Anderson, P.M.; Baxi, C.B.; Langhorn, A.; Luxon, J.L.; Mahdavi, M.A.; Schaffer, M.J.; Schaubel, K.M.; "" class="author-name" title=" (General Atomics Co., San Diego, CA (United States))" data-affiliation=" (General Atomics Co., San Diego, CA (United States))" >Smith, J.P>

1992-01-01

In this paper, a particle exhaust scheme using a cryocondensation pump in the advanced divertor configuration of the DIII-D tokamak is described. In this configuration, the pump is located inside a baffle chamber within the tokamak, designed to receive particles reflected off the divertor strike region. A concentric coaxial loop with forced-convection flow of two-phase helium is selected as the cryocondensation surface. The pumping configuration is optimized by Monte Carlo techniques to provide maximum exhaust efficiency while minimizing the deleterious effects of impingement of energetic plasma particles on cryogenic surfaces. Heat loading contributions from various sources on the cryogenic surfaces are estimated, based on which the cryogenic surfaces are estimated, based on which the cryogenic flow loop for the pump is designed. The mechanical aspects of the pump, designed to meet the many challenging requirements of operating the cryopump internal to the tokamak vacuum and in close proximity with the high-temperature plasma, are also outlined

[Incorrect programming of a target controlled infusion pump. Case SENSAR of the trimester].

Science.gov (United States)

2014-10-01

We report the case of a patient who underwent surgical aortic valve replacement. During general anaesthesia maintenance, the patient received a remifentanyl infusion via a target controlled infusion (TCI) system. The infusion pump that was prepared to deliver the infusion showed malfunction at the beginning of the surgery, so it was quickly replaced with a second pump. After a few minutes into the surgery, the patient presented with hypotension refractory to treatment. The remifentanyl syringe also emptied faster than expected. On reviewing the TCI pump, it was found that it was erroneously programmed for propofol instead of remifentanyl, thus the patient had received a very high dose of remifentanyl that was probably the cause of the haemodynamic disturbances. The incident was an error in equipment use, facilitated by hurry, lack of checking of the equipment prior to its use, and the complex and unclear design of the devices' screens. After analysis of this incident, all TCI pumps were reviewed, and all the programs for infrequently used drugs were deleted. Furthermore, 2 pumps were selected for exclusive use in the cardiac surgery theatre, one with propofol-only programming, and the other with remifentanyl-only programming, both clearly marked and situated in fixed places in that theatre. Copyright © 2014 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Published by Elsevier España. All rights reserved.

An analytical method for defining the pump`s power optimum of a water-to-water heat pump heating system using COP

Directory of Open Access Journals (Sweden)

Nyers Jozsef

2017-01-01

Full Text Available This paper analyzes the energy efficiency of the heat pump and the complete heat pump heating system. Essentially, the maximum of the coefficient of performance of the heat pump and the heat pump heating system are investigated and determined by applying a new analytical optimization procedure. The analyzed physical system consists of the water-to-water heat pump, circulation and well pump. In the analytical optimization procedure the "first derivative equal to zero" mathematical method is applied. The objective function is the coefficient of performance of the heat pump, and the heat pump heating system. By using the analytical optimization procedure and the objective function, as the result, the local and the total energy optimum conditions with respect to the mass flow rate of hot and cold water i. e. the power of circulation or well pump are defined.

Investigation of the correlation between noise and vibration characteristics and unsteady flow in a circulator pump

Energy Technology Data Exchange (ETDEWEB)

Wu, Denghao; Ren, Yun; Mou, Jiegang; Gu, Yunqing [Zhejiang University of Technology, Hangzhou (China)

2017-05-15

Circulator pumps have wide engineering applications but the acoustics, vibration and unsteady flow structures of the circulator pump are still not fully understood. We investigated the noise and vibration characteristics and unsteady flow structures in a circulator pump at different flow rates. Three-dimensional, unsteady RANS equations were solved on high-quality structured meshes with SST k-ω turbulence model numerically. Measurements were made in a semi-anechoic chamber to get an overview of noise and vibration level of a pump at different flow rates. The 1/3 octave-band filter technique was applied to obtain the explicit frequency spectra of sound, pressure fluctuations and vibration signals and their principal frequencies were identified successfully. The air-borne noise level of the designed condition is lower than that of the off-design conditions, and the highest sound pressure level is found at part-load condition. The acoustic emission from the pump is mainly caused by unsteady flow structures and pressure fluctuations. In addition, both the link between air- borne noise and pressure fluctuation, and the correlation between vibration and unsteady hydrodynamic forces, were quantitatively examined and verified. This work offers good data to understand noise and vibration characteristics of circulator pumps and the relationships among the noise, vibration and unsteady flow structures.

The effect of Clostridium difficile infection on cardiac surgery outcomes.

Science.gov (United States)

Lemaire, Anthony; Dombrovskiy, Viktor; Batsides, George; Scholz, Peter; Solina, Al; Brownstone, Nicholas; Spotnitz, Alan; Lee, Leonard Y

2015-02-01

Clostridium difficile (CD) is a common cause of healthcare-associated infectious colitis that complicates about 1% of all hospital stays in the U.S. The impact of CD on outcomes after coronary artery bypass grafting (CABG) and valvular surgery (VS) is not well known. The Nationwide Inpatient Sample (2002-2009) was queried to identify CABG and VS patients utilizing International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) diagnosis codes. Rates of CD, post-operative endocarditis and mediastinitis, hospital mortality rate, and resource utilization were evaluated. We identified 421,294 and 90,923 patients of age 40 yrs and older who underwent CABG and VS, respectively. The CD infection was more likely to develop in patients undergoing VS than in those having CABG (odds ratio [OR] 1.8; 95% confidence interval [CI] 1.64-1.92) and was more likely after urgent or emergency admission than after elective admission (OR 1.8; 95% CI 1.68-1.94). There was a greater likelihood of mediastinitis in patients with CD after CABG than in non-complicated cases without CD, both by univariable (OR 6.0; 95% CI 3.07-11.62) and multivariable analysis with adjustment for patient age, gender, race, type of admission, and co-morbidities (OR 3.1; 95% CI 1.49-6.51). The infection thus was most likely a result of the antibiotics used to treat mediastinitis, as the patients treated for mediastinitis were most likely to develop CD. There was a significant association in patients with CD and endocarditis who underwent VS but not in patients who did not have CD. The CD infection in these patients thus was most likely a result of the antibiotics used to treat endocarditis. Endocarditis and CD developed 3.2 times (95% CI 2.65-3.97) as often as in patients without CD, a finding that was confirmed by multivariable analysis (OR 2.2; 95% CI 1.70-2.84). At the same time, in patients having VS, there was no significant association of CD and mediastinitis. Clostridium

Advanced Design Mixer Pump Tank 18 Design Modifications Summary Report

International Nuclear Information System (INIS)

Adkins, B.J.

2002-01-01

The Westinghouse Savannah River Company (WSRC) is preparing to retrieve high level waste (HLW) from Tank 18 in early FY03 to provide feed for the Defense Waste Processing Facility (DWPF) and to support tank closure in FY04. As part of the Tank 18 project, WSRC will install a single Advanced Design Mixer Pump (ADMP) in the center riser of Tank 18 to mobilize, suspend, and mix radioactive sludge in preparation for transfer to Tank 7. The use of a single ADMP is a change to the current baseline of four (4) standard slurry pumps used during previous waste retrieval campaigns. The ADMP was originally conceived by Hanford and supported by SRS to provide a more reliable and maintainable mixer pump for use throughout the DOE complex. The ADMP underwent an extensive test program at SRS between 1998 and 2002 to assess reliability and hydraulic performance. The ADMP ran for approximately 4,200 hours over the four-year period. A detailed tear down and inspection of the pump following the 4,2 00-hour run revealed that the gas mechanical seals and anti-friction bearings would need to be refurbished/replaced prior to deployment in Tank 18. Design modifications were also needed to meet current Authorization Basis safety requirements. This report documents the modifications made to the ADMP in support of Tank 18 deployment. This report meets the requirements of Tanks Focus Area (TFA) Milestone 3591.4-1, ''Issue Report on Modifications Made to the ADMP,'' contained in Technical Task Plan (TTP) SR16WT51, ''WSRC Retrieval and Closure.''

The development of a cavitation free sodium pump for the breeder reactor

International Nuclear Information System (INIS)

Baladi, J.Y.; Nyilas, C.P.

1986-12-01

The sodium pumps for a liquid metal fast breeder reactor must be designed for exceptionally high reliability and long life. The principal adverse factor which tends to limit the primary pump life is cavitation which becomes potentially severe under off-design flow conditions caused by the requirement of two loop operations which resulted in a large operating flow range. This problem prompted an extensive study which included experimental investigations of scaled down and full size pumps. The investigations involved visual observations, acoustic signature recordings, and physical characteristic measurements of the model and full size impellers. The blade configuration of the model was modified several times. After each modification intensive testing was conducted with feedback to established design criteria. The results obtained from the final configuration showed excellent cavitation performance. This configuration was then machined on the full scale impeller and tested. The results confirmed acceptable performance in the entire range of operating conditions. This paper describes the test facilities erected for this study, discusses the experimental techniques employed, and presents the experimental techniques employed, and presents a sample of the experimental results

Plasma chemistry of the sealed-off slab CO laser active medium pumped by radio-frequency discharge with liquid-nitrogen-cooled electrodes

Science.gov (United States)

Ionin, A. A.; Kozlov, A. Yu.; Seleznev, L. V.; Sinitsyn, D. V.

2017-09-01

The long-term time behavior of the output power of a sealed-off cryogenic slab CO laser pumped by a repetitively pulsed RF discharge and operating on the overtone (λ = 2.6-3.5 μm) vibrational-rotational transitions of the CO molecule was studied experimentally. It is shown that adding of an anomalously large amount of oxygen (up to 50% with respect to the CO concentration) to the initial gas mixture CO : He = 1 : 10 leads to a manyfold (by several tens of times) increase in the duration of the laser operating cycle (until lasing failure due to the degradation of the active medium). In this case, the laser life-time without replacement of the active medium reaches 105-106 pulses. Using various diagnostics (including luminescence spectroscopy and IR and UV absorption spectroscopy), regularities in the time-behavior of the concentrations of the main component of the active medium (CO molecules) and the products of plasmachemical reactions (O3, CO2) generated in the discharge gap during the laser operating cycle are revealed. Time correlation between the characteristics of the active medium and the laser output power are analyzed. A phenomenological approach to describing the entirety of plasmachemical, purely chemical, gas-dynamic, and diffusion processes determining the behavior of the laser output characteristics throughout the laser operating cycle is offered.

Seawater pumping as an electricity storage solution for photovoltaic energy systems

International Nuclear Information System (INIS)

Manfrida, Giampaolo; Secchi, Riccardo

2014-01-01

The stochastic nature of several renewable energy sources has raised the problem of designing and building storage facilities, which can help the electricity grid to sustain larger and larger contribution of renewable energy. Seawater pumped electricity storage is proposed as a good option for PV (Photovoltaic) or solar thermal power plants, located in suitable places close to the coast line. Solar radiation has a natural daily cycle, and storage reservoirs of limited capacity can substantially reduce the load to the electricity grid. Different modes of pump operation (fixed or variable speed) are considered, the preliminary sizing of the PV field and seawater reservoir is performed, and the results are comparatively assessed over a year-long simulated operation. The results show that PV pumped storage, even if not profitable in the present situation of the renewable energy Italian electricity market, is effective in decreasing the load on the transmission grid, and would possibly be attractive in the future, also in the light of developing off-grid applications. - Highlights: • A grid-connected seawater pumping system using photovoltaic power is proposed and its performance analyzed. • Year-round simulations are run with different sizes of photovoltaic field and reservoir. • An analysis is run about the profitability of the storage system, examining performance indexes and the cost of plant. • The system proposed appears near to attract the interest of the market

Dynamic behaviour of pump-turbine runner: From disk to prototype runner

International Nuclear Information System (INIS)

Huang, X X; Egusquiza, E; Valero, C; Presas, A

2013-01-01

In recent decades, in order to increase output power of hydroelectric turbomachinery, the design head and the flow rate of the hydraulic turbines have been increased greatly. This has led to serious vibratory problems. The pump-turbines have to work at various operation conditions to satisfy the requirements of the power grid. However, larger hydraulic forces will result in high vibration levels on the turbines, especially, when the machines operate at off-design conditions. Due to the economic considerations, the pump-turbines are built as light as possible, which will change the dynamic response of the structures. According to industrial cases, the fatigue damage of the pump-turbine runner induced by hydraulic dynamic forces usually happens on the outer edge of the crown, which is near the leading edges of blades. To better understand the reasons for this kind of fatigue, it is extremely important to investigate the dynamic response behaviour of the hydraulic turbine, especially the runner, by experimental measurement and numerical simulation. The pump-turbine runner has a similar dynamic response behaviour of the circular disk. Therefore, in this paper the dynamic response analyses for circular disks with different dimensions and disk-blades-disk structures were carried out to better understand the fundamental dynamic behaviour for the complex turbomachinery. The influences of the pattern and number of blades were discussed in detail

Electromagnetic pump technology

International Nuclear Information System (INIS)

Prabhakar, R.

1994-01-01

Fast Breeder Reactors have an important role to play in our nuclear power programme. Liquid metal sodium is used as the coolant for removing fission heat generated in fast reactors and a distinctive physical property of sodium is its high electrical conductivity. This enables application of electromagnetic (EM) pumps, working on same principle as electric motors, for pumping liquid sodium. Due to its lower efficiency as compared to centrifugal pumps, use of EM pumps has been restricted to reactor auxiliary circuits and experimental facilities. As part of our efforts to manufacture fast reactor components indigenously, work on the development of two types of EM pumps namely flat linear induction pump (FLIP) and annular linear induction pump (ALIP) has been undertaken. Design procedures based on an equivalent circuit approach have been established and results from testing a 5.6 x 10E-3 Cum/s (20 Cum/h) FLIP in a sodium loop were used to validate the procedure. (author). 7 refs., 6 figs

Assessment of feasibility and efficacy of Class IV laser therapy for postoperative pain relief in off-pump coronary artery bypass surgery patients: A pilot study

Directory of Open Access Journals (Sweden)

Anil Karlekar

2015-01-01

Full Text Available Background: Laser therapy, for its established analgesic properties with minimal side effects, has been used for the treatment of chronic pain. However, it has not been used for the treatment of acute postoperative pain. This pilot study was designed to assess the feasibility and efficacy of Class IV laser on postoperative pain relief following off-pump coronary artery bypass graft (OPCABG surgery, as a component of multimodal analgesia (MMA technique. Methods: This open observational prospective study comprised of 100 adult patients (84 male, 16 female who underwent OPCABG through sternotomy. For postoperative analgesia, they were subjected to laser therapy subjected to laser therapy in addition to the standard institutional pain management protocol comprising of IV infusion/bolus of tramadol and paracetamol and fentanyl bolus as rescue analgesic. Pain intensity was measured by Verbal Rating Scale (VRS. The laser therapy was scheduled as once a day regime for three consecutive postoperative days (PODs starting on POD 1, 30 min following tracheal extubation. The subsequent laser applications were also scheduled at the same time of the day as on day 1 if VRS was ≥5. 10 W Class IV laser was applied over 150 cm 2 sternal wound area for 150 s. VRS was used to assess pain severity and was recorded for statistical analysis using Friedman Test. Results: The mean (standard deviation [SD] VRS of all the 100 patients just before application of the first dose of laser was 7.31 (0.94 while on MMT; the same fell to 4.0 (1.279 and 3.40 (2.697 at 1 h and 24 h respectively following first dose of laser. The change of VRS over first 24 h among all the 100 patients was statistically significant (P = 0.000. Laser was re-applied in 40 patients whose VRS was ≥5 (mean [SD] - 6.38 [0.868] at 24 th h. After receiving the 2 nd dose of laser the VRS scores fell significantly (P = 0.000 and became 0 at 54 th h. No patients required 3 rd dose of the laser. No patient

Advanced heat pump for the recovery of volatile organic compounds

Energy Technology Data Exchange (ETDEWEB)

1992-03-01

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

Pumping life

DEFF Research Database (Denmark)

Sitsel, Oleg; Dach, Ingrid; Hoffmann, Robert Daniel

2012-01-01

The name PUMPKIN may suggest a research centre focused on American Halloween traditions or the investigation of the growth of vegetables – however this would be misleading. Researchers at PUMPKIN, short for Centre for Membrane Pumps in Cells and Disease, are in fact interested in a large family o......’. Here we illustrate that the pumping of ions means nothing less than the pumping of life....

Strategic market approach for entering the Indian solar water pump market : plan the marketing strategy for solar off-grid applications

OpenAIRE

Almanasreh, Khalil

2011-01-01

This study examines the strategic market approach for investing in solar water pumps market (SWP) in India, and Punjab state as a business case. The main research question is: What is an appropriate strategic market approach to invest in solar water pump market in India? The study focuses on the marketing strategy and strategic planning to enter the Indian market. The thesis follows the qualitative study design where the data was collected by observing the market and interviewing main sta...

Champagne Heat Pump

Science.gov (United States)

Jones, Jack A.

2004-01-01

The term champagne heat pump denotes a developmental heat pump that exploits a cycle of absorption and desorption of carbon dioxide in an alcohol or other organic liquid. Whereas most heat pumps in common use in the United States are energized by mechanical compression, the champagne heat pump is energized by heating. The concept of heat pumps based on other absorption cycles energized by heat has been understood for years, but some of these heat pumps are outlawed in many areas because of the potential hazards posed by leakage of working fluids. For example, in the case of the water/ammonia cycle, there are potential hazards of toxicity and flammability. The organic-liquid/carbon dioxide absorption/desorption cycle of the champagne heat pump is similar to the water/ammonia cycle, but carbon dioxide is nontoxic and environmentally benign, and one can choose an alcohol or other organic liquid that is also relatively nontoxic and environmentally benign. Two candidate nonalcohol organic liquids are isobutyl acetate and amyl acetate. Although alcohols and many other organic liquids are flammable, they present little or no flammability hazard in the champagne heat pump because only the nonflammable carbon dioxide component of the refrigerant mixture is circulated to the evaporator and condenser heat exchangers, which are the only components of the heat pump in direct contact with air in habitable spaces.

Two-stage optical parametric chirped-pulse amplifier using sub-nanosecond pump pulse generated by stimulated Brillouin scattering compression

Science.gov (United States)

Ogino, Jumpei; Miyamoto, Sho; Matsuyama, Takahiro; Sueda, Keiichi; Yoshida, Hidetsugu; Tsubakimoto, Koji; Miyanaga, Noriaki

2014-12-01

We demonstrate optical parametric chirped-pulse amplification (OPCPA) based on two-beam pumping, using sub-nanosecond pulses generated by stimulated Brillouin scattering compression. Seed pulse energy, duration, and center wavelength were 5 nJ, 220 ps, and ˜1065 nm, respectively. The 532 nm pulse from a Q-switched Nd:YAG laser was compressed to ˜400 ps in heavy fluorocarbon FC-40 liquid. Stacking of two time-delayed pump pulses reduced the amplifier gain fluctuation. Using a walk-off-compensated two-stage OPCPA at a pump energy of 34 mJ, a total gain of 1.6 × 105 was obtained, yielding an output energy of 0.8 mJ. The amplified chirped pulse was compressed to 97 fs.

Breastfeeding FAQs: Pumping

Science.gov (United States)

... of pump is best? You can buy or rent a breast pump from lactation consultants, hospitals, retail ... place to do it. Many companies offer their employees pumping and nursing areas. If yours doesn't, ...

Efficiency and threshold pump intensity of CW solar-pumped solid-state lasers

Science.gov (United States)

Hwang, In H.; Lee, Ja H.

1991-01-01

The authors consider the relation between the threshold pumping intensity, the material properties, the resonator parameters, and the ultimate slope efficiencies of various solid-state laser materials for solar pumping. They clarify the relation between the threshold pump intensity and the material parameters and the relation between the ultimate slope efficiency and the laser resonator parameters such that a design criterion for the solar-pumped solid-state laser can be established. Among the laser materials evaluated, alexandrite has the highest slope efficiency of about 12.6 percent; however, it does not seem to be practical for a solar-pumped laser application because of its high threshold pump intensity. Cr:Nd:GSGG is the most promising for solar-pumped lasing. Its threshold pump intensity is about 100 air-mass-zero (AM0) solar constants and its slope efficiency is about 12 percent when thermal deformation is completely prevented.

Pumping station design for a pumped-storage wind-hydro power plant

International Nuclear Information System (INIS)

Anagnostopoulos, John S.; Papantonis, Dimitris E.

2007-01-01

This work presents a numerical study of the optimum sizing and design of a pumping station unit in a hybrid wind-hydro plant. The standard design that consists of a number of identical pumps operating in parallel is examined in comparison with two other configurations, using one variable-speed pump or an additional set of smaller jockey pumps. The aim is to reduce the amount of the wind generated energy that cannot be transformed to hydraulic energy due to power operation limits of the pumps and the resulting step-wise operation of the pumping station. The plant operation for a period of one year is simulated by a comprehensive evaluation algorithm, which also performs a detailed economic analysis of the plant using dynamic evaluation methods. A preliminary study of the entire plant sizing is carried out at first using an optimization tool based on evolutionary algorithms. The performance of the three examined pumping station units is then computed and analyzed in a comparative study. The results reveal that the use of a variable-speed pump constitutes the most effective and profitable solution, and its superiority is more pronounced for less dispersed wind power potential

Investigation on Flow-Induced Noise due to Backflow in Low Specific Speed Centrifugal Pumps

Directory of Open Access Journals (Sweden)

Qiaorui Si

2013-01-01

Full Text Available Flow-induced noise causes disturbances during the operation of centrifugal pumps and also affects their performance. The pumps often work at off-design conditions, mainly at part-load conditions, because of frequent changes in the pump device system. Consequently numerous unstable phenomena occur. In low specific speed centrifugal pumps the main disturbance is the inlet backflow, which is considered as one of the most important factors of flow-induced noise and vibration. In this study, a test rig of the flow-induced noise and vibration of the centrifugal pump was built to collect signals under various operating conditions. The three-dimensional unsteady flow of centrifugal pumps was calculated based on the Reynolds-averaged equations that resemble the shear stress transport (SST k-ω turbulence model. The results show that the blade passing frequency and shaft frequency are dominant in the spectrum of flow-induced noise, whereas the shaft component, amplitude value at shaft frequency, and peak frequencies around the shaft increase with decreasing flow. Through flow field analysis, the inlet backflow of the impeller occurs under 0.7 times the design flow. The pressure pulsation spectrum with backflow conditions validates the flow-induced noise findings. The velocity characteristics of the backflow zone at the inlet pipe were analyzed, and the dynamic characteristics of the backflow eddy during one impeller rotating period were simultaneously obtained by employing the backflow conditions. A flow visualization experiment was performed to confirm the numerical calculations.

Developing an Integrated Treatment Pathway for a Post-Coronary Artery Bypass Grating (CABG) Geriatric Patient with Comorbid Hypertension and Type 1 Diabetes Mellitus for Treating Acute Hypoglycemia and Electrolyte Imbalance.

Science.gov (United States)

Naqvi, Atta Abbas; Shah, Amna; Ahmad, Rizwan; Ahmad, Niyaz

2017-01-01

The ailments afflicting the elderly population is a well-defined specialty of medicine. It calls for an immaculately designed health-care plan to treat diseases in geriatrics. For chronic illnesses such as diabetes mellitus (DM), coronary heart disease, and hypertension (HTN), they require proper management throughout the rest of patient's life. An integrated treatment pathway helps in treatment decision-making and improving standards of health care for the patient. This case describes an exclusive clinical pharmacist-driven designing of an integrated treatment pathway for a post-coronary artery bypass grafting (CABG) geriatric male patient with DM type I and HTN for the treatment of hypoglycemia and electrolyte imbalance. The treatment begins addressing the chief complaints which were vomiting and unconsciousness. Biochemical screening is essential to establish a diagnosis of electrolyte imbalance along with blood glucose level after which the integrated pathway defines the treatment course. This individualized treatment pathway provides an outline of the course of treatment of acute hypoglycemia, electrolyte imbalance as well as some unconfirmed diagnosis, namely, acute coronary syndrome and respiratory tract infection for a post-CABG geriatric patient with HTN and type 1 DM. The eligibility criterion for patients to be treated according to treatment pathway is to fall in the defined category.

BWR series pump recirculation system

International Nuclear Information System (INIS)

Dillmann, C.W.

1992-01-01

This patent describes a recirculation system for driving reactor coolant water contained in an annular downcomer defined between a boiling water reactor vessel and a reactor core spaced radially inwardly therefrom. It comprises a plurality of circumferentially spaced second pumps disposed in the downcomer, each including an inlet for receiving from the downcomer a portion of the coolant water as pump inlet flow, and an outlet for discharging the pump inlet flow pressurized in the second pump as pump outlet flow; and means for increasing pressure of the pump inlet flow at the pump inlet including a first pump disposed in series flow with the second pump for first receiving the pump inlet flow from the downcomer and discharging to the second pump inlet flow pressurized in the first pump

Perfil ventilatório dos pacientes submetidos a cirurgia de revascularização do miocárdio Ventilatory profile of patients undergoing CABG surgery

Directory of Open Access Journals (Sweden)

Katiane Tremarin Morsch

2009-06-01

Full Text Available OBJETIVO: Avaliar o perfil ventilatório, radiológico e clínico dos pacientes submetidos a cirurgia eletiva de revascularização do miocárdio em hospital de referência em cardiologia no sul do Brasil. MÉTODOS: A amostra foi composta por 108 indivíduos submetidos a cirurgia eletiva de revascularização do miocárdio no Instituto de Cardiologia do Rio Grande do Sul (IC-FUC, no período de abril de 2006 a fevereiro de 2007. A abordagem cirúrgica realizada foi a da esternotomia mediana e os enxertos foram com ponte de safena e/ou artéria mamária interna. Os volumes e capacidades pulmonares, bem como a presença de distúrbios ventilatórios, foram avaliados por meio da espirometria e a força muscular ventilatória da manovacuometria. As avaliações foram realizadas no período pré-operatório e no sexto dia de pós-operatório. RESULTADOS: Observou-se redução significativa do VEF1 e da CVF quando comparados os valores pré-operatórios com os do sexto dia de pós-operatório (POBJECTIVE: To assess the ventilatory, radiological and clinical profile of patients undergoing elective CABG in a cardiology reference hospital in South Brazil. METHODS: This study included 108 patients undergoing elective CABG surgery, in the period between April 2006 and February 2007 at the Cardiology Institute of Rio Grande do Sul (IC-FUC. The surgical procedure involved median sternotomy, and the saphenous vein and/or internal mammary artery were used for grafting. Lung volume and capacity, as well as the possible existence of ventilatory changes, were assessed by spirometry, and the ventilatory muscle strength was assessed using a vaccum manometer. All evaluations were performed on the preoperative period and on the sixth postoperative day. RESULTS: Preoperative levels of FEV1 and FVC were significantly reduced on the 6th postoperative day (P<0.001 when compared to the preoperative levels. A significant decrease of ventilatory muscle strength, expressed

The Effect of Milrinone on the Right Ventriclular Function in Patients with Reduced Right Ventricular Function Undergoing Off-pump Coronary Artery Bypass Graft Surgery

Science.gov (United States)

Lee, Jong Hwa; Oh, Young Jun; Shim, Yon Hee; Hong, Yong Woo; Yi, Gijong

2006-01-01

This investigation evaluated the effect of continuous milrinone infusion on right ventriclular (RV) function during off-pump coronary artery bypass graft (OPCAB) surgery in patients with reduced RV function. Fifty patients scheduled for OPCAB, with thermodilution RV ejection fraction (RVEF) milrinone (0.5 µg/kg/min) or control (saline) group. Hemodynamic variables and RV volumetric data measured by thermodilution method were collected as follows: after anesthesia induction (T1); 10 min after heart displacement for obtuse marginal artery anastomosis (T2); after pericardial closure (T3). Cardiac index and heart rate increased and systemic vascular resistance significantly decreased in milrinone group at T2. Initially lower RVEF of milrinone group was eventually comparable to control group after milrinone infusion. RVEF did not significantly change at T2 and T3 in both groups. RV end-diastolic volume in milrinone group consistently decreased from the baseline at T2 and T3. Continuous infusion of milrinone without a bolus demonstrated potentially beneficial effect on cardiac output and RV afterload in patients with reduced RV function during OPCAB. However, aggressive augmentation of intravascular volume seems to be necessary to maximize the effect of the milrinone in these patients. PMID:17043419

Pumps in wearable ultrafiltration devices: pumps in wuf devices.

Science.gov (United States)

Armignacco, Paolo; Garzotto, Francesco; Bellini, Corrado; Neri, Mauro; Lorenzin, Anna; Sartori, Marco; Ronco, Claudio

2015-01-01

The wearable artificial kidney (WAK) is a device that is supposed to operate like a real kidney, which permits prolonged, frequent, and continuous dialysis treatments for patients with end-stage renal disease (ESRD). Its functioning is mainly related to its pumping system, as well as to its dialysate-generating and alarm/shutoff ones. A pump is defined as a device that moves fluids by mechanical action. In such a context, blood pumps pull blood from the access side of the dialysis catheter and return the blood at the same rate of flow. The main aim of this paper is to review the current literature on blood pumps, describing the way they have been functioning thus far and how they are being engineered, giving details about the most important parameters that define their quality, thus allowing the production of a radar comparative graph, and listing ideal pumps' features. © 2015 S. Karger AG, Basel.

An Optimization Scheme for Water Pump Control in Smart Fish Farm with Efficient Energy Consumption

Directory of Open Access Journals (Sweden)

Israr Ullah

2018-06-01

Full Text Available Healthy fish production requires intensive care and ensuring stable and healthy production environment inside the farm tank is a challenging task. An Internet of Things (IoT based automated system is highly desirable that can continuously monitor the fish tanks with optimal resources utilization. Significant cost reduction can be achieved if farm equipment and water pumps are operated only when required using optimization schemes. In this paper, we present a general system design for smart fish farms. We have developed an optimization scheme for water pump control to maintain desired water level in fish tank with efficient energy consumption through appropriate selection of pumping flow rate and tank filling level. Proposed optimization scheme attempts to achieve a trade-off between pumping duration and flow rate through selection of optimized water level. Kalman filter algorithm is applied to remove error in sensor readings. We observed through simulation results that optimization scheme achieve significant reduction in energy consumption as compared to the two alternate schemes, i.e., pumping with maximum and minimum flow rates. Proposed system can help in collecting the data about the farm for long-term analysis and better decision making in future for efficient resource utilization and overall profit maximization.

A case of transient central diabetes insipidus after aorto-coronary bypass operation.

Science.gov (United States)

Yu, Chung-Hoon; Cho, Jang-Hee; Jung, Hee-Yeon; Lim, Jeong-Hoon; Jin, Mi-Kyung; Kwon, Owen; Hong, Kyung-Deuk; Choi, Ji-Young; Yoon, Se-Hee; Kim, Chan-Duck; Kim, Yong-Lim; Kim, Gun-Jik; Park, Sun-Hee

2012-09-01

Diabetes insipidus (DI) is characterized by excessive urination and thirst. This disease results from inadequate output of antidiuretic hormone (ADH) from the pituitary gland or the absence of the normal response to ADH in the kidney. We present a case of transient central DI in a patient who underwent a cardiopulmonary bypass (CPB) for coronary artery bypass grafting (CABG). A 44-yr-old male underwent a CABG operation. An hour after the operation, the patient developed polyuria and was diagnosed with central DI. The patient responded to desmopressin and completely recovered five days after surgery. It is probable that transient cerebral ischemia resulted in the dysfunction of osmotic receptors in the hypothalamus or hypothalamus-pituitary axis during CPB. It is also possible that cardiac standstill altered the left atrial non-osmotic receptor function and suppressed ADH release. Therefore, we suggest that central DI is a possible cause of polyuria after CPB.

TFTR ultrahigh-vacuum pumping system incorporating mercury diffusion pumps

International Nuclear Information System (INIS)

Sink, D.A.; Sniderman, M.

1976-06-01

The TFTR vacuum vessel will have a system of four 61 cm diameter mercury diffusion pumps to provide a base pressure in the 10 -8 to 10 -9 Torr range as well as a low impurity level within the vessel. The system, called the Torus Vacuum Pumping System (TVPS), will be employed with the aid of an occasional 250 0 C bakeout in situ as well as periodic applications of aggressive discharge cleaning. The TVPS is an ultrahigh-vacuum (UHV) system using no elastomers as well as being a closed system with respect to tritium or any tritiated gases. The backing system employing approximately 75 all-metal isolation valves is designed with the features of redundancy and flexibility employed in a variety of ways to meet the fundamental requirements and functions enumerated for the TVPS. Since the design, is one which is a modification of the conceptual design of the TVPS, those features which have changed are discussed. Calculations are presented for the major performance parameters anticipated for the TVPS and include conductances, effective pumping speeds, base pressures, operating parameters, getter pump parameters, and calculations of time constants associated with leak checking. Modifications in the vacuum pumping system for the guard regions on the twelve bellows sections are presented so that it is compatible with the main TVPS. The bellows pumping system consists of a mechanical pump unit, a zirconium aluminum getter pump unit and a residual gas analyzer. The control and management of the TVPS is described with particular attention given to providing both manual and automatic control at a local station and at the TFTR Central Control. Such operations as testing, maintenance, leak checking, startup, bakeout, and various other operations are considered in some detail. Various aspects related to normal pulsing, discharge cleaning, non-tritium operations and tritium operations are also taken into consideration. A cost estimate is presented

Mild anastomotic stenosis in patient-specific CABG model may enhance graft patency: a new hypothesis.

Directory of Open Access Journals (Sweden)

Yunlong Huo

Full Text Available It is well known that flow patterns at the anastomosis of coronary artery bypass graft (CABG are complex and may affect the long-term patency. Various attempts at optimal designs of anastomosis have not improved long-term patency. Here, we hypothesize that mild anastomotic stenosis (area stenosis of about 40-60% may be adaptive to enhance the hemodynamic conditions, which may contribute to slower progression of atherosclerosis. We further hypothesize that proximal/distal sites to the stenosis have converse changes that may be a risk factor for the diffuse expansion of atherosclerosis from the site of stenosis. Twelve (12 patient-specific models with various stenotic degrees were extracted from computed tomography images using a validated segmentation software package. A 3-D finite element model was used to compute flow patterns including wall shear stress (WSS and its spatial and temporal gradients (WSS gradient, WSSG, and oscillatory shear index, OSI. The flow simulations showed that mild anastomotic stenosis significantly increased WSS (>15 dynes · cm(-2 and decreased OSI (<0.02 to result in a more uniform distribution of hemodynamic parameters inside anastomosis albeit proximal/distal sites to the stenosis have a decrease of WSS (<4 dynes · cm(-2. These findings have significant implications for graft adaptation and long-term patency.

Mild anastomotic stenosis in patient-specific CABG model may enhance graft patency: a new hypothesis.

Science.gov (United States)

Huo, Yunlong; Luo, Tong; Guccione, Julius M; Teague, Shawn D; Tan, Wenchang; Navia, José A; Kassab, Ghassan S

2013-01-01

It is well known that flow patterns at the anastomosis of coronary artery bypass graft (CABG) are complex and may affect the long-term patency. Various attempts at optimal designs of anastomosis have not improved long-term patency. Here, we hypothesize that mild anastomotic stenosis (area stenosis of about 40-60%) may be adaptive to enhance the hemodynamic conditions, which may contribute to slower progression of atherosclerosis. We further hypothesize that proximal/distal sites to the stenosis have converse changes that may be a risk factor for the diffuse expansion of atherosclerosis from the site of stenosis. Twelve (12) patient-specific models with various stenotic degrees were extracted from computed tomography images using a validated segmentation software package. A 3-D finite element model was used to compute flow patterns including wall shear stress (WSS) and its spatial and temporal gradients (WSS gradient, WSSG, and oscillatory shear index, OSI). The flow simulations showed that mild anastomotic stenosis significantly increased WSS (>15 dynes · cm(-2)) and decreased OSI (<0.02) to result in a more uniform distribution of hemodynamic parameters inside anastomosis albeit proximal/distal sites to the stenosis have a decrease of WSS (<4 dynes · cm(-2)). These findings have significant implications for graft adaptation and long-term patency.

Photovoltaic pump systems

Science.gov (United States)

Klockgether, J.; Kiessling, K. P.

1983-09-01

Solar pump systems for the irrigation of fields and for water supply in regions with much sunshine are discussed. For surface water and sources with a hoisting depth of 12 m, a system with immersion pumps is used. For deep sources with larger hoisting depths, an underwater motor pump was developed. Both types of pump system meet the requirements of simple installation and manipulation, safe operation, maintenance free, and high efficiency reducing the number of solar cells needed.

Damages on pumps and systems the handbook for the operation of centrifugal pumps

CERN Document Server

Merkle, Thomas

2014-01-01

Damage on Pumps and Systems. The Handbook for the Operation of Centrifugal Pumps offers a combination of the theoretical basics and practical experience for the operation of circulation pumps in the engineering industry. Centrifugal pumps and systems are extremely vulnerable to damage from a variety of causes, but the resulting breakdown can be prevented by ensuring that these pumps and systems are operated properly. This book provides a total overview of operating centrifugal pumps, including condition monitoring, preventive maintenance, life cycle costs, energy savings and economic aspects. Extra emphasis is given to the potential damage to these pumps and systems, and what can be done to prevent breakdown. Addresses specific issues about pumping of metal chips, sand, abrasive dust and other solids in fluidsEmphasis on economic and efficiency aspects of predictive maintenance and condition monitoring Uses life cycle costs (LCC) to evaluate and calculate the costs of pumping systems

Electrokinetic pump

Science.gov (United States)

Patel, Kamlesh D.

2007-11-20

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

Intrathecal Pump Exposure to Electromagnetic Interference: A Report of Device Interrogation following Multiple ECT Sessions.

Science.gov (United States)

Bicket, Mark C; Hanna, George M

2016-02-01

Intrathecal drug delivery systems represent an increasingly common treatment modality for patients with a variety of conditions, including chronic pain and spasticity. Pumps rely on electronic programming to properly control and administer highly concentrated medications. Electromagnetic interference (EMI) is a known exposure that may cause a potential patient safety issue stemming from direct patient injury, pump damage, or changes to pump operation or flow rate. The objective of our case report was to describe an approach to evaluating a patient with a pump prior to and following exposure to EMI from electroconvulsive therapy (ECT), as well as to document findings from device interrogations associated with this event. Case report. Academic university-based pain management center. We present the case of a patient with an intrathecal pump who underwent multiple exposures to EMI in the form of 42 ECT sessions. Interrogation of the intrathecal drug delivery system revealed no safety issues following ECT sessions. At no time were error messages, unintentional changes in event logs, unintentional changes in pump settings, or evidence of pump stall or over-infusion noted. Communication with multiple entities (patient, family, consulting physicians, and device manufacturer) and maintaining vigilance through device interrogation both before and after EMI exposure are appropriate safeguards to mitigate the risk and detect potential adverse events of EMI with intrathecal drug delivery systems. Given the infrequent reports of device exposure to ECT, best practices may be derived from experience with EMI exposure from magnetic resonance imaging (MRI). Although routine EMI exposure to intrathecal drug delivery systems should be avoided, we describe one patient with repeated exposure to ECT without apparent complication.

Decrease of total antioxidant capacity during coronary artery bypass surgery.

Science.gov (United States)

Kunt, Alper Sami; Selek, Sahbettin; Celik, Hakim; Demir, Deniz; Erel, Ozcan; Andac, Mehmet Halit

2006-09-01

Cardiac surgery induces an oxidative stress, which may lead to impairment of cardiac function. In this study, we aimed to measure the changes of oxidative and antioxidative status of patients undergoing coronary artery bypass surgery (CABG). We studied 79 patients who underwent CABG with and without cardiopulmonary bypass (CPB). Of the 79 patients, 39 had CPB and 40 did not. Blood samples were drawn before, during, and after the surgery. Antioxidant status was evaluated by measuring total antioxidant capacity (TAC), and oxidative status was evaluated by measuring total peroxide (TP) levels and oxidative stress index (OSI). TP and OSI levels increased, while TAC decreased progressively after the beginning of surgery, for all patients. There were negative correlations between TAC levels and aortic cross-clamping period and anastomosis time ( r = -0.553, p antioxidant vitamins such as vitamins C and E may be beneficial for patients undergoing CABG.

Air source integrated heat pump simulation model for EnergyPlus

Energy Technology Data Exchange (ETDEWEB)

Shen, Bo; New, Joshua; Baxter, Van

2017-12-01

An Air Source Integrated Heat Pump (AS-IHP) is an air source, multi-functional spacing conditioning unit with water heating function (WH), which can lead to great energy savings by recovering the condensing waste heat for domestic water heating. This paper summarizes development of the EnergyPlus AS-IHP model, introducing the physics, sub-models, working modes, and control logic. Based on the model, building energy simulations were conducted to demonstrate greater than 50% annual energy savings, in comparison to a baseline heat pump with electric water heater, over 10 US cities, using the EnergyPlus quick-service restaurant template building. We assessed water heating energy saving potentials using AS-IHP versus both gas and electric baseline systems, and pointed out climate zones where AS-IHPs are promising. In addition, a grid integration strategy was investigated to reveal further energy saving and electricity cost reduction potentials, via increasing the water heating set point temperature during off-peak hours and using larger water tanks.

Performance analysis of diesel engine heat pump incorporated with heat recovery

International Nuclear Information System (INIS)

Shah, N.N.; Huang, M.J.; Hewitt, N.J.

2016-01-01

Highlights: • Diesel engine heat pump with heat recovery. • Water-to-water source heat pump based on R134a. • Possibility for different flow temperature for heat distribution system. • Possible retrofit application in off-gas or weak electricity network area. • Potential to diversify use of fossil fuel, primary energy and CO_2 emission savings. - Abstract: This paper presents experimental study of diesel engine heat pump (DEHP) system to find potential as retrofit technology in off-gas or weak electricity network area to replace existing gas/oil/electric heating system in domestic sector. Test set-up of diesel engine driven water-to-water heat pump system was built which included heat recovery arrangement from the engine coolant & exhaust gas. The system was designed to meet typical house heating demand in Northern Ireland. Performance of DEHP was evaluated to meet house-heating demand at different flow temperature (35, 45, 55 & 65 °C), a typical requirement of underfloor space heating, medium/high temperature radiators and domestic hot water. The performance was evaluated against four-evaporator water inlet temperature (0, 5, 10 & 15 °C) and at three different engine speed 1600, 2000 & 2400 rpm. Experiment results were analysed in terms of heating/cooling capacity, heat recovery, total heat output, primary energy ratio (PER), isentropic efficiency, etc. Test results showed that DEHP is able to meet house-heating demand with help of heat recovery with reduced system size. Heat recovery contributed in a range of 22–39% in total heat output. It is possible to achieve high flow temperature in a range of 74 °C with help of heat recovery. Overall system PER varied in a range of 0.93–1.33. Speed increment and flow temperature has significant impact on heat recovery, total heat output and PER. A case scenario with different flow temperature to match house-heating demand has been presented to show working potential with different heat distribution system

Liquid metal pump

International Nuclear Information System (INIS)

Pennell, W.E.

1981-01-01

A liquid metal pump comprising a shaft support structure which is isolated from the pump housing for better preservation of alignment of shaft bearings. The shaft carries an impeller and the support structure carries an impeller cage which is slidably disposed in a diffuser so as to allow complete removal of pump internals for inspection and repair. The diffuser is concentrically supported in the pump housing which also takes up all reaction forces generated by the discharge of the liquid metal from the diffuser, with floating seals arranged between impeller cage and the diffuser. The space between the diffuser and the pump housing permits the incoming liquid to essentially surround the diffuser. (author)

Rotary piston blood pumps: past developments and future potential of a unique pump type.

Science.gov (United States)

Wappenschmidt, Johannes; Autschbach, Rüdiger; Steinseifer, Ulrich; Schmitz-Rode, Thomas; Margreiter, Raimund; Klima, Günter; Goetzenich, Andreas

2016-08-01

The design of implantable blood pumps is either based on displacement pumps with membranes or rotary pumps. Both pump types have limitations to meet the clinical requirements. Rotary piston blood pumps have the potential to overcome these limitations and to merge the benefits. Compared to membrane pumps, they are smaller and with no need for wear-affected membranes and valves. Compared to rotary pumps, the blood flow is pulsatile instead of a non-physiological continuous flow. Furthermore, the risk of flow-induced blood damage and platelet activation may be reduced due to low shear stress to the blood. The past developments of rotary piston blood pumps are summarized and the main problem for long-term application is identified: insufficient seals. A new approach with seal-less drives is proposed and current research on a simplified rotary piston design is presented. Expert commentary: The development of blood pumps focuses mainly on the improvement of rotary pumps. However, medical complications indicate that inherent limitations of this pump type remain and restrict the next substantial step forward in the therapy of heart failure patients. Thus, research on different pump types is reasonable. If the development of reliable drives and bearings succeeds, rotary piston blood pumps become a promising alternative.

Implantable cardioverter-defibrillators improve survival after coronary artery bypass grafting in patients with severely impaired left ventricular function

Directory of Open Access Journals (Sweden)

Pasque Michael K

2007-01-01

Full Text Available Abstract Objective Patients with severe left ventricular (LV dysfunction have a poor long term survival despite complete surgical revascularization. Recent data suggests that the use of Implantable Cardioverter-Defibrillator (ICD improves survival in patients with severe LV dysfunction. We compared the survival impact of ICD implantation in patients with severe LV dysfunction who underwent CABG. Methods Between January 1996 and August 2004, 305 patients with LV ejection fraction (EF ≤25% had CABG surgery at our institution. Demographics of patients who had received an ICD (ICD+ in the post -operative period was compared to those without ICD (ICD-. Survival was evaluated by the Kaplan-Meier method. Results Of the entire group, 35 (11.5% patients received an ICD with a median of 2 (+/-2 years after CABG. Indication for ICD implantation was clinical evidence of non sustained ventricular tachycardia (NSVT. There were no differences between the 2 groups with respect to age, gender, NYHA classification, number of bypasses, or other co-morbidities. Survival at 1, 3 and 5 years was 88%, 79%, and 67% for the ICD- group compared to 94%, 89% and 83% for the ICD+ group, respectively (figure, p Conclusion Implantation of ICD after CABG confers improved short and long term survival benefit to patients with severe LV dysfunction. Prophylactic ICD implantation in the setting of severe LV dysfunction and CABG surgery should be considered.

High-vacuum plasma pump

International Nuclear Information System (INIS)

Dorodnov, A.M.; Minajchev, V.E.; Miroshkin, S.I.

1980-01-01

The action of an electric-arc high-vacuum pump intended for evacuating the volumes in which the operation processes are followed by a high gas evolution is considered. The operation of the pump is based on the principle of controlling the getter feed according to the gas load and effect of plasma sorbtion pumping. The pump performances are given. The starting pressure is about 5 Pa, the limiting residual pressure is about 5x10 -6 Pa, the pumping out rate of nitrogen in the pressure range 5x10 -5 -5x10 -3 Pa accounts for about 4000 l/s, the power consumption comes to 6 kW. Analyzing the results of the test operation of the pump, it has been concluded that its principal advantages are the high starting pressure, controlled getter feed rate and possibility of pumping out the gases which are usually pumped out with difficulty. The operation reliability of the pump is defined mainly by reliable operation of the ignition system of the vacuum arc [ru

Pumping machinery theory and practice

CERN Document Server

Badr, Hassan M

2014-01-01

Pumping Machinery Theory and Practice comprehensively covers the theoretical foundation and applications of pumping machinery. Key features: Covers characteristics of centrifugal pumps, axial flow pumps and displacement pumpsConsiders pumping machinery performance and operational-type problemsCovers advanced topics in pumping machinery including multiphase flow principles, and two and three-phase flow pumping systemsCovers different methods of flow rate control and relevance to machine efficiency and energy consumptionCovers different methods of flow rate control and relevance to machine effi

Metabolic control after years of completing a clinical trial on sensor-augmented pump therapy.

Science.gov (United States)

Quirós, Carmen; Giménez, Marga; Orois, Aida; Conget, Ignacio

2015-11-01

Sensor-augmented pump (SAP) therapy has been shown to be effective and safe for improving metabolic control in patients with type 1 diabetes mellitus (T1DM) in a number of trials. Our objective was to assess glycemic control in a group of T1DM patients on insulin pump or SAP therapy after years of participating in the SWITCH (Sensing With Insulin pump Therapy To Control HbA1c) trial and their return to routine medical monitoring. A retrospective, observational study of 20 patients who participated in the SWITCH trial at our hospital from 2008 to 2010. HbA1c values were compared at the start, during (at the end of the periods with/without SAP use - Sensor On/Sensor Off period respectively - of the cross-over design), and 3 years after study completion. HbA1c values of patients who continued SAP therapy (n=6) or only used insulin pump (n=14) were also compared. Twenty patients with T1DM (44.4±9.3 years, 60% women, baseline HbA1c level 8.43±0.55%) were enrolled into the SWITCH study). Three years after study completion, HbA1c level was 7.79±0.77 in patients on pump alone, with no significant change from the value at the end of the Off period of the study (7.85±0.57%; p=0.961). As compared to the end of the On period, HbA1c worsened less in patients who remained on SAP than in those on pump alone (0.18±0.42 vs. 0.55±0.71%; p=0.171), despite the fact that levels were similar at study start (8.41±0.60 vs. 8.47±0.45; p=0.831) and at the end of the On period (7.24±0.48 vs. 7.38±0.61; p=0.566). Frequency of CGM use in patients who continued SAP therapy was high (61.2% of the time in the last 3 months). Our study suggests that the additional benefit of SAP therapy achieved in a clinical trial may persist in the long term in routine clinical care of patients with T1DM. Copyright © 2015 SEEN. Published by Elsevier España, S.L.U. All rights reserved.

Intensity Noise Transfer Through a Diode-pumped Titanium Sapphire Laser System

DEFF Research Database (Denmark)

Tawfieq, Mahmoud; Hansen, Anders Kragh; Jensen, Ole Bjarlin

2017-01-01

higher RIN than a setup with only a single nonlinear crystal. The Ti:S is shown to have a cut-off frequency around 500 kHz, which means that noise structures of the pump laser above this frequency are strongly suppressed. Finally, the majority of the Ti:S noise seems to originate from the laser itself......In this paper, we investigate the noise performance and transfer in a titanium sapphire (Ti:S) laser system. This system consists of a DBR tapered diode laser, which is frequency doubled in two cascaded nonlinear crystals and used to pump the Ti:S laser oscillator. This investigation includes...... electrical noise characterizations of the utilized power supplies, the optical noise of the fundamental light, the second harmonic light, and finally the optical noise of the femtosecond pulses emitted by the Ti:S laser. Noise features originating from the electric power supply are evident throughout...

Energy Efficiency Modelling of Residential Air Source Heat Pump Water Heater

Directory of Open Access Journals (Sweden)

Cong Toan Tran

2016-03-01

Full Text Available The heat pump water heater is one of the most energy efficient technologies for heating water for household use. The present work proposes a simplified model of coefficient of performance and examines its predictive capability. The model is based on polynomial functions where the variables are temperatures and the coefficients are derived from the Australian standard test data, using regression technics. The model enables to estimate the coefficient of performance of the same heat pump water heater under other test standards (i.e. US, Japanese, European and Korean standards. The resulting estimations over a heat-up phase and a full test cycle including a draw off pattern are in close agreement with the measured data. Thus the model allows manufacturers to avoid the need to carry out physical tests for some standards and to reduce product cost. The limitations of the methodology proposed are also discussed.

Association Between Physician Teamwork and Health System Outcomes After Coronary Artery Bypass Grafting.

Science.gov (United States)

Hollingsworth, John M; Funk, Russell J; Garrison, Spencer A; Owen-Smith, Jason; Kaufman, Samuel A; Pagani, Francis D; Nallamothu, Brahmajee K

2016-11-01

Patients undergoing coronary artery bypass grafting (CABG) must often see multiple providers dispersed across many care locations. To test whether teamwork (assessed with the bipartite clustering coefficient) among these physicians is a determinant of surgical outcomes, we examined national Medicare data from patients undergoing CABG. Among Medicare beneficiaries who underwent CABG between 2008 and 2011, we mapped relationships between all physicians who treated them during their surgical episodes, including both surgeons and nonsurgeons. After aggregating across CABG episodes in a year to construct the physician social networks serving each health system, we then assessed the level of physician teamwork in these networks with the bipartite clustering coefficient. Finally, we fit a series of multivariable regression models to evaluate associations between a health system's teamwork level and its 60-day surgical outcomes. We observed substantial variation in the level of teamwork between health systems performing CABG (SD for the bipartite clustering coefficient was 0.09). Although health systems with high and low teamwork levels treated beneficiaries with comparable comorbidity scores, these health systems differed over several sociocultural and healthcare capacity factors (eg, physician staff size and surgical caseload). After controlling for these differences, health systems with higher teamwork levels had significantly lower 60-day rates of emergency department visit, readmission, and mortality. Health systems with physicians who tend to work together in tightly-knit groups during CABG episodes realize better surgical outcomes. As such, delivery system reforms focused on building teamwork may have positive effects on surgical care. © 2016 American Heart Association, Inc.

Determinants and Long-Term Outcomes of Percutaneous Coronary Interventions vs. Surgery for Multivessel Disease According to Clinical Presentation.

Science.gov (United States)

Hong, Sung-Jin; Kim, Byeong-Keuk; Shin, Sanghoon; Suh, Yongsung; Kim, Seunghwan; Ahn, Chul-Min; Kim, Jung-Sun; Ko, Young-Guk; Choi, Donghoon; Hong, Myeong-Ki; Jang, Yangsoo

2018-03-23

The long-term outcome of percutaneous coronary intervention (PCI) vs. coronary artery bypass graft (CABG), particularly for patients with non-ST-elevation acute coronary syndrome (NSTE-ACS), remains controversial.Methods and Results:We retrospectively analyzed 2,827 patients (stable coronary artery disease [SCAD], n=1,601; NSTE-ACS, n=1,226) who underwent either PCI (n=1,732) or CABG (n=1,095). The 8-year composite of cardiac death and myocardial infarction (MI) was compared between PCI and CABG before and after propensity matching. For patients with NSTE-ACS, PCI was performed more frequently for those with higher Thrombolysis in Myocardial Infarction risk score and 3-vessel disease, and PCI led to significantly higher 8-year composite of cardiac death and MI than CABG (14.1% vs. 5.9%, hazard ratio [HR]=2.22, 95% confidence interval [CI]=1.37-3.58, P=0.001). There was a significant interaction between clinical presentation and revascularization strategy (P-interaction=0.001). However, after matching, the benefit of CABG vs. PCI was attenuated in patients with NSTE-ACS, whereas it was pronounced in those with SCAD. Interactions between clinical presentation and revascularization strategy were not observed (P-interaction=0.574). Although the determinants of PCI vs. CABG in real-world clinical practice differ according to the clinical presentation, a significant interaction between clinical presentation and revascularization strategy was not noted for long-term outcomes. The revascularization strategy for patients with NSTE-ACS can be based on the criteria applied to patients with SCAD.

Association Between Physician Teamwork and Health System Outcomes Following Coronary Artery Bypass Grafting

Science.gov (United States)

Hollingsworth, John M.; Funk, Russell J.; Garrison, Spencer A.; Owen-Smith, Jason; Kaufman, Samuel A.; Pagani, Francis D.; Nallamothu, Brahmajee K.

2017-01-01

Background Patients undergoing coronary artery bypass grafting (CABG) must often see multiple providers dispersed across many care locations. To test whether “teamwork” (assessed with the bipartite clustering coefficient) among these physicians is a determinant of surgical outcomes, we examined national Medicare data from patients undergoing CABG. Methods and Results Among Medicare beneficiaries who underwent CABG between 2008 and 2011, we mapped relationships between all physicians who treated them during their surgical episodes, including both surgeons and nonsurgeons. After aggregating across CABG episodes in a year to construct the physician social networks serving each health system, we then assessed the level of physician teamwork in these networks with the bipartite clustering coefficient. Finally, we fit a series of multivariable regression models to evaluate associations between a health system’s teamwork level and its 60-day surgical outcomes. We observed substantial variation in the level of teamwork between health systems performing CABG (standard deviation for the bipartite clustering coefficient was 0.09). While health systems with high and low teamwork levels treated beneficiaries with comparable comorbidity scores, these health systems differed over several sociocultural and healthcare capacity factors (e.g., physician staff size, surgical caseload). After controlling for these differences, health systems with higher teamwork levels had significantly lower 60-day rates of emergency department visit, readmission, and mortality. Conclusions Health systems with physicians who tend to work together in tightly knit groups during CABG episodes realize better surgical outcomes. As such, delivery system reforms focused on building teamwork may have positive effects on surgical care. PMID:28263939

Short-term supervised inpatient physiotherapy exercise protocol improves cardiac autonomic function after coronary artery bypass graft surgery--a randomised controlled trial.

Science.gov (United States)

Mendes, Renata Gonçalves; Simões, Rodrigo Polaquini; De Souza Melo Costa, Fernando; Pantoni, Camila Bianca Falasco; Di Thommazo, Luciana; Luzzi, Sérgio; Catai, Aparecida Maria; Arena, Ross; Borghi-Silva, Audrey

2010-01-01

Coronary artery bypass grafting (CABG) is accompanied by severe impairment of cardiac autonomous regulation (CAR). This study aimed to determine whether a short-term physiotherapy exercise protocol post-CABG, during inpatient cardiac rehabilitation (CR), might improve CAR. Seventy-four patients eligible for CABG were recruited and randomised into physiotherapy exercise group (EG) or physiotherapy usual care group (UCG). EG patients underwent a short-term supervised inpatient physiotherapy exercise protocol consisting of an early mobilisation with progressive exercises plus usual care (respiratory exercises). UCG only received respiratory exercises. Forty-seven patients (24 EG and 23 UGC) completed the study. Outcome measures of CAR included linear and non-linear measures of heart rate variability (HRV) assessed before discharge. By hospital discharge, EG presented significantly higher parasympathetic HRV values [rMSSD, high frequency (HF), SD1)], global power (STD RR, SD2), non-linear HRV indexes [detrended fluctuation analysis (DFA)alpha1, DFAalpha2, approximate entropy (ApEn)] and mean RR compared to UCG (pexercise protocol during inpatient CR improves CAR at the time of discharge. Thus, exercise-based inpatient CR might be an effective non-pharmacological tool to improve autonomic cardiac tone in patient's post-CABG.

Follow-up of coronary artery bypass graft patency: diagnostic efficiency of high-pitch dual-source 256-slice MDCT findings.